/build/llvm-toolchain-snapshot-14~++20210903100615+fd66b44ec19e/clang/include/clang/AST/ASTContext.h

Bug Summary

File:	clang/include/clang/AST/ASTContext.h
Warning:	line 1529, column 9 Access to field 'TypeForDecl' results in a dereference of a null pointer (loaded from variable 'Decl')

Annotated Source Code

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clang -cc1 -cc1 -triple x86_64-pc-linux-gnu -analyze -disable-free -disable-llvm-verifier -discard-value-names -main-file-name SemaDeclCXX.cpp -analyzer-store=region -analyzer-opt-analyze-nested-blocks -analyzer-checker=core -analyzer-checker=apiModeling -analyzer-checker=unix -analyzer-checker=deadcode -analyzer-checker=cplusplus -analyzer-checker=security.insecureAPI.UncheckedReturn -analyzer-checker=security.insecureAPI.getpw -analyzer-checker=security.insecureAPI.gets -analyzer-checker=security.insecureAPI.mktemp -analyzer-checker=security.insecureAPI.mkstemp -analyzer-checker=security.insecureAPI.vfork -analyzer-checker=nullability.NullPassedToNonnull -analyzer-checker=nullability.NullReturnedFromNonnull -analyzer-output plist -w -setup-static-analyzer -analyzer-config-compatibility-mode=true -mrelocation-model pic -pic-level 2 -mframe-pointer=none -relaxed-aliasing -fmath-errno -fno-rounding-math -mconstructor-aliases -munwind-tables -target-cpu x86-64 -tune-cpu generic -debugger-tuning=gdb -ffunction-sections -fdata-sections -fcoverage-compilation-dir=/build/llvm-toolchain-snapshot-14~++20210903100615+fd66b44ec19e/build-llvm/tools/clang/lib/Sema -resource-dir /usr/lib/llvm-14/lib/clang/14.0.0 -D _GNU_SOURCE -D __STDC_CONSTANT_MACROS -D __STDC_FORMAT_MACROS -D __STDC_LIMIT_MACROS -I /build/llvm-toolchain-snapshot-14~++20210903100615+fd66b44ec19e/build-llvm/tools/clang/lib/Sema -I /build/llvm-toolchain-snapshot-14~++20210903100615+fd66b44ec19e/clang/lib/Sema -I /build/llvm-toolchain-snapshot-14~++20210903100615+fd66b44ec19e/clang/include -I /build/llvm-toolchain-snapshot-14~++20210903100615+fd66b44ec19e/build-llvm/tools/clang/include -I /build/llvm-toolchain-snapshot-14~++20210903100615+fd66b44ec19e/build-llvm/include -I /build/llvm-toolchain-snapshot-14~++20210903100615+fd66b44ec19e/llvm/include -D NDEBUG -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/10/../../../../include/c++/10 -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/10/../../../../include/x86_64-linux-gnu/c++/10 -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/10/../../../../include/c++/10/backward -internal-isystem /usr/lib/llvm-14/lib/clang/14.0.0/include -internal-isystem /usr/local/include -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/10/../../../../x86_64-linux-gnu/include -internal-externc-isystem /usr/include/x86_64-linux-gnu -internal-externc-isystem /include -internal-externc-isystem /usr/include -O2 -Wno-unused-parameter -Wwrite-strings -Wno-missing-field-initializers -Wno-long-long -Wno-maybe-uninitialized -Wno-class-memaccess -Wno-redundant-move -Wno-pessimizing-move -Wno-noexcept-type -Wno-comment -std=c++14 -fdeprecated-macro -fdebug-compilation-dir=/build/llvm-toolchain-snapshot-14~++20210903100615+fd66b44ec19e/build-llvm/tools/clang/lib/Sema -fdebug-prefix-map=/build/llvm-toolchain-snapshot-14~++20210903100615+fd66b44ec19e=. -ferror-limit 19 -fvisibility-inlines-hidden -stack-protector 2 -fgnuc-version=4.2.1 -vectorize-loops -vectorize-slp -analyzer-output=html -analyzer-config stable-report-filename=true -faddrsig -D__GCC_HAVE_DWARF2_CFI_ASM=1 -o /tmp/scan-build-2021-09-04-040900-46481-1 -x c++ /build/llvm-toolchain-snapshot-14~++20210903100615+fd66b44ec19e/clang/lib/Sema/SemaDeclCXX.cpp

/build/llvm-toolchain-snapshot-14~++20210903100615+fd66b44ec19e/clang/lib/Sema/SemaDeclCXX.cpp

→

1//===------ SemaDeclCXX.cpp - Semantic Analysis for C++ Declarations ------===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8//
9//  This file implements semantic analysis for C++ declarations.
10//
11//===----------------------------------------------------------------------===//

13#include "clang/AST/ASTConsumer.h"
14#include "clang/AST/ASTContext.h"
15#include "clang/AST/ASTLambda.h"
16#include "clang/AST/ASTMutationListener.h"
17#include "clang/AST/CXXInheritance.h"
18#include "clang/AST/CharUnits.h"
19#include "clang/AST/ComparisonCategories.h"
20#include "clang/AST/EvaluatedExprVisitor.h"
21#include "clang/AST/ExprCXX.h"
22#include "clang/AST/RecordLayout.h"
23#include "clang/AST/RecursiveASTVisitor.h"
24#include "clang/AST/StmtVisitor.h"
25#include "clang/AST/TypeLoc.h"
26#include "clang/AST/TypeOrdering.h"
27#include "clang/Basic/AttributeCommonInfo.h"
28#include "clang/Basic/PartialDiagnostic.h"
29#include "clang/Basic/TargetInfo.h"
30#include "clang/Lex/LiteralSupport.h"
31#include "clang/Lex/Preprocessor.h"
32#include "clang/Sema/CXXFieldCollector.h"
33#include "clang/Sema/DeclSpec.h"
34#include "clang/Sema/Initialization.h"
35#include "clang/Sema/Lookup.h"
36#include "clang/Sema/ParsedTemplate.h"
37#include "clang/Sema/Scope.h"
38#include "clang/Sema/ScopeInfo.h"
39#include "clang/Sema/SemaInternal.h"
40#include "clang/Sema/Template.h"
41#include "llvm/ADT/ScopeExit.h"
42#include "llvm/ADT/SmallString.h"
43#include "llvm/ADT/STLExtras.h"
44#include "llvm/ADT/StringExtras.h"
45#include <map>
46#include <set>

48using namespace clang;

50//===----------------------------------------------------------------------===//
51// CheckDefaultArgumentVisitor
52//===----------------------------------------------------------------------===//

54namespace {
55/// CheckDefaultArgumentVisitor - C++ [dcl.fct.default] Traverses
56/// the default argument of a parameter to determine whether it
57/// contains any ill-formed subexpressions. For example, this will
58/// diagnose the use of local variables or parameters within the
59/// default argument expression.
60class CheckDefaultArgumentVisitor
  : public ConstStmtVisitor<CheckDefaultArgumentVisitor, bool> {
Sema &S;
const Expr *DefaultArg;

65public:
CheckDefaultArgumentVisitor(Sema &S, const Expr *DefaultArg)
    : S(S), DefaultArg(DefaultArg) {}

bool VisitExpr(const Expr *Node);
bool VisitDeclRefExpr(const DeclRefExpr *DRE);
bool VisitCXXThisExpr(const CXXThisExpr *ThisE);
bool VisitLambdaExpr(const LambdaExpr *Lambda);
bool VisitPseudoObjectExpr(const PseudoObjectExpr *POE);
74};

76/// VisitExpr - Visit all of the children of this expression.
77bool CheckDefaultArgumentVisitor::VisitExpr(const Expr *Node) {
bool IsInvalid = false;
for (const Stmt *SubStmt : Node->children())
  IsInvalid |= Visit(SubStmt);
return IsInvalid;
82}

84/// VisitDeclRefExpr - Visit a reference to a declaration, to
85/// determine whether this declaration can be used in the default
86/// argument expression.
87bool CheckDefaultArgumentVisitor::VisitDeclRefExpr(const DeclRefExpr *DRE) {
const NamedDecl *Decl = DRE->getDecl();
if (const auto *Param = dyn_cast<ParmVarDecl>(Decl)) {
  // C++ [dcl.fct.default]p9:
  //   [...] parameters of a function shall not be used in default
  //   argument expressions, even if they are not evaluated. [...]
  //
  // C++17 [dcl.fct.default]p9 (by CWG 2082):
  //   [...] A parameter shall not appear as a potentially-evaluated
  //   expression in a default argument. [...]
  //
  if (DRE->isNonOdrUse() != NOUR_Unevaluated)
    return S.Diag(DRE->getBeginLoc(),
                  diag::err_param_default_argument_references_param)
           << Param->getDeclName() << DefaultArg->getSourceRange();
} else if (const auto *VDecl = dyn_cast<VarDecl>(Decl)) {
  // C++ [dcl.fct.default]p7:
  //   Local variables shall not be used in default argument
  //   expressions.
  //
  // C++17 [dcl.fct.default]p7 (by CWG 2082):
  //   A local variable shall not appear as a potentially-evaluated
  //   expression in a default argument.
  //
  // C++20 [dcl.fct.default]p7 (DR as part of P0588R1, see also CWG 2346):
  //   Note: A local variable cannot be odr-used (6.3) in a default argument.
  //
  if (VDecl->isLocalVarDecl() && !DRE->isNonOdrUse())
    return S.Diag(DRE->getBeginLoc(),
                  diag::err_param_default_argument_references_local)
           << VDecl->getDeclName() << DefaultArg->getSourceRange();
}

return false;
121}

123/// VisitCXXThisExpr - Visit a C++ "this" expression.
124bool CheckDefaultArgumentVisitor::VisitCXXThisExpr(const CXXThisExpr *ThisE) {
// C++ [dcl.fct.default]p8:
//   The keyword this shall not be used in a default argument of a
//   member function.
return S.Diag(ThisE->getBeginLoc(),
              diag::err_param_default_argument_references_this)
       << ThisE->getSourceRange();
131}

133bool CheckDefaultArgumentVisitor::VisitPseudoObjectExpr(
  const PseudoObjectExpr *POE) {
bool Invalid = false;
for (const Expr *E : POE->semantics()) {
  // Look through bindings.
  if (const auto *OVE = dyn_cast<OpaqueValueExpr>(E)) {
    E = OVE->getSourceExpr();
    assert(E && "pseudo-object binding without source expression?")(static_cast<void> (0));
  }

  Invalid |= Visit(E);
}
return Invalid;
146}

148bool CheckDefaultArgumentVisitor::VisitLambdaExpr(const LambdaExpr *Lambda) {
// C++11 [expr.lambda.prim]p13:
//   A lambda-expression appearing in a default argument shall not
//   implicitly or explicitly capture any entity.
if (Lambda->capture_begin() == Lambda->capture_end())
  return false;

return S.Diag(Lambda->getBeginLoc(), diag::err_lambda_capture_default_arg);
156}
157} // namespace

159void
160Sema::ImplicitExceptionSpecification::CalledDecl(SourceLocation CallLoc,
                                               const CXXMethodDecl *Method) {
// If we have an MSAny spec already, don't bother.
if (!Method || ComputedEST == EST_MSAny)
  return;

const FunctionProtoType *Proto
  = Method->getType()->getAs<FunctionProtoType>();
Proto = Self->ResolveExceptionSpec(CallLoc, Proto);
if (!Proto)
  return;

ExceptionSpecificationType EST = Proto->getExceptionSpecType();

// If we have a throw-all spec at this point, ignore the function.
if (ComputedEST == EST_None)
  return;

if (EST == EST_None && Method->hasAttr<NoThrowAttr>())
  EST = EST_BasicNoexcept;

switch (EST) {
case EST_Unparsed:
case EST_Uninstantiated:
case EST_Unevaluated:
  llvm_unreachable("should not see unresolved exception specs here")__builtin_unreachable();

// If this function can throw any exceptions, make a note of that.
case EST_MSAny:
case EST_None:
  // FIXME: Whichever we see last of MSAny and None determines our result.
  // We should make a consistent, order-independent choice here.
  ClearExceptions();
  ComputedEST = EST;
  return;
case EST_NoexceptFalse:
  ClearExceptions();
  ComputedEST = EST_None;
  return;
// FIXME: If the call to this decl is using any of its default arguments, we
// need to search them for potentially-throwing calls.
// If this function has a basic noexcept, it doesn't affect the outcome.
case EST_BasicNoexcept:
case EST_NoexceptTrue:
case EST_NoThrow:
  return;
// If we're still at noexcept(true) and there's a throw() callee,
// change to that specification.
case EST_DynamicNone:
  if (ComputedEST == EST_BasicNoexcept)
    ComputedEST = EST_DynamicNone;
  return;
case EST_DependentNoexcept:
  llvm_unreachable(__builtin_unreachable()
      "should not generate implicit declarations for dependent cases")__builtin_unreachable();
case EST_Dynamic:
  break;
}
assert(EST == EST_Dynamic && "EST case not considered earlier.")(static_cast<void> (0));
assert(ComputedEST != EST_None &&(static_cast<void> (0))
       "Shouldn't collect exceptions when throw-all is guaranteed.")(static_cast<void> (0));
ComputedEST = EST_Dynamic;
// Record the exceptions in this function's exception specification.
for (const auto &E : Proto->exceptions())
  if (ExceptionsSeen.insert(Self->Context.getCanonicalType(E)).second)
    Exceptions.push_back(E);
226}

228void Sema::ImplicitExceptionSpecification::CalledStmt(Stmt *S) {
if (!S || ComputedEST == EST_MSAny)
  return;

// FIXME:
//
// C++0x [except.spec]p14:
//   [An] implicit exception-specification specifies the type-id T if and
// only if T is allowed by the exception-specification of a function directly
// invoked by f's implicit definition; f shall allow all exceptions if any
// function it directly invokes allows all exceptions, and f shall allow no
// exceptions if every function it directly invokes allows no exceptions.
//
// Note in particular that if an implicit exception-specification is generated
// for a function containing a throw-expression, that specification can still
// be noexcept(true).
//
// Note also that 'directly invoked' is not defined in the standard, and there
// is no indication that we should only consider potentially-evaluated calls.
//
// Ultimately we should implement the intent of the standard: the exception
// specification should be the set of exceptions which can be thrown by the
// implicit definition. For now, we assume that any non-nothrow expression can
// throw any exception.

if (Self->canThrow(S))
  ComputedEST = EST_None;
255}

257ExprResult Sema::ConvertParamDefaultArgument(ParmVarDecl *Param, Expr *Arg,
                                           SourceLocation EqualLoc) {
if (RequireCompleteType(Param->getLocation(), Param->getType(),
                        diag::err_typecheck_decl_incomplete_type))
  return true;

// C++ [dcl.fct.default]p5
//   A default argument expression is implicitly converted (clause
//   4) to the parameter type. The default argument expression has
//   the same semantic constraints as the initializer expression in
//   a declaration of a variable of the parameter type, using the
//   copy-initialization semantics (8.5).
InitializedEntity Entity = InitializedEntity::InitializeParameter(Context,
                                                                  Param);
InitializationKind Kind = InitializationKind::CreateCopy(Param->getLocation(),
                                                         EqualLoc);
InitializationSequence InitSeq(*this, Entity, Kind, Arg);
ExprResult Result = InitSeq.Perform(*this, Entity, Kind, Arg);
if (Result.isInvalid())
  return true;
Arg = Result.getAs<Expr>();

CheckCompletedExpr(Arg, EqualLoc);
Arg = MaybeCreateExprWithCleanups(Arg);

return Arg;
283}

285void Sema::SetParamDefaultArgument(ParmVarDecl *Param, Expr *Arg,
                                 SourceLocation EqualLoc) {
// Add the default argument to the parameter
Param->setDefaultArg(Arg);

// We have already instantiated this parameter; provide each of the
// instantiations with the uninstantiated default argument.
UnparsedDefaultArgInstantiationsMap::iterator InstPos
  = UnparsedDefaultArgInstantiations.find(Param);
if (InstPos != UnparsedDefaultArgInstantiations.end()) {
  for (unsigned I = 0, N = InstPos->second.size(); I != N; ++I)
    InstPos->second[I]->setUninstantiatedDefaultArg(Arg);

  // We're done tracking this parameter's instantiations.
  UnparsedDefaultArgInstantiations.erase(InstPos);
}
301}

303/// ActOnParamDefaultArgument - Check whether the default argument
304/// provided for a function parameter is well-formed. If so, attach it
305/// to the parameter declaration.
306void
307Sema::ActOnParamDefaultArgument(Decl *param, SourceLocation EqualLoc,
                              Expr *DefaultArg) {
if (!param || !DefaultArg)
  return;

ParmVarDecl *Param = cast<ParmVarDecl>(param);
UnparsedDefaultArgLocs.erase(Param);

auto Fail = [&] {
  Param->setInvalidDecl();
  Param->setDefaultArg(new (Context) OpaqueValueExpr(
      EqualLoc, Param->getType().getNonReferenceType(), VK_PRValue));
};

// Default arguments are only permitted in C++
if (!getLangOpts().CPlusPlus) {
  Diag(EqualLoc, diag::err_param_default_argument)
    << DefaultArg->getSourceRange();
  return Fail();
}

// Check for unexpanded parameter packs.
if (DiagnoseUnexpandedParameterPack(DefaultArg, UPPC_DefaultArgument)) {
  return Fail();
}

// C++11 [dcl.fct.default]p3
//   A default argument expression [...] shall not be specified for a
//   parameter pack.
if (Param->isParameterPack()) {
  Diag(EqualLoc, diag::err_param_default_argument_on_parameter_pack)
      << DefaultArg->getSourceRange();
  // Recover by discarding the default argument.
  Param->setDefaultArg(nullptr);
  return;
}

ExprResult Result = ConvertParamDefaultArgument(Param, DefaultArg, EqualLoc);
if (Result.isInvalid())
  return Fail();

DefaultArg = Result.getAs<Expr>();

// Check that the default argument is well-formed
CheckDefaultArgumentVisitor DefaultArgChecker(*this, DefaultArg);
if (DefaultArgChecker.Visit(DefaultArg))
  return Fail();

SetParamDefaultArgument(Param, DefaultArg, EqualLoc);
356}

358/// ActOnParamUnparsedDefaultArgument - We've seen a default
359/// argument for a function parameter, but we can't parse it yet
360/// because we're inside a class definition. Note that this default
361/// argument will be parsed later.
362void Sema::ActOnParamUnparsedDefaultArgument(Decl *param,
                                           SourceLocation EqualLoc,
                                           SourceLocation ArgLoc) {
if (!param)
  return;

ParmVarDecl *Param = cast<ParmVarDecl>(param);
Param->setUnparsedDefaultArg();
UnparsedDefaultArgLocs[Param] = ArgLoc;
371}

373/// ActOnParamDefaultArgumentError - Parsing or semantic analysis of
374/// the default argument for the parameter param failed.
375void Sema::ActOnParamDefaultArgumentError(Decl *param,
                                        SourceLocation EqualLoc) {
if (!param)
  return;

ParmVarDecl *Param = cast<ParmVarDecl>(param);
Param->setInvalidDecl();
UnparsedDefaultArgLocs.erase(Param);
Param->setDefaultArg(new (Context) OpaqueValueExpr(
    EqualLoc, Param->getType().getNonReferenceType(), VK_PRValue));
385}

387/// CheckExtraCXXDefaultArguments - Check for any extra default
388/// arguments in the declarator, which is not a function declaration
389/// or definition and therefore is not permitted to have default
390/// arguments. This routine should be invoked for every declarator
391/// that is not a function declaration or definition.
392void Sema::CheckExtraCXXDefaultArguments(Declarator &D) {
// C++ [dcl.fct.default]p3
//   A default argument expression shall be specified only in the
//   parameter-declaration-clause of a function declaration or in a
//   template-parameter (14.1). It shall not be specified for a
//   parameter pack. If it is specified in a
//   parameter-declaration-clause, it shall not occur within a
//   declarator or abstract-declarator of a parameter-declaration.
bool MightBeFunction = D.isFunctionDeclarationContext();
for (unsigned i = 0, e = D.getNumTypeObjects(); i != e; ++i) {
  DeclaratorChunk &chunk = D.getTypeObject(i);
  if (chunk.Kind == DeclaratorChunk::Function) {
    if (MightBeFunction) {
      // This is a function declaration. It can have default arguments, but
      // keep looking in case its return type is a function type with default
      // arguments.
      MightBeFunction = false;
      continue;
    }
    for (unsigned argIdx = 0, e = chunk.Fun.NumParams; argIdx != e;
         ++argIdx) {
      ParmVarDecl *Param = cast<ParmVarDecl>(chunk.Fun.Params[argIdx].Param);
      if (Param->hasUnparsedDefaultArg()) {
        std::unique_ptr<CachedTokens> Toks =
            std::move(chunk.Fun.Params[argIdx].DefaultArgTokens);
        SourceRange SR;
        if (Toks->size() > 1)
          SR = SourceRange((*Toks)[1].getLocation(),
                           Toks->back().getLocation());
        else
          SR = UnparsedDefaultArgLocs[Param];
        Diag(Param->getLocation(), diag::err_param_default_argument_nonfunc)
          << SR;
      } else if (Param->getDefaultArg()) {
        Diag(Param->getLocation(), diag::err_param_default_argument_nonfunc)
          << Param->getDefaultArg()->getSourceRange();
        Param->setDefaultArg(nullptr);
      }
    }
  } else if (chunk.Kind != DeclaratorChunk::Paren) {
    MightBeFunction = false;
  }
}
435}

437static bool functionDeclHasDefaultArgument(const FunctionDecl *FD) {
return std::any_of(FD->param_begin(), FD->param_end(), [](ParmVarDecl *P) {
  return P->hasDefaultArg() && !P->hasInheritedDefaultArg();
});
441}

443/// MergeCXXFunctionDecl - Merge two declarations of the same C++
444/// function, once we already know that they have the same
445/// type. Subroutine of MergeFunctionDecl. Returns true if there was an
446/// error, false otherwise.
447bool Sema::MergeCXXFunctionDecl(FunctionDecl *New, FunctionDecl *Old,
                              Scope *S) {
bool Invalid = false;

// The declaration context corresponding to the scope is the semantic
// parent, unless this is a local function declaration, in which case
// it is that surrounding function.
DeclContext *ScopeDC = New->isLocalExternDecl()
                           ? New->getLexicalDeclContext()
                           : New->getDeclContext();

// Find the previous declaration for the purpose of default arguments.
FunctionDecl *PrevForDefaultArgs = Old;
for (/**/; PrevForDefaultArgs;
     // Don't bother looking back past the latest decl if this is a local
     // extern declaration; nothing else could work.
     PrevForDefaultArgs = New->isLocalExternDecl()
                              ? nullptr
                              : PrevForDefaultArgs->getPreviousDecl()) {
  // Ignore hidden declarations.
  if (!LookupResult::isVisible(*this, PrevForDefaultArgs))
    continue;

  if (S && !isDeclInScope(PrevForDefaultArgs, ScopeDC, S) &&
      !New->isCXXClassMember()) {
    // Ignore default arguments of old decl if they are not in
    // the same scope and this is not an out-of-line definition of
    // a member function.
    continue;
  }

  if (PrevForDefaultArgs->isLocalExternDecl() != New->isLocalExternDecl()) {
    // If only one of these is a local function declaration, then they are
    // declared in different scopes, even though isDeclInScope may think
    // they're in the same scope. (If both are local, the scope check is
    // sufficient, and if neither is local, then they are in the same scope.)
    continue;
  }

  // We found the right previous declaration.
  break;
}

// C++ [dcl.fct.default]p4:
//   For non-template functions, default arguments can be added in
//   later declarations of a function in the same
//   scope. Declarations in different scopes have completely
//   distinct sets of default arguments. That is, declarations in
//   inner scopes do not acquire default arguments from
//   declarations in outer scopes, and vice versa. In a given
//   function declaration, all parameters subsequent to a
//   parameter with a default argument shall have default
//   arguments supplied in this or previous declarations. A
//   default argument shall not be redefined by a later
//   declaration (not even to the same value).
//
// C++ [dcl.fct.default]p6:
//   Except for member functions of class templates, the default arguments
//   in a member function definition that appears outside of the class
//   definition are added to the set of default arguments provided by the
//   member function declaration in the class definition.
for (unsigned p = 0, NumParams = PrevForDefaultArgs
                                     ? PrevForDefaultArgs->getNumParams()
                                     : 0;
     p < NumParams; ++p) {
  ParmVarDecl *OldParam = PrevForDefaultArgs->getParamDecl(p);
  ParmVarDecl *NewParam = New->getParamDecl(p);

  bool OldParamHasDfl = OldParam ? OldParam->hasDefaultArg() : false;
  bool NewParamHasDfl = NewParam->hasDefaultArg();

  if (OldParamHasDfl && NewParamHasDfl) {
    unsigned DiagDefaultParamID =
      diag::err_param_default_argument_redefinition;

    // MSVC accepts that default parameters be redefined for member functions
    // of template class. The new default parameter's value is ignored.
    Invalid = true;
    if (getLangOpts().MicrosoftExt) {
      CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(New);
      if (MD && MD->getParent()->getDescribedClassTemplate()) {
        // Merge the old default argument into the new parameter.
        NewParam->setHasInheritedDefaultArg();
        if (OldParam->hasUninstantiatedDefaultArg())
          NewParam->setUninstantiatedDefaultArg(
                                    OldParam->getUninstantiatedDefaultArg());
        else
          NewParam->setDefaultArg(OldParam->getInit());
        DiagDefaultParamID = diag::ext_param_default_argument_redefinition;
        Invalid = false;
      }
    }

    // FIXME: If we knew where the '=' was, we could easily provide a fix-it
    // hint here. Alternatively, we could walk the type-source information
    // for NewParam to find the last source location in the type... but it
    // isn't worth the effort right now. This is the kind of test case that
    // is hard to get right:
    //   int f(int);
    //   void g(int (*fp)(int) = f);
    //   void g(int (*fp)(int) = &f);
    Diag(NewParam->getLocation(), DiagDefaultParamID)
      << NewParam->getDefaultArgRange();

    // Look for the function declaration where the default argument was
    // actually written, which may be a declaration prior to Old.
    for (auto Older = PrevForDefaultArgs;
         OldParam->hasInheritedDefaultArg(); /**/) {
      Older = Older->getPreviousDecl();
      OldParam = Older->getParamDecl(p);
    }

    Diag(OldParam->getLocation(), diag::note_previous_definition)
      << OldParam->getDefaultArgRange();
  } else if (OldParamHasDfl) {
    // Merge the old default argument into the new parameter unless the new
    // function is a friend declaration in a template class. In the latter
    // case the default arguments will be inherited when the friend
    // declaration will be instantiated.
    if (New->getFriendObjectKind() == Decl::FOK_None ||
        !New->getLexicalDeclContext()->isDependentContext()) {
      // It's important to use getInit() here;  getDefaultArg()
      // strips off any top-level ExprWithCleanups.
      NewParam->setHasInheritedDefaultArg();
      if (OldParam->hasUnparsedDefaultArg())
        NewParam->setUnparsedDefaultArg();
      else if (OldParam->hasUninstantiatedDefaultArg())
        NewParam->setUninstantiatedDefaultArg(
                                     OldParam->getUninstantiatedDefaultArg());
      else
        NewParam->setDefaultArg(OldParam->getInit());
    }
  } else if (NewParamHasDfl) {
    if (New->getDescribedFunctionTemplate()) {
      // Paragraph 4, quoted above, only applies to non-template functions.
      Diag(NewParam->getLocation(),
           diag::err_param_default_argument_template_redecl)
        << NewParam->getDefaultArgRange();
      Diag(PrevForDefaultArgs->getLocation(),
           diag::note_template_prev_declaration)
          << false;
    } else if (New->getTemplateSpecializationKind()
                 != TSK_ImplicitInstantiation &&
               New->getTemplateSpecializationKind() != TSK_Undeclared) {
      // C++ [temp.expr.spec]p21:
      //   Default function arguments shall not be specified in a declaration
      //   or a definition for one of the following explicit specializations:
      //     - the explicit specialization of a function template;
      //     - the explicit specialization of a member function template;
      //     - the explicit specialization of a member function of a class
      //       template where the class template specialization to which the
      //       member function specialization belongs is implicitly
      //       instantiated.
      Diag(NewParam->getLocation(), diag::err_template_spec_default_arg)
        << (New->getTemplateSpecializationKind() ==TSK_ExplicitSpecialization)
        << New->getDeclName()
        << NewParam->getDefaultArgRange();
    } else if (New->getDeclContext()->isDependentContext()) {
      // C++ [dcl.fct.default]p6 (DR217):
      //   Default arguments for a member function of a class template shall
      //   be specified on the initial declaration of the member function
      //   within the class template.
      //
      // Reading the tea leaves a bit in DR217 and its reference to DR205
      // leads me to the conclusion that one cannot add default function
      // arguments for an out-of-line definition of a member function of a
      // dependent type.
      int WhichKind = 2;
      if (CXXRecordDecl *Record
            = dyn_cast<CXXRecordDecl>(New->getDeclContext())) {
        if (Record->getDescribedClassTemplate())
          WhichKind = 0;
        else if (isa<ClassTemplatePartialSpecializationDecl>(Record))
          WhichKind = 1;
        else
          WhichKind = 2;
      }

      Diag(NewParam->getLocation(),
           diag::err_param_default_argument_member_template_redecl)
        << WhichKind
        << NewParam->getDefaultArgRange();
    }
  }
}

// DR1344: If a default argument is added outside a class definition and that
// default argument makes the function a special member function, the program
// is ill-formed. This can only happen for constructors.
if (isa<CXXConstructorDecl>(New) &&
    New->getMinRequiredArguments() < Old->getMinRequiredArguments()) {
  CXXSpecialMember NewSM = getSpecialMember(cast<CXXMethodDecl>(New)),
                   OldSM = getSpecialMember(cast<CXXMethodDecl>(Old));
  if (NewSM != OldSM) {
    ParmVarDecl *NewParam = New->getParamDecl(New->getMinRequiredArguments());
    assert(NewParam->hasDefaultArg())(static_cast<void> (0));
    Diag(NewParam->getLocation(), diag::err_default_arg_makes_ctor_special)
      << NewParam->getDefaultArgRange() << NewSM;
    Diag(Old->getLocation(), diag::note_previous_declaration);
  }
}

const FunctionDecl *Def;
// C++11 [dcl.constexpr]p1: If any declaration of a function or function
// template has a constexpr specifier then all its declarations shall
// contain the constexpr specifier.
if (New->getConstexprKind() != Old->getConstexprKind()) {
  Diag(New->getLocation(), diag::err_constexpr_redecl_mismatch)
      << New << static_cast<int>(New->getConstexprKind())
      << static_cast<int>(Old->getConstexprKind());
  Diag(Old->getLocation(), diag::note_previous_declaration);
  Invalid = true;
} else if (!Old->getMostRecentDecl()->isInlined() && New->isInlined() &&
           Old->isDefined(Def) &&
           // If a friend function is inlined but does not have 'inline'
           // specifier, it is a definition. Do not report attribute conflict
           // in this case, redefinition will be diagnosed later.
           (New->isInlineSpecified() ||
            New->getFriendObjectKind() == Decl::FOK_None)) {
  // C++11 [dcl.fcn.spec]p4:
  //   If the definition of a function appears in a translation unit before its
  //   first declaration as inline, the program is ill-formed.
  Diag(New->getLocation(), diag::err_inline_decl_follows_def) << New;
  Diag(Def->getLocation(), diag::note_previous_definition);
  Invalid = true;
}

// C++17 [temp.deduct.guide]p3:
//   Two deduction guide declarations in the same translation unit
//   for the same class template shall not have equivalent
//   parameter-declaration-clauses.
if (isa<CXXDeductionGuideDecl>(New) &&
    !New->isFunctionTemplateSpecialization() && isVisible(Old)) {
  Diag(New->getLocation(), diag::err_deduction_guide_redeclared);
  Diag(Old->getLocation(), diag::note_previous_declaration);
}

// C++11 [dcl.fct.default]p4: If a friend declaration specifies a default
// argument expression, that declaration shall be a definition and shall be
// the only declaration of the function or function template in the
// translation unit.
if (Old->getFriendObjectKind() == Decl::FOK_Undeclared &&
    functionDeclHasDefaultArgument(Old)) {
  Diag(New->getLocation(), diag::err_friend_decl_with_def_arg_redeclared);
  Diag(Old->getLocation(), diag::note_previous_declaration);
  Invalid = true;
}

// C++11 [temp.friend]p4 (DR329):
//   When a function is defined in a friend function declaration in a class
//   template, the function is instantiated when the function is odr-used.
//   The same restrictions on multiple declarations and definitions that
//   apply to non-template function declarations and definitions also apply
//   to these implicit definitions.
const FunctionDecl *OldDefinition = nullptr;
if (New->isThisDeclarationInstantiatedFromAFriendDefinition() &&
    Old->isDefined(OldDefinition, true))
  CheckForFunctionRedefinition(New, OldDefinition);

return Invalid;
707}

709NamedDecl *
710Sema::ActOnDecompositionDeclarator(Scope *S, Declarator &D,
                                 MultiTemplateParamsArg TemplateParamLists) {
assert(D.isDecompositionDeclarator())(static_cast<void> (0));
const DecompositionDeclarator &Decomp = D.getDecompositionDeclarator();

// The syntax only allows a decomposition declarator as a simple-declaration,
// a for-range-declaration, or a condition in Clang, but we parse it in more
// cases than that.
if (!D.mayHaveDecompositionDeclarator()) {
  Diag(Decomp.getLSquareLoc(), diag::err_decomp_decl_context)
    << Decomp.getSourceRange();
  return nullptr;
}

if (!TemplateParamLists.empty()) {
  // FIXME: There's no rule against this, but there are also no rules that
  // would actually make it usable, so we reject it for now.
  Diag(TemplateParamLists.front()->getTemplateLoc(),
       diag::err_decomp_decl_template);
  return nullptr;
}

Diag(Decomp.getLSquareLoc(),
     !getLangOpts().CPlusPlus17
         ? diag::ext_decomp_decl
         : D.getContext() == DeclaratorContext::Condition
               ? diag::ext_decomp_decl_cond
               : diag::warn_cxx14_compat_decomp_decl)
    << Decomp.getSourceRange();

// The semantic context is always just the current context.
DeclContext *const DC = CurContext;

// C++17 [dcl.dcl]/8:
//   The decl-specifier-seq shall contain only the type-specifier auto
//   and cv-qualifiers.
// C++2a [dcl.dcl]/8:
//   If decl-specifier-seq contains any decl-specifier other than static,
//   thread_local, auto, or cv-qualifiers, the program is ill-formed.
auto &DS = D.getDeclSpec();
{
  SmallVector<StringRef, 8> BadSpecifiers;
  SmallVector<SourceLocation, 8> BadSpecifierLocs;
  SmallVector<StringRef, 8> CPlusPlus20Specifiers;
  SmallVector<SourceLocation, 8> CPlusPlus20SpecifierLocs;
  if (auto SCS = DS.getStorageClassSpec()) {
    if (SCS == DeclSpec::SCS_static) {
      CPlusPlus20Specifiers.push_back(DeclSpec::getSpecifierName(SCS));
      CPlusPlus20SpecifierLocs.push_back(DS.getStorageClassSpecLoc());
    } else {
      BadSpecifiers.push_back(DeclSpec::getSpecifierName(SCS));
      BadSpecifierLocs.push_back(DS.getStorageClassSpecLoc());
    }
  }
  if (auto TSCS = DS.getThreadStorageClassSpec()) {
    CPlusPlus20Specifiers.push_back(DeclSpec::getSpecifierName(TSCS));
    CPlusPlus20SpecifierLocs.push_back(DS.getThreadStorageClassSpecLoc());
  }
  if (DS.hasConstexprSpecifier()) {
    BadSpecifiers.push_back(
        DeclSpec::getSpecifierName(DS.getConstexprSpecifier()));
    BadSpecifierLocs.push_back(DS.getConstexprSpecLoc());
  }
  if (DS.isInlineSpecified()) {
    BadSpecifiers.push_back("inline");
    BadSpecifierLocs.push_back(DS.getInlineSpecLoc());
  }
  if (!BadSpecifiers.empty()) {
    auto &&Err = Diag(BadSpecifierLocs.front(), diag::err_decomp_decl_spec);
    Err << (int)BadSpecifiers.size()
        << llvm::join(BadSpecifiers.begin(), BadSpecifiers.end(), " ");
    // Don't add FixItHints to remove the specifiers; we do still respect
    // them when building the underlying variable.
    for (auto Loc : BadSpecifierLocs)
      Err << SourceRange(Loc, Loc);
  } else if (!CPlusPlus20Specifiers.empty()) {
    auto &&Warn = Diag(CPlusPlus20SpecifierLocs.front(),
                       getLangOpts().CPlusPlus20
                           ? diag::warn_cxx17_compat_decomp_decl_spec
                           : diag::ext_decomp_decl_spec);
    Warn << (int)CPlusPlus20Specifiers.size()
         << llvm::join(CPlusPlus20Specifiers.begin(),
                       CPlusPlus20Specifiers.end(), " ");
    for (auto Loc : CPlusPlus20SpecifierLocs)
      Warn << SourceRange(Loc, Loc);
  }
  // We can't recover from it being declared as a typedef.
  if (DS.getStorageClassSpec() == DeclSpec::SCS_typedef)
    return nullptr;
}

// C++2a [dcl.struct.bind]p1:
//   A cv that includes volatile is deprecated
if ((DS.getTypeQualifiers() & DeclSpec::TQ_volatile) &&
    getLangOpts().CPlusPlus20)
  Diag(DS.getVolatileSpecLoc(),
       diag::warn_deprecated_volatile_structured_binding);

TypeSourceInfo *TInfo = GetTypeForDeclarator(D, S);
QualType R = TInfo->getType();

if (DiagnoseUnexpandedParameterPack(D.getIdentifierLoc(), TInfo,
                                    UPPC_DeclarationType))
  D.setInvalidType();

// The syntax only allows a single ref-qualifier prior to the decomposition
// declarator. No other declarator chunks are permitted. Also check the type
// specifier here.
if (DS.getTypeSpecType() != DeclSpec::TST_auto ||
    D.hasGroupingParens() || D.getNumTypeObjects() > 1 ||
    (D.getNumTypeObjects() == 1 &&
     D.getTypeObject(0).Kind != DeclaratorChunk::Reference)) {
  Diag(Decomp.getLSquareLoc(),
       (D.hasGroupingParens() ||
        (D.getNumTypeObjects() &&
         D.getTypeObject(0).Kind == DeclaratorChunk::Paren))
           ? diag::err_decomp_decl_parens
           : diag::err_decomp_decl_type)
      << R;

  // In most cases, there's no actual problem with an explicitly-specified
  // type, but a function type won't work here, and ActOnVariableDeclarator
  // shouldn't be called for such a type.
  if (R->isFunctionType())
    D.setInvalidType();
}

// Build the BindingDecls.
SmallVector<BindingDecl*, 8> Bindings;

// Build the BindingDecls.
for (auto &B : D.getDecompositionDeclarator().bindings()) {
  // Check for name conflicts.
  DeclarationNameInfo NameInfo(B.Name, B.NameLoc);
  LookupResult Previous(*this, NameInfo, LookupOrdinaryName,
                        ForVisibleRedeclaration);
  LookupName(Previous, S,
             /*CreateBuiltins*/DC->getRedeclContext()->isTranslationUnit());

  // It's not permitted to shadow a template parameter name.
  if (Previous.isSingleResult() &&
      Previous.getFoundDecl()->isTemplateParameter()) {
    DiagnoseTemplateParameterShadow(D.getIdentifierLoc(),
                                    Previous.getFoundDecl());
    Previous.clear();
  }

  auto *BD = BindingDecl::Create(Context, DC, B.NameLoc, B.Name);

  // Find the shadowed declaration before filtering for scope.
  NamedDecl *ShadowedDecl = D.getCXXScopeSpec().isEmpty()
                                ? getShadowedDeclaration(BD, Previous)
                                : nullptr;

  bool ConsiderLinkage = DC->isFunctionOrMethod() &&
                         DS.getStorageClassSpec() == DeclSpec::SCS_extern;
  FilterLookupForScope(Previous, DC, S, ConsiderLinkage,
                       /*AllowInlineNamespace*/false);

  if (!Previous.empty()) {
    auto *Old = Previous.getRepresentativeDecl();
    Diag(B.NameLoc, diag::err_redefinition) << B.Name;
    Diag(Old->getLocation(), diag::note_previous_definition);
  } else if (ShadowedDecl && !D.isRedeclaration()) {
    CheckShadow(BD, ShadowedDecl, Previous);
  }
  PushOnScopeChains(BD, S, true);
  Bindings.push_back(BD);
  ParsingInitForAutoVars.insert(BD);
}

// There are no prior lookup results for the variable itself, because it
// is unnamed.
DeclarationNameInfo NameInfo((IdentifierInfo *)nullptr,
                             Decomp.getLSquareLoc());
LookupResult Previous(*this, NameInfo, LookupOrdinaryName,
                      ForVisibleRedeclaration);

// Build the variable that holds the non-decomposed object.
bool AddToScope = true;
NamedDecl *New =
    ActOnVariableDeclarator(S, D, DC, TInfo, Previous,
                            MultiTemplateParamsArg(), AddToScope, Bindings);
if (AddToScope) {
  S->AddDecl(New);
  CurContext->addHiddenDecl(New);
}

if (isInOpenMPDeclareTargetContext())
  checkDeclIsAllowedInOpenMPTarget(nullptr, New);

return New;
902}

904static bool checkSimpleDecomposition(
  Sema &S, ArrayRef<BindingDecl *> Bindings, ValueDecl *Src,
  QualType DecompType, const llvm::APSInt &NumElems, QualType ElemType,
  llvm::function_ref<ExprResult(SourceLocation, Expr *, unsigned)> GetInit) {
if ((int64_t)Bindings.size() != NumElems) {
  S.Diag(Src->getLocation(), diag::err_decomp_decl_wrong_number_bindings)
      << DecompType << (unsigned)Bindings.size()
      << (unsigned)NumElems.getLimitedValue(UINT_MAX(2147483647 *2U +1U))
      << toString(NumElems, 10) << (NumElems < Bindings.size());
  return true;
}

unsigned I = 0;
for (auto *B : Bindings) {
  SourceLocation Loc = B->getLocation();
  ExprResult E = S.BuildDeclRefExpr(Src, DecompType, VK_LValue, Loc);
  if (E.isInvalid())
    return true;
  E = GetInit(Loc, E.get(), I++);
  if (E.isInvalid())
    return true;
  B->setBinding(ElemType, E.get());
}

return false;
929}

931static bool checkArrayLikeDecomposition(Sema &S,
                                      ArrayRef<BindingDecl *> Bindings,
                                      ValueDecl *Src, QualType DecompType,
                                      const llvm::APSInt &NumElems,
                                      QualType ElemType) {
return checkSimpleDecomposition(
    S, Bindings, Src, DecompType, NumElems, ElemType,
    [&](SourceLocation Loc, Expr *Base, unsigned I) -> ExprResult {
      ExprResult E = S.ActOnIntegerConstant(Loc, I);
      if (E.isInvalid())
        return ExprError();
      return S.CreateBuiltinArraySubscriptExpr(Base, Loc, E.get(), Loc);
    });
944}

946static bool checkArrayDecomposition(Sema &S, ArrayRef<BindingDecl*> Bindings,
                                  ValueDecl *Src, QualType DecompType,
                                  const ConstantArrayType *CAT) {
return checkArrayLikeDecomposition(S, Bindings, Src, DecompType,
                                   llvm::APSInt(CAT->getSize()),
                                   CAT->getElementType());
952}

954static bool checkVectorDecomposition(Sema &S, ArrayRef<BindingDecl*> Bindings,
                                   ValueDecl *Src, QualType DecompType,
                                   const VectorType *VT) {
return checkArrayLikeDecomposition(
    S, Bindings, Src, DecompType, llvm::APSInt::get(VT->getNumElements()),
    S.Context.getQualifiedType(VT->getElementType(),
                               DecompType.getQualifiers()));
961}

963static bool checkComplexDecomposition(Sema &S,
                                    ArrayRef<BindingDecl *> Bindings,
                                    ValueDecl *Src, QualType DecompType,
                                    const ComplexType *CT) {
return checkSimpleDecomposition(
    S, Bindings, Src, DecompType, llvm::APSInt::get(2),
    S.Context.getQualifiedType(CT->getElementType(),
                               DecompType.getQualifiers()),
    [&](SourceLocation Loc, Expr *Base, unsigned I) -> ExprResult {
      return S.CreateBuiltinUnaryOp(Loc, I ? UO_Imag : UO_Real, Base);
    });
974}

976static std::string printTemplateArgs(const PrintingPolicy &PrintingPolicy,
                                   TemplateArgumentListInfo &Args,
                                   const TemplateParameterList *Params) {
SmallString<128> SS;
llvm::raw_svector_ostream OS(SS);
bool First = true;
unsigned I = 0;
for (auto &Arg : Args.arguments()) {
  if (!First)
    OS << ", ";
  Arg.getArgument().print(
      PrintingPolicy, OS,
      TemplateParameterList::shouldIncludeTypeForArgument(Params, I));
  First = false;
  I++;
}
return std::string(OS.str());
993}

995static bool lookupStdTypeTraitMember(Sema &S, LookupResult &TraitMemberLookup,
                                   SourceLocation Loc, StringRef Trait,
                                   TemplateArgumentListInfo &Args,
                                   unsigned DiagID) {
auto DiagnoseMissing = [&] {
  if (DiagID)
    S.Diag(Loc, DiagID) << printTemplateArgs(S.Context.getPrintingPolicy(),
                                             Args, /*Params*/ nullptr);
  return true;
};

// FIXME: Factor out duplication with lookupPromiseType in SemaCoroutine.
NamespaceDecl *Std = S.getStdNamespace();
if (!Std)
  return DiagnoseMissing();

// Look up the trait itself, within namespace std. We can diagnose various
// problems with this lookup even if we've been asked to not diagnose a
// missing specialization, because this can only fail if the user has been
// declaring their own names in namespace std or we don't support the
// standard library implementation in use.
LookupResult Result(S, &S.PP.getIdentifierTable().get(Trait),
                    Loc, Sema::LookupOrdinaryName);
if (!S.LookupQualifiedName(Result, Std))
  return DiagnoseMissing();
if (Result.isAmbiguous())
  return true;

ClassTemplateDecl *TraitTD = Result.getAsSingle<ClassTemplateDecl>();
if (!TraitTD) {
  Result.suppressDiagnostics();
  NamedDecl *Found = *Result.begin();
  S.Diag(Loc, diag::err_std_type_trait_not_class_template) << Trait;
  S.Diag(Found->getLocation(), diag::note_declared_at);
  return true;
}

// Build the template-id.
QualType TraitTy = S.CheckTemplateIdType(TemplateName(TraitTD), Loc, Args);
if (TraitTy.isNull())
  return true;
if (!S.isCompleteType(Loc, TraitTy)) {
  if (DiagID)
    S.RequireCompleteType(
        Loc, TraitTy, DiagID,
        printTemplateArgs(S.Context.getPrintingPolicy(), Args,
                          TraitTD->getTemplateParameters()));
  return true;
}

CXXRecordDecl *RD = TraitTy->getAsCXXRecordDecl();
assert(RD && "specialization of class template is not a class?")(static_cast<void> (0));

// Look up the member of the trait type.
S.LookupQualifiedName(TraitMemberLookup, RD);
return TraitMemberLookup.isAmbiguous();
1051}

1053static TemplateArgumentLoc
1054getTrivialIntegralTemplateArgument(Sema &S, SourceLocation Loc, QualType T,
                                 uint64_t I) {
TemplateArgument Arg(S.Context, S.Context.MakeIntValue(I, T), T);
return S.getTrivialTemplateArgumentLoc(Arg, T, Loc);
1058}

1060static TemplateArgumentLoc
1061getTrivialTypeTemplateArgument(Sema &S, SourceLocation Loc, QualType T) {
return S.getTrivialTemplateArgumentLoc(TemplateArgument(T), QualType(), Loc);
1063}

1065namespace { enum class IsTupleLike { TupleLike, NotTupleLike, Error }; }

1067static IsTupleLike isTupleLike(Sema &S, SourceLocation Loc, QualType T,
                             llvm::APSInt &Size) {
EnterExpressionEvaluationContext ContextRAII(
    S, Sema::ExpressionEvaluationContext::ConstantEvaluated);

DeclarationName Value = S.PP.getIdentifierInfo("value");
LookupResult R(S, Value, Loc, Sema::LookupOrdinaryName);

// Form template argument list for tuple_size<T>.
TemplateArgumentListInfo Args(Loc, Loc);
Args.addArgument(getTrivialTypeTemplateArgument(S, Loc, T));

// If there's no tuple_size specialization or the lookup of 'value' is empty,
// it's not tuple-like.
if (lookupStdTypeTraitMember(S, R, Loc, "tuple_size", Args, /*DiagID*/ 0) ||
    R.empty())
  return IsTupleLike::NotTupleLike;

// If we get this far, we've committed to the tuple interpretation, but
// we can still fail if there actually isn't a usable ::value.

struct ICEDiagnoser : Sema::VerifyICEDiagnoser {
  LookupResult &R;
  TemplateArgumentListInfo &Args;
  ICEDiagnoser(LookupResult &R, TemplateArgumentListInfo &Args)
      : R(R), Args(Args) {}
  Sema::SemaDiagnosticBuilder diagnoseNotICE(Sema &S,
                                             SourceLocation Loc) override {
    return S.Diag(Loc, diag::err_decomp_decl_std_tuple_size_not_constant)
           << printTemplateArgs(S.Context.getPrintingPolicy(), Args,
                                /*Params*/ nullptr);
  }
} Diagnoser(R, Args);

ExprResult E =
    S.BuildDeclarationNameExpr(CXXScopeSpec(), R, /*NeedsADL*/false);
if (E.isInvalid())
  return IsTupleLike::Error;

E = S.VerifyIntegerConstantExpression(E.get(), &Size, Diagnoser);
if (E.isInvalid())
  return IsTupleLike::Error;

return IsTupleLike::TupleLike;
1111}

1113/// \return std::tuple_element<I, T>::type.
1114static QualType getTupleLikeElementType(Sema &S, SourceLocation Loc,
                                      unsigned I, QualType T) {
// Form template argument list for tuple_element<I, T>.
TemplateArgumentListInfo Args(Loc, Loc);
Args.addArgument(
    getTrivialIntegralTemplateArgument(S, Loc, S.Context.getSizeType(), I));
Args.addArgument(getTrivialTypeTemplateArgument(S, Loc, T));

DeclarationName TypeDN = S.PP.getIdentifierInfo("type");
LookupResult R(S, TypeDN, Loc, Sema::LookupOrdinaryName);
if (lookupStdTypeTraitMember(
        S, R, Loc, "tuple_element", Args,
        diag::err_decomp_decl_std_tuple_element_not_specialized))
  return QualType();

auto *TD = R.getAsSingle<TypeDecl>();
if (!TD) {
  R.suppressDiagnostics();
  S.Diag(Loc, diag::err_decomp_decl_std_tuple_element_not_specialized)
      << printTemplateArgs(S.Context.getPrintingPolicy(), Args,
                           /*Params*/ nullptr);
  if (!R.empty())
    S.Diag(R.getRepresentativeDecl()->getLocation(), diag::note_declared_at);
  return QualType();
}

return S.Context.getTypeDeclType(TD);
1141}

1143namespace {
1144struct InitializingBinding {
Sema &S;
InitializingBinding(Sema &S, BindingDecl *BD) : S(S) {
  Sema::CodeSynthesisContext Ctx;
  Ctx.Kind = Sema::CodeSynthesisContext::InitializingStructuredBinding;
  Ctx.PointOfInstantiation = BD->getLocation();
  Ctx.Entity = BD;
  S.pushCodeSynthesisContext(Ctx);
}
~InitializingBinding() {
  S.popCodeSynthesisContext();
}
1156};
1157}

1159static bool checkTupleLikeDecomposition(Sema &S,
                                      ArrayRef<BindingDecl *> Bindings,
                                      VarDecl *Src, QualType DecompType,
                                      const llvm::APSInt &TupleSize) {
if ((int64_t)Bindings.size() != TupleSize) {
  S.Diag(Src->getLocation(), diag::err_decomp_decl_wrong_number_bindings)
      << DecompType << (unsigned)Bindings.size()
      << (unsigned)TupleSize.getLimitedValue(UINT_MAX(2147483647 *2U +1U))
      << toString(TupleSize, 10) << (TupleSize < Bindings.size());
  return true;
}

if (Bindings.empty())
  return false;

DeclarationName GetDN = S.PP.getIdentifierInfo("get");

// [dcl.decomp]p3:
//   The unqualified-id get is looked up in the scope of E by class member
//   access lookup ...
LookupResult MemberGet(S, GetDN, Src->getLocation(), Sema::LookupMemberName);
bool UseMemberGet = false;
if (S.isCompleteType(Src->getLocation(), DecompType)) {
  if (auto *RD = DecompType->getAsCXXRecordDecl())
    S.LookupQualifiedName(MemberGet, RD);
  if (MemberGet.isAmbiguous())
    return true;
  //   ... and if that finds at least one declaration that is a function
  //   template whose first template parameter is a non-type parameter ...
  for (NamedDecl *D : MemberGet) {
    if (FunctionTemplateDecl *FTD =
            dyn_cast<FunctionTemplateDecl>(D->getUnderlyingDecl())) {
      TemplateParameterList *TPL = FTD->getTemplateParameters();
      if (TPL->size() != 0 &&
          isa<NonTypeTemplateParmDecl>(TPL->getParam(0))) {
        //   ... the initializer is e.get<i>().
        UseMemberGet = true;
        break;
      }
    }
  }
}

unsigned I = 0;
for (auto *B : Bindings) {
  InitializingBinding InitContext(S, B);
  SourceLocation Loc = B->getLocation();

  ExprResult E = S.BuildDeclRefExpr(Src, DecompType, VK_LValue, Loc);
  if (E.isInvalid())
    return true;

  //   e is an lvalue if the type of the entity is an lvalue reference and
  //   an xvalue otherwise
  if (!Src->getType()->isLValueReferenceType())
    E = ImplicitCastExpr::Create(S.Context, E.get()->getType(), CK_NoOp,
                                 E.get(), nullptr, VK_XValue,
                                 FPOptionsOverride());

  TemplateArgumentListInfo Args(Loc, Loc);
  Args.addArgument(
      getTrivialIntegralTemplateArgument(S, Loc, S.Context.getSizeType(), I));

  if (UseMemberGet) {
    //   if [lookup of member get] finds at least one declaration, the
    //   initializer is e.get<i-1>().
    E = S.BuildMemberReferenceExpr(E.get(), DecompType, Loc, false,
                                   CXXScopeSpec(), SourceLocation(), nullptr,
                                   MemberGet, &Args, nullptr);
    if (E.isInvalid())
      return true;

    E = S.BuildCallExpr(nullptr, E.get(), Loc, None, Loc);
  } else {
    //   Otherwise, the initializer is get<i-1>(e), where get is looked up
    //   in the associated namespaces.
    Expr *Get = UnresolvedLookupExpr::Create(
        S.Context, nullptr, NestedNameSpecifierLoc(), SourceLocation(),
        DeclarationNameInfo(GetDN, Loc), /*RequiresADL*/true, &Args,
        UnresolvedSetIterator(), UnresolvedSetIterator());

    Expr *Arg = E.get();
    E = S.BuildCallExpr(nullptr, Get, Loc, Arg, Loc);
  }
  if (E.isInvalid())
    return true;
  Expr *Init = E.get();

  //   Given the type T designated by std::tuple_element<i - 1, E>::type,
  QualType T = getTupleLikeElementType(S, Loc, I, DecompType);
  if (T.isNull())
    return true;

  //   each vi is a variable of type "reference to T" initialized with the
  //   initializer, where the reference is an lvalue reference if the
  //   initializer is an lvalue and an rvalue reference otherwise
  QualType RefType =
      S.BuildReferenceType(T, E.get()->isLValue(), Loc, B->getDeclName());
  if (RefType.isNull())
    return true;
  auto *RefVD = VarDecl::Create(
      S.Context, Src->getDeclContext(), Loc, Loc,
      B->getDeclName().getAsIdentifierInfo(), RefType,
      S.Context.getTrivialTypeSourceInfo(T, Loc), Src->getStorageClass());
  RefVD->setLexicalDeclContext(Src->getLexicalDeclContext());
  RefVD->setTSCSpec(Src->getTSCSpec());
  RefVD->setImplicit();
  if (Src->isInlineSpecified())
    RefVD->setInlineSpecified();
  RefVD->getLexicalDeclContext()->addHiddenDecl(RefVD);

  InitializedEntity Entity = InitializedEntity::InitializeBinding(RefVD);
  InitializationKind Kind = InitializationKind::CreateCopy(Loc, Loc);
  InitializationSequence Seq(S, Entity, Kind, Init);
  E = Seq.Perform(S, Entity, Kind, Init);
  if (E.isInvalid())
    return true;
  E = S.ActOnFinishFullExpr(E.get(), Loc, /*DiscardedValue*/ false);
  if (E.isInvalid())
    return true;
  RefVD->setInit(E.get());
  S.CheckCompleteVariableDeclaration(RefVD);

  E = S.BuildDeclarationNameExpr(CXXScopeSpec(),
                                 DeclarationNameInfo(B->getDeclName(), Loc),
                                 RefVD);
  if (E.isInvalid())
    return true;

  B->setBinding(T, E.get());
  I++;
}

return false;
1293}

1295/// Find the base class to decompose in a built-in decomposition of a class type.
1296/// This base class search is, unfortunately, not quite like any other that we
1297/// perform anywhere else in C++.
1298static DeclAccessPair findDecomposableBaseClass(Sema &S, SourceLocation Loc,
                                              const CXXRecordDecl *RD,
                                              CXXCastPath &BasePath) {
auto BaseHasFields = [](const CXXBaseSpecifier *Specifier,
                        CXXBasePath &Path) {
  return Specifier->getType()->getAsCXXRecordDecl()->hasDirectFields();
};

const CXXRecordDecl *ClassWithFields = nullptr;
AccessSpecifier AS = AS_public;
if (RD->hasDirectFields())
  // [dcl.decomp]p4:
  //   Otherwise, all of E's non-static data members shall be public direct
  //   members of E ...
  ClassWithFields = RD;
else {
  //   ... or of ...
  CXXBasePaths Paths;
  Paths.setOrigin(const_cast<CXXRecordDecl*>(RD));
  if (!RD->lookupInBases(BaseHasFields, Paths)) {
    // If no classes have fields, just decompose RD itself. (This will work
    // if and only if zero bindings were provided.)
    return DeclAccessPair::make(const_cast<CXXRecordDecl*>(RD), AS_public);
  }

  CXXBasePath *BestPath = nullptr;
  for (auto &P : Paths) {
    if (!BestPath)
      BestPath = &P;
    else if (!S.Context.hasSameType(P.back().Base->getType(),
                                    BestPath->back().Base->getType())) {
      //   ... the same ...
      S.Diag(Loc, diag::err_decomp_decl_multiple_bases_with_members)
        << false << RD << BestPath->back().Base->getType()
        << P.back().Base->getType();
      return DeclAccessPair();
    } else if (P.Access < BestPath->Access) {
      BestPath = &P;
    }
  }

  //   ... unambiguous ...
  QualType BaseType = BestPath->back().Base->getType();
  if (Paths.isAmbiguous(S.Context.getCanonicalType(BaseType))) {
    S.Diag(Loc, diag::err_decomp_decl_ambiguous_base)
      << RD << BaseType << S.getAmbiguousPathsDisplayString(Paths);
    return DeclAccessPair();
  }

  //   ... [accessible, implied by other rules] base class of E.
  S.CheckBaseClassAccess(Loc, BaseType, S.Context.getRecordType(RD),
                         *BestPath, diag::err_decomp_decl_inaccessible_base);
  AS = BestPath->Access;

  ClassWithFields = BaseType->getAsCXXRecordDecl();
  S.BuildBasePathArray(Paths, BasePath);
}

// The above search did not check whether the selected class itself has base
// classes with fields, so check that now.
CXXBasePaths Paths;
if (ClassWithFields->lookupInBases(BaseHasFields, Paths)) {
  S.Diag(Loc, diag::err_decomp_decl_multiple_bases_with_members)
    << (ClassWithFields == RD) << RD << ClassWithFields
    << Paths.front().back().Base->getType();
  return DeclAccessPair();
}

return DeclAccessPair::make(const_cast<CXXRecordDecl*>(ClassWithFields), AS);
1367}

1369static bool checkMemberDecomposition(Sema &S, ArrayRef<BindingDecl*> Bindings,
                                   ValueDecl *Src, QualType DecompType,
                                   const CXXRecordDecl *OrigRD) {
if (S.RequireCompleteType(Src->getLocation(), DecompType,
                          diag::err_incomplete_type))
  return true;

CXXCastPath BasePath;
DeclAccessPair BasePair =
    findDecomposableBaseClass(S, Src->getLocation(), OrigRD, BasePath);
const CXXRecordDecl *RD = cast_or_null<CXXRecordDecl>(BasePair.getDecl());
if (!RD)
  return true;
QualType BaseType = S.Context.getQualifiedType(S.Context.getRecordType(RD),
                                               DecompType.getQualifiers());

auto DiagnoseBadNumberOfBindings = [&]() -> bool {
  unsigned NumFields =
      std::count_if(RD->field_begin(), RD->field_end(),
                    [](FieldDecl *FD) { return !FD->isUnnamedBitfield(); });
  assert(Bindings.size() != NumFields)(static_cast<void> (0));
  S.Diag(Src->getLocation(), diag::err_decomp_decl_wrong_number_bindings)
      << DecompType << (unsigned)Bindings.size() << NumFields << NumFields
      << (NumFields < Bindings.size());
  return true;
};

//   all of E's non-static data members shall be [...] well-formed
//   when named as e.name in the context of the structured binding,
//   E shall not have an anonymous union member, ...
unsigned I = 0;
for (auto *FD : RD->fields()) {
  if (FD->isUnnamedBitfield())
    continue;

  // All the non-static data members are required to be nameable, so they
  // must all have names.
  if (!FD->getDeclName()) {
    if (RD->isLambda()) {
      S.Diag(Src->getLocation(), diag::err_decomp_decl_lambda);
      S.Diag(RD->getLocation(), diag::note_lambda_decl);
      return true;
    }

    if (FD->isAnonymousStructOrUnion()) {
      S.Diag(Src->getLocation(), diag::err_decomp_decl_anon_union_member)
        << DecompType << FD->getType()->isUnionType();
      S.Diag(FD->getLocation(), diag::note_declared_at);
      return true;
    }

    // FIXME: Are there any other ways we could have an anonymous member?
  }

  // We have a real field to bind.
  if (I >= Bindings.size())
    return DiagnoseBadNumberOfBindings();
  auto *B = Bindings[I++];
  SourceLocation Loc = B->getLocation();

  // The field must be accessible in the context of the structured binding.
  // We already checked that the base class is accessible.
  // FIXME: Add 'const' to AccessedEntity's classes so we can remove the
  // const_cast here.
  S.CheckStructuredBindingMemberAccess(
      Loc, const_cast<CXXRecordDecl *>(OrigRD),
      DeclAccessPair::make(FD, CXXRecordDecl::MergeAccess(
                                   BasePair.getAccess(), FD->getAccess())));

  // Initialize the binding to Src.FD.
  ExprResult E = S.BuildDeclRefExpr(Src, DecompType, VK_LValue, Loc);
  if (E.isInvalid())
    return true;
  E = S.ImpCastExprToType(E.get(), BaseType, CK_UncheckedDerivedToBase,
                          VK_LValue, &BasePath);
  if (E.isInvalid())
    return true;
  E = S.BuildFieldReferenceExpr(E.get(), /*IsArrow*/ false, Loc,
                                CXXScopeSpec(), FD,
                                DeclAccessPair::make(FD, FD->getAccess()),
                                DeclarationNameInfo(FD->getDeclName(), Loc));
  if (E.isInvalid())
    return true;

  // If the type of the member is T, the referenced type is cv T, where cv is
  // the cv-qualification of the decomposition expression.
  //
  // FIXME: We resolve a defect here: if the field is mutable, we do not add
  // 'const' to the type of the field.
  Qualifiers Q = DecompType.getQualifiers();
  if (FD->isMutable())
    Q.removeConst();
  B->setBinding(S.BuildQualifiedType(FD->getType(), Loc, Q), E.get());
}

if (I != Bindings.size())
  return DiagnoseBadNumberOfBindings();

return false;
1468}

1470void Sema::CheckCompleteDecompositionDeclaration(DecompositionDecl *DD) {
QualType DecompType = DD->getType();

// If the type of the decomposition is dependent, then so is the type of
// each binding.
if (DecompType->isDependentType()) {
  for (auto *B : DD->bindings())
    B->setType(Context.DependentTy);
  return;
}

DecompType = DecompType.getNonReferenceType();
ArrayRef<BindingDecl*> Bindings = DD->bindings();

// C++1z [dcl.decomp]/2:
//   If E is an array type [...]
// As an extension, we also support decomposition of built-in complex and
// vector types.
if (auto *CAT = Context.getAsConstantArrayType(DecompType)) {
  if (checkArrayDecomposition(*this, Bindings, DD, DecompType, CAT))
    DD->setInvalidDecl();
  return;
}
if (auto *VT = DecompType->getAs<VectorType>()) {
  if (checkVectorDecomposition(*this, Bindings, DD, DecompType, VT))
    DD->setInvalidDecl();
  return;
}
if (auto *CT = DecompType->getAs<ComplexType>()) {
  if (checkComplexDecomposition(*this, Bindings, DD, DecompType, CT))
    DD->setInvalidDecl();
  return;
}

// C++1z [dcl.decomp]/3:
//   if the expression std::tuple_size<E>::value is a well-formed integral
//   constant expression, [...]
llvm::APSInt TupleSize(32);
switch (isTupleLike(*this, DD->getLocation(), DecompType, TupleSize)) {
case IsTupleLike::Error:
  DD->setInvalidDecl();
  return;

case IsTupleLike::TupleLike:
  if (checkTupleLikeDecomposition(*this, Bindings, DD, DecompType, TupleSize))
    DD->setInvalidDecl();
  return;

case IsTupleLike::NotTupleLike:
  break;
}

// C++1z [dcl.dcl]/8:
//   [E shall be of array or non-union class type]
CXXRecordDecl *RD = DecompType->getAsCXXRecordDecl();
if (!RD || RD->isUnion()) {
  Diag(DD->getLocation(), diag::err_decomp_decl_unbindable_type)
      << DD << !RD << DecompType;
  DD->setInvalidDecl();
  return;
}

// C++1z [dcl.decomp]/4:
//   all of E's non-static data members shall be [...] direct members of
//   E or of the same unambiguous public base class of E, ...
if (checkMemberDecomposition(*this, Bindings, DD, DecompType, RD))
  DD->setInvalidDecl();
1537}

1539/// Merge the exception specifications of two variable declarations.
1540///
1541/// This is called when there's a redeclaration of a VarDecl. The function
1542/// checks if the redeclaration might have an exception specification and
1543/// validates compatibility and merges the specs if necessary.
1544void Sema::MergeVarDeclExceptionSpecs(VarDecl *New, VarDecl *Old) {
// Shortcut if exceptions are disabled.
if (!getLangOpts().CXXExceptions)
  return;

assert(Context.hasSameType(New->getType(), Old->getType()) &&(static_cast<void> (0))
       "Should only be called if types are otherwise the same.")(static_cast<void> (0));

QualType NewType = New->getType();
QualType OldType = Old->getType();

// We're only interested in pointers and references to functions, as well
// as pointers to member functions.
if (const ReferenceType *R = NewType->getAs<ReferenceType>()) {
  NewType = R->getPointeeType();
  OldType = OldType->castAs<ReferenceType>()->getPointeeType();
} else if (const PointerType *P = NewType->getAs<PointerType>()) {
  NewType = P->getPointeeType();
  OldType = OldType->castAs<PointerType>()->getPointeeType();
} else if (const MemberPointerType *M = NewType->getAs<MemberPointerType>()) {
  NewType = M->getPointeeType();
  OldType = OldType->castAs<MemberPointerType>()->getPointeeType();
}

if (!NewType->isFunctionProtoType())
  return;

// There's lots of special cases for functions. For function pointers, system
// libraries are hopefully not as broken so that we don't need these
// workarounds.
if (CheckEquivalentExceptionSpec(
      OldType->getAs<FunctionProtoType>(), Old->getLocation(),
      NewType->getAs<FunctionProtoType>(), New->getLocation())) {
  New->setInvalidDecl();
}
1579}

1581/// CheckCXXDefaultArguments - Verify that the default arguments for a
1582/// function declaration are well-formed according to C++
1583/// [dcl.fct.default].
1584void Sema::CheckCXXDefaultArguments(FunctionDecl *FD) {
unsigned NumParams = FD->getNumParams();
unsigned ParamIdx = 0;

// This checking doesn't make sense for explicit specializations; their
// default arguments are determined by the declaration we're specializing,
// not by FD.
if (FD->getTemplateSpecializationKind() == TSK_ExplicitSpecialization)
  return;
if (auto *FTD = FD->getDescribedFunctionTemplate())
  if (FTD->isMemberSpecialization())
    return;

// Find first parameter with a default argument
for (; ParamIdx < NumParams; ++ParamIdx) {
  ParmVarDecl *Param = FD->getParamDecl(ParamIdx);
  if (Param->hasDefaultArg())
    break;
}

// C++20 [dcl.fct.default]p4:
//   In a given function declaration, each parameter subsequent to a parameter
//   with a default argument shall have a default argument supplied in this or
//   a previous declaration, unless the parameter was expanded from a
//   parameter pack, or shall be a function parameter pack.
for (; ParamIdx < NumParams; ++ParamIdx) {
  ParmVarDecl *Param = FD->getParamDecl(ParamIdx);
  if (!Param->hasDefaultArg() && !Param->isParameterPack() &&
      !(CurrentInstantiationScope &&
        CurrentInstantiationScope->isLocalPackExpansion(Param))) {
    if (Param->isInvalidDecl())
      /* We already complained about this parameter. */;
    else if (Param->getIdentifier())
      Diag(Param->getLocation(),
           diag::err_param_default_argument_missing_name)
        << Param->getIdentifier();
    else
      Diag(Param->getLocation(),
           diag::err_param_default_argument_missing);
  }
}
1625}

1627/// Check that the given type is a literal type. Issue a diagnostic if not,
1628/// if Kind is Diagnose.
1629/// \return \c true if a problem has been found (and optionally diagnosed).
1630template <typename... Ts>
1631static bool CheckLiteralType(Sema &SemaRef, Sema::CheckConstexprKind Kind,
                           SourceLocation Loc, QualType T, unsigned DiagID,
                           Ts &&...DiagArgs) {
if (T->isDependentType())
  return false;

switch (Kind) {
case Sema::CheckConstexprKind::Diagnose:
  return SemaRef.RequireLiteralType(Loc, T, DiagID,
                                    std::forward<Ts>(DiagArgs)...);

case Sema::CheckConstexprKind::CheckValid:
  return !T->isLiteralType(SemaRef.Context);
}

llvm_unreachable("unknown CheckConstexprKind")__builtin_unreachable();
1647}

1649/// Determine whether a destructor cannot be constexpr due to
1650static bool CheckConstexprDestructorSubobjects(Sema &SemaRef,
                                             const CXXDestructorDecl *DD,
                                             Sema::CheckConstexprKind Kind) {
auto Check = [&](SourceLocation Loc, QualType T, const FieldDecl *FD) {
  const CXXRecordDecl *RD =
      T->getBaseElementTypeUnsafe()->getAsCXXRecordDecl();
  if (!RD || RD->hasConstexprDestructor())
    return true;

  if (Kind == Sema::CheckConstexprKind::Diagnose) {
    SemaRef.Diag(DD->getLocation(), diag::err_constexpr_dtor_subobject)
        << static_cast<int>(DD->getConstexprKind()) << !FD
        << (FD ? FD->getDeclName() : DeclarationName()) << T;
    SemaRef.Diag(Loc, diag::note_constexpr_dtor_subobject)
        << !FD << (FD ? FD->getDeclName() : DeclarationName()) << T;
  }
  return false;
};

const CXXRecordDecl *RD = DD->getParent();
for (const CXXBaseSpecifier &B : RD->bases())
  if (!Check(B.getBaseTypeLoc(), B.getType(), nullptr))
    return false;
for (const FieldDecl *FD : RD->fields())
  if (!Check(FD->getLocation(), FD->getType(), FD))
    return false;
return true;
1677}

1679/// Check whether a function's parameter types are all literal types. If so,
1680/// return true. If not, produce a suitable diagnostic and return false.
1681static bool CheckConstexprParameterTypes(Sema &SemaRef,
                                       const FunctionDecl *FD,
                                       Sema::CheckConstexprKind Kind) {
unsigned ArgIndex = 0;
const auto *FT = FD->getType()->castAs<FunctionProtoType>();
for (FunctionProtoType::param_type_iterator i = FT->param_type_begin(),
                                            e = FT->param_type_end();
     i != e; ++i, ++ArgIndex) {
  const ParmVarDecl *PD = FD->getParamDecl(ArgIndex);
  SourceLocation ParamLoc = PD->getLocation();
  if (CheckLiteralType(SemaRef, Kind, ParamLoc, *i,
                       diag::err_constexpr_non_literal_param, ArgIndex + 1,
                       PD->getSourceRange(), isa<CXXConstructorDecl>(FD),
                       FD->isConsteval()))
    return false;
}
return true;
1698}

1700/// Check whether a function's return type is a literal type. If so, return
1701/// true. If not, produce a suitable diagnostic and return false.
1702static bool CheckConstexprReturnType(Sema &SemaRef, const FunctionDecl *FD,
                                   Sema::CheckConstexprKind Kind) {
if (CheckLiteralType(SemaRef, Kind, FD->getLocation(), FD->getReturnType(),
                     diag::err_constexpr_non_literal_return,
                     FD->isConsteval()))
  return false;
return true;
1709}

1711/// Get diagnostic %select index for tag kind for
1712/// record diagnostic message.
1713/// WARNING: Indexes apply to particular diagnostics only!
1714///
1715/// \returns diagnostic %select index.
1716static unsigned getRecordDiagFromTagKind(TagTypeKind Tag) {
switch (Tag) {
case TTK_Struct: return 0;
case TTK_Interface: return 1;
case TTK_Class:  return 2;
default: llvm_unreachable("Invalid tag kind for record diagnostic!")__builtin_unreachable();
}
1723}

1725static bool CheckConstexprFunctionBody(Sema &SemaRef, const FunctionDecl *Dcl,
                                     Stmt *Body,
                                     Sema::CheckConstexprKind Kind);

1729// Check whether a function declaration satisfies the requirements of a
1730// constexpr function definition or a constexpr constructor definition. If so,
1731// return true. If not, produce appropriate diagnostics (unless asked not to by
1732// Kind) and return false.
1733//
1734// This implements C++11 [dcl.constexpr]p3,4, as amended by DR1360.
1735bool Sema::CheckConstexprFunctionDefinition(const FunctionDecl *NewFD,
                                          CheckConstexprKind Kind) {
const CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(NewFD);
if (MD && MD->isInstance()) {
  // C++11 [dcl.constexpr]p4:
  //  The definition of a constexpr constructor shall satisfy the following
  //  constraints:
  //  - the class shall not have any virtual base classes;
  //
  // FIXME: This only applies to constructors and destructors, not arbitrary
  // member functions.
  const CXXRecordDecl *RD = MD->getParent();
  if (RD->getNumVBases()) {
    if (Kind == CheckConstexprKind::CheckValid)
      return false;

    Diag(NewFD->getLocation(), diag::err_constexpr_virtual_base)
      << isa<CXXConstructorDecl>(NewFD)
      << getRecordDiagFromTagKind(RD->getTagKind()) << RD->getNumVBases();
    for (const auto &I : RD->vbases())
      Diag(I.getBeginLoc(), diag::note_constexpr_virtual_base_here)
          << I.getSourceRange();
    return false;
  }
}

if (!isa<CXXConstructorDecl>(NewFD)) {
  // C++11 [dcl.constexpr]p3:
  //  The definition of a constexpr function shall satisfy the following
  //  constraints:
  // - it shall not be virtual; (removed in C++20)
  const CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(NewFD);
  if (Method && Method->isVirtual()) {
    if (getLangOpts().CPlusPlus20) {
      if (Kind == CheckConstexprKind::Diagnose)
        Diag(Method->getLocation(), diag::warn_cxx17_compat_constexpr_virtual);
    } else {
      if (Kind == CheckConstexprKind::CheckValid)
        return false;

      Method = Method->getCanonicalDecl();
      Diag(Method->getLocation(), diag::err_constexpr_virtual);

      // If it's not obvious why this function is virtual, find an overridden
      // function which uses the 'virtual' keyword.
      const CXXMethodDecl *WrittenVirtual = Method;
      while (!WrittenVirtual->isVirtualAsWritten())
        WrittenVirtual = *WrittenVirtual->begin_overridden_methods();
      if (WrittenVirtual != Method)
        Diag(WrittenVirtual->getLocation(),
             diag::note_overridden_virtual_function);
      return false;
    }
  }

  // - its return type shall be a literal type;
  if (!CheckConstexprReturnType(*this, NewFD, Kind))
    return false;
}

if (auto *Dtor = dyn_cast<CXXDestructorDecl>(NewFD)) {
  // A destructor can be constexpr only if the defaulted destructor could be;
  // we don't need to check the members and bases if we already know they all
  // have constexpr destructors.
  if (!Dtor->getParent()->defaultedDestructorIsConstexpr()) {
    if (Kind == CheckConstexprKind::CheckValid)
      return false;
    if (!CheckConstexprDestructorSubobjects(*this, Dtor, Kind))
      return false;
  }
}

// - each of its parameter types shall be a literal type;
if (!CheckConstexprParameterTypes(*this, NewFD, Kind))
  return false;

Stmt *Body = NewFD->getBody();
assert(Body &&(static_cast<void> (0))
       "CheckConstexprFunctionDefinition called on function with no body")(static_cast<void> (0));
return CheckConstexprFunctionBody(*this, NewFD, Body, Kind);
1815}

1817/// Check the given declaration statement is legal within a constexpr function
1818/// body. C++11 [dcl.constexpr]p3,p4, and C++1y [dcl.constexpr]p3.
1819///
1820/// \return true if the body is OK (maybe only as an extension), false if we
1821///         have diagnosed a problem.
1822static bool CheckConstexprDeclStmt(Sema &SemaRef, const FunctionDecl *Dcl,
                                 DeclStmt *DS, SourceLocation &Cxx1yLoc,
                                 Sema::CheckConstexprKind Kind) {
// C++11 [dcl.constexpr]p3 and p4:
//  The definition of a constexpr function(p3) or constructor(p4) [...] shall
//  contain only
for (const auto *DclIt : DS->decls()) {
  switch (DclIt->getKind()) {
  case Decl::StaticAssert:
  case Decl::Using:
  case Decl::UsingShadow:
  case Decl::UsingDirective:
  case Decl::UnresolvedUsingTypename:
  case Decl::UnresolvedUsingValue:
  case Decl::UsingEnum:
    //   - static_assert-declarations
    //   - using-declarations,
    //   - using-directives,
    //   - using-enum-declaration
    continue;

  case Decl::Typedef:
  case Decl::TypeAlias: {
    //   - typedef declarations and alias-declarations that do not define
    //     classes or enumerations,
    const auto *TN = cast<TypedefNameDecl>(DclIt);
    if (TN->getUnderlyingType()->isVariablyModifiedType()) {
      // Don't allow variably-modified types in constexpr functions.
      if (Kind == Sema::CheckConstexprKind::Diagnose) {
        TypeLoc TL = TN->getTypeSourceInfo()->getTypeLoc();
        SemaRef.Diag(TL.getBeginLoc(), diag::err_constexpr_vla)
          << TL.getSourceRange() << TL.getType()
          << isa<CXXConstructorDecl>(Dcl);
      }
      return false;
    }
    continue;
  }

  case Decl::Enum:
  case Decl::CXXRecord:
    // C++1y allows types to be defined, not just declared.
    if (cast<TagDecl>(DclIt)->isThisDeclarationADefinition()) {
      if (Kind == Sema::CheckConstexprKind::Diagnose) {
        SemaRef.Diag(DS->getBeginLoc(),
                     SemaRef.getLangOpts().CPlusPlus14
                         ? diag::warn_cxx11_compat_constexpr_type_definition
                         : diag::ext_constexpr_type_definition)
            << isa<CXXConstructorDecl>(Dcl);
      } else if (!SemaRef.getLangOpts().CPlusPlus14) {
        return false;
      }
    }
    continue;

  case Decl::EnumConstant:
  case Decl::IndirectField:
  case Decl::ParmVar:
    // These can only appear with other declarations which are banned in
    // C++11 and permitted in C++1y, so ignore them.
    continue;

  case Decl::Var:
  case Decl::Decomposition: {
    // C++1y [dcl.constexpr]p3 allows anything except:
    //   a definition of a variable of non-literal type or of static or
    //   thread storage duration or [before C++2a] for which no
    //   initialization is performed.
    const auto *VD = cast<VarDecl>(DclIt);
    if (VD->isThisDeclarationADefinition()) {
      if (VD->isStaticLocal()) {
        if (Kind == Sema::CheckConstexprKind::Diagnose) {
          SemaRef.Diag(VD->getLocation(),
                       diag::err_constexpr_local_var_static)
            << isa<CXXConstructorDecl>(Dcl)
            << (VD->getTLSKind() == VarDecl::TLS_Dynamic);
        }
        return false;
      }
      if (CheckLiteralType(SemaRef, Kind, VD->getLocation(), VD->getType(),
                           diag::err_constexpr_local_var_non_literal_type,
                           isa<CXXConstructorDecl>(Dcl)))
        return false;
      if (!VD->getType()->isDependentType() &&
          !VD->hasInit() && !VD->isCXXForRangeDecl()) {
        if (Kind == Sema::CheckConstexprKind::Diagnose) {
          SemaRef.Diag(
              VD->getLocation(),
              SemaRef.getLangOpts().CPlusPlus20
                  ? diag::warn_cxx17_compat_constexpr_local_var_no_init
                  : diag::ext_constexpr_local_var_no_init)
              << isa<CXXConstructorDecl>(Dcl);
        } else if (!SemaRef.getLangOpts().CPlusPlus20) {
          return false;
        }
        continue;
      }
    }
    if (Kind == Sema::CheckConstexprKind::Diagnose) {
      SemaRef.Diag(VD->getLocation(),
                   SemaRef.getLangOpts().CPlusPlus14
                    ? diag::warn_cxx11_compat_constexpr_local_var
                    : diag::ext_constexpr_local_var)
        << isa<CXXConstructorDecl>(Dcl);
    } else if (!SemaRef.getLangOpts().CPlusPlus14) {
      return false;
    }
    continue;
  }

  case Decl::NamespaceAlias:
  case Decl::Function:
    // These are disallowed in C++11 and permitted in C++1y. Allow them
    // everywhere as an extension.
    if (!Cxx1yLoc.isValid())
      Cxx1yLoc = DS->getBeginLoc();
    continue;

  default:
    if (Kind == Sema::CheckConstexprKind::Diagnose) {
      SemaRef.Diag(DS->getBeginLoc(), diag::err_constexpr_body_invalid_stmt)
          << isa<CXXConstructorDecl>(Dcl) << Dcl->isConsteval();
    }
    return false;
  }
}

return true;
1950}

1952/// Check that the given field is initialized within a constexpr constructor.
1953///
1954/// \param Dcl The constexpr constructor being checked.
1955/// \param Field The field being checked. This may be a member of an anonymous
1956///        struct or union nested within the class being checked.
1957/// \param Inits All declarations, including anonymous struct/union members and
1958///        indirect members, for which any initialization was provided.
1959/// \param Diagnosed Whether we've emitted the error message yet. Used to attach
1960///        multiple notes for different members to the same error.
1961/// \param Kind Whether we're diagnosing a constructor as written or determining
1962///        whether the formal requirements are satisfied.
1963/// \return \c false if we're checking for validity and the constructor does
1964///         not satisfy the requirements on a constexpr constructor.
1965static bool CheckConstexprCtorInitializer(Sema &SemaRef,
                                        const FunctionDecl *Dcl,
                                        FieldDecl *Field,
                                        llvm::SmallSet<Decl*, 16> &Inits,
                                        bool &Diagnosed,
                                        Sema::CheckConstexprKind Kind) {
// In C++20 onwards, there's nothing to check for validity.
if (Kind == Sema::CheckConstexprKind::CheckValid &&
    SemaRef.getLangOpts().CPlusPlus20)
  return true;

if (Field->isInvalidDecl())
  return true;

if (Field->isUnnamedBitfield())
  return true;

// Anonymous unions with no variant members and empty anonymous structs do not
// need to be explicitly initialized. FIXME: Anonymous structs that contain no
// indirect fields don't need initializing.
if (Field->isAnonymousStructOrUnion() &&
    (Field->getType()->isUnionType()
         ? !Field->getType()->getAsCXXRecordDecl()->hasVariantMembers()
         : Field->getType()->getAsCXXRecordDecl()->isEmpty()))
  return true;

if (!Inits.count(Field)) {
  if (Kind == Sema::CheckConstexprKind::Diagnose) {
    if (!Diagnosed) {
      SemaRef.Diag(Dcl->getLocation(),
                   SemaRef.getLangOpts().CPlusPlus20
                       ? diag::warn_cxx17_compat_constexpr_ctor_missing_init
                       : diag::ext_constexpr_ctor_missing_init);
      Diagnosed = true;
    }
    SemaRef.Diag(Field->getLocation(),
                 diag::note_constexpr_ctor_missing_init);
  } else if (!SemaRef.getLangOpts().CPlusPlus20) {
    return false;
  }
} else if (Field->isAnonymousStructOrUnion()) {
  const RecordDecl *RD = Field->getType()->castAs<RecordType>()->getDecl();
  for (auto *I : RD->fields())
    // If an anonymous union contains an anonymous struct of which any member
    // is initialized, all members must be initialized.
    if (!RD->isUnion() || Inits.count(I))
      if (!CheckConstexprCtorInitializer(SemaRef, Dcl, I, Inits, Diagnosed,
                                         Kind))
        return false;
}
return true;
2016}

2018/// Check the provided statement is allowed in a constexpr function
2019/// definition.
2020static bool
2021CheckConstexprFunctionStmt(Sema &SemaRef, const FunctionDecl *Dcl, Stmt *S,
                         SmallVectorImpl<SourceLocation> &ReturnStmts,
                         SourceLocation &Cxx1yLoc, SourceLocation &Cxx2aLoc,
                         Sema::CheckConstexprKind Kind) {
// - its function-body shall be [...] a compound-statement that contains only
switch (S->getStmtClass()) {
case Stmt::NullStmtClass:
  //   - null statements,
  return true;

case Stmt::DeclStmtClass:
  //   - static_assert-declarations
  //   - using-declarations,
  //   - using-directives,
  //   - typedef declarations and alias-declarations that do not define
  //     classes or enumerations,
  if (!CheckConstexprDeclStmt(SemaRef, Dcl, cast<DeclStmt>(S), Cxx1yLoc, Kind))
    return false;
  return true;

case Stmt::ReturnStmtClass:
  //   - and exactly one return statement;
  if (isa<CXXConstructorDecl>(Dcl)) {
    // C++1y allows return statements in constexpr constructors.
    if (!Cxx1yLoc.isValid())
      Cxx1yLoc = S->getBeginLoc();
    return true;
  }

  ReturnStmts.push_back(S->getBeginLoc());
  return true;

case Stmt::CompoundStmtClass: {
  // C++1y allows compound-statements.
  if (!Cxx1yLoc.isValid())
    Cxx1yLoc = S->getBeginLoc();

  CompoundStmt *CompStmt = cast<CompoundStmt>(S);
  for (auto *BodyIt : CompStmt->body()) {
    if (!CheckConstexprFunctionStmt(SemaRef, Dcl, BodyIt, ReturnStmts,
                                    Cxx1yLoc, Cxx2aLoc, Kind))
      return false;
  }
  return true;
}

case Stmt::AttributedStmtClass:
  if (!Cxx1yLoc.isValid())
    Cxx1yLoc = S->getBeginLoc();
  return true;

case Stmt::IfStmtClass: {
  // C++1y allows if-statements.
  if (!Cxx1yLoc.isValid())
    Cxx1yLoc = S->getBeginLoc();

  IfStmt *If = cast<IfStmt>(S);
  if (!CheckConstexprFunctionStmt(SemaRef, Dcl, If->getThen(), ReturnStmts,
                                  Cxx1yLoc, Cxx2aLoc, Kind))
    return false;
  if (If->getElse() &&
      !CheckConstexprFunctionStmt(SemaRef, Dcl, If->getElse(), ReturnStmts,
                                  Cxx1yLoc, Cxx2aLoc, Kind))
    return false;
  return true;
}

case Stmt::WhileStmtClass:
case Stmt::DoStmtClass:
case Stmt::ForStmtClass:
case Stmt::CXXForRangeStmtClass:
case Stmt::ContinueStmtClass:
  // C++1y allows all of these. We don't allow them as extensions in C++11,
  // because they don't make sense without variable mutation.
  if (!SemaRef.getLangOpts().CPlusPlus14)
    break;
  if (!Cxx1yLoc.isValid())
    Cxx1yLoc = S->getBeginLoc();
  for (Stmt *SubStmt : S->children())
    if (SubStmt &&
        !CheckConstexprFunctionStmt(SemaRef, Dcl, SubStmt, ReturnStmts,
                                    Cxx1yLoc, Cxx2aLoc, Kind))
      return false;
  return true;

case Stmt::SwitchStmtClass:
case Stmt::CaseStmtClass:
case Stmt::DefaultStmtClass:
case Stmt::BreakStmtClass:
  // C++1y allows switch-statements, and since they don't need variable
  // mutation, we can reasonably allow them in C++11 as an extension.
  if (!Cxx1yLoc.isValid())
    Cxx1yLoc = S->getBeginLoc();
  for (Stmt *SubStmt : S->children())
    if (SubStmt &&
        !CheckConstexprFunctionStmt(SemaRef, Dcl, SubStmt, ReturnStmts,
                                    Cxx1yLoc, Cxx2aLoc, Kind))
      return false;
  return true;

case Stmt::GCCAsmStmtClass:
case Stmt::MSAsmStmtClass:
  // C++2a allows inline assembly statements.
case Stmt::CXXTryStmtClass:
  if (Cxx2aLoc.isInvalid())
    Cxx2aLoc = S->getBeginLoc();
  for (Stmt *SubStmt : S->children()) {
    if (SubStmt &&
        !CheckConstexprFunctionStmt(SemaRef, Dcl, SubStmt, ReturnStmts,
                                    Cxx1yLoc, Cxx2aLoc, Kind))
      return false;
  }
  return true;

case Stmt::CXXCatchStmtClass:
  // Do not bother checking the language mode (already covered by the
  // try block check).
  if (!CheckConstexprFunctionStmt(SemaRef, Dcl,
                                  cast<CXXCatchStmt>(S)->getHandlerBlock(),
                                  ReturnStmts, Cxx1yLoc, Cxx2aLoc, Kind))
    return false;
  return true;

default:
  if (!isa<Expr>(S))
    break;

  // C++1y allows expression-statements.
  if (!Cxx1yLoc.isValid())
    Cxx1yLoc = S->getBeginLoc();
  return true;
}

if (Kind == Sema::CheckConstexprKind::Diagnose) {
  SemaRef.Diag(S->getBeginLoc(), diag::err_constexpr_body_invalid_stmt)
      << isa<CXXConstructorDecl>(Dcl) << Dcl->isConsteval();
}
return false;
2159}

2161/// Check the body for the given constexpr function declaration only contains
2162/// the permitted types of statement. C++11 [dcl.constexpr]p3,p4.
2163///
2164/// \return true if the body is OK, false if we have found or diagnosed a
2165/// problem.
2166static bool CheckConstexprFunctionBody(Sema &SemaRef, const FunctionDecl *Dcl,
                                     Stmt *Body,
                                     Sema::CheckConstexprKind Kind) {
SmallVector<SourceLocation, 4> ReturnStmts;

if (isa<CXXTryStmt>(Body)) {
  // C++11 [dcl.constexpr]p3:
  //  The definition of a constexpr function shall satisfy the following
  //  constraints: [...]
  // - its function-body shall be = delete, = default, or a
  //   compound-statement
  //
  // C++11 [dcl.constexpr]p4:
  //  In the definition of a constexpr constructor, [...]
  // - its function-body shall not be a function-try-block;
  //
  // This restriction is lifted in C++2a, as long as inner statements also
  // apply the general constexpr rules.
  switch (Kind) {
  case Sema::CheckConstexprKind::CheckValid:
    if (!SemaRef.getLangOpts().CPlusPlus20)
      return false;
    break;

  case Sema::CheckConstexprKind::Diagnose:
    SemaRef.Diag(Body->getBeginLoc(),
         !SemaRef.getLangOpts().CPlusPlus20
             ? diag::ext_constexpr_function_try_block_cxx20
             : diag::warn_cxx17_compat_constexpr_function_try_block)
        << isa<CXXConstructorDecl>(Dcl);
    break;
  }
}

// - its function-body shall be [...] a compound-statement that contains only
//   [... list of cases ...]
//
// Note that walking the children here is enough to properly check for
// CompoundStmt and CXXTryStmt body.
SourceLocation Cxx1yLoc, Cxx2aLoc;
for (Stmt *SubStmt : Body->children()) {
  if (SubStmt &&
      !CheckConstexprFunctionStmt(SemaRef, Dcl, SubStmt, ReturnStmts,
                                  Cxx1yLoc, Cxx2aLoc, Kind))
    return false;
}

if (Kind == Sema::CheckConstexprKind::CheckValid) {
  // If this is only valid as an extension, report that we don't satisfy the
  // constraints of the current language.
  if ((Cxx2aLoc.isValid() && !SemaRef.getLangOpts().CPlusPlus20) ||
      (Cxx1yLoc.isValid() && !SemaRef.getLangOpts().CPlusPlus17))
    return false;
} else if (Cxx2aLoc.isValid()) {
  SemaRef.Diag(Cxx2aLoc,
       SemaRef.getLangOpts().CPlusPlus20
         ? diag::warn_cxx17_compat_constexpr_body_invalid_stmt
         : diag::ext_constexpr_body_invalid_stmt_cxx20)
    << isa<CXXConstructorDecl>(Dcl);
} else if (Cxx1yLoc.isValid()) {
  SemaRef.Diag(Cxx1yLoc,
       SemaRef.getLangOpts().CPlusPlus14
         ? diag::warn_cxx11_compat_constexpr_body_invalid_stmt
         : diag::ext_constexpr_body_invalid_stmt)
    << isa<CXXConstructorDecl>(Dcl);
}

if (const CXXConstructorDecl *Constructor
      = dyn_cast<CXXConstructorDecl>(Dcl)) {
  const CXXRecordDecl *RD = Constructor->getParent();
  // DR1359:
  // - every non-variant non-static data member and base class sub-object
  //   shall be initialized;
  // DR1460:
  // - if the class is a union having variant members, exactly one of them
  //   shall be initialized;
  if (RD->isUnion()) {
    if (Constructor->getNumCtorInitializers() == 0 &&
        RD->hasVariantMembers()) {
      if (Kind == Sema::CheckConstexprKind::Diagnose) {
        SemaRef.Diag(
            Dcl->getLocation(),
            SemaRef.getLangOpts().CPlusPlus20
                ? diag::warn_cxx17_compat_constexpr_union_ctor_no_init
                : diag::ext_constexpr_union_ctor_no_init);
      } else if (!SemaRef.getLangOpts().CPlusPlus20) {
        return false;
      }
    }
  } else if (!Constructor->isDependentContext() &&
             !Constructor->isDelegatingConstructor()) {
    assert(RD->getNumVBases() == 0 && "constexpr ctor with virtual bases")(static_cast<void> (0));

    // Skip detailed checking if we have enough initializers, and we would
    // allow at most one initializer per member.
    bool AnyAnonStructUnionMembers = false;
    unsigned Fields = 0;
    for (CXXRecordDecl::field_iterator I = RD->field_begin(),
         E = RD->field_end(); I != E; ++I, ++Fields) {
      if (I->isAnonymousStructOrUnion()) {
        AnyAnonStructUnionMembers = true;
        break;
      }
    }
    // DR1460:
    // - if the class is a union-like class, but is not a union, for each of
    //   its anonymous union members having variant members, exactly one of
    //   them shall be initialized;
    if (AnyAnonStructUnionMembers ||
        Constructor->getNumCtorInitializers() != RD->getNumBases() + Fields) {
      // Check initialization of non-static data members. Base classes are
      // always initialized so do not need to be checked. Dependent bases
      // might not have initializers in the member initializer list.
      llvm::SmallSet<Decl*, 16> Inits;
      for (const auto *I: Constructor->inits()) {
        if (FieldDecl *FD = I->getMember())
          Inits.insert(FD);
        else if (IndirectFieldDecl *ID = I->getIndirectMember())
          Inits.insert(ID->chain_begin(), ID->chain_end());
      }

      bool Diagnosed = false;
      for (auto *I : RD->fields())
        if (!CheckConstexprCtorInitializer(SemaRef, Dcl, I, Inits, Diagnosed,
                                           Kind))
          return false;
    }
  }
} else {
  if (ReturnStmts.empty()) {
    // C++1y doesn't require constexpr functions to contain a 'return'
    // statement. We still do, unless the return type might be void, because
    // otherwise if there's no return statement, the function cannot
    // be used in a core constant expression.
    bool OK = SemaRef.getLangOpts().CPlusPlus14 &&
              (Dcl->getReturnType()->isVoidType() ||
               Dcl->getReturnType()->isDependentType());
    switch (Kind) {
    case Sema::CheckConstexprKind::Diagnose:
      SemaRef.Diag(Dcl->getLocation(),
                   OK ? diag::warn_cxx11_compat_constexpr_body_no_return
                      : diag::err_constexpr_body_no_return)
          << Dcl->isConsteval();
      if (!OK)
        return false;
      break;

    case Sema::CheckConstexprKind::CheckValid:
      // The formal requirements don't include this rule in C++14, even
      // though the "must be able to produce a constant expression" rules
      // still imply it in some cases.
      if (!SemaRef.getLangOpts().CPlusPlus14)
        return false;
      break;
    }
  } else if (ReturnStmts.size() > 1) {
    switch (Kind) {
    case Sema::CheckConstexprKind::Diagnose:
      SemaRef.Diag(
          ReturnStmts.back(),
          SemaRef.getLangOpts().CPlusPlus14
              ? diag::warn_cxx11_compat_constexpr_body_multiple_return
              : diag::ext_constexpr_body_multiple_return);
      for (unsigned I = 0; I < ReturnStmts.size() - 1; ++I)
        SemaRef.Diag(ReturnStmts[I],
                     diag::note_constexpr_body_previous_return);
      break;

    case Sema::CheckConstexprKind::CheckValid:
      if (!SemaRef.getLangOpts().CPlusPlus14)
        return false;
      break;
    }
  }
}

// C++11 [dcl.constexpr]p5:
//   if no function argument values exist such that the function invocation
//   substitution would produce a constant expression, the program is
//   ill-formed; no diagnostic required.
// C++11 [dcl.constexpr]p3:
//   - every constructor call and implicit conversion used in initializing the
//     return value shall be one of those allowed in a constant expression.
// C++11 [dcl.constexpr]p4:
//   - every constructor involved in initializing non-static data members and
//     base class sub-objects shall be a constexpr constructor.
//
// Note that this rule is distinct from the "requirements for a constexpr
// function", so is not checked in CheckValid mode.
SmallVector<PartialDiagnosticAt, 8> Diags;
if (Kind == Sema::CheckConstexprKind::Diagnose &&
    !Expr::isPotentialConstantExpr(Dcl, Diags)) {
  SemaRef.Diag(Dcl->getLocation(),
               diag::ext_constexpr_function_never_constant_expr)
      << isa<CXXConstructorDecl>(Dcl) << Dcl->isConsteval();
  for (size_t I = 0, N = Diags.size(); I != N; ++I)
    SemaRef.Diag(Diags[I].first, Diags[I].second);
  // Don't return false here: we allow this for compatibility in
  // system headers.
}

return true;
2368}

2370/// Get the class that is directly named by the current context. This is the
2371/// class for which an unqualified-id in this scope could name a constructor
2372/// or destructor.
2373///
2374/// If the scope specifier denotes a class, this will be that class.
2375/// If the scope specifier is empty, this will be the class whose
2376/// member-specification we are currently within. Otherwise, there
2377/// is no such class.
2378CXXRecordDecl *Sema::getCurrentClass(Scope *, const CXXScopeSpec *SS) {
assert(getLangOpts().CPlusPlus && "No class names in C!")(static_cast<void> (0));

if (SS && SS->isInvalid())
  return nullptr;

if (SS && SS->isNotEmpty()) {
  DeclContext *DC = computeDeclContext(*SS, true);
  return dyn_cast_or_null<CXXRecordDecl>(DC);
}

return dyn_cast_or_null<CXXRecordDecl>(CurContext);
2390}

2392/// isCurrentClassName - Determine whether the identifier II is the
2393/// name of the class type currently being defined. In the case of
2394/// nested classes, this will only return true if II is the name of
2395/// the innermost class.
2396bool Sema::isCurrentClassName(const IdentifierInfo &II, Scope *S,
                            const CXXScopeSpec *SS) {
CXXRecordDecl *CurDecl = getCurrentClass(S, SS);
return CurDecl && &II == CurDecl->getIdentifier();
2400}

2402/// Determine whether the identifier II is a typo for the name of
2403/// the class type currently being defined. If so, update it to the identifier
2404/// that should have been used.
2405bool Sema::isCurrentClassNameTypo(IdentifierInfo *&II, const CXXScopeSpec *SS) {
assert(getLangOpts().CPlusPlus && "No class names in C!")(static_cast<void> (0));

if (!getLangOpts().SpellChecking)
  return false;

CXXRecordDecl *CurDecl;
if (SS && SS->isSet() && !SS->isInvalid()) {
  DeclContext *DC = computeDeclContext(*SS, true);
  CurDecl = dyn_cast_or_null<CXXRecordDecl>(DC);
} else
  CurDecl = dyn_cast_or_null<CXXRecordDecl>(CurContext);

if (CurDecl && CurDecl->getIdentifier() && II != CurDecl->getIdentifier() &&
    3 * II->getName().edit_distance(CurDecl->getIdentifier()->getName())
        < II->getLength()) {
  II = CurDecl->getIdentifier();
  return true;
}

return false;
2426}

2428/// Determine whether the given class is a base class of the given
2429/// class, including looking at dependent bases.
2430static bool findCircularInheritance(const CXXRecordDecl *Class,
                                  const CXXRecordDecl *Current) {
SmallVector<const CXXRecordDecl*, 8> Queue;

Class = Class->getCanonicalDecl();
while (true) {
  for (const auto &I : Current->bases()) {
    CXXRecordDecl *Base = I.getType()->getAsCXXRecordDecl();
    if (!Base)
      continue;

    Base = Base->getDefinition();
    if (!Base)
      continue;

    if (Base->getCanonicalDecl() == Class)
      return true;

    Queue.push_back(Base);
  }

  if (Queue.empty())
    return false;

  Current = Queue.pop_back_val();
}

return false;
2458}

2460/// Check the validity of a C++ base class specifier.
2461///
2462/// \returns a new CXXBaseSpecifier if well-formed, emits diagnostics
2463/// and returns NULL otherwise.
2464CXXBaseSpecifier *
2465Sema::CheckBaseSpecifier(CXXRecordDecl *Class,
                       SourceRange SpecifierRange,
                       bool Virtual, AccessSpecifier Access,
                       TypeSourceInfo *TInfo,
                       SourceLocation EllipsisLoc) {
QualType BaseType = TInfo->getType();
if (BaseType->containsErrors()) {
  // Already emitted a diagnostic when parsing the error type.
  return nullptr;
}
// C++ [class.union]p1:
//   A union shall not have base classes.
if (Class->isUnion()) {
  Diag(Class->getLocation(), diag::err_base_clause_on_union)
    << SpecifierRange;
  return nullptr;
}

if (EllipsisLoc.isValid() &&
    !TInfo->getType()->containsUnexpandedParameterPack()) {
  Diag(EllipsisLoc, diag::err_pack_expansion_without_parameter_packs)
    << TInfo->getTypeLoc().getSourceRange();
  EllipsisLoc = SourceLocation();
}

SourceLocation BaseLoc = TInfo->getTypeLoc().getBeginLoc();

if (BaseType->isDependentType()) {
  // Make sure that we don't have circular inheritance among our dependent
  // bases. For non-dependent bases, the check for completeness below handles
  // this.
  if (CXXRecordDecl *BaseDecl = BaseType->getAsCXXRecordDecl()) {
    if (BaseDecl->getCanonicalDecl() == Class->getCanonicalDecl() ||
        ((BaseDecl = BaseDecl->getDefinition()) &&
         findCircularInheritance(Class, BaseDecl))) {
      Diag(BaseLoc, diag::err_circular_inheritance)
        << BaseType << Context.getTypeDeclType(Class);

      if (BaseDecl->getCanonicalDecl() != Class->getCanonicalDecl())
        Diag(BaseDecl->getLocation(), diag::note_previous_decl)
          << BaseType;

      return nullptr;
    }
  }

  // Make sure that we don't make an ill-formed AST where the type of the
  // Class is non-dependent and its attached base class specifier is an
  // dependent type, which violates invariants in many clang code paths (e.g.
  // constexpr evaluator). If this case happens (in errory-recovery mode), we
  // explicitly mark the Class decl invalid. The diagnostic was already
  // emitted.
  if (!Class->getTypeForDecl()->isDependentType())
    Class->setInvalidDecl();
  return new (Context) CXXBaseSpecifier(SpecifierRange, Virtual,
                                        Class->getTagKind() == TTK_Class,
                                        Access, TInfo, EllipsisLoc);
}

// Base specifiers must be record types.
if (!BaseType->isRecordType()) {
  Diag(BaseLoc, diag::err_base_must_be_class) << SpecifierRange;
  return nullptr;
}

// C++ [class.union]p1:
//   A union shall not be used as a base class.
if (BaseType->isUnionType()) {
  Diag(BaseLoc, diag::err_union_as_base_class) << SpecifierRange;
  return nullptr;
}

// For the MS ABI, propagate DLL attributes to base class templates.
if (Context.getTargetInfo().getCXXABI().isMicrosoft()) {
  if (Attr *ClassAttr = getDLLAttr(Class)) {
    if (auto *BaseTemplate = dyn_cast_or_null<ClassTemplateSpecializationDecl>(
            BaseType->getAsCXXRecordDecl())) {
      propagateDLLAttrToBaseClassTemplate(Class, ClassAttr, BaseTemplate,
                                          BaseLoc);
    }
  }
}

// C++ [class.derived]p2:
//   The class-name in a base-specifier shall not be an incompletely
//   defined class.
if (RequireCompleteType(BaseLoc, BaseType,
                        diag::err_incomplete_base_class, SpecifierRange)) {
  Class->setInvalidDecl();
  return nullptr;
}

// If the base class is polymorphic or isn't empty, the new one is/isn't, too.
RecordDecl *BaseDecl = BaseType->castAs<RecordType>()->getDecl();
assert(BaseDecl && "Record type has no declaration")(static_cast<void> (0));
BaseDecl = BaseDecl->getDefinition();
assert(BaseDecl && "Base type is not incomplete, but has no definition")(static_cast<void> (0));
CXXRecordDecl *CXXBaseDecl = cast<CXXRecordDecl>(BaseDecl);
assert(CXXBaseDecl && "Base type is not a C++ type")(static_cast<void> (0));

// Microsoft docs say:
// "If a base-class has a code_seg attribute, derived classes must have the
// same attribute."
const auto *BaseCSA = CXXBaseDecl->getAttr<CodeSegAttr>();
const auto *DerivedCSA = Class->getAttr<CodeSegAttr>();
if ((DerivedCSA || BaseCSA) &&
    (!BaseCSA || !DerivedCSA || BaseCSA->getName() != DerivedCSA->getName())) {
  Diag(Class->getLocation(), diag::err_mismatched_code_seg_base);
  Diag(CXXBaseDecl->getLocation(), diag::note_base_class_specified_here)
    << CXXBaseDecl;
  return nullptr;
}

// A class which contains a flexible array member is not suitable for use as a
// base class:
//   - If the layout determines that a base comes before another base,
//     the flexible array member would index into the subsequent base.
//   - If the layout determines that base comes before the derived class,
//     the flexible array member would index into the derived class.
if (CXXBaseDecl->hasFlexibleArrayMember()) {
  Diag(BaseLoc, diag::err_base_class_has_flexible_array_member)
    << CXXBaseDecl->getDeclName();
  return nullptr;
}

// C++ [class]p3:
//   If a class is marked final and it appears as a base-type-specifier in
//   base-clause, the program is ill-formed.
if (FinalAttr *FA = CXXBaseDecl->getAttr<FinalAttr>()) {
  Diag(BaseLoc, diag::err_class_marked_final_used_as_base)
    << CXXBaseDecl->getDeclName()
    << FA->isSpelledAsSealed();
  Diag(CXXBaseDecl->getLocation(), diag::note_entity_declared_at)
      << CXXBaseDecl->getDeclName() << FA->getRange();
  return nullptr;
}

if (BaseDecl->isInvalidDecl())
  Class->setInvalidDecl();

// Create the base specifier.
return new (Context) CXXBaseSpecifier(SpecifierRange, Virtual,
                                      Class->getTagKind() == TTK_Class,
                                      Access, TInfo, EllipsisLoc);
2609}

2611/// ActOnBaseSpecifier - Parsed a base specifier. A base specifier is
2612/// one entry in the base class list of a class specifier, for
2613/// example:
2614///    class foo : public bar, virtual private baz {
2615/// 'public bar' and 'virtual private baz' are each base-specifiers.
2616BaseResult
2617Sema::ActOnBaseSpecifier(Decl *classdecl, SourceRange SpecifierRange,
                       ParsedAttributes &Attributes,
                       bool Virtual, AccessSpecifier Access,
                       ParsedType basetype, SourceLocation BaseLoc,
                       SourceLocation EllipsisLoc) {
if (!classdecl)
  return true;

AdjustDeclIfTemplate(classdecl);
CXXRecordDecl *Class = dyn_cast<CXXRecordDecl>(classdecl);
if (!Class)
  return true;

// We haven't yet attached the base specifiers.
Class->setIsParsingBaseSpecifiers();

// We do not support any C++11 attributes on base-specifiers yet.
// Diagnose any attributes we see.
for (const ParsedAttr &AL : Attributes) {
  if (AL.isInvalid() || AL.getKind() == ParsedAttr::IgnoredAttribute)
    continue;
  Diag(AL.getLoc(), AL.getKind() == ParsedAttr::UnknownAttribute
                        ? (unsigned)diag::warn_unknown_attribute_ignored
                        : (unsigned)diag::err_base_specifier_attribute)
      << AL << AL.getRange();
}

TypeSourceInfo *TInfo = nullptr;
GetTypeFromParser(basetype, &TInfo);

if (EllipsisLoc.isInvalid() &&
    DiagnoseUnexpandedParameterPack(SpecifierRange.getBegin(), TInfo,
                                    UPPC_BaseType))
  return true;

if (CXXBaseSpecifier *BaseSpec = CheckBaseSpecifier(Class, SpecifierRange,
                                                    Virtual, Access, TInfo,
                                                    EllipsisLoc))
  return BaseSpec;
else
  Class->setInvalidDecl();

return true;
2660}

2662/// Use small set to collect indirect bases.  As this is only used
2663/// locally, there's no need to abstract the small size parameter.
2664typedef llvm::SmallPtrSet<QualType, 4> IndirectBaseSet;

2666/// Recursively add the bases of Type.  Don't add Type itself.
2667static void
2668NoteIndirectBases(ASTContext &Context, IndirectBaseSet &Set,
                const QualType &Type)
2670{
// Even though the incoming type is a base, it might not be
// a class -- it could be a template parm, for instance.
if (auto Rec = Type->getAs<RecordType>()) {
  auto Decl = Rec->getAsCXXRecordDecl();

  // Iterate over its bases.
  for (const auto &BaseSpec : Decl->bases()) {
    QualType Base = Context.getCanonicalType(BaseSpec.getType())
      .getUnqualifiedType();
    if (Set.insert(Base).second)
      // If we've not already seen it, recurse.
      NoteIndirectBases(Context, Set, Base);
  }
}
2685}

2687/// Performs the actual work of attaching the given base class
2688/// specifiers to a C++ class.
2689bool Sema::AttachBaseSpecifiers(CXXRecordDecl *Class,
                              MutableArrayRef<CXXBaseSpecifier *> Bases) {
if (Bases.empty())
  return false;

// Used to keep track of which base types we have already seen, so
// that we can properly diagnose redundant direct base types. Note
// that the key is always the unqualified canonical type of the base
// class.
std::map<QualType, CXXBaseSpecifier*, QualTypeOrdering> KnownBaseTypes;

// Used to track indirect bases so we can see if a direct base is
// ambiguous.
IndirectBaseSet IndirectBaseTypes;

// Copy non-redundant base specifiers into permanent storage.
unsigned NumGoodBases = 0;
bool Invalid = false;
for (unsigned idx = 0; idx < Bases.size(); ++idx) {
  QualType NewBaseType
    = Context.getCanonicalType(Bases[idx]->getType());
  NewBaseType = NewBaseType.getLocalUnqualifiedType();

  CXXBaseSpecifier *&KnownBase = KnownBaseTypes[NewBaseType];
  if (KnownBase) {
    // C++ [class.mi]p3:
    //   A class shall not be specified as a direct base class of a
    //   derived class more than once.
    Diag(Bases[idx]->getBeginLoc(), diag::err_duplicate_base_class)
        << KnownBase->getType() << Bases[idx]->getSourceRange();

    // Delete the duplicate base class specifier; we're going to
    // overwrite its pointer later.
    Context.Deallocate(Bases[idx]);

    Invalid = true;
  } else {
    // Okay, add this new base class.
    KnownBase = Bases[idx];
    Bases[NumGoodBases++] = Bases[idx];

    // Note this base's direct & indirect bases, if there could be ambiguity.
    if (Bases.size() > 1)
      NoteIndirectBases(Context, IndirectBaseTypes, NewBaseType);

    if (const RecordType *Record = NewBaseType->getAs<RecordType>()) {
      const CXXRecordDecl *RD = cast<CXXRecordDecl>(Record->getDecl());
      if (Class->isInterface() &&
            (!RD->isInterfaceLike() ||
             KnownBase->getAccessSpecifier() != AS_public)) {
        // The Microsoft extension __interface does not permit bases that
        // are not themselves public interfaces.
        Diag(KnownBase->getBeginLoc(), diag::err_invalid_base_in_interface)
            << getRecordDiagFromTagKind(RD->getTagKind()) << RD
            << RD->getSourceRange();
        Invalid = true;
      }
      if (RD->hasAttr<WeakAttr>())
        Class->addAttr(WeakAttr::CreateImplicit(Context));
    }
  }
}

// Attach the remaining base class specifiers to the derived class.
Class->setBases(Bases.data(), NumGoodBases);

// Check that the only base classes that are duplicate are virtual.
for (unsigned idx = 0; idx < NumGoodBases; ++idx) {
  // Check whether this direct base is inaccessible due to ambiguity.
  QualType BaseType = Bases[idx]->getType();

  // Skip all dependent types in templates being used as base specifiers.
  // Checks below assume that the base specifier is a CXXRecord.
  if (BaseType->isDependentType())
    continue;

  CanQualType CanonicalBase = Context.getCanonicalType(BaseType)
    .getUnqualifiedType();

  if (IndirectBaseTypes.count(CanonicalBase)) {
    CXXBasePaths Paths(/*FindAmbiguities=*/true, /*RecordPaths=*/true,
                       /*DetectVirtual=*/true);
    bool found
      = Class->isDerivedFrom(CanonicalBase->getAsCXXRecordDecl(), Paths);
    assert(found)(static_cast<void> (0));
    (void)found;

    if (Paths.isAmbiguous(CanonicalBase))
      Diag(Bases[idx]->getBeginLoc(), diag::warn_inaccessible_base_class)
          << BaseType << getAmbiguousPathsDisplayString(Paths)
          << Bases[idx]->getSourceRange();
    else
      assert(Bases[idx]->isVirtual())(static_cast<void> (0));
  }

  // Delete the base class specifier, since its data has been copied
  // into the CXXRecordDecl.
  Context.Deallocate(Bases[idx]);
}

return Invalid;
2790}

2792/// ActOnBaseSpecifiers - Attach the given base specifiers to the
2793/// class, after checking whether there are any duplicate base
2794/// classes.
2795void Sema::ActOnBaseSpecifiers(Decl *ClassDecl,
                             MutableArrayRef<CXXBaseSpecifier *> Bases) {
if (!ClassDecl || Bases.empty())
  return;

AdjustDeclIfTemplate(ClassDecl);
AttachBaseSpecifiers(cast<CXXRecordDecl>(ClassDecl), Bases);
2802}

2804/// Determine whether the type \p Derived is a C++ class that is
2805/// derived from the type \p Base.
2806bool Sema::IsDerivedFrom(SourceLocation Loc, QualType Derived, QualType Base) {
if (!getLangOpts().CPlusPlus)
  return false;

CXXRecordDecl *DerivedRD = Derived->getAsCXXRecordDecl();
if (!DerivedRD)
  return false;

CXXRecordDecl *BaseRD = Base->getAsCXXRecordDecl();
if (!BaseRD)
  return false;

// If either the base or the derived type is invalid, don't try to
// check whether one is derived from the other.
if (BaseRD->isInvalidDecl() || DerivedRD->isInvalidDecl())
  return false;

// FIXME: In a modules build, do we need the entire path to be visible for us
// to be able to use the inheritance relationship?
if (!isCompleteType(Loc, Derived) && !DerivedRD->isBeingDefined())
  return false;

return DerivedRD->isDerivedFrom(BaseRD);
2829}

2831/// Determine whether the type \p Derived is a C++ class that is
2832/// derived from the type \p Base.
2833bool Sema::IsDerivedFrom(SourceLocation Loc, QualType Derived, QualType Base,
                       CXXBasePaths &Paths) {
if (!getLangOpts().CPlusPlus)
  return false;

CXXRecordDecl *DerivedRD = Derived->getAsCXXRecordDecl();
if (!DerivedRD)
  return false;

CXXRecordDecl *BaseRD = Base->getAsCXXRecordDecl();
if (!BaseRD)
  return false;

if (!isCompleteType(Loc, Derived) && !DerivedRD->isBeingDefined())
  return false;

return DerivedRD->isDerivedFrom(BaseRD, Paths);
2850}

2852static void BuildBasePathArray(const CXXBasePath &Path,
                             CXXCastPath &BasePathArray) {
// We first go backward and check if we have a virtual base.
// FIXME: It would be better if CXXBasePath had the base specifier for
// the nearest virtual base.
unsigned Start = 0;
for (unsigned I = Path.size(); I != 0; --I) {
  if (Path[I - 1].Base->isVirtual()) {
    Start = I - 1;
    break;
  }
}

// Now add all bases.
for (unsigned I = Start, E = Path.size(); I != E; ++I)
  BasePathArray.push_back(const_cast<CXXBaseSpecifier*>(Path[I].Base));
2868}


2871void Sema::BuildBasePathArray(const CXXBasePaths &Paths,
                            CXXCastPath &BasePathArray) {
assert(BasePathArray.empty() && "Base path array must be empty!")(static_cast<void> (0));
assert(Paths.isRecordingPaths() && "Must record paths!")(static_cast<void> (0));
return ::BuildBasePathArray(Paths.front(), BasePathArray);
2876}
2877/// CheckDerivedToBaseConversion - Check whether the Derived-to-Base
2878/// conversion (where Derived and Base are class types) is
2879/// well-formed, meaning that the conversion is unambiguous (and
2880/// that all of the base classes are accessible). Returns true
2881/// and emits a diagnostic if the code is ill-formed, returns false
2882/// otherwise. Loc is the location where this routine should point to
2883/// if there is an error, and Range is the source range to highlight
2884/// if there is an error.
2885///
2886/// If either InaccessibleBaseID or AmbiguousBaseConvID are 0, then the
2887/// diagnostic for the respective type of error will be suppressed, but the
2888/// check for ill-formed code will still be performed.
2889bool
2890Sema::CheckDerivedToBaseConversion(QualType Derived, QualType Base,
                                 unsigned InaccessibleBaseID,
                                 unsigned AmbiguousBaseConvID,
                                 SourceLocation Loc, SourceRange Range,
                                 DeclarationName Name,
                                 CXXCastPath *BasePath,
                                 bool IgnoreAccess) {
// First, determine whether the path from Derived to Base is
// ambiguous. This is slightly more expensive than checking whether
// the Derived to Base conversion exists, because here we need to
// explore multiple paths to determine if there is an ambiguity.
CXXBasePaths Paths(/*FindAmbiguities=*/true, /*RecordPaths=*/true,
                   /*DetectVirtual=*/false);
bool DerivationOkay = IsDerivedFrom(Loc, Derived, Base, Paths);
if (!DerivationOkay)
  return true;

const CXXBasePath *Path = nullptr;
if (!Paths.isAmbiguous(Context.getCanonicalType(Base).getUnqualifiedType()))
  Path = &Paths.front();

// For MSVC compatibility, check if Derived directly inherits from Base. Clang
// warns about this hierarchy under -Winaccessible-base, but MSVC allows the
// user to access such bases.
if (!Path && getLangOpts().MSVCCompat) {
  for (const CXXBasePath &PossiblePath : Paths) {
    if (PossiblePath.size() == 1) {
      Path = &PossiblePath;
      if (AmbiguousBaseConvID)
        Diag(Loc, diag::ext_ms_ambiguous_direct_base)
            << Base << Derived << Range;
      break;
    }
  }
}

if (Path) {
  if (!IgnoreAccess) {
    // Check that the base class can be accessed.
    switch (
        CheckBaseClassAccess(Loc, Base, Derived, *Path, InaccessibleBaseID)) {
    case AR_inaccessible:
      return true;
    case AR_accessible:
    case AR_dependent:
    case AR_delayed:
      break;
    }
  }

  // Build a base path if necessary.
  if (BasePath)
    ::BuildBasePathArray(*Path, *BasePath);
  return false;
}

if (AmbiguousBaseConvID) {
  // We know that the derived-to-base conversion is ambiguous, and
  // we're going to produce a diagnostic. Perform the derived-to-base
  // search just one more time to compute all of the possible paths so
  // that we can print them out. This is more expensive than any of
  // the previous derived-to-base checks we've done, but at this point
  // performance isn't as much of an issue.
  Paths.clear();
  Paths.setRecordingPaths(true);
  bool StillOkay = IsDerivedFrom(Loc, Derived, Base, Paths);
  assert(StillOkay && "Can only be used with a derived-to-base conversion")(static_cast<void> (0));
  (void)StillOkay;

  // Build up a textual representation of the ambiguous paths, e.g.,
  // D -> B -> A, that will be used to illustrate the ambiguous
  // conversions in the diagnostic. We only print one of the paths
  // to each base class subobject.
  std::string PathDisplayStr = getAmbiguousPathsDisplayString(Paths);

  Diag(Loc, AmbiguousBaseConvID)
  << Derived << Base << PathDisplayStr << Range << Name;
}
return true;
2969}

2971bool
2972Sema::CheckDerivedToBaseConversion(QualType Derived, QualType Base,
                                 SourceLocation Loc, SourceRange Range,
                                 CXXCastPath *BasePath,
                                 bool IgnoreAccess) {
return CheckDerivedToBaseConversion(
    Derived, Base, diag::err_upcast_to_inaccessible_base,
    diag::err_ambiguous_derived_to_base_conv, Loc, Range, DeclarationName(),
    BasePath, IgnoreAccess);
2980}


2983/// Builds a string representing ambiguous paths from a
2984/// specific derived class to different subobjects of the same base
2985/// class.
2986///
2987/// This function builds a string that can be used in error messages
2988/// to show the different paths that one can take through the
2989/// inheritance hierarchy to go from the derived class to different
2990/// subobjects of a base class. The result looks something like this:
2991/// @code
2992/// struct D -> struct B -> struct A
2993/// struct D -> struct C -> struct A
2994/// @endcode
2995std::string Sema::getAmbiguousPathsDisplayString(CXXBasePaths &Paths) {
std::string PathDisplayStr;
std::set<unsigned> DisplayedPaths;
for (CXXBasePaths::paths_iterator Path = Paths.begin();
     Path != Paths.end(); ++Path) {
  if (DisplayedPaths.insert(Path->back().SubobjectNumber).second) {
    // We haven't displayed a path to this particular base
    // class subobject yet.
    PathDisplayStr += "\n    ";
    PathDisplayStr += Context.getTypeDeclType(Paths.getOrigin()).getAsString();
    for (CXXBasePath::const_iterator Element = Path->begin();
         Element != Path->end(); ++Element)
      PathDisplayStr += " -> " + Element->Base->getType().getAsString();
  }
}

return PathDisplayStr;
3012}

3014//===----------------------------------------------------------------------===//
3015// C++ class member Handling
3016//===----------------------------------------------------------------------===//

3018/// ActOnAccessSpecifier - Parsed an access specifier followed by a colon.
3019bool Sema::ActOnAccessSpecifier(AccessSpecifier Access, SourceLocation ASLoc,
                              SourceLocation ColonLoc,
                              const ParsedAttributesView &Attrs) {
assert(Access != AS_none && "Invalid kind for syntactic access specifier!")(static_cast<void> (0));
AccessSpecDecl *ASDecl = AccessSpecDecl::Create(Context, Access, CurContext,
                                                ASLoc, ColonLoc);
CurContext->addHiddenDecl(ASDecl);
return ProcessAccessDeclAttributeList(ASDecl, Attrs);
3027}

3029/// CheckOverrideControl - Check C++11 override control semantics.
3030void Sema::CheckOverrideControl(NamedDecl *D) {
if (D->isInvalidDecl())
  return;

// We only care about "override" and "final" declarations.
if (!D->hasAttr<OverrideAttr>() && !D->hasAttr<FinalAttr>())
  return;

CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(D);

// We can't check dependent instance methods.
if (MD && MD->isInstance() &&
    (MD->getParent()->hasAnyDependentBases() ||
     MD->getType()->isDependentType()))
  return;

if (MD && !MD->isVirtual()) {
  // If we have a non-virtual method, check if if hides a virtual method.
  // (In that case, it's most likely the method has the wrong type.)
  SmallVector<CXXMethodDecl *, 8> OverloadedMethods;
  FindHiddenVirtualMethods(MD, OverloadedMethods);

  if (!OverloadedMethods.empty()) {
    if (OverrideAttr *OA = D->getAttr<OverrideAttr>()) {
      Diag(OA->getLocation(),
           diag::override_keyword_hides_virtual_member_function)
        << "override" << (OverloadedMethods.size() > 1);
    } else if (FinalAttr *FA = D->getAttr<FinalAttr>()) {
      Diag(FA->getLocation(),
           diag::override_keyword_hides_virtual_member_function)
        << (FA->isSpelledAsSealed() ? "sealed" : "final")
        << (OverloadedMethods.size() > 1);
    }
    NoteHiddenVirtualMethods(MD, OverloadedMethods);
    MD->setInvalidDecl();
    return;
  }
  // Fall through into the general case diagnostic.
  // FIXME: We might want to attempt typo correction here.
}

if (!MD || !MD->isVirtual()) {
  if (OverrideAttr *OA = D->getAttr<OverrideAttr>()) {
    Diag(OA->getLocation(),
         diag::override_keyword_only_allowed_on_virtual_member_functions)
      << "override" << FixItHint::CreateRemoval(OA->getLocation());
    D->dropAttr<OverrideAttr>();
  }
  if (FinalAttr *FA = D->getAttr<FinalAttr>()) {
    Diag(FA->getLocation(),
         diag::override_keyword_only_allowed_on_virtual_member_functions)
      << (FA->isSpelledAsSealed() ? "sealed" : "final")
      << FixItHint::CreateRemoval(FA->getLocation());
    D->dropAttr<FinalAttr>();
  }
  return;
}

// C++11 [class.virtual]p5:
//   If a function is marked with the virt-specifier override and
//   does not override a member function of a base class, the program is
//   ill-formed.
bool HasOverriddenMethods = MD->size_overridden_methods() != 0;
if (MD->hasAttr<OverrideAttr>() && !HasOverriddenMethods)
  Diag(MD->getLocation(), diag::err_function_marked_override_not_overriding)
    << MD->getDeclName();
3096}

3098void Sema::DiagnoseAbsenceOfOverrideControl(NamedDecl *D, bool Inconsistent) {
if (D->isInvalidDecl() || D->hasAttr<OverrideAttr>())
  return;
CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(D);
if (!MD || MD->isImplicit() || MD->hasAttr<FinalAttr>())
  return;

SourceLocation Loc = MD->getLocation();
SourceLocation SpellingLoc = Loc;
if (getSourceManager().isMacroArgExpansion(Loc))
  SpellingLoc = getSourceManager().getImmediateExpansionRange(Loc).getBegin();
SpellingLoc = getSourceManager().getSpellingLoc(SpellingLoc);
if (SpellingLoc.isValid() && getSourceManager().isInSystemHeader(SpellingLoc))
    return;

if (MD->size_overridden_methods() > 0) {
  auto EmitDiag = [&](unsigned DiagInconsistent, unsigned DiagSuggest) {
    unsigned DiagID =
        Inconsistent && !Diags.isIgnored(DiagInconsistent, MD->getLocation())
            ? DiagInconsistent
            : DiagSuggest;
    Diag(MD->getLocation(), DiagID) << MD->getDeclName();
    const CXXMethodDecl *OMD = *MD->begin_overridden_methods();
    Diag(OMD->getLocation(), diag::note_overridden_virtual_function);
  };
  if (isa<CXXDestructorDecl>(MD))
    EmitDiag(
        diag::warn_inconsistent_destructor_marked_not_override_overriding,
        diag::warn_suggest_destructor_marked_not_override_overriding);
  else
    EmitDiag(diag::warn_inconsistent_function_marked_not_override_overriding,
             diag::warn_suggest_function_marked_not_override_overriding);
}
3131}

3133/// CheckIfOverriddenFunctionIsMarkedFinal - Checks whether a virtual member
3134/// function overrides a virtual member function marked 'final', according to
3135/// C++11 [class.virtual]p4.
3136bool Sema::CheckIfOverriddenFunctionIsMarkedFinal(const CXXMethodDecl *New,
                                                const CXXMethodDecl *Old) {
FinalAttr *FA = Old->getAttr<FinalAttr>();
if (!FA)
  return false;

Diag(New->getLocation(), diag::err_final_function_overridden)
  << New->getDeclName()
  << FA->isSpelledAsSealed();
Diag(Old->getLocation(), diag::note_overridden_virtual_function);
return true;
3147}

3149static bool InitializationHasSideEffects(const FieldDecl &FD) {
const Type *T = FD.getType()->getBaseElementTypeUnsafe();
// FIXME: Destruction of ObjC lifetime types has side-effects.
if (const CXXRecordDecl *RD = T->getAsCXXRecordDecl())
  return !RD->isCompleteDefinition() ||
         !RD->hasTrivialDefaultConstructor() ||
         !RD->hasTrivialDestructor();
return false;
3157}

3159static const ParsedAttr *getMSPropertyAttr(const ParsedAttributesView &list) {
ParsedAttributesView::const_iterator Itr =
    llvm::find_if(list, [](const ParsedAttr &AL) {
      return AL.isDeclspecPropertyAttribute();
    });
if (Itr != list.end())
  return &*Itr;
return nullptr;
3167}

3169// Check if there is a field shadowing.
3170void Sema::CheckShadowInheritedFields(const SourceLocation &Loc,
                                    DeclarationName FieldName,
                                    const CXXRecordDecl *RD,
                                    bool DeclIsField) {
if (Diags.isIgnored(diag::warn_shadow_field, Loc))
  return;

// To record a shadowed field in a base
std::map<CXXRecordDecl*, NamedDecl*> Bases;
auto FieldShadowed = [&](const CXXBaseSpecifier *Specifier,
                         CXXBasePath &Path) {
  const auto Base = Specifier->getType()->getAsCXXRecordDecl();
  // Record an ambiguous path directly
  if (Bases.find(Base) != Bases.end())
    return true;
  for (const auto Field : Base->lookup(FieldName)) {
    if ((isa<FieldDecl>(Field) || isa<IndirectFieldDecl>(Field)) &&
        Field->getAccess() != AS_private) {
      assert(Field->getAccess() != AS_none)(static_cast<void> (0));
      assert(Bases.find(Base) == Bases.end())(static_cast<void> (0));
      Bases[Base] = Field;
      return true;
    }
  }
  return false;
};

CXXBasePaths Paths(/*FindAmbiguities=*/true, /*RecordPaths=*/true,
                   /*DetectVirtual=*/true);
if (!RD->lookupInBases(FieldShadowed, Paths))
  return;

for (const auto &P : Paths) {
  auto Base = P.back().Base->getType()->getAsCXXRecordDecl();
  auto It = Bases.find(Base);
  // Skip duplicated bases
  if (It == Bases.end())
    continue;
  auto BaseField = It->second;
  assert(BaseField->getAccess() != AS_private)(static_cast<void> (0));
  if (AS_none !=
      CXXRecordDecl::MergeAccess(P.Access, BaseField->getAccess())) {
    Diag(Loc, diag::warn_shadow_field)
      << FieldName << RD << Base << DeclIsField;
    Diag(BaseField->getLocation(), diag::note_shadow_field);
    Bases.erase(It);
  }
}
3218}

3220/// ActOnCXXMemberDeclarator - This is invoked when a C++ class member
3221/// declarator is parsed. 'AS' is the access specifier, 'BW' specifies the
3222/// bitfield width if there is one, 'InitExpr' specifies the initializer if
3223/// one has been parsed, and 'InitStyle' is set if an in-class initializer is
3224/// present (but parsing it has been deferred).
3225NamedDecl *
3226Sema::ActOnCXXMemberDeclarator(Scope *S, AccessSpecifier AS, Declarator &D,
                             MultiTemplateParamsArg TemplateParameterLists,
                             Expr *BW, const VirtSpecifiers &VS,
                             InClassInitStyle InitStyle) {
const DeclSpec &DS = D.getDeclSpec();
DeclarationNameInfo NameInfo = GetNameForDeclarator(D);
DeclarationName Name = NameInfo.getName();
SourceLocation Loc = NameInfo.getLoc();

// For anonymous bitfields, the location should point to the type.
if (Loc.isInvalid())
  Loc = D.getBeginLoc();

Expr *BitWidth = static_cast<Expr*>(BW);

assert(isa<CXXRecordDecl>(CurContext))(static_cast<void> (0));
assert(!DS.isFriendSpecified())(static_cast<void> (0));

bool isFunc = D.isDeclarationOfFunction();
const ParsedAttr *MSPropertyAttr =
    getMSPropertyAttr(D.getDeclSpec().getAttributes());

if (cast<CXXRecordDecl>(CurContext)->isInterface()) {
  // The Microsoft extension __interface only permits public member functions
  // and prohibits constructors, destructors, operators, non-public member
  // functions, static methods and data members.
  unsigned InvalidDecl;
  bool ShowDeclName = true;
  if (!isFunc &&
      (DS.getStorageClassSpec() == DeclSpec::SCS_typedef || MSPropertyAttr))
    InvalidDecl = 0;
  else if (!isFunc)
    InvalidDecl = 1;
  else if (AS != AS_public)
    InvalidDecl = 2;
  else if (DS.getStorageClassSpec() == DeclSpec::SCS_static)
    InvalidDecl = 3;
  else switch (Name.getNameKind()) {
    case DeclarationName::CXXConstructorName:
      InvalidDecl = 4;
      ShowDeclName = false;
      break;

    case DeclarationName::CXXDestructorName:
      InvalidDecl = 5;
      ShowDeclName = false;
      break;

    case DeclarationName::CXXOperatorName:
    case DeclarationName::CXXConversionFunctionName:
      InvalidDecl = 6;
      break;

    default:
      InvalidDecl = 0;
      break;
  }

  if (InvalidDecl) {
    if (ShowDeclName)
      Diag(Loc, diag::err_invalid_member_in_interface)
        << (InvalidDecl-1) << Name;
    else
      Diag(Loc, diag::err_invalid_member_in_interface)
        << (InvalidDecl-1) << "";
    return nullptr;
  }
}

// C++ 9.2p6: A member shall not be declared to have automatic storage
// duration (auto, register) or with the extern storage-class-specifier.
// C++ 7.1.1p8: The mutable specifier can be applied only to names of class
// data members and cannot be applied to names declared const or static,
// and cannot be applied to reference members.
switch (DS.getStorageClassSpec()) {
case DeclSpec::SCS_unspecified:
case DeclSpec::SCS_typedef:
case DeclSpec::SCS_static:
  break;
case DeclSpec::SCS_mutable:
  if (isFunc) {
    Diag(DS.getStorageClassSpecLoc(), diag::err_mutable_function);

    // FIXME: It would be nicer if the keyword was ignored only for this
    // declarator. Otherwise we could get follow-up errors.
    D.getMutableDeclSpec().ClearStorageClassSpecs();
  }
  break;
default:
  Diag(DS.getStorageClassSpecLoc(),
       diag::err_storageclass_invalid_for_member);
  D.getMutableDeclSpec().ClearStorageClassSpecs();
  break;
}

bool isInstField = ((DS.getStorageClassSpec() == DeclSpec::SCS_unspecified ||
                     DS.getStorageClassSpec() == DeclSpec::SCS_mutable) &&
                    !isFunc);

if (DS.hasConstexprSpecifier() && isInstField) {
  SemaDiagnosticBuilder B =
      Diag(DS.getConstexprSpecLoc(), diag::err_invalid_constexpr_member);
  SourceLocation ConstexprLoc = DS.getConstexprSpecLoc();
  if (InitStyle == ICIS_NoInit) {
    B << 0 << 0;
    if (D.getDeclSpec().getTypeQualifiers() & DeclSpec::TQ_const)
      B << FixItHint::CreateRemoval(ConstexprLoc);
    else {
      B << FixItHint::CreateReplacement(ConstexprLoc, "const");
      D.getMutableDeclSpec().ClearConstexprSpec();
      const char *PrevSpec;
      unsigned DiagID;
      bool Failed = D.getMutableDeclSpec().SetTypeQual(
          DeclSpec::TQ_const, ConstexprLoc, PrevSpec, DiagID, getLangOpts());
      (void)Failed;
      assert(!Failed && "Making a constexpr member const shouldn't fail")(static_cast<void> (0));
    }
  } else {
    B << 1;
    const char *PrevSpec;
    unsigned DiagID;
    if (D.getMutableDeclSpec().SetStorageClassSpec(
        *this, DeclSpec::SCS_static, ConstexprLoc, PrevSpec, DiagID,
        Context.getPrintingPolicy())) {
      assert(DS.getStorageClassSpec() == DeclSpec::SCS_mutable &&(static_cast<void> (0))
             "This is the only DeclSpec that should fail to be applied")(static_cast<void> (0));
      B << 1;
    } else {
      B << 0 << FixItHint::CreateInsertion(ConstexprLoc, "static ");
      isInstField = false;
    }
  }
}

NamedDecl *Member;
if (isInstField) {
  CXXScopeSpec &SS = D.getCXXScopeSpec();

  // Data members must have identifiers for names.
  if (!Name.isIdentifier()) {
    Diag(Loc, diag::err_bad_variable_name)
      << Name;
    return nullptr;
  }

  IdentifierInfo *II = Name.getAsIdentifierInfo();

  // Member field could not be with "template" keyword.
  // So TemplateParameterLists should be empty in this case.
  if (TemplateParameterLists.size()) {
    TemplateParameterList* TemplateParams = TemplateParameterLists[0];
    if (TemplateParams->size()) {
      // There is no such thing as a member field template.
      Diag(D.getIdentifierLoc(), diag::err_template_member)
          << II
          << SourceRange(TemplateParams->getTemplateLoc(),
              TemplateParams->getRAngleLoc());
    } else {
      // There is an extraneous 'template<>' for this member.
      Diag(TemplateParams->getTemplateLoc(),
          diag::err_template_member_noparams)
          << II
          << SourceRange(TemplateParams->getTemplateLoc(),
              TemplateParams->getRAngleLoc());
    }
    return nullptr;
  }

  if (SS.isSet() && !SS.isInvalid()) {
    // The user provided a superfluous scope specifier inside a class
    // definition:
    //
    // class X {
    //   int X::member;
    // };
    if (DeclContext *DC = computeDeclContext(SS, false))
      diagnoseQualifiedDeclaration(SS, DC, Name, D.getIdentifierLoc(),
                                   D.getName().getKind() ==
                                       UnqualifiedIdKind::IK_TemplateId);
    else
      Diag(D.getIdentifierLoc(), diag::err_member_qualification)
        << Name << SS.getRange();

    SS.clear();
  }

  if (MSPropertyAttr) {
    Member = HandleMSProperty(S, cast<CXXRecordDecl>(CurContext), Loc, D,
                              BitWidth, InitStyle, AS, *MSPropertyAttr);
    if (!Member)
      return nullptr;
    isInstField = false;
  } else {
    Member = HandleField(S, cast<CXXRecordDecl>(CurContext), Loc, D,
                              BitWidth, InitStyle, AS);
    if (!Member)
      return nullptr;
  }

  CheckShadowInheritedFields(Loc, Name, cast<CXXRecordDecl>(CurContext));
} else {
  Member = HandleDeclarator(S, D, TemplateParameterLists);
  if (!Member)
    return nullptr;

  // Non-instance-fields can't have a bitfield.
  if (BitWidth) {
    if (Member->isInvalidDecl()) {
      // don't emit another diagnostic.
    } else if (isa<VarDecl>(Member) || isa<VarTemplateDecl>(Member)) {
      // C++ 9.6p3: A bit-field shall not be a static member.
      // "static member 'A' cannot be a bit-field"
      Diag(Loc, diag::err_static_not_bitfield)
        << Name << BitWidth->getSourceRange();
    } else if (isa<TypedefDecl>(Member)) {
      // "typedef member 'x' cannot be a bit-field"
      Diag(Loc, diag::err_typedef_not_bitfield)
        << Name << BitWidth->getSourceRange();
    } else {
      // A function typedef ("typedef int f(); f a;").
      // C++ 9.6p3: A bit-field shall have integral or enumeration type.
      Diag(Loc, diag::err_not_integral_type_bitfield)
        << Name << cast<ValueDecl>(Member)->getType()
        << BitWidth->getSourceRange();
    }

    BitWidth = nullptr;
    Member->setInvalidDecl();
  }

  NamedDecl *NonTemplateMember = Member;
  if (FunctionTemplateDecl *FunTmpl = dyn_cast<FunctionTemplateDecl>(Member))
    NonTemplateMember = FunTmpl->getTemplatedDecl();
  else if (VarTemplateDecl *VarTmpl = dyn_cast<VarTemplateDecl>(Member))
    NonTemplateMember = VarTmpl->getTemplatedDecl();

  Member->setAccess(AS);

  // If we have declared a member function template or static data member
  // template, set the access of the templated declaration as well.
  if (NonTemplateMember != Member)
    NonTemplateMember->setAccess(AS);

  // C++ [temp.deduct.guide]p3:
  //   A deduction guide [...] for a member class template [shall be
  //   declared] with the same access [as the template].
  if (auto *DG = dyn_cast<CXXDeductionGuideDecl>(NonTemplateMember)) {
    auto *TD = DG->getDeducedTemplate();
    // Access specifiers are only meaningful if both the template and the
    // deduction guide are from the same scope.
    if (AS != TD->getAccess() &&
        TD->getDeclContext()->getRedeclContext()->Equals(
            DG->getDeclContext()->getRedeclContext())) {
      Diag(DG->getBeginLoc(), diag::err_deduction_guide_wrong_access);
      Diag(TD->getBeginLoc(), diag::note_deduction_guide_template_access)
          << TD->getAccess();
      const AccessSpecDecl *LastAccessSpec = nullptr;
      for (const auto *D : cast<CXXRecordDecl>(CurContext)->decls()) {
        if (const auto *AccessSpec = dyn_cast<AccessSpecDecl>(D))
          LastAccessSpec = AccessSpec;
      }
      assert(LastAccessSpec && "differing access with no access specifier")(static_cast<void> (0));
      Diag(LastAccessSpec->getBeginLoc(), diag::note_deduction_guide_access)
          << AS;
    }
  }
}

if (VS.isOverrideSpecified())
  Member->addAttr(OverrideAttr::Create(Context, VS.getOverrideLoc(),
                                       AttributeCommonInfo::AS_Keyword));
if (VS.isFinalSpecified())
  Member->addAttr(FinalAttr::Create(
      Context, VS.getFinalLoc(), AttributeCommonInfo::AS_Keyword,
      static_cast<FinalAttr::Spelling>(VS.isFinalSpelledSealed())));

if (VS.getLastLocation().isValid()) {
  // Update the end location of a method that has a virt-specifiers.
  if (CXXMethodDecl *MD = dyn_cast_or_null<CXXMethodDecl>(Member))
    MD->setRangeEnd(VS.getLastLocation());
}

CheckOverrideControl(Member);

assert((Name || isInstField) && "No identifier for non-field ?")(static_cast<void> (0));

if (isInstField) {
  FieldDecl *FD = cast<FieldDecl>(Member);
  FieldCollector->Add(FD);

  if (!Diags.isIgnored(diag::warn_unused_private_field, FD->getLocation())) {
    // Remember all explicit private FieldDecls that have a name, no side
    // effects and are not part of a dependent type declaration.
    if (!FD->isImplicit() && FD->getDeclName() &&
        FD->getAccess() == AS_private &&
        !FD->hasAttr<UnusedAttr>() &&
        !FD->getParent()->isDependentContext() &&
        !InitializationHasSideEffects(*FD))
      UnusedPrivateFields.insert(FD);
  }
}

return Member;
3529}

3531namespace {
class UninitializedFieldVisitor
    : public EvaluatedExprVisitor<UninitializedFieldVisitor> {
  Sema &S;
  // List of Decls to generate a warning on.  Also remove Decls that become
  // initialized.
  llvm::SmallPtrSetImpl<ValueDecl*> &Decls;
  // List of base classes of the record.  Classes are removed after their
  // initializers.
  llvm::SmallPtrSetImpl<QualType> &BaseClasses;
  // Vector of decls to be removed from the Decl set prior to visiting the
  // nodes.  These Decls may have been initialized in the prior initializer.
  llvm::SmallVector<ValueDecl*, 4> DeclsToRemove;
  // If non-null, add a note to the warning pointing back to the constructor.
  const CXXConstructorDecl *Constructor;
  // Variables to hold state when processing an initializer list.  When
  // InitList is true, special case initialization of FieldDecls matching
  // InitListFieldDecl.
  bool InitList;
  FieldDecl *InitListFieldDecl;
  llvm::SmallVector<unsigned, 4> InitFieldIndex;

public:
  typedef EvaluatedExprVisitor<UninitializedFieldVisitor> Inherited;
  UninitializedFieldVisitor(Sema &S,
                            llvm::SmallPtrSetImpl<ValueDecl*> &Decls,
                            llvm::SmallPtrSetImpl<QualType> &BaseClasses)
    : Inherited(S.Context), S(S), Decls(Decls), BaseClasses(BaseClasses),
      Constructor(nullptr), InitList(false), InitListFieldDecl(nullptr) {}

  // Returns true if the use of ME is not an uninitialized use.
  bool IsInitListMemberExprInitialized(MemberExpr *ME,
                                       bool CheckReferenceOnly) {
    llvm::SmallVector<FieldDecl*, 4> Fields;
    bool ReferenceField = false;
    while (ME) {
      FieldDecl *FD = dyn_cast<FieldDecl>(ME->getMemberDecl());
      if (!FD)
        return false;
      Fields.push_back(FD);
      if (FD->getType()->isReferenceType())
        ReferenceField = true;
      ME = dyn_cast<MemberExpr>(ME->getBase()->IgnoreParenImpCasts());
    }

    // Binding a reference to an uninitialized field is not an
    // uninitialized use.
    if (CheckReferenceOnly && !ReferenceField)
      return true;

    llvm::SmallVector<unsigned, 4> UsedFieldIndex;
    // Discard the first field since it is the field decl that is being
    // initialized.
    for (auto I = Fields.rbegin() + 1, E = Fields.rend(); I != E; ++I) {
      UsedFieldIndex.push_back((*I)->getFieldIndex());
    }

    for (auto UsedIter = UsedFieldIndex.begin(),
              UsedEnd = UsedFieldIndex.end(),
              OrigIter = InitFieldIndex.begin(),
              OrigEnd = InitFieldIndex.end();
         UsedIter != UsedEnd && OrigIter != OrigEnd; ++UsedIter, ++OrigIter) {
      if (*UsedIter < *OrigIter)
        return true;
      if (*UsedIter > *OrigIter)
        break;
    }

    return false;
  }

  void HandleMemberExpr(MemberExpr *ME, bool CheckReferenceOnly,
                        bool AddressOf) {
    if (isa<EnumConstantDecl>(ME->getMemberDecl()))
      return;

    // FieldME is the inner-most MemberExpr that is not an anonymous struct
    // or union.
    MemberExpr *FieldME = ME;

    bool AllPODFields = FieldME->getType().isPODType(S.Context);

    Expr *Base = ME;
    while (MemberExpr *SubME =
               dyn_cast<MemberExpr>(Base->IgnoreParenImpCasts())) {

      if (isa<VarDecl>(SubME->getMemberDecl()))
        return;

      if (FieldDecl *FD = dyn_cast<FieldDecl>(SubME->getMemberDecl()))
        if (!FD->isAnonymousStructOrUnion())
          FieldME = SubME;

      if (!FieldME->getType().isPODType(S.Context))
        AllPODFields = false;

      Base = SubME->getBase();
    }

    if (!isa<CXXThisExpr>(Base->IgnoreParenImpCasts())) {
      Visit(Base);
      return;
    }

    if (AddressOf && AllPODFields)
      return;

    ValueDecl* FoundVD = FieldME->getMemberDecl();

    if (ImplicitCastExpr *BaseCast = dyn_cast<ImplicitCastExpr>(Base)) {
      while (isa<ImplicitCastExpr>(BaseCast->getSubExpr())) {
        BaseCast = cast<ImplicitCastExpr>(BaseCast->getSubExpr());
      }

      if (BaseCast->getCastKind() == CK_UncheckedDerivedToBase) {
        QualType T = BaseCast->getType();
        if (T->isPointerType() &&
            BaseClasses.count(T->getPointeeType())) {
          S.Diag(FieldME->getExprLoc(), diag::warn_base_class_is_uninit)
              << T->getPointeeType() << FoundVD;
        }
      }
    }

    if (!Decls.count(FoundVD))
      return;

    const bool IsReference = FoundVD->getType()->isReferenceType();

    if (InitList && !AddressOf && FoundVD == InitListFieldDecl) {
      // Special checking for initializer lists.
      if (IsInitListMemberExprInitialized(ME, CheckReferenceOnly)) {
        return;
      }
    } else {
      // Prevent double warnings on use of unbounded references.
      if (CheckReferenceOnly && !IsReference)
        return;
    }

    unsigned diag = IsReference
        ? diag::warn_reference_field_is_uninit
        : diag::warn_field_is_uninit;
    S.Diag(FieldME->getExprLoc(), diag) << FoundVD;
    if (Constructor)
      S.Diag(Constructor->getLocation(),
             diag::note_uninit_in_this_constructor)
        << (Constructor->isDefaultConstructor() && Constructor->isImplicit());

  }

  void HandleValue(Expr *E, bool AddressOf) {
    E = E->IgnoreParens();

    if (MemberExpr *ME = dyn_cast<MemberExpr>(E)) {
      HandleMemberExpr(ME, false /*CheckReferenceOnly*/,
                       AddressOf /*AddressOf*/);
      return;
    }

    if (ConditionalOperator *CO = dyn_cast<ConditionalOperator>(E)) {
      Visit(CO->getCond());
      HandleValue(CO->getTrueExpr(), AddressOf);
      HandleValue(CO->getFalseExpr(), AddressOf);
      return;
    }

    if (BinaryConditionalOperator *BCO =
            dyn_cast<BinaryConditionalOperator>(E)) {
      Visit(BCO->getCond());
      HandleValue(BCO->getFalseExpr(), AddressOf);
      return;
    }

    if (OpaqueValueExpr *OVE = dyn_cast<OpaqueValueExpr>(E)) {
      HandleValue(OVE->getSourceExpr(), AddressOf);
      return;
    }

    if (BinaryOperator *BO = dyn_cast<BinaryOperator>(E)) {
      switch (BO->getOpcode()) {
      default:
        break;
      case(BO_PtrMemD):
      case(BO_PtrMemI):
        HandleValue(BO->getLHS(), AddressOf);
        Visit(BO->getRHS());
        return;
      case(BO_Comma):
        Visit(BO->getLHS());
        HandleValue(BO->getRHS(), AddressOf);
        return;
      }
    }

    Visit(E);
  }

  void CheckInitListExpr(InitListExpr *ILE) {
    InitFieldIndex.push_back(0);
    for (auto Child : ILE->children()) {
      if (InitListExpr *SubList = dyn_cast<InitListExpr>(Child)) {
        CheckInitListExpr(SubList);
      } else {
        Visit(Child);
      }
      ++InitFieldIndex.back();
    }
    InitFieldIndex.pop_back();
  }

  void CheckInitializer(Expr *E, const CXXConstructorDecl *FieldConstructor,
                        FieldDecl *Field, const Type *BaseClass) {
    // Remove Decls that may have been initialized in the previous
    // initializer.
    for (ValueDecl* VD : DeclsToRemove)
      Decls.erase(VD);
    DeclsToRemove.clear();

    Constructor = FieldConstructor;
    InitListExpr *ILE = dyn_cast<InitListExpr>(E);

    if (ILE && Field) {
      InitList = true;
      InitListFieldDecl = Field;
      InitFieldIndex.clear();
      CheckInitListExpr(ILE);
    } else {
      InitList = false;
      Visit(E);
    }

    if (Field)
      Decls.erase(Field);
    if (BaseClass)
      BaseClasses.erase(BaseClass->getCanonicalTypeInternal());
  }

  void VisitMemberExpr(MemberExpr *ME) {
    // All uses of unbounded reference fields will warn.
    HandleMemberExpr(ME, true /*CheckReferenceOnly*/, false /*AddressOf*/);
  }

  void VisitImplicitCastExpr(ImplicitCastExpr *E) {
    if (E->getCastKind() == CK_LValueToRValue) {
      HandleValue(E->getSubExpr(), false /*AddressOf*/);
      return;
    }

    Inherited::VisitImplicitCastExpr(E);
  }

  void VisitCXXConstructExpr(CXXConstructExpr *E) {
    if (E->getConstructor()->isCopyConstructor()) {
      Expr *ArgExpr = E->getArg(0);
      if (InitListExpr *ILE = dyn_cast<InitListExpr>(ArgExpr))
        if (ILE->getNumInits() == 1)
          ArgExpr = ILE->getInit(0);
      if (ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(ArgExpr))
        if (ICE->getCastKind() == CK_NoOp)
          ArgExpr = ICE->getSubExpr();
      HandleValue(ArgExpr, false /*AddressOf*/);
      return;
    }
    Inherited::VisitCXXConstructExpr(E);
  }

  void VisitCXXMemberCallExpr(CXXMemberCallExpr *E) {
    Expr *Callee = E->getCallee();
    if (isa<MemberExpr>(Callee)) {
      HandleValue(Callee, false /*AddressOf*/);
      for (auto Arg : E->arguments())
        Visit(Arg);
      return;
    }

    Inherited::VisitCXXMemberCallExpr(E);
  }

  void VisitCallExpr(CallExpr *E) {
    // Treat std::move as a use.
    if (E->isCallToStdMove()) {
      HandleValue(E->getArg(0), /*AddressOf=*/false);
      return;
    }

    Inherited::VisitCallExpr(E);
  }

  void VisitCXXOperatorCallExpr(CXXOperatorCallExpr *E) {
    Expr *Callee = E->getCallee();

    if (isa<UnresolvedLookupExpr>(Callee))
      return Inherited::VisitCXXOperatorCallExpr(E);

    Visit(Callee);
    for (auto Arg : E->arguments())
      HandleValue(Arg->IgnoreParenImpCasts(), false /*AddressOf*/);
  }

  void VisitBinaryOperator(BinaryOperator *E) {
    // If a field assignment is detected, remove the field from the
    // uninitiailized field set.
    if (E->getOpcode() == BO_Assign)
      if (MemberExpr *ME = dyn_cast<MemberExpr>(E->getLHS()))
        if (FieldDecl *FD = dyn_cast<FieldDecl>(ME->getMemberDecl()))
          if (!FD->getType()->isReferenceType())
            DeclsToRemove.push_back(FD);

    if (E->isCompoundAssignmentOp()) {
      HandleValue(E->getLHS(), false /*AddressOf*/);
      Visit(E->getRHS());
      return;
    }

    Inherited::VisitBinaryOperator(E);
  }

  void VisitUnaryOperator(UnaryOperator *E) {
    if (E->isIncrementDecrementOp()) {
      HandleValue(E->getSubExpr(), false /*AddressOf*/);
      return;
    }
    if (E->getOpcode() == UO_AddrOf) {
      if (MemberExpr *ME = dyn_cast<MemberExpr>(E->getSubExpr())) {
        HandleValue(ME->getBase(), true /*AddressOf*/);
        return;
      }
    }

    Inherited::VisitUnaryOperator(E);
  }
};

// Diagnose value-uses of fields to initialize themselves, e.g.
//   foo(foo)
// where foo is not also a parameter to the constructor.
// Also diagnose across field uninitialized use such as
//   x(y), y(x)
// TODO: implement -Wuninitialized and fold this into that framework.
static void DiagnoseUninitializedFields(
    Sema &SemaRef, const CXXConstructorDecl *Constructor) {

  if (SemaRef.getDiagnostics().isIgnored(diag::warn_field_is_uninit,
                                         Constructor->getLocation())) {
    return;
  }

  if (Constructor->isInvalidDecl())
    return;

  const CXXRecordDecl *RD = Constructor->getParent();

  if (RD->isDependentContext())
    return;

  // Holds fields that are uninitialized.
  llvm::SmallPtrSet<ValueDecl*, 4> UninitializedFields;

  // At the beginning, all fields are uninitialized.
  for (auto *I : RD->decls()) {
    if (auto *FD = dyn_cast<FieldDecl>(I)) {
      UninitializedFields.insert(FD);
    } else if (auto *IFD = dyn_cast<IndirectFieldDecl>(I)) {
      UninitializedFields.insert(IFD->getAnonField());
    }
  }

  llvm::SmallPtrSet<QualType, 4> UninitializedBaseClasses;
  for (auto I : RD->bases())
    UninitializedBaseClasses.insert(I.getType().getCanonicalType());

  if (UninitializedFields.empty() && UninitializedBaseClasses.empty())
    return;

  UninitializedFieldVisitor UninitializedChecker(SemaRef,
                                                 UninitializedFields,
                                                 UninitializedBaseClasses);

  for (const auto *FieldInit : Constructor->inits()) {
    if (UninitializedFields.empty() && UninitializedBaseClasses.empty())
      break;

    Expr *InitExpr = FieldInit->getInit();
    if (!InitExpr)
      continue;

    if (CXXDefaultInitExpr *Default =
            dyn_cast<CXXDefaultInitExpr>(InitExpr)) {
      InitExpr = Default->getExpr();
      if (!InitExpr)
        continue;
      // In class initializers will point to the constructor.
      UninitializedChecker.CheckInitializer(InitExpr, Constructor,
                                            FieldInit->getAnyMember(),
                                            FieldInit->getBaseClass());
    } else {
      UninitializedChecker.CheckInitializer(InitExpr, nullptr,
                                            FieldInit->getAnyMember(),
                                            FieldInit->getBaseClass());
    }
  }
}
3934} // namespace

3936/// Enter a new C++ default initializer scope. After calling this, the
3937/// caller must call \ref ActOnFinishCXXInClassMemberInitializer, even if
3938/// parsing or instantiating the initializer failed.
3939void Sema::ActOnStartCXXInClassMemberInitializer() {
// Create a synthetic function scope to represent the call to the constructor
// that notionally surrounds a use of this initializer.
PushFunctionScope();
3943}

3945void Sema::ActOnStartTrailingRequiresClause(Scope *S, Declarator &D) {
if (!D.isFunctionDeclarator())
  return;
auto &FTI = D.getFunctionTypeInfo();
if (!FTI.Params)
  return;
for (auto &Param : ArrayRef<DeclaratorChunk::ParamInfo>(FTI.Params,
                                                        FTI.NumParams)) {
  auto *ParamDecl = cast<NamedDecl>(Param.Param);
  if (ParamDecl->getDeclName())
    PushOnScopeChains(ParamDecl, S, /*AddToContext=*/false);
}
3957}

3959ExprResult Sema::ActOnFinishTrailingRequiresClause(ExprResult ConstraintExpr) {
return ActOnRequiresClause(ConstraintExpr);
3961}

3963ExprResult Sema::ActOnRequiresClause(ExprResult ConstraintExpr) {
if (ConstraintExpr.isInvalid())
  return ExprError();

ConstraintExpr = CorrectDelayedTyposInExpr(ConstraintExpr);
if (ConstraintExpr.isInvalid())
  return ExprError();

if (DiagnoseUnexpandedParameterPack(ConstraintExpr.get(),
                                    UPPC_RequiresClause))
  return ExprError();

return ConstraintExpr;
3976}

3978/// This is invoked after parsing an in-class initializer for a
3979/// non-static C++ class member, and after instantiating an in-class initializer
3980/// in a class template. Such actions are deferred until the class is complete.
3981void Sema::ActOnFinishCXXInClassMemberInitializer(Decl *D,
                                                SourceLocation InitLoc,
                                                Expr *InitExpr) {
// Pop the notional constructor scope we created earlier.
PopFunctionScopeInfo(nullptr, D);

FieldDecl *FD = dyn_cast<FieldDecl>(D);
assert((isa<MSPropertyDecl>(D) || FD->getInClassInitStyle() != ICIS_NoInit) &&(static_cast<void> (0))
       "must set init style when field is created")(static_cast<void> (0));

if (!InitExpr) {
  D->setInvalidDecl();
  if (FD)
    FD->removeInClassInitializer();
  return;
}

if (DiagnoseUnexpandedParameterPack(InitExpr, UPPC_Initializer)) {
  FD->setInvalidDecl();
  FD->removeInClassInitializer();
  return;
}

ExprResult Init = InitExpr;
if (!FD->getType()->isDependentType() && !InitExpr->isTypeDependent()) {
  InitializedEntity Entity =
      InitializedEntity::InitializeMemberFromDefaultMemberInitializer(FD);
  InitializationKind Kind =
      FD->getInClassInitStyle() == ICIS_ListInit
          ? InitializationKind::CreateDirectList(InitExpr->getBeginLoc(),
                                                 InitExpr->getBeginLoc(),
                                                 InitExpr->getEndLoc())
          : InitializationKind::CreateCopy(InitExpr->getBeginLoc(), InitLoc);
  InitializationSequence Seq(*this, Entity, Kind, InitExpr);
  Init = Seq.Perform(*this, Entity, Kind, InitExpr);
  if (Init.isInvalid()) {
    FD->setInvalidDecl();
    return;
  }
}

// C++11 [class.base.init]p7:
//   The initialization of each base and member constitutes a
//   full-expression.
Init = ActOnFinishFullExpr(Init.get(), InitLoc, /*DiscardedValue*/ false);
if (Init.isInvalid()) {
  FD->setInvalidDecl();
  return;
}

InitExpr = Init.get();

FD->setInClassInitializer(InitExpr);
4034}

4036/// Find the direct and/or virtual base specifiers that
4037/// correspond to the given base type, for use in base initialization
4038/// within a constructor.
4039static bool FindBaseInitializer(Sema &SemaRef,
                              CXXRecordDecl *ClassDecl,
                              QualType BaseType,
                              const CXXBaseSpecifier *&DirectBaseSpec,
                              const CXXBaseSpecifier *&VirtualBaseSpec) {
// First, check for a direct base class.
DirectBaseSpec = nullptr;
for (const auto &Base : ClassDecl->bases()) {
  if (SemaRef.Context.hasSameUnqualifiedType(BaseType, Base.getType())) {
    // We found a direct base of this type. That's what we're
    // initializing.
    DirectBaseSpec = &Base;
    break;
  }
}

// Check for a virtual base class.
// FIXME: We might be able to short-circuit this if we know in advance that
// there are no virtual bases.
VirtualBaseSpec = nullptr;
if (!DirectBaseSpec || !DirectBaseSpec->isVirtual()) {
  // We haven't found a base yet; search the class hierarchy for a
  // virtual base class.
  CXXBasePaths Paths(/*FindAmbiguities=*/true, /*RecordPaths=*/true,
                     /*DetectVirtual=*/false);
  if (SemaRef.IsDerivedFrom(ClassDecl->getLocation(),
                            SemaRef.Context.getTypeDeclType(ClassDecl),
                            BaseType, Paths)) {
    for (CXXBasePaths::paths_iterator Path = Paths.begin();
         Path != Paths.end(); ++Path) {
      if (Path->back().Base->isVirtual()) {
        VirtualBaseSpec = Path->back().Base;
        break;
      }
    }
  }
}

return DirectBaseSpec || VirtualBaseSpec;
4078}

4080/// Handle a C++ member initializer using braced-init-list syntax.
4081MemInitResult
4082Sema::ActOnMemInitializer(Decl *ConstructorD,
                        Scope *S,
                        CXXScopeSpec &SS,
                        IdentifierInfo *MemberOrBase,
                        ParsedType TemplateTypeTy,
                        const DeclSpec &DS,
                        SourceLocation IdLoc,
                        Expr *InitList,
                        SourceLocation EllipsisLoc) {
return BuildMemInitializer(ConstructorD, S, SS, MemberOrBase, TemplateTypeTy,
1
Calling 'Sema::BuildMemInitializer'→
                           DS, IdLoc, InitList,
                           EllipsisLoc);
4094}

4096/// Handle a C++ member initializer using parentheses syntax.
4097MemInitResult
4098Sema::ActOnMemInitializer(Decl *ConstructorD,
                        Scope *S,
                        CXXScopeSpec &SS,
                        IdentifierInfo *MemberOrBase,
                        ParsedType TemplateTypeTy,
                        const DeclSpec &DS,
                        SourceLocation IdLoc,
                        SourceLocation LParenLoc,
                        ArrayRef<Expr *> Args,
                        SourceLocation RParenLoc,
                        SourceLocation EllipsisLoc) {
Expr *List = ParenListExpr::Create(Context, LParenLoc, Args, RParenLoc);
return BuildMemInitializer(ConstructorD, S, SS, MemberOrBase, TemplateTypeTy,
                           DS, IdLoc, List, EllipsisLoc);
4112}

4114namespace {

4116// Callback to only accept typo corrections that can be a valid C++ member
4117// intializer: either a non-static field member or a base class.
4118class MemInitializerValidatorCCC final : public CorrectionCandidateCallback {
4119public:
explicit MemInitializerValidatorCCC(CXXRecordDecl *ClassDecl)
    : ClassDecl(ClassDecl) {}

bool ValidateCandidate(const TypoCorrection &candidate) override {
  if (NamedDecl *ND = candidate.getCorrectionDecl()) {
    if (FieldDecl *Member = dyn_cast<FieldDecl>(ND))
      return Member->getDeclContext()->getRedeclContext()->Equals(ClassDecl);
    return isa<TypeDecl>(ND);
  }
  return false;
}

std::unique_ptr<CorrectionCandidateCallback> clone() override {
  return std::make_unique<MemInitializerValidatorCCC>(*this);
}

4136private:
CXXRecordDecl *ClassDecl;
4138};

4140}

4142ValueDecl *Sema::tryLookupCtorInitMemberDecl(CXXRecordDecl *ClassDecl,
                                           CXXScopeSpec &SS,
                                           ParsedType TemplateTypeTy,
                                           IdentifierInfo *MemberOrBase) {
if (SS.getScopeRep() || TemplateTypeTy)
  return nullptr;
for (auto *D : ClassDecl->lookup(MemberOrBase))
  if (isa<FieldDecl>(D) || isa<IndirectFieldDecl>(D))
    return cast<ValueDecl>(D);
return nullptr;
4152}

4154/// Handle a C++ member initializer.
4155MemInitResult
4156Sema::BuildMemInitializer(Decl *ConstructorD,
                        Scope *S,
                        CXXScopeSpec &SS,
                        IdentifierInfo *MemberOrBase,
                        ParsedType TemplateTypeTy,
                        const DeclSpec &DS,
                        SourceLocation IdLoc,
                        Expr *Init,
                        SourceLocation EllipsisLoc) {
ExprResult Res = CorrectDelayedTyposInExpr(Init, /*InitDecl=*/nullptr,
                                           /*RecoverUncorrectedTypos=*/true);
if (!Res.isUsable())
2
←
Calling 'ActionResult::isUsable'→
5
←
Returning from 'ActionResult::isUsable'→
6
←
Taking false branch→
  return true;
Init = Res.get();

if (!ConstructorD)
7
←
Assuming 'ConstructorD' is non-null→
8
←
Taking false branch→
  return true;

AdjustDeclIfTemplate(ConstructorD);

CXXConstructorDecl *Constructor
  = dyn_cast<CXXConstructorDecl>(ConstructorD);
9
←
Assuming 'ConstructorD' is a 'CXXConstructorDecl'→
if (!Constructor9.1
'Constructor' is non-null
1
'Constructor' is non-null
1
'Constructor' is non-null
1
'Constructor' is non-null
1
'Constructor' is non-null
1
'Constructor' is non-null
) {
10
←
Taking false branch→
  // The user wrote a constructor initializer on a function that is
  // not a C++ constructor. Ignore the error for now, because we may
  // have more member initializers coming; we'll diagnose it just
  // once in ActOnMemInitializers.
  return true;
}

CXXRecordDecl *ClassDecl = Constructor->getParent();

// C++ [class.base.init]p2:
//   Names in a mem-initializer-id are looked up in the scope of the
//   constructor's class and, if not found in that scope, are looked
//   up in the scope containing the constructor's definition.
//   [Note: if the constructor's class contains a member with the
//   same name as a direct or virtual base class of the class, a
//   mem-initializer-id naming the member or base class and composed
//   of a single identifier refers to the class member. A
//   mem-initializer-id for the hidden base class may be specified
//   using a qualified name. ]

// Look for a member, first.
if (ValueDecl *Member = tryLookupCtorInitMemberDecl(
11
←
Assuming 'Member' is null→
12
←
Taking false branch→
        ClassDecl, SS, TemplateTypeTy, MemberOrBase)) {
  if (EllipsisLoc.isValid())
    Diag(EllipsisLoc, diag::err_pack_expansion_member_init)
        << MemberOrBase
        << SourceRange(IdLoc, Init->getSourceRange().getEnd());

  return BuildMemberInitializer(Member, Init, IdLoc);
}
// It didn't name a member, so see if it names a class.
QualType BaseType;
TypeSourceInfo *TInfo = nullptr;

if (TemplateTypeTy) {
13
←
Calling 'OpaquePtr::operator bool'→
16
←
Returning from 'OpaquePtr::operator bool'→
17
←
Taking false branch→
  BaseType = GetTypeFromParser(TemplateTypeTy, &TInfo);
  if (BaseType.isNull())
    return true;
} else if (DS.getTypeSpecType() == TST_decltype) {
18
←
Assuming the condition is false→
19
←
Taking false branch→
  BaseType = BuildDecltypeType(DS.getRepAsExpr(), DS.getTypeSpecTypeLoc());
} else if (DS.getTypeSpecType() == TST_decltype_auto) {
20
←
Assuming the condition is false→
21
←
Taking false branch→
  Diag(DS.getTypeSpecTypeLoc(), diag::err_decltype_auto_invalid);
  return true;
} else {
  LookupResult R(*this, MemberOrBase, IdLoc, LookupOrdinaryName);
  LookupParsedName(R, S, &SS);

  TypeDecl *TyD = R.getAsSingle<TypeDecl>();
22
←
'TyD' initialized here→
  if (!TyD) {
23
←
Assuming 'TyD' is null→
24
←
Taking true branch→
    if (R.isAmbiguous()) return true;
25
←
Assuming the condition is false→
26
←
Taking false branch→

    // We don't want access-control diagnostics here.
    R.suppressDiagnostics();

    if (SS.isSet() && isDependentScopeSpecifier(SS)) {
27
←
Calling 'CXXScopeSpec::isSet'→
30
←
Returning from 'CXXScopeSpec::isSet'→
31
←
Assuming the condition is true→
32
←
Taking true branch→
      bool NotUnknownSpecialization = false;
      DeclContext *DC = computeDeclContext(SS, false);
      if (CXXRecordDecl *Record33.1
'Record' is null
1
'Record' is null
1
'Record' is null
1
'Record' is null
1
'Record' is null
1
'Record' is null
 = dyn_cast_or_null<CXXRecordDecl>(DC))
33
←
Assuming null pointer is passed into cast→
34
←
Taking false branch→
        NotUnknownSpecialization = !Record->hasAnyDependentBases();

      if (!NotUnknownSpecialization34.1
'NotUnknownSpecialization' is false
1
'NotUnknownSpecialization' is false
1
'NotUnknownSpecialization' is false
1
'NotUnknownSpecialization' is false
1
'NotUnknownSpecialization' is false
1
'NotUnknownSpecialization' is false
) {
35
←
Taking true branch→
        // When the scope specifier can refer to a member of an unknown
        // specialization, we take it as a type name.
        BaseType = CheckTypenameType(ETK_None, SourceLocation(),
                                     SS.getWithLocInContext(Context),
                                     *MemberOrBase, IdLoc);
        if (BaseType.isNull())
36
←
Calling 'QualType::isNull'→
42
←
Returning from 'QualType::isNull'→
43
←
Taking false branch→
          return true;

        TInfo = Context.CreateTypeSourceInfo(BaseType);
        DependentNameTypeLoc TL =
            TInfo->getTypeLoc().castAs<DependentNameTypeLoc>();
        if (!TL.isNull()) {
44
←
Taking true branch→
          TL.setNameLoc(IdLoc);
          TL.setElaboratedKeywordLoc(SourceLocation());
          TL.setQualifierLoc(SS.getWithLocInContext(Context));
        }

        R.clear();
        R.setLookupName(MemberOrBase);
      }
    }

    // If no results were found, try to correct typos.
    TypoCorrection Corr;
    MemInitializerValidatorCCC CCC(ClassDecl);
    if (R.empty() && BaseType.isNull() &&
45
←
Assuming the condition is false→
        (Corr = CorrectTypo(R.getLookupNameInfo(), R.getLookupKind(), S, &SS,
                            CCC, CTK_ErrorRecovery, ClassDecl))) {
      if (FieldDecl *Member = Corr.getCorrectionDeclAs<FieldDecl>()) {
        // We have found a non-static data member with a similar
        // name to what was typed; complain and initialize that
        // member.
        diagnoseTypo(Corr,
                     PDiag(diag::err_mem_init_not_member_or_class_suggest)
                       << MemberOrBase << true);
        return BuildMemberInitializer(Member, Init, IdLoc);
      } else if (TypeDecl *Type = Corr.getCorrectionDeclAs<TypeDecl>()) {
        const CXXBaseSpecifier *DirectBaseSpec;
        const CXXBaseSpecifier *VirtualBaseSpec;
        if (FindBaseInitializer(*this, ClassDecl,
                                Context.getTypeDeclType(Type),
                                DirectBaseSpec, VirtualBaseSpec)) {
          // We have found a direct or virtual base class with a
          // similar name to what was typed; complain and initialize
          // that base class.
          diagnoseTypo(Corr,
                       PDiag(diag::err_mem_init_not_member_or_class_suggest)
                         << MemberOrBase << false,
                       PDiag() /*Suppress note, we provide our own.*/);

          const CXXBaseSpecifier *BaseSpec = DirectBaseSpec ? DirectBaseSpec
                                                            : VirtualBaseSpec;
          Diag(BaseSpec->getBeginLoc(), diag::note_base_class_specified_here)
              << BaseSpec->getType() << BaseSpec->getSourceRange();

          TyD = Type;
        }
      }
    }

    if (!TyD45.1
'TyD' is null
1
'TyD' is null
1
'TyD' is null
1
'TyD' is null
1
'TyD' is null
1
'TyD' is null
 && BaseType.isNull()) {
46
←
Calling 'QualType::isNull'→
52
←
Returning from 'QualType::isNull'→
53
←
Taking false branch→
      Diag(IdLoc, diag::err_mem_init_not_member_or_class)
        << MemberOrBase << SourceRange(IdLoc,Init->getSourceRange().getEnd());
      return true;
    }
  }

  if (BaseType.isNull()) {
54
←
Calling 'QualType::isNull'→
60
←
Returning from 'QualType::isNull'→
61
←
Taking true branch→
    BaseType = Context.getTypeDeclType(TyD);
62
←
Passing null pointer value via 1st parameter 'Decl'→
63
←
Calling 'ASTContext::getTypeDeclType'→
    MarkAnyDeclReferenced(TyD->getLocation(), TyD, /*OdrUse=*/false);
    if (SS.isSet()) {
      BaseType = Context.getElaboratedType(ETK_None, SS.getScopeRep(),
                                           BaseType);
      TInfo = Context.CreateTypeSourceInfo(BaseType);
      ElaboratedTypeLoc TL = TInfo->getTypeLoc().castAs<ElaboratedTypeLoc>();
      TL.getNamedTypeLoc().castAs<TypeSpecTypeLoc>().setNameLoc(IdLoc);
      TL.setElaboratedKeywordLoc(SourceLocation());
      TL.setQualifierLoc(SS.getWithLocInContext(Context));
    }
  }
}

if (!TInfo)
  TInfo = Context.getTrivialTypeSourceInfo(BaseType, IdLoc);

return BuildBaseInitializer(BaseType, TInfo, Init, ClassDecl, EllipsisLoc);
4326}

4328MemInitResult
4329Sema::BuildMemberInitializer(ValueDecl *Member, Expr *Init,
                           SourceLocation IdLoc) {
FieldDecl *DirectMember = dyn_cast<FieldDecl>(Member);
IndirectFieldDecl *IndirectMember = dyn_cast<IndirectFieldDecl>(Member);
assert((DirectMember || IndirectMember) &&(static_cast<void> (0))
       "Member must be a FieldDecl or IndirectFieldDecl")(static_cast<void> (0));

if (DiagnoseUnexpandedParameterPack(Init, UPPC_Initializer))
  return true;

if (Member->isInvalidDecl())
  return true;

MultiExprArg Args;
if (ParenListExpr *ParenList = dyn_cast<ParenListExpr>(Init)) {
  Args = MultiExprArg(ParenList->getExprs(), ParenList->getNumExprs());
} else if (InitListExpr *InitList = dyn_cast<InitListExpr>(Init)) {
  Args = MultiExprArg(InitList->getInits(), InitList->getNumInits());
} else {
  // Template instantiation doesn't reconstruct ParenListExprs for us.
  Args = Init;
}

SourceRange InitRange = Init->getSourceRange();

if (Member->getType()->isDependentType() || Init->isTypeDependent()) {
  // Can't check initialization for a member of dependent type or when
  // any of the arguments are type-dependent expressions.
  DiscardCleanupsInEvaluationContext();
} else {
  bool InitList = false;
  if (isa<InitListExpr>(Init)) {
    InitList = true;
    Args = Init;
  }

  // Initialize the member.
  InitializedEntity MemberEntity =
    DirectMember ? InitializedEntity::InitializeMember(DirectMember, nullptr)
                 : InitializedEntity::InitializeMember(IndirectMember,
                                                       nullptr);
  InitializationKind Kind =
      InitList ? InitializationKind::CreateDirectList(
                     IdLoc, Init->getBeginLoc(), Init->getEndLoc())
               : InitializationKind::CreateDirect(IdLoc, InitRange.getBegin(),
                                                  InitRange.getEnd());

  InitializationSequence InitSeq(*this, MemberEntity, Kind, Args);
  ExprResult MemberInit = InitSeq.Perform(*this, MemberEntity, Kind, Args,
                                          nullptr);
  if (!MemberInit.isInvalid()) {
    // C++11 [class.base.init]p7:
    //   The initialization of each base and member constitutes a
    //   full-expression.
    MemberInit = ActOnFinishFullExpr(MemberInit.get(), InitRange.getBegin(),
                                     /*DiscardedValue*/ false);
  }

  if (MemberInit.isInvalid()) {
    // Args were sensible expressions but we couldn't initialize the member
    // from them. Preserve them in a RecoveryExpr instead.
    Init = CreateRecoveryExpr(InitRange.getBegin(), InitRange.getEnd(), Args,
                              Member->getType())
               .get();
    if (!Init)
      return true;
  } else {
    Init = MemberInit.get();
  }
}

if (DirectMember) {
  return new (Context) CXXCtorInitializer(Context, DirectMember, IdLoc,
                                          InitRange.getBegin(), Init,
                                          InitRange.getEnd());
} else {
  return new (Context) CXXCtorInitializer(Context, IndirectMember, IdLoc,
                                          InitRange.getBegin(), Init,
                                          InitRange.getEnd());
}
4409}

4411MemInitResult
4412Sema::BuildDelegatingInitializer(TypeSourceInfo *TInfo, Expr *Init,
                               CXXRecordDecl *ClassDecl) {
SourceLocation NameLoc = TInfo->getTypeLoc().getLocalSourceRange().getBegin();
if (!LangOpts.CPlusPlus11)
  return Diag(NameLoc, diag::err_delegating_ctor)
    << TInfo->getTypeLoc().getLocalSourceRange();
Diag(NameLoc, diag::warn_cxx98_compat_delegating_ctor);

bool InitList = true;
MultiExprArg Args = Init;
if (ParenListExpr *ParenList = dyn_cast<ParenListExpr>(Init)) {
  InitList = false;
  Args = MultiExprArg(ParenList->getExprs(), ParenList->getNumExprs());
}

SourceRange InitRange = Init->getSourceRange();
// Initialize the object.
InitializedEntity DelegationEntity = InitializedEntity::InitializeDelegation(
                                   QualType(ClassDecl->getTypeForDecl(), 0));
InitializationKind Kind =
    InitList ? InitializationKind::CreateDirectList(
                   NameLoc, Init->getBeginLoc(), Init->getEndLoc())
             : InitializationKind::CreateDirect(NameLoc, InitRange.getBegin(),
                                                InitRange.getEnd());
InitializationSequence InitSeq(*this, DelegationEntity, Kind, Args);
ExprResult DelegationInit = InitSeq.Perform(*this, DelegationEntity, Kind,
                                            Args, nullptr);
if (!DelegationInit.isInvalid()) {
  assert((DelegationInit.get()->containsErrors() ||(static_cast<void> (0))
          cast<CXXConstructExpr>(DelegationInit.get())->getConstructor()) &&(static_cast<void> (0))
         "Delegating constructor with no target?")(static_cast<void> (0));

  // C++11 [class.base.init]p7:
  //   The initialization of each base and member constitutes a
  //   full-expression.
  DelegationInit = ActOnFinishFullExpr(
      DelegationInit.get(), InitRange.getBegin(), /*DiscardedValue*/ false);
}

if (DelegationInit.isInvalid()) {
  DelegationInit =
      CreateRecoveryExpr(InitRange.getBegin(), InitRange.getEnd(), Args,
                         QualType(ClassDecl->getTypeForDecl(), 0));
  if (DelegationInit.isInvalid())
    return true;
} else {
  // If we are in a dependent context, template instantiation will
  // perform this type-checking again. Just save the arguments that we
  // received in a ParenListExpr.
  // FIXME: This isn't quite ideal, since our ASTs don't capture all
  // of the information that we have about the base
  // initializer. However, deconstructing the ASTs is a dicey process,
  // and this approach is far more likely to get the corner cases right.
  if (CurContext->isDependentContext())
    DelegationInit = Init;
}

return new (Context) CXXCtorInitializer(Context, TInfo, InitRange.getBegin(),
                                        DelegationInit.getAs<Expr>(),
                                        InitRange.getEnd());
4472}

4474MemInitResult
4475Sema::BuildBaseInitializer(QualType BaseType, TypeSourceInfo *BaseTInfo,
                         Expr *Init, CXXRecordDecl *ClassDecl,
                         SourceLocation EllipsisLoc) {
SourceLocation BaseLoc
  = BaseTInfo->getTypeLoc().getLocalSourceRange().getBegin();

if (!BaseType->isDependentType() && !BaseType->isRecordType())
  return Diag(BaseLoc, diag::err_base_init_does_not_name_class)
           << BaseType << BaseTInfo->getTypeLoc().getLocalSourceRange();

// C++ [class.base.init]p2:
//   [...] Unless the mem-initializer-id names a nonstatic data
//   member of the constructor's class or a direct or virtual base
//   of that class, the mem-initializer is ill-formed. A
//   mem-initializer-list can initialize a base class using any
//   name that denotes that base class type.

// We can store the initializers in "as-written" form and delay analysis until
// instantiation if the constructor is dependent. But not for dependent
// (broken) code in a non-template! SetCtorInitializers does not expect this.
bool Dependent = CurContext->isDependentContext() &&
                 (BaseType->isDependentType() || Init->isTypeDependent());

SourceRange InitRange = Init->getSourceRange();
if (EllipsisLoc.isValid()) {
  // This is a pack expansion.
  if (!BaseType->containsUnexpandedParameterPack())  {
    Diag(EllipsisLoc, diag::err_pack_expansion_without_parameter_packs)
      << SourceRange(BaseLoc, InitRange.getEnd());

    EllipsisLoc = SourceLocation();
  }
} else {
  // Check for any unexpanded parameter packs.
  if (DiagnoseUnexpandedParameterPack(BaseLoc, BaseTInfo, UPPC_Initializer))
    return true;

  if (DiagnoseUnexpandedParameterPack(Init, UPPC_Initializer))
    return true;
}

// Check for direct and virtual base classes.
const CXXBaseSpecifier *DirectBaseSpec = nullptr;
const CXXBaseSpecifier *VirtualBaseSpec = nullptr;
if (!Dependent) {
  if (Context.hasSameUnqualifiedType(QualType(ClassDecl->getTypeForDecl(),0),
                                     BaseType))
    return BuildDelegatingInitializer(BaseTInfo, Init, ClassDecl);

  FindBaseInitializer(*this, ClassDecl, BaseType, DirectBaseSpec,
                      VirtualBaseSpec);

  // C++ [base.class.init]p2:
  // Unless the mem-initializer-id names a nonstatic data member of the
  // constructor's class or a direct or virtual base of that class, the
  // mem-initializer is ill-formed.
  if (!DirectBaseSpec && !VirtualBaseSpec) {
    // If the class has any dependent bases, then it's possible that
    // one of those types will resolve to the same type as
    // BaseType. Therefore, just treat this as a dependent base
    // class initialization.  FIXME: Should we try to check the
    // initialization anyway? It seems odd.
    if (ClassDecl->hasAnyDependentBases())
      Dependent = true;
    else
      return Diag(BaseLoc, diag::err_not_direct_base_or_virtual)
        << BaseType << Context.getTypeDeclType(ClassDecl)
        << BaseTInfo->getTypeLoc().getLocalSourceRange();
  }
}

if (Dependent) {
  DiscardCleanupsInEvaluationContext();

  return new (Context) CXXCtorInitializer(Context, BaseTInfo,
                                          /*IsVirtual=*/false,
                                          InitRange.getBegin(), Init,
                                          InitRange.getEnd(), EllipsisLoc);
}

// C++ [base.class.init]p2:
//   If a mem-initializer-id is ambiguous because it designates both
//   a direct non-virtual base class and an inherited virtual base
//   class, the mem-initializer is ill-formed.
if (DirectBaseSpec && VirtualBaseSpec)
  return Diag(BaseLoc, diag::err_base_init_direct_and_virtual)
    << BaseType << BaseTInfo->getTypeLoc().getLocalSourceRange();

const CXXBaseSpecifier *BaseSpec = DirectBaseSpec;
if (!BaseSpec)
  BaseSpec = VirtualBaseSpec;

// Initialize the base.
bool InitList = true;
MultiExprArg Args = Init;
if (ParenListExpr *ParenList = dyn_cast<ParenListExpr>(Init)) {
  InitList = false;
  Args = MultiExprArg(ParenList->getExprs(), ParenList->getNumExprs());
}

InitializedEntity BaseEntity =
  InitializedEntity::InitializeBase(Context, BaseSpec, VirtualBaseSpec);
InitializationKind Kind =
    InitList ? InitializationKind::CreateDirectList(BaseLoc)
             : InitializationKind::CreateDirect(BaseLoc, InitRange.getBegin(),
                                                InitRange.getEnd());
InitializationSequence InitSeq(*this, BaseEntity, Kind, Args);
ExprResult BaseInit = InitSeq.Perform(*this, BaseEntity, Kind, Args, nullptr);
if (!BaseInit.isInvalid()) {
  // C++11 [class.base.init]p7:
  //   The initialization of each base and member constitutes a
  //   full-expression.
  BaseInit = ActOnFinishFullExpr(BaseInit.get(), InitRange.getBegin(),
                                 /*DiscardedValue*/ false);
}

if (BaseInit.isInvalid()) {
  BaseInit = CreateRecoveryExpr(InitRange.getBegin(), InitRange.getEnd(),
                                Args, BaseType);
  if (BaseInit.isInvalid())
    return true;
} else {
  // If we are in a dependent context, template instantiation will
  // perform this type-checking again. Just save the arguments that we
  // received in a ParenListExpr.
  // FIXME: This isn't quite ideal, since our ASTs don't capture all
  // of the information that we have about the base
  // initializer. However, deconstructing the ASTs is a dicey process,
  // and this approach is far more likely to get the corner cases right.
  if (CurContext->isDependentContext())
    BaseInit = Init;
}

return new (Context) CXXCtorInitializer(Context, BaseTInfo,
                                        BaseSpec->isVirtual(),
                                        InitRange.getBegin(),
                                        BaseInit.getAs<Expr>(),
                                        InitRange.getEnd(), EllipsisLoc);
4613}

4615// Create a static_cast\<T&&>(expr).
4616static Expr *CastForMoving(Sema &SemaRef, Expr *E, QualType T = QualType()) {
if (T.isNull()) T = E->getType();
QualType TargetType = SemaRef.BuildReferenceType(
    T, /*SpelledAsLValue*/false, SourceLocation(), DeclarationName());
SourceLocation ExprLoc = E->getBeginLoc();
TypeSourceInfo *TargetLoc = SemaRef.Context.getTrivialTypeSourceInfo(
    TargetType, ExprLoc);

return SemaRef.BuildCXXNamedCast(ExprLoc, tok::kw_static_cast, TargetLoc, E,
                                 SourceRange(ExprLoc, ExprLoc),
                                 E->getSourceRange()).get();
4627}

4629/// ImplicitInitializerKind - How an implicit base or member initializer should
4630/// initialize its base or member.
4631enum ImplicitInitializerKind {
IIK_Default,
IIK_Copy,
IIK_Move,
IIK_Inherit
4636};

4638static bool
4639BuildImplicitBaseInitializer(Sema &SemaRef, CXXConstructorDecl *Constructor,
                           ImplicitInitializerKind ImplicitInitKind,
                           CXXBaseSpecifier *BaseSpec,
                           bool IsInheritedVirtualBase,
                           CXXCtorInitializer *&CXXBaseInit) {
InitializedEntity InitEntity
  = InitializedEntity::InitializeBase(SemaRef.Context, BaseSpec,
                                      IsInheritedVirtualBase);

ExprResult BaseInit;

switch (ImplicitInitKind) {
case IIK_Inherit:
case IIK_Default: {
  InitializationKind InitKind
    = InitializationKind::CreateDefault(Constructor->getLocation());
  InitializationSequence InitSeq(SemaRef, InitEntity, InitKind, None);
  BaseInit = InitSeq.Perform(SemaRef, InitEntity, InitKind, None);
  break;
}

case IIK_Move:
case IIK_Copy: {
  bool Moving = ImplicitInitKind == IIK_Move;
  ParmVarDecl *Param = Constructor->getParamDecl(0);
  QualType ParamType = Param->getType().getNonReferenceType();

  Expr *CopyCtorArg =
    DeclRefExpr::Create(SemaRef.Context, NestedNameSpecifierLoc(),
                        SourceLocation(), Param, false,
                        Constructor->getLocation(), ParamType,
                        VK_LValue, nullptr);

  SemaRef.MarkDeclRefReferenced(cast<DeclRefExpr>(CopyCtorArg));

  // Cast to the base class to avoid ambiguities.
  QualType ArgTy =
    SemaRef.Context.getQualifiedType(BaseSpec->getType().getUnqualifiedType(),
                                     ParamType.getQualifiers());

  if (Moving) {
    CopyCtorArg = CastForMoving(SemaRef, CopyCtorArg);
  }

  CXXCastPath BasePath;
  BasePath.push_back(BaseSpec);
  CopyCtorArg = SemaRef.ImpCastExprToType(CopyCtorArg, ArgTy,
                                          CK_UncheckedDerivedToBase,
                                          Moving ? VK_XValue : VK_LValue,
                                          &BasePath).get();

  InitializationKind InitKind
    = InitializationKind::CreateDirect(Constructor->getLocation(),
                                       SourceLocation(), SourceLocation());
  InitializationSequence InitSeq(SemaRef, InitEntity, InitKind, CopyCtorArg);
  BaseInit = InitSeq.Perform(SemaRef, InitEntity, InitKind, CopyCtorArg);
  break;
}
}

BaseInit = SemaRef.MaybeCreateExprWithCleanups(BaseInit);
if (BaseInit.isInvalid())
  return true;

CXXBaseInit =
  new (SemaRef.Context) CXXCtorInitializer(SemaRef.Context,
             SemaRef.Context.getTrivialTypeSourceInfo(BaseSpec->getType(),
                                                      SourceLocation()),
                                           BaseSpec->isVirtual(),
                                           SourceLocation(),
                                           BaseInit.getAs<Expr>(),
                                           SourceLocation(),
                                           SourceLocation());

return false;
4714}

4716static bool RefersToRValueRef(Expr *MemRef) {
ValueDecl *Referenced = cast<MemberExpr>(MemRef)->getMemberDecl();
return Referenced->getType()->isRValueReferenceType();
4719}

4721static bool
4722BuildImplicitMemberInitializer(Sema &SemaRef, CXXConstructorDecl *Constructor,
                             ImplicitInitializerKind ImplicitInitKind,
                             FieldDecl *Field, IndirectFieldDecl *Indirect,
                             CXXCtorInitializer *&CXXMemberInit) {
if (Field->isInvalidDecl())
  return true;

SourceLocation Loc = Constructor->getLocation();

if (ImplicitInitKind == IIK_Copy || ImplicitInitKind == IIK_Move) {
  bool Moving = ImplicitInitKind == IIK_Move;
  ParmVarDecl *Param = Constructor->getParamDecl(0);
  QualType ParamType = Param->getType().getNonReferenceType();

  // Suppress copying zero-width bitfields.
  if (Field->isZeroLengthBitField(SemaRef.Context))
    return false;

  Expr *MemberExprBase =
    DeclRefExpr::Create(SemaRef.Context, NestedNameSpecifierLoc(),
                        SourceLocation(), Param, false,
                        Loc, ParamType, VK_LValue, nullptr);

  SemaRef.MarkDeclRefReferenced(cast<DeclRefExpr>(MemberExprBase));

  if (Moving) {
    MemberExprBase = CastForMoving(SemaRef, MemberExprBase);
  }

  // Build a reference to this field within the parameter.
  CXXScopeSpec SS;
  LookupResult MemberLookup(SemaRef, Field->getDeclName(), Loc,
                            Sema::LookupMemberName);
  MemberLookup.addDecl(Indirect ? cast<ValueDecl>(Indirect)
                                : cast<ValueDecl>(Field), AS_public);
  MemberLookup.resolveKind();
  ExprResult CtorArg
    = SemaRef.BuildMemberReferenceExpr(MemberExprBase,
                                       ParamType, Loc,
                                       /*IsArrow=*/false,
                                       SS,
                                       /*TemplateKWLoc=*/SourceLocation(),
                                       /*FirstQualifierInScope=*/nullptr,
                                       MemberLookup,
                                       /*TemplateArgs=*/nullptr,
                                       /*S*/nullptr);
  if (CtorArg.isInvalid())
    return true;

  // C++11 [class.copy]p15:
  //   - if a member m has rvalue reference type T&&, it is direct-initialized
  //     with static_cast<T&&>(x.m);
  if (RefersToRValueRef(CtorArg.get())) {
    CtorArg = CastForMoving(SemaRef, CtorArg.get());
  }

  InitializedEntity Entity =
      Indirect ? InitializedEntity::InitializeMember(Indirect, nullptr,
                                                     /*Implicit*/ true)
               : InitializedEntity::InitializeMember(Field, nullptr,
                                                     /*Implicit*/ true);

  // Direct-initialize to use the copy constructor.
  InitializationKind InitKind =
    InitializationKind::CreateDirect(Loc, SourceLocation(), SourceLocation());

  Expr *CtorArgE = CtorArg.getAs<Expr>();
  InitializationSequence InitSeq(SemaRef, Entity, InitKind, CtorArgE);
  ExprResult MemberInit =
      InitSeq.Perform(SemaRef, Entity, InitKind, MultiExprArg(&CtorArgE, 1));
  MemberInit = SemaRef.MaybeCreateExprWithCleanups(MemberInit);
  if (MemberInit.isInvalid())
    return true;

  if (Indirect)
    CXXMemberInit = new (SemaRef.Context) CXXCtorInitializer(
        SemaRef.Context, Indirect, Loc, Loc, MemberInit.getAs<Expr>(), Loc);
  else
    CXXMemberInit = new (SemaRef.Context) CXXCtorInitializer(
        SemaRef.Context, Field, Loc, Loc, MemberInit.getAs<Expr>(), Loc);
  return false;
}

assert((ImplicitInitKind == IIK_Default || ImplicitInitKind == IIK_Inherit) &&(static_cast<void> (0))
       "Unhandled implicit init kind!")(static_cast<void> (0));

QualType FieldBaseElementType =
  SemaRef.Context.getBaseElementType(Field->getType());

if (FieldBaseElementType->isRecordType()) {
  InitializedEntity InitEntity =
      Indirect ? InitializedEntity::InitializeMember(Indirect, nullptr,
                                                     /*Implicit*/ true)
               : InitializedEntity::InitializeMember(Field, nullptr,
                                                     /*Implicit*/ true);
  InitializationKind InitKind =
    InitializationKind::CreateDefault(Loc);

  InitializationSequence InitSeq(SemaRef, InitEntity, InitKind, None);
  ExprResult MemberInit =
    InitSeq.Perform(SemaRef, InitEntity, InitKind, None);

  MemberInit = SemaRef.MaybeCreateExprWithCleanups(MemberInit);
  if (MemberInit.isInvalid())
    return true;

  if (Indirect)
    CXXMemberInit = new (SemaRef.Context) CXXCtorInitializer(SemaRef.Context,
                                                             Indirect, Loc,
                                                             Loc,
                                                             MemberInit.get(),
                                                             Loc);
  else
    CXXMemberInit = new (SemaRef.Context) CXXCtorInitializer(SemaRef.Context,
                                                             Field, Loc, Loc,
                                                             MemberInit.get(),
                                                             Loc);
  return false;
}

if (!Field->getParent()->isUnion()) {
  if (FieldBaseElementType->isReferenceType()) {
    SemaRef.Diag(Constructor->getLocation(),
                 diag::err_uninitialized_member_in_ctor)
    << (int)Constructor->isImplicit()
    << SemaRef.Context.getTagDeclType(Constructor->getParent())
    << 0 << Field->getDeclName();
    SemaRef.Diag(Field->getLocation(), diag::note_declared_at);
    return true;
  }

  if (FieldBaseElementType.isConstQualified()) {
    SemaRef.Diag(Constructor->getLocation(),
                 diag::err_uninitialized_member_in_ctor)
    << (int)Constructor->isImplicit()
    << SemaRef.Context.getTagDeclType(Constructor->getParent())
    << 1 << Field->getDeclName();
    SemaRef.Diag(Field->getLocation(), diag::note_declared_at);
    return true;
  }
}

if (FieldBaseElementType.hasNonTrivialObjCLifetime()) {
  // ARC and Weak:
  //   Default-initialize Objective-C pointers to NULL.
  CXXMemberInit
    = new (SemaRef.Context) CXXCtorInitializer(SemaRef.Context, Field,
                                               Loc, Loc,
               new (SemaRef.Context) ImplicitValueInitExpr(Field->getType()),
                                               Loc);
  return false;
}

// Nothing to initialize.
CXXMemberInit = nullptr;
return false;
4878}

4880namespace {
4881struct BaseAndFieldInfo {
Sema &S;
CXXConstructorDecl *Ctor;
bool AnyErrorsInInits;
ImplicitInitializerKind IIK;
llvm::DenseMap<const void *, CXXCtorInitializer*> AllBaseFields;
SmallVector<CXXCtorInitializer*, 8> AllToInit;
llvm::DenseMap<TagDecl*, FieldDecl*> ActiveUnionMember;

BaseAndFieldInfo(Sema &S, CXXConstructorDecl *Ctor, bool ErrorsInInits)
  : S(S), Ctor(Ctor), AnyErrorsInInits(ErrorsInInits) {
  bool Generated = Ctor->isImplicit() || Ctor->isDefaulted();
  if (Ctor->getInheritedConstructor())
    IIK = IIK_Inherit;
  else if (Generated && Ctor->isCopyConstructor())
    IIK = IIK_Copy;
  else if (Generated && Ctor->isMoveConstructor())
    IIK = IIK_Move;
  else
    IIK = IIK_Default;
}

bool isImplicitCopyOrMove() const {
  switch (IIK) {
  case IIK_Copy:
  case IIK_Move:
    return true;

  case IIK_Default:
  case IIK_Inherit:
    return false;
  }

  llvm_unreachable("Invalid ImplicitInitializerKind!")__builtin_unreachable();
}

bool addFieldInitializer(CXXCtorInitializer *Init) {
  AllToInit.push_back(Init);

  // Check whether this initializer makes the field "used".
  if (Init->getInit()->HasSideEffects(S.Context))
    S.UnusedPrivateFields.remove(Init->getAnyMember());

  return false;
}

bool isInactiveUnionMember(FieldDecl *Field) {
  RecordDecl *Record = Field->getParent();
  if (!Record->isUnion())
    return false;

  if (FieldDecl *Active =
          ActiveUnionMember.lookup(Record->getCanonicalDecl()))
    return Active != Field->getCanonicalDecl();

  // In an implicit copy or move constructor, ignore any in-class initializer.
  if (isImplicitCopyOrMove())
    return true;

  // If there's no explicit initialization, the field is active only if it
  // has an in-class initializer...
  if (Field->hasInClassInitializer())
    return false;
  // ... or it's an anonymous struct or union whose class has an in-class
  // initializer.
  if (!Field->isAnonymousStructOrUnion())
    return true;
  CXXRecordDecl *FieldRD = Field->getType()->getAsCXXRecordDecl();
  return !FieldRD->hasInClassInitializer();
}

/// Determine whether the given field is, or is within, a union member
/// that is inactive (because there was an initializer given for a different
/// member of the union, or because the union was not initialized at all).
bool isWithinInactiveUnionMember(FieldDecl *Field,
                                 IndirectFieldDecl *Indirect) {
  if (!Indirect)
    return isInactiveUnionMember(Field);

  for (auto *C : Indirect->chain()) {
    FieldDecl *Field = dyn_cast<FieldDecl>(C);
    if (Field && isInactiveUnionMember(Field))
      return true;
  }
  return false;
}
4967};
4968}

4970/// Determine whether the given type is an incomplete or zero-lenfgth
4971/// array type.
4972static bool isIncompleteOrZeroLengthArrayType(ASTContext &Context, QualType T) {
if (T->isIncompleteArrayType())
  return true;

while (const ConstantArrayType *ArrayT = Context.getAsConstantArrayType(T)) {
  if (!ArrayT->getSize())
    return true;

  T = ArrayT->getElementType();
}

return false;
4984}

4986static bool CollectFieldInitializer(Sema &SemaRef, BaseAndFieldInfo &Info,
                                  FieldDecl *Field,
                                  IndirectFieldDecl *Indirect = nullptr) {
if (Field->isInvalidDecl())
  return false;

// Overwhelmingly common case: we have a direct initializer for this field.
if (CXXCtorInitializer *Init =
        Info.AllBaseFields.lookup(Field->getCanonicalDecl()))
  return Info.addFieldInitializer(Init);

// C++11 [class.base.init]p8:
//   if the entity is a non-static data member that has a
//   brace-or-equal-initializer and either
//   -- the constructor's class is a union and no other variant member of that
//      union is designated by a mem-initializer-id or
//   -- the constructor's class is not a union, and, if the entity is a member
//      of an anonymous union, no other member of that union is designated by
//      a mem-initializer-id,
//   the entity is initialized as specified in [dcl.init].
//
// We also apply the same rules to handle anonymous structs within anonymous
// unions.
if (Info.isWithinInactiveUnionMember(Field, Indirect))
  return false;

if (Field->hasInClassInitializer() && !Info.isImplicitCopyOrMove()) {
  ExprResult DIE =
      SemaRef.BuildCXXDefaultInitExpr(Info.Ctor->getLocation(), Field);
  if (DIE.isInvalid())
    return true;

  auto Entity = InitializedEntity::InitializeMember(Field, nullptr, true);
  SemaRef.checkInitializerLifetime(Entity, DIE.get());

  CXXCtorInitializer *Init;
  if (Indirect)
    Init = new (SemaRef.Context)
        CXXCtorInitializer(SemaRef.Context, Indirect, SourceLocation(),
                           SourceLocation(), DIE.get(), SourceLocation());
  else
    Init = new (SemaRef.Context)
        CXXCtorInitializer(SemaRef.Context, Field, SourceLocation(),
                           SourceLocation(), DIE.get(), SourceLocation());
  return Info.addFieldInitializer(Init);
}

// Don't initialize incomplete or zero-length arrays.
if (isIncompleteOrZeroLengthArrayType(SemaRef.Context, Field->getType()))
  return false;

// Don't try to build an implicit initializer if there were semantic
// errors in any of the initializers (and therefore we might be
// missing some that the user actually wrote).
if (Info.AnyErrorsInInits)
  return false;

CXXCtorInitializer *Init = nullptr;
if (BuildImplicitMemberInitializer(Info.S, Info.Ctor, Info.IIK, Field,
                                   Indirect, Init))
  return true;

if (!Init)
  return false;

return Info.addFieldInitializer(Init);
5052}

5054bool
5055Sema::SetDelegatingInitializer(CXXConstructorDecl *Constructor,
                             CXXCtorInitializer *Initializer) {
assert(Initializer->isDelegatingInitializer())(static_cast<void> (0));
Constructor->setNumCtorInitializers(1);
CXXCtorInitializer **initializer =
  new (Context) CXXCtorInitializer*[1];
memcpy(initializer, &Initializer, sizeof (CXXCtorInitializer*));
Constructor->setCtorInitializers(initializer);

if (CXXDestructorDecl *Dtor = LookupDestructor(Constructor->getParent())) {
  MarkFunctionReferenced(Initializer->getSourceLocation(), Dtor);
  DiagnoseUseOfDecl(Dtor, Initializer->getSourceLocation());
}

DelegatingCtorDecls.push_back(Constructor);

DiagnoseUninitializedFields(*this, Constructor);

return false;
5074}

5076bool Sema::SetCtorInitializers(CXXConstructorDecl *Constructor, bool AnyErrors,
                             ArrayRef<CXXCtorInitializer *> Initializers) {
if (Constructor->isDependentContext()) {
  // Just store the initializers as written, they will be checked during
  // instantiation.
  if (!Initializers.empty()) {
    Constructor->setNumCtorInitializers(Initializers.size());
    CXXCtorInitializer **baseOrMemberInitializers =
      new (Context) CXXCtorInitializer*[Initializers.size()];
    memcpy(baseOrMemberInitializers, Initializers.data(),
           Initializers.size() * sizeof(CXXCtorInitializer*));
    Constructor->setCtorInitializers(baseOrMemberInitializers);
  }

  // Let template instantiation know whether we had errors.
  if (AnyErrors)
    Constructor->setInvalidDecl();

  return false;
}

BaseAndFieldInfo Info(*this, Constructor, AnyErrors);

// We need to build the initializer AST according to order of construction
// and not what user specified in the Initializers list.
CXXRecordDecl *ClassDecl = Constructor->getParent()->getDefinition();
if (!ClassDecl)
  return true;

bool HadError = false;

for (unsigned i = 0; i < Initializers.size(); i++) {
  CXXCtorInitializer *Member = Initializers[i];

  if (Member->isBaseInitializer())
    Info.AllBaseFields[Member->getBaseClass()->getAs<RecordType>()] = Member;
  else {
    Info.AllBaseFields[Member->getAnyMember()->getCanonicalDecl()] = Member;

    if (IndirectFieldDecl *F = Member->getIndirectMember()) {
      for (auto *C : F->chain()) {
        FieldDecl *FD = dyn_cast<FieldDecl>(C);
        if (FD && FD->getParent()->isUnion())
          Info.ActiveUnionMember.insert(std::make_pair(
              FD->getParent()->getCanonicalDecl(), FD->getCanonicalDecl()));
      }
    } else if (FieldDecl *FD = Member->getMember()) {
      if (FD->getParent()->isUnion())
        Info.ActiveUnionMember.insert(std::make_pair(
            FD->getParent()->getCanonicalDecl(), FD->getCanonicalDecl()));
    }
  }
}

// Keep track of the direct virtual bases.
llvm::SmallPtrSet<CXXBaseSpecifier *, 16> DirectVBases;
for (auto &I : ClassDecl->bases()) {
  if (I.isVirtual())
    DirectVBases.insert(&I);
}

// Push virtual bases before others.
for (auto &VBase : ClassDecl->vbases()) {
  if (CXXCtorInitializer *Value
      = Info.AllBaseFields.lookup(VBase.getType()->getAs<RecordType>())) {
    // [class.base.init]p7, per DR257:
    //   A mem-initializer where the mem-initializer-id names a virtual base
    //   class is ignored during execution of a constructor of any class that
    //   is not the most derived class.
    if (ClassDecl->isAbstract()) {
      // FIXME: Provide a fixit to remove the base specifier. This requires
      // tracking the location of the associated comma for a base specifier.
      Diag(Value->getSourceLocation(), diag::warn_abstract_vbase_init_ignored)
        << VBase.getType() << ClassDecl;
      DiagnoseAbstractType(ClassDecl);
    }

    Info.AllToInit.push_back(Value);
  } else if (!AnyErrors && !ClassDecl->isAbstract()) {
    // [class.base.init]p8, per DR257:
    //   If a given [...] base class is not named by a mem-initializer-id
    //   [...] and the entity is not a virtual base class of an abstract
    //   class, then [...] the entity is default-initialized.
    bool IsInheritedVirtualBase = !DirectVBases.count(&VBase);
    CXXCtorInitializer *CXXBaseInit;
    if (BuildImplicitBaseInitializer(*this, Constructor, Info.IIK,
                                     &VBase, IsInheritedVirtualBase,
                                     CXXBaseInit)) {
      HadError = true;
      continue;
    }

    Info.AllToInit.push_back(CXXBaseInit);
  }
}

// Non-virtual bases.
for (auto &Base : ClassDecl->bases()) {
  // Virtuals are in the virtual base list and already constructed.
  if (Base.isVirtual())
    continue;

  if (CXXCtorInitializer *Value
        = Info.AllBaseFields.lookup(Base.getType()->getAs<RecordType>())) {
    Info.AllToInit.push_back(Value);
  } else if (!AnyErrors) {
    CXXCtorInitializer *CXXBaseInit;
    if (BuildImplicitBaseInitializer(*this, Constructor, Info.IIK,
                                     &Base, /*IsInheritedVirtualBase=*/false,
                                     CXXBaseInit)) {
      HadError = true;
      continue;
    }

    Info.AllToInit.push_back(CXXBaseInit);
  }
}

// Fields.
for (auto *Mem : ClassDecl->decls()) {
  if (auto *F = dyn_cast<FieldDecl>(Mem)) {
    // C++ [class.bit]p2:
    //   A declaration for a bit-field that omits the identifier declares an
    //   unnamed bit-field. Unnamed bit-fields are not members and cannot be
    //   initialized.
    if (F->isUnnamedBitfield())
      continue;

    // If we're not generating the implicit copy/move constructor, then we'll
    // handle anonymous struct/union fields based on their individual
    // indirect fields.
    if (F->isAnonymousStructOrUnion() && !Info.isImplicitCopyOrMove())
      continue;

    if (CollectFieldInitializer(*this, Info, F))
      HadError = true;
    continue;
  }

  // Beyond this point, we only consider default initialization.
  if (Info.isImplicitCopyOrMove())
    continue;

  if (auto *F = dyn_cast<IndirectFieldDecl>(Mem)) {
    if (F->getType()->isIncompleteArrayType()) {
      assert(ClassDecl->hasFlexibleArrayMember() &&(static_cast<void> (0))
             "Incomplete array type is not valid")(static_cast<void> (0));
      continue;
    }

    // Initialize each field of an anonymous struct individually.
    if (CollectFieldInitializer(*this, Info, F->getAnonField(), F))
      HadError = true;

    continue;
  }
}

unsigned NumInitializers = Info.AllToInit.size();
if (NumInitializers > 0) {
  Constructor->setNumCtorInitializers(NumInitializers);
  CXXCtorInitializer **baseOrMemberInitializers =
    new (Context) CXXCtorInitializer*[NumInitializers];
  memcpy(baseOrMemberInitializers, Info.AllToInit.data(),
         NumInitializers * sizeof(CXXCtorInitializer*));
  Constructor->setCtorInitializers(baseOrMemberInitializers);

  // Constructors implicitly reference the base and member
  // destructors.
  MarkBaseAndMemberDestructorsReferenced(Constructor->getLocation(),
                                         Constructor->getParent());
}

return HadError;
5250}

5252static void PopulateKeysForFields(FieldDecl *Field, SmallVectorImpl<const void*> &IdealInits) {
if (const RecordType *RT = Field->getType()->getAs<RecordType>()) {
  const RecordDecl *RD = RT->getDecl();
  if (RD->isAnonymousStructOrUnion()) {
    for (auto *Field : RD->fields())
      PopulateKeysForFields(Field, IdealInits);
    return;
  }
}
IdealInits.push_back(Field->getCanonicalDecl());
5262}

5264static const void *GetKeyForBase(ASTContext &Context, QualType BaseType) {
return Context.getCanonicalType(BaseType).getTypePtr();
5266}

5268static const void *GetKeyForMember(ASTContext &Context,
                                 CXXCtorInitializer *Member) {
if (!Member->isAnyMemberInitializer())
  return GetKeyForBase(Context, QualType(Member->getBaseClass(), 0));

return Member->getAnyMember()->getCanonicalDecl();
5274}

5276static void AddInitializerToDiag(const Sema::SemaDiagnosticBuilder &Diag,
                               const CXXCtorInitializer *Previous,
                               const CXXCtorInitializer *Current) {
if (Previous->isAnyMemberInitializer())
  Diag << 0 << Previous->getAnyMember();
else
  Diag << 1 << Previous->getTypeSourceInfo()->getType();

if (Current->isAnyMemberInitializer())
  Diag << 0 << Current->getAnyMember();
else
  Diag << 1 << Current->getTypeSourceInfo()->getType();
5288}

5290static void DiagnoseBaseOrMemInitializerOrder(
  Sema &SemaRef, const CXXConstructorDecl *Constructor,
  ArrayRef<CXXCtorInitializer *> Inits) {
if (Constructor->getDeclContext()->isDependentContext())
  return;

// Don't check initializers order unless the warning is enabled at the
// location of at least one initializer.
bool ShouldCheckOrder = false;
for (unsigned InitIndex = 0; InitIndex != Inits.size(); ++InitIndex) {
  CXXCtorInitializer *Init = Inits[InitIndex];
  if (!SemaRef.Diags.isIgnored(diag::warn_initializer_out_of_order,
                               Init->getSourceLocation())) {
    ShouldCheckOrder = true;
    break;
  }
}
if (!ShouldCheckOrder)
  return;

// Build the list of bases and members in the order that they'll
// actually be initialized.  The explicit initializers should be in
// this same order but may be missing things.
SmallVector<const void*, 32> IdealInitKeys;

const CXXRecordDecl *ClassDecl = Constructor->getParent();

// 1. Virtual bases.
for (const auto &VBase : ClassDecl->vbases())
  IdealInitKeys.push_back(GetKeyForBase(SemaRef.Context, VBase.getType()));

// 2. Non-virtual bases.
for (const auto &Base : ClassDecl->bases()) {
  if (Base.isVirtual())
    continue;
  IdealInitKeys.push_back(GetKeyForBase(SemaRef.Context, Base.getType()));
}

// 3. Direct fields.
for (auto *Field : ClassDecl->fields()) {
  if (Field->isUnnamedBitfield())
    continue;

  PopulateKeysForFields(Field, IdealInitKeys);
}

unsigned NumIdealInits = IdealInitKeys.size();
unsigned IdealIndex = 0;

// Track initializers that are in an incorrect order for either a warning or
// note if multiple ones occur.
SmallVector<unsigned> WarnIndexes;
// Correlates the index of an initializer in the init-list to the index of
// the field/base in the class.
SmallVector<std::pair<unsigned, unsigned>, 32> CorrelatedInitOrder;

for (unsigned InitIndex = 0; InitIndex != Inits.size(); ++InitIndex) {
  const void *InitKey = GetKeyForMember(SemaRef.Context, Inits[InitIndex]);

  // Scan forward to try to find this initializer in the idealized
  // initializers list.
  for (; IdealIndex != NumIdealInits; ++IdealIndex)
    if (InitKey == IdealInitKeys[IdealIndex])
      break;

  // If we didn't find this initializer, it must be because we
  // scanned past it on a previous iteration.  That can only
  // happen if we're out of order;  emit a warning.
  if (IdealIndex == NumIdealInits && InitIndex) {
    WarnIndexes.push_back(InitIndex);

    // Move back to the initializer's location in the ideal list.
    for (IdealIndex = 0; IdealIndex != NumIdealInits; ++IdealIndex)
      if (InitKey == IdealInitKeys[IdealIndex])
        break;

    assert(IdealIndex < NumIdealInits &&(static_cast<void> (0))
           "initializer not found in initializer list")(static_cast<void> (0));
  }
  CorrelatedInitOrder.emplace_back(IdealIndex, InitIndex);
}

if (WarnIndexes.empty())
  return;

// Sort based on the ideal order, first in the pair.
llvm::sort(CorrelatedInitOrder,
           [](auto &LHS, auto &RHS) { return LHS.first < RHS.first; });

// Introduce a new scope as SemaDiagnosticBuilder needs to be destroyed to
// emit the diagnostic before we can try adding notes.
{
  Sema::SemaDiagnosticBuilder D = SemaRef.Diag(
      Inits[WarnIndexes.front() - 1]->getSourceLocation(),
      WarnIndexes.size() == 1 ? diag::warn_initializer_out_of_order
                              : diag::warn_some_initializers_out_of_order);

  for (unsigned I = 0; I < CorrelatedInitOrder.size(); ++I) {
    if (CorrelatedInitOrder[I].second == I)
      continue;
    // Ideally we would be using InsertFromRange here, but clang doesn't
    // appear to handle InsertFromRange correctly when the source range is
    // modified by another fix-it.
    D << FixItHint::CreateReplacement(
        Inits[I]->getSourceRange(),
        Lexer::getSourceText(
            CharSourceRange::getTokenRange(
                Inits[CorrelatedInitOrder[I].second]->getSourceRange()),
            SemaRef.getSourceManager(), SemaRef.getLangOpts()));
  }

  // If there is only 1 item out of order, the warning expects the name and
  // type of each being added to it.
  if (WarnIndexes.size() == 1) {
    AddInitializerToDiag(D, Inits[WarnIndexes.front() - 1],
                         Inits[WarnIndexes.front()]);
    return;
  }
}
// More than 1 item to warn, create notes letting the user know which ones
// are bad.
for (unsigned WarnIndex : WarnIndexes) {
  const clang::CXXCtorInitializer *PrevInit = Inits[WarnIndex - 1];
  auto D = SemaRef.Diag(PrevInit->getSourceLocation(),
                        diag::note_initializer_out_of_order);
  AddInitializerToDiag(D, PrevInit, Inits[WarnIndex]);
  D << PrevInit->getSourceRange();
}
5418}

5420namespace {
5421bool CheckRedundantInit(Sema &S,
                      CXXCtorInitializer *Init,
                      CXXCtorInitializer *&PrevInit) {
if (!PrevInit) {
  PrevInit = Init;
  return false;
}

if (FieldDecl *Field = Init->getAnyMember())
  S.Diag(Init->getSourceLocation(),
         diag::err_multiple_mem_initialization)
    << Field->getDeclName()
    << Init->getSourceRange();
else {
  const Type *BaseClass = Init->getBaseClass();
  assert(BaseClass && "neither field nor base")(static_cast<void> (0));
  S.Diag(Init->getSourceLocation(),
         diag::err_multiple_base_initialization)
    << QualType(BaseClass, 0)
    << Init->getSourceRange();
}
S.Diag(PrevInit->getSourceLocation(), diag::note_previous_initializer)
  << 0 << PrevInit->getSourceRange();

return true;
5446}

5448typedef std::pair<NamedDecl *, CXXCtorInitializer *> UnionEntry;
5449typedef llvm::DenseMap<RecordDecl*, UnionEntry> RedundantUnionMap;

5451bool CheckRedundantUnionInit(Sema &S,
                           CXXCtorInitializer *Init,
                           RedundantUnionMap &Unions) {
FieldDecl *Field = Init->getAnyMember();
RecordDecl *Parent = Field->getParent();
NamedDecl *Child = Field;

while (Parent->isAnonymousStructOrUnion() || Parent->isUnion()) {
  if (Parent->isUnion()) {
    UnionEntry &En = Unions[Parent];
    if (En.first && En.first != Child) {
      S.Diag(Init->getSourceLocation(),
             diag::err_multiple_mem_union_initialization)
        << Field->getDeclName()
        << Init->getSourceRange();
      S.Diag(En.second->getSourceLocation(), diag::note_previous_initializer)
        << 0 << En.second->getSourceRange();
      return true;
    }
    if (!En.first) {
      En.first = Child;
      En.second = Init;
    }
    if (!Parent->isAnonymousStructOrUnion())
      return false;
  }

  Child = Parent;
  Parent = cast<RecordDecl>(Parent->getDeclContext());
}

return false;
5483}
5484} // namespace

5486/// ActOnMemInitializers - Handle the member initializers for a constructor.
5487void Sema::ActOnMemInitializers(Decl *ConstructorDecl,
                              SourceLocation ColonLoc,
                              ArrayRef<CXXCtorInitializer*> MemInits,
                              bool AnyErrors) {
if (!ConstructorDecl)
  return;

AdjustDeclIfTemplate(ConstructorDecl);

CXXConstructorDecl *Constructor
  = dyn_cast<CXXConstructorDecl>(ConstructorDecl);

if (!Constructor) {
  Diag(ColonLoc, diag::err_only_constructors_take_base_inits);
  return;
}

// Mapping for the duplicate initializers check.
// For member initializers, this is keyed with a FieldDecl*.
// For base initializers, this is keyed with a Type*.
llvm::DenseMap<const void *, CXXCtorInitializer *> Members;

// Mapping for the inconsistent anonymous-union initializers check.
RedundantUnionMap MemberUnions;

bool HadError = false;
for (unsigned i = 0; i < MemInits.size(); i++) {
  CXXCtorInitializer *Init = MemInits[i];

  // Set the source order index.
  Init->setSourceOrder(i);

  if (Init->isAnyMemberInitializer()) {
    const void *Key = GetKeyForMember(Context, Init);
    if (CheckRedundantInit(*this, Init, Members[Key]) ||
        CheckRedundantUnionInit(*this, Init, MemberUnions))
      HadError = true;
  } else if (Init->isBaseInitializer()) {
    const void *Key = GetKeyForMember(Context, Init);
    if (CheckRedundantInit(*this, Init, Members[Key]))
      HadError = true;
  } else {
    assert(Init->isDelegatingInitializer())(static_cast<void> (0));
    // This must be the only initializer
    if (MemInits.size() != 1) {
      Diag(Init->getSourceLocation(),
           diag::err_delegating_initializer_alone)
        << Init->getSourceRange() << MemInits[i ? 0 : 1]->getSourceRange();
      // We will treat this as being the only initializer.
    }
    SetDelegatingInitializer(Constructor, MemInits[i]);
    // Return immediately as the initializer is set.
    return;
  }
}

if (HadError)
  return;

DiagnoseBaseOrMemInitializerOrder(*this, Constructor, MemInits);

SetCtorInitializers(Constructor, AnyErrors, MemInits);

DiagnoseUninitializedFields(*this, Constructor);
5551}

5553void
5554Sema::MarkBaseAndMemberDestructorsReferenced(SourceLocation Location,
                                           CXXRecordDecl *ClassDecl) {
// Ignore dependent contexts. Also ignore unions, since their members never
// have destructors implicitly called.
if (ClassDecl->isDependentContext() || ClassDecl->isUnion())
  return;

// FIXME: all the access-control diagnostics are positioned on the
// field/base declaration.  That's probably good; that said, the
// user might reasonably want to know why the destructor is being
// emitted, and we currently don't say.

// Non-static data members.
for (auto *Field : ClassDecl->fields()) {
  if (Field->isInvalidDecl())
    continue;

  // Don't destroy incomplete or zero-length arrays.
  if (isIncompleteOrZeroLengthArrayType(Context, Field->getType()))
    continue;

  QualType FieldType = Context.getBaseElementType(Field->getType());

  const RecordType* RT = FieldType->getAs<RecordType>();
  if (!RT)
    continue;

  CXXRecordDecl *FieldClassDecl = cast<CXXRecordDecl>(RT->getDecl());
  if (FieldClassDecl->isInvalidDecl())
    continue;
  if (FieldClassDecl->hasIrrelevantDestructor())
    continue;
  // The destructor for an implicit anonymous union member is never invoked.
  if (FieldClassDecl->isUnion() && FieldClassDecl->isAnonymousStructOrUnion())
    continue;

  CXXDestructorDecl *Dtor = LookupDestructor(FieldClassDecl);
  assert(Dtor && "No dtor found for FieldClassDecl!")(static_cast<void> (0));
  CheckDestructorAccess(Field->getLocation(), Dtor,
                        PDiag(diag::err_access_dtor_field)
                          << Field->getDeclName()
                          << FieldType);

  MarkFunctionReferenced(Location, Dtor);
  DiagnoseUseOfDecl(Dtor, Location);
}

// We only potentially invoke the destructors of potentially constructed
// subobjects.
bool VisitVirtualBases = !ClassDecl->isAbstract();

// If the destructor exists and has already been marked used in the MS ABI,
// then virtual base destructors have already been checked and marked used.
// Skip checking them again to avoid duplicate diagnostics.
if (Context.getTargetInfo().getCXXABI().isMicrosoft()) {
  CXXDestructorDecl *Dtor = ClassDecl->getDestructor();
  if (Dtor && Dtor->isUsed())
    VisitVirtualBases = false;
}

llvm::SmallPtrSet<const RecordType *, 8> DirectVirtualBases;

// Bases.
for (const auto &Base : ClassDecl->bases()) {
  const RecordType *RT = Base.getType()->getAs<RecordType>();
  if (!RT)
    continue;

  // Remember direct virtual bases.
  if (Base.isVirtual()) {
    if (!VisitVirtualBases)
      continue;
    DirectVirtualBases.insert(RT);
  }

  CXXRecordDecl *BaseClassDecl = cast<CXXRecordDecl>(RT->getDecl());
  // If our base class is invalid, we probably can't get its dtor anyway.
  if (BaseClassDecl->isInvalidDecl())
    continue;
  if (BaseClassDecl->hasIrrelevantDestructor())
    continue;

  CXXDestructorDecl *Dtor = LookupDestructor(BaseClassDecl);
  assert(Dtor && "No dtor found for BaseClassDecl!")(static_cast<void> (0));

  // FIXME: caret should be on the start of the class name
  CheckDestructorAccess(Base.getBeginLoc(), Dtor,
                        PDiag(diag::err_access_dtor_base)
                            << Base.getType() << Base.getSourceRange(),
                        Context.getTypeDeclType(ClassDecl));

  MarkFunctionReferenced(Location, Dtor);
  DiagnoseUseOfDecl(Dtor, Location);
}

if (VisitVirtualBases)
  MarkVirtualBaseDestructorsReferenced(Location, ClassDecl,
                                       &DirectVirtualBases);
5652}

5654void Sema::MarkVirtualBaseDestructorsReferenced(
  SourceLocation Location, CXXRecordDecl *ClassDecl,
  llvm::SmallPtrSetImpl<const RecordType *> *DirectVirtualBases) {
// Virtual bases.
for (const auto &VBase : ClassDecl->vbases()) {
  // Bases are always records in a well-formed non-dependent class.
  const RecordType *RT = VBase.getType()->castAs<RecordType>();

  // Ignore already visited direct virtual bases.
  if (DirectVirtualBases && DirectVirtualBases->count(RT))
    continue;

  CXXRecordDecl *BaseClassDecl = cast<CXXRecordDecl>(RT->getDecl());
  // If our base class is invalid, we probably can't get its dtor anyway.
  if (BaseClassDecl->isInvalidDecl())
    continue;
  if (BaseClassDecl->hasIrrelevantDestructor())
    continue;

  CXXDestructorDecl *Dtor = LookupDestructor(BaseClassDecl);
  assert(Dtor && "No dtor found for BaseClassDecl!")(static_cast<void> (0));
  if (CheckDestructorAccess(
          ClassDecl->getLocation(), Dtor,
          PDiag(diag::err_access_dtor_vbase)
              << Context.getTypeDeclType(ClassDecl) << VBase.getType(),
          Context.getTypeDeclType(ClassDecl)) ==
      AR_accessible) {
    CheckDerivedToBaseConversion(
        Context.getTypeDeclType(ClassDecl), VBase.getType(),
        diag::err_access_dtor_vbase, 0, ClassDecl->getLocation(),
        SourceRange(), DeclarationName(), nullptr);
  }

  MarkFunctionReferenced(Location, Dtor);
  DiagnoseUseOfDecl(Dtor, Location);
}
5690}

5692void Sema::ActOnDefaultCtorInitializers(Decl *CDtorDecl) {
if (!CDtorDecl)
  return;

if (CXXConstructorDecl *Constructor
    = dyn_cast<CXXConstructorDecl>(CDtorDecl)) {
  SetCtorInitializers(Constructor, /*AnyErrors=*/false);
  DiagnoseUninitializedFields(*this, Constructor);
}
5701}

5703bool Sema::isAbstractType(SourceLocation Loc, QualType T) {
if (!getLangOpts().CPlusPlus)
  return false;

const auto *RD = Context.getBaseElementType(T)->getAsCXXRecordDecl();
if (!RD)
  return false;

// FIXME: Per [temp.inst]p1, we are supposed to trigger instantiation of a
// class template specialization here, but doing so breaks a lot of code.

// We can't answer whether something is abstract until it has a
// definition. If it's currently being defined, we'll walk back
// over all the declarations when we have a full definition.
const CXXRecordDecl *Def = RD->getDefinition();
if (!Def || Def->isBeingDefined())
  return false;

return RD->isAbstract();
5722}

5724bool Sema::RequireNonAbstractType(SourceLocation Loc, QualType T,
                                TypeDiagnoser &Diagnoser) {
if (!isAbstractType(Loc, T))
  return false;

T = Context.getBaseElementType(T);
Diagnoser.diagnose(*this, Loc, T);
DiagnoseAbstractType(T->getAsCXXRecordDecl());
return true;
5733}

5735void Sema::DiagnoseAbstractType(const CXXRecordDecl *RD) {
// Check if we've already emitted the list of pure virtual functions
// for this class.
if (PureVirtualClassDiagSet && PureVirtualClassDiagSet->count(RD))
  return;

// If the diagnostic is suppressed, don't emit the notes. We're only
// going to emit them once, so try to attach them to a diagnostic we're
// actually going to show.
if (Diags.isLastDiagnosticIgnored())
  return;

CXXFinalOverriderMap FinalOverriders;
RD->getFinalOverriders(FinalOverriders);

// Keep a set of seen pure methods so we won't diagnose the same method
// more than once.
llvm::SmallPtrSet<const CXXMethodDecl *, 8> SeenPureMethods;

for (CXXFinalOverriderMap::iterator M = FinalOverriders.begin(),
                                 MEnd = FinalOverriders.end();
     M != MEnd;
     ++M) {
  for (OverridingMethods::iterator SO = M->second.begin(),
                                SOEnd = M->second.end();
       SO != SOEnd; ++SO) {
    // C++ [class.abstract]p4:
    //   A class is abstract if it contains or inherits at least one
    //   pure virtual function for which the final overrider is pure
    //   virtual.

    //
    if (SO->second.size() != 1)
      continue;

    if (!SO->second.front().Method->isPure())
      continue;

    if (!SeenPureMethods.insert(SO->second.front().Method).second)
      continue;

    Diag(SO->second.front().Method->getLocation(),
         diag::note_pure_virtual_function)
      << SO->second.front().Method->getDeclName() << RD->getDeclName();
  }
}

if (!PureVirtualClassDiagSet)
  PureVirtualClassDiagSet.reset(new RecordDeclSetTy);
PureVirtualClassDiagSet->insert(RD);
5785}

5787namespace {
5788struct AbstractUsageInfo {
Sema &S;
CXXRecordDecl *Record;
CanQualType AbstractType;
bool Invalid;

AbstractUsageInfo(Sema &S, CXXRecordDecl *Record)
  : S(S), Record(Record),
    AbstractType(S.Context.getCanonicalType(
                 S.Context.getTypeDeclType(Record))),
    Invalid(false) {}

void DiagnoseAbstractType() {
  if (Invalid) return;
  S.DiagnoseAbstractType(Record);
  Invalid = true;
}

void CheckType(const NamedDecl *D, TypeLoc TL, Sema::AbstractDiagSelID Sel);
5807};

5809struct CheckAbstractUsage {
AbstractUsageInfo &Info;
const NamedDecl *Ctx;

CheckAbstractUsage(AbstractUsageInfo &Info, const NamedDecl *Ctx)
  : Info(Info), Ctx(Ctx) {}

void Visit(TypeLoc TL, Sema::AbstractDiagSelID Sel) {
  switch (TL.getTypeLocClass()) {
5818#define ABSTRACT_TYPELOC(CLASS, PARENT)
5819#define TYPELOC(CLASS, PARENT) \
  case TypeLoc::CLASS: Check(TL.castAs<CLASS##TypeLoc>(), Sel); break;
5821#include "clang/AST/TypeLocNodes.def"
  }
}

void Check(FunctionProtoTypeLoc TL, Sema::AbstractDiagSelID Sel) {
  Visit(TL.getReturnLoc(), Sema::AbstractReturnType);
  for (unsigned I = 0, E = TL.getNumParams(); I != E; ++I) {
    if (!TL.getParam(I))
      continue;

    TypeSourceInfo *TSI = TL.getParam(I)->getTypeSourceInfo();
    if (TSI) Visit(TSI->getTypeLoc(), Sema::AbstractParamType);
  }
}

void Check(ArrayTypeLoc TL, Sema::AbstractDiagSelID Sel) {
  Visit(TL.getElementLoc(), Sema::AbstractArrayType);
}

void Check(TemplateSpecializationTypeLoc TL, Sema::AbstractDiagSelID Sel) {
  // Visit the type parameters from a permissive context.
  for (unsigned I = 0, E = TL.getNumArgs(); I != E; ++I) {
    TemplateArgumentLoc TAL = TL.getArgLoc(I);
    if (TAL.getArgument().getKind() == TemplateArgument::Type)
      if (TypeSourceInfo *TSI = TAL.getTypeSourceInfo())
        Visit(TSI->getTypeLoc(), Sema::AbstractNone);
    // TODO: other template argument types?
  }
}

// Visit pointee types from a permissive context.
5852#define CheckPolymorphic(Type)void Check(Type TL, Sema::AbstractDiagSelID Sel) { Visit(TL.getNextTypeLoc
(), Sema::AbstractNone); } \
void Check(Type TL, Sema::AbstractDiagSelID Sel) { \
  Visit(TL.getNextTypeLoc(), Sema::AbstractNone); \
}
CheckPolymorphic(PointerTypeLoc)void Check(PointerTypeLoc TL, Sema::AbstractDiagSelID Sel) { Visit
(TL.getNextTypeLoc(), Sema::AbstractNone); }
CheckPolymorphic(ReferenceTypeLoc)void Check(ReferenceTypeLoc TL, Sema::AbstractDiagSelID Sel) {
 Visit(TL.getNextTypeLoc(), Sema::AbstractNone); }
CheckPolymorphic(MemberPointerTypeLoc)void Check(MemberPointerTypeLoc TL, Sema::AbstractDiagSelID Sel
) { Visit(TL.getNextTypeLoc(), Sema::AbstractNone); }
CheckPolymorphic(BlockPointerTypeLoc)void Check(BlockPointerTypeLoc TL, Sema::AbstractDiagSelID Sel
) { Visit(TL.getNextTypeLoc(), Sema::AbstractNone); }
CheckPolymorphic(AtomicTypeLoc)void Check(AtomicTypeLoc TL, Sema::AbstractDiagSelID Sel) { Visit
(TL.getNextTypeLoc(), Sema::AbstractNone); }

/// Handle all the types we haven't given a more specific
/// implementation for above.
void Check(TypeLoc TL, Sema::AbstractDiagSelID Sel) {
  // Every other kind of type that we haven't called out already
  // that has an inner type is either (1) sugar or (2) contains that
  // inner type in some way as a subobject.
  if (TypeLoc Next = TL.getNextTypeLoc())
    return Visit(Next, Sel);

  // If there's no inner type and we're in a permissive context,
  // don't diagnose.
  if (Sel == Sema::AbstractNone) return;

  // Check whether the type matches the abstract type.
  QualType T = TL.getType();
  if (T->isArrayType()) {
    Sel = Sema::AbstractArrayType;
    T = Info.S.Context.getBaseElementType(T);
  }
  CanQualType CT = T->getCanonicalTypeUnqualified().getUnqualifiedType();
  if (CT != Info.AbstractType) return;

  // It matched; do some magic.
  if (Sel == Sema::AbstractArrayType) {
    Info.S.Diag(Ctx->getLocation(), diag::err_array_of_abstract_type)
      << T << TL.getSourceRange();
  } else {
    Info.S.Diag(Ctx->getLocation(), diag::err_abstract_type_in_decl)
      << Sel << T << TL.getSourceRange();
  }
  Info.DiagnoseAbstractType();
}
5894};

5896void AbstractUsageInfo::CheckType(const NamedDecl *D, TypeLoc TL,
                                Sema::AbstractDiagSelID Sel) {
CheckAbstractUsage(*this, D).Visit(TL, Sel);
5899}

5901}

5903/// Check for invalid uses of an abstract type in a method declaration.
5904static void CheckAbstractClassUsage(AbstractUsageInfo &Info,
                                  CXXMethodDecl *MD) {
// No need to do the check on definitions, which require that
// the return/param types be complete.
if (MD->doesThisDeclarationHaveABody())
  return;

// For safety's sake, just ignore it if we don't have type source
// information.  This should never happen for non-implicit methods,
// but...
if (TypeSourceInfo *TSI = MD->getTypeSourceInfo())
  Info.CheckType(MD, TSI->getTypeLoc(), Sema::AbstractNone);
5916}

5918/// Check for invalid uses of an abstract type within a class definition.
5919static void CheckAbstractClassUsage(AbstractUsageInfo &Info,
                                  CXXRecordDecl *RD) {
for (auto *D : RD->decls()) {
  if (D->isImplicit()) continue;

  // Methods and method templates.
  if (isa<CXXMethodDecl>(D)) {
    CheckAbstractClassUsage(Info, cast<CXXMethodDecl>(D));
  } else if (isa<FunctionTemplateDecl>(D)) {
    FunctionDecl *FD = cast<FunctionTemplateDecl>(D)->getTemplatedDecl();
    CheckAbstractClassUsage(Info, cast<CXXMethodDecl>(FD));

  // Fields and static variables.
  } else if (isa<FieldDecl>(D)) {
    FieldDecl *FD = cast<FieldDecl>(D);
    if (TypeSourceInfo *TSI = FD->getTypeSourceInfo())
      Info.CheckType(FD, TSI->getTypeLoc(), Sema::AbstractFieldType);
  } else if (isa<VarDecl>(D)) {
    VarDecl *VD = cast<VarDecl>(D);
    if (TypeSourceInfo *TSI = VD->getTypeSourceInfo())
      Info.CheckType(VD, TSI->getTypeLoc(), Sema::AbstractVariableType);

  // Nested classes and class templates.
  } else if (isa<CXXRecordDecl>(D)) {
    CheckAbstractClassUsage(Info, cast<CXXRecordDecl>(D));
  } else if (isa<ClassTemplateDecl>(D)) {
    CheckAbstractClassUsage(Info,
                           cast<ClassTemplateDecl>(D)->getTemplatedDecl());
  }
}
5949}

5951static void ReferenceDllExportedMembers(Sema &S, CXXRecordDecl *Class) {
Attr *ClassAttr = getDLLAttr(Class);
if (!ClassAttr)
  return;

assert(ClassAttr->getKind() == attr::DLLExport)(static_cast<void> (0));

TemplateSpecializationKind TSK = Class->getTemplateSpecializationKind();

if (TSK == TSK_ExplicitInstantiationDeclaration)
  // Don't go any further if this is just an explicit instantiation
  // declaration.
  return;

// Add a context note to explain how we got to any diagnostics produced below.
struct MarkingClassDllexported {
  Sema &S;
  MarkingClassDllexported(Sema &S, CXXRecordDecl *Class,
                          SourceLocation AttrLoc)
      : S(S) {
    Sema::CodeSynthesisContext Ctx;
    Ctx.Kind = Sema::CodeSynthesisContext::MarkingClassDllexported;
    Ctx.PointOfInstantiation = AttrLoc;
    Ctx.Entity = Class;
    S.pushCodeSynthesisContext(Ctx);
  }
  ~MarkingClassDllexported() {
    S.popCodeSynthesisContext();
  }
} MarkingDllexportedContext(S, Class, ClassAttr->getLocation());

if (S.Context.getTargetInfo().getTriple().isWindowsGNUEnvironment())
  S.MarkVTableUsed(Class->getLocation(), Class, true);

for (Decl *Member : Class->decls()) {
  // Skip members that were not marked exported.
  if (!Member->hasAttr<DLLExportAttr>())
    continue;

  // Defined static variables that are members of an exported base
  // class must be marked export too.
  auto *VD = dyn_cast<VarDecl>(Member);
  if (VD && VD->getStorageClass() == SC_Static &&
      TSK == TSK_ImplicitInstantiation)
    S.MarkVariableReferenced(VD->getLocation(), VD);

  auto *MD = dyn_cast<CXXMethodDecl>(Member);
  if (!MD)
    continue;

  if (MD->isUserProvided()) {
    // Instantiate non-default class member functions ...

    // .. except for certain kinds of template specializations.
    if (TSK == TSK_ImplicitInstantiation && !ClassAttr->isInherited())
      continue;

    // If this is an MS ABI dllexport default constructor, instantiate any
    // default arguments.
    if (S.Context.getTargetInfo().getCXXABI().isMicrosoft()) {
      auto *CD = dyn_cast<CXXConstructorDecl>(MD);
      if (CD && CD->isDefaultConstructor() && TSK == TSK_Undeclared) {
        S.InstantiateDefaultCtorDefaultArgs(CD);
      }
    }

    S.MarkFunctionReferenced(Class->getLocation(), MD);

    // The function will be passed to the consumer when its definition is
    // encountered.
  } else if (MD->isExplicitlyDefaulted()) {
    // Synthesize and instantiate explicitly defaulted methods.
    S.MarkFunctionReferenced(Class->getLocation(), MD);

    if (TSK != TSK_ExplicitInstantiationDefinition) {
      // Except for explicit instantiation defs, we will not see the
      // definition again later, so pass it to the consumer now.
      S.Consumer.HandleTopLevelDecl(DeclGroupRef(MD));
    }
  } else if (!MD->isTrivial() ||
             MD->isCopyAssignmentOperator() ||
             MD->isMoveAssignmentOperator()) {
    // Synthesize and instantiate non-trivial implicit methods, and the copy
    // and move assignment operators. The latter are exported even if they
    // are trivial, because the address of an operator can be taken and
    // should compare equal across libraries.
    S.MarkFunctionReferenced(Class->getLocation(), MD);

    // There is no later point when we will see the definition of this
    // function, so pass it to the consumer now.
    S.Consumer.HandleTopLevelDecl(DeclGroupRef(MD));
  }
}
6044}

6046static void checkForMultipleExportedDefaultConstructors(Sema &S,
                                                      CXXRecordDecl *Class) {
// Only the MS ABI has default constructor closures, so we don't need to do
// this semantic checking anywhere else.
if (!S.Context.getTargetInfo().getCXXABI().isMicrosoft())
  return;

CXXConstructorDecl *LastExportedDefaultCtor = nullptr;
for (Decl *Member : Class->decls()) {
  // Look for exported default constructors.
  auto *CD = dyn_cast<CXXConstructorDecl>(Member);
  if (!CD || !CD->isDefaultConstructor())
    continue;
  auto *Attr = CD->getAttr<DLLExportAttr>();
  if (!Attr)
    continue;

  // If the class is non-dependent, mark the default arguments as ODR-used so
  // that we can properly codegen the constructor closure.
  if (!Class->isDependentContext()) {
    for (ParmVarDecl *PD : CD->parameters()) {
      (void)S.CheckCXXDefaultArgExpr(Attr->getLocation(), CD, PD);
      S.DiscardCleanupsInEvaluationContext();
    }
  }

  if (LastExportedDefaultCtor) {
    S.Diag(LastExportedDefaultCtor->getLocation(),
           diag::err_attribute_dll_ambiguous_default_ctor)
        << Class;
    S.Diag(CD->getLocation(), diag::note_entity_declared_at)
        << CD->getDeclName();
    return;
  }
  LastExportedDefaultCtor = CD;
}
6082}

6084static void checkCUDADeviceBuiltinSurfaceClassTemplate(Sema &S,
                                                     CXXRecordDecl *Class) {
bool ErrorReported = false;
auto reportIllegalClassTemplate = [&ErrorReported](Sema &S,
                                                   ClassTemplateDecl *TD) {
  if (ErrorReported)
    return;
  S.Diag(TD->getLocation(),
         diag::err_cuda_device_builtin_surftex_cls_template)
      << /*surface*/ 0 << TD;
  ErrorReported = true;
};

ClassTemplateDecl *TD = Class->getDescribedClassTemplate();
if (!TD) {
  auto *SD = dyn_cast<ClassTemplateSpecializationDecl>(Class);
  if (!SD) {
    S.Diag(Class->getLocation(),
           diag::err_cuda_device_builtin_surftex_ref_decl)
        << /*surface*/ 0 << Class;
    S.Diag(Class->getLocation(),
           diag::note_cuda_device_builtin_surftex_should_be_template_class)
        << Class;
    return;
  }
  TD = SD->getSpecializedTemplate();
}

TemplateParameterList *Params = TD->getTemplateParameters();
unsigned N = Params->size();

if (N != 2) {
  reportIllegalClassTemplate(S, TD);
  S.Diag(TD->getLocation(),
         diag::note_cuda_device_builtin_surftex_cls_should_have_n_args)
      << TD << 2;
}
if (N > 0 && !isa<TemplateTypeParmDecl>(Params->getParam(0))) {
  reportIllegalClassTemplate(S, TD);
  S.Diag(TD->getLocation(),
         diag::note_cuda_device_builtin_surftex_cls_should_have_match_arg)
      << TD << /*1st*/ 0 << /*type*/ 0;
}
if (N > 1) {
  auto *NTTP = dyn_cast<NonTypeTemplateParmDecl>(Params->getParam(1));
  if (!NTTP || !NTTP->getType()->isIntegralOrEnumerationType()) {
    reportIllegalClassTemplate(S, TD);
    S.Diag(TD->getLocation(),
           diag::note_cuda_device_builtin_surftex_cls_should_have_match_arg)
        << TD << /*2nd*/ 1 << /*integer*/ 1;
  }
}
6136}

6138static void checkCUDADeviceBuiltinTextureClassTemplate(Sema &S,
                                                     CXXRecordDecl *Class) {
bool ErrorReported = false;
auto reportIllegalClassTemplate = [&ErrorReported](Sema &S,
                                                   ClassTemplateDecl *TD) {
  if (ErrorReported)
    return;
  S.Diag(TD->getLocation(),
         diag::err_cuda_device_builtin_surftex_cls_template)
      << /*texture*/ 1 << TD;
  ErrorReported = true;
};

ClassTemplateDecl *TD = Class->getDescribedClassTemplate();
if (!TD) {
  auto *SD = dyn_cast<ClassTemplateSpecializationDecl>(Class);
  if (!SD) {
    S.Diag(Class->getLocation(),
           diag::err_cuda_device_builtin_surftex_ref_decl)
        << /*texture*/ 1 << Class;
    S.Diag(Class->getLocation(),
           diag::note_cuda_device_builtin_surftex_should_be_template_class)
        << Class;
    return;
  }
  TD = SD->getSpecializedTemplate();
}

TemplateParameterList *Params = TD->getTemplateParameters();
unsigned N = Params->size();

if (N != 3) {
  reportIllegalClassTemplate(S, TD);
  S.Diag(TD->getLocation(),
         diag::note_cuda_device_builtin_surftex_cls_should_have_n_args)
      << TD << 3;
}
if (N > 0 && !isa<TemplateTypeParmDecl>(Params->getParam(0))) {
  reportIllegalClassTemplate(S, TD);
  S.Diag(TD->getLocation(),
         diag::note_cuda_device_builtin_surftex_cls_should_have_match_arg)
      << TD << /*1st*/ 0 << /*type*/ 0;
}
if (N > 1) {
  auto *NTTP = dyn_cast<NonTypeTemplateParmDecl>(Params->getParam(1));
  if (!NTTP || !NTTP->getType()->isIntegralOrEnumerationType()) {
    reportIllegalClassTemplate(S, TD);
    S.Diag(TD->getLocation(),
           diag::note_cuda_device_builtin_surftex_cls_should_have_match_arg)
        << TD << /*2nd*/ 1 << /*integer*/ 1;
  }
}
if (N > 2) {
  auto *NTTP = dyn_cast<NonTypeTemplateParmDecl>(Params->getParam(2));
  if (!NTTP || !NTTP->getType()->isIntegralOrEnumerationType()) {
    reportIllegalClassTemplate(S, TD);
    S.Diag(TD->getLocation(),
           diag::note_cuda_device_builtin_surftex_cls_should_have_match_arg)
        << TD << /*3rd*/ 2 << /*integer*/ 1;
  }
}
6199}

6201void Sema::checkClassLevelCodeSegAttribute(CXXRecordDecl *Class) {
// Mark any compiler-generated routines with the implicit code_seg attribute.
for (auto *Method : Class->methods()) {
  if (Method->isUserProvided())
    continue;
  if (Attr *A = getImplicitCodeSegOrSectionAttrForFunction(Method, /*IsDefinition=*/true))
    Method->addAttr(A);
}
6209}

6211/// Check class-level dllimport/dllexport attribute.
6212void Sema::checkClassLevelDLLAttribute(CXXRecordDecl *Class) {
Attr *ClassAttr = getDLLAttr(Class);

// MSVC inherits DLL attributes to partial class template specializations.
if (Context.getTargetInfo().shouldDLLImportComdatSymbols() && !ClassAttr) {
  if (auto *Spec = dyn_cast<ClassTemplatePartialSpecializationDecl>(Class)) {
    if (Attr *TemplateAttr =
            getDLLAttr(Spec->getSpecializedTemplate()->getTemplatedDecl())) {
      auto *A = cast<InheritableAttr>(TemplateAttr->clone(getASTContext()));
      A->setInherited(true);
      ClassAttr = A;
    }
  }
}

if (!ClassAttr)
  return;

if (!Class->isExternallyVisible()) {
  Diag(Class->getLocation(), diag::err_attribute_dll_not_extern)
      << Class << ClassAttr;
  return;
}

if (Context.getTargetInfo().shouldDLLImportComdatSymbols() &&
    !ClassAttr->isInherited()) {
  // Diagnose dll attributes on members of class with dll attribute.
  for (Decl *Member : Class->decls()) {
    if (!isa<VarDecl>(Member) && !isa<CXXMethodDecl>(Member))
      continue;
    InheritableAttr *MemberAttr = getDLLAttr(Member);
    if (!MemberAttr || MemberAttr->isInherited() || Member->isInvalidDecl())
      continue;

    Diag(MemberAttr->getLocation(),
           diag::err_attribute_dll_member_of_dll_class)
        << MemberAttr << ClassAttr;
    Diag(ClassAttr->getLocation(), diag::note_previous_attribute);
    Member->setInvalidDecl();
  }
}

if (Class->getDescribedClassTemplate())
  // Don't inherit dll attribute until the template is instantiated.
  return;

// The class is either imported or exported.
const bool ClassExported = ClassAttr->getKind() == attr::DLLExport;

// Check if this was a dllimport attribute propagated from a derived class to
// a base class template specialization. We don't apply these attributes to
// static data members.
const bool PropagatedImport =
    !ClassExported &&
    cast<DLLImportAttr>(ClassAttr)->wasPropagatedToBaseTemplate();

TemplateSpecializationKind TSK = Class->getTemplateSpecializationKind();

// Ignore explicit dllexport on explicit class template instantiation
// declarations, except in MinGW mode.
if (ClassExported && !ClassAttr->isInherited() &&
    TSK == TSK_ExplicitInstantiationDeclaration &&
    !Context.getTargetInfo().getTriple().isWindowsGNUEnvironment()) {
  Class->dropAttr<DLLExportAttr>();
  return;
}

// Force declaration of implicit members so they can inherit the attribute.
ForceDeclarationOfImplicitMembers(Class);

// FIXME: MSVC's docs say all bases must be exportable, but this doesn't
// seem to be true in practice?

for (Decl *Member : Class->decls()) {
  VarDecl *VD = dyn_cast<VarDecl>(Member);
  CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(Member);

  // Only methods and static fields inherit the attributes.
  if (!VD && !MD)
    continue;

  if (MD) {
    // Don't process deleted methods.
    if (MD->isDeleted())
      continue;

    if (MD->isInlined()) {
      // MinGW does not import or export inline methods. But do it for
      // template instantiations.
      if (!Context.getTargetInfo().shouldDLLImportComdatSymbols() &&
          TSK != TSK_ExplicitInstantiationDeclaration &&
          TSK != TSK_ExplicitInstantiationDefinition)
        continue;

      // MSVC versions before 2015 don't export the move assignment operators
      // and move constructor, so don't attempt to import/export them if
      // we have a definition.
      auto *Ctor = dyn_cast<CXXConstructorDecl>(MD);
      if ((MD->isMoveAssignmentOperator() ||
           (Ctor && Ctor->isMoveConstructor())) &&
          !getLangOpts().isCompatibleWithMSVC(LangOptions::MSVC2015))
        continue;

      // MSVC2015 doesn't export trivial defaulted x-tor but copy assign
      // operator is exported anyway.
      if (getLangOpts().isCompatibleWithMSVC(LangOptions::MSVC2015) &&
          (Ctor || isa<CXXDestructorDecl>(MD)) && MD->isTrivial())
        continue;
    }
  }

  // Don't apply dllimport attributes to static data members of class template
  // instantiations when the attribute is propagated from a derived class.
  if (VD && PropagatedImport)
    continue;

  if (!cast<NamedDecl>(Member)->isExternallyVisible())
    continue;

  if (!getDLLAttr(Member)) {
    InheritableAttr *NewAttr = nullptr;

    // Do not export/import inline function when -fno-dllexport-inlines is
    // passed. But add attribute for later local static var check.
    if (!getLangOpts().DllExportInlines && MD && MD->isInlined() &&
        TSK != TSK_ExplicitInstantiationDeclaration &&
        TSK != TSK_ExplicitInstantiationDefinition) {
      if (ClassExported) {
        NewAttr = ::new (getASTContext())
            DLLExportStaticLocalAttr(getASTContext(), *ClassAttr);
      } else {
        NewAttr = ::new (getASTContext())
            DLLImportStaticLocalAttr(getASTContext(), *ClassAttr);
      }
    } else {
      NewAttr = cast<InheritableAttr>(ClassAttr->clone(getASTContext()));
    }

    NewAttr->setInherited(true);
    Member->addAttr(NewAttr);

    if (MD) {
      // Propagate DLLAttr to friend re-declarations of MD that have already
      // been constructed.
      for (FunctionDecl *FD = MD->getMostRecentDecl(); FD;
           FD = FD->getPreviousDecl()) {
        if (FD->getFriendObjectKind() == Decl::FOK_None)
          continue;
        assert(!getDLLAttr(FD) &&(static_cast<void> (0))
               "friend re-decl should not already have a DLLAttr")(static_cast<void> (0));
        NewAttr = cast<InheritableAttr>(ClassAttr->clone(getASTContext()));
        NewAttr->setInherited(true);
        FD->addAttr(NewAttr);
      }
    }
  }
}

if (ClassExported)
  DelayedDllExportClasses.push_back(Class);
6372}

6374/// Perform propagation of DLL attributes from a derived class to a
6375/// templated base class for MS compatibility.
6376void Sema::propagateDLLAttrToBaseClassTemplate(
  CXXRecordDecl *Class, Attr *ClassAttr,
  ClassTemplateSpecializationDecl *BaseTemplateSpec, SourceLocation BaseLoc) {
if (getDLLAttr(
        BaseTemplateSpec->getSpecializedTemplate()->getTemplatedDecl())) {
  // If the base class template has a DLL attribute, don't try to change it.
  return;
}

auto TSK = BaseTemplateSpec->getSpecializationKind();
if (!getDLLAttr(BaseTemplateSpec) &&
    (TSK == TSK_Undeclared || TSK == TSK_ExplicitInstantiationDeclaration ||
     TSK == TSK_ImplicitInstantiation)) {
  // The template hasn't been instantiated yet (or it has, but only as an
  // explicit instantiation declaration or implicit instantiation, which means
  // we haven't codegenned any members yet), so propagate the attribute.
  auto *NewAttr = cast<InheritableAttr>(ClassAttr->clone(getASTContext()));
  NewAttr->setInherited(true);
  BaseTemplateSpec->addAttr(NewAttr);

  // If this was an import, mark that we propagated it from a derived class to
  // a base class template specialization.
  if (auto *ImportAttr = dyn_cast<DLLImportAttr>(NewAttr))
    ImportAttr->setPropagatedToBaseTemplate();

  // If the template is already instantiated, checkDLLAttributeRedeclaration()
  // needs to be run again to work see the new attribute. Otherwise this will
  // get run whenever the template is instantiated.
  if (TSK != TSK_Undeclared)
    checkClassLevelDLLAttribute(BaseTemplateSpec);

  return;
}

if (getDLLAttr(BaseTemplateSpec)) {
  // The template has already been specialized or instantiated with an
  // attribute, explicitly or through propagation. We should not try to change
  // it.
  return;
}

// The template was previously instantiated or explicitly specialized without
// a dll attribute, It's too late for us to add an attribute, so warn that
// this is unsupported.
Diag(BaseLoc, diag::warn_attribute_dll_instantiated_base_class)
    << BaseTemplateSpec->isExplicitSpecialization();
Diag(ClassAttr->getLocation(), diag::note_attribute);
if (BaseTemplateSpec->isExplicitSpecialization()) {
  Diag(BaseTemplateSpec->getLocation(),
         diag::note_template_class_explicit_specialization_was_here)
      << BaseTemplateSpec;
} else {
  Diag(BaseTemplateSpec->getPointOfInstantiation(),
         diag::note_template_class_instantiation_was_here)
      << BaseTemplateSpec;
}
6432}

6434/// Determine the kind of defaulting that would be done for a given function.
6435///
6436/// If the function is both a default constructor and a copy / move constructor
6437/// (due to having a default argument for the first parameter), this picks
6438/// CXXDefaultConstructor.
6439///
6440/// FIXME: Check that case is properly handled by all callers.
6441Sema::DefaultedFunctionKind
6442Sema::getDefaultedFunctionKind(const FunctionDecl *FD) {
if (auto *MD = dyn_cast<CXXMethodDecl>(FD)) {
  if (const CXXConstructorDecl *Ctor = dyn_cast<CXXConstructorDecl>(FD)) {
    if (Ctor->isDefaultConstructor())
      return Sema::CXXDefaultConstructor;

    if (Ctor->isCopyConstructor())
      return Sema::CXXCopyConstructor;

    if (Ctor->isMoveConstructor())
      return Sema::CXXMoveConstructor;
  }

  if (MD->isCopyAssignmentOperator())
    return Sema::CXXCopyAssignment;

  if (MD->isMoveAssignmentOperator())
    return Sema::CXXMoveAssignment;

  if (isa<CXXDestructorDecl>(FD))
    return Sema::CXXDestructor;
}

switch (FD->getDeclName().getCXXOverloadedOperator()) {
case OO_EqualEqual:
  return DefaultedComparisonKind::Equal;

case OO_ExclaimEqual:
  return DefaultedComparisonKind::NotEqual;

case OO_Spaceship:
  // No point allowing this if <=> doesn't exist in the current language mode.
  if (!getLangOpts().CPlusPlus20)
    break;
  return DefaultedComparisonKind::ThreeWay;

case OO_Less:
case OO_LessEqual:
case OO_Greater:
case OO_GreaterEqual:
  // No point allowing this if <=> doesn't exist in the current language mode.
  if (!getLangOpts().CPlusPlus20)
    break;
  return DefaultedComparisonKind::Relational;

default:
  break;
}

// Not defaultable.
return DefaultedFunctionKind();
6493}

6495static void DefineDefaultedFunction(Sema &S, FunctionDecl *FD,
                                  SourceLocation DefaultLoc) {
Sema::DefaultedFunctionKind DFK = S.getDefaultedFunctionKind(FD);
if (DFK.isComparison())
  return S.DefineDefaultedComparison(DefaultLoc, FD, DFK.asComparison());

switch (DFK.asSpecialMember()) {
case Sema::CXXDefaultConstructor:
  S.DefineImplicitDefaultConstructor(DefaultLoc,
                                     cast<CXXConstructorDecl>(FD));
  break;
case Sema::CXXCopyConstructor:
  S.DefineImplicitCopyConstructor(DefaultLoc, cast<CXXConstructorDecl>(FD));
  break;
case Sema::CXXCopyAssignment:
  S.DefineImplicitCopyAssignment(DefaultLoc, cast<CXXMethodDecl>(FD));
  break;
case Sema::CXXDestructor:
  S.DefineImplicitDestructor(DefaultLoc, cast<CXXDestructorDecl>(FD));
  break;
case Sema::CXXMoveConstructor:
  S.DefineImplicitMoveConstructor(DefaultLoc, cast<CXXConstructorDecl>(FD));
  break;
case Sema::CXXMoveAssignment:
  S.DefineImplicitMoveAssignment(DefaultLoc, cast<CXXMethodDecl>(FD));
  break;
case Sema::CXXInvalid:
  llvm_unreachable("Invalid special member.")__builtin_unreachable();
}
6524}

6526/// Determine whether a type is permitted to be passed or returned in
6527/// registers, per C++ [class.temporary]p3.
6528static bool canPassInRegisters(Sema &S, CXXRecordDecl *D,
                             TargetInfo::CallingConvKind CCK) {
if (D->isDependentType() || D->isInvalidDecl())
  return false;

// Clang <= 4 used the pre-C++11 rule, which ignores move operations.
// The PS4 platform ABI follows the behavior of Clang 3.2.
if (CCK == TargetInfo::CCK_ClangABI4OrPS4)
  return !D->hasNonTrivialDestructorForCall() &&
         !D->hasNonTrivialCopyConstructorForCall();

if (CCK == TargetInfo::CCK_MicrosoftWin64) {
  bool CopyCtorIsTrivial = false, CopyCtorIsTrivialForCall = false;
  bool DtorIsTrivialForCall = false;

  // If a class has at least one non-deleted, trivial copy constructor, it
  // is passed according to the C ABI. Otherwise, it is passed indirectly.
  //
  // Note: This permits classes with non-trivial copy or move ctors to be
  // passed in registers, so long as they *also* have a trivial copy ctor,
  // which is non-conforming.
  if (D->needsImplicitCopyConstructor()) {
    if (!D->defaultedCopyConstructorIsDeleted()) {
      if (D->hasTrivialCopyConstructor())
        CopyCtorIsTrivial = true;
      if (D->hasTrivialCopyConstructorForCall())
        CopyCtorIsTrivialForCall = true;
    }
  } else {
    for (const CXXConstructorDecl *CD : D->ctors()) {
      if (CD->isCopyConstructor() && !CD->isDeleted()) {
        if (CD->isTrivial())
          CopyCtorIsTrivial = true;
        if (CD->isTrivialForCall())
          CopyCtorIsTrivialForCall = true;
      }
    }
  }

  if (D->needsImplicitDestructor()) {
    if (!D->defaultedDestructorIsDeleted() &&
        D->hasTrivialDestructorForCall())
      DtorIsTrivialForCall = true;
  } else if (const auto *DD = D->getDestructor()) {
    if (!DD->isDeleted() && DD->isTrivialForCall())
      DtorIsTrivialForCall = true;
  }

  // If the copy ctor and dtor are both trivial-for-calls, pass direct.
  if (CopyCtorIsTrivialForCall && DtorIsTrivialForCall)
    return true;

  // If a class has a destructor, we'd really like to pass it indirectly
  // because it allows us to elide copies.  Unfortunately, MSVC makes that
  // impossible for small types, which it will pass in a single register or
  // stack slot. Most objects with dtors are large-ish, so handle that early.
  // We can't call out all large objects as being indirect because there are
  // multiple x64 calling conventions and the C++ ABI code shouldn't dictate
  // how we pass large POD types.

  // Note: This permits small classes with nontrivial destructors to be
  // passed in registers, which is non-conforming.
  bool isAArch64 = S.Context.getTargetInfo().getTriple().isAArch64();
  uint64_t TypeSize = isAArch64 ? 128 : 64;

  if (CopyCtorIsTrivial &&
      S.getASTContext().getTypeSize(D->getTypeForDecl()) <= TypeSize)
    return true;
  return false;
}

// Per C++ [class.temporary]p3, the relevant condition is:
//   each copy constructor, move constructor, and destructor of X is
//   either trivial or deleted, and X has at least one non-deleted copy
//   or move constructor
bool HasNonDeletedCopyOrMove = false;

if (D->needsImplicitCopyConstructor() &&
    !D->defaultedCopyConstructorIsDeleted()) {
  if (!D->hasTrivialCopyConstructorForCall())
    return false;
  HasNonDeletedCopyOrMove = true;
}

if (S.getLangOpts().CPlusPlus11 && D->needsImplicitMoveConstructor() &&
    !D->defaultedMoveConstructorIsDeleted()) {
  if (!D->hasTrivialMoveConstructorForCall())
    return false;
  HasNonDeletedCopyOrMove = true;
}

if (D->needsImplicitDestructor() && !D->defaultedDestructorIsDeleted() &&
    !D->hasTrivialDestructorForCall())
  return false;

for (const CXXMethodDecl *MD : D->methods()) {
  if (MD->isDeleted())
    continue;

  auto *CD = dyn_cast<CXXConstructorDecl>(MD);
  if (CD && CD->isCopyOrMoveConstructor())
    HasNonDeletedCopyOrMove = true;
  else if (!isa<CXXDestructorDecl>(MD))
    continue;

  if (!MD->isTrivialForCall())
    return false;
}

return HasNonDeletedCopyOrMove;
6638}

6640/// Report an error regarding overriding, along with any relevant
6641/// overridden methods.
6642///
6643/// \param DiagID the primary error to report.
6644/// \param MD the overriding method.
6645static bool
6646ReportOverrides(Sema &S, unsigned DiagID, const CXXMethodDecl *MD,
              llvm::function_ref<bool(const CXXMethodDecl *)> Report) {
bool IssuedDiagnostic = false;
for (const CXXMethodDecl *O : MD->overridden_methods()) {
  if (Report(O)) {
    if (!IssuedDiagnostic) {
      S.Diag(MD->getLocation(), DiagID) << MD->getDeclName();
      IssuedDiagnostic = true;
    }
    S.Diag(O->getLocation(), diag::note_overridden_virtual_function);
  }
}
return IssuedDiagnostic;
6659}

6661/// Perform semantic checks on a class definition that has been
6662/// completing, introducing implicitly-declared members, checking for
6663/// abstract types, etc.
6664///
6665/// \param S The scope in which the class was parsed. Null if we didn't just
6666///        parse a class definition.
6667/// \param Record The completed class.
6668void Sema::CheckCompletedCXXClass(Scope *S, CXXRecordDecl *Record) {
if (!Record)
  return;

if (Record->isAbstract() && !Record->isInvalidDecl()) {
  AbstractUsageInfo Info(*this, Record);
  CheckAbstractClassUsage(Info, Record);
}

// If this is not an aggregate type and has no user-declared constructor,
// complain about any non-static data members of reference or const scalar
// type, since they will never get initializers.
if (!Record->isInvalidDecl() && !Record->isDependentType() &&
    !Record->isAggregate() && !Record->hasUserDeclaredConstructor() &&
    !Record->isLambda()) {
  bool Complained = false;
  for (const auto *F : Record->fields()) {
    if (F->hasInClassInitializer() || F->isUnnamedBitfield())
      continue;

    if (F->getType()->isReferenceType() ||
        (F->getType().isConstQualified() && F->getType()->isScalarType())) {
      if (!Complained) {
        Diag(Record->getLocation(), diag::warn_no_constructor_for_refconst)
          << Record->getTagKind() << Record;
        Complained = true;
      }

      Diag(F->getLocation(), diag::note_refconst_member_not_initialized)
        << F->getType()->isReferenceType()
        << F->getDeclName();
    }
  }
}

if (Record->getIdentifier()) {
  // C++ [class.mem]p13:
  //   If T is the name of a class, then each of the following shall have a
  //   name different from T:
  //     - every member of every anonymous union that is a member of class T.
  //
  // C++ [class.mem]p14:
  //   In addition, if class T has a user-declared constructor (12.1), every
  //   non-static data member of class T shall have a name different from T.
  DeclContext::lookup_result R = Record->lookup(Record->getDeclName());
  for (DeclContext::lookup_iterator I = R.begin(), E = R.end(); I != E;
       ++I) {
    NamedDecl *D = (*I)->getUnderlyingDecl();
    if (((isa<FieldDecl>(D) || isa<UnresolvedUsingValueDecl>(D)) &&
         Record->hasUserDeclaredConstructor()) ||
        isa<IndirectFieldDecl>(D)) {
      Diag((*I)->getLocation(), diag::err_member_name_of_class)
        << D->getDeclName();
      break;
    }
  }
}

// Warn if the class has virtual methods but non-virtual public destructor.
if (Record->isPolymorphic() && !Record->isDependentType()) {
  CXXDestructorDecl *dtor = Record->getDestructor();
  if ((!dtor || (!dtor->isVirtual() && dtor->getAccess() == AS_public)) &&
      !Record->hasAttr<FinalAttr>())
    Diag(dtor ? dtor->getLocation() : Record->getLocation(),
         diag::warn_non_virtual_dtor) << Context.getRecordType(Record);
}

if (Record->isAbstract()) {
  if (FinalAttr *FA = Record->getAttr<FinalAttr>()) {
    Diag(Record->getLocation(), diag::warn_abstract_final_class)
      << FA->isSpelledAsSealed();
    DiagnoseAbstractType(Record);
  }
}

// Warn if the class has a final destructor but is not itself marked final.
if (!Record->hasAttr<FinalAttr>()) {
  if (const CXXDestructorDecl *dtor = Record->getDestructor()) {
    if (const FinalAttr *FA = dtor->getAttr<FinalAttr>()) {
      Diag(FA->getLocation(), diag::warn_final_dtor_non_final_class)
          << FA->isSpelledAsSealed()
          << FixItHint::CreateInsertion(
                 getLocForEndOfToken(Record->getLocation()),
                 (FA->isSpelledAsSealed() ? " sealed" : " final"));
      Diag(Record->getLocation(),
           diag::note_final_dtor_non_final_class_silence)
          << Context.getRecordType(Record) << FA->isSpelledAsSealed();
    }
  }
}

// See if trivial_abi has to be dropped.
if (Record->hasAttr<TrivialABIAttr>())
  checkIllFormedTrivialABIStruct(*Record);

// Set HasTrivialSpecialMemberForCall if the record has attribute
// "trivial_abi".
bool HasTrivialABI = Record->hasAttr<TrivialABIAttr>();

if (HasTrivialABI)
  Record->setHasTrivialSpecialMemberForCall();

// Explicitly-defaulted secondary comparison functions (!=, <, <=, >, >=).
// We check these last because they can depend on the properties of the
// primary comparison functions (==, <=>).
llvm::SmallVector<FunctionDecl*, 5> DefaultedSecondaryComparisons;

// Perform checks that can't be done until we know all the properties of a
// member function (whether it's defaulted, deleted, virtual, overriding,
// ...).
auto CheckCompletedMemberFunction = [&](CXXMethodDecl *MD) {
  // A static function cannot override anything.
  if (MD->getStorageClass() == SC_Static) {
    if (ReportOverrides(*this, diag::err_static_overrides_virtual, MD,
                        [](const CXXMethodDecl *) { return true; }))
      return;
  }

  // A deleted function cannot override a non-deleted function and vice
  // versa.
  if (ReportOverrides(*this,
                      MD->isDeleted() ? diag::err_deleted_override
                                      : diag::err_non_deleted_override,
                      MD, [&](const CXXMethodDecl *V) {
                        return MD->isDeleted() != V->isDeleted();
                      })) {
    if (MD->isDefaulted() && MD->isDeleted())
      // Explain why this defaulted function was deleted.
      DiagnoseDeletedDefaultedFunction(MD);
    return;
  }

  // A consteval function cannot override a non-consteval function and vice
  // versa.
  if (ReportOverrides(*this,
                      MD->isConsteval() ? diag::err_consteval_override
                                        : diag::err_non_consteval_override,
                      MD, [&](const CXXMethodDecl *V) {
                        return MD->isConsteval() != V->isConsteval();
                      })) {
    if (MD->isDefaulted() && MD->isDeleted())
      // Explain why this defaulted function was deleted.
      DiagnoseDeletedDefaultedFunction(MD);
    return;
  }
};

auto CheckForDefaultedFunction = [&](FunctionDecl *FD) -> bool {
  if (!FD || FD->isInvalidDecl() || !FD->isExplicitlyDefaulted())
    return false;

  DefaultedFunctionKind DFK = getDefaultedFunctionKind(FD);
  if (DFK.asComparison() == DefaultedComparisonKind::NotEqual ||
      DFK.asComparison() == DefaultedComparisonKind::Relational) {
    DefaultedSecondaryComparisons.push_back(FD);
    return true;
  }

  CheckExplicitlyDefaultedFunction(S, FD);
  return false;
};

auto CompleteMemberFunction = [&](CXXMethodDecl *M) {
  // Check whether the explicitly-defaulted members are valid.
  bool Incomplete = CheckForDefaultedFunction(M);

  // Skip the rest of the checks for a member of a dependent class.
  if (Record->isDependentType())
    return;

  // For an explicitly defaulted or deleted special member, we defer
  // determining triviality until the class is complete. That time is now!
  CXXSpecialMember CSM = getSpecialMember(M);
  if (!M->isImplicit() && !M->isUserProvided()) {
    if (CSM != CXXInvalid) {
      M->setTrivial(SpecialMemberIsTrivial(M, CSM));
      // Inform the class that we've finished declaring this member.
      Record->finishedDefaultedOrDeletedMember(M);
      M->setTrivialForCall(
          HasTrivialABI ||
          SpecialMemberIsTrivial(M, CSM, TAH_ConsiderTrivialABI));
      Record->setTrivialForCallFlags(M);
    }
  }

  // Set triviality for the purpose of calls if this is a user-provided
  // copy/move constructor or destructor.
  if ((CSM == CXXCopyConstructor || CSM == CXXMoveConstructor ||
       CSM == CXXDestructor) && M->isUserProvided()) {
    M->setTrivialForCall(HasTrivialABI);
    Record->setTrivialForCallFlags(M);
  }

  if (!M->isInvalidDecl() && M->isExplicitlyDefaulted() &&
      M->hasAttr<DLLExportAttr>()) {
    if (getLangOpts().isCompatibleWithMSVC(LangOptions::MSVC2015) &&
        M->isTrivial() &&
        (CSM == CXXDefaultConstructor || CSM == CXXCopyConstructor ||
         CSM == CXXDestructor))
      M->dropAttr<DLLExportAttr>();

    if (M->hasAttr<DLLExportAttr>()) {
      // Define after any fields with in-class initializers have been parsed.
      DelayedDllExportMemberFunctions.push_back(M);
    }
  }

  // Define defaulted constexpr virtual functions that override a base class
  // function right away.
  // FIXME: We can defer doing this until the vtable is marked as used.
  if (M->isDefaulted() && M->isConstexpr() && M->size_overridden_methods())
    DefineDefaultedFunction(*this, M, M->getLocation());

  if (!Incomplete)
    CheckCompletedMemberFunction(M);
};

// Check the destructor before any other member function. We need to
// determine whether it's trivial in order to determine whether the claas
// type is a literal type, which is a prerequisite for determining whether
// other special member functions are valid and whether they're implicitly
// 'constexpr'.
if (CXXDestructorDecl *Dtor = Record->getDestructor())
  CompleteMemberFunction(Dtor);

bool HasMethodWithOverrideControl = false,
     HasOverridingMethodWithoutOverrideControl = false;
for (auto *D : Record->decls()) {
  if (auto *M = dyn_cast<CXXMethodDecl>(D)) {
    // FIXME: We could do this check for dependent types with non-dependent
    // bases.
    if (!Record->isDependentType()) {
      // See if a method overloads virtual methods in a base
      // class without overriding any.
      if (!M->isStatic())
        DiagnoseHiddenVirtualMethods(M);
      if (M->hasAttr<OverrideAttr>())
        HasMethodWithOverrideControl = true;
      else if (M->size_overridden_methods() > 0)
        HasOverridingMethodWithoutOverrideControl = true;
    }

    if (!isa<CXXDestructorDecl>(M))
      CompleteMemberFunction(M);
  } else if (auto *F = dyn_cast<FriendDecl>(D)) {
    CheckForDefaultedFunction(
        dyn_cast_or_null<FunctionDecl>(F->getFriendDecl()));
  }
}

if (HasOverridingMethodWithoutOverrideControl) {
  bool HasInconsistentOverrideControl = HasMethodWithOverrideControl;
  for (auto *M : Record->methods())
    DiagnoseAbsenceOfOverrideControl(M, HasInconsistentOverrideControl);
}

// Check the defaulted secondary comparisons after any other member functions.
for (FunctionDecl *FD : DefaultedSecondaryComparisons) {
  CheckExplicitlyDefaultedFunction(S, FD);

  // If this is a member function, we deferred checking it until now.
  if (auto *MD = dyn_cast<CXXMethodDecl>(FD))
    CheckCompletedMemberFunction(MD);
}

// ms_struct is a request to use the same ABI rules as MSVC.  Check
// whether this class uses any C++ features that are implemented
// completely differently in MSVC, and if so, emit a diagnostic.
// That diagnostic defaults to an error, but we allow projects to
// map it down to a warning (or ignore it).  It's a fairly common
// practice among users of the ms_struct pragma to mass-annotate
// headers, sweeping up a bunch of types that the project doesn't
// really rely on MSVC-compatible layout for.  We must therefore
// support "ms_struct except for C++ stuff" as a secondary ABI.
// Don't emit this diagnostic if the feature was enabled as a
// language option (as opposed to via a pragma or attribute), as
// the option -mms-bitfields otherwise essentially makes it impossible
// to build C++ code, unless this diagnostic is turned off.
if (Record->isMsStruct(Context) && !Context.getLangOpts().MSBitfields &&
    (Record->isPolymorphic() || Record->getNumBases())) {
  Diag(Record->getLocation(), diag::warn_cxx_ms_struct);
}

checkClassLevelDLLAttribute(Record);
checkClassLevelCodeSegAttribute(Record);

bool ClangABICompat4 =
    Context.getLangOpts().getClangABICompat() <= LangOptions::ClangABI::Ver4;
TargetInfo::CallingConvKind CCK =
    Context.getTargetInfo().getCallingConvKind(ClangABICompat4);
bool CanPass = canPassInRegisters(*this, Record, CCK);

// Do not change ArgPassingRestrictions if it has already been set to
// APK_CanNeverPassInRegs.
if (Record->getArgPassingRestrictions() != RecordDecl::APK_CanNeverPassInRegs)
  Record->setArgPassingRestrictions(CanPass
                                        ? RecordDecl::APK_CanPassInRegs
                                        : RecordDecl::APK_CannotPassInRegs);

// If canPassInRegisters returns true despite the record having a non-trivial
// destructor, the record is destructed in the callee. This happens only when
// the record or one of its subobjects has a field annotated with trivial_abi
// or a field qualified with ObjC __strong/__weak.
if (Context.getTargetInfo().getCXXABI().areArgsDestroyedLeftToRightInCallee())
  Record->setParamDestroyedInCallee(true);
else if (Record->hasNonTrivialDestructor())
  Record->setParamDestroyedInCallee(CanPass);

if (getLangOpts().ForceEmitVTables) {
  // If we want to emit all the vtables, we need to mark it as used.  This
  // is especially required for cases like vtable assumption loads.
  MarkVTableUsed(Record->getInnerLocStart(), Record);
}

if (getLangOpts().CUDA) {
  if (Record->hasAttr<CUDADeviceBuiltinSurfaceTypeAttr>())
    checkCUDADeviceBuiltinSurfaceClassTemplate(*this, Record);
  else if (Record->hasAttr<CUDADeviceBuiltinTextureTypeAttr>())
    checkCUDADeviceBuiltinTextureClassTemplate(*this, Record);
}
6988}

6990/// Look up the special member function that would be called by a special
6991/// member function for a subobject of class type.
6992///
6993/// \param Class The class type of the subobject.
6994/// \param CSM The kind of special member function.
6995/// \param FieldQuals If the subobject is a field, its cv-qualifiers.
6996/// \param ConstRHS True if this is a copy operation with a const object
6997///        on its RHS, that is, if the argument to the outer special member
6998///        function is 'const' and this is not a field marked 'mutable'.
6999static Sema::SpecialMemberOverloadResult lookupCallFromSpecialMember(
  Sema &S, CXXRecordDecl *Class, Sema::CXXSpecialMember CSM,
  unsigned FieldQuals, bool ConstRHS) {
unsigned LHSQuals = 0;
if (CSM == Sema::CXXCopyAssignment || CSM == Sema::CXXMoveAssignment)
  LHSQuals = FieldQuals;

unsigned RHSQuals = FieldQuals;
if (CSM == Sema::CXXDefaultConstructor || CSM == Sema::CXXDestructor)
  RHSQuals = 0;
else if (ConstRHS)
  RHSQuals |= Qualifiers::Const;

return S.LookupSpecialMember(Class, CSM,
                             RHSQuals & Qualifiers::Const,
                             RHSQuals & Qualifiers::Volatile,
                             false,
                             LHSQuals & Qualifiers::Const,
                             LHSQuals & Qualifiers::Volatile);
7018}

7020class Sema::InheritedConstructorInfo {
Sema &S;
SourceLocation UseLoc;

/// A mapping from the base classes through which the constructor was
/// inherited to the using shadow declaration in that base class (or a null
/// pointer if the constructor was declared in that base class).
llvm::DenseMap<CXXRecordDecl *, ConstructorUsingShadowDecl *>
    InheritedFromBases;

7030public:
InheritedConstructorInfo(Sema &S, SourceLocation UseLoc,
                         ConstructorUsingShadowDecl *Shadow)
    : S(S), UseLoc(UseLoc) {
  bool DiagnosedMultipleConstructedBases = false;
  CXXRecordDecl *ConstructedBase = nullptr;
  BaseUsingDecl *ConstructedBaseIntroducer = nullptr;

  // Find the set of such base class subobjects and check that there's a
  // unique constructed subobject.
  for (auto *D : Shadow->redecls()) {
    auto *DShadow = cast<ConstructorUsingShadowDecl>(D);
    auto *DNominatedBase = DShadow->getNominatedBaseClass();
    auto *DConstructedBase = DShadow->getConstructedBaseClass();

    InheritedFromBases.insert(
        std::make_pair(DNominatedBase->getCanonicalDecl(),
                       DShadow->getNominatedBaseClassShadowDecl()));
    if (DShadow->constructsVirtualBase())
      InheritedFromBases.insert(
          std::make_pair(DConstructedBase->getCanonicalDecl(),
                         DShadow->getConstructedBaseClassShadowDecl()));
    else
      assert(DNominatedBase == DConstructedBase)(static_cast<void> (0));

    // [class.inhctor.init]p2:
    //   If the constructor was inherited from multiple base class subobjects
    //   of type B, the program is ill-formed.
    if (!ConstructedBase) {
      ConstructedBase = DConstructedBase;
      ConstructedBaseIntroducer = D->getIntroducer();
    } else if (ConstructedBase != DConstructedBase &&
               !Shadow->isInvalidDecl()) {
      if (!DiagnosedMultipleConstructedBases) {
        S.Diag(UseLoc, diag::err_ambiguous_inherited_constructor)
            << Shadow->getTargetDecl();
        S.Diag(ConstructedBaseIntroducer->getLocation(),
               diag::note_ambiguous_inherited_constructor_using)
            << ConstructedBase;
        DiagnosedMultipleConstructedBases = true;
      }
      S.Diag(D->getIntroducer()->getLocation(),
             diag::note_ambiguous_inherited_constructor_using)
          << DConstructedBase;
    }
  }

  if (DiagnosedMultipleConstructedBases)
    Shadow->setInvalidDecl();
}

/// Find the constructor to use for inherited construction of a base class,
/// and whether that base class constructor inherits the constructor from a
/// virtual base class (in which case it won't actually invoke it).
std::pair<CXXConstructorDecl *, bool>
findConstructorForBase(CXXRecordDecl *Base, CXXConstructorDecl *Ctor) const {
  auto It = InheritedFromBases.find(Base->getCanonicalDecl());
  if (It == InheritedFromBases.end())
    return std::make_pair(nullptr, false);

  // This is an intermediary class.
  if (It->second)
    return std::make_pair(
        S.findInheritingConstructor(UseLoc, Ctor, It->second),
        It->second->constructsVirtualBase());

  // This is the base class from which the constructor was inherited.
  return std::make_pair(Ctor, false);
}
7099};

7101/// Is the special member function which would be selected to perform the
7102/// specified operation on the specified class type a constexpr constructor?
7103static bool
7104specialMemberIsConstexpr(Sema &S, CXXRecordDecl *ClassDecl,
                       Sema::CXXSpecialMember CSM, unsigned Quals,
                       bool ConstRHS,
                       CXXConstructorDecl *InheritedCtor = nullptr,
                       Sema::InheritedConstructorInfo *Inherited = nullptr) {
// If we're inheriting a constructor, see if we need to call it for this base
// class.
if (InheritedCtor) {
  assert(CSM == Sema::CXXDefaultConstructor)(static_cast<void> (0));
  auto BaseCtor =
      Inherited->findConstructorForBase(ClassDecl, InheritedCtor).first;
  if (BaseCtor)
    return BaseCtor->isConstexpr();
}

if (CSM == Sema::CXXDefaultConstructor)
  return ClassDecl->hasConstexprDefaultConstructor();
if (CSM == Sema::CXXDestructor)
  return ClassDecl->hasConstexprDestructor();

Sema::SpecialMemberOverloadResult SMOR =
    lookupCallFromSpecialMember(S, ClassDecl, CSM, Quals, ConstRHS);
if (!SMOR.getMethod())
  // A constructor we wouldn't select can't be "involved in initializing"
  // anything.
  return true;
return SMOR.getMethod()->isConstexpr();
7131}

7133/// Determine whether the specified special member function would be constexpr
7134/// if it were implicitly defined.
7135static bool defaultedSpecialMemberIsConstexpr(
  Sema &S, CXXRecordDecl *ClassDecl, Sema::CXXSpecialMember CSM,
  bool ConstArg, CXXConstructorDecl *InheritedCtor = nullptr,
  Sema::InheritedConstructorInfo *Inherited = nullptr) {
if (!S.getLangOpts().CPlusPlus11)
  return false;

// C++11 [dcl.constexpr]p4:
// In the definition of a constexpr constructor [...]
bool Ctor = true;
switch (CSM) {
case Sema::CXXDefaultConstructor:
  if (Inherited)
    break;
  // Since default constructor lookup is essentially trivial (and cannot
  // involve, for instance, template instantiation), we compute whether a
  // defaulted default constructor is constexpr directly within CXXRecordDecl.
  //
  // This is important for performance; we need to know whether the default
  // constructor is constexpr to determine whether the type is a literal type.
  return ClassDecl->defaultedDefaultConstructorIsConstexpr();

case Sema::CXXCopyConstructor:
case Sema::CXXMoveConstructor:
  // For copy or move constructors, we need to perform overload resolution.
  break;

case Sema::CXXCopyAssignment:
case Sema::CXXMoveAssignment:
  if (!S.getLangOpts().CPlusPlus14)
    return false;
  // In C++1y, we need to perform overload resolution.
  Ctor = false;
  break;

case Sema::CXXDestructor:
  return ClassDecl->defaultedDestructorIsConstexpr();

case Sema::CXXInvalid:
  return false;
}

//   -- if the class is a non-empty union, or for each non-empty anonymous
//      union member of a non-union class, exactly one non-static data member
//      shall be initialized; [DR1359]
//
// If we squint, this is guaranteed, since exactly one non-static data member
// will be initialized (if the constructor isn't deleted), we just don't know
// which one.
if (Ctor && ClassDecl->isUnion())
  return CSM == Sema::CXXDefaultConstructor
             ? ClassDecl->hasInClassInitializer() ||
                   !ClassDecl->hasVariantMembers()
             : true;

//   -- the class shall not have any virtual base classes;
if (Ctor && ClassDecl->getNumVBases())
  return false;

// C++1y [class.copy]p26:
//   -- [the class] is a literal type, and
if (!Ctor && !ClassDecl->isLiteral())
  return false;

//   -- every constructor involved in initializing [...] base class
//      sub-objects shall be a constexpr constructor;
//   -- the assignment operator selected to copy/move each direct base
//      class is a constexpr function, and
for (const auto &B : ClassDecl->bases()) {
  const RecordType *BaseType = B.getType()->getAs<RecordType>();
  if (!BaseType) continue;

  CXXRecordDecl *BaseClassDecl = cast<CXXRecordDecl>(BaseType->getDecl());
  if (!specialMemberIsConstexpr(S, BaseClassDecl, CSM, 0, ConstArg,
                                InheritedCtor, Inherited))
    return false;
}

//   -- every constructor involved in initializing non-static data members
//      [...] shall be a constexpr constructor;
//   -- every non-static data member and base class sub-object shall be
//      initialized
//   -- for each non-static data member of X that is of class type (or array
//      thereof), the assignment operator selected to copy/move that member is
//      a constexpr function
for (const auto *F : ClassDecl->fields()) {
  if (F->isInvalidDecl())
    continue;
  if (CSM == Sema::CXXDefaultConstructor && F->hasInClassInitializer())
    continue;
  QualType BaseType = S.Context.getBaseElementType(F->getType());
  if (const RecordType *RecordTy = BaseType->getAs<RecordType>()) {
    CXXRecordDecl *FieldRecDecl = cast<CXXRecordDecl>(RecordTy->getDecl());
    if (!specialMemberIsConstexpr(S, FieldRecDecl, CSM,
                                  BaseType.getCVRQualifiers(),
                                  ConstArg && !F->isMutable()))
      return false;
  } else if (CSM == Sema::CXXDefaultConstructor) {
    return false;
  }
}

// All OK, it's constexpr!
return true;
7239}

7241namespace {
7242/// RAII object to register a defaulted function as having its exception
7243/// specification computed.
7244struct ComputingExceptionSpec {
Sema &S;

ComputingExceptionSpec(Sema &S, FunctionDecl *FD, SourceLocation Loc)
    : S(S) {
  Sema::CodeSynthesisContext Ctx;
  Ctx.Kind = Sema::CodeSynthesisContext::ExceptionSpecEvaluation;
  Ctx.PointOfInstantiation = Loc;
  Ctx.Entity = FD;
  S.pushCodeSynthesisContext(Ctx);
}
~ComputingExceptionSpec() {
  S.popCodeSynthesisContext();
}
7258};
7259}

7261static Sema::ImplicitExceptionSpecification
7262ComputeDefaultedSpecialMemberExceptionSpec(
  Sema &S, SourceLocation Loc, CXXMethodDecl *MD, Sema::CXXSpecialMember CSM,
  Sema::InheritedConstructorInfo *ICI);

7266static Sema::ImplicitExceptionSpecification
7267ComputeDefaultedComparisonExceptionSpec(Sema &S, SourceLocation Loc,
                                      FunctionDecl *FD,
                                      Sema::DefaultedComparisonKind DCK);

7271static Sema::ImplicitExceptionSpecification
7272computeImplicitExceptionSpec(Sema &S, SourceLocation Loc, FunctionDecl *FD) {
auto DFK = S.getDefaultedFunctionKind(FD);
if (DFK.isSpecialMember())
  return ComputeDefaultedSpecialMemberExceptionSpec(
      S, Loc, cast<CXXMethodDecl>(FD), DFK.asSpecialMember(), nullptr);
if (DFK.isComparison())
  return ComputeDefaultedComparisonExceptionSpec(S, Loc, FD,
                                                 DFK.asComparison());

auto *CD = cast<CXXConstructorDecl>(FD);
assert(CD->getInheritedConstructor() &&(static_cast<void> (0))
       "only defaulted functions and inherited constructors have implicit "(static_cast<void> (0))
       "exception specs")(static_cast<void> (0));
Sema::InheritedConstructorInfo ICI(
    S, Loc, CD->getInheritedConstructor().getShadowDecl());
return ComputeDefaultedSpecialMemberExceptionSpec(
    S, Loc, CD, Sema::CXXDefaultConstructor, &ICI);
7289}

7291static FunctionProtoType::ExtProtoInfo getImplicitMethodEPI(Sema &S,
                                                          CXXMethodDecl *MD) {
FunctionProtoType::ExtProtoInfo EPI;

// Build an exception specification pointing back at this member.
EPI.ExceptionSpec.Type = EST_Unevaluated;
EPI.ExceptionSpec.SourceDecl = MD;

// Set the calling convention to the default for C++ instance methods.
EPI.ExtInfo = EPI.ExtInfo.withCallingConv(
    S.Context.getDefaultCallingConvention(/*IsVariadic=*/false,
                                          /*IsCXXMethod=*/true));
return EPI;
7304}

7306void Sema::EvaluateImplicitExceptionSpec(SourceLocation Loc, FunctionDecl *FD) {
const FunctionProtoType *FPT = FD->getType()->castAs<FunctionProtoType>();
if (FPT->getExceptionSpecType() != EST_Unevaluated)
  return;

// Evaluate the exception specification.
auto IES = computeImplicitExceptionSpec(*this, Loc, FD);
auto ESI = IES.getExceptionSpec();

// Update the type of the special member to use it.
UpdateExceptionSpec(FD, ESI);
7317}

7319void Sema::CheckExplicitlyDefaultedFunction(Scope *S, FunctionDecl *FD) {
assert(FD->isExplicitlyDefaulted() && "not explicitly-defaulted")(static_cast<void> (0));

DefaultedFunctionKind DefKind = getDefaultedFunctionKind(FD);
if (!DefKind) {
  assert(FD->getDeclContext()->isDependentContext())(static_cast<void> (0));
  return;
}

if (DefKind.isComparison())
  UnusedPrivateFields.clear();

if (DefKind.isSpecialMember()
        ? CheckExplicitlyDefaultedSpecialMember(cast<CXXMethodDecl>(FD),
                                                DefKind.asSpecialMember())
        : CheckExplicitlyDefaultedComparison(S, FD, DefKind.asComparison()))
  FD->setInvalidDecl();
7336}

7338bool Sema::CheckExplicitlyDefaultedSpecialMember(CXXMethodDecl *MD,
                                               CXXSpecialMember CSM) {
CXXRecordDecl *RD = MD->getParent();

assert(MD->isExplicitlyDefaulted() && CSM != CXXInvalid &&(static_cast<void> (0))
       "not an explicitly-defaulted special member")(static_cast<void> (0));

// Defer all checking for special members of a dependent type.
if (RD->isDependentType())
  return false;

// Whether this was the first-declared instance of the constructor.
// This affects whether we implicitly add an exception spec and constexpr.
bool First = MD == MD->getCanonicalDecl();

bool HadError = false;

// C++11 [dcl.fct.def.default]p1:
//   A function that is explicitly defaulted shall
//     -- be a special member function [...] (checked elsewhere),
//     -- have the same type (except for ref-qualifiers, and except that a
//        copy operation can take a non-const reference) as an implicit
//        declaration, and
//     -- not have default arguments.
// C++2a changes the second bullet to instead delete the function if it's
// defaulted on its first declaration, unless it's "an assignment operator,
// and its return type differs or its parameter type is not a reference".
bool DeleteOnTypeMismatch = getLangOpts().CPlusPlus20 && First;
bool ShouldDeleteForTypeMismatch = false;
unsigned ExpectedParams = 1;
if (CSM == CXXDefaultConstructor || CSM == CXXDestructor)
  ExpectedParams = 0;
if (MD->getNumParams() != ExpectedParams) {
  // This checks for default arguments: a copy or move constructor with a
  // default argument is classified as a default constructor, and assignment
  // operations and destructors can't have default arguments.
  Diag(MD->getLocation(), diag::err_defaulted_special_member_params)
    << CSM << MD->getSourceRange();
  HadError = true;
} else if (MD->isVariadic()) {
  if (DeleteOnTypeMismatch)
    ShouldDeleteForTypeMismatch = true;
  else {
    Diag(MD->getLocation(), diag::err_defaulted_special_member_variadic)
      << CSM << MD->getSourceRange();
    HadError = true;
  }
}

const FunctionProtoType *Type = MD->getType()->getAs<FunctionProtoType>();

bool CanHaveConstParam = false;
if (CSM == CXXCopyConstructor)
  CanHaveConstParam = RD->implicitCopyConstructorHasConstParam();
else if (CSM == CXXCopyAssignment)
  CanHaveConstParam = RD->implicitCopyAssignmentHasConstParam();

QualType ReturnType = Context.VoidTy;
if (CSM == CXXCopyAssignment || CSM == CXXMoveAssignment) {
  // Check for return type matching.
  ReturnType = Type->getReturnType();

  QualType DeclType = Context.getTypeDeclType(RD);
  DeclType = Context.getAddrSpaceQualType(DeclType, MD->getMethodQualifiers().getAddressSpace());
  QualType ExpectedReturnType = Context.getLValueReferenceType(DeclType);

  if (!Context.hasSameType(ReturnType, ExpectedReturnType)) {
    Diag(MD->getLocation(), diag::err_defaulted_special_member_return_type)
      << (CSM == CXXMoveAssignment) << ExpectedReturnType;
    HadError = true;
  }

  // A defaulted special member cannot have cv-qualifiers.
  if (Type->getMethodQuals().hasConst() || Type->getMethodQuals().hasVolatile()) {
    if (DeleteOnTypeMismatch)
      ShouldDeleteForTypeMismatch = true;
    else {
      Diag(MD->getLocation(), diag::err_defaulted_special_member_quals)
        << (CSM == CXXMoveAssignment) << getLangOpts().CPlusPlus14;
      HadError = true;
    }
  }
}

// Check for parameter type matching.
QualType ArgType = ExpectedParams ? Type->getParamType(0) : QualType();
bool HasConstParam = false;
if (ExpectedParams && ArgType->isReferenceType()) {
  // Argument must be reference to possibly-const T.
  QualType ReferentType = ArgType->getPointeeType();
  HasConstParam = ReferentType.isConstQualified();

  if (ReferentType.isVolatileQualified()) {
    if (DeleteOnTypeMismatch)
      ShouldDeleteForTypeMismatch = true;
    else {
      Diag(MD->getLocation(),
           diag::err_defaulted_special_member_volatile_param) << CSM;
      HadError = true;
    }
  }

  if (HasConstParam && !CanHaveConstParam) {
    if (DeleteOnTypeMismatch)
      ShouldDeleteForTypeMismatch = true;
    else if (CSM == CXXCopyConstructor || CSM == CXXCopyAssignment) {
      Diag(MD->getLocation(),
           diag::err_defaulted_special_member_copy_const_param)
        << (CSM == CXXCopyAssignment);
      // FIXME: Explain why this special member can't be const.
      HadError = true;
    } else {
      Diag(MD->getLocation(),
           diag::err_defaulted_special_member_move_const_param)
        << (CSM == CXXMoveAssignment);
      HadError = true;
    }
  }
} else if (ExpectedParams) {
  // A copy assignment operator can take its argument by value, but a
  // defaulted one cannot.
  assert(CSM == CXXCopyAssignment && "unexpected non-ref argument")(static_cast<void> (0));
  Diag(MD->getLocation(), diag::err_defaulted_copy_assign_not_ref);
  HadError = true;
}

// C++11 [dcl.fct.def.default]p2:
//   An explicitly-defaulted function may be declared constexpr only if it
//   would have been implicitly declared as constexpr,
// Do not apply this rule to members of class templates, since core issue 1358
// makes such functions always instantiate to constexpr functions. For
// functions which cannot be constexpr (for non-constructors in C++11 and for
// destructors in C++14 and C++17), this is checked elsewhere.
//
// FIXME: This should not apply if the member is deleted.
bool Constexpr = defaultedSpecialMemberIsConstexpr(*this, RD, CSM,
                                                   HasConstParam);
if ((getLangOpts().CPlusPlus20 ||
     (getLangOpts().CPlusPlus14 ? !isa<CXXDestructorDecl>(MD)
                                : isa<CXXConstructorDecl>(MD))) &&
    MD->isConstexpr() && !Constexpr &&
    MD->getTemplatedKind() == FunctionDecl::TK_NonTemplate) {
  Diag(MD->getBeginLoc(), MD->isConsteval()
                              ? diag::err_incorrect_defaulted_consteval
                              : diag::err_incorrect_defaulted_constexpr)
      << CSM;
  // FIXME: Explain why the special member can't be constexpr.
  HadError = true;
}

if (First) {
  // C++2a [dcl.fct.def.default]p3:
  //   If a function is explicitly defaulted on its first declaration, it is
  //   implicitly considered to be constexpr if the implicit declaration
  //   would be.
  MD->setConstexprKind(Constexpr ? (MD->isConsteval()
                                        ? ConstexprSpecKind::Consteval
                                        : ConstexprSpecKind::Constexpr)
                                 : ConstexprSpecKind::Unspecified);

  if (!Type->hasExceptionSpec()) {
    // C++2a [except.spec]p3:
    //   If a declaration of a function does not have a noexcept-specifier
    //   [and] is defaulted on its first declaration, [...] the exception
    //   specification is as specified below
    FunctionProtoType::ExtProtoInfo EPI = Type->getExtProtoInfo();
    EPI.ExceptionSpec.Type = EST_Unevaluated;
    EPI.ExceptionSpec.SourceDecl = MD;
    MD->setType(Context.getFunctionType(ReturnType,
                                        llvm::makeArrayRef(&ArgType,
                                                           ExpectedParams),
                                        EPI));
  }
}

if (ShouldDeleteForTypeMismatch || ShouldDeleteSpecialMember(MD, CSM)) {
  if (First) {
    SetDeclDeleted(MD, MD->getLocation());
    if (!inTemplateInstantiation() && !HadError) {
      Diag(MD->getLocation(), diag::warn_defaulted_method_deleted) << CSM;
      if (ShouldDeleteForTypeMismatch) {
        Diag(MD->getLocation(), diag::note_deleted_type_mismatch) << CSM;
      } else {
        ShouldDeleteSpecialMember(MD, CSM, nullptr, /*Diagnose*/true);
      }
    }
    if (ShouldDeleteForTypeMismatch && !HadError) {
      Diag(MD->getLocation(),
           diag::warn_cxx17_compat_defaulted_method_type_mismatch) << CSM;
    }
  } else {
    // C++11 [dcl.fct.def.default]p4:
    //   [For a] user-provided explicitly-defaulted function [...] if such a
    //   function is implicitly defined as deleted, the program is ill-formed.
    Diag(MD->getLocation(), diag::err_out_of_line_default_deletes) << CSM;
    assert(!ShouldDeleteForTypeMismatch && "deleted non-first decl")(static_cast<void> (0));
    ShouldDeleteSpecialMember(MD, CSM, nullptr, /*Diagnose*/true);
    HadError = true;
  }
}

return HadError;
7540}

7542namespace {
7543/// Helper class for building and checking a defaulted comparison.
7544///
7545/// Defaulted functions are built in two phases:
7546///
7547///  * First, the set of operations that the function will perform are
7548///    identified, and some of them are checked. If any of the checked
7549///    operations is invalid in certain ways, the comparison function is
7550///    defined as deleted and no body is built.
7551///  * Then, if the function is not defined as deleted, the body is built.
7552///
7553/// This is accomplished by performing two visitation steps over the eventual
7554/// body of the function.
7555template<typename Derived, typename ResultList, typename Result,
       typename Subobject>
7557class DefaultedComparisonVisitor {
7558public:
using DefaultedComparisonKind = Sema::DefaultedComparisonKind;

DefaultedComparisonVisitor(Sema &S, CXXRecordDecl *RD, FunctionDecl *FD,
                           DefaultedComparisonKind DCK)
    : S(S), RD(RD), FD(FD), DCK(DCK) {
  if (auto *Info = FD->getDefaultedFunctionInfo()) {
    // FIXME: Change CreateOverloadedBinOp to take an ArrayRef instead of an
    // UnresolvedSet to avoid this copy.
    Fns.assign(Info->getUnqualifiedLookups().begin(),
               Info->getUnqualifiedLookups().end());
  }
}

ResultList visit() {
  // The type of an lvalue naming a parameter of this function.
  QualType ParamLvalType =
      FD->getParamDecl(0)->getType().getNonReferenceType();

  ResultList Results;

  switch (DCK) {
  case DefaultedComparisonKind::None:
    llvm_unreachable("not a defaulted comparison")__builtin_unreachable();

  case DefaultedComparisonKind::Equal:
  case DefaultedComparisonKind::ThreeWay:
    getDerived().visitSubobjects(Results, RD, ParamLvalType.getQualifiers());
    return Results;

  case DefaultedComparisonKind::NotEqual:
  case DefaultedComparisonKind::Relational:
    Results.add(getDerived().visitExpandedSubobject(
        ParamLvalType, getDerived().getCompleteObject()));
    return Results;
  }
  llvm_unreachable("")__builtin_unreachable();
}

7597protected:
Derived &getDerived() { return static_cast<Derived&>(*this); }

/// Visit the expanded list of subobjects of the given type, as specified in
/// C++2a [class.compare.default].
///
/// \return \c true if the ResultList object said we're done, \c false if not.
bool visitSubobjects(ResultList &Results, CXXRecordDecl *Record,
                     Qualifiers Quals) {
  // C++2a [class.compare.default]p4:
  //   The direct base class subobjects of C
  for (CXXBaseSpecifier &Base : Record->bases())
    if (Results.add(getDerived().visitSubobject(
            S.Context.getQualifiedType(Base.getType(), Quals),
            getDerived().getBase(&Base))))
      return true;

  //   followed by the non-static data members of C
  for (FieldDecl *Field : Record->fields()) {
    // Recursively expand anonymous structs.
    if (Field->isAnonymousStructOrUnion()) {
      if (visitSubobjects(Results, Field->getType()->getAsCXXRecordDecl(),
                          Quals))
        return true;
      continue;
    }

    // Figure out the type of an lvalue denoting this field.
    Qualifiers FieldQuals = Quals;
    if (Field->isMutable())
      FieldQuals.removeConst();
    QualType FieldType =
        S.Context.getQualifiedType(Field->getType(), FieldQuals);

    if (Results.add(getDerived().visitSubobject(
            FieldType, getDerived().getField(Field))))
      return true;
  }

  //   form a list of subobjects.
  return false;
}

Result visitSubobject(QualType Type, Subobject Subobj) {
  //   In that list, any subobject of array type is recursively expanded
  const ArrayType *AT = S.Context.getAsArrayType(Type);
  if (auto *CAT = dyn_cast_or_null<ConstantArrayType>(AT))
    return getDerived().visitSubobjectArray(CAT->getElementType(),
                                            CAT->getSize(), Subobj);
  return getDerived().visitExpandedSubobject(Type, Subobj);
}

Result visitSubobjectArray(QualType Type, const llvm::APInt &Size,
                           Subobject Subobj) {
  return getDerived().visitSubobject(Type, Subobj);
}

7654protected:
Sema &S;
CXXRecordDecl *RD;
FunctionDecl *FD;
DefaultedComparisonKind DCK;
UnresolvedSet<16> Fns;
7660};

7662/// Information about a defaulted comparison, as determined by
7663/// DefaultedComparisonAnalyzer.
7664struct DefaultedComparisonInfo {
bool Deleted = false;
bool Constexpr = true;
ComparisonCategoryType Category = ComparisonCategoryType::StrongOrdering;

static DefaultedComparisonInfo deleted() {
  DefaultedComparisonInfo Deleted;
  Deleted.Deleted = true;
  return Deleted;
}

bool add(const DefaultedComparisonInfo &R) {
  Deleted |= R.Deleted;
  Constexpr &= R.Constexpr;
  Category = commonComparisonType(Category, R.Category);
  return Deleted;
}
7681};

7683/// An element in the expanded list of subobjects of a defaulted comparison, as
7684/// specified in C++2a [class.compare.default]p4.
7685struct DefaultedComparisonSubobject {
enum { CompleteObject, Member, Base } Kind;
NamedDecl *Decl;
SourceLocation Loc;
7689};

7691/// A visitor over the notional body of a defaulted comparison that determines
7692/// whether that body would be deleted or constexpr.
7693class DefaultedComparisonAnalyzer
  : public DefaultedComparisonVisitor<DefaultedComparisonAnalyzer,
                                      DefaultedComparisonInfo,
                                      DefaultedComparisonInfo,
                                      DefaultedComparisonSubobject> {
7698public:
enum DiagnosticKind { NoDiagnostics, ExplainDeleted, ExplainConstexpr };

7701private:
DiagnosticKind Diagnose;

7704public:
using Base = DefaultedComparisonVisitor;
using Result = DefaultedComparisonInfo;
using Subobject = DefaultedComparisonSubobject;

friend Base;

DefaultedComparisonAnalyzer(Sema &S, CXXRecordDecl *RD, FunctionDecl *FD,
                            DefaultedComparisonKind DCK,
                            DiagnosticKind Diagnose = NoDiagnostics)
    : Base(S, RD, FD, DCK), Diagnose(Diagnose) {}

Result visit() {
  if ((DCK == DefaultedComparisonKind::Equal ||
       DCK == DefaultedComparisonKind::ThreeWay) &&
      RD->hasVariantMembers()) {
    // C++2a [class.compare.default]p2 [P2002R0]:
    //   A defaulted comparison operator function for class C is defined as
    //   deleted if [...] C has variant members.
    if (Diagnose == ExplainDeleted) {
      S.Diag(FD->getLocation(), diag::note_defaulted_comparison_union)
        << FD << RD->isUnion() << RD;
    }
    return Result::deleted();
  }

  return Base::visit();
}

7733private:
Subobject getCompleteObject() {
  return Subobject{Subobject::CompleteObject, RD, FD->getLocation()};
}

Subobject getBase(CXXBaseSpecifier *Base) {
  return Subobject{Subobject::Base, Base->getType()->getAsCXXRecordDecl(),
                   Base->getBaseTypeLoc()};
}

Subobject getField(FieldDecl *Field) {
  return Subobject{Subobject::Member, Field, Field->getLocation()};
}

Result visitExpandedSubobject(QualType Type, Subobject Subobj) {
  // C++2a [class.compare.default]p2 [P2002R0]:
  //   A defaulted <=> or == operator function for class C is defined as
  //   deleted if any non-static data member of C is of reference type
  if (Type->isReferenceType()) {
    if (Diagnose == ExplainDeleted) {
      S.Diag(Subobj.Loc, diag::note_defaulted_comparison_reference_member)
          << FD << RD;
    }
    return Result::deleted();
  }

  // [...] Let xi be an lvalue denoting the ith element [...]
  OpaqueValueExpr Xi(FD->getLocation(), Type, VK_LValue);
  Expr *Args[] = {&Xi, &Xi};

  // All operators start by trying to apply that same operator recursively.
  OverloadedOperatorKind OO = FD->getOverloadedOperator();
  assert(OO != OO_None && "not an overloaded operator!")(static_cast<void> (0));
  return visitBinaryOperator(OO, Args, Subobj);
}

Result
visitBinaryOperator(OverloadedOperatorKind OO, ArrayRef<Expr *> Args,
                    Subobject Subobj,
                    OverloadCandidateSet *SpaceshipCandidates = nullptr) {
  // Note that there is no need to consider rewritten candidates here if
  // we've already found there is no viable 'operator<=>' candidate (and are
  // considering synthesizing a '<=>' from '==' and '<').
  OverloadCandidateSet CandidateSet(
      FD->getLocation(), OverloadCandidateSet::CSK_Operator,
      OverloadCandidateSet::OperatorRewriteInfo(
          OO, /*AllowRewrittenCandidates=*/!SpaceshipCandidates));

  /// C++2a [class.compare.default]p1 [P2002R0]:
  ///   [...] the defaulted function itself is never a candidate for overload
  ///   resolution [...]
  CandidateSet.exclude(FD);

  if (Args[0]->getType()->isOverloadableType())
    S.LookupOverloadedBinOp(CandidateSet, OO, Fns, Args);
  else
    // FIXME: We determine whether this is a valid expression by checking to
    // see if there's a viable builtin operator candidate for it. That isn't
    // really what the rules ask us to do, but should give the right results.
    S.AddBuiltinOperatorCandidates(OO, FD->getLocation(), Args, CandidateSet);

  Result R;

  OverloadCandidateSet::iterator Best;
  switch (CandidateSet.BestViableFunction(S, FD->getLocation(), Best)) {
  case OR_Success: {
    // C++2a [class.compare.secondary]p2 [P2002R0]:
    //   The operator function [...] is defined as deleted if [...] the
    //   candidate selected by overload resolution is not a rewritten
    //   candidate.
    if ((DCK == DefaultedComparisonKind::NotEqual ||
         DCK == DefaultedComparisonKind::Relational) &&
        !Best->RewriteKind) {
      if (Diagnose == ExplainDeleted) {
        S.Diag(Best->Function->getLocation(),
               diag::note_defaulted_comparison_not_rewritten_callee)
            << FD;
      }
      return Result::deleted();
    }

    // Throughout C++2a [class.compare]: if overload resolution does not
    // result in a usable function, the candidate function is defined as
    // deleted. This requires that we selected an accessible function.
    //
    // Note that this only considers the access of the function when named
    // within the type of the subobject, and not the access path for any
    // derived-to-base conversion.
    CXXRecordDecl *ArgClass = Args[0]->getType()->getAsCXXRecordDecl();
    if (ArgClass && Best->FoundDecl.getDecl() &&
        Best->FoundDecl.getDecl()->isCXXClassMember()) {
      QualType ObjectType = Subobj.Kind == Subobject::Member
                                ? Args[0]->getType()
                                : S.Context.getRecordType(RD);
      if (!S.isMemberAccessibleForDeletion(
              ArgClass, Best->FoundDecl, ObjectType, Subobj.Loc,
              Diagnose == ExplainDeleted
                  ? S.PDiag(diag::note_defaulted_comparison_inaccessible)
                        << FD << Subobj.Kind << Subobj.Decl
                  : S.PDiag()))
        return Result::deleted();
    }

    bool NeedsDeducing =
        OO == OO_Spaceship && FD->getReturnType()->isUndeducedAutoType();

    if (FunctionDecl *BestFD = Best->Function) {
      // C++2a [class.compare.default]p3 [P2002R0]:
      //   A defaulted comparison function is constexpr-compatible if
      //   [...] no overlod resolution performed [...] results in a
      //   non-constexpr function.
      assert(!BestFD->isDeleted() && "wrong overload resolution result")(static_cast<void> (0));
      // If it's not constexpr, explain why not.
      if (Diagnose == ExplainConstexpr && !BestFD->isConstexpr()) {
        if (Subobj.Kind != Subobject::CompleteObject)
          S.Diag(Subobj.Loc, diag::note_defaulted_comparison_not_constexpr)
            << Subobj.Kind << Subobj.Decl;
        S.Diag(BestFD->getLocation(),
               diag::note_defaulted_comparison_not_constexpr_here);
        // Bail out after explaining; we don't want any more notes.
        return Result::deleted();
      }
      R.Constexpr &= BestFD->isConstexpr();

      if (NeedsDeducing) {
        // If any callee has an undeduced return type, deduce it now.
        // FIXME: It's not clear how a failure here should be handled. For
        // now, we produce an eager diagnostic, because that is forward
        // compatible with most (all?) other reasonable options.
        if (BestFD->getReturnType()->isUndeducedType() &&
            S.DeduceReturnType(BestFD, FD->getLocation(),
                               /*Diagnose=*/false)) {
          // Don't produce a duplicate error when asked to explain why the
          // comparison is deleted: we diagnosed that when initially checking
          // the defaulted operator.
          if (Diagnose == NoDiagnostics) {
            S.Diag(
                FD->getLocation(),
                diag::err_defaulted_comparison_cannot_deduce_undeduced_auto)
                << Subobj.Kind << Subobj.Decl;
            S.Diag(
                Subobj.Loc,
                diag::note_defaulted_comparison_cannot_deduce_undeduced_auto)
                << Subobj.Kind << Subobj.Decl;
            S.Diag(BestFD->getLocation(),
                   diag::note_defaulted_comparison_cannot_deduce_callee)
                << Subobj.Kind << Subobj.Decl;
          }
          return Result::deleted();
        }
        auto *Info = S.Context.CompCategories.lookupInfoForType(
            BestFD->getCallResultType());
        if (!Info) {
          if (Diagnose == ExplainDeleted) {
            S.Diag(Subobj.Loc, diag::note_defaulted_comparison_cannot_deduce)
                << Subobj.Kind << Subobj.Decl
                << BestFD->getCallResultType().withoutLocalFastQualifiers();
            S.Diag(BestFD->getLocation(),
                   diag::note_defaulted_comparison_cannot_deduce_callee)
                << Subobj.Kind << Subobj.Decl;
          }
          return Result::deleted();
        }
        R.Category = Info->Kind;
      }
    } else {
      QualType T = Best->BuiltinParamTypes[0];
      assert(T == Best->BuiltinParamTypes[1] &&(static_cast<void> (0))
             "builtin comparison for different types?")(static_cast<void> (0));
      assert(Best->BuiltinParamTypes[2].isNull() &&(static_cast<void> (0))
             "invalid builtin comparison")(static_cast<void> (0));

      if (NeedsDeducing) {
        Optional<ComparisonCategoryType> Cat =
            getComparisonCategoryForBuiltinCmp(T);
        assert(Cat && "no category for builtin comparison?")(static_cast<void> (0));
        R.Category = *Cat;
      }
    }

    // Note that we might be rewriting to a different operator. That call is
    // not considered until we come to actually build the comparison function.
    break;
  }

  case OR_Ambiguous:
    if (Diagnose == ExplainDeleted) {
      unsigned Kind = 0;
      if (FD->getOverloadedOperator() == OO_Spaceship && OO != OO_Spaceship)
        Kind = OO == OO_EqualEqual ? 1 : 2;
      CandidateSet.NoteCandidates(
          PartialDiagnosticAt(
              Subobj.Loc, S.PDiag(diag::note_defaulted_comparison_ambiguous)
                              << FD << Kind << Subobj.Kind << Subobj.Decl),
          S, OCD_AmbiguousCandidates, Args);
    }
    R = Result::deleted();
    break;

  case OR_Deleted:
    if (Diagnose == ExplainDeleted) {
      if ((DCK == DefaultedComparisonKind::NotEqual ||
           DCK == DefaultedComparisonKind::Relational) &&
          !Best->RewriteKind) {
        S.Diag(Best->Function->getLocation(),
               diag::note_defaulted_comparison_not_rewritten_callee)
            << FD;
      } else {
        S.Diag(Subobj.Loc,
               diag::note_defaulted_comparison_calls_deleted)
            << FD << Subobj.Kind << Subobj.Decl;
        S.NoteDeletedFunction(Best->Function);
      }
    }
    R = Result::deleted();
    break;

  case OR_No_Viable_Function:
    // If there's no usable candidate, we're done unless we can rewrite a
    // '<=>' in terms of '==' and '<'.
    if (OO == OO_Spaceship &&
        S.Context.CompCategories.lookupInfoForType(FD->getReturnType())) {
      // For any kind of comparison category return type, we need a usable
      // '==' and a usable '<'.
      if (!R.add(visitBinaryOperator(OO_EqualEqual, Args, Subobj,
                                     &CandidateSet)))
        R.add(visitBinaryOperator(OO_Less, Args, Subobj, &CandidateSet));
      break;
    }

    if (Diagnose == ExplainDeleted) {
      S.Diag(Subobj.Loc, diag::note_defaulted_comparison_no_viable_function)
          << FD << Subobj.Kind << Subobj.Decl;

      // For a three-way comparison, list both the candidates for the
      // original operator and the candidates for the synthesized operator.
      if (SpaceshipCandidates) {
        SpaceshipCandidates->NoteCandidates(
            S, Args,
            SpaceshipCandidates->CompleteCandidates(S, OCD_AllCandidates,
                                                    Args, FD->getLocation()));
        S.Diag(Subobj.Loc,
               diag::note_defaulted_comparison_no_viable_function_synthesized)
            << (OO == OO_EqualEqual ? 0 : 1);
      }

      CandidateSet.NoteCandidates(
          S, Args,
          CandidateSet.CompleteCandidates(S, OCD_AllCandidates, Args,
                                          FD->getLocation()));
    }
    R = Result::deleted();
    break;
  }

  return R;
}
7990};

7992/// A list of statements.
7993struct StmtListResult {
bool IsInvalid = false;
llvm::SmallVector<Stmt*, 16> Stmts;

bool add(const StmtResult &S) {
  IsInvalid |= S.isInvalid();
  if (IsInvalid)
    return true;
  Stmts.push_back(S.get());
  return false;
}
8004};

8006/// A visitor over the notional body of a defaulted comparison that synthesizes
8007/// the actual body.
8008class DefaultedComparisonSynthesizer
  : public DefaultedComparisonVisitor<DefaultedComparisonSynthesizer,
                                      StmtListResult, StmtResult,
                                      std::pair<ExprResult, ExprResult>> {
SourceLocation Loc;
unsigned ArrayDepth = 0;

8015public:
using Base = DefaultedComparisonVisitor;
using ExprPair = std::pair<ExprResult, ExprResult>;

friend Base;

DefaultedComparisonSynthesizer(Sema &S, CXXRecordDecl *RD, FunctionDecl *FD,
                               DefaultedComparisonKind DCK,
                               SourceLocation BodyLoc)
    : Base(S, RD, FD, DCK), Loc(BodyLoc) {}

/// Build a suitable function body for this defaulted comparison operator.
StmtResult build() {
  Sema::CompoundScopeRAII CompoundScope(S);

  StmtListResult Stmts = visit();
  if (Stmts.IsInvalid)
    return StmtError();

  ExprResult RetVal;
  switch (DCK) {
  case DefaultedComparisonKind::None:
    llvm_unreachable("not a defaulted comparison")__builtin_unreachable();

  case DefaultedComparisonKind::Equal: {
    // C++2a [class.eq]p3:
    //   [...] compar[e] the corresponding elements [...] until the first
    //   index i where xi == yi yields [...] false. If no such index exists,
    //   V is true. Otherwise, V is false.
    //
    // Join the comparisons with '&&'s and return the result. Use a right
    // fold (traversing the conditions right-to-left), because that
    // short-circuits more naturally.
    auto OldStmts = std::move(Stmts.Stmts);
    Stmts.Stmts.clear();
    ExprResult CmpSoFar;
    // Finish a particular comparison chain.
    auto FinishCmp = [&] {
      if (Expr *Prior = CmpSoFar.get()) {
        // Convert the last expression to 'return ...;'
        if (RetVal.isUnset() && Stmts.Stmts.empty())
          RetVal = CmpSoFar;
        // Convert any prior comparison to 'if (!(...)) return false;'
        else if (Stmts.add(buildIfNotCondReturnFalse(Prior)))
          return true;
        CmpSoFar = ExprResult();
      }
      return false;
    };
    for (Stmt *EAsStmt : llvm::reverse(OldStmts)) {
      Expr *E = dyn_cast<Expr>(EAsStmt);
      if (!E) {
        // Found an array comparison.
        if (FinishCmp() || Stmts.add(EAsStmt))
          return StmtError();
        continue;
      }

      if (CmpSoFar.isUnset()) {
        CmpSoFar = E;
        continue;
      }
      CmpSoFar = S.CreateBuiltinBinOp(Loc, BO_LAnd, E, CmpSoFar.get());
      if (CmpSoFar.isInvalid())
        return StmtError();
    }
    if (FinishCmp())
      return StmtError();
    std::reverse(Stmts.Stmts.begin(), Stmts.Stmts.end());
    //   If no such index exists, V is true.
    if (RetVal.isUnset())
      RetVal = S.ActOnCXXBoolLiteral(Loc, tok::kw_true);
    break;
  }

  case DefaultedComparisonKind::ThreeWay: {
    // Per C++2a [class.spaceship]p3, as a fallback add:
    // return static_cast<R>(std::strong_ordering::equal);
    QualType StrongOrdering = S.CheckComparisonCategoryType(
        ComparisonCategoryType::StrongOrdering, Loc,
        Sema::ComparisonCategoryUsage::DefaultedOperator);
    if (StrongOrdering.isNull())
      return StmtError();
    VarDecl *EqualVD = S.Context.CompCategories.getInfoForType(StrongOrdering)
                           .getValueInfo(ComparisonCategoryResult::Equal)
                           ->VD;
    RetVal = getDecl(EqualVD);
    if (RetVal.isInvalid())
      return StmtError();
    RetVal = buildStaticCastToR(RetVal.get());
    break;
  }

  case DefaultedComparisonKind::NotEqual:
  case DefaultedComparisonKind::Relational:
    RetVal = cast<Expr>(Stmts.Stmts.pop_back_val());
    break;
  }

  // Build the final return statement.
  if (RetVal.isInvalid())
    return StmtError();
  StmtResult ReturnStmt = S.BuildReturnStmt(Loc, RetVal.get());
  if (ReturnStmt.isInvalid())
    return StmtError();
  Stmts.Stmts.push_back(ReturnStmt.get());

  return S.ActOnCompoundStmt(Loc, Loc, Stmts.Stmts, /*IsStmtExpr=*/false);
}

8125private:
ExprResult getDecl(ValueDecl *VD) {
  return S.BuildDeclarationNameExpr(
      CXXScopeSpec(), DeclarationNameInfo(VD->getDeclName(), Loc), VD);
}

ExprResult getParam(unsigned I) {
  ParmVarDecl *PD = FD->getParamDecl(I);
  return getDecl(PD);
}

ExprPair getCompleteObject() {
  unsigned Param = 0;
  ExprResult LHS;
  if (isa<CXXMethodDecl>(FD)) {
    // LHS is '*this'.
    LHS = S.ActOnCXXThis(Loc);
    if (!LHS.isInvalid())
      LHS = S.CreateBuiltinUnaryOp(Loc, UO_Deref, LHS.get());
  } else {
    LHS = getParam(Param++);
  }
  ExprResult RHS = getParam(Param++);
  assert(Param == FD->getNumParams())(static_cast<void> (0));
  return {LHS, RHS};
}

ExprPair getBase(CXXBaseSpecifier *Base) {
  ExprPair Obj = getCompleteObject();
  if (Obj.first.isInvalid() || Obj.second.isInvalid())
    return {ExprError(), ExprError()};
  CXXCastPath Path = {Base};
  return {S.ImpCastExprToType(Obj.first.get(), Base->getType(),
                              CK_DerivedToBase, VK_LValue, &Path),
          S.ImpCastExprToType(Obj.second.get(), Base->getType(),
                              CK_DerivedToBase, VK_LValue, &Path)};
}

ExprPair getField(FieldDecl *Field) {
  ExprPair Obj = getCompleteObject();
  if (Obj.first.isInvalid() || Obj.second.isInvalid())
    return {ExprError(), ExprError()};

  DeclAccessPair Found = DeclAccessPair::make(Field, Field->getAccess());
  DeclarationNameInfo NameInfo(Field->getDeclName(), Loc);
  return {S.BuildFieldReferenceExpr(Obj.first.get(), /*IsArrow=*/false, Loc,
                                    CXXScopeSpec(), Field, Found, NameInfo),
          S.BuildFieldReferenceExpr(Obj.second.get(), /*IsArrow=*/false, Loc,
                                    CXXScopeSpec(), Field, Found, NameInfo)};
}

// FIXME: When expanding a subobject, register a note in the code synthesis
// stack to say which subobject we're comparing.

StmtResult buildIfNotCondReturnFalse(ExprResult Cond) {
  if (Cond.isInvalid())
    return StmtError();

  ExprResult NotCond = S.CreateBuiltinUnaryOp(Loc, UO_LNot, Cond.get());
  if (NotCond.isInvalid())
    return StmtError();

  ExprResult False = S.ActOnCXXBoolLiteral(Loc, tok::kw_false);
  assert(!False.isInvalid() && "should never fail")(static_cast<void> (0));
  StmtResult ReturnFalse = S.BuildReturnStmt(Loc, False.get());
  if (ReturnFalse.isInvalid())
    return StmtError();

  return S.ActOnIfStmt(Loc, false, Loc, nullptr,
                       S.ActOnCondition(nullptr, Loc, NotCond.get(),
                                        Sema::ConditionKind::Boolean),
                       Loc, ReturnFalse.get(), SourceLocation(), nullptr);
}

StmtResult visitSubobjectArray(QualType Type, llvm::APInt Size,
                               ExprPair Subobj) {
  QualType SizeType = S.Context.getSizeType();
  Size = Size.zextOrTrunc(S.Context.getTypeSize(SizeType));

  // Build 'size_t i$n = 0'.
  IdentifierInfo *IterationVarName = nullptr;
  {
    SmallString<8> Str;
    llvm::raw_svector_ostream OS(Str);
    OS << "i" << ArrayDepth;
    IterationVarName = &S.Context.Idents.get(OS.str());
  }
  VarDecl *IterationVar = VarDecl::Create(
      S.Context, S.CurContext, Loc, Loc, IterationVarName, SizeType,
      S.Context.getTrivialTypeSourceInfo(SizeType, Loc), SC_None);
  llvm::APInt Zero(S.Context.getTypeSize(SizeType), 0);
  IterationVar->setInit(
      IntegerLiteral::Create(S.Context, Zero, SizeType, Loc));
  Stmt *Init = new (S.Context) DeclStmt(DeclGroupRef(IterationVar), Loc, Loc);

  auto IterRef = [&] {
    ExprResult Ref = S.BuildDeclarationNameExpr(
        CXXScopeSpec(), DeclarationNameInfo(IterationVarName, Loc),
        IterationVar);
    assert(!Ref.isInvalid() && "can't reference our own variable?")(static_cast<void> (0));
    return Ref.get();
  };

  // Build 'i$n != Size'.
  ExprResult Cond = S.CreateBuiltinBinOp(
      Loc, BO_NE, IterRef(),
      IntegerLiteral::Create(S.Context, Size, SizeType, Loc));
  assert(!Cond.isInvalid() && "should never fail")(static_cast<void> (0));

  // Build '++i$n'.
  ExprResult Inc = S.CreateBuiltinUnaryOp(Loc, UO_PreInc, IterRef());
  assert(!Inc.isInvalid() && "should never fail")(static_cast<void> (0));

  // Build 'a[i$n]' and 'b[i$n]'.
  auto Index = [&](ExprResult E) {
    if (E.isInvalid())
      return ExprError();
    return S.CreateBuiltinArraySubscriptExpr(E.get(), Loc, IterRef(), Loc);
  };
  Subobj.first = Index(Subobj.first);
  Subobj.second = Index(Subobj.second);

  // Compare the array elements.
  ++ArrayDepth;
  StmtResult Substmt = visitSubobject(Type, Subobj);
  --ArrayDepth;

  if (Substmt.isInvalid())
    return StmtError();

  // For the inner level of an 'operator==', build 'if (!cmp) return false;'.
  // For outer levels or for an 'operator<=>' we already have a suitable
  // statement that returns as necessary.
  if (Expr *ElemCmp = dyn_cast<Expr>(Substmt.get())) {
    assert(DCK == DefaultedComparisonKind::Equal &&(static_cast<void> (0))
           "should have non-expression statement")(static_cast<void> (0));
    Substmt = buildIfNotCondReturnFalse(ElemCmp);
    if (Substmt.isInvalid())
      return StmtError();
  }

  // Build 'for (...) ...'
  return S.ActOnForStmt(Loc, Loc, Init,
                        S.ActOnCondition(nullptr, Loc, Cond.get(),
                                         Sema::ConditionKind::Boolean),
                        S.MakeFullDiscardedValueExpr(Inc.get()), Loc,
                        Substmt.get());
}

StmtResult visitExpandedSubobject(QualType Type, ExprPair Obj) {
  if (Obj.first.isInvalid() || Obj.second.isInvalid())
    return StmtError();

  OverloadedOperatorKind OO = FD->getOverloadedOperator();
  BinaryOperatorKind Opc = BinaryOperator::getOverloadedOpcode(OO);
  ExprResult Op;
  if (Type->isOverloadableType())
    Op = S.CreateOverloadedBinOp(Loc, Opc, Fns, Obj.first.get(),
                                 Obj.second.get(), /*PerformADL=*/true,
                                 /*AllowRewrittenCandidates=*/true, FD);
  else
    Op = S.CreateBuiltinBinOp(Loc, Opc, Obj.first.get(), Obj.second.get());
  if (Op.isInvalid())
    return StmtError();

  switch (DCK) {
  case DefaultedComparisonKind::None:
    llvm_unreachable("not a defaulted comparison")__builtin_unreachable();

  case DefaultedComparisonKind::Equal:
    // Per C++2a [class.eq]p2, each comparison is individually contextually
    // converted to bool.
    Op = S.PerformContextuallyConvertToBool(Op.get());
    if (Op.isInvalid())
      return StmtError();
    return Op.get();

  case DefaultedComparisonKind::ThreeWay: {
    // Per C++2a [class.spaceship]p3, form:
    //   if (R cmp = static_cast<R>(op); cmp != 0)
    //     return cmp;
    QualType R = FD->getReturnType();
    Op = buildStaticCastToR(Op.get());
    if (Op.isInvalid())
      return StmtError();

    // R cmp = ...;
    IdentifierInfo *Name = &S.Context.Idents.get("cmp");
    VarDecl *VD =
        VarDecl::Create(S.Context, S.CurContext, Loc, Loc, Name, R,
                        S.Context.getTrivialTypeSourceInfo(R, Loc), SC_None);
    S.AddInitializerToDecl(VD, Op.get(), /*DirectInit=*/false);
    Stmt *InitStmt = new (S.Context) DeclStmt(DeclGroupRef(VD), Loc, Loc);

    // cmp != 0
    ExprResult VDRef = getDecl(VD);
    if (VDRef.isInvalid())
      return StmtError();
    llvm::APInt ZeroVal(S.Context.getIntWidth(S.Context.IntTy), 0);
    Expr *Zero =
        IntegerLiteral::Create(S.Context, ZeroVal, S.Context.IntTy, Loc);
    ExprResult Comp;
    if (VDRef.get()->getType()->isOverloadableType())
      Comp = S.CreateOverloadedBinOp(Loc, BO_NE, Fns, VDRef.get(), Zero, true,
                                     true, FD);
    else
      Comp = S.CreateBuiltinBinOp(Loc, BO_NE, VDRef.get(), Zero);
    if (Comp.isInvalid())
      return StmtError();
    Sema::ConditionResult Cond = S.ActOnCondition(
        nullptr, Loc, Comp.get(), Sema::ConditionKind::Boolean);
    if (Cond.isInvalid())
      return StmtError();

    // return cmp;
    VDRef = getDecl(VD);
    if (VDRef.isInvalid())
      return StmtError();
    StmtResult ReturnStmt = S.BuildReturnStmt(Loc, VDRef.get());
    if (ReturnStmt.isInvalid())
      return StmtError();

    // if (...)
    return S.ActOnIfStmt(Loc, /*IsConstexpr=*/false, Loc, InitStmt, Cond, Loc,
                         ReturnStmt.get(),
                         /*ElseLoc=*/SourceLocation(), /*Else=*/nullptr);
  }

  case DefaultedComparisonKind::NotEqual:
  case DefaultedComparisonKind::Relational:
    // C++2a [class.compare.secondary]p2:
    //   Otherwise, the operator function yields x @ y.
    return Op.get();
  }
  llvm_unreachable("")__builtin_unreachable();
}

/// Build "static_cast<R>(E)".
ExprResult buildStaticCastToR(Expr *E) {
  QualType R = FD->getReturnType();
  assert(!R->isUndeducedType() && "type should have been deduced already")(static_cast<void> (0));

  // Don't bother forming a no-op cast in the common case.
  if (E->isPRValue() && S.Context.hasSameType(E->getType(), R))
    return E;
  return S.BuildCXXNamedCast(Loc, tok::kw_static_cast,
                             S.Context.getTrivialTypeSourceInfo(R, Loc), E,
                             SourceRange(Loc, Loc), SourceRange(Loc, Loc));
}
8374};
8375}

8377/// Perform the unqualified lookups that might be needed to form a defaulted
8378/// comparison function for the given operator.
8379static void lookupOperatorsForDefaultedComparison(Sema &Self, Scope *S,
                                                UnresolvedSetImpl &Operators,
                                                OverloadedOperatorKind Op) {
auto Lookup = [&](OverloadedOperatorKind OO) {
  Self.LookupOverloadedOperatorName(OO, S, Operators);
};

// Every defaulted operator looks up itself.
Lookup(Op);
// ... and the rewritten form of itself, if any.
if (OverloadedOperatorKind ExtraOp = getRewrittenOverloadedOperator(Op))
  Lookup(ExtraOp);

// For 'operator<=>', we also form a 'cmp != 0' expression, and might
// synthesize a three-way comparison from '<' and '=='. In a dependent
// context, we also need to look up '==' in case we implicitly declare a
// defaulted 'operator=='.
if (Op == OO_Spaceship) {
  Lookup(OO_ExclaimEqual);
  Lookup(OO_Less);
  Lookup(OO_EqualEqual);
}
8401}

8403bool Sema::CheckExplicitlyDefaultedComparison(Scope *S, FunctionDecl *FD,
                                            DefaultedComparisonKind DCK) {
assert(DCK != DefaultedComparisonKind::None && "not a defaulted comparison")(static_cast<void> (0));

CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(FD->getLexicalDeclContext());
assert(RD && "defaulted comparison is not defaulted in a class")(static_cast<void> (0));

// Perform any unqualified lookups we're going to need to default this
// function.
if (S) {
  UnresolvedSet<32> Operators;
  lookupOperatorsForDefaultedComparison(*this, S, Operators,
                                        FD->getOverloadedOperator());
  FD->setDefaultedFunctionInfo(FunctionDecl::DefaultedFunctionInfo::Create(
      Context, Operators.pairs()));
}

// C++2a [class.compare.default]p1:
//   A defaulted comparison operator function for some class C shall be a
//   non-template function declared in the member-specification of C that is
//    -- a non-static const member of C having one parameter of type
//       const C&, or
//    -- a friend of C having two parameters of type const C& or two
//       parameters of type C.
QualType ExpectedParmType1 = Context.getRecordType(RD);
QualType ExpectedParmType2 =
    Context.getLValueReferenceType(ExpectedParmType1.withConst());
if (isa<CXXMethodDecl>(FD))
  ExpectedParmType1 = ExpectedParmType2;
for (const ParmVarDecl *Param : FD->parameters()) {
  if (!Param->getType()->isDependentType() &&
      !Context.hasSameType(Param->getType(), ExpectedParmType1) &&
      !Context.hasSameType(Param->getType(), ExpectedParmType2)) {
    // Don't diagnose an implicit 'operator=='; we will have diagnosed the
    // corresponding defaulted 'operator<=>' already.
    if (!FD->isImplicit()) {
      Diag(FD->getLocation(), diag::err_defaulted_comparison_param)
          << (int)DCK << Param->getType() << ExpectedParmType1
          << !isa<CXXMethodDecl>(FD)
          << ExpectedParmType2 << Param->getSourceRange();
    }
    return true;
  }
}
if (FD->getNumParams() == 2 &&
    !Context.hasSameType(FD->getParamDecl(0)->getType(),
                         FD->getParamDecl(1)->getType())) {
  if (!FD->isImplicit()) {
    Diag(FD->getLocation(), diag::err_defaulted_comparison_param_mismatch)
        << (int)DCK
        << FD->getParamDecl(0)->getType()
        << FD->getParamDecl(0)->getSourceRange()
        << FD->getParamDecl(1)->getType()
        << FD->getParamDecl(1)->getSourceRange();
  }
  return true;
}

// ... non-static const member ...
if (auto *MD = dyn_cast<CXXMethodDecl>(FD)) {
  assert(!MD->isStatic() && "comparison function cannot be a static member")(static_cast<void> (0));
  if (!MD->isConst()) {
    SourceLocation InsertLoc;
    if (FunctionTypeLoc Loc = MD->getFunctionTypeLoc())
      InsertLoc = getLocForEndOfToken(Loc.getRParenLoc());
    // Don't diagnose an implicit 'operator=='; we will have diagnosed the
    // corresponding defaulted 'operator<=>' already.
    if (!MD->isImplicit()) {
      Diag(MD->getLocation(), diag::err_defaulted_comparison_non_const)
        << (int)DCK << FixItHint::CreateInsertion(InsertLoc, " const");
    }

    // Add the 'const' to the type to recover.
    const auto *FPT = MD->getType()->castAs<FunctionProtoType>();
    FunctionProtoType::ExtProtoInfo EPI = FPT->getExtProtoInfo();
    EPI.TypeQuals.addConst();
    MD->setType(Context.getFunctionType(FPT->getReturnType(),
                                        FPT->getParamTypes(), EPI));
  }
} else {
  // A non-member function declared in a class must be a friend.
  assert(FD->getFriendObjectKind() && "expected a friend declaration")(static_cast<void> (0));
}

// C++2a [class.eq]p1, [class.rel]p1:
//   A [defaulted comparison other than <=>] shall have a declared return
//   type bool.
if (DCK != DefaultedComparisonKind::ThreeWay &&
    !FD->getDeclaredReturnType()->isDependentType() &&
    !Context.hasSameType(FD->getDeclaredReturnType(), Context.BoolTy)) {
  Diag(FD->getLocation(), diag::err_defaulted_comparison_return_type_not_bool)
      << (int)DCK << FD->getDeclaredReturnType() << Context.BoolTy
      << FD->getReturnTypeSourceRange();
  return true;
}
// C++2a [class.spaceship]p2 [P2002R0]:
//   Let R be the declared return type [...]. If R is auto, [...]. Otherwise,
//   R shall not contain a placeholder type.
if (DCK == DefaultedComparisonKind::ThreeWay &&
    FD->getDeclaredReturnType()->getContainedDeducedType() &&
    !Context.hasSameType(FD->getDeclaredReturnType(),
                         Context.getAutoDeductType())) {
  Diag(FD->getLocation(),
       diag::err_defaulted_comparison_deduced_return_type_not_auto)
      << (int)DCK << FD->getDeclaredReturnType() << Context.AutoDeductTy
      << FD->getReturnTypeSourceRange();
  return true;
}

// For a defaulted function in a dependent class, defer all remaining checks
// until instantiation.
if (RD->isDependentType())
  return false;

// Determine whether the function should be defined as deleted.
DefaultedComparisonInfo Info =
    DefaultedComparisonAnalyzer(*this, RD, FD, DCK).visit();

bool First = FD == FD->getCanonicalDecl();

// If we want to delete the function, then do so; there's nothing else to
// check in that case.
if (Info.Deleted) {
  if (!First) {
    // C++11 [dcl.fct.def.default]p4:
    //   [For a] user-provided explicitly-defaulted function [...] if such a
    //   function is implicitly defined as deleted, the program is ill-formed.
    //
    // This is really just a consequence of the general rule that you can
    // only delete a function on its first declaration.
    Diag(FD->getLocation(), diag::err_non_first_default_compare_deletes)
        << FD->isImplicit() << (int)DCK;
    DefaultedComparisonAnalyzer(*this, RD, FD, DCK,
                                DefaultedComparisonAnalyzer::ExplainDeleted)
        .visit();
    return true;
  }

  SetDeclDeleted(FD, FD->getLocation());
  if (!inTemplateInstantiation() && !FD->isImplicit()) {
    Diag(FD->getLocation(), diag::warn_defaulted_comparison_deleted)
        << (int)DCK;
    DefaultedComparisonAnalyzer(*this, RD, FD, DCK,
                                DefaultedComparisonAnalyzer::ExplainDeleted)
        .visit();
  }
  return false;
}

// C++2a [class.spaceship]p2:
//   The return type is deduced as the common comparison type of R0, R1, ...
if (DCK == DefaultedComparisonKind::ThreeWay &&
    FD->getDeclaredReturnType()->isUndeducedAutoType()) {
  SourceLocation RetLoc = FD->getReturnTypeSourceRange().getBegin();
  if (RetLoc.isInvalid())
    RetLoc = FD->getBeginLoc();
  // FIXME: Should we really care whether we have the complete type and the
  // 'enumerator' constants here? A forward declaration seems sufficient.
  QualType Cat = CheckComparisonCategoryType(
      Info.Category, RetLoc, ComparisonCategoryUsage::DefaultedOperator);
  if (Cat.isNull())
    return true;
  Context.adjustDeducedFunctionResultType(
      FD, SubstAutoType(FD->getDeclaredReturnType(), Cat));
}

// C++2a [dcl.fct.def.default]p3 [P2002R0]:
//   An explicitly-defaulted function that is not defined as deleted may be
//   declared constexpr or consteval only if it is constexpr-compatible.
// C++2a [class.compare.default]p3 [P2002R0]:
//   A defaulted comparison function is constexpr-compatible if it satisfies
//   the requirements for a constexpr function [...]
// The only relevant requirements are that the parameter and return types are
// literal types. The remaining conditions are checked by the analyzer.
if (FD->isConstexpr()) {
  if (CheckConstexprReturnType(*this, FD, CheckConstexprKind::Diagnose) &&
      CheckConstexprParameterTypes(*this, FD, CheckConstexprKind::Diagnose) &&
      !Info.Constexpr) {
    Diag(FD->getBeginLoc(),
         diag::err_incorrect_defaulted_comparison_constexpr)
        << FD->isImplicit() << (int)DCK << FD->isConsteval();
    DefaultedComparisonAnalyzer(*this, RD, FD, DCK,
                                DefaultedComparisonAnalyzer::ExplainConstexpr)
        .visit();
  }
}

// C++2a [dcl.fct.def.default]p3 [P2002R0]:
//   If a constexpr-compatible function is explicitly defaulted on its first
//   declaration, it is implicitly considered to be constexpr.
// FIXME: Only applying this to the first declaration seems problematic, as
// simple reorderings can affect the meaning of the program.
if (First && !FD->isConstexpr() && Info.Constexpr)
  FD->setConstexprKind(ConstexprSpecKind::Constexpr);

// C++2a [except.spec]p3:
//   If a declaration of a function does not have a noexcept-specifier
//   [and] is defaulted on its first declaration, [...] the exception
//   specification is as specified below
if (FD->getExceptionSpecType() == EST_None) {
  auto *FPT = FD->getType()->castAs<FunctionProtoType>();
  FunctionProtoType::ExtProtoInfo EPI = FPT->getExtProtoInfo();
  EPI.ExceptionSpec.Type = EST_Unevaluated;
  EPI.ExceptionSpec.SourceDecl = FD;
  FD->setType(Context.getFunctionType(FPT->getReturnType(),
                                      FPT->getParamTypes(), EPI));
}

return false;
8612}

8614void Sema::DeclareImplicitEqualityComparison(CXXRecordDecl *RD,
                                           FunctionDecl *Spaceship) {
Sema::CodeSynthesisContext Ctx;
Ctx.Kind = Sema::CodeSynthesisContext::DeclaringImplicitEqualityComparison;
Ctx.PointOfInstantiation = Spaceship->getEndLoc();
Ctx.Entity = Spaceship;
pushCodeSynthesisContext(Ctx);

if (FunctionDecl *EqualEqual = SubstSpaceshipAsEqualEqual(RD, Spaceship))
  EqualEqual->setImplicit();

popCodeSynthesisContext();
8626}

8628void Sema::DefineDefaultedComparison(SourceLocation UseLoc, FunctionDecl *FD,
                                   DefaultedComparisonKind DCK) {
assert(FD->isDefaulted() && !FD->isDeleted() &&(static_cast<void> (0))
       !FD->doesThisDeclarationHaveABody())(static_cast<void> (0));
if (FD->willHaveBody() || FD->isInvalidDecl())
  return;

SynthesizedFunctionScope Scope(*this, FD);

// Add a context note for diagnostics produced after this point.
Scope.addContextNote(UseLoc);

{
  // Build and set up the function body.
  CXXRecordDecl *RD = cast<CXXRecordDecl>(FD->getLexicalParent());
  SourceLocation BodyLoc =
      FD->getEndLoc().isValid() ? FD->getEndLoc() : FD->getLocation();
  StmtResult Body =
      DefaultedComparisonSynthesizer(*this, RD, FD, DCK, BodyLoc).build();
  if (Body.isInvalid()) {
    FD->setInvalidDecl();
    return;
  }
  FD->setBody(Body.get());
  FD->markUsed(Context);
}

// The exception specification is needed because we are defining the
// function. Note that this will reuse the body we just built.
ResolveExceptionSpec(UseLoc, FD->getType()->castAs<FunctionProtoType>());

if (ASTMutationListener *L = getASTMutationListener())
  L->CompletedImplicitDefinition(FD);
8661}

8663static Sema::ImplicitExceptionSpecification
8664ComputeDefaultedComparisonExceptionSpec(Sema &S, SourceLocation Loc,
                                      FunctionDecl *FD,
                                      Sema::DefaultedComparisonKind DCK) {
ComputingExceptionSpec CES(S, FD, Loc);
Sema::ImplicitExceptionSpecification ExceptSpec(S);

if (FD->isInvalidDecl())
  return ExceptSpec;

// The common case is that we just defined the comparison function. In that
// case, just look at whether the body can throw.
if (FD->hasBody()) {
  ExceptSpec.CalledStmt(FD->getBody());
} else {
  // Otherwise, build a body so we can check it. This should ideally only
  // happen when we're not actually marking the function referenced. (This is
  // only really important for efficiency: we don't want to build and throw
  // away bodies for comparison functions more than we strictly need to.)

  // Pretend to synthesize the function body in an unevaluated context.
  // Note that we can't actually just go ahead and define the function here:
  // we are not permitted to mark its callees as referenced.
  Sema::SynthesizedFunctionScope Scope(S, FD);
  EnterExpressionEvaluationContext Context(
      S, Sema::ExpressionEvaluationContext::Unevaluated);

  CXXRecordDecl *RD = cast<CXXRecordDecl>(FD->getLexicalParent());
  SourceLocation BodyLoc =
      FD->getEndLoc().isValid() ? FD->getEndLoc() : FD->getLocation();
  StmtResult Body =
      DefaultedComparisonSynthesizer(S, RD, FD, DCK, BodyLoc).build();
  if (!Body.isInvalid())
    ExceptSpec.CalledStmt(Body.get());

  // FIXME: Can we hold onto this body and just transform it to potentially
  // evaluated when we're asked to define the function rather than rebuilding
  // it? Either that, or we should only build the bits of the body that we
  // need (the expressions, not the statements).
}

return ExceptSpec;
8705}

8707void Sema::CheckDelayedMemberExceptionSpecs() {
decltype(DelayedOverridingExceptionSpecChecks) Overriding;
decltype(DelayedEquivalentExceptionSpecChecks) Equivalent;

std::swap(Overriding, DelayedOverridingExceptionSpecChecks);
std::swap(Equivalent, DelayedEquivalentExceptionSpecChecks);

// Perform any deferred checking of exception specifications for virtual
// destructors.
for (auto &Check : Overriding)
  CheckOverridingFunctionExceptionSpec(Check.first, Check.second);

// Perform any deferred checking of exception specifications for befriended
// special members.
for (auto &Check : Equivalent)
  CheckEquivalentExceptionSpec(Check.second, Check.first);
8723}

8725namespace {
8726/// CRTP base class for visiting operations performed by a special member
8727/// function (or inherited constructor).
8728template<typename Derived>
8729struct SpecialMemberVisitor {
Sema &S;
CXXMethodDecl *MD;
Sema::CXXSpecialMember CSM;
Sema::InheritedConstructorInfo *ICI;

// Properties of the special member, computed for convenience.
bool IsConstructor = false, IsAssignment = false, ConstArg = false;

SpecialMemberVisitor(Sema &S, CXXMethodDecl *MD, Sema::CXXSpecialMember CSM,
                     Sema::InheritedConstructorInfo *ICI)
    : S(S), MD(MD), CSM(CSM), ICI(ICI) {
  switch (CSM) {
  case Sema::CXXDefaultConstructor:
  case Sema::CXXCopyConstructor:
  case Sema::CXXMoveConstructor:
    IsConstructor = true;
    break;
  case Sema::CXXCopyAssignment:
  case Sema::CXXMoveAssignment:
    IsAssignment = true;
    break;
  case Sema::CXXDestructor:
    break;
  case Sema::CXXInvalid:
    llvm_unreachable("invalid special member kind")__builtin_unreachable();
  }

  if (MD->getNumParams()) {
    if (const ReferenceType *RT =
            MD->getParamDecl(0)->getType()->getAs<ReferenceType>())
      ConstArg = RT->getPointeeType().isConstQualified();
  }
}

Derived &getDerived() { return static_cast<Derived&>(*this); }

/// Is this a "move" special member?
bool isMove() const {
  return CSM == Sema::CXXMoveConstructor || CSM == Sema::CXXMoveAssignment;
}

/// Look up the corresponding special member in the given class.
Sema::SpecialMemberOverloadResult lookupIn(CXXRecordDecl *Class,
                                           unsigned Quals, bool IsMutable) {
  return lookupCallFromSpecialMember(S, Class, CSM, Quals,
                                     ConstArg && !IsMutable);
}

/// Look up the constructor for the specified base class to see if it's
/// overridden due to this being an inherited constructor.
Sema::SpecialMemberOverloadResult lookupInheritedCtor(CXXRecordDecl *Class) {
  if (!ICI)
    return {};
  assert(CSM == Sema::CXXDefaultConstructor)(static_cast<void> (0));
  auto *BaseCtor =
    cast<CXXConstructorDecl>(MD)->getInheritedConstructor().getConstructor();
  if (auto *MD = ICI->findConstructorForBase(Class, BaseCtor).first)
    return MD;
  return {};
}

/// A base or member subobject.
typedef llvm::PointerUnion<CXXBaseSpecifier*, FieldDecl*> Subobject;

/// Get the location to use for a subobject in diagnostics.
static SourceLocation getSubobjectLoc(Subobject Subobj) {
  // FIXME: For an indirect virtual base, the direct base leading to
  // the indirect virtual base would be a more useful choice.
  if (auto *B = Subobj.dyn_cast<CXXBaseSpecifier*>())
    return B->getBaseTypeLoc();
  else
    return Subobj.get<FieldDecl*>()->getLocation();
}

enum BasesToVisit {
  /// Visit all non-virtual (direct) bases.
  VisitNonVirtualBases,
  /// Visit all direct bases, virtual or not.
  VisitDirectBases,
  /// Visit all non-virtual bases, and all virtual bases if the class
  /// is not abstract.
  VisitPotentiallyConstructedBases,
  /// Visit all direct or virtual bases.
  VisitAllBases
};

// Visit the bases and members of the class.
bool visit(BasesToVisit Bases) {
  CXXRecordDecl *RD = MD->getParent();

  if (Bases == VisitPotentiallyConstructedBases)
    Bases = RD->isAbstract() ? VisitNonVirtualBases : VisitAllBases;

  for (auto &B : RD->bases())
    if ((Bases == VisitDirectBases || !B.isVirtual()) &&
        getDerived().visitBase(&B))
      return true;

  if (Bases == VisitAllBases)
    for (auto &B : RD->vbases())
      if (getDerived().visitBase(&B))
        return true;

  for (auto *F : RD->fields())
    if (!F->isInvalidDecl() && !F->isUnnamedBitfield() &&
        getDerived().visitField(F))
      return true;

  return false;
}
8840};
8841}

8843namespace {
8844struct SpecialMemberDeletionInfo
  : SpecialMemberVisitor<SpecialMemberDeletionInfo> {
bool Diagnose;

SourceLocation Loc;

bool AllFieldsAreConst;

SpecialMemberDeletionInfo(Sema &S, CXXMethodDecl *MD,
                          Sema::CXXSpecialMember CSM,
                          Sema::InheritedConstructorInfo *ICI, bool Diagnose)
    : SpecialMemberVisitor(S, MD, CSM, ICI), Diagnose(Diagnose),
      Loc(MD->getLocation()), AllFieldsAreConst(true) {}

bool inUnion() const { return MD->getParent()->isUnion(); }

Sema::CXXSpecialMember getEffectiveCSM() {
  return ICI ? Sema::CXXInvalid : CSM;
}

bool shouldDeleteForVariantObjCPtrMember(FieldDecl *FD, QualType FieldType);

bool visitBase(CXXBaseSpecifier *Base) { return shouldDeleteForBase(Base); }
bool visitField(FieldDecl *Field) { return shouldDeleteForField(Field); }

bool shouldDeleteForBase(CXXBaseSpecifier *Base);
bool shouldDeleteForField(FieldDecl *FD);
bool shouldDeleteForAllConstMembers();

bool shouldDeleteForClassSubobject(CXXRecordDecl *Class, Subobject Subobj,
                                   unsigned Quals);
bool shouldDeleteForSubobjectCall(Subobject Subobj,
                                  Sema::SpecialMemberOverloadResult SMOR,
                                  bool IsDtorCallInCtor);

bool isAccessible(Subobject Subobj, CXXMethodDecl *D);
8880};
8881}

8883/// Is the given special member inaccessible when used on the given
8884/// sub-object.
8885bool SpecialMemberDeletionInfo::isAccessible(Subobject Subobj,
                                           CXXMethodDecl *target) {
/// If we're operating on a base class, the object type is the
/// type of this special member.
QualType objectTy;
AccessSpecifier access = target->getAccess();
if (CXXBaseSpecifier *base = Subobj.dyn_cast<CXXBaseSpecifier*>()) {
  objectTy = S.Context.getTypeDeclType(MD->getParent());
  access = CXXRecordDecl::MergeAccess(base->getAccessSpecifier(), access);

// If we're operating on a field, the object type is the type of the field.
} else {
  objectTy = S.Context.getTypeDeclType(target->getParent());
}

return S.isMemberAccessibleForDeletion(
    target->getParent(), DeclAccessPair::make(target, access), objectTy);
8902}

8904/// Check whether we should delete a special member due to the implicit
8905/// definition containing a call to a special member of a subobject.
8906bool SpecialMemberDeletionInfo::shouldDeleteForSubobjectCall(
  Subobject Subobj, Sema::SpecialMemberOverloadResult SMOR,
  bool IsDtorCallInCtor) {
CXXMethodDecl *Decl = SMOR.getMethod();
FieldDecl *Field = Subobj.dyn_cast<FieldDecl*>();

int DiagKind = -1;

if (SMOR.getKind() == Sema::SpecialMemberOverloadResult::NoMemberOrDeleted)
  DiagKind = !Decl ? 0 : 1;
else if (SMOR.getKind() == Sema::SpecialMemberOverloadResult::Ambiguous)
  DiagKind = 2;
else if (!isAccessible(Subobj, Decl))
  DiagKind = 3;
else if (!IsDtorCallInCtor && Field && Field->getParent()->isUnion() &&
         !Decl->isTrivial()) {
  // A member of a union must have a trivial corresponding special member.
  // As a weird special case, a destructor call from a union's constructor
  // must be accessible and non-deleted, but need not be trivial. Such a
  // destructor is never actually called, but is semantically checked as
  // if it were.
  DiagKind = 4;
}

if (DiagKind == -1)
  return false;

if (Diagnose) {
  if (Field) {
    S.Diag(Field->getLocation(),
           diag::note_deleted_special_member_class_subobject)
      << getEffectiveCSM() << MD->getParent() << /*IsField*/true
      << Field << DiagKind << IsDtorCallInCtor << /*IsObjCPtr*/false;
  } else {
    CXXBaseSpecifier *Base = Subobj.get<CXXBaseSpecifier*>();
    S.Diag(Base->getBeginLoc(),
           diag::note_deleted_special_member_class_subobject)
        << getEffectiveCSM() << MD->getParent() << /*IsField*/ false
        << Base->getType() << DiagKind << IsDtorCallInCtor
        << /*IsObjCPtr*/false;
  }

  if (DiagKind == 1)
    S.NoteDeletedFunction(Decl);
  // FIXME: Explain inaccessibility if DiagKind == 3.
}

return true;
8954}

8956/// Check whether we should delete a special member function due to having a
8957/// direct or virtual base class or non-static data member of class type M.
8958bool SpecialMemberDeletionInfo::shouldDeleteForClassSubobject(
  CXXRecordDecl *Class, Subobject Subobj, unsigned Quals) {
FieldDecl *Field = Subobj.dyn_cast<FieldDecl*>();
bool IsMutable = Field && Field->isMutable();

// C++11 [class.ctor]p5:
// -- any direct or virtual base class, or non-static data member with no
//    brace-or-equal-initializer, has class type M (or array thereof) and
//    either M has no default constructor or overload resolution as applied
//    to M's default constructor results in an ambiguity or in a function
//    that is deleted or inaccessible
// C++11 [class.copy]p11, C++11 [class.copy]p23:
// -- a direct or virtual base class B that cannot be copied/moved because
//    overload resolution, as applied to B's corresponding special member,
//    results in an ambiguity or a function that is deleted or inaccessible
//    from the defaulted special member
// C++11 [class.dtor]p5:
// -- any direct or virtual base class [...] has a type with a destructor
//    that is deleted or inaccessible
if (!(CSM == Sema::CXXDefaultConstructor &&
      Field && Field->hasInClassInitializer()) &&
    shouldDeleteForSubobjectCall(Subobj, lookupIn(Class, Quals, IsMutable),
                                 false))
  return true;

// C++11 [class.ctor]p5, C++11 [class.copy]p11:
// -- any direct or virtual base class or non-static data member has a
//    type with a destructor that is deleted or inaccessible
if (IsConstructor) {
  Sema::SpecialMemberOverloadResult SMOR =
      S.LookupSpecialMember(Class, Sema::CXXDestructor,
                            false, false, false, false, false);
  if (shouldDeleteForSubobjectCall(Subobj, SMOR, true))
    return true;
}

return false;
8995}

8997bool SpecialMemberDeletionInfo::shouldDeleteForVariantObjCPtrMember(
  FieldDecl *FD, QualType FieldType) {
// The defaulted special functions are defined as deleted if this is a variant
// member with a non-trivial ownership type, e.g., ObjC __strong or __weak
// type under ARC.
if (!FieldType.hasNonTrivialObjCLifetime())
  return false;

// Don't make the defaulted default constructor defined as deleted if the
// member has an in-class initializer.
if (CSM == Sema::CXXDefaultConstructor && FD->hasInClassInitializer())
  return false;

if (Diagnose) {
  auto *ParentClass = cast<CXXRecordDecl>(FD->getParent());
  S.Diag(FD->getLocation(),
         diag::note_deleted_special_member_class_subobject)
      << getEffectiveCSM() << ParentClass << /*IsField*/true
      << FD << 4 << /*IsDtorCallInCtor*/false << /*IsObjCPtr*/true;
}

return true;
9019}

9021/// Check whether we should delete a special member function due to the class
9022/// having a particular direct or virtual base class.
9023bool SpecialMemberDeletionInfo::shouldDeleteForBase(CXXBaseSpecifier *Base) {
CXXRecordDecl *BaseClass = Base->getType()->getAsCXXRecordDecl();
// If program is correct, BaseClass cannot be null, but if it is, the error
// must be reported elsewhere.
if (!BaseClass)
  return false;
// If we have an inheriting constructor, check whether we're calling an
// inherited constructor instead of a default constructor.
Sema::SpecialMemberOverloadResult SMOR = lookupInheritedCtor(BaseClass);
if (auto *BaseCtor = SMOR.getMethod()) {
  // Note that we do not check access along this path; other than that,
  // this is the same as shouldDeleteForSubobjectCall(Base, BaseCtor, false);
  // FIXME: Check that the base has a usable destructor! Sink this into
  // shouldDeleteForClassSubobject.
  if (BaseCtor->isDeleted() && Diagnose) {
    S.Diag(Base->getBeginLoc(),
           diag::note_deleted_special_member_class_subobject)
        << getEffectiveCSM() << MD->getParent() << /*IsField*/ false
        << Base->getType() << /*Deleted*/ 1 << /*IsDtorCallInCtor*/ false
        << /*IsObjCPtr*/false;
    S.NoteDeletedFunction(BaseCtor);
  }
  return BaseCtor->isDeleted();
}
return shouldDeleteForClassSubobject(BaseClass, Base, 0);
9048}

9050/// Check whether we should delete a special member function due to the class
9051/// having a particular non-static data member.
9052bool SpecialMemberDeletionInfo::shouldDeleteForField(FieldDecl *FD) {
QualType FieldType = S.Context.getBaseElementType(FD->getType());
CXXRecordDecl *FieldRecord = FieldType->getAsCXXRecordDecl();

if (inUnion() && shouldDeleteForVariantObjCPtrMember(FD, FieldType))
  return true;

if (CSM == Sema::CXXDefaultConstructor) {
  // For a default constructor, all references must be initialized in-class
  // and, if a union, it must have a non-const member.
  if (FieldType->isReferenceType() && !FD->hasInClassInitializer()) {
    if (Diagnose)
      S.Diag(FD->getLocation(), diag::note_deleted_default_ctor_uninit_field)
        << !!ICI << MD->getParent() << FD << FieldType << /*Reference*/0;
    return true;
  }
  // C++11 [class.ctor]p5: any non-variant non-static data member of
  // const-qualified type (or array thereof) with no
  // brace-or-equal-initializer does not have a user-provided default
  // constructor.
  if (!inUnion() && FieldType.isConstQualified() &&
      !FD->hasInClassInitializer() &&
      (!FieldRecord || !FieldRecord->hasUserProvidedDefaultConstructor())) {
    if (Diagnose)
      S.Diag(FD->getLocation(), diag::note_deleted_default_ctor_uninit_field)
        << !!ICI << MD->getParent() << FD << FD->getType() << /*Const*/1;
    return true;
  }

  if (inUnion() && !FieldType.isConstQualified())
    AllFieldsAreConst = false;
} else if (CSM == Sema::CXXCopyConstructor) {
  // For a copy constructor, data members must not be of rvalue reference
  // type.
  if (FieldType->isRValueReferenceType()) {
    if (Diagnose)
      S.Diag(FD->getLocation(), diag::note_deleted_copy_ctor_rvalue_reference)
        << MD->getParent() << FD << FieldType;
    return true;
  }
} else if (IsAssignment) {
  // For an assignment operator, data members must not be of reference type.
  if (FieldType->isReferenceType()) {
    if (Diagnose)
      S.Diag(FD->getLocation(), diag::note_deleted_assign_field)
        << isMove() << MD->getParent() << FD << FieldType << /*Reference*/0;
    return true;
  }
  if (!FieldRecord && FieldType.isConstQualified()) {
    // C++11 [class.copy]p23:
    // -- a non-static data member of const non-class type (or array thereof)
    if (Diagnose)
      S.Diag(FD->getLocation(), diag::note_deleted_assign_field)
        << isMove() << MD->getParent() << FD << FD->getType() << /*Const*/1;
    return true;
  }
}

if (FieldRecord) {
  // Some additional restrictions exist on the variant members.
  if (!inUnion() && FieldRecord->isUnion() &&
      FieldRecord->isAnonymousStructOrUnion()) {
    bool AllVariantFieldsAreConst = true;

    // FIXME: Handle anonymous unions declared within anonymous unions.
    for (auto *UI : FieldRecord->fields()) {
      QualType UnionFieldType = S.Context.getBaseElementType(UI->getType());

      if (shouldDeleteForVariantObjCPtrMember(&*UI, UnionFieldType))
        return true;

      if (!UnionFieldType.isConstQualified())
        AllVariantFieldsAreConst = false;

      CXXRecordDecl *UnionFieldRecord = UnionFieldType->getAsCXXRecordDecl();
      if (UnionFieldRecord &&
          shouldDeleteForClassSubobject(UnionFieldRecord, UI,
                                        UnionFieldType.getCVRQualifiers()))
        return true;
    }

    // At least one member in each anonymous union must be non-const
    if (CSM == Sema::CXXDefaultConstructor && AllVariantFieldsAreConst &&
        !FieldRecord->field_empty()) {
      if (Diagnose)
        S.Diag(FieldRecord->getLocation(),
               diag::note_deleted_default_ctor_all_const)
          << !!ICI << MD->getParent() << /*anonymous union*/1;
      return true;
    }

    // Don't check the implicit member of the anonymous union type.
    // This is technically non-conformant, but sanity demands it.
    return false;
  }

  if (shouldDeleteForClassSubobject(FieldRecord, FD,
                                    FieldType.getCVRQualifiers()))
    return true;
}

return false;
9154}

9156/// C++11 [class.ctor] p5:
9157///   A defaulted default constructor for a class X is defined as deleted if
9158/// X is a union and all of its variant members are of const-qualified type.
9159bool SpecialMemberDeletionInfo::shouldDeleteForAllConstMembers() {
// This is a silly definition, because it gives an empty union a deleted
// default constructor. Don't do that.
if (CSM == Sema::CXXDefaultConstructor && inUnion() && AllFieldsAreConst) {
  bool AnyFields = false;
  for (auto *F : MD->getParent()->fields())
    if ((AnyFields = !F->isUnnamedBitfield()))
      break;
  if (!AnyFields)
    return false;
  if (Diagnose)
    S.Diag(MD->getParent()->getLocation(),
           diag::note_deleted_default_ctor_all_const)
      << !!ICI << MD->getParent() << /*not anonymous union*/0;
  return true;
}
return false;
9176}

9178/// Determine whether a defaulted special member function should be defined as
9179/// deleted, as specified in C++11 [class.ctor]p5, C++11 [class.copy]p11,
9180/// C++11 [class.copy]p23, and C++11 [class.dtor]p5.
9181bool Sema::ShouldDeleteSpecialMember(CXXMethodDecl *MD, CXXSpecialMember CSM,
                                   InheritedConstructorInfo *ICI,
                                   bool Diagnose) {
if (MD->isInvalidDecl())
  return false;
CXXRecordDecl *RD = MD->getParent();
assert(!RD->isDependentType() && "do deletion after instantiation")(static_cast<void> (0));
if (!LangOpts.CPlusPlus11 || RD->isInvalidDecl())
  return false;

// C++11 [expr.lambda.prim]p19:
//   The closure type associated with a lambda-expression has a
//   deleted (8.4.3) default constructor and a deleted copy
//   assignment operator.
// C++2a adds back these operators if the lambda has no lambda-capture.
if (RD->isLambda() && !RD->lambdaIsDefaultConstructibleAndAssignable() &&
    (CSM == CXXDefaultConstructor || CSM == CXXCopyAssignment)) {
  if (Diagnose)
    Diag(RD->getLocation(), diag::note_lambda_decl);
  return true;
}

// For an anonymous struct or union, the copy and assignment special members
// will never be used, so skip the check. For an anonymous union declared at
// namespace scope, the constructor and destructor are used.
if (CSM != CXXDefaultConstructor && CSM != CXXDestructor &&
    RD->isAnonymousStructOrUnion())
  return false;

// C++11 [class.copy]p7, p18:
//   If the class definition declares a move constructor or move assignment
//   operator, an implicitly declared copy constructor or copy assignment
//   operator is defined as deleted.
if (MD->isImplicit() &&
    (CSM == CXXCopyConstructor || CSM == CXXCopyAssignment)) {
  CXXMethodDecl *UserDeclaredMove = nullptr;

  // In Microsoft mode up to MSVC 2013, a user-declared move only causes the
  // deletion of the corresponding copy operation, not both copy operations.
  // MSVC 2015 has adopted the standards conforming behavior.
  bool DeletesOnlyMatchingCopy =
      getLangOpts().MSVCCompat &&
      !getLangOpts().isCompatibleWithMSVC(LangOptions::MSVC2015);

  if (RD->hasUserDeclaredMoveConstructor() &&
      (!DeletesOnlyMatchingCopy || CSM == CXXCopyConstructor)) {
    if (!Diagnose) return true;

    // Find any user-declared move constructor.
    for (auto *I : RD->ctors()) {
      if (I->isMoveConstructor()) {
        UserDeclaredMove = I;
        break;
      }
    }
    assert(UserDeclaredMove)(static_cast<void> (0));
  } else if (RD->hasUserDeclaredMoveAssignment() &&
             (!DeletesOnlyMatchingCopy || CSM == CXXCopyAssignment)) {
    if (!Diagnose) return true;

    // Find any user-declared move assignment operator.
    for (auto *I : RD->methods()) {
      if (I->isMoveAssignmentOperator()) {
        UserDeclaredMove = I;
        break;
      }
    }
    assert(UserDeclaredMove)(static_cast<void> (0));
  }

  if (UserDeclaredMove) {
    Diag(UserDeclaredMove->getLocation(),
         diag::note_deleted_copy_user_declared_move)
      << (CSM == CXXCopyAssignment) << RD
      << UserDeclaredMove->isMoveAssignmentOperator();
    return true;
  }
}

// Do access control from the special member function
ContextRAII MethodContext(*this, MD);

// C++11 [class.dtor]p5:
// -- for a virtual destructor, lookup of the non-array deallocation function
//    results in an ambiguity or in a function that is deleted or inaccessible
if (CSM == CXXDestructor && MD->isVirtual()) {
  FunctionDecl *OperatorDelete = nullptr;
  DeclarationName Name =
    Context.DeclarationNames.getCXXOperatorName(OO_Delete);
  if (FindDeallocationFunction(MD->getLocation(), MD->getParent(), Name,
                               OperatorDelete, /*Diagnose*/false)) {
    if (Diagnose)
      Diag(RD->getLocation(), diag::note_deleted_dtor_no_operator_delete);
    return true;
  }
}

SpecialMemberDeletionInfo SMI(*this, MD, CSM, ICI, Diagnose);

// Per DR1611, do not consider virtual bases of constructors of abstract
// classes, since we are not going to construct them.
// Per DR1658, do not consider virtual bases of destructors of abstract
// classes either.
// Per DR2180, for assignment operators we only assign (and thus only
// consider) direct bases.
if (SMI.visit(SMI.IsAssignment ? SMI.VisitDirectBases
                               : SMI.VisitPotentiallyConstructedBases))
  return true;

if (SMI.shouldDeleteForAllConstMembers())
  return true;

if (getLangOpts().CUDA) {
  // We should delete the special member in CUDA mode if target inference
  // failed.
  // For inherited constructors (non-null ICI), CSM may be passed so that MD
  // is treated as certain special member, which may not reflect what special
  // member MD really is. However inferCUDATargetForImplicitSpecialMember
  // expects CSM to match MD, therefore recalculate CSM.
  assert(ICI || CSM == getSpecialMember(MD))(static_cast<void> (0));
  auto RealCSM = CSM;
  if (ICI)
    RealCSM = getSpecialMember(MD);

  return inferCUDATargetForImplicitSpecialMember(RD, RealCSM, MD,
                                                 SMI.ConstArg, Diagnose);
}

return false;
9310}

9312void Sema::DiagnoseDeletedDefaultedFunction(FunctionDecl *FD) {
DefaultedFunctionKind DFK = getDefaultedFunctionKind(FD);
assert(DFK && "not a defaultable function")(static_cast<void> (0));
assert(FD->isDefaulted() && FD->isDeleted() && "not defaulted and deleted")(static_cast<void> (0));

if (DFK.isSpecialMember()) {
  ShouldDeleteSpecialMember(cast<CXXMethodDecl>(FD), DFK.asSpecialMember(),
                            nullptr, /*Diagnose=*/true);
} else {
  DefaultedComparisonAnalyzer(
      *this, cast<CXXRecordDecl>(FD->getLexicalDeclContext()), FD,
      DFK.asComparison(), DefaultedComparisonAnalyzer::ExplainDeleted)
      .visit();
}
9326}

9328/// Perform lookup for a special member of the specified kind, and determine
9329/// whether it is trivial. If the triviality can be determined without the
9330/// lookup, skip it. This is intended for use when determining whether a
9331/// special member of a containing object is trivial, and thus does not ever
9332/// perform overload resolution for default constructors.
9333///
9334/// If \p Selected is not \c NULL, \c *Selected will be filled in with the
9335/// member that was most likely to be intended to be trivial, if any.
9336///
9337/// If \p ForCall is true, look at CXXRecord::HasTrivialSpecialMembersForCall to
9338/// determine whether the special member is trivial.
9339static bool findTrivialSpecialMember(Sema &S, CXXRecordDecl *RD,
                                   Sema::CXXSpecialMember CSM, unsigned Quals,
                                   bool ConstRHS,
                                   Sema::TrivialABIHandling TAH,
                                   CXXMethodDecl **Selected) {
if (Selected)
  *Selected = nullptr;

switch (CSM) {
case Sema::CXXInvalid:
  llvm_unreachable("not a special member")__builtin_unreachable();

case Sema::CXXDefaultConstructor:
  // C++11 [class.ctor]p5:
  //   A default constructor is trivial if:
  //    - all the [direct subobjects] have trivial default constructors
  //
  // Note, no overload resolution is performed in this case.
  if (RD->hasTrivialDefaultConstructor())
    return true;

  if (Selected) {
    // If there's a default constructor which could have been trivial, dig it
    // out. Otherwise, if there's any user-provided default constructor, point
    // to that as an example of why there's not a trivial one.
    CXXConstructorDecl *DefCtor = nullptr;
    if (RD->needsImplicitDefaultConstructor())
      S.DeclareImplicitDefaultConstructor(RD);
    for (auto *CI : RD->ctors()) {
      if (!CI->isDefaultConstructor())
        continue;
      DefCtor = CI;
      if (!DefCtor->isUserProvided())
        break;
    }

    *Selected = DefCtor;
  }

  return false;

case Sema::CXXDestructor:
  // C++11 [class.dtor]p5:
  //   A destructor is trivial if:
  //    - all the direct [subobjects] have trivial destructors
  if (RD->hasTrivialDestructor() ||
      (TAH == Sema::TAH_ConsiderTrivialABI &&
       RD->hasTrivialDestructorForCall()))
    return true;

  if (Selected) {
    if (RD->needsImplicitDestructor())
      S.DeclareImplicitDestructor(RD);
    *Selected = RD->getDestructor();
  }

  return false;

case Sema::CXXCopyConstructor:
  // C++11 [class.copy]p12:
  //   A copy constructor is trivial if:
  //    - the constructor selected to copy each direct [subobject] is trivial
  if (RD->hasTrivialCopyConstructor() ||
      (TAH == Sema::TAH_ConsiderTrivialABI &&
       RD->hasTrivialCopyConstructorForCall())) {
    if (Quals == Qualifiers::Const)
      // We must either select the trivial copy constructor or reach an
      // ambiguity; no need to actually perform overload resolution.
      return true;
  } else if (!Selected) {
    return false;
  }
  // In C++98, we are not supposed to perform overload resolution here, but we
  // treat that as a language defect, as suggested on cxx-abi-dev, to treat
  // cases like B as having a non-trivial copy constructor:
  //   struct A { template<typename T> A(T&); };
  //   struct B { mutable A a; };
  goto NeedOverloadResolution;

case Sema::CXXCopyAssignment:
  // C++11 [class.copy]p25:
  //   A copy assignment operator is trivial if:
  //    - the assignment operator selected to copy each direct [subobject] is
  //      trivial
  if (RD->hasTrivialCopyAssignment()) {
    if (Quals == Qualifiers::Const)
      return true;
  } else if (!Selected) {
    return false;
  }
  // In C++98, we are not supposed to perform overload resolution here, but we
  // treat that as a language defect.
  goto NeedOverloadResolution;

case Sema::CXXMoveConstructor:
case Sema::CXXMoveAssignment:
NeedOverloadResolution:
  Sema::SpecialMemberOverloadResult SMOR =
      lookupCallFromSpecialMember(S, RD, CSM, Quals, ConstRHS);

  // The standard doesn't describe how to behave if the lookup is ambiguous.
  // We treat it as not making the member non-trivial, just like the standard
  // mandates for the default constructor. This should rarely matter, because
  // the member will also be deleted.
  if (SMOR.getKind() == Sema::SpecialMemberOverloadResult::Ambiguous)
    return true;

  if (!SMOR.getMethod()) {
    assert(SMOR.getKind() ==(static_cast<void> (0))
           Sema::SpecialMemberOverloadResult::NoMemberOrDeleted)(static_cast<void> (0));
    return false;
  }

  // We deliberately don't check if we found a deleted special member. We're
  // not supposed to!
  if (Selected)
    *Selected = SMOR.getMethod();

  if (TAH == Sema::TAH_ConsiderTrivialABI &&
      (CSM == Sema::CXXCopyConstructor || CSM == Sema::CXXMoveConstructor))
    return SMOR.getMethod()->isTrivialForCall();
  return SMOR.getMethod()->isTrivial();
}

llvm_unreachable("unknown special method kind")__builtin_unreachable();
9464}

9466static CXXConstructorDecl *findUserDeclaredCtor(CXXRecordDecl *RD) {
for (auto *CI : RD->ctors())
  if (!CI->isImplicit())
    return CI;

// Look for constructor templates.
typedef CXXRecordDecl::specific_decl_iterator<FunctionTemplateDecl> tmpl_iter;
for (tmpl_iter TI(RD->decls_begin()), TE(RD->decls_end()); TI != TE; ++TI) {
  if (CXXConstructorDecl *CD =
        dyn_cast<CXXConstructorDecl>(TI->getTemplatedDecl()))
    return CD;
}

return nullptr;
9480}

9482/// The kind of subobject we are checking for triviality. The values of this
9483/// enumeration are used in diagnostics.
9484enum TrivialSubobjectKind {
/// The subobject is a base class.
TSK_BaseClass,
/// The subobject is a non-static data member.
TSK_Field,
/// The object is actually the complete object.
TSK_CompleteObject
9491};

9493/// Check whether the special member selected for a given type would be trivial.
9494static bool checkTrivialSubobjectCall(Sema &S, SourceLocation SubobjLoc,
                                    QualType SubType, bool ConstRHS,
                                    Sema::CXXSpecialMember CSM,
                                    TrivialSubobjectKind Kind,
                                    Sema::TrivialABIHandling TAH, bool Diagnose) {
CXXRecordDecl *SubRD = SubType->getAsCXXRecordDecl();
if (!SubRD)
  return true;

CXXMethodDecl *Selected;
if (findTrivialSpecialMember(S, SubRD, CSM, SubType.getCVRQualifiers(),
                             ConstRHS, TAH, Diagnose ? &Selected : nullptr))
  return true;

if (Diagnose) {
  if (ConstRHS)
    SubType.addConst();

  if (!Selected && CSM == Sema::CXXDefaultConstructor) {
    S.Diag(SubobjLoc, diag::note_nontrivial_no_def_ctor)
      << Kind << SubType.getUnqualifiedType();
    if (CXXConstructorDecl *CD = findUserDeclaredCtor(SubRD))
      S.Diag(CD->getLocation(), diag::note_user_declared_ctor);
  } else if (!Selected)
    S.Diag(SubobjLoc, diag::note_nontrivial_no_copy)
      << Kind << SubType.getUnqualifiedType() << CSM << SubType;
  else if (Selected->isUserProvided()) {
    if (Kind == TSK_CompleteObject)
      S.Diag(Selected->getLocation(), diag::note_nontrivial_user_provided)
        << Kind << SubType.getUnqualifiedType() << CSM;
    else {
      S.Diag(SubobjLoc, diag::note_nontrivial_user_provided)
        << Kind << SubType.getUnqualifiedType() << CSM;
      S.Diag(Selected->getLocation(), diag::note_declared_at);
    }
  } else {
    if (Kind != TSK_CompleteObject)
      S.Diag(SubobjLoc, diag::note_nontrivial_subobject)
        << Kind << SubType.getUnqualifiedType() << CSM;

    // Explain why the defaulted or deleted special member isn't trivial.
    S.SpecialMemberIsTrivial(Selected, CSM, Sema::TAH_IgnoreTrivialABI,
                             Diagnose);
  }
}

return false;
9541}

9543/// Check whether the members of a class type allow a special member to be
9544/// trivial.
9545static bool checkTrivialClassMembers(Sema &S, CXXRecordDecl *RD,
                                   Sema::CXXSpecialMember CSM,
                                   bool ConstArg,
                                   Sema::TrivialABIHandling TAH,
                                   bool Diagnose) {
for (const auto *FI : RD->fields()) {
  if (FI->isInvalidDecl() || FI->isUnnamedBitfield())
    continue;

  QualType FieldType = S.Context.getBaseElementType(FI->getType());

  // Pretend anonymous struct or union members are members of this class.
  if (FI->isAnonymousStructOrUnion()) {
    if (!checkTrivialClassMembers(S, FieldType->getAsCXXRecordDecl(),
                                  CSM, ConstArg, TAH, Diagnose))
      return false;
    continue;
  }

  // C++11 [class.ctor]p5:
  //   A default constructor is trivial if [...]
  //    -- no non-static data member of its class has a
  //       brace-or-equal-initializer
  if (CSM == Sema::CXXDefaultConstructor && FI->hasInClassInitializer()) {
    if (Diagnose)
      S.Diag(FI->getLocation(), diag::note_nontrivial_default_member_init)
          << FI;
    return false;
  }

  // Objective C ARC 4.3.5:
  //   [...] nontrivally ownership-qualified types are [...] not trivially
  //   default constructible, copy constructible, move constructible, copy
  //   assignable, move assignable, or destructible [...]
  if (FieldType.hasNonTrivialObjCLifetime()) {
    if (Diagnose)
      S.Diag(FI->getLocation(), diag::note_nontrivial_objc_ownership)
        << RD << FieldType.getObjCLifetime();
    return false;
  }

  bool ConstRHS = ConstArg && !FI->isMutable();
  if (!checkTrivialSubobjectCall(S, FI->getLocation(), FieldType, ConstRHS,
                                 CSM, TSK_Field, TAH, Diagnose))
    return false;
}

return true;
9593}

9595/// Diagnose why the specified class does not have a trivial special member of
9596/// the given kind.
9597void Sema::DiagnoseNontrivial(const CXXRecordDecl *RD, CXXSpecialMember CSM) {
QualType Ty = Context.getRecordType(RD);

bool ConstArg = (CSM == CXXCopyConstructor || CSM == CXXCopyAssignment);
checkTrivialSubobjectCall(*this, RD->getLocation(), Ty, ConstArg, CSM,
                          TSK_CompleteObject, TAH_IgnoreTrivialABI,
                          /*Diagnose*/true);
9604}

9606/// Determine whether a defaulted or deleted special member function is trivial,
9607/// as specified in C++11 [class.ctor]p5, C++11 [class.copy]p12,
9608/// C++11 [class.copy]p25, and C++11 [class.dtor]p5.
9609bool Sema::SpecialMemberIsTrivial(CXXMethodDecl *MD, CXXSpecialMember CSM,
                                TrivialABIHandling TAH, bool Diagnose) {
assert(!MD->isUserProvided() && CSM != CXXInvalid && "not special enough")(static_cast<void> (0));

CXXRecordDecl *RD = MD->getParent();

bool ConstArg = false;

// C++11 [class.copy]p12, p25: [DR1593]
//   A [special member] is trivial if [...] its parameter-type-list is
//   equivalent to the parameter-type-list of an implicit declaration [...]
switch (CSM) {
case CXXDefaultConstructor:
case CXXDestructor:
  // Trivial default constructors and destructors cannot have parameters.
  break;

case CXXCopyConstructor:
case CXXCopyAssignment: {
  // Trivial copy operations always have const, non-volatile parameter types.
  ConstArg = true;
  const ParmVarDecl *Param0 = MD->getParamDecl(0);
  const ReferenceType *RT = Param0->getType()->getAs<ReferenceType>();
  if (!RT || RT->getPointeeType().getCVRQualifiers() != Qualifiers::Const) {
    if (Diagnose)
      Diag(Param0->getLocation(), diag::note_nontrivial_param_type)
        << Param0->getSourceRange() << Param0->getType()
        << Context.getLValueReferenceType(
             Context.getRecordType(RD).withConst());
    return false;
  }
  break;
}

case CXXMoveConstructor:
case CXXMoveAssignment: {
  // Trivial move operations always have non-cv-qualified parameters.
  const ParmVarDecl *Param0 = MD->getParamDecl(0);
  const RValueReferenceType *RT =
    Param0->getType()->getAs<RValueReferenceType>();
  if (!RT || RT->getPointeeType().getCVRQualifiers()) {
    if (Diagnose)
      Diag(Param0->getLocation(), diag::note_nontrivial_param_type)
        << Param0->getSourceRange() << Param0->getType()
        << Context.getRValueReferenceType(Context.getRecordType(RD));
    return false;
  }
  break;
}

case CXXInvalid:
  llvm_unreachable("not a special member")__builtin_unreachable();
}

if (MD->getMinRequiredArguments() < MD->getNumParams()) {
  if (Diagnose)
    Diag(MD->getParamDecl(MD->getMinRequiredArguments())->getLocation(),
         diag::note_nontrivial_default_arg)
      << MD->getParamDecl(MD->getMinRequiredArguments())->getSourceRange();
  return false;
}
if (MD->isVariadic()) {
  if (Diagnose)
    Diag(MD->getLocation(), diag::note_nontrivial_variadic);
  return false;
}

// C++11 [class.ctor]p5, C++11 [class.dtor]p5:
//   A copy/move [constructor or assignment operator] is trivial if
//    -- the [member] selected to copy/move each direct base class subobject
//       is trivial
//
// C++11 [class.copy]p12, C++11 [class.copy]p25:
//   A [default constructor or destructor] is trivial if
//    -- all the direct base classes have trivial [default constructors or
//       destructors]
for (const auto &BI : RD->bases())
  if (!checkTrivialSubobjectCall(*this, BI.getBeginLoc(), BI.getType(),
                                 ConstArg, CSM, TSK_BaseClass, TAH, Diagnose))
    return false;

// C++11 [class.ctor]p5, C++11 [class.dtor]p5:
//   A copy/move [constructor or assignment operator] for a class X is
//   trivial if
//    -- for each non-static data member of X that is of class type (or array
//       thereof), the constructor selected to copy/move that member is
//       trivial
//
// C++11 [class.copy]p12, C++11 [class.copy]p25:
//   A [default constructor or destructor] is trivial if
//    -- for all of the non-static data members of its class that are of class
//       type (or array thereof), each such class has a trivial [default
//       constructor or destructor]
if (!checkTrivialClassMembers(*this, RD, CSM, ConstArg, TAH, Diagnose))
  return false;

// C++11 [class.dtor]p5:
//   A destructor is trivial if [...]
//    -- the destructor is not virtual
if (CSM == CXXDestructor && MD->isVirtual()) {
  if (Diagnose)
    Diag(MD->getLocation(), diag::note_nontrivial_virtual_dtor) << RD;
  return false;
}

// C++11 [class.ctor]p5, C++11 [class.copy]p12, C++11 [class.copy]p25:
//   A [special member] for class X is trivial if [...]
//    -- class X has no virtual functions and no virtual base classes
if (CSM != CXXDestructor && MD->getParent()->isDynamicClass()) {
  if (!Diagnose)
    return false;

  if (RD->getNumVBases()) {
    // Check for virtual bases. We already know that the corresponding
    // member in all bases is trivial, so vbases must all be direct.
    CXXBaseSpecifier &BS = *RD->vbases_begin();
    assert(BS.isVirtual())(static_cast<void> (0));
    Diag(BS.getBeginLoc(), diag::note_nontrivial_has_virtual) << RD << 1;
    return false;
  }

  // Must have a virtual method.
  for (const auto *MI : RD->methods()) {
    if (MI->isVirtual()) {
      SourceLocation MLoc = MI->getBeginLoc();
      Diag(MLoc, diag::note_nontrivial_has_virtual) << RD << 0;
      return false;
    }
  }

  llvm_unreachable("dynamic class with no vbases and no virtual functions")__builtin_unreachable();
}

// Looks like it's trivial!
return true;
9744}

9746namespace {
9747struct FindHiddenVirtualMethod {
Sema *S;
CXXMethodDecl *Method;
llvm::SmallPtrSet<const CXXMethodDecl *, 8> OverridenAndUsingBaseMethods;
SmallVector<CXXMethodDecl *, 8> OverloadedMethods;

9753private:
/// Check whether any most overridden method from MD in Methods
static bool CheckMostOverridenMethods(
    const CXXMethodDecl *MD,
    const llvm::SmallPtrSetImpl<const CXXMethodDecl *> &Methods) {
  if (MD->size_overridden_methods() == 0)
    return Methods.count(MD->getCanonicalDecl());
  for (const CXXMethodDecl *O : MD->overridden_methods())
    if (CheckMostOverridenMethods(O, Methods))
      return true;
  return false;
}

9766public:
/// Member lookup function that determines whether a given C++
/// method overloads virtual methods in a base class without overriding any,
/// to be used with CXXRecordDecl::lookupInBases().
bool operator()(const CXXBaseSpecifier *Specifier, CXXBasePath &Path) {
  RecordDecl *BaseRecord =
      Specifier->getType()->castAs<RecordType>()->getDecl();

  DeclarationName Name = Method->getDeclName();
  assert(Name.getNameKind() == DeclarationName::Identifier)(static_cast<void> (0));

  bool foundSameNameMethod = false;
  SmallVector<CXXMethodDecl *, 8> overloadedMethods;
  for (Path.Decls = BaseRecord->lookup(Name).begin();
       Path.Decls != DeclContext::lookup_iterator(); ++Path.Decls) {
    NamedDecl *D = *Path.Decls;
    if (CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(D)) {
      MD = MD->getCanonicalDecl();
      foundSameNameMethod = true;
      // Interested only in hidden virtual methods.
      if (!MD->isVirtual())
        continue;
      // If the method we are checking overrides a method from its base
      // don't warn about the other overloaded methods. Clang deviates from
      // GCC by only diagnosing overloads of inherited virtual functions that
      // do not override any other virtual functions in the base. GCC's
      // -Woverloaded-virtual diagnoses any derived function hiding a virtual
      // function from a base class. These cases may be better served by a
      // warning (not specific to virtual functions) on call sites when the
      // call would select a different function from the base class, were it
      // visible.
      // See FIXME in test/SemaCXX/warn-overload-virtual.cpp for an example.
      if (!S->IsOverload(Method, MD, false))
        return true;
      // Collect the overload only if its hidden.
      if (!CheckMostOverridenMethods(MD, OverridenAndUsingBaseMethods))
        overloadedMethods.push_back(MD);
    }
  }

  if (foundSameNameMethod)
    OverloadedMethods.append(overloadedMethods.begin(),
                             overloadedMethods.end());
  return foundSameNameMethod;
}
9811};
9812} // end anonymous namespace

9814/// Add the most overriden methods from MD to Methods
9815static void AddMostOverridenMethods(const CXXMethodDecl *MD,
                      llvm::SmallPtrSetImpl<const CXXMethodDecl *>& Methods) {
if (MD->size_overridden_methods() == 0)
  Methods.insert(MD->getCanonicalDecl());
else
  for (const CXXMethodDecl *O : MD->overridden_methods())
    AddMostOverridenMethods(O, Methods);
9822}

9824/// Check if a method overloads virtual methods in a base class without
9825/// overriding any.
9826void Sema::FindHiddenVirtualMethods(CXXMethodDecl *MD,
                        SmallVectorImpl<CXXMethodDecl*> &OverloadedMethods) {
if (!MD->getDeclName().isIdentifier())
  return;

CXXBasePaths Paths(/*FindAmbiguities=*/true, // true to look in all bases.
                   /*bool RecordPaths=*/false,
                   /*bool DetectVirtual=*/false);
FindHiddenVirtualMethod FHVM;
FHVM.Method = MD;
FHVM.S = this;

// Keep the base methods that were overridden or introduced in the subclass
// by 'using' in a set. A base method not in this set is hidden.
CXXRecordDecl *DC = MD->getParent();
DeclContext::lookup_result R = DC->lookup(MD->getDeclName());
for (DeclContext::lookup_iterator I = R.begin(), E = R.end(); I != E; ++I) {
  NamedDecl *ND = *I;
  if (UsingShadowDecl *shad = dyn_cast<UsingShadowDecl>(*I))
    ND = shad->getTargetDecl();
  if (CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(ND))
    AddMostOverridenMethods(MD, FHVM.OverridenAndUsingBaseMethods);
}

if (DC->lookupInBases(FHVM, Paths))
  OverloadedMethods = FHVM.OverloadedMethods;
9852}

9854void Sema::NoteHiddenVirtualMethods(CXXMethodDecl *MD,
                        SmallVectorImpl<CXXMethodDecl*> &OverloadedMethods) {
for (unsigned i = 0, e = OverloadedMethods.size(); i != e; ++i) {
  CXXMethodDecl *overloadedMD = OverloadedMethods[i];
  PartialDiagnostic PD = PDiag(
       diag::note_hidden_overloaded_virtual_declared_here) << overloadedMD;
  HandleFunctionTypeMismatch(PD, MD->getType(), overloadedMD->getType());
  Diag(overloadedMD->getLocation(), PD);
}
9863}

9865/// Diagnose methods which overload virtual methods in a base class
9866/// without overriding any.
9867void Sema::DiagnoseHiddenVirtualMethods(CXXMethodDecl *MD) {
if (MD->isInvalidDecl())
  return;

if (Diags.isIgnored(diag::warn_overloaded_virtual, MD->getLocation()))
  return;

SmallVector<CXXMethodDecl *, 8> OverloadedMethods;
FindHiddenVirtualMethods(MD, OverloadedMethods);
if (!OverloadedMethods.empty()) {
  Diag(MD->getLocation(), diag::warn_overloaded_virtual)
    << MD << (OverloadedMethods.size() > 1);

  NoteHiddenVirtualMethods(MD, OverloadedMethods);
}
9882}

9884void Sema::checkIllFormedTrivialABIStruct(CXXRecordDecl &RD) {
auto PrintDiagAndRemoveAttr = [&](unsigned N) {
  // No diagnostics if this is a template instantiation.
  if (!isTemplateInstantiation(RD.getTemplateSpecializationKind())) {
    Diag(RD.getAttr<TrivialABIAttr>()->getLocation(),
         diag::ext_cannot_use_trivial_abi) << &RD;
    Diag(RD.getAttr<TrivialABIAttr>()->getLocation(),
         diag::note_cannot_use_trivial_abi_reason) << &RD << N;
  }
  RD.dropAttr<TrivialABIAttr>();
};

// Ill-formed if the copy and move constructors are deleted.
auto HasNonDeletedCopyOrMoveConstructor = [&]() {
  // If the type is dependent, then assume it might have
  // implicit copy or move ctor because we won't know yet at this point.
  if (RD.isDependentType())
    return true;
  if (RD.needsImplicitCopyConstructor() &&
      !RD.defaultedCopyConstructorIsDeleted())
    return true;
  if (RD.needsImplicitMoveConstructor() &&
      !RD.defaultedMoveConstructorIsDeleted())
    return true;
  for (const CXXConstructorDecl *CD : RD.ctors())
    if (CD->isCopyOrMoveConstructor() && !CD->isDeleted())
      return true;
  return false;
};

if (!HasNonDeletedCopyOrMoveConstructor()) {
  PrintDiagAndRemoveAttr(0);
  return;
}

// Ill-formed if the struct has virtual functions.
if (RD.isPolymorphic()) {
  PrintDiagAndRemoveAttr(1);
  return;
}

for (const auto &B : RD.bases()) {
  // Ill-formed if the base class is non-trivial for the purpose of calls or a
  // virtual base.
  if (!B.getType()->isDependentType() &&
      !B.getType()->getAsCXXRecordDecl()->canPassInRegisters()) {
    PrintDiagAndRemoveAttr(2);
    return;
  }

  if (B.isVirtual()) {
    PrintDiagAndRemoveAttr(3);
    return;
  }
}

for (const auto *FD : RD.fields()) {
  // Ill-formed if the field is an ObjectiveC pointer or of a type that is
  // non-trivial for the purpose of calls.
  QualType FT = FD->getType();
  if (FT.getObjCLifetime() == Qualifiers::OCL_Weak) {
    PrintDiagAndRemoveAttr(4);
    return;
  }

  if (const auto *RT = FT->getBaseElementTypeUnsafe()->getAs<RecordType>())
    if (!RT->isDependentType() &&
        !cast<CXXRecordDecl>(RT->getDecl())->canPassInRegisters()) {
      PrintDiagAndRemoveAttr(5);
      return;
    }
}
9956}

9958void Sema::ActOnFinishCXXMemberSpecification(
  Scope *S, SourceLocation RLoc, Decl *TagDecl, SourceLocation LBrac,
  SourceLocation RBrac, const ParsedAttributesView &AttrList) {
if (!TagDecl)
  return;

AdjustDeclIfTemplate(TagDecl);

for (const ParsedAttr &AL : AttrList) {
  if (AL.getKind() != ParsedAttr::AT_Visibility)
    continue;
  AL.setInvalid();
  Diag(AL.getLoc(), diag::warn_attribute_after_definition_ignored) << AL;
}

ActOnFields(S, RLoc, TagDecl, llvm::makeArrayRef(
            // strict aliasing violation!
            reinterpret_cast<Decl**>(FieldCollector->getCurFields()),
            FieldCollector->getCurNumFields()), LBrac, RBrac, AttrList);

CheckCompletedCXXClass(S, cast<CXXRecordDecl>(TagDecl));
9979}

9981/// Find the equality comparison functions that should be implicitly declared
9982/// in a given class definition, per C++2a [class.compare.default]p3.
9983static void findImplicitlyDeclaredEqualityComparisons(
  ASTContext &Ctx, CXXRecordDecl *RD,
  llvm::SmallVectorImpl<FunctionDecl *> &Spaceships) {
DeclarationName EqEq = Ctx.DeclarationNames.getCXXOperatorName(OO_EqualEqual);
if (!RD->lookup(EqEq).empty())
  // Member operator== explicitly declared: no implicit operator==s.
  return;

// Traverse friends looking for an '==' or a '<=>'.
for (FriendDecl *Friend : RD->friends()) {
  FunctionDecl *FD = dyn_cast_or_null<FunctionDecl>(Friend->getFriendDecl());
  if (!FD) continue;

  if (FD->getOverloadedOperator() == OO_EqualEqual) {
    // Friend operator== explicitly declared: no implicit operator==s.
    Spaceships.clear();
    return;
  }

  if (FD->getOverloadedOperator() == OO_Spaceship &&
      FD->isExplicitlyDefaulted())
    Spaceships.push_back(FD);
}

// Look for members named 'operator<=>'.
DeclarationName Cmp = Ctx.DeclarationNames.getCXXOperatorName(OO_Spaceship);
for (NamedDecl *ND : RD->lookup(Cmp)) {
  // Note that we could find a non-function here (either a function template
  // or a using-declaration). Neither case results in an implicit
  // 'operator=='.
  if (auto *FD = dyn_cast<FunctionDecl>(ND))
    if (FD->isExplicitlyDefaulted())
      Spaceships.push_back(FD);
}
10017}

10019/// AddImplicitlyDeclaredMembersToClass - Adds any implicitly-declared
10020/// special functions, such as the default constructor, copy
10021/// constructor, or destructor, to the given C++ class (C++
10022/// [special]p1).  This routine can only be executed just before the
10023/// definition of the class is complete.
10024void Sema::AddImplicitlyDeclaredMembersToClass(CXXRecordDecl *ClassDecl) {
// Don't add implicit special members to templated classes.
// FIXME: This means unqualified lookups for 'operator=' within a class
// template don't work properly.
if (!ClassDecl->isDependentType()) {
  if (ClassDecl->needsImplicitDefaultConstructor()) {
    ++getASTContext().NumImplicitDefaultConstructors;

    if (ClassDecl->hasInheritedConstructor())
      DeclareImplicitDefaultConstructor(ClassDecl);
  }

  if (ClassDecl->needsImplicitCopyConstructor()) {
    ++getASTContext().NumImplicitCopyConstructors;

    // If the properties or semantics of the copy constructor couldn't be
    // determined while the class was being declared, force a declaration
    // of it now.
    if (ClassDecl->needsOverloadResolutionForCopyConstructor() ||
        ClassDecl->hasInheritedConstructor())
      DeclareImplicitCopyConstructor(ClassDecl);
    // For the MS ABI we need to know whether the copy ctor is deleted. A
    // prerequisite for deleting the implicit copy ctor is that the class has
    // a move ctor or move assignment that is either user-declared or whose
    // semantics are inherited from a subobject. FIXME: We should provide a
    // more direct way for CodeGen to ask whether the constructor was deleted.
    else if (Context.getTargetInfo().getCXXABI().isMicrosoft() &&
             (ClassDecl->hasUserDeclaredMoveConstructor() ||
              ClassDecl->needsOverloadResolutionForMoveConstructor() ||
              ClassDecl->hasUserDeclaredMoveAssignment() ||
              ClassDecl->needsOverloadResolutionForMoveAssignment()))
      DeclareImplicitCopyConstructor(ClassDecl);
  }

  if (getLangOpts().CPlusPlus11 &&
      ClassDecl->needsImplicitMoveConstructor()) {
    ++getASTContext().NumImplicitMoveConstructors;

    if (ClassDecl->needsOverloadResolutionForMoveConstructor() ||
        ClassDecl->hasInheritedConstructor())
      DeclareImplicitMoveConstructor(ClassDecl);
  }

  if (ClassDecl->needsImplicitCopyAssignment()) {
    ++getASTContext().NumImplicitCopyAssignmentOperators;

    // If we have a dynamic class, then the copy assignment operator may be
    // virtual, so we have to declare it immediately. This ensures that, e.g.,
    // it shows up in the right place in the vtable and that we diagnose
    // problems with the implicit exception specification.
    if (ClassDecl->isDynamicClass() ||
        ClassDecl->needsOverloadResolutionForCopyAssignment() ||
        ClassDecl->hasInheritedAssignment())
      DeclareImplicitCopyAssignment(ClassDecl);
  }

  if (getLangOpts().CPlusPlus11 && ClassDecl->needsImplicitMoveAssignment()) {
    ++getASTContext().NumImplicitMoveAssignmentOperators;

    // Likewise for the move assignment operator.
    if (ClassDecl->isDynamicClass() ||
        ClassDecl->needsOverloadResolutionForMoveAssignment() ||
        ClassDecl->hasInheritedAssignment())
      DeclareImplicitMoveAssignment(ClassDecl);
  }

  if (ClassDecl->needsImplicitDestructor()) {
    ++getASTContext().NumImplicitDestructors;

    // If we have a dynamic class, then the destructor may be virtual, so we
    // have to declare the destructor immediately. This ensures that, e.g., it
    // shows up in the right place in the vtable and that we diagnose problems
    // with the implicit exception specification.
    if (ClassDecl->isDynamicClass() ||
        ClassDecl->needsOverloadResolutionForDestructor())
      DeclareImplicitDestructor(ClassDecl);
  }
}

// C++2a [class.compare.default]p3:
//   If the member-specification does not explicitly declare any member or
//   friend named operator==, an == operator function is declared implicitly
//   for each defaulted three-way comparison operator function defined in
//   the member-specification
// FIXME: Consider doing this lazily.
// We do this during the initial parse for a class template, not during
// instantiation, so that we can handle unqualified lookups for 'operator=='
// when parsing the template.
if (getLangOpts().CPlusPlus20 && !inTemplateInstantiation()) {
  llvm::SmallVector<FunctionDecl *, 4> DefaultedSpaceships;
  findImplicitlyDeclaredEqualityComparisons(Context, ClassDecl,
                                            DefaultedSpaceships);
  for (auto *FD : DefaultedSpaceships)
    DeclareImplicitEqualityComparison(ClassDecl, FD);
}
10119}

10121unsigned
10122Sema::ActOnReenterTemplateScope(Decl *D,
                              llvm::function_ref<Scope *()> EnterScope) {
if (!D)
  return 0;
AdjustDeclIfTemplate(D);

// In order to get name lookup right, reenter template scopes in order from
// outermost to innermost.
SmallVector<TemplateParameterList *, 4> ParameterLists;
DeclContext *LookupDC = dyn_cast<DeclContext>(D);

if (DeclaratorDecl *DD = dyn_cast<DeclaratorDecl>(D)) {
  for (unsigned i = 0; i < DD->getNumTemplateParameterLists(); ++i)
    ParameterLists.push_back(DD->getTemplateParameterList(i));

  if (FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) {
    if (FunctionTemplateDecl *FTD = FD->getDescribedFunctionTemplate())
      ParameterLists.push_back(FTD->getTemplateParameters());
  } else if (VarDecl *VD = dyn_cast<VarDecl>(D)) {
    LookupDC = VD->getDeclContext();

    if (VarTemplateDecl *VTD = VD->getDescribedVarTemplate())
      ParameterLists.push_back(VTD->getTemplateParameters());
    else if (auto *PSD = dyn_cast<VarTemplatePartialSpecializationDecl>(D))
      ParameterLists.push_back(PSD->getTemplateParameters());
  }
} else if (TagDecl *TD = dyn_cast<TagDecl>(D)) {
  for (unsigned i = 0; i < TD->getNumTemplateParameterLists(); ++i)
    ParameterLists.push_back(TD->getTemplateParameterList(i));

  if (CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(TD)) {
    if (ClassTemplateDecl *CTD = RD->getDescribedClassTemplate())
      ParameterLists.push_back(CTD->getTemplateParameters());
    else if (auto *PSD = dyn_cast<ClassTemplatePartialSpecializationDecl>(D))
      ParameterLists.push_back(PSD->getTemplateParameters());
  }
}
// FIXME: Alias declarations and concepts.

unsigned Count = 0;
Scope *InnermostTemplateScope = nullptr;
for (TemplateParameterList *Params : ParameterLists) {
  // Ignore explicit specializations; they don't contribute to the template
  // depth.
  if (Params->size() == 0)
    continue;

  InnermostTemplateScope = EnterScope();
  for (NamedDecl *Param : *Params) {
    if (Param->getDeclName()) {
      InnermostTemplateScope->AddDecl(Param);
      IdResolver.AddDecl(Param);
    }
  }
  ++Count;
}

// Associate the new template scopes with the corresponding entities.
if (InnermostTemplateScope) {
  assert(LookupDC && "no enclosing DeclContext for template lookup")(static_cast<void> (0));
  EnterTemplatedContext(InnermostTemplateScope, LookupDC);
}

return Count;
10186}

10188void Sema::ActOnStartDelayedMemberDeclarations(Scope *S, Decl *RecordD) {
if (!RecordD) return;
AdjustDeclIfTemplate(RecordD);
CXXRecordDecl *Record = cast<CXXRecordDecl>(RecordD);
PushDeclContext(S, Record);
10193}

10195void Sema::ActOnFinishDelayedMemberDeclarations(Scope *S, Decl *RecordD) {
if (!RecordD) return;
PopDeclContext();
10198}

10200/// This is used to implement the constant expression evaluation part of the
10201/// attribute enable_if extension. There is nothing in standard C++ which would
10202/// require reentering parameters.
10203void Sema::ActOnReenterCXXMethodParameter(Scope *S, ParmVarDecl *Param) {
if (!Param)
  return;

S->AddDecl(Param);
if (Param->getDeclName())
  IdResolver.AddDecl(Param);
10210}

10212/// ActOnStartDelayedCXXMethodDeclaration - We have completed
10213/// parsing a top-level (non-nested) C++ class, and we are now
10214/// parsing those parts of the given Method declaration that could
10215/// not be parsed earlier (C++ [class.mem]p2), such as default
10216/// arguments. This action should enter the scope of the given
10217/// Method declaration as if we had just parsed the qualified method
10218/// name. However, it should not bring the parameters into scope;
10219/// that will be performed by ActOnDelayedCXXMethodParameter.
10220void Sema::ActOnStartDelayedCXXMethodDeclaration(Scope *S, Decl *MethodD) {
10221}

10223/// ActOnDelayedCXXMethodParameter - We've already started a delayed
10224/// C++ method declaration. We're (re-)introducing the given
10225/// function parameter into scope for use in parsing later parts of
10226/// the method declaration. For example, we could see an
10227/// ActOnParamDefaultArgument event for this parameter.
10228void Sema::ActOnDelayedCXXMethodParameter(Scope *S, Decl *ParamD) {
if (!ParamD)
  return;

ParmVarDecl *Param = cast<ParmVarDecl>(ParamD);

S->AddDecl(Param);
if (Param->getDeclName())
  IdResolver.AddDecl(Param);
10237}

10239/// ActOnFinishDelayedCXXMethodDeclaration - We have finished
10240/// processing the delayed method declaration for Method. The method
10241/// declaration is now considered finished. There may be a separate
10242/// ActOnStartOfFunctionDef action later (not necessarily
10243/// immediately!) for this method, if it was also defined inside the
10244/// class body.
10245void Sema::ActOnFinishDelayedCXXMethodDeclaration(Scope *S, Decl *MethodD) {
if (!MethodD)
  return;

AdjustDeclIfTemplate(MethodD);

FunctionDecl *Method = cast<FunctionDecl>(MethodD);

// Now that we have our default arguments, check the constructor
// again. It could produce additional diagnostics or affect whether
// the class has implicitly-declared destructors, among other
// things.
if (CXXConstructorDecl *Constructor = dyn_cast<CXXConstructorDecl>(Method))
  CheckConstructor(Constructor);

// Check the default arguments, which we may have added.
if (!Method->isInvalidDecl())
  CheckCXXDefaultArguments(Method);
10263}

10265// Emit the given diagnostic for each non-address-space qualifier.
10266// Common part of CheckConstructorDeclarator and CheckDestructorDeclarator.
10267static void checkMethodTypeQualifiers(Sema &S, Declarator &D, unsigned DiagID) {
const DeclaratorChunk::FunctionTypeInfo &FTI = D.getFunctionTypeInfo();
if (FTI.hasMethodTypeQualifiers() && !D.isInvalidType()) {
  bool DiagOccured = false;
  FTI.MethodQualifiers->forEachQualifier(
      [DiagID, &S, &DiagOccured](DeclSpec::TQ, StringRef QualName,
                                 SourceLocation SL) {
        // This diagnostic should be emitted on any qualifier except an addr
        // space qualifier. However, forEachQualifier currently doesn't visit
        // addr space qualifiers, so there's no way to write this condition
        // right now; we just diagnose on everything.
        S.Diag(SL, DiagID) << QualName << SourceRange(SL);
        DiagOccured = true;
      });
  if (DiagOccured)
    D.setInvalidType();
}
10284}

10286/// CheckConstructorDeclarator - Called by ActOnDeclarator to check
10287/// the well-formedness of the constructor declarator @p D with type @p
10288/// R. If there are any errors in the declarator, this routine will
10289/// emit diagnostics and set the invalid bit to true.  In any case, the type
10290/// will be updated to reflect a well-formed type for the constructor and
10291/// returned.
10292QualType Sema::CheckConstructorDeclarator(Declarator &D, QualType R,
                                        StorageClass &SC) {
bool isVirtual = D.getDeclSpec().isVirtualSpecified();

// C++ [class.ctor]p3:
//   A constructor shall not be virtual (10.3) or static (9.4). A
//   constructor can be invoked for a const, volatile or const
//   volatile object. A constructor shall not be declared const,
//   volatile, or const volatile (9.3.2).
if (isVirtual) {
  if (!D.isInvalidType())
    Diag(D.getIdentifierLoc(), diag::err_constructor_cannot_be)
      << "virtual" << SourceRange(D.getDeclSpec().getVirtualSpecLoc())
      << SourceRange(D.getIdentifierLoc());
  D.setInvalidType();
}
if (SC == SC_Static) {
  if (!D.isInvalidType())
    Diag(D.getIdentifierLoc(), diag::err_constructor_cannot_be)
      << "static" << SourceRange(D.getDeclSpec().getStorageClassSpecLoc())
      << SourceRange(D.getIdentifierLoc());
  D.setInvalidType();
  SC = SC_None;
}

if (unsigned TypeQuals = D.getDeclSpec().getTypeQualifiers()) {
  diagnoseIgnoredQualifiers(
      diag::err_constructor_return_type, TypeQuals, SourceLocation(),
      D.getDeclSpec().getConstSpecLoc(), D.getDeclSpec().getVolatileSpecLoc(),
      D.getDeclSpec().getRestrictSpecLoc(),
      D.getDeclSpec().getAtomicSpecLoc());
  D.setInvalidType();
}

checkMethodTypeQualifiers(*this, D, diag::err_invalid_qualified_constructor);

// C++0x [class.ctor]p4:
//   A constructor shall not be declared with a ref-qualifier.
DeclaratorChunk::FunctionTypeInfo &FTI = D.getFunctionTypeInfo();
if (FTI.hasRefQualifier()) {
  Diag(FTI.getRefQualifierLoc(), diag::err_ref_qualifier_constructor)
    << FTI.RefQualifierIsLValueRef
    << FixItHint::CreateRemoval(FTI.getRefQualifierLoc());
  D.setInvalidType();
}

// Rebuild the function type "R" without any type qualifiers (in
// case any of the errors above fired) and with "void" as the
// return type, since constructors don't have return types.
const FunctionProtoType *Proto = R->castAs<FunctionProtoType>();
if (Proto->getReturnType() == Context.VoidTy && !D.isInvalidType())
  return R;

FunctionProtoType::ExtProtoInfo EPI = Proto->getExtProtoInfo();
EPI.TypeQuals = Qualifiers();
EPI.RefQualifier = RQ_None;

return Context.getFunctionType(Context.VoidTy, Proto->getParamTypes(), EPI);
10350}

10352/// CheckConstructor - Checks a fully-formed constructor for
10353/// well-formedness, issuing any diagnostics required. Returns true if
10354/// the constructor declarator is invalid.
10355void Sema::CheckConstructor(CXXConstructorDecl *Constructor) {
CXXRecordDecl *ClassDecl
  = dyn_cast<CXXRecordDecl>(Constructor->getDeclContext());
if (!ClassDecl)
  return Constructor->setInvalidDecl();

// C++ [class.copy]p3:
//   A declaration of a constructor for a class X is ill-formed if
//   its first parameter is of type (optionally cv-qualified) X and
//   either there are no other parameters or else all other
//   parameters have default arguments.
if (!Constructor->isInvalidDecl() &&
    Constructor->hasOneParamOrDefaultArgs() &&
    Constructor->getTemplateSpecializationKind() !=
        TSK_ImplicitInstantiation) {
  QualType ParamType = Constructor->getParamDecl(0)->getType();
  QualType ClassTy = Context.getTagDeclType(ClassDecl);
  if (Context.getCanonicalType(ParamType).getUnqualifiedType() == ClassTy) {
    SourceLocation ParamLoc = Constructor->getParamDecl(0)->getLocation();
    const char *ConstRef
      = Constructor->getParamDecl(0)->getIdentifier() ? "const &"
                                                      : " const &";
    Diag(ParamLoc, diag::err_constructor_byvalue_arg)
      << FixItHint::CreateInsertion(ParamLoc, ConstRef);

    // FIXME: Rather that making the constructor invalid, we should endeavor
    // to fix the type.
    Constructor->setInvalidDecl();
  }
}
10385}

10387/// CheckDestructor - Checks a fully-formed destructor definition for
10388/// well-formedness, issuing any diagnostics required.  Returns true
10389/// on error.
10390bool Sema::CheckDestructor(CXXDestructorDecl *Destructor) {
CXXRecordDecl *RD = Destructor->getParent();

if (!Destructor->getOperatorDelete() && Destructor->isVirtual()) {
  SourceLocation Loc;

  if (!Destructor->isImplicit())
    Loc = Destructor->getLocation();
  else
    Loc = RD->getLocation();

  // If we have a virtual destructor, look up the deallocation function
  if (FunctionDecl *OperatorDelete =
          FindDeallocationFunctionForDestructor(Loc, RD)) {
    Expr *ThisArg = nullptr;

    // If the notional 'delete this' expression requires a non-trivial
    // conversion from 'this' to the type of a destroying operator delete's
    // first parameter, perform that conversion now.
    if (OperatorDelete->isDestroyingOperatorDelete()) {
      QualType ParamType = OperatorDelete->getParamDecl(0)->getType();
      if (!declaresSameEntity(ParamType->getAsCXXRecordDecl(), RD)) {
        // C++ [class.dtor]p13:
        //   ... as if for the expression 'delete this' appearing in a
        //   non-virtual destructor of the destructor's class.
        ContextRAII SwitchContext(*this, Destructor);
        ExprResult This =
            ActOnCXXThis(OperatorDelete->getParamDecl(0)->getLocation());
        assert(!This.isInvalid() && "couldn't form 'this' expr in dtor?")(static_cast<void> (0));
        This = PerformImplicitConversion(This.get(), ParamType, AA_Passing);
        if (This.isInvalid()) {
          // FIXME: Register this as a context note so that it comes out
          // in the right order.
          Diag(Loc, diag::note_implicit_delete_this_in_destructor_here);
          return true;
        }
        ThisArg = This.get();
      }
    }

    DiagnoseUseOfDecl(OperatorDelete, Loc);
    MarkFunctionReferenced(Loc, OperatorDelete);
    Destructor->setOperatorDelete(OperatorDelete, ThisArg);
  }
}

return false;
10437}

10439/// CheckDestructorDeclarator - Called by ActOnDeclarator to check
10440/// the well-formednes of the destructor declarator @p D with type @p
10441/// R. If there are any errors in the declarator, this routine will
10442/// emit diagnostics and set the declarator to invalid.  Even if this happens,
10443/// will be updated to reflect a well-formed type for the destructor and
10444/// returned.
10445QualType Sema::CheckDestructorDeclarator(Declarator &D, QualType R,
                                       StorageClass& SC) {
// C++ [class.dtor]p1:
//   [...] A typedef-name that names a class is a class-name
//   (7.1.3); however, a typedef-name that names a class shall not
//   be used as the identifier in the declarator for a destructor
//   declaration.
QualType DeclaratorType = GetTypeFromParser(D.getName().DestructorName);
if (const TypedefType *TT = DeclaratorType->getAs<TypedefType>())
  Diag(D.getIdentifierLoc(), diag::ext_destructor_typedef_name)
    << DeclaratorType << isa<TypeAliasDecl>(TT->getDecl());
else if (const TemplateSpecializationType *TST =
           DeclaratorType->getAs<TemplateSpecializationType>())
  if (TST->isTypeAlias())
    Diag(D.getIdentifierLoc(), diag::ext_destructor_typedef_name)
      << DeclaratorType << 1;

// C++ [class.dtor]p2:
//   A destructor is used to destroy objects of its class type. A
//   destructor takes no parameters, and no return type can be
//   specified for it (not even void). The address of a destructor
//   shall not be taken. A destructor shall not be static. A
//   destructor can be invoked for a const, volatile or const
//   volatile object. A destructor shall not be declared const,
//   volatile or const volatile (9.3.2).
if (SC == SC_Static) {
  if (!D.isInvalidType())
    Diag(D.getIdentifierLoc(), diag::err_destructor_cannot_be)
      << "static" << SourceRange(D.getDeclSpec().getStorageClassSpecLoc())
      << SourceRange(D.getIdentifierLoc())
      << FixItHint::CreateRemoval(D.getDeclSpec().getStorageClassSpecLoc());

  SC = SC_None;
}
if (!D.isInvalidType()) {
  // Destructors don't have return types, but the parser will
  // happily parse something like:
  //
  //   class X {
  //     float ~X();
  //   };
  //
  // The return type will be eliminated later.
  if (D.getDeclSpec().hasTypeSpecifier())
    Diag(D.getIdentifierLoc(), diag::err_destructor_return_type)
      << SourceRange(D.getDeclSpec().getTypeSpecTypeLoc())
      << SourceRange(D.getIdentifierLoc());
  else if (unsigned TypeQuals = D.getDeclSpec().getTypeQualifiers()) {
    diagnoseIgnoredQualifiers(diag::err_destructor_return_type, TypeQuals,
                              SourceLocation(),
                              D.getDeclSpec().getConstSpecLoc(),
                              D.getDeclSpec().getVolatileSpecLoc(),
                              D.getDeclSpec().getRestrictSpecLoc(),
                              D.getDeclSpec().getAtomicSpecLoc());
    D.setInvalidType();
  }
}

checkMethodTypeQualifiers(*this, D, diag::err_invalid_qualified_destructor);

// C++0x [class.dtor]p2:
//   A destructor shall not be declared with a ref-qualifier.
DeclaratorChunk::FunctionTypeInfo &FTI = D.getFunctionTypeInfo();
if (FTI.hasRefQualifier()) {
  Diag(FTI.getRefQualifierLoc(), diag::err_ref_qualifier_destructor)
    << FTI.RefQualifierIsLValueRef
    << FixItHint::CreateRemoval(FTI.getRefQualifierLoc());
  D.setInvalidType();
}

// Make sure we don't have any parameters.
if (FTIHasNonVoidParameters(FTI)) {
  Diag(D.getIdentifierLoc(), diag::err_destructor_with_params);

  // Delete the parameters.
  FTI.freeParams();
  D.setInvalidType();
}

// Make sure the destructor isn't variadic.
if (FTI.isVariadic) {
  Diag(D.getIdentifierLoc(), diag::err_destructor_variadic);
  D.setInvalidType();
}

// Rebuild the function type "R" without any type qualifiers or
// parameters (in case any of the errors above fired) and with
// "void" as the return type, since destructors don't have return
// types.
if (!D.isInvalidType())
  return R;

const FunctionProtoType *Proto = R->castAs<FunctionProtoType>();
FunctionProtoType::ExtProtoInfo EPI = Proto->getExtProtoInfo();
EPI.Variadic = false;
EPI.TypeQuals = Qualifiers();
EPI.RefQualifier = RQ_None;
return Context.getFunctionType(Context.VoidTy, None, EPI);
10543}

10545static void extendLeft(SourceRange &R, SourceRange Before) {
if (Before.isInvalid())
  return;
R.setBegin(Before.getBegin());
if (R.getEnd().isInvalid())
  R.setEnd(Before.getEnd());
10551}

10553static void extendRight(SourceRange &R, SourceRange After) {
if (After.isInvalid())
  return;
if (R.getBegin().isInvalid())
  R.setBegin(After.getBegin());
R.setEnd(After.getEnd());
10559}

10561/// CheckConversionDeclarator - Called by ActOnDeclarator to check the
10562/// well-formednes of the conversion function declarator @p D with
10563/// type @p R. If there are any errors in the declarator, this routine
10564/// will emit diagnostics and return true. Otherwise, it will return
10565/// false. Either way, the type @p R will be updated to reflect a
10566/// well-formed type for the conversion operator.
10567void Sema::CheckConversionDeclarator(Declarator &D, QualType &R,
                                   StorageClass& SC) {
// C++ [class.conv.fct]p1:
//   Neither parameter types nor return type can be specified. The
//   type of a conversion function (8.3.5) is "function taking no
//   parameter returning conversion-type-id."
if (SC == SC_Static) {
  if (!D.isInvalidType())
    Diag(D.getIdentifierLoc(), diag::err_conv_function_not_member)
      << SourceRange(D.getDeclSpec().getStorageClassSpecLoc())
      << D.getName().getSourceRange();
  D.setInvalidType();
  SC = SC_None;
}

TypeSourceInfo *ConvTSI = nullptr;
QualType ConvType =
    GetTypeFromParser(D.getName().ConversionFunctionId, &ConvTSI);

const DeclSpec &DS = D.getDeclSpec();
if (DS.hasTypeSpecifier() && !D.isInvalidType()) {
  // Conversion functions don't have return types, but the parser will
  // happily parse something like:
  //
  //   class X {
  //     float operator bool();
  //   };
  //
  // The return type will be changed later anyway.
  Diag(D.getIdentifierLoc(), diag::err_conv_function_return_type)
    << SourceRange(DS.getTypeSpecTypeLoc())
    << SourceRange(D.getIdentifierLoc());
  D.setInvalidType();
} else if (DS.getTypeQualifiers() && !D.isInvalidType()) {
  // It's also plausible that the user writes type qualifiers in the wrong
  // place, such as:
  //   struct S { const operator int(); };
  // FIXME: we could provide a fixit to move the qualifiers onto the
  // conversion type.
  Diag(D.getIdentifierLoc(), diag::err_conv_function_with_complex_decl)
      << SourceRange(D.getIdentifierLoc()) << 0;
  D.setInvalidType();
}

const auto *Proto = R->castAs<FunctionProtoType>();

// Make sure we don't have any parameters.
if (Proto->getNumParams() > 0) {
  Diag(D.getIdentifierLoc(), diag::err_conv_function_with_params);

  // Delete the parameters.
  D.getFunctionTypeInfo().freeParams();
  D.setInvalidType();
} else if (Proto->isVariadic()) {
  Diag(D.getIdentifierLoc(), diag::err_conv_function_variadic);
  D.setInvalidType();
}

// Diagnose "&operator bool()" and other such nonsense.  This
// is actually a gcc extension which we don't support.
if (Proto->getReturnType() != ConvType) {
  bool NeedsTypedef = false;
  SourceRange Before, After;

  // Walk the chunks and extract information on them for our diagnostic.
  bool PastFunctionChunk = false;
  for (auto &Chunk : D.type_objects()) {
    switch (Chunk.Kind) {
    case DeclaratorChunk::Function:
      if (!PastFunctionChunk) {
        if (Chunk.Fun.HasTrailingReturnType) {
          TypeSourceInfo *TRT = nullptr;
          GetTypeFromParser(Chunk.Fun.getTrailingReturnType(), &TRT);
          if (TRT) extendRight(After, TRT->getTypeLoc().getSourceRange());
        }
        PastFunctionChunk = true;
        break;
      }
      LLVM_FALLTHROUGH[[gnu::fallthrough]];
    case DeclaratorChunk::Array:
      NeedsTypedef = true;
      extendRight(After, Chunk.getSourceRange());
      break;

    case DeclaratorChunk::Pointer:
    case DeclaratorChunk::BlockPointer:
    case DeclaratorChunk::Reference:
    case DeclaratorChunk::MemberPointer:
    case DeclaratorChunk::Pipe:
      extendLeft(Before, Chunk.getSourceRange());
      break;

    case DeclaratorChunk::Paren:
      extendLeft(Before, Chunk.Loc);
      extendRight(After, Chunk.EndLoc);
      break;
    }
  }

  SourceLocation Loc = Before.isValid() ? Before.getBegin() :
                       After.isValid()  ? After.getBegin() :
                                          D.getIdentifierLoc();
  auto &&DB = Diag(Loc, diag::err_conv_function_with_complex_decl);
  DB << Before << After;

  if (!NeedsTypedef) {
    DB << /*don't need a typedef*/0;

    // If we can provide a correct fix-it hint, do so.
    if (After.isInvalid() && ConvTSI) {
      SourceLocation InsertLoc =
          getLocForEndOfToken(ConvTSI->getTypeLoc().getEndLoc());
      DB << FixItHint::CreateInsertion(InsertLoc, " ")
         << FixItHint::CreateInsertionFromRange(
                InsertLoc, CharSourceRange::getTokenRange(Before))
         << FixItHint::CreateRemoval(Before);
    }
  } else if (!Proto->getReturnType()->isDependentType()) {
    DB << /*typedef*/1 << Proto->getReturnType();
  } else if (getLangOpts().CPlusPlus11) {
    DB << /*alias template*/2 << Proto->getReturnType();
  } else {
    DB << /*might not be fixable*/3;
  }

  // Recover by incorporating the other type chunks into the result type.
  // Note, this does *not* change the name of the function. This is compatible
  // with the GCC extension:
  //   struct S { &operator int(); } s;
  //   int &r = s.operator int(); // ok in GCC
  //   S::operator int&() {} // error in GCC, function name is 'operator int'.
  ConvType = Proto->getReturnType();
}

// C++ [class.conv.fct]p4:
//   The conversion-type-id shall not represent a function type nor
//   an array type.
if (ConvType->isArrayType()) {
  Diag(D.getIdentifierLoc(), diag::err_conv_function_to_array);
  ConvType = Context.getPointerType(ConvType);
  D.setInvalidType();
} else if (ConvType->isFunctionType()) {
  Diag(D.getIdentifierLoc(), diag::err_conv_function_to_function);
  ConvType = Context.getPointerType(ConvType);
  D.setInvalidType();
}

// Rebuild the function type "R" without any parameters (in case any
// of the errors above fired) and with the conversion type as the
// return type.
if (D.isInvalidType())
  R = Context.getFunctionType(ConvType, None, Proto->getExtProtoInfo());

// C++0x explicit conversion operators.
if (DS.hasExplicitSpecifier() && !getLangOpts().CPlusPlus20)
  Diag(DS.getExplicitSpecLoc(),
       getLangOpts().CPlusPlus11
           ? diag::warn_cxx98_compat_explicit_conversion_functions
           : diag::ext_explicit_conversion_functions)
      << SourceRange(DS.getExplicitSpecRange());
10727}

10729/// ActOnConversionDeclarator - Called by ActOnDeclarator to complete
10730/// the declaration of the given C++ conversion function. This routine
10731/// is responsible for recording the conversion function in the C++
10732/// class, if possible.
10733Decl *Sema::ActOnConversionDeclarator(CXXConversionDecl *Conversion) {
assert(Conversion && "Expected to receive a conversion function declaration")(static_cast<void> (0));

CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(Conversion->getDeclContext());

// Make sure we aren't redeclaring the conversion function.
QualType ConvType = Context.getCanonicalType(Conversion->getConversionType());
// C++ [class.conv.fct]p1:
//   [...] A conversion function is never used to convert a
//   (possibly cv-qualified) object to the (possibly cv-qualified)
//   same object type (or a reference to it), to a (possibly
//   cv-qualified) base class of that type (or a reference to it),
//   or to (possibly cv-qualified) void.
QualType ClassType
  = Context.getCanonicalType(Context.getTypeDeclType(ClassDecl));
if (const ReferenceType *ConvTypeRef = ConvType->getAs<ReferenceType>())
  ConvType = ConvTypeRef->getPointeeType();
if (Conversion->getTemplateSpecializationKind() != TSK_Undeclared &&
    Conversion->getTemplateSpecializationKind() != TSK_ExplicitSpecialization)
  /* Suppress diagnostics for instantiations. */;
else if (Conversion->size_overridden_methods() != 0)
  /* Suppress diagnostics for overriding virtual function in a base class. */;
else if (ConvType->isRecordType()) {
  ConvType = Context.getCanonicalType(ConvType).getUnqualifiedType();
  if (ConvType == ClassType)
    Diag(Conversion->getLocation(), diag::warn_conv_to_self_not_used)
      << ClassType;
  else if (IsDerivedFrom(Conversion->getLocation(), ClassType, ConvType))
    Diag(Conversion->getLocation(), diag::warn_conv_to_base_not_used)
      <<  ClassType << ConvType;
} else if (ConvType->isVoidType()) {
  Diag(Conversion->getLocation(), diag::warn_conv_to_void_not_used)
    << ClassType << ConvType;
}

if (FunctionTemplateDecl *ConversionTemplate
                              = Conversion->getDescribedFunctionTemplate())
  return ConversionTemplate;

return Conversion;
10773}

10775namespace {
10776/// Utility class to accumulate and print a diagnostic listing the invalid
10777/// specifier(s) on a declaration.
10778struct BadSpecifierDiagnoser {
BadSpecifierDiagnoser(Sema &S, SourceLocation Loc, unsigned DiagID)
    : S(S), Diagnostic(S.Diag(Loc, DiagID)) {}
~BadSpecifierDiagnoser() {
  Diagnostic << Specifiers;
}

template<typename T> void check(SourceLocation SpecLoc, T Spec) {
  return check(SpecLoc, DeclSpec::getSpecifierName(Spec));
}
void check(SourceLocation SpecLoc, DeclSpec::TST Spec) {
  return check(SpecLoc,
               DeclSpec::getSpecifierName(Spec, S.getPrintingPolicy()));
}
void check(SourceLocation SpecLoc, const char *Spec) {
  if (SpecLoc.isInvalid()) return;
  Diagnostic << SourceRange(SpecLoc, SpecLoc);
  if (!Specifiers.empty()) Specifiers += " ";
  Specifiers += Spec;
}

Sema &S;
Sema::SemaDiagnosticBuilder Diagnostic;
std::string Specifiers;
10802};
10803}

10805/// Check the validity of a declarator that we parsed for a deduction-guide.
10806/// These aren't actually declarators in the grammar, so we need to check that
10807/// the user didn't specify any pieces that are not part of the deduction-guide
10808/// grammar.
10809void Sema::CheckDeductionGuideDeclarator(Declarator &D, QualType &R,
                                       StorageClass &SC) {
TemplateName GuidedTemplate = D.getName().TemplateName.get().get();
TemplateDecl *GuidedTemplateDecl = GuidedTemplate.getAsTemplateDecl();
assert(GuidedTemplateDecl && "missing template decl for deduction guide")(static_cast<void> (0));

// C++ [temp.deduct.guide]p3:
//   A deduction-gide shall be declared in the same scope as the
//   corresponding class template.
if (!CurContext->getRedeclContext()->Equals(
        GuidedTemplateDecl->getDeclContext()->getRedeclContext())) {
  Diag(D.getIdentifierLoc(), diag::err_deduction_guide_wrong_scope)
    << GuidedTemplateDecl;
  Diag(GuidedTemplateDecl->getLocation(), diag::note_template_decl_here);
}

auto &DS = D.getMutableDeclSpec();
// We leave 'friend' and 'virtual' to be rejected in the normal way.
if (DS.hasTypeSpecifier() || DS.getTypeQualifiers() ||
    DS.getStorageClassSpecLoc().isValid() || DS.isInlineSpecified() ||
    DS.isNoreturnSpecified() || DS.hasConstexprSpecifier()) {
  BadSpecifierDiagnoser Diagnoser(
      *this, D.getIdentifierLoc(),
      diag::err_deduction_guide_invalid_specifier);

  Diagnoser.check(DS.getStorageClassSpecLoc(), DS.getStorageClassSpec());
  DS.ClearStorageClassSpecs();
  SC = SC_None;

  // 'explicit' is permitted.
  Diagnoser.check(DS.getInlineSpecLoc(), "inline");
  Diagnoser.check(DS.getNoreturnSpecLoc(), "_Noreturn");
  Diagnoser.check(DS.getConstexprSpecLoc(), "constexpr");
  DS.ClearConstexprSpec();

  Diagnoser.check(DS.getConstSpecLoc(), "const");
  Diagnoser.check(DS.getRestrictSpecLoc(), "__restrict");
  Diagnoser.check(DS.getVolatileSpecLoc(), "volatile");
  Diagnoser.check(DS.getAtomicSpecLoc(), "_Atomic");
  Diagnoser.check(DS.getUnalignedSpecLoc(), "__unaligned");
  DS.ClearTypeQualifiers();

  Diagnoser.check(DS.getTypeSpecComplexLoc(), DS.getTypeSpecComplex());
  Diagnoser.check(DS.getTypeSpecSignLoc(), DS.getTypeSpecSign());
  Diagnoser.check(DS.getTypeSpecWidthLoc(), DS.getTypeSpecWidth());
  Diagnoser.check(DS.getTypeSpecTypeLoc(), DS.getTypeSpecType());
  DS.ClearTypeSpecType();
}

if (D.isInvalidType())
  return;

// Check the declarator is simple enough.
bool FoundFunction = false;
for (const DeclaratorChunk &Chunk : llvm::reverse(D.type_objects())) {
  if (Chunk.Kind == DeclaratorChunk::Paren)
    continue;
  if (Chunk.Kind != DeclaratorChunk::Function || FoundFunction) {
    Diag(D.getDeclSpec().getBeginLoc(),
         diag::err_deduction_guide_with_complex_decl)
        << D.getSourceRange();
    break;
  }
  if (!Chunk.Fun.hasTrailingReturnType()) {
    Diag(D.getName().getBeginLoc(),
         diag::err_deduction_guide_no_trailing_return_type);
    break;
  }

  // Check that the return type is written as a specialization of
  // the template specified as the deduction-guide's name.
  ParsedType TrailingReturnType = Chunk.Fun.getTrailingReturnType();
  TypeSourceInfo *TSI = nullptr;
  QualType RetTy = GetTypeFromParser(TrailingReturnType, &TSI);
  assert(TSI && "deduction guide has valid type but invalid return type?")(static_cast<void> (0));
  bool AcceptableReturnType = false;
  bool MightInstantiateToSpecialization = false;
  if (auto RetTST =
          TSI->getTypeLoc().getAs<TemplateSpecializationTypeLoc>()) {
    TemplateName SpecifiedName = RetTST.getTypePtr()->getTemplateName();
    bool TemplateMatches =
        Context.hasSameTemplateName(SpecifiedName, GuidedTemplate);
    if (SpecifiedName.getKind() == TemplateName::Template && TemplateMatches)
      AcceptableReturnType = true;
    else {
      // This could still instantiate to the right type, unless we know it
      // names the wrong class template.
      auto *TD = SpecifiedName.getAsTemplateDecl();
      MightInstantiateToSpecialization = !(TD && isa<ClassTemplateDecl>(TD) &&
                                           !TemplateMatches);
    }
  } else if (!RetTy.hasQualifiers() && RetTy->isDependentType()) {
    MightInstantiateToSpecialization = true;
  }

  if (!AcceptableReturnType) {
    Diag(TSI->getTypeLoc().getBeginLoc(),
         diag::err_deduction_guide_bad_trailing_return_type)
        << GuidedTemplate << TSI->getType()
        << MightInstantiateToSpecialization
        << TSI->getTypeLoc().getSourceRange();
  }

  // Keep going to check that we don't have any inner declarator pieces (we
  // could still have a function returning a pointer to a function).
  FoundFunction = true;
}

if (D.isFunctionDefinition())
  Diag(D.getIdentifierLoc(), diag::err_deduction_guide_defines_function);
10919}

10921//===----------------------------------------------------------------------===//
10922// Namespace Handling
10923//===----------------------------------------------------------------------===//

10925/// Diagnose a mismatch in 'inline' qualifiers when a namespace is
10926/// reopened.
10927static void DiagnoseNamespaceInlineMismatch(Sema &S, SourceLocation KeywordLoc,
                                          SourceLocation Loc,
                                          IdentifierInfo *II, bool *IsInline,
                                          NamespaceDecl *PrevNS) {
assert(*IsInline != PrevNS->isInline())(static_cast<void> (0));

if (PrevNS->isInline())
  // The user probably just forgot the 'inline', so suggest that it
  // be added back.
  S.Diag(Loc, diag::warn_inline_namespace_reopened_noninline)
    << FixItHint::CreateInsertion(KeywordLoc, "inline ");
else
  S.Diag(Loc, diag::err_inline_namespace_mismatch);

S.Diag(PrevNS->getLocation(), diag::note_previous_definition);
*IsInline = PrevNS->isInline();
10943}

10945/// ActOnStartNamespaceDef - This is called at the start of a namespace
10946/// definition.
10947Decl *Sema::ActOnStartNamespaceDef(
  Scope *NamespcScope, SourceLocation InlineLoc, SourceLocation NamespaceLoc,
  SourceLocation IdentLoc, IdentifierInfo *II, SourceLocation LBrace,
  const ParsedAttributesView &AttrList, UsingDirectiveDecl *&UD) {
SourceLocation StartLoc = InlineLoc.isValid() ? InlineLoc : NamespaceLoc;
// For anonymous namespace, take the location of the left brace.
SourceLocation Loc = II ? IdentLoc : LBrace;
bool IsInline = InlineLoc.isValid();
bool IsInvalid = false;
bool IsStd = false;
bool AddToKnown = false;
Scope *DeclRegionScope = NamespcScope->getParent();

NamespaceDecl *PrevNS = nullptr;
if (II) {
  // C++ [namespace.def]p2:
  //   The identifier in an original-namespace-definition shall not
  //   have been previously defined in the declarative region in
  //   which the original-namespace-definition appears. The
  //   identifier in an original-namespace-definition is the name of
  //   the namespace. Subsequently in that declarative region, it is
  //   treated as an original-namespace-name.
  //
  // Since namespace names are unique in their scope, and we don't
  // look through using directives, just look for any ordinary names
  // as if by qualified name lookup.
  LookupResult R(*this, II, IdentLoc, LookupOrdinaryName,
                 ForExternalRedeclaration);
  LookupQualifiedName(R, CurContext->getRedeclContext());
  NamedDecl *PrevDecl =
      R.isSingleResult() ? R.getRepresentativeDecl() : nullptr;
  PrevNS = dyn_cast_or_null<NamespaceDecl>(PrevDecl);

  if (PrevNS) {
    // This is an extended namespace definition.
    if (IsInline != PrevNS->isInline())
      DiagnoseNamespaceInlineMismatch(*this, NamespaceLoc, Loc, II,
                                      &IsInline, PrevNS);
  } else if (PrevDecl) {
    // This is an invalid name redefinition.
    Diag(Loc, diag::err_redefinition_different_kind)
      << II;
    Diag(PrevDecl->getLocation(), diag::note_previous_definition);
    IsInvalid = true;
    // Continue on to push Namespc as current DeclContext and return it.
  } else if (II->isStr("std") &&
             CurContext->getRedeclContext()->isTranslationUnit()) {
    // This is the first "real" definition of the namespace "std", so update
    // our cache of the "std" namespace to point at this definition.
    PrevNS = getStdNamespace();
    IsStd = true;
    AddToKnown = !IsInline;
  } else {
    // We've seen this namespace for the first time.
    AddToKnown = !IsInline;
  }
} else {
  // Anonymous namespaces.

  // Determine whether the parent already has an anonymous namespace.
  DeclContext *Parent = CurContext->getRedeclContext();
  if (TranslationUnitDecl *TU = dyn_cast<TranslationUnitDecl>(Parent)) {
    PrevNS = TU->getAnonymousNamespace();
  } else {
    NamespaceDecl *ND = cast<NamespaceDecl>(Parent);
    PrevNS = ND->getAnonymousNamespace();
  }

  if (PrevNS && IsInline != PrevNS->isInline())
    DiagnoseNamespaceInlineMismatch(*this, NamespaceLoc, NamespaceLoc, II,
                                    &IsInline, PrevNS);
}

NamespaceDecl *Namespc = NamespaceDecl::Create(Context, CurContext, IsInline,
                                               StartLoc, Loc, II, PrevNS);
if (IsInvalid)
  Namespc->setInvalidDecl();

ProcessDeclAttributeList(DeclRegionScope, Namespc, AttrList);
AddPragmaAttributes(DeclRegionScope, Namespc);

// FIXME: Should we be merging attributes?
if (const VisibilityAttr *Attr = Namespc->getAttr<VisibilityAttr>())
  PushNamespaceVisibilityAttr(Attr, Loc);

if (IsStd)
  StdNamespace = Namespc;
if (AddToKnown)
  KnownNamespaces[Namespc] = false;

if (II) {
  PushOnScopeChains(Namespc, DeclRegionScope);
} else {
  // Link the anonymous namespace into its parent.
  DeclContext *Parent = CurContext->getRedeclContext();
  if (TranslationUnitDecl *TU = dyn_cast<TranslationUnitDecl>(Parent)) {
    TU->setAnonymousNamespace(Namespc);
  } else {
    cast<NamespaceDecl>(Parent)->setAnonymousNamespace(Namespc);
  }

  CurContext->addDecl(Namespc);

  // C++ [namespace.unnamed]p1.  An unnamed-namespace-definition
  //   behaves as if it were replaced by
  //     namespace unique { /* empty body */ }
  //     using namespace unique;
  //     namespace unique { namespace-body }
  //   where all occurrences of 'unique' in a translation unit are
  //   replaced by the same identifier and this identifier differs
  //   from all other identifiers in the entire program.

  // We just create the namespace with an empty name and then add an
  // implicit using declaration, just like the standard suggests.
  //
  // CodeGen enforces the "universally unique" aspect by giving all
  // declarations semantically contained within an anonymous
  // namespace internal linkage.

  if (!PrevNS) {
    UD = UsingDirectiveDecl::Create(Context, Parent,
                                    /* 'using' */ LBrace,
                                    /* 'namespace' */ SourceLocation(),
                                    /* qualifier */ NestedNameSpecifierLoc(),
                                    /* identifier */ SourceLocation(),
                                    Namespc,
                                    /* Ancestor */ Parent);
    UD->setImplicit();
    Parent->addDecl(UD);
  }
}

ActOnDocumentableDecl(Namespc);

// Although we could have an invalid decl (i.e. the namespace name is a
// redefinition), push it as current DeclContext and try to continue parsing.
// FIXME: We should be able to push Namespc here, so that the each DeclContext
// for the namespace has the declarations that showed up in that particular
// namespace definition.
PushDeclContext(NamespcScope, Namespc);
return Namespc;
11088}

11090/// getNamespaceDecl - Returns the namespace a decl represents. If the decl
11091/// is a namespace alias, returns the namespace it points to.
11092static inline NamespaceDecl *getNamespaceDecl(NamedDecl *D) {
if (NamespaceAliasDecl *AD = dyn_cast_or_null<NamespaceAliasDecl>(D))
  return AD->getNamespace();
return dyn_cast_or_null<NamespaceDecl>(D);
11096}

11098/// ActOnFinishNamespaceDef - This callback is called after a namespace is
11099/// exited. Decl is the DeclTy returned by ActOnStartNamespaceDef.
11100void Sema::ActOnFinishNamespaceDef(Decl *Dcl, SourceLocation RBrace) {
NamespaceDecl *Namespc = dyn_cast_or_null<NamespaceDecl>(Dcl);
assert(Namespc && "Invalid parameter, expected NamespaceDecl")(static_cast<void> (0));
Namespc->setRBraceLoc(RBrace);
PopDeclContext();
if (Namespc->hasAttr<VisibilityAttr>())
  PopPragmaVisibility(true, RBrace);
// If this namespace contains an export-declaration, export it now.
if (DeferredExportedNamespaces.erase(Namespc))
  Dcl->setModuleOwnershipKind(Decl::ModuleOwnershipKind::VisibleWhenImported);
11110}

11112CXXRecordDecl *Sema::getStdBadAlloc() const {
return cast_or_null<CXXRecordDecl>(
                                StdBadAlloc.get(Context.getExternalSource()));
11115}

11117EnumDecl *Sema::getStdAlignValT() const {
return cast_or_null<EnumDecl>(StdAlignValT.get(Context.getExternalSource()));
11119}

11121NamespaceDecl *Sema::getStdNamespace() const {
return cast_or_null<NamespaceDecl>(
                               StdNamespace.get(Context.getExternalSource()));
11124}

11126NamespaceDecl *Sema::lookupStdExperimentalNamespace() {
if (!StdExperimentalNamespaceCache) {
  if (auto Std = getStdNamespace()) {
    LookupResult Result(*this, &PP.getIdentifierTable().get("experimental"),
                        SourceLocation(), LookupNamespaceName);
    if (!LookupQualifiedName(Result, Std) ||
        !(StdExperimentalNamespaceCache =
              Result.getAsSingle<NamespaceDecl>()))
      Result.suppressDiagnostics();
  }
}
return StdExperimentalNamespaceCache;
11138}

11140namespace {

11142enum UnsupportedSTLSelect {
USS_InvalidMember,
USS_MissingMember,
USS_NonTrivial,
USS_Other
11147};

11149struct InvalidSTLDiagnoser {
Sema &S;
SourceLocation Loc;
QualType TyForDiags;

QualType operator()(UnsupportedSTLSelect Sel = USS_Other, StringRef Name = "",
                    const VarDecl *VD = nullptr) {
  {
    auto D = S.Diag(Loc, diag::err_std_compare_type_not_supported)
             << TyForDiags << ((int)Sel);
    if (Sel == USS_InvalidMember || Sel == USS_MissingMember) {
      assert(!Name.empty())(static_cast<void> (0));
      D << Name;
    }
  }
  if (Sel == USS_InvalidMember) {
    S.Diag(VD->getLocation(), diag::note_var_declared_here)
        << VD << VD->getSourceRange();
  }
  return QualType();
}
11170};
11171} // namespace

11173QualType Sema::CheckComparisonCategoryType(ComparisonCategoryType Kind,
                                         SourceLocation Loc,
                                         ComparisonCategoryUsage Usage) {
assert(getLangOpts().CPlusPlus &&(static_cast<void> (0))
       "Looking for comparison category type outside of C++.")(static_cast<void> (0));

// Use an elaborated type for diagnostics which has a name containing the
// prepended 'std' namespace but not any inline namespace names.
auto TyForDiags = [&](ComparisonCategoryInfo *Info) {
  auto *NNS =
      NestedNameSpecifier::Create(Context, nullptr, getStdNamespace());
  return Context.getElaboratedType(ETK_None, NNS, Info->getType());
};

// Check if we've already successfully checked the comparison category type
// before. If so, skip checking it again.
ComparisonCategoryInfo *Info = Context.CompCategories.lookupInfo(Kind);
if (Info && FullyCheckedComparisonCategories[static_cast<unsigned>(Kind)]) {
  // The only thing we need to check is that the type has a reachable
  // definition in the current context.
  if (RequireCompleteType(Loc, TyForDiags(Info), diag::err_incomplete_type))
    return QualType();

  return Info->getType();
}

// If lookup failed
if (!Info) {
  std::string NameForDiags = "std::";
  NameForDiags += ComparisonCategories::getCategoryString(Kind);
  Diag(Loc, diag::err_implied_comparison_category_type_not_found)
      << NameForDiags << (int)Usage;
  return QualType();
}

assert(Info->Kind == Kind)(static_cast<void> (0));
assert(Info->Record)(static_cast<void> (0));

// Update the Record decl in case we encountered a forward declaration on our
// first pass. FIXME: This is a bit of a hack.
if (Info->Record->hasDefinition())
  Info->Record = Info->Record->getDefinition();

if (RequireCompleteType(Loc, TyForDiags(Info), diag::err_incomplete_type))
  return QualType();

InvalidSTLDiagnoser UnsupportedSTLError{*this, Loc, TyForDiags(Info)};

if (!Info->Record->isTriviallyCopyable())
  return UnsupportedSTLError(USS_NonTrivial);

for (const CXXBaseSpecifier &BaseSpec : Info->Record->bases()) {
  CXXRecordDecl *Base = BaseSpec.getType()->getAsCXXRecordDecl();
  // Tolerate empty base classes.
  if (Base->isEmpty())
    continue;
  // Reject STL implementations which have at least one non-empty base.
  return UnsupportedSTLError();
}

// Check that the STL has implemented the types using a single integer field.
// This expectation allows better codegen for builtin operators. We require:
//   (1) The class has exactly one field.
//   (2) The field is an integral or enumeration type.
auto FIt = Info->Record->field_begin(), FEnd = Info->Record->field_end();
if (std::distance(FIt, FEnd) != 1 ||
    !FIt->getType()->isIntegralOrEnumerationType()) {
  return UnsupportedSTLError();
}

// Build each of the require values and store them in Info.
for (ComparisonCategoryResult CCR :
     ComparisonCategories::getPossibleResultsForType(Kind)) {
  StringRef MemName = ComparisonCategories::getResultString(CCR);
  ComparisonCategoryInfo::ValueInfo *ValInfo = Info->lookupValueInfo(CCR);

  if (!ValInfo)
    return UnsupportedSTLError(USS_MissingMember, MemName);

  VarDecl *VD = ValInfo->VD;
  assert(VD && "should not be null!")(static_cast<void> (0));

  // Attempt to diagnose reasons why the STL definition of this type
  // might be foobar, including it failing to be a constant expression.
  // TODO Handle more ways the lookup or result can be invalid.
  if (!VD->isStaticDataMember() ||
      !VD->isUsableInConstantExpressions(Context))
    return UnsupportedSTLError(USS_InvalidMember, MemName, VD);

  // Attempt to evaluate the var decl as a constant expression and extract
  // the value of its first field as a ICE. If this fails, the STL
  // implementation is not supported.
  if (!ValInfo->hasValidIntValue())
    return UnsupportedSTLError();

  MarkVariableReferenced(Loc, VD);
}

// We've successfully built the required types and expressions. Update
// the cache and return the newly cached value.
FullyCheckedComparisonCategories[static_cast<unsigned>(Kind)] = true;
return Info->getType();
11275}

11277/// Retrieve the special "std" namespace, which may require us to
11278/// implicitly define the namespace.
11279NamespaceDecl *Sema::getOrCreateStdNamespace() {
if (!StdNamespace) {
  // The "std" namespace has not yet been defined, so build one implicitly.
  StdNamespace = NamespaceDecl::Create(Context,
                                       Context.getTranslationUnitDecl(),
                                       /*Inline=*/false,
                                       SourceLocation(), SourceLocation(),
                                       &PP.getIdentifierTable().get("std"),
                                       /*PrevDecl=*/nullptr);
  getStdNamespace()->setImplicit(true);
}

return getStdNamespace();
11292}

11294bool Sema::isStdInitializerList(QualType Ty, QualType *Element) {
assert(getLangOpts().CPlusPlus &&(static_cast<void> (0))
       "Looking for std::initializer_list outside of C++.")(static_cast<void> (0));

// We're looking for implicit instantiations of
// template <typename E> class std::initializer_list.

if (!StdNamespace) // If we haven't seen namespace std yet, this can't be it.
  return false;

ClassTemplateDecl *Template = nullptr;
const TemplateArgument *Arguments = nullptr;

if (const RecordType *RT = Ty->getAs<RecordType>()) {

  ClassTemplateSpecializationDecl *Specialization =
      dyn_cast<ClassTemplateSpecializationDecl>(RT->getDecl());
  if (!Specialization)
    return false;

  Template = Specialization->getSpecializedTemplate();
  Arguments = Specialization->getTemplateArgs().data();
} else if (const TemplateSpecializationType *TST =
               Ty->getAs<TemplateSpecializationType>()) {
  Template = dyn_cast_or_null<ClassTemplateDecl>(
      TST->getTemplateName().getAsTemplateDecl());
  Arguments = TST->getArgs();
}
if (!Template)
  return false;

if (!StdInitializerList) {
  // Haven't recognized std::initializer_list yet, maybe this is it.
  CXXRecordDecl *TemplateClass = Template->getTemplatedDecl();
  if (TemplateClass->getIdentifier() !=
          &PP.getIdentifierTable().get("initializer_list") ||
      !getStdNamespace()->InEnclosingNamespaceSetOf(
          TemplateClass->getDeclContext()))
    return false;
  // This is a template called std::initializer_list, but is it the right
  // template?
  TemplateParameterList *Params = Template->getTemplateParameters();
  if (Params->getMinRequiredArguments() != 1)
    return false;
  if (!isa<TemplateTypeParmDecl>(Params->getParam(0)))
    return false;

  // It's the right template.
  StdInitializerList = Template;
}

if (Template->getCanonicalDecl() != StdInitializerList->getCanonicalDecl())
  return false;

// This is an instance of std::initializer_list. Find the argument type.
if (Element)
  *Element = Arguments[0].getAsType();
return true;
11352}

11354static ClassTemplateDecl *LookupStdInitializerList(Sema &S, SourceLocation Loc){
NamespaceDecl *Std = S.getStdNamespace();
if (!Std) {
  S.Diag(Loc, diag::err_implied_std_initializer_list_not_found);
  return nullptr;
}

LookupResult Result(S, &S.PP.getIdentifierTable().get("initializer_list"),
                    Loc, Sema::LookupOrdinaryName);
if (!S.LookupQualifiedName(Result, Std)) {
  S.Diag(Loc, diag::err_implied_std_initializer_list_not_found);
  return nullptr;
}
ClassTemplateDecl *Template = Result.getAsSingle<ClassTemplateDecl>();
if (!Template) {
  Result.suppressDiagnostics();
  // We found something weird. Complain about the first thing we found.
  NamedDecl *Found = *Result.begin();
  S.Diag(Found->getLocation(), diag::err_malformed_std_initializer_list);
  return nullptr;
}

// We found some template called std::initializer_list. Now verify that it's
// correct.
TemplateParameterList *Params = Template->getTemplateParameters();
if (Params->getMinRequiredArguments() != 1 ||
    !isa<TemplateTypeParmDecl>(Params->getParam(0))) {
  S.Diag(Template->getLocation(), diag::err_malformed_std_initializer_list);
  return nullptr;
}

return Template;
11386}

11388QualType Sema::BuildStdInitializerList(QualType Element, SourceLocation Loc) {
if (!StdInitializerList) {
  StdInitializerList = LookupStdInitializerList(*this, Loc);
  if (!StdInitializerList)
    return QualType();
}

TemplateArgumentListInfo Args(Loc, Loc);
Args.addArgument(TemplateArgumentLoc(TemplateArgument(Element),
                                     Context.getTrivialTypeSourceInfo(Element,
                                                                      Loc)));
return Context.getCanonicalType(
    CheckTemplateIdType(TemplateName(StdInitializerList), Loc, Args));
11401}

11403bool Sema::isInitListConstructor(const FunctionDecl *Ctor) {
// C++ [dcl.init.list]p2:
//   A constructor is an initializer-list constructor if its first parameter
//   is of type std::initializer_list<E> or reference to possibly cv-qualified
//   std::initializer_list<E> for some type E, and either there are no other
//   parameters or else all other parameters have default arguments.
if (!Ctor->hasOneParamOrDefaultArgs())
  return false;

QualType ArgType = Ctor->getParamDecl(0)->getType();
if (const ReferenceType *RT = ArgType->getAs<ReferenceType>())
  ArgType = RT->getPointeeType().getUnqualifiedType();

return isStdInitializerList(ArgType, nullptr);
11417}

11419/// Determine whether a using statement is in a context where it will be
11420/// apply in all contexts.
11421static bool IsUsingDirectiveInToplevelContext(DeclContext *CurContext) {
switch (CurContext->getDeclKind()) {
  case Decl::TranslationUnit:
    return true;
  case Decl::LinkageSpec:
    return IsUsingDirectiveInToplevelContext(CurContext->getParent());
  default:
    return false;
}
11430}

11432namespace {

11434// Callback to only accept typo corrections that are namespaces.
11435class NamespaceValidatorCCC final : public CorrectionCandidateCallback {
11436public:
bool ValidateCandidate(const TypoCorrection &candidate) override {
  if (NamedDecl *ND = candidate.getCorrectionDecl())
    return isa<NamespaceDecl>(ND) || isa<NamespaceAliasDecl>(ND);
  return false;
}

std::unique_ptr<CorrectionCandidateCallback> clone() override {
  return std::make_unique<NamespaceValidatorCCC>(*this);
}
11446};

11448}

11450static bool TryNamespaceTypoCorrection(Sema &S, LookupResult &R, Scope *Sc,
                                     CXXScopeSpec &SS,
                                     SourceLocation IdentLoc,
                                     IdentifierInfo *Ident) {
R.clear();
NamespaceValidatorCCC CCC{};
if (TypoCorrection Corrected =
        S.CorrectTypo(R.getLookupNameInfo(), R.getLookupKind(), Sc, &SS, CCC,
                      Sema::CTK_ErrorRecovery)) {
  if (DeclContext *DC = S.computeDeclContext(SS, false)) {
    std::string CorrectedStr(Corrected.getAsString(S.getLangOpts()));
    bool DroppedSpecifier = Corrected.WillReplaceSpecifier() &&
                            Ident->getName().equals(CorrectedStr);
    S.diagnoseTypo(Corrected,
                   S.PDiag(diag::err_using_directive_member_suggest)
                     << Ident << DC << DroppedSpecifier << SS.getRange(),
                   S.PDiag(diag::note_namespace_defined_here));
  } else {
    S.diagnoseTypo(Corrected,
                   S.PDiag(diag::err_using_directive_suggest) << Ident,
                   S.PDiag(diag::note_namespace_defined_here));
  }
  R.addDecl(Corrected.getFoundDecl());
  return true;
}
return false;
11476}

11478Decl *Sema::ActOnUsingDirective(Scope *S, SourceLocation UsingLoc,
                              SourceLocation NamespcLoc, CXXScopeSpec &SS,
                              SourceLocation IdentLoc,
                              IdentifierInfo *NamespcName,
                              const ParsedAttributesView &AttrList) {
assert(!SS.isInvalid() && "Invalid CXXScopeSpec.")(static_cast<void> (0));
assert(NamespcName && "Invalid NamespcName.")(static_cast<void> (0));
assert(IdentLoc.isValid() && "Invalid NamespceName location.")(static_cast<void> (0));

// This can only happen along a recovery path.
while (S->isTemplateParamScope())
  S = S->getParent();
assert(S->getFlags() & Scope::DeclScope && "Invalid Scope.")(static_cast<void> (0));

UsingDirectiveDecl *UDir = nullptr;
NestedNameSpecifier *Qualifier = nullptr;
if (SS.isSet())
  Qualifier = SS.getScopeRep();

// Lookup namespace name.
LookupResult R(*this, NamespcName, IdentLoc, LookupNamespaceName);
LookupParsedName(R, S, &SS);
if (R.isAmbiguous())
  return nullptr;

if (R.empty()) {
  R.clear();
  // Allow "using namespace std;" or "using namespace ::std;" even if
  // "std" hasn't been defined yet, for GCC compatibility.
  if ((!Qualifier || Qualifier->getKind() == NestedNameSpecifier::Global) &&
      NamespcName->isStr("std")) {
    Diag(IdentLoc, diag::ext_using_undefined_std);
    R.addDecl(getOrCreateStdNamespace());
    R.resolveKind();
  }
  // Otherwise, attempt typo correction.
  else TryNamespaceTypoCorrection(*this, R, S, SS, IdentLoc, NamespcName);
}

if (!R.empty()) {
  NamedDecl *Named = R.getRepresentativeDecl();
  NamespaceDecl *NS = R.getAsSingle<NamespaceDecl>();
  assert(NS && "expected namespace decl")(static_cast<void> (0));

  // The use of a nested name specifier may trigger deprecation warnings.
  DiagnoseUseOfDecl(Named, IdentLoc);

  // C++ [namespace.udir]p1:
  //   A using-directive specifies that the names in the nominated
  //   namespace can be used in the scope in which the
  //   using-directive appears after the using-directive. During
  //   unqualified name lookup (3.4.1), the names appear as if they
  //   were declared in the nearest enclosing namespace which
  //   contains both the using-directive and the nominated
  //   namespace. [Note: in this context, "contains" means "contains
  //   directly or indirectly". ]

  // Find enclosing context containing both using-directive and
  // nominated namespace.
  DeclContext *CommonAncestor = NS;
  while (CommonAncestor && !CommonAncestor->Encloses(CurContext))
    CommonAncestor = CommonAncestor->getParent();

  UDir = UsingDirectiveDecl::Create(Context, CurContext, UsingLoc, NamespcLoc,
                                    SS.getWithLocInContext(Context),
                                    IdentLoc, Named, CommonAncestor);

  if (IsUsingDirectiveInToplevelContext(CurContext) &&
      !SourceMgr.isInMainFile(SourceMgr.getExpansionLoc(IdentLoc))) {
    Diag(IdentLoc, diag::warn_using_directive_in_header);
  }

  PushUsingDirective(S, UDir);
} else {
  Diag(IdentLoc, diag::err_expected_namespace_name) << SS.getRange();
}

if (UDir)
  ProcessDeclAttributeList(S, UDir, AttrList);

return UDir;
11559}

11561void Sema::PushUsingDirective(Scope *S, UsingDirectiveDecl *UDir) {
// If the scope has an associated entity and the using directive is at
// namespace or translation unit scope, add the UsingDirectiveDecl into
// its lookup structure so qualified name lookup can find it.
DeclContext *Ctx = S->getEntity();
if (Ctx && !Ctx->isFunctionOrMethod())
  Ctx->addDecl(UDir);
else
  // Otherwise, it is at block scope. The using-directives will affect lookup
  // only to the end of the scope.
  S->PushUsingDirective(UDir);
11572}

11574Decl *Sema::ActOnUsingDeclaration(Scope *S, AccessSpecifier AS,
                                SourceLocation UsingLoc,
                                SourceLocation TypenameLoc, CXXScopeSpec &SS,
                                UnqualifiedId &Name,
                                SourceLocation EllipsisLoc,
                                const ParsedAttributesView &AttrList) {
assert(S->getFlags() & Scope::DeclScope && "Invalid Scope.")(static_cast<void> (0));

if (SS.isEmpty()) {
  Diag(Name.getBeginLoc(), diag::err_using_requires_qualname);
  return nullptr;
}

switch (Name.getKind()) {
case UnqualifiedIdKind::IK_ImplicitSelfParam:
case UnqualifiedIdKind::IK_Identifier:
case UnqualifiedIdKind::IK_OperatorFunctionId:
case UnqualifiedIdKind::IK_LiteralOperatorId:
case UnqualifiedIdKind::IK_ConversionFunctionId:
  break;

case UnqualifiedIdKind::IK_ConstructorName:
case UnqualifiedIdKind::IK_ConstructorTemplateId:
  // C++11 inheriting constructors.
  Diag(Name.getBeginLoc(),
       getLangOpts().CPlusPlus11
           ? diag::warn_cxx98_compat_using_decl_constructor
           : diag::err_using_decl_constructor)
      << SS.getRange();

  if (getLangOpts().CPlusPlus11) break;

  return nullptr;

case UnqualifiedIdKind::IK_DestructorName:
  Diag(Name.getBeginLoc(), diag::err_using_decl_destructor) << SS.getRange();
  return nullptr;

case UnqualifiedIdKind::IK_TemplateId:
  Diag(Name.getBeginLoc(), diag::err_using_decl_template_id)
      << SourceRange(Name.TemplateId->LAngleLoc, Name.TemplateId->RAngleLoc);
  return nullptr;

case UnqualifiedIdKind::IK_DeductionGuideName:
  llvm_unreachable("cannot parse qualified deduction guide name")__builtin_unreachable();
}

DeclarationNameInfo TargetNameInfo = GetNameFromUnqualifiedId(Name);
DeclarationName TargetName = TargetNameInfo.getName();
if (!TargetName)
  return nullptr;

// Warn about access declarations.
if (UsingLoc.isInvalid()) {
  Diag(Name.getBeginLoc(), getLangOpts().CPlusPlus11
                               ? diag::err_access_decl
                               : diag::warn_access_decl_deprecated)
      << FixItHint::CreateInsertion(SS.getRange().getBegin(), "using ");
}

if (EllipsisLoc.isInvalid()) {
  if (DiagnoseUnexpandedParameterPack(SS, UPPC_UsingDeclaration) ||
      DiagnoseUnexpandedParameterPack(TargetNameInfo, UPPC_UsingDeclaration))
    return nullptr;
} else {
  if (!SS.getScopeRep()->containsUnexpandedParameterPack() &&
      !TargetNameInfo.containsUnexpandedParameterPack()) {
    Diag(EllipsisLoc, diag::err_pack_expansion_without_parameter_packs)
      << SourceRange(SS.getBeginLoc(), TargetNameInfo.getEndLoc());
    EllipsisLoc = SourceLocation();
  }
}

NamedDecl *UD =
    BuildUsingDeclaration(S, AS, UsingLoc, TypenameLoc.isValid(), TypenameLoc,
                          SS, TargetNameInfo, EllipsisLoc, AttrList,
                          /*IsInstantiation*/ false,
                          AttrList.hasAttribute(ParsedAttr::AT_UsingIfExists));
if (UD)
  PushOnScopeChains(UD, S, /*AddToContext*/ false);

return UD;
11656}

11658Decl *Sema::ActOnUsingEnumDeclaration(Scope *S, AccessSpecifier AS,
                                    SourceLocation UsingLoc,
                                    SourceLocation EnumLoc,
                                    const DeclSpec &DS) {
switch (DS.getTypeSpecType()) {
case DeclSpec::TST_error:
  // This will already have been diagnosed
  return nullptr;

case DeclSpec::TST_enum:
  break;

case DeclSpec::TST_typename:
  Diag(DS.getTypeSpecTypeLoc(), diag::err_using_enum_is_dependent);
  return nullptr;

default:
  llvm_unreachable("unexpected DeclSpec type")__builtin_unreachable();
}

// As with enum-decls, we ignore attributes for now.
auto *Enum = cast<EnumDecl>(DS.getRepAsDecl());
if (auto *Def = Enum->getDefinition())
  Enum = Def;

auto *UD = BuildUsingEnumDeclaration(S, AS, UsingLoc, EnumLoc,
                                     DS.getTypeSpecTypeNameLoc(), Enum);
if (UD)
  PushOnScopeChains(UD, S, /*AddToContext*/ false);

return UD;
11689}

11691/// Determine whether a using declaration considers the given
11692/// declarations as "equivalent", e.g., if they are redeclarations of
11693/// the same entity or are both typedefs of the same type.
11694static bool
11695IsEquivalentForUsingDecl(ASTContext &Context, NamedDecl *D1, NamedDecl *D2) {
if (D1->getCanonicalDecl() == D2->getCanonicalDecl())
  return true;

if (TypedefNameDecl *TD1 = dyn_cast<TypedefNameDecl>(D1))
  if (TypedefNameDecl *TD2 = dyn_cast<TypedefNameDecl>(D2))
    return Context.hasSameType(TD1->getUnderlyingType(),
                               TD2->getUnderlyingType());

// Two using_if_exists using-declarations are equivalent if both are
// unresolved.
if (isa<UnresolvedUsingIfExistsDecl>(D1) &&
    isa<UnresolvedUsingIfExistsDecl>(D2))
  return true;

return false;
11711}


11714/// Determines whether to create a using shadow decl for a particular
11715/// decl, given the set of decls existing prior to this using lookup.
11716bool Sema::CheckUsingShadowDecl(BaseUsingDecl *BUD, NamedDecl *Orig,
                              const LookupResult &Previous,
                              UsingShadowDecl *&PrevShadow) {
// Diagnose finding a decl which is not from a base class of the
// current class.  We do this now because there are cases where this
// function will silently decide not to build a shadow decl, which
// will pre-empt further diagnostics.
//
// We don't need to do this in C++11 because we do the check once on
// the qualifier.
//
// FIXME: diagnose the following if we care enough:
//   struct A { int foo; };
//   struct B : A { using A::foo; };
//   template <class T> struct C : A {};
//   template <class T> struct D : C<T> { using B::foo; } // <---
// This is invalid (during instantiation) in C++03 because B::foo
// resolves to the using decl in B, which is not a base class of D<T>.
// We can't diagnose it immediately because C<T> is an unknown
// specialization. The UsingShadowDecl in D<T> then points directly
// to A::foo, which will look well-formed when we instantiate.
// The right solution is to not collapse the shadow-decl chain.
if (!getLangOpts().CPlusPlus11 && CurContext->isRecord())
  if (auto *Using = dyn_cast<UsingDecl>(BUD)) {
    DeclContext *OrigDC = Orig->getDeclContext();

    // Handle enums and anonymous structs.
    if (isa<EnumDecl>(OrigDC))
      OrigDC = OrigDC->getParent();
    CXXRecordDecl *OrigRec = cast<CXXRecordDecl>(OrigDC);
    while (OrigRec->isAnonymousStructOrUnion())
      OrigRec = cast<CXXRecordDecl>(OrigRec->getDeclContext());

    if (cast<CXXRecordDecl>(CurContext)->isProvablyNotDerivedFrom(OrigRec)) {
      if (OrigDC == CurContext) {
        Diag(Using->getLocation(),
             diag::err_using_decl_nested_name_specifier_is_current_class)
            << Using->getQualifierLoc().getSourceRange();
        Diag(Orig->getLocation(), diag::note_using_decl_target);
        Using->setInvalidDecl();
        return true;
      }

      Diag(Using->getQualifierLoc().getBeginLoc(),
           diag::err_using_decl_nested_name_specifier_is_not_base_class)
          << Using->getQualifier() << cast<CXXRecordDecl>(CurContext)
          << Using->getQualifierLoc().getSourceRange();
      Diag(Orig->getLocation(), diag::note_using_decl_target);
      Using->setInvalidDecl();
      return true;
    }
  }

if (Previous.empty()) return false;

NamedDecl *Target = Orig;
if (isa<UsingShadowDecl>(Target))
  Target = cast<UsingShadowDecl>(Target)->getTargetDecl();

// If the target happens to be one of the previous declarations, we
// don't have a conflict.
//
// FIXME: but we might be increasing its access, in which case we
// should redeclare it.
NamedDecl *NonTag = nullptr, *Tag = nullptr;
bool FoundEquivalentDecl = false;
for (LookupResult::iterator I = Previous.begin(), E = Previous.end();
       I != E; ++I) {
  NamedDecl *D = (*I)->getUnderlyingDecl();
  // We can have UsingDecls in our Previous results because we use the same
  // LookupResult for checking whether the UsingDecl itself is a valid
  // redeclaration.
  if (isa<UsingDecl>(D) || isa<UsingPackDecl>(D) || isa<UsingEnumDecl>(D))
    continue;

  if (auto *RD = dyn_cast<CXXRecordDecl>(D)) {
    // C++ [class.mem]p19:
    //   If T is the name of a class, then [every named member other than
    //   a non-static data member] shall have a name different from T
    if (RD->isInjectedClassName() && !isa<FieldDecl>(Target) &&
        !isa<IndirectFieldDecl>(Target) &&
        !isa<UnresolvedUsingValueDecl>(Target) &&
        DiagnoseClassNameShadow(
            CurContext,
            DeclarationNameInfo(BUD->getDeclName(), BUD->getLocation())))
      return true;
  }

  if (IsEquivalentForUsingDecl(Context, D, Target)) {
    if (UsingShadowDecl *Shadow = dyn_cast<UsingShadowDecl>(*I))
      PrevShadow = Shadow;
    FoundEquivalentDecl = true;
  } else if (isEquivalentInternalLinkageDeclaration(D, Target)) {
    // We don't conflict with an existing using shadow decl of an equivalent
    // declaration, but we're not a redeclaration of it.
    FoundEquivalentDecl = true;
  }

  if (isVisible(D))
    (isa<TagDecl>(D) ? Tag : NonTag) = D;
}

if (FoundEquivalentDecl)
  return false;

// Always emit a diagnostic for a mismatch between an unresolved
// using_if_exists and a resolved using declaration in either direction.
if (isa<UnresolvedUsingIfExistsDecl>(Target) !=
    (isa_and_nonnull<UnresolvedUsingIfExistsDecl>(NonTag))) {
  if (!NonTag && !Tag)
    return false;
  Diag(BUD->getLocation(), diag::err_using_decl_conflict);
  Diag(Target->getLocation(), diag::note_using_decl_target);
  Diag((NonTag ? NonTag : Tag)->getLocation(),
       diag::note_using_decl_conflict);
  BUD->setInvalidDecl();
  return true;
}

if (FunctionDecl *FD = Target->getAsFunction()) {
  NamedDecl *OldDecl = nullptr;
  switch (CheckOverload(nullptr, FD, Previous, OldDecl,
                        /*IsForUsingDecl*/ true)) {
  case Ovl_Overload:
    return false;

  case Ovl_NonFunction:
    Diag(BUD->getLocation(), diag::err_using_decl_conflict);
    break;

  // We found a decl with the exact signature.
  case Ovl_Match:
    // If we're in a record, we want to hide the target, so we
    // return true (without a diagnostic) to tell the caller not to
    // build a shadow decl.
    if (CurContext->isRecord())
      return true;

    // If we're not in a record, this is an error.
    Diag(BUD->getLocation(), diag::err_using_decl_conflict);
    break;
  }

  Diag(Target->getLocation(), diag::note_using_decl_target);
  Diag(OldDecl->getLocation(), diag::note_using_decl_conflict);
  BUD->setInvalidDecl();
  return true;
}

// Target is not a function.

if (isa<TagDecl>(Target)) {
  // No conflict between a tag and a non-tag.
  if (!Tag) return false;

  Diag(BUD->getLocation(), diag::err_using_decl_conflict);
  Diag(Target->getLocation(), diag::note_using_decl_target);
  Diag(Tag->getLocation(), diag::note_using_decl_conflict);
  BUD->setInvalidDecl();
  return true;
}

// No conflict between a tag and a non-tag.
if (!NonTag) return false;

Diag(BUD->getLocation(), diag::err_using_decl_conflict);
Diag(Target->getLocation(), diag::note_using_decl_target);
Diag(NonTag->getLocation(), diag::note_using_decl_conflict);
BUD->setInvalidDecl();
return true;
11886}

11888/// Determine whether a direct base class is a virtual base class.
11889static bool isVirtualDirectBase(CXXRecordDecl *Derived, CXXRecordDecl *Base) {
if (!Derived->getNumVBases())
  return false;
for (auto &B : Derived->bases())
  if (B.getType()->getAsCXXRecordDecl() == Base)
    return B.isVirtual();
llvm_unreachable("not a direct base class")__builtin_unreachable();
11896}

11898/// Builds a shadow declaration corresponding to a 'using' declaration.
11899UsingShadowDecl *Sema::BuildUsingShadowDecl(Scope *S, BaseUsingDecl *BUD,
                                          NamedDecl *Orig,
                                          UsingShadowDecl *PrevDecl) {
// If we resolved to another shadow declaration, just coalesce them.
NamedDecl *Target = Orig;
if (isa<UsingShadowDecl>(Target)) {
  Target = cast<UsingShadowDecl>(Target)->getTargetDecl();
  assert(!isa<UsingShadowDecl>(Target) && "nested shadow declaration")(static_cast<void> (0));
}

NamedDecl *NonTemplateTarget = Target;
if (auto *TargetTD = dyn_cast<TemplateDecl>(Target))
  NonTemplateTarget = TargetTD->getTemplatedDecl();

UsingShadowDecl *Shadow;
if (NonTemplateTarget && isa<CXXConstructorDecl>(NonTemplateTarget)) {
  UsingDecl *Using = cast<UsingDecl>(BUD);
  bool IsVirtualBase =
      isVirtualDirectBase(cast<CXXRecordDecl>(CurContext),
                          Using->getQualifier()->getAsRecordDecl());
  Shadow = ConstructorUsingShadowDecl::Create(
      Context, CurContext, Using->getLocation(), Using, Orig, IsVirtualBase);
} else {
  Shadow = UsingShadowDecl::Create(Context, CurContext, BUD->getLocation(),
                                   Target->getDeclName(), BUD, Target);
}
BUD->addShadowDecl(Shadow);

Shadow->setAccess(BUD->getAccess());
if (Orig->isInvalidDecl() || BUD->isInvalidDecl())
  Shadow->setInvalidDecl();

Shadow->setPreviousDecl(PrevDecl);

if (S)
  PushOnScopeChains(Shadow, S);
else
  CurContext->addDecl(Shadow);


return Shadow;
11940}

11942/// Hides a using shadow declaration.  This is required by the current
11943/// using-decl implementation when a resolvable using declaration in a
11944/// class is followed by a declaration which would hide or override
11945/// one or more of the using decl's targets; for example:
11946///
11947///   struct Base { void foo(int); };
11948///   struct Derived : Base {
11949///     using Base::foo;
11950///     void foo(int);
11951///   };
11952///
11953/// The governing language is C++03 [namespace.udecl]p12:
11954///
11955///   When a using-declaration brings names from a base class into a
11956///   derived class scope, member functions in the derived class
11957///   override and/or hide member functions with the same name and
11958///   parameter types in a base class (rather than conflicting).
11959///
11960/// There are two ways to implement this:
11961///   (1) optimistically create shadow decls when they're not hidden
11962///       by existing declarations, or
11963///   (2) don't create any shadow decls (or at least don't make them
11964///       visible) until we've fully parsed/instantiated the class.
11965/// The problem with (1) is that we might have to retroactively remove
11966/// a shadow decl, which requires several O(n) operations because the
11967/// decl structures are (very reasonably) not designed for removal.
11968/// (2) avoids this but is very fiddly and phase-dependent.
11969void Sema::HideUsingShadowDecl(Scope *S, UsingShadowDecl *Shadow) {
if (Shadow->getDeclName().getNameKind() ==
      DeclarationName::CXXConversionFunctionName)
  cast<CXXRecordDecl>(Shadow->getDeclContext())->removeConversion(Shadow);

// Remove it from the DeclContext...
Shadow->getDeclContext()->removeDecl(Shadow);

// ...and the scope, if applicable...
if (S) {
  S->RemoveDecl(Shadow);
  IdResolver.RemoveDecl(Shadow);
}

// ...and the using decl.
Shadow->getIntroducer()->removeShadowDecl(Shadow);

// TODO: complain somehow if Shadow was used.  It shouldn't
// be possible for this to happen, because...?
11988}

11990/// Find the base specifier for a base class with the given type.
11991static CXXBaseSpecifier *findDirectBaseWithType(CXXRecordDecl *Derived,
                                              QualType DesiredBase,
                                              bool &AnyDependentBases) {
// Check whether the named type is a direct base class.
CanQualType CanonicalDesiredBase = DesiredBase->getCanonicalTypeUnqualified()
  .getUnqualifiedType();
for (auto &Base : Derived->bases()) {
  CanQualType BaseType = Base.getType()->getCanonicalTypeUnqualified();
  if (CanonicalDesiredBase == BaseType)
    return &Base;
  if (BaseType->isDependentType())
    AnyDependentBases = true;
}
return nullptr;
12005}

12007namespace {
12008class UsingValidatorCCC final : public CorrectionCandidateCallback {
12009public:
UsingValidatorCCC(bool HasTypenameKeyword, bool IsInstantiation,
                  NestedNameSpecifier *NNS, CXXRecordDecl *RequireMemberOf)
    : HasTypenameKeyword(HasTypenameKeyword),
      IsInstantiation(IsInstantiation), OldNNS(NNS),
      RequireMemberOf(RequireMemberOf) {}

bool ValidateCandidate(const TypoCorrection &Candidate) override {
  NamedDecl *ND = Candidate.getCorrectionDecl();

  // Keywords are not valid here.
  if (!ND || isa<NamespaceDecl>(ND))
    return false;

  // Completely unqualified names are invalid for a 'using' declaration.
  if (Candidate.WillReplaceSpecifier() && !Candidate.getCorrectionSpecifier())
    return false;

  // FIXME: Don't correct to a name that CheckUsingDeclRedeclaration would
  // reject.

  if (RequireMemberOf) {
    auto *FoundRecord = dyn_cast<CXXRecordDecl>(ND);
    if (FoundRecord && FoundRecord->isInjectedClassName()) {
      // No-one ever wants a using-declaration to name an injected-class-name
      // of a base class, unless they're declaring an inheriting constructor.
      ASTContext &Ctx = ND->getASTContext();
      if (!Ctx.getLangOpts().CPlusPlus11)
        return false;
      QualType FoundType = Ctx.getRecordType(FoundRecord);

      // Check that the injected-class-name is named as a member of its own
      // type; we don't want to suggest 'using Derived::Base;', since that
      // means something else.
      NestedNameSpecifier *Specifier =
          Candidate.WillReplaceSpecifier()
              ? Candidate.getCorrectionSpecifier()
              : OldNNS;
      if (!Specifier->getAsType() ||
          !Ctx.hasSameType(QualType(Specifier->getAsType(), 0), FoundType))
        return false;

      // Check that this inheriting constructor declaration actually names a
      // direct base class of the current class.
      bool AnyDependentBases = false;
      if (!findDirectBaseWithType(RequireMemberOf,
                                  Ctx.getRecordType(FoundRecord),
                                  AnyDependentBases) &&
          !AnyDependentBases)
        return false;
    } else {
      auto *RD = dyn_cast<CXXRecordDecl>(ND->getDeclContext());
      if (!RD || RequireMemberOf->isProvablyNotDerivedFrom(RD))
        return false;

      // FIXME: Check that the base class member is accessible?
    }
  } else {
    auto *FoundRecord = dyn_cast<CXXRecordDecl>(ND);
    if (FoundRecord && FoundRecord->isInjectedClassName())
      return false;
  }

  if (isa<TypeDecl>(ND))
    return HasTypenameKeyword || !IsInstantiation;

  return !HasTypenameKeyword;
}

std::unique_ptr<CorrectionCandidateCallback> clone() override {
  return std::make_unique<UsingValidatorCCC>(*this);
}

12082private:
bool HasTypenameKeyword;
bool IsInstantiation;
NestedNameSpecifier *OldNNS;
CXXRecordDecl *RequireMemberOf;
12087};
12088} // end anonymous namespace

12090/// Remove decls we can't actually see from a lookup being used to declare
12091/// shadow using decls.
12092///
12093/// \param S - The scope of the potential shadow decl
12094/// \param Previous - The lookup of a potential shadow decl's name.
12095void Sema::FilterUsingLookup(Scope *S, LookupResult &Previous) {
// It is really dumb that we have to do this.
LookupResult::Filter F = Previous.makeFilter();
while (F.hasNext()) {
  NamedDecl *D = F.next();
  if (!isDeclInScope(D, CurContext, S))
    F.erase();
  // If we found a local extern declaration that's not ordinarily visible,
  // and this declaration is being added to a non-block scope, ignore it.
  // We're only checking for scope conflicts here, not also for violations
  // of the linkage rules.
  else if (!CurContext->isFunctionOrMethod() && D->isLocalExternDecl() &&
           !(D->getIdentifierNamespace() & Decl::IDNS_Ordinary))
    F.erase();
}
F.done();
12111}

12113/// Builds a using declaration.
12114///
12115/// \param IsInstantiation - Whether this call arises from an
12116///   instantiation of an unresolved using declaration.  We treat
12117///   the lookup differently for these declarations.
12118NamedDecl *Sema::BuildUsingDeclaration(
  Scope *S, AccessSpecifier AS, SourceLocation UsingLoc,
  bool HasTypenameKeyword, SourceLocation TypenameLoc, CXXScopeSpec &SS,
  DeclarationNameInfo NameInfo, SourceLocation EllipsisLoc,
  const ParsedAttributesView &AttrList, bool IsInstantiation,
  bool IsUsingIfExists) {
assert(!SS.isInvalid() && "Invalid CXXScopeSpec.")(static_cast<void> (0));
SourceLocation IdentLoc = NameInfo.getLoc();
assert(IdentLoc.isValid() && "Invalid TargetName location.")(static_cast<void> (0));

// FIXME: We ignore attributes for now.

// For an inheriting constructor declaration, the name of the using
// declaration is the name of a constructor in this class, not in the
// base class.
DeclarationNameInfo UsingName = NameInfo;
if (UsingName.getName().getNameKind() == DeclarationName::CXXConstructorName)
  if (auto *RD = dyn_cast<CXXRecordDecl>(CurContext))
    UsingName.setName(Context.DeclarationNames.getCXXConstructorName(
        Context.getCanonicalType(Context.getRecordType(RD))));

// Do the redeclaration lookup in the current scope.
LookupResult Previous(*this, UsingName, LookupUsingDeclName,
                      ForVisibleRedeclaration);
Previous.setHideTags(false);
if (S) {
  LookupName(Previous, S);

  FilterUsingLookup(S, Previous);
} else {
  assert(IsInstantiation && "no scope in non-instantiation")(static_cast<void> (0));
  if (CurContext->isRecord())
    LookupQualifiedName(Previous, CurContext);
  else {
    // No redeclaration check is needed here; in non-member contexts we
    // diagnosed all possible conflicts with other using-declarations when
    // building the template:
    //
    // For a dependent non-type using declaration, the only valid case is
    // if we instantiate to a single enumerator. We check for conflicts
    // between shadow declarations we introduce, and we check in the template
    // definition for conflicts between a non-type using declaration and any
    // other declaration, which together covers all cases.
    //
    // A dependent typename using declaration will never successfully
    // instantiate, since it will always name a class member, so we reject
    // that in the template definition.
  }
}

// Check for invalid redeclarations.
if (CheckUsingDeclRedeclaration(UsingLoc, HasTypenameKeyword,
                                SS, IdentLoc, Previous))
  return nullptr;

// 'using_if_exists' doesn't make sense on an inherited constructor.
if (IsUsingIfExists && UsingName.getName().getNameKind() ==
                           DeclarationName::CXXConstructorName) {
  Diag(UsingLoc, diag::err_using_if_exists_on_ctor);
  return nullptr;
}

DeclContext *LookupContext = computeDeclContext(SS);
NestedNameSpecifierLoc QualifierLoc = SS.getWithLocInContext(Context);
if (!LookupContext || EllipsisLoc.isValid()) {
  NamedDecl *D;
  // Dependent scope, or an unexpanded pack
  if (!LookupContext && CheckUsingDeclQualifier(UsingLoc, HasTypenameKeyword,
                                                SS, NameInfo, IdentLoc))
    return nullptr;

  if (HasTypenameKeyword) {
    // FIXME: not all declaration name kinds are legal here
    D = UnresolvedUsingTypenameDecl::Create(Context, CurContext,
                                            UsingLoc, TypenameLoc,
                                            QualifierLoc,
                                            IdentLoc, NameInfo.getName(),
                                            EllipsisLoc);
  } else {
    D = UnresolvedUsingValueDecl::Create(Context, CurContext, UsingLoc,
                                         QualifierLoc, NameInfo, EllipsisLoc);
  }
  D->setAccess(AS);
  CurContext->addDecl(D);
  ProcessDeclAttributeList(S, D, AttrList);
  return D;
}

auto Build = [&](bool Invalid) {
  UsingDecl *UD =
      UsingDecl::Create(Context, CurContext, UsingLoc, QualifierLoc,
                        UsingName, HasTypenameKeyword);
  UD->setAccess(AS);
  CurContext->addDecl(UD);
  ProcessDeclAttributeList(S, UD, AttrList);
  UD->setInvalidDecl(Invalid);
  return UD;
};
auto BuildInvalid = [&]{ return Build(true); };
auto BuildValid = [&]{ return Build(false); };

if (RequireCompleteDeclContext(SS, LookupContext))
  return BuildInvalid();

// Look up the target name.
LookupResult R(*this, NameInfo, LookupOrdinaryName);

// Unlike most lookups, we don't always want to hide tag
// declarations: tag names are visible through the using declaration
// even if hidden by ordinary names, *except* in a dependent context
// where it's important for the sanity of two-phase lookup.
if (!IsInstantiation)
  R.setHideTags(false);

// For the purposes of this lookup, we have a base object type
// equal to that of the current context.
if (CurContext->isRecord()) {
  R.setBaseObjectType(
                 Context.getTypeDeclType(cast<CXXRecordDecl>(CurContext)));
}

LookupQualifiedName(R, LookupContext);

// Validate the context, now we have a lookup
if (CheckUsingDeclQualifier(UsingLoc, HasTypenameKeyword, SS, NameInfo,
                            IdentLoc, &R))
  return nullptr;

if (R.empty() && IsUsingIfExists)
  R.addDecl(UnresolvedUsingIfExistsDecl::Create(Context, CurContext, UsingLoc,
                                                UsingName.getName()),
            AS_public);

// Try to correct typos if possible. If constructor name lookup finds no
// results, that means the named class has no explicit constructors, and we
// suppressed declaring implicit ones (probably because it's dependent or
// invalid).
if (R.empty() &&
    NameInfo.getName().getNameKind() != DeclarationName::CXXConstructorName) {
  // HACK 2017-01-08: Work around an issue with libstdc++'s detection of
  // ::gets. Sometimes it believes that glibc provides a ::gets in cases where
  // it does not. The issue was fixed in libstdc++ 6.3 (2016-12-21) and later.
  auto *II = NameInfo.getName().getAsIdentifierInfo();
  if (getLangOpts().CPlusPlus14 && II && II->isStr("gets") &&
      CurContext->isStdNamespace() &&
      isa<TranslationUnitDecl>(LookupContext) &&
      getSourceManager().isInSystemHeader(UsingLoc))
    return nullptr;
  UsingValidatorCCC CCC(HasTypenameKeyword, IsInstantiation, SS.getScopeRep(),
                        dyn_cast<CXXRecordDecl>(CurContext));
  if (TypoCorrection Corrected =
          CorrectTypo(R.getLookupNameInfo(), R.getLookupKind(), S, &SS, CCC,
                      CTK_ErrorRecovery)) {
    // We reject candidates where DroppedSpecifier == true, hence the
    // literal '0' below.
    diagnoseTypo(Corrected, PDiag(diag::err_no_member_suggest)
                              << NameInfo.getName() << LookupContext << 0
                              << SS.getRange());

    // If we picked a correction with no attached Decl we can't do anything
    // useful with it, bail out.
    NamedDecl *ND = Corrected.getCorrectionDecl();
    if (!ND)
      return BuildInvalid();

    // If we corrected to an inheriting constructor, handle it as one.
    auto *RD = dyn_cast<CXXRecordDecl>(ND);
    if (RD && RD->isInjectedClassName()) {
      // The parent of the injected class name is the class itself.
      RD = cast<CXXRecordDecl>(RD->getParent());

      // Fix up the information we'll use to build the using declaration.
      if (Corrected.WillReplaceSpecifier()) {
        NestedNameSpecifierLocBuilder Builder;
        Builder.MakeTrivial(Context, Corrected.getCorrectionSpecifier(),
                            QualifierLoc.getSourceRange());
        QualifierLoc = Builder.getWithLocInContext(Context);
      }

      // In this case, the name we introduce is the name of a derived class
      // constructor.
      auto *CurClass = cast<CXXRecordDecl>(CurContext);
      UsingName.setName(Context.DeclarationNames.getCXXConstructorName(
          Context.getCanonicalType(Context.getRecordType(CurClass))));
      UsingName.setNamedTypeInfo(nullptr);
      for (auto *Ctor : LookupConstructors(RD))
        R.addDecl(Ctor);
      R.resolveKind();
    } else {
      // FIXME: Pick up all the declarations if we found an overloaded
      // function.
      UsingName.setName(ND->getDeclName());
      R.addDecl(ND);
    }
  } else {
    Diag(IdentLoc, diag::err_no_member)
      << NameInfo.getName() << LookupContext << SS.getRange();
    return BuildInvalid();
  }
}

if (R.isAmbiguous())
  return BuildInvalid();

if (HasTypenameKeyword) {
  // If we asked for a typename and got a non-type decl, error out.
  if (!R.getAsSingle<TypeDecl>() &&
      !R.getAsSingle<UnresolvedUsingIfExistsDecl>()) {
    Diag(IdentLoc, diag::err_using_typename_non_type);
    for (LookupResult::iterator I = R.begin(), E = R.end(); I != E; ++I)
      Diag((*I)->getUnderlyingDecl()->getLocation(),
           diag::note_using_decl_target);
    return BuildInvalid();
  }
} else {
  // If we asked for a non-typename and we got a type, error out,
  // but only if this is an instantiation of an unresolved using
  // decl.  Otherwise just silently find the type name.
  if (IsInstantiation && R.getAsSingle<TypeDecl>()) {
    Diag(IdentLoc, diag::err_using_dependent_value_is_type);
    Diag(R.getFoundDecl()->getLocation(), diag::note_using_decl_target);
    return BuildInvalid();
  }
}

// C++14 [namespace.udecl]p6:
// A using-declaration shall not name a namespace.
if (R.getAsSingle<NamespaceDecl>()) {
  Diag(IdentLoc, diag::err_using_decl_can_not_refer_to_namespace)
    << SS.getRange();
  return BuildInvalid();
}

UsingDecl *UD = BuildValid();

// Some additional rules apply to inheriting constructors.
if (UsingName.getName().getNameKind() ==
      DeclarationName::CXXConstructorName) {
  // Suppress access diagnostics; the access check is instead performed at the
  // point of use for an inheriting constructor.
  R.suppressDiagnostics();
  if (CheckInheritingConstructorUsingDecl(UD))
    return UD;
}

for (LookupResult::iterator I = R.begin(), E = R.end(); I != E; ++I) {
  UsingShadowDecl *PrevDecl = nullptr;
  if (!CheckUsingShadowDecl(UD, *I, Previous, PrevDecl))
    BuildUsingShadowDecl(S, UD, *I, PrevDecl);
}

return UD;
12370}

12372NamedDecl *Sema::BuildUsingEnumDeclaration(Scope *S, AccessSpecifier AS,
                                         SourceLocation UsingLoc,
                                         SourceLocation EnumLoc,
                                         SourceLocation NameLoc,
                                         EnumDecl *ED) {
bool Invalid = false;

if (CurContext->getRedeclContext()->isRecord()) {
  /// In class scope, check if this is a duplicate, for better a diagnostic.
  DeclarationNameInfo UsingEnumName(ED->getDeclName(), NameLoc);
  LookupResult Previous(*this, UsingEnumName, LookupUsingDeclName,
                        ForVisibleRedeclaration);

  LookupName(Previous, S);

  for (NamedDecl *D : Previous)
    if (UsingEnumDecl *UED = dyn_cast<UsingEnumDecl>(D))
      if (UED->getEnumDecl() == ED) {
        Diag(UsingLoc, diag::err_using_enum_decl_redeclaration)
            << SourceRange(EnumLoc, NameLoc);
        Diag(D->getLocation(), diag::note_using_enum_decl) << 1;
        Invalid = true;
        break;
      }
}

if (RequireCompleteEnumDecl(ED, NameLoc))
  Invalid = true;

UsingEnumDecl *UD = UsingEnumDecl::Create(Context, CurContext, UsingLoc,
                                          EnumLoc, NameLoc, ED);
UD->setAccess(AS);
CurContext->addDecl(UD);

if (Invalid) {
  UD->setInvalidDecl();
  return UD;
}

// Create the shadow decls for each enumerator
for (EnumConstantDecl *EC : ED->enumerators()) {
  UsingShadowDecl *PrevDecl = nullptr;
  DeclarationNameInfo DNI(EC->getDeclName(), EC->getLocation());
  LookupResult Previous(*this, DNI, LookupOrdinaryName,
                        ForVisibleRedeclaration);
  LookupName(Previous, S);
  FilterUsingLookup(S, Previous);

  if (!CheckUsingShadowDecl(UD, EC, Previous, PrevDecl))
    BuildUsingShadowDecl(S, UD, EC, PrevDecl);
}

return UD;
12425}

12427NamedDecl *Sema::BuildUsingPackDecl(NamedDecl *InstantiatedFrom,
                                  ArrayRef<NamedDecl *> Expansions) {
assert(isa<UnresolvedUsingValueDecl>(InstantiatedFrom) ||(static_cast<void> (0))
       isa<UnresolvedUsingTypenameDecl>(InstantiatedFrom) ||(static_cast<void> (0))
       isa<UsingPackDecl>(InstantiatedFrom))(static_cast<void> (0));

auto *UPD =
    UsingPackDecl::Create(Context, CurContext, InstantiatedFrom, Expansions);
UPD->setAccess(InstantiatedFrom->getAccess());
CurContext->addDecl(UPD);
return UPD;
12438}

12440/// Additional checks for a using declaration referring to a constructor name.
12441bool Sema::CheckInheritingConstructorUsingDecl(UsingDecl *UD) {
assert(!UD->hasTypename() && "expecting a constructor name")(static_cast<void> (0));

const Type *SourceType = UD->getQualifier()->getAsType();
assert(SourceType &&(static_cast<void> (0))
       "Using decl naming constructor doesn't have type in scope spec.")(static_cast<void> (0));
CXXRecordDecl *TargetClass = cast<CXXRecordDecl>(CurContext);

// Check whether the named type is a direct base class.
bool AnyDependentBases = false;
auto *Base = findDirectBaseWithType(TargetClass, QualType(SourceType, 0),
                                    AnyDependentBases);
if (!Base && !AnyDependentBases) {
  Diag(UD->getUsingLoc(),
       diag::err_using_decl_constructor_not_in_direct_base)
    << UD->getNameInfo().getSourceRange()
    << QualType(SourceType, 0) << TargetClass;
  UD->setInvalidDecl();
  return true;
}

if (Base)
  Base->setInheritConstructors();

return false;
12466}

12468/// Checks that the given using declaration is not an invalid
12469/// redeclaration.  Note that this is checking only for the using decl
12470/// itself, not for any ill-formedness among the UsingShadowDecls.
12471bool Sema::CheckUsingDeclRedeclaration(SourceLocation UsingLoc,
                                     bool HasTypenameKeyword,
                                     const CXXScopeSpec &SS,
                                     SourceLocation NameLoc,
                                     const LookupResult &Prev) {
NestedNameSpecifier *Qual = SS.getScopeRep();

// C++03 [namespace.udecl]p8:
// C++0x [namespace.udecl]p10:
//   A using-declaration is a declaration and can therefore be used
//   repeatedly where (and only where) multiple declarations are
//   allowed.
//
// That's in non-member contexts.
if (!CurContext->getRedeclContext()->isRecord()) {
  // A dependent qualifier outside a class can only ever resolve to an
  // enumeration type. Therefore it conflicts with any other non-type
  // declaration in the same scope.
  // FIXME: How should we check for dependent type-type conflicts at block
  // scope?
  if (Qual->isDependent() && !HasTypenameKeyword) {
    for (auto *D : Prev) {
      if (!isa<TypeDecl>(D) && !isa<UsingDecl>(D) && !isa<UsingPackDecl>(D)) {
        bool OldCouldBeEnumerator =
            isa<UnresolvedUsingValueDecl>(D) || isa<EnumConstantDecl>(D);
        Diag(NameLoc,
             OldCouldBeEnumerator ? diag::err_redefinition
                                  : diag::err_redefinition_different_kind)
            << Prev.getLookupName();
        Diag(D->getLocation(), diag::note_previous_definition);
        return true;
      }
    }
  }
  return false;
}

const NestedNameSpecifier *CNNS =
    Context.getCanonicalNestedNameSpecifier(Qual);
for (LookupResult::iterator I = Prev.begin(), E = Prev.end(); I != E; ++I) {
  NamedDecl *D = *I;

  bool DTypename;
  NestedNameSpecifier *DQual;
  if (UsingDecl *UD = dyn_cast<UsingDecl>(D)) {
    DTypename = UD->hasTypename();
    DQual = UD->getQualifier();
  } else if (UnresolvedUsingValueDecl *UD
               = dyn_cast<UnresolvedUsingValueDecl>(D)) {
    DTypename = false;
    DQual = UD->getQualifier();
  } else if (UnresolvedUsingTypenameDecl *UD
               = dyn_cast<UnresolvedUsingTypenameDecl>(D)) {
    DTypename = true;
    DQual = UD->getQualifier();
  } else continue;

  // using decls differ if one says 'typename' and the other doesn't.
  // FIXME: non-dependent using decls?
  if (HasTypenameKeyword != DTypename) continue;

  // using decls differ if they name different scopes (but note that
  // template instantiation can cause this check to trigger when it
  // didn't before instantiation).
  if (CNNS != Context.getCanonicalNestedNameSpecifier(DQual))
    continue;

  Diag(NameLoc, diag::err_using_decl_redeclaration) << SS.getRange();
  Diag(D->getLocation(), diag::note_using_decl) << 1;
  return true;
}

return false;
12544}

12546/// Checks that the given nested-name qualifier used in a using decl
12547/// in the current context is appropriately related to the current
12548/// scope.  If an error is found, diagnoses it and returns true.
12549/// R is nullptr, if the caller has not (yet) done a lookup, otherwise it's the
12550/// result of that lookup. UD is likewise nullptr, except when we have an
12551/// already-populated UsingDecl whose shadow decls contain the same information
12552/// (i.e. we're instantiating a UsingDecl with non-dependent scope).
12553bool Sema::CheckUsingDeclQualifier(SourceLocation UsingLoc, bool HasTypename,
                                 const CXXScopeSpec &SS,
                                 const DeclarationNameInfo &NameInfo,
                                 SourceLocation NameLoc,
                                 const LookupResult *R, const UsingDecl *UD) {
DeclContext *NamedContext = computeDeclContext(SS);
assert(bool(NamedContext) == (R || UD) && !(R && UD) &&(static_cast<void> (0))
       "resolvable context must have exactly one set of decls")(static_cast<void> (0));

// C++ 20 permits using an enumerator that does not have a class-hierarchy
// relationship.
bool Cxx20Enumerator = false;
if (NamedContext) {
  EnumConstantDecl *EC = nullptr;
  if (R)
    EC = R->getAsSingle<EnumConstantDecl>();
  else if (UD && UD->shadow_size() == 1)
    EC = dyn_cast<EnumConstantDecl>(UD->shadow_begin()->getTargetDecl());
  if (EC)
    Cxx20Enumerator = getLangOpts().CPlusPlus20;

  if (auto *ED = dyn_cast<EnumDecl>(NamedContext)) {
    // C++14 [namespace.udecl]p7:
    // A using-declaration shall not name a scoped enumerator.
    // C++20 p1099 permits enumerators.
    if (EC && R && ED->isScoped())
      Diag(SS.getBeginLoc(),
           getLangOpts().CPlusPlus20
               ? diag::warn_cxx17_compat_using_decl_scoped_enumerator
               : diag::ext_using_decl_scoped_enumerator)
          << SS.getRange();

    // We want to consider the scope of the enumerator
    NamedContext = ED->getDeclContext();
  }
}

if (!CurContext->isRecord()) {
  // C++03 [namespace.udecl]p3:
  // C++0x [namespace.udecl]p8:
  //   A using-declaration for a class member shall be a member-declaration.
  // C++20 [namespace.udecl]p7
  //   ... other than an enumerator ...

  // If we weren't able to compute a valid scope, it might validly be a
  // dependent class or enumeration scope. If we have a 'typename' keyword,
  // the scope must resolve to a class type.
  if (NamedContext ? !NamedContext->getRedeclContext()->isRecord()
                   : !HasTypename)
    return false; // OK

  Diag(NameLoc,
       Cxx20Enumerator
           ? diag::warn_cxx17_compat_using_decl_class_member_enumerator
           : diag::err_using_decl_can_not_refer_to_class_member)
      << SS.getRange();

  if (Cxx20Enumerator)
    return false; // OK

  auto *RD = NamedContext
                 ? cast<CXXRecordDecl>(NamedContext->getRedeclContext())
                 : nullptr;
  if (RD && !RequireCompleteDeclContext(const_cast<CXXScopeSpec &>(SS), RD)) {
    // See if there's a helpful fixit

    if (!R) {
      // We will have already diagnosed the problem on the template
      // definition,  Maybe we should do so again?
    } else if (R->getAsSingle<TypeDecl>()) {
      if (getLangOpts().CPlusPlus11) {
        // Convert 'using X::Y;' to 'using Y = X::Y;'.
        Diag(SS.getBeginLoc(), diag::note_using_decl_class_member_workaround)
          << 0 // alias declaration
          << FixItHint::CreateInsertion(SS.getBeginLoc(),
                                        NameInfo.getName().getAsString() +
                                            " = ");
      } else {
        // Convert 'using X::Y;' to 'typedef X::Y Y;'.
        SourceLocation InsertLoc = getLocForEndOfToken(NameInfo.getEndLoc());
        Diag(InsertLoc, diag::note_using_decl_class_member_workaround)
          << 1 // typedef declaration
          << FixItHint::CreateReplacement(UsingLoc, "typedef")
          << FixItHint::CreateInsertion(
                 InsertLoc, " " + NameInfo.getName().getAsString());
      }
    } else if (R->getAsSingle<VarDecl>()) {
      // Don't provide a fixit outside C++11 mode; we don't want to suggest
      // repeating the type of the static data member here.
      FixItHint FixIt;
      if (getLangOpts().CPlusPlus11) {
        // Convert 'using X::Y;' to 'auto &Y = X::Y;'.
        FixIt = FixItHint::CreateReplacement(
            UsingLoc, "auto &" + NameInfo.getName().getAsString() + " = ");
      }

      Diag(UsingLoc, diag::note_using_decl_class_member_workaround)
        << 2 // reference declaration
        << FixIt;
    } else if (R->getAsSingle<EnumConstantDecl>()) {
      // Don't provide a fixit outside C++11 mode; we don't want to suggest
      // repeating the type of the enumeration here, and we can't do so if
      // the type is anonymous.
      FixItHint FixIt;
      if (getLangOpts().CPlusPlus11) {
        // Convert 'using X::Y;' to 'auto &Y = X::Y;'.
        FixIt = FixItHint::CreateReplacement(
            UsingLoc,
            "constexpr auto " + NameInfo.getName().getAsString() + " = ");
      }

      Diag(UsingLoc, diag::note_using_decl_class_member_workaround)
        << (getLangOpts().CPlusPlus11 ? 4 : 3) // const[expr] variable
        << FixIt;
    }
  }

  return true; // Fail
}

// If the named context is dependent, we can't decide much.
if (!NamedContext) {
  // FIXME: in C++0x, we can diagnose if we can prove that the
  // nested-name-specifier does not refer to a base class, which is
  // still possible in some cases.

  // Otherwise we have to conservatively report that things might be
  // okay.
  return false;
}

// The current scope is a record.
if (!NamedContext->isRecord()) {
  // Ideally this would point at the last name in the specifier,
  // but we don't have that level of source info.
  Diag(SS.getBeginLoc(),
       Cxx20Enumerator
           ? diag::warn_cxx17_compat_using_decl_non_member_enumerator
           : diag::err_using_decl_nested_name_specifier_is_not_class)
      << SS.getScopeRep() << SS.getRange();

  if (Cxx20Enumerator)
    return false; // OK

  return true;
}

if (!NamedContext->isDependentContext() &&
    RequireCompleteDeclContext(const_cast<CXXScopeSpec&>(SS), NamedContext))
  return true;

if (getLangOpts().CPlusPlus11) {
  // C++11 [namespace.udecl]p3:
  //   In a using-declaration used as a member-declaration, the
  //   nested-name-specifier shall name a base class of the class
  //   being defined.

  if (cast<CXXRecordDecl>(CurContext)->isProvablyNotDerivedFrom(
                               cast<CXXRecordDecl>(NamedContext))) {

    if (Cxx20Enumerator) {
      Diag(NameLoc, diag::warn_cxx17_compat_using_decl_non_member_enumerator)
          << SS.getRange();
      return false;
    }

    if (CurContext == NamedContext) {
      Diag(SS.getBeginLoc(),
           diag::err_using_decl_nested_name_specifier_is_current_class)
          << SS.getRange();
      return !getLangOpts().CPlusPlus20;
    }

    if (!cast<CXXRecordDecl>(NamedContext)->isInvalidDecl()) {
      Diag(SS.getBeginLoc(),
           diag::err_using_decl_nested_name_specifier_is_not_base_class)
          << SS.getScopeRep() << cast<CXXRecordDecl>(CurContext)
          << SS.getRange();
    }
    return true;
  }

  return false;
}

// C++03 [namespace.udecl]p4:
//   A using-declaration used as a member-declaration shall refer
//   to a member of a base class of the class being defined [etc.].

// Salient point: SS doesn't have to name a base class as long as
// lookup only finds members from base classes.  Therefore we can
// diagnose here only if we can prove that that can't happen,
// i.e. if the class hierarchies provably don't intersect.

// TODO: it would be nice if "definitely valid" results were cached
// in the UsingDecl and UsingShadowDecl so that these checks didn't
// need to be repeated.

llvm::SmallPtrSet<const CXXRecordDecl *, 4> Bases;
auto Collect = [&Bases](const CXXRecordDecl *Base) {
  Bases.insert(Base);
  return true;
};

// Collect all bases. Return false if we find a dependent base.
if (!cast<CXXRecordDecl>(CurContext)->forallBases(Collect))
  return false;

// Returns true if the base is dependent or is one of the accumulated base
// classes.
auto IsNotBase = [&Bases](const CXXRecordDecl *Base) {
  return !Bases.count(Base);
};

// Return false if the class has a dependent base or if it or one
// of its bases is present in the base set of the current context.
if (Bases.count(cast<CXXRecordDecl>(NamedContext)) ||
    !cast<CXXRecordDecl>(NamedContext)->forallBases(IsNotBase))
  return false;

Diag(SS.getRange().getBegin(),
     diag::err_using_decl_nested_name_specifier_is_not_base_class)
  << SS.getScopeRep()
  << cast<CXXRecordDecl>(CurContext)
  << SS.getRange();

return true;
12780}

12782Decl *Sema::ActOnAliasDeclaration(Scope *S, AccessSpecifier AS,
                                MultiTemplateParamsArg TemplateParamLists,
                                SourceLocation UsingLoc, UnqualifiedId &Name,
                                const ParsedAttributesView &AttrList,
                                TypeResult Type, Decl *DeclFromDeclSpec) {
// Skip up to the relevant declaration scope.
while (S->isTemplateParamScope())
  S = S->getParent();
assert((S->getFlags() & Scope::DeclScope) &&(static_cast<void> (0))
       "got alias-declaration outside of declaration scope")(static_cast<void> (0));

if (Type.isInvalid())
  return nullptr;

bool Invalid = false;
DeclarationNameInfo NameInfo = GetNameFromUnqualifiedId(Name);
TypeSourceInfo *TInfo = nullptr;
GetTypeFromParser(Type.get(), &TInfo);

if (DiagnoseClassNameShadow(CurContext, NameInfo))
  return nullptr;

if (DiagnoseUnexpandedParameterPack(Name.StartLocation, TInfo,
                                    UPPC_DeclarationType)) {
  Invalid = true;
  TInfo = Context.getTrivialTypeSourceInfo(Context.IntTy,
                                           TInfo->getTypeLoc().getBeginLoc());
}

LookupResult Previous(*this, NameInfo, LookupOrdinaryName,
                      TemplateParamLists.size()
                          ? forRedeclarationInCurContext()
                          : ForVisibleRedeclaration);
LookupName(Previous, S);

// Warn about shadowing the name of a template parameter.
if (Previous.isSingleResult() &&
    Previous.getFoundDecl()->isTemplateParameter()) {
  DiagnoseTemplateParameterShadow(Name.StartLocation,Previous.getFoundDecl());
  Previous.clear();
}

assert(Name.Kind == UnqualifiedIdKind::IK_Identifier &&(static_cast<void> (0))
       "name in alias declaration must be an identifier")(static_cast<void> (0));
TypeAliasDecl *NewTD = TypeAliasDecl::Create(Context, CurContext, UsingLoc,
                                             Name.StartLocation,
                                             Name.Identifier, TInfo);

NewTD->setAccess(AS);

if (Invalid)
  NewTD->setInvalidDecl();

ProcessDeclAttributeList(S, NewTD, AttrList);
AddPragmaAttributes(S, NewTD);

CheckTypedefForVariablyModifiedType(S, NewTD);
Invalid |= NewTD->isInvalidDecl();

bool Redeclaration = false;

NamedDecl *NewND;
if (TemplateParamLists.size()) {
  TypeAliasTemplateDecl *OldDecl = nullptr;
  TemplateParameterList *OldTemplateParams = nullptr;

  if (TemplateParamLists.size() != 1) {
    Diag(UsingLoc, diag::err_alias_template_extra_headers)
      << SourceRange(TemplateParamLists[1]->getTemplateLoc(),
       TemplateParamLists[TemplateParamLists.size()-1]->getRAngleLoc());
  }
  TemplateParameterList *TemplateParams = TemplateParamLists[0];

  // Check that we can declare a template here.
  if (CheckTemplateDeclScope(S, TemplateParams))
    return nullptr;

  // Only consider previous declarations in the same scope.
  FilterLookupForScope(Previous, CurContext, S, /*ConsiderLinkage*/false,
                       /*ExplicitInstantiationOrSpecialization*/false);
  if (!Previous.empty()) {
    Redeclaration = true;

    OldDecl = Previous.getAsSingle<TypeAliasTemplateDecl>();
    if (!OldDecl && !Invalid) {
      Diag(UsingLoc, diag::err_redefinition_different_kind)
        << Name.Identifier;

      NamedDecl *OldD = Previous.getRepresentativeDecl();
      if (OldD->getLocation().isValid())
        Diag(OldD->getLocation(), diag::note_previous_definition);

      Invalid = true;
    }

    if (!Invalid && OldDecl && !OldDecl->isInvalidDecl()) {
      if (TemplateParameterListsAreEqual(TemplateParams,
                                         OldDecl->getTemplateParameters(),
                                         /*Complain=*/true,
                                         TPL_TemplateMatch))
        OldTemplateParams =
            OldDecl->getMostRecentDecl()->getTemplateParameters();
      else
        Invalid = true;

      TypeAliasDecl *OldTD = OldDecl->getTemplatedDecl();
      if (!Invalid &&
          !Context.hasSameType(OldTD->getUnderlyingType(),
                               NewTD->getUnderlyingType())) {
        // FIXME: The C++0x standard does not clearly say this is ill-formed,
        // but we can't reasonably accept it.
        Diag(NewTD->getLocation(), diag::err_redefinition_different_typedef)
          << 2 << NewTD->getUnderlyingType() << OldTD->getUnderlyingType();
        if (OldTD->getLocation().isValid())
          Diag(OldTD->getLocation(), diag::note_previous_definition);
        Invalid = true;
      }
    }
  }

  // Merge any previous default template arguments into our parameters,
  // and check the parameter list.
  if (CheckTemplateParameterList(TemplateParams, OldTemplateParams,
                                 TPC_TypeAliasTemplate))
    return nullptr;

  TypeAliasTemplateDecl *NewDecl =
    TypeAliasTemplateDecl::Create(Context, CurContext, UsingLoc,
                                  Name.Identifier, TemplateParams,
                                  NewTD);
  NewTD->setDescribedAliasTemplate(NewDecl);

  NewDecl->setAccess(AS);

  if (Invalid)
    NewDecl->setInvalidDecl();
  else if (OldDecl) {
    NewDecl->setPreviousDecl(OldDecl);
    CheckRedeclarationModuleOwnership(NewDecl, OldDecl);
  }

  NewND = NewDecl;
} else {
  if (auto *TD = dyn_cast_or_null<TagDecl>(DeclFromDeclSpec)) {
    setTagNameForLinkagePurposes(TD, NewTD);
    handleTagNumbering(TD, S);
  }
  ActOnTypedefNameDecl(S, CurContext, NewTD, Previous, Redeclaration);
  NewND = NewTD;
}

PushOnScopeChains(NewND, S);
ActOnDocumentableDecl(NewND);
return NewND;
12936}

12938Decl *Sema::ActOnNamespaceAliasDef(Scope *S, SourceLocation NamespaceLoc,
                                 SourceLocation AliasLoc,
                                 IdentifierInfo *Alias, CXXScopeSpec &SS,
                                 SourceLocation IdentLoc,
                                 IdentifierInfo *Ident) {

// Lookup the namespace name.
LookupResult R(*this, Ident, IdentLoc, LookupNamespaceName);
LookupParsedName(R, S, &SS);

if (R.isAmbiguous())
  return nullptr;

if (R.empty()) {
  if (!TryNamespaceTypoCorrection(*this, R, S, SS, IdentLoc, Ident)) {
    Diag(IdentLoc, diag::err_expected_namespace_name) << SS.getRange();
    return nullptr;
  }
}
assert(!R.isAmbiguous() && !R.empty())(static_cast<void> (0));
NamedDecl *ND = R.getRepresentativeDecl();

// Check if we have a previous declaration with the same name.
LookupResult PrevR(*this, Alias, AliasLoc, LookupOrdinaryName,
                   ForVisibleRedeclaration);
LookupName(PrevR, S);

// Check we're not shadowing a template parameter.
if (PrevR.isSingleResult() && PrevR.getFoundDecl()->isTemplateParameter()) {
  DiagnoseTemplateParameterShadow(AliasLoc, PrevR.getFoundDecl());
  PrevR.clear();
}

// Filter out any other lookup result from an enclosing scope.
FilterLookupForScope(PrevR, CurContext, S, /*ConsiderLinkage*/false,
                     /*AllowInlineNamespace*/false);

// Find the previous declaration and check that we can redeclare it.
NamespaceAliasDecl *Prev = nullptr;
if (PrevR.isSingleResult()) {
  NamedDecl *PrevDecl = PrevR.getRepresentativeDecl();
  if (NamespaceAliasDecl *AD = dyn_cast<NamespaceAliasDecl>(PrevDecl)) {
    // We already have an alias with the same name that points to the same
    // namespace; check that it matches.
    if (AD->getNamespace()->Equals(getNamespaceDecl(ND))) {
      Prev = AD;
    } else if (isVisible(PrevDecl)) {
      Diag(AliasLoc, diag::err_redefinition_different_namespace_alias)
        << Alias;
      Diag(AD->getLocation(), diag::note_previous_namespace_alias)
        << AD->getNamespace();
      return nullptr;
    }
  } else if (isVisible(PrevDecl)) {
    unsigned DiagID = isa<NamespaceDecl>(PrevDecl->getUnderlyingDecl())
                          ? diag::err_redefinition
                          : diag::err_redefinition_different_kind;
    Diag(AliasLoc, DiagID) << Alias;
    Diag(PrevDecl->getLocation(), diag::note_previous_definition);
    return nullptr;
  }
}

// The use of a nested name specifier may trigger deprecation warnings.
DiagnoseUseOfDecl(ND, IdentLoc);

NamespaceAliasDecl *AliasDecl =
  NamespaceAliasDecl::Create(Context, CurContext, NamespaceLoc, AliasLoc,
                             Alias, SS.getWithLocInContext(Context),
                             IdentLoc, ND);
if (Prev)
  AliasDecl->setPreviousDecl(Prev);

PushOnScopeChains(AliasDecl, S);
return AliasDecl;
13013}

13015namespace {
13016struct SpecialMemberExceptionSpecInfo
  : SpecialMemberVisitor<SpecialMemberExceptionSpecInfo> {
SourceLocation Loc;
Sema::ImplicitExceptionSpecification ExceptSpec;

SpecialMemberExceptionSpecInfo(Sema &S, CXXMethodDecl *MD,
                               Sema::CXXSpecialMember CSM,
                               Sema::InheritedConstructorInfo *ICI,
                               SourceLocation Loc)
    : SpecialMemberVisitor(S, MD, CSM, ICI), Loc(Loc), ExceptSpec(S) {}

bool visitBase(CXXBaseSpecifier *Base);
bool visitField(FieldDecl *FD);

void visitClassSubobject(CXXRecordDecl *Class, Subobject Subobj,
                         unsigned Quals);

void visitSubobjectCall(Subobject Subobj,
                        Sema::SpecialMemberOverloadResult SMOR);
13035};
13036}

13038bool SpecialMemberExceptionSpecInfo::visitBase(CXXBaseSpecifier *Base) {
auto *RT = Base->getType()->getAs<RecordType>();
if (!RT)
  return false;

auto *BaseClass = cast<CXXRecordDecl>(RT->getDecl());
Sema::SpecialMemberOverloadResult SMOR = lookupInheritedCtor(BaseClass);
if (auto *BaseCtor = SMOR.getMethod()) {
  visitSubobjectCall(Base, BaseCtor);
  return false;
}

visitClassSubobject(BaseClass, Base, 0);
return false;
13052}

13054bool SpecialMemberExceptionSpecInfo::visitField(FieldDecl *FD) {
if (CSM == Sema::CXXDefaultConstructor && FD->hasInClassInitializer()) {
  Expr *E = FD->getInClassInitializer();
  if (!E)
    // FIXME: It's a little wasteful to build and throw away a
    // CXXDefaultInitExpr here.
    // FIXME: We should have a single context note pointing at Loc, and
    // this location should be MD->getLocation() instead, since that's
    // the location where we actually use the default init expression.
    E = S.BuildCXXDefaultInitExpr(Loc, FD).get();
  if (E)
    ExceptSpec.CalledExpr(E);
} else if (auto *RT = S.Context.getBaseElementType(FD->getType())
                          ->getAs<RecordType>()) {
  visitClassSubobject(cast<CXXRecordDecl>(RT->getDecl()), FD,
                      FD->getType().getCVRQualifiers());
}
return false;
13072}

13074void SpecialMemberExceptionSpecInfo::visitClassSubobject(CXXRecordDecl *Class,
                                                       Subobject Subobj,
                                                       unsigned Quals) {
FieldDecl *Field = Subobj.dyn_cast<FieldDecl*>();
bool IsMutable = Field && Field->isMutable();
visitSubobjectCall(Subobj, lookupIn(Class, Quals, IsMutable));
13080}

13082void SpecialMemberExceptionSpecInfo::visitSubobjectCall(
  Subobject Subobj, Sema::SpecialMemberOverloadResult SMOR) {
// Note, if lookup fails, it doesn't matter what exception specification we
// choose because the special member will be deleted.
if (CXXMethodDecl *MD = SMOR.getMethod())
  ExceptSpec.CalledDecl(getSubobjectLoc(Subobj), MD);
13088}

13090bool Sema::tryResolveExplicitSpecifier(ExplicitSpecifier &ExplicitSpec) {
llvm::APSInt Result;
ExprResult Converted = CheckConvertedConstantExpression(
    ExplicitSpec.getExpr(), Context.BoolTy, Result, CCEK_ExplicitBool);
ExplicitSpec.setExpr(Converted.get());
if (Converted.isUsable() && !Converted.get()->isValueDependent()) {
  ExplicitSpec.setKind(Result.getBoolValue()
                           ? ExplicitSpecKind::ResolvedTrue
                           : ExplicitSpecKind::ResolvedFalse);
  return true;
}
ExplicitSpec.setKind(ExplicitSpecKind::Unresolved);
return false;
13103}

13105ExplicitSpecifier Sema::ActOnExplicitBoolSpecifier(Expr *ExplicitExpr) {
ExplicitSpecifier ES(ExplicitExpr, ExplicitSpecKind::Unresolved);
if (!ExplicitExpr->isTypeDependent())
  tryResolveExplicitSpecifier(ES);
return ES;
13110}

13112static Sema::ImplicitExceptionSpecification
13113ComputeDefaultedSpecialMemberExceptionSpec(
  Sema &S, SourceLocation Loc, CXXMethodDecl *MD, Sema::CXXSpecialMember CSM,
  Sema::InheritedConstructorInfo *ICI) {
ComputingExceptionSpec CES(S, MD, Loc);

CXXRecordDecl *ClassDecl = MD->getParent();

// C++ [except.spec]p14:
//   An implicitly declared special member function (Clause 12) shall have an
//   exception-specification. [...]
SpecialMemberExceptionSpecInfo Info(S, MD, CSM, ICI, MD->getLocation());
if (ClassDecl->isInvalidDecl())
  return Info.ExceptSpec;

// FIXME: If this diagnostic fires, we're probably missing a check for
// attempting to resolve an exception specification before it's known
// at a higher level.
if (S.RequireCompleteType(MD->getLocation(),
                          S.Context.getRecordType(ClassDecl),
                          diag::err_exception_spec_incomplete_type))
  return Info.ExceptSpec;

// C++1z [except.spec]p7:
//   [Look for exceptions thrown by] a constructor selected [...] to
//   initialize a potentially constructed subobject,
// C++1z [except.spec]p8:
//   The exception specification for an implicitly-declared destructor, or a
//   destructor without a noexcept-specifier, is potentially-throwing if and
//   only if any of the destructors for any of its potentially constructed
//   subojects is potentially throwing.
// FIXME: We respect the first rule but ignore the "potentially constructed"
// in the second rule to resolve a core issue (no number yet) that would have
// us reject:
//   struct A { virtual void f() = 0; virtual ~A() noexcept(false) = 0; };
//   struct B : A {};
//   struct C : B { void f(); };
// ... due to giving B::~B() a non-throwing exception specification.
Info.visit(Info.IsConstructor ? Info.VisitPotentiallyConstructedBases
                              : Info.VisitAllBases);

return Info.ExceptSpec;
13154}

13156namespace {
13157/// RAII object to register a special member as being currently declared.
13158struct DeclaringSpecialMember {
Sema &S;
Sema::SpecialMemberDecl D;
Sema::ContextRAII SavedContext;
bool WasAlreadyBeingDeclared;

DeclaringSpecialMember(Sema &S, CXXRecordDecl *RD, Sema::CXXSpecialMember CSM)
    : S(S), D(RD, CSM), SavedContext(S, RD) {
  WasAlreadyBeingDeclared = !S.SpecialMembersBeingDeclared.insert(D).second;
  if (WasAlreadyBeingDeclared)
    // This almost never happens, but if it does, ensure that our cache
    // doesn't contain a stale result.
    S.SpecialMemberCache.clear();
  else {
    // Register a note to be produced if we encounter an error while
    // declaring the special member.
    Sema::CodeSynthesisContext Ctx;
    Ctx.Kind = Sema::CodeSynthesisContext::DeclaringSpecialMember;
    // FIXME: We don't have a location to use here. Using the class's
    // location maintains the fiction that we declare all special members
    // with the class, but (1) it's not clear that lying about that helps our
    // users understand what's going on, and (2) there may be outer contexts
    // on the stack (some of which are relevant) and printing them exposes
    // our lies.
    Ctx.PointOfInstantiation = RD->getLocation();
    Ctx.Entity = RD;
    Ctx.SpecialMember = CSM;
    S.pushCodeSynthesisContext(Ctx);
  }
}
~DeclaringSpecialMember() {
  if (!WasAlreadyBeingDeclared) {
    S.SpecialMembersBeingDeclared.erase(D);
    S.popCodeSynthesisContext();
  }
}

/// Are we already trying to declare this special member?
bool isAlreadyBeingDeclared() const {
  return WasAlreadyBeingDeclared;
}
13199};
13200}

13202void Sema::CheckImplicitSpecialMemberDeclaration(Scope *S, FunctionDecl *FD) {
// Look up any existing declarations, but don't trigger declaration of all
// implicit special members with this name.
DeclarationName Name = FD->getDeclName();
LookupResult R(*this, Name, SourceLocation(), LookupOrdinaryName,
               ForExternalRedeclaration);
for (auto *D : FD->getParent()->lookup(Name))
  if (auto *Acceptable = R.getAcceptableDecl(D))
    R.addDecl(Acceptable);
R.resolveKind();
R.suppressDiagnostics();

CheckFunctionDeclaration(S, FD, R, /*IsMemberSpecialization*/false);
13215}

13217void Sema::setupImplicitSpecialMemberType(CXXMethodDecl *SpecialMem,
                                        QualType ResultTy,
                                        ArrayRef<QualType> Args) {
// Build an exception specification pointing back at this constructor.
FunctionProtoType::ExtProtoInfo EPI = getImplicitMethodEPI(*this, SpecialMem);

LangAS AS = getDefaultCXXMethodAddrSpace();
if (AS != LangAS::Default) {
  EPI.TypeQuals.addAddressSpace(AS);
}

auto QT = Context.getFunctionType(ResultTy, Args, EPI);
SpecialMem->setType(QT);

// During template instantiation of implicit special member functions we need
// a reliable TypeSourceInfo for the function prototype in order to allow
// functions to be substituted.
if (inTemplateInstantiation() &&
    cast<CXXRecordDecl>(SpecialMem->getParent())->isLambda()) {
  TypeSourceInfo *TSI =
      Context.getTrivialTypeSourceInfo(SpecialMem->getType());
  SpecialMem->setTypeSourceInfo(TSI);
}
13240}

13242CXXConstructorDecl *Sema::DeclareImplicitDefaultConstructor(
                                                   CXXRecordDecl *ClassDecl) {
// C++ [class.ctor]p5:
//   A default constructor for a class X is a constructor of class X
//   that can be called without an argument. If there is no
//   user-declared constructor for class X, a default constructor is
//   implicitly declared. An implicitly-declared default constructor
//   is an inline public member of its class.
assert(ClassDecl->needsImplicitDefaultConstructor() &&(static_cast<void> (0))
       "Should not build implicit default constructor!")(static_cast<void> (0));

DeclaringSpecialMember DSM(*this, ClassDecl, CXXDefaultConstructor);
if (DSM.isAlreadyBeingDeclared())
  return nullptr;

bool Constexpr = defaultedSpecialMemberIsConstexpr(*this, ClassDecl,
                                                   CXXDefaultConstructor,
                                                   false);

// Create the actual constructor declaration.
CanQualType ClassType
  = Context.getCanonicalType(Context.getTypeDeclType(ClassDecl));
SourceLocation ClassLoc = ClassDecl->getLocation();
DeclarationName Name
  = Context.DeclarationNames.getCXXConstructorName(ClassType);
DeclarationNameInfo NameInfo(Name, ClassLoc);
CXXConstructorDecl *DefaultCon = CXXConstructorDecl::Create(
    Context, ClassDecl, ClassLoc, NameInfo, /*Type*/ QualType(),
    /*TInfo=*/nullptr, ExplicitSpecifier(),
    getCurFPFeatures().isFPConstrained(),
    /*isInline=*/true, /*isImplicitlyDeclared=*/true,
    Constexpr ? ConstexprSpecKind::Constexpr
              : ConstexprSpecKind::Unspecified);
DefaultCon->setAccess(AS_public);
DefaultCon->setDefaulted();

if (getLangOpts().CUDA) {
  inferCUDATargetForImplicitSpecialMember(ClassDecl, CXXDefaultConstructor,
                                          DefaultCon,
                                          /* ConstRHS */ false,
                                          /* Diagnose */ false);
}

setupImplicitSpecialMemberType(DefaultCon, Context.VoidTy, None);

// We don't need to use SpecialMemberIsTrivial here; triviality for default
// constructors is easy to compute.
DefaultCon->setTrivial(ClassDecl->hasTrivialDefaultConstructor());

// Note that we have declared this constructor.
++getASTContext().NumImplicitDefaultConstructorsDeclared;

Scope *S = getScopeForContext(ClassDecl);
CheckImplicitSpecialMemberDeclaration(S, DefaultCon);

if (ShouldDeleteSpecialMember(DefaultCon, CXXDefaultConstructor))
  SetDeclDeleted(DefaultCon, ClassLoc);

if (S)
  PushOnScopeChains(DefaultCon, S, false);
ClassDecl->addDecl(DefaultCon);

return DefaultCon;
13305}

13307void Sema::DefineImplicitDefaultConstructor(SourceLocation CurrentLocation,
                                          CXXConstructorDecl *Constructor) {
assert((Constructor->isDefaulted() && Constructor->isDefaultConstructor() &&(static_cast<void> (0))
        !Constructor->doesThisDeclarationHaveABody() &&(static_cast<void> (0))
        !Constructor->isDeleted()) &&(static_cast<void> (0))
  "DefineImplicitDefaultConstructor - call it for implicit default ctor")(static_cast<void> (0));
if (Constructor->willHaveBody() || Constructor->isInvalidDecl())
  return;

CXXRecordDecl *ClassDecl = Constructor->getParent();
assert(ClassDecl && "DefineImplicitDefaultConstructor - invalid constructor")(static_cast<void> (0));

SynthesizedFunctionScope Scope(*this, Constructor);

// The exception specification is needed because we are defining the
// function.
ResolveExceptionSpec(CurrentLocation,
                     Constructor->getType()->castAs<FunctionProtoType>());
MarkVTableUsed(CurrentLocation, ClassDecl);

// Add a context note for diagnostics produced after this point.
Scope.addContextNote(CurrentLocation);

if (SetCtorInitializers(Constructor, /*AnyErrors=*/false)) {
  Constructor->setInvalidDecl();
  return;
}

SourceLocation Loc = Constructor->getEndLoc().isValid()
                         ? Constructor->getEndLoc()
                         : Constructor->getLocation();
Constructor->setBody(new (Context) CompoundStmt(Loc));
Constructor->markUsed(Context);

if (ASTMutationListener *L = getASTMutationListener()) {
  L->CompletedImplicitDefinition(Constructor);
}

DiagnoseUninitializedFields(*this, Constructor);
13346}

13348void Sema::ActOnFinishDelayedMemberInitializers(Decl *D) {
// Perform any delayed checks on exception specifications.
CheckDelayedMemberExceptionSpecs();
13351}

13353/// Find or create the fake constructor we synthesize to model constructing an
13354/// object of a derived class via a constructor of a base class.
13355CXXConstructorDecl *
13356Sema::findInheritingConstructor(SourceLocation Loc,
                              CXXConstructorDecl *BaseCtor,
                              ConstructorUsingShadowDecl *Shadow) {
CXXRecordDecl *Derived = Shadow->getParent();
SourceLocation UsingLoc = Shadow->getLocation();

// FIXME: Add a new kind of DeclarationName for an inherited constructor.
// For now we use the name of the base class constructor as a member of the
// derived class to indicate a (fake) inherited constructor name.
DeclarationName Name = BaseCtor->getDeclName();

// Check to see if we already have a fake constructor for this inherited
// constructor call.
for (NamedDecl *Ctor : Derived->lookup(Name))
  if (declaresSameEntity(cast<CXXConstructorDecl>(Ctor)
                             ->getInheritedConstructor()
                             .getConstructor(),
                         BaseCtor))
    return cast<CXXConstructorDecl>(Ctor);

DeclarationNameInfo NameInfo(Name, UsingLoc);
TypeSourceInfo *TInfo =
    Context.getTrivialTypeSourceInfo(BaseCtor->getType(), UsingLoc);
FunctionProtoTypeLoc ProtoLoc =
    TInfo->getTypeLoc().IgnoreParens().castAs<FunctionProtoTypeLoc>();

// Check the inherited constructor is valid and find the list of base classes
// from which it was inherited.
InheritedConstructorInfo ICI(*this, Loc, Shadow);

bool Constexpr =
    BaseCtor->isConstexpr() &&
    defaultedSpecialMemberIsConstexpr(*this, Derived, CXXDefaultConstructor,
                                      false, BaseCtor, &ICI);

CXXConstructorDecl *DerivedCtor = CXXConstructorDecl::Create(
    Context, Derived, UsingLoc, NameInfo, TInfo->getType(), TInfo,
    BaseCtor->getExplicitSpecifier(), getCurFPFeatures().isFPConstrained(),
    /*isInline=*/true,
    /*isImplicitlyDeclared=*/true,
    Constexpr ? BaseCtor->getConstexprKind() : ConstexprSpecKind::Unspecified,
    InheritedConstructor(Shadow, BaseCtor),
    BaseCtor->getTrailingRequiresClause());
if (Shadow->isInvalidDecl())
  DerivedCtor->setInvalidDecl();

// Build an unevaluated exception specification for this fake constructor.
const FunctionProtoType *FPT = TInfo->getType()->castAs<FunctionProtoType>();
FunctionProtoType::ExtProtoInfo EPI = FPT->getExtProtoInfo();
EPI.ExceptionSpec.Type = EST_Unevaluated;
EPI.ExceptionSpec.SourceDecl = DerivedCtor;
DerivedCtor->setType(Context.getFunctionType(FPT->getReturnType(),
                                             FPT->getParamTypes(), EPI));

// Build the parameter declarations.
SmallVector<ParmVarDecl *, 16> ParamDecls;
for (unsigned I = 0, N = FPT->getNumParams(); I != N; ++I) {
  TypeSourceInfo *TInfo =
      Context.getTrivialTypeSourceInfo(FPT->getParamType(I), UsingLoc);
  ParmVarDecl *PD = ParmVarDecl::Create(
      Context, DerivedCtor, UsingLoc, UsingLoc, /*IdentifierInfo=*/nullptr,
      FPT->getParamType(I), TInfo, SC_None, /*DefArg=*/nullptr);
  PD->setScopeInfo(0, I);
  PD->setImplicit();
  // Ensure attributes are propagated onto parameters (this matters for
  // format, pass_object_size, ...).
  mergeDeclAttributes(PD, BaseCtor->getParamDecl(I));
  ParamDecls.push_back(PD);
  ProtoLoc.setParam(I, PD);
}

// Set up the new constructor.
assert(!BaseCtor->isDeleted() && "should not use deleted constructor")(static_cast<void> (0));
DerivedCtor->setAccess(BaseCtor->getAccess());
DerivedCtor->setParams(ParamDecls);
Derived->addDecl(DerivedCtor);

if (ShouldDeleteSpecialMember(DerivedCtor, CXXDefaultConstructor, &ICI))
  SetDeclDeleted(DerivedCtor, UsingLoc);

return DerivedCtor;
13437}

13439void Sema::NoteDeletedInheritingConstructor(CXXConstructorDecl *Ctor) {
InheritedConstructorInfo ICI(*this, Ctor->getLocation(),
                             Ctor->getInheritedConstructor().getShadowDecl());
ShouldDeleteSpecialMember(Ctor, CXXDefaultConstructor, &ICI,
                          /*Diagnose*/true);
13444}

13446void Sema::DefineInheritingConstructor(SourceLocation CurrentLocation,
                                     CXXConstructorDecl *Constructor) {
CXXRecordDecl *ClassDecl = Constructor->getParent();
assert(Constructor->getInheritedConstructor() &&(static_cast<void> (0))
       !Constructor->doesThisDeclarationHaveABody() &&(static_cast<void> (0))
       !Constructor->isDeleted())(static_cast<void> (0));
if (Constructor->willHaveBody() || Constructor->isInvalidDecl())
  return;

// Initializations are performed "as if by a defaulted default constructor",
// so enter the appropriate scope.
SynthesizedFunctionScope Scope(*this, Constructor);

// The exception specification is needed because we are defining the
// function.
ResolveExceptionSpec(CurrentLocation,
                     Constructor->getType()->castAs<FunctionProtoType>());
MarkVTableUsed(CurrentLocation, ClassDecl);

// Add a context note for diagnostics produced after this point.
Scope.addContextNote(CurrentLocation);

ConstructorUsingShadowDecl *Shadow =
    Constructor->getInheritedConstructor().getShadowDecl();
CXXConstructorDecl *InheritedCtor =
    Constructor->getInheritedConstructor().getConstructor();

// [class.inhctor.init]p1:
//   initialization proceeds as if a defaulted default constructor is used to
//   initialize the D object and each base class subobject from which the
//   constructor was inherited

InheritedConstructorInfo ICI(*this, CurrentLocation, Shadow);
CXXRecordDecl *RD = Shadow->getParent();
SourceLocation InitLoc = Shadow->getLocation();

// Build explicit initializers for all base classes from which the
// constructor was inherited.
SmallVector<CXXCtorInitializer*, 8> Inits;
for (bool VBase : {false, true}) {
  for (CXXBaseSpecifier &B : VBase ? RD->vbases() : RD->bases()) {
    if (B.isVirtual() != VBase)
      continue;

    auto *BaseRD = B.getType()->getAsCXXRecordDecl();
    if (!BaseRD)
      continue;

    auto BaseCtor = ICI.findConstructorForBase(BaseRD, InheritedCtor);
    if (!BaseCtor.first)
      continue;

    MarkFunctionReferenced(CurrentLocation, BaseCtor.first);
    ExprResult Init = new (Context) CXXInheritedCtorInitExpr(
        InitLoc, B.getType(), BaseCtor.first, VBase, BaseCtor.second);

    auto *TInfo = Context.getTrivialTypeSourceInfo(B.getType(), InitLoc);
    Inits.push_back(new (Context) CXXCtorInitializer(
        Context, TInfo, VBase, InitLoc, Init.get(), InitLoc,
        SourceLocation()));
  }
}

// We now proceed as if for a defaulted default constructor, with the relevant
// initializers replaced.

if (SetCtorInitializers(Constructor, /*AnyErrors*/false, Inits)) {
  Constructor->setInvalidDecl();
  return;
}

Constructor->setBody(new (Context) CompoundStmt(InitLoc));
Constructor->markUsed(Context);

if (ASTMutationListener *L = getASTMutationListener()) {
  L->CompletedImplicitDefinition(Constructor);
}

DiagnoseUninitializedFields(*this, Constructor);
13525}

13527CXXDestructorDecl *Sema::DeclareImplicitDestructor(CXXRecordDecl *ClassDecl) {
// C++ [class.dtor]p2:
//   If a class has no user-declared destructor, a destructor is
//   declared implicitly. An implicitly-declared destructor is an
//   inline public member of its class.
assert(ClassDecl->needsImplicitDestructor())(static_cast<void> (0));

DeclaringSpecialMember DSM(*this, ClassDecl, CXXDestructor);
if (DSM.isAlreadyBeingDeclared())
  return nullptr;

bool Constexpr = defaultedSpecialMemberIsConstexpr(*this, ClassDecl,
                                                   CXXDestructor,
                                                   false);

// Create the actual destructor declaration.
CanQualType ClassType
  = Context.getCanonicalType(Context.getTypeDeclType(ClassDecl));
SourceLocation ClassLoc = ClassDecl->getLocation();
DeclarationName Name
  = Context.DeclarationNames.getCXXDestructorName(ClassType);
DeclarationNameInfo NameInfo(Name, ClassLoc);
CXXDestructorDecl *Destructor = CXXDestructorDecl::Create(
    Context, ClassDecl, ClassLoc, NameInfo, QualType(), nullptr,
    getCurFPFeatures().isFPConstrained(),
    /*isInline=*/true,
    /*isImplicitlyDeclared=*/true,
    Constexpr ? ConstexprSpecKind::Constexpr
              : ConstexprSpecKind::Unspecified);
Destructor->setAccess(AS_public);
Destructor->setDefaulted();

if (getLangOpts().CUDA) {
  inferCUDATargetForImplicitSpecialMember(ClassDecl, CXXDestructor,
                                          Destructor,
                                          /* ConstRHS */ false,
                                          /* Diagnose */ false);
}

setupImplicitSpecialMemberType(Destructor, Context.VoidTy, None);

// We don't need to use SpecialMemberIsTrivial here; triviality for
// destructors is easy to compute.
Destructor->setTrivial(ClassDecl->hasTrivialDestructor());
Destructor->setTrivialForCall(ClassDecl->hasAttr<TrivialABIAttr>() ||
                              ClassDecl->hasTrivialDestructorForCall());

// Note that we have declared this destructor.
++getASTContext().NumImplicitDestructorsDeclared;

Scope *S = getScopeForContext(ClassDecl);
CheckImplicitSpecialMemberDeclaration(S, Destructor);

// We can't check whether an implicit destructor is deleted before we complete
// the definition of the class, because its validity depends on the alignment
// of the class. We'll check this from ActOnFields once the class is complete.
if (ClassDecl->isCompleteDefinition() &&
    ShouldDeleteSpecialMember(Destructor, CXXDestructor))
  SetDeclDeleted(Destructor, ClassLoc);

// Introduce this destructor into its scope.
if (S)
  PushOnScopeChains(Destructor, S, false);
ClassDecl->addDecl(Destructor);

return Destructor;
13593}

13595void Sema::DefineImplicitDestructor(SourceLocation CurrentLocation,
                                  CXXDestructorDecl *Destructor) {
assert((Destructor->isDefaulted() &&(static_cast<void> (0))
        !Destructor->doesThisDeclarationHaveABody() &&(static_cast<void> (0))
        !Destructor->isDeleted()) &&(static_cast<void> (0))
       "DefineImplicitDestructor - call it for implicit default dtor")(static_cast<void> (0));
if (Destructor->willHaveBody() || Destructor->isInvalidDecl())
  return;

CXXRecordDecl *ClassDecl = Destructor->getParent();
assert(ClassDecl && "DefineImplicitDestructor - invalid destructor")(static_cast<void> (0));

SynthesizedFunctionScope Scope(*this, Destructor);

// The exception specification is needed because we are defining the
// function.
ResolveExceptionSpec(CurrentLocation,
                     Destructor->getType()->castAs<FunctionProtoType>());
MarkVTableUsed(CurrentLocation, ClassDecl);

// Add a context note for diagnostics produced after this point.
Scope.addContextNote(CurrentLocation);

MarkBaseAndMemberDestructorsReferenced(Destructor->getLocation(),
                                       Destructor->getParent());

if (CheckDestructor(Destructor)) {
  Destructor->setInvalidDecl();
  return;
}

SourceLocation Loc = Destructor->getEndLoc().isValid()
                         ? Destructor->getEndLoc()
                         : Destructor->getLocation();
Destructor->setBody(new (Context) CompoundStmt(Loc));
Destructor->markUsed(Context);

if (ASTMutationListener *L = getASTMutationListener()) {
  L->CompletedImplicitDefinition(Destructor);
}
13635}

13637void Sema::CheckCompleteDestructorVariant(SourceLocation CurrentLocation,
                                        CXXDestructorDecl *Destructor) {
if (Destructor->isInvalidDecl())
  return;

CXXRecordDecl *ClassDecl = Destructor->getParent();
assert(Context.getTargetInfo().getCXXABI().isMicrosoft() &&(static_cast<void> (0))
       "implicit complete dtors unneeded outside MS ABI")(static_cast<void> (0));
assert(ClassDecl->getNumVBases() > 0 &&(static_cast<void> (0))
       "complete dtor only exists for classes with vbases")(static_cast<void> (0));

SynthesizedFunctionScope Scope(*this, Destructor);

// Add a context note for diagnostics produced after this point.
Scope.addContextNote(CurrentLocation);

MarkVirtualBaseDestructorsReferenced(Destructor->getLocation(), ClassDecl);
13654}

13656/// Perform any semantic analysis which needs to be delayed until all
13657/// pending class member declarations have been parsed.
13658void Sema::ActOnFinishCXXMemberDecls() {
// If the context is an invalid C++ class, just suppress these checks.
if (CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(CurContext)) {
  if (Record->isInvalidDecl()) {
    DelayedOverridingExceptionSpecChecks.clear();
    DelayedEquivalentExceptionSpecChecks.clear();
    return;
  }
  checkForMultipleExportedDefaultConstructors(*this, Record);
}
13668}

13670void Sema::ActOnFinishCXXNonNestedClass() {
referenceDLLExportedClassMethods();

if (!DelayedDllExportMemberFunctions.empty()) {
  SmallVector<CXXMethodDecl*, 4> WorkList;
  std::swap(DelayedDllExportMemberFunctions, WorkList);
  for (CXXMethodDecl *M : WorkList) {
    DefineDefaultedFunction(*this, M, M->getLocation());

    // Pass the method to the consumer to get emitted. This is not necessary
    // for explicit instantiation definitions, as they will get emitted
    // anyway.
    if (M->getParent()->getTemplateSpecializationKind() !=
        TSK_ExplicitInstantiationDefinition)
      ActOnFinishInlineFunctionDef(M);
  }
}
13687}

13689void Sema::referenceDLLExportedClassMethods() {
if (!DelayedDllExportClasses.empty()) {
  // Calling ReferenceDllExportedMembers might cause the current function to
  // be called again, so use a local copy of DelayedDllExportClasses.
  SmallVector<CXXRecordDecl *, 4> WorkList;
  std::swap(DelayedDllExportClasses, WorkList);
  for (CXXRecordDecl *Class : WorkList)
    ReferenceDllExportedMembers(*this, Class);
}
13698}

13700void Sema::AdjustDestructorExceptionSpec(CXXDestructorDecl *Destructor) {
assert(getLangOpts().CPlusPlus11 &&(static_cast<void> (0))
       "adjusting dtor exception specs was introduced in c++11")(static_cast<void> (0));

if (Destructor->isDependentContext())
  return;

// C++11 [class.dtor]p3:
//   A declaration of a destructor that does not have an exception-
//   specification is implicitly considered to have the same exception-
//   specification as an implicit declaration.
const auto *DtorType = Destructor->getType()->castAs<FunctionProtoType>();
if (DtorType->hasExceptionSpec())
  return;

// Replace the destructor's type, building off the existing one. Fortunately,
// the only thing of interest in the destructor type is its extended info.
// The return and arguments are fixed.
FunctionProtoType::ExtProtoInfo EPI = DtorType->getExtProtoInfo();
EPI.ExceptionSpec.Type = EST_Unevaluated;
EPI.ExceptionSpec.SourceDecl = Destructor;
Destructor->setType(Context.getFunctionType(Context.VoidTy, None, EPI));

// FIXME: If the destructor has a body that could throw, and the newly created
// spec doesn't allow exceptions, we should emit a warning, because this
// change in behavior can break conforming C++03 programs at runtime.
// However, we don't have a body or an exception specification yet, so it
// needs to be done somewhere else.
13728}

13730namespace {
13731/// An abstract base class for all helper classes used in building the
13732//  copy/move operators. These classes serve as factory functions and help us
13733//  avoid using the same Expr* in the AST twice.
13734class ExprBuilder {
ExprBuilder(const ExprBuilder&) = delete;
ExprBuilder &operator=(const ExprBuilder&) = delete;

13738protected:
static Expr *assertNotNull(Expr *E) {
  assert(E && "Expression construction must not fail.")(static_cast<void> (0));
  return E;
}

13744public:
ExprBuilder() {}
virtual ~ExprBuilder() {}

virtual Expr *build(Sema &S, SourceLocation Loc) const = 0;
13749};

13751class RefBuilder: public ExprBuilder {
VarDecl *Var;
QualType VarType;

13755public:
Expr *build(Sema &S, SourceLocation Loc) const override {
  return assertNotNull(S.BuildDeclRefExpr(Var, VarType, VK_LValue, Loc));
}

RefBuilder(VarDecl *Var, QualType VarType)
    : Var(Var), VarType(VarType) {}
13762};

13764class ThisBuilder: public ExprBuilder {
13765public:
Expr *build(Sema &S, SourceLocation Loc) const override {
  return assertNotNull(S.ActOnCXXThis(Loc).getAs<Expr>());
}
13769};

13771class CastBuilder: public ExprBuilder {
const ExprBuilder &Builder;
QualType Type;
ExprValueKind Kind;
const CXXCastPath &Path;

13777public:
Expr *build(Sema &S, SourceLocation Loc) const override {
  return assertNotNull(S.ImpCastExprToType(Builder.build(S, Loc), Type,
                                           CK_UncheckedDerivedToBase, Kind,
                                           &Path).get());
}

CastBuilder(const ExprBuilder &Builder, QualType Type, ExprValueKind Kind,
            const CXXCastPath &Path)
    : Builder(Builder), Type(Type), Kind(Kind), Path(Path) {}
13787};

13789class DerefBuilder: public ExprBuilder {
const ExprBuilder &Builder;

13792public:
Expr *build(Sema &S, SourceLocation Loc) const override {
  return assertNotNull(
      S.CreateBuiltinUnaryOp(Loc, UO_Deref, Builder.build(S, Loc)).get());
}

DerefBuilder(const ExprBuilder &Builder) : Builder(Builder) {}
13799};

13801class MemberBuilder: public ExprBuilder {
const ExprBuilder &Builder;
QualType Type;
CXXScopeSpec SS;
bool IsArrow;
LookupResult &MemberLookup;

13808public:
Expr *build(Sema &S, SourceLocation Loc) const override {
  return assertNotNull(S.BuildMemberReferenceExpr(
      Builder.build(S, Loc), Type, Loc, IsArrow, SS, SourceLocation(),
      nullptr, MemberLookup, nullptr, nullptr).get());
}

MemberBuilder(const ExprBuilder &Builder, QualType Type, bool IsArrow,
              LookupResult &MemberLookup)
    : Builder(Builder), Type(Type), IsArrow(IsArrow),
      MemberLookup(MemberLookup) {}
13819};

13821class MoveCastBuilder: public ExprBuilder {
const ExprBuilder &Builder;

13824public:
Expr *build(Sema &S, SourceLocation Loc) const override {
  return assertNotNull(CastForMoving(S, Builder.build(S, Loc)));
}

MoveCastBuilder(const ExprBuilder &Builder) : Builder(Builder) {}
13830};

13832class LvalueConvBuilder: public ExprBuilder {
const ExprBuilder &Builder;

13835public:
Expr *build(Sema &S, SourceLocation Loc) const override {
  return assertNotNull(
      S.DefaultLvalueConversion(Builder.build(S, Loc)).get());
}

LvalueConvBuilder(const ExprBuilder &Builder) : Builder(Builder) {}
13842};

13844class SubscriptBuilder: public ExprBuilder {
const ExprBuilder &Base;
const ExprBuilder &Index;

13848public:
Expr *build(Sema &S, SourceLocation Loc) const override {
  return assertNotNull(S.CreateBuiltinArraySubscriptExpr(
      Base.build(S, Loc), Loc, Index.build(S, Loc), Loc).get());
}

SubscriptBuilder(const ExprBuilder &Base, const ExprBuilder &Index)
    : Base(Base), Index(Index) {}
13856};

13858} // end anonymous namespace

13860/// When generating a defaulted copy or move assignment operator, if a field
13861/// should be copied with __builtin_memcpy rather than via explicit assignments,
13862/// do so. This optimization only applies for arrays of scalars, and for arrays
13863/// of class type where the selected copy/move-assignment operator is trivial.
13864static StmtResult
13865buildMemcpyForAssignmentOp(Sema &S, SourceLocation Loc, QualType T,
                         const ExprBuilder &ToB, const ExprBuilder &FromB) {
// Compute the size of the memory buffer to be copied.
QualType SizeType = S.Context.getSizeType();
llvm::APInt Size(S.Context.getTypeSize(SizeType),
                 S.Context.getTypeSizeInChars(T).getQuantity());

// Take the address of the field references for "from" and "to". We
// directly construct UnaryOperators here because semantic analysis
// does not permit us to take the address of an xvalue.
Expr *From = FromB.build(S, Loc);
From = UnaryOperator::Create(
    S.Context, From, UO_AddrOf, S.Context.getPointerType(From->getType()),
    VK_PRValue, OK_Ordinary, Loc, false, S.CurFPFeatureOverrides());
Expr *To = ToB.build(S, Loc);
To = UnaryOperator::Create(
    S.Context, To, UO_AddrOf, S.Context.getPointerType(To->getType()),
    VK_PRValue, OK_Ordinary, Loc, false, S.CurFPFeatureOverrides());

const Type *E = T->getBaseElementTypeUnsafe();
bool NeedsCollectableMemCpy =
    E->isRecordType() &&
    E->castAs<RecordType>()->getDecl()->hasObjectMember();

// Create a reference to the __builtin_objc_memmove_collectable function
StringRef MemCpyName = NeedsCollectableMemCpy ?
  "__builtin_objc_memmove_collectable" :
  "__builtin_memcpy";
LookupResult R(S, &S.Context.Idents.get(MemCpyName), Loc,
               Sema::LookupOrdinaryName);
S.LookupName(R, S.TUScope, true);

FunctionDecl *MemCpy = R.getAsSingle<FunctionDecl>();
if (!MemCpy)
  // Something went horribly wrong earlier, and we will have complained
  // about it.
  return StmtError();

ExprResult MemCpyRef = S.BuildDeclRefExpr(MemCpy, S.Context.BuiltinFnTy,
                                          VK_PRValue, Loc, nullptr);
assert(MemCpyRef.isUsable() && "Builtin reference cannot fail")(static_cast<void> (0));

Expr *CallArgs[] = {
  To, From, IntegerLiteral::Create(S.Context, Size, SizeType, Loc)
};
ExprResult Call = S.BuildCallExpr(/*Scope=*/nullptr, MemCpyRef.get(),
                                  Loc, CallArgs, Loc);

assert(!Call.isInvalid() && "Call to __builtin_memcpy cannot fail!")(static_cast<void> (0));
return Call.getAs<Stmt>();
13915}

13917/// Builds a statement that copies/moves the given entity from \p From to
13918/// \c To.
13919///
13920/// This routine is used to copy/move the members of a class with an
13921/// implicitly-declared copy/move assignment operator. When the entities being
13922/// copied are arrays, this routine builds for loops to copy them.
13923///
13924/// \param S The Sema object used for type-checking.
13925///
13926/// \param Loc The location where the implicit copy/move is being generated.
13927///
13928/// \param T The type of the expressions being copied/moved. Both expressions
13929/// must have this type.
13930///
13931/// \param To The expression we are copying/moving to.
13932///
13933/// \param From The expression we are copying/moving from.
13934///
13935/// \param CopyingBaseSubobject Whether we're copying/moving a base subobject.
13936/// Otherwise, it's a non-static member subobject.
13937///
13938/// \param Copying Whether we're copying or moving.
13939///
13940/// \param Depth Internal parameter recording the depth of the recursion.
13941///
13942/// \returns A statement or a loop that copies the expressions, or StmtResult(0)
13943/// if a memcpy should be used instead.
13944static StmtResult
13945buildSingleCopyAssignRecursively(Sema &S, SourceLocation Loc, QualType T,
                               const ExprBuilder &To, const ExprBuilder &From,
                               bool CopyingBaseSubobject, bool Copying,
                               unsigned Depth = 0) {
// C++11 [class.copy]p28:
//   Each subobject is assigned in the manner appropriate to its type:
//
//     - if the subobject is of class type, as if by a call to operator= with
//       the subobject as the object expression and the corresponding
//       subobject of x as a single function argument (as if by explicit
//       qualification; that is, ignoring any possible virtual overriding
//       functions in more derived classes);
//
// C++03 [class.copy]p13:
//     - if the subobject is of class type, the copy assignment operator for
//       the class is used (as if by explicit qualification; that is,
//       ignoring any possible virtual overriding functions in more derived
//       classes);
if (const RecordType *RecordTy = T->getAs<RecordType>()) {
  CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(RecordTy->getDecl());

  // Look for operator=.
  DeclarationName Name
    = S.Context.DeclarationNames.getCXXOperatorName(OO_Equal);
  LookupResult OpLookup(S, Name, Loc, Sema::LookupOrdinaryName);
  S.LookupQualifiedName(OpLookup, ClassDecl, false);

  // Prior to C++11, filter out any result that isn't a copy/move-assignment
  // operator.
  if (!S.getLangOpts().CPlusPlus11) {
    LookupResult::Filter F = OpLookup.makeFilter();
    while (F.hasNext()) {
      NamedDecl *D = F.next();
      if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(D))
        if (Method->isCopyAssignmentOperator() ||
            (!Copying && Method->isMoveAssignmentOperator()))
          continue;

      F.erase();
    }
    F.done();
  }

  // Suppress the protected check (C++ [class.protected]) for each of the
  // assignment operators we found. This strange dance is required when
  // we're assigning via a base classes's copy-assignment operator. To
  // ensure that we're getting the right base class subobject (without
  // ambiguities), we need to cast "this" to that subobject type; to
  // ensure that we don't go through the virtual call mechanism, we need
  // to qualify the operator= name with the base class (see below). However,
  // this means that if the base class has a protected copy assignment
  // operator, the protected member access check will fail. So, we
  // rewrite "protected" access to "public" access in this case, since we
  // know by construction that we're calling from a derived class.
  if (CopyingBaseSubobject) {
    for (LookupResult::iterator L = OpLookup.begin(), LEnd = OpLookup.end();
         L != LEnd; ++L) {
      if (L.getAccess() == AS_protected)
        L.setAccess(AS_public);
    }
  }

  // Create the nested-name-specifier that will be used to qualify the
  // reference to operator=; this is required to suppress the virtual
  // call mechanism.
  CXXScopeSpec SS;
  const Type *CanonicalT = S.Context.getCanonicalType(T.getTypePtr());
  SS.MakeTrivial(S.Context,
                 NestedNameSpecifier::Create(S.Context, nullptr, false,
                                             CanonicalT),
                 Loc);

  // Create the reference to operator=.
  ExprResult OpEqualRef
    = S.BuildMemberReferenceExpr(To.build(S, Loc), T, Loc, /*IsArrow=*/false,
                                 SS, /*TemplateKWLoc=*/SourceLocation(),
                                 /*FirstQualifierInScope=*/nullptr,
                                 OpLookup,
                                 /*TemplateArgs=*/nullptr, /*S*/nullptr,
                                 /*SuppressQualifierCheck=*/true);
  if (OpEqualRef.isInvalid())
    return StmtError();

  // Build the call to the assignment operator.

  Expr *FromInst = From.build(S, Loc);
  ExprResult Call = S.BuildCallToMemberFunction(/*Scope=*/nullptr,
                                                OpEqualRef.getAs<Expr>(),
                                                Loc, FromInst, Loc);
  if (Call.isInvalid())
    return StmtError();

  // If we built a call to a trivial 'operator=' while copying an array,
  // bail out. We'll replace the whole shebang with a memcpy.
  CXXMemberCallExpr *CE = dyn_cast<CXXMemberCallExpr>(Call.get());
  if (CE && CE->getMethodDecl()->isTrivial() && Depth)
    return StmtResult((Stmt*)nullptr);

  // Convert to an expression-statement, and clean up any produced
  // temporaries.
  return S.ActOnExprStmt(Call);
}

//     - if the subobject is of scalar type, the built-in assignment
//       operator is used.
const ConstantArrayType *ArrayTy = S.Context.getAsConstantArrayType(T);
if (!ArrayTy) {
  ExprResult Assignment = S.CreateBuiltinBinOp(
      Loc, BO_Assign, To.build(S, Loc), From.build(S, Loc));
  if (Assignment.isInvalid())
    return StmtError();
  return S.ActOnExprStmt(Assignment);
}

//     - if the subobject is an array, each element is assigned, in the
//       manner appropriate to the element type;

// Construct a loop over the array bounds, e.g.,
//
//   for (__SIZE_TYPE__ i0 = 0; i0 != array-size; ++i0)
//
// that will copy each of the array elements.
QualType SizeType = S.Context.getSizeType();

// Create the iteration variable.
IdentifierInfo *IterationVarName = nullptr;
{
  SmallString<8> Str;
  llvm::raw_svector_ostream OS(Str);
  OS << "__i" << Depth;
  IterationVarName = &S.Context.Idents.get(OS.str());
}
VarDecl *IterationVar = VarDecl::Create(S.Context, S.CurContext, Loc, Loc,
                                        IterationVarName, SizeType,
                          S.Context.getTrivialTypeSourceInfo(SizeType, Loc),
                                        SC_None);

// Initialize the iteration variable to zero.
llvm::APInt Zero(S.Context.getTypeSize(SizeType), 0);
IterationVar->setInit(IntegerLiteral::Create(S.Context, Zero, SizeType, Loc));

// Creates a reference to the iteration variable.
RefBuilder IterationVarRef(IterationVar, SizeType);
LvalueConvBuilder IterationVarRefRVal(IterationVarRef);

// Create the DeclStmt that holds the iteration variable.
Stmt *InitStmt = new (S.Context) DeclStmt(DeclGroupRef(IterationVar),Loc,Loc);

// Subscript the "from" and "to" expressions with the iteration variable.
SubscriptBuilder FromIndexCopy(From, IterationVarRefRVal);
MoveCastBuilder FromIndexMove(FromIndexCopy);
const ExprBuilder *FromIndex;
if (Copying)
  FromIndex = &FromIndexCopy;
else
  FromIndex = &FromIndexMove;

SubscriptBuilder ToIndex(To, IterationVarRefRVal);

// Build the copy/move for an individual element of the array.
StmtResult Copy =
  buildSingleCopyAssignRecursively(S, Loc, ArrayTy->getElementType(),
                                   ToIndex, *FromIndex, CopyingBaseSubobject,
                                   Copying, Depth + 1);
// Bail out if copying fails or if we determined that we should use memcpy.
if (Copy.isInvalid() || !Copy.get())
  return Copy;

// Create the comparison against the array bound.
llvm::APInt Upper
  = ArrayTy->getSize().zextOrTrunc(S.Context.getTypeSize(SizeType));
Expr *Comparison = BinaryOperator::Create(
    S.Context, IterationVarRefRVal.build(S, Loc),
    IntegerLiteral::Create(S.Context, Upper, SizeType, Loc), BO_NE,
    S.Context.BoolTy, VK_PRValue, OK_Ordinary, Loc,
    S.CurFPFeatureOverrides());

// Create the pre-increment of the iteration variable. We can determine
// whether the increment will overflow based on the value of the array
// bound.
Expr *Increment = UnaryOperator::Create(
    S.Context, IterationVarRef.build(S, Loc), UO_PreInc, SizeType, VK_LValue,
    OK_Ordinary, Loc, Upper.isMaxValue(), S.CurFPFeatureOverrides());

// Construct the loop that copies all elements of this array.
return S.ActOnForStmt(
    Loc, Loc, InitStmt,
    S.ActOnCondition(nullptr, Loc, Comparison, Sema::ConditionKind::Boolean),
    S.MakeFullDiscardedValueExpr(Increment), Loc, Copy.get());
14134}

14136static StmtResult
14137buildSingleCopyAssign(Sema &S, SourceLocation Loc, QualType T,
                    const ExprBuilder &To, const ExprBuilder &From,
                    bool CopyingBaseSubobject, bool Copying) {
// Maybe we should use a memcpy?
if (T->isArrayType() && !T.isConstQualified() && !T.isVolatileQualified() &&
    T.isTriviallyCopyableType(S.Context))
  return buildMemcpyForAssignmentOp(S, Loc, T, To, From);

StmtResult Result(buildSingleCopyAssignRecursively(S, Loc, T, To, From,
                                                   CopyingBaseSubobject,
                                                   Copying, 0));

// If we ended up picking a trivial assignment operator for an array of a
// non-trivially-copyable class type, just emit a memcpy.
if (!Result.isInvalid() && !Result.get())
  return buildMemcpyForAssignmentOp(S, Loc, T, To, From);

return Result;
14155}

14157CXXMethodDecl *Sema::DeclareImplicitCopyAssignment(CXXRecordDecl *ClassDecl) {
// Note: The following rules are largely analoguous to the copy
// constructor rules. Note that virtual bases are not taken into account
// for determining the argument type of the operator. Note also that
// operators taking an object instead of a reference are allowed.
assert(ClassDecl->needsImplicitCopyAssignment())(static_cast<void> (0));

DeclaringSpecialMember DSM(*this, ClassDecl, CXXCopyAssignment);
if (DSM.isAlreadyBeingDeclared())
  return nullptr;

QualType ArgType = Context.getTypeDeclType(ClassDecl);
LangAS AS = getDefaultCXXMethodAddrSpace();
if (AS != LangAS::Default)
  ArgType = Context.getAddrSpaceQualType(ArgType, AS);
QualType RetType = Context.getLValueReferenceType(ArgType);
bool Const = ClassDecl->implicitCopyAssignmentHasConstParam();
if (Const)
  ArgType = ArgType.withConst();

ArgType = Context.getLValueReferenceType(ArgType);

bool Constexpr = defaultedSpecialMemberIsConstexpr(*this, ClassDecl,
                                                   CXXCopyAssignment,
                                                   Const);

//   An implicitly-declared copy assignment operator is an inline public
//   member of its class.
DeclarationName Name = Context.DeclarationNames.getCXXOperatorName(OO_Equal);
SourceLocation ClassLoc = ClassDecl->getLocation();
DeclarationNameInfo NameInfo(Name, ClassLoc);
CXXMethodDecl *CopyAssignment = CXXMethodDecl::Create(
    Context, ClassDecl, ClassLoc, NameInfo, QualType(),
    /*TInfo=*/nullptr, /*StorageClass=*/SC_None,
    getCurFPFeatures().isFPConstrained(),
    /*isInline=*/true,
    Constexpr ? ConstexprSpecKind::Constexpr : ConstexprSpecKind::Unspecified,
    SourceLocation());
CopyAssignment->setAccess(AS_public);
CopyAssignment->setDefaulted();
CopyAssignment->setImplicit();

if (getLangOpts().CUDA) {
  inferCUDATargetForImplicitSpecialMember(ClassDecl, CXXCopyAssignment,
                                          CopyAssignment,
                                          /* ConstRHS */ Const,
                                          /* Diagnose */ false);
}

setupImplicitSpecialMemberType(CopyAssignment, RetType, ArgType);

// Add the parameter to the operator.
ParmVarDecl *FromParam = ParmVarDecl::Create(Context, CopyAssignment,
                                             ClassLoc, ClassLoc,
                                             /*Id=*/nullptr, ArgType,
                                             /*TInfo=*/nullptr, SC_None,
                                             nullptr);
CopyAssignment->setParams(FromParam);

CopyAssignment->setTrivial(
  ClassDecl->needsOverloadResolutionForCopyAssignment()
    ? SpecialMemberIsTrivial(CopyAssignment, CXXCopyAssignment)
    : ClassDecl->hasTrivialCopyAssignment());

// Note that we have added this copy-assignment operator.
++getASTContext().NumImplicitCopyAssignmentOperatorsDeclared;

Scope *S = getScopeForContext(ClassDecl);
CheckImplicitSpecialMemberDeclaration(S, CopyAssignment);

if (ShouldDeleteSpecialMember(CopyAssignment, CXXCopyAssignment)) {
  ClassDecl->setImplicitCopyAssignmentIsDeleted();
  SetDeclDeleted(CopyAssignment, ClassLoc);
}

if (S)
  PushOnScopeChains(CopyAssignment, S, false);
ClassDecl->addDecl(CopyAssignment);

return CopyAssignment;
14237}

14239/// Diagnose an implicit copy operation for a class which is odr-used, but
14240/// which is deprecated because the class has a user-declared copy constructor,
14241/// copy assignment operator, or destructor.
14242static void diagnoseDeprecatedCopyOperation(Sema &S, CXXMethodDecl *CopyOp) {
assert(CopyOp->isImplicit())(static_cast<void> (0));

CXXRecordDecl *RD = CopyOp->getParent();
CXXMethodDecl *UserDeclaredOperation = nullptr;

// In Microsoft mode, assignment operations don't affect constructors and
// vice versa.
if (RD->hasUserDeclaredDestructor()) {
  UserDeclaredOperation = RD->getDestructor();
} else if (!isa<CXXConstructorDecl>(CopyOp) &&
           RD->hasUserDeclaredCopyConstructor() &&
           !S.getLangOpts().MSVCCompat) {
  // Find any user-declared copy constructor.
  for (auto *I : RD->ctors()) {
    if (I->isCopyConstructor()) {
      UserDeclaredOperation = I;
      break;
    }
  }
  assert(UserDeclaredOperation)(static_cast<void> (0));
} else if (isa<CXXConstructorDecl>(CopyOp) &&
           RD->hasUserDeclaredCopyAssignment() &&
           !S.getLangOpts().MSVCCompat) {
  // Find any user-declared move assignment operator.
  for (auto *I : RD->methods()) {
    if (I->isCopyAssignmentOperator()) {
      UserDeclaredOperation = I;
      break;
    }
  }
  assert(UserDeclaredOperation)(static_cast<void> (0));
}

if (UserDeclaredOperation) {
  bool UDOIsUserProvided = UserDeclaredOperation->isUserProvided();
  bool UDOIsDestructor = isa<CXXDestructorDecl>(UserDeclaredOperation);
  bool IsCopyAssignment = !isa<CXXConstructorDecl>(CopyOp);
  unsigned DiagID =
      (UDOIsUserProvided && UDOIsDestructor)
          ? diag::warn_deprecated_copy_with_user_provided_dtor
      : (UDOIsUserProvided && !UDOIsDestructor)
          ? diag::warn_deprecated_copy_with_user_provided_copy
      : (!UDOIsUserProvided && UDOIsDestructor)
          ? diag::warn_deprecated_copy_with_dtor
          : diag::warn_deprecated_copy;
  S.Diag(UserDeclaredOperation->getLocation(), DiagID)
      << RD << IsCopyAssignment;
}
14291}

14293void Sema::DefineImplicitCopyAssignment(SourceLocation CurrentLocation,
                                      CXXMethodDecl *CopyAssignOperator) {
assert((CopyAssignOperator->isDefaulted() &&(static_cast<void> (0))
        CopyAssignOperator->isOverloadedOperator() &&(static_cast<void> (0))
        CopyAssignOperator->getOverloadedOperator() == OO_Equal &&(static_cast<void> (0))
        !CopyAssignOperator->doesThisDeclarationHaveABody() &&(static_cast<void> (0))
        !CopyAssignOperator->isDeleted()) &&(static_cast<void> (0))
       "DefineImplicitCopyAssignment called for wrong function")(static_cast<void> (0));
if (CopyAssignOperator->willHaveBody() || CopyAssignOperator->isInvalidDecl())
  return;

CXXRecordDecl *ClassDecl = CopyAssignOperator->getParent();
if (ClassDecl->isInvalidDecl()) {
  CopyAssignOperator->setInvalidDecl();
  return;
}

SynthesizedFunctionScope Scope(*this, CopyAssignOperator);

// The exception specification is needed because we are defining the
// function.
ResolveExceptionSpec(CurrentLocation,
                     CopyAssignOperator->getType()->castAs<FunctionProtoType>());

// Add a context note for diagnostics produced after this point.
Scope.addContextNote(CurrentLocation);

// C++11 [class.copy]p18:
//   The [definition of an implicitly declared copy assignment operator] is
//   deprecated if the class has a user-declared copy constructor or a
//   user-declared destructor.
if (getLangOpts().CPlusPlus11 && CopyAssignOperator->isImplicit())
  diagnoseDeprecatedCopyOperation(*this, CopyAssignOperator);

// C++0x [class.copy]p30:
//   The implicitly-defined or explicitly-defaulted copy assignment operator
//   for a non-union class X performs memberwise copy assignment of its
//   subobjects. The direct base classes of X are assigned first, in the
//   order of their declaration in the base-specifier-list, and then the
//   immediate non-static data members of X are assigned, in the order in
//   which they were declared in the class definition.

// The statements that form the synthesized function body.
SmallVector<Stmt*, 8> Statements;

// The parameter for the "other" object, which we are copying from.
ParmVarDecl *Other = CopyAssignOperator->getParamDecl(0);
Qualifiers OtherQuals = Other->getType().getQualifiers();
QualType OtherRefType = Other->getType();
if (const LValueReferenceType *OtherRef
                              = OtherRefType->getAs<LValueReferenceType>()) {
  OtherRefType = OtherRef->getPointeeType();
  OtherQuals = OtherRefType.getQualifiers();
}

// Our location for everything implicitly-generated.
SourceLocation Loc = CopyAssignOperator->getEndLoc().isValid()
                         ? CopyAssignOperator->getEndLoc()
                         : CopyAssignOperator->getLocation();

// Builds a DeclRefExpr for the "other" object.
RefBuilder OtherRef(Other, OtherRefType);

// Builds the "this" pointer.
ThisBuilder This;

// Assign base classes.
bool Invalid = false;
for (auto &Base : ClassDecl->bases()) {
  // Form the assignment:
  //   static_cast<Base*>(this)->Base::operator=(static_cast<Base&>(other));
  QualType BaseType = Base.getType().getUnqualifiedType();
  if (!BaseType->isRecordType()) {
    Invalid = true;
    continue;
  }

  CXXCastPath BasePath;
  BasePath.push_back(&Base);

  // Construct the "from" expression, which is an implicit cast to the
  // appropriately-qualified base type.
  CastBuilder From(OtherRef, Context.getQualifiedType(BaseType, OtherQuals),
                   VK_LValue, BasePath);

  // Dereference "this".
  DerefBuilder DerefThis(This);
  CastBuilder To(DerefThis,
                 Context.getQualifiedType(
                     BaseType, CopyAssignOperator->getMethodQualifiers()),
                 VK_LValue, BasePath);

  // Build the copy.
  StmtResult Copy = buildSingleCopyAssign(*this, Loc, BaseType,
                                          To, From,
                                          /*CopyingBaseSubobject=*/true,
                                          /*Copying=*/true);
  if (Copy.isInvalid()) {
    CopyAssignOperator->setInvalidDecl();
    return;
  }

  // Success! Record the copy.
  Statements.push_back(Copy.getAs<Expr>());
}

// Assign non-static members.
for (auto *Field : ClassDecl->fields()) {
  // FIXME: We should form some kind of AST representation for the implied
  // memcpy in a union copy operation.
  if (Field->isUnnamedBitfield() || Field->getParent()->isUnion())
    continue;

  if (Field->isInvalidDecl()) {
    Invalid = true;
    continue;
  }

  // Check for members of reference type; we can't copy those.
  if (Field->getType()->isReferenceType()) {
    Diag(ClassDecl->getLocation(), diag::err_uninitialized_member_for_assign)
      << Context.getTagDeclType(ClassDecl) << 0 << Field->getDeclName();
    Diag(Field->getLocation(), diag::note_declared_at);
    Invalid = true;
    continue;
  }

  // Check for members of const-qualified, non-class type.
  QualType BaseType = Context.getBaseElementType(Field->getType());
  if (!BaseType->getAs<RecordType>() && BaseType.isConstQualified()) {
    Diag(ClassDecl->getLocation(), diag::err_uninitialized_member_for_assign)
      << Context.getTagDeclType(ClassDecl) << 1 << Field->getDeclName();
    Diag(Field->getLocation(), diag::note_declared_at);
    Invalid = true;
    continue;
  }

  // Suppress assigning zero-width bitfields.
  if (Field->isZeroLengthBitField(Context))
    continue;

  QualType FieldType = Field->getType().getNonReferenceType();
  if (FieldType->isIncompleteArrayType()) {
    assert(ClassDecl->hasFlexibleArrayMember() &&(static_cast<void> (0))
           "Incomplete array type is not valid")(static_cast<void> (0));
    continue;
  }

  // Build references to the field in the object we're copying from and to.
  CXXScopeSpec SS; // Intentionally empty
  LookupResult MemberLookup(*this, Field->getDeclName(), Loc,
                            LookupMemberName);
  MemberLookup.addDecl(Field);
  MemberLookup.resolveKind();

  MemberBuilder From(OtherRef, OtherRefType, /*IsArrow=*/false, MemberLookup);

  MemberBuilder To(This, getCurrentThisType(), /*IsArrow=*/true, MemberLookup);

  // Build the copy of this field.
  StmtResult Copy = buildSingleCopyAssign(*this, Loc, FieldType,
                                          To, From,
                                          /*CopyingBaseSubobject=*/false,
                                          /*Copying=*/true);
  if (Copy.isInvalid()) {
    CopyAssignOperator->setInvalidDecl();
    return;
  }

  // Success! Record the copy.
  Statements.push_back(Copy.getAs<Stmt>());
}

if (!Invalid) {
  // Add a "return *this;"
  ExprResult ThisObj = CreateBuiltinUnaryOp(Loc, UO_Deref, This.build(*this, Loc));

  StmtResult Return = BuildReturnStmt(Loc, ThisObj.get());
  if (Return.isInvalid())
    Invalid = true;
  else
    Statements.push_back(Return.getAs<Stmt>());
}

if (Invalid) {
  CopyAssignOperator->setInvalidDecl();
  return;
}

StmtResult Body;
{
  CompoundScopeRAII CompoundScope(*this);
  Body = ActOnCompoundStmt(Loc, Loc, Statements,
                           /*isStmtExpr=*/false);
  assert(!Body.isInvalid() && "Compound statement creation cannot fail")(static_cast<void> (0));
}
CopyAssignOperator->setBody(Body.getAs<Stmt>());
CopyAssignOperator->markUsed(Context);

if (ASTMutationListener *L = getASTMutationListener()) {
  L->CompletedImplicitDefinition(CopyAssignOperator);
}
14495}

14497CXXMethodDecl *Sema::DeclareImplicitMoveAssignment(CXXRecordDecl *ClassDecl) {
assert(ClassDecl->needsImplicitMoveAssignment())(static_cast<void> (0));

DeclaringSpecialMember DSM(*this, ClassDecl, CXXMoveAssignment);
if (DSM.isAlreadyBeingDeclared())
  return nullptr;

// Note: The following rules are largely analoguous to the move
// constructor rules.

QualType ArgType = Context.getTypeDeclType(ClassDecl);
LangAS AS = getDefaultCXXMethodAddrSpace();
if (AS != LangAS::Default)
  ArgType = Context.getAddrSpaceQualType(ArgType, AS);
QualType RetType = Context.getLValueReferenceType(ArgType);
ArgType = Context.getRValueReferenceType(ArgType);

bool Constexpr = defaultedSpecialMemberIsConstexpr(*this, ClassDecl,
                                                   CXXMoveAssignment,
                                                   false);

//   An implicitly-declared move assignment operator is an inline public
//   member of its class.
DeclarationName Name = Context.DeclarationNames.getCXXOperatorName(OO_Equal);
SourceLocation ClassLoc = ClassDecl->getLocation();
DeclarationNameInfo NameInfo(Name, ClassLoc);
CXXMethodDecl *MoveAssignment = CXXMethodDecl::Create(
    Context, ClassDecl, ClassLoc, NameInfo, QualType(),
    /*TInfo=*/nullptr, /*StorageClass=*/SC_None,
    getCurFPFeatures().isFPConstrained(),
    /*isInline=*/true,
    Constexpr ? ConstexprSpecKind::Constexpr : ConstexprSpecKind::Unspecified,
    SourceLocation());
MoveAssignment->setAccess(AS_public);
MoveAssignment->setDefaulted();
MoveAssignment->setImplicit();

if (getLangOpts().CUDA) {
  inferCUDATargetForImplicitSpecialMember(ClassDecl, CXXMoveAssignment,
                                          MoveAssignment,
                                          /* ConstRHS */ false,
                                          /* Diagnose */ false);
}

setupImplicitSpecialMemberType(MoveAssignment, RetType, ArgType);

// Add the parameter to the operator.
ParmVarDecl *FromParam = ParmVarDecl::Create(Context, MoveAssignment,
                                             ClassLoc, ClassLoc,
                                             /*Id=*/nullptr, ArgType,
                                             /*TInfo=*/nullptr, SC_None,
                                             nullptr);
MoveAssignment->setParams(FromParam);

MoveAssignment->setTrivial(
  ClassDecl->needsOverloadResolutionForMoveAssignment()
    ? SpecialMemberIsTrivial(MoveAssignment, CXXMoveAssignment)
    : ClassDecl->hasTrivialMoveAssignment());

// Note that we have added this copy-assignment operator.
++getASTContext().NumImplicitMoveAssignmentOperatorsDeclared;

Scope *S = getScopeForContext(ClassDecl);
CheckImplicitSpecialMemberDeclaration(S, MoveAssignment);

if (ShouldDeleteSpecialMember(MoveAssignment, CXXMoveAssignment)) {
  ClassDecl->setImplicitMoveAssignmentIsDeleted();
  SetDeclDeleted(MoveAssignment, ClassLoc);
}

if (S)
  PushOnScopeChains(MoveAssignment, S, false);
ClassDecl->addDecl(MoveAssignment);

return MoveAssignment;
14572}

14574/// Check if we're implicitly defining a move assignment operator for a class
14575/// with virtual bases. Such a move assignment might move-assign the virtual
14576/// base multiple times.
14577static void checkMoveAssignmentForRepeatedMove(Sema &S, CXXRecordDecl *Class,
                                             SourceLocation CurrentLocation) {
assert(!Class->isDependentContext() && "should not define dependent move")(static_cast<void> (0));

// Only a virtual base could get implicitly move-assigned multiple times.
// Only a non-trivial move assignment can observe this. We only want to
// diagnose if we implicitly define an assignment operator that assigns
// two base classes, both of which move-assign the same virtual base.
if (Class->getNumVBases() == 0 || Class->hasTrivialMoveAssignment() ||
    Class->getNumBases() < 2)
  return;

llvm::SmallVector<CXXBaseSpecifier *, 16> Worklist;
typedef llvm::DenseMap<CXXRecordDecl*, CXXBaseSpecifier*> VBaseMap;
VBaseMap VBases;

for (auto &BI : Class->bases()) {
  Worklist.push_back(&BI);
  while (!Worklist.empty()) {
    CXXBaseSpecifier *BaseSpec = Worklist.pop_back_val();
    CXXRecordDecl *Base = BaseSpec->getType()->getAsCXXRecordDecl();

    // If the base has no non-trivial move assignment operators,
    // we don't care about moves from it.
    if (!Base->hasNonTrivialMoveAssignment())
      continue;

    // If there's nothing virtual here, skip it.
    if (!BaseSpec->isVirtual() && !Base->getNumVBases())
      continue;

    // If we're not actually going to call a move assignment for this base,
    // or the selected move assignment is trivial, skip it.
    Sema::SpecialMemberOverloadResult SMOR =
      S.LookupSpecialMember(Base, Sema::CXXMoveAssignment,
                            /*ConstArg*/false, /*VolatileArg*/false,
                            /*RValueThis*/true, /*ConstThis*/false,
                            /*VolatileThis*/false);
    if (!SMOR.getMethod() || SMOR.getMethod()->isTrivial() ||
        !SMOR.getMethod()->isMoveAssignmentOperator())
      continue;

    if (BaseSpec->isVirtual()) {
      // We're going to move-assign this virtual base, and its move
      // assignment operator is not trivial. If this can happen for
      // multiple distinct direct bases of Class, diagnose it. (If it
      // only happens in one base, we'll diagnose it when synthesizing
      // that base class's move assignment operator.)
      CXXBaseSpecifier *&Existing =
          VBases.insert(std::make_pair(Base->getCanonicalDecl(), &BI))
              .first->second;
      if (Existing && Existing != &BI) {
        S.Diag(CurrentLocation, diag::warn_vbase_moved_multiple_times)
          << Class << Base;
        S.Diag(Existing->getBeginLoc(), diag::note_vbase_moved_here)
            << (Base->getCanonicalDecl() ==
                Existing->getType()->getAsCXXRecordDecl()->getCanonicalDecl())
            << Base << Existing->getType() << Existing->getSourceRange();
        S.Diag(BI.getBeginLoc(), diag::note_vbase_moved_here)
            << (Base->getCanonicalDecl() ==
                BI.getType()->getAsCXXRecordDecl()->getCanonicalDecl())
            << Base << BI.getType() << BaseSpec->getSourceRange();

        // Only diagnose each vbase once.
        Existing = nullptr;
      }
    } else {
      // Only walk over bases that have defaulted move assignment operators.
      // We assume that any user-provided move assignment operator handles
      // the multiple-moves-of-vbase case itself somehow.
      if (!SMOR.getMethod()->isDefaulted())
        continue;

      // We're going to move the base classes of Base. Add them to the list.
      for (auto &BI : Base->bases())
        Worklist.push_back(&BI);
    }
  }
}
14656}

14658void Sema::DefineImplicitMoveAssignment(SourceLocation CurrentLocation,
                                      CXXMethodDecl *MoveAssignOperator) {
assert((MoveAssignOperator->isDefaulted() &&(static_cast<void> (0))
        MoveAssignOperator->isOverloadedOperator() &&(static_cast<void> (0))
        MoveAssignOperator->getOverloadedOperator() == OO_Equal &&(static_cast<void> (0))
        !MoveAssignOperator->doesThisDeclarationHaveABody() &&(static_cast<void> (0))
        !MoveAssignOperator->isDeleted()) &&(static_cast<void> (0))
       "DefineImplicitMoveAssignment called for wrong function")(static_cast<void> (0));
if (MoveAssignOperator->willHaveBody() || MoveAssignOperator->isInvalidDecl())
  return;

CXXRecordDecl *ClassDecl = MoveAssignOperator->getParent();
if (ClassDecl->isInvalidDecl()) {
  MoveAssignOperator->setInvalidDecl();
  return;
}

// C++0x [class.copy]p28:
//   The implicitly-defined or move assignment operator for a non-union class
//   X performs memberwise move assignment of its subobjects. The direct base
//   classes of X are assigned first, in the order of their declaration in the
//   base-specifier-list, and then the immediate non-static data members of X
//   are assigned, in the order in which they were declared in the class
//   definition.

// Issue a warning if our implicit move assignment operator will move
// from a virtual base more than once.
checkMoveAssignmentForRepeatedMove(*this, ClassDecl, CurrentLocation);

SynthesizedFunctionScope Scope(*this, MoveAssignOperator);

// The exception specification is needed because we are defining the
// function.
ResolveExceptionSpec(CurrentLocation,
                     MoveAssignOperator->getType()->castAs<FunctionProtoType>());

// Add a context note for diagnostics produced after this point.
Scope.addContextNote(CurrentLocation);

// The statements that form the synthesized function body.
SmallVector<Stmt*, 8> Statements;

// The parameter for the "other" object, which we are move from.
ParmVarDecl *Other = MoveAssignOperator->getParamDecl(0);
QualType OtherRefType =
    Other->getType()->castAs<RValueReferenceType>()->getPointeeType();

// Our location for everything implicitly-generated.
SourceLocation Loc = MoveAssignOperator->getEndLoc().isValid()
                         ? MoveAssignOperator->getEndLoc()
                         : MoveAssignOperator->getLocation();

// Builds a reference to the "other" object.
RefBuilder OtherRef(Other, OtherRefType);
// Cast to rvalue.
MoveCastBuilder MoveOther(OtherRef);

// Builds the "this" pointer.
ThisBuilder This;

// Assign base classes.
bool Invalid = false;
for (auto &Base : ClassDecl->bases()) {
  // C++11 [class.copy]p28:
  //   It is unspecified whether subobjects representing virtual base classes
  //   are assigned more than once by the implicitly-defined copy assignment
  //   operator.
  // FIXME: Do not assign to a vbase that will be assigned by some other base
  // class. For a move-assignment, this can result in the vbase being moved
  // multiple times.

  // Form the assignment:
  //   static_cast<Base*>(this)->Base::operator=(static_cast<Base&&>(other));
  QualType BaseType = Base.getType().getUnqualifiedType();
  if (!BaseType->isRecordType()) {
    Invalid = true;
    continue;
  }

  CXXCastPath BasePath;
  BasePath.push_back(&Base);

  // Construct the "from" expression, which is an implicit cast to the
  // appropriately-qualified base type.
  CastBuilder From(OtherRef, BaseType, VK_XValue, BasePath);

  // Dereference "this".
  DerefBuilder DerefThis(This);

  // Implicitly cast "this" to the appropriately-qualified base type.
  CastBuilder To(DerefThis,
                 Context.getQualifiedType(
                     BaseType, MoveAssignOperator->getMethodQualifiers()),
                 VK_LValue, BasePath);

  // Build the move.
  StmtResult Move = buildSingleCopyAssign(*this, Loc, BaseType,
                                          To, From,
                                          /*CopyingBaseSubobject=*/true,
                                          /*Copying=*/false);
  if (Move.isInvalid()) {
    MoveAssignOperator->setInvalidDecl();
    return;
  }

  // Success! Record the move.
  Statements.push_back(Move.getAs<Expr>());
}

// Assign non-static members.
for (auto *Field : ClassDecl->fields()) {
  // FIXME: We should form some kind of AST representation for the implied
  // memcpy in a union copy operation.
  if (Field->isUnnamedBitfield() || Field->getParent()->isUnion())
    continue;

  if (Field->isInvalidDecl()) {
    Invalid = true;
    continue;
  }

  // Check for members of reference type; we can't move those.
  if (Field->getType()->isReferenceType()) {
    Diag(ClassDecl->getLocation(), diag::err_uninitialized_member_for_assign)
      << Context.getTagDeclType(ClassDecl) << 0 << Field->getDeclName();
    Diag(Field->getLocation(), diag::note_declared_at);
    Invalid = true;
    continue;
  }

  // Check for members of const-qualified, non-class type.
  QualType BaseType = Context.getBaseElementType(Field->getType());
  if (!BaseType->getAs<RecordType>() && BaseType.isConstQualified()) {
    Diag(ClassDecl->getLocation(), diag::err_uninitialized_member_for_assign)
      << Context.getTagDeclType(ClassDecl) << 1 << Field->getDeclName();
    Diag(Field->getLocation(), diag::note_declared_at);
    Invalid = true;
    continue;
  }

  // Suppress assigning zero-width bitfields.
  if (Field->isZeroLengthBitField(Context))
    continue;

  QualType FieldType = Field->getType().getNonReferenceType();
  if (FieldType->isIncompleteArrayType()) {
    assert(ClassDecl->hasFlexibleArrayMember() &&(static_cast<void> (0))
           "Incomplete array type is not valid")(static_cast<void> (0));
    continue;
  }

  // Build references to the field in the object we're copying from and to.
  LookupResult MemberLookup(*this, Field->getDeclName(), Loc,
                            LookupMemberName);
  MemberLookup.addDecl(Field);
  MemberLookup.resolveKind();
  MemberBuilder From(MoveOther, OtherRefType,
                     /*IsArrow=*/false, MemberLookup);
  MemberBuilder To(This, getCurrentThisType(),
                   /*IsArrow=*/true, MemberLookup);

  assert(!From.build(*this, Loc)->isLValue() && // could be xvalue or prvalue(static_cast<void> (0))
      "Member reference with rvalue base must be rvalue except for reference "(static_cast<void> (0))
      "members, which aren't allowed for move assignment.")(static_cast<void> (0));

  // Build the move of this field.
  StmtResult Move = buildSingleCopyAssign(*this, Loc, FieldType,
                                          To, From,
                                          /*CopyingBaseSubobject=*/false,
                                          /*Copying=*/false);
  if (Move.isInvalid()) {
    MoveAssignOperator->setInvalidDecl();
    return;
  }

  // Success! Record the copy.
  Statements.push_back(Move.getAs<Stmt>());
}

if (!Invalid) {
  // Add a "return *this;"
  ExprResult ThisObj =
      CreateBuiltinUnaryOp(Loc, UO_Deref, This.build(*this, Loc));

  StmtResult Return = BuildReturnStmt(Loc, ThisObj.get());
  if (Return.isInvalid())
    Invalid = true;
  else
    Statements.push_back(Return.getAs<Stmt>());
}

if (Invalid) {
  MoveAssignOperator->setInvalidDecl();
  return;
}

StmtResult Body;
{
  CompoundScopeRAII CompoundScope(*this);
  Body = ActOnCompoundStmt(Loc, Loc, Statements,
                           /*isStmtExpr=*/false);
  assert(!Body.isInvalid() && "Compound statement creation cannot fail")(static_cast<void> (0));
}
MoveAssignOperator->setBody(Body.getAs<Stmt>());
MoveAssignOperator->markUsed(Context);

if (ASTMutationListener *L = getASTMutationListener()) {
  L->CompletedImplicitDefinition(MoveAssignOperator);
}
14867}

14869CXXConstructorDecl *Sema::DeclareImplicitCopyConstructor(
                                                  CXXRecordDecl *ClassDecl) {
// C++ [class.copy]p4:
//   If the class definition does not explicitly declare a copy
//   constructor, one is declared implicitly.
assert(ClassDecl->needsImplicitCopyConstructor())(static_cast<void> (0));

DeclaringSpecialMember DSM(*this, ClassDecl, CXXCopyConstructor);
if (DSM.isAlreadyBeingDeclared())
  return nullptr;

QualType ClassType = Context.getTypeDeclType(ClassDecl);
QualType ArgType = ClassType;
bool Const = ClassDecl->implicitCopyConstructorHasConstParam();
if (Const)
  ArgType = ArgType.withConst();

LangAS AS = getDefaultCXXMethodAddrSpace();
if (AS != LangAS::Default)
  ArgType = Context.getAddrSpaceQualType(ArgType, AS);

ArgType = Context.getLValueReferenceType(ArgType);

bool Constexpr = defaultedSpecialMemberIsConstexpr(*this, ClassDecl,
                                                   CXXCopyConstructor,
                                                   Const);

DeclarationName Name
  = Context.DeclarationNames.getCXXConstructorName(
                                         Context.getCanonicalType(ClassType));
SourceLocation ClassLoc = ClassDecl->getLocation();
DeclarationNameInfo NameInfo(Name, ClassLoc);

//   An implicitly-declared copy constructor is an inline public
//   member of its class.
CXXConstructorDecl *CopyConstructor = CXXConstructorDecl::Create(
    Context, ClassDecl, ClassLoc, NameInfo, QualType(), /*TInfo=*/nullptr,
    ExplicitSpecifier(), getCurFPFeatures().isFPConstrained(),
    /*isInline=*/true,
    /*isImplicitlyDeclared=*/true,
    Constexpr ? ConstexprSpecKind::Constexpr
              : ConstexprSpecKind::Unspecified);
CopyConstructor->setAccess(AS_public);
CopyConstructor->setDefaulted();

if (getLangOpts().CUDA) {
  inferCUDATargetForImplicitSpecialMember(ClassDecl, CXXCopyConstructor,
                                          CopyConstructor,
                                          /* ConstRHS */ Const,
                                          /* Diagnose */ false);
}

setupImplicitSpecialMemberType(CopyConstructor, Context.VoidTy, ArgType);

// During template instantiation of special member functions we need a
// reliable TypeSourceInfo for the parameter types in order to allow functions
// to be substituted.
TypeSourceInfo *TSI = nullptr;
if (inTemplateInstantiation() && ClassDecl->isLambda())
  TSI = Context.getTrivialTypeSourceInfo(ArgType);

// Add the parameter to the constructor.
ParmVarDecl *FromParam =
    ParmVarDecl::Create(Context, CopyConstructor, ClassLoc, ClassLoc,
                        /*IdentifierInfo=*/nullptr, ArgType,
                        /*TInfo=*/TSI, SC_None, nullptr);
CopyConstructor->setParams(FromParam);

CopyConstructor->setTrivial(
    ClassDecl->needsOverloadResolutionForCopyConstructor()
        ? SpecialMemberIsTrivial(CopyConstructor, CXXCopyConstructor)
        : ClassDecl->hasTrivialCopyConstructor());

CopyConstructor->setTrivialForCall(
    ClassDecl->hasAttr<TrivialABIAttr>() ||
    (ClassDecl->needsOverloadResolutionForCopyConstructor()
         ? SpecialMemberIsTrivial(CopyConstructor, CXXCopyConstructor,
           TAH_ConsiderTrivialABI)
         : ClassDecl->hasTrivialCopyConstructorForCall()));

// Note that we have declared this constructor.
++getASTContext().NumImplicitCopyConstructorsDeclared;

Scope *S = getScopeForContext(ClassDecl);
CheckImplicitSpecialMemberDeclaration(S, CopyConstructor);

if (ShouldDeleteSpecialMember(CopyConstructor, CXXCopyConstructor)) {
  ClassDecl->setImplicitCopyConstructorIsDeleted();
  SetDeclDeleted(CopyConstructor, ClassLoc);
}

if (S)
  PushOnScopeChains(CopyConstructor, S, false);
ClassDecl->addDecl(CopyConstructor);

return CopyConstructor;
14965}

14967void Sema::DefineImplicitCopyConstructor(SourceLocation CurrentLocation,
                                       CXXConstructorDecl *CopyConstructor) {
assert((CopyConstructor->isDefaulted() &&(static_cast<void> (0))
        CopyConstructor->isCopyConstructor() &&(static_cast<void> (0))
        !CopyConstructor->doesThisDeclarationHaveABody() &&(static_cast<void> (0))
        !CopyConstructor->isDeleted()) &&(static_cast<void> (0))
       "DefineImplicitCopyConstructor - call it for implicit copy ctor")(static_cast<void> (0));
if (CopyConstructor->willHaveBody() || CopyConstructor->isInvalidDecl())
  return;

CXXRecordDecl *ClassDecl = CopyConstructor->getParent();
assert(ClassDecl && "DefineImplicitCopyConstructor - invalid constructor")(static_cast<void> (0));

SynthesizedFunctionScope Scope(*this, CopyConstructor);

// The exception specification is needed because we are defining the
// function.
ResolveExceptionSpec(CurrentLocation,
                     CopyConstructor->getType()->castAs<FunctionProtoType>());
MarkVTableUsed(CurrentLocation, ClassDecl);

// Add a context note for diagnostics produced after this point.
Scope.addContextNote(CurrentLocation);

// C++11 [class.copy]p7:
//   The [definition of an implicitly declared copy constructor] is
//   deprecated if the class has a user-declared copy assignment operator
//   or a user-declared destructor.
if (getLangOpts().CPlusPlus11 && CopyConstructor->isImplicit())
  diagnoseDeprecatedCopyOperation(*this, CopyConstructor);

if (SetCtorInitializers(CopyConstructor, /*AnyErrors=*/false)) {
  CopyConstructor->setInvalidDecl();
}  else {
  SourceLocation Loc = CopyConstructor->getEndLoc().isValid()
                           ? CopyConstructor->getEndLoc()
                           : CopyConstructor->getLocation();
  Sema::CompoundScopeRAII CompoundScope(*this);
  CopyConstructor->setBody(
      ActOnCompoundStmt(Loc, Loc, None, /*isStmtExpr=*/false).getAs<Stmt>());
  CopyConstructor->markUsed(Context);
}

if (ASTMutationListener *L = getASTMutationListener()) {
  L->CompletedImplicitDefinition(CopyConstructor);
}
15013}

15015CXXConstructorDecl *Sema::DeclareImplicitMoveConstructor(
                                                  CXXRecordDecl *ClassDecl) {
assert(ClassDecl->needsImplicitMoveConstructor())(static_cast<void> (0));

DeclaringSpecialMember DSM(*this, ClassDecl, CXXMoveConstructor);
if (DSM.isAlreadyBeingDeclared())
  return nullptr;

QualType ClassType = Context.getTypeDeclType(ClassDecl);

QualType ArgType = ClassType;
LangAS AS = getDefaultCXXMethodAddrSpace();
if (AS != LangAS::Default)
  ArgType = Context.getAddrSpaceQualType(ClassType, AS);
ArgType = Context.getRValueReferenceType(ArgType);

bool Constexpr = defaultedSpecialMemberIsConstexpr(*this, ClassDecl,
                                                   CXXMoveConstructor,
                                                   false);

DeclarationName Name
  = Context.DeclarationNames.getCXXConstructorName(
                                         Context.getCanonicalType(ClassType));
SourceLocation ClassLoc = ClassDecl->getLocation();
DeclarationNameInfo NameInfo(Name, ClassLoc);

// C++11 [class.copy]p11:
//   An implicitly-declared copy/move constructor is an inline public
//   member of its class.
CXXConstructorDecl *MoveConstructor = CXXConstructorDecl::Create(
    Context, ClassDecl, ClassLoc, NameInfo, QualType(), /*TInfo=*/nullptr,
    ExplicitSpecifier(), getCurFPFeatures().isFPConstrained(),
    /*isInline=*/true,
    /*isImplicitlyDeclared=*/true,
    Constexpr ? ConstexprSpecKind::Constexpr
              : ConstexprSpecKind::Unspecified);
MoveConstructor->setAccess(AS_public);
MoveConstructor->setDefaulted();

if (getLangOpts().CUDA) {
  inferCUDATargetForImplicitSpecialMember(ClassDecl, CXXMoveConstructor,
                                          MoveConstructor,
                                          /* ConstRHS */ false,
                                          /* Diagnose */ false);
}

setupImplicitSpecialMemberType(MoveConstructor, Context.VoidTy, ArgType);

// Add the parameter to the constructor.
ParmVarDecl *FromParam = ParmVarDecl::Create(Context, MoveConstructor,
                                             ClassLoc, ClassLoc,
                                             /*IdentifierInfo=*/nullptr,
                                             ArgType, /*TInfo=*/nullptr,
                                             SC_None, nullptr);
MoveConstructor->setParams(FromParam);

MoveConstructor->setTrivial(
    ClassDecl->needsOverloadResolutionForMoveConstructor()
        ? SpecialMemberIsTrivial(MoveConstructor, CXXMoveConstructor)
        : ClassDecl->hasTrivialMoveConstructor());

MoveConstructor->setTrivialForCall(
    ClassDecl->hasAttr<TrivialABIAttr>() ||
    (ClassDecl->needsOverloadResolutionForMoveConstructor()
         ? SpecialMemberIsTrivial(MoveConstructor, CXXMoveConstructor,
                                  TAH_ConsiderTrivialABI)
         : ClassDecl->hasTrivialMoveConstructorForCall()));

// Note that we have declared this constructor.
++getASTContext().NumImplicitMoveConstructorsDeclared;

Scope *S = getScopeForContext(ClassDecl);
CheckImplicitSpecialMemberDeclaration(S, MoveConstructor);

if (ShouldDeleteSpecialMember(MoveConstructor, CXXMoveConstructor)) {
  ClassDecl->setImplicitMoveConstructorIsDeleted();
  SetDeclDeleted(MoveConstructor, ClassLoc);
}

if (S)
  PushOnScopeChains(MoveConstructor, S, false);
ClassDecl->addDecl(MoveConstructor);

return MoveConstructor;
15099}

15101void Sema::DefineImplicitMoveConstructor(SourceLocation CurrentLocation,
                                       CXXConstructorDecl *MoveConstructor) {
assert((MoveConstructor->isDefaulted() &&(static_cast<void> (0))
        MoveConstructor->isMoveConstructor() &&(static_cast<void> (0))
        !MoveConstructor->doesThisDeclarationHaveABody() &&(static_cast<void> (0))
        !MoveConstructor->isDeleted()) &&(static_cast<void> (0))
       "DefineImplicitMoveConstructor - call it for implicit move ctor")(static_cast<void> (0));
if (MoveConstructor->willHaveBody() || MoveConstructor->isInvalidDecl())
  return;

CXXRecordDecl *ClassDecl = MoveConstructor->getParent();
assert(ClassDecl && "DefineImplicitMoveConstructor - invalid constructor")(static_cast<void> (0));

SynthesizedFunctionScope Scope(*this, MoveConstructor);

// The exception specification is needed because we are defining the
// function.
ResolveExceptionSpec(CurrentLocation,
                     MoveConstructor->getType()->castAs<FunctionProtoType>());
MarkVTableUsed(CurrentLocation, ClassDecl);

// Add a context note for diagnostics produced after this point.
Scope.addContextNote(CurrentLocation);

if (SetCtorInitializers(MoveConstructor, /*AnyErrors=*/false)) {
  MoveConstructor->setInvalidDecl();
} else {
  SourceLocation Loc = MoveConstructor->getEndLoc().isValid()
                           ? MoveConstructor->getEndLoc()
                           : MoveConstructor->getLocation();
  Sema::CompoundScopeRAII CompoundScope(*this);
  MoveConstructor->setBody(ActOnCompoundStmt(
      Loc, Loc, None, /*isStmtExpr=*/ false).getAs<Stmt>());
  MoveConstructor->markUsed(Context);
}

if (ASTMutationListener *L = getASTMutationListener()) {
  L->CompletedImplicitDefinition(MoveConstructor);
}
15140}

15142bool Sema::isImplicitlyDeleted(FunctionDecl *FD) {
return FD->isDeleted() && FD->isDefaulted() && isa<CXXMethodDecl>(FD);
15144}

15146void Sema::DefineImplicitLambdaToFunctionPointerConversion(
                          SourceLocation CurrentLocation,
                          CXXConversionDecl *Conv) {
SynthesizedFunctionScope Scope(*this, Conv);
assert(!Conv->getReturnType()->isUndeducedType())(static_cast<void> (0));

QualType ConvRT = Conv->getType()->castAs<FunctionType>()->getReturnType();
CallingConv CC =
    ConvRT->getPointeeType()->castAs<FunctionType>()->getCallConv();

CXXRecordDecl *Lambda = Conv->getParent();
FunctionDecl *CallOp = Lambda->getLambdaCallOperator();
FunctionDecl *Invoker = Lambda->getLambdaStaticInvoker(CC);

if (auto *TemplateArgs = Conv->getTemplateSpecializationArgs()) {
  CallOp = InstantiateFunctionDeclaration(
      CallOp->getDescribedFunctionTemplate(), TemplateArgs, CurrentLocation);
  if (!CallOp)
    return;

  Invoker = InstantiateFunctionDeclaration(
      Invoker->getDescribedFunctionTemplate(), TemplateArgs, CurrentLocation);
  if (!Invoker)
    return;
}

if (CallOp->isInvalidDecl())
  return;

// Mark the call operator referenced (and add to pending instantiations
// if necessary).
// For both the conversion and static-invoker template specializations
// we construct their body's in this function, so no need to add them
// to the PendingInstantiations.
MarkFunctionReferenced(CurrentLocation, CallOp);

// Fill in the __invoke function with a dummy implementation. IR generation
// will fill in the actual details. Update its type in case it contained
// an 'auto'.
Invoker->markUsed(Context);
Invoker->setReferenced();
Invoker->setType(Conv->getReturnType()->getPointeeType());
Invoker->setBody(new (Context) CompoundStmt(Conv->getLocation()));

// Construct the body of the conversion function { return __invoke; }.
Expr *FunctionRef = BuildDeclRefExpr(Invoker, Invoker->getType(),
                                     VK_LValue, Conv->getLocation());
assert(FunctionRef && "Can't refer to __invoke function?")(static_cast<void> (0));
Stmt *Return = BuildReturnStmt(Conv->getLocation(), FunctionRef).get();
Conv->setBody(CompoundStmt::Create(Context, Return, Conv->getLocation(),
                                   Conv->getLocation()));
Conv->markUsed(Context);
Conv->setReferenced();

if (ASTMutationListener *L = getASTMutationListener()) {
  L->CompletedImplicitDefinition(Conv);
  L->CompletedImplicitDefinition(Invoker);
}
15204}



15208void Sema::DefineImplicitLambdaToBlockPointerConversion(
     SourceLocation CurrentLocation,
     CXXConversionDecl *Conv)
15211{
assert(!Conv->getParent()->isGenericLambda())(static_cast<void> (0));

SynthesizedFunctionScope Scope(*this, Conv);

// Copy-initialize the lambda object as needed to capture it.
Expr *This = ActOnCXXThis(CurrentLocation).get();
Expr *DerefThis =CreateBuiltinUnaryOp(CurrentLocation, UO_Deref, This).get();

ExprResult BuildBlock = BuildBlockForLambdaConversion(CurrentLocation,
                                                      Conv->getLocation(),
                                                      Conv, DerefThis);

// If we're not under ARC, make sure we still get the _Block_copy/autorelease
// behavior.  Note that only the general conversion function does this
// (since it's unusable otherwise); in the case where we inline the
// block literal, it has block literal lifetime semantics.
if (!BuildBlock.isInvalid() && !getLangOpts().ObjCAutoRefCount)
  BuildBlock = ImplicitCastExpr::Create(
      Context, BuildBlock.get()->getType(), CK_CopyAndAutoreleaseBlockObject,
      BuildBlock.get(), nullptr, VK_PRValue, FPOptionsOverride());

if (BuildBlock.isInvalid()) {
  Diag(CurrentLocation, diag::note_lambda_to_block_conv);
  Conv->setInvalidDecl();
  return;
}

// Create the return statement that returns the block from the conversion
// function.
StmtResult Return = BuildReturnStmt(Conv->getLocation(), BuildBlock.get());
if (Return.isInvalid()) {
  Diag(CurrentLocation, diag::note_lambda_to_block_conv);
  Conv->setInvalidDecl();
  return;
}

// Set the body of the conversion function.
Stmt *ReturnS = Return.get();
Conv->setBody(CompoundStmt::Create(Context, ReturnS, Conv->getLocation(),
                                   Conv->getLocation()));
Conv->markUsed(Context);

// We're done; notify the mutation listener, if any.
if (ASTMutationListener *L = getASTMutationListener()) {
  L->CompletedImplicitDefinition(Conv);
}
15258}

15260/// Determine whether the given list arguments contains exactly one
15261/// "real" (non-default) argument.
15262static bool hasOneRealArgument(MultiExprArg Args) {
switch (Args.size()) {
case 0:
  return false;

default:
  if (!Args[1]->isDefaultArgument())
    return false;

  LLVM_FALLTHROUGH[[gnu::fallthrough]];
case 1:
  return !Args[0]->isDefaultArgument();
}

return false;
15277}

15279ExprResult
15280Sema::BuildCXXConstructExpr(SourceLocation ConstructLoc, QualType DeclInitType,
                          NamedDecl *FoundDecl,
                          CXXConstructorDecl *Constructor,
                          MultiExprArg ExprArgs,
                          bool HadMultipleCandidates,
                          bool IsListInitialization,
                          bool IsStdInitListInitialization,
                          bool RequiresZeroInit,
                          unsigned ConstructKind,
                          SourceRange ParenRange) {
bool Elidable = false;

// C++0x [class.copy]p34:
//   When certain criteria are met, an implementation is allowed to
//   omit the copy/move construction of a class object, even if the
//   copy/move constructor and/or destructor for the object have
//   side effects. [...]
//     - when a temporary class object that has not been bound to a
//       reference (12.2) would be copied/moved to a class object
//       with the same cv-unqualified type, the copy/move operation
//       can be omitted by constructing the temporary object
//       directly into the target of the omitted copy/move
if (ConstructKind == CXXConstructExpr::CK_Complete && Constructor &&
    Constructor->isCopyOrMoveConstructor() && hasOneRealArgument(ExprArgs)) {
  Expr *SubExpr = ExprArgs[0];
  Elidable = SubExpr->isTemporaryObject(
      Context, cast<CXXRecordDecl>(FoundDecl->getDeclContext()));
}

return BuildCXXConstructExpr(ConstructLoc, DeclInitType,
                             FoundDecl, Constructor,
                             Elidable, ExprArgs, HadMultipleCandidates,
                             IsListInitialization,
                             IsStdInitListInitialization, RequiresZeroInit,
                             ConstructKind, ParenRange);
15315}

15317ExprResult
15318Sema::BuildCXXConstructExpr(SourceLocation ConstructLoc, QualType DeclInitType,
                          NamedDecl *FoundDecl,
                          CXXConstructorDecl *Constructor,
                          bool Elidable,
                          MultiExprArg ExprArgs,
                          bool HadMultipleCandidates,
                          bool IsListInitialization,
                          bool IsStdInitListInitialization,
                          bool RequiresZeroInit,
                          unsigned ConstructKind,
                          SourceRange ParenRange) {
if (auto *Shadow = dyn_cast<ConstructorUsingShadowDecl>(FoundDecl)) {
  Constructor = findInheritingConstructor(ConstructLoc, Constructor, Shadow);
  if (DiagnoseUseOfDecl(Constructor, ConstructLoc))
    return ExprError();
}

return BuildCXXConstructExpr(
    ConstructLoc, DeclInitType, Constructor, Elidable, ExprArgs,
    HadMultipleCandidates, IsListInitialization, IsStdInitListInitialization,
    RequiresZeroInit, ConstructKind, ParenRange);
15339}

15341/// BuildCXXConstructExpr - Creates a complete call to a constructor,
15342/// including handling of its default argument expressions.
15343ExprResult
15344Sema::BuildCXXConstructExpr(SourceLocation ConstructLoc, QualType DeclInitType,
                          CXXConstructorDecl *Constructor,
                          bool Elidable,
                          MultiExprArg ExprArgs,
                          bool HadMultipleCandidates,
                          bool IsListInitialization,
                          bool IsStdInitListInitialization,
                          bool RequiresZeroInit,
                          unsigned ConstructKind,
                          SourceRange ParenRange) {
assert(declaresSameEntity((static_cast<void> (0))
           Constructor->getParent(),(static_cast<void> (0))
           DeclInitType->getBaseElementTypeUnsafe()->getAsCXXRecordDecl()) &&(static_cast<void> (0))
       "given constructor for wrong type")(static_cast<void> (0));
MarkFunctionReferenced(ConstructLoc, Constructor);
if (getLangOpts().CUDA && !CheckCUDACall(ConstructLoc, Constructor))
  return ExprError();
if (getLangOpts().SYCLIsDevice &&
    !checkSYCLDeviceFunction(ConstructLoc, Constructor))
  return ExprError();

return CheckForImmediateInvocation(
    CXXConstructExpr::Create(
        Context, DeclInitType, ConstructLoc, Constructor, Elidable, ExprArgs,
        HadMultipleCandidates, IsListInitialization,
        IsStdInitListInitialization, RequiresZeroInit,
        static_cast<CXXConstructExpr::ConstructionKind>(ConstructKind),
        ParenRange),
    Constructor);
15373}

15375ExprResult Sema::BuildCXXDefaultInitExpr(SourceLocation Loc, FieldDecl *Field) {
assert(Field->hasInClassInitializer())(static_cast<void> (0));

// If we already have the in-class initializer nothing needs to be done.
if (Field->getInClassInitializer())
  return CXXDefaultInitExpr::Create(Context, Loc, Field, CurContext);

// If we might have already tried and failed to instantiate, don't try again.
if (Field->isInvalidDecl())
  return ExprError();

// Maybe we haven't instantiated the in-class initializer. Go check the
// pattern FieldDecl to see if it has one.
CXXRecordDecl *ParentRD = cast<CXXRecordDecl>(Field->getParent());

if (isTemplateInstantiation(ParentRD->getTemplateSpecializationKind())) {
  CXXRecordDecl *ClassPattern = ParentRD->getTemplateInstantiationPattern();
  DeclContext::lookup_result Lookup =
      ClassPattern->lookup(Field->getDeclName());

  FieldDecl *Pattern = nullptr;
  for (auto L : Lookup) {
    if (isa<FieldDecl>(L)) {
      Pattern = cast<FieldDecl>(L);
      break;
    }
  }
  assert(Pattern && "We must have set the Pattern!")(static_cast<void> (0));

  if (!Pattern->hasInClassInitializer() ||
      InstantiateInClassInitializer(Loc, Field, Pattern,
                                    getTemplateInstantiationArgs(Field))) {
    // Don't diagnose this again.
    Field->setInvalidDecl();
    return ExprError();
  }
  return CXXDefaultInitExpr::Create(Context, Loc, Field, CurContext);
}

// DR1351:
//   If the brace-or-equal-initializer of a non-static data member
//   invokes a defaulted default constructor of its class or of an
//   enclosing class in a potentially evaluated subexpression, the
//   program is ill-formed.
//
// This resolution is unworkable: the exception specification of the
// default constructor can be needed in an unevaluated context, in
// particular, in the operand of a noexcept-expression, and we can be
// unable to compute an exception specification for an enclosed class.
//
// Any attempt to resolve the exception specification of a defaulted default
// constructor before the initializer is lexically complete will ultimately
// come here at which point we can diagnose it.
RecordDecl *OutermostClass = ParentRD->getOuterLexicalRecordContext();
Diag(Loc, diag::err_default_member_initializer_not_yet_parsed)
    << OutermostClass << Field;
Diag(Field->getEndLoc(),
     diag::note_default_member_initializer_not_yet_parsed);
// Recover by marking the field invalid, unless we're in a SFINAE context.
if (!isSFINAEContext())
  Field->setInvalidDecl();
return ExprError();
15437}

15439void Sema::FinalizeVarWithDestructor(VarDecl *VD, const RecordType *Record) {
if (VD->isInvalidDecl()) return;
// If initializing the variable failed, don't also diagnose problems with
// the desctructor, they're likely related.
if (VD->getInit() && VD->getInit()->containsErrors())
  return;

CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(Record->getDecl());
if (ClassDecl->isInvalidDecl()) return;
if (ClassDecl->hasIrrelevantDestructor()) return;
if (ClassDecl->isDependentContext()) return;

if (VD->isNoDestroy(getASTContext()))
  return;

CXXDestructorDecl *Destructor = LookupDestructor(ClassDecl);

// If this is an array, we'll require the destructor during initialization, so
// we can skip over this. We still want to emit exit-time destructor warnings
// though.
if (!VD->getType()->isArrayType()) {
  MarkFunctionReferenced(VD->getLocation(), Destructor);
  CheckDestructorAccess(VD->getLocation(), Destructor,
                        PDiag(diag::err_access_dtor_var)
                            << VD->getDeclName() << VD->getType());
  DiagnoseUseOfDecl(Destructor, VD->getLocation());
}

if (Destructor->isTrivial()) return;

// If the destructor is constexpr, check whether the variable has constant
// destruction now.
if (Destructor->isConstexpr()) {
  bool HasConstantInit = false;
  if (VD->getInit() && !VD->getInit()->isValueDependent())
    HasConstantInit = VD->evaluateValue();
  SmallVector<PartialDiagnosticAt, 8> Notes;
  if (!VD->evaluateDestruction(Notes) && VD->isConstexpr() &&
      HasConstantInit) {
    Diag(VD->getLocation(),
         diag::err_constexpr_var_requires_const_destruction) << VD;
    for (unsigned I = 0, N = Notes.size(); I != N; ++I)
      Diag(Notes[I].first, Notes[I].second);
  }
}

if (!VD->hasGlobalStorage()) return;

// Emit warning for non-trivial dtor in global scope (a real global,
// class-static, function-static).
Diag(VD->getLocation(), diag::warn_exit_time_destructor);

// TODO: this should be re-enabled for static locals by !CXAAtExit
if (!VD->isStaticLocal())
  Diag(VD->getLocation(), diag::warn_global_destructor);
15494}

15496/// Given a constructor and the set of arguments provided for the
15497/// constructor, convert the arguments and add any required default arguments
15498/// to form a proper call to this constructor.
15499///
15500/// \returns true if an error occurred, false otherwise.
15501bool Sema::CompleteConstructorCall(CXXConstructorDecl *Constructor,
                                 QualType DeclInitType, MultiExprArg ArgsPtr,
                                 SourceLocation Loc,
                                 SmallVectorImpl<Expr *> &ConvertedArgs,
                                 bool AllowExplicit,
                                 bool IsListInitialization) {
// FIXME: This duplicates a lot of code from Sema::ConvertArgumentsForCall.
unsigned NumArgs = ArgsPtr.size();
Expr **Args = ArgsPtr.data();

const auto *Proto = Constructor->getType()->castAs<FunctionProtoType>();
unsigned NumParams = Proto->getNumParams();

// If too few arguments are available, we'll fill in the rest with defaults.
if (NumArgs < NumParams)
  ConvertedArgs.reserve(NumParams);
else
  ConvertedArgs.reserve(NumArgs);

VariadicCallType CallType =
  Proto->isVariadic() ? VariadicConstructor : VariadicDoesNotApply;
SmallVector<Expr *, 8> AllArgs;
bool Invalid = GatherArgumentsForCall(Loc, Constructor,
                                      Proto, 0,
                                      llvm::makeArrayRef(Args, NumArgs),
                                      AllArgs,
                                      CallType, AllowExplicit,
                                      IsListInitialization);
ConvertedArgs.append(AllArgs.begin(), AllArgs.end());

DiagnoseSentinelCalls(Constructor, Loc, AllArgs);

CheckConstructorCall(Constructor, DeclInitType,
                     llvm::makeArrayRef(AllArgs.data(), AllArgs.size()),
                     Proto, Loc);

return Invalid;
15538}

15540static inline bool
15541CheckOperatorNewDeleteDeclarationScope(Sema &SemaRef,
                                     const FunctionDecl *FnDecl) {
const DeclContext *DC = FnDecl->getDeclContext()->getRedeclContext();
if (isa<NamespaceDecl>(DC)) {
  return SemaRef.Diag(FnDecl->getLocation(),
                      diag::err_operator_new_delete_declared_in_namespace)
    << FnDecl->getDeclName();
}

if (isa<TranslationUnitDecl>(DC) &&
    FnDecl->getStorageClass() == SC_Static) {
  return SemaRef.Diag(FnDecl->getLocation(),
                      diag::err_operator_new_delete_declared_static)
    << FnDecl->getDeclName();
}

return false;
15558}

15560static CanQualType RemoveAddressSpaceFromPtr(Sema &SemaRef,
                                           const PointerType *PtrTy) {
auto &Ctx = SemaRef.Context;
Qualifiers PtrQuals = PtrTy->getPointeeType().getQualifiers();
PtrQuals.removeAddressSpace();
return Ctx.getPointerType(Ctx.getCanonicalType(Ctx.getQualifiedType(
    PtrTy->getPointeeType().getUnqualifiedType(), PtrQuals)));
15567}

15569static inline bool
15570CheckOperatorNewDeleteTypes(Sema &SemaRef, const FunctionDecl *FnDecl,
                          CanQualType ExpectedResultType,
                          CanQualType ExpectedFirstParamType,
                          unsigned DependentParamTypeDiag,
                          unsigned InvalidParamTypeDiag) {
QualType ResultType =
    FnDecl->getType()->castAs<FunctionType>()->getReturnType();

if (SemaRef.getLangOpts().OpenCLCPlusPlus) {
  // The operator is valid on any address space for OpenCL.
  // Drop address space from actual and expected result types.
  if (const auto *PtrTy = ResultType->getAs<PointerType>())
    ResultType = RemoveAddressSpaceFromPtr(SemaRef, PtrTy);

  if (auto ExpectedPtrTy = ExpectedResultType->getAs<PointerType>())
    ExpectedResultType = RemoveAddressSpaceFromPtr(SemaRef, ExpectedPtrTy);
}

// Check that the result type is what we expect.
if (SemaRef.Context.getCanonicalType(ResultType) != ExpectedResultType) {
  // Reject even if the type is dependent; an operator delete function is
  // required to have a non-dependent result type.
  return SemaRef.Diag(
             FnDecl->getLocation(),
             ResultType->isDependentType()
                 ? diag::err_operator_new_delete_dependent_result_type
                 : diag::err_operator_new_delete_invalid_result_type)
         << FnDecl->getDeclName() << ExpectedResultType;
}

// A function template must have at least 2 parameters.
if (FnDecl->getDescribedFunctionTemplate() && FnDecl->getNumParams() < 2)
  return SemaRef.Diag(FnDecl->getLocation(),
                    diag::err_operator_new_delete_template_too_few_parameters)
      << FnDecl->getDeclName();

// The function decl must have at least 1 parameter.
if (FnDecl->getNumParams() == 0)
  return SemaRef.Diag(FnDecl->getLocation(),
                      diag::err_operator_new_delete_too_few_parameters)
    << FnDecl->getDeclName();

QualType FirstParamType = FnDecl->getParamDecl(0)->getType();
if (SemaRef.getLangOpts().OpenCLCPlusPlus) {
  // The operator is valid on any address space for OpenCL.
  // Drop address space from actual and expected first parameter types.
  if (const auto *PtrTy =
          FnDecl->getParamDecl(0)->getType()->getAs<PointerType>())
    FirstParamType = RemoveAddressSpaceFromPtr(SemaRef, PtrTy);

  if (auto ExpectedPtrTy = ExpectedFirstParamType->getAs<PointerType>())
    ExpectedFirstParamType =
        RemoveAddressSpaceFromPtr(SemaRef, ExpectedPtrTy);
}

// Check that the first parameter type is what we expect.
if (SemaRef.Context.getCanonicalType(FirstParamType).getUnqualifiedType() !=
    ExpectedFirstParamType) {
  // The first parameter type is not allowed to be dependent. As a tentative
  // DR resolution, we allow a dependent parameter type if it is the right
  // type anyway, to allow destroying operator delete in class templates.
  return SemaRef.Diag(FnDecl->getLocation(), FirstParamType->isDependentType()
                                                 ? DependentParamTypeDiag
                                                 : InvalidParamTypeDiag)
         << FnDecl->getDeclName() << ExpectedFirstParamType;
}

return false;
15638}

15640static bool
15641CheckOperatorNewDeclaration(Sema &SemaRef, const FunctionDecl *FnDecl) {
// C++ [basic.stc.dynamic.allocation]p1:
//   A program is ill-formed if an allocation function is declared in a
//   namespace scope other than global scope or declared static in global
//   scope.
if (CheckOperatorNewDeleteDeclarationScope(SemaRef, FnDecl))
  return true;

CanQualType SizeTy =
  SemaRef.Context.getCanonicalType(SemaRef.Context.getSizeType());

// C++ [basic.stc.dynamic.allocation]p1:
//  The return type shall be void*. The first parameter shall have type
//  std::size_t.
if (CheckOperatorNewDeleteTypes(SemaRef, FnDecl, SemaRef.Context.VoidPtrTy,
                                SizeTy,
                                diag::err_operator_new_dependent_param_type,
                                diag::err_operator_new_param_type))
  return true;

// C++ [basic.stc.dynamic.allocation]p1:
//  The first parameter shall not have an associated default argument.
if (FnDecl->getParamDecl(0)->hasDefaultArg())
  return SemaRef.Diag(FnDecl->getLocation(),
                      diag::err_operator_new_default_arg)
    << FnDecl->getDeclName() << FnDecl->getParamDecl(0)->getDefaultArgRange();

return false;
15669}

15671static bool
15672CheckOperatorDeleteDeclaration(Sema &SemaRef, FunctionDecl *FnDecl) {
// C++ [basic.stc.dynamic.deallocation]p1:
//   A program is ill-formed if deallocation functions are declared in a
//   namespace scope other than global scope or declared static in global
//   scope.
if (CheckOperatorNewDeleteDeclarationScope(SemaRef, FnDecl))
  return true;

auto *MD = dyn_cast<CXXMethodDecl>(FnDecl);

// C++ P0722:
//   Within a class C, the first parameter of a destroying operator delete
//   shall be of type C *. The first parameter of any other deallocation
//   function shall be of type void *.
CanQualType ExpectedFirstParamType =
    MD && MD->isDestroyingOperatorDelete()
        ? SemaRef.Context.getCanonicalType(SemaRef.Context.getPointerType(
              SemaRef.Context.getRecordType(MD->getParent())))
        : SemaRef.Context.VoidPtrTy;

// C++ [basic.stc.dynamic.deallocation]p2:
//   Each deallocation function shall return void
if (CheckOperatorNewDeleteTypes(
        SemaRef, FnDecl, SemaRef.Context.VoidTy, ExpectedFirstParamType,
        diag::err_operator_delete_dependent_param_type,
        diag::err_operator_delete_param_type))
  return true;

// C++ P0722:
//   A destroying operator delete shall be a usual deallocation function.
if (MD && !MD->getParent()->isDependentContext() &&
    MD->isDestroyingOperatorDelete() &&
    !SemaRef.isUsualDeallocationFunction(MD)) {
  SemaRef.Diag(MD->getLocation(),
               diag::err_destroying_operator_delete_not_usual);
  return true;
}

return false;
15711}

15713/// CheckOverloadedOperatorDeclaration - Check whether the declaration
15714/// of this overloaded operator is well-formed. If so, returns false;
15715/// otherwise, emits appropriate diagnostics and returns true.
15716bool Sema::CheckOverloadedOperatorDeclaration(FunctionDecl *FnDecl) {
assert(FnDecl && FnDecl->isOverloadedOperator() &&(static_cast<void> (0))
       "Expected an overloaded operator declaration")(static_cast<void> (0));

OverloadedOperatorKind Op = FnDecl->getOverloadedOperator();

// C++ [over.oper]p5:
//   The allocation and deallocation functions, operator new,
//   operator new[], operator delete and operator delete[], are
//   described completely in 3.7.3. The attributes and restrictions
//   found in the rest of this subclause do not apply to them unless
//   explicitly stated in 3.7.3.
if (Op == OO_Delete || Op == OO_Array_Delete)
  return CheckOperatorDeleteDeclaration(*this, FnDecl);

if (Op == OO_New || Op == OO_Array_New)
  return CheckOperatorNewDeclaration(*this, FnDecl);

// C++ [over.oper]p6:
//   An operator function shall either be a non-static member
//   function or be a non-member function and have at least one
//   parameter whose type is a class, a reference to a class, an
//   enumeration, or a reference to an enumeration.
if (CXXMethodDecl *MethodDecl = dyn_cast<CXXMethodDecl>(FnDecl)) {
  if (MethodDecl->isStatic())
    return Diag(FnDecl->getLocation(),
                diag::err_operator_overload_static) << FnDecl->getDeclName();
} else {
  bool ClassOrEnumParam = false;
  for (auto Param : FnDecl->parameters()) {
    QualType ParamType = Param->getType().getNonReferenceType();
    if (ParamType->isDependentType() || ParamType->isRecordType() ||
        ParamType->isEnumeralType()) {
      ClassOrEnumParam = true;
      break;
    }
  }

  if (!ClassOrEnumParam)
    return Diag(FnDecl->getLocation(),
                diag::err_operator_overload_needs_class_or_enum)
      << FnDecl->getDeclName();
}

// C++ [over.oper]p8:
//   An operator function cannot have default arguments (8.3.6),
//   except where explicitly stated below.
//
// Only the function-call operator allows default arguments
// (C++ [over.call]p1).
if (Op != OO_Call) {
  for (auto Param : FnDecl->parameters()) {
    if (Param->hasDefaultArg())
      return Diag(Param->getLocation(),
                  diag::err_operator_overload_default_arg)
        << FnDecl->getDeclName() << Param->getDefaultArgRange();
  }
}

static const bool OperatorUses[NUM_OVERLOADED_OPERATORS][3] = {
  { false, false, false }
15777#define OVERLOADED_OPERATOR(Name,Spelling,Token,Unary,Binary,MemberOnly) \
  , { Unary, Binary, MemberOnly }
15779#include "clang/Basic/OperatorKinds.def"
};

bool CanBeUnaryOperator = OperatorUses[Op][0];
bool CanBeBinaryOperator = OperatorUses[Op][1];
bool MustBeMemberOperator = OperatorUses[Op][2];

// C++ [over.oper]p8:
//   [...] Operator functions cannot have more or fewer parameters
//   than the number required for the corresponding operator, as
//   described in the rest of this subclause.
unsigned NumParams = FnDecl->getNumParams()
                   + (isa<CXXMethodDecl>(FnDecl)? 1 : 0);
if (Op != OO_Call &&
    ((NumParams == 1 && !CanBeUnaryOperator) ||
     (NumParams == 2 && !CanBeBinaryOperator) ||
     (NumParams < 1) || (NumParams > 2))) {
  // We have the wrong number of parameters.
  unsigned ErrorKind;
  if (CanBeUnaryOperator && CanBeBinaryOperator) {
    ErrorKind = 2;  // 2 -> unary or binary.
  } else if (CanBeUnaryOperator) {
    ErrorKind = 0;  // 0 -> unary
  } else {
    assert(CanBeBinaryOperator &&(static_cast<void> (0))
           "All non-call overloaded operators are unary or binary!")(static_cast<void> (0));
    ErrorKind = 1;  // 1 -> binary
  }

  return Diag(FnDecl->getLocation(), diag::err_operator_overload_must_be)
    << FnDecl->getDeclName() << NumParams << ErrorKind;
}

// Overloaded operators other than operator() cannot be variadic.
if (Op != OO_Call &&
    FnDecl->getType()->castAs<FunctionProtoType>()->isVariadic()) {
  return Diag(FnDecl->getLocation(), diag::err_operator_overload_variadic)
    << FnDecl->getDeclName();
}

// Some operators must be non-static member functions.
if (MustBeMemberOperator && !isa<CXXMethodDecl>(FnDecl)) {
  return Diag(FnDecl->getLocation(),
              diag::err_operator_overload_must_be_member)
    << FnDecl->getDeclName();
}

// C++ [over.inc]p1:
//   The user-defined function called operator++ implements the
//   prefix and postfix ++ operator. If this function is a member
//   function with no parameters, or a non-member function with one
//   parameter of class or enumeration type, it defines the prefix
//   increment operator ++ for objects of that type. If the function
//   is a member function with one parameter (which shall be of type
//   int) or a non-member function with two parameters (the second
//   of which shall be of type int), it defines the postfix
//   increment operator ++ for objects of that type.
if ((Op == OO_PlusPlus || Op == OO_MinusMinus) && NumParams == 2) {
  ParmVarDecl *LastParam = FnDecl->getParamDecl(FnDecl->getNumParams() - 1);
  QualType ParamType = LastParam->getType();

  if (!ParamType->isSpecificBuiltinType(BuiltinType::Int) &&
      !ParamType->isDependentType())
    return Diag(LastParam->getLocation(),
                diag::err_operator_overload_post_incdec_must_be_int)
      << LastParam->getType() << (Op == OO_MinusMinus);
}

return false;
15848}

15850static bool
15851checkLiteralOperatorTemplateParameterList(Sema &SemaRef,
                                        FunctionTemplateDecl *TpDecl) {
TemplateParameterList *TemplateParams = TpDecl->getTemplateParameters();

// Must have one or two template parameters.
if (TemplateParams->size() == 1) {
  NonTypeTemplateParmDecl *PmDecl =
      dyn_cast<NonTypeTemplateParmDecl>(TemplateParams->getParam(0));

  // The template parameter must be a char parameter pack.
  if (PmDecl && PmDecl->isTemplateParameterPack() &&
      SemaRef.Context.hasSameType(PmDecl->getType(), SemaRef.Context.CharTy))
    return false;

  // C++20 [over.literal]p5:
  //   A string literal operator template is a literal operator template
  //   whose template-parameter-list comprises a single non-type
  //   template-parameter of class type.
  //
  // As a DR resolution, we also allow placeholders for deduced class
  // template specializations.
  if (SemaRef.getLangOpts().CPlusPlus20 &&
      !PmDecl->isTemplateParameterPack() &&
      (PmDecl->getType()->isRecordType() ||
       PmDecl->getType()->getAs<DeducedTemplateSpecializationType>()))
    return false;
} else if (TemplateParams->size() == 2) {
  TemplateTypeParmDecl *PmType =
      dyn_cast<TemplateTypeParmDecl>(TemplateParams->getParam(0));
  NonTypeTemplateParmDecl *PmArgs =
      dyn_cast<NonTypeTemplateParmDecl>(TemplateParams->getParam(1));

  // The second template parameter must be a parameter pack with the
  // first template parameter as its type.
  if (PmType && PmArgs && !PmType->isTemplateParameterPack() &&
      PmArgs->isTemplateParameterPack()) {
    const TemplateTypeParmType *TArgs =
        PmArgs->getType()->getAs<TemplateTypeParmType>();
    if (TArgs && TArgs->getDepth() == PmType->getDepth() &&
        TArgs->getIndex() == PmType->getIndex()) {
      if (!SemaRef.inTemplateInstantiation())
        SemaRef.Diag(TpDecl->getLocation(),
                     diag::ext_string_literal_operator_template);
      return false;
    }
  }
}

SemaRef.Diag(TpDecl->getTemplateParameters()->getSourceRange().getBegin(),
             diag::err_literal_operator_template)
    << TpDecl->getTemplateParameters()->getSourceRange();
return true;
15903}

15905/// CheckLiteralOperatorDeclaration - Check whether the declaration
15906/// of this literal operator function is well-formed. If so, returns
15907/// false; otherwise, emits appropriate diagnostics and returns true.
15908bool Sema::CheckLiteralOperatorDeclaration(FunctionDecl *FnDecl) {
if (isa<CXXMethodDecl>(FnDecl)) {
  Diag(FnDecl->getLocation(), diag::err_literal_operator_outside_namespace)
    << FnDecl->getDeclName();
  return true;
}

if (FnDecl->isExternC()) {
  Diag(FnDecl->getLocation(), diag::err_literal_operator_extern_c);
  if (const LinkageSpecDecl *LSD =
          FnDecl->getDeclContext()->getExternCContext())
    Diag(LSD->getExternLoc(), diag::note_extern_c_begins_here);
  return true;
}

// This might be the definition of a literal operator template.
FunctionTemplateDecl *TpDecl = FnDecl->getDescribedFunctionTemplate();

// This might be a specialization of a literal operator template.
if (!TpDecl)
  TpDecl = FnDecl->getPrimaryTemplate();

// template <char...> type operator "" name() and
// template <class T, T...> type operator "" name() are the only valid
// template signatures, and the only valid signatures with no parameters.
//
// C++20 also allows template <SomeClass T> type operator "" name().
if (TpDecl) {
  if (FnDecl->param_size() != 0) {
    Diag(FnDecl->getLocation(),
         diag::err_literal_operator_template_with_params);
    return true;
  }

  if (checkLiteralOperatorTemplateParameterList(*this, TpDecl))
    return true;

} else if (FnDecl->param_size() == 1) {
  const ParmVarDecl *Param = FnDecl->getParamDecl(0);

  QualType ParamType = Param->getType().getUnqualifiedType();

  // Only unsigned long long int, long double, any character type, and const
  // char * are allowed as the only parameters.
  if (ParamType->isSpecificBuiltinType(BuiltinType::ULongLong) ||
      ParamType->isSpecificBuiltinType(BuiltinType::LongDouble) ||
      Context.hasSameType(ParamType, Context.CharTy) ||
      Context.hasSameType(ParamType, Context.WideCharTy) ||
      Context.hasSameType(ParamType, Context.Char8Ty) ||
      Context.hasSameType(ParamType, Context.Char16Ty) ||
      Context.hasSameType(ParamType, Context.Char32Ty)) {
  } else if (const PointerType *Ptr = ParamType->getAs<PointerType>()) {
    QualType InnerType = Ptr->getPointeeType();

    // Pointer parameter must be a const char *.
    if (!(Context.hasSameType(InnerType.getUnqualifiedType(),
                              Context.CharTy) &&
          InnerType.isConstQualified() && !InnerType.isVolatileQualified())) {
      Diag(Param->getSourceRange().getBegin(),
           diag::err_literal_operator_param)
          << ParamType << "'const char *'" << Param->getSourceRange();
      return true;
    }

  } else if (ParamType->isRealFloatingType()) {
    Diag(Param->getSourceRange().getBegin(), diag::err_literal_operator_param)
        << ParamType << Context.LongDoubleTy << Param->getSourceRange();
    return true;

  } else if (ParamType->isIntegerType()) {
    Diag(Param->getSourceRange().getBegin(), diag::err_literal_operator_param)
        << ParamType << Context.UnsignedLongLongTy << Param->getSourceRange();
    return true;

  } else {
    Diag(Param->getSourceRange().getBegin(),
         diag::err_literal_operator_invalid_param)
        << ParamType << Param->getSourceRange();
    return true;
  }

} else if (FnDecl->param_size() == 2) {
  FunctionDecl::param_iterator Param = FnDecl->param_begin();

  // First, verify that the first parameter is correct.

  QualType FirstParamType = (*Param)->getType().getUnqualifiedType();

  // Two parameter function must have a pointer to const as a
  // first parameter; let's strip those qualifiers.
  const PointerType *PT = FirstParamType->getAs<PointerType>();

  if (!PT) {
    Diag((*Param)->getSourceRange().getBegin(),
         diag::err_literal_operator_param)
        << FirstParamType << "'const char *'" << (*Param)->getSourceRange();
    return true;
  }

  QualType PointeeType = PT->getPointeeType();
  // First parameter must be const
  if (!PointeeType.isConstQualified() || PointeeType.isVolatileQualified()) {
    Diag((*Param)->getSourceRange().getBegin(),
         diag::err_literal_operator_param)
        << FirstParamType << "'const char *'" << (*Param)->getSourceRange();
    return true;
  }

  QualType InnerType = PointeeType.getUnqualifiedType();
  // Only const char *, const wchar_t*, const char8_t*, const char16_t*, and
  // const char32_t* are allowed as the first parameter to a two-parameter
  // function
  if (!(Context.hasSameType(InnerType, Context.CharTy) ||
        Context.hasSameType(InnerType, Context.WideCharTy) ||
        Context.hasSameType(InnerType, Context.Char8Ty) ||
        Context.hasSameType(InnerType, Context.Char16Ty) ||
        Context.hasSameType(InnerType, Context.Char32Ty))) {
    Diag((*Param)->getSourceRange().getBegin(),
         diag::err_literal_operator_param)
        << FirstParamType << "'const char *'" << (*Param)->getSourceRange();
    return true;
  }

  // Move on to the second and final parameter.
  ++Param;

  // The second parameter must be a std::size_t.
  QualType SecondParamType = (*Param)->getType().getUnqualifiedType();
  if (!Context.hasSameType(SecondParamType, Context.getSizeType())) {
    Diag((*Param)->getSourceRange().getBegin(),
         diag::err_literal_operator_param)
        << SecondParamType << Context.getSizeType()
        << (*Param)->getSourceRange();
    return true;
  }
} else {
  Diag(FnDecl->getLocation(), diag::err_literal_operator_bad_param_count);
  return true;
}

// Parameters are good.

// A parameter-declaration-clause containing a default argument is not
// equivalent to any of the permitted forms.
for (auto Param : FnDecl->parameters()) {
  if (Param->hasDefaultArg()) {
    Diag(Param->getDefaultArgRange().getBegin(),
         diag::err_literal_operator_default_argument)
      << Param->getDefaultArgRange();
    break;
  }
}

StringRef LiteralName
  = FnDecl->getDeclName().getCXXLiteralIdentifier()->getName();
if (LiteralName[0] != '_' &&
    !getSourceManager().isInSystemHeader(FnDecl->getLocation())) {
  // C++11 [usrlit.suffix]p1:
  //   Literal suffix identifiers that do not start with an underscore
  //   are reserved for future standardization.
  Diag(FnDecl->getLocation(), diag::warn_user_literal_reserved)
    << StringLiteralParser::isValidUDSuffix(getLangOpts(), LiteralName);
}

return false;
16073}

16075/// ActOnStartLinkageSpecification - Parsed the beginning of a C++
16076/// linkage specification, including the language and (if present)
16077/// the '{'. ExternLoc is the location of the 'extern', Lang is the
16078/// language string literal. LBraceLoc, if valid, provides the location of
16079/// the '{' brace. Otherwise, this linkage specification does not
16080/// have any braces.
16081Decl *Sema::ActOnStartLinkageSpecification(Scope *S, SourceLocation ExternLoc,
                                         Expr *LangStr,
                                         SourceLocation LBraceLoc) {
StringLiteral *Lit = cast<StringLiteral>(LangStr);
if (!Lit->isAscii()) {
  Diag(LangStr->getExprLoc(), diag::err_language_linkage_spec_not_ascii)
    << LangStr->getSourceRange();
  return nullptr;
}

StringRef Lang = Lit->getString();
LinkageSpecDecl::LanguageIDs Language;
if (Lang == "C")
  Language = LinkageSpecDecl::lang_c;
else if (Lang == "C++")
  Language = LinkageSpecDecl::lang_cxx;
else {
  Diag(LangStr->getExprLoc(), diag::err_language_linkage_spec_unknown)
    << LangStr->getSourceRange();
  return nullptr;
}

// FIXME: Add all the various semantics of linkage specifications

LinkageSpecDecl *D = LinkageSpecDecl::Create(Context, CurContext, ExternLoc,
                                             LangStr->getExprLoc(), Language,
                                             LBraceLoc.isValid());
CurContext->addDecl(D);
PushDeclContext(S, D);
return D;
16111}

16113/// ActOnFinishLinkageSpecification - Complete the definition of
16114/// the C++ linkage specification LinkageSpec. If RBraceLoc is
16115/// valid, it's the position of the closing '}' brace in a linkage
16116/// specification that uses braces.
16117Decl *Sema::ActOnFinishLinkageSpecification(Scope *S,
                                          Decl *LinkageSpec,
                                          SourceLocation RBraceLoc) {
if (RBraceLoc.isValid()) {
  LinkageSpecDecl* LSDecl = cast<LinkageSpecDecl>(LinkageSpec);
  LSDecl->setRBraceLoc(RBraceLoc);
}
PopDeclContext();
return LinkageSpec;
16126}

16128Decl *Sema::ActOnEmptyDeclaration(Scope *S,
                                const ParsedAttributesView &AttrList,
                                SourceLocation SemiLoc) {
Decl *ED = EmptyDecl::Create(Context, CurContext, SemiLoc);
// Attribute declarations appertain to empty declaration so we handle
// them here.
ProcessDeclAttributeList(S, ED, AttrList);

CurContext->addDecl(ED);
return ED;
16138}

16140/// Perform semantic analysis for the variable declaration that
16141/// occurs within a C++ catch clause, returning the newly-created
16142/// variable.
16143VarDecl *Sema::BuildExceptionDeclaration(Scope *S,
                                       TypeSourceInfo *TInfo,
                                       SourceLocation StartLoc,
                                       SourceLocation Loc,
                                       IdentifierInfo *Name) {
bool Invalid = false;
QualType ExDeclType = TInfo->getType();

// Arrays and functions decay.
if (ExDeclType->isArrayType())
  ExDeclType = Context.getArrayDecayedType(ExDeclType);
else if (ExDeclType->isFunctionType())
  ExDeclType = Context.getPointerType(ExDeclType);

// C++ 15.3p1: The exception-declaration shall not denote an incomplete type.
// The exception-declaration shall not denote a pointer or reference to an
// incomplete type, other than [cv] void*.
// N2844 forbids rvalue references.
if (!ExDeclType->isDependentType() && ExDeclType->isRValueReferenceType()) {
  Diag(Loc, diag::err_catch_rvalue_ref);
  Invalid = true;
}

if (ExDeclType->isVariablyModifiedType()) {
  Diag(Loc, diag::err_catch_variably_modified) << ExDeclType;
  Invalid = true;
}

QualType BaseType = ExDeclType;
int Mode = 0; // 0 for direct type, 1 for pointer, 2 for reference
unsigned DK = diag::err_catch_incomplete;
if (const PointerType *Ptr = BaseType->getAs<PointerType>()) {
  BaseType = Ptr->getPointeeType();
  Mode = 1;
  DK = diag::err_catch_incomplete_ptr;
} else if (const ReferenceType *Ref = BaseType->getAs<ReferenceType>()) {
  // For the purpose of error recovery, we treat rvalue refs like lvalue refs.
  BaseType = Ref->getPointeeType();
  Mode = 2;
  DK = diag::err_catch_incomplete_ref;
}
if (!Invalid && (Mode == 0 || !BaseType->isVoidType()) &&
    !BaseType->isDependentType() && RequireCompleteType(Loc, BaseType, DK))
  Invalid = true;

if (!Invalid && Mode != 1 && BaseType->isSizelessType()) {
  Diag(Loc, diag::err_catch_sizeless) << (Mode == 2 ? 1 : 0) << BaseType;
  Invalid = true;
}

if (!Invalid && !ExDeclType->isDependentType() &&
    RequireNonAbstractType(Loc, ExDeclType,
                           diag::err_abstract_type_in_decl,
                           AbstractVariableType))
  Invalid = true;

// Only the non-fragile NeXT runtime currently supports C++ catches
// of ObjC types, and no runtime supports catching ObjC types by value.
if (!Invalid && getLangOpts().ObjC) {
  QualType T = ExDeclType;
  if (const ReferenceType *RT = T->getAs<ReferenceType>())
    T = RT->getPointeeType();

  if (T->isObjCObjectType()) {
    Diag(Loc, diag::err_objc_object_catch);
    Invalid = true;
  } else if (T->isObjCObjectPointerType()) {
    // FIXME: should this be a test for macosx-fragile specifically?
    if (getLangOpts().ObjCRuntime.isFragile())
      Diag(Loc, diag::warn_objc_pointer_cxx_catch_fragile);
  }
}

VarDecl *ExDecl = VarDecl::Create(Context, CurContext, StartLoc, Loc, Name,
                                  ExDeclType, TInfo, SC_None);
ExDecl->setExceptionVariable(true);

// In ARC, infer 'retaining' for variables of retainable type.
if (getLangOpts().ObjCAutoRefCount && inferObjCARCLifetime(ExDecl))
  Invalid = true;

if (!Invalid && !ExDeclType->isDependentType()) {
  if (const RecordType *recordType = ExDeclType->getAs<RecordType>()) {
    // Insulate this from anything else we might currently be parsing.
    EnterExpressionEvaluationContext scope(
        *this, ExpressionEvaluationContext::PotentiallyEvaluated);

    // C++ [except.handle]p16:
    //   The object declared in an exception-declaration or, if the
    //   exception-declaration does not specify a name, a temporary (12.2) is
    //   copy-initialized (8.5) from the exception object. [...]
    //   The object is destroyed when the handler exits, after the destruction
    //   of any automatic objects initialized within the handler.
    //
    // We just pretend to initialize the object with itself, then make sure
    // it can be destroyed later.
    QualType initType = Context.getExceptionObjectType(ExDeclType);

    InitializedEntity entity =
      InitializedEntity::InitializeVariable(ExDecl);
    InitializationKind initKind =
      InitializationKind::CreateCopy(Loc, SourceLocation());

    Expr *opaqueValue =
      new (Context) OpaqueValueExpr(Loc, initType, VK_LValue, OK_Ordinary);
    InitializationSequence sequence(*this, entity, initKind, opaqueValue);
    ExprResult result = sequence.Perform(*this, entity, initKind, opaqueValue);
    if (result.isInvalid())
      Invalid = true;
    else {
      // If the constructor used was non-trivial, set this as the
      // "initializer".
      CXXConstructExpr *construct = result.getAs<CXXConstructExpr>();
      if (!construct->getConstructor()->isTrivial()) {
        Expr *init = MaybeCreateExprWithCleanups(construct);
        ExDecl->setInit(init);
      }

      // And make sure it's destructable.
      FinalizeVarWithDestructor(ExDecl, recordType);
    }
  }
}

if (Invalid)
  ExDecl->setInvalidDecl();

return ExDecl;
16271}

16273/// ActOnExceptionDeclarator - Parsed the exception-declarator in a C++ catch
16274/// handler.
16275Decl *Sema::ActOnExceptionDeclarator(Scope *S, Declarator &D) {
TypeSourceInfo *TInfo = GetTypeForDeclarator(D, S);
bool Invalid = D.isInvalidType();

// Check for unexpanded parameter packs.
if (DiagnoseUnexpandedParameterPack(D.getIdentifierLoc(), TInfo,
                                    UPPC_ExceptionType)) {
  TInfo = Context.getTrivialTypeSourceInfo(Context.IntTy,
                                           D.getIdentifierLoc());
  Invalid = true;
}

IdentifierInfo *II = D.getIdentifier();
if (NamedDecl *PrevDecl = LookupSingleName(S, II, D.getIdentifierLoc(),
                                           LookupOrdinaryName,
                                           ForVisibleRedeclaration)) {
  // The scope should be freshly made just for us. There is just no way
  // it contains any previous declaration, except for function parameters in
  // a function-try-block's catch statement.
  assert(!S->isDeclScope(PrevDecl))(static_cast<void> (0));
  if (isDeclInScope(PrevDecl, CurContext, S)) {
    Diag(D.getIdentifierLoc(), diag::err_redefinition)
      << D.getIdentifier();
    Diag(PrevDecl->getLocation(), diag::note_previous_definition);
    Invalid = true;
  } else if (PrevDecl->isTemplateParameter())
    // Maybe we will complain about the shadowed template parameter.
    DiagnoseTemplateParameterShadow(D.getIdentifierLoc(), PrevDecl);
}

if (D.getCXXScopeSpec().isSet() && !Invalid) {
  Diag(D.getIdentifierLoc(), diag::err_qualified_catch_declarator)
    << D.getCXXScopeSpec().getRange();
  Invalid = true;
}

VarDecl *ExDecl = BuildExceptionDeclaration(
    S, TInfo, D.getBeginLoc(), D.getIdentifierLoc(), D.getIdentifier());
if (Invalid)
  ExDecl->setInvalidDecl();

// Add the exception declaration into this scope.
if (II)
  PushOnScopeChains(ExDecl, S);
else
  CurContext->addDecl(ExDecl);

ProcessDeclAttributes(S, ExDecl, D);
return ExDecl;
16324}

16326Decl *Sema::ActOnStaticAssertDeclaration(SourceLocation StaticAssertLoc,
                                       Expr *AssertExpr,
                                       Expr *AssertMessageExpr,
                                       SourceLocation RParenLoc) {
StringLiteral *AssertMessage =
    AssertMessageExpr ? cast<StringLiteral>(AssertMessageExpr) : nullptr;

if (DiagnoseUnexpandedParameterPack(AssertExpr, UPPC_StaticAssertExpression))
  return nullptr;

return BuildStaticAssertDeclaration(StaticAssertLoc, AssertExpr,
                                    AssertMessage, RParenLoc, false);
16338}

16340Decl *Sema::BuildStaticAssertDeclaration(SourceLocation StaticAssertLoc,
                                       Expr *AssertExpr,
                                       StringLiteral *AssertMessage,
                                       SourceLocation RParenLoc,
                                       bool Failed) {
assert(AssertExpr != nullptr && "Expected non-null condition")(static_cast<void> (0));
if (!AssertExpr->isTypeDependent() && !AssertExpr->isValueDependent() &&
    !Failed) {
  // In a static_assert-declaration, the constant-expression shall be a
  // constant expression that can be contextually converted to bool.
  ExprResult Converted = PerformContextuallyConvertToBool(AssertExpr);
  if (Converted.isInvalid())
    Failed = true;

  ExprResult FullAssertExpr =
      ActOnFinishFullExpr(Converted.get(), StaticAssertLoc,
                          /*DiscardedValue*/ false,
                          /*IsConstexpr*/ true);
  if (FullAssertExpr.isInvalid())
    Failed = true;
  else
    AssertExpr = FullAssertExpr.get();

  llvm::APSInt Cond;
  if (!Failed && VerifyIntegerConstantExpression(
                     AssertExpr, &Cond,
                     diag::err_static_assert_expression_is_not_constant)
                     .isInvalid())
    Failed = true;

  if (!Failed && !Cond) {
    SmallString<256> MsgBuffer;
    llvm::raw_svector_ostream Msg(MsgBuffer);
    if (AssertMessage)
      AssertMessage->printPretty(Msg, nullptr, getPrintingPolicy());

    Expr *InnerCond = nullptr;
    std::string InnerCondDescription;
    std::tie(InnerCond, InnerCondDescription) =
      findFailedBooleanCondition(Converted.get());
    if (InnerCond && isa<ConceptSpecializationExpr>(InnerCond)) {
      // Drill down into concept specialization expressions to see why they
      // weren't satisfied.
      Diag(StaticAssertLoc, diag::err_static_assert_failed)
        << !AssertMessage << Msg.str() << AssertExpr->getSourceRange();
      ConstraintSatisfaction Satisfaction;
      if (!CheckConstraintSatisfaction(InnerCond, Satisfaction))
        DiagnoseUnsatisfiedConstraint(Satisfaction);
    } else if (InnerCond && !isa<CXXBoolLiteralExpr>(InnerCond)
                         && !isa<IntegerLiteral>(InnerCond)) {
      Diag(StaticAssertLoc, diag::err_static_assert_requirement_failed)
        << InnerCondDescription << !AssertMessage
        << Msg.str() << InnerCond->getSourceRange();
    } else {
      Diag(StaticAssertLoc, diag::err_static_assert_failed)
        << !AssertMessage << Msg.str() << AssertExpr->getSourceRange();
    }
    Failed = true;
  }
} else {
  ExprResult FullAssertExpr = ActOnFinishFullExpr(AssertExpr, StaticAssertLoc,
                                                  /*DiscardedValue*/false,
                                                  /*IsConstexpr*/true);
  if (FullAssertExpr.isInvalid())
    Failed = true;
  else
    AssertExpr = FullAssertExpr.get();
}

Decl *Decl = StaticAssertDecl::Create(Context, CurContext, StaticAssertLoc,
                                      AssertExpr, AssertMessage, RParenLoc,
                                      Failed);

CurContext->addDecl(Decl);
return Decl;
16415}

16417/// Perform semantic analysis of the given friend type declaration.
16418///
16419/// \returns A friend declaration that.
16420FriendDecl *Sema::CheckFriendTypeDecl(SourceLocation LocStart,
                                    SourceLocation FriendLoc,
                                    TypeSourceInfo *TSInfo) {
assert(TSInfo && "NULL TypeSourceInfo for friend type declaration")(static_cast<void> (0));

QualType T = TSInfo->getType();
SourceRange TypeRange = TSInfo->getTypeLoc().getLocalSourceRange();

// C++03 [class.friend]p2:
//   An elaborated-type-specifier shall be used in a friend declaration
//   for a class.*
//
//   * The class-key of the elaborated-type-specifier is required.
if (!CodeSynthesisContexts.empty()) {
  // Do not complain about the form of friend template types during any kind
  // of code synthesis. For template instantiation, we will have complained
  // when the template was defined.
} else {
  if (!T->isElaboratedTypeSpecifier()) {
    // If we evaluated the type to a record type, suggest putting
    // a tag in front.
    if (const RecordType *RT = T->getAs<RecordType>()) {
      RecordDecl *RD = RT->getDecl();

      SmallString<16> InsertionText(" ");
      InsertionText += RD->getKindName();

      Diag(TypeRange.getBegin(),
           getLangOpts().CPlusPlus11 ?
             diag::warn_cxx98_compat_unelaborated_friend_type :
             diag::ext_unelaborated_friend_type)
        << (unsigned) RD->getTagKind()
        << T
        << FixItHint::CreateInsertion(getLocForEndOfToken(FriendLoc),
                                      InsertionText);
    } else {
      Diag(FriendLoc,
           getLangOpts().CPlusPlus11 ?
             diag::warn_cxx98_compat_nonclass_type_friend :
             diag::ext_nonclass_type_friend)
        << T
        << TypeRange;
    }
  } else if (T->getAs<EnumType>()) {
    Diag(FriendLoc,
         getLangOpts().CPlusPlus11 ?
           diag::warn_cxx98_compat_enum_friend :
           diag::ext_enum_friend)
      << T
      << TypeRange;
  }

  // C++11 [class.friend]p3:
  //   A friend declaration that does not declare a function shall have one
  //   of the following forms:
  //     friend elaborated-type-specifier ;
  //     friend simple-type-specifier ;
  //     friend typename-specifier ;
  if (getLangOpts().CPlusPlus11 && LocStart != FriendLoc)
    Diag(FriendLoc, diag::err_friend_not_first_in_declaration) << T;
}

//   If the type specifier in a friend declaration designates a (possibly
//   cv-qualified) class type, that class is declared as a friend; otherwise,
//   the friend declaration is ignored.
return FriendDecl::Create(Context, CurContext,
                          TSInfo->getTypeLoc().getBeginLoc(), TSInfo,
                          FriendLoc);
16488}

16490/// Handle a friend tag declaration where the scope specifier was
16491/// templated.
16492Decl *Sema::ActOnTemplatedFriendTag(Scope *S, SourceLocation FriendLoc,
                                  unsigned TagSpec, SourceLocation TagLoc,
                                  CXXScopeSpec &SS, IdentifierInfo *Name,
                                  SourceLocation NameLoc,
                                  const ParsedAttributesView &Attr,
                                  MultiTemplateParamsArg TempParamLists) {
TagTypeKind Kind = TypeWithKeyword::getTagTypeKindForTypeSpec(TagSpec);

bool IsMemberSpecialization = false;
bool Invalid = false;

if (TemplateParameterList *TemplateParams =
        MatchTemplateParametersToScopeSpecifier(
            TagLoc, NameLoc, SS, nullptr, TempParamLists, /*friend*/ true,
            IsMemberSpecialization, Invalid)) {
  if (TemplateParams->size() > 0) {
    // This is a declaration of a class template.
    if (Invalid)
      return nullptr;

    return CheckClassTemplate(S, TagSpec, TUK_Friend, TagLoc, SS, Name,
                              NameLoc, Attr, TemplateParams, AS_public,
                              /*ModulePrivateLoc=*/SourceLocation(),
                              FriendLoc, TempParamLists.size() - 1,
                              TempParamLists.data()).get();
  } else {
    // The "template<>" header is extraneous.
    Diag(TemplateParams->getTemplateLoc(), diag::err_template_tag_noparams)
      << TypeWithKeyword::getTagTypeKindName(Kind) << Name;
    IsMemberSpecialization = true;
  }
}

if (Invalid) return nullptr;

bool isAllExplicitSpecializations = true;
for (unsigned I = TempParamLists.size(); I-- > 0; ) {
  if (TempParamLists[I]->size()) {
    isAllExplicitSpecializations = false;
    break;
  }
}

// FIXME: don't ignore attributes.

// If it's explicit specializations all the way down, just forget
// about the template header and build an appropriate non-templated
// friend.  TODO: for source fidelity, remember the headers.
if (isAllExplicitSpecializations) {
  if (SS.isEmpty()) {
    bool Owned = false;
    bool IsDependent = false;
    return ActOnTag(S, TagSpec, TUK_Friend, TagLoc, SS, Name, NameLoc,
                    Attr, AS_public,
                    /*ModulePrivateLoc=*/SourceLocation(),
                    MultiTemplateParamsArg(), Owned, IsDependent,
                    /*ScopedEnumKWLoc=*/SourceLocation(),
                    /*ScopedEnumUsesClassTag=*/false,
                    /*UnderlyingType=*/TypeResult(),
                    /*IsTypeSpecifier=*/false,
                    /*IsTemplateParamOrArg=*/false);
  }

  NestedNameSpecifierLoc QualifierLoc = SS.getWithLocInContext(Context);
  ElaboratedTypeKeyword Keyword
    = TypeWithKeyword::getKeywordForTagTypeKind(Kind);
  QualType T = CheckTypenameType(Keyword, TagLoc, QualifierLoc,
                                 *Name, NameLoc);
  if (T.isNull())
    return nullptr;

  TypeSourceInfo *TSI = Context.CreateTypeSourceInfo(T);
  if (isa<DependentNameType>(T)) {
    DependentNameTypeLoc TL =
        TSI->getTypeLoc().castAs<DependentNameTypeLoc>();
    TL.setElaboratedKeywordLoc(TagLoc);
    TL.setQualifierLoc(QualifierLoc);
    TL.setNameLoc(NameLoc);
  } else {
    ElaboratedTypeLoc TL = TSI->getTypeLoc().castAs<ElaboratedTypeLoc>();
    TL.setElaboratedKeywordLoc(TagLoc);
    TL.setQualifierLoc(QualifierLoc);
    TL.getNamedTypeLoc().castAs<TypeSpecTypeLoc>().setNameLoc(NameLoc);
  }

  FriendDecl *Friend = FriendDecl::Create(Context, CurContext, NameLoc,
                                          TSI, FriendLoc, TempParamLists);
  Friend->setAccess(AS_public);
  CurContext->addDecl(Friend);
  return Friend;
}

assert(SS.isNotEmpty() && "valid templated tag with no SS and no direct?")(static_cast<void> (0));



// Handle the case of a templated-scope friend class.  e.g.
//   template <class T> class A<T>::B;
// FIXME: we don't support these right now.
Diag(NameLoc, diag::warn_template_qualified_friend_unsupported)
  << SS.getScopeRep() << SS.getRange() << cast<CXXRecordDecl>(CurContext);
ElaboratedTypeKeyword ETK = TypeWithKeyword::getKeywordForTagTypeKind(Kind);
QualType T = Context.getDependentNameType(ETK, SS.getScopeRep(), Name);
TypeSourceInfo *TSI = Context.CreateTypeSourceInfo(T);
DependentNameTypeLoc TL = TSI->getTypeLoc().castAs<DependentNameTypeLoc>();
TL.setElaboratedKeywordLoc(TagLoc);
TL.setQualifierLoc(SS.getWithLocInContext(Context));
TL.setNameLoc(NameLoc);

FriendDecl *Friend = FriendDecl::Create(Context, CurContext, NameLoc,
                                        TSI, FriendLoc, TempParamLists);
Friend->setAccess(AS_public);
Friend->setUnsupportedFriend(true);
CurContext->addDecl(Friend);
return Friend;
16607}

16609/// Handle a friend type declaration.  This works in tandem with
16610/// ActOnTag.
16611///
16612/// Notes on friend class templates:
16613///
16614/// We generally treat friend class declarations as if they were
16615/// declaring a class.  So, for example, the elaborated type specifier
16616/// in a friend declaration is required to obey the restrictions of a
16617/// class-head (i.e. no typedefs in the scope chain), template
16618/// parameters are required to match up with simple template-ids, &c.
16619/// However, unlike when declaring a template specialization, it's
16620/// okay to refer to a template specialization without an empty
16621/// template parameter declaration, e.g.
16622///   friend class A<T>::B<unsigned>;
16623/// We permit this as a special case; if there are any template
16624/// parameters present at all, require proper matching, i.e.
16625///   template <> template \<class T> friend class A<int>::B;
16626Decl *Sema::ActOnFriendTypeDecl(Scope *S, const DeclSpec &DS,
                              MultiTemplateParamsArg TempParams) {
SourceLocation Loc = DS.getBeginLoc();

assert(DS.isFriendSpecified())(static_cast<void> (0));
assert(DS.getStorageClassSpec() == DeclSpec::SCS_unspecified)(static_cast<void> (0));

// C++ [class.friend]p3:
// A friend declaration that does not declare a function shall have one of
// the following forms:
//     friend elaborated-type-specifier ;
//     friend simple-type-specifier ;
//     friend typename-specifier ;
//
// Any declaration with a type qualifier does not have that form. (It's
// legal to specify a qualified type as a friend, you just can't write the
// keywords.)
if (DS.getTypeQualifiers()) {
  if (DS.getTypeQualifiers() & DeclSpec::TQ_const)
    Diag(DS.getConstSpecLoc(), diag::err_friend_decl_spec) << "const";
  if (DS.getTypeQualifiers() & DeclSpec::TQ_volatile)
    Diag(DS.getVolatileSpecLoc(), diag::err_friend_decl_spec) << "volatile";
  if (DS.getTypeQualifiers() & DeclSpec::TQ_restrict)
    Diag(DS.getRestrictSpecLoc(), diag::err_friend_decl_spec) << "restrict";
  if (DS.getTypeQualifiers() & DeclSpec::TQ_atomic)
    Diag(DS.getAtomicSpecLoc(), diag::err_friend_decl_spec) << "_Atomic";
  if (DS.getTypeQualifiers() & DeclSpec::TQ_unaligned)
    Diag(DS.getUnalignedSpecLoc(), diag::err_friend_decl_spec) << "__unaligned";
}

// Try to convert the decl specifier to a type.  This works for
// friend templates because ActOnTag never produces a ClassTemplateDecl
// for a TUK_Friend.
Declarator TheDeclarator(DS, DeclaratorContext::Member);
TypeSourceInfo *TSI = GetTypeForDeclarator(TheDeclarator, S);
QualType T = TSI->getType();
if (TheDeclarator.isInvalidType())
  return nullptr;

if (DiagnoseUnexpandedParameterPack(Loc, TSI, UPPC_FriendDeclaration))
  return nullptr;

// This is definitely an error in C++98.  It's probably meant to
// be forbidden in C++0x, too, but the specification is just
// poorly written.
//
// The problem is with declarations like the following:
//   template <T> friend A<T>::foo;
// where deciding whether a class C is a friend or not now hinges
// on whether there exists an instantiation of A that causes
// 'foo' to equal C.  There are restrictions on class-heads
// (which we declare (by fiat) elaborated friend declarations to
// be) that makes this tractable.
//
// FIXME: handle "template <> friend class A<T>;", which
// is possibly well-formed?  Who even knows?
if (TempParams.size() && !T->isElaboratedTypeSpecifier()) {
  Diag(Loc, diag::err_tagless_friend_type_template)
    << DS.getSourceRange();
  return nullptr;
}

// C++98 [class.friend]p1: A friend of a class is a function
//   or class that is not a member of the class . . .
// This is fixed in DR77, which just barely didn't make the C++03
// deadline.  It's also a very silly restriction that seriously
// affects inner classes and which nobody else seems to implement;
// thus we never diagnose it, not even in -pedantic.
//
// But note that we could warn about it: it's always useless to
// friend one of your own members (it's not, however, worthless to
// friend a member of an arbitrary specialization of your template).

Decl *D;
if (!TempParams.empty())
  D = FriendTemplateDecl::Create(Context, CurContext, Loc,
                                 TempParams,
                                 TSI,
                                 DS.getFriendSpecLoc());
else
  D = CheckFriendTypeDecl(Loc, DS.getFriendSpecLoc(), TSI);

if (!D)
  return nullptr;

D->setAccess(AS_public);
CurContext->addDecl(D);

return D;
16715}

16717NamedDecl *Sema::ActOnFriendFunctionDecl(Scope *S, Declarator &D,
                                      MultiTemplateParamsArg TemplateParams) {
const DeclSpec &DS = D.getDeclSpec();

assert(DS.isFriendSpecified())(static_cast<void> (0));
assert(DS.getStorageClassSpec() == DeclSpec::SCS_unspecified)(static_cast<void> (0));

SourceLocation Loc = D.getIdentifierLoc();
TypeSourceInfo *TInfo = GetTypeForDeclarator(D, S);

// C++ [class.friend]p1
//   A friend of a class is a function or class....
// Note that this sees through typedefs, which is intended.
// It *doesn't* see through dependent types, which is correct
// according to [temp.arg.type]p3:
//   If a declaration acquires a function type through a
//   type dependent on a template-parameter and this causes
//   a declaration that does not use the syntactic form of a
//   function declarator to have a function type, the program
//   is ill-formed.
if (!TInfo->getType()->isFunctionType()) {
  Diag(Loc, diag::err_unexpected_friend);

  // It might be worthwhile to try to recover by creating an
  // appropriate declaration.
  return nullptr;
}

// C++ [namespace.memdef]p3
//  - If a friend declaration in a non-local class first declares a
//    class or function, the friend class or function is a member
//    of the innermost enclosing namespace.
//  - The name of the friend is not found by simple name lookup
//    until a matching declaration is provided in that namespace
//    scope (either before or after the class declaration granting
//    friendship).
//  - If a friend function is called, its name may be found by the
//    name lookup that considers functions from namespaces and
//    classes associated with the types of the function arguments.
//  - When looking for a prior declaration of a class or a function
//    declared as a friend, scopes outside the innermost enclosing
//    namespace scope are not considered.

CXXScopeSpec &SS = D.getCXXScopeSpec();
DeclarationNameInfo NameInfo = GetNameForDeclarator(D);
assert(NameInfo.getName())(static_cast<void> (0));

// Check for unexpanded parameter packs.
if (DiagnoseUnexpandedParameterPack(Loc, TInfo, UPPC_FriendDeclaration) ||
    DiagnoseUnexpandedParameterPack(NameInfo, UPPC_FriendDeclaration) ||
    DiagnoseUnexpandedParameterPack(SS, UPPC_FriendDeclaration))
  return nullptr;

// The context we found the declaration in, or in which we should
// create the declaration.
DeclContext *DC;
Scope *DCScope = S;
LookupResult Previous(*this, NameInfo, LookupOrdinaryName,
                      ForExternalRedeclaration);

// There are five cases here.
//   - There's no scope specifier and we're in a local class. Only look
//     for functions declared in the immediately-enclosing block scope.
// We recover from invalid scope qualifiers as if they just weren't there.
FunctionDecl *FunctionContainingLocalClass = nullptr;
if ((SS.isInvalid() || !SS.isSet()) &&
    (FunctionContainingLocalClass =
         cast<CXXRecordDecl>(CurContext)->isLocalClass())) {
  // C++11 [class.friend]p11:
  //   If a friend declaration appears in a local class and the name
  //   specified is an unqualified name, a prior declaration is
  //   looked up without considering scopes that are outside the
  //   innermost enclosing non-class scope. For a friend function
  //   declaration, if there is no prior declaration, the program is
  //   ill-formed.

  // Find the innermost enclosing non-class scope. This is the block
  // scope containing the local class definition (or for a nested class,
  // the outer local class).
  DCScope = S->getFnParent();

  // Look up the function name in the scope.
  Previous.clear(LookupLocalFriendName);
  LookupName(Previous, S, /*AllowBuiltinCreation*/false);

  if (!Previous.empty()) {
    // All possible previous declarations must have the same context:
    // either they were declared at block scope or they are members of
    // one of the enclosing local classes.
    DC = Previous.getRepresentativeDecl()->getDeclContext();
  } else {
    // This is ill-formed, but provide the context that we would have
    // declared the function in, if we were permitted to, for error recovery.
    DC = FunctionContainingLocalClass;
  }
  adjustContextForLocalExternDecl(DC);

  // C++ [class.friend]p6:
  //   A function can be defined in a friend declaration of a class if and
  //   only if the class is a non-local class (9.8), the function name is
  //   unqualified, and the function has namespace scope.
  if (D.isFunctionDefinition()) {
    Diag(NameInfo.getBeginLoc(), diag::err_friend_def_in_local_class);
  }

//   - There's no scope specifier, in which case we just go to the
//     appropriate scope and look for a function or function template
//     there as appropriate.
} else if (SS.isInvalid() || !SS.isSet()) {
  // C++11 [namespace.memdef]p3:
  //   If the name in a friend declaration is neither qualified nor
  //   a template-id and the declaration is a function or an
  //   elaborated-type-specifier, the lookup to determine whether
  //   the entity has been previously declared shall not consider
  //   any scopes outside the innermost enclosing namespace.
  bool isTemplateId =
      D.getName().getKind() == UnqualifiedIdKind::IK_TemplateId;

  // Find the appropriate context according to the above.
  DC = CurContext;

  // Skip class contexts.  If someone can cite chapter and verse
  // for this behavior, that would be nice --- it's what GCC and
  // EDG do, and it seems like a reasonable intent, but the spec
  // really only says that checks for unqualified existing
  // declarations should stop at the nearest enclosing namespace,
  // not that they should only consider the nearest enclosing
  // namespace.
  while (DC->isRecord())
    DC = DC->getParent();

  DeclContext *LookupDC = DC->getNonTransparentContext();
  while (true) {
    LookupQualifiedName(Previous, LookupDC);

    if (!Previous.empty()) {
      DC = LookupDC;
      break;
    }

    if (isTemplateId) {
      if (isa<TranslationUnitDecl>(LookupDC)) break;
    } else {
      if (LookupDC->isFileContext()) break;
    }
    LookupDC = LookupDC->getParent();
  }

  DCScope = getScopeForDeclContext(S, DC);

//   - There's a non-dependent scope specifier, in which case we
//     compute it and do a previous lookup there for a function
//     or function template.
} else if (!SS.getScopeRep()->isDependent()) {
  DC = computeDeclContext(SS);
  if (!DC) return nullptr;

  if (RequireCompleteDeclContext(SS, DC)) return nullptr;

  LookupQualifiedName(Previous, DC);

  // C++ [class.friend]p1: A friend of a class is a function or
  //   class that is not a member of the class . . .
  if (DC->Equals(CurContext))
    Diag(DS.getFriendSpecLoc(),
         getLangOpts().CPlusPlus11 ?
           diag::warn_cxx98_compat_friend_is_member :
           diag::err_friend_is_member);

  if (D.isFunctionDefinition()) {
    // C++ [class.friend]p6:
    //   A function can be defined in a friend declaration of a class if and
    //   only if the class is a non-local class (9.8), the function name is
    //   unqualified, and the function has namespace scope.
    //
    // FIXME: We should only do this if the scope specifier names the
    // innermost enclosing namespace; otherwise the fixit changes the
    // meaning of the code.
    SemaDiagnosticBuilder DB
      = Diag(SS.getRange().getBegin(), diag::err_qualified_friend_def);

    DB << SS.getScopeRep();
    if (DC->isFileContext())
      DB << FixItHint::CreateRemoval(SS.getRange());
    SS.clear();
  }

//   - There's a scope specifier that does not match any template
//     parameter lists, in which case we use some arbitrary context,
//     create a method or method template, and wait for instantiation.
//   - There's a scope specifier that does match some template
//     parameter lists, which we don't handle right now.
} else {
  if (D.isFunctionDefinition()) {
    // C++ [class.friend]p6:
    //   A function can be defined in a friend declaration of a class if and
    //   only if the class is a non-local class (9.8), the function name is
    //   unqualified, and the function has namespace scope.
    Diag(SS.getRange().getBegin(), diag::err_qualified_friend_def)
      << SS.getScopeRep();
  }

  DC = CurContext;
  assert(isa<CXXRecordDecl>(DC) && "friend declaration not in class?")(static_cast<void> (0));
}

if (!DC->isRecord()) {
  int DiagArg = -1;
  switch (D.getName().getKind()) {
  case UnqualifiedIdKind::IK_ConstructorTemplateId:
  case UnqualifiedIdKind::IK_ConstructorName:
    DiagArg = 0;
    break;
  case UnqualifiedIdKind::IK_DestructorName:
    DiagArg = 1;
    break;
  case UnqualifiedIdKind::IK_ConversionFunctionId:
    DiagArg = 2;
    break;
  case UnqualifiedIdKind::IK_DeductionGuideName:
    DiagArg = 3;
    break;
  case UnqualifiedIdKind::IK_Identifier:
  case UnqualifiedIdKind::IK_ImplicitSelfParam:
  case UnqualifiedIdKind::IK_LiteralOperatorId:
  case UnqualifiedIdKind::IK_OperatorFunctionId:
  case UnqualifiedIdKind::IK_TemplateId:
    break;
  }
  // This implies that it has to be an operator or function.
  if (DiagArg >= 0) {
    Diag(Loc, diag::err_introducing_special_friend) << DiagArg;
    return nullptr;
  }
}

// FIXME: This is an egregious hack to cope with cases where the scope stack
// does not contain the declaration context, i.e., in an out-of-line
// definition of a class.
Scope FakeDCScope(S, Scope::DeclScope, Diags);
if (!DCScope) {
  FakeDCScope.setEntity(DC);
  DCScope = &FakeDCScope;
}

bool AddToScope = true;
NamedDecl *ND = ActOnFunctionDeclarator(DCScope, D, DC, TInfo, Previous,
                                        TemplateParams, AddToScope);
if (!ND) return nullptr;

assert(ND->getLexicalDeclContext() == CurContext)(static_cast<void> (0));

// If we performed typo correction, we might have added a scope specifier
// and changed the decl context.
DC = ND->getDeclContext();

// Add the function declaration to the appropriate lookup tables,
// adjusting the redeclarations list as necessary.  We don't
// want to do this yet if the friending class is dependent.
//
// Also update the scope-based lookup if the target context's
// lookup context is in lexical scope.
if (!CurContext->isDependentContext()) {
  DC = DC->getRedeclContext();
  DC->makeDeclVisibleInContext(ND);
  if (Scope *EnclosingScope = getScopeForDeclContext(S, DC))
    PushOnScopeChains(ND, EnclosingScope, /*AddToContext=*/ false);
}

FriendDecl *FrD = FriendDecl::Create(Context, CurContext,
                                     D.getIdentifierLoc(), ND,
                                     DS.getFriendSpecLoc());
FrD->setAccess(AS_public);
CurContext->addDecl(FrD);

if (ND->isInvalidDecl()) {
  FrD->setInvalidDecl();
} else {
  if (DC->isRecord()) CheckFriendAccess(ND);

  FunctionDecl *FD;
  if (FunctionTemplateDecl *FTD = dyn_cast<FunctionTemplateDecl>(ND))
    FD = FTD->getTemplatedDecl();
  else
    FD = cast<FunctionDecl>(ND);

  // C++11 [dcl.fct.default]p4: If a friend declaration specifies a
  // default argument expression, that declaration shall be a definition
  // and shall be the only declaration of the function or function
  // template in the translation unit.
  if (functionDeclHasDefaultArgument(FD)) {
    // We can't look at FD->getPreviousDecl() because it may not have been set
    // if we're in a dependent context. If the function is known to be a
    // redeclaration, we will have narrowed Previous down to the right decl.
    if (D.isRedeclaration()) {
      Diag(FD->getLocation(), diag::err_friend_decl_with_def_arg_redeclared);
      Diag(Previous.getRepresentativeDecl()->getLocation(),
           diag::note_previous_declaration);
    } else if (!D.isFunctionDefinition())
      Diag(FD->getLocation(), diag::err_friend_decl_with_def_arg_must_be_def);
  }

  // Mark templated-scope function declarations as unsupported.
  if (FD->getNumTemplateParameterLists() && SS.isValid()) {
    Diag(FD->getLocation(), diag::warn_template_qualified_friend_unsupported)
      << SS.getScopeRep() << SS.getRange()
      << cast<CXXRecordDecl>(CurContext);
    FrD->setUnsupportedFriend(true);
  }
}

warnOnReservedIdentifier(ND);

return ND;
17031}

17033void Sema::SetDeclDeleted(Decl *Dcl, SourceLocation DelLoc) {
AdjustDeclIfTemplate(Dcl);

FunctionDecl *Fn = dyn_cast_or_null<FunctionDecl>(Dcl);
if (!Fn) {
  Diag(DelLoc, diag::err_deleted_non_function);
  return;
}

// Deleted function does not have a body.
Fn->setWillHaveBody(false);

if (const FunctionDecl *Prev = Fn->getPreviousDecl()) {
  // Don't consider the implicit declaration we generate for explicit
  // specializations. FIXME: Do not generate these implicit declarations.
  if ((Prev->getTemplateSpecializationKind() != TSK_ExplicitSpecialization ||
       Prev->getPreviousDecl()) &&
      !Prev->isDefined()) {
    Diag(DelLoc, diag::err_deleted_decl_not_first);
    Diag(Prev->getLocation().isInvalid() ? DelLoc : Prev->getLocation(),
         Prev->isImplicit() ? diag::note_previous_implicit_declaration
                            : diag::note_previous_declaration);
    // We can't recover from this; the declaration might have already
    // been used.
    Fn->setInvalidDecl();
    return;
  }

  // To maintain the invariant that functions are only deleted on their first
  // declaration, mark the implicitly-instantiated declaration of the
  // explicitly-specialized function as deleted instead of marking the
  // instantiated redeclaration.
  Fn = Fn->getCanonicalDecl();
}

// dllimport/dllexport cannot be deleted.
if (const InheritableAttr *DLLAttr = getDLLAttr(Fn)) {
  Diag(Fn->getLocation(), diag::err_attribute_dll_deleted) << DLLAttr;
  Fn->setInvalidDecl();
}

// C++11 [basic.start.main]p3:
//   A program that defines main as deleted [...] is ill-formed.
if (Fn->isMain())
  Diag(DelLoc, diag::err_deleted_main);

// C++11 [dcl.fct.def.delete]p4:
//  A deleted function is implicitly inline.
Fn->setImplicitlyInline();
Fn->setDeletedAsWritten();
17083}

17085void Sema::SetDeclDefaulted(Decl *Dcl, SourceLocation DefaultLoc) {
if (!Dcl || Dcl->isInvalidDecl())
  return;

auto *FD = dyn_cast<FunctionDecl>(Dcl);
if (!FD) {
  if (auto *FTD = dyn_cast<FunctionTemplateDecl>(Dcl)) {
    if (getDefaultedFunctionKind(FTD->getTemplatedDecl()).isComparison()) {
      Diag(DefaultLoc, diag::err_defaulted_comparison_template);
      return;
    }
  }

  Diag(DefaultLoc, diag::err_default_special_members)
      << getLangOpts().CPlusPlus20;
  return;
}

// Reject if this can't possibly be a defaultable function.
DefaultedFunctionKind DefKind = getDefaultedFunctionKind(FD);
if (!DefKind &&
    // A dependent function that doesn't locally look defaultable can
    // still instantiate to a defaultable function if it's a constructor
    // or assignment operator.
    (!FD->isDependentContext() ||
     (!isa<CXXConstructorDecl>(FD) &&
      FD->getDeclName().getCXXOverloadedOperator() != OO_Equal))) {
  Diag(DefaultLoc, diag::err_default_special_members)
      << getLangOpts().CPlusPlus20;
  return;
}

if (DefKind.isComparison() &&
    !isa<CXXRecordDecl>(FD->getLexicalDeclContext())) {
  Diag(FD->getLocation(), diag::err_defaulted_comparison_out_of_class)
      << (int)DefKind.asComparison();
  return;
}

// Issue compatibility warning. We already warned if the operator is
// 'operator<=>' when parsing the '<=>' token.
if (DefKind.isComparison() &&
    DefKind.asComparison() != DefaultedComparisonKind::ThreeWay) {
  Diag(DefaultLoc, getLangOpts().CPlusPlus20
                       ? diag::warn_cxx17_compat_defaulted_comparison
                       : diag::ext_defaulted_comparison);
}

FD->setDefaulted();
FD->setExplicitlyDefaulted();

// Defer checking functions that are defaulted in a dependent context.
if (FD->isDependentContext())
  return;

// Unset that we will have a body for this function. We might not,
// if it turns out to be trivial, and we don't need this marking now
// that we've marked it as defaulted.
FD->setWillHaveBody(false);

// If this definition appears within the record, do the checking when
// the record is complete. This is always the case for a defaulted
// comparison.
if (DefKind.isComparison())
  return;
auto *MD = cast<CXXMethodDecl>(FD);

const FunctionDecl *Primary = FD;
if (const FunctionDecl *Pattern = FD->getTemplateInstantiationPattern())
  // Ask the template instantiation pattern that actually had the
  // '= default' on it.
  Primary = Pattern;

// If the method was defaulted on its first declaration, we will have
// already performed the checking in CheckCompletedCXXClass. Such a
// declaration doesn't trigger an implicit definition.
if (Primary->getCanonicalDecl()->isDefaulted())
  return;

// FIXME: Once we support defining comparisons out of class, check for a
// defaulted comparison here.
if (CheckExplicitlyDefaultedSpecialMember(MD, DefKind.asSpecialMember()))
  MD->setInvalidDecl();
else
  DefineDefaultedFunction(*this, MD, DefaultLoc);
17170}

17172static void SearchForReturnInStmt(Sema &Self, Stmt *S) {
for (Stmt *SubStmt : S->children()) {
  if (!SubStmt)
    continue;
  if (isa<ReturnStmt>(SubStmt))
    Self.Diag(SubStmt->getBeginLoc(),
              diag::err_return_in_constructor_handler);
  if (!isa<Expr>(SubStmt))
    SearchForReturnInStmt(Self, SubStmt);
}
17182}

17184void Sema::DiagnoseReturnInConstructorExceptionHandler(CXXTryStmt *TryBlock) {
for (unsigned I = 0, E = TryBlock->getNumHandlers(); I != E; ++I) {
  CXXCatchStmt *Handler = TryBlock->getHandler(I);
  SearchForReturnInStmt(*this, Handler);
}
17189}

17191bool Sema::CheckOverridingFunctionAttributes(const CXXMethodDecl *New,
                                           const CXXMethodDecl *Old) {
const auto *NewFT = New->getType()->castAs<FunctionProtoType>();
const auto *OldFT = Old->getType()->castAs<FunctionProtoType>();

if (OldFT->hasExtParameterInfos()) {
  for (unsigned I = 0, E = OldFT->getNumParams(); I != E; ++I)
    // A parameter of the overriding method should be annotated with noescape
    // if the corresponding parameter of the overridden method is annotated.
    if (OldFT->getExtParameterInfo(I).isNoEscape() &&
        !NewFT->getExtParameterInfo(I).isNoEscape()) {
      Diag(New->getParamDecl(I)->getLocation(),
           diag::warn_overriding_method_missing_noescape);
      Diag(Old->getParamDecl(I)->getLocation(),
           diag::note_overridden_marked_noescape);
    }
}

// Virtual overrides must have the same code_seg.
const auto *OldCSA = Old->getAttr<CodeSegAttr>();
const auto *NewCSA = New->getAttr<CodeSegAttr>();
if ((NewCSA || OldCSA) &&
    (!OldCSA || !NewCSA || NewCSA->getName() != OldCSA->getName())) {
  Diag(New->getLocation(), diag::err_mismatched_code_seg_override);
  Diag(Old->getLocation(), diag::note_previous_declaration);
  return true;
}

CallingConv NewCC = NewFT->getCallConv(), OldCC = OldFT->getCallConv();

// If the calling conventions match, everything is fine
if (NewCC == OldCC)
  return false;

// If the calling conventions mismatch because the new function is static,
// suppress the calling convention mismatch error; the error about static
// function override (err_static_overrides_virtual from
// Sema::CheckFunctionDeclaration) is more clear.
if (New->getStorageClass() == SC_Static)
  return false;

Diag(New->getLocation(),
     diag::err_conflicting_overriding_cc_attributes)
  << New->getDeclName() << New->getType() << Old->getType();
Diag(Old->getLocation(), diag::note_overridden_virtual_function);
return true;
17237}

17239bool Sema::CheckOverridingFunctionReturnType(const CXXMethodDecl *New,
                                           const CXXMethodDecl *Old) {
QualType NewTy = New->getType()->castAs<FunctionType>()->getReturnType();
QualType OldTy = Old->getType()->castAs<FunctionType>()->getReturnType();

if (Context.hasSameType(NewTy, OldTy) ||
    NewTy->isDependentType() || OldTy->isDependentType())
  return false;

// Check if the return types are covariant
QualType NewClassTy, OldClassTy;

/// Both types must be pointers or references to classes.
if (const PointerType *NewPT = NewTy->getAs<PointerType>()) {
  if (const PointerType *OldPT = OldTy->getAs<PointerType>()) {
    NewClassTy = NewPT->getPointeeType();
    OldClassTy = OldPT->getPointeeType();
  }
} else if (const ReferenceType *NewRT = NewTy->getAs<ReferenceType>()) {
  if (const ReferenceType *OldRT = OldTy->getAs<ReferenceType>()) {
    if (NewRT->getTypeClass() == OldRT->getTypeClass()) {
      NewClassTy = NewRT->getPointeeType();
      OldClassTy = OldRT->getPointeeType();
    }
  }
}

// The return types aren't either both pointers or references to a class type.
if (NewClassTy.isNull()) {
  Diag(New->getLocation(),
       diag::err_different_return_type_for_overriding_virtual_function)
      << New->getDeclName() << NewTy << OldTy
      << New->getReturnTypeSourceRange();
  Diag(Old->getLocation(), diag::note_overridden_virtual_function)
      << Old->getReturnTypeSourceRange();

  return true;
}

if (!Context.hasSameUnqualifiedType(NewClassTy, OldClassTy)) {
  // C++14 [class.virtual]p8:
  //   If the class type in the covariant return type of D::f differs from
  //   that of B::f, the class type in the return type of D::f shall be
  //   complete at the point of declaration of D::f or shall be the class
  //   type D.
  if (const RecordType *RT = NewClassTy->getAs<RecordType>()) {
    if (!RT->isBeingDefined() &&
        RequireCompleteType(New->getLocation(), NewClassTy,
                            diag::err_covariant_return_incomplete,
                            New->getDeclName()))
      return true;
  }

  // Check if the new class derives from the old class.
  if (!IsDerivedFrom(New->getLocation(), NewClassTy, OldClassTy)) {
    Diag(New->getLocation(), diag::err_covariant_return_not_derived)
        << New->getDeclName() << NewTy << OldTy
        << New->getReturnTypeSourceRange();
    Diag(Old->getLocation(), diag::note_overridden_virtual_function)
        << Old->getReturnTypeSourceRange();
    return true;
  }

  // Check if we the conversion from derived to base is valid.
  if (CheckDerivedToBaseConversion(
          NewClassTy, OldClassTy,
          diag::err_covariant_return_inaccessible_base,
          diag::err_covariant_return_ambiguous_derived_to_base_conv,
          New->getLocation(), New->getReturnTypeSourceRange(),
          New->getDeclName(), nullptr)) {
    // FIXME: this note won't trigger for delayed access control
    // diagnostics, and it's impossible to get an undelayed error
    // here from access control during the original parse because
    // the ParsingDeclSpec/ParsingDeclarator are still in scope.
    Diag(Old->getLocation(), diag::note_overridden_virtual_function)
        << Old->getReturnTypeSourceRange();
    return true;
  }
}

// The qualifiers of the return types must be the same.
if (NewTy.getLocalCVRQualifiers() != OldTy.getLocalCVRQualifiers()) {
  Diag(New->getLocation(),
       diag::err_covariant_return_type_different_qualifications)
      << New->getDeclName() << NewTy << OldTy
      << New->getReturnTypeSourceRange();
  Diag(Old->getLocation(), diag::note_overridden_virtual_function)
      << Old->getReturnTypeSourceRange();
  return true;
}


// The new class type must have the same or less qualifiers as the old type.
if (NewClassTy.isMoreQualifiedThan(OldClassTy)) {
  Diag(New->getLocation(),
       diag::err_covariant_return_type_class_type_more_qualified)
      << New->getDeclName() << NewTy << OldTy
      << New->getReturnTypeSourceRange();
  Diag(Old->getLocation(), diag::note_overridden_virtual_function)
      << Old->getReturnTypeSourceRange();
  return true;
}

return false;
17343}

17345/// Mark the given method pure.
17346///
17347/// \param Method the method to be marked pure.
17348///
17349/// \param InitRange the source range that covers the "0" initializer.
17350bool Sema::CheckPureMethod(CXXMethodDecl *Method, SourceRange InitRange) {
SourceLocation EndLoc = InitRange.getEnd();
if (EndLoc.isValid())
  Method->setRangeEnd(EndLoc);

if (Method->isVirtual() || Method->getParent()->isDependentContext()) {
  Method->setPure();
  return false;
}

if (!Method->isInvalidDecl())
  Diag(Method->getLocation(), diag::err_non_virtual_pure)
    << Method->getDeclName() << InitRange;
return true;
17364}

17366void Sema::ActOnPureSpecifier(Decl *D, SourceLocation ZeroLoc) {
if (D->getFriendObjectKind())
  Diag(D->getLocation(), diag::err_pure_friend);
else if (auto *M = dyn_cast<CXXMethodDecl>(D))
  CheckPureMethod(M, ZeroLoc);
else
  Diag(D->getLocation(), diag::err_illegal_initializer);
17373}

17375/// Determine whether the given declaration is a global variable or
17376/// static data member.
17377static bool isNonlocalVariable(const Decl *D) {
if (const VarDecl *Var = dyn_cast_or_null<VarDecl>(D))
  return Var->hasGlobalStorage();

return false;
17382}

17384/// Invoked when we are about to parse an initializer for the declaration
17385/// 'Dcl'.
17386///
17387/// After this method is called, according to [C++ 3.4.1p13], if 'Dcl' is a
17388/// static data member of class X, names should be looked up in the scope of
17389/// class X. If the declaration had a scope specifier, a scope will have
17390/// been created and passed in for this purpose. Otherwise, S will be null.
17391void Sema::ActOnCXXEnterDeclInitializer(Scope *S, Decl *D) {
// If there is no declaration, there was an error parsing it.
if (!D || D->isInvalidDecl())
  return;

// We will always have a nested name specifier here, but this declaration
// might not be out of line if the specifier names the current namespace:
//   extern int n;
//   int ::n = 0;
if (S && D->isOutOfLine())
  EnterDeclaratorContext(S, D->getDeclContext());

// If we are parsing the initializer for a static data member, push a
// new expression evaluation context that is associated with this static
// data member.
if (isNonlocalVariable(D))
  PushExpressionEvaluationContext(
      ExpressionEvaluationContext::PotentiallyEvaluated, D);
17409}

17411/// Invoked after we are finished parsing an initializer for the declaration D.
17412void Sema::ActOnCXXExitDeclInitializer(Scope *S, Decl *D) {
// If there is no declaration, there was an error parsing it.
if (!D || D->isInvalidDecl())
  return;

if (isNonlocalVariable(D))
  PopExpressionEvaluationContext();

if (S && D->isOutOfLine())
  ExitDeclaratorContext(S);
17422}

17424/// ActOnCXXConditionDeclarationExpr - Parsed a condition declaration of a
17425/// C++ if/switch/while/for statement.
17426/// e.g: "if (int x = f()) {...}"
17427DeclResult Sema::ActOnCXXConditionDeclaration(Scope *S, Declarator &D) {
// C++ 6.4p2:
// The declarator shall not specify a function or an array.
// The type-specifier-seq shall not contain typedef and shall not declare a
// new class or enumeration.
assert(D.getDeclSpec().getStorageClassSpec() != DeclSpec::SCS_typedef &&(static_cast<void> (0))
       "Parser allowed 'typedef' as storage class of condition decl.")(static_cast<void> (0));

Decl *Dcl = ActOnDeclarator(S, D);
if (!Dcl)
  return true;

if (isa<FunctionDecl>(Dcl)) { // The declarator shall not specify a function.
  Diag(Dcl->getLocation(), diag::err_invalid_use_of_function_type)
    << D.getSourceRange();
  return true;
}

return Dcl;
17446}

17448void Sema::LoadExternalVTableUses() {
if (!ExternalSource)
  return;

SmallVector<ExternalVTableUse, 4> VTables;
ExternalSource->ReadUsedVTables(VTables);
SmallVector<VTableUse, 4> NewUses;
for (unsigned I = 0, N = VTables.size(); I != N; ++I) {
  llvm::DenseMap<CXXRecordDecl *, bool>::iterator Pos
    = VTablesUsed.find(VTables[I].Record);
  // Even if a definition wasn't required before, it may be required now.
  if (Pos != VTablesUsed.end()) {
    if (!Pos->second && VTables[I].DefinitionRequired)
      Pos->second = true;
    continue;
  }

  VTablesUsed[VTables[I].Record] = VTables[I].DefinitionRequired;
  NewUses.push_back(VTableUse(VTables[I].Record, VTables[I].Location));
}

VTableUses.insert(VTableUses.begin(), NewUses.begin(), NewUses.end());
17470}

17472void Sema::MarkVTableUsed(SourceLocation Loc, CXXRecordDecl *Class,
                        bool DefinitionRequired) {
// Ignore any vtable uses in unevaluated operands or for classes that do
// not have a vtable.
if (!Class->isDynamicClass() || Class->isDependentContext() ||
    CurContext->isDependentContext() || isUnevaluatedContext())
  return;
// Do not mark as used if compiling for the device outside of the target
// region.
if (TUKind != TU_Prefix && LangOpts.OpenMP && LangOpts.OpenMPIsDevice &&
    !isInOpenMPDeclareTargetContext() &&
    !isInOpenMPTargetExecutionDirective()) {
  if (!DefinitionRequired)
    MarkVirtualMembersReferenced(Loc, Class);
  return;
}

// Try to insert this class into the map.
LoadExternalVTableUses();
Class = Class->getCanonicalDecl();
std::pair<llvm::DenseMap<CXXRecordDecl *, bool>::iterator, bool>
  Pos = VTablesUsed.insert(std::make_pair(Class, DefinitionRequired));
if (!Pos.second) {
  // If we already had an entry, check to see if we are promoting this vtable
  // to require a definition. If so, we need to reappend to the VTableUses
  // list, since we may have already processed the first entry.
  if (DefinitionRequired && !Pos.first->second) {
    Pos.first->second = true;
  } else {
    // Otherwise, we can early exit.
    return;
  }
} else {
  // The Microsoft ABI requires that we perform the destructor body
  // checks (i.e. operator delete() lookup) when the vtable is marked used, as
  // the deleting destructor is emitted with the vtable, not with the
  // destructor definition as in the Itanium ABI.
  if (Context.getTargetInfo().getCXXABI().isMicrosoft()) {
    CXXDestructorDecl *DD = Class->getDestructor();
    if (DD && DD->isVirtual() && !DD->isDeleted()) {
      if (Class->hasUserDeclaredDestructor() && !DD->isDefined()) {
        // If this is an out-of-line declaration, marking it referenced will
        // not do anything. Manually call CheckDestructor to look up operator
        // delete().
        ContextRAII SavedContext(*this, DD);
        CheckDestructor(DD);
      } else {
        MarkFunctionReferenced(Loc, Class->getDestructor());
      }
    }
  }
}

// Local classes need to have their virtual members marked
// immediately. For all other classes, we mark their virtual members
// at the end of the translation unit.
if (Class->isLocalClass())
  MarkVirtualMembersReferenced(Loc, Class);
else
  VTableUses.push_back(std::make_pair(Class, Loc));
17532}

17534bool Sema::DefineUsedVTables() {
LoadExternalVTableUses();
if (VTableUses.empty())
  return false;

// Note: The VTableUses vector could grow as a result of marking
// the members of a class as "used", so we check the size each
// time through the loop and prefer indices (which are stable) to
// iterators (which are not).
bool DefinedAnything = false;
for (unsigned I = 0; I != VTableUses.size(); ++I) {
  CXXRecordDecl *Class = VTableUses[I].first->getDefinition();
  if (!Class)
    continue;
  TemplateSpecializationKind ClassTSK =
      Class->getTemplateSpecializationKind();

  SourceLocation Loc = VTableUses[I].second;

  bool DefineVTable = true;

  // If this class has a key function, but that key function is
  // defined in another translation unit, we don't need to emit the
  // vtable even though we're using it.
  const CXXMethodDecl *KeyFunction = Context.getCurrentKeyFunction(Class);
  if (KeyFunction && !KeyFunction->hasBody()) {
    // The key function is in another translation unit.
    DefineVTable = false;
    TemplateSpecializationKind TSK =
        KeyFunction->getTemplateSpecializationKind();
    assert(TSK != TSK_ExplicitInstantiationDefinition &&(static_cast<void> (0))
           TSK != TSK_ImplicitInstantiation &&(static_cast<void> (0))
           "Instantiations don't have key functions")(static_cast<void> (0));
    (void)TSK;
  } else if (!KeyFunction) {
    // If we have a class with no key function that is the subject
    // of an explicit instantiation declaration, suppress the
    // vtable; it will live with the explicit instantiation
    // definition.
    bool IsExplicitInstantiationDeclaration =
        ClassTSK == TSK_ExplicitInstantiationDeclaration;
    for (auto R : Class->redecls()) {
      TemplateSpecializationKind TSK
        = cast<CXXRecordDecl>(R)->getTemplateSpecializationKind();
      if (TSK == TSK_ExplicitInstantiationDeclaration)
        IsExplicitInstantiationDeclaration = true;
      else if (TSK == TSK_ExplicitInstantiationDefinition) {
        IsExplicitInstantiationDeclaration = false;
        break;
      }
    }

    if (IsExplicitInstantiationDeclaration)
      DefineVTable = false;
  }

  // The exception specifications for all virtual members may be needed even
  // if we are not providing an authoritative form of the vtable in this TU.
  // We may choose to emit it available_externally anyway.
  if (!DefineVTable) {
    MarkVirtualMemberExceptionSpecsNeeded(Loc, Class);
    continue;
  }

  // Mark all of the virtual members of this class as referenced, so
  // that we can build a vtable. Then, tell the AST consumer that a
  // vtable for this class is required.
  DefinedAnything = true;
  MarkVirtualMembersReferenced(Loc, Class);
  CXXRecordDecl *Canonical = Class->getCanonicalDecl();
  if (VTablesUsed[Canonical])
    Consumer.HandleVTable(Class);

  // Warn if we're emitting a weak vtable. The vtable will be weak if there is
  // no key function or the key function is inlined. Don't warn in C++ ABIs
  // that lack key functions, since the user won't be able to make one.
  if (Context.getTargetInfo().getCXXABI().hasKeyFunctions() &&
      Class->isExternallyVisible() && ClassTSK != TSK_ImplicitInstantiation) {
    const FunctionDecl *KeyFunctionDef = nullptr;
    if (!KeyFunction || (KeyFunction->hasBody(KeyFunctionDef) &&
                         KeyFunctionDef->isInlined())) {
      Diag(Class->getLocation(),
           ClassTSK == TSK_ExplicitInstantiationDefinition
               ? diag::warn_weak_template_vtable
               : diag::warn_weak_vtable)
          << Class;
    }
  }
}
VTableUses.clear();

return DefinedAnything;
17626}

17628void Sema::MarkVirtualMemberExceptionSpecsNeeded(SourceLocation Loc,
                                               const CXXRecordDecl *RD) {
for (const auto *I : RD->methods())
  if (I->isVirtual() && !I->isPure())
    ResolveExceptionSpec(Loc, I->getType()->castAs<FunctionProtoType>());
17633}

17635void Sema::MarkVirtualMembersReferenced(SourceLocation Loc,
                                      const CXXRecordDecl *RD,
                                      bool ConstexprOnly) {
// Mark all functions which will appear in RD's vtable as used.
CXXFinalOverriderMap FinalOverriders;
RD->getFinalOverriders(FinalOverriders);
for (CXXFinalOverriderMap::const_iterator I = FinalOverriders.begin(),
                                          E = FinalOverriders.end();
     I != E; ++I) {
  for (OverridingMethods::const_iterator OI = I->second.begin(),
                                         OE = I->second.end();
       OI != OE; ++OI) {
    assert(OI->second.size() > 0 && "no final overrider")(static_cast<void> (0));
    CXXMethodDecl *Overrider = OI->second.front().Method;

    // C++ [basic.def.odr]p2:
    //   [...] A virtual member function is used if it is not pure. [...]
    if (!Overrider->isPure() && (!ConstexprOnly || Overrider->isConstexpr()))
      MarkFunctionReferenced(Loc, Overrider);
  }
}

// Only classes that have virtual bases need a VTT.
if (RD->getNumVBases() == 0)
  return;

for (const auto &I : RD->bases()) {
  const auto *Base =
      cast<CXXRecordDecl>(I.getType()->castAs<RecordType>()->getDecl());
  if (Base->getNumVBases() == 0)
    continue;
  MarkVirtualMembersReferenced(Loc, Base);
}
17668}

17670/// SetIvarInitializers - This routine builds initialization ASTs for the
17671/// Objective-C implementation whose ivars need be initialized.
17672void Sema::SetIvarInitializers(ObjCImplementationDecl *ObjCImplementation) {
if (!getLangOpts().CPlusPlus)
  return;
if (ObjCInterfaceDecl *OID = ObjCImplementation->getClassInterface()) {
  SmallVector<ObjCIvarDecl*, 8> ivars;
  CollectIvarsToConstructOrDestruct(OID, ivars);
  if (ivars.empty())
    return;
  SmallVector<CXXCtorInitializer*, 32> AllToInit;
  for (unsigned i = 0; i < ivars.size(); i++) {
    FieldDecl *Field = ivars[i];
    if (Field->isInvalidDecl())
      continue;

    CXXCtorInitializer *Member;
    InitializedEntity InitEntity = InitializedEntity::InitializeMember(Field);
    InitializationKind InitKind =
      InitializationKind::CreateDefault(ObjCImplementation->getLocation());

    InitializationSequence InitSeq(*this, InitEntity, InitKind, None);
    ExprResult MemberInit =
      InitSeq.Perform(*this, InitEntity, InitKind, None);
    MemberInit = MaybeCreateExprWithCleanups(MemberInit);
    // Note, MemberInit could actually come back empty if no initialization
    // is required (e.g., because it would call a trivial default constructor)
    if (!MemberInit.get() || MemberInit.isInvalid())
      continue;

    Member =
      new (Context) CXXCtorInitializer(Context, Field, SourceLocation(),
                                       SourceLocation(),
                                       MemberInit.getAs<Expr>(),
                                       SourceLocation());
    AllToInit.push_back(Member);

    // Be sure that the destructor is accessible and is marked as referenced.
    if (const RecordType *RecordTy =
            Context.getBaseElementType(Field->getType())
                ->getAs<RecordType>()) {
      CXXRecordDecl *RD = cast<CXXRecordDecl>(RecordTy->getDecl());
      if (CXXDestructorDecl *Destructor = LookupDestructor(RD)) {
        MarkFunctionReferenced(Field->getLocation(), Destructor);
        CheckDestructorAccess(Field->getLocation(), Destructor,
                          PDiag(diag::err_access_dtor_ivar)
                            << Context.getBaseElementType(Field->getType()));
      }
    }
  }
  ObjCImplementation->setIvarInitializers(Context,
                                          AllToInit.data(), AllToInit.size());
}
17723}

17725static
17726void DelegatingCycleHelper(CXXConstructorDecl* Ctor,
                         llvm::SmallPtrSet<CXXConstructorDecl*, 4> &Valid,
                         llvm::SmallPtrSet<CXXConstructorDecl*, 4> &Invalid,
                         llvm::SmallPtrSet<CXXConstructorDecl*, 4> &Current,
                         Sema &S) {
if (Ctor->isInvalidDecl())
  return;

CXXConstructorDecl *Target = Ctor->getTargetConstructor();

// Target may not be determinable yet, for instance if this is a dependent
// call in an uninstantiated template.
if (Target) {
  const FunctionDecl *FNTarget = nullptr;
  (void)Target->hasBody(FNTarget);
  Target = const_cast<CXXConstructorDecl*>(
    cast_or_null<CXXConstructorDecl>(FNTarget));
}

CXXConstructorDecl *Canonical = Ctor->getCanonicalDecl(),
                   // Avoid dereferencing a null pointer here.
                   *TCanonical = Target? Target->getCanonicalDecl() : nullptr;

if (!Current.insert(Canonical).second)
  return;

// We know that beyond here, we aren't chaining into a cycle.
if (!Target || !Target->isDelegatingConstructor() ||
    Target->isInvalidDecl() || Valid.count(TCanonical)) {
  Valid.insert(Current.begin(), Current.end());
  Current.clear();
// We've hit a cycle.
} else if (TCanonical == Canonical || Invalid.count(TCanonical) ||
           Current.count(TCanonical)) {
  // If we haven't diagnosed this cycle yet, do so now.
  if (!Invalid.count(TCanonical)) {
    S.Diag((*Ctor->init_begin())->getSourceLocation(),
           diag::warn_delegating_ctor_cycle)
      << Ctor;

    // Don't add a note for a function delegating directly to itself.
    if (TCanonical != Canonical)
      S.Diag(Target->getLocation(), diag::note_it_delegates_to);

    CXXConstructorDecl *C = Target;
    while (C->getCanonicalDecl() != Canonical) {
      const FunctionDecl *FNTarget = nullptr;
      (void)C->getTargetConstructor()->hasBody(FNTarget);
      assert(FNTarget && "Ctor cycle through bodiless function")(static_cast<void> (0));

      C = const_cast<CXXConstructorDecl*>(
        cast<CXXConstructorDecl>(FNTarget));
      S.Diag(C->getLocation(), diag::note_which_delegates_to);
    }
  }

  Invalid.insert(Current.begin(), Current.end());
  Current.clear();
} else {
  DelegatingCycleHelper(Target, Valid, Invalid, Current, S);
}
17787}


17790void Sema::CheckDelegatingCtorCycles() {
llvm::SmallPtrSet<CXXConstructorDecl*, 4> Valid, Invalid, Current;

for (DelegatingCtorDeclsType::iterator
       I = DelegatingCtorDecls.begin(ExternalSource),
       E = DelegatingCtorDecls.end();
     I != E; ++I)
  DelegatingCycleHelper(*I, Valid, Invalid, Current, *this);

for (auto CI = Invalid.begin(), CE = Invalid.end(); CI != CE; ++CI)
  (*CI)->setInvalidDecl();
17801}

17803namespace {
/// AST visitor that finds references to the 'this' expression.
class FindCXXThisExpr : public RecursiveASTVisitor<FindCXXThisExpr> {
  Sema &S;

public:
  explicit FindCXXThisExpr(Sema &S) : S(S) { }

  bool VisitCXXThisExpr(CXXThisExpr *E) {
    S.Diag(E->getLocation(), diag::err_this_static_member_func)
      << E->isImplicit();
    return false;
  }
};
17817}

17819bool Sema::checkThisInStaticMemberFunctionType(CXXMethodDecl *Method) {
TypeSourceInfo *TSInfo = Method->getTypeSourceInfo();
if (!TSInfo)
  return false;

TypeLoc TL = TSInfo->getTypeLoc();
FunctionProtoTypeLoc ProtoTL = TL.getAs<FunctionProtoTypeLoc>();
if (!ProtoTL)
  return false;

// C++11 [expr.prim.general]p3:
//   [The expression this] shall not appear before the optional
//   cv-qualifier-seq and it shall not appear within the declaration of a
//   static member function (although its type and value category are defined
//   within a static member function as they are within a non-static member
//   function). [ Note: this is because declaration matching does not occur
//  until the complete declarator is known. - end note ]
const FunctionProtoType *Proto = ProtoTL.getTypePtr();
FindCXXThisExpr Finder(*this);

// If the return type came after the cv-qualifier-seq, check it now.
if (Proto->hasTrailingReturn() &&
    !Finder.TraverseTypeLoc(ProtoTL.getReturnLoc()))
  return true;

// Check the exception specification.
if (checkThisInStaticMemberFunctionExceptionSpec(Method))
  return true;

// Check the trailing requires clause
if (Expr *E = Method->getTrailingRequiresClause())
  if (!Finder.TraverseStmt(E))
    return true;

return checkThisInStaticMemberFunctionAttributes(Method);
17854}

17856bool Sema::checkThisInStaticMemberFunctionExceptionSpec(CXXMethodDecl *Method) {
TypeSourceInfo *TSInfo = Method->getTypeSourceInfo();
if (!TSInfo)
  return false;

TypeLoc TL = TSInfo->getTypeLoc();
FunctionProtoTypeLoc ProtoTL = TL.getAs<FunctionProtoTypeLoc>();
if (!ProtoTL)
  return false;

const FunctionProtoType *Proto = ProtoTL.getTypePtr();
FindCXXThisExpr Finder(*this);

switch (Proto->getExceptionSpecType()) {
case EST_Unparsed:
case EST_Uninstantiated:
case EST_Unevaluated:
case EST_BasicNoexcept:
case EST_NoThrow:
case EST_DynamicNone:
case EST_MSAny:
case EST_None:
  break;

case EST_DependentNoexcept:
case EST_NoexceptFalse:
case EST_NoexceptTrue:
  if (!Finder.TraverseStmt(Proto->getNoexceptExpr()))
    return true;
  LLVM_FALLTHROUGH[[gnu::fallthrough]];

case EST_Dynamic:
  for (const auto &E : Proto->exceptions()) {
    if (!Finder.TraverseType(E))
      return true;
  }
  break;
}

return false;
17896}

17898bool Sema::checkThisInStaticMemberFunctionAttributes(CXXMethodDecl *Method) {
FindCXXThisExpr Finder(*this);

// Check attributes.
for (const auto *A : Method->attrs()) {
  // FIXME: This should be emitted by tblgen.
  Expr *Arg = nullptr;
  ArrayRef<Expr *> Args;
  if (const auto *G = dyn_cast<GuardedByAttr>(A))
    Arg = G->getArg();
  else if (const auto *G = dyn_cast<PtGuardedByAttr>(A))
    Arg = G->getArg();
  else if (const auto *AA = dyn_cast<AcquiredAfterAttr>(A))
    Args = llvm::makeArrayRef(AA->args_begin(), AA->args_size());
  else if (const auto *AB = dyn_cast<AcquiredBeforeAttr>(A))
    Args = llvm::makeArrayRef(AB->args_begin(), AB->args_size());
  else if (const auto *ETLF = dyn_cast<ExclusiveTrylockFunctionAttr>(A)) {
    Arg = ETLF->getSuccessValue();
    Args = llvm::makeArrayRef(ETLF->args_begin(), ETLF->args_size());
  } else if (const auto *STLF = dyn_cast<SharedTrylockFunctionAttr>(A)) {
    Arg = STLF->getSuccessValue();
    Args = llvm::makeArrayRef(STLF->args_begin(), STLF->args_size());
  } else if (const auto *LR = dyn_cast<LockReturnedAttr>(A))
    Arg = LR->getArg();
  else if (const auto *LE = dyn_cast<LocksExcludedAttr>(A))
    Args = llvm::makeArrayRef(LE->args_begin(), LE->args_size());
  else if (const auto *RC = dyn_cast<RequiresCapabilityAttr>(A))
    Args = llvm::makeArrayRef(RC->args_begin(), RC->args_size());
  else if (const auto *AC = dyn_cast<AcquireCapabilityAttr>(A))
    Args = llvm::makeArrayRef(AC->args_begin(), AC->args_size());
  else if (const auto *AC = dyn_cast<TryAcquireCapabilityAttr>(A))
    Args = llvm::makeArrayRef(AC->args_begin(), AC->args_size());
  else if (const auto *RC = dyn_cast<ReleaseCapabilityAttr>(A))
    Args = llvm::makeArrayRef(RC->args_begin(), RC->args_size());

  if (Arg && !Finder.TraverseStmt(Arg))
    return true;

  for (unsigned I = 0, N = Args.size(); I != N; ++I) {
    if (!Finder.TraverseStmt(Args[I]))
      return true;
  }
}

return false;
17943}

17945void Sema::checkExceptionSpecification(
  bool IsTopLevel, ExceptionSpecificationType EST,
  ArrayRef<ParsedType> DynamicExceptions,
  ArrayRef<SourceRange> DynamicExceptionRanges, Expr *NoexceptExpr,
  SmallVectorImpl<QualType> &Exceptions,
  FunctionProtoType::ExceptionSpecInfo &ESI) {
Exceptions.clear();
ESI.Type = EST;
if (EST == EST_Dynamic) {
  Exceptions.reserve(DynamicExceptions.size());
  for (unsigned ei = 0, ee = DynamicExceptions.size(); ei != ee; ++ei) {
    // FIXME: Preserve type source info.
    QualType ET = GetTypeFromParser(DynamicExceptions[ei]);

    if (IsTopLevel) {
      SmallVector<UnexpandedParameterPack, 2> Unexpanded;
      collectUnexpandedParameterPacks(ET, Unexpanded);
      if (!Unexpanded.empty()) {
        DiagnoseUnexpandedParameterPacks(
            DynamicExceptionRanges[ei].getBegin(), UPPC_ExceptionType,
            Unexpanded);
        continue;
      }
    }

    // Check that the type is valid for an exception spec, and
    // drop it if not.
    if (!CheckSpecifiedExceptionType(ET, DynamicExceptionRanges[ei]))
      Exceptions.push_back(ET);
  }
  ESI.Exceptions = Exceptions;
  return;
}

if (isComputedNoexcept(EST)) {
  assert((NoexceptExpr->isTypeDependent() ||(static_cast<void> (0))
          NoexceptExpr->getType()->getCanonicalTypeUnqualified() ==(static_cast<void> (0))
          Context.BoolTy) &&(static_cast<void> (0))
         "Parser should have made sure that the expression is boolean")(static_cast<void> (0));
  if (IsTopLevel && DiagnoseUnexpandedParameterPack(NoexceptExpr)) {
    ESI.Type = EST_BasicNoexcept;
    return;
  }

  ESI.NoexceptExpr = NoexceptExpr;
  return;
}
17992}

17994void Sema::actOnDelayedExceptionSpecification(Decl *MethodD,
           ExceptionSpecificationType EST,
           SourceRange SpecificationRange,
           ArrayRef<ParsedType> DynamicExceptions,
           ArrayRef<SourceRange> DynamicExceptionRanges,
           Expr *NoexceptExpr) {
if (!MethodD)
  return;

// Dig out the method we're referring to.
if (FunctionTemplateDecl *FunTmpl = dyn_cast<FunctionTemplateDecl>(MethodD))
  MethodD = FunTmpl->getTemplatedDecl();

CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(MethodD);
if (!Method)
  return;

// Check the exception specification.
llvm::SmallVector<QualType, 4> Exceptions;
FunctionProtoType::ExceptionSpecInfo ESI;
checkExceptionSpecification(/*IsTopLevel*/true, EST, DynamicExceptions,
                            DynamicExceptionRanges, NoexceptExpr, Exceptions,
                            ESI);

// Update the exception specification on the function type.
Context.adjustExceptionSpec(Method, ESI, /*AsWritten*/true);

if (Method->isStatic())
  checkThisInStaticMemberFunctionExceptionSpec(Method);

if (Method->isVirtual()) {
  // Check overrides, which we previously had to delay.
  for (const CXXMethodDecl *O : Method->overridden_methods())
    CheckOverridingFunctionExceptionSpec(Method, O);
}
18029}

18031/// HandleMSProperty - Analyze a __delcspec(property) field of a C++ class.
18032///
18033MSPropertyDecl *Sema::HandleMSProperty(Scope *S, RecordDecl *Record,
                                     SourceLocation DeclStart, Declarator &D,
                                     Expr *BitWidth,
                                     InClassInitStyle InitStyle,
                                     AccessSpecifier AS,
                                     const ParsedAttr &MSPropertyAttr) {
IdentifierInfo *II = D.getIdentifier();
if (!II) {
  Diag(DeclStart, diag::err_anonymous_property);
  return nullptr;
}
SourceLocation Loc = D.getIdentifierLoc();

TypeSourceInfo *TInfo = GetTypeForDeclarator(D, S);
QualType T = TInfo->getType();
if (getLangOpts().CPlusPlus) {
  CheckExtraCXXDefaultArguments(D);

  if (DiagnoseUnexpandedParameterPack(D.getIdentifierLoc(), TInfo,
                                      UPPC_DataMemberType)) {
    D.setInvalidType();
    T = Context.IntTy;
    TInfo = Context.getTrivialTypeSourceInfo(T, Loc);
  }
}

DiagnoseFunctionSpecifiers(D.getDeclSpec());

if (D.getDeclSpec().isInlineSpecified())
  Diag(D.getDeclSpec().getInlineSpecLoc(), diag::err_inline_non_function)
      << getLangOpts().CPlusPlus17;
if (DeclSpec::TSCS TSCS = D.getDeclSpec().getThreadStorageClassSpec())
  Diag(D.getDeclSpec().getThreadStorageClassSpecLoc(),
       diag::err_invalid_thread)
    << DeclSpec::getSpecifierName(TSCS);

// Check to see if this name was declared as a member previously
NamedDecl *PrevDecl = nullptr;
LookupResult Previous(*this, II, Loc, LookupMemberName,
                      ForVisibleRedeclaration);
LookupName(Previous, S);
switch (Previous.getResultKind()) {
case LookupResult::Found:
case LookupResult::FoundUnresolvedValue:
  PrevDecl = Previous.getAsSingle<NamedDecl>();
  break;

case LookupResult::FoundOverloaded:
  PrevDecl = Previous.getRepresentativeDecl();
  break;

case LookupResult::NotFound:
case LookupResult::NotFoundInCurrentInstantiation:
case LookupResult::Ambiguous:
  break;
}

if (PrevDecl && PrevDecl->isTemplateParameter()) {
  // Maybe we will complain about the shadowed template parameter.
  DiagnoseTemplateParameterShadow(D.getIdentifierLoc(), PrevDecl);
  // Just pretend that we didn't see the previous declaration.
  PrevDecl = nullptr;
}

if (PrevDecl && !isDeclInScope(PrevDecl, Record, S))
  PrevDecl = nullptr;

SourceLocation TSSL = D.getBeginLoc();
MSPropertyDecl *NewPD =
    MSPropertyDecl::Create(Context, Record, Loc, II, T, TInfo, TSSL,
                           MSPropertyAttr.getPropertyDataGetter(),
                           MSPropertyAttr.getPropertyDataSetter());
ProcessDeclAttributes(TUScope, NewPD, D);
NewPD->setAccess(AS);

if (NewPD->isInvalidDecl())
  Record->setInvalidDecl();

if (D.getDeclSpec().isModulePrivateSpecified())
  NewPD->setModulePrivate();

if (NewPD->isInvalidDecl() && PrevDecl) {
  // Don't introduce NewFD into scope; there's already something
  // with the same name in the same scope.
} else if (II) {
  PushOnScopeChains(NewPD, S);
} else
  Record->addDecl(NewPD);

return NewPD;
18123}

18125void Sema::ActOnStartFunctionDeclarationDeclarator(
  Declarator &Declarator, unsigned TemplateParameterDepth) {
auto &Info = InventedParameterInfos.emplace_back();
TemplateParameterList *ExplicitParams = nullptr;
ArrayRef<TemplateParameterList *> ExplicitLists =
    Declarator.getTemplateParameterLists();
if (!ExplicitLists.empty()) {
  bool IsMemberSpecialization, IsInvalid;
  ExplicitParams = MatchTemplateParametersToScopeSpecifier(
      Declarator.getBeginLoc(), Declarator.getIdentifierLoc(),
      Declarator.getCXXScopeSpec(), /*TemplateId=*/nullptr,
      ExplicitLists, /*IsFriend=*/false, IsMemberSpecialization, IsInvalid,
      /*SuppressDiagnostic=*/true);
}
if (ExplicitParams) {
  Info.AutoTemplateParameterDepth = ExplicitParams->getDepth();
  for (NamedDecl *Param : *ExplicitParams)
    Info.TemplateParams.push_back(Param);
  Info.NumExplicitTemplateParams = ExplicitParams->size();
} else {
  Info.AutoTemplateParameterDepth = TemplateParameterDepth;
  Info.NumExplicitTemplateParams = 0;
}
18148}

18150void Sema::ActOnFinishFunctionDeclarationDeclarator(Declarator &Declarator) {
auto &FSI = InventedParameterInfos.back();
if (FSI.TemplateParams.size() > FSI.NumExplicitTemplateParams) {
  if (FSI.NumExplicitTemplateParams != 0) {
    TemplateParameterList *ExplicitParams =
        Declarator.getTemplateParameterLists().back();
    Declarator.setInventedTemplateParameterList(
        TemplateParameterList::Create(
            Context, ExplicitParams->getTemplateLoc(),
            ExplicitParams->getLAngleLoc(), FSI.TemplateParams,
            ExplicitParams->getRAngleLoc(),
            ExplicitParams->getRequiresClause()));
  } else {
    Declarator.setInventedTemplateParameterList(
        TemplateParameterList::Create(
            Context, SourceLocation(), SourceLocation(), FSI.TemplateParams,
            SourceLocation(), /*RequiresClause=*/nullptr));
  }
}
InventedParameterInfos.pop_back();
18170}

←

/build/llvm-toolchain-snapshot-14~++20210903100615+fd66b44ec19e/clang/include/clang/Sema/Ownership.h

→

1//===- Ownership.h - Parser ownership helpers -------------------*- C++ -*-===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8//
9//  This file contains classes for managing ownership of Stmt and Expr nodes.
10//
11//===----------------------------------------------------------------------===//

13#ifndef LLVM_CLANG_SEMA_OWNERSHIP_H
14#define LLVM_CLANG_SEMA_OWNERSHIP_H

16#include "clang/AST/Expr.h"
17#include "clang/Basic/LLVM.h"
18#include "llvm/ADT/ArrayRef.h"
19#include "llvm/Support/PointerLikeTypeTraits.h"
20#include "llvm/Support/type_traits.h"
21#include <cassert>
22#include <cstddef>
23#include <cstdint>

25//===----------------------------------------------------------------------===//
26// OpaquePtr
27//===----------------------------------------------------------------------===//

29namespace clang {

31class CXXBaseSpecifier;
32class CXXCtorInitializer;
33class Decl;
34class Expr;
35class ParsedTemplateArgument;
36class QualType;
37class Stmt;
38class TemplateName;
39class TemplateParameterList;

/// Wrapper for void* pointer.
/// \tparam PtrTy Either a pointer type like 'T*' or a type that behaves like
///               a pointer.
///
/// This is a very simple POD type that wraps a pointer that the Parser
/// doesn't know about but that Sema or another client does.  The PtrTy
/// template argument is used to make sure that "Decl" pointers are not
/// compatible with "Type" pointers for example.
template <class PtrTy>
class OpaquePtr {
  void *Ptr = nullptr;

  explicit OpaquePtr(void *Ptr) : Ptr(Ptr) {}

  using Traits = llvm::PointerLikeTypeTraits<PtrTy>;

public:
  OpaquePtr(std::nullptr_t = nullptr) {}

  static OpaquePtr make(PtrTy P) { OpaquePtr OP; OP.set(P); return OP; }

  /// Returns plain pointer to the entity pointed by this wrapper.
  /// \tparam PointeeT Type of pointed entity.
  ///
  /// It is identical to getPtrAs<PointeeT*>.
  template <typename PointeeT> PointeeT* getPtrTo() const {
    return get();
  }

  /// Returns pointer converted to the specified type.
  /// \tparam PtrT Result pointer type.  There must be implicit conversion
  ///              from PtrTy to PtrT.
  ///
  /// In contrast to getPtrTo, this method allows the return type to be
  /// a smart pointer.
  template <typename PtrT> PtrT getPtrAs() const {
    return get();
  }

  PtrTy get() const {
    return Traits::getFromVoidPointer(Ptr);
  }

  void set(PtrTy P) {
    Ptr = Traits::getAsVoidPointer(P);
  }

  explicit operator bool() const { return Ptr != nullptr; }
14
←
Assuming the condition is false→
15
←
Returning zero, which participates in a condition later→

  void *getAsOpaquePtr() const { return Ptr; }
  static OpaquePtr getFromOpaquePtr(void *P) { return OpaquePtr(P); }
};

/// UnionOpaquePtr - A version of OpaquePtr suitable for membership
/// in a union.
template <class T> struct UnionOpaquePtr {
  void *Ptr;

  static UnionOpaquePtr make(OpaquePtr<T> P) {
    UnionOpaquePtr OP = { P.getAsOpaquePtr() };
    return OP;
  }

  OpaquePtr<T> get() const { return OpaquePtr<T>::getFromOpaquePtr(Ptr); }
  operator OpaquePtr<T>() const { return get(); }

  UnionOpaquePtr &operator=(OpaquePtr<T> P) {
    Ptr = P.getAsOpaquePtr();
    return *this;
  }
};

113} // namespace clang

115namespace llvm {

template <class T>
struct PointerLikeTypeTraits<clang::OpaquePtr<T>> {
  static constexpr int NumLowBitsAvailable = 0;

  static inline void *getAsVoidPointer(clang::OpaquePtr<T> P) {
    // FIXME: Doesn't work? return P.getAs< void >();
    return P.getAsOpaquePtr();
  }

  static inline clang::OpaquePtr<T> getFromVoidPointer(void *P) {
    return clang::OpaquePtr<T>::getFromOpaquePtr(P);
  }
};

131} // namespace llvm

133namespace clang {

// Basic
136class StreamingDiagnostic;

138// Determines whether the low bit of the result pointer for the
139// given UID is always zero. If so, ActionResult will use that bit
140// for it's "invalid" flag.
141template <class Ptr> struct IsResultPtrLowBitFree {
static const bool value = false;
};

/// ActionResult - This structure is used while parsing/acting on
/// expressions, stmts, etc.  It encapsulates both the object returned by
/// the action, plus a sense of whether or not it is valid.
/// When CompressInvalid is true, the "invalid" flag will be
/// stored in the low bit of the Val pointer.
template<class PtrTy,
         bool CompressInvalid = IsResultPtrLowBitFree<PtrTy>::value>
class ActionResult {
  PtrTy Val;
  bool Invalid;

public:
  ActionResult(bool Invalid = false) : Val(PtrTy()), Invalid(Invalid) {}
  ActionResult(PtrTy val) : Val(val), Invalid(false) {}
  ActionResult(const DiagnosticBuilder &) : Val(PtrTy()), Invalid(true) {}

  // These two overloads prevent void* -> bool conversions.
  ActionResult(const void *) = delete;
  ActionResult(volatile void *) = delete;

  bool isInvalid() const { return Invalid; }
  bool isUsable() const { return !Invalid && Val; }
  bool isUnset() const { return !Invalid && !Val; }

  PtrTy get() const { return Val; }
  template <typename T> T *getAs() { return static_cast<T*>(get()); }

  void set(PtrTy V) { Val = V; }

  const ActionResult &operator=(PtrTy RHS) {
    Val = RHS;
    Invalid = false;
    return *this;
  }
};

// This ActionResult partial specialization places the "invalid"
// flag into the low bit of the pointer.
template<typename PtrTy>
class ActionResult<PtrTy, true> {
  // A pointer whose low bit is 1 if this result is invalid, 0
  // otherwise.
  uintptr_t PtrWithInvalid;

  using PtrTraits = llvm::PointerLikeTypeTraits<PtrTy>;

public:
  ActionResult(bool Invalid = false)
      : PtrWithInvalid(static_cast<uintptr_t>(Invalid)) {}

  ActionResult(PtrTy V) {
    void *VP = PtrTraits::getAsVoidPointer(V);
    PtrWithInvalid = reinterpret_cast<uintptr_t>(VP);
    assert((PtrWithInvalid & 0x01) == 0 && "Badly aligned pointer")(static_cast<void> (0));
  }

  ActionResult(const DiagnosticBuilder &) : PtrWithInvalid(0x01) {}

  // These two overloads prevent void* -> bool conversions.
  ActionResult(const void *) = delete;
  ActionResult(volatile void *) = delete;

  bool isInvalid() const { return PtrWithInvalid & 0x01; }
  bool isUsable() const { return PtrWithInvalid > 0x01; }
3
←
Assuming field 'PtrWithInvalid' is > 1→
4
←
Returning the value 1, which participates in a condition later→
  bool isUnset() const { return PtrWithInvalid == 0; }

  PtrTy get() const {
    void *VP = reinterpret_cast<void *>(PtrWithInvalid & ~0x01);
    return PtrTraits::getFromVoidPointer(VP);
  }

  template <typename T> T *getAs() { return static_cast<T*>(get()); }

  void set(PtrTy V) {
    void *VP = PtrTraits::getAsVoidPointer(V);
    PtrWithInvalid = reinterpret_cast<uintptr_t>(VP);
    assert((PtrWithInvalid & 0x01) == 0 && "Badly aligned pointer")(static_cast<void> (0));
  }

  const ActionResult &operator=(PtrTy RHS) {
    void *VP = PtrTraits::getAsVoidPointer(RHS);
    PtrWithInvalid = reinterpret_cast<uintptr_t>(VP);
    assert((PtrWithInvalid & 0x01) == 0 && "Badly aligned pointer")(static_cast<void> (0));
    return *this;
  }

  // For types where we can fit a flag in with the pointer, provide
  // conversions to/from pointer type.
  static ActionResult getFromOpaquePointer(void *P) {
    ActionResult Result;
    Result.PtrWithInvalid = (uintptr_t)P;
    return Result;
  }
  void *getAsOpaquePointer() const { return (void*)PtrWithInvalid; }
};

/// An opaque type for threading parsed type information through the
/// parser.
using ParsedType = OpaquePtr<QualType>;
using UnionParsedType = UnionOpaquePtr<QualType>;

// We can re-use the low bit of expression, statement, base, and
// member-initializer pointers for the "invalid" flag of
// ActionResult.
template<> struct IsResultPtrLowBitFree<Expr*> {
  static const bool value = true;
};
template<> struct IsResultPtrLowBitFree<Stmt*> {
  static const bool value = true;
};
template<> struct IsResultPtrLowBitFree<CXXBaseSpecifier*> {
  static const bool value = true;
};
template<> struct IsResultPtrLowBitFree<CXXCtorInitializer*> {
  static const bool value = true;
};

using ExprResult = ActionResult<Expr *>;
using StmtResult = ActionResult<Stmt *>;
using TypeResult = ActionResult<ParsedType>;
using BaseResult = ActionResult<CXXBaseSpecifier *>;
using MemInitResult = ActionResult<CXXCtorInitializer *>;

using DeclResult = ActionResult<Decl *>;
using ParsedTemplateTy = OpaquePtr<TemplateName>;
using UnionParsedTemplateTy = UnionOpaquePtr<TemplateName>;

using MultiExprArg = MutableArrayRef<Expr *>;
using MultiStmtArg = MutableArrayRef<Stmt *>;
using ASTTemplateArgsPtr = MutableArrayRef<ParsedTemplateArgument>;
using MultiTypeArg = MutableArrayRef<ParsedType>;
using MultiTemplateParamsArg = MutableArrayRef<TemplateParameterList *>;

inline ExprResult ExprError() { return ExprResult(true); }
inline StmtResult StmtError() { return StmtResult(true); }
inline TypeResult TypeError() { return TypeResult(true); }

inline ExprResult ExprError(const StreamingDiagnostic &) {
  return ExprError();
}
inline StmtResult StmtError(const StreamingDiagnostic &) {
  return StmtError();
}

inline ExprResult ExprEmpty() { return ExprResult(false); }
inline StmtResult StmtEmpty() { return StmtResult(false); }

inline Expr *AssertSuccess(ExprResult R) {
  assert(!R.isInvalid() && "operation was asserted to never fail!")(static_cast<void> (0));
  return R.get();
}

inline Stmt *AssertSuccess(StmtResult R) {
  assert(!R.isInvalid() && "operation was asserted to never fail!")(static_cast<void> (0));
  return R.get();
}

302} // namespace clang

304#endif // LLVM_CLANG_SEMA_OWNERSHIP_H

←

/build/llvm-toolchain-snapshot-14~++20210903100615+fd66b44ec19e/clang/include/clang/Sema/DeclSpec.h

→

1//===--- DeclSpec.h - Parsed declaration specifiers -------------*- C++ -*-===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8///
9/// \file
10/// This file defines the classes used to store parsed information about
11/// declaration-specifiers and declarators.
12///
13/// \verbatim
14///   static const int volatile x, *y, *(*(*z)[10])(const void *x);
15///   ------------------------- -  --  ---------------------------
16///     declaration-specifiers  \  |   /
17///                            declarators
18/// \endverbatim
19///
20//===----------------------------------------------------------------------===//

22#ifndef LLVM_CLANG_SEMA_DECLSPEC_H
23#define LLVM_CLANG_SEMA_DECLSPEC_H

25#include "clang/AST/DeclCXX.h"
26#include "clang/AST/DeclObjCCommon.h"
27#include "clang/AST/NestedNameSpecifier.h"
28#include "clang/Basic/ExceptionSpecificationType.h"
29#include "clang/Basic/Lambda.h"
30#include "clang/Basic/OperatorKinds.h"
31#include "clang/Basic/Specifiers.h"
32#include "clang/Lex/Token.h"
33#include "clang/Sema/Ownership.h"
34#include "clang/Sema/ParsedAttr.h"
35#include "llvm/ADT/SmallVector.h"
36#include "llvm/Support/Compiler.h"
37#include "llvm/Support/ErrorHandling.h"

39namespace clang {
class ASTContext;
class CXXRecordDecl;
class TypeLoc;
class LangOptions;
class IdentifierInfo;
class NamespaceAliasDecl;
class NamespaceDecl;
class ObjCDeclSpec;
class Sema;
class Declarator;
struct TemplateIdAnnotation;

52/// Represents a C++ nested-name-specifier or a global scope specifier.
53///
54/// These can be in 3 states:
55///   1) Not present, identified by isEmpty()
56///   2) Present, identified by isNotEmpty()
57///      2.a) Valid, identified by isValid()
58///      2.b) Invalid, identified by isInvalid().
59///
60/// isSet() is deprecated because it mostly corresponded to "valid" but was
61/// often used as if it meant "present".
62///
63/// The actual scope is described by getScopeRep().
64class CXXScopeSpec {
SourceRange Range;
NestedNameSpecifierLocBuilder Builder;

68public:
SourceRange getRange() const { return Range; }
void setRange(SourceRange R) { Range = R; }
void setBeginLoc(SourceLocation Loc) { Range.setBegin(Loc); }
void setEndLoc(SourceLocation Loc) { Range.setEnd(Loc); }
SourceLocation getBeginLoc() const { return Range.getBegin(); }
SourceLocation getEndLoc() const { return Range.getEnd(); }

/// Retrieve the representation of the nested-name-specifier.
NestedNameSpecifier *getScopeRep() const {
  return Builder.getRepresentation();
}

/// Extend the current nested-name-specifier by another
/// nested-name-specifier component of the form 'type::'.
///
/// \param Context The AST context in which this nested-name-specifier
/// resides.
///
/// \param TemplateKWLoc The location of the 'template' keyword, if present.
///
/// \param TL The TypeLoc that describes the type preceding the '::'.
///
/// \param ColonColonLoc The location of the trailing '::'.
void Extend(ASTContext &Context, SourceLocation TemplateKWLoc, TypeLoc TL,
            SourceLocation ColonColonLoc);

/// Extend the current nested-name-specifier by another
/// nested-name-specifier component of the form 'identifier::'.
///
/// \param Context The AST context in which this nested-name-specifier
/// resides.
///
/// \param Identifier The identifier.
///
/// \param IdentifierLoc The location of the identifier.
///
/// \param ColonColonLoc The location of the trailing '::'.
void Extend(ASTContext &Context, IdentifierInfo *Identifier,
            SourceLocation IdentifierLoc, SourceLocation ColonColonLoc);

/// Extend the current nested-name-specifier by another
/// nested-name-specifier component of the form 'namespace::'.
///
/// \param Context The AST context in which this nested-name-specifier
/// resides.
///
/// \param Namespace The namespace.
///
/// \param NamespaceLoc The location of the namespace name.
///
/// \param ColonColonLoc The location of the trailing '::'.
void Extend(ASTContext &Context, NamespaceDecl *Namespace,
            SourceLocation NamespaceLoc, SourceLocation ColonColonLoc);

/// Extend the current nested-name-specifier by another
/// nested-name-specifier component of the form 'namespace-alias::'.
///
/// \param Context The AST context in which this nested-name-specifier
/// resides.
///
/// \param Alias The namespace alias.
///
/// \param AliasLoc The location of the namespace alias
/// name.
///
/// \param ColonColonLoc The location of the trailing '::'.
void Extend(ASTContext &Context, NamespaceAliasDecl *Alias,
            SourceLocation AliasLoc, SourceLocation ColonColonLoc);

/// Turn this (empty) nested-name-specifier into the global
/// nested-name-specifier '::'.
void MakeGlobal(ASTContext &Context, SourceLocation ColonColonLoc);

/// Turns this (empty) nested-name-specifier into '__super'
/// nested-name-specifier.
///
/// \param Context The AST context in which this nested-name-specifier
/// resides.
///
/// \param RD The declaration of the class in which nested-name-specifier
/// appeared.
///
/// \param SuperLoc The location of the '__super' keyword.
/// name.
///
/// \param ColonColonLoc The location of the trailing '::'.
void MakeSuper(ASTContext &Context, CXXRecordDecl *RD,
               SourceLocation SuperLoc, SourceLocation ColonColonLoc);

/// Make a new nested-name-specifier from incomplete source-location
/// information.
///
/// FIXME: This routine should be used very, very rarely, in cases where we
/// need to synthesize a nested-name-specifier. Most code should instead use
/// \c Adopt() with a proper \c NestedNameSpecifierLoc.
void MakeTrivial(ASTContext &Context, NestedNameSpecifier *Qualifier,
                 SourceRange R);

/// Adopt an existing nested-name-specifier (with source-range
/// information).
void Adopt(NestedNameSpecifierLoc Other);

/// Retrieve a nested-name-specifier with location information, copied
/// into the given AST context.
///
/// \param Context The context into which this nested-name-specifier will be
/// copied.
NestedNameSpecifierLoc getWithLocInContext(ASTContext &Context) const;

/// Retrieve the location of the name in the last qualifier
/// in this nested name specifier.
///
/// For example, the location of \c bar
/// in
/// \verbatim
///   \::foo::bar<0>::
///           ^~~
/// \endverbatim
SourceLocation getLastQualifierNameLoc() const;

/// No scope specifier.
bool isEmpty() const { return Range.isInvalid() && getScopeRep() == nullptr; }
/// A scope specifier is present, but may be valid or invalid.
bool isNotEmpty() const { return !isEmpty(); }

/// An error occurred during parsing of the scope specifier.
bool isInvalid() const { return Range.isValid() && getScopeRep() == nullptr; }
/// A scope specifier is present, and it refers to a real scope.
bool isValid() const { return getScopeRep() != nullptr; }

/// Indicate that this nested-name-specifier is invalid.
void SetInvalid(SourceRange R) {
  assert(R.isValid() && "Must have a valid source range")(static_cast<void> (0));
  if (Range.getBegin().isInvalid())
    Range.setBegin(R.getBegin());
  Range.setEnd(R.getEnd());
  Builder.Clear();
}

/// Deprecated.  Some call sites intend isNotEmpty() while others intend
/// isValid().
bool isSet() const { return getScopeRep() != nullptr; }
28
←
Assuming the condition is true→
29
←
Returning the value 1, which participates in a condition later→

void clear() {
  Range = SourceRange();
  Builder.Clear();
}

/// Retrieve the data associated with the source-location information.
char *location_data() const { return Builder.getBuffer().first; }

/// Retrieve the size of the data associated with source-location
/// information.
unsigned location_size() const { return Builder.getBuffer().second; }
223};

225/// Captures information about "declaration specifiers".
226///
227/// "Declaration specifiers" encompasses storage-class-specifiers,
228/// type-specifiers, type-qualifiers, and function-specifiers.
229class DeclSpec {
230public:
/// storage-class-specifier
/// \note The order of these enumerators is important for diagnostics.
enum SCS {
  SCS_unspecified = 0,
  SCS_typedef,
  SCS_extern,
  SCS_static,
  SCS_auto,
  SCS_register,
  SCS_private_extern,
  SCS_mutable
};

// Import thread storage class specifier enumeration and constants.
// These can be combined with SCS_extern and SCS_static.
typedef ThreadStorageClassSpecifier TSCS;
static const TSCS TSCS_unspecified = clang::TSCS_unspecified;
static const TSCS TSCS___thread = clang::TSCS___thread;
static const TSCS TSCS_thread_local = clang::TSCS_thread_local;
static const TSCS TSCS__Thread_local = clang::TSCS__Thread_local;

enum TSC {
  TSC_unspecified,
  TSC_imaginary,
  TSC_complex
};

// Import type specifier type enumeration and constants.
typedef TypeSpecifierType TST;
static const TST TST_unspecified = clang::TST_unspecified;
static const TST TST_void = clang::TST_void;
static const TST TST_char = clang::TST_char;
static const TST TST_wchar = clang::TST_wchar;
static const TST TST_char8 = clang::TST_char8;
static const TST TST_char16 = clang::TST_char16;
static const TST TST_char32 = clang::TST_char32;
static const TST TST_int = clang::TST_int;
static const TST TST_int128 = clang::TST_int128;
static const TST TST_extint = clang::TST_extint;
static const TST TST_half = clang::TST_half;
static const TST TST_BFloat16 = clang::TST_BFloat16;
static const TST TST_float = clang::TST_float;
static const TST TST_double = clang::TST_double;
static const TST TST_float16 = clang::TST_Float16;
static const TST TST_accum = clang::TST_Accum;
static const TST TST_fract = clang::TST_Fract;
static const TST TST_float128 = clang::TST_float128;
static const TST TST_bool = clang::TST_bool;
static const TST TST_decimal32 = clang::TST_decimal32;
static const TST TST_decimal64 = clang::TST_decimal64;
static const TST TST_decimal128 = clang::TST_decimal128;
static const TST TST_enum = clang::TST_enum;
static const TST TST_union = clang::TST_union;
static const TST TST_struct = clang::TST_struct;
static const TST TST_interface = clang::TST_interface;
static const TST TST_class = clang::TST_class;
static const TST TST_typename = clang::TST_typename;
static const TST TST_typeofType = clang::TST_typeofType;
static const TST TST_typeofExpr = clang::TST_typeofExpr;
static const TST TST_decltype = clang::TST_decltype;
static const TST TST_decltype_auto = clang::TST_decltype_auto;
static const TST TST_underlyingType = clang::TST_underlyingType;
static const TST TST_auto = clang::TST_auto;
static const TST TST_auto_type = clang::TST_auto_type;
static const TST TST_unknown_anytype = clang::TST_unknown_anytype;
static const TST TST_atomic = clang::TST_atomic;
297#define GENERIC_IMAGE_TYPE(ImgType, Id) \
static const TST TST_##ImgType##_t = clang::TST_##ImgType##_t;
299#include "clang/Basic/OpenCLImageTypes.def"
static const TST TST_error = clang::TST_error;

// type-qualifiers
enum TQ {   // NOTE: These flags must be kept in sync with Qualifiers::TQ.
  TQ_unspecified = 0,
  TQ_const       = 1,
  TQ_restrict    = 2,
  TQ_volatile    = 4,
  TQ_unaligned   = 8,
  // This has no corresponding Qualifiers::TQ value, because it's not treated
  // as a qualifier in our type system.
  TQ_atomic      = 16
};

/// ParsedSpecifiers - Flags to query which specifiers were applied.  This is
/// returned by getParsedSpecifiers.
enum ParsedSpecifiers {
  PQ_None                  = 0,
  PQ_StorageClassSpecifier = 1,
  PQ_TypeSpecifier         = 2,
  PQ_TypeQualifier         = 4,
  PQ_FunctionSpecifier     = 8
  // FIXME: Attributes should be included here.
};

325private:
// storage-class-specifier
/*SCS*/unsigned StorageClassSpec : 3;
/*TSCS*/unsigned ThreadStorageClassSpec : 2;
unsigned SCS_extern_in_linkage_spec : 1;

// type-specifier
/*TypeSpecifierWidth*/ unsigned TypeSpecWidth : 2;
/*TSC*/unsigned TypeSpecComplex : 2;
/*TSS*/unsigned TypeSpecSign : 2;
/*TST*/unsigned TypeSpecType : 6;
unsigned TypeAltiVecVector : 1;
unsigned TypeAltiVecPixel : 1;
unsigned TypeAltiVecBool : 1;
unsigned TypeSpecOwned : 1;
unsigned TypeSpecPipe : 1;
unsigned TypeSpecSat : 1;
unsigned ConstrainedAuto : 1;

// type-qualifiers
unsigned TypeQualifiers : 5;  // Bitwise OR of TQ.

// function-specifier
unsigned FS_inline_specified : 1;
unsigned FS_forceinline_specified: 1;
unsigned FS_virtual_specified : 1;
unsigned FS_noreturn_specified : 1;

// friend-specifier
unsigned Friend_specified : 1;

// constexpr-specifier
unsigned ConstexprSpecifier : 2;

union {
  UnionParsedType TypeRep;
  Decl *DeclRep;
  Expr *ExprRep;
  TemplateIdAnnotation *TemplateIdRep;
};

/// ExplicitSpecifier - Store information about explicit spicifer.
ExplicitSpecifier FS_explicit_specifier;

// attributes.
ParsedAttributes Attrs;

// Scope specifier for the type spec, if applicable.
CXXScopeSpec TypeScope;

// SourceLocation info.  These are null if the item wasn't specified or if
// the setting was synthesized.
SourceRange Range;

SourceLocation StorageClassSpecLoc, ThreadStorageClassSpecLoc;
SourceRange TSWRange;
SourceLocation TSCLoc, TSSLoc, TSTLoc, AltiVecLoc, TSSatLoc;
/// TSTNameLoc - If TypeSpecType is any of class, enum, struct, union,
/// typename, then this is the location of the named type (if present);
/// otherwise, it is the same as TSTLoc. Hence, the pair TSTLoc and
/// TSTNameLoc provides source range info for tag types.
SourceLocation TSTNameLoc;
SourceRange TypeofParensRange;
SourceLocation TQ_constLoc, TQ_restrictLoc, TQ_volatileLoc, TQ_atomicLoc,
    TQ_unalignedLoc;
SourceLocation FS_inlineLoc, FS_virtualLoc, FS_explicitLoc, FS_noreturnLoc;
SourceLocation FS_explicitCloseParenLoc;
SourceLocation FS_forceinlineLoc;
SourceLocation FriendLoc, ModulePrivateLoc, ConstexprLoc;
SourceLocation TQ_pipeLoc;

WrittenBuiltinSpecs writtenBS;
void SaveWrittenBuiltinSpecs();

ObjCDeclSpec *ObjCQualifiers;

static bool isTypeRep(TST T) {
  return (T == TST_typename || T == TST_typeofType ||
          T == TST_underlyingType || T == TST_atomic);
}
static bool isExprRep(TST T) {
  return (T == TST_typeofExpr || T == TST_decltype || T == TST_extint);
}
static bool isTemplateIdRep(TST T) {
  return (T == TST_auto || T == TST_decltype_auto);
}

DeclSpec(const DeclSpec &) = delete;
void operator=(const DeclSpec &) = delete;
414public:
static bool isDeclRep(TST T) {
  return (T == TST_enum || T == TST_struct ||
          T == TST_interface || T == TST_union ||
          T == TST_class);
}

DeclSpec(AttributeFactory &attrFactory)
    : StorageClassSpec(SCS_unspecified),
      ThreadStorageClassSpec(TSCS_unspecified),
      SCS_extern_in_linkage_spec(false),
      TypeSpecWidth(static_cast<unsigned>(TypeSpecifierWidth::Unspecified)),
      TypeSpecComplex(TSC_unspecified),
      TypeSpecSign(static_cast<unsigned>(TypeSpecifierSign::Unspecified)),
      TypeSpecType(TST_unspecified), TypeAltiVecVector(false),
      TypeAltiVecPixel(false), TypeAltiVecBool(false), TypeSpecOwned(false),
      TypeSpecPipe(false), TypeSpecSat(false), ConstrainedAuto(false),
      TypeQualifiers(TQ_unspecified), FS_inline_specified(false),
      FS_forceinline_specified(false), FS_virtual_specified(false),
      FS_noreturn_specified(false), Friend_specified(false),
      ConstexprSpecifier(
          static_cast<unsigned>(ConstexprSpecKind::Unspecified)),
      FS_explicit_specifier(), Attrs(attrFactory), writtenBS(),
      ObjCQualifiers(nullptr) {}

// storage-class-specifier
SCS getStorageClassSpec() const { return (SCS)StorageClassSpec; }
TSCS getThreadStorageClassSpec() const {
  return (TSCS)ThreadStorageClassSpec;
}
bool isExternInLinkageSpec() const { return SCS_extern_in_linkage_spec; }
void setExternInLinkageSpec(bool Value) {
  SCS_extern_in_linkage_spec = Value;
}

SourceLocation getStorageClassSpecLoc() const { return StorageClassSpecLoc; }
SourceLocation getThreadStorageClassSpecLoc() const {
  return ThreadStorageClassSpecLoc;
}

void ClearStorageClassSpecs() {
  StorageClassSpec           = DeclSpec::SCS_unspecified;
  ThreadStorageClassSpec     = DeclSpec::TSCS_unspecified;
  SCS_extern_in_linkage_spec = false;
  StorageClassSpecLoc        = SourceLocation();
  ThreadStorageClassSpecLoc  = SourceLocation();
}

void ClearTypeSpecType() {
  TypeSpecType = DeclSpec::TST_unspecified;
  TypeSpecOwned = false;
  TSTLoc = SourceLocation();
}

// type-specifier
TypeSpecifierWidth getTypeSpecWidth() const {
  return static_cast<TypeSpecifierWidth>(TypeSpecWidth);
}
TSC getTypeSpecComplex() const { return (TSC)TypeSpecComplex; }
TypeSpecifierSign getTypeSpecSign() const {
  return static_cast<TypeSpecifierSign>(TypeSpecSign);
}
TST getTypeSpecType() const { return (TST)TypeSpecType; }
bool isTypeAltiVecVector() const { return TypeAltiVecVector; }
bool isTypeAltiVecPixel() const { return TypeAltiVecPixel; }
bool isTypeAltiVecBool() const { return TypeAltiVecBool; }
bool isTypeSpecOwned() const { return TypeSpecOwned; }
bool isTypeRep() const { return isTypeRep((TST) TypeSpecType); }
bool isTypeSpecPipe() const { return TypeSpecPipe; }
bool isTypeSpecSat() const { return TypeSpecSat; }
bool isConstrainedAuto() const { return ConstrainedAuto; }

ParsedType getRepAsType() const {
  assert(isTypeRep((TST) TypeSpecType) && "DeclSpec does not store a type")(static_cast<void> (0));
  return TypeRep;
}
Decl *getRepAsDecl() const {
  assert(isDeclRep((TST) TypeSpecType) && "DeclSpec does not store a decl")(static_cast<void> (0));
  return DeclRep;
}
Expr *getRepAsExpr() const {
  assert(isExprRep((TST) TypeSpecType) && "DeclSpec does not store an expr")(static_cast<void> (0));
  return ExprRep;
}
TemplateIdAnnotation *getRepAsTemplateId() const {
  assert(isTemplateIdRep((TST) TypeSpecType) &&(static_cast<void> (0))
         "DeclSpec does not store a template id")(static_cast<void> (0));
  return TemplateIdRep;
}
CXXScopeSpec &getTypeSpecScope() { return TypeScope; }
const CXXScopeSpec &getTypeSpecScope() const { return TypeScope; }

SourceRange getSourceRange() const LLVM_READONLY__attribute__((__pure__)) { return Range; }
SourceLocation getBeginLoc() const LLVM_READONLY__attribute__((__pure__)) { return Range.getBegin(); }
SourceLocation getEndLoc() const LLVM_READONLY__attribute__((__pure__)) { return Range.getEnd(); }

SourceLocation getTypeSpecWidthLoc() const { return TSWRange.getBegin(); }
SourceRange getTypeSpecWidthRange() const { return TSWRange; }
SourceLocation getTypeSpecComplexLoc() const { return TSCLoc; }
SourceLocation getTypeSpecSignLoc() const { return TSSLoc; }
SourceLocation getTypeSpecTypeLoc() const { return TSTLoc; }
SourceLocation getAltiVecLoc() const { return AltiVecLoc; }
SourceLocation getTypeSpecSatLoc() const { return TSSatLoc; }

SourceLocation getTypeSpecTypeNameLoc() const {
  assert(isDeclRep((TST) TypeSpecType) || TypeSpecType == TST_typename)(static_cast<void> (0));
  return TSTNameLoc;
}

SourceRange getTypeofParensRange() const { return TypeofParensRange; }
void setTypeofParensRange(SourceRange range) { TypeofParensRange = range; }

bool hasAutoTypeSpec() const {
  return (TypeSpecType == TST_auto || TypeSpecType == TST_auto_type ||
          TypeSpecType == TST_decltype_auto);
}

bool hasTagDefinition() const;

/// Turn a type-specifier-type into a string like "_Bool" or "union".
static const char *getSpecifierName(DeclSpec::TST T,
                                    const PrintingPolicy &Policy);
static const char *getSpecifierName(DeclSpec::TQ Q);
static const char *getSpecifierName(TypeSpecifierSign S);
static const char *getSpecifierName(DeclSpec::TSC C);
static const char *getSpecifierName(TypeSpecifierWidth W);
static const char *getSpecifierName(DeclSpec::SCS S);
static const char *getSpecifierName(DeclSpec::TSCS S);
static const char *getSpecifierName(ConstexprSpecKind C);

// type-qualifiers

/// getTypeQualifiers - Return a set of TQs.
unsigned getTypeQualifiers() const { return TypeQualifiers; }
SourceLocation getConstSpecLoc() const { return TQ_constLoc; }
SourceLocation getRestrictSpecLoc() const { return TQ_restrictLoc; }
SourceLocation getVolatileSpecLoc() const { return TQ_volatileLoc; }
SourceLocation getAtomicSpecLoc() const { return TQ_atomicLoc; }
SourceLocation getUnalignedSpecLoc() const { return TQ_unalignedLoc; }
SourceLocation getPipeLoc() const { return TQ_pipeLoc; }

/// Clear out all of the type qualifiers.
void ClearTypeQualifiers() {
  TypeQualifiers = 0;
  TQ_constLoc = SourceLocation();
  TQ_restrictLoc = SourceLocation();
  TQ_volatileLoc = SourceLocation();
  TQ_atomicLoc = SourceLocation();
  TQ_unalignedLoc = SourceLocation();
  TQ_pipeLoc = SourceLocation();
}

// function-specifier
bool isInlineSpecified() const {
  return FS_inline_specified | FS_forceinline_specified;
}
SourceLocation getInlineSpecLoc() const {
  return FS_inline_specified ? FS_inlineLoc : FS_forceinlineLoc;
}

ExplicitSpecifier getExplicitSpecifier() const {
  return FS_explicit_specifier;
}

bool isVirtualSpecified() const { return FS_virtual_specified; }
SourceLocation getVirtualSpecLoc() const { return FS_virtualLoc; }

bool hasExplicitSpecifier() const {
  return FS_explicit_specifier.isSpecified();
}
SourceLocation getExplicitSpecLoc() const { return FS_explicitLoc; }
SourceRange getExplicitSpecRange() const {
  return FS_explicit_specifier.getExpr()
             ? SourceRange(FS_explicitLoc, FS_explicitCloseParenLoc)
             : SourceRange(FS_explicitLoc);
}

bool isNoreturnSpecified() const { return FS_noreturn_specified; }
SourceLocation getNoreturnSpecLoc() const { return FS_noreturnLoc; }

void ClearFunctionSpecs() {
  FS_inline_specified = false;
  FS_inlineLoc = SourceLocation();
  FS_forceinline_specified = false;
  FS_forceinlineLoc = SourceLocation();
  FS_virtual_specified = false;
  FS_virtualLoc = SourceLocation();
  FS_explicit_specifier = ExplicitSpecifier();
  FS_explicitLoc = SourceLocation();
  FS_explicitCloseParenLoc = SourceLocation();
  FS_noreturn_specified = false;
  FS_noreturnLoc = SourceLocation();
}

/// This method calls the passed in handler on each CVRU qual being
/// set.
/// Handle - a handler to be invoked.
void forEachCVRUQualifier(
    llvm::function_ref<void(TQ, StringRef, SourceLocation)> Handle);

/// This method calls the passed in handler on each qual being
/// set.
/// Handle - a handler to be invoked.
void forEachQualifier(
    llvm::function_ref<void(TQ, StringRef, SourceLocation)> Handle);

/// Return true if any type-specifier has been found.
bool hasTypeSpecifier() const {
  return getTypeSpecType() != DeclSpec::TST_unspecified ||
         getTypeSpecWidth() != TypeSpecifierWidth::Unspecified ||
         getTypeSpecComplex() != DeclSpec::TSC_unspecified ||
         getTypeSpecSign() != TypeSpecifierSign::Unspecified;
}

/// Return a bitmask of which flavors of specifiers this
/// DeclSpec includes.
unsigned getParsedSpecifiers() const;

/// isEmpty - Return true if this declaration specifier is completely empty:
/// no tokens were parsed in the production of it.
bool isEmpty() const {
  return getParsedSpecifiers() == DeclSpec::PQ_None;
}

void SetRangeStart(SourceLocation Loc) { Range.setBegin(Loc); }
void SetRangeEnd(SourceLocation Loc) { Range.setEnd(Loc); }

/// These methods set the specified attribute of the DeclSpec and
/// return false if there was no error.  If an error occurs (for
/// example, if we tried to set "auto" on a spec with "extern"
/// already set), they return true and set PrevSpec and DiagID
/// such that
///   Diag(Loc, DiagID) << PrevSpec;
/// will yield a useful result.
///
/// TODO: use a more general approach that still allows these
/// diagnostics to be ignored when desired.
bool SetStorageClassSpec(Sema &S, SCS SC, SourceLocation Loc,
                         const char *&PrevSpec, unsigned &DiagID,
                         const PrintingPolicy &Policy);
bool SetStorageClassSpecThread(TSCS TSC, SourceLocation Loc,
                               const char *&PrevSpec, unsigned &DiagID);
bool SetTypeSpecWidth(TypeSpecifierWidth W, SourceLocation Loc,
                      const char *&PrevSpec, unsigned &DiagID,
                      const PrintingPolicy &Policy);
bool SetTypeSpecComplex(TSC C, SourceLocation Loc, const char *&PrevSpec,
                        unsigned &DiagID);
bool SetTypeSpecSign(TypeSpecifierSign S, SourceLocation Loc,
                     const char *&PrevSpec, unsigned &DiagID);
bool SetTypeSpecType(TST T, SourceLocation Loc, const char *&PrevSpec,
                     unsigned &DiagID, const PrintingPolicy &Policy);
bool SetTypeSpecType(TST T, SourceLocation Loc, const char *&PrevSpec,
                     unsigned &DiagID, ParsedType Rep,
                     const PrintingPolicy &Policy);
bool SetTypeSpecType(TST T, SourceLocation Loc, const char *&PrevSpec,
                     unsigned &DiagID, TypeResult Rep,
                     const PrintingPolicy &Policy) {
  if (Rep.isInvalid())
    return SetTypeSpecError();
  return SetTypeSpecType(T, Loc, PrevSpec, DiagID, Rep.get(), Policy);
}
bool SetTypeSpecType(TST T, SourceLocation Loc, const char *&PrevSpec,
                     unsigned &DiagID, Decl *Rep, bool Owned,
                     const PrintingPolicy &Policy);
bool SetTypeSpecType(TST T, SourceLocation TagKwLoc,
                     SourceLocation TagNameLoc, const char *&PrevSpec,
                     unsigned &DiagID, ParsedType Rep,
                     const PrintingPolicy &Policy);
bool SetTypeSpecType(TST T, SourceLocation TagKwLoc,
                     SourceLocation TagNameLoc, const char *&PrevSpec,
                     unsigned &DiagID, Decl *Rep, bool Owned,
                     const PrintingPolicy &Policy);
bool SetTypeSpecType(TST T, SourceLocation Loc, const char *&PrevSpec,
                     unsigned &DiagID, TemplateIdAnnotation *Rep,
                     const PrintingPolicy &Policy);

bool SetTypeSpecType(TST T, SourceLocation Loc, const char *&PrevSpec,
                     unsigned &DiagID, Expr *Rep,
                     const PrintingPolicy &policy);
bool SetTypeAltiVecVector(bool isAltiVecVector, SourceLocation Loc,
                     const char *&PrevSpec, unsigned &DiagID,
                     const PrintingPolicy &Policy);
bool SetTypeAltiVecPixel(bool isAltiVecPixel, SourceLocation Loc,
                     const char *&PrevSpec, unsigned &DiagID,
                     const PrintingPolicy &Policy);
bool SetTypeAltiVecBool(bool isAltiVecBool, SourceLocation Loc,
                     const char *&PrevSpec, unsigned &DiagID,
                     const PrintingPolicy &Policy);
bool SetTypePipe(bool isPipe, SourceLocation Loc,
                     const char *&PrevSpec, unsigned &DiagID,
                     const PrintingPolicy &Policy);
bool SetExtIntType(SourceLocation KWLoc, Expr *BitWidth,
                   const char *&PrevSpec, unsigned &DiagID,
                   const PrintingPolicy &Policy);
bool SetTypeSpecSat(SourceLocation Loc, const char *&PrevSpec,
                    unsigned &DiagID);
bool SetTypeSpecError();
void UpdateDeclRep(Decl *Rep) {
  assert(isDeclRep((TST) TypeSpecType))(static_cast<void> (0));
  DeclRep = Rep;
}
void UpdateTypeRep(ParsedType Rep) {
  assert(isTypeRep((TST) TypeSpecType))(static_cast<void> (0));
  TypeRep = Rep;
}
void UpdateExprRep(Expr *Rep) {
  assert(isExprRep((TST) TypeSpecType))(static_cast<void> (0));
  ExprRep = Rep;
}

bool SetTypeQual(TQ T, SourceLocation Loc);

bool SetTypeQual(TQ T, SourceLocation Loc, const char *&PrevSpec,
                 unsigned &DiagID, const LangOptions &Lang);

bool setFunctionSpecInline(SourceLocation Loc, const char *&PrevSpec,
                           unsigned &DiagID);
bool setFunctionSpecForceInline(SourceLocation Loc, const char *&PrevSpec,
                                unsigned &DiagID);
bool setFunctionSpecVirtual(SourceLocation Loc, const char *&PrevSpec,
                            unsigned &DiagID);
bool setFunctionSpecExplicit(SourceLocation Loc, const char *&PrevSpec,
                             unsigned &DiagID, ExplicitSpecifier ExplicitSpec,
                             SourceLocation CloseParenLoc);
bool setFunctionSpecNoreturn(SourceLocation Loc, const char *&PrevSpec,
                             unsigned &DiagID);

bool SetFriendSpec(SourceLocation Loc, const char *&PrevSpec,
                   unsigned &DiagID);
bool setModulePrivateSpec(SourceLocation Loc, const char *&PrevSpec,
                          unsigned &DiagID);
bool SetConstexprSpec(ConstexprSpecKind ConstexprKind, SourceLocation Loc,
                      const char *&PrevSpec, unsigned &DiagID);

bool isFriendSpecified() const { return Friend_specified; }
SourceLocation getFriendSpecLoc() const { return FriendLoc; }

bool isModulePrivateSpecified() const { return ModulePrivateLoc.isValid(); }
SourceLocation getModulePrivateSpecLoc() const { return ModulePrivateLoc; }

ConstexprSpecKind getConstexprSpecifier() const {
  return ConstexprSpecKind(ConstexprSpecifier);
}

SourceLocation getConstexprSpecLoc() const { return ConstexprLoc; }
bool hasConstexprSpecifier() const {
  return getConstexprSpecifier() != ConstexprSpecKind::Unspecified;
}

void ClearConstexprSpec() {
  ConstexprSpecifier = static_cast<unsigned>(ConstexprSpecKind::Unspecified);
  ConstexprLoc = SourceLocation();
}

AttributePool &getAttributePool() const {
  return Attrs.getPool();
}

/// Concatenates two attribute lists.
///
/// The GCC attribute syntax allows for the following:
///
/// \code
/// short __attribute__(( unused, deprecated ))
/// int __attribute__(( may_alias, aligned(16) )) var;
/// \endcode
///
/// This declares 4 attributes using 2 lists. The following syntax is
/// also allowed and equivalent to the previous declaration.
///
/// \code
/// short __attribute__((unused)) __attribute__((deprecated))
/// int __attribute__((may_alias)) __attribute__((aligned(16))) var;
/// \endcode
///
void addAttributes(ParsedAttributesView &AL) {
  Attrs.addAll(AL.begin(), AL.end());
}

bool hasAttributes() const { return !Attrs.empty(); }

ParsedAttributes &getAttributes() { return Attrs; }
const ParsedAttributes &getAttributes() const { return Attrs; }

void takeAttributesFrom(ParsedAttributes &attrs) {
  Attrs.takeAllFrom(attrs);
}

/// Finish - This does final analysis of the declspec, issuing diagnostics for
/// things like "_Imaginary" (lacking an FP type).  After calling this method,
/// DeclSpec is guaranteed self-consistent, even if an error occurred.
void Finish(Sema &S, const PrintingPolicy &Policy);

const WrittenBuiltinSpecs& getWrittenBuiltinSpecs() const {
  return writtenBS;
}

ObjCDeclSpec *getObjCQualifiers() const { return ObjCQualifiers; }
void setObjCQualifiers(ObjCDeclSpec *quals) { ObjCQualifiers = quals; }

/// Checks if this DeclSpec can stand alone, without a Declarator.
///
/// Only tag declspecs can stand alone.
bool isMissingDeclaratorOk();
818};

820/// Captures information about "declaration specifiers" specific to
821/// Objective-C.
822class ObjCDeclSpec {
823public:
/// ObjCDeclQualifier - Qualifier used on types in method
/// declarations.  Not all combinations are sensible.  Parameters
/// can be one of { in, out, inout } with one of { bycopy, byref }.
/// Returns can either be { oneway } or not.
///
/// This should be kept in sync with Decl::ObjCDeclQualifier.
enum ObjCDeclQualifier {
  DQ_None = 0x0,
  DQ_In = 0x1,
  DQ_Inout = 0x2,
  DQ_Out = 0x4,
  DQ_Bycopy = 0x8,
  DQ_Byref = 0x10,
  DQ_Oneway = 0x20,
  DQ_CSNullability = 0x40
};

ObjCDeclSpec()
    : objcDeclQualifier(DQ_None),
      PropertyAttributes(ObjCPropertyAttribute::kind_noattr), Nullability(0),
      GetterName(nullptr), SetterName(nullptr) {}

ObjCDeclQualifier getObjCDeclQualifier() const {
  return (ObjCDeclQualifier)objcDeclQualifier;
}
void setObjCDeclQualifier(ObjCDeclQualifier DQVal) {
  objcDeclQualifier = (ObjCDeclQualifier) (objcDeclQualifier | DQVal);
}
void clearObjCDeclQualifier(ObjCDeclQualifier DQVal) {
  objcDeclQualifier = (ObjCDeclQualifier) (objcDeclQualifier & ~DQVal);
}

ObjCPropertyAttribute::Kind getPropertyAttributes() const {
  return ObjCPropertyAttribute::Kind(PropertyAttributes);
}
void setPropertyAttributes(ObjCPropertyAttribute::Kind PRVal) {
  PropertyAttributes =
      (ObjCPropertyAttribute::Kind)(PropertyAttributes | PRVal);
}

NullabilityKind getNullability() const {
  assert((static_cast<void> (0))
      ((getObjCDeclQualifier() & DQ_CSNullability) ||(static_cast<void> (0))
       (getPropertyAttributes() & ObjCPropertyAttribute::kind_nullability)) &&(static_cast<void> (0))
      "Objective-C declspec doesn't have nullability")(static_cast<void> (0));
  return static_cast<NullabilityKind>(Nullability);
}

SourceLocation getNullabilityLoc() const {
  assert((static_cast<void> (0))
      ((getObjCDeclQualifier() & DQ_CSNullability) ||(static_cast<void> (0))
       (getPropertyAttributes() & ObjCPropertyAttribute::kind_nullability)) &&(static_cast<void> (0))
      "Objective-C declspec doesn't have nullability")(static_cast<void> (0));
  return NullabilityLoc;
}

void setNullability(SourceLocation loc, NullabilityKind kind) {
  assert((static_cast<void> (0))
      ((getObjCDeclQualifier() & DQ_CSNullability) ||(static_cast<void> (0))
       (getPropertyAttributes() & ObjCPropertyAttribute::kind_nullability)) &&(static_cast<void> (0))
      "Set the nullability declspec or property attribute first")(static_cast<void> (0));
  Nullability = static_cast<unsigned>(kind);
  NullabilityLoc = loc;
}

const IdentifierInfo *getGetterName() const { return GetterName; }
IdentifierInfo *getGetterName() { return GetterName; }
SourceLocation getGetterNameLoc() const { return GetterNameLoc; }
void setGetterName(IdentifierInfo *name, SourceLocation loc) {
  GetterName = name;
  GetterNameLoc = loc;
}

const IdentifierInfo *getSetterName() const { return SetterName; }
IdentifierInfo *getSetterName() { return SetterName; }
SourceLocation getSetterNameLoc() const { return SetterNameLoc; }
void setSetterName(IdentifierInfo *name, SourceLocation loc) {
  SetterName = name;
  SetterNameLoc = loc;
}

905private:
// FIXME: These two are unrelated and mutually exclusive. So perhaps
// we can put them in a union to reflect their mutual exclusivity
// (space saving is negligible).
unsigned objcDeclQualifier : 7;

// NOTE: VC++ treats enums as signed, avoid using ObjCPropertyAttribute::Kind
unsigned PropertyAttributes : NumObjCPropertyAttrsBits;

unsigned Nullability : 2;

SourceLocation NullabilityLoc;

IdentifierInfo *GetterName;    // getter name or NULL if no getter
IdentifierInfo *SetterName;    // setter name or NULL if no setter
SourceLocation GetterNameLoc; // location of the getter attribute's value
SourceLocation SetterNameLoc; // location of the setter attribute's value

923};

925/// Describes the kind of unqualified-id parsed.
926enum class UnqualifiedIdKind {
/// An identifier.
IK_Identifier,
/// An overloaded operator name, e.g., operator+.
IK_OperatorFunctionId,
/// A conversion function name, e.g., operator int.
IK_ConversionFunctionId,
/// A user-defined literal name, e.g., operator "" _i.
IK_LiteralOperatorId,
/// A constructor name.
IK_ConstructorName,
/// A constructor named via a template-id.
IK_ConstructorTemplateId,
/// A destructor name.
IK_DestructorName,
/// A template-id, e.g., f<int>.
IK_TemplateId,
/// An implicit 'self' parameter
IK_ImplicitSelfParam,
/// A deduction-guide name (a template-name)
IK_DeductionGuideName
947};

949/// Represents a C++ unqualified-id that has been parsed.
950class UnqualifiedId {
951private:
UnqualifiedId(const UnqualifiedId &Other) = delete;
const UnqualifiedId &operator=(const UnqualifiedId &) = delete;

955public:
/// Describes the kind of unqualified-id parsed.
UnqualifiedIdKind Kind;

struct OFI {
  /// The kind of overloaded operator.
  OverloadedOperatorKind Operator;

  /// The source locations of the individual tokens that name
  /// the operator, e.g., the "new", "[", and "]" tokens in
  /// operator new [].
  ///
  /// Different operators have different numbers of tokens in their name,
  /// up to three. Any remaining source locations in this array will be
  /// set to an invalid value for operators with fewer than three tokens.
  SourceLocation SymbolLocations[3];
};

/// Anonymous union that holds extra data associated with the
/// parsed unqualified-id.
union {
  /// When Kind == IK_Identifier, the parsed identifier, or when
  /// Kind == IK_UserLiteralId, the identifier suffix.
  IdentifierInfo *Identifier;

  /// When Kind == IK_OperatorFunctionId, the overloaded operator
  /// that we parsed.
  struct OFI OperatorFunctionId;

  /// When Kind == IK_ConversionFunctionId, the type that the
  /// conversion function names.
  UnionParsedType ConversionFunctionId;

  /// When Kind == IK_ConstructorName, the class-name of the type
  /// whose constructor is being referenced.
  UnionParsedType ConstructorName;

  /// When Kind == IK_DestructorName, the type referred to by the
  /// class-name.
  UnionParsedType DestructorName;

  /// When Kind == IK_DeductionGuideName, the parsed template-name.
  UnionParsedTemplateTy TemplateName;

  /// When Kind == IK_TemplateId or IK_ConstructorTemplateId,
  /// the template-id annotation that contains the template name and
  /// template arguments.
  TemplateIdAnnotation *TemplateId;
};

/// The location of the first token that describes this unqualified-id,
/// which will be the location of the identifier, "operator" keyword,
/// tilde (for a destructor), or the template name of a template-id.
SourceLocation StartLocation;

/// The location of the last token that describes this unqualified-id.
SourceLocation EndLocation;

UnqualifiedId()
    : Kind(UnqualifiedIdKind::IK_Identifier), Identifier(nullptr) {}

/// Clear out this unqualified-id, setting it to default (invalid)
/// state.
void clear() {
  Kind = UnqualifiedIdKind::IK_Identifier;
  Identifier = nullptr;
  StartLocation = SourceLocation();
  EndLocation = SourceLocation();
}

/// Determine whether this unqualified-id refers to a valid name.
bool isValid() const { return StartLocation.isValid(); }

/// Determine whether this unqualified-id refers to an invalid name.
bool isInvalid() const { return !isValid(); }

/// Determine what kind of name we have.
UnqualifiedIdKind getKind() const { return Kind; }

/// Specify that this unqualified-id was parsed as an identifier.
///
/// \param Id the parsed identifier.
/// \param IdLoc the location of the parsed identifier.
void setIdentifier(const IdentifierInfo *Id, SourceLocation IdLoc) {
  Kind = UnqualifiedIdKind::IK_Identifier;
  Identifier = const_cast<IdentifierInfo *>(Id);
  StartLocation = EndLocation = IdLoc;
}

/// Specify that this unqualified-id was parsed as an
/// operator-function-id.
///
/// \param OperatorLoc the location of the 'operator' keyword.
///
/// \param Op the overloaded operator.
///
/// \param SymbolLocations the locations of the individual operator symbols
/// in the operator.
void setOperatorFunctionId(SourceLocation OperatorLoc,
                           OverloadedOperatorKind Op,
                           SourceLocation SymbolLocations[3]);

/// Specify that this unqualified-id was parsed as a
/// conversion-function-id.
///
/// \param OperatorLoc the location of the 'operator' keyword.
///
/// \param Ty the type to which this conversion function is converting.
///
/// \param EndLoc the location of the last token that makes up the type name.
void setConversionFunctionId(SourceLocation OperatorLoc,
                             ParsedType Ty,
                             SourceLocation EndLoc) {
  Kind = UnqualifiedIdKind::IK_ConversionFunctionId;
  StartLocation = OperatorLoc;
  EndLocation = EndLoc;
  ConversionFunctionId = Ty;
}

/// Specific that this unqualified-id was parsed as a
/// literal-operator-id.
///
/// \param Id the parsed identifier.
///
/// \param OpLoc the location of the 'operator' keyword.
///
/// \param IdLoc the location of the identifier.
void setLiteralOperatorId(const IdentifierInfo *Id, SourceLocation OpLoc,
                            SourceLocation IdLoc) {
  Kind = UnqualifiedIdKind::IK_LiteralOperatorId;
  Identifier = const_cast<IdentifierInfo *>(Id);
  StartLocation = OpLoc;
  EndLocation = IdLoc;
}

/// Specify that this unqualified-id was parsed as a constructor name.
///
/// \param ClassType the class type referred to by the constructor name.
///
/// \param ClassNameLoc the location of the class name.
///
/// \param EndLoc the location of the last token that makes up the type name.
void setConstructorName(ParsedType ClassType,
                        SourceLocation ClassNameLoc,
                        SourceLocation EndLoc) {
  Kind = UnqualifiedIdKind::IK_ConstructorName;
  StartLocation = ClassNameLoc;
  EndLocation = EndLoc;
  ConstructorName = ClassType;
}

/// Specify that this unqualified-id was parsed as a
/// template-id that names a constructor.
///
/// \param TemplateId the template-id annotation that describes the parsed
/// template-id. This UnqualifiedId instance will take ownership of the
/// \p TemplateId and will free it on destruction.
void setConstructorTemplateId(TemplateIdAnnotation *TemplateId);

/// Specify that this unqualified-id was parsed as a destructor name.
///
/// \param TildeLoc the location of the '~' that introduces the destructor
/// name.
///
/// \param ClassType the name of the class referred to by the destructor name.
void setDestructorName(SourceLocation TildeLoc,
                       ParsedType ClassType,
                       SourceLocation EndLoc) {
  Kind = UnqualifiedIdKind::IK_DestructorName;
  StartLocation = TildeLoc;
  EndLocation = EndLoc;
  DestructorName = ClassType;
}

/// Specify that this unqualified-id was parsed as a template-id.
///
/// \param TemplateId the template-id annotation that describes the parsed
/// template-id. This UnqualifiedId instance will take ownership of the
/// \p TemplateId and will free it on destruction.
void setTemplateId(TemplateIdAnnotation *TemplateId);

/// Specify that this unqualified-id was parsed as a template-name for
/// a deduction-guide.
///
/// \param Template The parsed template-name.
/// \param TemplateLoc The location of the parsed template-name.
void setDeductionGuideName(ParsedTemplateTy Template,
                           SourceLocation TemplateLoc) {
  Kind = UnqualifiedIdKind::IK_DeductionGuideName;
  TemplateName = Template;
  StartLocation = EndLocation = TemplateLoc;
}

/// Specify that this unqualified-id is an implicit 'self'
/// parameter.
///
/// \param Id the identifier.
void setImplicitSelfParam(const IdentifierInfo *Id) {
  Kind = UnqualifiedIdKind::IK_ImplicitSelfParam;
  Identifier = const_cast<IdentifierInfo *>(Id);
  StartLocation = EndLocation = SourceLocation();
}

/// Return the source range that covers this unqualified-id.
SourceRange getSourceRange() const LLVM_READONLY__attribute__((__pure__)) {
  return SourceRange(StartLocation, EndLocation);
}
SourceLocation getBeginLoc() const LLVM_READONLY__attribute__((__pure__)) { return StartLocation; }
SourceLocation getEndLoc() const LLVM_READONLY__attribute__((__pure__)) { return EndLocation; }
1164};

1166/// A set of tokens that has been cached for later parsing.
1167typedef SmallVector<Token, 4> CachedTokens;

1169/// One instance of this struct is used for each type in a
1170/// declarator that is parsed.
1171///
1172/// This is intended to be a small value object.
1173struct DeclaratorChunk {
DeclaratorChunk() {};

enum {
  Pointer, Reference, Array, Function, BlockPointer, MemberPointer, Paren, Pipe
} Kind;

/// Loc - The place where this type was defined.
SourceLocation Loc;
/// EndLoc - If valid, the place where this chunck ends.
SourceLocation EndLoc;

SourceRange getSourceRange() const {
  if (EndLoc.isInvalid())
    return SourceRange(Loc, Loc);
  return SourceRange(Loc, EndLoc);
}

ParsedAttributesView AttrList;

struct PointerTypeInfo {
  /// The type qualifiers: const/volatile/restrict/unaligned/atomic.
  unsigned TypeQuals : 5;

  /// The location of the const-qualifier, if any.
  SourceLocation ConstQualLoc;

  /// The location of the volatile-qualifier, if any.
  SourceLocation VolatileQualLoc;

  /// The location of the restrict-qualifier, if any.
  SourceLocation RestrictQualLoc;

  /// The location of the _Atomic-qualifier, if any.
  SourceLocation AtomicQualLoc;

  /// The location of the __unaligned-qualifier, if any.
  SourceLocation UnalignedQualLoc;

  void destroy() {
  }
};

struct ReferenceTypeInfo {
  /// The type qualifier: restrict. [GNU] C++ extension
  bool HasRestrict : 1;
  /// True if this is an lvalue reference, false if it's an rvalue reference.
  bool LValueRef : 1;
  void destroy() {
  }
};

struct ArrayTypeInfo {
  /// The type qualifiers for the array:
  /// const/volatile/restrict/__unaligned/_Atomic.
  unsigned TypeQuals : 5;

  /// True if this dimension included the 'static' keyword.
  unsigned hasStatic : 1;

  /// True if this dimension was [*].  In this case, NumElts is null.
  unsigned isStar : 1;

  /// This is the size of the array, or null if [] or [*] was specified.
  /// Since the parser is multi-purpose, and we don't want to impose a root
  /// expression class on all clients, NumElts is untyped.
  Expr *NumElts;

  void destroy() {}
};

/// ParamInfo - An array of paraminfo objects is allocated whenever a function
/// declarator is parsed.  There are two interesting styles of parameters
/// here:
/// K&R-style identifier lists and parameter type lists.  K&R-style identifier
/// lists will have information about the identifier, but no type information.
/// Parameter type lists will have type info (if the actions module provides
/// it), but may have null identifier info: e.g. for 'void foo(int X, int)'.
struct ParamInfo {
  IdentifierInfo *Ident;
  SourceLocation IdentLoc;
  Decl *Param;

  /// DefaultArgTokens - When the parameter's default argument
  /// cannot be parsed immediately (because it occurs within the
  /// declaration of a member function), it will be stored here as a
  /// sequence of tokens to be parsed once the class definition is
  /// complete. Non-NULL indicates that there is a default argument.
  std::unique_ptr<CachedTokens> DefaultArgTokens;

  ParamInfo() = default;
  ParamInfo(IdentifierInfo *ident, SourceLocation iloc,
            Decl *param,
            std::unique_ptr<CachedTokens> DefArgTokens = nullptr)
    : Ident(ident), IdentLoc(iloc), Param(param),
      DefaultArgTokens(std::move(DefArgTokens)) {}
};

struct TypeAndRange {
  ParsedType Ty;
  SourceRange Range;
};

struct FunctionTypeInfo {
  /// hasPrototype - This is true if the function had at least one typed
  /// parameter.  If the function is () or (a,b,c), then it has no prototype,
  /// and is treated as a K&R-style function.
  unsigned hasPrototype : 1;

  /// isVariadic - If this function has a prototype, and if that
  /// proto ends with ',...)', this is true. When true, EllipsisLoc
  /// contains the location of the ellipsis.
  unsigned isVariadic : 1;

  /// Can this declaration be a constructor-style initializer?
  unsigned isAmbiguous : 1;

  /// Whether the ref-qualifier (if any) is an lvalue reference.
  /// Otherwise, it's an rvalue reference.
  unsigned RefQualifierIsLValueRef : 1;

  /// ExceptionSpecType - An ExceptionSpecificationType value.
  unsigned ExceptionSpecType : 4;

  /// DeleteParams - If this is true, we need to delete[] Params.
  unsigned DeleteParams : 1;

  /// HasTrailingReturnType - If this is true, a trailing return type was
  /// specified.
  unsigned HasTrailingReturnType : 1;

  /// The location of the left parenthesis in the source.
  SourceLocation LParenLoc;

  /// When isVariadic is true, the location of the ellipsis in the source.
  SourceLocation EllipsisLoc;

  /// The location of the right parenthesis in the source.
  SourceLocation RParenLoc;

  /// NumParams - This is the number of formal parameters specified by the
  /// declarator.
  unsigned NumParams;

  /// NumExceptionsOrDecls - This is the number of types in the
  /// dynamic-exception-decl, if the function has one. In C, this is the
  /// number of declarations in the function prototype.
  unsigned NumExceptionsOrDecls;

  /// The location of the ref-qualifier, if any.
  ///
  /// If this is an invalid location, there is no ref-qualifier.
  SourceLocation RefQualifierLoc;

  /// The location of the 'mutable' qualifer in a lambda-declarator, if
  /// any.
  SourceLocation MutableLoc;

  /// The beginning location of the exception specification, if any.
  SourceLocation ExceptionSpecLocBeg;

  /// The end location of the exception specification, if any.
  SourceLocation ExceptionSpecLocEnd;

  /// Params - This is a pointer to a new[]'d array of ParamInfo objects that
  /// describe the parameters specified by this function declarator.  null if
  /// there are no parameters specified.
  ParamInfo *Params;

  /// DeclSpec for the function with the qualifier related info.
  DeclSpec *MethodQualifiers;

  /// AtttibuteFactory for the MethodQualifiers.
  AttributeFactory *QualAttrFactory;

  union {
    /// Pointer to a new[]'d array of TypeAndRange objects that
    /// contain the types in the function's dynamic exception specification
    /// and their locations, if there is one.
    TypeAndRange *Exceptions;

    /// Pointer to the expression in the noexcept-specifier of this
    /// function, if it has one.
    Expr *NoexceptExpr;

    /// Pointer to the cached tokens for an exception-specification
    /// that has not yet been parsed.
    CachedTokens *ExceptionSpecTokens;

    /// Pointer to a new[]'d array of declarations that need to be available
    /// for lookup inside the function body, if one exists. Does not exist in
    /// C++.
    NamedDecl **DeclsInPrototype;
  };

  /// If HasTrailingReturnType is true, this is the trailing return
  /// type specified.
  UnionParsedType TrailingReturnType;

  /// If HasTrailingReturnType is true, this is the location of the trailing
  /// return type.
  SourceLocation TrailingReturnTypeLoc;

  /// Reset the parameter list to having zero parameters.
  ///
  /// This is used in various places for error recovery.
  void freeParams() {
    for (unsigned I = 0; I < NumParams; ++I)
      Params[I].DefaultArgTokens.reset();
    if (DeleteParams) {
      delete[] Params;
      DeleteParams = false;
    }
    NumParams = 0;
  }

  void destroy() {
    freeParams();
    delete QualAttrFactory;
    delete MethodQualifiers;
    switch (getExceptionSpecType()) {
    default:
      break;
    case EST_Dynamic:
      delete[] Exceptions;
      break;
    case EST_Unparsed:
      delete ExceptionSpecTokens;
      break;
    case EST_None:
      if (NumExceptionsOrDecls != 0)
        delete[] DeclsInPrototype;
      break;
    }
  }

  DeclSpec &getOrCreateMethodQualifiers() {
    if (!MethodQualifiers) {
      QualAttrFactory = new AttributeFactory();
      MethodQualifiers = new DeclSpec(*QualAttrFactory);
    }
    return *MethodQualifiers;
  }

  /// isKNRPrototype - Return true if this is a K&R style identifier list,
  /// like "void foo(a,b,c)".  In a function definition, this will be followed
  /// by the parameter type definitions.
  bool isKNRPrototype() const { return !hasPrototype && NumParams != 0; }

  SourceLocation getLParenLoc() const { return LParenLoc; }

  SourceLocation getEllipsisLoc() const { return EllipsisLoc; }

  SourceLocation getRParenLoc() const { return RParenLoc; }

  SourceLocation getExceptionSpecLocBeg() const {
    return ExceptionSpecLocBeg;
  }

  SourceLocation getExceptionSpecLocEnd() const {
    return ExceptionSpecLocEnd;
  }

  SourceRange getExceptionSpecRange() const {
    return SourceRange(getExceptionSpecLocBeg(), getExceptionSpecLocEnd());
  }

  /// Retrieve the location of the ref-qualifier, if any.
  SourceLocation getRefQualifierLoc() const { return RefQualifierLoc; }

  /// Retrieve the location of the 'const' qualifier.
  SourceLocation getConstQualifierLoc() const {
    assert(MethodQualifiers)(static_cast<void> (0));
    return MethodQualifiers->getConstSpecLoc();
  }

  /// Retrieve the location of the 'volatile' qualifier.
  SourceLocation getVolatileQualifierLoc() const {
    assert(MethodQualifiers)(static_cast<void> (0));
    return MethodQualifiers->getVolatileSpecLoc();
  }

  /// Retrieve the location of the 'restrict' qualifier.
  SourceLocation getRestrictQualifierLoc() const {
    assert(MethodQualifiers)(static_cast<void> (0));
    return MethodQualifiers->getRestrictSpecLoc();
  }

  /// Retrieve the location of the 'mutable' qualifier, if any.
  SourceLocation getMutableLoc() const { return MutableLoc; }

  /// Determine whether this function declaration contains a
  /// ref-qualifier.
  bool hasRefQualifier() const { return getRefQualifierLoc().isValid(); }

  /// Determine whether this lambda-declarator contains a 'mutable'
  /// qualifier.
  bool hasMutableQualifier() const { return getMutableLoc().isValid(); }

  /// Determine whether this method has qualifiers.
  bool hasMethodTypeQualifiers() const {
    return MethodQualifiers && (MethodQualifiers->getTypeQualifiers() ||
                                MethodQualifiers->getAttributes().size());
  }

  /// Get the type of exception specification this function has.
  ExceptionSpecificationType getExceptionSpecType() const {
    return static_cast<ExceptionSpecificationType>(ExceptionSpecType);
  }

  /// Get the number of dynamic exception specifications.
  unsigned getNumExceptions() const {
    assert(ExceptionSpecType != EST_None)(static_cast<void> (0));
    return NumExceptionsOrDecls;
  }

  /// Get the non-parameter decls defined within this function
  /// prototype. Typically these are tag declarations.
  ArrayRef<NamedDecl *> getDeclsInPrototype() const {
    assert(ExceptionSpecType == EST_None)(static_cast<void> (0));
    return llvm::makeArrayRef(DeclsInPrototype, NumExceptionsOrDecls);
  }

  /// Determine whether this function declarator had a
  /// trailing-return-type.
  bool hasTrailingReturnType() const { return HasTrailingReturnType; }

  /// Get the trailing-return-type for this function declarator.
  ParsedType getTrailingReturnType() const {
    assert(HasTrailingReturnType)(static_cast<void> (0));
    return TrailingReturnType;
  }

  /// Get the trailing-return-type location for this function declarator.
  SourceLocation getTrailingReturnTypeLoc() const {
    assert(HasTrailingReturnType)(static_cast<void> (0));
    return TrailingReturnTypeLoc;
  }
};

struct BlockPointerTypeInfo {
  /// For now, sema will catch these as invalid.
  /// The type qualifiers: const/volatile/restrict/__unaligned/_Atomic.
  unsigned TypeQuals : 5;

  void destroy() {
  }
};

struct MemberPointerTypeInfo {
  /// The type qualifiers: const/volatile/restrict/__unaligned/_Atomic.
  unsigned TypeQuals : 5;
  /// Location of the '*' token.
  SourceLocation StarLoc;
  // CXXScopeSpec has a constructor, so it can't be a direct member.
  // So we need some pointer-aligned storage and a bit of trickery.
  alignas(CXXScopeSpec) char ScopeMem[sizeof(CXXScopeSpec)];
  CXXScopeSpec &Scope() {
    return *reinterpret_cast<CXXScopeSpec *>(ScopeMem);
  }
  const CXXScopeSpec &Scope() const {
    return *reinterpret_cast<const CXXScopeSpec *>(ScopeMem);
  }
  void destroy() {
    Scope().~CXXScopeSpec();
  }
};

struct PipeTypeInfo {
  /// The access writes.
  unsigned AccessWrites : 3;

  void destroy() {}
};

union {
  PointerTypeInfo       Ptr;
  ReferenceTypeInfo     Ref;
  ArrayTypeInfo         Arr;
  FunctionTypeInfo      Fun;
  BlockPointerTypeInfo  Cls;
  MemberPointerTypeInfo Mem;
  PipeTypeInfo          PipeInfo;
};

void destroy() {
  switch (Kind) {
  case DeclaratorChunk::Function:      return Fun.destroy();
  case DeclaratorChunk::Pointer:       return Ptr.destroy();
  case DeclaratorChunk::BlockPointer:  return Cls.destroy();
  case DeclaratorChunk::Reference:     return Ref.destroy();
  case DeclaratorChunk::Array:         return Arr.destroy();
  case DeclaratorChunk::MemberPointer: return Mem.destroy();
  case DeclaratorChunk::Paren:         return;
  case DeclaratorChunk::Pipe:          return PipeInfo.destroy();
  }
}

/// If there are attributes applied to this declaratorchunk, return
/// them.
const ParsedAttributesView &getAttrs() const { return AttrList; }
ParsedAttributesView &getAttrs() { return AttrList; }

/// Return a DeclaratorChunk for a pointer.
static DeclaratorChunk getPointer(unsigned TypeQuals, SourceLocation Loc,
                                  SourceLocation ConstQualLoc,
                                  SourceLocation VolatileQualLoc,
                                  SourceLocation RestrictQualLoc,
                                  SourceLocation AtomicQualLoc,
                                  SourceLocation UnalignedQualLoc) {
  DeclaratorChunk I;
  I.Kind                = Pointer;
  I.Loc                 = Loc;
  new (&I.Ptr) PointerTypeInfo;
  I.Ptr.TypeQuals       = TypeQuals;
  I.Ptr.ConstQualLoc    = ConstQualLoc;
  I.Ptr.VolatileQualLoc = VolatileQualLoc;
  I.Ptr.RestrictQualLoc = RestrictQualLoc;
  I.Ptr.AtomicQualLoc   = AtomicQualLoc;
  I.Ptr.UnalignedQualLoc = UnalignedQualLoc;
  return I;
}

/// Return a DeclaratorChunk for a reference.
static DeclaratorChunk getReference(unsigned TypeQuals, SourceLocation Loc,
                                    bool lvalue) {
  DeclaratorChunk I;
  I.Kind            = Reference;
  I.Loc             = Loc;
  I.Ref.HasRestrict = (TypeQuals & DeclSpec::TQ_restrict) != 0;
  I.Ref.LValueRef   = lvalue;
  return I;
}

/// Return a DeclaratorChunk for an array.
static DeclaratorChunk getArray(unsigned TypeQuals,
                                bool isStatic, bool isStar, Expr *NumElts,
                                SourceLocation LBLoc, SourceLocation RBLoc) {
  DeclaratorChunk I;
  I.Kind          = Array;
  I.Loc           = LBLoc;
  I.EndLoc        = RBLoc;
  I.Arr.TypeQuals = TypeQuals;
  I.Arr.hasStatic = isStatic;
  I.Arr.isStar    = isStar;
  I.Arr.NumElts   = NumElts;
  return I;
}

/// DeclaratorChunk::getFunction - Return a DeclaratorChunk for a function.
/// "TheDeclarator" is the declarator that this will be added to.
static DeclaratorChunk getFunction(bool HasProto,
                                   bool IsAmbiguous,
                                   SourceLocation LParenLoc,
                                   ParamInfo *Params, unsigned NumParams,
                                   SourceLocation EllipsisLoc,
                                   SourceLocation RParenLoc,
                                   bool RefQualifierIsLvalueRef,
                                   SourceLocation RefQualifierLoc,
                                   SourceLocation MutableLoc,
                                   ExceptionSpecificationType ESpecType,
                                   SourceRange ESpecRange,
                                   ParsedType *Exceptions,
                                   SourceRange *ExceptionRanges,
                                   unsigned NumExceptions,
                                   Expr *NoexceptExpr,
                                   CachedTokens *ExceptionSpecTokens,
                                   ArrayRef<NamedDecl *> DeclsInPrototype,
                                   SourceLocation LocalRangeBegin,
                                   SourceLocation LocalRangeEnd,
                                   Declarator &TheDeclarator,
                                   TypeResult TrailingReturnType =
                                                  TypeResult(),
                                   SourceLocation TrailingReturnTypeLoc =
                                                  SourceLocation(),
                                   DeclSpec *MethodQualifiers = nullptr);

/// Return a DeclaratorChunk for a block.
static DeclaratorChunk getBlockPointer(unsigned TypeQuals,
                                       SourceLocation Loc) {
  DeclaratorChunk I;
  I.Kind          = BlockPointer;
  I.Loc           = Loc;
  I.Cls.TypeQuals = TypeQuals;
  return I;
}

/// Return a DeclaratorChunk for a block.
static DeclaratorChunk getPipe(unsigned TypeQuals,
                               SourceLocation Loc) {
  DeclaratorChunk I;
  I.Kind          = Pipe;
  I.Loc           = Loc;
  I.Cls.TypeQuals = TypeQuals;
  return I;
}

static DeclaratorChunk getMemberPointer(const CXXScopeSpec &SS,
                                        unsigned TypeQuals,
                                        SourceLocation StarLoc,
                                        SourceLocation EndLoc) {
  DeclaratorChunk I;
  I.Kind          = MemberPointer;
  I.Loc           = SS.getBeginLoc();
  I.EndLoc = EndLoc;
  new (&I.Mem) MemberPointerTypeInfo;
  I.Mem.StarLoc = StarLoc;
  I.Mem.TypeQuals = TypeQuals;
  new (I.Mem.ScopeMem) CXXScopeSpec(SS);
  return I;
}

/// Return a DeclaratorChunk for a paren.
static DeclaratorChunk getParen(SourceLocation LParenLoc,
                                SourceLocation RParenLoc) {
  DeclaratorChunk I;
  I.Kind          = Paren;
  I.Loc           = LParenLoc;
  I.EndLoc        = RParenLoc;
  return I;
}

bool isParen() const {
  return Kind == Paren;
}
1698};

1700/// A parsed C++17 decomposition declarator of the form
1701///   '[' identifier-list ']'
1702class DecompositionDeclarator {
1703public:
struct Binding {
  IdentifierInfo *Name;
  SourceLocation NameLoc;
};

1709private:
/// The locations of the '[' and ']' tokens.
SourceLocation LSquareLoc, RSquareLoc;

/// The bindings.
Binding *Bindings;
unsigned NumBindings : 31;
unsigned DeleteBindings : 1;

friend class Declarator;

1720public:
DecompositionDeclarator()
    : Bindings(nullptr), NumBindings(0), DeleteBindings(false) {}
DecompositionDeclarator(const DecompositionDeclarator &G) = delete;
DecompositionDeclarator &operator=(const DecompositionDeclarator &G) = delete;
~DecompositionDeclarator() {
  if (DeleteBindings)
    delete[] Bindings;
}

void clear() {
  LSquareLoc = RSquareLoc = SourceLocation();
  if (DeleteBindings)
    delete[] Bindings;
  Bindings = nullptr;
  NumBindings = 0;
  DeleteBindings = false;
}

ArrayRef<Binding> bindings() const {
  return llvm::makeArrayRef(Bindings, NumBindings);
}

bool isSet() const { return LSquareLoc.isValid(); }

SourceLocation getLSquareLoc() const { return LSquareLoc; }
SourceLocation getRSquareLoc() const { return RSquareLoc; }
SourceRange getSourceRange() const {
  return SourceRange(LSquareLoc, RSquareLoc);
}
1750};

1752/// Described the kind of function definition (if any) provided for
1753/// a function.
1754enum class FunctionDefinitionKind {
Declaration,
Definition,
Defaulted,
Deleted
1759};

1761enum class DeclaratorContext {
File,                // File scope declaration.
Prototype,           // Within a function prototype.
ObjCResult,          // An ObjC method result type.
ObjCParameter,       // An ObjC method parameter type.
KNRTypeList,         // K&R type definition list for formals.
TypeName,            // Abstract declarator for types.
FunctionalCast,      // Type in a C++ functional cast expression.
Member,              // Struct/Union field.
Block,               // Declaration within a block in a function.
ForInit,             // Declaration within first part of a for loop.
SelectionInit,       // Declaration within optional init stmt of if/switch.
Condition,           // Condition declaration in a C++ if/switch/while/for.
TemplateParam,       // Within a template parameter list.
CXXNew,              // C++ new-expression.
CXXCatch,            // C++ catch exception-declaration
ObjCCatch,           // Objective-C catch exception-declaration
BlockLiteral,        // Block literal declarator.
LambdaExpr,          // Lambda-expression declarator.
LambdaExprParameter, // Lambda-expression parameter declarator.
ConversionId,        // C++ conversion-type-id.
TrailingReturn,      // C++11 trailing-type-specifier.
TrailingReturnVar,   // C++11 trailing-type-specifier for variable.
TemplateArg,         // Any template argument (in template argument list).
TemplateTypeArg,     // Template type argument (in default argument).
AliasDecl,           // C++11 alias-declaration.
AliasTemplate,       // C++11 alias-declaration template.
RequiresExpr         // C++2a requires-expression.
1789};

1791/// Information about one declarator, including the parsed type
1792/// information and the identifier.
1793///
1794/// When the declarator is fully formed, this is turned into the appropriate
1795/// Decl object.
1796///
1797/// Declarators come in two types: normal declarators and abstract declarators.
1798/// Abstract declarators are used when parsing types, and don't have an
1799/// identifier.  Normal declarators do have ID's.
1800///
1801/// Instances of this class should be a transient object that lives on the
1802/// stack, not objects that are allocated in large quantities on the heap.
1803class Declarator {

1805private:
const DeclSpec &DS;
CXXScopeSpec SS;
UnqualifiedId Name;
SourceRange Range;

/// Where we are parsing this declarator.
DeclaratorContext Context;

/// The C++17 structured binding, if any. This is an alternative to a Name.
DecompositionDeclarator BindingGroup;

/// DeclTypeInfo - This holds each type that the declarator includes as it is
/// parsed.  This is pushed from the identifier out, which means that element
/// #0 will be the most closely bound to the identifier, and
/// DeclTypeInfo.back() will be the least closely bound.
SmallVector<DeclaratorChunk, 8> DeclTypeInfo;

/// InvalidType - Set by Sema::GetTypeForDeclarator().
unsigned InvalidType : 1;

/// GroupingParens - Set by Parser::ParseParenDeclarator().
unsigned GroupingParens : 1;

/// FunctionDefinition - Is this Declarator for a function or member
/// definition and, if so, what kind?
///
/// Actually a FunctionDefinitionKind.
unsigned FunctionDefinition : 2;

/// Is this Declarator a redeclaration?
unsigned Redeclaration : 1;

/// true if the declaration is preceded by \c __extension__.
unsigned Extension : 1;

/// Indicates whether this is an Objective-C instance variable.
unsigned ObjCIvar : 1;

/// Indicates whether this is an Objective-C 'weak' property.
unsigned ObjCWeakProperty : 1;

/// Indicates whether the InlineParams / InlineBindings storage has been used.
unsigned InlineStorageUsed : 1;

/// Indicates whether this declarator has an initializer.
unsigned HasInitializer : 1;

/// Attrs - Attributes.
ParsedAttributes Attrs;

/// The asm label, if specified.
Expr *AsmLabel;

/// \brief The constraint-expression specified by the trailing
/// requires-clause, or null if no such clause was specified.
Expr *TrailingRequiresClause;

/// If this declarator declares a template, its template parameter lists.
ArrayRef<TemplateParameterList *> TemplateParameterLists;

/// If the declarator declares an abbreviated function template, the innermost
/// template parameter list containing the invented and explicit template
/// parameters (if any).
TemplateParameterList *InventedTemplateParameterList;

1871#ifndef _MSC_VER
union {
1873#endif
  /// InlineParams - This is a local array used for the first function decl
  /// chunk to avoid going to the heap for the common case when we have one
  /// function chunk in the declarator.
  DeclaratorChunk::ParamInfo InlineParams[16];
  DecompositionDeclarator::Binding InlineBindings[16];
1879#ifndef _MSC_VER
};
1881#endif

/// If this is the second or subsequent declarator in this declaration,
/// the location of the comma before this declarator.
SourceLocation CommaLoc;

/// If provided, the source location of the ellipsis used to describe
/// this declarator as a parameter pack.
SourceLocation EllipsisLoc;

friend struct DeclaratorChunk;

1893public:
Declarator(const DeclSpec &ds, DeclaratorContext C)
    : DS(ds), Range(ds.getSourceRange()), Context(C),
      InvalidType(DS.getTypeSpecType() == DeclSpec::TST_error),
      GroupingParens(false), FunctionDefinition(static_cast<unsigned>(
                                 FunctionDefinitionKind::Declaration)),
      Redeclaration(false), Extension(false), ObjCIvar(false),
      ObjCWeakProperty(false), InlineStorageUsed(false),
      HasInitializer(false), Attrs(ds.getAttributePool().getFactory()),
      AsmLabel(nullptr), TrailingRequiresClause(nullptr),
      InventedTemplateParameterList(nullptr) {}

~Declarator() {
  clear();
}
/// getDeclSpec - Return the declaration-specifier that this declarator was
/// declared with.
const DeclSpec &getDeclSpec() const { return DS; }

/// getMutableDeclSpec - Return a non-const version of the DeclSpec.  This
/// should be used with extreme care: declspecs can often be shared between
/// multiple declarators, so mutating the DeclSpec affects all of the
/// Declarators.  This should only be done when the declspec is known to not
/// be shared or when in error recovery etc.
DeclSpec &getMutableDeclSpec() { return const_cast<DeclSpec &>(DS); }

AttributePool &getAttributePool() const {
  return Attrs.getPool();
}

/// getCXXScopeSpec - Return the C++ scope specifier (global scope or
/// nested-name-specifier) that is part of the declarator-id.
const CXXScopeSpec &getCXXScopeSpec() const { return SS; }
CXXScopeSpec &getCXXScopeSpec() { return SS; }

/// Retrieve the name specified by this declarator.
UnqualifiedId &getName() { return Name; }

const DecompositionDeclarator &getDecompositionDeclarator() const {
  return BindingGroup;
}

DeclaratorContext getContext() const { return Context; }

bool isPrototypeContext() const {
  return (Context == DeclaratorContext::Prototype ||
          Context == DeclaratorContext::ObjCParameter ||
          Context == DeclaratorContext::ObjCResult ||
          Context == DeclaratorContext::LambdaExprParameter);
}

/// Get the source range that spans this declarator.
SourceRange getSourceRange() const LLVM_READONLY__attribute__((__pure__)) { return Range; }
SourceLocation getBeginLoc() const LLVM_READONLY__attribute__((__pure__)) { return Range.getBegin(); }
SourceLocation getEndLoc() const LLVM_READONLY__attribute__((__pure__)) { return Range.getEnd(); }

void SetSourceRange(SourceRange R) { Range = R; }
/// SetRangeBegin - Set the start of the source range to Loc, unless it's
/// invalid.
void SetRangeBegin(SourceLocation Loc) {
  if (!Loc.isInvalid())
    Range.setBegin(Loc);
}
/// SetRangeEnd - Set the end of the source range to Loc, unless it's invalid.
void SetRangeEnd(SourceLocation Loc) {
  if (!Loc.isInvalid())
    Range.setEnd(Loc);
}
/// ExtendWithDeclSpec - Extend the declarator source range to include the
/// given declspec, unless its location is invalid. Adopts the range start if
/// the current range start is invalid.
void ExtendWithDeclSpec(const DeclSpec &DS) {
  SourceRange SR = DS.getSourceRange();
  if (Range.getBegin().isInvalid())
    Range.setBegin(SR.getBegin());
  if (!SR.getEnd().isInvalid())
    Range.setEnd(SR.getEnd());
}

/// Reset the contents of this Declarator.
void clear() {
  SS.clear();
  Name.clear();
  Range = DS.getSourceRange();
  BindingGroup.clear();

  for (unsigned i = 0, e = DeclTypeInfo.size(); i != e; ++i)
    DeclTypeInfo[i].destroy();
  DeclTypeInfo.clear();
  Attrs.clear();
  AsmLabel = nullptr;
  InlineStorageUsed = false;
  HasInitializer = false;
  ObjCIvar = false;
  ObjCWeakProperty = false;
  CommaLoc = SourceLocation();
  EllipsisLoc = SourceLocation();
}

/// mayOmitIdentifier - Return true if the identifier is either optional or
/// not allowed.  This is true for typenames, prototypes, and template
/// parameter lists.
bool mayOmitIdentifier() const {
  switch (Context) {
  case DeclaratorContext::File:
  case DeclaratorContext::KNRTypeList:
  case DeclaratorContext::Member:
  case DeclaratorContext::Block:
  case DeclaratorContext::ForInit:
  case DeclaratorContext::SelectionInit:
  case DeclaratorContext::Condition:
    return false;

  case DeclaratorContext::TypeName:
  case DeclaratorContext::FunctionalCast:
  case DeclaratorContext::AliasDecl:
  case DeclaratorContext::AliasTemplate:
  case DeclaratorContext::Prototype:
  case DeclaratorContext::LambdaExprParameter:
  case DeclaratorContext::ObjCParameter:
  case DeclaratorContext::ObjCResult:
  case DeclaratorContext::TemplateParam:
  case DeclaratorContext::CXXNew:
  case DeclaratorContext::CXXCatch:
  case DeclaratorContext::ObjCCatch:
  case DeclaratorContext::BlockLiteral:
  case DeclaratorContext::LambdaExpr:
  case DeclaratorContext::ConversionId:
  case DeclaratorContext::TemplateArg:
  case DeclaratorContext::TemplateTypeArg:
  case DeclaratorContext::TrailingReturn:
  case DeclaratorContext::TrailingReturnVar:
  case DeclaratorContext::RequiresExpr:
    return true;
  }
  llvm_unreachable("unknown context kind!")__builtin_unreachable();
}

/// mayHaveIdentifier - Return true if the identifier is either optional or
/// required.  This is true for normal declarators and prototypes, but not
/// typenames.
bool mayHaveIdentifier() const {
  switch (Context) {
  case DeclaratorContext::File:
  case DeclaratorContext::KNRTypeList:
  case DeclaratorContext::Member:
  case DeclaratorContext::Block:
  case DeclaratorContext::ForInit:
  case DeclaratorContext::SelectionInit:
  case DeclaratorContext::Condition:
  case DeclaratorContext::Prototype:
  case DeclaratorContext::LambdaExprParameter:
  case DeclaratorContext::TemplateParam:
  case DeclaratorContext::CXXCatch:
  case DeclaratorContext::ObjCCatch:
  case DeclaratorContext::RequiresExpr:
    return true;

  case DeclaratorContext::TypeName:
  case DeclaratorContext::FunctionalCast:
  case DeclaratorContext::CXXNew:
  case DeclaratorContext::AliasDecl:
  case DeclaratorContext::AliasTemplate:
  case DeclaratorContext::ObjCParameter:
  case DeclaratorContext::ObjCResult:
  case DeclaratorContext::BlockLiteral:
  case DeclaratorContext::LambdaExpr:
  case DeclaratorContext::ConversionId:
  case DeclaratorContext::TemplateArg:
  case DeclaratorContext::TemplateTypeArg:
  case DeclaratorContext::TrailingReturn:
  case DeclaratorContext::TrailingReturnVar:
    return false;
  }
  llvm_unreachable("unknown context kind!")__builtin_unreachable();
}

/// Return true if the context permits a C++17 decomposition declarator.
bool mayHaveDecompositionDeclarator() const {
  switch (Context) {
  case DeclaratorContext::File:
    // FIXME: It's not clear that the proposal meant to allow file-scope
    // structured bindings, but it does.
  case DeclaratorContext::Block:
  case DeclaratorContext::ForInit:
  case DeclaratorContext::SelectionInit:
  case DeclaratorContext::Condition:
    return true;

  case DeclaratorContext::Member:
  case DeclaratorContext::Prototype:
  case DeclaratorContext::TemplateParam:
  case DeclaratorContext::RequiresExpr:
    // Maybe one day...
    return false;

  // These contexts don't allow any kind of non-abstract declarator.
  case DeclaratorContext::KNRTypeList:
  case DeclaratorContext::TypeName:
  case DeclaratorContext::FunctionalCast:
  case DeclaratorContext::AliasDecl:
  case DeclaratorContext::AliasTemplate:
  case DeclaratorContext::LambdaExprParameter:
  case DeclaratorContext::ObjCParameter:
  case DeclaratorContext::ObjCResult:
  case DeclaratorContext::CXXNew:
  case DeclaratorContext::CXXCatch:
  case DeclaratorContext::ObjCCatch:
  case DeclaratorContext::BlockLiteral:
  case DeclaratorContext::LambdaExpr:
  case DeclaratorContext::ConversionId:
  case DeclaratorContext::TemplateArg:
  case DeclaratorContext::TemplateTypeArg:
  case DeclaratorContext::TrailingReturn:
  case DeclaratorContext::TrailingReturnVar:
    return false;
  }
  llvm_unreachable("unknown context kind!")__builtin_unreachable();
}

/// mayBeFollowedByCXXDirectInit - Return true if the declarator can be
/// followed by a C++ direct initializer, e.g. "int x(1);".
bool mayBeFollowedByCXXDirectInit() const {
  if (hasGroupingParens()) return false;

  if (getDeclSpec().getStorageClassSpec() == DeclSpec::SCS_typedef)
    return false;

  if (getDeclSpec().getStorageClassSpec() == DeclSpec::SCS_extern &&
      Context != DeclaratorContext::File)
    return false;

  // Special names can't have direct initializers.
  if (Name.getKind() != UnqualifiedIdKind::IK_Identifier)
    return false;

  switch (Context) {
  case DeclaratorContext::File:
  case DeclaratorContext::Block:
  case DeclaratorContext::ForInit:
  case DeclaratorContext::SelectionInit:
  case DeclaratorContext::TrailingReturnVar:
    return true;

  case DeclaratorContext::Condition:
    // This may not be followed by a direct initializer, but it can't be a
    // function declaration either, and we'd prefer to perform a tentative
    // parse in order to produce the right diagnostic.
    return true;

  case DeclaratorContext::KNRTypeList:
  case DeclaratorContext::Member:
  case DeclaratorContext::Prototype:
  case DeclaratorContext::LambdaExprParameter:
  case DeclaratorContext::ObjCParameter:
  case DeclaratorContext::ObjCResult:
  case DeclaratorContext::TemplateParam:
  case DeclaratorContext::CXXCatch:
  case DeclaratorContext::ObjCCatch:
  case DeclaratorContext::TypeName:
  case DeclaratorContext::FunctionalCast: // FIXME
  case DeclaratorContext::CXXNew:
  case DeclaratorContext::AliasDecl:
  case DeclaratorContext::AliasTemplate:
  case DeclaratorContext::BlockLiteral:
  case DeclaratorContext::LambdaExpr:
  case DeclaratorContext::ConversionId:
  case DeclaratorContext::TemplateArg:
  case DeclaratorContext::TemplateTypeArg:
  case DeclaratorContext::TrailingReturn:
  case DeclaratorContext::RequiresExpr:
    return false;
  }
  llvm_unreachable("unknown context kind!")__builtin_unreachable();
}

/// isPastIdentifier - Return true if we have parsed beyond the point where
/// the name would appear. (This may happen even if we haven't actually parsed
/// a name, perhaps because this context doesn't require one.)
bool isPastIdentifier() const { return Name.isValid(); }

/// hasName - Whether this declarator has a name, which might be an
/// identifier (accessible via getIdentifier()) or some kind of
/// special C++ name (constructor, destructor, etc.), or a structured
/// binding (which is not exactly a name, but occupies the same position).
bool hasName() const {
  return Name.getKind() != UnqualifiedIdKind::IK_Identifier ||
         Name.Identifier || isDecompositionDeclarator();
}

/// Return whether this declarator is a decomposition declarator.
bool isDecompositionDeclarator() const {
  return BindingGroup.isSet();
}

IdentifierInfo *getIdentifier() const {
  if (Name.getKind() == UnqualifiedIdKind::IK_Identifier)
    return Name.Identifier;

  return nullptr;
}
SourceLocation getIdentifierLoc() const { return Name.StartLocation; }

/// Set the name of this declarator to be the given identifier.
void SetIdentifier(IdentifierInfo *Id, SourceLocation IdLoc) {
  Name.setIdentifier(Id, IdLoc);
}

/// Set the decomposition bindings for this declarator.
void
setDecompositionBindings(SourceLocation LSquareLoc,
                         ArrayRef<DecompositionDeclarator::Binding> Bindings,
                         SourceLocation RSquareLoc);

/// AddTypeInfo - Add a chunk to this declarator. Also extend the range to
/// EndLoc, which should be the last token of the chunk.
/// This function takes attrs by R-Value reference because it takes ownership
/// of those attributes from the parameter.
void AddTypeInfo(const DeclaratorChunk &TI, ParsedAttributes &&attrs,
                 SourceLocation EndLoc) {
  DeclTypeInfo.push_back(TI);
  DeclTypeInfo.back().getAttrs().addAll(attrs.begin(), attrs.end());
  getAttributePool().takeAllFrom(attrs.getPool());

  if (!EndLoc.isInvalid())
    SetRangeEnd(EndLoc);
}

/// AddTypeInfo - Add a chunk to this declarator. Also extend the range to
/// EndLoc, which should be the last token of the chunk.
void AddTypeInfo(const DeclaratorChunk &TI, SourceLocation EndLoc) {
  DeclTypeInfo.push_back(TI);

  if (!EndLoc.isInvalid())
    SetRangeEnd(EndLoc);
}

/// Add a new innermost chunk to this declarator.
void AddInnermostTypeInfo(const DeclaratorChunk &TI) {
  DeclTypeInfo.insert(DeclTypeInfo.begin(), TI);
}

/// Return the number of types applied to this declarator.
unsigned getNumTypeObjects() const { return DeclTypeInfo.size(); }

/// Return the specified TypeInfo from this declarator.  TypeInfo #0 is
/// closest to the identifier.
const DeclaratorChunk &getTypeObject(unsigned i) const {
  assert(i < DeclTypeInfo.size() && "Invalid type chunk")(static_cast<void> (0));
  return DeclTypeInfo[i];
}
DeclaratorChunk &getTypeObject(unsigned i) {
  assert(i < DeclTypeInfo.size() && "Invalid type chunk")(static_cast<void> (0));
  return DeclTypeInfo[i];
}

typedef SmallVectorImpl<DeclaratorChunk>::const_iterator type_object_iterator;
typedef llvm::iterator_range<type_object_iterator> type_object_range;

/// Returns the range of type objects, from the identifier outwards.
type_object_range type_objects() const {
  return type_object_range(DeclTypeInfo.begin(), DeclTypeInfo.end());
}

void DropFirstTypeObject() {
  assert(!DeclTypeInfo.empty() && "No type chunks to drop.")(static_cast<void> (0));
  DeclTypeInfo.front().destroy();
  DeclTypeInfo.erase(DeclTypeInfo.begin());
}

/// Return the innermost (closest to the declarator) chunk of this
/// declarator that is not a parens chunk, or null if there are no
/// non-parens chunks.
const DeclaratorChunk *getInnermostNonParenChunk() const {
  for (unsigned i = 0, i_end = DeclTypeInfo.size(); i < i_end; ++i) {
    if (!DeclTypeInfo[i].isParen())
      return &DeclTypeInfo[i];
  }
  return nullptr;
}

/// Return the outermost (furthest from the declarator) chunk of
/// this declarator that is not a parens chunk, or null if there are
/// no non-parens chunks.
const DeclaratorChunk *getOutermostNonParenChunk() const {
  for (unsigned i = DeclTypeInfo.size(), i_end = 0; i != i_end; --i) {
    if (!DeclTypeInfo[i-1].isParen())
      return &DeclTypeInfo[i-1];
  }
  return nullptr;
}

/// isArrayOfUnknownBound - This method returns true if the declarator
/// is a declarator for an array of unknown bound (looking through
/// parentheses).
bool isArrayOfUnknownBound() const {
  const DeclaratorChunk *chunk = getInnermostNonParenChunk();
  return (chunk && chunk->Kind == DeclaratorChunk::Array &&
          !chunk->Arr.NumElts);
}

/// isFunctionDeclarator - This method returns true if the declarator
/// is a function declarator (looking through parentheses).
/// If true is returned, then the reference type parameter idx is
/// assigned with the index of the declaration chunk.
bool isFunctionDeclarator(unsigned& idx) const {
  for (unsigned i = 0, i_end = DeclTypeInfo.size(); i < i_end; ++i) {
    switch (DeclTypeInfo[i].Kind) {
    case DeclaratorChunk::Function:
      idx = i;
      return true;
    case DeclaratorChunk::Paren:
      continue;
    case DeclaratorChunk::Pointer:
    case DeclaratorChunk::Reference:
    case DeclaratorChunk::Array:
    case DeclaratorChunk::BlockPointer:
    case DeclaratorChunk::MemberPointer:
    case DeclaratorChunk::Pipe:
      return false;
    }
    llvm_unreachable("Invalid type chunk")__builtin_unreachable();
  }
  return false;
}

/// isFunctionDeclarator - Once this declarator is fully parsed and formed,
/// this method returns true if the identifier is a function declarator
/// (looking through parentheses).
bool isFunctionDeclarator() const {
  unsigned index;
  return isFunctionDeclarator(index);
}

/// getFunctionTypeInfo - Retrieves the function type info object
/// (looking through parentheses).
DeclaratorChunk::FunctionTypeInfo &getFunctionTypeInfo() {
  assert(isFunctionDeclarator() && "Not a function declarator!")(static_cast<void> (0));
  unsigned index = 0;
  isFunctionDeclarator(index);
  return DeclTypeInfo[index].Fun;
}

/// getFunctionTypeInfo - Retrieves the function type info object
/// (looking through parentheses).
const DeclaratorChunk::FunctionTypeInfo &getFunctionTypeInfo() const {
  return const_cast<Declarator*>(this)->getFunctionTypeInfo();
}

/// Determine whether the declaration that will be produced from
/// this declaration will be a function.
///
/// A declaration can declare a function even if the declarator itself
/// isn't a function declarator, if the type specifier refers to a function
/// type. This routine checks for both cases.
bool isDeclarationOfFunction() const;

/// Return true if this declaration appears in a context where a
/// function declarator would be a function declaration.
bool isFunctionDeclarationContext() const {
  if (getDeclSpec().getStorageClassSpec() == DeclSpec::SCS_typedef)
    return false;

  switch (Context) {
  case DeclaratorContext::File:
  case DeclaratorContext::Member:
  case DeclaratorContext::Block:
  case DeclaratorContext::ForInit:
  case DeclaratorContext::SelectionInit:
    return true;

  case DeclaratorContext::Condition:
  case DeclaratorContext::KNRTypeList:
  case DeclaratorContext::TypeName:
  case DeclaratorContext::FunctionalCast:
  case DeclaratorContext::AliasDecl:
  case DeclaratorContext::AliasTemplate:
  case DeclaratorContext::Prototype:
  case DeclaratorContext::LambdaExprParameter:
  case DeclaratorContext::ObjCParameter:
  case DeclaratorContext::ObjCResult:
  case DeclaratorContext::TemplateParam:
  case DeclaratorContext::CXXNew:
  case DeclaratorContext::CXXCatch:
  case DeclaratorContext::ObjCCatch:
  case DeclaratorContext::BlockLiteral:
  case DeclaratorContext::LambdaExpr:
  case DeclaratorContext::ConversionId:
  case DeclaratorContext::TemplateArg:
  case DeclaratorContext::TemplateTypeArg:
  case DeclaratorContext::TrailingReturn:
  case DeclaratorContext::TrailingReturnVar:
  case DeclaratorContext::RequiresExpr:
    return false;
  }
  llvm_unreachable("unknown context kind!")__builtin_unreachable();
}

/// Determine whether this declaration appears in a context where an
/// expression could appear.
bool isExpressionContext() const {
  switch (Context) {
  case DeclaratorContext::File:
  case DeclaratorContext::KNRTypeList:
  case DeclaratorContext::Member:

  // FIXME: sizeof(...) permits an expression.
  case DeclaratorContext::TypeName:

  case DeclaratorContext::FunctionalCast:
  case DeclaratorContext::AliasDecl:
  case DeclaratorContext::AliasTemplate:
  case DeclaratorContext::Prototype:
  case DeclaratorContext::LambdaExprParameter:
  case DeclaratorContext::ObjCParameter:
  case DeclaratorContext::ObjCResult:
  case DeclaratorContext::TemplateParam:
  case DeclaratorContext::CXXNew:
  case DeclaratorContext::CXXCatch:
  case DeclaratorContext::ObjCCatch:
  case DeclaratorContext::BlockLiteral:
  case DeclaratorContext::LambdaExpr:
  case DeclaratorContext::ConversionId:
  case DeclaratorContext::TrailingReturn:
  case DeclaratorContext::TrailingReturnVar:
  case DeclaratorContext::TemplateTypeArg:
  case DeclaratorContext::RequiresExpr:
    return false;

  case DeclaratorContext::Block:
  case DeclaratorContext::ForInit:
  case DeclaratorContext::SelectionInit:
  case DeclaratorContext::Condition:
  case DeclaratorContext::TemplateArg:
    return true;
  }

  llvm_unreachable("unknown context kind!")__builtin_unreachable();
}

/// Return true if a function declarator at this position would be a
/// function declaration.
bool isFunctionDeclaratorAFunctionDeclaration() const {
  if (!isFunctionDeclarationContext())
    return false;

  for (unsigned I = 0, N = getNumTypeObjects(); I != N; ++I)
    if (getTypeObject(I).Kind != DeclaratorChunk::Paren)
      return false;

  return true;
}

/// Determine whether a trailing return type was written (at any
/// level) within this declarator.
bool hasTrailingReturnType() const {
  for (const auto &Chunk : type_objects())
    if (Chunk.Kind == DeclaratorChunk::Function &&
        Chunk.Fun.hasTrailingReturnType())
      return true;
  return false;
}
/// Get the trailing return type appearing (at any level) within this
/// declarator.
ParsedType getTrailingReturnType() const {
  for (const auto &Chunk : type_objects())
    if (Chunk.Kind == DeclaratorChunk::Function &&
        Chunk.Fun.hasTrailingReturnType())
      return Chunk.Fun.getTrailingReturnType();
  return ParsedType();
}

/// \brief Sets a trailing requires clause for this declarator.
void setTrailingRequiresClause(Expr *TRC) {
  TrailingRequiresClause = TRC;

  SetRangeEnd(TRC->getEndLoc());
}

/// \brief Sets a trailing requires clause for this declarator.
Expr *getTrailingRequiresClause() {
  return TrailingRequiresClause;
}

/// \brief Determine whether a trailing requires clause was written in this
/// declarator.
bool hasTrailingRequiresClause() const {
  return TrailingRequiresClause != nullptr;
}

/// Sets the template parameter lists that preceded the declarator.
void setTemplateParameterLists(ArrayRef<TemplateParameterList *> TPLs) {
  TemplateParameterLists = TPLs;
}

/// The template parameter lists that preceded the declarator.
ArrayRef<TemplateParameterList *> getTemplateParameterLists() const {
  return TemplateParameterLists;
}

/// Sets the template parameter list generated from the explicit template
/// parameters along with any invented template parameters from
/// placeholder-typed parameters.
void setInventedTemplateParameterList(TemplateParameterList *Invented) {
  InventedTemplateParameterList = Invented;
}

/// The template parameter list generated from the explicit template
/// parameters along with any invented template parameters from
/// placeholder-typed parameters, if there were any such parameters.
TemplateParameterList * getInventedTemplateParameterList() const {
  return InventedTemplateParameterList;
}

/// takeAttributes - Takes attributes from the given parsed-attributes
/// set and add them to this declarator.
///
/// These examples both add 3 attributes to "var":
///  short int var __attribute__((aligned(16),common,deprecated));
///  short int x, __attribute__((aligned(16)) var
///                                 __attribute__((common,deprecated));
///
/// Also extends the range of the declarator.
void takeAttributes(ParsedAttributes &attrs, SourceLocation lastLoc) {
  Attrs.takeAllFrom(attrs);

  if (!lastLoc.isInvalid())
    SetRangeEnd(lastLoc);
}

const ParsedAttributes &getAttributes() const { return Attrs; }
ParsedAttributes &getAttributes() { return Attrs; }

/// hasAttributes - do we contain any attributes?
bool hasAttributes() const {
  if (!getAttributes().empty() || getDeclSpec().hasAttributes())
    return true;
  for (unsigned i = 0, e = getNumTypeObjects(); i != e; ++i)
    if (!getTypeObject(i).getAttrs().empty())
      return true;
  return false;
}

/// Return a source range list of C++11 attributes associated
/// with the declarator.
void getCXX11AttributeRanges(SmallVectorImpl<SourceRange> &Ranges) {
  for (const ParsedAttr &AL : Attrs)
    if (AL.isCXX11Attribute())
      Ranges.push_back(AL.getRange());
}

void setAsmLabel(Expr *E) { AsmLabel = E; }
Expr *getAsmLabel() const { return AsmLabel; }

void setExtension(bool Val = true) { Extension = Val; }
bool getExtension() const { return Extension; }

void setObjCIvar(bool Val = true) { ObjCIvar = Val; }
bool isObjCIvar() const { return ObjCIvar; }

void setObjCWeakProperty(bool Val = true) { ObjCWeakProperty = Val; }
bool isObjCWeakProperty() const { return ObjCWeakProperty; }

void setInvalidType(bool Val = true) { InvalidType = Val; }
bool isInvalidType() const {
  return InvalidType || DS.getTypeSpecType() == DeclSpec::TST_error;
}

void setGroupingParens(bool flag) { GroupingParens = flag; }
bool hasGroupingParens() const { return GroupingParens; }

bool isFirstDeclarator() const { return !CommaLoc.isValid(); }
SourceLocation getCommaLoc() const { return CommaLoc; }
void setCommaLoc(SourceLocation CL) { CommaLoc = CL; }

bool hasEllipsis() const { return EllipsisLoc.isValid(); }
SourceLocation getEllipsisLoc() const { return EllipsisLoc; }
void setEllipsisLoc(SourceLocation EL) { EllipsisLoc = EL; }

void setFunctionDefinitionKind(FunctionDefinitionKind Val) {
  FunctionDefinition = static_cast<unsigned>(Val);
}

bool isFunctionDefinition() const {
  return getFunctionDefinitionKind() != FunctionDefinitionKind::Declaration;
}

FunctionDefinitionKind getFunctionDefinitionKind() const {
  return (FunctionDefinitionKind)FunctionDefinition;
}

void setHasInitializer(bool Val = true) { HasInitializer = Val; }
bool hasInitializer() const { return HasInitializer; }

/// Returns true if this declares a real member and not a friend.
bool isFirstDeclarationOfMember() {
  return getContext() == DeclaratorContext::Member &&
         !getDeclSpec().isFriendSpecified();
}

/// Returns true if this declares a static member.  This cannot be called on a
/// declarator outside of a MemberContext because we won't know until
/// redeclaration time if the decl is static.
bool isStaticMember();

/// Returns true if this declares a constructor or a destructor.
bool isCtorOrDtor();

void setRedeclaration(bool Val) { Redeclaration = Val; }
bool isRedeclaration() const { return Redeclaration; }
2603};

2605/// This little struct is used to capture information about
2606/// structure field declarators, which is basically just a bitfield size.
2607struct FieldDeclarator {
Declarator D;
Expr *BitfieldSize;
explicit FieldDeclarator(const DeclSpec &DS)
    : D(DS, DeclaratorContext::Member), BitfieldSize(nullptr) {}
2612};

2614/// Represents a C++11 virt-specifier-seq.
2615class VirtSpecifiers {
2616public:
enum Specifier {
  VS_None = 0,
  VS_Override = 1,
  VS_Final = 2,
  VS_Sealed = 4,
  // Represents the __final keyword, which is legal for gcc in pre-C++11 mode.
  VS_GNU_Final = 8,
  VS_Abstract = 16
};

VirtSpecifiers() : Specifiers(0), LastSpecifier(VS_None) { }

bool SetSpecifier(Specifier VS, SourceLocation Loc,
                  const char *&PrevSpec);

bool isUnset() const { return Specifiers == 0; }

bool isOverrideSpecified() const { return Specifiers & VS_Override; }
SourceLocation getOverrideLoc() const { return VS_overrideLoc; }

bool isFinalSpecified() const { return Specifiers & (VS_Final | VS_Sealed | VS_GNU_Final); }
bool isFinalSpelledSealed() const { return Specifiers & VS_Sealed; }
SourceLocation getFinalLoc() const { return VS_finalLoc; }
SourceLocation getAbstractLoc() const { return VS_abstractLoc; }

void clear() { Specifiers = 0; }

static const char *getSpecifierName(Specifier VS);

SourceLocation getFirstLocation() const { return FirstLocation; }
SourceLocation getLastLocation() const { return LastLocation; }
Specifier getLastSpecifier() const { return LastSpecifier; }

2650private:
unsigned Specifiers;
Specifier LastSpecifier;

SourceLocation VS_overrideLoc, VS_finalLoc, VS_abstractLoc;
SourceLocation FirstLocation;
SourceLocation LastLocation;
2657};

2659enum class LambdaCaptureInitKind {
NoInit,     //!< [a]
CopyInit,   //!< [a = b], [a = {b}]
DirectInit, //!< [a(b)]
ListInit    //!< [a{b}]
2664};

2666/// Represents a complete lambda introducer.
2667struct LambdaIntroducer {
/// An individual capture in a lambda introducer.
struct LambdaCapture {
  LambdaCaptureKind Kind;
  SourceLocation Loc;
  IdentifierInfo *Id;
  SourceLocation EllipsisLoc;
  LambdaCaptureInitKind InitKind;
  ExprResult Init;
  ParsedType InitCaptureType;
  SourceRange ExplicitRange;

  LambdaCapture(LambdaCaptureKind Kind, SourceLocation Loc,
                IdentifierInfo *Id, SourceLocation EllipsisLoc,
                LambdaCaptureInitKind InitKind, ExprResult Init,
                ParsedType InitCaptureType,
                SourceRange ExplicitRange)
      : Kind(Kind), Loc(Loc), Id(Id), EllipsisLoc(EllipsisLoc),
        InitKind(InitKind), Init(Init), InitCaptureType(InitCaptureType),
        ExplicitRange(ExplicitRange) {}
};

SourceRange Range;
SourceLocation DefaultLoc;
LambdaCaptureDefault Default;
SmallVector<LambdaCapture, 4> Captures;

LambdaIntroducer()
  : Default(LCD_None) {}

/// Append a capture in a lambda introducer.
void addCapture(LambdaCaptureKind Kind,
                SourceLocation Loc,
                IdentifierInfo* Id,
                SourceLocation EllipsisLoc,
                LambdaCaptureInitKind InitKind,
                ExprResult Init,
                ParsedType InitCaptureType,
                SourceRange ExplicitRange) {
  Captures.push_back(LambdaCapture(Kind, Loc, Id, EllipsisLoc, InitKind, Init,
                                   InitCaptureType, ExplicitRange));
}
2709};

2711struct InventedTemplateParameterInfo {
/// The number of parameters in the template parameter list that were
/// explicitly specified by the user, as opposed to being invented by use
/// of an auto parameter.
unsigned NumExplicitTemplateParams = 0;

/// If this is a generic lambda or abbreviated function template, use this
/// as the depth of each 'auto' parameter, during initial AST construction.
unsigned AutoTemplateParameterDepth = 0;

/// Store the list of the template parameters for a generic lambda or an
/// abbreviated function template.
/// If this is a generic lambda or abbreviated function template, this holds
/// the explicit template parameters followed by the auto parameters
/// converted into TemplateTypeParmDecls.
/// It can be used to construct the generic lambda or abbreviated template's
/// template parameter list during initial AST construction.
SmallVector<NamedDecl*, 4> TemplateParams;
2729};

2731} // end namespace clang

2733#endif // LLVM_CLANG_SEMA_DECLSPEC_H

←

/build/llvm-toolchain-snapshot-14~++20210903100615+fd66b44ec19e/clang/include/clang/AST/Type.h

→

1//===- Type.h - C Language Family Type Representation -----------*- C++ -*-===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8//
9/// \file
10/// C Language Family Type Representation
11///
12/// This file defines the clang::Type interface and subclasses, used to
13/// represent types for languages in the C family.
14//
15//===----------------------------------------------------------------------===//

17#ifndef LLVM_CLANG_AST_TYPE_H
18#define LLVM_CLANG_AST_TYPE_H

20#include "clang/AST/DependenceFlags.h"
21#include "clang/AST/NestedNameSpecifier.h"
22#include "clang/AST/TemplateName.h"
23#include "clang/Basic/AddressSpaces.h"
24#include "clang/Basic/AttrKinds.h"
25#include "clang/Basic/Diagnostic.h"
26#include "clang/Basic/ExceptionSpecificationType.h"
27#include "clang/Basic/LLVM.h"
28#include "clang/Basic/Linkage.h"
29#include "clang/Basic/PartialDiagnostic.h"
30#include "clang/Basic/SourceLocation.h"
31#include "clang/Basic/Specifiers.h"
32#include "clang/Basic/Visibility.h"
33#include "llvm/ADT/APInt.h"
34#include "llvm/ADT/APSInt.h"
35#include "llvm/ADT/ArrayRef.h"
36#include "llvm/ADT/FoldingSet.h"
37#include "llvm/ADT/None.h"
38#include "llvm/ADT/Optional.h"
39#include "llvm/ADT/PointerIntPair.h"
40#include "llvm/ADT/PointerUnion.h"
41#include "llvm/ADT/StringRef.h"
42#include "llvm/ADT/Twine.h"
43#include "llvm/ADT/iterator_range.h"
44#include "llvm/Support/Casting.h"
45#include "llvm/Support/Compiler.h"
46#include "llvm/Support/ErrorHandling.h"
47#include "llvm/Support/PointerLikeTypeTraits.h"
48#include "llvm/Support/TrailingObjects.h"
49#include "llvm/Support/type_traits.h"
50#include <cassert>
51#include <cstddef>
52#include <cstdint>
53#include <cstring>
54#include <string>
55#include <type_traits>
56#include <utility>

58namespace clang {

60class ExtQuals;
61class QualType;
62class ConceptDecl;
63class TagDecl;
64class TemplateParameterList;
65class Type;

67enum {
TypeAlignmentInBits = 4,
TypeAlignment = 1 << TypeAlignmentInBits
70};

72namespace serialization {
template <class T> class AbstractTypeReader;
template <class T> class AbstractTypeWriter;
75}

77} // namespace clang

79namespace llvm {

template <typename T>
struct PointerLikeTypeTraits;
template<>
struct PointerLikeTypeTraits< ::clang::Type*> {
  static inline void *getAsVoidPointer(::clang::Type *P) { return P; }

  static inline ::clang::Type *getFromVoidPointer(void *P) {
    return static_cast< ::clang::Type*>(P);
  }

  static constexpr int NumLowBitsAvailable = clang::TypeAlignmentInBits;
};

template<>
struct PointerLikeTypeTraits< ::clang::ExtQuals*> {
  static inline void *getAsVoidPointer(::clang::ExtQuals *P) { return P; }

  static inline ::clang::ExtQuals *getFromVoidPointer(void *P) {
    return static_cast< ::clang::ExtQuals*>(P);
  }

  static constexpr int NumLowBitsAvailable = clang::TypeAlignmentInBits;
};

105} // namespace llvm

107namespace clang {

109class ASTContext;
110template <typename> class CanQual;
111class CXXRecordDecl;
112class DeclContext;
113class EnumDecl;
114class Expr;
115class ExtQualsTypeCommonBase;
116class FunctionDecl;
117class IdentifierInfo;
118class NamedDecl;
119class ObjCInterfaceDecl;
120class ObjCProtocolDecl;
121class ObjCTypeParamDecl;
122struct PrintingPolicy;
123class RecordDecl;
124class Stmt;
125class TagDecl;
126class TemplateArgument;
127class TemplateArgumentListInfo;
128class TemplateArgumentLoc;
129class TemplateTypeParmDecl;
130class TypedefNameDecl;
131class UnresolvedUsingTypenameDecl;

133using CanQualType = CanQual<Type>;

135// Provide forward declarations for all of the *Type classes.
136#define TYPE(Class, Base) class Class##Type;
137#include "clang/AST/TypeNodes.inc"

139/// The collection of all-type qualifiers we support.
140/// Clang supports five independent qualifiers:
141/// * C99: const, volatile, and restrict
142/// * MS: __unaligned
143/// * Embedded C (TR18037): address spaces
144/// * Objective C: the GC attributes (none, weak, or strong)
145class Qualifiers {
146public:
enum TQ { // NOTE: These flags must be kept in sync with DeclSpec::TQ.
  Const    = 0x1,
  Restrict = 0x2,
  Volatile = 0x4,
  CVRMask = Const | Volatile | Restrict
};

enum GC {
  GCNone = 0,
  Weak,
  Strong
};

enum ObjCLifetime {
  /// There is no lifetime qualification on this type.
  OCL_None,

  /// This object can be modified without requiring retains or
  /// releases.
  OCL_ExplicitNone,

  /// Assigning into this object requires the old value to be
  /// released and the new value to be retained.  The timing of the
  /// release of the old value is inexact: it may be moved to
  /// immediately after the last known point where the value is
  /// live.
  OCL_Strong,

  /// Reading or writing from this object requires a barrier call.
  OCL_Weak,

  /// Assigning into this object requires a lifetime extension.
  OCL_Autoreleasing
};

enum {
  /// The maximum supported address space number.
  /// 23 bits should be enough for anyone.
  MaxAddressSpace = 0x7fffffu,

  /// The width of the "fast" qualifier mask.
  FastWidth = 3,

  /// The fast qualifier mask.
  FastMask = (1 << FastWidth) - 1
};

/// Returns the common set of qualifiers while removing them from
/// the given sets.
static Qualifiers removeCommonQualifiers(Qualifiers &L, Qualifiers &R) {
  // If both are only CVR-qualified, bit operations are sufficient.
  if (!(L.Mask & ~CVRMask) && !(R.Mask & ~CVRMask)) {
    Qualifiers Q;
    Q.Mask = L.Mask & R.Mask;
    L.Mask &= ~Q.Mask;
    R.Mask &= ~Q.Mask;
    return Q;
  }

  Qualifiers Q;
  unsigned CommonCRV = L.getCVRQualifiers() & R.getCVRQualifiers();
  Q.addCVRQualifiers(CommonCRV);
  L.removeCVRQualifiers(CommonCRV);
  R.removeCVRQualifiers(CommonCRV);

  if (L.getObjCGCAttr() == R.getObjCGCAttr()) {
    Q.setObjCGCAttr(L.getObjCGCAttr());
    L.removeObjCGCAttr();
    R.removeObjCGCAttr();
  }

  if (L.getObjCLifetime() == R.getObjCLifetime()) {
    Q.setObjCLifetime(L.getObjCLifetime());
    L.removeObjCLifetime();
    R.removeObjCLifetime();
  }

  if (L.getAddressSpace() == R.getAddressSpace()) {
    Q.setAddressSpace(L.getAddressSpace());
    L.removeAddressSpace();
    R.removeAddressSpace();
  }
  return Q;
}

static Qualifiers fromFastMask(unsigned Mask) {
  Qualifiers Qs;
  Qs.addFastQualifiers(Mask);
  return Qs;
}

static Qualifiers fromCVRMask(unsigned CVR) {
  Qualifiers Qs;
  Qs.addCVRQualifiers(CVR);
  return Qs;
}

static Qualifiers fromCVRUMask(unsigned CVRU) {
  Qualifiers Qs;
  Qs.addCVRUQualifiers(CVRU);
  return Qs;
}

// Deserialize qualifiers from an opaque representation.
static Qualifiers fromOpaqueValue(unsigned opaque) {
  Qualifiers Qs;
  Qs.Mask = opaque;
  return Qs;
}

// Serialize these qualifiers into an opaque representation.
unsigned getAsOpaqueValue() const {
  return Mask;
}

bool hasConst() const { return Mask & Const; }
bool hasOnlyConst() const { return Mask == Const; }
void removeConst() { Mask &= ~Const; }
void addConst() { Mask |= Const; }

bool hasVolatile() const { return Mask & Volatile; }
bool hasOnlyVolatile() const { return Mask == Volatile; }
void removeVolatile() { Mask &= ~Volatile; }
void addVolatile() { Mask |= Volatile; }

bool hasRestrict() const { return Mask & Restrict; }
bool hasOnlyRestrict() const { return Mask == Restrict; }
void removeRestrict() { Mask &= ~Restrict; }
void addRestrict() { Mask |= Restrict; }

bool hasCVRQualifiers() const { return getCVRQualifiers(); }
unsigned getCVRQualifiers() const { return Mask & CVRMask; }
unsigned getCVRUQualifiers() const { return Mask & (CVRMask | UMask); }

void setCVRQualifiers(unsigned mask) {
  assert(!(mask & ~CVRMask) && "bitmask contains non-CVR bits")(static_cast<void> (0));
  Mask = (Mask & ~CVRMask) | mask;
}
void removeCVRQualifiers(unsigned mask) {
  assert(!(mask & ~CVRMask) && "bitmask contains non-CVR bits")(static_cast<void> (0));
  Mask &= ~mask;
}
void removeCVRQualifiers() {
  removeCVRQualifiers(CVRMask);
}
void addCVRQualifiers(unsigned mask) {
  assert(!(mask & ~CVRMask) && "bitmask contains non-CVR bits")(static_cast<void> (0));
  Mask |= mask;
}
void addCVRUQualifiers(unsigned mask) {
  assert(!(mask & ~CVRMask & ~UMask) && "bitmask contains non-CVRU bits")(static_cast<void> (0));
  Mask |= mask;
}

bool hasUnaligned() const { return Mask & UMask; }
void setUnaligned(bool flag) {
  Mask = (Mask & ~UMask) | (flag ? UMask : 0);
}
void removeUnaligned() { Mask &= ~UMask; }
void addUnaligned() { Mask |= UMask; }

bool hasObjCGCAttr() const { return Mask & GCAttrMask; }
GC getObjCGCAttr() const { return GC((Mask & GCAttrMask) >> GCAttrShift); }
void setObjCGCAttr(GC type) {
  Mask = (Mask & ~GCAttrMask) | (type << GCAttrShift);
}
void removeObjCGCAttr() { setObjCGCAttr(GCNone); }
void addObjCGCAttr(GC type) {
  assert(type)(static_cast<void> (0));
  setObjCGCAttr(type);
}
Qualifiers withoutObjCGCAttr() const {
  Qualifiers qs = *this;
  qs.removeObjCGCAttr();
  return qs;
}
Qualifiers withoutObjCLifetime() const {
  Qualifiers qs = *this;
  qs.removeObjCLifetime();
  return qs;
}
Qualifiers withoutAddressSpace() const {
  Qualifiers qs = *this;
  qs.removeAddressSpace();
  return qs;
}

bool hasObjCLifetime() const { return Mask & LifetimeMask; }
ObjCLifetime getObjCLifetime() const {
  return ObjCLifetime((Mask & LifetimeMask) >> LifetimeShift);
}
void setObjCLifetime(ObjCLifetime type) {
  Mask = (Mask & ~LifetimeMask) | (type << LifetimeShift);
}
void removeObjCLifetime() { setObjCLifetime(OCL_None); }
void addObjCLifetime(ObjCLifetime type) {
  assert(type)(static_cast<void> (0));
  assert(!hasObjCLifetime())(static_cast<void> (0));
  Mask |= (type << LifetimeShift);
}

/// True if the lifetime is neither None or ExplicitNone.
bool hasNonTrivialObjCLifetime() const {
  ObjCLifetime lifetime = getObjCLifetime();
  return (lifetime > OCL_ExplicitNone);
}

/// True if the lifetime is either strong or weak.
bool hasStrongOrWeakObjCLifetime() const {
  ObjCLifetime lifetime = getObjCLifetime();
  return (lifetime == OCL_Strong || lifetime == OCL_Weak);
}

bool hasAddressSpace() const { return Mask & AddressSpaceMask; }
LangAS getAddressSpace() const {
  return static_cast<LangAS>(Mask >> AddressSpaceShift);
}
bool hasTargetSpecificAddressSpace() const {
  return isTargetAddressSpace(getAddressSpace());
}
/// Get the address space attribute value to be printed by diagnostics.
unsigned getAddressSpaceAttributePrintValue() const {
  auto Addr = getAddressSpace();
  // This function is not supposed to be used with language specific
  // address spaces. If that happens, the diagnostic message should consider
  // printing the QualType instead of the address space value.
  assert(Addr == LangAS::Default || hasTargetSpecificAddressSpace())(static_cast<void> (0));
  if (Addr != LangAS::Default)
    return toTargetAddressSpace(Addr);
  // TODO: The diagnostic messages where Addr may be 0 should be fixed
  // since it cannot differentiate the situation where 0 denotes the default
  // address space or user specified __attribute__((address_space(0))).
  return 0;
}
void setAddressSpace(LangAS space) {
  assert((unsigned)space <= MaxAddressSpace)(static_cast<void> (0));
  Mask = (Mask & ~AddressSpaceMask)
       | (((uint32_t) space) << AddressSpaceShift);
}
void removeAddressSpace() { setAddressSpace(LangAS::Default); }
void addAddressSpace(LangAS space) {
  assert(space != LangAS::Default)(static_cast<void> (0));
  setAddressSpace(space);
}

// Fast qualifiers are those that can be allocated directly
// on a QualType object.
bool hasFastQualifiers() const { return getFastQualifiers(); }
unsigned getFastQualifiers() const { return Mask & FastMask; }
void setFastQualifiers(unsigned mask) {
  assert(!(mask & ~FastMask) && "bitmask contains non-fast qualifier bits")(static_cast<void> (0));
  Mask = (Mask & ~FastMask) | mask;
}
void removeFastQualifiers(unsigned mask) {
  assert(!(mask & ~FastMask) && "bitmask contains non-fast qualifier bits")(static_cast<void> (0));
  Mask &= ~mask;
}
void removeFastQualifiers() {
  removeFastQualifiers(FastMask);
}
void addFastQualifiers(unsigned mask) {
  assert(!(mask & ~FastMask) && "bitmask contains non-fast qualifier bits")(static_cast<void> (0));
  Mask |= mask;
}

/// Return true if the set contains any qualifiers which require an ExtQuals
/// node to be allocated.
bool hasNonFastQualifiers() const { return Mask & ~FastMask; }
Qualifiers getNonFastQualifiers() const {
  Qualifiers Quals = *this;
  Quals.setFastQualifiers(0);
  return Quals;
}

/// Return true if the set contains any qualifiers.
bool hasQualifiers() const { return Mask; }
bool empty() const { return !Mask; }

/// Add the qualifiers from the given set to this set.
void addQualifiers(Qualifiers Q) {
  // If the other set doesn't have any non-boolean qualifiers, just
  // bit-or it in.
  if (!(Q.Mask & ~CVRMask))
    Mask |= Q.Mask;
  else {
    Mask |= (Q.Mask & CVRMask);
    if (Q.hasAddressSpace())
      addAddressSpace(Q.getAddressSpace());
    if (Q.hasObjCGCAttr())
      addObjCGCAttr(Q.getObjCGCAttr());
    if (Q.hasObjCLifetime())
      addObjCLifetime(Q.getObjCLifetime());
  }
}

/// Remove the qualifiers from the given set from this set.
void removeQualifiers(Qualifiers Q) {
  // If the other set doesn't have any non-boolean qualifiers, just
  // bit-and the inverse in.
  if (!(Q.Mask & ~CVRMask))
    Mask &= ~Q.Mask;
  else {
    Mask &= ~(Q.Mask & CVRMask);
    if (getObjCGCAttr() == Q.getObjCGCAttr())
      removeObjCGCAttr();
    if (getObjCLifetime() == Q.getObjCLifetime())
      removeObjCLifetime();
    if (getAddressSpace() == Q.getAddressSpace())
      removeAddressSpace();
  }
}

/// Add the qualifiers from the given set to this set, given that
/// they don't conflict.
void addConsistentQualifiers(Qualifiers qs) {
  assert(getAddressSpace() == qs.getAddressSpace() ||(static_cast<void> (0))
         !hasAddressSpace() || !qs.hasAddressSpace())(static_cast<void> (0));
  assert(getObjCGCAttr() == qs.getObjCGCAttr() ||(static_cast<void> (0))
         !hasObjCGCAttr() || !qs.hasObjCGCAttr())(static_cast<void> (0));
  assert(getObjCLifetime() == qs.getObjCLifetime() ||(static_cast<void> (0))
         !hasObjCLifetime() || !qs.hasObjCLifetime())(static_cast<void> (0));
  Mask |= qs.Mask;
}

/// Returns true if address space A is equal to or a superset of B.
/// OpenCL v2.0 defines conversion rules (OpenCLC v2.0 s6.5.5) and notion of
/// overlapping address spaces.
/// CL1.1 or CL1.2:
///   every address space is a superset of itself.
/// CL2.0 adds:
///   __generic is a superset of any address space except for __constant.
static bool isAddressSpaceSupersetOf(LangAS A, LangAS B) {
  // Address spaces must match exactly.
  return A == B ||
         // Otherwise in OpenCLC v2.0 s6.5.5: every address space except
         // for __constant can be used as __generic.
         (A == LangAS::opencl_generic && B != LangAS::opencl_constant) ||
         // We also define global_device and global_host address spaces,
         // to distinguish global pointers allocated on host from pointers
         // allocated on device, which are a subset of __global.
         (A == LangAS::opencl_global && (B == LangAS::opencl_global_device ||
                                         B == LangAS::opencl_global_host)) ||
         (A == LangAS::sycl_global && (B == LangAS::sycl_global_device ||
                                       B == LangAS::sycl_global_host)) ||
         // Consider pointer size address spaces to be equivalent to default.
         ((isPtrSizeAddressSpace(A) || A == LangAS::Default) &&
          (isPtrSizeAddressSpace(B) || B == LangAS::Default)) ||
         // Default is a superset of SYCL address spaces.
         (A == LangAS::Default &&
          (B == LangAS::sycl_private || B == LangAS::sycl_local ||
           B == LangAS::sycl_global || B == LangAS::sycl_global_device ||
           B == LangAS::sycl_global_host)) ||
         // In HIP device compilation, any cuda address space is allowed
         // to implicitly cast into the default address space.
         (A == LangAS::Default &&
          (B == LangAS::cuda_constant || B == LangAS::cuda_device ||
           B == LangAS::cuda_shared));
}

/// Returns true if the address space in these qualifiers is equal to or
/// a superset of the address space in the argument qualifiers.
bool isAddressSpaceSupersetOf(Qualifiers other) const {
  return isAddressSpaceSupersetOf(getAddressSpace(), other.getAddressSpace());
}

/// Determines if these qualifiers compatibly include another set.
/// Generally this answers the question of whether an object with the other
/// qualifiers can be safely used as an object with these qualifiers.
bool compatiblyIncludes(Qualifiers other) const {
  return isAddressSpaceSupersetOf(other) &&
         // ObjC GC qualifiers can match, be added, or be removed, but can't
         // be changed.
         (getObjCGCAttr() == other.getObjCGCAttr() || !hasObjCGCAttr() ||
          !other.hasObjCGCAttr()) &&
         // ObjC lifetime qualifiers must match exactly.
         getObjCLifetime() == other.getObjCLifetime() &&
         // CVR qualifiers may subset.
         (((Mask & CVRMask) | (other.Mask & CVRMask)) == (Mask & CVRMask)) &&
         // U qualifier may superset.
         (!other.hasUnaligned() || hasUnaligned());
}

/// Determines if these qualifiers compatibly include another set of
/// qualifiers from the narrow perspective of Objective-C ARC lifetime.
///
/// One set of Objective-C lifetime qualifiers compatibly includes the other
/// if the lifetime qualifiers match, or if both are non-__weak and the
/// including set also contains the 'const' qualifier, or both are non-__weak
/// and one is None (which can only happen in non-ARC modes).
bool compatiblyIncludesObjCLifetime(Qualifiers other) const {
  if (getObjCLifetime() == other.getObjCLifetime())
    return true;

  if (getObjCLifetime() == OCL_Weak || other.getObjCLifetime() == OCL_Weak)
    return false;

  if (getObjCLifetime() == OCL_None || other.getObjCLifetime() == OCL_None)
    return true;

  return hasConst();
}

/// Determine whether this set of qualifiers is a strict superset of
/// another set of qualifiers, not considering qualifier compatibility.
bool isStrictSupersetOf(Qualifiers Other) const;

bool operator==(Qualifiers Other) const { return Mask == Other.Mask; }
bool operator!=(Qualifiers Other) const { return Mask != Other.Mask; }

explicit operator bool() const { return hasQualifiers(); }

Qualifiers &operator+=(Qualifiers R) {
  addQualifiers(R);
  return *this;
}

// Union two qualifier sets.  If an enumerated qualifier appears
// in both sets, use the one from the right.
friend Qualifiers operator+(Qualifiers L, Qualifiers R) {
  L += R;
  return L;
}

Qualifiers &operator-=(Qualifiers R) {
  removeQualifiers(R);
  return *this;
}

/// Compute the difference between two qualifier sets.
friend Qualifiers operator-(Qualifiers L, Qualifiers R) {
  L -= R;
  return L;
}

std::string getAsString() const;
std::string getAsString(const PrintingPolicy &Policy) const;

static std::string getAddrSpaceAsString(LangAS AS);

bool isEmptyWhenPrinted(const PrintingPolicy &Policy) const;
void print(raw_ostream &OS, const PrintingPolicy &Policy,
           bool appendSpaceIfNonEmpty = false) const;

void Profile(llvm::FoldingSetNodeID &ID) const {
  ID.AddInteger(Mask);
}

594private:
// bits:     |0 1 2|3|4 .. 5|6  ..  8|9   ...   31|
//           |C R V|U|GCAttr|Lifetime|AddressSpace|
uint32_t Mask = 0;

static const uint32_t UMask = 0x8;
static const uint32_t UShift = 3;
static const uint32_t GCAttrMask = 0x30;
static const uint32_t GCAttrShift = 4;
static const uint32_t LifetimeMask = 0x1C0;
static const uint32_t LifetimeShift = 6;
static const uint32_t AddressSpaceMask =
    ~(CVRMask | UMask | GCAttrMask | LifetimeMask);
static const uint32_t AddressSpaceShift = 9;
608};

610/// A std::pair-like structure for storing a qualified type split
611/// into its local qualifiers and its locally-unqualified type.
612struct SplitQualType {
/// The locally-unqualified type.
const Type *Ty = nullptr;

/// The local qualifiers.
Qualifiers Quals;

SplitQualType() = default;
SplitQualType(const Type *ty, Qualifiers qs) : Ty(ty), Quals(qs) {}

SplitQualType getSingleStepDesugaredType() const; // end of this file

// Make std::tie work.
std::pair<const Type *,Qualifiers> asPair() const {
  return std::pair<const Type *, Qualifiers>(Ty, Quals);
}

friend bool operator==(SplitQualType a, SplitQualType b) {
  return a.Ty == b.Ty && a.Quals == b.Quals;
}
friend bool operator!=(SplitQualType a, SplitQualType b) {
  return a.Ty != b.Ty || a.Quals != b.Quals;
}
635};

637/// The kind of type we are substituting Objective-C type arguments into.
638///
639/// The kind of substitution affects the replacement of type parameters when
640/// no concrete type information is provided, e.g., when dealing with an
641/// unspecialized type.
642enum class ObjCSubstitutionContext {
/// An ordinary type.
Ordinary,

/// The result type of a method or function.
Result,

/// The parameter type of a method or function.
Parameter,

/// The type of a property.
Property,

/// The superclass of a type.
Superclass,
657};

659/// A (possibly-)qualified type.
660///
661/// For efficiency, we don't store CV-qualified types as nodes on their
662/// own: instead each reference to a type stores the qualifiers.  This
663/// greatly reduces the number of nodes we need to allocate for types (for
664/// example we only need one for 'int', 'const int', 'volatile int',
665/// 'const volatile int', etc).
666///
667/// As an added efficiency bonus, instead of making this a pair, we
668/// just store the two bits we care about in the low bits of the
669/// pointer.  To handle the packing/unpacking, we make QualType be a
670/// simple wrapper class that acts like a smart pointer.  A third bit
671/// indicates whether there are extended qualifiers present, in which
672/// case the pointer points to a special structure.
673class QualType {
friend class QualifierCollector;

// Thankfully, these are efficiently composable.
llvm::PointerIntPair<llvm::PointerUnion<const Type *, const ExtQuals *>,
                     Qualifiers::FastWidth> Value;

const ExtQuals *getExtQualsUnsafe() const {
  return Value.getPointer().get<const ExtQuals*>();
}

const Type *getTypePtrUnsafe() const {
  return Value.getPointer().get<const Type*>();
}

const ExtQualsTypeCommonBase *getCommonPtr() const {
  assert(!isNull() && "Cannot retrieve a NULL type pointer")(static_cast<void> (0));
  auto CommonPtrVal = reinterpret_cast<uintptr_t>(Value.getOpaqueValue());
  CommonPtrVal &= ~(uintptr_t)((1 << TypeAlignmentInBits) - 1);
  return reinterpret_cast<ExtQualsTypeCommonBase*>(CommonPtrVal);
}

695public:
QualType() = default;
QualType(const Type *Ptr, unsigned Quals) : Value(Ptr, Quals) {}
QualType(const ExtQuals *Ptr, unsigned Quals) : Value(Ptr, Quals) {}

unsigned getLocalFastQualifiers() const { return Value.getInt(); }
void setLocalFastQualifiers(unsigned Quals) { Value.setInt(Quals); }

/// Retrieves a pointer to the underlying (unqualified) type.
///
/// This function requires that the type not be NULL. If the type might be
/// NULL, use the (slightly less efficient) \c getTypePtrOrNull().
const Type *getTypePtr() const;

const Type *getTypePtrOrNull() const;

/// Retrieves a pointer to the name of the base type.
const IdentifierInfo *getBaseTypeIdentifier() const;

/// Divides a QualType into its unqualified type and a set of local
/// qualifiers.
SplitQualType split() const;

void *getAsOpaquePtr() const { return Value.getOpaqueValue(); }

static QualType getFromOpaquePtr(const void *Ptr) {
  QualType T;
  T.Value.setFromOpaqueValue(const_cast<void*>(Ptr));
  return T;
}

const Type &operator*() const {
  return *getTypePtr();
}

const Type *operator->() const {
  return getTypePtr();
}

bool isCanonical() const;
bool isCanonicalAsParam() const;

/// Return true if this QualType doesn't point to a type yet.
bool isNull() const {
  return Value.getPointer().isNull();
37
←
Calling 'PointerUnion::isNull'→
40
←
Returning from 'PointerUnion::isNull'→
41
←
Returning zero, which participates in a condition later→
47
←
Calling 'PointerUnion::isNull'→
50
←
Returning from 'PointerUnion::isNull'→
51
←
Returning zero, which participates in a condition later→
55
←
Calling 'PointerUnion::isNull'→
58
←
Returning from 'PointerUnion::isNull'→
59
←
Returning the value 1, which participates in a condition later→
}

/// Determine whether this particular QualType instance has the
/// "const" qualifier set, without looking through typedefs that may have
/// added "const" at a different level.
bool isLocalConstQualified() const {
  return (getLocalFastQualifiers() & Qualifiers::Const);
}

/// Determine whether this type is const-qualified.
bool isConstQualified() const;

/// Determine whether this particular QualType instance has the
/// "restrict" qualifier set, without looking through typedefs that may have
/// added "restrict" at a different level.
bool isLocalRestrictQualified() const {
  return (getLocalFastQualifiers() & Qualifiers::Restrict);
}

/// Determine whether this type is restrict-qualified.
bool isRestrictQualified() const;

/// Determine whether this particular QualType instance has the
/// "volatile" qualifier set, without looking through typedefs that may have
/// added "volatile" at a different level.
bool isLocalVolatileQualified() const {
  return (getLocalFastQualifiers() & Qualifiers::Volatile);
}

/// Determine whether this type is volatile-qualified.
bool isVolatileQualified() const;

/// Determine whether this particular QualType instance has any
/// qualifiers, without looking through any typedefs that might add
/// qualifiers at a different level.
bool hasLocalQualifiers() const {
  return getLocalFastQualifiers() || hasLocalNonFastQualifiers();
}

/// Determine whether this type has any qualifiers.
bool hasQualifiers() const;

/// Determine whether this particular QualType instance has any
/// "non-fast" qualifiers, e.g., those that are stored in an ExtQualType
/// instance.
bool hasLocalNonFastQualifiers() const {
  return Value.getPointer().is<const ExtQuals*>();
}

/// Retrieve the set of qualifiers local to this particular QualType
/// instance, not including any qualifiers acquired through typedefs or
/// other sugar.
Qualifiers getLocalQualifiers() const;

/// Retrieve the set of qualifiers applied to this type.
Qualifiers getQualifiers() const;

/// Retrieve the set of CVR (const-volatile-restrict) qualifiers
/// local to this particular QualType instance, not including any qualifiers
/// acquired through typedefs or other sugar.
unsigned getLocalCVRQualifiers() const {
  return getLocalFastQualifiers();
}

/// Retrieve the set of CVR (const-volatile-restrict) qualifiers
/// applied to this type.
unsigned getCVRQualifiers() const;

bool isConstant(const ASTContext& Ctx) const {
  return QualType::isConstant(*this, Ctx);
}

/// Determine whether this is a Plain Old Data (POD) type (C++ 3.9p10).
bool isPODType(const ASTContext &Context) const;

/// Return true if this is a POD type according to the rules of the C++98
/// standard, regardless of the current compilation's language.
bool isCXX98PODType(const ASTContext &Context) const;

/// Return true if this is a POD type according to the more relaxed rules
/// of the C++11 standard, regardless of the current compilation's language.
/// (C++0x [basic.types]p9). Note that, unlike
/// CXXRecordDecl::isCXX11StandardLayout, this takes DRs into account.
bool isCXX11PODType(const ASTContext &Context) const;

/// Return true if this is a trivial type per (C++0x [basic.types]p9)
bool isTrivialType(const ASTContext &Context) const;

/// Return true if this is a trivially copyable type (C++0x [basic.types]p9)
bool isTriviallyCopyableType(const ASTContext &Context) const;


/// Returns true if it is a class and it might be dynamic.
bool mayBeDynamicClass() const;

/// Returns true if it is not a class or if the class might not be dynamic.
bool mayBeNotDynamicClass() const;

// Don't promise in the API that anything besides 'const' can be
// easily added.

/// Add the `const` type qualifier to this QualType.
void addConst() {
  addFastQualifiers(Qualifiers::Const);
}
QualType withConst() const {
  return withFastQualifiers(Qualifiers::Const);
}

/// Add the `volatile` type qualifier to this QualType.
void addVolatile() {
  addFastQualifiers(Qualifiers::Volatile);
}
QualType withVolatile() const {
  return withFastQualifiers(Qualifiers::Volatile);
}

/// Add the `restrict` qualifier to this QualType.
void addRestrict() {
  addFastQualifiers(Qualifiers::Restrict);
}
QualType withRestrict() const {
  return withFastQualifiers(Qualifiers::Restrict);
}

QualType withCVRQualifiers(unsigned CVR) const {
  return withFastQualifiers(CVR);
}

void addFastQualifiers(unsigned TQs) {
  assert(!(TQs & ~Qualifiers::FastMask)(static_cast<void> (0))
         && "non-fast qualifier bits set in mask!")(static_cast<void> (0));
  Value.setInt(Value.getInt() | TQs);
}

void removeLocalConst();
void removeLocalVolatile();
void removeLocalRestrict();
void removeLocalCVRQualifiers(unsigned Mask);

void removeLocalFastQualifiers() { Value.setInt(0); }
void removeLocalFastQualifiers(unsigned Mask) {
  assert(!(Mask & ~Qualifiers::FastMask) && "mask has non-fast qualifiers")(static_cast<void> (0));
  Value.setInt(Value.getInt() & ~Mask);
}

// Creates a type with the given qualifiers in addition to any
// qualifiers already on this type.
QualType withFastQualifiers(unsigned TQs) const {
  QualType T = *this;
  T.addFastQualifiers(TQs);
  return T;
}

// Creates a type with exactly the given fast qualifiers, removing
// any existing fast qualifiers.
QualType withExactLocalFastQualifiers(unsigned TQs) const {
  return withoutLocalFastQualifiers().withFastQualifiers(TQs);
}

// Removes fast qualifiers, but leaves any extended qualifiers in place.
QualType withoutLocalFastQualifiers() const {
  QualType T = *this;
  T.removeLocalFastQualifiers();
  return T;
}

QualType getCanonicalType() const;

/// Return this type with all of the instance-specific qualifiers
/// removed, but without removing any qualifiers that may have been applied
/// through typedefs.
QualType getLocalUnqualifiedType() const { return QualType(getTypePtr(), 0); }

/// Retrieve the unqualified variant of the given type,
/// removing as little sugar as possible.
///
/// This routine looks through various kinds of sugar to find the
/// least-desugared type that is unqualified. For example, given:
///
/// \code
/// typedef int Integer;
/// typedef const Integer CInteger;
/// typedef CInteger DifferenceType;
/// \endcode
///
/// Executing \c getUnqualifiedType() on the type \c DifferenceType will
/// desugar until we hit the type \c Integer, which has no qualifiers on it.
///
/// The resulting type might still be qualified if it's sugar for an array
/// type.  To strip qualifiers even from within a sugared array type, use
/// ASTContext::getUnqualifiedArrayType.
inline QualType getUnqualifiedType() const;

/// Retrieve the unqualified variant of the given type, removing as little
/// sugar as possible.
///
/// Like getUnqualifiedType(), but also returns the set of
/// qualifiers that were built up.
///
/// The resulting type might still be qualified if it's sugar for an array
/// type.  To strip qualifiers even from within a sugared array type, use
/// ASTContext::getUnqualifiedArrayType.
inline SplitQualType getSplitUnqualifiedType() const;

/// Determine whether this type is more qualified than the other
/// given type, requiring exact equality for non-CVR qualifiers.
bool isMoreQualifiedThan(QualType Other) const;

/// Determine whether this type is at least as qualified as the other
/// given type, requiring exact equality for non-CVR qualifiers.
bool isAtLeastAsQualifiedAs(QualType Other) const;

QualType getNonReferenceType() const;

/// Determine the type of a (typically non-lvalue) expression with the
/// specified result type.
///
/// This routine should be used for expressions for which the return type is
/// explicitly specified (e.g., in a cast or call) and isn't necessarily
/// an lvalue. It removes a top-level reference (since there are no
/// expressions of reference type) and deletes top-level cvr-qualifiers
/// from non-class types (in C++) or all types (in C).
QualType getNonLValueExprType(const ASTContext &Context) const;

/// Remove an outer pack expansion type (if any) from this type. Used as part
/// of converting the type of a declaration to the type of an expression that
/// references that expression. It's meaningless for an expression to have a
/// pack expansion type.
QualType getNonPackExpansionType() const;

/// Return the specified type with any "sugar" removed from
/// the type.  This takes off typedefs, typeof's etc.  If the outer level of
/// the type is already concrete, it returns it unmodified.  This is similar
/// to getting the canonical type, but it doesn't remove *all* typedefs.  For
/// example, it returns "T*" as "T*", (not as "int*"), because the pointer is
/// concrete.
///
/// Qualifiers are left in place.
QualType getDesugaredType(const ASTContext &Context) const {
  return getDesugaredType(*this, Context);
}

SplitQualType getSplitDesugaredType() const {
  return getSplitDesugaredType(*this);
}

/// Return the specified type with one level of "sugar" removed from
/// the type.
///
/// This routine takes off the first typedef, typeof, etc. If the outer level
/// of the type is already concrete, it returns it unmodified.
QualType getSingleStepDesugaredType(const ASTContext &Context) const {
  return getSingleStepDesugaredTypeImpl(*this, Context);
}

/// Returns the specified type after dropping any
/// outer-level parentheses.
QualType IgnoreParens() const {
  if (isa<ParenType>(*this))
    return QualType::IgnoreParens(*this);
  return *this;
}

/// Indicate whether the specified types and qualifiers are identical.
friend bool operator==(const QualType &LHS, const QualType &RHS) {
  return LHS.Value == RHS.Value;
}
friend bool operator!=(const QualType &LHS, const QualType &RHS) {
  return LHS.Value != RHS.Value;
}
friend bool operator<(const QualType &LHS, const QualType &RHS) {
  return LHS.Value < RHS.Value;
}

static std::string getAsString(SplitQualType split,
                               const PrintingPolicy &Policy) {
  return getAsString(split.Ty, split.Quals, Policy);
}
static std::string getAsString(const Type *ty, Qualifiers qs,
                               const PrintingPolicy &Policy);

std::string getAsString() const;
std::string getAsString(const PrintingPolicy &Policy) const;

void print(raw_ostream &OS, const PrintingPolicy &Policy,
           const Twine &PlaceHolder = Twine(),
           unsigned Indentation = 0) const;

static void print(SplitQualType split, raw_ostream &OS,
                  const PrintingPolicy &policy, const Twine &PlaceHolder,
                  unsigned Indentation = 0) {
  return print(split.Ty, split.Quals, OS, policy, PlaceHolder, Indentation);
}

static void print(const Type *ty, Qualifiers qs,
                  raw_ostream &OS, const PrintingPolicy &policy,
                  const Twine &PlaceHolder,
                  unsigned Indentation = 0);

void getAsStringInternal(std::string &Str,
                         const PrintingPolicy &Policy) const;

static void getAsStringInternal(SplitQualType split, std::string &out,
                                const PrintingPolicy &policy) {
  return getAsStringInternal(split.Ty, split.Quals, out, policy);
}

static void getAsStringInternal(const Type *ty, Qualifiers qs,
                                std::string &out,
                                const PrintingPolicy &policy);

class StreamedQualTypeHelper {
  const QualType &T;
  const PrintingPolicy &Policy;
  const Twine &PlaceHolder;
  unsigned Indentation;

public:
  StreamedQualTypeHelper(const QualType &T, const PrintingPolicy &Policy,
                         const Twine &PlaceHolder, unsigned Indentation)
      : T(T), Policy(Policy), PlaceHolder(PlaceHolder),
        Indentation(Indentation) {}

  friend raw_ostream &operator<<(raw_ostream &OS,
                                 const StreamedQualTypeHelper &SQT) {
    SQT.T.print(OS, SQT.Policy, SQT.PlaceHolder, SQT.Indentation);
    return OS;
  }
};

StreamedQualTypeHelper stream(const PrintingPolicy &Policy,
                              const Twine &PlaceHolder = Twine(),
                              unsigned Indentation = 0) const {
  return StreamedQualTypeHelper(*this, Policy, PlaceHolder, Indentation);
}

void dump(const char *s) const;
void dump() const;
void dump(llvm::raw_ostream &OS, const ASTContext &Context) const;

void Profile(llvm::FoldingSetNodeID &ID) const {
  ID.AddPointer(getAsOpaquePtr());
}

/// Check if this type has any address space qualifier.
inline bool hasAddressSpace() const;

/// Return the address space of this type.
inline LangAS getAddressSpace() const;

/// Returns true if address space qualifiers overlap with T address space
/// qualifiers.
/// OpenCL C defines conversion rules for pointers to different address spaces
/// and notion of overlapping address spaces.
/// CL1.1 or CL1.2:
///   address spaces overlap iff they are they same.
/// OpenCL C v2.0 s6.5.5 adds:
///   __generic overlaps with any address space except for __constant.
bool isAddressSpaceOverlapping(QualType T) const {
  Qualifiers Q = getQualifiers();
  Qualifiers TQ = T.getQualifiers();
  // Address spaces overlap if at least one of them is a superset of another
  return Q.isAddressSpaceSupersetOf(TQ) || TQ.isAddressSpaceSupersetOf(Q);
}

/// Returns gc attribute of this type.
inline Qualifiers::GC getObjCGCAttr() const;

/// true when Type is objc's weak.
bool isObjCGCWeak() const {
  return getObjCGCAttr() == Qualifiers::Weak;
}

/// true when Type is objc's strong.
bool isObjCGCStrong() const {
  return getObjCGCAttr() == Qualifiers::Strong;
}

/// Returns lifetime attribute of this type.
Qualifiers::ObjCLifetime getObjCLifetime() const {
  return getQualifiers().getObjCLifetime();
}

bool hasNonTrivialObjCLifetime() const {
  return getQualifiers().hasNonTrivialObjCLifetime();
}

bool hasStrongOrWeakObjCLifetime() const {
  return getQualifiers().hasStrongOrWeakObjCLifetime();
}

// true when Type is objc's weak and weak is enabled but ARC isn't.
bool isNonWeakInMRRWithObjCWeak(const ASTContext &Context) const;

enum PrimitiveDefaultInitializeKind {
  /// The type does not fall into any of the following categories. Note that
  /// this case is zero-valued so that values of this enum can be used as a
  /// boolean condition for non-triviality.
  PDIK_Trivial,

  /// The type is an Objective-C retainable pointer type that is qualified
  /// with the ARC __strong qualifier.
  PDIK_ARCStrong,

  /// The type is an Objective-C retainable pointer type that is qualified
  /// with the ARC __weak qualifier.
  PDIK_ARCWeak,

  /// The type is a struct containing a field whose type is not PCK_Trivial.
  PDIK_Struct
};

/// Functions to query basic properties of non-trivial C struct types.

/// Check if this is a non-trivial type that would cause a C struct
/// transitively containing this type to be non-trivial to default initialize
/// and return the kind.
PrimitiveDefaultInitializeKind
isNonTrivialToPrimitiveDefaultInitialize() const;

enum PrimitiveCopyKind {
  /// The type does not fall into any of the following categories. Note that
  /// this case is zero-valued so that values of this enum can be used as a
  /// boolean condition for non-triviality.
  PCK_Trivial,

  /// The type would be trivial except that it is volatile-qualified. Types
  /// that fall into one of the other non-trivial cases may additionally be
  /// volatile-qualified.
  PCK_VolatileTrivial,

  /// The type is an Objective-C retainable pointer type that is qualified
  /// with the ARC __strong qualifier.
  PCK_ARCStrong,

  /// The type is an Objective-C retainable pointer type that is qualified
  /// with the ARC __weak qualifier.
  PCK_ARCWeak,

  /// The type is a struct containing a field whose type is neither
  /// PCK_Trivial nor PCK_VolatileTrivial.
  /// Note that a C++ struct type does not necessarily match this; C++ copying
  /// semantics are too complex to express here, in part because they depend
  /// on the exact constructor or assignment operator that is chosen by
  /// overload resolution to do the copy.
  PCK_Struct
};

/// Check if this is a non-trivial type that would cause a C struct
/// transitively containing this type to be non-trivial to copy and return the
/// kind.
PrimitiveCopyKind isNonTrivialToPrimitiveCopy() const;

/// Check if this is a non-trivial type that would cause a C struct
/// transitively containing this type to be non-trivial to destructively
/// move and return the kind. Destructive move in this context is a C++-style
/// move in which the source object is placed in a valid but unspecified state
/// after it is moved, as opposed to a truly destructive move in which the
/// source object is placed in an uninitialized state.
PrimitiveCopyKind isNonTrivialToPrimitiveDestructiveMove() const;

enum DestructionKind {
  DK_none,
  DK_cxx_destructor,
  DK_objc_strong_lifetime,
  DK_objc_weak_lifetime,
  DK_nontrivial_c_struct
};

/// Returns a nonzero value if objects of this type require
/// non-trivial work to clean up after.  Non-zero because it's
/// conceivable that qualifiers (objc_gc(weak)?) could make
/// something require destruction.
DestructionKind isDestructedType() const {
  return isDestructedTypeImpl(*this);
}

/// Check if this is or contains a C union that is non-trivial to
/// default-initialize, which is a union that has a member that is non-trivial
/// to default-initialize. If this returns true,
/// isNonTrivialToPrimitiveDefaultInitialize returns PDIK_Struct.
bool hasNonTrivialToPrimitiveDefaultInitializeCUnion() const;

/// Check if this is or contains a C union that is non-trivial to destruct,
/// which is a union that has a member that is non-trivial to destruct. If
/// this returns true, isDestructedType returns DK_nontrivial_c_struct.
bool hasNonTrivialToPrimitiveDestructCUnion() const;

/// Check if this is or contains a C union that is non-trivial to copy, which
/// is a union that has a member that is non-trivial to copy. If this returns
/// true, isNonTrivialToPrimitiveCopy returns PCK_Struct.
bool hasNonTrivialToPrimitiveCopyCUnion() const;

/// Determine whether expressions of the given type are forbidden
/// from being lvalues in C.
///
/// The expression types that are forbidden to be lvalues are:
///   - 'void', but not qualified void
///   - function types
///
/// The exact rule here is C99 6.3.2.1:
///   An lvalue is an expression with an object type or an incomplete
///   type other than void.
bool isCForbiddenLValueType() const;

/// Substitute type arguments for the Objective-C type parameters used in the
/// subject type.
///
/// \param ctx ASTContext in which the type exists.
///
/// \param typeArgs The type arguments that will be substituted for the
/// Objective-C type parameters in the subject type, which are generally
/// computed via \c Type::getObjCSubstitutions. If empty, the type
/// parameters will be replaced with their bounds or id/Class, as appropriate
/// for the context.
///
/// \param context The context in which the subject type was written.
///
/// \returns the resulting type.
QualType substObjCTypeArgs(ASTContext &ctx,
                           ArrayRef<QualType> typeArgs,
                           ObjCSubstitutionContext context) const;

/// Substitute type arguments from an object type for the Objective-C type
/// parameters used in the subject type.
///
/// This operation combines the computation of type arguments for
/// substitution (\c Type::getObjCSubstitutions) with the actual process of
/// substitution (\c QualType::substObjCTypeArgs) for the convenience of
/// callers that need to perform a single substitution in isolation.
///
/// \param objectType The type of the object whose member type we're
/// substituting into. For example, this might be the receiver of a message
/// or the base of a property access.
///
/// \param dc The declaration context from which the subject type was
/// retrieved, which indicates (for example) which type parameters should
/// be substituted.
///
/// \param context The context in which the subject type was written.
///
/// \returns the subject type after replacing all of the Objective-C type
/// parameters with their corresponding arguments.
QualType substObjCMemberType(QualType objectType,
                             const DeclContext *dc,
                             ObjCSubstitutionContext context) const;

/// Strip Objective-C "__kindof" types from the given type.
QualType stripObjCKindOfType(const ASTContext &ctx) const;

/// Remove all qualifiers including _Atomic.
QualType getAtomicUnqualifiedType() const;

1294private:
// These methods are implemented in a separate translation unit;
// "static"-ize them to avoid creating temporary QualTypes in the
// caller.
static bool isConstant(QualType T, const ASTContext& Ctx);
static QualType getDesugaredType(QualType T, const ASTContext &Context);
static SplitQualType getSplitDesugaredType(QualType T);
static SplitQualType getSplitUnqualifiedTypeImpl(QualType type);
static QualType getSingleStepDesugaredTypeImpl(QualType type,
                                               const ASTContext &C);
static QualType IgnoreParens(QualType T);
static DestructionKind isDestructedTypeImpl(QualType type);

/// Check if \param RD is or contains a non-trivial C union.
static bool hasNonTrivialToPrimitiveDefaultInitializeCUnion(const RecordDecl *RD);
static bool hasNonTrivialToPrimitiveDestructCUnion(const RecordDecl *RD);
static bool hasNonTrivialToPrimitiveCopyCUnion(const RecordDecl *RD);
1311};

1313} // namespace clang

1315namespace llvm {

1317/// Implement simplify_type for QualType, so that we can dyn_cast from QualType
1318/// to a specific Type class.
1319template<> struct simplify_type< ::clang::QualType> {
using SimpleType = const ::clang::Type *;

static SimpleType getSimplifiedValue(::clang::QualType Val) {
  return Val.getTypePtr();
}
1325};

1327// Teach SmallPtrSet that QualType is "basically a pointer".
1328template<>
1329struct PointerLikeTypeTraits<clang::QualType> {
static inline void *getAsVoidPointer(clang::QualType P) {
  return P.getAsOpaquePtr();
}

static inline clang::QualType getFromVoidPointer(void *P) {
  return clang::QualType::getFromOpaquePtr(P);
}

// Various qualifiers go in low bits.
static constexpr int NumLowBitsAvailable = 0;
1340};

1342} // namespace llvm

1344namespace clang {

1346/// Base class that is common to both the \c ExtQuals and \c Type
1347/// classes, which allows \c QualType to access the common fields between the
1348/// two.
1349class ExtQualsTypeCommonBase {
friend class ExtQuals;
friend class QualType;
friend class Type;

/// The "base" type of an extended qualifiers type (\c ExtQuals) or
/// a self-referential pointer (for \c Type).
///
/// This pointer allows an efficient mapping from a QualType to its
/// underlying type pointer.
const Type *const BaseType;

/// The canonical type of this type.  A QualType.
QualType CanonicalType;

ExtQualsTypeCommonBase(const Type *baseType, QualType canon)
    : BaseType(baseType), CanonicalType(canon) {}
1366};

1368/// We can encode up to four bits in the low bits of a
1369/// type pointer, but there are many more type qualifiers that we want
1370/// to be able to apply to an arbitrary type.  Therefore we have this
1371/// struct, intended to be heap-allocated and used by QualType to
1372/// store qualifiers.
1373///
1374/// The current design tags the 'const', 'restrict', and 'volatile' qualifiers
1375/// in three low bits on the QualType pointer; a fourth bit records whether
1376/// the pointer is an ExtQuals node. The extended qualifiers (address spaces,
1377/// Objective-C GC attributes) are much more rare.
1378class ExtQuals : public ExtQualsTypeCommonBase, public llvm::FoldingSetNode {
// NOTE: changing the fast qualifiers should be straightforward as
// long as you don't make 'const' non-fast.
// 1. Qualifiers:
//    a) Modify the bitmasks (Qualifiers::TQ and DeclSpec::TQ).
//       Fast qualifiers must occupy the low-order bits.
//    b) Update Qualifiers::FastWidth and FastMask.
// 2. QualType:
//    a) Update is{Volatile,Restrict}Qualified(), defined inline.
//    b) Update remove{Volatile,Restrict}, defined near the end of
//       this header.
// 3. ASTContext:
//    a) Update get{Volatile,Restrict}Type.

/// The immutable set of qualifiers applied by this node. Always contains
/// extended qualifiers.
Qualifiers Quals;

ExtQuals *this_() { return this; }

1398public:
ExtQuals(const Type *baseType, QualType canon, Qualifiers quals)
    : ExtQualsTypeCommonBase(baseType,
                             canon.isNull() ? QualType(this_(), 0) : canon),
      Quals(quals) {
  assert(Quals.hasNonFastQualifiers()(static_cast<void> (0))
         && "ExtQuals created with no fast qualifiers")(static_cast<void> (0));
  assert(!Quals.hasFastQualifiers()(static_cast<void> (0))
         && "ExtQuals created with fast qualifiers")(static_cast<void> (0));
}

Qualifiers getQualifiers() const { return Quals; }

bool hasObjCGCAttr() const { return Quals.hasObjCGCAttr(); }
Qualifiers::GC getObjCGCAttr() const { return Quals.getObjCGCAttr(); }

bool hasObjCLifetime() const { return Quals.hasObjCLifetime(); }
Qualifiers::ObjCLifetime getObjCLifetime() const {
  return Quals.getObjCLifetime();
}

bool hasAddressSpace() const { return Quals.hasAddressSpace(); }
LangAS getAddressSpace() const { return Quals.getAddressSpace(); }

const Type *getBaseType() const { return BaseType; }

1424public:
void Profile(llvm::FoldingSetNodeID &ID) const {
  Profile(ID, getBaseType(), Quals);
}

static void Profile(llvm::FoldingSetNodeID &ID,
                    const Type *BaseType,
                    Qualifiers Quals) {
  assert(!Quals.hasFastQualifiers() && "fast qualifiers in ExtQuals hash!")(static_cast<void> (0));
  ID.AddPointer(BaseType);
  Quals.Profile(ID);
}
1436};

1438/// The kind of C++11 ref-qualifier associated with a function type.
1439/// This determines whether a member function's "this" object can be an
1440/// lvalue, rvalue, or neither.
1441enum RefQualifierKind {
/// No ref-qualifier was provided.
RQ_None = 0,

/// An lvalue ref-qualifier was provided (\c &).
RQ_LValue,

/// An rvalue ref-qualifier was provided (\c &&).
RQ_RValue
1450};

1452/// Which keyword(s) were used to create an AutoType.
1453enum class AutoTypeKeyword {
/// auto
Auto,

/// decltype(auto)
DecltypeAuto,

/// __auto_type (GNU extension)
GNUAutoType
1462};

1464/// The base class of the type hierarchy.
1465///
1466/// A central concept with types is that each type always has a canonical
1467/// type.  A canonical type is the type with any typedef names stripped out
1468/// of it or the types it references.  For example, consider:
1469///
1470///  typedef int  foo;
1471///  typedef foo* bar;
1472///    'int *'    'foo *'    'bar'
1473///
1474/// There will be a Type object created for 'int'.  Since int is canonical, its
1475/// CanonicalType pointer points to itself.  There is also a Type for 'foo' (a
1476/// TypedefType).  Its CanonicalType pointer points to the 'int' Type.  Next
1477/// there is a PointerType that represents 'int*', which, like 'int', is
1478/// canonical.  Finally, there is a PointerType type for 'foo*' whose canonical
1479/// type is 'int*', and there is a TypedefType for 'bar', whose canonical type
1480/// is also 'int*'.
1481///
1482/// Non-canonical types are useful for emitting diagnostics, without losing
1483/// information about typedefs being used.  Canonical types are useful for type
1484/// comparisons (they allow by-pointer equality tests) and useful for reasoning
1485/// about whether something has a particular form (e.g. is a function type),
1486/// because they implicitly, recursively, strip all typedefs out of a type.
1487///
1488/// Types, once created, are immutable.
1489///
1490class alignas(8) Type : public ExtQualsTypeCommonBase {
1491public:
enum TypeClass {
1493#define TYPE(Class, Base) Class,
1494#define LAST_TYPE(Class) TypeLast = Class
1495#define ABSTRACT_TYPE(Class, Base)
1496#include "clang/AST/TypeNodes.inc"
};

1499private:
/// Bitfields required by the Type class.
class TypeBitfields {
  friend class Type;
  template <class T> friend class TypePropertyCache;

  /// TypeClass bitfield - Enum that specifies what subclass this belongs to.
  unsigned TC : 8;

  /// Store information on the type dependency.
  unsigned Dependence : llvm::BitWidth<TypeDependence>;

  /// True if the cache (i.e. the bitfields here starting with
  /// 'Cache') is valid.
  mutable unsigned CacheValid : 1;

  /// Linkage of this type.
  mutable unsigned CachedLinkage : 3;

  /// Whether this type involves and local or unnamed types.
  mutable unsigned CachedLocalOrUnnamed : 1;

  /// Whether this type comes from an AST file.
  mutable unsigned FromAST : 1;

  bool isCacheValid() const {
    return CacheValid;
  }

  Linkage getLinkage() const {
    assert(isCacheValid() && "getting linkage from invalid cache")(static_cast<void> (0));
    return static_cast<Linkage>(CachedLinkage);
  }

  bool hasLocalOrUnnamedType() const {
    assert(isCacheValid() && "getting linkage from invalid cache")(static_cast<void> (0));
    return CachedLocalOrUnnamed;
  }
};
enum { NumTypeBits = 8 + llvm::BitWidth<TypeDependence> + 6 };

1540protected:
// These classes allow subclasses to somewhat cleanly pack bitfields
// into Type.

class ArrayTypeBitfields {
  friend class ArrayType;

  unsigned : NumTypeBits;

  /// CVR qualifiers from declarations like
  /// 'int X[static restrict 4]'. For function parameters only.
  unsigned IndexTypeQuals : 3;

  /// Storage class qualifiers from declarations like
  /// 'int X[static restrict 4]'. For function parameters only.
  /// Actually an ArrayType::ArraySizeModifier.
  unsigned SizeModifier : 3;
};

class ConstantArrayTypeBitfields {
  friend class ConstantArrayType;

  unsigned : NumTypeBits + 3 + 3;

  /// Whether we have a stored size expression.
  unsigned HasStoredSizeExpr : 1;
};

class BuiltinTypeBitfields {
  friend class BuiltinType;

  unsigned : NumTypeBits;

  /// The kind (BuiltinType::Kind) of builtin type this is.
  unsigned Kind : 8;
};

/// FunctionTypeBitfields store various bits belonging to FunctionProtoType.
/// Only common bits are stored here. Additional uncommon bits are stored
/// in a trailing object after FunctionProtoType.
class FunctionTypeBitfields {
  friend class FunctionProtoType;
  friend class FunctionType;

  unsigned : NumTypeBits;

  /// Extra information which affects how the function is called, like
  /// regparm and the calling convention.
  unsigned ExtInfo : 13;

  /// The ref-qualifier associated with a \c FunctionProtoType.
  ///
  /// This is a value of type \c RefQualifierKind.
  unsigned RefQualifier : 2;

  /// Used only by FunctionProtoType, put here to pack with the
  /// other bitfields.
  /// The qualifiers are part of FunctionProtoType because...
  ///
  /// C++ 8.3.5p4: The return type, the parameter type list and the
  /// cv-qualifier-seq, [...], are part of the function type.
  unsigned FastTypeQuals : Qualifiers::FastWidth;
  /// Whether this function has extended Qualifiers.
  unsigned HasExtQuals : 1;

  /// The number of parameters this function has, not counting '...'.
  /// According to [implimits] 8 bits should be enough here but this is
  /// somewhat easy to exceed with metaprogramming and so we would like to
  /// keep NumParams as wide as reasonably possible.
  unsigned NumParams : 16;

  /// The type of exception specification this function has.
  unsigned ExceptionSpecType : 4;

  /// Whether this function has extended parameter information.
  unsigned HasExtParameterInfos : 1;

  /// Whether the function is variadic.
  unsigned Variadic : 1;

  /// Whether this function has a trailing return type.
  unsigned HasTrailingReturn : 1;
};

class ObjCObjectTypeBitfields {
  friend class ObjCObjectType;

  unsigned : NumTypeBits;

  /// The number of type arguments stored directly on this object type.
  unsigned NumTypeArgs : 7;

  /// The number of protocols stored directly on this object type.
  unsigned NumProtocols : 6;

  /// Whether this is a "kindof" type.
  unsigned IsKindOf : 1;
};

class ReferenceTypeBitfields {
  friend class ReferenceType;

  unsigned : NumTypeBits;

  /// True if the type was originally spelled with an lvalue sigil.
  /// This is never true of rvalue references but can also be false
  /// on lvalue references because of C++0x [dcl.typedef]p9,
  /// as follows:
  ///
  ///   typedef int &ref;    // lvalue, spelled lvalue
  ///   typedef int &&rvref; // rvalue
  ///   ref &a;              // lvalue, inner ref, spelled lvalue
  ///   ref &&a;             // lvalue, inner ref
  ///   rvref &a;            // lvalue, inner ref, spelled lvalue
  ///   rvref &&a;           // rvalue, inner ref
  unsigned SpelledAsLValue : 1;

  /// True if the inner type is a reference type.  This only happens
  /// in non-canonical forms.
  unsigned InnerRef : 1;
};

class TypeWithKeywordBitfields {
  friend class TypeWithKeyword;

  unsigned : NumTypeBits;

  /// An ElaboratedTypeKeyword.  8 bits for efficient access.
  unsigned Keyword : 8;
};

enum { NumTypeWithKeywordBits = 8 };

class ElaboratedTypeBitfields {
  friend class ElaboratedType;

  unsigned : NumTypeBits;
  unsigned : NumTypeWithKeywordBits;

  /// Whether the ElaboratedType has a trailing OwnedTagDecl.
  unsigned HasOwnedTagDecl : 1;
};

class VectorTypeBitfields {
  friend class VectorType;
  friend class DependentVectorType;

  unsigned : NumTypeBits;

  /// The kind of vector, either a generic vector type or some
  /// target-specific vector type such as for AltiVec or Neon.
  unsigned VecKind : 3;
  /// The number of elements in the vector.
  uint32_t NumElements;
};

class AttributedTypeBitfields {
  friend class AttributedType;

  unsigned : NumTypeBits;

  /// An AttributedType::Kind
  unsigned AttrKind : 32 - NumTypeBits;
};

class AutoTypeBitfields {
  friend class AutoType;

  unsigned : NumTypeBits;

  /// Was this placeholder type spelled as 'auto', 'decltype(auto)',
  /// or '__auto_type'?  AutoTypeKeyword value.
  unsigned Keyword : 2;

  /// The number of template arguments in the type-constraints, which is
  /// expected to be able to hold at least 1024 according to [implimits].
  /// However as this limit is somewhat easy to hit with template
  /// metaprogramming we'd prefer to keep it as large as possible.
  /// At the moment it has been left as a non-bitfield since this type
  /// safely fits in 64 bits as an unsigned, so there is no reason to
  /// introduce the performance impact of a bitfield.
  unsigned NumArgs;
};

class SubstTemplateTypeParmPackTypeBitfields {
  friend class SubstTemplateTypeParmPackType;

  unsigned : NumTypeBits;

  /// The number of template arguments in \c Arguments, which is
  /// expected to be able to hold at least 1024 according to [implimits].
  /// However as this limit is somewhat easy to hit with template
  /// metaprogramming we'd prefer to keep it as large as possible.
  /// At the moment it has been left as a non-bitfield since this type
  /// safely fits in 64 bits as an unsigned, so there is no reason to
  /// introduce the performance impact of a bitfield.
  unsigned NumArgs;
};

class TemplateSpecializationTypeBitfields {
  friend class TemplateSpecializationType;

  unsigned : NumTypeBits;

  /// Whether this template specialization type is a substituted type alias.
  unsigned TypeAlias : 1;

  /// The number of template arguments named in this class template
  /// specialization, which is expected to be able to hold at least 1024
  /// according to [implimits]. However, as this limit is somewhat easy to
  /// hit with template metaprogramming we'd prefer to keep it as large
  /// as possible. At the moment it has been left as a non-bitfield since
  /// this type safely fits in 64 bits as an unsigned, so there is no reason
  /// to introduce the performance impact of a bitfield.
  unsigned NumArgs;
};

class DependentTemplateSpecializationTypeBitfields {
  friend class DependentTemplateSpecializationType;

  unsigned : NumTypeBits;
  unsigned : NumTypeWithKeywordBits;

  /// The number of template arguments named in this class template
  /// specialization, which is expected to be able to hold at least 1024
  /// according to [implimits]. However, as this limit is somewhat easy to
  /// hit with template metaprogramming we'd prefer to keep it as large
  /// as possible. At the moment it has been left as a non-bitfield since
  /// this type safely fits in 64 bits as an unsigned, so there is no reason
  /// to introduce the performance impact of a bitfield.
  unsigned NumArgs;
};

class PackExpansionTypeBitfields {
  friend class PackExpansionType;

  unsigned : NumTypeBits;

  /// The number of expansions that this pack expansion will
  /// generate when substituted (+1), which is expected to be able to
  /// hold at least 1024 according to [implimits]. However, as this limit
  /// is somewhat easy to hit with template metaprogramming we'd prefer to
  /// keep it as large as possible. At the moment it has been left as a
  /// non-bitfield since this type safely fits in 64 bits as an unsigned, so
  /// there is no reason to introduce the performance impact of a bitfield.
  ///
  /// This field will only have a non-zero value when some of the parameter
  /// packs that occur within the pattern have been substituted but others
  /// have not.
  unsigned NumExpansions;
};

union {
  TypeBitfields TypeBits;
  ArrayTypeBitfields ArrayTypeBits;
  ConstantArrayTypeBitfields ConstantArrayTypeBits;
  AttributedTypeBitfields AttributedTypeBits;
  AutoTypeBitfields AutoTypeBits;
  BuiltinTypeBitfields BuiltinTypeBits;
  FunctionTypeBitfields FunctionTypeBits;
  ObjCObjectTypeBitfields ObjCObjectTypeBits;
  ReferenceTypeBitfields ReferenceTypeBits;
  TypeWithKeywordBitfields TypeWithKeywordBits;
  ElaboratedTypeBitfields ElaboratedTypeBits;
  VectorTypeBitfields VectorTypeBits;
  SubstTemplateTypeParmPackTypeBitfields SubstTemplateTypeParmPackTypeBits;
  TemplateSpecializationTypeBitfields TemplateSpecializationTypeBits;
  DependentTemplateSpecializationTypeBitfields
    DependentTemplateSpecializationTypeBits;
  PackExpansionTypeBitfields PackExpansionTypeBits;
};

1812private:
template <class T> friend class TypePropertyCache;

/// Set whether this type comes from an AST file.
void setFromAST(bool V = true) const {
  TypeBits.FromAST = V;
}

1820protected:
friend class ASTContext;

Type(TypeClass tc, QualType canon, TypeDependence Dependence)
    : ExtQualsTypeCommonBase(this,
                             canon.isNull() ? QualType(this_(), 0) : canon) {
  static_assert(sizeof(*this) <= 8 + sizeof(ExtQualsTypeCommonBase),
                "changing bitfields changed sizeof(Type)!");
  static_assert(alignof(decltype(*this)) % sizeof(void *) == 0,
                "Insufficient alignment!");
  TypeBits.TC = tc;
  TypeBits.Dependence = static_cast<unsigned>(Dependence);
  TypeBits.CacheValid = false;
  TypeBits.CachedLocalOrUnnamed = false;
  TypeBits.CachedLinkage = NoLinkage;
  TypeBits.FromAST = false;
}

// silence VC++ warning C4355: 'this' : used in base member initializer list
Type *this_() { return this; }

void setDependence(TypeDependence D) {
  TypeBits.Dependence = static_cast<unsigned>(D);
}

void addDependence(TypeDependence D) { setDependence(getDependence() | D); }

1847public:
friend class ASTReader;
friend class ASTWriter;
template <class T> friend class serialization::AbstractTypeReader;
template <class T> friend class serialization::AbstractTypeWriter;

Type(const Type &) = delete;
Type(Type &&) = delete;
Type &operator=(const Type &) = delete;
Type &operator=(Type &&) = delete;

TypeClass getTypeClass() const { return static_cast<TypeClass>(TypeBits.TC); }

/// Whether this type comes from an AST file.
bool isFromAST() const { return TypeBits.FromAST; }

/// Whether this type is or contains an unexpanded parameter
/// pack, used to support C++0x variadic templates.
///
/// A type that contains a parameter pack shall be expanded by the
/// ellipsis operator at some point. For example, the typedef in the
/// following example contains an unexpanded parameter pack 'T':
///
/// \code
/// template<typename ...T>
/// struct X {
///   typedef T* pointer_types; // ill-formed; T is a parameter pack.
/// };
/// \endcode
///
/// Note that this routine does not specify which
bool containsUnexpandedParameterPack() const {
  return getDependence() & TypeDependence::UnexpandedPack;
}

/// Determines if this type would be canonical if it had no further
/// qualification.
bool isCanonicalUnqualified() const {
  return CanonicalType == QualType(this, 0);
}

/// Pull a single level of sugar off of this locally-unqualified type.
/// Users should generally prefer SplitQualType::getSingleStepDesugaredType()
/// or QualType::getSingleStepDesugaredType(const ASTContext&).
QualType getLocallyUnqualifiedSingleStepDesugaredType() const;

/// As an extension, we classify types as one of "sized" or "sizeless";
/// every type is one or the other.  Standard types are all sized;
/// sizeless types are purely an extension.
///
/// Sizeless types contain data with no specified size, alignment,
/// or layout.
bool isSizelessType() const;
bool isSizelessBuiltinType() const;

/// Determines if this is a sizeless type supported by the
/// 'arm_sve_vector_bits' type attribute, which can be applied to a single
/// SVE vector or predicate, excluding tuple types such as svint32x4_t.
bool isVLSTBuiltinType() const;

/// Returns the representative type for the element of an SVE builtin type.
/// This is used to represent fixed-length SVE vectors created with the
/// 'arm_sve_vector_bits' type attribute as VectorType.
QualType getSveEltType(const ASTContext &Ctx) const;

/// Types are partitioned into 3 broad categories (C99 6.2.5p1):
/// object types, function types, and incomplete types.

/// Return true if this is an incomplete type.
/// A type that can describe objects, but which lacks information needed to
/// determine its size (e.g. void, or a fwd declared struct). Clients of this
/// routine will need to determine if the size is actually required.
///
/// Def If non-null, and the type refers to some kind of declaration
/// that can be completed (such as a C struct, C++ class, or Objective-C
/// class), will be set to the declaration.
bool isIncompleteType(NamedDecl **Def = nullptr) const;

/// Return true if this is an incomplete or object
/// type, in other words, not a function type.
bool isIncompleteOrObjectType() const {
  return !isFunctionType();
}

/// Determine whether this type is an object type.
bool isObjectType() const {
  // C++ [basic.types]p8:
  //   An object type is a (possibly cv-qualified) type that is not a
  //   function type, not a reference type, and not a void type.
  return !isReferenceType() && !isFunctionType() && !isVoidType();
}

/// Return true if this is a literal type
/// (C++11 [basic.types]p10)
bool isLiteralType(const ASTContext &Ctx) const;

/// Determine if this type is a structural type, per C++20 [temp.param]p7.
bool isStructuralType() const;

/// Test if this type is a standard-layout type.
/// (C++0x [basic.type]p9)
bool isStandardLayoutType() const;

/// Helper methods to distinguish type categories. All type predicates
/// operate on the canonical type, ignoring typedefs and qualifiers.

/// Returns true if the type is a builtin type.
bool isBuiltinType() const;

/// Test for a particular builtin type.
bool isSpecificBuiltinType(unsigned K) const;

/// Test for a type which does not represent an actual type-system type but
/// is instead used as a placeholder for various convenient purposes within
/// Clang.  All such types are BuiltinTypes.
bool isPlaceholderType() const;
const BuiltinType *getAsPlaceholderType() const;

/// Test for a specific placeholder type.
bool isSpecificPlaceholderType(unsigned K) const;

/// Test for a placeholder type other than Overload; see
/// BuiltinType::isNonOverloadPlaceholderType.
bool isNonOverloadPlaceholderType() const;

/// isIntegerType() does *not* include complex integers (a GCC extension).
/// isComplexIntegerType() can be used to test for complex integers.
bool isIntegerType() const;     // C99 6.2.5p17 (int, char, bool, enum)
bool isEnumeralType() const;

/// Determine whether this type is a scoped enumeration type.
bool isScopedEnumeralType() const;
bool isBooleanType() const;
bool isCharType() const;
bool isWideCharType() const;
bool isChar8Type() const;
bool isChar16Type() const;
bool isChar32Type() const;
bool isAnyCharacterType() const;
bool isIntegralType(const ASTContext &Ctx) const;

/// Determine whether this type is an integral or enumeration type.
bool isIntegralOrEnumerationType() const;

/// Determine whether this type is an integral or unscoped enumeration type.
bool isIntegralOrUnscopedEnumerationType() const;
bool isUnscopedEnumerationType() const;

/// Floating point categories.
bool isRealFloatingType() const; // C99 6.2.5p10 (float, double, long double)
/// isComplexType() does *not* include complex integers (a GCC extension).
/// isComplexIntegerType() can be used to test for complex integers.
bool isComplexType() const;      // C99 6.2.5p11 (complex)
bool isAnyComplexType() const;   // C99 6.2.5p11 (complex) + Complex Int.
bool isFloatingType() const;     // C99 6.2.5p11 (real floating + complex)
bool isHalfType() const;         // OpenCL 6.1.1.1, NEON (IEEE 754-2008 half)
bool isFloat16Type() const;      // C11 extension ISO/IEC TS 18661
bool isBFloat16Type() const;
bool isFloat128Type() const;
bool isRealType() const;         // C99 6.2.5p17 (real floating + integer)
bool isArithmeticType() const;   // C99 6.2.5p18 (integer + floating)
bool isVoidType() const;         // C99 6.2.5p19
bool isScalarType() const;       // C99 6.2.5p21 (arithmetic + pointers)
bool isAggregateType() const;
bool isFundamentalType() const;
bool isCompoundType() const;

// Type Predicates: Check to see if this type is structurally the specified
// type, ignoring typedefs and qualifiers.
bool isFunctionType() const;
bool isFunctionNoProtoType() const { return getAs<FunctionNoProtoType>(); }
bool isFunctionProtoType() const { return getAs<FunctionProtoType>(); }
bool isPointerType() const;
bool isAnyPointerType() const;   // Any C pointer or ObjC object pointer
bool isBlockPointerType() const;
bool isVoidPointerType() const;
bool isReferenceType() const;
bool isLValueReferenceType() const;
bool isRValueReferenceType() const;
bool isObjectPointerType() const;
bool isFunctionPointerType() const;
bool isFunctionReferenceType() const;
bool isMemberPointerType() const;
bool isMemberFunctionPointerType() const;
bool isMemberDataPointerType() const;
bool isArrayType() const;
bool isConstantArrayType() const;
bool isIncompleteArrayType() const;
bool isVariableArrayType() const;
bool isDependentSizedArrayType() const;
bool isRecordType() const;
bool isClassType() const;
bool isStructureType() const;
bool isObjCBoxableRecordType() const;
bool isInterfaceType() const;
bool isStructureOrClassType() const;
bool isUnionType() const;
bool isComplexIntegerType() const;            // GCC _Complex integer type.
bool isVectorType() const;                    // GCC vector type.
bool isExtVectorType() const;                 // Extended vector type.
bool isMatrixType() const;                    // Matrix type.
bool isConstantMatrixType() const;            // Constant matrix type.
bool isDependentAddressSpaceType() const;     // value-dependent address space qualifier
bool isObjCObjectPointerType() const;         // pointer to ObjC object
bool isObjCRetainableType() const;            // ObjC object or block pointer
bool isObjCLifetimeType() const;              // (array of)* retainable type
bool isObjCIndirectLifetimeType() const;      // (pointer to)* lifetime type
bool isObjCNSObjectType() const;              // __attribute__((NSObject))
bool isObjCIndependentClassType() const;      // __attribute__((objc_independent_class))
// FIXME: change this to 'raw' interface type, so we can used 'interface' type
// for the common case.
bool isObjCObjectType() const;                // NSString or typeof(*(id)0)
bool isObjCQualifiedInterfaceType() const;    // NSString<foo>
bool isObjCQualifiedIdType() const;           // id<foo>
bool isObjCQualifiedClassType() const;        // Class<foo>
bool isObjCObjectOrInterfaceType() const;
bool isObjCIdType() const;                    // id
bool isDecltypeType() const;
/// Was this type written with the special inert-in-ARC __unsafe_unretained
/// qualifier?
///
/// This approximates the answer to the following question: if this
/// translation unit were compiled in ARC, would this type be qualified
/// with __unsafe_unretained?
bool isObjCInertUnsafeUnretainedType() const {
  return hasAttr(attr::ObjCInertUnsafeUnretained);
}

/// Whether the type is Objective-C 'id' or a __kindof type of an
/// object type, e.g., __kindof NSView * or __kindof id
/// <NSCopying>.
///
/// \param bound Will be set to the bound on non-id subtype types,
/// which will be (possibly specialized) Objective-C class type, or
/// null for 'id.
bool isObjCIdOrObjectKindOfType(const ASTContext &ctx,
                                const ObjCObjectType *&bound) const;

bool isObjCClassType() const;                 // Class

/// Whether the type is Objective-C 'Class' or a __kindof type of an
/// Class type, e.g., __kindof Class <NSCopying>.
///
/// Unlike \c isObjCIdOrObjectKindOfType, there is no relevant bound
/// here because Objective-C's type system cannot express "a class
/// object for a subclass of NSFoo".
bool isObjCClassOrClassKindOfType() const;

bool isBlockCompatibleObjCPointerType(ASTContext &ctx) const;
bool isObjCSelType() const;                 // Class
bool isObjCBuiltinType() const;               // 'id' or 'Class'
bool isObjCARCBridgableType() const;
bool isCARCBridgableType() const;
bool isTemplateTypeParmType() const;          // C++ template type parameter
bool isNullPtrType() const;                   // C++11 std::nullptr_t
bool isNothrowT() const;                      // C++   std::nothrow_t
bool isAlignValT() const;                     // C++17 std::align_val_t
bool isStdByteType() const;                   // C++17 std::byte
bool isAtomicType() const;                    // C11 _Atomic()
bool isUndeducedAutoType() const;             // C++11 auto or
                                              // C++14 decltype(auto)
bool isTypedefNameType() const;               // typedef or alias template

2110#define IMAGE_TYPE(ImgType, Id, SingletonId, Access, Suffix) \
bool is##Id##Type() const;
2112#include "clang/Basic/OpenCLImageTypes.def"

bool isImageType() const;                     // Any OpenCL image type

bool isSamplerT() const;                      // OpenCL sampler_t
bool isEventT() const;                        // OpenCL event_t
bool isClkEventT() const;                     // OpenCL clk_event_t
bool isQueueT() const;                        // OpenCL queue_t
bool isReserveIDT() const;                    // OpenCL reserve_id_t

2122#define EXT_OPAQUE_TYPE(ExtType, Id, Ext) \
bool is##Id##Type() const;
2124#include "clang/Basic/OpenCLExtensionTypes.def"
// Type defined in cl_intel_device_side_avc_motion_estimation OpenCL extension
bool isOCLIntelSubgroupAVCType() const;
bool isOCLExtOpaqueType() const;              // Any OpenCL extension type

bool isPipeType() const;                      // OpenCL pipe type
bool isExtIntType() const;                    // Extended Int Type
bool isOpenCLSpecificType() const;            // Any OpenCL specific type

/// Determines if this type, which must satisfy
/// isObjCLifetimeType(), is implicitly __unsafe_unretained rather
/// than implicitly __strong.
bool isObjCARCImplicitlyUnretainedType() const;

/// Check if the type is the CUDA device builtin surface type.
bool isCUDADeviceBuiltinSurfaceType() const;
/// Check if the type is the CUDA device builtin texture type.
bool isCUDADeviceBuiltinTextureType() const;

/// Return the implicit lifetime for this type, which must not be dependent.
Qualifiers::ObjCLifetime getObjCARCImplicitLifetime() const;

enum ScalarTypeKind {
  STK_CPointer,
  STK_BlockPointer,
  STK_ObjCObjectPointer,
  STK_MemberPointer,
  STK_Bool,
  STK_Integral,
  STK_Floating,
  STK_IntegralComplex,
  STK_FloatingComplex,
  STK_FixedPoint
};

/// Given that this is a scalar type, classify it.
ScalarTypeKind getScalarTypeKind() const;

TypeDependence getDependence() const {
  return static_cast<TypeDependence>(TypeBits.Dependence);
}

/// Whether this type is an error type.
bool containsErrors() const {
  return getDependence() & TypeDependence::Error;
}

/// Whether this type is a dependent type, meaning that its definition
/// somehow depends on a template parameter (C++ [temp.dep.type]).
bool isDependentType() const {
  return getDependence() & TypeDependence::Dependent;
}

/// Determine whether this type is an instantiation-dependent type,
/// meaning that the type involves a template parameter (even if the
/// definition does not actually depend on the type substituted for that
/// template parameter).
bool isInstantiationDependentType() const {
  return getDependence() & TypeDependence::Instantiation;
}

/// Determine whether this type is an undeduced type, meaning that
/// it somehow involves a C++11 'auto' type or similar which has not yet been
/// deduced.
bool isUndeducedType() const;

/// Whether this type is a variably-modified type (C99 6.7.5).
bool isVariablyModifiedType() const {
  return getDependence() & TypeDependence::VariablyModified;
}

/// Whether this type involves a variable-length array type
/// with a definite size.
bool hasSizedVLAType() const;

/// Whether this type is or contains a local or unnamed type.
bool hasUnnamedOrLocalType() const;

bool isOverloadableType() const;

/// Determine wither this type is a C++ elaborated-type-specifier.
bool isElaboratedTypeSpecifier() const;

bool canDecayToPointerType() const;

/// Whether this type is represented natively as a pointer.  This includes
/// pointers, references, block pointers, and Objective-C interface,
/// qualified id, and qualified interface types, as well as nullptr_t.
bool hasPointerRepresentation() const;

/// Whether this type can represent an objective pointer type for the
/// purpose of GC'ability
bool hasObjCPointerRepresentation() const;

/// Determine whether this type has an integer representation
/// of some sort, e.g., it is an integer type or a vector.
bool hasIntegerRepresentation() const;

/// Determine whether this type has an signed integer representation
/// of some sort, e.g., it is an signed integer type or a vector.
bool hasSignedIntegerRepresentation() const;

/// Determine whether this type has an unsigned integer representation
/// of some sort, e.g., it is an unsigned integer type or a vector.
bool hasUnsignedIntegerRepresentation() const;

/// Determine whether this type has a floating-point representation
/// of some sort, e.g., it is a floating-point type or a vector thereof.
bool hasFloatingRepresentation() const;

// Type Checking Functions: Check to see if this type is structurally the
// specified type, ignoring typedefs and qualifiers, and return a pointer to
// the best type we can.
const RecordType *getAsStructureType() const;
/// NOTE: getAs*ArrayType are methods on ASTContext.
const RecordType *getAsUnionType() const;
const ComplexType *getAsComplexIntegerType() const; // GCC complex int type.
const ObjCObjectType *getAsObjCInterfaceType() const;

// The following is a convenience method that returns an ObjCObjectPointerType
// for object declared using an interface.
const ObjCObjectPointerType *getAsObjCInterfacePointerType() const;
const ObjCObjectPointerType *getAsObjCQualifiedIdType() const;
const ObjCObjectPointerType *getAsObjCQualifiedClassType() const;
const ObjCObjectType *getAsObjCQualifiedInterfaceType() const;

/// Retrieves the CXXRecordDecl that this type refers to, either
/// because the type is a RecordType or because it is the injected-class-name
/// type of a class template or class template partial specialization.
CXXRecordDecl *getAsCXXRecordDecl() const;

/// Retrieves the RecordDecl this type refers to.
RecordDecl *getAsRecordDecl() const;

/// Retrieves the TagDecl that this type refers to, either
/// because the type is a TagType or because it is the injected-class-name
/// type of a class template or class template partial specialization.
TagDecl *getAsTagDecl() const;

/// If this is a pointer or reference to a RecordType, return the
/// CXXRecordDecl that the type refers to.
///
/// If this is not a pointer or reference, or the type being pointed to does
/// not refer to a CXXRecordDecl, returns NULL.
const CXXRecordDecl *getPointeeCXXRecordDecl() const;

/// Get the DeducedType whose type will be deduced for a variable with
/// an initializer of this type. This looks through declarators like pointer
/// types, but not through decltype or typedefs.
DeducedType *getContainedDeducedType() const;

/// Get the AutoType whose type will be deduced for a variable with
/// an initializer of this type. This looks through declarators like pointer
/// types, but not through decltype or typedefs.
AutoType *getContainedAutoType() const {
  return dyn_cast_or_null<AutoType>(getContainedDeducedType());
}

/// Determine whether this type was written with a leading 'auto'
/// corresponding to a trailing return type (possibly for a nested
/// function type within a pointer to function type or similar).
bool hasAutoForTrailingReturnType() const;

/// Member-template getAs<specific type>'.  Look through sugar for
/// an instance of \<specific type>.   This scheme will eventually
/// replace the specific getAsXXXX methods above.
///
/// There are some specializations of this member template listed
/// immediately following this class.
template <typename T> const T *getAs() const;

/// Member-template getAsAdjusted<specific type>. Look through specific kinds
/// of sugar (parens, attributes, etc) for an instance of \<specific type>.
/// This is used when you need to walk over sugar nodes that represent some
/// kind of type adjustment from a type that was written as a \<specific type>
/// to another type that is still canonically a \<specific type>.
template <typename T> const T *getAsAdjusted() const;

/// A variant of getAs<> for array types which silently discards
/// qualifiers from the outermost type.
const ArrayType *getAsArrayTypeUnsafe() const;

/// Member-template castAs<specific type>.  Look through sugar for
/// the underlying instance of \<specific type>.
///
/// This method has the same relationship to getAs<T> as cast<T> has
/// to dyn_cast<T>; which is to say, the underlying type *must*
/// have the intended type, and this method will never return null.
template <typename T> const T *castAs() const;

/// A variant of castAs<> for array type which silently discards
/// qualifiers from the outermost type.
const ArrayType *castAsArrayTypeUnsafe() const;

/// Determine whether this type had the specified attribute applied to it
/// (looking through top-level type sugar).
bool hasAttr(attr::Kind AK) const;

/// Get the base element type of this type, potentially discarding type
/// qualifiers.  This should never be used when type qualifiers
/// are meaningful.
const Type *getBaseElementTypeUnsafe() const;

/// If this is an array type, return the element type of the array,
/// potentially with type qualifiers missing.
/// This should never be used when type qualifiers are meaningful.
const Type *getArrayElementTypeNoTypeQual() const;

/// If this is a pointer type, return the pointee type.
/// If this is an array type, return the array element type.
/// This should never be used when type qualifiers are meaningful.
const Type *getPointeeOrArrayElementType() const;

/// If this is a pointer, ObjC object pointer, or block
/// pointer, this returns the respective pointee.
QualType getPointeeType() const;

/// Return the specified type with any "sugar" removed from the type,
/// removing any typedefs, typeofs, etc., as well as any qualifiers.
const Type *getUnqualifiedDesugaredType() const;

/// More type predicates useful for type checking/promotion
bool isPromotableIntegerType() const; // C99 6.3.1.1p2

/// Return true if this is an integer type that is
/// signed, according to C99 6.2.5p4 [char, signed char, short, int, long..],
/// or an enum decl which has a signed representation.
bool isSignedIntegerType() const;

/// Return true if this is an integer type that is
/// unsigned, according to C99 6.2.5p6 [which returns true for _Bool],
/// or an enum decl which has an unsigned representation.
bool isUnsignedIntegerType() const;

/// Determines whether this is an integer type that is signed or an
/// enumeration types whose underlying type is a signed integer type.
bool isSignedIntegerOrEnumerationType() const;

/// Determines whether this is an integer type that is unsigned or an
/// enumeration types whose underlying type is a unsigned integer type.
bool isUnsignedIntegerOrEnumerationType() const;

/// Return true if this is a fixed point type according to
/// ISO/IEC JTC1 SC22 WG14 N1169.
bool isFixedPointType() const;

/// Return true if this is a fixed point or integer type.
bool isFixedPointOrIntegerType() const;

/// Return true if this is a saturated fixed point type according to
/// ISO/IEC JTC1 SC22 WG14 N1169. This type can be signed or unsigned.
bool isSaturatedFixedPointType() const;

/// Return true if this is a saturated fixed point type according to
/// ISO/IEC JTC1 SC22 WG14 N1169. This type can be signed or unsigned.
bool isUnsaturatedFixedPointType() const;

/// Return true if this is a fixed point type that is signed according
/// to ISO/IEC JTC1 SC22 WG14 N1169. This type can also be saturated.
bool isSignedFixedPointType() const;

/// Return true if this is a fixed point type that is unsigned according
/// to ISO/IEC JTC1 SC22 WG14 N1169. This type can also be saturated.
bool isUnsignedFixedPointType() const;

/// Return true if this is not a variable sized type,
/// according to the rules of C99 6.7.5p3.  It is not legal to call this on
/// incomplete types.
bool isConstantSizeType() const;

/// Returns true if this type can be represented by some
/// set of type specifiers.
bool isSpecifierType() const;

/// Determine the linkage of this type.
Linkage getLinkage() const;

/// Determine the visibility of this type.
Visibility getVisibility() const {
  return getLinkageAndVisibility().getVisibility();
}

/// Return true if the visibility was explicitly set is the code.
bool isVisibilityExplicit() const {
  return getLinkageAndVisibility().isVisibilityExplicit();
}

/// Determine the linkage and visibility of this type.
LinkageInfo getLinkageAndVisibility() const;

/// True if the computed linkage is valid. Used for consistency
/// checking. Should always return true.
bool isLinkageValid() const;

/// Determine the nullability of the given type.
///
/// Note that nullability is only captured as sugar within the type
/// system, not as part of the canonical type, so nullability will
/// be lost by canonicalization and desugaring.
Optional<NullabilityKind> getNullability(const ASTContext &context) const;

/// Determine whether the given type can have a nullability
/// specifier applied to it, i.e., if it is any kind of pointer type.
///
/// \param ResultIfUnknown The value to return if we don't yet know whether
///        this type can have nullability because it is dependent.
bool canHaveNullability(bool ResultIfUnknown = true) const;

/// Retrieve the set of substitutions required when accessing a member
/// of the Objective-C receiver type that is declared in the given context.
///
/// \c *this is the type of the object we're operating on, e.g., the
/// receiver for a message send or the base of a property access, and is
/// expected to be of some object or object pointer type.
///
/// \param dc The declaration context for which we are building up a
/// substitution mapping, which should be an Objective-C class, extension,
/// category, or method within.
///
/// \returns an array of type arguments that can be substituted for
/// the type parameters of the given declaration context in any type described
/// within that context, or an empty optional to indicate that no
/// substitution is required.
Optional<ArrayRef<QualType>>
getObjCSubstitutions(const DeclContext *dc) const;

/// Determines if this is an ObjC interface type that may accept type
/// parameters.
bool acceptsObjCTypeParams() const;

const char *getTypeClassName() const;

QualType getCanonicalTypeInternal() const {
  return CanonicalType;
}

CanQualType getCanonicalTypeUnqualified() const; // in CanonicalType.h
void dump() const;
void dump(llvm::raw_ostream &OS, const ASTContext &Context) const;
2463};

2465/// This will check for a TypedefType by removing any existing sugar
2466/// until it reaches a TypedefType or a non-sugared type.
2467template <> const TypedefType *Type::getAs() const;

2469/// This will check for a TemplateSpecializationType by removing any
2470/// existing sugar until it reaches a TemplateSpecializationType or a
2471/// non-sugared type.
2472template <> const TemplateSpecializationType *Type::getAs() const;

2474/// This will check for an AttributedType by removing any existing sugar
2475/// until it reaches an AttributedType or a non-sugared type.
2476template <> const AttributedType *Type::getAs() const;

2478// We can do canonical leaf types faster, because we don't have to
2479// worry about preserving child type decoration.
2480#define TYPE(Class, Base)
2481#define LEAF_TYPE(Class) \
2482template <> inline const Class##Type *Type::getAs() const { \
return dyn_cast<Class##Type>(CanonicalType); \
2484} \
2485template <> inline const Class##Type *Type::castAs() const { \
return cast<Class##Type>(CanonicalType); \
2487}
2488#include "clang/AST/TypeNodes.inc"

2490/// This class is used for builtin types like 'int'.  Builtin
2491/// types are always canonical and have a literal name field.
2492class BuiltinType : public Type {
2493public:
enum Kind {
2495// OpenCL image types
2496#define IMAGE_TYPE(ImgType, Id, SingletonId, Access, Suffix) Id,
2497#include "clang/Basic/OpenCLImageTypes.def"
2498// OpenCL extension types
2499#define EXT_OPAQUE_TYPE(ExtType, Id, Ext) Id,
2500#include "clang/Basic/OpenCLExtensionTypes.def"
2501// SVE Types
2502#define SVE_TYPE(Name, Id, SingletonId) Id,
2503#include "clang/Basic/AArch64SVEACLETypes.def"
2504// PPC MMA Types
2505#define PPC_VECTOR_TYPE(Name, Id, Size) Id,
2506#include "clang/Basic/PPCTypes.def"
2507// RVV Types
2508#define RVV_TYPE(Name, Id, SingletonId) Id,
2509#include "clang/Basic/RISCVVTypes.def"
2510// All other builtin types
2511#define BUILTIN_TYPE(Id, SingletonId) Id,
2512#define LAST_BUILTIN_TYPE(Id) LastKind = Id
2513#include "clang/AST/BuiltinTypes.def"
};

2516private:
friend class ASTContext; // ASTContext creates these.

BuiltinType(Kind K)
    : Type(Builtin, QualType(),
           K == Dependent ? TypeDependence::DependentInstantiation
                          : TypeDependence::None) {
  BuiltinTypeBits.Kind = K;
}

2526public:
Kind getKind() const { return static_cast<Kind>(BuiltinTypeBits.Kind); }
StringRef getName(const PrintingPolicy &Policy) const;

const char *getNameAsCString(const PrintingPolicy &Policy) const {
  // The StringRef is null-terminated.
  StringRef str = getName(Policy);
  assert(!str.empty() && str.data()[str.size()] == '\0')(static_cast<void> (0));
  return str.data();
}

bool isSugared() const { return false; }
QualType desugar() const { return QualType(this, 0); }

bool isInteger() const {
  return getKind() >= Bool && getKind() <= Int128;
}

bool isSignedInteger() const {
  return getKind() >= Char_S && getKind() <= Int128;
}

bool isUnsignedInteger() const {
  return getKind() >= Bool && getKind() <= UInt128;
}

bool isFloatingPoint() const {
  return getKind() >= Half && getKind() <= Float128;
}

/// Determines whether the given kind corresponds to a placeholder type.
static bool isPlaceholderTypeKind(Kind K) {
  return K >= Overload;
}

/// Determines whether this type is a placeholder type, i.e. a type
/// which cannot appear in arbitrary positions in a fully-formed
/// expression.
bool isPlaceholderType() const {
  return isPlaceholderTypeKind(getKind());
}

/// Determines whether this type is a placeholder type other than
/// Overload.  Most placeholder types require only syntactic
/// information about their context in order to be resolved (e.g.
/// whether it is a call expression), which means they can (and
/// should) be resolved in an earlier "phase" of analysis.
/// Overload expressions sometimes pick up further information
/// from their context, like whether the context expects a
/// specific function-pointer type, and so frequently need
/// special treatment.
bool isNonOverloadPlaceholderType() const {
  return getKind() > Overload;
}

static bool classof(const Type *T) { return T->getTypeClass() == Builtin; }
2582};

2584/// Complex values, per C99 6.2.5p11.  This supports the C99 complex
2585/// types (_Complex float etc) as well as the GCC integer complex extensions.
2586class ComplexType : public Type, public llvm::FoldingSetNode {
friend class ASTContext; // ASTContext creates these.

QualType ElementType;

ComplexType(QualType Element, QualType CanonicalPtr)
    : Type(Complex, CanonicalPtr, Element->getDependence()),
      ElementType(Element) {}

2595public:
QualType getElementType() const { return ElementType; }

bool isSugared() const { return false; }
QualType desugar() const { return QualType(this, 0); }

void Profile(llvm::FoldingSetNodeID &ID) {
  Profile(ID, getElementType());
}

static void Profile(llvm::FoldingSetNodeID &ID, QualType Element) {
  ID.AddPointer(Element.getAsOpaquePtr());
}

static bool classof(const Type *T) { return T->getTypeClass() == Complex; }
2610};

2612/// Sugar for parentheses used when specifying types.
2613class ParenType : public Type, public llvm::FoldingSetNode {
friend class ASTContext; // ASTContext creates these.

QualType Inner;

ParenType(QualType InnerType, QualType CanonType)
    : Type(Paren, CanonType, InnerType->getDependence()), Inner(InnerType) {}

2621public:
QualType getInnerType() const { return Inner; }

bool isSugared() const { return true; }
QualType desugar() const { return getInnerType(); }

void Profile(llvm::FoldingSetNodeID &ID) {
  Profile(ID, getInnerType());
}

static void Profile(llvm::FoldingSetNodeID &ID, QualType Inner) {
  Inner.Profile(ID);
}

static bool classof(const Type *T) { return T->getTypeClass() == Paren; }
2636};

2638/// PointerType - C99 6.7.5.1 - Pointer Declarators.
2639class PointerType : public Type, public llvm::FoldingSetNode {
friend class ASTContext; // ASTContext creates these.

QualType PointeeType;

PointerType(QualType Pointee, QualType CanonicalPtr)
    : Type(Pointer, CanonicalPtr, Pointee->getDependence()),
      PointeeType(Pointee) {}

2648public:
QualType getPointeeType() const { return PointeeType; }

bool isSugared() const { return false; }
QualType desugar() const { return QualType(this, 0); }

void Profile(llvm::FoldingSetNodeID &ID) {
  Profile(ID, getPointeeType());
}

static void Profile(llvm::FoldingSetNodeID &ID, QualType Pointee) {
  ID.AddPointer(Pointee.getAsOpaquePtr());
}

static bool classof(const Type *T) { return T->getTypeClass() == Pointer; }
2663};

2665/// Represents a type which was implicitly adjusted by the semantic
2666/// engine for arbitrary reasons.  For example, array and function types can
2667/// decay, and function types can have their calling conventions adjusted.
2668class AdjustedType : public Type, public llvm::FoldingSetNode {
QualType OriginalTy;
QualType AdjustedTy;

2672protected:
friend class ASTContext; // ASTContext creates these.

AdjustedType(TypeClass TC, QualType OriginalTy, QualType AdjustedTy,
             QualType CanonicalPtr)
    : Type(TC, CanonicalPtr, OriginalTy->getDependence()),
      OriginalTy(OriginalTy), AdjustedTy(AdjustedTy) {}

2680public:
QualType getOriginalType() const { return OriginalTy; }
QualType getAdjustedType() const { return AdjustedTy; }

bool isSugared() const { return true; }
QualType desugar() const { return AdjustedTy; }

void Profile(llvm::FoldingSetNodeID &ID) {
  Profile(ID, OriginalTy, AdjustedTy);
}

static void Profile(llvm::FoldingSetNodeID &ID, QualType Orig, QualType New) {
  ID.AddPointer(Orig.getAsOpaquePtr());
  ID.AddPointer(New.getAsOpaquePtr());
}

static bool classof(const Type *T) {
  return T->getTypeClass() == Adjusted || T->getTypeClass() == Decayed;
}
2699};

2701/// Represents a pointer type decayed from an array or function type.
2702class DecayedType : public AdjustedType {
friend class ASTContext; // ASTContext creates these.

inline
DecayedType(QualType OriginalType, QualType Decayed, QualType Canonical);

2708public:
QualType getDecayedType() const { return getAdjustedType(); }

inline QualType getPointeeType() const;

static bool classof(const Type *T) { return T->getTypeClass() == Decayed; }
2714};

2716/// Pointer to a block type.
2717/// This type is to represent types syntactically represented as
2718/// "void (^)(int)", etc. Pointee is required to always be a function type.
2719class BlockPointerType : public Type, public llvm::FoldingSetNode {
friend class ASTContext; // ASTContext creates these.

// Block is some kind of pointer type
QualType PointeeType;

BlockPointerType(QualType Pointee, QualType CanonicalCls)
    : Type(BlockPointer, CanonicalCls, Pointee->getDependence()),
      PointeeType(Pointee) {}

2729public:
// Get the pointee type. Pointee is required to always be a function type.
QualType getPointeeType() const { return PointeeType; }

bool isSugared() const { return false; }
QualType desugar() const { return QualType(this, 0); }

void Profile(llvm::FoldingSetNodeID &ID) {
    Profile(ID, getPointeeType());
}

static void Profile(llvm::FoldingSetNodeID &ID, QualType Pointee) {
    ID.AddPointer(Pointee.getAsOpaquePtr());
}

static bool classof(const Type *T) {
  return T->getTypeClass() == BlockPointer;
}
2747};

2749/// Base for LValueReferenceType and RValueReferenceType
2750class ReferenceType : public Type, public llvm::FoldingSetNode {
QualType PointeeType;

2753protected:
ReferenceType(TypeClass tc, QualType Referencee, QualType CanonicalRef,
              bool SpelledAsLValue)
    : Type(tc, CanonicalRef, Referencee->getDependence()),
      PointeeType(Referencee) {
  ReferenceTypeBits.SpelledAsLValue = SpelledAsLValue;
  ReferenceTypeBits.InnerRef = Referencee->isReferenceType();
}

2762public:
bool isSpelledAsLValue() const { return ReferenceTypeBits.SpelledAsLValue; }
bool isInnerRef() const { return ReferenceTypeBits.InnerRef; }

QualType getPointeeTypeAsWritten() const { return PointeeType; }

QualType getPointeeType() const {
  // FIXME: this might strip inner qualifiers; okay?
  const ReferenceType *T = this;
  while (T->isInnerRef())
    T = T->PointeeType->castAs<ReferenceType>();
  return T->PointeeType;
}

void Profile(llvm::FoldingSetNodeID &ID) {
  Profile(ID, PointeeType, isSpelledAsLValue());
}

static void Profile(llvm::FoldingSetNodeID &ID,
                    QualType Referencee,
                    bool SpelledAsLValue) {
  ID.AddPointer(Referencee.getAsOpaquePtr());
  ID.AddBoolean(SpelledAsLValue);
}

static bool classof(const Type *T) {
  return T->getTypeClass() == LValueReference ||
         T->getTypeClass() == RValueReference;
}
2791};

2793/// An lvalue reference type, per C++11 [dcl.ref].
2794class LValueReferenceType : public ReferenceType {
friend class ASTContext; // ASTContext creates these

LValueReferenceType(QualType Referencee, QualType CanonicalRef,
                    bool SpelledAsLValue)
    : ReferenceType(LValueReference, Referencee, CanonicalRef,
                    SpelledAsLValue) {}

2802public:
bool isSugared() const { return false; }
QualType desugar() const { return QualType(this, 0); }

static bool classof(const Type *T) {
  return T->getTypeClass() == LValueReference;
}
2809};

2811/// An rvalue reference type, per C++11 [dcl.ref].
2812class RValueReferenceType : public ReferenceType {
friend class ASTContext; // ASTContext creates these

RValueReferenceType(QualType Referencee, QualType CanonicalRef)
     : ReferenceType(RValueReference, Referencee, CanonicalRef, false) {}

2818public:
bool isSugared() const { return false; }
QualType desugar() const { return QualType(this, 0); }

static bool classof(const Type *T) {
  return T->getTypeClass() == RValueReference;
}
2825};

2827/// A pointer to member type per C++ 8.3.3 - Pointers to members.
2828///
2829/// This includes both pointers to data members and pointer to member functions.
2830class MemberPointerType : public Type, public llvm::FoldingSetNode {
friend class ASTContext; // ASTContext creates these.

QualType PointeeType;

/// The class of which the pointee is a member. Must ultimately be a
/// RecordType, but could be a typedef or a template parameter too.
const Type *Class;

MemberPointerType(QualType Pointee, const Type *Cls, QualType CanonicalPtr)
    : Type(MemberPointer, CanonicalPtr,
           (Cls->getDependence() & ~TypeDependence::VariablyModified) |
               Pointee->getDependence()),
      PointeeType(Pointee), Class(Cls) {}

2845public:
QualType getPointeeType() const { return PointeeType; }

/// Returns true if the member type (i.e. the pointee type) is a
/// function type rather than a data-member type.
bool isMemberFunctionPointer() const {
  return PointeeType->isFunctionProtoType();
}

/// Returns true if the member type (i.e. the pointee type) is a
/// data type rather than a function type.
bool isMemberDataPointer() const {
  return !PointeeType->isFunctionProtoType();
}

const Type *getClass() const { return Class; }
CXXRecordDecl *getMostRecentCXXRecordDecl() const;

bool isSugared() const { return false; }
QualType desugar() const { return QualType(this, 0); }

void Profile(llvm::FoldingSetNodeID &ID) {
  Profile(ID, getPointeeType(), getClass());
}

static void Profile(llvm::FoldingSetNodeID &ID, QualType Pointee,
                    const Type *Class) {
  ID.AddPointer(Pointee.getAsOpaquePtr());
  ID.AddPointer(Class);
}

static bool classof(const Type *T) {
  return T->getTypeClass() == MemberPointer;
}
2879};

2881/// Represents an array type, per C99 6.7.5.2 - Array Declarators.
2882class ArrayType : public Type, public llvm::FoldingSetNode {
2883public:
/// Capture whether this is a normal array (e.g. int X[4])
/// an array with a static size (e.g. int X[static 4]), or an array
/// with a star size (e.g. int X[*]).
/// 'static' is only allowed on function parameters.
enum ArraySizeModifier {
  Normal, Static, Star
};

2892private:
/// The element type of the array.
QualType ElementType;

2896protected:
friend class ASTContext; // ASTContext creates these.

ArrayType(TypeClass tc, QualType et, QualType can, ArraySizeModifier sm,
          unsigned tq, const Expr *sz = nullptr);

2902public:
QualType getElementType() const { return ElementType; }

ArraySizeModifier getSizeModifier() const {
  return ArraySizeModifier(ArrayTypeBits.SizeModifier);
}

Qualifiers getIndexTypeQualifiers() const {
  return Qualifiers::fromCVRMask(getIndexTypeCVRQualifiers());
}

unsigned getIndexTypeCVRQualifiers() const {
  return ArrayTypeBits.IndexTypeQuals;
}

static bool classof(const Type *T) {
  return T->getTypeClass() == ConstantArray ||
         T->getTypeClass() == VariableArray ||
         T->getTypeClass() == IncompleteArray ||
         T->getTypeClass() == DependentSizedArray;
}
2923};

2925/// Represents the canonical version of C arrays with a specified constant size.
2926/// For example, the canonical type for 'int A[4 + 4*100]' is a
2927/// ConstantArrayType where the element type is 'int' and the size is 404.
2928class ConstantArrayType final
  : public ArrayType,
    private llvm::TrailingObjects<ConstantArrayType, const Expr *> {
friend class ASTContext; // ASTContext creates these.
friend TrailingObjects;

llvm::APInt Size; // Allows us to unique the type.

ConstantArrayType(QualType et, QualType can, const llvm::APInt &size,
                  const Expr *sz, ArraySizeModifier sm, unsigned tq)
    : ArrayType(ConstantArray, et, can, sm, tq, sz), Size(size) {
  ConstantArrayTypeBits.HasStoredSizeExpr = sz != nullptr;
  if (ConstantArrayTypeBits.HasStoredSizeExpr) {
    assert(!can.isNull() && "canonical constant array should not have size")(static_cast<void> (0));
    *getTrailingObjects<const Expr*>() = sz;
  }
}

unsigned numTrailingObjects(OverloadToken<const Expr*>) const {
  return ConstantArrayTypeBits.HasStoredSizeExpr;
}

2950public:
const llvm::APInt &getSize() const { return Size; }
const Expr *getSizeExpr() const {
  return ConstantArrayTypeBits.HasStoredSizeExpr
             ? *getTrailingObjects<const Expr *>()
             : nullptr;
}
bool isSugared() const { return false; }
QualType desugar() const { return QualType(this, 0); }

/// Determine the number of bits required to address a member of
// an array with the given element type and number of elements.
static unsigned getNumAddressingBits(const ASTContext &Context,
                                     QualType ElementType,
                                     const llvm::APInt &NumElements);

/// Determine the maximum number of active bits that an array's size
/// can require, which limits the maximum size of the array.
static unsigned getMaxSizeBits(const ASTContext &Context);

void Profile(llvm::FoldingSetNodeID &ID, const ASTContext &Ctx) {
  Profile(ID, Ctx, getElementType(), getSize(), getSizeExpr(),
          getSizeModifier(), getIndexTypeCVRQualifiers());
}

static void Profile(llvm::FoldingSetNodeID &ID, const ASTContext &Ctx,
                    QualType ET, const llvm::APInt &ArraySize,
                    const Expr *SizeExpr, ArraySizeModifier SizeMod,
                    unsigned TypeQuals);

static bool classof(const Type *T) {
  return T->getTypeClass() == ConstantArray;
}
2983};

2985/// Represents a C array with an unspecified size.  For example 'int A[]' has
2986/// an IncompleteArrayType where the element type is 'int' and the size is
2987/// unspecified.
2988class IncompleteArrayType : public ArrayType {
friend class ASTContext; // ASTContext creates these.

IncompleteArrayType(QualType et, QualType can,
                    ArraySizeModifier sm, unsigned tq)
    : ArrayType(IncompleteArray, et, can, sm, tq) {}

2995public:
friend class StmtIteratorBase;

bool isSugared() const { return false; }
QualType desugar() const { return QualType(this, 0); }

static bool classof(const Type *T) {
  return T->getTypeClass() == IncompleteArray;
}

void Profile(llvm::FoldingSetNodeID &ID) {
  Profile(ID, getElementType(), getSizeModifier(),
          getIndexTypeCVRQualifiers());
}

static void Profile(llvm::FoldingSetNodeID &ID, QualType ET,
                    ArraySizeModifier SizeMod, unsigned TypeQuals) {
  ID.AddPointer(ET.getAsOpaquePtr());
  ID.AddInteger(SizeMod);
  ID.AddInteger(TypeQuals);
}
3016};

3018/// Represents a C array with a specified size that is not an
3019/// integer-constant-expression.  For example, 'int s[x+foo()]'.
3020/// Since the size expression is an arbitrary expression, we store it as such.
3021///
3022/// Note: VariableArrayType's aren't uniqued (since the expressions aren't) and
3023/// should not be: two lexically equivalent variable array types could mean
3024/// different things, for example, these variables do not have the same type
3025/// dynamically:
3026///
3027/// void foo(int x) {
3028///   int Y[x];
3029///   ++x;
3030///   int Z[x];
3031/// }
3032class VariableArrayType : public ArrayType {
friend class ASTContext; // ASTContext creates these.

/// An assignment-expression. VLA's are only permitted within
/// a function block.
Stmt *SizeExpr;

/// The range spanned by the left and right array brackets.
SourceRange Brackets;

VariableArrayType(QualType et, QualType can, Expr *e,
                  ArraySizeModifier sm, unsigned tq,
                  SourceRange brackets)
    : ArrayType(VariableArray, et, can, sm, tq, e),
      SizeExpr((Stmt*) e), Brackets(brackets) {}

3048public:
friend class StmtIteratorBase;

Expr *getSizeExpr() const {
  // We use C-style casts instead of cast<> here because we do not wish
  // to have a dependency of Type.h on Stmt.h/Expr.h.
  return (Expr*) SizeExpr;
}

SourceRange getBracketsRange() const { return Brackets; }
SourceLocation getLBracketLoc() const { return Brackets.getBegin(); }
SourceLocation getRBracketLoc() const { return Brackets.getEnd(); }

bool isSugared() const { return false; }
QualType desugar() const { return QualType(this, 0); }

static bool classof(const Type *T) {
  return T->getTypeClass() == VariableArray;
}

void Profile(llvm::FoldingSetNodeID &ID) {
  llvm_unreachable("Cannot unique VariableArrayTypes.")__builtin_unreachable();
}
3071};

3073/// Represents an array type in C++ whose size is a value-dependent expression.
3074///
3075/// For example:
3076/// \code
3077/// template<typename T, int Size>
3078/// class array {
3079///   T data[Size];
3080/// };
3081/// \endcode
3082///
3083/// For these types, we won't actually know what the array bound is
3084/// until template instantiation occurs, at which point this will
3085/// become either a ConstantArrayType or a VariableArrayType.
3086class DependentSizedArrayType : public ArrayType {
friend class ASTContext; // ASTContext creates these.

const ASTContext &Context;

/// An assignment expression that will instantiate to the
/// size of the array.
///
/// The expression itself might be null, in which case the array
/// type will have its size deduced from an initializer.
Stmt *SizeExpr;

/// The range spanned by the left and right array brackets.
SourceRange Brackets;

DependentSizedArrayType(const ASTContext &Context, QualType et, QualType can,
                        Expr *e, ArraySizeModifier sm, unsigned tq,
                        SourceRange brackets);

3105public:
friend class StmtIteratorBase;

Expr *getSizeExpr() const {
  // We use C-style casts instead of cast<> here because we do not wish
  // to have a dependency of Type.h on Stmt.h/Expr.h.
  return (Expr*) SizeExpr;
}

SourceRange getBracketsRange() const { return Brackets; }
SourceLocation getLBracketLoc() const { return Brackets.getBegin(); }
SourceLocation getRBracketLoc() const { return Brackets.getEnd(); }

bool isSugared() const { return false; }
QualType desugar() const { return QualType(this, 0); }

static bool classof(const Type *T) {
  return T->getTypeClass() == DependentSizedArray;
}

void Profile(llvm::FoldingSetNodeID &ID) {
  Profile(ID, Context, getElementType(),
          getSizeModifier(), getIndexTypeCVRQualifiers(), getSizeExpr());
}

static void Profile(llvm::FoldingSetNodeID &ID, const ASTContext &Context,
                    QualType ET, ArraySizeModifier SizeMod,
                    unsigned TypeQuals, Expr *E);
3133};

3135/// Represents an extended address space qualifier where the input address space
3136/// value is dependent. Non-dependent address spaces are not represented with a
3137/// special Type subclass; they are stored on an ExtQuals node as part of a QualType.
3138///
3139/// For example:
3140/// \code
3141/// template<typename T, int AddrSpace>
3142/// class AddressSpace {
3143///   typedef T __attribute__((address_space(AddrSpace))) type;
3144/// }
3145/// \endcode
3146class DependentAddressSpaceType : public Type, public llvm::FoldingSetNode {
friend class ASTContext;

const ASTContext &Context;
Expr *AddrSpaceExpr;
QualType PointeeType;
SourceLocation loc;

DependentAddressSpaceType(const ASTContext &Context, QualType PointeeType,
                          QualType can, Expr *AddrSpaceExpr,
                          SourceLocation loc);

3158public:
Expr *getAddrSpaceExpr() const { return AddrSpaceExpr; }
QualType getPointeeType() const { return PointeeType; }
SourceLocation getAttributeLoc() const { return loc; }

bool isSugared() const { return false; }
QualType desugar() const { return QualType(this, 0); }

static bool classof(const Type *T) {
  return T->getTypeClass() == DependentAddressSpace;
}

void Profile(llvm::FoldingSetNodeID &ID) {
  Profile(ID, Context, getPointeeType(), getAddrSpaceExpr());
}

static void Profile(llvm::FoldingSetNodeID &ID, const ASTContext &Context,
                    QualType PointeeType, Expr *AddrSpaceExpr);
3176};

3178/// Represents an extended vector type where either the type or size is
3179/// dependent.
3180///
3181/// For example:
3182/// \code
3183/// template<typename T, int Size>
3184/// class vector {
3185///   typedef T __attribute__((ext_vector_type(Size))) type;
3186/// }
3187/// \endcode
3188class DependentSizedExtVectorType : public Type, public llvm::FoldingSetNode {
friend class ASTContext;

const ASTContext &Context;
Expr *SizeExpr;

/// The element type of the array.
QualType ElementType;

SourceLocation loc;

DependentSizedExtVectorType(const ASTContext &Context, QualType ElementType,
                            QualType can, Expr *SizeExpr, SourceLocation loc);

3202public:
Expr *getSizeExpr() const { return SizeExpr; }
QualType getElementType() const { return ElementType; }
SourceLocation getAttributeLoc() const { return loc; }

bool isSugared() const { return false; }
QualType desugar() const { return QualType(this, 0); }

static bool classof(const Type *T) {
  return T->getTypeClass() == DependentSizedExtVector;
}

void Profile(llvm::FoldingSetNodeID &ID) {
  Profile(ID, Context, getElementType(), getSizeExpr());
}

static void Profile(llvm::FoldingSetNodeID &ID, const ASTContext &Context,
                    QualType ElementType, Expr *SizeExpr);
3220};


3223/// Represents a GCC generic vector type. This type is created using
3224/// __attribute__((vector_size(n)), where "n" specifies the vector size in
3225/// bytes; or from an Altivec __vector or vector declaration.
3226/// Since the constructor takes the number of vector elements, the
3227/// client is responsible for converting the size into the number of elements.
3228class VectorType : public Type, public llvm::FoldingSetNode {
3229public:
enum VectorKind {
  /// not a target-specific vector type
  GenericVector,

  /// is AltiVec vector
  AltiVecVector,

  /// is AltiVec 'vector Pixel'
  AltiVecPixel,

  /// is AltiVec 'vector bool ...'
  AltiVecBool,

  /// is ARM Neon vector
  NeonVector,

  /// is ARM Neon polynomial vector
  NeonPolyVector,

  /// is AArch64 SVE fixed-length data vector
  SveFixedLengthDataVector,

  /// is AArch64 SVE fixed-length predicate vector
  SveFixedLengthPredicateVector
};

3256protected:
friend class ASTContext; // ASTContext creates these.

/// The element type of the vector.
QualType ElementType;

VectorType(QualType vecType, unsigned nElements, QualType canonType,
           VectorKind vecKind);

VectorType(TypeClass tc, QualType vecType, unsigned nElements,
           QualType canonType, VectorKind vecKind);

3268public:
QualType getElementType() const { return ElementType; }
unsigned getNumElements() const { return VectorTypeBits.NumElements; }

bool isSugared() const { return false; }
QualType desugar() const { return QualType(this, 0); }

VectorKind getVectorKind() const {
  return VectorKind(VectorTypeBits.VecKind);
}

void Profile(llvm::FoldingSetNodeID &ID) {
  Profile(ID, getElementType(), getNumElements(),
          getTypeClass(), getVectorKind());
}

static void Profile(llvm::FoldingSetNodeID &ID, QualType ElementType,
                    unsigned NumElements, TypeClass TypeClass,
                    VectorKind VecKind) {
  ID.AddPointer(ElementType.getAsOpaquePtr());
  ID.AddInteger(NumElements);
  ID.AddInteger(TypeClass);
  ID.AddInteger(VecKind);
}

static bool classof(const Type *T) {
  return T->getTypeClass() == Vector || T->getTypeClass() == ExtVector;
}
3296};

3298/// Represents a vector type where either the type or size is dependent.
3299////
3300/// For example:
3301/// \code
3302/// template<typename T, int Size>
3303/// class vector {
3304///   typedef T __attribute__((vector_size(Size))) type;
3305/// }
3306/// \endcode
3307class DependentVectorType : public Type, public llvm::FoldingSetNode {
friend class ASTContext;

const ASTContext &Context;
QualType ElementType;
Expr *SizeExpr;
SourceLocation Loc;

DependentVectorType(const ASTContext &Context, QualType ElementType,
                         QualType CanonType, Expr *SizeExpr,
                         SourceLocation Loc, VectorType::VectorKind vecKind);

3319public:
Expr *getSizeExpr() const { return SizeExpr; }
QualType getElementType() const { return ElementType; }
SourceLocation getAttributeLoc() const { return Loc; }
VectorType::VectorKind getVectorKind() const {
  return VectorType::VectorKind(VectorTypeBits.VecKind);
}

bool isSugared() const { return false; }
QualType desugar() const { return QualType(this, 0); }

static bool classof(const Type *T) {
  return T->getTypeClass() == DependentVector;
}

void Profile(llvm::FoldingSetNodeID &ID) {
  Profile(ID, Context, getElementType(), getSizeExpr(), getVectorKind());
}

static void Profile(llvm::FoldingSetNodeID &ID, const ASTContext &Context,
                    QualType ElementType, const Expr *SizeExpr,
                    VectorType::VectorKind VecKind);
3341};

3343/// ExtVectorType - Extended vector type. This type is created using
3344/// __attribute__((ext_vector_type(n)), where "n" is the number of elements.
3345/// Unlike vector_size, ext_vector_type is only allowed on typedef's. This
3346/// class enables syntactic extensions, like Vector Components for accessing
3347/// points (as .xyzw), colors (as .rgba), and textures (modeled after OpenGL
3348/// Shading Language).
3349class ExtVectorType : public VectorType {
friend class ASTContext; // ASTContext creates these.

ExtVectorType(QualType vecType, unsigned nElements, QualType canonType)
    : VectorType(ExtVector, vecType, nElements, canonType, GenericVector) {}

3355public:
static int getPointAccessorIdx(char c) {
  switch (c) {
  default: return -1;
  case 'x': case 'r': return 0;
  case 'y': case 'g': return 1;
  case 'z': case 'b': return 2;
  case 'w': case 'a': return 3;
  }
}

static int getNumericAccessorIdx(char c) {
  switch (c) {
    default: return -1;
    case '0': return 0;
    case '1': return 1;
    case '2': return 2;
    case '3': return 3;
    case '4': return 4;
    case '5': return 5;
    case '6': return 6;
    case '7': return 7;
    case '8': return 8;
    case '9': return 9;
    case 'A':
    case 'a': return 10;
    case 'B':
    case 'b': return 11;
    case 'C':
    case 'c': return 12;
    case 'D':
    case 'd': return 13;
    case 'E':
    case 'e': return 14;
    case 'F':
    case 'f': return 15;
  }
}

static int getAccessorIdx(char c, bool isNumericAccessor) {
  if (isNumericAccessor)
    return getNumericAccessorIdx(c);
  else
    return getPointAccessorIdx(c);
}

bool isAccessorWithinNumElements(char c, bool isNumericAccessor) const {
  if (int idx = getAccessorIdx(c, isNumericAccessor)+1)
    return unsigned(idx-1) < getNumElements();
  return false;
}

bool isSugared() const { return false; }
QualType desugar() const { return QualType(this, 0); }

static bool classof(const Type *T) {
  return T->getTypeClass() == ExtVector;
}
3413};

3415/// Represents a matrix type, as defined in the Matrix Types clang extensions.
3416/// __attribute__((matrix_type(rows, columns))), where "rows" specifies
3417/// number of rows and "columns" specifies the number of columns.
3418class MatrixType : public Type, public llvm::FoldingSetNode {
3419protected:
friend class ASTContext;

/// The element type of the matrix.
QualType ElementType;

MatrixType(QualType ElementTy, QualType CanonElementTy);

MatrixType(TypeClass TypeClass, QualType ElementTy, QualType CanonElementTy,
           const Expr *RowExpr = nullptr, const Expr *ColumnExpr = nullptr);

3430public:
/// Returns type of the elements being stored in the matrix
QualType getElementType() const { return ElementType; }

/// Valid elements types are the following:
/// * an integer type (as in C2x 6.2.5p19), but excluding enumerated types
///   and _Bool
/// * the standard floating types float or double
/// * a half-precision floating point type, if one is supported on the target
static bool isValidElementType(QualType T) {
  return T->isDependentType() ||
         (T->isRealType() && !T->isBooleanType() && !T->isEnumeralType());
}

bool isSugared() const { return false; }
QualType desugar() const { return QualType(this, 0); }

static bool classof(const Type *T) {
  return T->getTypeClass() == ConstantMatrix ||
         T->getTypeClass() == DependentSizedMatrix;
}
3451};

3453/// Represents a concrete matrix type with constant number of rows and columns
3454class ConstantMatrixType final : public MatrixType {
3455protected:
friend class ASTContext;

/// Number of rows and columns.
unsigned NumRows;
unsigned NumColumns;

static constexpr unsigned MaxElementsPerDimension = (1 << 20) - 1;

ConstantMatrixType(QualType MatrixElementType, unsigned NRows,
                   unsigned NColumns, QualType CanonElementType);

ConstantMatrixType(TypeClass typeClass, QualType MatrixType, unsigned NRows,
                   unsigned NColumns, QualType CanonElementType);

3470public:
/// Returns the number of rows in the matrix.
unsigned getNumRows() const { return NumRows; }

/// Returns the number of columns in the matrix.
unsigned getNumColumns() const { return NumColumns; }

/// Returns the number of elements required to embed the matrix into a vector.
unsigned getNumElementsFlattened() const {
  return getNumRows() * getNumColumns();
}

/// Returns true if \p NumElements is a valid matrix dimension.
static constexpr bool isDimensionValid(size_t NumElements) {
  return NumElements > 0 && NumElements <= MaxElementsPerDimension;
}

/// Returns the maximum number of elements per dimension.
static constexpr unsigned getMaxElementsPerDimension() {
  return MaxElementsPerDimension;
}

void Profile(llvm::FoldingSetNodeID &ID) {
  Profile(ID, getElementType(), getNumRows(), getNumColumns(),
          getTypeClass());
}

static void Profile(llvm::FoldingSetNodeID &ID, QualType ElementType,
                    unsigned NumRows, unsigned NumColumns,
                    TypeClass TypeClass) {
  ID.AddPointer(ElementType.getAsOpaquePtr());
  ID.AddInteger(NumRows);
  ID.AddInteger(NumColumns);
  ID.AddInteger(TypeClass);
}

static bool classof(const Type *T) {
  return T->getTypeClass() == ConstantMatrix;
}
3509};

3511/// Represents a matrix type where the type and the number of rows and columns
3512/// is dependent on a template.
3513class DependentSizedMatrixType final : public MatrixType {
friend class ASTContext;

const ASTContext &Context;
Expr *RowExpr;
Expr *ColumnExpr;

SourceLocation loc;

DependentSizedMatrixType(const ASTContext &Context, QualType ElementType,
                         QualType CanonicalType, Expr *RowExpr,
                         Expr *ColumnExpr, SourceLocation loc);

3526public:
Expr *getRowExpr() const { return RowExpr; }
Expr *getColumnExpr() const { return ColumnExpr; }
SourceLocation getAttributeLoc() const { return loc; }

static bool classof(const Type *T) {
  return T->getTypeClass() == DependentSizedMatrix;
}

void Profile(llvm::FoldingSetNodeID &ID) {
  Profile(ID, Context, getElementType(), getRowExpr(), getColumnExpr());
}

static void Profile(llvm::FoldingSetNodeID &ID, const ASTContext &Context,
                    QualType ElementType, Expr *RowExpr, Expr *ColumnExpr);
3541};

3543/// FunctionType - C99 6.7.5.3 - Function Declarators.  This is the common base
3544/// class of FunctionNoProtoType and FunctionProtoType.
3545class FunctionType : public Type {
// The type returned by the function.
QualType ResultType;

3549public:
/// Interesting information about a specific parameter that can't simply
/// be reflected in parameter's type. This is only used by FunctionProtoType
/// but is in FunctionType to make this class available during the
/// specification of the bases of FunctionProtoType.
///
/// It makes sense to model language features this way when there's some
/// sort of parameter-specific override (such as an attribute) that
/// affects how the function is called.  For example, the ARC ns_consumed
/// attribute changes whether a parameter is passed at +0 (the default)
/// or +1 (ns_consumed).  This must be reflected in the function type,
/// but isn't really a change to the parameter type.
///
/// One serious disadvantage of modelling language features this way is
/// that they generally do not work with language features that attempt
/// to destructure types.  For example, template argument deduction will
/// not be able to match a parameter declared as
///   T (*)(U)
/// against an argument of type
///   void (*)(__attribute__((ns_consumed)) id)
/// because the substitution of T=void, U=id into the former will
/// not produce the latter.
class ExtParameterInfo {
  enum {
    ABIMask = 0x0F,
    IsConsumed = 0x10,
    HasPassObjSize = 0x20,
    IsNoEscape = 0x40,
  };
  unsigned char Data = 0;

public:
  ExtParameterInfo() = default;

  /// Return the ABI treatment of this parameter.
  ParameterABI getABI() const { return ParameterABI(Data & ABIMask); }
  ExtParameterInfo withABI(ParameterABI kind) const {
    ExtParameterInfo copy = *this;
    copy.Data = (copy.Data & ~ABIMask) | unsigned(kind);
    return copy;
  }

  /// Is this parameter considered "consumed" by Objective-C ARC?
  /// Consumed parameters must have retainable object type.
  bool isConsumed() const { return (Data & IsConsumed); }
  ExtParameterInfo withIsConsumed(bool consumed) const {
    ExtParameterInfo copy = *this;
    if (consumed)
      copy.Data |= IsConsumed;
    else
      copy.Data &= ~IsConsumed;
    return copy;
  }

  bool hasPassObjectSize() const { return Data & HasPassObjSize; }
  ExtParameterInfo withHasPassObjectSize() const {
    ExtParameterInfo Copy = *this;
    Copy.Data |= HasPassObjSize;
    return Copy;
  }

  bool isNoEscape() const { return Data & IsNoEscape; }
  ExtParameterInfo withIsNoEscape(bool NoEscape) const {
    ExtParameterInfo Copy = *this;
    if (NoEscape)
      Copy.Data |= IsNoEscape;
    else
      Copy.Data &= ~IsNoEscape;
    return Copy;
  }

  unsigned char getOpaqueValue() const { return Data; }
  static ExtParameterInfo getFromOpaqueValue(unsigned char data) {
    ExtParameterInfo result;
    result.Data = data;
    return result;
  }

  friend bool operator==(ExtParameterInfo lhs, ExtParameterInfo rhs) {
    return lhs.Data == rhs.Data;
  }

  friend bool operator!=(ExtParameterInfo lhs, ExtParameterInfo rhs) {
    return lhs.Data != rhs.Data;
  }
};

/// A class which abstracts out some details necessary for
/// making a call.
///
/// It is not actually used directly for storing this information in
/// a FunctionType, although FunctionType does currently use the
/// same bit-pattern.
///
// If you add a field (say Foo), other than the obvious places (both,
// constructors, compile failures), what you need to update is
// * Operator==
// * getFoo
// * withFoo
// * functionType. Add Foo, getFoo.
// * ASTContext::getFooType
// * ASTContext::mergeFunctionTypes
// * FunctionNoProtoType::Profile
// * FunctionProtoType::Profile
// * TypePrinter::PrintFunctionProto
// * AST read and write
// * Codegen
class ExtInfo {
  friend class FunctionType;

  // Feel free to rearrange or add bits, but if you go over 16, you'll need to
  // adjust the Bits field below, and if you add bits, you'll need to adjust
  // Type::FunctionTypeBitfields::ExtInfo as well.

  // |  CC  |noreturn|produces|nocallersavedregs|regparm|nocfcheck|cmsenscall|
  // |0 .. 4|   5    |    6   |       7         |8 .. 10|    11   |    12    |
  //
  // regparm is either 0 (no regparm attribute) or the regparm value+1.
  enum { CallConvMask = 0x1F };
  enum { NoReturnMask = 0x20 };
  enum { ProducesResultMask = 0x40 };
  enum { NoCallerSavedRegsMask = 0x80 };
  enum {
    RegParmMask =  0x700,
    RegParmOffset = 8
  };
  enum { NoCfCheckMask = 0x800 };
  enum { CmseNSCallMask = 0x1000 };
  uint16_t Bits = CC_C;

  ExtInfo(unsigned Bits) : Bits(static_cast<uint16_t>(Bits)) {}

public:
  // Constructor with no defaults. Use this when you know that you
  // have all the elements (when reading an AST file for example).
  ExtInfo(bool noReturn, bool hasRegParm, unsigned regParm, CallingConv cc,
          bool producesResult, bool noCallerSavedRegs, bool NoCfCheck,
          bool cmseNSCall) {
    assert((!hasRegParm || regParm < 7) && "Invalid regparm value")(static_cast<void> (0));
    Bits = ((unsigned)cc) | (noReturn ? NoReturnMask : 0) |
           (producesResult ? ProducesResultMask : 0) |
           (noCallerSavedRegs ? NoCallerSavedRegsMask : 0) |
           (hasRegParm ? ((regParm + 1) << RegParmOffset) : 0) |
           (NoCfCheck ? NoCfCheckMask : 0) |
           (cmseNSCall ? CmseNSCallMask : 0);
  }

  // Constructor with all defaults. Use when for example creating a
  // function known to use defaults.
  ExtInfo() = default;

  // Constructor with just the calling convention, which is an important part
  // of the canonical type.
  ExtInfo(CallingConv CC) : Bits(CC) {}

  bool getNoReturn() const { return Bits & NoReturnMask; }
  bool getProducesResult() const { return Bits & ProducesResultMask; }
  bool getCmseNSCall() const { return Bits & CmseNSCallMask; }
  bool getNoCallerSavedRegs() const { return Bits & NoCallerSavedRegsMask; }
  bool getNoCfCheck() const { return Bits & NoCfCheckMask; }
  bool getHasRegParm() const { return ((Bits & RegParmMask) >> RegParmOffset) != 0; }

  unsigned getRegParm() const {
    unsigned RegParm = (Bits & RegParmMask) >> RegParmOffset;
    if (RegParm > 0)
      --RegParm;
    return RegParm;
  }

  CallingConv getCC() const { return CallingConv(Bits & CallConvMask); }

  bool operator==(ExtInfo Other) const {
    return Bits == Other.Bits;
  }
  bool operator!=(ExtInfo Other) const {
    return Bits != Other.Bits;
  }

  // Note that we don't have setters. That is by design, use
  // the following with methods instead of mutating these objects.

  ExtInfo withNoReturn(bool noReturn) const {
    if (noReturn)
      return ExtInfo(Bits | NoReturnMask);
    else
      return ExtInfo(Bits & ~NoReturnMask);
  }

  ExtInfo withProducesResult(bool producesResult) const {
    if (producesResult)
      return ExtInfo(Bits | ProducesResultMask);
    else
      return ExtInfo(Bits & ~ProducesResultMask);
  }

  ExtInfo withCmseNSCall(bool cmseNSCall) const {
    if (cmseNSCall)
      return ExtInfo(Bits | CmseNSCallMask);
    else
      return ExtInfo(Bits & ~CmseNSCallMask);
  }

  ExtInfo withNoCallerSavedRegs(bool noCallerSavedRegs) const {
    if (noCallerSavedRegs)
      return ExtInfo(Bits | NoCallerSavedRegsMask);
    else
      return ExtInfo(Bits & ~NoCallerSavedRegsMask);
  }

  ExtInfo withNoCfCheck(bool noCfCheck) const {
    if (noCfCheck)
      return ExtInfo(Bits | NoCfCheckMask);
    else
      return ExtInfo(Bits & ~NoCfCheckMask);
  }

  ExtInfo withRegParm(unsigned RegParm) const {
    assert(RegParm < 7 && "Invalid regparm value")(static_cast<void> (0));
    return ExtInfo((Bits & ~RegParmMask) |
                   ((RegParm + 1) << RegParmOffset));
  }

  ExtInfo withCallingConv(CallingConv cc) const {
    return ExtInfo((Bits & ~CallConvMask) | (unsigned) cc);
  }

  void Profile(llvm::FoldingSetNodeID &ID) const {
    ID.AddInteger(Bits);
  }
};

/// A simple holder for a QualType representing a type in an
/// exception specification. Unfortunately needed by FunctionProtoType
/// because TrailingObjects cannot handle repeated types.
struct ExceptionType { QualType Type; };

/// A simple holder for various uncommon bits which do not fit in
/// FunctionTypeBitfields. Aligned to alignof(void *) to maintain the
/// alignment of subsequent objects in TrailingObjects. You must update
/// hasExtraBitfields in FunctionProtoType after adding extra data here.
struct alignas(void *) FunctionTypeExtraBitfields {
  /// The number of types in the exception specification.
  /// A whole unsigned is not needed here and according to
  /// [implimits] 8 bits would be enough here.
  unsigned NumExceptionType;
};

3796protected:
FunctionType(TypeClass tc, QualType res, QualType Canonical,
             TypeDependence Dependence, ExtInfo Info)
    : Type(tc, Canonical, Dependence), ResultType(res) {
  FunctionTypeBits.ExtInfo = Info.Bits;
}

Qualifiers getFastTypeQuals() const {
  return Qualifiers::fromFastMask(FunctionTypeBits.FastTypeQuals);
}

3807public:
QualType getReturnType() const { return ResultType; }

bool getHasRegParm() const { return getExtInfo().getHasRegParm(); }
unsigned getRegParmType() const { return getExtInfo().getRegParm(); }

/// Determine whether this function type includes the GNU noreturn
/// attribute. The C++11 [[noreturn]] attribute does not affect the function
/// type.
bool getNoReturnAttr() const { return getExtInfo().getNoReturn(); }

bool getCmseNSCallAttr() const { return getExtInfo().getCmseNSCall(); }
CallingConv getCallConv() const { return getExtInfo().getCC(); }
ExtInfo getExtInfo() const { return ExtInfo(FunctionTypeBits.ExtInfo); }

static_assert((~Qualifiers::FastMask & Qualifiers::CVRMask) == 0,
              "Const, volatile and restrict are assumed to be a subset of "
              "the fast qualifiers.");

bool isConst() const { return getFastTypeQuals().hasConst(); }
bool isVolatile() const { return getFastTypeQuals().hasVolatile(); }
bool isRestrict() const { return getFastTypeQuals().hasRestrict(); }

/// Determine the type of an expression that calls a function of
/// this type.
QualType getCallResultType(const ASTContext &Context) const {
  return getReturnType().getNonLValueExprType(Context);
}

static StringRef getNameForCallConv(CallingConv CC);

static bool classof(const Type *T) {
  return T->getTypeClass() == FunctionNoProto ||
         T->getTypeClass() == FunctionProto;
}
3842};

3844/// Represents a K&R-style 'int foo()' function, which has
3845/// no information available about its arguments.
3846class FunctionNoProtoType : public FunctionType, public llvm::FoldingSetNode {
friend class ASTContext; // ASTContext creates these.

FunctionNoProtoType(QualType Result, QualType Canonical, ExtInfo Info)
    : FunctionType(FunctionNoProto, Result, Canonical,
                   Result->getDependence() &
                       ~(TypeDependence::DependentInstantiation |
                         TypeDependence::UnexpandedPack),
                   Info) {}

3856public:
// No additional state past what FunctionType provides.

bool isSugared() const { return false; }
QualType desugar() const { return QualType(this, 0); }

void Profile(llvm::FoldingSetNodeID &ID) {
  Profile(ID, getReturnType(), getExtInfo());
}

static void Profile(llvm::FoldingSetNodeID &ID, QualType ResultType,
                    ExtInfo Info) {
  Info.Profile(ID);
  ID.AddPointer(ResultType.getAsOpaquePtr());
}

static bool classof(const Type *T) {
  return T->getTypeClass() == FunctionNoProto;
}
3875};

3877/// Represents a prototype with parameter type info, e.g.
3878/// 'int foo(int)' or 'int foo(void)'.  'void' is represented as having no
3879/// parameters, not as having a single void parameter. Such a type can have
3880/// an exception specification, but this specification is not part of the
3881/// canonical type. FunctionProtoType has several trailing objects, some of
3882/// which optional. For more information about the trailing objects see
3883/// the first comment inside FunctionProtoType.
3884class FunctionProtoType final
  : public FunctionType,
    public llvm::FoldingSetNode,
    private llvm::TrailingObjects<
        FunctionProtoType, QualType, SourceLocation,
        FunctionType::FunctionTypeExtraBitfields, FunctionType::ExceptionType,
        Expr *, FunctionDecl *, FunctionType::ExtParameterInfo, Qualifiers> {
friend class ASTContext; // ASTContext creates these.
friend TrailingObjects;

// FunctionProtoType is followed by several trailing objects, some of
// which optional. They are in order:
//
// * An array of getNumParams() QualType holding the parameter types.
//   Always present. Note that for the vast majority of FunctionProtoType,
//   these will be the only trailing objects.
//
// * Optionally if the function is variadic, the SourceLocation of the
//   ellipsis.
//
// * Optionally if some extra data is stored in FunctionTypeExtraBitfields
//   (see FunctionTypeExtraBitfields and FunctionTypeBitfields):
//   a single FunctionTypeExtraBitfields. Present if and only if
//   hasExtraBitfields() is true.
//
// * Optionally exactly one of:
//   * an array of getNumExceptions() ExceptionType,
//   * a single Expr *,
//   * a pair of FunctionDecl *,
//   * a single FunctionDecl *
//   used to store information about the various types of exception
//   specification. See getExceptionSpecSize for the details.
//
// * Optionally an array of getNumParams() ExtParameterInfo holding
//   an ExtParameterInfo for each of the parameters. Present if and
//   only if hasExtParameterInfos() is true.
//
// * Optionally a Qualifiers object to represent extra qualifiers that can't
//   be represented by FunctionTypeBitfields.FastTypeQuals. Present if and only
//   if hasExtQualifiers() is true.
//
// The optional FunctionTypeExtraBitfields has to be before the data
// related to the exception specification since it contains the number
// of exception types.
//
// We put the ExtParameterInfos last.  If all were equal, it would make
// more sense to put these before the exception specification, because
// it's much easier to skip past them compared to the elaborate switch
// required to skip the exception specification.  However, all is not
// equal; ExtParameterInfos are used to model very uncommon features,
// and it's better not to burden the more common paths.

3936public:
/// Holds information about the various types of exception specification.
/// ExceptionSpecInfo is not stored as such in FunctionProtoType but is
/// used to group together the various bits of information about the
/// exception specification.
struct ExceptionSpecInfo {
  /// The kind of exception specification this is.
  ExceptionSpecificationType Type = EST_None;

  /// Explicitly-specified list of exception types.
  ArrayRef<QualType> Exceptions;

  /// Noexcept expression, if this is a computed noexcept specification.
  Expr *NoexceptExpr = nullptr;

  /// The function whose exception specification this is, for
  /// EST_Unevaluated and EST_Uninstantiated.
  FunctionDecl *SourceDecl = nullptr;

  /// The function template whose exception specification this is instantiated
  /// from, for EST_Uninstantiated.
  FunctionDecl *SourceTemplate = nullptr;

  ExceptionSpecInfo() = default;

  ExceptionSpecInfo(ExceptionSpecificationType EST) : Type(EST) {}
};

/// Extra information about a function prototype. ExtProtoInfo is not
/// stored as such in FunctionProtoType but is used to group together
/// the various bits of extra information about a function prototype.
struct ExtProtoInfo {
  FunctionType::ExtInfo ExtInfo;
  bool Variadic : 1;
  bool HasTrailingReturn : 1;
  Qualifiers TypeQuals;
  RefQualifierKind RefQualifier = RQ_None;
  ExceptionSpecInfo ExceptionSpec;
  const ExtParameterInfo *ExtParameterInfos = nullptr;
  SourceLocation EllipsisLoc;

  ExtProtoInfo() : Variadic(false), HasTrailingReturn(false) {}

  ExtProtoInfo(CallingConv CC)
      : ExtInfo(CC), Variadic(false), HasTrailingReturn(false) {}

  ExtProtoInfo withExceptionSpec(const ExceptionSpecInfo &ESI) {
    ExtProtoInfo Result(*this);
    Result.ExceptionSpec = ESI;
    return Result;
  }
};

3989private:
unsigned numTrailingObjects(OverloadToken<QualType>) const {
  return getNumParams();
}

unsigned numTrailingObjects(OverloadToken<SourceLocation>) const {
  return isVariadic();
}

unsigned numTrailingObjects(OverloadToken<FunctionTypeExtraBitfields>) const {
  return hasExtraBitfields();
}

unsigned numTrailingObjects(OverloadToken<ExceptionType>) const {
  return getExceptionSpecSize().NumExceptionType;
}

unsigned numTrailingObjects(OverloadToken<Expr *>) const {
  return getExceptionSpecSize().NumExprPtr;
}

unsigned numTrailingObjects(OverloadToken<FunctionDecl *>) const {
  return getExceptionSpecSize().NumFunctionDeclPtr;
}

unsigned numTrailingObjects(OverloadToken<ExtParameterInfo>) const {
  return hasExtParameterInfos() ? getNumParams() : 0;
}

/// Determine whether there are any argument types that
/// contain an unexpanded parameter pack.
static bool containsAnyUnexpandedParameterPack(const QualType *ArgArray,
                                               unsigned numArgs) {
  for (unsigned Idx = 0; Idx < numArgs; ++Idx)
    if (ArgArray[Idx]->containsUnexpandedParameterPack())
      return true;

  return false;
}

FunctionProtoType(QualType result, ArrayRef<QualType> params,
                  QualType canonical, const ExtProtoInfo &epi);

/// This struct is returned by getExceptionSpecSize and is used to
/// translate an ExceptionSpecificationType to the number and kind
/// of trailing objects related to the exception specification.
struct ExceptionSpecSizeHolder {
  unsigned NumExceptionType;
  unsigned NumExprPtr;
  unsigned NumFunctionDeclPtr;
};

/// Return the number and kind of trailing objects
/// related to the exception specification.
static ExceptionSpecSizeHolder
getExceptionSpecSize(ExceptionSpecificationType EST, unsigned NumExceptions) {
  switch (EST) {
  case EST_None:
  case EST_DynamicNone:
  case EST_MSAny:
  case EST_BasicNoexcept:
  case EST_Unparsed:
  case EST_NoThrow:
    return {0, 0, 0};

  case EST_Dynamic:
    return {NumExceptions, 0, 0};

  case EST_DependentNoexcept:
  case EST_NoexceptFalse:
  case EST_NoexceptTrue:
    return {0, 1, 0};

  case EST_Uninstantiated:
    return {0, 0, 2};

  case EST_Unevaluated:
    return {0, 0, 1};
  }
  llvm_unreachable("bad exception specification kind")__builtin_unreachable();
}

/// Return the number and kind of trailing objects
/// related to the exception specification.
ExceptionSpecSizeHolder getExceptionSpecSize() const {
  return getExceptionSpecSize(getExceptionSpecType(), getNumExceptions());
}

/// Whether the trailing FunctionTypeExtraBitfields is present.
static bool hasExtraBitfields(ExceptionSpecificationType EST) {
  // If the exception spec type is EST_Dynamic then we have > 0 exception
  // types and the exact number is stored in FunctionTypeExtraBitfields.
  return EST == EST_Dynamic;
}

/// Whether the trailing FunctionTypeExtraBitfields is present.
bool hasExtraBitfields() const {
  return hasExtraBitfields(getExceptionSpecType());
}

bool hasExtQualifiers() const {
  return FunctionTypeBits.HasExtQuals;
}

4093public:
unsigned getNumParams() const { return FunctionTypeBits.NumParams; }

QualType getParamType(unsigned i) const {
  assert(i < getNumParams() && "invalid parameter index")(static_cast<void> (0));
  return param_type_begin()[i];
}

ArrayRef<QualType> getParamTypes() const {
  return llvm::makeArrayRef(param_type_begin(), param_type_end());
}

ExtProtoInfo getExtProtoInfo() const {
  ExtProtoInfo EPI;
  EPI.ExtInfo = getExtInfo();
  EPI.Variadic = isVariadic();
  EPI.EllipsisLoc = getEllipsisLoc();
  EPI.HasTrailingReturn = hasTrailingReturn();
  EPI.ExceptionSpec = getExceptionSpecInfo();
  EPI.TypeQuals = getMethodQuals();
  EPI.RefQualifier = getRefQualifier();
  EPI.ExtParameterInfos = getExtParameterInfosOrNull();
  return EPI;
}

/// Get the kind of exception specification on this function.
ExceptionSpecificationType getExceptionSpecType() const {
  return static_cast<ExceptionSpecificationType>(
      FunctionTypeBits.ExceptionSpecType);
}

/// Return whether this function has any kind of exception spec.
bool hasExceptionSpec() const { return getExceptionSpecType() != EST_None; }

/// Return whether this function has a dynamic (throw) exception spec.
bool hasDynamicExceptionSpec() const {
  return isDynamicExceptionSpec(getExceptionSpecType());
}

/// Return whether this function has a noexcept exception spec.
bool hasNoexceptExceptionSpec() const {
  return isNoexceptExceptionSpec(getExceptionSpecType());
}

/// Return whether this function has a dependent exception spec.
bool hasDependentExceptionSpec() const;

/// Return whether this function has an instantiation-dependent exception
/// spec.
bool hasInstantiationDependentExceptionSpec() const;

/// Return all the available information about this type's exception spec.
ExceptionSpecInfo getExceptionSpecInfo() const {
  ExceptionSpecInfo Result;
  Result.Type = getExceptionSpecType();
  if (Result.Type == EST_Dynamic) {
    Result.Exceptions = exceptions();
  } else if (isComputedNoexcept(Result.Type)) {
    Result.NoexceptExpr = getNoexceptExpr();
  } else if (Result.Type == EST_Uninstantiated) {
    Result.SourceDecl = getExceptionSpecDecl();
    Result.SourceTemplate = getExceptionSpecTemplate();
  } else if (Result.Type == EST_Unevaluated) {
    Result.SourceDecl = getExceptionSpecDecl();
  }
  return Result;
}

/// Return the number of types in the exception specification.
unsigned getNumExceptions() const {
  return getExceptionSpecType() == EST_Dynamic
             ? getTrailingObjects<FunctionTypeExtraBitfields>()
                   ->NumExceptionType
             : 0;
}

/// Return the ith exception type, where 0 <= i < getNumExceptions().
QualType getExceptionType(unsigned i) const {
  assert(i < getNumExceptions() && "Invalid exception number!")(static_cast<void> (0));
  return exception_begin()[i];
}

/// Return the expression inside noexcept(expression), or a null pointer
/// if there is none (because the exception spec is not of this form).
Expr *getNoexceptExpr() const {
  if (!isComputedNoexcept(getExceptionSpecType()))
    return nullptr;
  return *getTrailingObjects<Expr *>();
}

/// If this function type has an exception specification which hasn't
/// been determined yet (either because it has not been evaluated or because
/// it has not been instantiated), this is the function whose exception
/// specification is represented by this type.
FunctionDecl *getExceptionSpecDecl() const {
  if (getExceptionSpecType() != EST_Uninstantiated &&
      getExceptionSpecType() != EST_Unevaluated)
    return nullptr;
  return getTrailingObjects<FunctionDecl *>()[0];
}

/// If this function type has an uninstantiated exception
/// specification, this is the function whose exception specification
/// should be instantiated to find the exception specification for
/// this type.
FunctionDecl *getExceptionSpecTemplate() const {
  if (getExceptionSpecType() != EST_Uninstantiated)
    return nullptr;
  return getTrailingObjects<FunctionDecl *>()[1];
}

/// Determine whether this function type has a non-throwing exception
/// specification.
CanThrowResult canThrow() const;

/// Determine whether this function type has a non-throwing exception
/// specification. If this depends on template arguments, returns
/// \c ResultIfDependent.
bool isNothrow(bool ResultIfDependent = false) const {
  return ResultIfDependent ? canThrow() != CT_Can : canThrow() == CT_Cannot;
}

/// Whether this function prototype is variadic.
bool isVariadic() const { return FunctionTypeBits.Variadic; }

SourceLocation getEllipsisLoc() const {
  return isVariadic() ? *getTrailingObjects<SourceLocation>()
                      : SourceLocation();
}

/// Determines whether this function prototype contains a
/// parameter pack at the end.
///
/// A function template whose last parameter is a parameter pack can be
/// called with an arbitrary number of arguments, much like a variadic
/// function.
bool isTemplateVariadic() const;

/// Whether this function prototype has a trailing return type.
bool hasTrailingReturn() const { return FunctionTypeBits.HasTrailingReturn; }

Qualifiers getMethodQuals() const {
  if (hasExtQualifiers())
    return *getTrailingObjects<Qualifiers>();
  else
    return getFastTypeQuals();
}

/// Retrieve the ref-qualifier associated with this function type.
RefQualifierKind getRefQualifier() const {
  return static_cast<RefQualifierKind>(FunctionTypeBits.RefQualifier);
}

using param_type_iterator = const QualType *;
using param_type_range = llvm::iterator_range<param_type_iterator>;

param_type_range param_types() const {
  return param_type_range(param_type_begin(), param_type_end());
}

param_type_iterator param_type_begin() const {
  return getTrailingObjects<QualType>();
}

param_type_iterator param_type_end() const {
  return param_type_begin() + getNumParams();
}

using exception_iterator = const QualType *;

ArrayRef<QualType> exceptions() const {
  return llvm::makeArrayRef(exception_begin(), exception_end());
}

exception_iterator exception_begin() const {
  return reinterpret_cast<exception_iterator>(
      getTrailingObjects<ExceptionType>());
}

exception_iterator exception_end() const {
  return exception_begin() + getNumExceptions();
}

/// Is there any interesting extra information for any of the parameters
/// of this function type?
bool hasExtParameterInfos() const {
  return FunctionTypeBits.HasExtParameterInfos;
}

ArrayRef<ExtParameterInfo> getExtParameterInfos() const {
  assert(hasExtParameterInfos())(static_cast<void> (0));
  return ArrayRef<ExtParameterInfo>(getTrailingObjects<ExtParameterInfo>(),
                                    getNumParams());
}

/// Return a pointer to the beginning of the array of extra parameter
/// information, if present, or else null if none of the parameters
/// carry it.  This is equivalent to getExtProtoInfo().ExtParameterInfos.
const ExtParameterInfo *getExtParameterInfosOrNull() const {
  if (!hasExtParameterInfos())
    return nullptr;
  return getTrailingObjects<ExtParameterInfo>();
}

ExtParameterInfo getExtParameterInfo(unsigned I) const {
  assert(I < getNumParams() && "parameter index out of range")(static_cast<void> (0));
  if (hasExtParameterInfos())
    return getTrailingObjects<ExtParameterInfo>()[I];
  return ExtParameterInfo();
}

ParameterABI getParameterABI(unsigned I) const {
  assert(I < getNumParams() && "parameter index out of range")(static_cast<void> (0));
  if (hasExtParameterInfos())
    return getTrailingObjects<ExtParameterInfo>()[I].getABI();
  return ParameterABI::Ordinary;
}

bool isParamConsumed(unsigned I) const {
  assert(I < getNumParams() && "parameter index out of range")(static_cast<void> (0));
  if (hasExtParameterInfos())
    return getTrailingObjects<ExtParameterInfo>()[I].isConsumed();
  return false;
}

bool isSugared() const { return false; }
QualType desugar() const { return QualType(this, 0); }

void printExceptionSpecification(raw_ostream &OS,
                                 const PrintingPolicy &Policy) const;

static bool classof(const Type *T) {
  return T->getTypeClass() == FunctionProto;
}

void Profile(llvm::FoldingSetNodeID &ID, const ASTContext &Ctx);
static void Profile(llvm::FoldingSetNodeID &ID, QualType Result,
                    param_type_iterator ArgTys, unsigned NumArgs,
                    const ExtProtoInfo &EPI, const ASTContext &Context,
                    bool Canonical);
4333};

4335/// Represents the dependent type named by a dependently-scoped
4336/// typename using declaration, e.g.
4337///   using typename Base<T>::foo;
4338///
4339/// Template instantiation turns these into the underlying type.
4340class UnresolvedUsingType : public Type {
friend class ASTContext; // ASTContext creates these.

UnresolvedUsingTypenameDecl *Decl;

UnresolvedUsingType(const UnresolvedUsingTypenameDecl *D)
    : Type(UnresolvedUsing, QualType(),
           TypeDependence::DependentInstantiation),
      Decl(const_cast<UnresolvedUsingTypenameDecl *>(D)) {}

4350public:
UnresolvedUsingTypenameDecl *getDecl() const { return Decl; }

bool isSugared() const { return false; }
QualType desugar() const { return QualType(this, 0); }

static bool classof(const Type *T) {
  return T->getTypeClass() == UnresolvedUsing;
}

void Profile(llvm::FoldingSetNodeID &ID) {
  return Profile(ID, Decl);
}

static void Profile(llvm::FoldingSetNodeID &ID,
                    UnresolvedUsingTypenameDecl *D) {
  ID.AddPointer(D);
}
4368};

4370class TypedefType : public Type {
TypedefNameDecl *Decl;

4373private:
friend class ASTContext; // ASTContext creates these.

TypedefType(TypeClass tc, const TypedefNameDecl *D, QualType underlying,
            QualType can);

4379public:
TypedefNameDecl *getDecl() const { return Decl; }

bool isSugared() const { return true; }
QualType desugar() const;

static bool classof(const Type *T) { return T->getTypeClass() == Typedef; }
4386};

4388/// Sugar type that represents a type that was qualified by a qualifier written
4389/// as a macro invocation.
4390class MacroQualifiedType : public Type {
friend class ASTContext; // ASTContext creates these.

QualType UnderlyingTy;
const IdentifierInfo *MacroII;

MacroQualifiedType(QualType UnderlyingTy, QualType CanonTy,
                   const IdentifierInfo *MacroII)
    : Type(MacroQualified, CanonTy, UnderlyingTy->getDependence()),
      UnderlyingTy(UnderlyingTy), MacroII(MacroII) {
  assert(isa<AttributedType>(UnderlyingTy) &&(static_cast<void> (0))
         "Expected a macro qualified type to only wrap attributed types.")(static_cast<void> (0));
}

4404public:
const IdentifierInfo *getMacroIdentifier() const { return MacroII; }
QualType getUnderlyingType() const { return UnderlyingTy; }

/// Return this attributed type's modified type with no qualifiers attached to
/// it.
QualType getModifiedType() const;

bool isSugared() const { return true; }
QualType desugar() const;

static bool classof(const Type *T) {
  return T->getTypeClass() == MacroQualified;
}
4418};

4420/// Represents a `typeof` (or __typeof__) expression (a GCC extension).
4421class TypeOfExprType : public Type {
Expr *TOExpr;

4424protected:
friend class ASTContext; // ASTContext creates these.

TypeOfExprType(Expr *E, QualType can = QualType());

4429public:
Expr *getUnderlyingExpr() const { return TOExpr; }

/// Remove a single level of sugar.
QualType desugar() const;

/// Returns whether this type directly provides sugar.
bool isSugared() const;

static bool classof(const Type *T) { return T->getTypeClass() == TypeOfExpr; }
4439};

4441/// Internal representation of canonical, dependent
4442/// `typeof(expr)` types.
4443///
4444/// This class is used internally by the ASTContext to manage
4445/// canonical, dependent types, only. Clients will only see instances
4446/// of this class via TypeOfExprType nodes.
4447class DependentTypeOfExprType
: public TypeOfExprType, public llvm::FoldingSetNode {
const ASTContext &Context;

4451public:
DependentTypeOfExprType(const ASTContext &Context, Expr *E)
    : TypeOfExprType(E), Context(Context) {}

void Profile(llvm::FoldingSetNodeID &ID) {
  Profile(ID, Context, getUnderlyingExpr());
}

static void Profile(llvm::FoldingSetNodeID &ID, const ASTContext &Context,
                    Expr *E);
4461};

4463/// Represents `typeof(type)`, a GCC extension.
4464class TypeOfType : public Type {
friend class ASTContext; // ASTContext creates these.

QualType TOType;

TypeOfType(QualType T, QualType can)
    : Type(TypeOf, can, T->getDependence()), TOType(T) {
  assert(!isa<TypedefType>(can) && "Invalid canonical type")(static_cast<void> (0));
}

4474public:
QualType getUnderlyingType() const { return TOType; }

/// Remove a single level of sugar.
QualType desugar() const { return getUnderlyingType(); }

/// Returns whether this type directly provides sugar.
bool isSugared() const { return true; }

static bool classof(const Type *T) { return T->getTypeClass() == TypeOf; }
4484};

4486/// Represents the type `decltype(expr)` (C++11).
4487class DecltypeType : public Type {
Expr *E;
QualType UnderlyingType;

4491protected:
friend class ASTContext; // ASTContext creates these.

DecltypeType(Expr *E, QualType underlyingType, QualType can = QualType());

4496public:
Expr *getUnderlyingExpr() const { return E; }
QualType getUnderlyingType() const { return UnderlyingType; }

/// Remove a single level of sugar.
QualType desugar() const;

/// Returns whether this type directly provides sugar.
bool isSugared() const;

static bool classof(const Type *T) { return T->getTypeClass() == Decltype; }
4507};

4509/// Internal representation of canonical, dependent
4510/// decltype(expr) types.
4511///
4512/// This class is used internally by the ASTContext to manage
4513/// canonical, dependent types, only. Clients will only see instances
4514/// of this class via DecltypeType nodes.
4515class DependentDecltypeType : public DecltypeType, public llvm::FoldingSetNode {
const ASTContext &Context;

4518public:
DependentDecltypeType(const ASTContext &Context, Expr *E);

void Profile(llvm::FoldingSetNodeID &ID) {
  Profile(ID, Context, getUnderlyingExpr());
}

static void Profile(llvm::FoldingSetNodeID &ID, const ASTContext &Context,
                    Expr *E);
4527};

4529/// A unary type transform, which is a type constructed from another.
4530class UnaryTransformType : public Type {
4531public:
enum UTTKind {
  EnumUnderlyingType
};

4536private:
/// The untransformed type.
QualType BaseType;

/// The transformed type if not dependent, otherwise the same as BaseType.
QualType UnderlyingType;

UTTKind UKind;

4545protected:
friend class ASTContext;

UnaryTransformType(QualType BaseTy, QualType UnderlyingTy, UTTKind UKind,
                   QualType CanonicalTy);

4551public:
bool isSugared() const { return !isDependentType(); }
QualType desugar() const { return UnderlyingType; }

QualType getUnderlyingType() const { return UnderlyingType; }
QualType getBaseType() const { return BaseType; }

UTTKind getUTTKind() const { return UKind; }

static bool classof(const Type *T) {
  return T->getTypeClass() == UnaryTransform;
}
4563};

4565/// Internal representation of canonical, dependent
4566/// __underlying_type(type) types.
4567///
4568/// This class is used internally by the ASTContext to manage
4569/// canonical, dependent types, only. Clients will only see instances
4570/// of this class via UnaryTransformType nodes.
4571class DependentUnaryTransformType : public UnaryTransformType,
                                  public llvm::FoldingSetNode {
4573public:
DependentUnaryTransformType(const ASTContext &C, QualType BaseType,
                            UTTKind UKind);

void Profile(llvm::FoldingSetNodeID &ID) {
  Profile(ID, getBaseType(), getUTTKind());
}

static void Profile(llvm::FoldingSetNodeID &ID, QualType BaseType,
                    UTTKind UKind) {
  ID.AddPointer(BaseType.getAsOpaquePtr());
  ID.AddInteger((unsigned)UKind);
}
4586};

4588class TagType : public Type {
friend class ASTReader;
template <class T> friend class serialization::AbstractTypeReader;

/// Stores the TagDecl associated with this type. The decl may point to any
/// TagDecl that declares the entity.
TagDecl *decl;

4596protected:
TagType(TypeClass TC, const TagDecl *D, QualType can);

4599public:
TagDecl *getDecl() const;

/// Determines whether this type is in the process of being defined.
bool isBeingDefined() const;

static bool classof(const Type *T) {
  return T->getTypeClass() == Enum || T->getTypeClass() == Record;
}
4608};

4610/// A helper class that allows the use of isa/cast/dyncast
4611/// to detect TagType objects of structs/unions/classes.
4612class RecordType : public TagType {
4613protected:
friend class ASTContext; // ASTContext creates these.

explicit RecordType(const RecordDecl *D)
    : TagType(Record, reinterpret_cast<const TagDecl*>(D), QualType()) {}
explicit RecordType(TypeClass TC, RecordDecl *D)
    : TagType(TC, reinterpret_cast<const TagDecl*>(D), QualType()) {}

4621public:
RecordDecl *getDecl() const {
  return reinterpret_cast<RecordDecl*>(TagType::getDecl());
}

/// Recursively check all fields in the record for const-ness. If any field
/// is declared const, return true. Otherwise, return false.
bool hasConstFields() const;

bool isSugared() const { return false; }
QualType desugar() const { return QualType(this, 0); }

static bool classof(const Type *T) { return T->getTypeClass() == Record; }
4634};

4636/// A helper class that allows the use of isa/cast/dyncast
4637/// to detect TagType objects of enums.
4638class EnumType : public TagType {
friend class ASTContext; // ASTContext creates these.

explicit EnumType(const EnumDecl *D)
    : TagType(Enum, reinterpret_cast<const TagDecl*>(D), QualType()) {}

4644public:
EnumDecl *getDecl() const {
  return reinterpret_cast<EnumDecl*>(TagType::getDecl());
}

bool isSugared() const { return false; }
QualType desugar() const { return QualType(this, 0); }

static bool classof(const Type *T) { return T->getTypeClass() == Enum; }
4653};

4655/// An attributed type is a type to which a type attribute has been applied.
4656///
4657/// The "modified type" is the fully-sugared type to which the attributed
4658/// type was applied; generally it is not canonically equivalent to the
4659/// attributed type. The "equivalent type" is the minimally-desugared type
4660/// which the type is canonically equivalent to.
4661///
4662/// For example, in the following attributed type:
4663///     int32_t __attribute__((vector_size(16)))
4664///   - the modified type is the TypedefType for int32_t
4665///   - the equivalent type is VectorType(16, int32_t)
4666///   - the canonical type is VectorType(16, int)
4667class AttributedType : public Type, public llvm::FoldingSetNode {
4668public:
using Kind = attr::Kind;

4671private:
friend class ASTContext; // ASTContext creates these

QualType ModifiedType;
QualType EquivalentType;

AttributedType(QualType canon, attr::Kind attrKind, QualType modified,
               QualType equivalent)
    : Type(Attributed, canon, equivalent->getDependence()),
      ModifiedType(modified), EquivalentType(equivalent) {
  AttributedTypeBits.AttrKind = attrKind;
}

4684public:
Kind getAttrKind() const {
  return static_cast<Kind>(AttributedTypeBits.AttrKind);
}

QualType getModifiedType() const { return ModifiedType; }
QualType getEquivalentType() const { return EquivalentType; }

bool isSugared() const { return true; }
QualType desugar() const { return getEquivalentType(); }

/// Does this attribute behave like a type qualifier?
///
/// A type qualifier adjusts a type to provide specialized rules for
/// a specific object, like the standard const and volatile qualifiers.
/// This includes attributes controlling things like nullability,
/// address spaces, and ARC ownership.  The value of the object is still
/// largely described by the modified type.
///
/// In contrast, many type attributes "rewrite" their modified type to
/// produce a fundamentally different type, not necessarily related in any
/// formalizable way to the original type.  For example, calling convention
/// and vector attributes are not simple type qualifiers.
///
/// Type qualifiers are often, but not always, reflected in the canonical
/// type.
bool isQualifier() const;

bool isMSTypeSpec() const;

bool isCallingConv() const;

llvm::Optional<NullabilityKind> getImmediateNullability() const;

/// Retrieve the attribute kind corresponding to the given
/// nullability kind.
static Kind getNullabilityAttrKind(NullabilityKind kind) {
  switch (kind) {
  case NullabilityKind::NonNull:
    return attr::TypeNonNull;

  case NullabilityKind::Nullable:
    return attr::TypeNullable;

  case NullabilityKind::NullableResult:
    return attr::TypeNullableResult;

  case NullabilityKind::Unspecified:
    return attr::TypeNullUnspecified;
  }
  llvm_unreachable("Unknown nullability kind.")__builtin_unreachable();
}

/// Strip off the top-level nullability annotation on the given
/// type, if it's there.
///
/// \param T The type to strip. If the type is exactly an
/// AttributedType specifying nullability (without looking through
/// type sugar), the nullability is returned and this type changed
/// to the underlying modified type.
///
/// \returns the top-level nullability, if present.
static Optional<NullabilityKind> stripOuterNullability(QualType &T);

void Profile(llvm::FoldingSetNodeID &ID) {
  Profile(ID, getAttrKind(), ModifiedType, EquivalentType);
}

static void Profile(llvm::FoldingSetNodeID &ID, Kind attrKind,
                    QualType modified, QualType equivalent) {
  ID.AddInteger(attrKind);
  ID.AddPointer(modified.getAsOpaquePtr());
  ID.AddPointer(equivalent.getAsOpaquePtr());
}

static bool classof(const Type *T) {
  return T->getTypeClass() == Attributed;
}
4762};

4764class TemplateTypeParmType : public Type, public llvm::FoldingSetNode {
friend class ASTContext; // ASTContext creates these

// Helper data collector for canonical types.
struct CanonicalTTPTInfo {
  unsigned Depth : 15;
  unsigned ParameterPack : 1;
  unsigned Index : 16;
};

union {
  // Info for the canonical type.
  CanonicalTTPTInfo CanTTPTInfo;

  // Info for the non-canonical type.
  TemplateTypeParmDecl *TTPDecl;
};

/// Build a non-canonical type.
TemplateTypeParmType(TemplateTypeParmDecl *TTPDecl, QualType Canon)
    : Type(TemplateTypeParm, Canon,
           TypeDependence::DependentInstantiation |
               (Canon->getDependence() & TypeDependence::UnexpandedPack)),
      TTPDecl(TTPDecl) {}

/// Build the canonical type.
TemplateTypeParmType(unsigned D, unsigned I, bool PP)
    : Type(TemplateTypeParm, QualType(this, 0),
           TypeDependence::DependentInstantiation |
               (PP ? TypeDependence::UnexpandedPack : TypeDependence::None)) {
  CanTTPTInfo.Depth = D;
  CanTTPTInfo.Index = I;
  CanTTPTInfo.ParameterPack = PP;
}

const CanonicalTTPTInfo& getCanTTPTInfo() const {
  QualType Can = getCanonicalTypeInternal();
  return Can->castAs<TemplateTypeParmType>()->CanTTPTInfo;
}

4804public:
unsigned getDepth() const { return getCanTTPTInfo().Depth; }
unsigned getIndex() const { return getCanTTPTInfo().Index; }
bool isParameterPack() const { return getCanTTPTInfo().ParameterPack; }

TemplateTypeParmDecl *getDecl() const {
  return isCanonicalUnqualified() ? nullptr : TTPDecl;
}

IdentifierInfo *getIdentifier() const;

bool isSugared() const { return false; }
QualType desugar() const { return QualType(this, 0); }

void Profile(llvm::FoldingSetNodeID &ID) {
  Profile(ID, getDepth(), getIndex(), isParameterPack(), getDecl());
}

static void Profile(llvm::FoldingSetNodeID &ID, unsigned Depth,
                    unsigned Index, bool ParameterPack,
                    TemplateTypeParmDecl *TTPDecl) {
  ID.AddInteger(Depth);
  ID.AddInteger(Index);
  ID.AddBoolean(ParameterPack);
  ID.AddPointer(TTPDecl);
}

static bool classof(const Type *T) {
  return T->getTypeClass() == TemplateTypeParm;
}
4834};

4836/// Represents the result of substituting a type for a template
4837/// type parameter.
4838///
4839/// Within an instantiated template, all template type parameters have
4840/// been replaced with these.  They are used solely to record that a
4841/// type was originally written as a template type parameter;
4842/// therefore they are never canonical.
4843class SubstTemplateTypeParmType : public Type, public llvm::FoldingSetNode {
friend class ASTContext;

// The original type parameter.
const TemplateTypeParmType *Replaced;

SubstTemplateTypeParmType(const TemplateTypeParmType *Param, QualType Canon)
    : Type(SubstTemplateTypeParm, Canon, Canon->getDependence()),
      Replaced(Param) {}

4853public:
/// Gets the template parameter that was substituted for.
const TemplateTypeParmType *getReplacedParameter() const {
  return Replaced;
}

/// Gets the type that was substituted for the template
/// parameter.
QualType getReplacementType() const {
  return getCanonicalTypeInternal();
}

bool isSugared() const { return true; }
QualType desugar() const { return getReplacementType(); }

void Profile(llvm::FoldingSetNodeID &ID) {
  Profile(ID, getReplacedParameter(), getReplacementType());
}

static void Profile(llvm::FoldingSetNodeID &ID,
                    const TemplateTypeParmType *Replaced,
                    QualType Replacement) {
  ID.AddPointer(Replaced);
  ID.AddPointer(Replacement.getAsOpaquePtr());
}

static bool classof(const Type *T) {
  return T->getTypeClass() == SubstTemplateTypeParm;
}
4882};

4884/// Represents the result of substituting a set of types for a template
4885/// type parameter pack.
4886///
4887/// When a pack expansion in the source code contains multiple parameter packs
4888/// and those parameter packs correspond to different levels of template
4889/// parameter lists, this type node is used to represent a template type
4890/// parameter pack from an outer level, which has already had its argument pack
4891/// substituted but that still lives within a pack expansion that itself
4892/// could not be instantiated. When actually performing a substitution into
4893/// that pack expansion (e.g., when all template parameters have corresponding
4894/// arguments), this type will be replaced with the \c SubstTemplateTypeParmType
4895/// at the current pack substitution index.
4896class SubstTemplateTypeParmPackType : public Type, public llvm::FoldingSetNode {
friend class ASTContext;

/// The original type parameter.
const TemplateTypeParmType *Replaced;

/// A pointer to the set of template arguments that this
/// parameter pack is instantiated with.
const TemplateArgument *Arguments;

SubstTemplateTypeParmPackType(const TemplateTypeParmType *Param,
                              QualType Canon,
                              const TemplateArgument &ArgPack);

4910public:
IdentifierInfo *getIdentifier() const { return Replaced->getIdentifier(); }

/// Gets the template parameter that was substituted for.
const TemplateTypeParmType *getReplacedParameter() const {
  return Replaced;
}

unsigned getNumArgs() const {
  return SubstTemplateTypeParmPackTypeBits.NumArgs;
}

bool isSugared() const { return false; }
QualType desugar() const { return QualType(this, 0); }

TemplateArgument getArgumentPack() const;

void Profile(llvm::FoldingSetNodeID &ID);
static void Profile(llvm::FoldingSetNodeID &ID,
                    const TemplateTypeParmType *Replaced,
                    const TemplateArgument &ArgPack);

static bool classof(const Type *T) {
  return T->getTypeClass() == SubstTemplateTypeParmPack;
}
4935};

4937/// Common base class for placeholders for types that get replaced by
4938/// placeholder type deduction: C++11 auto, C++14 decltype(auto), C++17 deduced
4939/// class template types, and constrained type names.
4940///
4941/// These types are usually a placeholder for a deduced type. However, before
4942/// the initializer is attached, or (usually) if the initializer is
4943/// type-dependent, there is no deduced type and the type is canonical. In
4944/// the latter case, it is also a dependent type.
4945class DeducedType : public Type {
4946protected:
DeducedType(TypeClass TC, QualType DeducedAsType,
            TypeDependence ExtraDependence)
    : Type(TC,
           // FIXME: Retain the sugared deduced type?
           DeducedAsType.isNull() ? QualType(this, 0)
                                  : DeducedAsType.getCanonicalType(),
           ExtraDependence | (DeducedAsType.isNull()
                                  ? TypeDependence::None
                                  : DeducedAsType->getDependence() &
                                        ~TypeDependence::VariablyModified)) {}

4958public:
bool isSugared() const { return !isCanonicalUnqualified(); }
QualType desugar() const { return getCanonicalTypeInternal(); }

/// Get the type deduced for this placeholder type, or null if it's
/// either not been deduced or was deduced to a dependent type.
QualType getDeducedType() const {
  return !isCanonicalUnqualified() ? getCanonicalTypeInternal() : QualType();
}
bool isDeduced() const {
  return !isCanonicalUnqualified() || isDependentType();
}

static bool classof(const Type *T) {
  return T->getTypeClass() == Auto ||
         T->getTypeClass() == DeducedTemplateSpecialization;
}
4975};

4977/// Represents a C++11 auto or C++14 decltype(auto) type, possibly constrained
4978/// by a type-constraint.
4979class alignas(8) AutoType : public DeducedType, public llvm::FoldingSetNode {
friend class ASTContext; // ASTContext creates these

ConceptDecl *TypeConstraintConcept;

AutoType(QualType DeducedAsType, AutoTypeKeyword Keyword,
         TypeDependence ExtraDependence, ConceptDecl *CD,
         ArrayRef<TemplateArgument> TypeConstraintArgs);

const TemplateArgument *getArgBuffer() const {
  return reinterpret_cast<const TemplateArgument*>(this+1);
}

TemplateArgument *getArgBuffer() {
  return reinterpret_cast<TemplateArgument*>(this+1);
}

4996public:
/// Retrieve the template arguments.
const TemplateArgument *getArgs() const {
  return getArgBuffer();
}

/// Retrieve the number of template arguments.
unsigned getNumArgs() const {
  return AutoTypeBits.NumArgs;
}

const TemplateArgument &getArg(unsigned Idx) const; // in TemplateBase.h

ArrayRef<TemplateArgument> getTypeConstraintArguments() const {
  return {getArgs(), getNumArgs()};
}

ConceptDecl *getTypeConstraintConcept() const {
  return TypeConstraintConcept;
}

bool isConstrained() const {
  return TypeConstraintConcept != nullptr;
}

bool isDecltypeAuto() const {
  return getKeyword() == AutoTypeKeyword::DecltypeAuto;
}

AutoTypeKeyword getKeyword() const {
  return (AutoTypeKeyword)AutoTypeBits.Keyword;
}

void Profile(llvm::FoldingSetNodeID &ID, const ASTContext &Context) {
  Profile(ID, Context, getDeducedType(), getKeyword(), isDependentType(),
          getTypeConstraintConcept(), getTypeConstraintArguments());
}

static void Profile(llvm::FoldingSetNodeID &ID, const ASTContext &Context,
                    QualType Deduced, AutoTypeKeyword Keyword,
                    bool IsDependent, ConceptDecl *CD,
                    ArrayRef<TemplateArgument> Arguments);

static bool classof(const Type *T) {
  return T->getTypeClass() == Auto;
}
5042};

5044/// Represents a C++17 deduced template specialization type.
5045class DeducedTemplateSpecializationType : public DeducedType,
                                        public llvm::FoldingSetNode {
friend class ASTContext; // ASTContext creates these

/// The name of the template whose arguments will be deduced.
TemplateName Template;

DeducedTemplateSpecializationType(TemplateName Template,
                                  QualType DeducedAsType,
                                  bool IsDeducedAsDependent)
    : DeducedType(DeducedTemplateSpecialization, DeducedAsType,
                  toTypeDependence(Template.getDependence()) |
                      (IsDeducedAsDependent
                           ? TypeDependence::DependentInstantiation
                           : TypeDependence::None)),
      Template(Template) {}

5062public:
/// Retrieve the name of the template that we are deducing.
TemplateName getTemplateName() const { return Template;}

void Profile(llvm::FoldingSetNodeID &ID) {
  Profile(ID, getTemplateName(), getDeducedType(), isDependentType());
}

static void Profile(llvm::FoldingSetNodeID &ID, TemplateName Template,
                    QualType Deduced, bool IsDependent) {
  Template.Profile(ID);
  ID.AddPointer(Deduced.getAsOpaquePtr());
  ID.AddBoolean(IsDependent);
}

static bool classof(const Type *T) {
  return T->getTypeClass() == DeducedTemplateSpecialization;
}
5080};

5082/// Represents a type template specialization; the template
5083/// must be a class template, a type alias template, or a template
5084/// template parameter.  A template which cannot be resolved to one of
5085/// these, e.g. because it is written with a dependent scope
5086/// specifier, is instead represented as a
5087/// @c DependentTemplateSpecializationType.
5088///
5089/// A non-dependent template specialization type is always "sugar",
5090/// typically for a \c RecordType.  For example, a class template
5091/// specialization type of \c vector<int> will refer to a tag type for
5092/// the instantiation \c std::vector<int, std::allocator<int>>
5093///
5094/// Template specializations are dependent if either the template or
5095/// any of the template arguments are dependent, in which case the
5096/// type may also be canonical.
5097///
5098/// Instances of this type are allocated with a trailing array of
5099/// TemplateArguments, followed by a QualType representing the
5100/// non-canonical aliased type when the template is a type alias
5101/// template.
5102class alignas(8) TemplateSpecializationType
  : public Type,
    public llvm::FoldingSetNode {
friend class ASTContext; // ASTContext creates these

/// The name of the template being specialized.  This is
/// either a TemplateName::Template (in which case it is a
/// ClassTemplateDecl*, a TemplateTemplateParmDecl*, or a
/// TypeAliasTemplateDecl*), a
/// TemplateName::SubstTemplateTemplateParmPack, or a
/// TemplateName::SubstTemplateTemplateParm (in which case the
/// replacement must, recursively, be one of these).
TemplateName Template;

TemplateSpecializationType(TemplateName T,
                           ArrayRef<TemplateArgument> Args,
                           QualType Canon,
                           QualType Aliased);

5121public:
/// Determine whether any of the given template arguments are dependent.
///
/// The converted arguments should be supplied when known; whether an
/// argument is dependent can depend on the conversions performed on it
/// (for example, a 'const int' passed as a template argument might be
/// dependent if the parameter is a reference but non-dependent if the
/// parameter is an int).
///
/// Note that the \p Args parameter is unused: this is intentional, to remind
/// the caller that they need to pass in the converted arguments, not the
/// specified arguments.
static bool
anyDependentTemplateArguments(ArrayRef<TemplateArgumentLoc> Args,
                              ArrayRef<TemplateArgument> Converted);
static bool
anyDependentTemplateArguments(const TemplateArgumentListInfo &,
                              ArrayRef<TemplateArgument> Converted);
static bool anyInstantiationDependentTemplateArguments(
    ArrayRef<TemplateArgumentLoc> Args);

/// True if this template specialization type matches a current
/// instantiation in the context in which it is found.
bool isCurrentInstantiation() const {
  return isa<InjectedClassNameType>(getCanonicalTypeInternal());
}

/// Determine if this template specialization type is for a type alias
/// template that has been substituted.
///
/// Nearly every template specialization type whose template is an alias
/// template will be substituted. However, this is not the case when
/// the specialization contains a pack expansion but the template alias
/// does not have a corresponding parameter pack, e.g.,
///
/// \code
/// template<typename T, typename U, typename V> struct S;
/// template<typename T, typename U> using A = S<T, int, U>;
/// template<typename... Ts> struct X {
///   typedef A<Ts...> type; // not a type alias
/// };
/// \endcode
bool isTypeAlias() const { return TemplateSpecializationTypeBits.TypeAlias; }

/// Get the aliased type, if this is a specialization of a type alias
/// template.
QualType getAliasedType() const {
  assert(isTypeAlias() && "not a type alias template specialization")(static_cast<void> (0));
  return *reinterpret_cast<const QualType*>(end());
}

using iterator = const TemplateArgument *;

iterator begin() const { return getArgs(); }
iterator end() const; // defined inline in TemplateBase.h

/// Retrieve the name of the template that we are specializing.
TemplateName getTemplateName() const { return Template; }

/// Retrieve the template arguments.
const TemplateArgument *getArgs() const {
  return reinterpret_cast<const TemplateArgument *>(this + 1);
}

/// Retrieve the number of template arguments.
unsigned getNumArgs() const {
  return TemplateSpecializationTypeBits.NumArgs;
}

/// Retrieve a specific template argument as a type.
/// \pre \c isArgType(Arg)
const TemplateArgument &getArg(unsigned Idx) const; // in TemplateBase.h

ArrayRef<TemplateArgument> template_arguments() const {
  return {getArgs(), getNumArgs()};
}

bool isSugared() const {
  return !isDependentType() || isCurrentInstantiation() || isTypeAlias();
}

QualType desugar() const {
  return isTypeAlias() ? getAliasedType() : getCanonicalTypeInternal();
}

void Profile(llvm::FoldingSetNodeID &ID, const ASTContext &Ctx) {
  Profile(ID, Template, template_arguments(), Ctx);
  if (isTypeAlias())
    getAliasedType().Profile(ID);
}

static void Profile(llvm::FoldingSetNodeID &ID, TemplateName T,
                    ArrayRef<TemplateArgument> Args,
                    const ASTContext &Context);

static bool classof(const Type *T) {
  return T->getTypeClass() == TemplateSpecialization;
}
5219};

5221/// Print a template argument list, including the '<' and '>'
5222/// enclosing the template arguments.
5223void printTemplateArgumentList(raw_ostream &OS,
                             ArrayRef<TemplateArgument> Args,
                             const PrintingPolicy &Policy,
                             const TemplateParameterList *TPL = nullptr);

5228void printTemplateArgumentList(raw_ostream &OS,
                             ArrayRef<TemplateArgumentLoc> Args,
                             const PrintingPolicy &Policy,
                             const TemplateParameterList *TPL = nullptr);

5233void printTemplateArgumentList(raw_ostream &OS,
                             const TemplateArgumentListInfo &Args,
                             const PrintingPolicy &Policy,
                             const TemplateParameterList *TPL = nullptr);

5238/// The injected class name of a C++ class template or class
5239/// template partial specialization.  Used to record that a type was
5240/// spelled with a bare identifier rather than as a template-id; the
5241/// equivalent for non-templated classes is just RecordType.
5242///
5243/// Injected class name types are always dependent.  Template
5244/// instantiation turns these into RecordTypes.
5245///
5246/// Injected class name types are always canonical.  This works
5247/// because it is impossible to compare an injected class name type
5248/// with the corresponding non-injected template type, for the same
5249/// reason that it is impossible to directly compare template
5250/// parameters from different dependent contexts: injected class name
5251/// types can only occur within the scope of a particular templated
5252/// declaration, and within that scope every template specialization
5253/// will canonicalize to the injected class name (when appropriate
5254/// according to the rules of the language).
5255class InjectedClassNameType : public Type {
friend class ASTContext; // ASTContext creates these.
friend class ASTNodeImporter;
friend class ASTReader; // FIXME: ASTContext::getInjectedClassNameType is not
                        // currently suitable for AST reading, too much
                        // interdependencies.
template <class T> friend class serialization::AbstractTypeReader;

CXXRecordDecl *Decl;

/// The template specialization which this type represents.
/// For example, in
///   template <class T> class A { ... };
/// this is A<T>, whereas in
///   template <class X, class Y> class A<B<X,Y> > { ... };
/// this is A<B<X,Y> >.
///
/// It is always unqualified, always a template specialization type,
/// and always dependent.
QualType InjectedType;

InjectedClassNameType(CXXRecordDecl *D, QualType TST)
    : Type(InjectedClassName, QualType(),
           TypeDependence::DependentInstantiation),
      Decl(D), InjectedType(TST) {
  assert(isa<TemplateSpecializationType>(TST))(static_cast<void> (0));
  assert(!TST.hasQualifiers())(static_cast<void> (0));
  assert(TST->isDependentType())(static_cast<void> (0));
}

5285public:
QualType getInjectedSpecializationType() const { return InjectedType; }

const TemplateSpecializationType *getInjectedTST() const {
  return cast<TemplateSpecializationType>(InjectedType.getTypePtr());
}

TemplateName getTemplateName() const {
  return getInjectedTST()->getTemplateName();
}

CXXRecordDecl *getDecl() const;

bool isSugared() const { return false; }
QualType desugar() const { return QualType(this, 0); }

static bool classof(const Type *T) {
  return T->getTypeClass() == InjectedClassName;
}
5304};

5306/// The kind of a tag type.
5307enum TagTypeKind {
/// The "struct" keyword.
TTK_Struct,

/// The "__interface" keyword.
TTK_Interface,

/// The "union" keyword.
TTK_Union,

/// The "class" keyword.
TTK_Class,

/// The "enum" keyword.
TTK_Enum
5322};

5324/// The elaboration keyword that precedes a qualified type name or
5325/// introduces an elaborated-type-specifier.
5326enum ElaboratedTypeKeyword {
/// The "struct" keyword introduces the elaborated-type-specifier.
ETK_Struct,

/// The "__interface" keyword introduces the elaborated-type-specifier.
ETK_Interface,

/// The "union" keyword introduces the elaborated-type-specifier.
ETK_Union,

/// The "class" keyword introduces the elaborated-type-specifier.
ETK_Class,

/// The "enum" keyword introduces the elaborated-type-specifier.
ETK_Enum,

/// The "typename" keyword precedes the qualified type name, e.g.,
/// \c typename T::type.
ETK_Typename,

/// No keyword precedes the qualified type name.
ETK_None
5348};

5350/// A helper class for Type nodes having an ElaboratedTypeKeyword.
5351/// The keyword in stored in the free bits of the base class.
5352/// Also provides a few static helpers for converting and printing
5353/// elaborated type keyword and tag type kind enumerations.
5354class TypeWithKeyword : public Type {
5355protected:
TypeWithKeyword(ElaboratedTypeKeyword Keyword, TypeClass tc,
                QualType Canonical, TypeDependence Dependence)
    : Type(tc, Canonical, Dependence) {
  TypeWithKeywordBits.Keyword = Keyword;
}

5362public:
ElaboratedTypeKeyword getKeyword() const {
  return static_cast<ElaboratedTypeKeyword>(TypeWithKeywordBits.Keyword);
}

/// Converts a type specifier (DeclSpec::TST) into an elaborated type keyword.
static ElaboratedTypeKeyword getKeywordForTypeSpec(unsigned TypeSpec);

/// Converts a type specifier (DeclSpec::TST) into a tag type kind.
/// It is an error to provide a type specifier which *isn't* a tag kind here.
static TagTypeKind getTagTypeKindForTypeSpec(unsigned TypeSpec);

/// Converts a TagTypeKind into an elaborated type keyword.
static ElaboratedTypeKeyword getKeywordForTagTypeKind(TagTypeKind Tag);

/// Converts an elaborated type keyword into a TagTypeKind.
/// It is an error to provide an elaborated type keyword
/// which *isn't* a tag kind here.
static TagTypeKind getTagTypeKindForKeyword(ElaboratedTypeKeyword Keyword);

static bool KeywordIsTagTypeKind(ElaboratedTypeKeyword Keyword);

static StringRef getKeywordName(ElaboratedTypeKeyword Keyword);

static StringRef getTagTypeKindName(TagTypeKind Kind) {
  return getKeywordName(getKeywordForTagTypeKind(Kind));
}

class CannotCastToThisType {};
static CannotCastToThisType classof(const Type *);
5392};

5394/// Represents a type that was referred to using an elaborated type
5395/// keyword, e.g., struct S, or via a qualified name, e.g., N::M::type,
5396/// or both.
5397///
5398/// This type is used to keep track of a type name as written in the
5399/// source code, including tag keywords and any nested-name-specifiers.
5400/// The type itself is always "sugar", used to express what was written
5401/// in the source code but containing no additional semantic information.
5402class ElaboratedType final
  : public TypeWithKeyword,
    public llvm::FoldingSetNode,
    private llvm::TrailingObjects<ElaboratedType, TagDecl *> {
friend class ASTContext; // ASTContext creates these
friend TrailingObjects;

/// The nested name specifier containing the qualifier.
NestedNameSpecifier *NNS;

/// The type that this qualified name refers to.
QualType NamedType;

/// The (re)declaration of this tag type owned by this occurrence is stored
/// as a trailing object if there is one. Use getOwnedTagDecl to obtain
/// it, or obtain a null pointer if there is none.

ElaboratedType(ElaboratedTypeKeyword Keyword, NestedNameSpecifier *NNS,
               QualType NamedType, QualType CanonType, TagDecl *OwnedTagDecl)
    : TypeWithKeyword(Keyword, Elaborated, CanonType,
                      // Any semantic dependence on the qualifier will have
                      // been incorporated into NamedType. We still need to
                      // track syntactic (instantiation / error / pack)
                      // dependence on the qualifier.
                      NamedType->getDependence() |
                          (NNS ? toSyntacticDependence(
                                     toTypeDependence(NNS->getDependence()))
                               : TypeDependence::None)),
      NNS(NNS), NamedType(NamedType) {
  ElaboratedTypeBits.HasOwnedTagDecl = false;
  if (OwnedTagDecl) {
    ElaboratedTypeBits.HasOwnedTagDecl = true;
    *getTrailingObjects<TagDecl *>() = OwnedTagDecl;
  }
  assert(!(Keyword == ETK_None && NNS == nullptr) &&(static_cast<void> (0))
         "ElaboratedType cannot have elaborated type keyword "(static_cast<void> (0))
         "and name qualifier both null.")(static_cast<void> (0));
}

5441public:
/// Retrieve the qualification on this type.
NestedNameSpecifier *getQualifier() const { return NNS; }

/// Retrieve the type named by the qualified-id.
QualType getNamedType() const { return NamedType; }

/// Remove a single level of sugar.
QualType desugar() const { return getNamedType(); }

/// Returns whether this type directly provides sugar.
bool isSugared() const { return true; }

/// Return the (re)declaration of this type owned by this occurrence of this
/// type, or nullptr if there is none.
TagDecl *getOwnedTagDecl() const {
  return ElaboratedTypeBits.HasOwnedTagDecl ? *getTrailingObjects<TagDecl *>()
                                            : nullptr;
}

void Profile(llvm::FoldingSetNodeID &ID) {
  Profile(ID, getKeyword(), NNS, NamedType, getOwnedTagDecl());
}

static void Profile(llvm::FoldingSetNodeID &ID, ElaboratedTypeKeyword Keyword,
                    NestedNameSpecifier *NNS, QualType NamedType,
                    TagDecl *OwnedTagDecl) {
  ID.AddInteger(Keyword);
  ID.AddPointer(NNS);
  NamedType.Profile(ID);
  ID.AddPointer(OwnedTagDecl);
}

static bool classof(const Type *T) { return T->getTypeClass() == Elaborated; }
5475};

5477/// Represents a qualified type name for which the type name is
5478/// dependent.
5479///
5480/// DependentNameType represents a class of dependent types that involve a
5481/// possibly dependent nested-name-specifier (e.g., "T::") followed by a
5482/// name of a type. The DependentNameType may start with a "typename" (for a
5483/// typename-specifier), "class", "struct", "union", or "enum" (for a
5484/// dependent elaborated-type-specifier), or nothing (in contexts where we
5485/// know that we must be referring to a type, e.g., in a base class specifier).
5486/// Typically the nested-name-specifier is dependent, but in MSVC compatibility
5487/// mode, this type is used with non-dependent names to delay name lookup until
5488/// instantiation.
5489class DependentNameType : public TypeWithKeyword, public llvm::FoldingSetNode {
friend class ASTContext; // ASTContext creates these

/// The nested name specifier containing the qualifier.
NestedNameSpecifier *NNS;

/// The type that this typename specifier refers to.
const IdentifierInfo *Name;

DependentNameType(ElaboratedTypeKeyword Keyword, NestedNameSpecifier *NNS,
                  const IdentifierInfo *Name, QualType CanonType)
    : TypeWithKeyword(Keyword, DependentName, CanonType,
                      TypeDependence::DependentInstantiation |
                          toTypeDependence(NNS->getDependence())),
      NNS(NNS), Name(Name) {}

5505public:
/// Retrieve the qualification on this type.
NestedNameSpecifier *getQualifier() const { return NNS; }

/// Retrieve the type named by the typename specifier as an identifier.
///
/// This routine will return a non-NULL identifier pointer when the
/// form of the original typename was terminated by an identifier,
/// e.g., "typename T::type".
const IdentifierInfo *getIdentifier() const {
  return Name;
}

bool isSugared() const { return false; }
QualType desugar() const { return QualType(this, 0); }

void Profile(llvm::FoldingSetNodeID &ID) {
  Profile(ID, getKeyword(), NNS, Name);
}

static void Profile(llvm::FoldingSetNodeID &ID, ElaboratedTypeKeyword Keyword,
                    NestedNameSpecifier *NNS, const IdentifierInfo *Name) {
  ID.AddInteger(Keyword);
  ID.AddPointer(NNS);
  ID.AddPointer(Name);
}

static bool classof(const Type *T) {
  return T->getTypeClass() == DependentName;
}
5535};

5537/// Represents a template specialization type whose template cannot be
5538/// resolved, e.g.
5539///   A<T>::template B<T>
5540class alignas(8) DependentTemplateSpecializationType
  : public TypeWithKeyword,
    public llvm::FoldingSetNode {
friend class ASTContext; // ASTContext creates these

/// The nested name specifier containing the qualifier.
NestedNameSpecifier *NNS;

/// The identifier of the template.
const IdentifierInfo *Name;

DependentTemplateSpecializationType(ElaboratedTypeKeyword Keyword,
                                    NestedNameSpecifier *NNS,
                                    const IdentifierInfo *Name,
                                    ArrayRef<TemplateArgument> Args,
                                    QualType Canon);

const TemplateArgument *getArgBuffer() const {
  return reinterpret_cast<const TemplateArgument*>(this+1);
}

TemplateArgument *getArgBuffer() {
  return reinterpret_cast<TemplateArgument*>(this+1);
}

5565public:
NestedNameSpecifier *getQualifier() const { return NNS; }
const IdentifierInfo *getIdentifier() const { return Name; }

/// Retrieve the template arguments.
const TemplateArgument *getArgs() const {
  return getArgBuffer();
}

/// Retrieve the number of template arguments.
unsigned getNumArgs() const {
  return DependentTemplateSpecializationTypeBits.NumArgs;
}

const TemplateArgument &getArg(unsigned Idx) const; // in TemplateBase.h

ArrayRef<TemplateArgument> template_arguments() const {
  return {getArgs(), getNumArgs()};
}

using iterator = const TemplateArgument *;

iterator begin() const { return getArgs(); }
iterator end() const; // inline in TemplateBase.h

bool isSugared() const { return false; }
QualType desugar() const { return QualType(this, 0); }

void Profile(llvm::FoldingSetNodeID &ID, const ASTContext &Context) {
  Profile(ID, Context, getKeyword(), NNS, Name, {getArgs(), getNumArgs()});
}

static void Profile(llvm::FoldingSetNodeID &ID,
                    const ASTContext &Context,
                    ElaboratedTypeKeyword Keyword,
                    NestedNameSpecifier *Qualifier,
                    const IdentifierInfo *Name,
                    ArrayRef<TemplateArgument> Args);

static bool classof(const Type *T) {
  return T->getTypeClass() == DependentTemplateSpecialization;
}
5607};

5609/// Represents a pack expansion of types.
5610///
5611/// Pack expansions are part of C++11 variadic templates. A pack
5612/// expansion contains a pattern, which itself contains one or more
5613/// "unexpanded" parameter packs. When instantiated, a pack expansion
5614/// produces a series of types, each instantiated from the pattern of
5615/// the expansion, where the Ith instantiation of the pattern uses the
5616/// Ith arguments bound to each of the unexpanded parameter packs. The
5617/// pack expansion is considered to "expand" these unexpanded
5618/// parameter packs.
5619///
5620/// \code
5621/// template<typename ...Types> struct tuple;
5622///
5623/// template<typename ...Types>
5624/// struct tuple_of_references {
5625///   typedef tuple<Types&...> type;
5626/// };
5627/// \endcode
5628///
5629/// Here, the pack expansion \c Types&... is represented via a
5630/// PackExpansionType whose pattern is Types&.
5631class PackExpansionType : public Type, public llvm::FoldingSetNode {
friend class ASTContext; // ASTContext creates these

/// The pattern of the pack expansion.
QualType Pattern;

PackExpansionType(QualType Pattern, QualType Canon,
                  Optional<unsigned> NumExpansions)
    : Type(PackExpansion, Canon,
           (Pattern->getDependence() | TypeDependence::Dependent |
            TypeDependence::Instantiation) &
               ~TypeDependence::UnexpandedPack),
      Pattern(Pattern) {
  PackExpansionTypeBits.NumExpansions =
      NumExpansions ? *NumExpansions + 1 : 0;
}

5648public:
/// Retrieve the pattern of this pack expansion, which is the
/// type that will be repeatedly instantiated when instantiating the
/// pack expansion itself.
QualType getPattern() const { return Pattern; }

/// Retrieve the number of expansions that this pack expansion will
/// generate, if known.
Optional<unsigned> getNumExpansions() const {
  if (PackExpansionTypeBits.NumExpansions)
    return PackExpansionTypeBits.NumExpansions - 1;
  return None;
}

bool isSugared() const { return false; }
QualType desugar() const { return QualType(this, 0); }

void Profile(llvm::FoldingSetNodeID &ID) {
  Profile(ID, getPattern(), getNumExpansions());
}

static void Profile(llvm::FoldingSetNodeID &ID, QualType Pattern,
                    Optional<unsigned> NumExpansions) {
  ID.AddPointer(Pattern.getAsOpaquePtr());
  ID.AddBoolean(NumExpansions.hasValue());
  if (NumExpansions)
    ID.AddInteger(*NumExpansions);
}

static bool classof(const Type *T) {
  return T->getTypeClass() == PackExpansion;
}
5680};

5682/// This class wraps the list of protocol qualifiers. For types that can
5683/// take ObjC protocol qualifers, they can subclass this class.
5684template <class T>
5685class ObjCProtocolQualifiers {
5686protected:
ObjCProtocolQualifiers() = default;

ObjCProtocolDecl * const *getProtocolStorage() const {
  return const_cast<ObjCProtocolQualifiers*>(this)->getProtocolStorage();
}

ObjCProtocolDecl **getProtocolStorage() {
  return static_cast<T*>(this)->getProtocolStorageImpl();
}

void setNumProtocols(unsigned N) {
  static_cast<T*>(this)->setNumProtocolsImpl(N);
}

void initialize(ArrayRef<ObjCProtocolDecl *> protocols) {
  setNumProtocols(protocols.size());
  assert(getNumProtocols() == protocols.size() &&(static_cast<void> (0))
         "bitfield overflow in protocol count")(static_cast<void> (0));
  if (!protocols.empty())
    memcpy(getProtocolStorage(), protocols.data(),
           protocols.size() * sizeof(ObjCProtocolDecl*));
}

5710public:
using qual_iterator = ObjCProtocolDecl * const *;
using qual_range = llvm::iterator_range<qual_iterator>;

qual_range quals() const { return qual_range(qual_begin(), qual_end()); }
qual_iterator qual_begin() const { return getProtocolStorage(); }
qual_iterator qual_end() const { return qual_begin() + getNumProtocols(); }

bool qual_empty() const { return getNumProtocols() == 0; }

/// Return the number of qualifying protocols in this type, or 0 if
/// there are none.
unsigned getNumProtocols() const {
  return static_cast<const T*>(this)->getNumProtocolsImpl();
}

/// Fetch a protocol by index.
ObjCProtocolDecl *getProtocol(unsigned I) const {
  assert(I < getNumProtocols() && "Out-of-range protocol access")(static_cast<void> (0));
  return qual_begin()[I];
}

/// Retrieve all of the protocol qualifiers.
ArrayRef<ObjCProtocolDecl *> getProtocols() const {
  return ArrayRef<ObjCProtocolDecl *>(qual_begin(), getNumProtocols());
}
5736};

5738/// Represents a type parameter type in Objective C. It can take
5739/// a list of protocols.
5740class ObjCTypeParamType : public Type,
                        public ObjCProtocolQualifiers<ObjCTypeParamType>,
                        public llvm::FoldingSetNode {
friend class ASTContext;
friend class ObjCProtocolQualifiers<ObjCTypeParamType>;

/// The number of protocols stored on this type.
unsigned NumProtocols : 6;

ObjCTypeParamDecl *OTPDecl;

/// The protocols are stored after the ObjCTypeParamType node. In the
/// canonical type, the list of protocols are sorted alphabetically
/// and uniqued.
ObjCProtocolDecl **getProtocolStorageImpl();

/// Return the number of qualifying protocols in this interface type,
/// or 0 if there are none.
unsigned getNumProtocolsImpl() const {
  return NumProtocols;
}

void setNumProtocolsImpl(unsigned N) {
  NumProtocols = N;
}

ObjCTypeParamType(const ObjCTypeParamDecl *D,
                  QualType can,
                  ArrayRef<ObjCProtocolDecl *> protocols);

5770public:
bool isSugared() const { return true; }
QualType desugar() const { return getCanonicalTypeInternal(); }

static bool classof(const Type *T) {
  return T->getTypeClass() == ObjCTypeParam;
}

void Profile(llvm::FoldingSetNodeID &ID);
static void Profile(llvm::FoldingSetNodeID &ID,
                    const ObjCTypeParamDecl *OTPDecl,
                    QualType CanonicalType,
                    ArrayRef<ObjCProtocolDecl *> protocols);

ObjCTypeParamDecl *getDecl() const { return OTPDecl; }
5785};

5787/// Represents a class type in Objective C.
5788///
5789/// Every Objective C type is a combination of a base type, a set of
5790/// type arguments (optional, for parameterized classes) and a list of
5791/// protocols.
5792///
5793/// Given the following declarations:
5794/// \code
5795///   \@class C<T>;
5796///   \@protocol P;
5797/// \endcode
5798///
5799/// 'C' is an ObjCInterfaceType C.  It is sugar for an ObjCObjectType
5800/// with base C and no protocols.
5801///
5802/// 'C<P>' is an unspecialized ObjCObjectType with base C and protocol list [P].
5803/// 'C<C*>' is a specialized ObjCObjectType with type arguments 'C*' and no
5804/// protocol list.
5805/// 'C<C*><P>' is a specialized ObjCObjectType with base C, type arguments 'C*',
5806/// and protocol list [P].
5807///
5808/// 'id' is a TypedefType which is sugar for an ObjCObjectPointerType whose
5809/// pointee is an ObjCObjectType with base BuiltinType::ObjCIdType
5810/// and no protocols.
5811///
5812/// 'id<P>' is an ObjCObjectPointerType whose pointee is an ObjCObjectType
5813/// with base BuiltinType::ObjCIdType and protocol list [P].  Eventually
5814/// this should get its own sugar class to better represent the source.
5815class ObjCObjectType : public Type,
                     public ObjCProtocolQualifiers<ObjCObjectType> {
friend class ObjCProtocolQualifiers<ObjCObjectType>;

// ObjCObjectType.NumTypeArgs - the number of type arguments stored
// after the ObjCObjectPointerType node.
// ObjCObjectType.NumProtocols - the number of protocols stored
// after the type arguments of ObjCObjectPointerType node.
//
// These protocols are those written directly on the type.  If
// protocol qualifiers ever become additive, the iterators will need
// to get kindof complicated.
//
// In the canonical object type, these are sorted alphabetically
// and uniqued.

/// Either a BuiltinType or an InterfaceType or sugar for either.
QualType BaseType;

/// Cached superclass type.
mutable llvm::PointerIntPair<const ObjCObjectType *, 1, bool>
  CachedSuperClassType;

QualType *getTypeArgStorage();
const QualType *getTypeArgStorage() const {
  return const_cast<ObjCObjectType *>(this)->getTypeArgStorage();
}

ObjCProtocolDecl **getProtocolStorageImpl();
/// Return the number of qualifying protocols in this interface type,
/// or 0 if there are none.
unsigned getNumProtocolsImpl() const {
  return ObjCObjectTypeBits.NumProtocols;
}
void setNumProtocolsImpl(unsigned N) {
  ObjCObjectTypeBits.NumProtocols = N;
}

5853protected:
enum Nonce_ObjCInterface { Nonce_ObjCInterface };

ObjCObjectType(QualType Canonical, QualType Base,
               ArrayRef<QualType> typeArgs,
               ArrayRef<ObjCProtocolDecl *> protocols,
               bool isKindOf);

ObjCObjectType(enum Nonce_ObjCInterface)
    : Type(ObjCInterface, QualType(), TypeDependence::None),
      BaseType(QualType(this_(), 0)) {
  ObjCObjectTypeBits.NumProtocols = 0;
  ObjCObjectTypeBits.NumTypeArgs = 0;
  ObjCObjectTypeBits.IsKindOf = 0;
}

void computeSuperClassTypeSlow() const;

5871public:
/// Gets the base type of this object type.  This is always (possibly
/// sugar for) one of:
///  - the 'id' builtin type (as opposed to the 'id' type visible to the
///    user, which is a typedef for an ObjCObjectPointerType)
///  - the 'Class' builtin type (same caveat)
///  - an ObjCObjectType (currently always an ObjCInterfaceType)
QualType getBaseType() const { return BaseType; }

bool isObjCId() const {
  return getBaseType()->isSpecificBuiltinType(BuiltinType::ObjCId);
}

bool isObjCClass() const {
  return getBaseType()->isSpecificBuiltinType(BuiltinType::ObjCClass);
}

bool isObjCUnqualifiedId() const { return qual_empty() && isObjCId(); }
bool isObjCUnqualifiedClass() const { return qual_empty() && isObjCClass(); }
bool isObjCUnqualifiedIdOrClass() const {
  if (!qual_empty()) return false;
  if (const BuiltinType *T = getBaseType()->getAs<BuiltinType>())
    return T->getKind() == BuiltinType::ObjCId ||
           T->getKind() == BuiltinType::ObjCClass;
  return false;
}
bool isObjCQualifiedId() const { return !qual_empty() && isObjCId(); }
bool isObjCQualifiedClass() const { return !qual_empty() && isObjCClass(); }

/// Gets the interface declaration for this object type, if the base type
/// really is an interface.
ObjCInterfaceDecl *getInterface() const;

/// Determine whether this object type is "specialized", meaning
/// that it has type arguments.
bool isSpecialized() const;

/// Determine whether this object type was written with type arguments.
bool isSpecializedAsWritten() const {
  return ObjCObjectTypeBits.NumTypeArgs > 0;
}

/// Determine whether this object type is "unspecialized", meaning
/// that it has no type arguments.
bool isUnspecialized() const { return !isSpecialized(); }

/// Determine whether this object type is "unspecialized" as
/// written, meaning that it has no type arguments.
bool isUnspecializedAsWritten() const { return !isSpecializedAsWritten(); }

/// Retrieve the type arguments of this object type (semantically).
ArrayRef<QualType> getTypeArgs() const;

/// Retrieve the type arguments of this object type as they were
/// written.
ArrayRef<QualType> getTypeArgsAsWritten() const {
  return llvm::makeArrayRef(getTypeArgStorage(),
                            ObjCObjectTypeBits.NumTypeArgs);
}

/// Whether this is a "__kindof" type as written.
bool isKindOfTypeAsWritten() const { return ObjCObjectTypeBits.IsKindOf; }

/// Whether this ia a "__kindof" type (semantically).
bool isKindOfType() const;

/// Retrieve the type of the superclass of this object type.
///
/// This operation substitutes any type arguments into the
/// superclass of the current class type, potentially producing a
/// specialization of the superclass type. Produces a null type if
/// there is no superclass.
QualType getSuperClassType() const {
  if (!CachedSuperClassType.getInt())
    computeSuperClassTypeSlow();

  assert(CachedSuperClassType.getInt() && "Superclass not set?")(static_cast<void> (0));
  return QualType(CachedSuperClassType.getPointer(), 0);
}

/// Strip off the Objective-C "kindof" type and (with it) any
/// protocol qualifiers.
QualType stripObjCKindOfTypeAndQuals(const ASTContext &ctx) const;

bool isSugared() const { return false; }
QualType desugar() const { return QualType(this, 0); }

static bool classof(const Type *T) {
  return T->getTypeClass() == ObjCObject ||
         T->getTypeClass() == ObjCInterface;
}
5962};

5964/// A class providing a concrete implementation
5965/// of ObjCObjectType, so as to not increase the footprint of
5966/// ObjCInterfaceType.  Code outside of ASTContext and the core type
5967/// system should not reference this type.
5968class ObjCObjectTypeImpl : public ObjCObjectType, public llvm::FoldingSetNode {
friend class ASTContext;

// If anyone adds fields here, ObjCObjectType::getProtocolStorage()
// will need to be modified.

ObjCObjectTypeImpl(QualType Canonical, QualType Base,
                   ArrayRef<QualType> typeArgs,
                   ArrayRef<ObjCProtocolDecl *> protocols,
                   bool isKindOf)
    : ObjCObjectType(Canonical, Base, typeArgs, protocols, isKindOf) {}

5980public:
void Profile(llvm::FoldingSetNodeID &ID);
static void Profile(llvm::FoldingSetNodeID &ID,
                    QualType Base,
                    ArrayRef<QualType> typeArgs,
                    ArrayRef<ObjCProtocolDecl *> protocols,
                    bool isKindOf);
5987};

5989inline QualType *ObjCObjectType::getTypeArgStorage() {
return reinterpret_cast<QualType *>(static_cast<ObjCObjectTypeImpl*>(this)+1);
5991}

5993inline ObjCProtocolDecl **ObjCObjectType::getProtocolStorageImpl() {
  return reinterpret_cast<ObjCProtocolDecl**>(
           getTypeArgStorage() + ObjCObjectTypeBits.NumTypeArgs);
5996}

5998inline ObjCProtocolDecl **ObjCTypeParamType::getProtocolStorageImpl() {
  return reinterpret_cast<ObjCProtocolDecl**>(
           static_cast<ObjCTypeParamType*>(this)+1);
6001}

6003/// Interfaces are the core concept in Objective-C for object oriented design.
6004/// They basically correspond to C++ classes.  There are two kinds of interface
6005/// types: normal interfaces like `NSString`, and qualified interfaces, which
6006/// are qualified with a protocol list like `NSString<NSCopyable, NSAmazing>`.
6007///
6008/// ObjCInterfaceType guarantees the following properties when considered
6009/// as a subtype of its superclass, ObjCObjectType:
6010///   - There are no protocol qualifiers.  To reinforce this, code which
6011///     tries to invoke the protocol methods via an ObjCInterfaceType will
6012///     fail to compile.
6013///   - It is its own base type.  That is, if T is an ObjCInterfaceType*,
6014///     T->getBaseType() == QualType(T, 0).
6015class ObjCInterfaceType : public ObjCObjectType {
friend class ASTContext; // ASTContext creates these.
friend class ASTReader;
friend class ObjCInterfaceDecl;
template <class T> friend class serialization::AbstractTypeReader;

mutable ObjCInterfaceDecl *Decl;

ObjCInterfaceType(const ObjCInterfaceDecl *D)
    : ObjCObjectType(Nonce_ObjCInterface),
      Decl(const_cast<ObjCInterfaceDecl*>(D)) {}

6027public:
/// Get the declaration of this interface.
ObjCInterfaceDecl *getDecl() const { return Decl; }

bool isSugared() const { return false; }
QualType desugar() const { return QualType(this, 0); }

static bool classof(const Type *T) {
  return T->getTypeClass() == ObjCInterface;
}

// Nonsense to "hide" certain members of ObjCObjectType within this
// class.  People asking for protocols on an ObjCInterfaceType are
// not going to get what they want: ObjCInterfaceTypes are
// guaranteed to have no protocols.
enum {
  qual_iterator,
  qual_begin,
  qual_end,
  getNumProtocols,
  getProtocol
};
6049};

6051inline ObjCInterfaceDecl *ObjCObjectType::getInterface() const {
QualType baseType = getBaseType();
while (const auto *ObjT = baseType->getAs<ObjCObjectType>()) {
  if (const auto *T = dyn_cast<ObjCInterfaceType>(ObjT))
    return T->getDecl();

  baseType = ObjT->getBaseType();
}

return nullptr;
6061}

6063/// Represents a pointer to an Objective C object.
6064///
6065/// These are constructed from pointer declarators when the pointee type is
6066/// an ObjCObjectType (or sugar for one).  In addition, the 'id' and 'Class'
6067/// types are typedefs for these, and the protocol-qualified types 'id<P>'
6068/// and 'Class<P>' are translated into these.
6069///
6070/// Pointers to pointers to Objective C objects are still PointerTypes;
6071/// only the first level of pointer gets it own type implementation.
6072class ObjCObjectPointerType : public Type, public llvm::FoldingSetNode {
friend class ASTContext; // ASTContext creates these.

QualType PointeeType;

ObjCObjectPointerType(QualType Canonical, QualType Pointee)
    : Type(ObjCObjectPointer, Canonical, Pointee->getDependence()),
      PointeeType(Pointee) {}

6081public:
/// Gets the type pointed to by this ObjC pointer.
/// The result will always be an ObjCObjectType or sugar thereof.
QualType getPointeeType() const { return PointeeType; }

/// Gets the type pointed to by this ObjC pointer.  Always returns non-null.
///
/// This method is equivalent to getPointeeType() except that
/// it discards any typedefs (or other sugar) between this
/// type and the "outermost" object type.  So for:
/// \code
///   \@class A; \@protocol P; \@protocol Q;
///   typedef A<P> AP;
///   typedef A A1;
///   typedef A1<P> A1P;
///   typedef A1P<Q> A1PQ;
/// \endcode
/// For 'A*', getObjectType() will return 'A'.
/// For 'A<P>*', getObjectType() will return 'A<P>'.
/// For 'AP*', getObjectType() will return 'A<P>'.
/// For 'A1*', getObjectType() will return 'A'.
/// For 'A1<P>*', getObjectType() will return 'A1<P>'.
/// For 'A1P*', getObjectType() will return 'A1<P>'.
/// For 'A1PQ*', getObjectType() will return 'A1<Q>', because
///   adding protocols to a protocol-qualified base discards the
///   old qualifiers (for now).  But if it didn't, getObjectType()
///   would return 'A1P<Q>' (and we'd have to make iterating over
///   qualifiers more complicated).
const ObjCObjectType *getObjectType() const {
  return PointeeType->castAs<ObjCObjectType>();
}

/// If this pointer points to an Objective C
/// \@interface type, gets the type for that interface.  Any protocol
/// qualifiers on the interface are ignored.
///
/// \return null if the base type for this pointer is 'id' or 'Class'
const ObjCInterfaceType *getInterfaceType() const;

/// If this pointer points to an Objective \@interface
/// type, gets the declaration for that interface.
///
/// \return null if the base type for this pointer is 'id' or 'Class'
ObjCInterfaceDecl *getInterfaceDecl() const {
  return getObjectType()->getInterface();
}

/// True if this is equivalent to the 'id' type, i.e. if
/// its object type is the primitive 'id' type with no protocols.
bool isObjCIdType() const {
  return getObjectType()->isObjCUnqualifiedId();
}

/// True if this is equivalent to the 'Class' type,
/// i.e. if its object tive is the primitive 'Class' type with no protocols.
bool isObjCClassType() const {
  return getObjectType()->isObjCUnqualifiedClass();
}

/// True if this is equivalent to the 'id' or 'Class' type,
bool isObjCIdOrClassType() const {
  return getObjectType()->isObjCUnqualifiedIdOrClass();
}

/// True if this is equivalent to 'id<P>' for some non-empty set of
/// protocols.
bool isObjCQualifiedIdType() const {
  return getObjectType()->isObjCQualifiedId();
}

/// True if this is equivalent to 'Class<P>' for some non-empty set of
/// protocols.
bool isObjCQualifiedClassType() const {
  return getObjectType()->isObjCQualifiedClass();
}

/// Whether this is a "__kindof" type.
bool isKindOfType() const { return getObjectType()->isKindOfType(); }

/// Whether this type is specialized, meaning that it has type arguments.
bool isSpecialized() const { return getObjectType()->isSpecialized(); }

/// Whether this type is specialized, meaning that it has type arguments.
bool isSpecializedAsWritten() const {
  return getObjectType()->isSpecializedAsWritten();
}

/// Whether this type is unspecialized, meaning that is has no type arguments.
bool isUnspecialized() const { return getObjectType()->isUnspecialized(); }

/// Determine whether this object type is "unspecialized" as
/// written, meaning that it has no type arguments.
bool isUnspecializedAsWritten() const { return !isSpecializedAsWritten(); }

/// Retrieve the type arguments for this type.
ArrayRef<QualType> getTypeArgs() const {
  return getObjectType()->getTypeArgs();
}

/// Retrieve the type arguments for this type.
ArrayRef<QualType> getTypeArgsAsWritten() const {
  return getObjectType()->getTypeArgsAsWritten();
}

/// An iterator over the qualifiers on the object type.  Provided
/// for convenience.  This will always iterate over the full set of
/// protocols on a type, not just those provided directly.
using qual_iterator = ObjCObjectType::qual_iterator;
using qual_range = llvm::iterator_range<qual_iterator>;

qual_range quals() const { return qual_range(qual_begin(), qual_end()); }

qual_iterator qual_begin() const {
  return getObjectType()->qual_begin();
}

qual_iterator qual_end() const {
  return getObjectType()->qual_end();
}

bool qual_empty() const { return getObjectType()->qual_empty(); }

/// Return the number of qualifying protocols on the object type.
unsigned getNumProtocols() const {
  return getObjectType()->getNumProtocols();
}

/// Retrieve a qualifying protocol by index on the object type.
ObjCProtocolDecl *getProtocol(unsigned I) const {
  return getObjectType()->getProtocol(I);
}

bool isSugared() const { return false; }
QualType desugar() const { return QualType(this, 0); }

/// Retrieve the type of the superclass of this object pointer type.
///
/// This operation substitutes any type arguments into the
/// superclass of the current class type, potentially producing a
/// pointer to a specialization of the superclass type. Produces a
/// null type if there is no superclass.
QualType getSuperClassType() const;

/// Strip off the Objective-C "kindof" type and (with it) any
/// protocol qualifiers.
const ObjCObjectPointerType *stripObjCKindOfTypeAndQuals(
                               const ASTContext &ctx) const;

void Profile(llvm::FoldingSetNodeID &ID) {
  Profile(ID, getPointeeType());
}

static void Profile(llvm::FoldingSetNodeID &ID, QualType T) {
  ID.AddPointer(T.getAsOpaquePtr());
}

static bool classof(const Type *T) {
  return T->getTypeClass() == ObjCObjectPointer;
}
6240};

6242class AtomicType : public Type, public llvm::FoldingSetNode {
friend class ASTContext; // ASTContext creates these.

QualType ValueType;

AtomicType(QualType ValTy, QualType Canonical)
    : Type(Atomic, Canonical, ValTy->getDependence()), ValueType(ValTy) {}

6250public:
/// Gets the type contained by this atomic type, i.e.
/// the type returned by performing an atomic load of this atomic type.
QualType getValueType() const { return ValueType; }

bool isSugared() const { return false; }
QualType desugar() const { return QualType(this, 0); }

void Profile(llvm::FoldingSetNodeID &ID) {
  Profile(ID, getValueType());
}

static void Profile(llvm::FoldingSetNodeID &ID, QualType T) {
  ID.AddPointer(T.getAsOpaquePtr());
}

static bool classof(const Type *T) {
  return T->getTypeClass() == Atomic;
}
6269};

6271/// PipeType - OpenCL20.
6272class PipeType : public Type, public llvm::FoldingSetNode {
friend class ASTContext; // ASTContext creates these.

QualType ElementType;
bool isRead;

PipeType(QualType elemType, QualType CanonicalPtr, bool isRead)
    : Type(Pipe, CanonicalPtr, elemType->getDependence()),
      ElementType(elemType), isRead(isRead) {}

6282public:
QualType getElementType() const { return ElementType; }

bool isSugared() const { return false; }

QualType desugar() const { return QualType(this, 0); }

void Profile(llvm::FoldingSetNodeID &ID) {
  Profile(ID, getElementType(), isReadOnly());
}

static void Profile(llvm::FoldingSetNodeID &ID, QualType T, bool isRead) {
  ID.AddPointer(T.getAsOpaquePtr());
  ID.AddBoolean(isRead);
}

static bool classof(const Type *T) {
  return T->getTypeClass() == Pipe;
}

bool isReadOnly() const { return isRead; }
6303};

6305/// A fixed int type of a specified bitwidth.
6306class ExtIntType final : public Type, public llvm::FoldingSetNode {
friend class ASTContext;
unsigned IsUnsigned : 1;
unsigned NumBits : 24;

6311protected:
ExtIntType(bool isUnsigned, unsigned NumBits);

6314public:
bool isUnsigned() const { return IsUnsigned; }
bool isSigned() const { return !IsUnsigned; }
unsigned getNumBits() const { return NumBits; }

bool isSugared() const { return false; }
QualType desugar() const { return QualType(this, 0); }

void Profile(llvm::FoldingSetNodeID &ID) {
  Profile(ID, isUnsigned(), getNumBits());
}

static void Profile(llvm::FoldingSetNodeID &ID, bool IsUnsigned,
                    unsigned NumBits) {
  ID.AddBoolean(IsUnsigned);
  ID.AddInteger(NumBits);
}

static bool classof(const Type *T) { return T->getTypeClass() == ExtInt; }
6333};

6335class DependentExtIntType final : public Type, public llvm::FoldingSetNode {
friend class ASTContext;
const ASTContext &Context;
llvm::PointerIntPair<Expr*, 1, bool> ExprAndUnsigned;

6340protected:
DependentExtIntType(const ASTContext &Context, bool IsUnsigned,
                    Expr *NumBits);

6344public:
bool isUnsigned() const;
bool isSigned() const { return !isUnsigned(); }
Expr *getNumBitsExpr() const;

bool isSugared() const { return false; }
QualType desugar() const { return QualType(this, 0); }

void Profile(llvm::FoldingSetNodeID &ID) {
  Profile(ID, Context, isUnsigned(), getNumBitsExpr());
}
static void Profile(llvm::FoldingSetNodeID &ID, const ASTContext &Context,
                    bool IsUnsigned, Expr *NumBitsExpr);

static bool classof(const Type *T) {
  return T->getTypeClass() == DependentExtInt;
}
6361};

6363/// A qualifier set is used to build a set of qualifiers.
6364class QualifierCollector : public Qualifiers {
6365public:
QualifierCollector(Qualifiers Qs = Qualifiers()) : Qualifiers(Qs) {}

/// Collect any qualifiers on the given type and return an
/// unqualified type.  The qualifiers are assumed to be consistent
/// with those already in the type.
const Type *strip(QualType type) {
  addFastQualifiers(type.getLocalFastQualifiers());
  if (!type.hasLocalNonFastQualifiers())
    return type.getTypePtrUnsafe();

  const ExtQuals *extQuals = type.getExtQualsUnsafe();
  addConsistentQualifiers(extQuals->getQualifiers());
  return extQuals->getBaseType();
}

/// Apply the collected qualifiers to the given type.
QualType apply(const ASTContext &Context, QualType QT) const;

/// Apply the collected qualifiers to the given type.
QualType apply(const ASTContext &Context, const Type* T) const;
6386};

6388/// A container of type source information.
6389///
6390/// A client can read the relevant info using TypeLoc wrappers, e.g:
6391/// @code
6392/// TypeLoc TL = TypeSourceInfo->getTypeLoc();
6393/// TL.getBeginLoc().print(OS, SrcMgr);
6394/// @endcode
6395class alignas(8) TypeSourceInfo {
// Contains a memory block after the class, used for type source information,
// allocated by ASTContext.
friend class ASTContext;

QualType Ty;

TypeSourceInfo(QualType ty) : Ty(ty) {}

6404public:
/// Return the type wrapped by this type source info.
QualType getType() const { return Ty; }

/// Return the TypeLoc wrapper for the type source info.
TypeLoc getTypeLoc() const; // implemented in TypeLoc.h

/// Override the type stored in this TypeSourceInfo. Use with caution!
void overrideType(QualType T) { Ty = T; }
6413};

6415// Inline function definitions.

6417inline SplitQualType SplitQualType::getSingleStepDesugaredType() const {
SplitQualType desugar =
  Ty->getLocallyUnqualifiedSingleStepDesugaredType().split();
desugar.Quals.addConsistentQualifiers(Quals);
return desugar;
6422}

6424inline const Type *QualType::getTypePtr() const {
return getCommonPtr()->BaseType;
6426}

6428inline const Type *QualType::getTypePtrOrNull() const {
return (isNull() ? nullptr : getCommonPtr()->BaseType);
6430}

6432inline SplitQualType QualType::split() const {
if (!hasLocalNonFastQualifiers())
  return SplitQualType(getTypePtrUnsafe(),
                       Qualifiers::fromFastMask(getLocalFastQualifiers()));

const ExtQuals *eq = getExtQualsUnsafe();
Qualifiers qs = eq->getQualifiers();
qs.addFastQualifiers(getLocalFastQualifiers());
return SplitQualType(eq->getBaseType(), qs);
6441}

6443inline Qualifiers QualType::getLocalQualifiers() const {
Qualifiers Quals;
if (hasLocalNonFastQualifiers())
  Quals = getExtQualsUnsafe()->getQualifiers();
Quals.addFastQualifiers(getLocalFastQualifiers());
return Quals;
6449}

6451inline Qualifiers QualType::getQualifiers() const {
Qualifiers quals = getCommonPtr()->CanonicalType.getLocalQualifiers();
quals.addFastQualifiers(getLocalFastQualifiers());
return quals;
6455}

6457inline unsigned QualType::getCVRQualifiers() const {
unsigned cvr = getCommonPtr()->CanonicalType.getLocalCVRQualifiers();
cvr |= getLocalCVRQualifiers();
return cvr;
6461}

6463inline QualType QualType::getCanonicalType() const {
QualType canon = getCommonPtr()->CanonicalType;
return canon.withFastQualifiers(getLocalFastQualifiers());
6466}

6468inline bool QualType::isCanonical() const {
return getTypePtr()->isCanonicalUnqualified();
6470}

6472inline bool QualType::isCanonicalAsParam() const {
if (!isCanonical()) return false;
if (hasLocalQualifiers()) return false;

const Type *T = getTypePtr();
if (T->isVariablyModifiedType() && T->hasSizedVLAType())
  return false;

return !isa<FunctionType>(T) && !isa<ArrayType>(T);
6481}

6483inline bool QualType::isConstQualified() const {
return isLocalConstQualified() ||
       getCommonPtr()->CanonicalType.isLocalConstQualified();
6486}

6488inline bool QualType::isRestrictQualified() const {
return isLocalRestrictQualified() ||
       getCommonPtr()->CanonicalType.isLocalRestrictQualified();
6491}


6494inline bool QualType::isVolatileQualified() const {
return isLocalVolatileQualified() ||
       getCommonPtr()->CanonicalType.isLocalVolatileQualified();
6497}

6499inline bool QualType::hasQualifiers() const {
return hasLocalQualifiers() ||
       getCommonPtr()->CanonicalType.hasLocalQualifiers();
6502}

6504inline QualType QualType::getUnqualifiedType() const {
if (!getTypePtr()->getCanonicalTypeInternal().hasLocalQualifiers())
  return QualType(getTypePtr(), 0);

return QualType(getSplitUnqualifiedTypeImpl(*this).Ty, 0);
6509}

6511inline SplitQualType QualType::getSplitUnqualifiedType() const {
if (!getTypePtr()->getCanonicalTypeInternal().hasLocalQualifiers())
  return split();

return getSplitUnqualifiedTypeImpl(*this);
6516}

6518inline void QualType::removeLocalConst() {
removeLocalFastQualifiers(Qualifiers::Const);
6520}

6522inline void QualType::removeLocalRestrict() {
removeLocalFastQualifiers(Qualifiers::Restrict);
6524}

6526inline void QualType::removeLocalVolatile() {
removeLocalFastQualifiers(Qualifiers::Volatile);
6528}

6530inline void QualType::removeLocalCVRQualifiers(unsigned Mask) {
assert(!(Mask & ~Qualifiers::CVRMask) && "mask has non-CVR bits")(static_cast<void> (0));
static_assert((int)Qualifiers::CVRMask == (int)Qualifiers::FastMask,
              "Fast bits differ from CVR bits!");

// Fast path: we don't need to touch the slow qualifiers.
removeLocalFastQualifiers(Mask);
6537}

6539/// Check if this type has any address space qualifier.
6540inline bool QualType::hasAddressSpace() const {
return getQualifiers().hasAddressSpace();
6542}

6544/// Return the address space of this type.
6545inline LangAS QualType::getAddressSpace() const {
return getQualifiers().getAddressSpace();
6547}

6549/// Return the gc attribute of this type.
6550inline Qualifiers::GC QualType::getObjCGCAttr() const {
return getQualifiers().getObjCGCAttr();
6552}

6554inline bool QualType::hasNonTrivialToPrimitiveDefaultInitializeCUnion() const {
if (auto *RD = getTypePtr()->getBaseElementTypeUnsafe()->getAsRecordDecl())
  return hasNonTrivialToPrimitiveDefaultInitializeCUnion(RD);
return false;
6558}

6560inline bool QualType::hasNonTrivialToPrimitiveDestructCUnion() const {
if (auto *RD = getTypePtr()->getBaseElementTypeUnsafe()->getAsRecordDecl())
  return hasNonTrivialToPrimitiveDestructCUnion(RD);
return false;
6564}

6566inline bool QualType::hasNonTrivialToPrimitiveCopyCUnion() const {
if (auto *RD = getTypePtr()->getBaseElementTypeUnsafe()->getAsRecordDecl())
  return hasNonTrivialToPrimitiveCopyCUnion(RD);
return false;
6570}

6572inline FunctionType::ExtInfo getFunctionExtInfo(const Type &t) {
if (const auto *PT = t.getAs<PointerType>()) {
  if (const auto *FT = PT->getPointeeType()->getAs<FunctionType>())
    return FT->getExtInfo();
} else if (const auto *FT = t.getAs<FunctionType>())
  return FT->getExtInfo();

return FunctionType::ExtInfo();
6580}

6582inline FunctionType::ExtInfo getFunctionExtInfo(QualType t) {
return getFunctionExtInfo(*t);
6584}

6586/// Determine whether this type is more
6587/// qualified than the Other type. For example, "const volatile int"
6588/// is more qualified than "const int", "volatile int", and
6589/// "int". However, it is not more qualified than "const volatile
6590/// int".
6591inline bool QualType::isMoreQualifiedThan(QualType other) const {
Qualifiers MyQuals = getQualifiers();
Qualifiers OtherQuals = other.getQualifiers();
return (MyQuals != OtherQuals && MyQuals.compatiblyIncludes(OtherQuals));
6595}

6597/// Determine whether this type is at last
6598/// as qualified as the Other type. For example, "const volatile
6599/// int" is at least as qualified as "const int", "volatile int",
6600/// "int", and "const volatile int".
6601inline bool QualType::isAtLeastAsQualifiedAs(QualType other) const {
Qualifiers OtherQuals = other.getQualifiers();

// Ignore __unaligned qualifier if this type is a void.
if (getUnqualifiedType()->isVoidType())
  OtherQuals.removeUnaligned();

return getQualifiers().compatiblyIncludes(OtherQuals);
6609}

6611/// If Type is a reference type (e.g., const
6612/// int&), returns the type that the reference refers to ("const
6613/// int"). Otherwise, returns the type itself. This routine is used
6614/// throughout Sema to implement C++ 5p6:
6615///
6616///   If an expression initially has the type "reference to T" (8.3.2,
6617///   8.5.3), the type is adjusted to "T" prior to any further
6618///   analysis, the expression designates the object or function
6619///   denoted by the reference, and the expression is an lvalue.
6620inline QualType QualType::getNonReferenceType() const {
if (const auto *RefType = (*this)->getAs<ReferenceType>())
  return RefType->getPointeeType();
else
  return *this;
6625}

6627inline bool QualType::isCForbiddenLValueType() const {
return ((getTypePtr()->isVoidType() && !hasQualifiers()) ||
        getTypePtr()->isFunctionType());
6630}

6632/// Tests whether the type is categorized as a fundamental type.
6633///
6634/// \returns True for types specified in C++0x [basic.fundamental].
6635inline bool Type::isFundamentalType() const {
return isVoidType() ||
       isNullPtrType() ||
       // FIXME: It's really annoying that we don't have an
       // 'isArithmeticType()' which agrees with the standard definition.
       (isArithmeticType() && !isEnumeralType());
6641}

6643/// Tests whether the type is categorized as a compound type.
6644///
6645/// \returns True for types specified in C++0x [basic.compound].
6646inline bool Type::isCompoundType() const {
// C++0x [basic.compound]p1:
//   Compound types can be constructed in the following ways:
//    -- arrays of objects of a given type [...];
return isArrayType() ||
//    -- functions, which have parameters of given types [...];
       isFunctionType() ||
//    -- pointers to void or objects or functions [...];
       isPointerType() ||
//    -- references to objects or functions of a given type. [...]
       isReferenceType() ||
//    -- classes containing a sequence of objects of various types, [...];
       isRecordType() ||
//    -- unions, which are classes capable of containing objects of different
//               types at different times;
       isUnionType() ||
//    -- enumerations, which comprise a set of named constant values. [...];
       isEnumeralType() ||
//    -- pointers to non-static class members, [...].
       isMemberPointerType();
6666}

6668inline bool Type::isFunctionType() const {
return isa<FunctionType>(CanonicalType);
6670}

6672inline bool Type::isPointerType() const {
return isa<PointerType>(CanonicalType);
6674}

6676inline bool Type::isAnyPointerType() const {
return isPointerType() || isObjCObjectPointerType();
6678}

6680inline bool Type::isBlockPointerType() const {
return isa<BlockPointerType>(CanonicalType);
6682}

6684inline bool Type::isReferenceType() const {
return isa<ReferenceType>(CanonicalType);
6686}

6688inline bool Type::isLValueReferenceType() const {
return isa<LValueReferenceType>(CanonicalType);
6690}

6692inline bool Type::isRValueReferenceType() const {
return isa<RValueReferenceType>(CanonicalType);
6694}

6696inline bool Type::isObjectPointerType() const {
// Note: an "object pointer type" is not the same thing as a pointer to an
// object type; rather, it is a pointer to an object type or a pointer to cv
// void.
if (const auto *T = getAs<PointerType>())
  return !T->getPointeeType()->isFunctionType();
else
  return false;
6704}

6706inline bool Type::isFunctionPointerType() const {
if (const auto *T = getAs<PointerType>())
  return T->getPointeeType()->isFunctionType();
else
  return false;
6711}

6713inline bool Type::isFunctionReferenceType() const {
if (const auto *T = getAs<ReferenceType>())
  return T->getPointeeType()->isFunctionType();
else
  return false;
6718}

6720inline bool Type::isMemberPointerType() const {
return isa<MemberPointerType>(CanonicalType);
6722}

6724inline bool Type::isMemberFunctionPointerType() const {
if (const auto *T = getAs<MemberPointerType>())
  return T->isMemberFunctionPointer();
else
  return false;
6729}

6731inline bool Type::isMemberDataPointerType() const {
if (const auto *T = getAs<MemberPointerType>())
  return T->isMemberDataPointer();
else
  return false;
6736}

6738inline bool Type::isArrayType() const {
return isa<ArrayType>(CanonicalType);
6740}

6742inline bool Type::isConstantArrayType() const {
return isa<ConstantArrayType>(CanonicalType);
6744}

6746inline bool Type::isIncompleteArrayType() const {
return isa<IncompleteArrayType>(CanonicalType);
6748}

6750inline bool Type::isVariableArrayType() const {
return isa<VariableArrayType>(CanonicalType);
6752}

6754inline bool Type::isDependentSizedArrayType() const {
return isa<DependentSizedArrayType>(CanonicalType);
6756}

6758inline bool Type::isBuiltinType() const {
return isa<BuiltinType>(CanonicalType);
6760}

6762inline bool Type::isRecordType() const {
return isa<RecordType>(CanonicalType);
6764}

6766inline bool Type::isEnumeralType() const {
return isa<EnumType>(CanonicalType);
6768}

6770inline bool Type::isAnyComplexType() const {
return isa<ComplexType>(CanonicalType);
6772}

6774inline bool Type::isVectorType() const {
return isa<VectorType>(CanonicalType);
6776}

6778inline bool Type::isExtVectorType() const {
return isa<ExtVectorType>(CanonicalType);
6780}

6782inline bool Type::isMatrixType() const {
return isa<MatrixType>(CanonicalType);
6784}

6786inline bool Type::isConstantMatrixType() const {
return isa<ConstantMatrixType>(CanonicalType);
6788}

6790inline bool Type::isDependentAddressSpaceType() const {
return isa<DependentAddressSpaceType>(CanonicalType);
6792}

6794inline bool Type::isObjCObjectPointerType() const {
return isa<ObjCObjectPointerType>(CanonicalType);
6796}

6798inline bool Type::isObjCObjectType() const {
return isa<ObjCObjectType>(CanonicalType);
6800}

6802inline bool Type::isObjCObjectOrInterfaceType() const {
return isa<ObjCInterfaceType>(CanonicalType) ||
  isa<ObjCObjectType>(CanonicalType);
6805}

6807inline bool Type::isAtomicType() const {
return isa<AtomicType>(CanonicalType);
6809}

6811inline bool Type::isUndeducedAutoType() const {
return isa<AutoType>(CanonicalType);
6813}

6815inline bool Type::isObjCQualifiedIdType() const {
if (const auto *OPT = getAs<ObjCObjectPointerType>())
  return OPT->isObjCQualifiedIdType();
return false;
6819}

6821inline bool Type::isObjCQualifiedClassType() const {
if (const auto *OPT = getAs<ObjCObjectPointerType>())
  return OPT->isObjCQualifiedClassType();
return false;
6825}

6827inline bool Type::isObjCIdType() const {
if (const auto *OPT = getAs<ObjCObjectPointerType>())
  return OPT->isObjCIdType();
return false;
6831}

6833inline bool Type::isObjCClassType() const {
if (const auto *OPT = getAs<ObjCObjectPointerType>())
  return OPT->isObjCClassType();
return false;
6837}

6839inline bool Type::isObjCSelType() const {
if (const auto *OPT = getAs<PointerType>())
  return OPT->getPointeeType()->isSpecificBuiltinType(BuiltinType::ObjCSel);
return false;
6843}

6845inline bool Type::isObjCBuiltinType() const {
return isObjCIdType() || isObjCClassType() || isObjCSelType();
6847}

6849inline bool Type::isDecltypeType() const {
return isa<DecltypeType>(this);
6851}

6853#define IMAGE_TYPE(ImgType, Id, SingletonId, Access, Suffix) \
inline bool Type::is##Id##Type() const { \
  return isSpecificBuiltinType(BuiltinType::Id); \
}
6857#include "clang/Basic/OpenCLImageTypes.def"

6859inline bool Type::isSamplerT() const {
return isSpecificBuiltinType(BuiltinType::OCLSampler);
6861}

6863inline bool Type::isEventT() const {
return isSpecificBuiltinType(BuiltinType::OCLEvent);
6865}

6867inline bool Type::isClkEventT() const {
return isSpecificBuiltinType(BuiltinType::OCLClkEvent);
6869}

6871inline bool Type::isQueueT() const {
return isSpecificBuiltinType(BuiltinType::OCLQueue);
6873}

6875inline bool Type::isReserveIDT() const {
return isSpecificBuiltinType(BuiltinType::OCLReserveID);
6877}

6879inline bool Type::isImageType() const {
6880#define IMAGE_TYPE(ImgType, Id, SingletonId, Access, Suffix) is##Id##Type() ||
return
6882#include "clang/Basic/OpenCLImageTypes.def"
    false; // end boolean or operation
6884}

6886inline bool Type::isPipeType() const {
return isa<PipeType>(CanonicalType);
6888}

6890inline bool Type::isExtIntType() const {
return isa<ExtIntType>(CanonicalType);
6892}

6894#define EXT_OPAQUE_TYPE(ExtType, Id, Ext) \
inline bool Type::is##Id##Type() const { \
  return isSpecificBuiltinType(BuiltinType::Id); \
}
6898#include "clang/Basic/OpenCLExtensionTypes.def"

6900inline bool Type::isOCLIntelSubgroupAVCType() const {
6901#define INTEL_SUBGROUP_AVC_TYPE(ExtType, Id) \
isOCLIntelSubgroupAVC##Id##Type() ||
return
6904#include "clang/Basic/OpenCLExtensionTypes.def"
  false; // end of boolean or operation
6906}

6908inline bool Type::isOCLExtOpaqueType() const {
6909#define EXT_OPAQUE_TYPE(ExtType, Id, Ext) is##Id##Type() ||
return
6911#include "clang/Basic/OpenCLExtensionTypes.def"
  false; // end of boolean or operation
6913}

6915inline bool Type::isOpenCLSpecificType() const {
return isSamplerT() || isEventT() || isImageType() || isClkEventT() ||
       isQueueT() || isReserveIDT() || isPipeType() || isOCLExtOpaqueType();
6918}

6920inline bool Type::isTemplateTypeParmType() const {
return isa<TemplateTypeParmType>(CanonicalType);
6922}

6924inline bool Type::isSpecificBuiltinType(unsigned K) const {
if (const BuiltinType *BT = getAs<BuiltinType>()) {
  return BT->getKind() == static_cast<BuiltinType::Kind>(K);
}
return false;
6929}

6931inline bool Type::isPlaceholderType() const {
if (const auto *BT = dyn_cast<BuiltinType>(this))
  return BT->isPlaceholderType();
return false;
6935}

6937inline const BuiltinType *Type::getAsPlaceholderType() const {
if (const auto *BT = dyn_cast<BuiltinType>(this))
  if (BT->isPlaceholderType())
    return BT;
return nullptr;
6942}

6944inline bool Type::isSpecificPlaceholderType(unsigned K) const {
assert(BuiltinType::isPlaceholderTypeKind((BuiltinType::Kind) K))(static_cast<void> (0));
return isSpecificBuiltinType(K);
6947}

6949inline bool Type::isNonOverloadPlaceholderType() const {
if (const auto *BT = dyn_cast<BuiltinType>(this))
  return BT->isNonOverloadPlaceholderType();
return false;
6953}

6955inline bool Type::isVoidType() const {
return isSpecificBuiltinType(BuiltinType::Void);
6957}

6959inline bool Type::isHalfType() const {
// FIXME: Should we allow complex __fp16? Probably not.
return isSpecificBuiltinType(BuiltinType::Half);
6962}

6964inline bool Type::isFloat16Type() const {
return isSpecificBuiltinType(BuiltinType::Float16);
6966}

6968inline bool Type::isBFloat16Type() const {
return isSpecificBuiltinType(BuiltinType::BFloat16);
6970}

6972inline bool Type::isFloat128Type() const {
return isSpecificBuiltinType(BuiltinType::Float128);
6974}

6976inline bool Type::isNullPtrType() const {
return isSpecificBuiltinType(BuiltinType::NullPtr);
6978}

6980bool IsEnumDeclComplete(EnumDecl *);
6981bool IsEnumDeclScoped(EnumDecl *);

6983inline bool Type::isIntegerType() const {
if (const auto *BT = dyn_cast<BuiltinType>(CanonicalType))
  return BT->getKind() >= BuiltinType::Bool &&
         BT->getKind() <= BuiltinType::Int128;
if (const EnumType *ET = dyn_cast<EnumType>(CanonicalType)) {
  // Incomplete enum types are not treated as integer types.
  // FIXME: In C++, enum types are never integer types.
  return IsEnumDeclComplete(ET->getDecl()) &&
    !IsEnumDeclScoped(ET->getDecl());
}
return isExtIntType();
6994}

6996inline bool Type::isFixedPointType() const {
if (const auto *BT = dyn_cast<BuiltinType>(CanonicalType)) {
  return BT->getKind() >= BuiltinType::ShortAccum &&
         BT->getKind() <= BuiltinType::SatULongFract;
}
return false;
7002}

7004inline bool Type::isFixedPointOrIntegerType() const {
return isFixedPointType() || isIntegerType();
7006}

7008inline bool Type::isSaturatedFixedPointType() const {
if (const auto *BT = dyn_cast<BuiltinType>(CanonicalType)) {
  return BT->getKind() >= BuiltinType::SatShortAccum &&
         BT->getKind() <= BuiltinType::SatULongFract;
}
return false;
7014}

7016inline bool Type::isUnsaturatedFixedPointType() const {
return isFixedPointType() && !isSaturatedFixedPointType();
7018}

7020inline bool Type::isSignedFixedPointType() const {
if (const auto *BT = dyn_cast<BuiltinType>(CanonicalType)) {
  return ((BT->getKind() >= BuiltinType::ShortAccum &&
           BT->getKind() <= BuiltinType::LongAccum) ||
          (BT->getKind() >= BuiltinType::ShortFract &&
           BT->getKind() <= BuiltinType::LongFract) ||
          (BT->getKind() >= BuiltinType::SatShortAccum &&
           BT->getKind() <= BuiltinType::SatLongAccum) ||
          (BT->getKind() >= BuiltinType::SatShortFract &&
           BT->getKind() <= BuiltinType::SatLongFract));
}
return false;
7032}

7034inline bool Type::isUnsignedFixedPointType() const {
return isFixedPointType() && !isSignedFixedPointType();
7036}

7038inline bool Type::isScalarType() const {
if (const auto *BT = dyn_cast<BuiltinType>(CanonicalType))
  return BT->getKind() > BuiltinType::Void &&
         BT->getKind() <= BuiltinType::NullPtr;
if (const EnumType *ET = dyn_cast<EnumType>(CanonicalType))
  // Enums are scalar types, but only if they are defined.  Incomplete enums
  // are not treated as scalar types.
  return IsEnumDeclComplete(ET->getDecl());
return isa<PointerType>(CanonicalType) ||
       isa<BlockPointerType>(CanonicalType) ||
       isa<MemberPointerType>(CanonicalType) ||
       isa<ComplexType>(CanonicalType) ||
       isa<ObjCObjectPointerType>(CanonicalType) ||
       isExtIntType();
7052}

7054inline bool Type::isIntegralOrEnumerationType() const {
if (const auto *BT = dyn_cast<BuiltinType>(CanonicalType))
  return BT->getKind() >= BuiltinType::Bool &&
         BT->getKind() <= BuiltinType::Int128;

// Check for a complete enum type; incomplete enum types are not properly an
// enumeration type in the sense required here.
if (const auto *ET = dyn_cast<EnumType>(CanonicalType))
  return IsEnumDeclComplete(ET->getDecl());

return isExtIntType();
7065}

7067inline bool Type::isBooleanType() const {
if (const auto *BT = dyn_cast<BuiltinType>(CanonicalType))
  return BT->getKind() == BuiltinType::Bool;
return false;
7071}

7073inline bool Type::isUndeducedType() const {
auto *DT = getContainedDeducedType();
return DT && !DT->isDeduced();
7076}

7078/// Determines whether this is a type for which one can define
7079/// an overloaded operator.
7080inline bool Type::isOverloadableType() const {
return isDependentType() || isRecordType() || isEnumeralType();
7082}

7084/// Determines whether this type is written as a typedef-name.
7085inline bool Type::isTypedefNameType() const {
if (getAs<TypedefType>())
  return true;
if (auto *TST = getAs<TemplateSpecializationType>())
  return TST->isTypeAlias();
return false;
7091}

7093/// Determines whether this type can decay to a pointer type.
7094inline bool Type::canDecayToPointerType() const {
return isFunctionType() || isArrayType();
7096}

7098inline bool Type::hasPointerRepresentation() const {
return (isPointerType() || isReferenceType() || isBlockPointerType() ||
        isObjCObjectPointerType() || isNullPtrType());
7101}

7103inline bool Type::hasObjCPointerRepresentation() const {
return isObjCObjectPointerType();
7105}

7107inline const Type *Type::getBaseElementTypeUnsafe() const {
const Type *type = this;
while (const ArrayType *arrayType = type->getAsArrayTypeUnsafe())
  type = arrayType->getElementType().getTypePtr();
return type;
7112}

7114inline const Type *Type::getPointeeOrArrayElementType() const {
const Type *type = this;
if (type->isAnyPointerType())
  return type->getPointeeType().getTypePtr();
else if (type->isArrayType())
  return type->getBaseElementTypeUnsafe();
return type;
7121}
7122/// Insertion operator for partial diagnostics. This allows sending adress
7123/// spaces into a diagnostic with <<.
7124inline const StreamingDiagnostic &operator<<(const StreamingDiagnostic &PD,
                                           LangAS AS) {
PD.AddTaggedVal(static_cast<std::underlying_type_t<LangAS>>(AS),
                DiagnosticsEngine::ArgumentKind::ak_addrspace);
return PD;
7129}

7131/// Insertion operator for partial diagnostics. This allows sending Qualifiers
7132/// into a diagnostic with <<.
7133inline const StreamingDiagnostic &operator<<(const StreamingDiagnostic &PD,
                                           Qualifiers Q) {
PD.AddTaggedVal(Q.getAsOpaqueValue(),
                DiagnosticsEngine::ArgumentKind::ak_qual);
return PD;
7138}

7140/// Insertion operator for partial diagnostics.  This allows sending QualType's
7141/// into a diagnostic with <<.
7142inline const StreamingDiagnostic &operator<<(const StreamingDiagnostic &PD,
                                           QualType T) {
PD.AddTaggedVal(reinterpret_cast<intptr_t>(T.getAsOpaquePtr()),
                DiagnosticsEngine::ak_qualtype);
return PD;
7147}

7149// Helper class template that is used by Type::getAs to ensure that one does
7150// not try to look through a qualified type to get to an array type.
7151template <typename T>
7152using TypeIsArrayType =
  std::integral_constant<bool, std::is_same<T, ArrayType>::value ||
                                   std::is_base_of<ArrayType, T>::value>;

7156// Member-template getAs<specific type>'.
7157template <typename T> const T *Type::getAs() const {
static_assert(!TypeIsArrayType<T>::value,
              "ArrayType cannot be used with getAs!");

// If this is directly a T type, return it.
if (const auto *Ty = dyn_cast<T>(this))
  return Ty;

// If the canonical form of this type isn't the right kind, reject it.
if (!isa<T>(CanonicalType))
  return nullptr;

// If this is a typedef for the type, strip the typedef off without
// losing all typedef information.
return cast<T>(getUnqualifiedDesugaredType());
7172}

7174template <typename T> const T *Type::getAsAdjusted() const {
static_assert(!TypeIsArrayType<T>::value, "ArrayType cannot be used with getAsAdjusted!");

// If this is directly a T type, return it.
if (const auto *Ty = dyn_cast<T>(this))
  return Ty;

// If the canonical form of this type isn't the right kind, reject it.
if (!isa<T>(CanonicalType))
  return nullptr;

// Strip off type adjustments that do not modify the underlying nature of the
// type.
const Type *Ty = this;
while (Ty) {
  if (const auto *A = dyn_cast<AttributedType>(Ty))
    Ty = A->getModifiedType().getTypePtr();
  else if (const auto *E = dyn_cast<ElaboratedType>(Ty))
    Ty = E->desugar().getTypePtr();
  else if (const auto *P = dyn_cast<ParenType>(Ty))
    Ty = P->desugar().getTypePtr();
  else if (const auto *A = dyn_cast<AdjustedType>(Ty))
    Ty = A->desugar().getTypePtr();
  else if (const auto *M = dyn_cast<MacroQualifiedType>(Ty))
    Ty = M->desugar().getTypePtr();
  else
    break;
}

// Just because the canonical type is correct does not mean we can use cast<>,
// since we may not have stripped off all the sugar down to the base type.
return dyn_cast<T>(Ty);
7206}

7208inline const ArrayType *Type::getAsArrayTypeUnsafe() const {
// If this is directly an array type, return it.
if (const auto *arr = dyn_cast<ArrayType>(this))
  return arr;

// If the canonical form of this type isn't the right kind, reject it.
if (!isa<ArrayType>(CanonicalType))
  return nullptr;

// If this is a typedef for the type, strip the typedef off without
// losing all typedef information.
return cast<ArrayType>(getUnqualifiedDesugaredType());
7220}

7222template <typename T> const T *Type::castAs() const {
static_assert(!TypeIsArrayType<T>::value,
              "ArrayType cannot be used with castAs!");

if (const auto *ty = dyn_cast<T>(this)) return ty;
assert(isa<T>(CanonicalType))(static_cast<void> (0));
return cast<T>(getUnqualifiedDesugaredType());
7229}

7231inline const ArrayType *Type::castAsArrayTypeUnsafe() const {
assert(isa<ArrayType>(CanonicalType))(static_cast<void> (0));
if (const auto *arr = dyn_cast<ArrayType>(this)) return arr;
return cast<ArrayType>(getUnqualifiedDesugaredType());
7235}

7237DecayedType::DecayedType(QualType OriginalType, QualType DecayedPtr,
                       QualType CanonicalPtr)
  : AdjustedType(Decayed, OriginalType, DecayedPtr, CanonicalPtr) {
7240#ifndef NDEBUG1
QualType Adjusted = getAdjustedType();
(void)AttributedType::stripOuterNullability(Adjusted);
assert(isa<PointerType>(Adjusted))(static_cast<void> (0));
7244#endif
7245}

7247QualType DecayedType::getPointeeType() const {
QualType Decayed = getDecayedType();
(void)AttributedType::stripOuterNullability(Decayed);
return cast<PointerType>(Decayed)->getPointeeType();
7251}

7253// Get the decimal string representation of a fixed point type, represented
7254// as a scaled integer.
7255// TODO: At some point, we should change the arguments to instead just accept an
7256// APFixedPoint instead of APSInt and scale.
7257void FixedPointValueToString(SmallVectorImpl<char> &Str, llvm::APSInt Val,
                           unsigned Scale);

7260} // namespace clang

7262#endif // LLVM_CLANG_AST_TYPE_H

←

/build/llvm-toolchain-snapshot-14~++20210903100615+fd66b44ec19e/llvm/include/llvm/ADT/PointerUnion.h

→

1//===- llvm/ADT/PointerUnion.h - Discriminated Union of 2 Ptrs --*- C++ -*-===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8//
9// This file defines the PointerUnion class, which is a discriminated union of
10// pointer types.
11//
12//===----------------------------------------------------------------------===//

14#ifndef LLVM_ADT_POINTERUNION_H
15#define LLVM_ADT_POINTERUNION_H

17#include "llvm/ADT/DenseMapInfo.h"
18#include "llvm/ADT/PointerIntPair.h"
19#include "llvm/Support/PointerLikeTypeTraits.h"
20#include <cassert>
21#include <cstddef>
22#include <cstdint>

24namespace llvm {

26namespace pointer_union_detail {
/// Determine the number of bits required to store integers with values < n.
/// This is ceil(log2(n)).
constexpr int bitsRequired(unsigned n) {
  return n > 1 ? 1 + bitsRequired((n + 1) / 2) : 0;
}

template <typename... Ts> constexpr int lowBitsAvailable() {
  return std::min<int>({PointerLikeTypeTraits<Ts>::NumLowBitsAvailable...});
}

/// Find the index of a type in a list of types. TypeIndex<T, Us...>::Index
/// is the index of T in Us, or sizeof...(Us) if T does not appear in the
/// list.
template <typename T, typename ...Us> struct TypeIndex;
template <typename T, typename ...Us> struct TypeIndex<T, T, Us...> {
  static constexpr int Index = 0;
};
template <typename T, typename U, typename... Us>
struct TypeIndex<T, U, Us...> {
  static constexpr int Index = 1 + TypeIndex<T, Us...>::Index;
};
template <typename T> struct TypeIndex<T> {
  static constexpr int Index = 0;
};

/// Find the first type in a list of types.
template <typename T, typename...> struct GetFirstType {
  using type = T;
};

/// Provide PointerLikeTypeTraits for void* that is used by PointerUnion
/// for the template arguments.
template <typename ...PTs> class PointerUnionUIntTraits {
public:
  static inline void *getAsVoidPointer(void *P) { return P; }
  static inline void *getFromVoidPointer(void *P) { return P; }
  static constexpr int NumLowBitsAvailable = lowBitsAvailable<PTs...>();
};

template <typename Derived, typename ValTy, int I, typename ...Types>
class PointerUnionMembers;

template <typename Derived, typename ValTy, int I>
class PointerUnionMembers<Derived, ValTy, I> {
protected:
  ValTy Val;
  PointerUnionMembers() = default;
  PointerUnionMembers(ValTy Val) : Val(Val) {}

  friend struct PointerLikeTypeTraits<Derived>;
};

template <typename Derived, typename ValTy, int I, typename Type,
          typename ...Types>
class PointerUnionMembers<Derived, ValTy, I, Type, Types...>
    : public PointerUnionMembers<Derived, ValTy, I + 1, Types...> {
  using Base = PointerUnionMembers<Derived, ValTy, I + 1, Types...>;
public:
  using Base::Base;
  PointerUnionMembers() = default;
  PointerUnionMembers(Type V)
      : Base(ValTy(const_cast<void *>(
                       PointerLikeTypeTraits<Type>::getAsVoidPointer(V)),
                   I)) {}

  using Base::operator=;
  Derived &operator=(Type V) {
    this->Val = ValTy(
        const_cast<void *>(PointerLikeTypeTraits<Type>::getAsVoidPointer(V)),
        I);
    return static_cast<Derived &>(*this);
  };
};
100}

102/// A discriminated union of two or more pointer types, with the discriminator
103/// in the low bit of the pointer.
104///
105/// This implementation is extremely efficient in space due to leveraging the
106/// low bits of the pointer, while exposing a natural and type-safe API.
107///
108/// Common use patterns would be something like this:
109///    PointerUnion<int*, float*> P;
110///    P = (int*)0;
111///    printf("%d %d", P.is<int*>(), P.is<float*>());  // prints "1 0"
112///    X = P.get<int*>();     // ok.
113///    Y = P.get<float*>();   // runtime assertion failure.
114///    Z = P.get<double*>();  // compile time failure.
115///    P = (float*)0;
116///    Y = P.get<float*>();   // ok.
117///    X = P.get<int*>();     // runtime assertion failure.
118template <typename... PTs>
119class PointerUnion
  : public pointer_union_detail::PointerUnionMembers<
        PointerUnion<PTs...>,
        PointerIntPair<
            void *, pointer_union_detail::bitsRequired(sizeof...(PTs)), int,
            pointer_union_detail::PointerUnionUIntTraits<PTs...>>,
        0, PTs...> {
// The first type is special because we want to directly cast a pointer to a
// default-initialized union to a pointer to the first type. But we don't
// want PointerUnion to be a 'template <typename First, typename ...Rest>'
// because it's much more convenient to have a name for the whole pack. So
// split off the first type here.
using First = typename pointer_union_detail::GetFirstType<PTs...>::type;
using Base = typename PointerUnion::PointerUnionMembers;

134public:
PointerUnion() = default;

PointerUnion(std::nullptr_t) : PointerUnion() {}
using Base::Base;

/// Test if the pointer held in the union is null, regardless of
/// which type it is.
bool isNull() const { return !this->Val.getPointer(); }
38
←
Assuming the condition is false→
39
←
Returning zero, which participates in a condition later→
48
←
Assuming the condition is false→
49
←
Returning zero, which participates in a condition later→
56
←
Assuming the condition is true→
57
←
Returning the value 1, which participates in a condition later→

explicit operator bool() const { return !isNull(); }

/// Test if the Union currently holds the type matching T.
template <typename T> bool is() const {
  constexpr int Index = pointer_union_detail::TypeIndex<T, PTs...>::Index;
  static_assert(Index < sizeof...(PTs),
                "PointerUnion::is<T> given type not in the union");
  return this->Val.getInt() == Index;
}

/// Returns the value of the specified pointer type.
///
/// If the specified pointer type is incorrect, assert.
template <typename T> T get() const {
  assert(is<T>() && "Invalid accessor called")(static_cast<void> (0));
  return PointerLikeTypeTraits<T>::getFromVoidPointer(this->Val.getPointer());
}

/// Returns the current pointer if it is of the specified pointer type,
/// otherwise returns null.
template <typename T> T dyn_cast() const {
  if (is<T>())
    return get<T>();
  return T();
}

/// If the union is set to the first pointer type get an address pointing to
/// it.
First const *getAddrOfPtr1() const {
  return const_cast<PointerUnion *>(this)->getAddrOfPtr1();
}

/// If the union is set to the first pointer type get an address pointing to
/// it.
First *getAddrOfPtr1() {
  assert(is<First>() && "Val is not the first pointer")(static_cast<void> (0));
  assert((static_cast<void> (0))
      PointerLikeTypeTraits<First>::getAsVoidPointer(get<First>()) ==(static_cast<void> (0))
          this->Val.getPointer() &&(static_cast<void> (0))
      "Can't get the address because PointerLikeTypeTraits changes the ptr")(static_cast<void> (0));
  return const_cast<First *>(
      reinterpret_cast<const First *>(this->Val.getAddrOfPointer()));
}

/// Assignment from nullptr which just clears the union.
const PointerUnion &operator=(std::nullptr_t) {
  this->Val.initWithPointer(nullptr);
  return *this;
}

/// Assignment from elements of the union.
using Base::operator=;

void *getOpaqueValue() const { return this->Val.getOpaqueValue(); }
static inline PointerUnion getFromOpaqueValue(void *VP) {
  PointerUnion V;
  V.Val = decltype(V.Val)::getFromOpaqueValue(VP);
  return V;
}
203};

205template <typename ...PTs>
206bool operator==(PointerUnion<PTs...> lhs, PointerUnion<PTs...> rhs) {
return lhs.getOpaqueValue() == rhs.getOpaqueValue();
208}

210template <typename ...PTs>
211bool operator!=(PointerUnion<PTs...> lhs, PointerUnion<PTs...> rhs) {
return lhs.getOpaqueValue() != rhs.getOpaqueValue();
213}

215template <typename ...PTs>
216bool operator<(PointerUnion<PTs...> lhs, PointerUnion<PTs...> rhs) {
return lhs.getOpaqueValue() < rhs.getOpaqueValue();
218}

220// Teach SmallPtrSet that PointerUnion is "basically a pointer", that has
221// # low bits available = min(PT1bits,PT2bits)-1.
222template <typename ...PTs>
223struct PointerLikeTypeTraits<PointerUnion<PTs...>> {
static inline void *getAsVoidPointer(const PointerUnion<PTs...> &P) {
  return P.getOpaqueValue();
}

static inline PointerUnion<PTs...> getFromVoidPointer(void *P) {
  return PointerUnion<PTs...>::getFromOpaqueValue(P);
}

// The number of bits available are the min of the pointer types minus the
// bits needed for the discriminator.
static constexpr int NumLowBitsAvailable = PointerLikeTypeTraits<decltype(
    PointerUnion<PTs...>::Val)>::NumLowBitsAvailable;
236};

238// Teach DenseMap how to use PointerUnions as keys.
239template <typename ...PTs> struct DenseMapInfo<PointerUnion<PTs...>> {
using Union = PointerUnion<PTs...>;
using FirstInfo =
    DenseMapInfo<typename pointer_union_detail::GetFirstType<PTs...>::type>;

static inline Union getEmptyKey() { return Union(FirstInfo::getEmptyKey()); }

static inline Union getTombstoneKey() {
  return Union(FirstInfo::getTombstoneKey());
}

static unsigned getHashValue(const Union &UnionVal) {
  intptr_t key = (intptr_t)UnionVal.getOpaqueValue();
  return DenseMapInfo<intptr_t>::getHashValue(key);
}

static bool isEqual(const Union &LHS, const Union &RHS) {
  return LHS == RHS;
}
258};

260} // end namespace llvm

262#endif // LLVM_ADT_POINTERUNION_H

←

/build/llvm-toolchain-snapshot-14~++20210903100615+fd66b44ec19e/clang/include/clang/AST/ASTContext.h

1//===- ASTContext.h - Context to hold long-lived AST nodes ------*- C++ -*-===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8//
9/// \file
10/// Defines the clang::ASTContext interface.
11//
12//===----------------------------------------------------------------------===//

14#ifndef LLVM_CLANG_AST_ASTCONTEXT_H
15#define LLVM_CLANG_AST_ASTCONTEXT_H

17#include "clang/AST/ASTContextAllocate.h"
18#include "clang/AST/ASTFwd.h"
19#include "clang/AST/CanonicalType.h"
20#include "clang/AST/CommentCommandTraits.h"
21#include "clang/AST/ComparisonCategories.h"
22#include "clang/AST/Decl.h"
23#include "clang/AST/DeclBase.h"
24#include "clang/AST/DeclarationName.h"
25#include "clang/AST/ExternalASTSource.h"
26#include "clang/AST/NestedNameSpecifier.h"
27#include "clang/AST/PrettyPrinter.h"
28#include "clang/AST/RawCommentList.h"
29#include "clang/AST/TemplateName.h"
30#include "clang/AST/Type.h"
31#include "clang/Basic/AddressSpaces.h"
32#include "clang/Basic/AttrKinds.h"
33#include "clang/Basic/IdentifierTable.h"
34#include "clang/Basic/LLVM.h"
35#include "clang/Basic/LangOptions.h"
36#include "clang/Basic/Linkage.h"
37#include "clang/Basic/NoSanitizeList.h"
38#include "clang/Basic/OperatorKinds.h"
39#include "clang/Basic/PartialDiagnostic.h"
40#include "clang/Basic/ProfileList.h"
41#include "clang/Basic/SourceLocation.h"
42#include "clang/Basic/Specifiers.h"
43#include "clang/Basic/TargetCXXABI.h"
44#include "clang/Basic/XRayLists.h"
45#include "llvm/ADT/APSInt.h"
46#include "llvm/ADT/ArrayRef.h"
47#include "llvm/ADT/DenseMap.h"
48#include "llvm/ADT/DenseSet.h"
49#include "llvm/ADT/FoldingSet.h"
50#include "llvm/ADT/IntrusiveRefCntPtr.h"
51#include "llvm/ADT/MapVector.h"
52#include "llvm/ADT/None.h"
53#include "llvm/ADT/Optional.h"
54#include "llvm/ADT/PointerIntPair.h"
55#include "llvm/ADT/PointerUnion.h"
56#include "llvm/ADT/SmallVector.h"
57#include "llvm/ADT/StringMap.h"
58#include "llvm/ADT/StringRef.h"
59#include "llvm/ADT/TinyPtrVector.h"
60#include "llvm/ADT/Triple.h"
61#include "llvm/ADT/iterator_range.h"
62#include "llvm/Support/AlignOf.h"
63#include "llvm/Support/Allocator.h"
64#include "llvm/Support/Casting.h"
65#include "llvm/Support/Compiler.h"
66#include "llvm/Support/TypeSize.h"
67#include <cassert>
68#include <cstddef>
69#include <cstdint>
70#include <iterator>
71#include <memory>
72#include <string>
73#include <type_traits>
74#include <utility>
75#include <vector>

77namespace llvm {

79class APFixedPoint;
80class FixedPointSemantics;
81struct fltSemantics;
82template <typename T, unsigned N> class SmallPtrSet;

84} // namespace llvm

86namespace clang {

88class APValue;
89class ASTMutationListener;
90class ASTRecordLayout;
91class AtomicExpr;
92class BlockExpr;
93class BuiltinTemplateDecl;
94class CharUnits;
95class ConceptDecl;
96class CXXABI;
97class CXXConstructorDecl;
98class CXXMethodDecl;
99class CXXRecordDecl;
100class DiagnosticsEngine;
101class ParentMapContext;
102class DynTypedNode;
103class DynTypedNodeList;
104class Expr;
105class GlobalDecl;
106class ItaniumMangleContext;
107class MangleContext;
108class MangleNumberingContext;
109class MaterializeTemporaryExpr;
110class MemberSpecializationInfo;
111class Module;
112struct MSGuidDeclParts;
113class ObjCCategoryDecl;
114class ObjCCategoryImplDecl;
115class ObjCContainerDecl;
116class ObjCImplDecl;
117class ObjCImplementationDecl;
118class ObjCInterfaceDecl;
119class ObjCIvarDecl;
120class ObjCMethodDecl;
121class ObjCPropertyDecl;
122class ObjCPropertyImplDecl;
123class ObjCProtocolDecl;
124class ObjCTypeParamDecl;
125class OMPTraitInfo;
126struct ParsedTargetAttr;
127class Preprocessor;
128class Stmt;
129class StoredDeclsMap;
130class TargetAttr;
131class TargetInfo;
132class TemplateDecl;
133class TemplateParameterList;
134class TemplateTemplateParmDecl;
135class TemplateTypeParmDecl;
136class UnresolvedSetIterator;
137class UsingShadowDecl;
138class VarTemplateDecl;
139class VTableContextBase;
140struct BlockVarCopyInit;

142namespace Builtin {

144class Context;

146} // namespace Builtin

148enum BuiltinTemplateKind : int;
149enum OpenCLTypeKind : uint8_t;

151namespace comments {

153class FullComment;

155} // namespace comments

157namespace interp {

159class Context;

161} // namespace interp

163namespace serialization {
164template <class> class AbstractTypeReader;
165} // namespace serialization

167enum class AlignRequirementKind {
/// The alignment was not explicit in code.
None,

/// The alignment comes from an alignment attribute on a typedef.
RequiredByTypedef,

/// The alignment comes from an alignment attribute on a record type.
RequiredByRecord,

/// The alignment comes from an alignment attribute on a enum type.
RequiredByEnum,
179};

181struct TypeInfo {
uint64_t Width = 0;
unsigned Align = 0;
AlignRequirementKind AlignRequirement;

TypeInfo() : AlignRequirement(AlignRequirementKind::None) {}
TypeInfo(uint64_t Width, unsigned Align,
         AlignRequirementKind AlignRequirement)
    : Width(Width), Align(Align), AlignRequirement(AlignRequirement) {}
bool isAlignRequired() {
  return AlignRequirement != AlignRequirementKind::None;
}
193};

195struct TypeInfoChars {
CharUnits Width;
CharUnits Align;
AlignRequirementKind AlignRequirement;

TypeInfoChars() : AlignRequirement(AlignRequirementKind::None) {}
TypeInfoChars(CharUnits Width, CharUnits Align,
              AlignRequirementKind AlignRequirement)
    : Width(Width), Align(Align), AlignRequirement(AlignRequirement) {}
bool isAlignRequired() {
  return AlignRequirement != AlignRequirementKind::None;
}
207};

209/// Holds long-lived AST nodes (such as types and decls) that can be
210/// referred to throughout the semantic analysis of a file.
211class ASTContext : public RefCountedBase<ASTContext> {
friend class NestedNameSpecifier;

mutable SmallVector<Type *, 0> Types;
mutable llvm::FoldingSet<ExtQuals> ExtQualNodes;
mutable llvm::FoldingSet<ComplexType> ComplexTypes;
mutable llvm::FoldingSet<PointerType> PointerTypes;
mutable llvm::FoldingSet<AdjustedType> AdjustedTypes;
mutable llvm::FoldingSet<BlockPointerType> BlockPointerTypes;
mutable llvm::FoldingSet<LValueReferenceType> LValueReferenceTypes;
mutable llvm::FoldingSet<RValueReferenceType> RValueReferenceTypes;
mutable llvm::FoldingSet<MemberPointerType> MemberPointerTypes;
mutable llvm::ContextualFoldingSet<ConstantArrayType, ASTContext &>
    ConstantArrayTypes;
mutable llvm::FoldingSet<IncompleteArrayType> IncompleteArrayTypes;
mutable std::vector<VariableArrayType*> VariableArrayTypes;
mutable llvm::FoldingSet<DependentSizedArrayType> DependentSizedArrayTypes;
mutable llvm::FoldingSet<DependentSizedExtVectorType>
  DependentSizedExtVectorTypes;
mutable llvm::FoldingSet<DependentAddressSpaceType>
    DependentAddressSpaceTypes;
mutable llvm::FoldingSet<VectorType> VectorTypes;
mutable llvm::FoldingSet<DependentVectorType> DependentVectorTypes;
mutable llvm::FoldingSet<ConstantMatrixType> MatrixTypes;
mutable llvm::FoldingSet<DependentSizedMatrixType> DependentSizedMatrixTypes;
mutable llvm::FoldingSet<FunctionNoProtoType> FunctionNoProtoTypes;
mutable llvm::ContextualFoldingSet<FunctionProtoType, ASTContext&>
  FunctionProtoTypes;
mutable llvm::FoldingSet<DependentTypeOfExprType> DependentTypeOfExprTypes;
mutable llvm::FoldingSet<DependentDecltypeType> DependentDecltypeTypes;
mutable llvm::FoldingSet<TemplateTypeParmType> TemplateTypeParmTypes;
mutable llvm::FoldingSet<ObjCTypeParamType> ObjCTypeParamTypes;
mutable llvm::FoldingSet<SubstTemplateTypeParmType>
  SubstTemplateTypeParmTypes;
mutable llvm::FoldingSet<SubstTemplateTypeParmPackType>
  SubstTemplateTypeParmPackTypes;
mutable llvm::ContextualFoldingSet<TemplateSpecializationType, ASTContext&>
  TemplateSpecializationTypes;
mutable llvm::FoldingSet<ParenType> ParenTypes;
mutable llvm::FoldingSet<ElaboratedType> ElaboratedTypes;
mutable llvm::FoldingSet<DependentNameType> DependentNameTypes;
mutable llvm::ContextualFoldingSet<DependentTemplateSpecializationType,
                                   ASTContext&>
  DependentTemplateSpecializationTypes;
llvm::FoldingSet<PackExpansionType> PackExpansionTypes;
mutable llvm::FoldingSet<ObjCObjectTypeImpl> ObjCObjectTypes;
mutable llvm::FoldingSet<ObjCObjectPointerType> ObjCObjectPointerTypes;
mutable llvm::FoldingSet<DependentUnaryTransformType>
  DependentUnaryTransformTypes;
mutable llvm::ContextualFoldingSet<AutoType, ASTContext&> AutoTypes;
mutable llvm::FoldingSet<DeducedTemplateSpecializationType>
  DeducedTemplateSpecializationTypes;
mutable llvm::FoldingSet<AtomicType> AtomicTypes;
llvm::FoldingSet<AttributedType> AttributedTypes;
mutable llvm::FoldingSet<PipeType> PipeTypes;
mutable llvm::FoldingSet<ExtIntType> ExtIntTypes;
mutable llvm::FoldingSet<DependentExtIntType> DependentExtIntTypes;

mutable llvm::FoldingSet<QualifiedTemplateName> QualifiedTemplateNames;
mutable llvm::FoldingSet<DependentTemplateName> DependentTemplateNames;
mutable llvm::FoldingSet<SubstTemplateTemplateParmStorage>
  SubstTemplateTemplateParms;
mutable llvm::ContextualFoldingSet<SubstTemplateTemplateParmPackStorage,
                                   ASTContext&>
  SubstTemplateTemplateParmPacks;

/// The set of nested name specifiers.
///
/// This set is managed by the NestedNameSpecifier class.
mutable llvm::FoldingSet<NestedNameSpecifier> NestedNameSpecifiers;
mutable NestedNameSpecifier *GlobalNestedNameSpecifier = nullptr;

/// A cache mapping from RecordDecls to ASTRecordLayouts.
///
/// This is lazily created.  This is intentionally not serialized.
mutable llvm::DenseMap<const RecordDecl*, const ASTRecordLayout*>
  ASTRecordLayouts;
mutable llvm::DenseMap<const ObjCContainerDecl*, const ASTRecordLayout*>
  ObjCLayouts;

/// A cache from types to size and alignment information.
using TypeInfoMap = llvm::DenseMap<const Type *, struct TypeInfo>;
mutable TypeInfoMap MemoizedTypeInfo;

/// A cache from types to unadjusted alignment information. Only ARM and
/// AArch64 targets need this information, keeping it separate prevents
/// imposing overhead on TypeInfo size.
using UnadjustedAlignMap = llvm::DenseMap<const Type *, unsigned>;
mutable UnadjustedAlignMap MemoizedUnadjustedAlign;

/// A cache mapping from CXXRecordDecls to key functions.
llvm::DenseMap<const CXXRecordDecl*, LazyDeclPtr> KeyFunctions;

/// Mapping from ObjCContainers to their ObjCImplementations.
llvm::DenseMap<ObjCContainerDecl*, ObjCImplDecl*> ObjCImpls;

/// Mapping from ObjCMethod to its duplicate declaration in the same
/// interface.
llvm::DenseMap<const ObjCMethodDecl*,const ObjCMethodDecl*> ObjCMethodRedecls;

/// Mapping from __block VarDecls to BlockVarCopyInit.
llvm::DenseMap<const VarDecl *, BlockVarCopyInit> BlockVarCopyInits;

/// Mapping from GUIDs to the corresponding MSGuidDecl.
mutable llvm::FoldingSet<MSGuidDecl> MSGuidDecls;

/// Mapping from APValues to the corresponding TemplateParamObjects.
mutable llvm::FoldingSet<TemplateParamObjectDecl> TemplateParamObjectDecls;

/// A cache mapping a string value to a StringLiteral object with the same
/// value.
///
/// This is lazily created.  This is intentionally not serialized.
mutable llvm::StringMap<StringLiteral *> StringLiteralCache;

/// MD5 hash of CUID. It is calculated when first used and cached by this
/// data member.
mutable std::string CUIDHash;

/// Representation of a "canonical" template template parameter that
/// is used in canonical template names.
class CanonicalTemplateTemplateParm : public llvm::FoldingSetNode {
  TemplateTemplateParmDecl *Parm;

public:
  CanonicalTemplateTemplateParm(TemplateTemplateParmDecl *Parm)
      : Parm(Parm) {}

  TemplateTemplateParmDecl *getParam() const { return Parm; }

  void Profile(llvm::FoldingSetNodeID &ID, const ASTContext &C) {
    Profile(ID, C, Parm);
  }

  static void Profile(llvm::FoldingSetNodeID &ID,
                      const ASTContext &C,
                      TemplateTemplateParmDecl *Parm);
};
mutable llvm::ContextualFoldingSet<CanonicalTemplateTemplateParm,
                                   const ASTContext&>
  CanonTemplateTemplateParms;

TemplateTemplateParmDecl *
  getCanonicalTemplateTemplateParmDecl(TemplateTemplateParmDecl *TTP) const;

/// The typedef for the __int128_t type.
mutable TypedefDecl *Int128Decl = nullptr;

/// The typedef for the __uint128_t type.
mutable TypedefDecl *UInt128Decl = nullptr;

/// The typedef for the target specific predefined
/// __builtin_va_list type.
mutable TypedefDecl *BuiltinVaListDecl = nullptr;

/// The typedef for the predefined \c __builtin_ms_va_list type.
mutable TypedefDecl *BuiltinMSVaListDecl = nullptr;

/// The typedef for the predefined \c id type.
mutable TypedefDecl *ObjCIdDecl = nullptr;

/// The typedef for the predefined \c SEL type.
mutable TypedefDecl *ObjCSelDecl = nullptr;

/// The typedef for the predefined \c Class type.
mutable TypedefDecl *ObjCClassDecl = nullptr;

/// The typedef for the predefined \c Protocol class in Objective-C.
mutable ObjCInterfaceDecl *ObjCProtocolClassDecl = nullptr;

/// The typedef for the predefined 'BOOL' type.
mutable TypedefDecl *BOOLDecl = nullptr;

// Typedefs which may be provided defining the structure of Objective-C
// pseudo-builtins
QualType ObjCIdRedefinitionType;
QualType ObjCClassRedefinitionType;
QualType ObjCSelRedefinitionType;

/// The identifier 'bool'.
mutable IdentifierInfo *BoolName = nullptr;

/// The identifier 'NSObject'.
mutable IdentifierInfo *NSObjectName = nullptr;

/// The identifier 'NSCopying'.
IdentifierInfo *NSCopyingName = nullptr;

/// The identifier '__make_integer_seq'.
mutable IdentifierInfo *MakeIntegerSeqName = nullptr;

/// The identifier '__type_pack_element'.
mutable IdentifierInfo *TypePackElementName = nullptr;

QualType ObjCConstantStringType;
mutable RecordDecl *CFConstantStringTagDecl = nullptr;
mutable TypedefDecl *CFConstantStringTypeDecl = nullptr;

mutable QualType ObjCSuperType;

QualType ObjCNSStringType;

/// The typedef declaration for the Objective-C "instancetype" type.
TypedefDecl *ObjCInstanceTypeDecl = nullptr;

/// The type for the C FILE type.
TypeDecl *FILEDecl = nullptr;

/// The type for the C jmp_buf type.
TypeDecl *jmp_bufDecl = nullptr;

/// The type for the C sigjmp_buf type.
TypeDecl *sigjmp_bufDecl = nullptr;

/// The type for the C ucontext_t type.
TypeDecl *ucontext_tDecl = nullptr;

/// Type for the Block descriptor for Blocks CodeGen.
///
/// Since this is only used for generation of debug info, it is not
/// serialized.
mutable RecordDecl *BlockDescriptorType = nullptr;

/// Type for the Block descriptor for Blocks CodeGen.
///
/// Since this is only used for generation of debug info, it is not
/// serialized.
mutable RecordDecl *BlockDescriptorExtendedType = nullptr;

/// Declaration for the CUDA cudaConfigureCall function.
FunctionDecl *cudaConfigureCallDecl = nullptr;

/// Keeps track of all declaration attributes.
///
/// Since so few decls have attrs, we keep them in a hash map instead of
/// wasting space in the Decl class.
llvm::DenseMap<const Decl*, AttrVec*> DeclAttrs;

/// A mapping from non-redeclarable declarations in modules that were
/// merged with other declarations to the canonical declaration that they were
/// merged into.
llvm::DenseMap<Decl*, Decl*> MergedDecls;

/// A mapping from a defining declaration to a list of modules (other
/// than the owning module of the declaration) that contain merged
/// definitions of that entity.
llvm::DenseMap<NamedDecl*, llvm::TinyPtrVector<Module*>> MergedDefModules;

/// Initializers for a module, in order. Each Decl will be either
/// something that has a semantic effect on startup (such as a variable with
/// a non-constant initializer), or an ImportDecl (which recursively triggers
/// initialization of another module).
struct PerModuleInitializers {
  llvm::SmallVector<Decl*, 4> Initializers;
  llvm::SmallVector<uint32_t, 4> LazyInitializers;

  void resolve(ASTContext &Ctx);
};
llvm::DenseMap<Module*, PerModuleInitializers*> ModuleInitializers;

ASTContext &this_() { return *this; }

473public:
/// A type synonym for the TemplateOrInstantiation mapping.
using TemplateOrSpecializationInfo =
    llvm::PointerUnion<VarTemplateDecl *, MemberSpecializationInfo *>;

478private:
friend class ASTDeclReader;
friend class ASTReader;
friend class ASTWriter;
template <class> friend class serialization::AbstractTypeReader;
friend class CXXRecordDecl;
friend class IncrementalParser;

/// A mapping to contain the template or declaration that
/// a variable declaration describes or was instantiated from,
/// respectively.
///
/// For non-templates, this value will be NULL. For variable
/// declarations that describe a variable template, this will be a
/// pointer to a VarTemplateDecl. For static data members
/// of class template specializations, this will be the
/// MemberSpecializationInfo referring to the member variable that was
/// instantiated or specialized. Thus, the mapping will keep track of
/// the static data member templates from which static data members of
/// class template specializations were instantiated.
///
/// Given the following example:
///
/// \code
/// template<typename T>
/// struct X {
///   static T value;
/// };
///
/// template<typename T>
///   T X<T>::value = T(17);
///
/// int *x = &X<int>::value;
/// \endcode
///
/// This mapping will contain an entry that maps from the VarDecl for
/// X<int>::value to the corresponding VarDecl for X<T>::value (within the
/// class template X) and will be marked TSK_ImplicitInstantiation.
llvm::DenseMap<const VarDecl *, TemplateOrSpecializationInfo>
TemplateOrInstantiation;

/// Keeps track of the declaration from which a using declaration was
/// created during instantiation.
///
/// The source and target declarations are always a UsingDecl, an
/// UnresolvedUsingValueDecl, or an UnresolvedUsingTypenameDecl.
///
/// For example:
/// \code
/// template<typename T>
/// struct A {
///   void f();
/// };
///
/// template<typename T>
/// struct B : A<T> {
///   using A<T>::f;
/// };
///
/// template struct B<int>;
/// \endcode
///
/// This mapping will contain an entry that maps from the UsingDecl in
/// B<int> to the UnresolvedUsingDecl in B<T>.
llvm::DenseMap<NamedDecl *, NamedDecl *> InstantiatedFromUsingDecl;

/// Like InstantiatedFromUsingDecl, but for using-enum-declarations. Maps
/// from the instantiated using-enum to the templated decl from whence it
/// came.
/// Note that using-enum-declarations cannot be dependent and
/// thus will never be instantiated from an "unresolved"
/// version thereof (as with using-declarations), so each mapping is from
/// a (resolved) UsingEnumDecl to a (resolved) UsingEnumDecl.
llvm::DenseMap<UsingEnumDecl *, UsingEnumDecl *>
    InstantiatedFromUsingEnumDecl;

/// Simlarly maps instantiated UsingShadowDecls to their origin.
llvm::DenseMap<UsingShadowDecl*, UsingShadowDecl*>
  InstantiatedFromUsingShadowDecl;

llvm::DenseMap<FieldDecl *, FieldDecl *> InstantiatedFromUnnamedFieldDecl;

/// Mapping that stores the methods overridden by a given C++
/// member function.
///
/// Since most C++ member functions aren't virtual and therefore
/// don't override anything, we store the overridden functions in
/// this map on the side rather than within the CXXMethodDecl structure.
using CXXMethodVector = llvm::TinyPtrVector<const CXXMethodDecl *>;
llvm::DenseMap<const CXXMethodDecl *, CXXMethodVector> OverriddenMethods;

/// Mapping from each declaration context to its corresponding
/// mangling numbering context (used for constructs like lambdas which
/// need to be consistently numbered for the mangler).
llvm::DenseMap<const DeclContext *, std::unique_ptr<MangleNumberingContext>>
    MangleNumberingContexts;
llvm::DenseMap<const Decl *, std::unique_ptr<MangleNumberingContext>>
    ExtraMangleNumberingContexts;

/// Side-table of mangling numbers for declarations which rarely
/// need them (like static local vars).
llvm::MapVector<const NamedDecl *, unsigned> MangleNumbers;
llvm::MapVector<const VarDecl *, unsigned> StaticLocalNumbers;
/// Mapping the associated device lambda mangling number if present.
mutable llvm::DenseMap<const CXXRecordDecl *, unsigned>
    DeviceLambdaManglingNumbers;

/// Mapping that stores parameterIndex values for ParmVarDecls when
/// that value exceeds the bitfield size of ParmVarDeclBits.ParameterIndex.
using ParameterIndexTable = llvm::DenseMap<const VarDecl *, unsigned>;
ParameterIndexTable ParamIndices;

ImportDecl *FirstLocalImport = nullptr;
ImportDecl *LastLocalImport = nullptr;

TranslationUnitDecl *TUDecl = nullptr;
mutable ExternCContextDecl *ExternCContext = nullptr;
mutable BuiltinTemplateDecl *MakeIntegerSeqDecl = nullptr;
mutable BuiltinTemplateDecl *TypePackElementDecl = nullptr;

/// The associated SourceManager object.
SourceManager &SourceMgr;

/// The language options used to create the AST associated with
///  this ASTContext object.
LangOptions &LangOpts;

/// NoSanitizeList object that is used by sanitizers to decide which
/// entities should not be instrumented.
std::unique_ptr<NoSanitizeList> NoSanitizeL;

/// Function filtering mechanism to determine whether a given function
/// should be imbued with the XRay "always" or "never" attributes.
std::unique_ptr<XRayFunctionFilter> XRayFilter;

/// ProfileList object that is used by the profile instrumentation
/// to decide which entities should be instrumented.
std::unique_ptr<ProfileList> ProfList;

/// The allocator used to create AST objects.
///
/// AST objects are never destructed; rather, all memory associated with the
/// AST objects will be released when the ASTContext itself is destroyed.
mutable llvm::BumpPtrAllocator BumpAlloc;

/// Allocator for partial diagnostics.
PartialDiagnostic::DiagStorageAllocator DiagAllocator;

/// The current C++ ABI.
std::unique_ptr<CXXABI> ABI;
CXXABI *createCXXABI(const TargetInfo &T);

/// The logical -> physical address space map.
const LangASMap *AddrSpaceMap = nullptr;

/// Address space map mangling must be used with language specific
/// address spaces (e.g. OpenCL/CUDA)
bool AddrSpaceMapMangling;

const TargetInfo *Target = nullptr;
const TargetInfo *AuxTarget = nullptr;
clang::PrintingPolicy PrintingPolicy;
std::unique_ptr<interp::Context> InterpContext;
std::unique_ptr<ParentMapContext> ParentMapCtx;

/// Keeps track of the deallocated DeclListNodes for future reuse.
DeclListNode *ListNodeFreeList = nullptr;

646public:
IdentifierTable &Idents;
SelectorTable &Selectors;
Builtin::Context &BuiltinInfo;
const TranslationUnitKind TUKind;
mutable DeclarationNameTable DeclarationNames;
IntrusiveRefCntPtr<ExternalASTSource> ExternalSource;
ASTMutationListener *Listener = nullptr;

/// Returns the clang bytecode interpreter context.
interp::Context &getInterpContext();

/// Returns the dynamic AST node parent map context.
ParentMapContext &getParentMapContext();

// A traversal scope limits the parts of the AST visible to certain analyses.
// RecursiveASTVisitor only visits specified children of TranslationUnitDecl.
// getParents() will only observe reachable parent edges.
//
// The scope is defined by a set of "top-level" declarations which will be
// visible under the TranslationUnitDecl.
// Initially, it is the entire TU, represented by {getTranslationUnitDecl()}.
//
// After setTraversalScope({foo, bar}), the exposed AST looks like:
// TranslationUnitDecl
//  - foo
//    - ...
//  - bar
//    - ...
// All other siblings of foo and bar are pruned from the tree.
// (However they are still accessible via TranslationUnitDecl->decls())
//
// Changing the scope clears the parent cache, which is expensive to rebuild.
std::vector<Decl *> getTraversalScope() const { return TraversalScope; }
void setTraversalScope(const std::vector<Decl *> &);

/// Forwards to get node parents from the ParentMapContext. New callers should
/// use ParentMapContext::getParents() directly.
template <typename NodeT> DynTypedNodeList getParents(const NodeT &Node);

const clang::PrintingPolicy &getPrintingPolicy() const {
  return PrintingPolicy;
}

void setPrintingPolicy(const clang::PrintingPolicy &Policy) {
  PrintingPolicy = Policy;
}

SourceManager& getSourceManager() { return SourceMgr; }
const SourceManager& getSourceManager() const { return SourceMgr; }

llvm::BumpPtrAllocator &getAllocator() const {
  return BumpAlloc;
}

void *Allocate(size_t Size, unsigned Align = 8) const {
  return BumpAlloc.Allocate(Size, Align);
}
template <typename T> T *Allocate(size_t Num = 1) const {
  return static_cast<T *>(Allocate(Num * sizeof(T), alignof(T)));
}
void Deallocate(void *Ptr) const {}

/// Allocates a \c DeclListNode or returns one from the \c ListNodeFreeList
/// pool.
DeclListNode *AllocateDeclListNode(clang::NamedDecl *ND) {
  if (DeclListNode *Alloc = ListNodeFreeList) {
    ListNodeFreeList = Alloc->Rest.dyn_cast<DeclListNode*>();
    Alloc->D = ND;
    Alloc->Rest = nullptr;
    return Alloc;
  }
  return new (*this) DeclListNode(ND);
}
/// Deallcates a \c DeclListNode by returning it to the \c ListNodeFreeList
/// pool.
void DeallocateDeclListNode(DeclListNode *N) {
  N->Rest = ListNodeFreeList;
  ListNodeFreeList = N;
}

/// Return the total amount of physical memory allocated for representing
/// AST nodes and type information.
size_t getASTAllocatedMemory() const {
  return BumpAlloc.getTotalMemory();
}

/// Return the total memory used for various side tables.
size_t getSideTableAllocatedMemory() const;

PartialDiagnostic::DiagStorageAllocator &getDiagAllocator() {
  return DiagAllocator;
}

const TargetInfo &getTargetInfo() const { return *Target; }
const TargetInfo *getAuxTargetInfo() const { return AuxTarget; }

/// getIntTypeForBitwidth -
/// sets integer QualTy according to specified details:
/// bitwidth, signed/unsigned.
/// Returns empty type if there is no appropriate target types.
QualType getIntTypeForBitwidth(unsigned DestWidth,
                               unsigned Signed) const;

/// getRealTypeForBitwidth -
/// sets floating point QualTy according to specified bitwidth.
/// Returns empty type if there is no appropriate target types.
QualType getRealTypeForBitwidth(unsigned DestWidth, bool ExplicitIEEE) const;

bool AtomicUsesUnsupportedLibcall(const AtomicExpr *E) const;

const LangOptions& getLangOpts() const { return LangOpts; }

// If this condition is false, typo correction must be performed eagerly
// rather than delayed in many places, as it makes use of dependent types.
// the condition is false for clang's C-only codepath, as it doesn't support
// dependent types yet.
bool isDependenceAllowed() const {
  return LangOpts.CPlusPlus || LangOpts.RecoveryAST;
}

const NoSanitizeList &getNoSanitizeList() const { return *NoSanitizeL; }

const XRayFunctionFilter &getXRayFilter() const {
  return *XRayFilter;
}

const ProfileList &getProfileList() const { return *ProfList; }

DiagnosticsEngine &getDiagnostics() const;

FullSourceLoc getFullLoc(SourceLocation Loc) const {
  return FullSourceLoc(Loc,SourceMgr);
}

/// Return the C++ ABI kind that should be used. The C++ ABI can be overriden
/// at compile time with `-fc++-abi=`. If this is not provided, we instead use
/// the default ABI set by the target.
TargetCXXABI::Kind getCXXABIKind() const;

/// All comments in this translation unit.
RawCommentList Comments;

/// True if comments are already loaded from ExternalASTSource.
mutable bool CommentsLoaded = false;

/// Mapping from declaration to directly attached comment.
///
/// Raw comments are owned by Comments list.  This mapping is populated
/// lazily.
mutable llvm::DenseMap<const Decl *, const RawComment *> DeclRawComments;

/// Mapping from canonical declaration to the first redeclaration in chain
/// that has a comment attached.
///
/// Raw comments are owned by Comments list.  This mapping is populated
/// lazily.
mutable llvm::DenseMap<const Decl *, const Decl *> RedeclChainComments;

/// Keeps track of redeclaration chains that don't have any comment attached.
/// Mapping from canonical declaration to redeclaration chain that has no
/// comments attached to any redeclaration. Specifically it's mapping to
/// the last redeclaration we've checked.
///
/// Shall not contain declarations that have comments attached to any
/// redeclaration in their chain.
mutable llvm::DenseMap<const Decl *, const Decl *> CommentlessRedeclChains;

/// Mapping from declarations to parsed comments attached to any
/// redeclaration.
mutable llvm::DenseMap<const Decl *, comments::FullComment *> ParsedComments;

/// Attaches \p Comment to \p OriginalD and to its redeclaration chain
/// and removes the redeclaration chain from the set of commentless chains.
///
/// Don't do anything if a comment has already been attached to \p OriginalD
/// or its redeclaration chain.
void cacheRawCommentForDecl(const Decl &OriginalD,
                            const RawComment &Comment) const;

/// \returns searches \p CommentsInFile for doc comment for \p D.
///
/// \p RepresentativeLocForDecl is used as a location for searching doc
/// comments. \p CommentsInFile is a mapping offset -> comment of files in the
/// same file where \p RepresentativeLocForDecl is.
RawComment *getRawCommentForDeclNoCacheImpl(
    const Decl *D, const SourceLocation RepresentativeLocForDecl,
    const std::map<unsigned, RawComment *> &CommentsInFile) const;

/// Return the documentation comment attached to a given declaration,
/// without looking into cache.
RawComment *getRawCommentForDeclNoCache(const Decl *D) const;

839public:
void addComment(const RawComment &RC);

/// Return the documentation comment attached to a given declaration.
/// Returns nullptr if no comment is attached.
///
/// \param OriginalDecl if not nullptr, is set to declaration AST node that
/// had the comment, if the comment we found comes from a redeclaration.
const RawComment *
getRawCommentForAnyRedecl(const Decl *D,
                          const Decl **OriginalDecl = nullptr) const;

/// Searches existing comments for doc comments that should be attached to \p
/// Decls. If any doc comment is found, it is parsed.
///
/// Requirement: All \p Decls are in the same file.
///
/// If the last comment in the file is already attached we assume
/// there are not comments left to be attached to \p Decls.
void attachCommentsToJustParsedDecls(ArrayRef<Decl *> Decls,
                                     const Preprocessor *PP);

/// Return parsed documentation comment attached to a given declaration.
/// Returns nullptr if no comment is attached.
///
/// \param PP the Preprocessor used with this TU.  Could be nullptr if
/// preprocessor is not available.
comments::FullComment *getCommentForDecl(const Decl *D,
                                         const Preprocessor *PP) const;

/// Return parsed documentation comment attached to a given declaration.
/// Returns nullptr if no comment is attached. Does not look at any
/// redeclarations of the declaration.
comments::FullComment *getLocalCommentForDeclUncached(const Decl *D) const;

comments::FullComment *cloneFullComment(comments::FullComment *FC,
                                       const Decl *D) const;

877private:
mutable comments::CommandTraits CommentCommandTraits;

/// Iterator that visits import declarations.
class import_iterator {
  ImportDecl *Import = nullptr;

public:
  using value_type = ImportDecl *;
  using reference = ImportDecl *;
  using pointer = ImportDecl *;
  using difference_type = int;
  using iterator_category = std::forward_iterator_tag;

  import_iterator() = default;
  explicit import_iterator(ImportDecl *Import) : Import(Import) {}

  reference operator*() const { return Import; }
  pointer operator->() const { return Import; }

  import_iterator &operator++() {
    Import = ASTContext::getNextLocalImport(Import);
    return *this;
  }

  import_iterator operator++(int) {
    import_iterator Other(*this);
    ++(*this);
    return Other;
  }

  friend bool operator==(import_iterator X, import_iterator Y) {
    return X.Import == Y.Import;
  }

  friend bool operator!=(import_iterator X, import_iterator Y) {
    return X.Import != Y.Import;
  }
};

917public:
comments::CommandTraits &getCommentCommandTraits() const {
  return CommentCommandTraits;
}

/// Retrieve the attributes for the given declaration.
AttrVec& getDeclAttrs(const Decl *D);

/// Erase the attributes corresponding to the given declaration.
void eraseDeclAttrs(const Decl *D);

/// If this variable is an instantiated static data member of a
/// class template specialization, returns the templated static data member
/// from which it was instantiated.
// FIXME: Remove ?
MemberSpecializationInfo *getInstantiatedFromStaticDataMember(
                                                         const VarDecl *Var);

/// Note that the static data member \p Inst is an instantiation of
/// the static data member template \p Tmpl of a class template.
void setInstantiatedFromStaticDataMember(VarDecl *Inst, VarDecl *Tmpl,
                                         TemplateSpecializationKind TSK,
                      SourceLocation PointOfInstantiation = SourceLocation());

TemplateOrSpecializationInfo
getTemplateOrSpecializationInfo(const VarDecl *Var);

void setTemplateOrSpecializationInfo(VarDecl *Inst,
                                     TemplateOrSpecializationInfo TSI);

/// If the given using decl \p Inst is an instantiation of
/// another (possibly unresolved) using decl, return it.
NamedDecl *getInstantiatedFromUsingDecl(NamedDecl *Inst);

/// Remember that the using decl \p Inst is an instantiation
/// of the using decl \p Pattern of a class template.
void setInstantiatedFromUsingDecl(NamedDecl *Inst, NamedDecl *Pattern);

/// If the given using-enum decl \p Inst is an instantiation of
/// another using-enum decl, return it.
UsingEnumDecl *getInstantiatedFromUsingEnumDecl(UsingEnumDecl *Inst);

/// Remember that the using enum decl \p Inst is an instantiation
/// of the using enum decl \p Pattern of a class template.
void setInstantiatedFromUsingEnumDecl(UsingEnumDecl *Inst,
                                      UsingEnumDecl *Pattern);

UsingShadowDecl *getInstantiatedFromUsingShadowDecl(UsingShadowDecl *Inst);
void setInstantiatedFromUsingShadowDecl(UsingShadowDecl *Inst,
                                        UsingShadowDecl *Pattern);

FieldDecl *getInstantiatedFromUnnamedFieldDecl(FieldDecl *Field);

void setInstantiatedFromUnnamedFieldDecl(FieldDecl *Inst, FieldDecl *Tmpl);

// Access to the set of methods overridden by the given C++ method.
using overridden_cxx_method_iterator = CXXMethodVector::const_iterator;
overridden_cxx_method_iterator
overridden_methods_begin(const CXXMethodDecl *Method) const;

overridden_cxx_method_iterator
overridden_methods_end(const CXXMethodDecl *Method) const;

unsigned overridden_methods_size(const CXXMethodDecl *Method) const;

using overridden_method_range =
    llvm::iterator_range<overridden_cxx_method_iterator>;

overridden_method_range overridden_methods(const CXXMethodDecl *Method) const;

/// Note that the given C++ \p Method overrides the given \p
/// Overridden method.
void addOverriddenMethod(const CXXMethodDecl *Method,
                         const CXXMethodDecl *Overridden);

/// Return C++ or ObjC overridden methods for the given \p Method.
///
/// An ObjC method is considered to override any method in the class's
/// base classes, its protocols, or its categories' protocols, that has
/// the same selector and is of the same kind (class or instance).
/// A method in an implementation is not considered as overriding the same
/// method in the interface or its categories.
void getOverriddenMethods(
                      const NamedDecl *Method,
                      SmallVectorImpl<const NamedDecl *> &Overridden) const;

/// Notify the AST context that a new import declaration has been
/// parsed or implicitly created within this translation unit.
void addedLocalImportDecl(ImportDecl *Import);

static ImportDecl *getNextLocalImport(ImportDecl *Import) {
  return Import->getNextLocalImport();
}

using import_range = llvm::iterator_range<import_iterator>;

import_range local_imports() const {
  return import_range(import_iterator(FirstLocalImport), import_iterator());
}

Decl *getPrimaryMergedDecl(Decl *D) {
  Decl *Result = MergedDecls.lookup(D);
  return Result ? Result : D;
}
void setPrimaryMergedDecl(Decl *D, Decl *Primary) {
  MergedDecls[D] = Primary;
}

/// Note that the definition \p ND has been merged into module \p M,
/// and should be visible whenever \p M is visible.
void mergeDefinitionIntoModule(NamedDecl *ND, Module *M,
                               bool NotifyListeners = true);

/// Clean up the merged definition list. Call this if you might have
/// added duplicates into the list.
void deduplicateMergedDefinitonsFor(NamedDecl *ND);

/// Get the additional modules in which the definition \p Def has
/// been merged.
ArrayRef<Module*> getModulesWithMergedDefinition(const NamedDecl *Def);

/// Add a declaration to the list of declarations that are initialized
/// for a module. This will typically be a global variable (with internal
/// linkage) that runs module initializers, such as the iostream initializer,
/// or an ImportDecl nominating another module that has initializers.
void addModuleInitializer(Module *M, Decl *Init);

void addLazyModuleInitializers(Module *M, ArrayRef<uint32_t> IDs);

/// Get the initializations to perform when importing a module, if any.
ArrayRef<Decl*> getModuleInitializers(Module *M);

TranslationUnitDecl *getTranslationUnitDecl() const {
  return TUDecl->getMostRecentDecl();
}
void addTranslationUnitDecl() {
  assert(!TUDecl || TUKind == TU_Incremental)(static_cast<void> (0));
  TranslationUnitDecl *NewTUDecl = TranslationUnitDecl::Create(*this);
  if (TraversalScope.empty() || TraversalScope.back() == TUDecl)
    TraversalScope = {NewTUDecl};
  if (TUDecl)
    NewTUDecl->setPreviousDecl(TUDecl);
  TUDecl = NewTUDecl;
}

ExternCContextDecl *getExternCContextDecl() const;
BuiltinTemplateDecl *getMakeIntegerSeqDecl() const;
BuiltinTemplateDecl *getTypePackElementDecl() const;

// Builtin Types.
CanQualType VoidTy;
CanQualType BoolTy;
CanQualType CharTy;
CanQualType WCharTy;  // [C++ 3.9.1p5].
CanQualType WideCharTy; // Same as WCharTy in C++, integer type in C99.
CanQualType WIntTy;   // [C99 7.24.1], integer type unchanged by default promotions.
CanQualType Char8Ty;  // [C++20 proposal]
CanQualType Char16Ty; // [C++0x 3.9.1p5], integer type in C99.
CanQualType Char32Ty; // [C++0x 3.9.1p5], integer type in C99.
CanQualType SignedCharTy, ShortTy, IntTy, LongTy, LongLongTy, Int128Ty;
CanQualType UnsignedCharTy, UnsignedShortTy, UnsignedIntTy, UnsignedLongTy;
CanQualType UnsignedLongLongTy, UnsignedInt128Ty;
CanQualType FloatTy, DoubleTy, LongDoubleTy, Float128Ty;
CanQualType ShortAccumTy, AccumTy,
    LongAccumTy;  // ISO/IEC JTC1 SC22 WG14 N1169 Extension
CanQualType UnsignedShortAccumTy, UnsignedAccumTy, UnsignedLongAccumTy;
CanQualType ShortFractTy, FractTy, LongFractTy;
CanQualType UnsignedShortFractTy, UnsignedFractTy, UnsignedLongFractTy;
CanQualType SatShortAccumTy, SatAccumTy, SatLongAccumTy;
CanQualType SatUnsignedShortAccumTy, SatUnsignedAccumTy,
    SatUnsignedLongAccumTy;
CanQualType SatShortFractTy, SatFractTy, SatLongFractTy;
CanQualType SatUnsignedShortFractTy, SatUnsignedFractTy,
    SatUnsignedLongFractTy;
CanQualType HalfTy; // [OpenCL 6.1.1.1], ARM NEON
CanQualType BFloat16Ty;
CanQualType Float16Ty; // C11 extension ISO/IEC TS 18661-3
CanQualType FloatComplexTy, DoubleComplexTy, LongDoubleComplexTy;
CanQualType Float128ComplexTy;
CanQualType VoidPtrTy, NullPtrTy;
CanQualType DependentTy, OverloadTy, BoundMemberTy, UnknownAnyTy;
CanQualType BuiltinFnTy;
CanQualType PseudoObjectTy, ARCUnbridgedCastTy;
CanQualType ObjCBuiltinIdTy, ObjCBuiltinClassTy, ObjCBuiltinSelTy;
CanQualType ObjCBuiltinBoolTy;
1102#define IMAGE_TYPE(ImgType, Id, SingletonId, Access, Suffix) \
CanQualType SingletonId;
1104#include "clang/Basic/OpenCLImageTypes.def"
CanQualType OCLSamplerTy, OCLEventTy, OCLClkEventTy;
CanQualType OCLQueueTy, OCLReserveIDTy;
CanQualType IncompleteMatrixIdxTy;
CanQualType OMPArraySectionTy, OMPArrayShapingTy, OMPIteratorTy;
1109#define EXT_OPAQUE_TYPE(ExtType, Id, Ext) \
CanQualType Id##Ty;
1111#include "clang/Basic/OpenCLExtensionTypes.def"
1112#define SVE_TYPE(Name, Id, SingletonId) \
CanQualType SingletonId;
1114#include "clang/Basic/AArch64SVEACLETypes.def"
1115#define PPC_VECTOR_TYPE(Name, Id, Size) \
CanQualType Id##Ty;
1117#include "clang/Basic/PPCTypes.def"
1118#define RVV_TYPE(Name, Id, SingletonId) \
CanQualType SingletonId;
1120#include "clang/Basic/RISCVVTypes.def"

// Types for deductions in C++0x [stmt.ranged]'s desugaring. Built on demand.
mutable QualType AutoDeductTy;     // Deduction against 'auto'.
mutable QualType AutoRRefDeductTy; // Deduction against 'auto &&'.

// Decl used to help define __builtin_va_list for some targets.
// The decl is built when constructing 'BuiltinVaListDecl'.
mutable Decl *VaListTagDecl = nullptr;

// Implicitly-declared type 'struct _GUID'.
mutable TagDecl *MSGuidTagDecl = nullptr;

/// Keep track of CUDA/HIP device-side variables ODR-used by host code.
llvm::DenseSet<const VarDecl *> CUDADeviceVarODRUsedByHost;

ASTContext(LangOptions &LOpts, SourceManager &SM, IdentifierTable &idents,
           SelectorTable &sels, Builtin::Context &builtins,
           TranslationUnitKind TUKind);
ASTContext(const ASTContext &) = delete;
ASTContext &operator=(const ASTContext &) = delete;
~ASTContext();

/// Attach an external AST source to the AST context.
///
/// The external AST source provides the ability to load parts of
/// the abstract syntax tree as needed from some external storage,
/// e.g., a precompiled header.
void setExternalSource(IntrusiveRefCntPtr<ExternalASTSource> Source);

/// Retrieve a pointer to the external AST source associated
/// with this AST context, if any.
ExternalASTSource *getExternalSource() const {
  return ExternalSource.get();
}

/// Attach an AST mutation listener to the AST context.
///
/// The AST mutation listener provides the ability to track modifications to
/// the abstract syntax tree entities committed after they were initially
/// created.
void setASTMutationListener(ASTMutationListener *Listener) {
  this->Listener = Listener;
}

/// Retrieve a pointer to the AST mutation listener associated
/// with this AST context, if any.
ASTMutationListener *getASTMutationListener() const { return Listener; }

void PrintStats() const;
const SmallVectorImpl<Type *>& getTypes() const { return Types; }

BuiltinTemplateDecl *buildBuiltinTemplateDecl(BuiltinTemplateKind BTK,
                                              const IdentifierInfo *II) const;

/// Create a new implicit TU-level CXXRecordDecl or RecordDecl
/// declaration.
RecordDecl *buildImplicitRecord(StringRef Name,
                                RecordDecl::TagKind TK = TTK_Struct) const;

/// Create a new implicit TU-level typedef declaration.
TypedefDecl *buildImplicitTypedef(QualType T, StringRef Name) const;

/// Retrieve the declaration for the 128-bit signed integer type.
TypedefDecl *getInt128Decl() const;

/// Retrieve the declaration for the 128-bit unsigned integer type.
TypedefDecl *getUInt128Decl() const;

//===--------------------------------------------------------------------===//
//                           Type Constructors
//===--------------------------------------------------------------------===//

1193private:
/// Return a type with extended qualifiers.
QualType getExtQualType(const Type *Base, Qualifiers Quals) const;

QualType getTypeDeclTypeSlow(const TypeDecl *Decl) const;

QualType getPipeType(QualType T, bool ReadOnly) const;

1201public:
/// Return the uniqued reference to the type for an address space
/// qualified type with the specified type and address space.
///
/// The resulting type has a union of the qualifiers from T and the address
/// space. If T already has an address space specifier, it is silently
/// replaced.
QualType getAddrSpaceQualType(QualType T, LangAS AddressSpace) const;

/// Remove any existing address space on the type and returns the type
/// with qualifiers intact (or that's the idea anyway)
///
/// The return type should be T with all prior qualifiers minus the address
/// space.
QualType removeAddrSpaceQualType(QualType T) const;

/// Apply Objective-C protocol qualifiers to the given type.
/// \param allowOnPointerType specifies if we can apply protocol
/// qualifiers on ObjCObjectPointerType. It can be set to true when
/// constructing the canonical type of a Objective-C type parameter.
QualType applyObjCProtocolQualifiers(QualType type,
    ArrayRef<ObjCProtocolDecl *> protocols, bool &hasError,
    bool allowOnPointerType = false) const;

/// Return the uniqued reference to the type for an Objective-C
/// gc-qualified type.
///
/// The resulting type has a union of the qualifiers from T and the gc
/// attribute.
QualType getObjCGCQualType(QualType T, Qualifiers::GC gcAttr) const;

/// Remove the existing address space on the type if it is a pointer size
/// address space and return the type with qualifiers intact.
QualType removePtrSizeAddrSpace(QualType T) const;

/// Return the uniqued reference to the type for a \c restrict
/// qualified type.
///
/// The resulting type has a union of the qualifiers from \p T and
/// \c restrict.
QualType getRestrictType(QualType T) const {
  return T.withFastQualifiers(Qualifiers::Restrict);
}

/// Return the uniqued reference to the type for a \c volatile
/// qualified type.
///
/// The resulting type has a union of the qualifiers from \p T and
/// \c volatile.
QualType getVolatileType(QualType T) const {
  return T.withFastQualifiers(Qualifiers::Volatile);
}

/// Return the uniqued reference to the type for a \c const
/// qualified type.
///
/// The resulting type has a union of the qualifiers from \p T and \c const.
///
/// It can be reasonably expected that this will always be equivalent to
/// calling T.withConst().
QualType getConstType(QualType T) const { return T.withConst(); }

/// Change the ExtInfo on a function type.
const FunctionType *adjustFunctionType(const FunctionType *Fn,
                                       FunctionType::ExtInfo EInfo);

/// Adjust the given function result type.
CanQualType getCanonicalFunctionResultType(QualType ResultType) const;

/// Change the result type of a function type once it is deduced.
void adjustDeducedFunctionResultType(FunctionDecl *FD, QualType ResultType);

/// Get a function type and produce the equivalent function type with the
/// specified exception specification. Type sugar that can be present on a
/// declaration of a function with an exception specification is permitted
/// and preserved. Other type sugar (for instance, typedefs) is not.
QualType getFunctionTypeWithExceptionSpec(
    QualType Orig, const FunctionProtoType::ExceptionSpecInfo &ESI);

/// Determine whether two function types are the same, ignoring
/// exception specifications in cases where they're part of the type.
bool hasSameFunctionTypeIgnoringExceptionSpec(QualType T, QualType U);

/// Change the exception specification on a function once it is
/// delay-parsed, instantiated, or computed.
void adjustExceptionSpec(FunctionDecl *FD,
                         const FunctionProtoType::ExceptionSpecInfo &ESI,
                         bool AsWritten = false);

/// Get a function type and produce the equivalent function type where
/// pointer size address spaces in the return type and parameter tyeps are
/// replaced with the default address space.
QualType getFunctionTypeWithoutPtrSizes(QualType T);

/// Determine whether two function types are the same, ignoring pointer sizes
/// in the return type and parameter types.
bool hasSameFunctionTypeIgnoringPtrSizes(QualType T, QualType U);

/// Return the uniqued reference to the type for a complex
/// number with the specified element type.
QualType getComplexType(QualType T) const;
CanQualType getComplexType(CanQualType T) const {
  return CanQualType::CreateUnsafe(getComplexType((QualType) T));
}

/// Return the uniqued reference to the type for a pointer to
/// the specified type.
QualType getPointerType(QualType T) const;
CanQualType getPointerType(CanQualType T) const {
  return CanQualType::CreateUnsafe(getPointerType((QualType) T));
}

/// Return the uniqued reference to a type adjusted from the original
/// type to a new type.
QualType getAdjustedType(QualType Orig, QualType New) const;
CanQualType getAdjustedType(CanQualType Orig, CanQualType New) const {
  return CanQualType::CreateUnsafe(
      getAdjustedType((QualType)Orig, (QualType)New));
}

/// Return the uniqued reference to the decayed version of the given
/// type.  Can only be called on array and function types which decay to
/// pointer types.
QualType getDecayedType(QualType T) const;
CanQualType getDecayedType(CanQualType T) const {
  return CanQualType::CreateUnsafe(getDecayedType((QualType) T));
}

/// Return the uniqued reference to the atomic type for the specified
/// type.
QualType getAtomicType(QualType T) const;

/// Return the uniqued reference to the type for a block of the
/// specified type.
QualType getBlockPointerType(QualType T) const;

/// Gets the struct used to keep track of the descriptor for pointer to
/// blocks.
QualType getBlockDescriptorType() const;

/// Return a read_only pipe type for the specified type.
QualType getReadPipeType(QualType T) const;

/// Return a write_only pipe type for the specified type.
QualType getWritePipeType(QualType T) const;

/// Return an extended integer type with the specified signedness and bit
/// count.
QualType getExtIntType(bool Unsigned, unsigned NumBits) const;

/// Return a dependent extended integer type with the specified signedness and
/// bit count.
QualType getDependentExtIntType(bool Unsigned, Expr *BitsExpr) const;

/// Gets the struct used to keep track of the extended descriptor for
/// pointer to blocks.
QualType getBlockDescriptorExtendedType() const;

/// Map an AST Type to an OpenCLTypeKind enum value.
OpenCLTypeKind getOpenCLTypeKind(const Type *T) const;

/// Get address space for OpenCL type.
LangAS getOpenCLTypeAddrSpace(const Type *T) const;

void setcudaConfigureCallDecl(FunctionDecl *FD) {
  cudaConfigureCallDecl = FD;
}

FunctionDecl *getcudaConfigureCallDecl() {
  return cudaConfigureCallDecl;
}

/// Returns true iff we need copy/dispose helpers for the given type.
bool BlockRequiresCopying(QualType Ty, const VarDecl *D);

/// Returns true, if given type has a known lifetime. HasByrefExtendedLayout
/// is set to false in this case. If HasByrefExtendedLayout returns true,
/// byref variable has extended lifetime.
bool getByrefLifetime(QualType Ty,
                      Qualifiers::ObjCLifetime &Lifetime,
                      bool &HasByrefExtendedLayout) const;

/// Return the uniqued reference to the type for an lvalue reference
/// to the specified type.
QualType getLValueReferenceType(QualType T, bool SpelledAsLValue = true)
  const;

/// Return the uniqued reference to the type for an rvalue reference
/// to the specified type.
QualType getRValueReferenceType(QualType T) const;

/// Return the uniqued reference to the type for a member pointer to
/// the specified type in the specified class.
///
/// The class \p Cls is a \c Type because it could be a dependent name.
QualType getMemberPointerType(QualType T, const Type *Cls) const;

/// Return a non-unique reference to the type for a variable array of
/// the specified element type.
QualType getVariableArrayType(QualType EltTy, Expr *NumElts,
                              ArrayType::ArraySizeModifier ASM,
                              unsigned IndexTypeQuals,
                              SourceRange Brackets) const;

/// Return a non-unique reference to the type for a dependently-sized
/// array of the specified element type.
///
/// FIXME: We will need these to be uniqued, or at least comparable, at some
/// point.
QualType getDependentSizedArrayType(QualType EltTy, Expr *NumElts,
                                    ArrayType::ArraySizeModifier ASM,
                                    unsigned IndexTypeQuals,
                                    SourceRange Brackets) const;

/// Return a unique reference to the type for an incomplete array of
/// the specified element type.
QualType getIncompleteArrayType(QualType EltTy,
                                ArrayType::ArraySizeModifier ASM,
                                unsigned IndexTypeQuals) const;

/// Return the unique reference to the type for a constant array of
/// the specified element type.
QualType getConstantArrayType(QualType EltTy, const llvm::APInt &ArySize,
                              const Expr *SizeExpr,
                              ArrayType::ArraySizeModifier ASM,
                              unsigned IndexTypeQuals) const;

/// Return a type for a constant array for a string literal of the
/// specified element type and length.
QualType getStringLiteralArrayType(QualType EltTy, unsigned Length) const;

/// Returns a vla type where known sizes are replaced with [*].
QualType getVariableArrayDecayedType(QualType Ty) const;

// Convenience struct to return information about a builtin vector type.
struct BuiltinVectorTypeInfo {
  QualType ElementType;
  llvm::ElementCount EC;
  unsigned NumVectors;
  BuiltinVectorTypeInfo(QualType ElementType, llvm::ElementCount EC,
                        unsigned NumVectors)
      : ElementType(ElementType), EC(EC), NumVectors(NumVectors) {}
};

/// Returns the element type, element count and number of vectors
/// (in case of tuple) for a builtin vector type.
BuiltinVectorTypeInfo
getBuiltinVectorTypeInfo(const BuiltinType *VecTy) const;

/// Return the unique reference to a scalable vector type of the specified
/// element type and scalable number of elements.
///
/// \pre \p EltTy must be a built-in type.
QualType getScalableVectorType(QualType EltTy, unsigned NumElts) const;

/// Return the unique reference to a vector type of the specified
/// element type and size.
///
/// \pre \p VectorType must be a built-in type.
QualType getVectorType(QualType VectorType, unsigned NumElts,
                       VectorType::VectorKind VecKind) const;
/// Return the unique reference to the type for a dependently sized vector of
/// the specified element type.
QualType getDependentVectorType(QualType VectorType, Expr *SizeExpr,
                                SourceLocation AttrLoc,
                                VectorType::VectorKind VecKind) const;

/// Return the unique reference to an extended vector type
/// of the specified element type and size.
///
/// \pre \p VectorType must be a built-in type.
QualType getExtVectorType(QualType VectorType, unsigned NumElts) const;

/// \pre Return a non-unique reference to the type for a dependently-sized
/// vector of the specified element type.
///
/// FIXME: We will need these to be uniqued, or at least comparable, at some
/// point.
QualType getDependentSizedExtVectorType(QualType VectorType,
                                        Expr *SizeExpr,
                                        SourceLocation AttrLoc) const;

/// Return the unique reference to the matrix type of the specified element
/// type and size
///
/// \pre \p ElementType must be a valid matrix element type (see
/// MatrixType::isValidElementType).
QualType getConstantMatrixType(QualType ElementType, unsigned NumRows,
                               unsigned NumColumns) const;

/// Return the unique reference to the matrix type of the specified element
/// type and size
QualType getDependentSizedMatrixType(QualType ElementType, Expr *RowExpr,
                                     Expr *ColumnExpr,
                                     SourceLocation AttrLoc) const;

QualType getDependentAddressSpaceType(QualType PointeeType,
                                      Expr *AddrSpaceExpr,
                                      SourceLocation AttrLoc) const;

/// Return a K&R style C function type like 'int()'.
QualType getFunctionNoProtoType(QualType ResultTy,
                                const FunctionType::ExtInfo &Info) const;

QualType getFunctionNoProtoType(QualType ResultTy) const {
  return getFunctionNoProtoType(ResultTy, FunctionType::ExtInfo());
}

/// Return a normal function type with a typed argument list.
QualType getFunctionType(QualType ResultTy, ArrayRef<QualType> Args,
                         const FunctionProtoType::ExtProtoInfo &EPI) const {
  return getFunctionTypeInternal(ResultTy, Args, EPI, false);
}

QualType adjustStringLiteralBaseType(QualType StrLTy) const;

1517private:
/// Return a normal function type with a typed argument list.
QualType getFunctionTypeInternal(QualType ResultTy, ArrayRef<QualType> Args,
                                 const FunctionProtoType::ExtProtoInfo &EPI,
                                 bool OnlyWantCanonical) const;

1523public:
/// Return the unique reference to the type for the specified type
/// declaration.
QualType getTypeDeclType(const TypeDecl *Decl,
                         const TypeDecl *PrevDecl = nullptr) const {
  assert(Decl && "Passed null for Decl param")(static_cast<void> (0));
  if (Decl->TypeForDecl) return QualType(Decl->TypeForDecl, 0);
64
←
Access to field 'TypeForDecl' results in a dereference of a null pointer (loaded from variable 'Decl')

  if (PrevDecl) {
    assert(PrevDecl->TypeForDecl && "previous decl has no TypeForDecl")(static_cast<void> (0));
    Decl->TypeForDecl = PrevDecl->TypeForDecl;
    return QualType(PrevDecl->TypeForDecl, 0);
  }

  return getTypeDeclTypeSlow(Decl);
}

/// Return the unique reference to the type for the specified
/// typedef-name decl.
QualType getTypedefType(const TypedefNameDecl *Decl,
                        QualType Underlying = QualType()) const;

QualType getRecordType(const RecordDecl *Decl) const;

QualType getEnumType(const EnumDecl *Decl) const;

QualType getInjectedClassNameType(CXXRecordDecl *Decl, QualType TST) const;

QualType getAttributedType(attr::Kind attrKind,
                           QualType modifiedType,
                           QualType equivalentType);

QualType getSubstTemplateTypeParmType(const TemplateTypeParmType *Replaced,
                                      QualType Replacement) const;
QualType getSubstTemplateTypeParmPackType(
                                        const TemplateTypeParmType *Replaced,
                                          const TemplateArgument &ArgPack);

QualType
getTemplateTypeParmType(unsigned Depth, unsigned Index,
                        bool ParameterPack,
                        TemplateTypeParmDecl *ParmDecl = nullptr) const;

QualType getTemplateSpecializationType(TemplateName T,
                                       ArrayRef<TemplateArgument> Args,
                                       QualType Canon = QualType()) const;

QualType
getCanonicalTemplateSpecializationType(TemplateName T,
                                       ArrayRef<TemplateArgument> Args) const;

QualType getTemplateSpecializationType(TemplateName T,
                                       const TemplateArgumentListInfo &Args,
                                       QualType Canon = QualType()) const;

TypeSourceInfo *
getTemplateSpecializationTypeInfo(TemplateName T, SourceLocation TLoc,
                                  const TemplateArgumentListInfo &Args,
                                  QualType Canon = QualType()) const;

QualType getParenType(QualType NamedType) const;

QualType getMacroQualifiedType(QualType UnderlyingTy,
                               const IdentifierInfo *MacroII) const;

QualType getElaboratedType(ElaboratedTypeKeyword Keyword,
                           NestedNameSpecifier *NNS, QualType NamedType,
                           TagDecl *OwnedTagDecl = nullptr) const;
QualType getDependentNameType(ElaboratedTypeKeyword Keyword,
                              NestedNameSpecifier *NNS,
                              const IdentifierInfo *Name,
                              QualType Canon = QualType()) const;

QualType getDependentTemplateSpecializationType(ElaboratedTypeKeyword Keyword,
                                                NestedNameSpecifier *NNS,
                                                const IdentifierInfo *Name,
                                  const TemplateArgumentListInfo &Args) const;
QualType getDependentTemplateSpecializationType(
    ElaboratedTypeKeyword Keyword, NestedNameSpecifier *NNS,
    const IdentifierInfo *Name, ArrayRef<TemplateArgument> Args) const;

TemplateArgument getInjectedTemplateArg(NamedDecl *ParamDecl);

/// Get a template argument list with one argument per template parameter
/// in a template parameter list, such as for the injected class name of
/// a class template.
void getInjectedTemplateArgs(const TemplateParameterList *Params,
                             SmallVectorImpl<TemplateArgument> &Args);

/// Form a pack expansion type with the given pattern.
/// \param NumExpansions The number of expansions for the pack, if known.
/// \param ExpectPackInType If \c false, we should not expect \p Pattern to
///        contain an unexpanded pack. This only makes sense if the pack
///        expansion is used in a context where the arity is inferred from
///        elsewhere, such as if the pattern contains a placeholder type or
///        if this is the canonical type of another pack expansion type.
QualType getPackExpansionType(QualType Pattern,
                              Optional<unsigned> NumExpansions,
                              bool ExpectPackInType = true);

QualType getObjCInterfaceType(const ObjCInterfaceDecl *Decl,
                              ObjCInterfaceDecl *PrevDecl = nullptr) const;

/// Legacy interface: cannot provide type arguments or __kindof.
QualType getObjCObjectType(QualType Base,
                           ObjCProtocolDecl * const *Protocols,
                           unsigned NumProtocols) const;

QualType getObjCObjectType(QualType Base,
                           ArrayRef<QualType> typeArgs,
                           ArrayRef<ObjCProtocolDecl *> protocols,
                           bool isKindOf) const;

QualType getObjCTypeParamType(const ObjCTypeParamDecl *Decl,
                              ArrayRef<ObjCProtocolDecl *> protocols) const;
void adjustObjCTypeParamBoundType(const ObjCTypeParamDecl *Orig,
                                  ObjCTypeParamDecl *New) const;

bool ObjCObjectAdoptsQTypeProtocols(QualType QT, ObjCInterfaceDecl *Decl);

/// QIdProtocolsAdoptObjCObjectProtocols - Checks that protocols in
/// QT's qualified-id protocol list adopt all protocols in IDecl's list
/// of protocols.
bool QIdProtocolsAdoptObjCObjectProtocols(QualType QT,
                                          ObjCInterfaceDecl *IDecl);

/// Return a ObjCObjectPointerType type for the given ObjCObjectType.
QualType getObjCObjectPointerType(QualType OIT) const;

/// GCC extension.
QualType getTypeOfExprType(Expr *e) const;
QualType getTypeOfType(QualType t) const;

QualType getReferenceQualifiedType(const Expr *e) const;

/// C++11 decltype.
QualType getDecltypeType(Expr *e, QualType UnderlyingType) const;

/// Unary type transforms
QualType getUnaryTransformType(QualType BaseType, QualType UnderlyingType,
                               UnaryTransformType::UTTKind UKind) const;

/// C++11 deduced auto type.
QualType getAutoType(QualType DeducedType, AutoTypeKeyword Keyword,
                     bool IsDependent, bool IsPack = false,
                     ConceptDecl *TypeConstraintConcept = nullptr,
                     ArrayRef<TemplateArgument> TypeConstraintArgs ={}) const;

/// C++11 deduction pattern for 'auto' type.
QualType getAutoDeductType() const;

/// C++11 deduction pattern for 'auto &&' type.
QualType getAutoRRefDeductType() const;

/// C++17 deduced class template specialization type.
QualType getDeducedTemplateSpecializationType(TemplateName Template,
                                              QualType DeducedType,
                                              bool IsDependent) const;

/// Return the unique reference to the type for the specified TagDecl
/// (struct/union/class/enum) decl.
QualType getTagDeclType(const TagDecl *Decl) const;

/// Return the unique type for "size_t" (C99 7.17), defined in
/// <stddef.h>.
///
/// The sizeof operator requires this (C99 6.5.3.4p4).
CanQualType getSizeType() const;

/// Return the unique signed counterpart of
/// the integer type corresponding to size_t.
CanQualType getSignedSizeType() const;

/// Return the unique type for "intmax_t" (C99 7.18.1.5), defined in
/// <stdint.h>.
CanQualType getIntMaxType() const;

/// Return the unique type for "uintmax_t" (C99 7.18.1.5), defined in
/// <stdint.h>.
CanQualType getUIntMaxType() const;

/// Return the unique wchar_t type available in C++ (and available as
/// __wchar_t as a Microsoft extension).
QualType getWCharType() const { return WCharTy; }

/// Return the type of wide characters. In C++, this returns the
/// unique wchar_t type. In C99, this returns a type compatible with the type
/// defined in <stddef.h> as defined by the target.
QualType getWideCharType() const { return WideCharTy; }

/// Return the type of "signed wchar_t".
///
/// Used when in C++, as a GCC extension.
QualType getSignedWCharType() const;

/// Return the type of "unsigned wchar_t".
///
/// Used when in C++, as a GCC extension.
QualType getUnsignedWCharType() const;

/// In C99, this returns a type compatible with the type
/// defined in <stddef.h> as defined by the target.
QualType getWIntType() const { return WIntTy; }

/// Return a type compatible with "intptr_t" (C99 7.18.1.4),
/// as defined by the target.
QualType getIntPtrType() const;

/// Return a type compatible with "uintptr_t" (C99 7.18.1.4),
/// as defined by the target.
QualType getUIntPtrType() const;

/// Return the unique type for "ptrdiff_t" (C99 7.17) defined in
/// <stddef.h>. Pointer - pointer requires this (C99 6.5.6p9).
QualType getPointerDiffType() const;

/// Return the unique unsigned counterpart of "ptrdiff_t"
/// integer type. The standard (C11 7.21.6.1p7) refers to this type
/// in the definition of %tu format specifier.
QualType getUnsignedPointerDiffType() const;

/// Return the unique type for "pid_t" defined in
/// <sys/types.h>. We need this to compute the correct type for vfork().
QualType getProcessIDType() const;

/// Return the C structure type used to represent constant CFStrings.
QualType getCFConstantStringType() const;

/// Returns the C struct type for objc_super
QualType getObjCSuperType() const;
void setObjCSuperType(QualType ST) { ObjCSuperType = ST; }

/// Get the structure type used to representation CFStrings, or NULL
/// if it hasn't yet been built.
QualType getRawCFConstantStringType() const {
  if (CFConstantStringTypeDecl)
    return getTypedefType(CFConstantStringTypeDecl);
  return QualType();
}
void setCFConstantStringType(QualType T);
TypedefDecl *getCFConstantStringDecl() const;
RecordDecl *getCFConstantStringTagDecl() const;

// This setter/getter represents the ObjC type for an NSConstantString.
void setObjCConstantStringInterface(ObjCInterfaceDecl *Decl);
QualType getObjCConstantStringInterface() const {
  return ObjCConstantStringType;
}

QualType getObjCNSStringType() const {
  return ObjCNSStringType;
}

void setObjCNSStringType(QualType T) {
  ObjCNSStringType = T;
}

/// Retrieve the type that \c id has been defined to, which may be
/// different from the built-in \c id if \c id has been typedef'd.
QualType getObjCIdRedefinitionType() const {
  if (ObjCIdRedefinitionType.isNull())
    return getObjCIdType();
  return ObjCIdRedefinitionType;
}

/// Set the user-written type that redefines \c id.
void setObjCIdRedefinitionType(QualType RedefType) {
  ObjCIdRedefinitionType = RedefType;
}

/// Retrieve the type that \c Class has been defined to, which may be
/// different from the built-in \c Class if \c Class has been typedef'd.
QualType getObjCClassRedefinitionType() const {
  if (ObjCClassRedefinitionType.isNull())
    return getObjCClassType();
  return ObjCClassRedefinitionType;
}

/// Set the user-written type that redefines 'SEL'.
void setObjCClassRedefinitionType(QualType RedefType) {
  ObjCClassRedefinitionType = RedefType;
}

/// Retrieve the type that 'SEL' has been defined to, which may be
/// different from the built-in 'SEL' if 'SEL' has been typedef'd.
QualType getObjCSelRedefinitionType() const {
  if (ObjCSelRedefinitionType.isNull())
    return getObjCSelType();
  return ObjCSelRedefinitionType;
}

/// Set the user-written type that redefines 'SEL'.
void setObjCSelRedefinitionType(QualType RedefType) {
  ObjCSelRedefinitionType = RedefType;
}

/// Retrieve the identifier 'NSObject'.
IdentifierInfo *getNSObjectName() const {
  if (!NSObjectName) {
    NSObjectName = &Idents.get("NSObject");
  }

  return NSObjectName;
}

/// Retrieve the identifier 'NSCopying'.
IdentifierInfo *getNSCopyingName() {
  if (!NSCopyingName) {
    NSCopyingName = &Idents.get("NSCopying");
  }

  return NSCopyingName;
}

CanQualType getNSUIntegerType() const;

CanQualType getNSIntegerType() const;

/// Retrieve the identifier 'bool'.
IdentifierInfo *getBoolName() const {
  if (!BoolName)
    BoolName = &Idents.get("bool");
  return BoolName;
}

IdentifierInfo *getMakeIntegerSeqName() const {
  if (!MakeIntegerSeqName)
    MakeIntegerSeqName = &Idents.get("__make_integer_seq");
  return MakeIntegerSeqName;
}

IdentifierInfo *getTypePackElementName() const {
  if (!TypePackElementName)
    TypePackElementName = &Idents.get("__type_pack_element");
  return TypePackElementName;
}

/// Retrieve the Objective-C "instancetype" type, if already known;
/// otherwise, returns a NULL type;
QualType getObjCInstanceType() {
  return getTypeDeclType(getObjCInstanceTypeDecl());
}

/// Retrieve the typedef declaration corresponding to the Objective-C
/// "instancetype" type.
TypedefDecl *getObjCInstanceTypeDecl();

/// Set the type for the C FILE type.
void setFILEDecl(TypeDecl *FILEDecl) { this->FILEDecl = FILEDecl; }

/// Retrieve the C FILE type.
QualType getFILEType() const {
  if (FILEDecl)
    return getTypeDeclType(FILEDecl);
  return QualType();
}

/// Set the type for the C jmp_buf type.
void setjmp_bufDecl(TypeDecl *jmp_bufDecl) {
  this->jmp_bufDecl = jmp_bufDecl;
}

/// Retrieve the C jmp_buf type.
QualType getjmp_bufType() const {
  if (jmp_bufDecl)
    return getTypeDeclType(jmp_bufDecl);
  return QualType();
}

/// Set the type for the C sigjmp_buf type.
void setsigjmp_bufDecl(TypeDecl *sigjmp_bufDecl) {
  this->sigjmp_bufDecl = sigjmp_bufDecl;
}

/// Retrieve the C sigjmp_buf type.
QualType getsigjmp_bufType() const {
  if (sigjmp_bufDecl)
    return getTypeDeclType(sigjmp_bufDecl);
  return QualType();
}

/// Set the type for the C ucontext_t type.
void setucontext_tDecl(TypeDecl *ucontext_tDecl) {
  this->ucontext_tDecl = ucontext_tDecl;
}

/// Retrieve the C ucontext_t type.
QualType getucontext_tType() const {
  if (ucontext_tDecl)
    return getTypeDeclType(ucontext_tDecl);
  return QualType();
}

/// The result type of logical operations, '<', '>', '!=', etc.
QualType getLogicalOperationType() const {
  return getLangOpts().CPlusPlus ? BoolTy : IntTy;
}

/// Emit the Objective-CC type encoding for the given type \p T into
/// \p S.
///
/// If \p Field is specified then record field names are also encoded.
void getObjCEncodingForType(QualType T, std::string &S,
                            const FieldDecl *Field=nullptr,
                            QualType *NotEncodedT=nullptr) const;

/// Emit the Objective-C property type encoding for the given
/// type \p T into \p S.
void getObjCEncodingForPropertyType(QualType T, std::string &S) const;

void getLegacyIntegralTypeEncoding(QualType &t) const;

/// Put the string version of the type qualifiers \p QT into \p S.
void getObjCEncodingForTypeQualifier(Decl::ObjCDeclQualifier QT,
                                     std::string &S) const;

/// Emit the encoded type for the function \p Decl into \p S.
///
/// This is in the same format as Objective-C method encodings.
///
/// \returns true if an error occurred (e.g., because one of the parameter
/// types is incomplete), false otherwise.
std::string getObjCEncodingForFunctionDecl(const FunctionDecl *Decl) const;

/// Emit the encoded type for the method declaration \p Decl into
/// \p S.
std::string getObjCEncodingForMethodDecl(const ObjCMethodDecl *Decl,
                                         bool Extended = false) const;

/// Return the encoded type for this block declaration.
std::string getObjCEncodingForBlock(const BlockExpr *blockExpr) const;

/// getObjCEncodingForPropertyDecl - Return the encoded type for
/// this method declaration. If non-NULL, Container must be either
/// an ObjCCategoryImplDecl or ObjCImplementationDecl; it should
/// only be NULL when getting encodings for protocol properties.
std::string getObjCEncodingForPropertyDecl(const ObjCPropertyDecl *PD,
                                           const Decl *Container) const;

bool ProtocolCompatibleWithProtocol(ObjCProtocolDecl *lProto,
                                    ObjCProtocolDecl *rProto) const;

ObjCPropertyImplDecl *getObjCPropertyImplDeclForPropertyDecl(
                                                const ObjCPropertyDecl *PD,
                                                const Decl *Container) const;

/// Return the size of type \p T for Objective-C encoding purpose,
/// in characters.
CharUnits getObjCEncodingTypeSize(QualType T) const;

/// Retrieve the typedef corresponding to the predefined \c id type
/// in Objective-C.
TypedefDecl *getObjCIdDecl() const;

/// Represents the Objective-CC \c id type.
///
/// This is set up lazily, by Sema.  \c id is always a (typedef for a)
/// pointer type, a pointer to a struct.
QualType getObjCIdType() const {
  return getTypeDeclType(getObjCIdDecl());
}

/// Retrieve the typedef corresponding to the predefined 'SEL' type
/// in Objective-C.
TypedefDecl *getObjCSelDecl() const;

/// Retrieve the type that corresponds to the predefined Objective-C
/// 'SEL' type.
QualType getObjCSelType() const {
  return getTypeDeclType(getObjCSelDecl());
}

/// Retrieve the typedef declaration corresponding to the predefined
/// Objective-C 'Class' type.
TypedefDecl *getObjCClassDecl() const;

/// Represents the Objective-C \c Class type.
///
/// This is set up lazily, by Sema.  \c Class is always a (typedef for a)
/// pointer type, a pointer to a struct.
QualType getObjCClassType() const {
  return getTypeDeclType(getObjCClassDecl());
}

/// Retrieve the Objective-C class declaration corresponding to
/// the predefined \c Protocol class.
ObjCInterfaceDecl *getObjCProtocolDecl() const;

/// Retrieve declaration of 'BOOL' typedef
TypedefDecl *getBOOLDecl() const {
  return BOOLDecl;
}

/// Save declaration of 'BOOL' typedef
void setBOOLDecl(TypedefDecl *TD) {
  BOOLDecl = TD;
}

/// type of 'BOOL' type.
QualType getBOOLType() const {
  return getTypeDeclType(getBOOLDecl());
}

/// Retrieve the type of the Objective-C \c Protocol class.
QualType getObjCProtoType() const {
  return getObjCInterfaceType(getObjCProtocolDecl());
}

/// Retrieve the C type declaration corresponding to the predefined
/// \c __builtin_va_list type.
TypedefDecl *getBuiltinVaListDecl() const;

/// Retrieve the type of the \c __builtin_va_list type.
QualType getBuiltinVaListType() const {
  return getTypeDeclType(getBuiltinVaListDecl());
}

/// Retrieve the C type declaration corresponding to the predefined
/// \c __va_list_tag type used to help define the \c __builtin_va_list type
/// for some targets.
Decl *getVaListTagDecl() const;

/// Retrieve the C type declaration corresponding to the predefined
/// \c __builtin_ms_va_list type.
TypedefDecl *getBuiltinMSVaListDecl() const;

/// Retrieve the type of the \c __builtin_ms_va_list type.
QualType getBuiltinMSVaListType() const {
  return getTypeDeclType(getBuiltinMSVaListDecl());
}

/// Retrieve the implicitly-predeclared 'struct _GUID' declaration.
TagDecl *getMSGuidTagDecl() const { return MSGuidTagDecl; }

/// Retrieve the implicitly-predeclared 'struct _GUID' type.
QualType getMSGuidType() const {
  assert(MSGuidTagDecl && "asked for GUID type but MS extensions disabled")(static_cast<void> (0));
  return getTagDeclType(MSGuidTagDecl);
}

/// Return whether a declaration to a builtin is allowed to be
/// overloaded/redeclared.
bool canBuiltinBeRedeclared(const FunctionDecl *) const;

/// Return a type with additional \c const, \c volatile, or
/// \c restrict qualifiers.
QualType getCVRQualifiedType(QualType T, unsigned CVR) const {
  return getQualifiedType(T, Qualifiers::fromCVRMask(CVR));
}

/// Un-split a SplitQualType.
QualType getQualifiedType(SplitQualType split) const {
  return getQualifiedType(split.Ty, split.Quals);
}

/// Return a type with additional qualifiers.
QualType getQualifiedType(QualType T, Qualifiers Qs) const {
  if (!Qs.hasNonFastQualifiers())
    return T.withFastQualifiers(Qs.getFastQualifiers());
  QualifierCollector Qc(Qs);
  const Type *Ptr = Qc.strip(T);
  return getExtQualType(Ptr, Qc);
}

/// Return a type with additional qualifiers.
QualType getQualifiedType(const Type *T, Qualifiers Qs) const {
  if (!Qs.hasNonFastQualifiers())
    return QualType(T, Qs.getFastQualifiers());
  return getExtQualType(T, Qs);
}

/// Return a type with the given lifetime qualifier.
///
/// \pre Neither type.ObjCLifetime() nor \p lifetime may be \c OCL_None.
QualType getLifetimeQualifiedType(QualType type,
                                  Qualifiers::ObjCLifetime lifetime) {
  assert(type.getObjCLifetime() == Qualifiers::OCL_None)(static_cast<void> (0));
  assert(lifetime != Qualifiers::OCL_None)(static_cast<void> (0));

  Qualifiers qs;
  qs.addObjCLifetime(lifetime);
  return getQualifiedType(type, qs);
}

/// getUnqualifiedObjCPointerType - Returns version of
/// Objective-C pointer type with lifetime qualifier removed.
QualType getUnqualifiedObjCPointerType(QualType type) const {
  if (!type.getTypePtr()->isObjCObjectPointerType() ||
      !type.getQualifiers().hasObjCLifetime())
    return type;
  Qualifiers Qs = type.getQualifiers();
  Qs.removeObjCLifetime();
  return getQualifiedType(type.getUnqualifiedType(), Qs);
}

unsigned char getFixedPointScale(QualType Ty) const;
unsigned char getFixedPointIBits(QualType Ty) const;
llvm::FixedPointSemantics getFixedPointSemantics(QualType Ty) const;
llvm::APFixedPoint getFixedPointMax(QualType Ty) const;
llvm::APFixedPoint getFixedPointMin(QualType Ty) const;

DeclarationNameInfo getNameForTemplate(TemplateName Name,
                                       SourceLocation NameLoc) const;

TemplateName getOverloadedTemplateName(UnresolvedSetIterator Begin,
                                       UnresolvedSetIterator End) const;
TemplateName getAssumedTemplateName(DeclarationName Name) const;

TemplateName getQualifiedTemplateName(NestedNameSpecifier *NNS,
                                      bool TemplateKeyword,
                                      TemplateDecl *Template) const;

TemplateName getDependentTemplateName(NestedNameSpecifier *NNS,
                                      const IdentifierInfo *Name) const;
TemplateName getDependentTemplateName(NestedNameSpecifier *NNS,
                                      OverloadedOperatorKind Operator) const;
TemplateName getSubstTemplateTemplateParm(TemplateTemplateParmDecl *param,
                                          TemplateName replacement) const;
TemplateName getSubstTemplateTemplateParmPack(TemplateTemplateParmDecl *Param,
                                      const TemplateArgument &ArgPack) const;

enum GetBuiltinTypeError {
  /// No error
  GE_None,

  /// Missing a type
  GE_Missing_type,

  /// Missing a type from <stdio.h>
  GE_Missing_stdio,

  /// Missing a type from <setjmp.h>
  GE_Missing_setjmp,

  /// Missing a type from <ucontext.h>
  GE_Missing_ucontext
};

QualType DecodeTypeStr(const char *&Str, const ASTContext &Context,
                       ASTContext::GetBuiltinTypeError &Error,
                       bool &RequireICE, bool AllowTypeModifiers) const;

/// Return the type for the specified builtin.
///
/// If \p IntegerConstantArgs is non-null, it is filled in with a bitmask of
/// arguments to the builtin that are required to be integer constant
/// expressions.
QualType GetBuiltinType(unsigned ID, GetBuiltinTypeError &Error,
                        unsigned *IntegerConstantArgs = nullptr) const;

/// Types and expressions required to build C++2a three-way comparisons
/// using operator<=>, including the values return by builtin <=> operators.
ComparisonCategories CompCategories;

2177private:
CanQualType getFromTargetType(unsigned Type) const;
TypeInfo getTypeInfoImpl(const Type *T) const;

//===--------------------------------------------------------------------===//
//                         Type Predicates.
//===--------------------------------------------------------------------===//

2185public:
/// Return one of the GCNone, Weak or Strong Objective-C garbage
/// collection attributes.
Qualifiers::GC getObjCGCAttrKind(QualType Ty) const;

/// Return true if the given vector types are of the same unqualified
/// type or if they are equivalent to the same GCC vector type.
///
/// \note This ignores whether they are target-specific (AltiVec or Neon)
/// types.
bool areCompatibleVectorTypes(QualType FirstVec, QualType SecondVec);

/// Return true if the given types are an SVE builtin and a VectorType that
/// is a fixed-length representation of the SVE builtin for a specific
/// vector-length.
bool areCompatibleSveTypes(QualType FirstType, QualType SecondType);

/// Return true if the given vector types are lax-compatible SVE vector types,
/// false otherwise.
bool areLaxCompatibleSveTypes(QualType FirstType, QualType SecondType);

/// Return true if the type has been explicitly qualified with ObjC ownership.
/// A type may be implicitly qualified with ownership under ObjC ARC, and in
/// some cases the compiler treats these differently.
bool hasDirectOwnershipQualifier(QualType Ty) const;

/// Return true if this is an \c NSObject object with its \c NSObject
/// attribute set.
static bool isObjCNSObjectType(QualType Ty) {
  return Ty->isObjCNSObjectType();
}

//===--------------------------------------------------------------------===//
//                         Type Sizing and Analysis
//===--------------------------------------------------------------------===//

/// Return the APFloat 'semantics' for the specified scalar floating
/// point type.
const llvm::fltSemantics &getFloatTypeSemantics(QualType T) const;

/// Get the size and alignment of the specified complete type in bits.
TypeInfo getTypeInfo(const Type *T) const;
TypeInfo getTypeInfo(QualType T) const { return getTypeInfo(T.getTypePtr()); }

/// Get default simd alignment of the specified complete type in bits.
unsigned getOpenMPDefaultSimdAlign(QualType T) const;

/// Return the size of the specified (complete) type \p T, in bits.
uint64_t getTypeSize(QualType T) const { return getTypeInfo(T).Width; }
uint64_t getTypeSize(const Type *T) const { return getTypeInfo(T).Width; }

/// Return the size of the character type, in bits.
uint64_t getCharWidth() const {
  return getTypeSize(CharTy);
}

/// Convert a size in bits to a size in characters.
CharUnits toCharUnitsFromBits(int64_t BitSize) const;

/// Convert a size in characters to a size in bits.
int64_t toBits(CharUnits CharSize) const;

/// Return the size of the specified (complete) type \p T, in
/// characters.
CharUnits getTypeSizeInChars(QualType T) const;
CharUnits getTypeSizeInChars(const Type *T) const;

Optional<CharUnits> getTypeSizeInCharsIfKnown(QualType Ty) const {
  if (Ty->isIncompleteType() || Ty->isDependentType())
    return None;
  return getTypeSizeInChars(Ty);
}

Optional<CharUnits> getTypeSizeInCharsIfKnown(const Type *Ty) const {
  return getTypeSizeInCharsIfKnown(QualType(Ty, 0));
}

/// Return the ABI-specified alignment of a (complete) type \p T, in
/// bits.
unsigned getTypeAlign(QualType T) const { return getTypeInfo(T).Align; }
unsigned getTypeAlign(const Type *T) const { return getTypeInfo(T).Align; }

/// Return the ABI-specified natural alignment of a (complete) type \p T,
/// before alignment adjustments, in bits.
///
/// This alignment is curently used only by ARM and AArch64 when passing
/// arguments of a composite type.
unsigned getTypeUnadjustedAlign(QualType T) const {
  return getTypeUnadjustedAlign(T.getTypePtr());
}
unsigned getTypeUnadjustedAlign(const Type *T) const;

/// Return the alignment of a type, in bits, or 0 if
/// the type is incomplete and we cannot determine the alignment (for
/// example, from alignment attributes). The returned alignment is the
/// Preferred alignment if NeedsPreferredAlignment is true, otherwise is the
/// ABI alignment.
unsigned getTypeAlignIfKnown(QualType T,
                             bool NeedsPreferredAlignment = false) const;

/// Return the ABI-specified alignment of a (complete) type \p T, in
/// characters.
CharUnits getTypeAlignInChars(QualType T) const;
CharUnits getTypeAlignInChars(const Type *T) const;

/// Return the PreferredAlignment of a (complete) type \p T, in
/// characters.
CharUnits getPreferredTypeAlignInChars(QualType T) const {
  return toCharUnitsFromBits(getPreferredTypeAlign(T));
}

/// getTypeUnadjustedAlignInChars - Return the ABI-specified alignment of a type,
/// in characters, before alignment adjustments. This method does not work on
/// incomplete types.
CharUnits getTypeUnadjustedAlignInChars(QualType T) const;
CharUnits getTypeUnadjustedAlignInChars(const Type *T) const;

// getTypeInfoDataSizeInChars - Return the size of a type, in chars. If the
// type is a record, its data size is returned.
TypeInfoChars getTypeInfoDataSizeInChars(QualType T) const;

TypeInfoChars getTypeInfoInChars(const Type *T) const;
TypeInfoChars getTypeInfoInChars(QualType T) const;

/// Determine if the alignment the type has was required using an
/// alignment attribute.
bool isAlignmentRequired(const Type *T) const;
bool isAlignmentRequired(QualType T) const;

/// Return the "preferred" alignment of the specified type \p T for
/// the current target, in bits.
///
/// This can be different than the ABI alignment in cases where it is
/// beneficial for performance or backwards compatibility preserving to
/// overalign a data type. (Note: despite the name, the preferred alignment
/// is ABI-impacting, and not an optimization.)
unsigned getPreferredTypeAlign(QualType T) const {
  return getPreferredTypeAlign(T.getTypePtr());
}
unsigned getPreferredTypeAlign(const Type *T) const;

/// Return the default alignment for __attribute__((aligned)) on
/// this target, to be used if no alignment value is specified.
unsigned getTargetDefaultAlignForAttributeAligned() const;

/// Return the alignment in bits that should be given to a
/// global variable with type \p T.
unsigned getAlignOfGlobalVar(QualType T) const;

/// Return the alignment in characters that should be given to a
/// global variable with type \p T.
CharUnits getAlignOfGlobalVarInChars(QualType T) const;

/// Return a conservative estimate of the alignment of the specified
/// decl \p D.
///
/// \pre \p D must not be a bitfield type, as bitfields do not have a valid
/// alignment.
///
/// If \p ForAlignof, references are treated like their underlying type
/// and  large arrays don't get any special treatment. If not \p ForAlignof
/// it computes the value expected by CodeGen: references are treated like
/// pointers and large arrays get extra alignment.
CharUnits getDeclAlign(const Decl *D, bool ForAlignof = false) const;

/// Return the alignment (in bytes) of the thrown exception object. This is
/// only meaningful for targets that allocate C++ exceptions in a system
/// runtime, such as those using the Itanium C++ ABI.
CharUnits getExnObjectAlignment() const;

/// Get or compute information about the layout of the specified
/// record (struct/union/class) \p D, which indicates its size and field
/// position information.
const ASTRecordLayout &getASTRecordLayout(const RecordDecl *D) const;

/// Get or compute information about the layout of the specified
/// Objective-C interface.
const ASTRecordLayout &getASTObjCInterfaceLayout(const ObjCInterfaceDecl *D)
  const;

void DumpRecordLayout(const RecordDecl *RD, raw_ostream &OS,
                      bool Simple = false) const;

/// Get or compute information about the layout of the specified
/// Objective-C implementation.
///
/// This may differ from the interface if synthesized ivars are present.
const ASTRecordLayout &
getASTObjCImplementationLayout(const ObjCImplementationDecl *D) const;

/// Get our current best idea for the key function of the
/// given record decl, or nullptr if there isn't one.
///
/// The key function is, according to the Itanium C++ ABI section 5.2.3:
///   ...the first non-pure virtual function that is not inline at the
///   point of class definition.
///
/// Other ABIs use the same idea.  However, the ARM C++ ABI ignores
/// virtual functions that are defined 'inline', which means that
/// the result of this computation can change.
const CXXMethodDecl *getCurrentKeyFunction(const CXXRecordDecl *RD);

/// Observe that the given method cannot be a key function.
/// Checks the key-function cache for the method's class and clears it
/// if matches the given declaration.
///
/// This is used in ABIs where out-of-line definitions marked
/// inline are not considered to be key functions.
///
/// \param method should be the declaration from the class definition
void setNonKeyFunction(const CXXMethodDecl *method);

/// Loading virtual member pointers using the virtual inheritance model
/// always results in an adjustment using the vbtable even if the index is
/// zero.
///
/// This is usually OK because the first slot in the vbtable points
/// backwards to the top of the MDC.  However, the MDC might be reusing a
/// vbptr from an nv-base.  In this case, the first slot in the vbtable
/// points to the start of the nv-base which introduced the vbptr and *not*
/// the MDC.  Modify the NonVirtualBaseAdjustment to account for this.
CharUnits getOffsetOfBaseWithVBPtr(const CXXRecordDecl *RD) const;

/// Get the offset of a FieldDecl or IndirectFieldDecl, in bits.
uint64_t getFieldOffset(const ValueDecl *FD) const;

/// Get the offset of an ObjCIvarDecl in bits.
uint64_t lookupFieldBitOffset(const ObjCInterfaceDecl *OID,
                              const ObjCImplementationDecl *ID,
                              const ObjCIvarDecl *Ivar) const;

/// Find the 'this' offset for the member path in a pointer-to-member
/// APValue.
CharUnits getMemberPointerPathAdjustment(const APValue &MP) const;

bool isNearlyEmpty(const CXXRecordDecl *RD) const;

VTableContextBase *getVTableContext();

/// If \p T is null pointer, assume the target in ASTContext.
MangleContext *createMangleContext(const TargetInfo *T = nullptr);

/// Creates a device mangle context to correctly mangle lambdas in a mixed
/// architecture compile by setting the lambda mangling number source to the
/// DeviceLambdaManglingNumber. Currently this asserts that the TargetInfo
/// (from the AuxTargetInfo) is a an itanium target.
MangleContext *createDeviceMangleContext(const TargetInfo &T);

void DeepCollectObjCIvars(const ObjCInterfaceDecl *OI, bool leafClass,
                          SmallVectorImpl<const ObjCIvarDecl*> &Ivars) const;

unsigned CountNonClassIvars(const ObjCInterfaceDecl *OI) const;
void CollectInheritedProtocols(const Decl *CDecl,
                        llvm::SmallPtrSet<ObjCProtocolDecl*, 8> &Protocols);

/// Return true if the specified type has unique object representations
/// according to (C++17 [meta.unary.prop]p9)
bool hasUniqueObjectRepresentations(QualType Ty) const;

//===--------------------------------------------------------------------===//
//                            Type Operators
//===--------------------------------------------------------------------===//

/// Return the canonical (structural) type corresponding to the
/// specified potentially non-canonical type \p T.
///
/// The non-canonical version of a type may have many "decorated" versions of
/// types.  Decorators can include typedefs, 'typeof' operators, etc. The
/// returned type is guaranteed to be free of any of these, allowing two
/// canonical types to be compared for exact equality with a simple pointer
/// comparison.
CanQualType getCanonicalType(QualType T) const {
  return CanQualType::CreateUnsafe(T.getCanonicalType());
}

const Type *getCanonicalType(const Type *T) const {
  return T->getCanonicalTypeInternal().getTypePtr();
}

/// Return the canonical parameter type corresponding to the specific
/// potentially non-canonical one.
///
/// Qualifiers are stripped off, functions are turned into function
/// pointers, and arrays decay one level into pointers.
CanQualType getCanonicalParamType(QualType T) const;

/// Determine whether the given types \p T1 and \p T2 are equivalent.
bool hasSameType(QualType T1, QualType T2) const {
  return getCanonicalType(T1) == getCanonicalType(T2);
}
bool hasSameType(const Type *T1, const Type *T2) const {
  return getCanonicalType(T1) == getCanonicalType(T2);
}

/// Return this type as a completely-unqualified array type,
/// capturing the qualifiers in \p Quals.
///
/// This will remove the minimal amount of sugaring from the types, similar
/// to the behavior of QualType::getUnqualifiedType().
///
/// \param T is the qualified type, which may be an ArrayType
///
/// \param Quals will receive the full set of qualifiers that were
/// applied to the array.
///
/// \returns if this is an array type, the completely unqualified array type
/// that corresponds to it. Otherwise, returns T.getUnqualifiedType().
QualType getUnqualifiedArrayType(QualType T, Qualifiers &Quals);

/// Determine whether the given types are equivalent after
/// cvr-qualifiers have been removed.
bool hasSameUnqualifiedType(QualType T1, QualType T2) const {
  return getCanonicalType(T1).getTypePtr() ==
         getCanonicalType(T2).getTypePtr();
}

bool hasSameNullabilityTypeQualifier(QualType SubT, QualType SuperT,
                                     bool IsParam) const {
  auto SubTnullability = SubT->getNullability(*this);
  auto SuperTnullability = SuperT->getNullability(*this);
  if (SubTnullability.hasValue() == SuperTnullability.hasValue()) {
    // Neither has nullability; return true
    if (!SubTnullability)
      return true;
    // Both have nullability qualifier.
    if (*SubTnullability == *SuperTnullability ||
        *SubTnullability == NullabilityKind::Unspecified ||
        *SuperTnullability == NullabilityKind::Unspecified)
      return true;

    if (IsParam) {
      // Ok for the superclass method parameter to be "nonnull" and the subclass
      // method parameter to be "nullable"
      return (*SuperTnullability == NullabilityKind::NonNull &&
              *SubTnullability == NullabilityKind::Nullable);
    }
    // For the return type, it's okay for the superclass method to specify
    // "nullable" and the subclass method specify "nonnull"
    return (*SuperTnullability == NullabilityKind::Nullable &&
            *SubTnullability == NullabilityKind::NonNull);
  }
  return true;
}

bool ObjCMethodsAreEqual(const ObjCMethodDecl *MethodDecl,
                         const ObjCMethodDecl *MethodImp);

bool UnwrapSimilarTypes(QualType &T1, QualType &T2);
void UnwrapSimilarArrayTypes(QualType &T1, QualType &T2);

/// Determine if two types are similar, according to the C++ rules. That is,
/// determine if they are the same other than qualifiers on the initial
/// sequence of pointer / pointer-to-member / array (and in Clang, object
/// pointer) types and their element types.
///
/// Clang offers a number of qualifiers in addition to the C++ qualifiers;
/// those qualifiers are also ignored in the 'similarity' check.
bool hasSimilarType(QualType T1, QualType T2);

/// Determine if two types are similar, ignoring only CVR qualifiers.
bool hasCvrSimilarType(QualType T1, QualType T2);

/// Retrieves the "canonical" nested name specifier for a
/// given nested name specifier.
///
/// The canonical nested name specifier is a nested name specifier
/// that uniquely identifies a type or namespace within the type
/// system. For example, given:
///
/// \code
/// namespace N {
///   struct S {
///     template<typename T> struct X { typename T* type; };
///   };
/// }
///
/// template<typename T> struct Y {
///   typename N::S::X<T>::type member;
/// };
/// \endcode
///
/// Here, the nested-name-specifier for N::S::X<T>:: will be
/// S::X<template-param-0-0>, since 'S' and 'X' are uniquely defined
/// by declarations in the type system and the canonical type for
/// the template type parameter 'T' is template-param-0-0.
NestedNameSpecifier *
getCanonicalNestedNameSpecifier(NestedNameSpecifier *NNS) const;

/// Retrieves the default calling convention for the current target.
CallingConv getDefaultCallingConvention(bool IsVariadic,
                                        bool IsCXXMethod,
                                        bool IsBuiltin = false) const;

/// Retrieves the "canonical" template name that refers to a
/// given template.
///
/// The canonical template name is the simplest expression that can
/// be used to refer to a given template. For most templates, this
/// expression is just the template declaration itself. For example,
/// the template std::vector can be referred to via a variety of
/// names---std::vector, \::std::vector, vector (if vector is in
/// scope), etc.---but all of these names map down to the same
/// TemplateDecl, which is used to form the canonical template name.
///
/// Dependent template names are more interesting. Here, the
/// template name could be something like T::template apply or
/// std::allocator<T>::template rebind, where the nested name
/// specifier itself is dependent. In this case, the canonical
/// template name uses the shortest form of the dependent
/// nested-name-specifier, which itself contains all canonical
/// types, values, and templates.
TemplateName getCanonicalTemplateName(TemplateName Name) const;

/// Determine whether the given template names refer to the same
/// template.
bool hasSameTemplateName(TemplateName X, TemplateName Y);

/// Retrieve the "canonical" template argument.
///
/// The canonical template argument is the simplest template argument
/// (which may be a type, value, expression, or declaration) that
/// expresses the value of the argument.
TemplateArgument getCanonicalTemplateArgument(const TemplateArgument &Arg)
  const;

/// Type Query functions.  If the type is an instance of the specified class,
/// return the Type pointer for the underlying maximally pretty type.  This
/// is a member of ASTContext because this may need to do some amount of
/// canonicalization, e.g. to move type qualifiers into the element type.
const ArrayType *getAsArrayType(QualType T) const;
const ConstantArrayType *getAsConstantArrayType(QualType T) const {
  return dyn_cast_or_null<ConstantArrayType>(getAsArrayType(T));
}
const VariableArrayType *getAsVariableArrayType(QualType T) const {
  return dyn_cast_or_null<VariableArrayType>(getAsArrayType(T));
}
const IncompleteArrayType *getAsIncompleteArrayType(QualType T) const {
  return dyn_cast_or_null<IncompleteArrayType>(getAsArrayType(T));
}
const DependentSizedArrayType *getAsDependentSizedArrayType(QualType T)
  const {
  return dyn_cast_or_null<DependentSizedArrayType>(getAsArrayType(T));
}

/// Return the innermost element type of an array type.
///
/// For example, will return "int" for int[m][n]
QualType getBaseElementType(const ArrayType *VAT) const;

/// Return the innermost element type of a type (which needn't
/// actually be an array type).
QualType getBaseElementType(QualType QT) const;

/// Return number of constant array elements.
uint64_t getConstantArrayElementCount(const ConstantArrayType *CA) const;

/// Perform adjustment on the parameter type of a function.
///
/// This routine adjusts the given parameter type @p T to the actual
/// parameter type used by semantic analysis (C99 6.7.5.3p[7,8],
/// C++ [dcl.fct]p3). The adjusted parameter type is returned.
QualType getAdjustedParameterType(QualType T) const;

/// Retrieve the parameter type as adjusted for use in the signature
/// of a function, decaying array and function types and removing top-level
/// cv-qualifiers.
QualType getSignatureParameterType(QualType T) const;

QualType getExceptionObjectType(QualType T) const;

/// Return the properly qualified result of decaying the specified
/// array type to a pointer.
///
/// This operation is non-trivial when handling typedefs etc.  The canonical
/// type of \p T must be an array type, this returns a pointer to a properly
/// qualified element of the array.
///
/// See C99 6.7.5.3p7 and C99 6.3.2.1p3.
QualType getArrayDecayedType(QualType T) const;

/// Return the type that \p PromotableType will promote to: C99
/// 6.3.1.1p2, assuming that \p PromotableType is a promotable integer type.
QualType getPromotedIntegerType(QualType PromotableType) const;

/// Recurses in pointer/array types until it finds an Objective-C
/// retainable type and returns its ownership.
Qualifiers::ObjCLifetime getInnerObjCOwnership(QualType T) const;

/// Whether this is a promotable bitfield reference according
/// to C99 6.3.1.1p2, bullet 2 (and GCC extensions).
///
/// \returns the type this bit-field will promote to, or NULL if no
/// promotion occurs.
QualType isPromotableBitField(Expr *E) const;

/// Return the highest ranked integer type, see C99 6.3.1.8p1.
///
/// If \p LHS > \p RHS, returns 1.  If \p LHS == \p RHS, returns 0.  If
/// \p LHS < \p RHS, return -1.
int getIntegerTypeOrder(QualType LHS, QualType RHS) const;

/// Compare the rank of the two specified floating point types,
/// ignoring the domain of the type (i.e. 'double' == '_Complex double').
///
/// If \p LHS > \p RHS, returns 1.  If \p LHS == \p RHS, returns 0.  If
/// \p LHS < \p RHS, return -1.
int getFloatingTypeOrder(QualType LHS, QualType RHS) const;

/// Compare the rank of two floating point types as above, but compare equal
/// if both types have the same floating-point semantics on the target (i.e.
/// long double and double on AArch64 will return 0).
int getFloatingTypeSemanticOrder(QualType LHS, QualType RHS) const;

/// Return a real floating point or a complex type (based on
/// \p typeDomain/\p typeSize).
///
/// \param typeDomain a real floating point or complex type.
/// \param typeSize a real floating point or complex type.
QualType getFloatingTypeOfSizeWithinDomain(QualType typeSize,
                                           QualType typeDomain) const;

unsigned getTargetAddressSpace(QualType T) const {
  return getTargetAddressSpace(T.getQualifiers());
}

unsigned getTargetAddressSpace(Qualifiers Q) const {
  return getTargetAddressSpace(Q.getAddressSpace());
}

unsigned getTargetAddressSpace(LangAS AS) const;

LangAS getLangASForBuiltinAddressSpace(unsigned AS) const;

/// Get target-dependent integer value for null pointer which is used for
/// constant folding.
uint64_t getTargetNullPointerValue(QualType QT) const;

bool addressSpaceMapManglingFor(LangAS AS) const {
  return AddrSpaceMapMangling || isTargetAddressSpace(AS);
}

2726private:
// Helper for integer ordering
unsigned getIntegerRank(const Type *T) const;

2730public:
//===--------------------------------------------------------------------===//
//                    Type Compatibility Predicates
//===--------------------------------------------------------------------===//

/// Compatibility predicates used to check assignment expressions.
bool typesAreCompatible(QualType T1, QualType T2,
                        bool CompareUnqualified = false); // C99 6.2.7p1

bool propertyTypesAreCompatible(QualType, QualType);
bool typesAreBlockPointerCompatible(QualType, QualType);

bool isObjCIdType(QualType T) const {
  return T == getObjCIdType();
}

bool isObjCClassType(QualType T) const {
  return T == getObjCClassType();
}

bool isObjCSelType(QualType T) const {
  return T == getObjCSelType();
}

bool ObjCQualifiedIdTypesAreCompatible(const ObjCObjectPointerType *LHS,
                                       const ObjCObjectPointerType *RHS,
                                       bool ForCompare);

bool ObjCQualifiedClassTypesAreCompatible(const ObjCObjectPointerType *LHS,
                                          const ObjCObjectPointerType *RHS);

// Check the safety of assignment from LHS to RHS
bool canAssignObjCInterfaces(const ObjCObjectPointerType *LHSOPT,
                             const ObjCObjectPointerType *RHSOPT);
bool canAssignObjCInterfaces(const ObjCObjectType *LHS,
                             const ObjCObjectType *RHS);
bool canAssignObjCInterfacesInBlockPointer(
                                        const ObjCObjectPointerType *LHSOPT,
                                        const ObjCObjectPointerType *RHSOPT,
                                        bool BlockReturnType);
bool areComparableObjCPointerTypes(QualType LHS, QualType RHS);
QualType areCommonBaseCompatible(const ObjCObjectPointerType *LHSOPT,
                                 const ObjCObjectPointerType *RHSOPT);
bool canBindObjCObjectType(QualType To, QualType From);

// Functions for calculating composite types
QualType mergeTypes(QualType, QualType, bool OfBlockPointer=false,
                    bool Unqualified = false, bool BlockReturnType = false);
QualType mergeFunctionTypes(QualType, QualType, bool OfBlockPointer=false,
                            bool Unqualified = false, bool AllowCXX = false);
QualType mergeFunctionParameterTypes(QualType, QualType,
                                     bool OfBlockPointer = false,
                                     bool Unqualified = false);
QualType mergeTransparentUnionType(QualType, QualType,
                                   bool OfBlockPointer=false,
                                   bool Unqualified = false);

QualType mergeObjCGCQualifiers(QualType, QualType);

/// This function merges the ExtParameterInfo lists of two functions. It
/// returns true if the lists are compatible. The merged list is returned in
/// NewParamInfos.
///
/// \param FirstFnType The type of the first function.
///
/// \param SecondFnType The type of the second function.
///
/// \param CanUseFirst This flag is set to true if the first function's
/// ExtParameterInfo list can be used as the composite list of
/// ExtParameterInfo.
///
/// \param CanUseSecond This flag is set to true if the second function's
/// ExtParameterInfo list can be used as the composite list of
/// ExtParameterInfo.
///
/// \param NewParamInfos The composite list of ExtParameterInfo. The list is
/// empty if none of the flags are set.
///
bool mergeExtParameterInfo(
    const FunctionProtoType *FirstFnType,
    const FunctionProtoType *SecondFnType,
    bool &CanUseFirst, bool &CanUseSecond,
    SmallVectorImpl<FunctionProtoType::ExtParameterInfo> &NewParamInfos);

void ResetObjCLayout(const ObjCContainerDecl *CD);

//===--------------------------------------------------------------------===//
//                    Integer Predicates
//===--------------------------------------------------------------------===//

// The width of an integer, as defined in C99 6.2.6.2. This is the number
// of bits in an integer type excluding any padding bits.
unsigned getIntWidth(QualType T) const;

// Per C99 6.2.5p6, for every signed integer type, there is a corresponding
// unsigned integer type.  This method takes a signed type, and returns the
// corresponding unsigned integer type.
// With the introduction of fixed point types in ISO N1169, this method also
// accepts fixed point types and returns the corresponding unsigned type for
// a given fixed point type.
QualType getCorrespondingUnsignedType(QualType T) const;

// Per C99 6.2.5p6, for every signed integer type, there is a corresponding
// unsigned integer type.  This method takes an unsigned type, and returns the
// corresponding signed integer type.
// With the introduction of fixed point types in ISO N1169, this method also
// accepts fixed point types and returns the corresponding signed type for
// a given fixed point type.
QualType getCorrespondingSignedType(QualType T) const;

// Per ISO N1169, this method accepts fixed point types and returns the
// corresponding saturated type for a given fixed point type.
QualType getCorrespondingSaturatedType(QualType Ty) const;

// This method accepts fixed point types and returns the corresponding signed
// type. Unlike getCorrespondingUnsignedType(), this only accepts unsigned
// fixed point types because there are unsigned integer types like bool and
// char8_t that don't have signed equivalents.
QualType getCorrespondingSignedFixedPointType(QualType Ty) const;

//===--------------------------------------------------------------------===//
//                    Integer Values
//===--------------------------------------------------------------------===//

/// Make an APSInt of the appropriate width and signedness for the
/// given \p Value and integer \p Type.
llvm::APSInt MakeIntValue(uint64_t Value, QualType Type) const {
  // If Type is a signed integer type larger than 64 bits, we need to be sure
  // to sign extend Res appropriately.
  llvm::APSInt Res(64, !Type->isSignedIntegerOrEnumerationType());
  Res = Value;
  unsigned Width = getIntWidth(Type);
  if (Width != Res.getBitWidth())
    return Res.extOrTrunc(Width);
  return Res;
}

bool isSentinelNullExpr(const Expr *E);

/// Get the implementation of the ObjCInterfaceDecl \p D, or nullptr if
/// none exists.
ObjCImplementationDecl *getObjCImplementation(ObjCInterfaceDecl *D);

/// Get the implementation of the ObjCCategoryDecl \p D, or nullptr if
/// none exists.
ObjCCategoryImplDecl *getObjCImplementation(ObjCCategoryDecl *D);

/// Return true if there is at least one \@implementation in the TU.
bool AnyObjCImplementation() {
  return !ObjCImpls.empty();
}

/// Set the implementation of ObjCInterfaceDecl.
void setObjCImplementation(ObjCInterfaceDecl *IFaceD,
                           ObjCImplementationDecl *ImplD);

/// Set the implementation of ObjCCategoryDecl.
void setObjCImplementation(ObjCCategoryDecl *CatD,
                           ObjCCategoryImplDecl *ImplD);

/// Get the duplicate declaration of a ObjCMethod in the same
/// interface, or null if none exists.
const ObjCMethodDecl *
getObjCMethodRedeclaration(const ObjCMethodDecl *MD) const;

void setObjCMethodRedeclaration(const ObjCMethodDecl *MD,
                                const ObjCMethodDecl *Redecl);

/// Returns the Objective-C interface that \p ND belongs to if it is
/// an Objective-C method/property/ivar etc. that is part of an interface,
/// otherwise returns null.
const ObjCInterfaceDecl *getObjContainingInterface(const NamedDecl *ND) const;

/// Set the copy initialization expression of a block var decl. \p CanThrow
/// indicates whether the copy expression can throw or not.
void setBlockVarCopyInit(const VarDecl* VD, Expr *CopyExpr, bool CanThrow);

/// Get the copy initialization expression of the VarDecl \p VD, or
/// nullptr if none exists.
BlockVarCopyInit getBlockVarCopyInit(const VarDecl* VD) const;

/// Allocate an uninitialized TypeSourceInfo.
///
/// The caller should initialize the memory held by TypeSourceInfo using
/// the TypeLoc wrappers.
///
/// \param T the type that will be the basis for type source info. This type
/// should refer to how the declarator was written in source code, not to
/// what type semantic analysis resolved the declarator to.
///
/// \param Size the size of the type info to create, or 0 if the size
/// should be calculated based on the type.
TypeSourceInfo *CreateTypeSourceInfo(QualType T, unsigned Size = 0) const;

/// Allocate a TypeSourceInfo where all locations have been
/// initialized to a given location, which defaults to the empty
/// location.
TypeSourceInfo *
getTrivialTypeSourceInfo(QualType T,
                         SourceLocation Loc = SourceLocation()) const;

/// Add a deallocation callback that will be invoked when the
/// ASTContext is destroyed.
///
/// \param Callback A callback function that will be invoked on destruction.
///
/// \param Data Pointer data that will be provided to the callback function
/// when it is called.
void AddDeallocation(void (*Callback)(void *), void *Data) const;

/// If T isn't trivially destructible, calls AddDeallocation to register it
/// for destruction.
template <typename T> void addDestruction(T *Ptr) const {
  if (!std::is_trivially_destructible<T>::value) {
    auto DestroyPtr = [](void *V) { static_cast<T *>(V)->~T(); };
    AddDeallocation(DestroyPtr, Ptr);
  }
}

GVALinkage GetGVALinkageForFunction(const FunctionDecl *FD) const;
GVALinkage GetGVALinkageForVariable(const VarDecl *VD);

/// Determines if the decl can be CodeGen'ed or deserialized from PCH
/// lazily, only when used; this is only relevant for function or file scoped
/// var definitions.
///
/// \returns true if the function/var must be CodeGen'ed/deserialized even if
/// it is not used.
bool DeclMustBeEmitted(const Decl *D);

/// Visits all versions of a multiversioned function with the passed
/// predicate.
void forEachMultiversionedFunctionVersion(
    const FunctionDecl *FD,
    llvm::function_ref<void(FunctionDecl *)> Pred) const;

const CXXConstructorDecl *
getCopyConstructorForExceptionObject(CXXRecordDecl *RD);

void addCopyConstructorForExceptionObject(CXXRecordDecl *RD,
                                          CXXConstructorDecl *CD);

void addTypedefNameForUnnamedTagDecl(TagDecl *TD, TypedefNameDecl *TND);

TypedefNameDecl *getTypedefNameForUnnamedTagDecl(const TagDecl *TD);

void addDeclaratorForUnnamedTagDecl(TagDecl *TD, DeclaratorDecl *DD);

DeclaratorDecl *getDeclaratorForUnnamedTagDecl(const TagDecl *TD);

void setManglingNumber(const NamedDecl *ND, unsigned Number);
unsigned getManglingNumber(const NamedDecl *ND) const;

void setStaticLocalNumber(const VarDecl *VD, unsigned Number);
unsigned getStaticLocalNumber(const VarDecl *VD) const;

/// Retrieve the context for computing mangling numbers in the given
/// DeclContext.
MangleNumberingContext &getManglingNumberContext(const DeclContext *DC);
enum NeedExtraManglingDecl_t { NeedExtraManglingDecl };
MangleNumberingContext &getManglingNumberContext(NeedExtraManglingDecl_t,
                                                 const Decl *D);

std::unique_ptr<MangleNumberingContext> createMangleNumberingContext() const;

/// Used by ParmVarDecl to store on the side the
/// index of the parameter when it exceeds the size of the normal bitfield.
void setParameterIndex(const ParmVarDecl *D, unsigned index);

/// Used by ParmVarDecl to retrieve on the side the
/// index of the parameter when it exceeds the size of the normal bitfield.
unsigned getParameterIndex(const ParmVarDecl *D) const;

/// Return a string representing the human readable name for the specified
/// function declaration or file name. Used by SourceLocExpr and
/// PredefinedExpr to cache evaluated results.
StringLiteral *getPredefinedStringLiteralFromCache(StringRef Key) const;

/// Return a declaration for the global GUID object representing the given
/// GUID value.
MSGuidDecl *getMSGuidDecl(MSGuidDeclParts Parts) const;

/// Return the template parameter object of the given type with the given
/// value.
TemplateParamObjectDecl *getTemplateParamObjectDecl(QualType T,
                                                    const APValue &V) const;

/// Parses the target attributes passed in, and returns only the ones that are
/// valid feature names.
ParsedTargetAttr filterFunctionTargetAttrs(const TargetAttr *TD) const;

void getFunctionFeatureMap(llvm::StringMap<bool> &FeatureMap,
                           const FunctionDecl *) const;
void getFunctionFeatureMap(llvm::StringMap<bool> &FeatureMap,
                           GlobalDecl GD) const;

//===--------------------------------------------------------------------===//
//                    Statistics
//===--------------------------------------------------------------------===//

/// The number of implicitly-declared default constructors.
unsigned NumImplicitDefaultConstructors = 0;

/// The number of implicitly-declared default constructors for
/// which declarations were built.
unsigned NumImplicitDefaultConstructorsDeclared = 0;

/// The number of implicitly-declared copy constructors.
unsigned NumImplicitCopyConstructors = 0;

/// The number of implicitly-declared copy constructors for
/// which declarations were built.
unsigned NumImplicitCopyConstructorsDeclared = 0;

/// The number of implicitly-declared move constructors.
unsigned NumImplicitMoveConstructors = 0;

/// The number of implicitly-declared move constructors for
/// which declarations were built.
unsigned NumImplicitMoveConstructorsDeclared = 0;

/// The number of implicitly-declared copy assignment operators.
unsigned NumImplicitCopyAssignmentOperators = 0;

/// The number of implicitly-declared copy assignment operators for
/// which declarations were built.
unsigned NumImplicitCopyAssignmentOperatorsDeclared = 0;

/// The number of implicitly-declared move assignment operators.
unsigned NumImplicitMoveAssignmentOperators = 0;

/// The number of implicitly-declared move assignment operators for
/// which declarations were built.
unsigned NumImplicitMoveAssignmentOperatorsDeclared = 0;

/// The number of implicitly-declared destructors.
unsigned NumImplicitDestructors = 0;

/// The number of implicitly-declared destructors for which
/// declarations were built.
unsigned NumImplicitDestructorsDeclared = 0;

3072public:
/// Initialize built-in types.
///
/// This routine may only be invoked once for a given ASTContext object.
/// It is normally invoked after ASTContext construction.
///
/// \param Target The target
void InitBuiltinTypes(const TargetInfo &Target,
                      const TargetInfo *AuxTarget = nullptr);

3082private:
void InitBuiltinType(CanQualType &R, BuiltinType::Kind K);

class ObjCEncOptions {
  unsigned Bits;

  ObjCEncOptions(unsigned Bits) : Bits(Bits) {}

public:
  ObjCEncOptions() : Bits(0) {}
  ObjCEncOptions(const ObjCEncOptions &RHS) : Bits(RHS.Bits) {}

3094#define OPT_LIST(V)                                                            \
V(ExpandPointedToStructures, 0)                                              \
V(ExpandStructures, 1)                                                       \
V(IsOutermostType, 2)                                                        \
V(EncodingProperty, 3)                                                       \
V(IsStructField, 4)                                                          \
V(EncodeBlockParameters, 5)                                                  \
V(EncodeClassNames, 6)                                                       \

3103#define V(N,I) ObjCEncOptions& set##N() { Bits |= 1 << I; return *this; }
3104OPT_LIST(V)
3105#undef V

3107#define V(N,I) bool N() const { return Bits & 1 << I; }
3108OPT_LIST(V)
3109#undef V

3111#undef OPT_LIST

  LLVM_NODISCARD[[clang::warn_unused_result]] ObjCEncOptions keepingOnly(ObjCEncOptions Mask) const {
    return Bits & Mask.Bits;
  }

  LLVM_NODISCARD[[clang::warn_unused_result]] ObjCEncOptions forComponentType() const {
    ObjCEncOptions Mask = ObjCEncOptions()
                              .setIsOutermostType()
                              .setIsStructField();
    return Bits & ~Mask.Bits;
  }
};

// Return the Objective-C type encoding for a given type.
void getObjCEncodingForTypeImpl(QualType t, std::string &S,
                                ObjCEncOptions Options,
                                const FieldDecl *Field,
                                QualType *NotEncodedT = nullptr) const;

// Adds the encoding of the structure's members.
void getObjCEncodingForStructureImpl(RecordDecl *RD, std::string &S,
                                     const FieldDecl *Field,
                                     bool includeVBases = true,
                                     QualType *NotEncodedT=nullptr) const;

3137public:
// Adds the encoding of a method parameter or return type.
void getObjCEncodingForMethodParameter(Decl::ObjCDeclQualifier QT,
                                       QualType T, std::string& S,
                                       bool Extended) const;

/// Returns true if this is an inline-initialized static data member
/// which is treated as a definition for MSVC compatibility.
bool isMSStaticDataMemberInlineDefinition(const VarDecl *VD) const;

enum class InlineVariableDefinitionKind {
  /// Not an inline variable.
  None,

  /// Weak definition of inline variable.
  Weak,

  /// Weak for now, might become strong later in this TU.
  WeakUnknown,

  /// Strong definition.
  Strong
};

/// Determine whether a definition of this inline variable should
/// be treated as a weak or strong definition. For compatibility with
/// C++14 and before, for a constexpr static data member, if there is an
/// out-of-line declaration of the member, we may promote it from weak to
/// strong.
InlineVariableDefinitionKind
getInlineVariableDefinitionKind(const VarDecl *VD) const;

3169private:
friend class DeclarationNameTable;
friend class DeclContext;

const ASTRecordLayout &
getObjCLayout(const ObjCInterfaceDecl *D,
              const ObjCImplementationDecl *Impl) const;

/// A set of deallocations that should be performed when the
/// ASTContext is destroyed.
// FIXME: We really should have a better mechanism in the ASTContext to
// manage running destructors for types which do variable sized allocation
// within the AST. In some places we thread the AST bump pointer allocator
// into the datastructures which avoids this mess during deallocation but is
// wasteful of memory, and here we require a lot of error prone book keeping
// in order to track and run destructors while we're tearing things down.
using DeallocationFunctionsAndArguments =
    llvm::SmallVector<std::pair<void (*)(void *), void *>, 16>;
mutable DeallocationFunctionsAndArguments Deallocations;

// FIXME: This currently contains the set of StoredDeclMaps used
// by DeclContext objects.  This probably should not be in ASTContext,
// but we include it here so that ASTContext can quickly deallocate them.
llvm::PointerIntPair<StoredDeclsMap *, 1> LastSDM;

std::vector<Decl *> TraversalScope;

std::unique_ptr<VTableContextBase> VTContext;

void ReleaseDeclContextMaps();

3200public:
enum PragmaSectionFlag : unsigned {
  PSF_None = 0,
  PSF_Read = 0x1,
  PSF_Write = 0x2,
  PSF_Execute = 0x4,
  PSF_Implicit = 0x8,
  PSF_ZeroInit = 0x10,
  PSF_Invalid = 0x80000000U,
};

struct SectionInfo {
  NamedDecl *Decl;
  SourceLocation PragmaSectionLocation;
  int SectionFlags;

  SectionInfo() = default;
  SectionInfo(NamedDecl *Decl, SourceLocation PragmaSectionLocation,
              int SectionFlags)
      : Decl(Decl), PragmaSectionLocation(PragmaSectionLocation),
        SectionFlags(SectionFlags) {}
};

llvm::StringMap<SectionInfo> SectionInfos;

/// Return a new OMPTraitInfo object owned by this context.
OMPTraitInfo &getNewOMPTraitInfo();

/// Whether a C++ static variable may be externalized.
bool mayExternalizeStaticVar(const Decl *D) const;

/// Whether a C++ static variable should be externalized.
bool shouldExternalizeStaticVar(const Decl *D) const;

StringRef getCUIDHash() const;

void AddSYCLKernelNamingDecl(const CXXRecordDecl *RD);
bool IsSYCLKernelNamingDecl(const NamedDecl *RD) const;
unsigned GetSYCLKernelNamingIndex(const NamedDecl *RD);
/// A SourceLocation to store whether we have evaluated a kernel name already,
/// and where it happened.  If so, we need to diagnose an illegal use of the
/// builtin.
llvm::MapVector<const SYCLUniqueStableNameExpr *, std::string>
    SYCLUniqueStableNameEvaluatedValues;

3245private:
/// All OMPTraitInfo objects live in this collection, one per
/// `pragma omp [begin] declare variant` directive.
SmallVector<std::unique_ptr<OMPTraitInfo>, 4> OMPTraitInfoVector;

/// A list of the (right now just lambda decls) declarations required to
/// name all the SYCL kernels in the translation unit, so that we can get the
/// correct kernel name, as well as implement
/// __builtin_sycl_unique_stable_name.
llvm::DenseMap<const DeclContext *,
               llvm::SmallPtrSet<const CXXRecordDecl *, 4>>
    SYCLKernelNamingTypes;
std::unique_ptr<ItaniumMangleContext> SYCLKernelFilterContext;
void FilterSYCLKernelNamingDecls(
    const CXXRecordDecl *RD,
    llvm::SmallVectorImpl<const CXXRecordDecl *> &Decls);
3261};

3263/// Insertion operator for diagnostics.
3264const StreamingDiagnostic &operator<<(const StreamingDiagnostic &DB,
                                    const ASTContext::SectionInfo &Section);

3267/// Utility function for constructing a nullary selector.
3268inline Selector GetNullarySelector(StringRef name, ASTContext &Ctx) {
IdentifierInfo* II = &Ctx.Idents.get(name);
return Ctx.Selectors.getSelector(0, &II);
3271}

3273/// Utility function for constructing an unary selector.
3274inline Selector GetUnarySelector(StringRef name, ASTContext &Ctx) {
IdentifierInfo* II = &Ctx.Idents.get(name);
return Ctx.Selectors.getSelector(1, &II);
3277}

3279} // namespace clang

3281// operator new and delete aren't allowed inside namespaces.

3283/// Placement new for using the ASTContext's allocator.
3284///
3285/// This placement form of operator new uses the ASTContext's allocator for
3286/// obtaining memory.
3287///
3288/// IMPORTANT: These are also declared in clang/AST/ASTContextAllocate.h!
3289/// Any changes here need to also be made there.
3290///
3291/// We intentionally avoid using a nothrow specification here so that the calls
3292/// to this operator will not perform a null check on the result -- the
3293/// underlying allocator never returns null pointers.
3294///
3295/// Usage looks like this (assuming there's an ASTContext 'Context' in scope):
3296/// @code
3297/// // Default alignment (8)
3298/// IntegerLiteral *Ex = new (Context) IntegerLiteral(arguments);
3299/// // Specific alignment
3300/// IntegerLiteral *Ex2 = new (Context, 4) IntegerLiteral(arguments);
3301/// @endcode
3302/// Memory allocated through this placement new operator does not need to be
3303/// explicitly freed, as ASTContext will free all of this memory when it gets
3304/// destroyed. Please note that you cannot use delete on the pointer.
3305///
3306/// @param Bytes The number of bytes to allocate. Calculated by the compiler.
3307/// @param C The ASTContext that provides the allocator.
3308/// @param Alignment The alignment of the allocated memory (if the underlying
3309///                  allocator supports it).
3310/// @return The allocated memory. Could be nullptr.
3311inline void *operator new(size_t Bytes, const clang::ASTContext &C,
                        size_t Alignment /* = 8 */) {
return C.Allocate(Bytes, Alignment);
3314}

3316/// Placement delete companion to the new above.
3317///
3318/// This operator is just a companion to the new above. There is no way of
3319/// invoking it directly; see the new operator for more details. This operator
3320/// is called implicitly by the compiler if a placement new expression using
3321/// the ASTContext throws in the object constructor.
3322inline void operator delete(void *Ptr, const clang::ASTContext &C, size_t) {
C.Deallocate(Ptr);
3324}

3326/// This placement form of operator new[] uses the ASTContext's allocator for
3327/// obtaining memory.
3328///
3329/// We intentionally avoid using a nothrow specification here so that the calls
3330/// to this operator will not perform a null check on the result -- the
3331/// underlying allocator never returns null pointers.
3332///
3333/// Usage looks like this (assuming there's an ASTContext 'Context' in scope):
3334/// @code
3335/// // Default alignment (8)
3336/// char *data = new (Context) char[10];
3337/// // Specific alignment
3338/// char *data = new (Context, 4) char[10];
3339/// @endcode
3340/// Memory allocated through this placement new[] operator does not need to be
3341/// explicitly freed, as ASTContext will free all of this memory when it gets
3342/// destroyed. Please note that you cannot use delete on the pointer.
3343///
3344/// @param Bytes The number of bytes to allocate. Calculated by the compiler.
3345/// @param C The ASTContext that provides the allocator.
3346/// @param Alignment The alignment of the allocated memory (if the underlying
3347///                  allocator supports it).
3348/// @return The allocated memory. Could be nullptr.
3349inline void *operator new[](size_t Bytes, const clang::ASTContext& C,
                          size_t Alignment /* = 8 */) {
return C.Allocate(Bytes, Alignment);
3352}

3354/// Placement delete[] companion to the new[] above.
3355///
3356/// This operator is just a companion to the new[] above. There is no way of
3357/// invoking it directly; see the new[] operator for more details. This operator
3358/// is called implicitly by the compiler if a placement new[] expression using
3359/// the ASTContext throws in the object constructor.
3360inline void operator delete[](void *Ptr, const clang::ASTContext &C, size_t) {
C.Deallocate(Ptr);
3362}

3364/// Create the representation of a LazyGenerationalUpdatePtr.
3365template <typename Owner, typename T,
        void (clang::ExternalASTSource::*Update)(Owner)>
3367typename clang::LazyGenerationalUpdatePtr<Owner, T, Update>::ValueType
  clang::LazyGenerationalUpdatePtr<Owner, T, Update>::makeValue(
      const clang::ASTContext &Ctx, T Value) {
// Note, this is implemented here so that ExternalASTSource.h doesn't need to
// include ASTContext.h. We explicitly instantiate it for all relevant types
// in ASTContext.cpp.
if (auto *Source = Ctx.getExternalSource())
  return new (Ctx) LazyData(Source, Value);
return Value;
3376}

3378#endif // LLVM_CLANG_AST_ASTCONTEXT_H