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

Bug Summary

File:	clang/lib/Sema/SemaExprCXX.cpp
Warning:	line 3820, column 3 Called C++ object pointer is null
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 SemaExprCXX.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/SemaExprCXX.cpp
1//===--- SemaExprCXX.cpp - Semantic Analysis for Expressions --------------===//
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/// Implements semantic analysis for C++ expressions.
11///
12//===----------------------------------------------------------------------===//

14#include "clang/Sema/Template.h"
15#include "clang/Sema/SemaInternal.h"
16#include "TreeTransform.h"
17#include "TypeLocBuilder.h"
18#include "clang/AST/ASTContext.h"
19#include "clang/AST/ASTLambda.h"
20#include "clang/AST/CXXInheritance.h"
21#include "clang/AST/CharUnits.h"
22#include "clang/AST/DeclObjC.h"
23#include "clang/AST/ExprCXX.h"
24#include "clang/AST/ExprObjC.h"
25#include "clang/AST/RecursiveASTVisitor.h"
26#include "clang/AST/TypeLoc.h"
27#include "clang/Basic/AlignedAllocation.h"
28#include "clang/Basic/PartialDiagnostic.h"
29#include "clang/Basic/TargetInfo.h"
30#include "clang/Lex/Preprocessor.h"
31#include "clang/Sema/DeclSpec.h"
32#include "clang/Sema/Initialization.h"
33#include "clang/Sema/Lookup.h"
34#include "clang/Sema/ParsedTemplate.h"
35#include "clang/Sema/Scope.h"
36#include "clang/Sema/ScopeInfo.h"
37#include "clang/Sema/SemaLambda.h"
38#include "clang/Sema/TemplateDeduction.h"
39#include "llvm/ADT/APInt.h"
40#include "llvm/ADT/STLExtras.h"
41#include "llvm/Support/ErrorHandling.h"
42using namespace clang;
43using namespace sema;

45/// Handle the result of the special case name lookup for inheriting
46/// constructor declarations. 'NS::X::X' and 'NS::X<...>::X' are treated as
47/// constructor names in member using declarations, even if 'X' is not the
48/// name of the corresponding type.
49ParsedType Sema::getInheritingConstructorName(CXXScopeSpec &SS,
                                            SourceLocation NameLoc,
                                            IdentifierInfo &Name) {
NestedNameSpecifier *NNS = SS.getScopeRep();

// Convert the nested-name-specifier into a type.
QualType Type;
switch (NNS->getKind()) {
case NestedNameSpecifier::TypeSpec:
case NestedNameSpecifier::TypeSpecWithTemplate:
  Type = QualType(NNS->getAsType(), 0);
  break;

case NestedNameSpecifier::Identifier:
  // Strip off the last layer of the nested-name-specifier and build a
  // typename type for it.
  assert(NNS->getAsIdentifier() == &Name && "not a constructor name")(static_cast<void> (0));
  Type = Context.getDependentNameType(ETK_None, NNS->getPrefix(),
                                      NNS->getAsIdentifier());
  break;

case NestedNameSpecifier::Global:
case NestedNameSpecifier::Super:
case NestedNameSpecifier::Namespace:
case NestedNameSpecifier::NamespaceAlias:
  llvm_unreachable("Nested name specifier is not a type for inheriting ctor")__builtin_unreachable();
}

// This reference to the type is located entirely at the location of the
// final identifier in the qualified-id.
return CreateParsedType(Type,
                        Context.getTrivialTypeSourceInfo(Type, NameLoc));
81}

83ParsedType Sema::getConstructorName(IdentifierInfo &II,
                                  SourceLocation NameLoc,
                                  Scope *S, CXXScopeSpec &SS,
                                  bool EnteringContext) {
CXXRecordDecl *CurClass = getCurrentClass(S, &SS);
assert(CurClass && &II == CurClass->getIdentifier() &&(static_cast<void> (0))
       "not a constructor name")(static_cast<void> (0));

// When naming a constructor as a member of a dependent context (eg, in a
// friend declaration or an inherited constructor declaration), form an
// unresolved "typename" type.
if (CurClass->isDependentContext() && !EnteringContext && SS.getScopeRep()) {
  QualType T = Context.getDependentNameType(ETK_None, SS.getScopeRep(), &II);
  return ParsedType::make(T);
}

if (SS.isNotEmpty() && RequireCompleteDeclContext(SS, CurClass))
  return ParsedType();

// Find the injected-class-name declaration. Note that we make no attempt to
// diagnose cases where the injected-class-name is shadowed: the only
// declaration that can validly shadow the injected-class-name is a
// non-static data member, and if the class contains both a non-static data
// member and a constructor then it is ill-formed (we check that in
// CheckCompletedCXXClass).
CXXRecordDecl *InjectedClassName = nullptr;
for (NamedDecl *ND : CurClass->lookup(&II)) {
  auto *RD = dyn_cast<CXXRecordDecl>(ND);
  if (RD && RD->isInjectedClassName()) {
    InjectedClassName = RD;
    break;
  }
}
if (!InjectedClassName) {
  if (!CurClass->isInvalidDecl()) {
    // FIXME: RequireCompleteDeclContext doesn't check dependent contexts
    // properly. Work around it here for now.
    Diag(SS.getLastQualifierNameLoc(),
         diag::err_incomplete_nested_name_spec) << CurClass << SS.getRange();
  }
  return ParsedType();
}

QualType T = Context.getTypeDeclType(InjectedClassName);
DiagnoseUseOfDecl(InjectedClassName, NameLoc);
MarkAnyDeclReferenced(NameLoc, InjectedClassName, /*OdrUse=*/false);

return ParsedType::make(T);
131}

133ParsedType Sema::getDestructorName(SourceLocation TildeLoc,
                                 IdentifierInfo &II,
                                 SourceLocation NameLoc,
                                 Scope *S, CXXScopeSpec &SS,
                                 ParsedType ObjectTypePtr,
                                 bool EnteringContext) {
// Determine where to perform name lookup.

// FIXME: This area of the standard is very messy, and the current
// wording is rather unclear about which scopes we search for the
// destructor name; see core issues 399 and 555. Issue 399 in
// particular shows where the current description of destructor name
// lookup is completely out of line with existing practice, e.g.,
// this appears to be ill-formed:
//
//   namespace N {
//     template <typename T> struct S {
//       ~S();
//     };
//   }
//
//   void f(N::S<int>* s) {
//     s->N::S<int>::~S();
//   }
//
// See also PR6358 and PR6359.
//
// For now, we accept all the cases in which the name given could plausibly
// be interpreted as a correct destructor name, issuing off-by-default
// extension diagnostics on the cases that don't strictly conform to the
// C++20 rules. This basically means we always consider looking in the
// nested-name-specifier prefix, the complete nested-name-specifier, and
// the scope, and accept if we find the expected type in any of the three
// places.

if (SS.isInvalid())
  return nullptr;

// Whether we've failed with a diagnostic already.
bool Failed = false;

llvm::SmallVector<NamedDecl*, 8> FoundDecls;
llvm::SmallPtrSet<CanonicalDeclPtr<Decl>, 8> FoundDeclSet;

// If we have an object type, it's because we are in a
// pseudo-destructor-expression or a member access expression, and
// we know what type we're looking for.
QualType SearchType =
    ObjectTypePtr ? GetTypeFromParser(ObjectTypePtr) : QualType();

auto CheckLookupResult = [&](LookupResult &Found) -> ParsedType {
  auto IsAcceptableResult = [&](NamedDecl *D) -> bool {
    auto *Type = dyn_cast<TypeDecl>(D->getUnderlyingDecl());
    if (!Type)
      return false;

    if (SearchType.isNull() || SearchType->isDependentType())
      return true;

    QualType T = Context.getTypeDeclType(Type);
    return Context.hasSameUnqualifiedType(T, SearchType);
  };

  unsigned NumAcceptableResults = 0;
  for (NamedDecl *D : Found) {
    if (IsAcceptableResult(D))
      ++NumAcceptableResults;

    // Don't list a class twice in the lookup failure diagnostic if it's
    // found by both its injected-class-name and by the name in the enclosing
    // scope.
    if (auto *RD = dyn_cast<CXXRecordDecl>(D))
      if (RD->isInjectedClassName())
        D = cast<NamedDecl>(RD->getParent());

    if (FoundDeclSet.insert(D).second)
      FoundDecls.push_back(D);
  }

  // As an extension, attempt to "fix" an ambiguity by erasing all non-type
  // results, and all non-matching results if we have a search type. It's not
  // clear what the right behavior is if destructor lookup hits an ambiguity,
  // but other compilers do generally accept at least some kinds of
  // ambiguity.
  if (Found.isAmbiguous() && NumAcceptableResults == 1) {
    Diag(NameLoc, diag::ext_dtor_name_ambiguous);
    LookupResult::Filter F = Found.makeFilter();
    while (F.hasNext()) {
      NamedDecl *D = F.next();
      if (auto *TD = dyn_cast<TypeDecl>(D->getUnderlyingDecl()))
        Diag(D->getLocation(), diag::note_destructor_type_here)
            << Context.getTypeDeclType(TD);
      else
        Diag(D->getLocation(), diag::note_destructor_nontype_here);

      if (!IsAcceptableResult(D))
        F.erase();
    }
    F.done();
  }

  if (Found.isAmbiguous())
    Failed = true;

  if (TypeDecl *Type = Found.getAsSingle<TypeDecl>()) {
    if (IsAcceptableResult(Type)) {
      QualType T = Context.getTypeDeclType(Type);
      MarkAnyDeclReferenced(Type->getLocation(), Type, /*OdrUse=*/false);
      return CreateParsedType(T,
                              Context.getTrivialTypeSourceInfo(T, NameLoc));
    }
  }

  return nullptr;
};

bool IsDependent = false;

auto LookupInObjectType = [&]() -> ParsedType {
  if (Failed || SearchType.isNull())
    return nullptr;

  IsDependent |= SearchType->isDependentType();

  LookupResult Found(*this, &II, NameLoc, LookupDestructorName);
  DeclContext *LookupCtx = computeDeclContext(SearchType);
  if (!LookupCtx)
    return nullptr;
  LookupQualifiedName(Found, LookupCtx);
  return CheckLookupResult(Found);
};

auto LookupInNestedNameSpec = [&](CXXScopeSpec &LookupSS) -> ParsedType {
  if (Failed)
    return nullptr;

  IsDependent |= isDependentScopeSpecifier(LookupSS);
  DeclContext *LookupCtx = computeDeclContext(LookupSS, EnteringContext);
  if (!LookupCtx)
    return nullptr;

  LookupResult Found(*this, &II, NameLoc, LookupDestructorName);
  if (RequireCompleteDeclContext(LookupSS, LookupCtx)) {
    Failed = true;
    return nullptr;
  }
  LookupQualifiedName(Found, LookupCtx);
  return CheckLookupResult(Found);
};

auto LookupInScope = [&]() -> ParsedType {
  if (Failed || !S)
    return nullptr;

  LookupResult Found(*this, &II, NameLoc, LookupDestructorName);
  LookupName(Found, S);
  return CheckLookupResult(Found);
};

// C++2a [basic.lookup.qual]p6:
//   In a qualified-id of the form
//
//     nested-name-specifier[opt] type-name :: ~ type-name
//
//   the second type-name is looked up in the same scope as the first.
//
// We interpret this as meaning that if you do a dual-scope lookup for the
// first name, you also do a dual-scope lookup for the second name, per
// C++ [basic.lookup.classref]p4:
//
//   If the id-expression in a class member access is a qualified-id of the
//   form
//
//     class-name-or-namespace-name :: ...
//
//   the class-name-or-namespace-name following the . or -> is first looked
//   up in the class of the object expression and the name, if found, is used.
//   Otherwise, it is looked up in the context of the entire
//   postfix-expression.
//
// This looks in the same scopes as for an unqualified destructor name:
//
// C++ [basic.lookup.classref]p3:
//   If the unqualified-id is ~ type-name, the type-name is looked up
//   in the context of the entire postfix-expression. If the type T
//   of the object expression is of a class type C, the type-name is
//   also looked up in the scope of class C. At least one of the
//   lookups shall find a name that refers to cv T.
//
// FIXME: The intent is unclear here. Should type-name::~type-name look in
// the scope anyway if it finds a non-matching name declared in the class?
// If both lookups succeed and find a dependent result, which result should
// we retain? (Same question for p->~type-name().)

if (NestedNameSpecifier *Prefix =
    SS.isSet() ? SS.getScopeRep()->getPrefix() : nullptr) {
  // This is
  //
  //   nested-name-specifier type-name :: ~ type-name
  //
  // Look for the second type-name in the nested-name-specifier.
  CXXScopeSpec PrefixSS;
  PrefixSS.Adopt(NestedNameSpecifierLoc(Prefix, SS.location_data()));
  if (ParsedType T = LookupInNestedNameSpec(PrefixSS))
    return T;
} else {
  // This is one of
  //
  //   type-name :: ~ type-name
  //   ~ type-name
  //
  // Look in the scope and (if any) the object type.
  if (ParsedType T = LookupInScope())
    return T;
  if (ParsedType T = LookupInObjectType())
    return T;
}

if (Failed)
  return nullptr;

if (IsDependent) {
  // We didn't find our type, but that's OK: it's dependent anyway.

  // FIXME: What if we have no nested-name-specifier?
  QualType T = CheckTypenameType(ETK_None, SourceLocation(),
                                 SS.getWithLocInContext(Context),
                                 II, NameLoc);
  return ParsedType::make(T);
}

// The remaining cases are all non-standard extensions imitating the behavior
// of various other compilers.
unsigned NumNonExtensionDecls = FoundDecls.size();

if (SS.isSet()) {
  // For compatibility with older broken C++ rules and existing code,
  //
  //   nested-name-specifier :: ~ type-name
  //
  // also looks for type-name within the nested-name-specifier.
  if (ParsedType T = LookupInNestedNameSpec(SS)) {
    Diag(SS.getEndLoc(), diag::ext_dtor_named_in_wrong_scope)
        << SS.getRange()
        << FixItHint::CreateInsertion(SS.getEndLoc(),
                                      ("::" + II.getName()).str());
    return T;
  }

  // For compatibility with other compilers and older versions of Clang,
  //
  //   nested-name-specifier type-name :: ~ type-name
  //
  // also looks for type-name in the scope. Unfortunately, we can't
  // reasonably apply this fallback for dependent nested-name-specifiers.
  if (SS.getScopeRep()->getPrefix()) {
    if (ParsedType T = LookupInScope()) {
      Diag(SS.getEndLoc(), diag::ext_qualified_dtor_named_in_lexical_scope)
          << FixItHint::CreateRemoval(SS.getRange());
      Diag(FoundDecls.back()->getLocation(), diag::note_destructor_type_here)
          << GetTypeFromParser(T);
      return T;
    }
  }
}

// We didn't find anything matching; tell the user what we did find (if
// anything).

// Don't tell the user about declarations we shouldn't have found.
FoundDecls.resize(NumNonExtensionDecls);

// List types before non-types.
std::stable_sort(FoundDecls.begin(), FoundDecls.end(),
                 [](NamedDecl *A, NamedDecl *B) {
                   return isa<TypeDecl>(A->getUnderlyingDecl()) >
                          isa<TypeDecl>(B->getUnderlyingDecl());
                 });

// Suggest a fixit to properly name the destroyed type.
auto MakeFixItHint = [&]{
  const CXXRecordDecl *Destroyed = nullptr;
  // FIXME: If we have a scope specifier, suggest its last component?
  if (!SearchType.isNull())
    Destroyed = SearchType->getAsCXXRecordDecl();
  else if (S)
    Destroyed = dyn_cast_or_null<CXXRecordDecl>(S->getEntity());
  if (Destroyed)
    return FixItHint::CreateReplacement(SourceRange(NameLoc),
                                        Destroyed->getNameAsString());
  return FixItHint();
};

if (FoundDecls.empty()) {
  // FIXME: Attempt typo-correction?
  Diag(NameLoc, diag::err_undeclared_destructor_name)
    << &II << MakeFixItHint();
} else if (!SearchType.isNull() && FoundDecls.size() == 1) {
  if (auto *TD = dyn_cast<TypeDecl>(FoundDecls[0]->getUnderlyingDecl())) {
    assert(!SearchType.isNull() &&(static_cast<void> (0))
           "should only reject a type result if we have a search type")(static_cast<void> (0));
    QualType T = Context.getTypeDeclType(TD);
    Diag(NameLoc, diag::err_destructor_expr_type_mismatch)
        << T << SearchType << MakeFixItHint();
  } else {
    Diag(NameLoc, diag::err_destructor_expr_nontype)
        << &II << MakeFixItHint();
  }
} else {
  Diag(NameLoc, SearchType.isNull() ? diag::err_destructor_name_nontype
                                    : diag::err_destructor_expr_mismatch)
      << &II << SearchType << MakeFixItHint();
}

for (NamedDecl *FoundD : FoundDecls) {
  if (auto *TD = dyn_cast<TypeDecl>(FoundD->getUnderlyingDecl()))
    Diag(FoundD->getLocation(), diag::note_destructor_type_here)
        << Context.getTypeDeclType(TD);
  else
    Diag(FoundD->getLocation(), diag::note_destructor_nontype_here)
        << FoundD;
}

return nullptr;
457}

459ParsedType Sema::getDestructorTypeForDecltype(const DeclSpec &DS,
                                            ParsedType ObjectType) {
if (DS.getTypeSpecType() == DeclSpec::TST_error)
  return nullptr;

if (DS.getTypeSpecType() == DeclSpec::TST_decltype_auto) {
  Diag(DS.getTypeSpecTypeLoc(), diag::err_decltype_auto_invalid);
  return nullptr;
}

assert(DS.getTypeSpecType() == DeclSpec::TST_decltype &&(static_cast<void> (0))
       "unexpected type in getDestructorType")(static_cast<void> (0));
QualType T = BuildDecltypeType(DS.getRepAsExpr(), DS.getTypeSpecTypeLoc());

// If we know the type of the object, check that the correct destructor
// type was named now; we can give better diagnostics this way.
QualType SearchType = GetTypeFromParser(ObjectType);
if (!SearchType.isNull() && !SearchType->isDependentType() &&
    !Context.hasSameUnqualifiedType(T, SearchType)) {
  Diag(DS.getTypeSpecTypeLoc(), diag::err_destructor_expr_type_mismatch)
    << T << SearchType;
  return nullptr;
}

return ParsedType::make(T);
484}

486bool Sema::checkLiteralOperatorId(const CXXScopeSpec &SS,
                                const UnqualifiedId &Name, bool IsUDSuffix) {
assert(Name.getKind() == UnqualifiedIdKind::IK_LiteralOperatorId)(static_cast<void> (0));
if (!IsUDSuffix) {
  // [over.literal] p8
  //
  // double operator""_Bq(long double);  // OK: not a reserved identifier
  // double operator"" _Bq(long double); // ill-formed, no diagnostic required
  IdentifierInfo *II = Name.Identifier;
  ReservedIdentifierStatus Status = II->isReserved(PP.getLangOpts());
  SourceLocation Loc = Name.getEndLoc();
  if (Status != ReservedIdentifierStatus::NotReserved &&
      !PP.getSourceManager().isInSystemHeader(Loc)) {
    Diag(Loc, diag::warn_reserved_extern_symbol)
        << II << static_cast<int>(Status)
        << FixItHint::CreateReplacement(
               Name.getSourceRange(),
               (StringRef("operator\"\"") + II->getName()).str());
  }
}

if (!SS.isValid())
  return false;

switch (SS.getScopeRep()->getKind()) {
case NestedNameSpecifier::Identifier:
case NestedNameSpecifier::TypeSpec:
case NestedNameSpecifier::TypeSpecWithTemplate:
  // Per C++11 [over.literal]p2, literal operators can only be declared at
  // namespace scope. Therefore, this unqualified-id cannot name anything.
  // Reject it early, because we have no AST representation for this in the
  // case where the scope is dependent.
  Diag(Name.getBeginLoc(), diag::err_literal_operator_id_outside_namespace)
      << SS.getScopeRep();
  return true;

case NestedNameSpecifier::Global:
case NestedNameSpecifier::Super:
case NestedNameSpecifier::Namespace:
case NestedNameSpecifier::NamespaceAlias:
  return false;
}

llvm_unreachable("unknown nested name specifier kind")__builtin_unreachable();
530}

532/// Build a C++ typeid expression with a type operand.
533ExprResult Sema::BuildCXXTypeId(QualType TypeInfoType,
                              SourceLocation TypeidLoc,
                              TypeSourceInfo *Operand,
                              SourceLocation RParenLoc) {
// C++ [expr.typeid]p4:
//   The top-level cv-qualifiers of the lvalue expression or the type-id
//   that is the operand of typeid are always ignored.
//   If the type of the type-id is a class type or a reference to a class
//   type, the class shall be completely-defined.
Qualifiers Quals;
QualType T
  = Context.getUnqualifiedArrayType(Operand->getType().getNonReferenceType(),
                                    Quals);
if (T->getAs<RecordType>() &&
    RequireCompleteType(TypeidLoc, T, diag::err_incomplete_typeid))
  return ExprError();

if (T->isVariablyModifiedType())
  return ExprError(Diag(TypeidLoc, diag::err_variably_modified_typeid) << T);

if (CheckQualifiedFunctionForTypeId(T, TypeidLoc))
  return ExprError();

return new (Context) CXXTypeidExpr(TypeInfoType.withConst(), Operand,
                                   SourceRange(TypeidLoc, RParenLoc));
558}

560/// Build a C++ typeid expression with an expression operand.
561ExprResult Sema::BuildCXXTypeId(QualType TypeInfoType,
                              SourceLocation TypeidLoc,
                              Expr *E,
                              SourceLocation RParenLoc) {
bool WasEvaluated = false;
if (E && !E->isTypeDependent()) {
  if (E->getType()->isPlaceholderType()) {
    ExprResult result = CheckPlaceholderExpr(E);
    if (result.isInvalid()) return ExprError();
    E = result.get();
  }

  QualType T = E->getType();
  if (const RecordType *RecordT = T->getAs<RecordType>()) {
    CXXRecordDecl *RecordD = cast<CXXRecordDecl>(RecordT->getDecl());
    // C++ [expr.typeid]p3:
    //   [...] If the type of the expression is a class type, the class
    //   shall be completely-defined.
    if (RequireCompleteType(TypeidLoc, T, diag::err_incomplete_typeid))
      return ExprError();

    // C++ [expr.typeid]p3:
    //   When typeid is applied to an expression other than an glvalue of a
    //   polymorphic class type [...] [the] expression is an unevaluated
    //   operand. [...]
    if (RecordD->isPolymorphic() && E->isGLValue()) {
      if (isUnevaluatedContext()) {
        // The operand was processed in unevaluated context, switch the
        // context and recheck the subexpression.
        ExprResult Result = TransformToPotentiallyEvaluated(E);
        if (Result.isInvalid())
          return ExprError();
        E = Result.get();
      }

      // We require a vtable to query the type at run time.
      MarkVTableUsed(TypeidLoc, RecordD);
      WasEvaluated = true;
    }
  }

  ExprResult Result = CheckUnevaluatedOperand(E);
  if (Result.isInvalid())
    return ExprError();
  E = Result.get();

  // C++ [expr.typeid]p4:
  //   [...] If the type of the type-id is a reference to a possibly
  //   cv-qualified type, the result of the typeid expression refers to a
  //   std::type_info object representing the cv-unqualified referenced
  //   type.
  Qualifiers Quals;
  QualType UnqualT = Context.getUnqualifiedArrayType(T, Quals);
  if (!Context.hasSameType(T, UnqualT)) {
    T = UnqualT;
    E = ImpCastExprToType(E, UnqualT, CK_NoOp, E->getValueKind()).get();
  }
}

if (E->getType()->isVariablyModifiedType())
  return ExprError(Diag(TypeidLoc, diag::err_variably_modified_typeid)
                   << E->getType());
else if (!inTemplateInstantiation() &&
         E->HasSideEffects(Context, WasEvaluated)) {
  // The expression operand for typeid is in an unevaluated expression
  // context, so side effects could result in unintended consequences.
  Diag(E->getExprLoc(), WasEvaluated
                            ? diag::warn_side_effects_typeid
                            : diag::warn_side_effects_unevaluated_context);
}

return new (Context) CXXTypeidExpr(TypeInfoType.withConst(), E,
                                   SourceRange(TypeidLoc, RParenLoc));
634}

636/// ActOnCXXTypeidOfType - Parse typeid( type-id ) or typeid (expression);
637ExprResult
638Sema::ActOnCXXTypeid(SourceLocation OpLoc, SourceLocation LParenLoc,
                   bool isType, void *TyOrExpr, SourceLocation RParenLoc) {
// typeid is not supported in OpenCL.
if (getLangOpts().OpenCLCPlusPlus) {
  return ExprError(Diag(OpLoc, diag::err_openclcxx_not_supported)
                   << "typeid");
}

// Find the std::type_info type.
if (!getStdNamespace())
  return ExprError(Diag(OpLoc, diag::err_need_header_before_typeid));

if (!CXXTypeInfoDecl) {
  IdentifierInfo *TypeInfoII = &PP.getIdentifierTable().get("type_info");
  LookupResult R(*this, TypeInfoII, SourceLocation(), LookupTagName);
  LookupQualifiedName(R, getStdNamespace());
  CXXTypeInfoDecl = R.getAsSingle<RecordDecl>();
  // Microsoft's typeinfo doesn't have type_info in std but in the global
  // namespace if _HAS_EXCEPTIONS is defined to 0. See PR13153.
  if (!CXXTypeInfoDecl && LangOpts.MSVCCompat) {
    LookupQualifiedName(R, Context.getTranslationUnitDecl());
    CXXTypeInfoDecl = R.getAsSingle<RecordDecl>();
  }
  if (!CXXTypeInfoDecl)
    return ExprError(Diag(OpLoc, diag::err_need_header_before_typeid));
}

if (!getLangOpts().RTTI) {
  return ExprError(Diag(OpLoc, diag::err_no_typeid_with_fno_rtti));
}

QualType TypeInfoType = Context.getTypeDeclType(CXXTypeInfoDecl);

if (isType) {
  // The operand is a type; handle it as such.
  TypeSourceInfo *TInfo = nullptr;
  QualType T = GetTypeFromParser(ParsedType::getFromOpaquePtr(TyOrExpr),
                                 &TInfo);
  if (T.isNull())
    return ExprError();

  if (!TInfo)
    TInfo = Context.getTrivialTypeSourceInfo(T, OpLoc);

  return BuildCXXTypeId(TypeInfoType, OpLoc, TInfo, RParenLoc);
}

// The operand is an expression.
ExprResult Result =
    BuildCXXTypeId(TypeInfoType, OpLoc, (Expr *)TyOrExpr, RParenLoc);

if (!getLangOpts().RTTIData && !Result.isInvalid())
  if (auto *CTE = dyn_cast<CXXTypeidExpr>(Result.get()))
    if (CTE->isPotentiallyEvaluated() && !CTE->isMostDerived(Context))
      Diag(OpLoc, diag::warn_no_typeid_with_rtti_disabled)
          << (getDiagnostics().getDiagnosticOptions().getFormat() ==
              DiagnosticOptions::MSVC);
return Result;
696}

698/// Grabs __declspec(uuid()) off a type, or returns 0 if we cannot resolve to
699/// a single GUID.
700static void
701getUuidAttrOfType(Sema &SemaRef, QualType QT,
                llvm::SmallSetVector<const UuidAttr *, 1> &UuidAttrs) {
// Optionally remove one level of pointer, reference or array indirection.
const Type *Ty = QT.getTypePtr();
if (QT->isPointerType() || QT->isReferenceType())
  Ty = QT->getPointeeType().getTypePtr();
else if (QT->isArrayType())
  Ty = Ty->getBaseElementTypeUnsafe();

const auto *TD = Ty->getAsTagDecl();
if (!TD)
  return;

if (const auto *Uuid = TD->getMostRecentDecl()->getAttr<UuidAttr>()) {
  UuidAttrs.insert(Uuid);
  return;
}

// __uuidof can grab UUIDs from template arguments.
if (const auto *CTSD = dyn_cast<ClassTemplateSpecializationDecl>(TD)) {
  const TemplateArgumentList &TAL = CTSD->getTemplateArgs();
  for (const TemplateArgument &TA : TAL.asArray()) {
    const UuidAttr *UuidForTA = nullptr;
    if (TA.getKind() == TemplateArgument::Type)
      getUuidAttrOfType(SemaRef, TA.getAsType(), UuidAttrs);
    else if (TA.getKind() == TemplateArgument::Declaration)
      getUuidAttrOfType(SemaRef, TA.getAsDecl()->getType(), UuidAttrs);

    if (UuidForTA)
      UuidAttrs.insert(UuidForTA);
  }
}
733}

735/// Build a Microsoft __uuidof expression with a type operand.
736ExprResult Sema::BuildCXXUuidof(QualType Type,
                              SourceLocation TypeidLoc,
                              TypeSourceInfo *Operand,
                              SourceLocation RParenLoc) {
MSGuidDecl *Guid = nullptr;
if (!Operand->getType()->isDependentType()) {
  llvm::SmallSetVector<const UuidAttr *, 1> UuidAttrs;
  getUuidAttrOfType(*this, Operand->getType(), UuidAttrs);
  if (UuidAttrs.empty())
    return ExprError(Diag(TypeidLoc, diag::err_uuidof_without_guid));
  if (UuidAttrs.size() > 1)
    return ExprError(Diag(TypeidLoc, diag::err_uuidof_with_multiple_guids));
  Guid = UuidAttrs.back()->getGuidDecl();
}

return new (Context)
    CXXUuidofExpr(Type, Operand, Guid, SourceRange(TypeidLoc, RParenLoc));
753}

755/// Build a Microsoft __uuidof expression with an expression operand.
756ExprResult Sema::BuildCXXUuidof(QualType Type, SourceLocation TypeidLoc,
                              Expr *E, SourceLocation RParenLoc) {
MSGuidDecl *Guid = nullptr;
if (!E->getType()->isDependentType()) {
  if (E->isNullPointerConstant(Context, Expr::NPC_ValueDependentIsNull)) {
    // A null pointer results in {00000000-0000-0000-0000-000000000000}.
    Guid = Context.getMSGuidDecl(MSGuidDecl::Parts{});
  } else {
    llvm::SmallSetVector<const UuidAttr *, 1> UuidAttrs;
    getUuidAttrOfType(*this, E->getType(), UuidAttrs);
    if (UuidAttrs.empty())
      return ExprError(Diag(TypeidLoc, diag::err_uuidof_without_guid));
    if (UuidAttrs.size() > 1)
      return ExprError(Diag(TypeidLoc, diag::err_uuidof_with_multiple_guids));
    Guid = UuidAttrs.back()->getGuidDecl();
  }
}

return new (Context)
    CXXUuidofExpr(Type, E, Guid, SourceRange(TypeidLoc, RParenLoc));
776}

778/// ActOnCXXUuidof - Parse __uuidof( type-id ) or __uuidof (expression);
779ExprResult
780Sema::ActOnCXXUuidof(SourceLocation OpLoc, SourceLocation LParenLoc,
                   bool isType, void *TyOrExpr, SourceLocation RParenLoc) {
QualType GuidType = Context.getMSGuidType();
GuidType.addConst();

if (isType) {
  // The operand is a type; handle it as such.
  TypeSourceInfo *TInfo = nullptr;
  QualType T = GetTypeFromParser(ParsedType::getFromOpaquePtr(TyOrExpr),
                                 &TInfo);
  if (T.isNull())
    return ExprError();

  if (!TInfo)
    TInfo = Context.getTrivialTypeSourceInfo(T, OpLoc);

  return BuildCXXUuidof(GuidType, OpLoc, TInfo, RParenLoc);
}

// The operand is an expression.
return BuildCXXUuidof(GuidType, OpLoc, (Expr*)TyOrExpr, RParenLoc);
801}

803/// ActOnCXXBoolLiteral - Parse {true,false} literals.
804ExprResult
805Sema::ActOnCXXBoolLiteral(SourceLocation OpLoc, tok::TokenKind Kind) {
assert((Kind == tok::kw_true || Kind == tok::kw_false) &&(static_cast<void> (0))
       "Unknown C++ Boolean value!")(static_cast<void> (0));
return new (Context)
    CXXBoolLiteralExpr(Kind == tok::kw_true, Context.BoolTy, OpLoc);
810}

812/// ActOnCXXNullPtrLiteral - Parse 'nullptr'.
813ExprResult
814Sema::ActOnCXXNullPtrLiteral(SourceLocation Loc) {
return new (Context) CXXNullPtrLiteralExpr(Context.NullPtrTy, Loc);
816}

818/// ActOnCXXThrow - Parse throw expressions.
819ExprResult
820Sema::ActOnCXXThrow(Scope *S, SourceLocation OpLoc, Expr *Ex) {
bool IsThrownVarInScope = false;
if (Ex) {
  // C++0x [class.copymove]p31:
  //   When certain criteria are met, an implementation is allowed to omit the
  //   copy/move construction of a class object [...]
  //
  //     - in a throw-expression, when the operand is the name of a
  //       non-volatile automatic object (other than a function or catch-
  //       clause parameter) whose scope does not extend beyond the end of the
  //       innermost enclosing try-block (if there is one), the copy/move
  //       operation from the operand to the exception object (15.1) can be
  //       omitted by constructing the automatic object directly into the
  //       exception object
  if (DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(Ex->IgnoreParens()))
    if (VarDecl *Var = dyn_cast<VarDecl>(DRE->getDecl())) {
      if (Var->hasLocalStorage() && !Var->getType().isVolatileQualified()) {
        for( ; S; S = S->getParent()) {
          if (S->isDeclScope(Var)) {
            IsThrownVarInScope = true;
            break;
          }

          if (S->getFlags() &
              (Scope::FnScope | Scope::ClassScope | Scope::BlockScope |
               Scope::FunctionPrototypeScope | Scope::ObjCMethodScope |
               Scope::TryScope))
            break;
        }
      }
    }
}

return BuildCXXThrow(OpLoc, Ex, IsThrownVarInScope);
854}

856ExprResult Sema::BuildCXXThrow(SourceLocation OpLoc, Expr *Ex,
                             bool IsThrownVarInScope) {
// Don't report an error if 'throw' is used in system headers.
if (!getLangOpts().CXXExceptions &&
    !getSourceManager().isInSystemHeader(OpLoc) && !getLangOpts().CUDA) {
  // Delay error emission for the OpenMP device code.
  targetDiag(OpLoc, diag::err_exceptions_disabled) << "throw";
}

// Exceptions aren't allowed in CUDA device code.
if (getLangOpts().CUDA)
  CUDADiagIfDeviceCode(OpLoc, diag::err_cuda_device_exceptions)
      << "throw" << CurrentCUDATarget();

if (getCurScope() && getCurScope()->isOpenMPSimdDirectiveScope())
  Diag(OpLoc, diag::err_omp_simd_region_cannot_use_stmt) << "throw";

if (Ex && !Ex->isTypeDependent()) {
  // Initialize the exception result.  This implicitly weeds out
  // abstract types or types with inaccessible copy constructors.

  // C++0x [class.copymove]p31:
  //   When certain criteria are met, an implementation is allowed to omit the
  //   copy/move construction of a class object [...]
  //
  //     - in a throw-expression, when the operand is the name of a
  //       non-volatile automatic object (other than a function or
  //       catch-clause
  //       parameter) whose scope does not extend beyond the end of the
  //       innermost enclosing try-block (if there is one), the copy/move
  //       operation from the operand to the exception object (15.1) can be
  //       omitted by constructing the automatic object directly into the
  //       exception object
  NamedReturnInfo NRInfo =
      IsThrownVarInScope ? getNamedReturnInfo(Ex) : NamedReturnInfo();

  QualType ExceptionObjectTy = Context.getExceptionObjectType(Ex->getType());
  if (CheckCXXThrowOperand(OpLoc, ExceptionObjectTy, Ex))
    return ExprError();

  InitializedEntity Entity = InitializedEntity::InitializeException(
      OpLoc, ExceptionObjectTy,
      /*NRVO=*/NRInfo.isCopyElidable());
  ExprResult Res = PerformMoveOrCopyInitialization(Entity, NRInfo, Ex);
  if (Res.isInvalid())
    return ExprError();
  Ex = Res.get();
}

// PPC MMA non-pointer types are not allowed as throw expr types.
if (Ex && Context.getTargetInfo().getTriple().isPPC64())
  CheckPPCMMAType(Ex->getType(), Ex->getBeginLoc());

return new (Context)
    CXXThrowExpr(Ex, Context.VoidTy, OpLoc, IsThrownVarInScope);
911}

913static void
914collectPublicBases(CXXRecordDecl *RD,
                 llvm::DenseMap<CXXRecordDecl *, unsigned> &SubobjectsSeen,
                 llvm::SmallPtrSetImpl<CXXRecordDecl *> &VBases,
                 llvm::SetVector<CXXRecordDecl *> &PublicSubobjectsSeen,
                 bool ParentIsPublic) {
for (const CXXBaseSpecifier &BS : RD->bases()) {
  CXXRecordDecl *BaseDecl = BS.getType()->getAsCXXRecordDecl();
  bool NewSubobject;
  // Virtual bases constitute the same subobject.  Non-virtual bases are
  // always distinct subobjects.
  if (BS.isVirtual())
    NewSubobject = VBases.insert(BaseDecl).second;
  else
    NewSubobject = true;

  if (NewSubobject)
    ++SubobjectsSeen[BaseDecl];

  // Only add subobjects which have public access throughout the entire chain.
  bool PublicPath = ParentIsPublic && BS.getAccessSpecifier() == AS_public;
  if (PublicPath)
    PublicSubobjectsSeen.insert(BaseDecl);

  // Recurse on to each base subobject.
  collectPublicBases(BaseDecl, SubobjectsSeen, VBases, PublicSubobjectsSeen,
                     PublicPath);
}
941}

943static void getUnambiguousPublicSubobjects(
  CXXRecordDecl *RD, llvm::SmallVectorImpl<CXXRecordDecl *> &Objects) {
llvm::DenseMap<CXXRecordDecl *, unsigned> SubobjectsSeen;
llvm::SmallSet<CXXRecordDecl *, 2> VBases;
llvm::SetVector<CXXRecordDecl *> PublicSubobjectsSeen;
SubobjectsSeen[RD] = 1;
PublicSubobjectsSeen.insert(RD);
collectPublicBases(RD, SubobjectsSeen, VBases, PublicSubobjectsSeen,
                   /*ParentIsPublic=*/true);

for (CXXRecordDecl *PublicSubobject : PublicSubobjectsSeen) {
  // Skip ambiguous objects.
  if (SubobjectsSeen[PublicSubobject] > 1)
    continue;

  Objects.push_back(PublicSubobject);
}
960}

962/// CheckCXXThrowOperand - Validate the operand of a throw.
963bool Sema::CheckCXXThrowOperand(SourceLocation ThrowLoc,
                              QualType ExceptionObjectTy, Expr *E) {
//   If the type of the exception would be an incomplete type or a pointer
//   to an incomplete type other than (cv) void the program is ill-formed.
QualType Ty = ExceptionObjectTy;
bool isPointer = false;
if (const PointerType* Ptr = Ty->getAs<PointerType>()) {
  Ty = Ptr->getPointeeType();
  isPointer = true;
}
if (!isPointer || !Ty->isVoidType()) {
  if (RequireCompleteType(ThrowLoc, Ty,
                          isPointer ? diag::err_throw_incomplete_ptr
                                    : diag::err_throw_incomplete,
                          E->getSourceRange()))
    return true;

  if (!isPointer && Ty->isSizelessType()) {
    Diag(ThrowLoc, diag::err_throw_sizeless) << Ty << E->getSourceRange();
    return true;
  }

  if (RequireNonAbstractType(ThrowLoc, ExceptionObjectTy,
                             diag::err_throw_abstract_type, E))
    return true;
}

// If the exception has class type, we need additional handling.
CXXRecordDecl *RD = Ty->getAsCXXRecordDecl();
if (!RD)
  return false;

// If we are throwing a polymorphic class type or pointer thereof,
// exception handling will make use of the vtable.
MarkVTableUsed(ThrowLoc, RD);

// If a pointer is thrown, the referenced object will not be destroyed.
if (isPointer)
  return false;

// If the class has a destructor, we must be able to call it.
if (!RD->hasIrrelevantDestructor()) {
  if (CXXDestructorDecl *Destructor = LookupDestructor(RD)) {
    MarkFunctionReferenced(E->getExprLoc(), Destructor);
    CheckDestructorAccess(E->getExprLoc(), Destructor,
                          PDiag(diag::err_access_dtor_exception) << Ty);
    if (DiagnoseUseOfDecl(Destructor, E->getExprLoc()))
      return true;
  }
}

// The MSVC ABI creates a list of all types which can catch the exception
// object.  This list also references the appropriate copy constructor to call
// if the object is caught by value and has a non-trivial copy constructor.
if (Context.getTargetInfo().getCXXABI().isMicrosoft()) {
  // We are only interested in the public, unambiguous bases contained within
  // the exception object.  Bases which are ambiguous or otherwise
  // inaccessible are not catchable types.
  llvm::SmallVector<CXXRecordDecl *, 2> UnambiguousPublicSubobjects;
  getUnambiguousPublicSubobjects(RD, UnambiguousPublicSubobjects);

  for (CXXRecordDecl *Subobject : UnambiguousPublicSubobjects) {
    // Attempt to lookup the copy constructor.  Various pieces of machinery
    // will spring into action, like template instantiation, which means this
    // cannot be a simple walk of the class's decls.  Instead, we must perform
    // lookup and overload resolution.
    CXXConstructorDecl *CD = LookupCopyingConstructor(Subobject, 0);
    if (!CD || CD->isDeleted())
      continue;

    // Mark the constructor referenced as it is used by this throw expression.
    MarkFunctionReferenced(E->getExprLoc(), CD);

    // Skip this copy constructor if it is trivial, we don't need to record it
    // in the catchable type data.
    if (CD->isTrivial())
      continue;

    // The copy constructor is non-trivial, create a mapping from this class
    // type to this constructor.
    // N.B.  The selection of copy constructor is not sensitive to this
    // particular throw-site.  Lookup will be performed at the catch-site to
    // ensure that the copy constructor is, in fact, accessible (via
    // friendship or any other means).
    Context.addCopyConstructorForExceptionObject(Subobject, CD);

    // We don't keep the instantiated default argument expressions around so
    // we must rebuild them here.
    for (unsigned I = 1, E = CD->getNumParams(); I != E; ++I) {
      if (CheckCXXDefaultArgExpr(ThrowLoc, CD, CD->getParamDecl(I)))
        return true;
    }
  }
}

// Under the Itanium C++ ABI, memory for the exception object is allocated by
// the runtime with no ability for the compiler to request additional
// alignment. Warn if the exception type requires alignment beyond the minimum
// guaranteed by the target C++ runtime.
if (Context.getTargetInfo().getCXXABI().isItaniumFamily()) {
  CharUnits TypeAlign = Context.getTypeAlignInChars(Ty);
  CharUnits ExnObjAlign = Context.getExnObjectAlignment();
  if (ExnObjAlign < TypeAlign) {
    Diag(ThrowLoc, diag::warn_throw_underaligned_obj);
    Diag(ThrowLoc, diag::note_throw_underaligned_obj)
        << Ty << (unsigned)TypeAlign.getQuantity()
        << (unsigned)ExnObjAlign.getQuantity();
  }
}

return false;
1074}

1076static QualType adjustCVQualifiersForCXXThisWithinLambda(
  ArrayRef<FunctionScopeInfo *> FunctionScopes, QualType ThisTy,
  DeclContext *CurSemaContext, ASTContext &ASTCtx) {

QualType ClassType = ThisTy->getPointeeType();
LambdaScopeInfo *CurLSI = nullptr;
DeclContext *CurDC = CurSemaContext;

// Iterate through the stack of lambdas starting from the innermost lambda to
// the outermost lambda, checking if '*this' is ever captured by copy - since
// that could change the cv-qualifiers of the '*this' object.
// The object referred to by '*this' starts out with the cv-qualifiers of its
// member function.  We then start with the innermost lambda and iterate
// outward checking to see if any lambda performs a by-copy capture of '*this'
// - and if so, any nested lambda must respect the 'constness' of that
// capturing lamdbda's call operator.
//

// Since the FunctionScopeInfo stack is representative of the lexical
// nesting of the lambda expressions during initial parsing (and is the best
// place for querying information about captures about lambdas that are
// partially processed) and perhaps during instantiation of function templates
// that contain lambda expressions that need to be transformed BUT not
// necessarily during instantiation of a nested generic lambda's function call
// operator (which might even be instantiated at the end of the TU) - at which
// time the DeclContext tree is mature enough to query capture information
// reliably - we use a two pronged approach to walk through all the lexically
// enclosing lambda expressions:
//
//  1) Climb down the FunctionScopeInfo stack as long as each item represents
//  a Lambda (i.e. LambdaScopeInfo) AND each LSI's 'closure-type' is lexically
//  enclosed by the call-operator of the LSI below it on the stack (while
//  tracking the enclosing DC for step 2 if needed).  Note the topmost LSI on
//  the stack represents the innermost lambda.
//
//  2) If we run out of enclosing LSI's, check if the enclosing DeclContext
//  represents a lambda's call operator.  If it does, we must be instantiating
//  a generic lambda's call operator (represented by the Current LSI, and
//  should be the only scenario where an inconsistency between the LSI and the
//  DeclContext should occur), so climb out the DeclContexts if they
//  represent lambdas, while querying the corresponding closure types
//  regarding capture information.

// 1) Climb down the function scope info stack.
for (int I = FunctionScopes.size();
     I-- && isa<LambdaScopeInfo>(FunctionScopes[I]) &&
     (!CurLSI || !CurLSI->Lambda || CurLSI->Lambda->getDeclContext() ==
                     cast<LambdaScopeInfo>(FunctionScopes[I])->CallOperator);
     CurDC = getLambdaAwareParentOfDeclContext(CurDC)) {
  CurLSI = cast<LambdaScopeInfo>(FunctionScopes[I]);

  if (!CurLSI->isCXXThisCaptured())
      continue;

  auto C = CurLSI->getCXXThisCapture();

  if (C.isCopyCapture()) {
    ClassType.removeLocalCVRQualifiers(Qualifiers::CVRMask);
    if (CurLSI->CallOperator->isConst())
      ClassType.addConst();
    return ASTCtx.getPointerType(ClassType);
  }
}

// 2) We've run out of ScopeInfos but check if CurDC is a lambda (which can
// happen during instantiation of its nested generic lambda call operator)
if (isLambdaCallOperator(CurDC)) {
  assert(CurLSI && "While computing 'this' capture-type for a generic "(static_cast<void> (0))
                   "lambda, we must have a corresponding LambdaScopeInfo")(static_cast<void> (0));
  assert(isGenericLambdaCallOperatorSpecialization(CurLSI->CallOperator) &&(static_cast<void> (0))
         "While computing 'this' capture-type for a generic lambda, when we "(static_cast<void> (0))
         "run out of enclosing LSI's, yet the enclosing DC is a "(static_cast<void> (0))
         "lambda-call-operator we must be (i.e. Current LSI) in a generic "(static_cast<void> (0))
         "lambda call oeprator")(static_cast<void> (0));
  assert(CurDC == getLambdaAwareParentOfDeclContext(CurLSI->CallOperator))(static_cast<void> (0));

  auto IsThisCaptured =
      [](CXXRecordDecl *Closure, bool &IsByCopy, bool &IsConst) {
    IsConst = false;
    IsByCopy = false;
    for (auto &&C : Closure->captures()) {
      if (C.capturesThis()) {
        if (C.getCaptureKind() == LCK_StarThis)
          IsByCopy = true;
        if (Closure->getLambdaCallOperator()->isConst())
          IsConst = true;
        return true;
      }
    }
    return false;
  };

  bool IsByCopyCapture = false;
  bool IsConstCapture = false;
  CXXRecordDecl *Closure = cast<CXXRecordDecl>(CurDC->getParent());
  while (Closure &&
         IsThisCaptured(Closure, IsByCopyCapture, IsConstCapture)) {
    if (IsByCopyCapture) {
      ClassType.removeLocalCVRQualifiers(Qualifiers::CVRMask);
      if (IsConstCapture)
        ClassType.addConst();
      return ASTCtx.getPointerType(ClassType);
    }
    Closure = isLambdaCallOperator(Closure->getParent())
                  ? cast<CXXRecordDecl>(Closure->getParent()->getParent())
                  : nullptr;
  }
}
return ASTCtx.getPointerType(ClassType);
1185}

1187QualType Sema::getCurrentThisType() {
DeclContext *DC = getFunctionLevelDeclContext();
QualType ThisTy = CXXThisTypeOverride;

if (CXXMethodDecl *method = dyn_cast<CXXMethodDecl>(DC)) {
  if (method && method->isInstance())
    ThisTy = method->getThisType();
}

if (ThisTy.isNull() && isLambdaCallOperator(CurContext) &&
    inTemplateInstantiation() && isa<CXXRecordDecl>(DC)) {

  // This is a lambda call operator that is being instantiated as a default
  // initializer. DC must point to the enclosing class type, so we can recover
  // the 'this' type from it.
  QualType ClassTy = Context.getTypeDeclType(cast<CXXRecordDecl>(DC));
  // There are no cv-qualifiers for 'this' within default initializers,
  // per [expr.prim.general]p4.
  ThisTy = Context.getPointerType(ClassTy);
}

// If we are within a lambda's call operator, the cv-qualifiers of 'this'
// might need to be adjusted if the lambda or any of its enclosing lambda's
// captures '*this' by copy.
if (!ThisTy.isNull() && isLambdaCallOperator(CurContext))
  return adjustCVQualifiersForCXXThisWithinLambda(FunctionScopes, ThisTy,
                                                  CurContext, Context);
return ThisTy;
1215}

1217Sema::CXXThisScopeRAII::CXXThisScopeRAII(Sema &S,
                                       Decl *ContextDecl,
                                       Qualifiers CXXThisTypeQuals,
                                       bool Enabled)
: S(S), OldCXXThisTypeOverride(S.CXXThisTypeOverride), Enabled(false)
1222{
if (!Enabled || !ContextDecl)
  return;

CXXRecordDecl *Record = nullptr;
if (ClassTemplateDecl *Template = dyn_cast<ClassTemplateDecl>(ContextDecl))
  Record = Template->getTemplatedDecl();
else
  Record = cast<CXXRecordDecl>(ContextDecl);

QualType T = S.Context.getRecordType(Record);
T = S.getASTContext().getQualifiedType(T, CXXThisTypeQuals);

S.CXXThisTypeOverride = S.Context.getPointerType(T);

this->Enabled = true;
1238}


1241Sema::CXXThisScopeRAII::~CXXThisScopeRAII() {
if (Enabled) {
  S.CXXThisTypeOverride = OldCXXThisTypeOverride;
}
1245}

1247static void buildLambdaThisCaptureFixit(Sema &Sema, LambdaScopeInfo *LSI) {
SourceLocation DiagLoc = LSI->IntroducerRange.getEnd();
assert(!LSI->isCXXThisCaptured())(static_cast<void> (0));
//  [=, this] {};   // until C++20: Error: this when = is the default
if (LSI->ImpCaptureStyle == CapturingScopeInfo::ImpCap_LambdaByval &&
    !Sema.getLangOpts().CPlusPlus20)
  return;
Sema.Diag(DiagLoc, diag::note_lambda_this_capture_fixit)
    << FixItHint::CreateInsertion(
           DiagLoc, LSI->NumExplicitCaptures > 0 ? ", this" : "this");
1257}

1259bool Sema::CheckCXXThisCapture(SourceLocation Loc, const bool Explicit,
  bool BuildAndDiagnose, const unsigned *const FunctionScopeIndexToStopAt,
  const bool ByCopy) {
// We don't need to capture this in an unevaluated context.
if (isUnevaluatedContext() && !Explicit)
  return true;

assert((!ByCopy || Explicit) && "cannot implicitly capture *this by value")(static_cast<void> (0));

const int MaxFunctionScopesIndex = FunctionScopeIndexToStopAt
                                       ? *FunctionScopeIndexToStopAt
                                       : FunctionScopes.size() - 1;

// Check that we can capture the *enclosing object* (referred to by '*this')
// by the capturing-entity/closure (lambda/block/etc) at
// MaxFunctionScopesIndex-deep on the FunctionScopes stack.

// Note: The *enclosing object* can only be captured by-value by a
// closure that is a lambda, using the explicit notation:
//    [*this] { ... }.
// Every other capture of the *enclosing object* results in its by-reference
// capture.

// For a closure 'L' (at MaxFunctionScopesIndex in the FunctionScopes
// stack), we can capture the *enclosing object* only if:
// - 'L' has an explicit byref or byval capture of the *enclosing object*
// -  or, 'L' has an implicit capture.
// AND
//   -- there is no enclosing closure
//   -- or, there is some enclosing closure 'E' that has already captured the
//      *enclosing object*, and every intervening closure (if any) between 'E'
//      and 'L' can implicitly capture the *enclosing object*.
//   -- or, every enclosing closure can implicitly capture the
//      *enclosing object*


unsigned NumCapturingClosures = 0;
for (int idx = MaxFunctionScopesIndex; idx >= 0; idx--) {
  if (CapturingScopeInfo *CSI =
          dyn_cast<CapturingScopeInfo>(FunctionScopes[idx])) {
    if (CSI->CXXThisCaptureIndex != 0) {
      // 'this' is already being captured; there isn't anything more to do.
      CSI->Captures[CSI->CXXThisCaptureIndex - 1].markUsed(BuildAndDiagnose);
      break;
    }
    LambdaScopeInfo *LSI = dyn_cast<LambdaScopeInfo>(CSI);
    if (LSI && isGenericLambdaCallOperatorSpecialization(LSI->CallOperator)) {
      // This context can't implicitly capture 'this'; fail out.
      if (BuildAndDiagnose) {
        Diag(Loc, diag::err_this_capture)
            << (Explicit && idx == MaxFunctionScopesIndex);
        if (!Explicit)
          buildLambdaThisCaptureFixit(*this, LSI);
      }
      return true;
    }
    if (CSI->ImpCaptureStyle == CapturingScopeInfo::ImpCap_LambdaByref ||
        CSI->ImpCaptureStyle == CapturingScopeInfo::ImpCap_LambdaByval ||
        CSI->ImpCaptureStyle == CapturingScopeInfo::ImpCap_Block ||
        CSI->ImpCaptureStyle == CapturingScopeInfo::ImpCap_CapturedRegion ||
        (Explicit && idx == MaxFunctionScopesIndex)) {
      // Regarding (Explicit && idx == MaxFunctionScopesIndex): only the first
      // iteration through can be an explicit capture, all enclosing closures,
      // if any, must perform implicit captures.

      // This closure can capture 'this'; continue looking upwards.
      NumCapturingClosures++;
      continue;
    }
    // This context can't implicitly capture 'this'; fail out.
    if (BuildAndDiagnose)
      Diag(Loc, diag::err_this_capture)
          << (Explicit && idx == MaxFunctionScopesIndex);

    if (!Explicit)
      buildLambdaThisCaptureFixit(*this, LSI);
    return true;
  }
  break;
}
if (!BuildAndDiagnose) return false;

// If we got here, then the closure at MaxFunctionScopesIndex on the
// FunctionScopes stack, can capture the *enclosing object*, so capture it
// (including implicit by-reference captures in any enclosing closures).

// In the loop below, respect the ByCopy flag only for the closure requesting
// the capture (i.e. first iteration through the loop below).  Ignore it for
// all enclosing closure's up to NumCapturingClosures (since they must be
// implicitly capturing the *enclosing  object* by reference (see loop
// above)).
assert((!ByCopy ||(static_cast<void> (0))
        dyn_cast<LambdaScopeInfo>(FunctionScopes[MaxFunctionScopesIndex])) &&(static_cast<void> (0))
       "Only a lambda can capture the enclosing object (referred to by "(static_cast<void> (0))
       "*this) by copy")(static_cast<void> (0));
QualType ThisTy = getCurrentThisType();
for (int idx = MaxFunctionScopesIndex; NumCapturingClosures;
     --idx, --NumCapturingClosures) {
  CapturingScopeInfo *CSI = cast<CapturingScopeInfo>(FunctionScopes[idx]);

  // The type of the corresponding data member (not a 'this' pointer if 'by
  // copy').
  QualType CaptureType = ThisTy;
  if (ByCopy) {
    // If we are capturing the object referred to by '*this' by copy, ignore
    // any cv qualifiers inherited from the type of the member function for
    // the type of the closure-type's corresponding data member and any use
    // of 'this'.
    CaptureType = ThisTy->getPointeeType();
    CaptureType.removeLocalCVRQualifiers(Qualifiers::CVRMask);
  }

  bool isNested = NumCapturingClosures > 1;
  CSI->addThisCapture(isNested, Loc, CaptureType, ByCopy);
}
return false;
1375}

1377ExprResult Sema::ActOnCXXThis(SourceLocation Loc) {
/// C++ 9.3.2: In the body of a non-static member function, the keyword this
/// is a non-lvalue expression whose value is the address of the object for
/// which the function is called.

QualType ThisTy = getCurrentThisType();
if (ThisTy.isNull())
  return Diag(Loc, diag::err_invalid_this_use);
return BuildCXXThisExpr(Loc, ThisTy, /*IsImplicit=*/false);
1386}

1388Expr *Sema::BuildCXXThisExpr(SourceLocation Loc, QualType Type,
                           bool IsImplicit) {
auto *This = new (Context) CXXThisExpr(Loc, Type, IsImplicit);
MarkThisReferenced(This);
return This;
1393}

1395void Sema::MarkThisReferenced(CXXThisExpr *This) {
CheckCXXThisCapture(This->getExprLoc());
1397}

1399bool Sema::isThisOutsideMemberFunctionBody(QualType BaseType) {
// If we're outside the body of a member function, then we'll have a specified
// type for 'this'.
if (CXXThisTypeOverride.isNull())
  return false;

// Determine whether we're looking into a class that's currently being
// defined.
CXXRecordDecl *Class = BaseType->getAsCXXRecordDecl();
return Class && Class->isBeingDefined();
1409}

1411/// Parse construction of a specified type.
1412/// Can be interpreted either as function-style casting ("int(x)")
1413/// or class type construction ("ClassType(x,y,z)")
1414/// or creation of a value-initialized type ("int()").
1415ExprResult
1416Sema::ActOnCXXTypeConstructExpr(ParsedType TypeRep,
                              SourceLocation LParenOrBraceLoc,
                              MultiExprArg exprs,
                              SourceLocation RParenOrBraceLoc,
                              bool ListInitialization) {
if (!TypeRep)
  return ExprError();

TypeSourceInfo *TInfo;
QualType Ty = GetTypeFromParser(TypeRep, &TInfo);
if (!TInfo)
  TInfo = Context.getTrivialTypeSourceInfo(Ty, SourceLocation());

auto Result = BuildCXXTypeConstructExpr(TInfo, LParenOrBraceLoc, exprs,
                                        RParenOrBraceLoc, ListInitialization);
// Avoid creating a non-type-dependent expression that contains typos.
// Non-type-dependent expressions are liable to be discarded without
// checking for embedded typos.
if (!Result.isInvalid() && Result.get()->isInstantiationDependent() &&
    !Result.get()->isTypeDependent())
  Result = CorrectDelayedTyposInExpr(Result.get());
else if (Result.isInvalid())
  Result = CreateRecoveryExpr(TInfo->getTypeLoc().getBeginLoc(),
                              RParenOrBraceLoc, exprs, Ty);
return Result;
1441}

1443ExprResult
1444Sema::BuildCXXTypeConstructExpr(TypeSourceInfo *TInfo,
                              SourceLocation LParenOrBraceLoc,
                              MultiExprArg Exprs,
                              SourceLocation RParenOrBraceLoc,
                              bool ListInitialization) {
QualType Ty = TInfo->getType();
SourceLocation TyBeginLoc = TInfo->getTypeLoc().getBeginLoc();

assert((!ListInitialization ||(static_cast<void> (0))
        (Exprs.size() == 1 && isa<InitListExpr>(Exprs[0]))) &&(static_cast<void> (0))
       "List initialization must have initializer list as expression.")(static_cast<void> (0));
SourceRange FullRange = SourceRange(TyBeginLoc, RParenOrBraceLoc);

InitializedEntity Entity = InitializedEntity::InitializeTemporary(TInfo);
InitializationKind Kind =
    Exprs.size()
        ? ListInitialization
              ? InitializationKind::CreateDirectList(
                    TyBeginLoc, LParenOrBraceLoc, RParenOrBraceLoc)
              : InitializationKind::CreateDirect(TyBeginLoc, LParenOrBraceLoc,
                                                 RParenOrBraceLoc)
        : InitializationKind::CreateValue(TyBeginLoc, LParenOrBraceLoc,
                                          RParenOrBraceLoc);

// C++1z [expr.type.conv]p1:
//   If the type is a placeholder for a deduced class type, [...perform class
//   template argument deduction...]
DeducedType *Deduced = Ty->getContainedDeducedType();
if (Deduced && isa<DeducedTemplateSpecializationType>(Deduced)) {
  Ty = DeduceTemplateSpecializationFromInitializer(TInfo, Entity,
                                                   Kind, Exprs);
  if (Ty.isNull())
    return ExprError();
  Entity = InitializedEntity::InitializeTemporary(TInfo, Ty);
}

if (Ty->isDependentType() || CallExpr::hasAnyTypeDependentArguments(Exprs)) {
  // FIXME: CXXUnresolvedConstructExpr does not model list-initialization
  // directly. We work around this by dropping the locations of the braces.
  SourceRange Locs = ListInitialization
                         ? SourceRange()
                         : SourceRange(LParenOrBraceLoc, RParenOrBraceLoc);
  return CXXUnresolvedConstructExpr::Create(Context, Ty.getNonReferenceType(),
                                            TInfo, Locs.getBegin(), Exprs,
                                            Locs.getEnd());
}

// C++ [expr.type.conv]p1:
// If the expression list is a parenthesized single expression, the type
// conversion expression is equivalent (in definedness, and if defined in
// meaning) to the corresponding cast expression.
if (Exprs.size() == 1 && !ListInitialization &&
    !isa<InitListExpr>(Exprs[0])) {
  Expr *Arg = Exprs[0];
  return BuildCXXFunctionalCastExpr(TInfo, Ty, LParenOrBraceLoc, Arg,
                                    RParenOrBraceLoc);
}

//   For an expression of the form T(), T shall not be an array type.
QualType ElemTy = Ty;
if (Ty->isArrayType()) {
  if (!ListInitialization)
    return ExprError(Diag(TyBeginLoc, diag::err_value_init_for_array_type)
                       << FullRange);
  ElemTy = Context.getBaseElementType(Ty);
}

// There doesn't seem to be an explicit rule against this but sanity demands
// we only construct objects with object types.
if (Ty->isFunctionType())
  return ExprError(Diag(TyBeginLoc, diag::err_init_for_function_type)
                     << Ty << FullRange);

// C++17 [expr.type.conv]p2:
//   If the type is cv void and the initializer is (), the expression is a
//   prvalue of the specified type that performs no initialization.
if (!Ty->isVoidType() &&
    RequireCompleteType(TyBeginLoc, ElemTy,
                        diag::err_invalid_incomplete_type_use, FullRange))
  return ExprError();

//   Otherwise, the expression is a prvalue of the specified type whose
//   result object is direct-initialized (11.6) with the initializer.
InitializationSequence InitSeq(*this, Entity, Kind, Exprs);
ExprResult Result = InitSeq.Perform(*this, Entity, Kind, Exprs);

if (Result.isInvalid())
  return Result;

Expr *Inner = Result.get();
if (CXXBindTemporaryExpr *BTE = dyn_cast_or_null<CXXBindTemporaryExpr>(Inner))
  Inner = BTE->getSubExpr();
if (!isa<CXXTemporaryObjectExpr>(Inner) &&
    !isa<CXXScalarValueInitExpr>(Inner)) {
  // If we created a CXXTemporaryObjectExpr, that node also represents the
  // functional cast. Otherwise, create an explicit cast to represent
  // the syntactic form of a functional-style cast that was used here.
  //
  // FIXME: Creating a CXXFunctionalCastExpr around a CXXConstructExpr
  // would give a more consistent AST representation than using a
  // CXXTemporaryObjectExpr. It's also weird that the functional cast
  // is sometimes handled by initialization and sometimes not.
  QualType ResultType = Result.get()->getType();
  SourceRange Locs = ListInitialization
                         ? SourceRange()
                         : SourceRange(LParenOrBraceLoc, RParenOrBraceLoc);
  Result = CXXFunctionalCastExpr::Create(
      Context, ResultType, Expr::getValueKindForType(Ty), TInfo, CK_NoOp,
      Result.get(), /*Path=*/nullptr, CurFPFeatureOverrides(),
      Locs.getBegin(), Locs.getEnd());
}

return Result;
1557}

1559bool Sema::isUsualDeallocationFunction(const CXXMethodDecl *Method) {
// [CUDA] Ignore this function, if we can't call it.
const FunctionDecl *Caller = dyn_cast<FunctionDecl>(CurContext);
if (getLangOpts().CUDA) {
  auto CallPreference = IdentifyCUDAPreference(Caller, Method);
  // If it's not callable at all, it's not the right function.
  if (CallPreference < CFP_WrongSide)
    return false;
  if (CallPreference == CFP_WrongSide) {
    // Maybe. We have to check if there are better alternatives.
    DeclContext::lookup_result R =
        Method->getDeclContext()->lookup(Method->getDeclName());
    for (const auto *D : R) {
      if (const auto *FD = dyn_cast<FunctionDecl>(D)) {
        if (IdentifyCUDAPreference(Caller, FD) > CFP_WrongSide)
          return false;
      }
    }
    // We've found no better variants.
  }
}

SmallVector<const FunctionDecl*, 4> PreventedBy;
bool Result = Method->isUsualDeallocationFunction(PreventedBy);

if (Result || !getLangOpts().CUDA || PreventedBy.empty())
  return Result;

// In case of CUDA, return true if none of the 1-argument deallocator
// functions are actually callable.
return llvm::none_of(PreventedBy, [&](const FunctionDecl *FD) {
  assert(FD->getNumParams() == 1 &&(static_cast<void> (0))
         "Only single-operand functions should be in PreventedBy")(static_cast<void> (0));
  return IdentifyCUDAPreference(Caller, FD) >= CFP_HostDevice;
});
1594}

1596/// Determine whether the given function is a non-placement
1597/// deallocation function.
1598static bool isNonPlacementDeallocationFunction(Sema &S, FunctionDecl *FD) {
if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(FD))
  return S.isUsualDeallocationFunction(Method);

if (FD->getOverloadedOperator() != OO_Delete &&
    FD->getOverloadedOperator() != OO_Array_Delete)
  return false;

unsigned UsualParams = 1;

if (S.getLangOpts().SizedDeallocation && UsualParams < FD->getNumParams() &&
    S.Context.hasSameUnqualifiedType(
        FD->getParamDecl(UsualParams)->getType(),
        S.Context.getSizeType()))
  ++UsualParams;

if (S.getLangOpts().AlignedAllocation && UsualParams < FD->getNumParams() &&
    S.Context.hasSameUnqualifiedType(
        FD->getParamDecl(UsualParams)->getType(),
        S.Context.getTypeDeclType(S.getStdAlignValT())))
  ++UsualParams;

return UsualParams == FD->getNumParams();
1621}

1623namespace {
struct UsualDeallocFnInfo {
  UsualDeallocFnInfo() : Found(), FD(nullptr) {}
  UsualDeallocFnInfo(Sema &S, DeclAccessPair Found)
      : Found(Found), FD(dyn_cast<FunctionDecl>(Found->getUnderlyingDecl())),
        Destroying(false), HasSizeT(false), HasAlignValT(false),
        CUDAPref(Sema::CFP_Native) {
    // A function template declaration is never a usual deallocation function.
    if (!FD)
      return;
    unsigned NumBaseParams = 1;
    if (FD->isDestroyingOperatorDelete()) {
      Destroying = true;
      ++NumBaseParams;
    }

    if (NumBaseParams < FD->getNumParams() &&
        S.Context.hasSameUnqualifiedType(
            FD->getParamDecl(NumBaseParams)->getType(),
            S.Context.getSizeType())) {
      ++NumBaseParams;
      HasSizeT = true;
    }

    if (NumBaseParams < FD->getNumParams() &&
        FD->getParamDecl(NumBaseParams)->getType()->isAlignValT()) {
      ++NumBaseParams;
      HasAlignValT = true;
    }

    // In CUDA, determine how much we'd like / dislike to call this.
    if (S.getLangOpts().CUDA)
      if (auto *Caller = dyn_cast<FunctionDecl>(S.CurContext))
        CUDAPref = S.IdentifyCUDAPreference(Caller, FD);
  }

  explicit operator bool() const { return FD; }

  bool isBetterThan(const UsualDeallocFnInfo &Other, bool WantSize,
                    bool WantAlign) const {
    // C++ P0722:
    //   A destroying operator delete is preferred over a non-destroying
    //   operator delete.
    if (Destroying != Other.Destroying)
      return Destroying;

    // C++17 [expr.delete]p10:
    //   If the type has new-extended alignment, a function with a parameter
    //   of type std::align_val_t is preferred; otherwise a function without
    //   such a parameter is preferred
    if (HasAlignValT != Other.HasAlignValT)
      return HasAlignValT == WantAlign;

    if (HasSizeT != Other.HasSizeT)
      return HasSizeT == WantSize;

    // Use CUDA call preference as a tiebreaker.
    return CUDAPref > Other.CUDAPref;
  }

  DeclAccessPair Found;
  FunctionDecl *FD;
  bool Destroying, HasSizeT, HasAlignValT;
  Sema::CUDAFunctionPreference CUDAPref;
};
1688}

1690/// Determine whether a type has new-extended alignment. This may be called when
1691/// the type is incomplete (for a delete-expression with an incomplete pointee
1692/// type), in which case it will conservatively return false if the alignment is
1693/// not known.
1694static bool hasNewExtendedAlignment(Sema &S, QualType AllocType) {
return S.getLangOpts().AlignedAllocation &&
       S.getASTContext().getTypeAlignIfKnown(AllocType) >
           S.getASTContext().getTargetInfo().getNewAlign();
1698}

1700/// Select the correct "usual" deallocation function to use from a selection of
1701/// deallocation functions (either global or class-scope).
1702static UsualDeallocFnInfo resolveDeallocationOverload(
  Sema &S, LookupResult &R, bool WantSize, bool WantAlign,
  llvm::SmallVectorImpl<UsualDeallocFnInfo> *BestFns = nullptr) {
UsualDeallocFnInfo Best;

for (auto I = R.begin(), E = R.end(); I != E; ++I) {
  UsualDeallocFnInfo Info(S, I.getPair());
  if (!Info || !isNonPlacementDeallocationFunction(S, Info.FD) ||
      Info.CUDAPref == Sema::CFP_Never)
    continue;

  if (!Best) {
    Best = Info;
    if (BestFns)
      BestFns->push_back(Info);
    continue;
  }

  if (Best.isBetterThan(Info, WantSize, WantAlign))
    continue;

  //   If more than one preferred function is found, all non-preferred
  //   functions are eliminated from further consideration.
  if (BestFns && Info.isBetterThan(Best, WantSize, WantAlign))
    BestFns->clear();

  Best = Info;
  if (BestFns)
    BestFns->push_back(Info);
}

return Best;
1734}

1736/// Determine whether a given type is a class for which 'delete[]' would call
1737/// a member 'operator delete[]' with a 'size_t' parameter. This implies that
1738/// we need to store the array size (even if the type is
1739/// trivially-destructible).
1740static bool doesUsualArrayDeleteWantSize(Sema &S, SourceLocation loc,
                                       QualType allocType) {
const RecordType *record =
  allocType->getBaseElementTypeUnsafe()->getAs<RecordType>();
if (!record) return false;

// Try to find an operator delete[] in class scope.

DeclarationName deleteName =
  S.Context.DeclarationNames.getCXXOperatorName(OO_Array_Delete);
LookupResult ops(S, deleteName, loc, Sema::LookupOrdinaryName);
S.LookupQualifiedName(ops, record->getDecl());

// We're just doing this for information.
ops.suppressDiagnostics();

// Very likely: there's no operator delete[].
if (ops.empty()) return false;

// If it's ambiguous, it should be illegal to call operator delete[]
// on this thing, so it doesn't matter if we allocate extra space or not.
if (ops.isAmbiguous()) return false;

// C++17 [expr.delete]p10:
//   If the deallocation functions have class scope, the one without a
//   parameter of type std::size_t is selected.
auto Best = resolveDeallocationOverload(
    S, ops, /*WantSize*/false,
    /*WantAlign*/hasNewExtendedAlignment(S, allocType));
return Best && Best.HasSizeT;
1770}

1772/// Parsed a C++ 'new' expression (C++ 5.3.4).
1773///
1774/// E.g.:
1775/// @code new (memory) int[size][4] @endcode
1776/// or
1777/// @code ::new Foo(23, "hello") @endcode
1778///
1779/// \param StartLoc The first location of the expression.
1780/// \param UseGlobal True if 'new' was prefixed with '::'.
1781/// \param PlacementLParen Opening paren of the placement arguments.
1782/// \param PlacementArgs Placement new arguments.
1783/// \param PlacementRParen Closing paren of the placement arguments.
1784/// \param TypeIdParens If the type is in parens, the source range.
1785/// \param D The type to be allocated, as well as array dimensions.
1786/// \param Initializer The initializing expression or initializer-list, or null
1787///   if there is none.
1788ExprResult
1789Sema::ActOnCXXNew(SourceLocation StartLoc, bool UseGlobal,
                SourceLocation PlacementLParen, MultiExprArg PlacementArgs,
                SourceLocation PlacementRParen, SourceRange TypeIdParens,
                Declarator &D, Expr *Initializer) {
Optional<Expr *> ArraySize;
// If the specified type is an array, unwrap it and save the expression.
if (D.getNumTypeObjects() > 0 &&
    D.getTypeObject(0).Kind == DeclaratorChunk::Array) {
  DeclaratorChunk &Chunk = D.getTypeObject(0);
  if (D.getDeclSpec().hasAutoTypeSpec())
    return ExprError(Diag(Chunk.Loc, diag::err_new_array_of_auto)
      << D.getSourceRange());
  if (Chunk.Arr.hasStatic)
    return ExprError(Diag(Chunk.Loc, diag::err_static_illegal_in_new)
      << D.getSourceRange());
  if (!Chunk.Arr.NumElts && !Initializer)
    return ExprError(Diag(Chunk.Loc, diag::err_array_new_needs_size)
      << D.getSourceRange());

  ArraySize = static_cast<Expr*>(Chunk.Arr.NumElts);
  D.DropFirstTypeObject();
}

// Every dimension shall be of constant size.
if (ArraySize) {
  for (unsigned I = 0, N = D.getNumTypeObjects(); I < N; ++I) {
    if (D.getTypeObject(I).Kind != DeclaratorChunk::Array)
      break;

    DeclaratorChunk::ArrayTypeInfo &Array = D.getTypeObject(I).Arr;
    if (Expr *NumElts = (Expr *)Array.NumElts) {
      if (!NumElts->isTypeDependent() && !NumElts->isValueDependent()) {
        // FIXME: GCC permits constant folding here. We should either do so consistently
        // or not do so at all, rather than changing behavior in C++14 onwards.
        if (getLangOpts().CPlusPlus14) {
          // C++1y [expr.new]p6: Every constant-expression in a noptr-new-declarator
          //   shall be a converted constant expression (5.19) of type std::size_t
          //   and shall evaluate to a strictly positive value.
          llvm::APSInt Value(Context.getIntWidth(Context.getSizeType()));
          Array.NumElts
           = CheckConvertedConstantExpression(NumElts, Context.getSizeType(), Value,
                                              CCEK_ArrayBound)
               .get();
        } else {
          Array.NumElts =
              VerifyIntegerConstantExpression(
                  NumElts, nullptr, diag::err_new_array_nonconst, AllowFold)
                  .get();
        }
        if (!Array.NumElts)
          return ExprError();
      }
    }
  }
}

TypeSourceInfo *TInfo = GetTypeForDeclarator(D, /*Scope=*/nullptr);
QualType AllocType = TInfo->getType();
if (D.isInvalidType())
  return ExprError();

SourceRange DirectInitRange;
if (ParenListExpr *List = dyn_cast_or_null<ParenListExpr>(Initializer))
  DirectInitRange = List->getSourceRange();

return BuildCXXNew(SourceRange(StartLoc, D.getEndLoc()), UseGlobal,
                   PlacementLParen, PlacementArgs, PlacementRParen,
                   TypeIdParens, AllocType, TInfo, ArraySize, DirectInitRange,
                   Initializer);
1858}

1860static bool isLegalArrayNewInitializer(CXXNewExpr::InitializationStyle Style,
                                     Expr *Init) {
if (!Init)
  return true;
if (ParenListExpr *PLE = dyn_cast<ParenListExpr>(Init))
  return PLE->getNumExprs() == 0;
if (isa<ImplicitValueInitExpr>(Init))
  return true;
else if (CXXConstructExpr *CCE = dyn_cast<CXXConstructExpr>(Init))
  return !CCE->isListInitialization() &&
         CCE->getConstructor()->isDefaultConstructor();
else if (Style == CXXNewExpr::ListInit) {
  assert(isa<InitListExpr>(Init) &&(static_cast<void> (0))
         "Shouldn't create list CXXConstructExprs for arrays.")(static_cast<void> (0));
  return true;
}
return false;
1877}

1879bool
1880Sema::isUnavailableAlignedAllocationFunction(const FunctionDecl &FD) const {
if (!getLangOpts().AlignedAllocationUnavailable)
  return false;
if (FD.isDefined())
  return false;
Optional<unsigned> AlignmentParam;
if (FD.isReplaceableGlobalAllocationFunction(&AlignmentParam) &&
    AlignmentParam.hasValue())
  return true;
return false;
1890}

1892// Emit a diagnostic if an aligned allocation/deallocation function that is not
1893// implemented in the standard library is selected.
1894void Sema::diagnoseUnavailableAlignedAllocation(const FunctionDecl &FD,
                                              SourceLocation Loc) {
if (isUnavailableAlignedAllocationFunction(FD)) {
  const llvm::Triple &T = getASTContext().getTargetInfo().getTriple();
  StringRef OSName = AvailabilityAttr::getPlatformNameSourceSpelling(
      getASTContext().getTargetInfo().getPlatformName());
  VersionTuple OSVersion = alignedAllocMinVersion(T.getOS());

  OverloadedOperatorKind Kind = FD.getDeclName().getCXXOverloadedOperator();
  bool IsDelete = Kind == OO_Delete || Kind == OO_Array_Delete;
  Diag(Loc, diag::err_aligned_allocation_unavailable)
      << IsDelete << FD.getType().getAsString() << OSName
      << OSVersion.getAsString() << OSVersion.empty();
  Diag(Loc, diag::note_silence_aligned_allocation_unavailable);
}
1909}

1911ExprResult
1912Sema::BuildCXXNew(SourceRange Range, bool UseGlobal,
                SourceLocation PlacementLParen,
                MultiExprArg PlacementArgs,
                SourceLocation PlacementRParen,
                SourceRange TypeIdParens,
                QualType AllocType,
                TypeSourceInfo *AllocTypeInfo,
                Optional<Expr *> ArraySize,
                SourceRange DirectInitRange,
                Expr *Initializer) {
SourceRange TypeRange = AllocTypeInfo->getTypeLoc().getSourceRange();
SourceLocation StartLoc = Range.getBegin();

CXXNewExpr::InitializationStyle initStyle;
if (DirectInitRange.isValid()) {
  assert(Initializer && "Have parens but no initializer.")(static_cast<void> (0));
  initStyle = CXXNewExpr::CallInit;
} else if (Initializer && isa<InitListExpr>(Initializer))
  initStyle = CXXNewExpr::ListInit;
else {
  assert((!Initializer || isa<ImplicitValueInitExpr>(Initializer) ||(static_cast<void> (0))
          isa<CXXConstructExpr>(Initializer)) &&(static_cast<void> (0))
         "Initializer expression that cannot have been implicitly created.")(static_cast<void> (0));
  initStyle = CXXNewExpr::NoInit;
}

Expr **Inits = &Initializer;
unsigned NumInits = Initializer ? 1 : 0;
if (ParenListExpr *List = dyn_cast_or_null<ParenListExpr>(Initializer)) {
  assert(initStyle == CXXNewExpr::CallInit && "paren init for non-call init")(static_cast<void> (0));
  Inits = List->getExprs();
  NumInits = List->getNumExprs();
}

// C++11 [expr.new]p15:
//   A new-expression that creates an object of type T initializes that
//   object as follows:
InitializationKind Kind
    //     - If the new-initializer is omitted, the object is default-
    //       initialized (8.5); if no initialization is performed,
    //       the object has indeterminate value
    = initStyle == CXXNewExpr::NoInit
          ? InitializationKind::CreateDefault(TypeRange.getBegin())
          //     - Otherwise, the new-initializer is interpreted according to
          //     the
          //       initialization rules of 8.5 for direct-initialization.
          : initStyle == CXXNewExpr::ListInit
                ? InitializationKind::CreateDirectList(
                      TypeRange.getBegin(), Initializer->getBeginLoc(),
                      Initializer->getEndLoc())
                : InitializationKind::CreateDirect(TypeRange.getBegin(),
                                                   DirectInitRange.getBegin(),
                                                   DirectInitRange.getEnd());

// C++11 [dcl.spec.auto]p6. Deduce the type which 'auto' stands in for.
auto *Deduced = AllocType->getContainedDeducedType();
if (Deduced && isa<DeducedTemplateSpecializationType>(Deduced)) {
  if (ArraySize)
    return ExprError(
        Diag(ArraySize ? (*ArraySize)->getExprLoc() : TypeRange.getBegin(),
             diag::err_deduced_class_template_compound_type)
        << /*array*/ 2
        << (ArraySize ? (*ArraySize)->getSourceRange() : TypeRange));

  InitializedEntity Entity
    = InitializedEntity::InitializeNew(StartLoc, AllocType);
  AllocType = DeduceTemplateSpecializationFromInitializer(
      AllocTypeInfo, Entity, Kind, MultiExprArg(Inits, NumInits));
  if (AllocType.isNull())
    return ExprError();
} else if (Deduced) {
  bool Braced = (initStyle == CXXNewExpr::ListInit);
  if (NumInits == 1) {
    if (auto p = dyn_cast_or_null<InitListExpr>(Inits[0])) {
      Inits = p->getInits();
      NumInits = p->getNumInits();
      Braced = true;
    }
  }

  if (initStyle == CXXNewExpr::NoInit || NumInits == 0)
    return ExprError(Diag(StartLoc, diag::err_auto_new_requires_ctor_arg)
                     << AllocType << TypeRange);
  if (NumInits > 1) {
    Expr *FirstBad = Inits[1];
    return ExprError(Diag(FirstBad->getBeginLoc(),
                          diag::err_auto_new_ctor_multiple_expressions)
                     << AllocType << TypeRange);
  }
  if (Braced && !getLangOpts().CPlusPlus17)
    Diag(Initializer->getBeginLoc(), diag::ext_auto_new_list_init)
        << AllocType << TypeRange;
  Expr *Deduce = Inits[0];
  QualType DeducedType;
  if (DeduceAutoType(AllocTypeInfo, Deduce, DeducedType) == DAR_Failed)
    return ExprError(Diag(StartLoc, diag::err_auto_new_deduction_failure)
                     << AllocType << Deduce->getType()
                     << TypeRange << Deduce->getSourceRange());
  if (DeducedType.isNull())
    return ExprError();
  AllocType = DeducedType;
}

// Per C++0x [expr.new]p5, the type being constructed may be a
// typedef of an array type.
if (!ArraySize) {
  if (const ConstantArrayType *Array
                            = Context.getAsConstantArrayType(AllocType)) {
    ArraySize = IntegerLiteral::Create(Context, Array->getSize(),
                                       Context.getSizeType(),
                                       TypeRange.getEnd());
    AllocType = Array->getElementType();
  }
}

if (CheckAllocatedType(AllocType, TypeRange.getBegin(), TypeRange))
  return ExprError();

// In ARC, infer 'retaining' for the allocated
if (getLangOpts().ObjCAutoRefCount &&
    AllocType.getObjCLifetime() == Qualifiers::OCL_None &&
    AllocType->isObjCLifetimeType()) {
  AllocType = Context.getLifetimeQualifiedType(AllocType,
                                  AllocType->getObjCARCImplicitLifetime());
}

QualType ResultType = Context.getPointerType(AllocType);

if (ArraySize && *ArraySize &&
    (*ArraySize)->getType()->isNonOverloadPlaceholderType()) {
  ExprResult result = CheckPlaceholderExpr(*ArraySize);
  if (result.isInvalid()) return ExprError();
  ArraySize = result.get();
}
// C++98 5.3.4p6: "The expression in a direct-new-declarator shall have
//   integral or enumeration type with a non-negative value."
// C++11 [expr.new]p6: The expression [...] shall be of integral or unscoped
//   enumeration type, or a class type for which a single non-explicit
//   conversion function to integral or unscoped enumeration type exists.
// C++1y [expr.new]p6: The expression [...] is implicitly converted to
//   std::size_t.
llvm::Optional<uint64_t> KnownArraySize;
if (ArraySize && *ArraySize && !(*ArraySize)->isTypeDependent()) {
  ExprResult ConvertedSize;
  if (getLangOpts().CPlusPlus14) {
    assert(Context.getTargetInfo().getIntWidth() && "Builtin type of size 0?")(static_cast<void> (0));

    ConvertedSize = PerformImplicitConversion(*ArraySize, Context.getSizeType(),
                                              AA_Converting);

    if (!ConvertedSize.isInvalid() &&
        (*ArraySize)->getType()->getAs<RecordType>())
      // Diagnose the compatibility of this conversion.
      Diag(StartLoc, diag::warn_cxx98_compat_array_size_conversion)
        << (*ArraySize)->getType() << 0 << "'size_t'";
  } else {
    class SizeConvertDiagnoser : public ICEConvertDiagnoser {
    protected:
      Expr *ArraySize;

    public:
      SizeConvertDiagnoser(Expr *ArraySize)
          : ICEConvertDiagnoser(/*AllowScopedEnumerations*/false, false, false),
            ArraySize(ArraySize) {}

      SemaDiagnosticBuilder diagnoseNotInt(Sema &S, SourceLocation Loc,
                                           QualType T) override {
        return S.Diag(Loc, diag::err_array_size_not_integral)
                 << S.getLangOpts().CPlusPlus11 << T;
      }

      SemaDiagnosticBuilder diagnoseIncomplete(
          Sema &S, SourceLocation Loc, QualType T) override {
        return S.Diag(Loc, diag::err_array_size_incomplete_type)
                 << T << ArraySize->getSourceRange();
      }

      SemaDiagnosticBuilder diagnoseExplicitConv(
          Sema &S, SourceLocation Loc, QualType T, QualType ConvTy) override {
        return S.Diag(Loc, diag::err_array_size_explicit_conversion) << T << ConvTy;
      }

      SemaDiagnosticBuilder noteExplicitConv(
          Sema &S, CXXConversionDecl *Conv, QualType ConvTy) override {
        return S.Diag(Conv->getLocation(), diag::note_array_size_conversion)
                 << ConvTy->isEnumeralType() << ConvTy;
      }

      SemaDiagnosticBuilder diagnoseAmbiguous(
          Sema &S, SourceLocation Loc, QualType T) override {
        return S.Diag(Loc, diag::err_array_size_ambiguous_conversion) << T;
      }

      SemaDiagnosticBuilder noteAmbiguous(
          Sema &S, CXXConversionDecl *Conv, QualType ConvTy) override {
        return S.Diag(Conv->getLocation(), diag::note_array_size_conversion)
                 << ConvTy->isEnumeralType() << ConvTy;
      }

      SemaDiagnosticBuilder diagnoseConversion(Sema &S, SourceLocation Loc,
                                               QualType T,
                                               QualType ConvTy) override {
        return S.Diag(Loc,
                      S.getLangOpts().CPlusPlus11
                        ? diag::warn_cxx98_compat_array_size_conversion
                        : diag::ext_array_size_conversion)
                 << T << ConvTy->isEnumeralType() << ConvTy;
      }
    } SizeDiagnoser(*ArraySize);

    ConvertedSize = PerformContextualImplicitConversion(StartLoc, *ArraySize,
                                                        SizeDiagnoser);
  }
  if (ConvertedSize.isInvalid())
    return ExprError();

  ArraySize = ConvertedSize.get();
  QualType SizeType = (*ArraySize)->getType();

  if (!SizeType->isIntegralOrUnscopedEnumerationType())
    return ExprError();

  // C++98 [expr.new]p7:
  //   The expression in a direct-new-declarator shall have integral type
  //   with a non-negative value.
  //
  // Let's see if this is a constant < 0. If so, we reject it out of hand,
  // per CWG1464. Otherwise, if it's not a constant, we must have an
  // unparenthesized array type.
  if (!(*ArraySize)->isValueDependent()) {
    // We've already performed any required implicit conversion to integer or
    // unscoped enumeration type.
    // FIXME: Per CWG1464, we are required to check the value prior to
    // converting to size_t. This will never find a negative array size in
    // C++14 onwards, because Value is always unsigned here!
    if (Optional<llvm::APSInt> Value =
            (*ArraySize)->getIntegerConstantExpr(Context)) {
      if (Value->isSigned() && Value->isNegative()) {
        return ExprError(Diag((*ArraySize)->getBeginLoc(),
                              diag::err_typecheck_negative_array_size)
                         << (*ArraySize)->getSourceRange());
      }

      if (!AllocType->isDependentType()) {
        unsigned ActiveSizeBits = ConstantArrayType::getNumAddressingBits(
            Context, AllocType, *Value);
        if (ActiveSizeBits > ConstantArrayType::getMaxSizeBits(Context))
          return ExprError(
              Diag((*ArraySize)->getBeginLoc(), diag::err_array_too_large)
              << toString(*Value, 10) << (*ArraySize)->getSourceRange());
      }

      KnownArraySize = Value->getZExtValue();
    } else if (TypeIdParens.isValid()) {
      // Can't have dynamic array size when the type-id is in parentheses.
      Diag((*ArraySize)->getBeginLoc(), diag::ext_new_paren_array_nonconst)
          << (*ArraySize)->getSourceRange()
          << FixItHint::CreateRemoval(TypeIdParens.getBegin())
          << FixItHint::CreateRemoval(TypeIdParens.getEnd());

      TypeIdParens = SourceRange();
    }
  }

  // Note that we do *not* convert the argument in any way.  It can
  // be signed, larger than size_t, whatever.
}

FunctionDecl *OperatorNew = nullptr;
FunctionDecl *OperatorDelete = nullptr;
unsigned Alignment =
    AllocType->isDependentType() ? 0 : Context.getTypeAlign(AllocType);
unsigned NewAlignment = Context.getTargetInfo().getNewAlign();
bool PassAlignment = getLangOpts().AlignedAllocation &&
                     Alignment > NewAlignment;

AllocationFunctionScope Scope = UseGlobal ? AFS_Global : AFS_Both;
if (!AllocType->isDependentType() &&
    !Expr::hasAnyTypeDependentArguments(PlacementArgs) &&
    FindAllocationFunctions(
        StartLoc, SourceRange(PlacementLParen, PlacementRParen), Scope, Scope,
        AllocType, ArraySize.hasValue(), PassAlignment, PlacementArgs,
        OperatorNew, OperatorDelete))
  return ExprError();

// If this is an array allocation, compute whether the usual array
// deallocation function for the type has a size_t parameter.
bool UsualArrayDeleteWantsSize = false;
if (ArraySize && !AllocType->isDependentType())
  UsualArrayDeleteWantsSize =
      doesUsualArrayDeleteWantSize(*this, StartLoc, AllocType);

SmallVector<Expr *, 8> AllPlaceArgs;
if (OperatorNew) {
  auto *Proto = OperatorNew->getType()->castAs<FunctionProtoType>();
  VariadicCallType CallType = Proto->isVariadic() ? VariadicFunction
                                                  : VariadicDoesNotApply;

  // We've already converted the placement args, just fill in any default
  // arguments. Skip the first parameter because we don't have a corresponding
  // argument. Skip the second parameter too if we're passing in the
  // alignment; we've already filled it in.
  unsigned NumImplicitArgs = PassAlignment ? 2 : 1;
  if (GatherArgumentsForCall(PlacementLParen, OperatorNew, Proto,
                             NumImplicitArgs, PlacementArgs, AllPlaceArgs,
                             CallType))
    return ExprError();

  if (!AllPlaceArgs.empty())
    PlacementArgs = AllPlaceArgs;

  // We would like to perform some checking on the given `operator new` call,
  // but the PlacementArgs does not contain the implicit arguments,
  // namely allocation size and maybe allocation alignment,
  // so we need to conjure them.

  QualType SizeTy = Context.getSizeType();
  unsigned SizeTyWidth = Context.getTypeSize(SizeTy);

  llvm::APInt SingleEltSize(
      SizeTyWidth, Context.getTypeSizeInChars(AllocType).getQuantity());

  // How many bytes do we want to allocate here?
  llvm::Optional<llvm::APInt> AllocationSize;
  if (!ArraySize.hasValue() && !AllocType->isDependentType()) {
    // For non-array operator new, we only want to allocate one element.
    AllocationSize = SingleEltSize;
  } else if (KnownArraySize.hasValue() && !AllocType->isDependentType()) {
    // For array operator new, only deal with static array size case.
    bool Overflow;
    AllocationSize = llvm::APInt(SizeTyWidth, *KnownArraySize)
                         .umul_ov(SingleEltSize, Overflow);
    (void)Overflow;
    assert((static_cast<void> (0))
        !Overflow &&(static_cast<void> (0))
        "Expected that all the overflows would have been handled already.")(static_cast<void> (0));
  }

  IntegerLiteral AllocationSizeLiteral(
      Context,
      AllocationSize.getValueOr(llvm::APInt::getNullValue(SizeTyWidth)),
      SizeTy, SourceLocation());
  // Otherwise, if we failed to constant-fold the allocation size, we'll
  // just give up and pass-in something opaque, that isn't a null pointer.
  OpaqueValueExpr OpaqueAllocationSize(SourceLocation(), SizeTy, VK_PRValue,
                                       OK_Ordinary, /*SourceExpr=*/nullptr);

  // Let's synthesize the alignment argument in case we will need it.
  // Since we *really* want to allocate these on stack, this is slightly ugly
  // because there might not be a `std::align_val_t` type.
  EnumDecl *StdAlignValT = getStdAlignValT();
  QualType AlignValT =
      StdAlignValT ? Context.getTypeDeclType(StdAlignValT) : SizeTy;
  IntegerLiteral AlignmentLiteral(
      Context,
      llvm::APInt(Context.getTypeSize(SizeTy),
                  Alignment / Context.getCharWidth()),
      SizeTy, SourceLocation());
  ImplicitCastExpr DesiredAlignment(ImplicitCastExpr::OnStack, AlignValT,
                                    CK_IntegralCast, &AlignmentLiteral,
                                    VK_PRValue, FPOptionsOverride());

  // Adjust placement args by prepending conjured size and alignment exprs.
  llvm::SmallVector<Expr *, 8> CallArgs;
  CallArgs.reserve(NumImplicitArgs + PlacementArgs.size());
  CallArgs.emplace_back(AllocationSize.hasValue()
                            ? static_cast<Expr *>(&AllocationSizeLiteral)
                            : &OpaqueAllocationSize);
  if (PassAlignment)
    CallArgs.emplace_back(&DesiredAlignment);
  CallArgs.insert(CallArgs.end(), PlacementArgs.begin(), PlacementArgs.end());

  DiagnoseSentinelCalls(OperatorNew, PlacementLParen, CallArgs);

  checkCall(OperatorNew, Proto, /*ThisArg=*/nullptr, CallArgs,
            /*IsMemberFunction=*/false, StartLoc, Range, CallType);

  // Warn if the type is over-aligned and is being allocated by (unaligned)
  // global operator new.
  if (PlacementArgs.empty() && !PassAlignment &&
      (OperatorNew->isImplicit() ||
       (OperatorNew->getBeginLoc().isValid() &&
        getSourceManager().isInSystemHeader(OperatorNew->getBeginLoc())))) {
    if (Alignment > NewAlignment)
      Diag(StartLoc, diag::warn_overaligned_type)
          << AllocType
          << unsigned(Alignment / Context.getCharWidth())
          << unsigned(NewAlignment / Context.getCharWidth());
  }
}

// Array 'new' can't have any initializers except empty parentheses.
// Initializer lists are also allowed, in C++11. Rely on the parser for the
// dialect distinction.
if (ArraySize && !isLegalArrayNewInitializer(initStyle, Initializer)) {
  SourceRange InitRange(Inits[0]->getBeginLoc(),
                        Inits[NumInits - 1]->getEndLoc());
  Diag(StartLoc, diag::err_new_array_init_args) << InitRange;
  return ExprError();
}

// If we can perform the initialization, and we've not already done so,
// do it now.
if (!AllocType->isDependentType() &&
    !Expr::hasAnyTypeDependentArguments(
        llvm::makeArrayRef(Inits, NumInits))) {
  // The type we initialize is the complete type, including the array bound.
  QualType InitType;
  if (KnownArraySize)
    InitType = Context.getConstantArrayType(
        AllocType,
        llvm::APInt(Context.getTypeSize(Context.getSizeType()),
                    *KnownArraySize),
        *ArraySize, ArrayType::Normal, 0);
  else if (ArraySize)
    InitType =
        Context.getIncompleteArrayType(AllocType, ArrayType::Normal, 0);
  else
    InitType = AllocType;

  InitializedEntity Entity
    = InitializedEntity::InitializeNew(StartLoc, InitType);
  InitializationSequence InitSeq(*this, Entity, Kind,
                                 MultiExprArg(Inits, NumInits));
  ExprResult FullInit = InitSeq.Perform(*this, Entity, Kind,
                                        MultiExprArg(Inits, NumInits));
  if (FullInit.isInvalid())
    return ExprError();

  // FullInit is our initializer; strip off CXXBindTemporaryExprs, because
  // we don't want the initialized object to be destructed.
  // FIXME: We should not create these in the first place.
  if (CXXBindTemporaryExpr *Binder =
          dyn_cast_or_null<CXXBindTemporaryExpr>(FullInit.get()))
    FullInit = Binder->getSubExpr();

  Initializer = FullInit.get();

  // FIXME: If we have a KnownArraySize, check that the array bound of the
  // initializer is no greater than that constant value.

  if (ArraySize && !*ArraySize) {
    auto *CAT = Context.getAsConstantArrayType(Initializer->getType());
    if (CAT) {
      // FIXME: Track that the array size was inferred rather than explicitly
      // specified.
      ArraySize = IntegerLiteral::Create(
          Context, CAT->getSize(), Context.getSizeType(), TypeRange.getEnd());
    } else {
      Diag(TypeRange.getEnd(), diag::err_new_array_size_unknown_from_init)
          << Initializer->getSourceRange();
    }
  }
}

// Mark the new and delete operators as referenced.
if (OperatorNew) {
  if (DiagnoseUseOfDecl(OperatorNew, StartLoc))
    return ExprError();
  MarkFunctionReferenced(StartLoc, OperatorNew);
}
if (OperatorDelete) {
  if (DiagnoseUseOfDecl(OperatorDelete, StartLoc))
    return ExprError();
  MarkFunctionReferenced(StartLoc, OperatorDelete);
}

return CXXNewExpr::Create(Context, UseGlobal, OperatorNew, OperatorDelete,
                          PassAlignment, UsualArrayDeleteWantsSize,
                          PlacementArgs, TypeIdParens, ArraySize, initStyle,
                          Initializer, ResultType, AllocTypeInfo, Range,
                          DirectInitRange);
2384}

2386/// Checks that a type is suitable as the allocated type
2387/// in a new-expression.
2388bool Sema::CheckAllocatedType(QualType AllocType, SourceLocation Loc,
                            SourceRange R) {
// C++ 5.3.4p1: "[The] type shall be a complete object type, but not an
//   abstract class type or array thereof.
if (AllocType->isFunctionType())
  return Diag(Loc, diag::err_bad_new_type)
    << AllocType << 0 << R;
else if (AllocType->isReferenceType())
  return Diag(Loc, diag::err_bad_new_type)
    << AllocType << 1 << R;
else if (!AllocType->isDependentType() &&
         RequireCompleteSizedType(
             Loc, AllocType, diag::err_new_incomplete_or_sizeless_type, R))
  return true;
else if (RequireNonAbstractType(Loc, AllocType,
                                diag::err_allocation_of_abstract_type))
  return true;
else if (AllocType->isVariablyModifiedType())
  return Diag(Loc, diag::err_variably_modified_new_type)
           << AllocType;
else if (AllocType.getAddressSpace() != LangAS::Default &&
         !getLangOpts().OpenCLCPlusPlus)
  return Diag(Loc, diag::err_address_space_qualified_new)
    << AllocType.getUnqualifiedType()
    << AllocType.getQualifiers().getAddressSpaceAttributePrintValue();
else if (getLangOpts().ObjCAutoRefCount) {
  if (const ArrayType *AT = Context.getAsArrayType(AllocType)) {
    QualType BaseAllocType = Context.getBaseElementType(AT);
    if (BaseAllocType.getObjCLifetime() == Qualifiers::OCL_None &&
        BaseAllocType->isObjCLifetimeType())
      return Diag(Loc, diag::err_arc_new_array_without_ownership)
        << BaseAllocType;
  }
}

return false;
2424}

2426static bool resolveAllocationOverload(
  Sema &S, LookupResult &R, SourceRange Range, SmallVectorImpl<Expr *> &Args,
  bool &PassAlignment, FunctionDecl *&Operator,
  OverloadCandidateSet *AlignedCandidates, Expr *AlignArg, bool Diagnose) {
OverloadCandidateSet Candidates(R.getNameLoc(),
                                OverloadCandidateSet::CSK_Normal);
for (LookupResult::iterator Alloc = R.begin(), AllocEnd = R.end();
     Alloc != AllocEnd; ++Alloc) {
  // Even member operator new/delete are implicitly treated as
  // static, so don't use AddMemberCandidate.
  NamedDecl *D = (*Alloc)->getUnderlyingDecl();

  if (FunctionTemplateDecl *FnTemplate = dyn_cast<FunctionTemplateDecl>(D)) {
    S.AddTemplateOverloadCandidate(FnTemplate, Alloc.getPair(),
                                   /*ExplicitTemplateArgs=*/nullptr, Args,
                                   Candidates,
                                   /*SuppressUserConversions=*/false);
    continue;
  }

  FunctionDecl *Fn = cast<FunctionDecl>(D);
  S.AddOverloadCandidate(Fn, Alloc.getPair(), Args, Candidates,
                         /*SuppressUserConversions=*/false);
}

// Do the resolution.
OverloadCandidateSet::iterator Best;
switch (Candidates.BestViableFunction(S, R.getNameLoc(), Best)) {
case OR_Success: {
  // Got one!
  FunctionDecl *FnDecl = Best->Function;
  if (S.CheckAllocationAccess(R.getNameLoc(), Range, R.getNamingClass(),
                              Best->FoundDecl) == Sema::AR_inaccessible)
    return true;

  Operator = FnDecl;
  return false;
}

case OR_No_Viable_Function:
  // C++17 [expr.new]p13:
  //   If no matching function is found and the allocated object type has
  //   new-extended alignment, the alignment argument is removed from the
  //   argument list, and overload resolution is performed again.
  if (PassAlignment) {
    PassAlignment = false;
    AlignArg = Args[1];
    Args.erase(Args.begin() + 1);
    return resolveAllocationOverload(S, R, Range, Args, PassAlignment,
                                     Operator, &Candidates, AlignArg,
                                     Diagnose);
  }

  // MSVC will fall back on trying to find a matching global operator new
  // if operator new[] cannot be found.  Also, MSVC will leak by not
  // generating a call to operator delete or operator delete[], but we
  // will not replicate that bug.
  // FIXME: Find out how this interacts with the std::align_val_t fallback
  // once MSVC implements it.
  if (R.getLookupName().getCXXOverloadedOperator() == OO_Array_New &&
      S.Context.getLangOpts().MSVCCompat) {
    R.clear();
    R.setLookupName(S.Context.DeclarationNames.getCXXOperatorName(OO_New));
    S.LookupQualifiedName(R, S.Context.getTranslationUnitDecl());
    // FIXME: This will give bad diagnostics pointing at the wrong functions.
    return resolveAllocationOverload(S, R, Range, Args, PassAlignment,
                                     Operator, /*Candidates=*/nullptr,
                                     /*AlignArg=*/nullptr, Diagnose);
  }

  if (Diagnose) {
    // If this is an allocation of the form 'new (p) X' for some object
    // pointer p (or an expression that will decay to such a pointer),
    // diagnose the missing inclusion of <new>.
    if (!R.isClassLookup() && Args.size() == 2 &&
        (Args[1]->getType()->isObjectPointerType() ||
         Args[1]->getType()->isArrayType())) {
      S.Diag(R.getNameLoc(), diag::err_need_header_before_placement_new)
          << R.getLookupName() << Range;
      // Listing the candidates is unlikely to be useful; skip it.
      return true;
    }

    // Finish checking all candidates before we note any. This checking can
    // produce additional diagnostics so can't be interleaved with our
    // emission of notes.
    //
    // For an aligned allocation, separately check the aligned and unaligned
    // candidates with their respective argument lists.
    SmallVector<OverloadCandidate*, 32> Cands;
    SmallVector<OverloadCandidate*, 32> AlignedCands;
    llvm::SmallVector<Expr*, 4> AlignedArgs;
    if (AlignedCandidates) {
      auto IsAligned = [](OverloadCandidate &C) {
        return C.Function->getNumParams() > 1 &&
               C.Function->getParamDecl(1)->getType()->isAlignValT();
      };
      auto IsUnaligned = [&](OverloadCandidate &C) { return !IsAligned(C); };

      AlignedArgs.reserve(Args.size() + 1);
      AlignedArgs.push_back(Args[0]);
      AlignedArgs.push_back(AlignArg);
      AlignedArgs.append(Args.begin() + 1, Args.end());
      AlignedCands = AlignedCandidates->CompleteCandidates(
          S, OCD_AllCandidates, AlignedArgs, R.getNameLoc(), IsAligned);

      Cands = Candidates.CompleteCandidates(S, OCD_AllCandidates, Args,
                                            R.getNameLoc(), IsUnaligned);
    } else {
      Cands = Candidates.CompleteCandidates(S, OCD_AllCandidates, Args,
                                            R.getNameLoc());
    }

    S.Diag(R.getNameLoc(), diag::err_ovl_no_viable_function_in_call)
        << R.getLookupName() << Range;
    if (AlignedCandidates)
      AlignedCandidates->NoteCandidates(S, AlignedArgs, AlignedCands, "",
                                        R.getNameLoc());
    Candidates.NoteCandidates(S, Args, Cands, "", R.getNameLoc());
  }
  return true;

case OR_Ambiguous:
  if (Diagnose) {
    Candidates.NoteCandidates(
        PartialDiagnosticAt(R.getNameLoc(),
                            S.PDiag(diag::err_ovl_ambiguous_call)
                                << R.getLookupName() << Range),
        S, OCD_AmbiguousCandidates, Args);
  }
  return true;

case OR_Deleted: {
  if (Diagnose) {
    Candidates.NoteCandidates(
        PartialDiagnosticAt(R.getNameLoc(),
                            S.PDiag(diag::err_ovl_deleted_call)
                                << R.getLookupName() << Range),
        S, OCD_AllCandidates, Args);
  }
  return true;
}
}
llvm_unreachable("Unreachable, bad result from BestViableFunction")__builtin_unreachable();
2570}

2572bool Sema::FindAllocationFunctions(SourceLocation StartLoc, SourceRange Range,
                                 AllocationFunctionScope NewScope,
                                 AllocationFunctionScope DeleteScope,
                                 QualType AllocType, bool IsArray,
                                 bool &PassAlignment, MultiExprArg PlaceArgs,
                                 FunctionDecl *&OperatorNew,
                                 FunctionDecl *&OperatorDelete,
                                 bool Diagnose) {
// --- Choosing an allocation function ---
// C++ 5.3.4p8 - 14 & 18
// 1) If looking in AFS_Global scope for allocation functions, only look in
//    the global scope. Else, if AFS_Class, only look in the scope of the
//    allocated class. If AFS_Both, look in both.
// 2) If an array size is given, look for operator new[], else look for
//   operator new.
// 3) The first argument is always size_t. Append the arguments from the
//   placement form.

SmallVector<Expr*, 8> AllocArgs;
AllocArgs.reserve((PassAlignment ? 2 : 1) + PlaceArgs.size());

// We don't care about the actual value of these arguments.
// FIXME: Should the Sema create the expression and embed it in the syntax
// tree? Or should the consumer just recalculate the value?
// FIXME: Using a dummy value will interact poorly with attribute enable_if.
IntegerLiteral Size(Context, llvm::APInt::getNullValue(
                    Context.getTargetInfo().getPointerWidth(0)),
                    Context.getSizeType(),
                    SourceLocation());
AllocArgs.push_back(&Size);

QualType AlignValT = Context.VoidTy;
if (PassAlignment) {
  DeclareGlobalNewDelete();
  AlignValT = Context.getTypeDeclType(getStdAlignValT());
}
CXXScalarValueInitExpr Align(AlignValT, nullptr, SourceLocation());
if (PassAlignment)
  AllocArgs.push_back(&Align);

AllocArgs.insert(AllocArgs.end(), PlaceArgs.begin(), PlaceArgs.end());

// C++ [expr.new]p8:
//   If the allocated type is a non-array type, the allocation
//   function's name is operator new and the deallocation function's
//   name is operator delete. If the allocated type is an array
//   type, the allocation function's name is operator new[] and the
//   deallocation function's name is operator delete[].
DeclarationName NewName = Context.DeclarationNames.getCXXOperatorName(
    IsArray ? OO_Array_New : OO_New);

QualType AllocElemType = Context.getBaseElementType(AllocType);

// Find the allocation function.
{
  LookupResult R(*this, NewName, StartLoc, LookupOrdinaryName);

  // C++1z [expr.new]p9:
  //   If the new-expression begins with a unary :: operator, the allocation
  //   function's name is looked up in the global scope. Otherwise, if the
  //   allocated type is a class type T or array thereof, the allocation
  //   function's name is looked up in the scope of T.
  if (AllocElemType->isRecordType() && NewScope != AFS_Global)
    LookupQualifiedName(R, AllocElemType->getAsCXXRecordDecl());

  // We can see ambiguity here if the allocation function is found in
  // multiple base classes.
  if (R.isAmbiguous())
    return true;

  //   If this lookup fails to find the name, or if the allocated type is not
  //   a class type, the allocation function's name is looked up in the
  //   global scope.
  if (R.empty()) {
    if (NewScope == AFS_Class)
      return true;

    LookupQualifiedName(R, Context.getTranslationUnitDecl());
  }

  if (getLangOpts().OpenCLCPlusPlus && R.empty()) {
    if (PlaceArgs.empty()) {
      Diag(StartLoc, diag::err_openclcxx_not_supported) << "default new";
    } else {
      Diag(StartLoc, diag::err_openclcxx_placement_new);
    }
    return true;
  }

  assert(!R.empty() && "implicitly declared allocation functions not found")(static_cast<void> (0));
  assert(!R.isAmbiguous() && "global allocation functions are ambiguous")(static_cast<void> (0));

  // We do our own custom access checks below.
  R.suppressDiagnostics();

  if (resolveAllocationOverload(*this, R, Range, AllocArgs, PassAlignment,
                                OperatorNew, /*Candidates=*/nullptr,
                                /*AlignArg=*/nullptr, Diagnose))
    return true;
}

// We don't need an operator delete if we're running under -fno-exceptions.
if (!getLangOpts().Exceptions) {
  OperatorDelete = nullptr;
  return false;
}

// Note, the name of OperatorNew might have been changed from array to
// non-array by resolveAllocationOverload.
DeclarationName DeleteName = Context.DeclarationNames.getCXXOperatorName(
    OperatorNew->getDeclName().getCXXOverloadedOperator() == OO_Array_New
        ? OO_Array_Delete
        : OO_Delete);

// C++ [expr.new]p19:
//
//   If the new-expression begins with a unary :: operator, the
//   deallocation function's name is looked up in the global
//   scope. Otherwise, if the allocated type is a class type T or an
//   array thereof, the deallocation function's name is looked up in
//   the scope of T. If this lookup fails to find the name, or if
//   the allocated type is not a class type or array thereof, the
//   deallocation function's name is looked up in the global scope.
LookupResult FoundDelete(*this, DeleteName, StartLoc, LookupOrdinaryName);
if (AllocElemType->isRecordType() && DeleteScope != AFS_Global) {
  auto *RD =
      cast<CXXRecordDecl>(AllocElemType->castAs<RecordType>()->getDecl());
  LookupQualifiedName(FoundDelete, RD);
}
if (FoundDelete.isAmbiguous())
  return true; // FIXME: clean up expressions?

// Filter out any destroying operator deletes. We can't possibly call such a
// function in this context, because we're handling the case where the object
// was not successfully constructed.
// FIXME: This is not covered by the language rules yet.
{
  LookupResult::Filter Filter = FoundDelete.makeFilter();
  while (Filter.hasNext()) {
    auto *FD = dyn_cast<FunctionDecl>(Filter.next()->getUnderlyingDecl());
    if (FD && FD->isDestroyingOperatorDelete())
      Filter.erase();
  }
  Filter.done();
}

bool FoundGlobalDelete = FoundDelete.empty();
if (FoundDelete.empty()) {
  FoundDelete.clear(LookupOrdinaryName);

  if (DeleteScope == AFS_Class)
    return true;

  DeclareGlobalNewDelete();
  LookupQualifiedName(FoundDelete, Context.getTranslationUnitDecl());
}

FoundDelete.suppressDiagnostics();

SmallVector<std::pair<DeclAccessPair,FunctionDecl*>, 2> Matches;

// Whether we're looking for a placement operator delete is dictated
// by whether we selected a placement operator new, not by whether
// we had explicit placement arguments.  This matters for things like
//   struct A { void *operator new(size_t, int = 0); ... };
//   A *a = new A()
//
// We don't have any definition for what a "placement allocation function"
// is, but we assume it's any allocation function whose
// parameter-declaration-clause is anything other than (size_t).
//
// FIXME: Should (size_t, std::align_val_t) also be considered non-placement?
// This affects whether an exception from the constructor of an overaligned
// type uses the sized or non-sized form of aligned operator delete.
bool isPlacementNew = !PlaceArgs.empty() || OperatorNew->param_size() != 1 ||
                      OperatorNew->isVariadic();

if (isPlacementNew) {
  // C++ [expr.new]p20:
  //   A declaration of a placement deallocation function matches the
  //   declaration of a placement allocation function if it has the
  //   same number of parameters and, after parameter transformations
  //   (8.3.5), all parameter types except the first are
  //   identical. [...]
  //
  // To perform this comparison, we compute the function type that
  // the deallocation function should have, and use that type both
  // for template argument deduction and for comparison purposes.
  QualType ExpectedFunctionType;
  {
    auto *Proto = OperatorNew->getType()->castAs<FunctionProtoType>();

    SmallVector<QualType, 4> ArgTypes;
    ArgTypes.push_back(Context.VoidPtrTy);
    for (unsigned I = 1, N = Proto->getNumParams(); I < N; ++I)
      ArgTypes.push_back(Proto->getParamType(I));

    FunctionProtoType::ExtProtoInfo EPI;
    // FIXME: This is not part of the standard's rule.
    EPI.Variadic = Proto->isVariadic();

    ExpectedFunctionType
      = Context.getFunctionType(Context.VoidTy, ArgTypes, EPI);
  }

  for (LookupResult::iterator D = FoundDelete.begin(),
                           DEnd = FoundDelete.end();
       D != DEnd; ++D) {
    FunctionDecl *Fn = nullptr;
    if (FunctionTemplateDecl *FnTmpl =
            dyn_cast<FunctionTemplateDecl>((*D)->getUnderlyingDecl())) {
      // Perform template argument deduction to try to match the
      // expected function type.
      TemplateDeductionInfo Info(StartLoc);
      if (DeduceTemplateArguments(FnTmpl, nullptr, ExpectedFunctionType, Fn,
                                  Info))
        continue;
    } else
      Fn = cast<FunctionDecl>((*D)->getUnderlyingDecl());

    if (Context.hasSameType(adjustCCAndNoReturn(Fn->getType(),
                                                ExpectedFunctionType,
                                                /*AdjustExcpetionSpec*/true),
                            ExpectedFunctionType))
      Matches.push_back(std::make_pair(D.getPair(), Fn));
  }

  if (getLangOpts().CUDA)
    EraseUnwantedCUDAMatches(dyn_cast<FunctionDecl>(CurContext), Matches);
} else {
  // C++1y [expr.new]p22:
  //   For a non-placement allocation function, the normal deallocation
  //   function lookup is used
  //
  // Per [expr.delete]p10, this lookup prefers a member operator delete
  // without a size_t argument, but prefers a non-member operator delete
  // with a size_t where possible (which it always is in this case).
  llvm::SmallVector<UsualDeallocFnInfo, 4> BestDeallocFns;
  UsualDeallocFnInfo Selected = resolveDeallocationOverload(
      *this, FoundDelete, /*WantSize*/ FoundGlobalDelete,
      /*WantAlign*/ hasNewExtendedAlignment(*this, AllocElemType),
      &BestDeallocFns);
  if (Selected)
    Matches.push_back(std::make_pair(Selected.Found, Selected.FD));
  else {
    // If we failed to select an operator, all remaining functions are viable
    // but ambiguous.
    for (auto Fn : BestDeallocFns)
      Matches.push_back(std::make_pair(Fn.Found, Fn.FD));
  }
}

// C++ [expr.new]p20:
//   [...] If the lookup finds a single matching deallocation
//   function, that function will be called; otherwise, no
//   deallocation function will be called.
if (Matches.size() == 1) {
  OperatorDelete = Matches[0].second;

  // C++1z [expr.new]p23:
  //   If the lookup finds a usual deallocation function (3.7.4.2)
  //   with a parameter of type std::size_t and that function, considered
  //   as a placement deallocation function, would have been
  //   selected as a match for the allocation function, the program
  //   is ill-formed.
  if (getLangOpts().CPlusPlus11 && isPlacementNew &&
      isNonPlacementDeallocationFunction(*this, OperatorDelete)) {
    UsualDeallocFnInfo Info(*this,
                            DeclAccessPair::make(OperatorDelete, AS_public));
    // Core issue, per mail to core reflector, 2016-10-09:
    //   If this is a member operator delete, and there is a corresponding
    //   non-sized member operator delete, this isn't /really/ a sized
    //   deallocation function, it just happens to have a size_t parameter.
    bool IsSizedDelete = Info.HasSizeT;
    if (IsSizedDelete && !FoundGlobalDelete) {
      auto NonSizedDelete =
          resolveDeallocationOverload(*this, FoundDelete, /*WantSize*/false,
                                      /*WantAlign*/Info.HasAlignValT);
      if (NonSizedDelete && !NonSizedDelete.HasSizeT &&
          NonSizedDelete.HasAlignValT == Info.HasAlignValT)
        IsSizedDelete = false;
    }

    if (IsSizedDelete) {
      SourceRange R = PlaceArgs.empty()
                          ? SourceRange()
                          : SourceRange(PlaceArgs.front()->getBeginLoc(),
                                        PlaceArgs.back()->getEndLoc());
      Diag(StartLoc, diag::err_placement_new_non_placement_delete) << R;
      if (!OperatorDelete->isImplicit())
        Diag(OperatorDelete->getLocation(), diag::note_previous_decl)
            << DeleteName;
    }
  }

  CheckAllocationAccess(StartLoc, Range, FoundDelete.getNamingClass(),
                        Matches[0].first);
} else if (!Matches.empty()) {
  // We found multiple suitable operators. Per [expr.new]p20, that means we
  // call no 'operator delete' function, but we should at least warn the user.
  // FIXME: Suppress this warning if the construction cannot throw.
  Diag(StartLoc, diag::warn_ambiguous_suitable_delete_function_found)
    << DeleteName << AllocElemType;

  for (auto &Match : Matches)
    Diag(Match.second->getLocation(),
         diag::note_member_declared_here) << DeleteName;
}

return false;
2882}

2884/// DeclareGlobalNewDelete - Declare the global forms of operator new and
2885/// delete. These are:
2886/// @code
2887///   // C++03:
2888///   void* operator new(std::size_t) throw(std::bad_alloc);
2889///   void* operator new[](std::size_t) throw(std::bad_alloc);
2890///   void operator delete(void *) throw();
2891///   void operator delete[](void *) throw();
2892///   // C++11:
2893///   void* operator new(std::size_t);
2894///   void* operator new[](std::size_t);
2895///   void operator delete(void *) noexcept;
2896///   void operator delete[](void *) noexcept;
2897///   // C++1y:
2898///   void* operator new(std::size_t);
2899///   void* operator new[](std::size_t);
2900///   void operator delete(void *) noexcept;
2901///   void operator delete[](void *) noexcept;
2902///   void operator delete(void *, std::size_t) noexcept;
2903///   void operator delete[](void *, std::size_t) noexcept;
2904/// @endcode
2905/// Note that the placement and nothrow forms of new are *not* implicitly
2906/// declared. Their use requires including \<new\>.
2907void Sema::DeclareGlobalNewDelete() {
if (GlobalNewDeleteDeclared)
  return;

// The implicitly declared new and delete operators
// are not supported in OpenCL.
if (getLangOpts().OpenCLCPlusPlus)
  return;

// C++ [basic.std.dynamic]p2:
//   [...] The following allocation and deallocation functions (18.4) are
//   implicitly declared in global scope in each translation unit of a
//   program
//
//     C++03:
//     void* operator new(std::size_t) throw(std::bad_alloc);
//     void* operator new[](std::size_t) throw(std::bad_alloc);
//     void  operator delete(void*) throw();
//     void  operator delete[](void*) throw();
//     C++11:
//     void* operator new(std::size_t);
//     void* operator new[](std::size_t);
//     void  operator delete(void*) noexcept;
//     void  operator delete[](void*) noexcept;
//     C++1y:
//     void* operator new(std::size_t);
//     void* operator new[](std::size_t);
//     void  operator delete(void*) noexcept;
//     void  operator delete[](void*) noexcept;
//     void  operator delete(void*, std::size_t) noexcept;
//     void  operator delete[](void*, std::size_t) noexcept;
//
//   These implicit declarations introduce only the function names operator
//   new, operator new[], operator delete, operator delete[].
//
// Here, we need to refer to std::bad_alloc, so we will implicitly declare
// "std" or "bad_alloc" as necessary to form the exception specification.
// However, we do not make these implicit declarations visible to name
// lookup.
if (!StdBadAlloc && !getLangOpts().CPlusPlus11) {
  // The "std::bad_alloc" class has not yet been declared, so build it
  // implicitly.
  StdBadAlloc = CXXRecordDecl::Create(Context, TTK_Class,
                                      getOrCreateStdNamespace(),
                                      SourceLocation(), SourceLocation(),
                                    &PP.getIdentifierTable().get("bad_alloc"),
                                      nullptr);
  getStdBadAlloc()->setImplicit(true);
}
if (!StdAlignValT && getLangOpts().AlignedAllocation) {
  // The "std::align_val_t" enum class has not yet been declared, so build it
  // implicitly.
  auto *AlignValT = EnumDecl::Create(
      Context, getOrCreateStdNamespace(), SourceLocation(), SourceLocation(),
      &PP.getIdentifierTable().get("align_val_t"), nullptr, true, true, true);
  AlignValT->setIntegerType(Context.getSizeType());
  AlignValT->setPromotionType(Context.getSizeType());
  AlignValT->setImplicit(true);
  StdAlignValT = AlignValT;
}

GlobalNewDeleteDeclared = true;

QualType VoidPtr = Context.getPointerType(Context.VoidTy);
QualType SizeT = Context.getSizeType();

auto DeclareGlobalAllocationFunctions = [&](OverloadedOperatorKind Kind,
                                            QualType Return, QualType Param) {
  llvm::SmallVector<QualType, 3> Params;
  Params.push_back(Param);

  // Create up to four variants of the function (sized/aligned).
  bool HasSizedVariant = getLangOpts().SizedDeallocation &&
                         (Kind == OO_Delete || Kind == OO_Array_Delete);
  bool HasAlignedVariant = getLangOpts().AlignedAllocation;

  int NumSizeVariants = (HasSizedVariant ? 2 : 1);
  int NumAlignVariants = (HasAlignedVariant ? 2 : 1);
  for (int Sized = 0; Sized < NumSizeVariants; ++Sized) {
    if (Sized)
      Params.push_back(SizeT);

    for (int Aligned = 0; Aligned < NumAlignVariants; ++Aligned) {
      if (Aligned)
        Params.push_back(Context.getTypeDeclType(getStdAlignValT()));

      DeclareGlobalAllocationFunction(
          Context.DeclarationNames.getCXXOperatorName(Kind), Return, Params);

      if (Aligned)
        Params.pop_back();
    }
  }
};

DeclareGlobalAllocationFunctions(OO_New, VoidPtr, SizeT);
DeclareGlobalAllocationFunctions(OO_Array_New, VoidPtr, SizeT);
DeclareGlobalAllocationFunctions(OO_Delete, Context.VoidTy, VoidPtr);
DeclareGlobalAllocationFunctions(OO_Array_Delete, Context.VoidTy, VoidPtr);
3006}

3008/// DeclareGlobalAllocationFunction - Declares a single implicit global
3009/// allocation function if it doesn't already exist.
3010void Sema::DeclareGlobalAllocationFunction(DeclarationName Name,
                                         QualType Return,
                                         ArrayRef<QualType> Params) {
DeclContext *GlobalCtx = Context.getTranslationUnitDecl();

// Check if this function is already declared.
DeclContext::lookup_result R = GlobalCtx->lookup(Name);
for (DeclContext::lookup_iterator Alloc = R.begin(), AllocEnd = R.end();
     Alloc != AllocEnd; ++Alloc) {
  // Only look at non-template functions, as it is the predefined,
  // non-templated allocation function we are trying to declare here.
  if (FunctionDecl *Func = dyn_cast<FunctionDecl>(*Alloc)) {
    if (Func->getNumParams() == Params.size()) {
      llvm::SmallVector<QualType, 3> FuncParams;
      for (auto *P : Func->parameters())
        FuncParams.push_back(
            Context.getCanonicalType(P->getType().getUnqualifiedType()));
      if (llvm::makeArrayRef(FuncParams) == Params) {
        // Make the function visible to name lookup, even if we found it in
        // an unimported module. It either is an implicitly-declared global
        // allocation function, or is suppressing that function.
        Func->setVisibleDespiteOwningModule();
        return;
      }
    }
  }
}

FunctionProtoType::ExtProtoInfo EPI(Context.getDefaultCallingConvention(
    /*IsVariadic=*/false, /*IsCXXMethod=*/false, /*IsBuiltin=*/true));

QualType BadAllocType;
bool HasBadAllocExceptionSpec
  = (Name.getCXXOverloadedOperator() == OO_New ||
     Name.getCXXOverloadedOperator() == OO_Array_New);
if (HasBadAllocExceptionSpec) {
  if (!getLangOpts().CPlusPlus11) {
    BadAllocType = Context.getTypeDeclType(getStdBadAlloc());
    assert(StdBadAlloc && "Must have std::bad_alloc declared")(static_cast<void> (0));
    EPI.ExceptionSpec.Type = EST_Dynamic;
    EPI.ExceptionSpec.Exceptions = llvm::makeArrayRef(BadAllocType);
  }
  if (getLangOpts().NewInfallible) {
    EPI.ExceptionSpec.Type = EST_DynamicNone;
  }
} else {
  EPI.ExceptionSpec =
      getLangOpts().CPlusPlus11 ? EST_BasicNoexcept : EST_DynamicNone;
}

auto CreateAllocationFunctionDecl = [&](Attr *ExtraAttr) {
  QualType FnType = Context.getFunctionType(Return, Params, EPI);
  FunctionDecl *Alloc = FunctionDecl::Create(
      Context, GlobalCtx, SourceLocation(), SourceLocation(), Name, FnType,
      /*TInfo=*/nullptr, SC_None, getCurFPFeatures().isFPConstrained(), false,
      true);
  Alloc->setImplicit();
  // Global allocation functions should always be visible.
  Alloc->setVisibleDespiteOwningModule();

  if (HasBadAllocExceptionSpec && getLangOpts().NewInfallible)
    Alloc->addAttr(
        ReturnsNonNullAttr::CreateImplicit(Context, Alloc->getLocation()));

  Alloc->addAttr(VisibilityAttr::CreateImplicit(
      Context, LangOpts.GlobalAllocationFunctionVisibilityHidden
                   ? VisibilityAttr::Hidden
                   : VisibilityAttr::Default));

  llvm::SmallVector<ParmVarDecl *, 3> ParamDecls;
  for (QualType T : Params) {
    ParamDecls.push_back(ParmVarDecl::Create(
        Context, Alloc, SourceLocation(), SourceLocation(), nullptr, T,
        /*TInfo=*/nullptr, SC_None, nullptr));
    ParamDecls.back()->setImplicit();
  }
  Alloc->setParams(ParamDecls);
  if (ExtraAttr)
    Alloc->addAttr(ExtraAttr);
  AddKnownFunctionAttributesForReplaceableGlobalAllocationFunction(Alloc);
  Context.getTranslationUnitDecl()->addDecl(Alloc);
  IdResolver.tryAddTopLevelDecl(Alloc, Name);
};

if (!LangOpts.CUDA)
  CreateAllocationFunctionDecl(nullptr);
else {
  // Host and device get their own declaration so each can be
  // defined or re-declared independently.
  CreateAllocationFunctionDecl(CUDAHostAttr::CreateImplicit(Context));
  CreateAllocationFunctionDecl(CUDADeviceAttr::CreateImplicit(Context));
}
3102}

3104FunctionDecl *Sema::FindUsualDeallocationFunction(SourceLocation StartLoc,
                                                bool CanProvideSize,
                                                bool Overaligned,
                                                DeclarationName Name) {
DeclareGlobalNewDelete();

LookupResult FoundDelete(*this, Name, StartLoc, LookupOrdinaryName);
LookupQualifiedName(FoundDelete, Context.getTranslationUnitDecl());

// FIXME: It's possible for this to result in ambiguity, through a
// user-declared variadic operator delete or the enable_if attribute. We
// should probably not consider those cases to be usual deallocation
// functions. But for now we just make an arbitrary choice in that case.
auto Result = resolveDeallocationOverload(*this, FoundDelete, CanProvideSize,
                                          Overaligned);
assert(Result.FD && "operator delete missing from global scope?")(static_cast<void> (0));
return Result.FD;
3121}

3123FunctionDecl *Sema::FindDeallocationFunctionForDestructor(SourceLocation Loc,
                                                        CXXRecordDecl *RD) {
DeclarationName Name = Context.DeclarationNames.getCXXOperatorName(OO_Delete);

FunctionDecl *OperatorDelete = nullptr;
if (FindDeallocationFunction(Loc, RD, Name, OperatorDelete))
  return nullptr;
if (OperatorDelete)
  return OperatorDelete;

// If there's no class-specific operator delete, look up the global
// non-array delete.
return FindUsualDeallocationFunction(
    Loc, true, hasNewExtendedAlignment(*this, Context.getRecordType(RD)),
    Name);
3138}

3140bool Sema::FindDeallocationFunction(SourceLocation StartLoc, CXXRecordDecl *RD,
                                  DeclarationName Name,
                                  FunctionDecl *&Operator, bool Diagnose) {
LookupResult Found(*this, Name, StartLoc, LookupOrdinaryName);
// Try to find operator delete/operator delete[] in class scope.
LookupQualifiedName(Found, RD);

if (Found.isAmbiguous())
  return true;

Found.suppressDiagnostics();

bool Overaligned = hasNewExtendedAlignment(*this, Context.getRecordType(RD));

// C++17 [expr.delete]p10:
//   If the deallocation functions have class scope, the one without a
//   parameter of type std::size_t is selected.
llvm::SmallVector<UsualDeallocFnInfo, 4> Matches;
resolveDeallocationOverload(*this, Found, /*WantSize*/ false,
                            /*WantAlign*/ Overaligned, &Matches);

// If we could find an overload, use it.
if (Matches.size() == 1) {
  Operator = cast<CXXMethodDecl>(Matches[0].FD);

  // FIXME: DiagnoseUseOfDecl?
  if (Operator->isDeleted()) {
    if (Diagnose) {
      Diag(StartLoc, diag::err_deleted_function_use);
      NoteDeletedFunction(Operator);
    }
    return true;
  }

  if (CheckAllocationAccess(StartLoc, SourceRange(), Found.getNamingClass(),
                            Matches[0].Found, Diagnose) == AR_inaccessible)
    return true;

  return false;
}

// We found multiple suitable operators; complain about the ambiguity.
// FIXME: The standard doesn't say to do this; it appears that the intent
// is that this should never happen.
if (!Matches.empty()) {
  if (Diagnose) {
    Diag(StartLoc, diag::err_ambiguous_suitable_delete_member_function_found)
      << Name << RD;
    for (auto &Match : Matches)
      Diag(Match.FD->getLocation(), diag::note_member_declared_here) << Name;
  }
  return true;
}

// We did find operator delete/operator delete[] declarations, but
// none of them were suitable.
if (!Found.empty()) {
  if (Diagnose) {
    Diag(StartLoc, diag::err_no_suitable_delete_member_function_found)
      << Name << RD;

    for (NamedDecl *D : Found)
      Diag(D->getUnderlyingDecl()->getLocation(),
           diag::note_member_declared_here) << Name;
  }
  return true;
}

Operator = nullptr;
return false;
3210}

3212namespace {
3213/// Checks whether delete-expression, and new-expression used for
3214///  initializing deletee have the same array form.
3215class MismatchingNewDeleteDetector {
3216public:
enum MismatchResult {
  /// Indicates that there is no mismatch or a mismatch cannot be proven.
  NoMismatch,
  /// Indicates that variable is initialized with mismatching form of \a new.
  VarInitMismatches,
  /// Indicates that member is initialized with mismatching form of \a new.
  MemberInitMismatches,
  /// Indicates that 1 or more constructors' definitions could not been
  /// analyzed, and they will be checked again at the end of translation unit.
  AnalyzeLater
};

/// \param EndOfTU True, if this is the final analysis at the end of
/// translation unit. False, if this is the initial analysis at the point
/// delete-expression was encountered.
explicit MismatchingNewDeleteDetector(bool EndOfTU)
    : Field(nullptr), IsArrayForm(false), EndOfTU(EndOfTU),
      HasUndefinedConstructors(false) {}

/// Checks whether pointee of a delete-expression is initialized with
/// matching form of new-expression.
///
/// If return value is \c VarInitMismatches or \c MemberInitMismatches at the
/// point where delete-expression is encountered, then a warning will be
/// issued immediately. If return value is \c AnalyzeLater at the point where
/// delete-expression is seen, then member will be analyzed at the end of
/// translation unit. \c AnalyzeLater is returned iff at least one constructor
/// couldn't be analyzed. If at least one constructor initializes the member
/// with matching type of new, the return value is \c NoMismatch.
MismatchResult analyzeDeleteExpr(const CXXDeleteExpr *DE);
/// Analyzes a class member.
/// \param Field Class member to analyze.
/// \param DeleteWasArrayForm Array form-ness of the delete-expression used
/// for deleting the \p Field.
MismatchResult analyzeField(FieldDecl *Field, bool DeleteWasArrayForm);
FieldDecl *Field;
/// List of mismatching new-expressions used for initialization of the pointee
llvm::SmallVector<const CXXNewExpr *, 4> NewExprs;
/// Indicates whether delete-expression was in array form.
bool IsArrayForm;

3258private:
const bool EndOfTU;
/// Indicates that there is at least one constructor without body.
bool HasUndefinedConstructors;
/// Returns \c CXXNewExpr from given initialization expression.
/// \param E Expression used for initializing pointee in delete-expression.
/// E can be a single-element \c InitListExpr consisting of new-expression.
const CXXNewExpr *getNewExprFromInitListOrExpr(const Expr *E);
/// Returns whether member is initialized with mismatching form of
/// \c new either by the member initializer or in-class initialization.
///
/// If bodies of all constructors are not visible at the end of translation
/// unit or at least one constructor initializes member with the matching
/// form of \c new, mismatch cannot be proven, and this function will return
/// \c NoMismatch.
MismatchResult analyzeMemberExpr(const MemberExpr *ME);
/// Returns whether variable is initialized with mismatching form of
/// \c new.
///
/// If variable is initialized with matching form of \c new or variable is not
/// initialized with a \c new expression, this function will return true.
/// If variable is initialized with mismatching form of \c new, returns false.
/// \param D Variable to analyze.
bool hasMatchingVarInit(const DeclRefExpr *D);
/// Checks whether the constructor initializes pointee with mismatching
/// form of \c new.
///
/// Returns true, if member is initialized with matching form of \c new in
/// member initializer list. Returns false, if member is initialized with the
/// matching form of \c new in this constructor's initializer or given
/// constructor isn't defined at the point where delete-expression is seen, or
/// member isn't initialized by the constructor.
bool hasMatchingNewInCtor(const CXXConstructorDecl *CD);
/// Checks whether member is initialized with matching form of
/// \c new in member initializer list.
bool hasMatchingNewInCtorInit(const CXXCtorInitializer *CI);
/// Checks whether member is initialized with mismatching form of \c new by
/// in-class initializer.
MismatchResult analyzeInClassInitializer();
3297};
3298}

3300MismatchingNewDeleteDetector::MismatchResult
3301MismatchingNewDeleteDetector::analyzeDeleteExpr(const CXXDeleteExpr *DE) {
NewExprs.clear();
assert(DE && "Expected delete-expression")(static_cast<void> (0));
IsArrayForm = DE->isArrayForm();
const Expr *E = DE->getArgument()->IgnoreParenImpCasts();
if (const MemberExpr *ME = dyn_cast<const MemberExpr>(E)) {
  return analyzeMemberExpr(ME);
} else if (const DeclRefExpr *D = dyn_cast<const DeclRefExpr>(E)) {
  if (!hasMatchingVarInit(D))
    return VarInitMismatches;
}
return NoMismatch;
3313}

3315const CXXNewExpr *
3316MismatchingNewDeleteDetector::getNewExprFromInitListOrExpr(const Expr *E) {
assert(E != nullptr && "Expected a valid initializer expression")(static_cast<void> (0));
E = E->IgnoreParenImpCasts();
if (const InitListExpr *ILE = dyn_cast<const InitListExpr>(E)) {
  if (ILE->getNumInits() == 1)
    E = dyn_cast<const CXXNewExpr>(ILE->getInit(0)->IgnoreParenImpCasts());
}

return dyn_cast_or_null<const CXXNewExpr>(E);
3325}

3327bool MismatchingNewDeleteDetector::hasMatchingNewInCtorInit(
  const CXXCtorInitializer *CI) {
const CXXNewExpr *NE = nullptr;
if (Field == CI->getMember() &&
    (NE = getNewExprFromInitListOrExpr(CI->getInit()))) {
  if (NE->isArray() == IsArrayForm)
    return true;
  else
    NewExprs.push_back(NE);
}
return false;
3338}

3340bool MismatchingNewDeleteDetector::hasMatchingNewInCtor(
  const CXXConstructorDecl *CD) {
if (CD->isImplicit())
  return false;
const FunctionDecl *Definition = CD;
if (!CD->isThisDeclarationADefinition() && !CD->isDefined(Definition)) {
  HasUndefinedConstructors = true;
  return EndOfTU;
}
for (const auto *CI : cast<const CXXConstructorDecl>(Definition)->inits()) {
  if (hasMatchingNewInCtorInit(CI))
    return true;
}
return false;
3354}

3356MismatchingNewDeleteDetector::MismatchResult
3357MismatchingNewDeleteDetector::analyzeInClassInitializer() {
assert(Field != nullptr && "This should be called only for members")(static_cast<void> (0));
const Expr *InitExpr = Field->getInClassInitializer();
if (!InitExpr)
  return EndOfTU ? NoMismatch : AnalyzeLater;
if (const CXXNewExpr *NE = getNewExprFromInitListOrExpr(InitExpr)) {
  if (NE->isArray() != IsArrayForm) {
    NewExprs.push_back(NE);
    return MemberInitMismatches;
  }
}
return NoMismatch;
3369}

3371MismatchingNewDeleteDetector::MismatchResult
3372MismatchingNewDeleteDetector::analyzeField(FieldDecl *Field,
                                         bool DeleteWasArrayForm) {
assert(Field != nullptr && "Analysis requires a valid class member.")(static_cast<void> (0));
this->Field = Field;
IsArrayForm = DeleteWasArrayForm;
const CXXRecordDecl *RD = cast<const CXXRecordDecl>(Field->getParent());
for (const auto *CD : RD->ctors()) {
  if (hasMatchingNewInCtor(CD))
    return NoMismatch;
}
if (HasUndefinedConstructors)
  return EndOfTU ? NoMismatch : AnalyzeLater;
if (!NewExprs.empty())
  return MemberInitMismatches;
return Field->hasInClassInitializer() ? analyzeInClassInitializer()
                                      : NoMismatch;
3388}

3390MismatchingNewDeleteDetector::MismatchResult
3391MismatchingNewDeleteDetector::analyzeMemberExpr(const MemberExpr *ME) {
assert(ME != nullptr && "Expected a member expression")(static_cast<void> (0));
if (FieldDecl *F = dyn_cast<FieldDecl>(ME->getMemberDecl()))
  return analyzeField(F, IsArrayForm);
return NoMismatch;
3396}

3398bool MismatchingNewDeleteDetector::hasMatchingVarInit(const DeclRefExpr *D) {
const CXXNewExpr *NE = nullptr;
if (const VarDecl *VD = dyn_cast<const VarDecl>(D->getDecl())) {
  if (VD->hasInit() && (NE = getNewExprFromInitListOrExpr(VD->getInit())) &&
      NE->isArray() != IsArrayForm) {
    NewExprs.push_back(NE);
  }
}
return NewExprs.empty();
3407}

3409static void
3410DiagnoseMismatchedNewDelete(Sema &SemaRef, SourceLocation DeleteLoc,
                          const MismatchingNewDeleteDetector &Detector) {
SourceLocation EndOfDelete = SemaRef.getLocForEndOfToken(DeleteLoc);
FixItHint H;
if (!Detector.IsArrayForm)
  H = FixItHint::CreateInsertion(EndOfDelete, "[]");
else {
  SourceLocation RSquare = Lexer::findLocationAfterToken(
      DeleteLoc, tok::l_square, SemaRef.getSourceManager(),
      SemaRef.getLangOpts(), true);
  if (RSquare.isValid())
    H = FixItHint::CreateRemoval(SourceRange(EndOfDelete, RSquare));
}
SemaRef.Diag(DeleteLoc, diag::warn_mismatched_delete_new)
    << Detector.IsArrayForm << H;

for (const auto *NE : Detector.NewExprs)
  SemaRef.Diag(NE->getExprLoc(), diag::note_allocated_here)
      << Detector.IsArrayForm;
3429}

3431void Sema::AnalyzeDeleteExprMismatch(const CXXDeleteExpr *DE) {
if (Diags.isIgnored(diag::warn_mismatched_delete_new, SourceLocation()))
  return;
MismatchingNewDeleteDetector Detector(/*EndOfTU=*/false);
switch (Detector.analyzeDeleteExpr(DE)) {
case MismatchingNewDeleteDetector::VarInitMismatches:
case MismatchingNewDeleteDetector::MemberInitMismatches: {
  DiagnoseMismatchedNewDelete(*this, DE->getBeginLoc(), Detector);
  break;
}
case MismatchingNewDeleteDetector::AnalyzeLater: {
  DeleteExprs[Detector.Field].push_back(
      std::make_pair(DE->getBeginLoc(), DE->isArrayForm()));
  break;
}
case MismatchingNewDeleteDetector::NoMismatch:
  break;
}
3449}

3451void Sema::AnalyzeDeleteExprMismatch(FieldDecl *Field, SourceLocation DeleteLoc,
                                   bool DeleteWasArrayForm) {
MismatchingNewDeleteDetector Detector(/*EndOfTU=*/true);
switch (Detector.analyzeField(Field, DeleteWasArrayForm)) {
case MismatchingNewDeleteDetector::VarInitMismatches:
  llvm_unreachable("This analysis should have been done for class members.")__builtin_unreachable();
case MismatchingNewDeleteDetector::AnalyzeLater:
  llvm_unreachable("Analysis cannot be postponed any point beyond end of "__builtin_unreachable()
                   "translation unit.")__builtin_unreachable();
case MismatchingNewDeleteDetector::MemberInitMismatches:
  DiagnoseMismatchedNewDelete(*this, DeleteLoc, Detector);
  break;
case MismatchingNewDeleteDetector::NoMismatch:
  break;
}
3466}

3468/// ActOnCXXDelete - Parsed a C++ 'delete' expression (C++ 5.3.5), as in:
3469/// @code ::delete ptr; @endcode
3470/// or
3471/// @code delete [] ptr; @endcode
3472ExprResult
3473Sema::ActOnCXXDelete(SourceLocation StartLoc, bool UseGlobal,
                   bool ArrayForm, Expr *ExE) {
// C++ [expr.delete]p1:
//   The operand shall have a pointer type, or a class type having a single
//   non-explicit conversion function to a pointer type. The result has type
//   void.
//
// DR599 amends "pointer type" to "pointer to object type" in both cases.

ExprResult Ex = ExE;
FunctionDecl *OperatorDelete = nullptr;
bool ArrayFormAsWritten = ArrayForm;
bool UsualArrayDeleteWantsSize = false;

if (!Ex.get()->isTypeDependent()) {
  // Perform lvalue-to-rvalue cast, if needed.
  Ex = DefaultLvalueConversion(Ex.get());
  if (Ex.isInvalid())
    return ExprError();

  QualType Type = Ex.get()->getType();

  class DeleteConverter : public ContextualImplicitConverter {
  public:
    DeleteConverter() : ContextualImplicitConverter(false, true) {}

    bool match(QualType ConvType) override {
      // FIXME: If we have an operator T* and an operator void*, we must pick
      // the operator T*.
      if (const PointerType *ConvPtrType = ConvType->getAs<PointerType>())
        if (ConvPtrType->getPointeeType()->isIncompleteOrObjectType())
          return true;
      return false;
    }

    SemaDiagnosticBuilder diagnoseNoMatch(Sema &S, SourceLocation Loc,
                                          QualType T) override {
      return S.Diag(Loc, diag::err_delete_operand) << T;
    }

    SemaDiagnosticBuilder diagnoseIncomplete(Sema &S, SourceLocation Loc,
                                             QualType T) override {
      return S.Diag(Loc, diag::err_delete_incomplete_class_type) << T;
    }

    SemaDiagnosticBuilder diagnoseExplicitConv(Sema &S, SourceLocation Loc,
                                               QualType T,
                                               QualType ConvTy) override {
      return S.Diag(Loc, diag::err_delete_explicit_conversion) << T << ConvTy;
    }

    SemaDiagnosticBuilder noteExplicitConv(Sema &S, CXXConversionDecl *Conv,
                                           QualType ConvTy) override {
      return S.Diag(Conv->getLocation(), diag::note_delete_conversion)
        << ConvTy;
    }

    SemaDiagnosticBuilder diagnoseAmbiguous(Sema &S, SourceLocation Loc,
                                            QualType T) override {
      return S.Diag(Loc, diag::err_ambiguous_delete_operand) << T;
    }

    SemaDiagnosticBuilder noteAmbiguous(Sema &S, CXXConversionDecl *Conv,
                                        QualType ConvTy) override {
      return S.Diag(Conv->getLocation(), diag::note_delete_conversion)
        << ConvTy;
    }

    SemaDiagnosticBuilder diagnoseConversion(Sema &S, SourceLocation Loc,
                                             QualType T,
                                             QualType ConvTy) override {
      llvm_unreachable("conversion functions are permitted")__builtin_unreachable();
    }
  } Converter;

  Ex = PerformContextualImplicitConversion(StartLoc, Ex.get(), Converter);
  if (Ex.isInvalid())
    return ExprError();
  Type = Ex.get()->getType();
  if (!Converter.match(Type))
    // FIXME: PerformContextualImplicitConversion should return ExprError
    //        itself in this case.
    return ExprError();

  QualType Pointee = Type->castAs<PointerType>()->getPointeeType();
  QualType PointeeElem = Context.getBaseElementType(Pointee);

  if (Pointee.getAddressSpace() != LangAS::Default &&
      !getLangOpts().OpenCLCPlusPlus)
    return Diag(Ex.get()->getBeginLoc(),
                diag::err_address_space_qualified_delete)
           << Pointee.getUnqualifiedType()
           << Pointee.getQualifiers().getAddressSpaceAttributePrintValue();

  CXXRecordDecl *PointeeRD = nullptr;
  if (Pointee->isVoidType() && !isSFINAEContext()) {
    // The C++ standard bans deleting a pointer to a non-object type, which
    // effectively bans deletion of "void*". However, most compilers support
    // this, so we treat it as a warning unless we're in a SFINAE context.
    Diag(StartLoc, diag::ext_delete_void_ptr_operand)
      << Type << Ex.get()->getSourceRange();
  } else if (Pointee->isFunctionType() || Pointee->isVoidType() ||
             Pointee->isSizelessType()) {
    return ExprError(Diag(StartLoc, diag::err_delete_operand)
      << Type << Ex.get()->getSourceRange());
  } else if (!Pointee->isDependentType()) {
    // FIXME: This can result in errors if the definition was imported from a
    // module but is hidden.
    if (!RequireCompleteType(StartLoc, Pointee,
                             diag::warn_delete_incomplete, Ex.get())) {
      if (const RecordType *RT = PointeeElem->getAs<RecordType>())
        PointeeRD = cast<CXXRecordDecl>(RT->getDecl());
    }
  }

  if (Pointee->isArrayType() && !ArrayForm) {
    Diag(StartLoc, diag::warn_delete_array_type)
        << Type << Ex.get()->getSourceRange()
        << FixItHint::CreateInsertion(getLocForEndOfToken(StartLoc), "[]");
    ArrayForm = true;
  }

  DeclarationName DeleteName = Context.DeclarationNames.getCXXOperatorName(
                                    ArrayForm ? OO_Array_Delete : OO_Delete);

  if (PointeeRD) {
    if (!UseGlobal &&
        FindDeallocationFunction(StartLoc, PointeeRD, DeleteName,
                                 OperatorDelete))
      return ExprError();

    // If we're allocating an array of records, check whether the
    // usual operator delete[] has a size_t parameter.
    if (ArrayForm) {
      // If the user specifically asked to use the global allocator,
      // we'll need to do the lookup into the class.
      if (UseGlobal)
        UsualArrayDeleteWantsSize =
          doesUsualArrayDeleteWantSize(*this, StartLoc, PointeeElem);

      // Otherwise, the usual operator delete[] should be the
      // function we just found.
      else if (OperatorDelete && isa<CXXMethodDecl>(OperatorDelete))
        UsualArrayDeleteWantsSize =
          UsualDeallocFnInfo(*this,
                             DeclAccessPair::make(OperatorDelete, AS_public))
            .HasSizeT;
    }

    if (!PointeeRD->hasIrrelevantDestructor())
      if (CXXDestructorDecl *Dtor = LookupDestructor(PointeeRD)) {
        MarkFunctionReferenced(StartLoc,
                                  const_cast<CXXDestructorDecl*>(Dtor));
        if (DiagnoseUseOfDecl(Dtor, StartLoc))
          return ExprError();
      }

    CheckVirtualDtorCall(PointeeRD->getDestructor(), StartLoc,
                         /*IsDelete=*/true, /*CallCanBeVirtual=*/true,
                         /*WarnOnNonAbstractTypes=*/!ArrayForm,
                         SourceLocation());
  }

  if (!OperatorDelete) {
    if (getLangOpts().OpenCLCPlusPlus) {
      Diag(StartLoc, diag::err_openclcxx_not_supported) << "default delete";
      return ExprError();
    }

    bool IsComplete = isCompleteType(StartLoc, Pointee);
    bool CanProvideSize =
        IsComplete && (!ArrayForm || UsualArrayDeleteWantsSize ||
                       Pointee.isDestructedType());
    bool Overaligned = hasNewExtendedAlignment(*this, Pointee);

    // Look for a global declaration.
    OperatorDelete = FindUsualDeallocationFunction(StartLoc, CanProvideSize,
                                                   Overaligned, DeleteName);
  }

  MarkFunctionReferenced(StartLoc, OperatorDelete);

  // Check access and ambiguity of destructor if we're going to call it.
  // Note that this is required even for a virtual delete.
  bool IsVirtualDelete = false;
  if (PointeeRD) {
    if (CXXDestructorDecl *Dtor = LookupDestructor(PointeeRD)) {
      CheckDestructorAccess(Ex.get()->getExprLoc(), Dtor,
                            PDiag(diag::err_access_dtor) << PointeeElem);
      IsVirtualDelete = Dtor->isVirtual();
    }
  }

  DiagnoseUseOfDecl(OperatorDelete, StartLoc);

  // Convert the operand to the type of the first parameter of operator
  // delete. This is only necessary if we selected a destroying operator
  // delete that we are going to call (non-virtually); converting to void*
  // is trivial and left to AST consumers to handle.
  QualType ParamType = OperatorDelete->getParamDecl(0)->getType();
  if (!IsVirtualDelete && !ParamType->getPointeeType()->isVoidType()) {
    Qualifiers Qs = Pointee.getQualifiers();
    if (Qs.hasCVRQualifiers()) {
      // Qualifiers are irrelevant to this conversion; we're only looking
      // for access and ambiguity.
      Qs.removeCVRQualifiers();
      QualType Unqual = Context.getPointerType(
          Context.getQualifiedType(Pointee.getUnqualifiedType(), Qs));
      Ex = ImpCastExprToType(Ex.get(), Unqual, CK_NoOp);
    }
    Ex = PerformImplicitConversion(Ex.get(), ParamType, AA_Passing);
    if (Ex.isInvalid())
      return ExprError();
  }
}

CXXDeleteExpr *Result = new (Context) CXXDeleteExpr(
    Context.VoidTy, UseGlobal, ArrayForm, ArrayFormAsWritten,
    UsualArrayDeleteWantsSize, OperatorDelete, Ex.get(), StartLoc);
AnalyzeDeleteExprMismatch(Result);
return Result;
3694}

3696static bool resolveBuiltinNewDeleteOverload(Sema &S, CallExpr *TheCall,
                                          bool IsDelete,
                                          FunctionDecl *&Operator) {

DeclarationName NewName = S.Context.DeclarationNames.getCXXOperatorName(
    IsDelete ? OO_Delete : OO_New);
5
←
Assuming 'IsDelete' is false→
6
←
'?' condition is false→

LookupResult R(S, NewName, TheCall->getBeginLoc(), Sema::LookupOrdinaryName);
S.LookupQualifiedName(R, S.Context.getTranslationUnitDecl());
assert(!R.empty() && "implicitly declared allocation functions not found")(static_cast<void> (0));
assert(!R.isAmbiguous() && "global allocation functions are ambiguous")(static_cast<void> (0));

// We do our own custom access checks below.
R.suppressDiagnostics();

SmallVector<Expr *, 8> Args(TheCall->arg_begin(), TheCall->arg_end());
OverloadCandidateSet Candidates(R.getNameLoc(),
                                OverloadCandidateSet::CSK_Normal);
for (LookupResult::iterator FnOvl = R.begin(), FnOvlEnd = R.end();
7
←
Loop condition is false. Execution continues on line 3733→
     FnOvl != FnOvlEnd; ++FnOvl) {
  // Even member operator new/delete are implicitly treated as
  // static, so don't use AddMemberCandidate.
  NamedDecl *D = (*FnOvl)->getUnderlyingDecl();

  if (FunctionTemplateDecl *FnTemplate = dyn_cast<FunctionTemplateDecl>(D)) {
    S.AddTemplateOverloadCandidate(FnTemplate, FnOvl.getPair(),
                                   /*ExplicitTemplateArgs=*/nullptr, Args,
                                   Candidates,
                                   /*SuppressUserConversions=*/false);
    continue;
  }

  FunctionDecl *Fn = cast<FunctionDecl>(D);
  S.AddOverloadCandidate(Fn, FnOvl.getPair(), Args, Candidates,
                         /*SuppressUserConversions=*/false);
}

SourceRange Range = TheCall->getSourceRange();

// Do the resolution.
OverloadCandidateSet::iterator Best;
switch (Candidates.BestViableFunction(S, R.getNameLoc(), Best)) {
8
←
Control jumps to 'case OR_Success:'  at line 3738→
case OR_Success: {
  // Got one!
  FunctionDecl *FnDecl = Best->Function;
  assert(R.getNamingClass() == nullptr &&(static_cast<void> (0))
         "class members should not be considered")(static_cast<void> (0));

  if (!FnDecl->isReplaceableGlobalAllocationFunction()) {
9
←
Assuming the condition is false→
10
←
Taking false branch→
    S.Diag(R.getNameLoc(), diag::err_builtin_operator_new_delete_not_usual)
        << (IsDelete ? 1 : 0) << Range;
    S.Diag(FnDecl->getLocation(), diag::note_non_usual_function_declared_here)
        << R.getLookupName() << FnDecl->getSourceRange();
    return true;
  }

  Operator = FnDecl;
  return false;
11
←
Returning zero, which participates in a condition later→
}

case OR_No_Viable_Function:
  Candidates.NoteCandidates(
      PartialDiagnosticAt(R.getNameLoc(),
                          S.PDiag(diag::err_ovl_no_viable_function_in_call)
                              << R.getLookupName() << Range),
      S, OCD_AllCandidates, Args);
  return true;

case OR_Ambiguous:
  Candidates.NoteCandidates(
      PartialDiagnosticAt(R.getNameLoc(),
                          S.PDiag(diag::err_ovl_ambiguous_call)
                              << R.getLookupName() << Range),
      S, OCD_AmbiguousCandidates, Args);
  return true;

case OR_Deleted: {
  Candidates.NoteCandidates(
      PartialDiagnosticAt(R.getNameLoc(), S.PDiag(diag::err_ovl_deleted_call)
                                              << R.getLookupName() << Range),
      S, OCD_AllCandidates, Args);
  return true;
}
}
llvm_unreachable("Unreachable, bad result from BestViableFunction")__builtin_unreachable();
3781}

3783ExprResult
3784Sema::SemaBuiltinOperatorNewDeleteOverloaded(ExprResult TheCallResult,
                                           bool IsDelete) {
CallExpr *TheCall = cast<CallExpr>(TheCallResult.get());
1
The object is a 'CallExpr'→
if (!getLangOpts().CPlusPlus) {
2
←
Assuming field 'CPlusPlus' is not equal to 0→
3
←
Taking false branch→
  Diag(TheCall->getExprLoc(), diag::err_builtin_requires_language)
      << (IsDelete ? "__builtin_operator_delete" : "__builtin_operator_new")
      << "C++";
  return ExprError();
}
// CodeGen assumes it can find the global new and delete to call,
// so ensure that they are declared.
DeclareGlobalNewDelete();

FunctionDecl *OperatorNewOrDelete = nullptr;
if (resolveBuiltinNewDeleteOverload(*this, TheCall, IsDelete,
4
←
Calling 'resolveBuiltinNewDeleteOverload'→
12
←
Returning from 'resolveBuiltinNewDeleteOverload'→
13
←
Taking false branch→
                                    OperatorNewOrDelete))
  return ExprError();
assert(OperatorNewOrDelete && "should be found")(static_cast<void> (0));

DiagnoseUseOfDecl(OperatorNewOrDelete, TheCall->getExprLoc());
MarkFunctionReferenced(TheCall->getExprLoc(), OperatorNewOrDelete);

TheCall->setType(OperatorNewOrDelete->getReturnType());
for (unsigned i = 0; i != TheCall->getNumArgs(); ++i) {
14
←
Assuming the condition is false→
15
←
Loop condition is false. Execution continues on line 3817→
  QualType ParamTy = OperatorNewOrDelete->getParamDecl(i)->getType();
  InitializedEntity Entity =
      InitializedEntity::InitializeParameter(Context, ParamTy, false);
  ExprResult Arg = PerformCopyInitialization(
      Entity, TheCall->getArg(i)->getBeginLoc(), TheCall->getArg(i));
  if (Arg.isInvalid())
    return ExprError();
  TheCall->setArg(i, Arg.get());
}
auto Callee = dyn_cast<ImplicitCastExpr>(TheCall->getCallee());
16
←
Assuming the object is not a 'ImplicitCastExpr'→
17
←
'Callee' initialized to a null pointer value→
assert(Callee && Callee->getCastKind() == CK_BuiltinFnToFnPtr &&(static_cast<void> (0))
       "Callee expected to be implicit cast to a builtin function pointer")(static_cast<void> (0));
Callee->setType(OperatorNewOrDelete->getType());
18
←
Called C++ object pointer is null

return TheCallResult;
3823}

3825void Sema::CheckVirtualDtorCall(CXXDestructorDecl *dtor, SourceLocation Loc,
                              bool IsDelete, bool CallCanBeVirtual,
                              bool WarnOnNonAbstractTypes,
                              SourceLocation DtorLoc) {
if (!dtor || dtor->isVirtual() || !CallCanBeVirtual || isUnevaluatedContext())
  return;

// C++ [expr.delete]p3:
//   In the first alternative (delete object), if the static type of the
//   object to be deleted is different from its dynamic type, the static
//   type shall be a base class of the dynamic type of the object to be
//   deleted and the static type shall have a virtual destructor or the
//   behavior is undefined.
//
const CXXRecordDecl *PointeeRD = dtor->getParent();
// Note: a final class cannot be derived from, no issue there
if (!PointeeRD->isPolymorphic() || PointeeRD->hasAttr<FinalAttr>())
  return;

// If the superclass is in a system header, there's nothing that can be done.
// The `delete` (where we emit the warning) can be in a system header,
// what matters for this warning is where the deleted type is defined.
if (getSourceManager().isInSystemHeader(PointeeRD->getLocation()))
  return;

QualType ClassType = dtor->getThisType()->getPointeeType();
if (PointeeRD->isAbstract()) {
  // If the class is abstract, we warn by default, because we're
  // sure the code has undefined behavior.
  Diag(Loc, diag::warn_delete_abstract_non_virtual_dtor) << (IsDelete ? 0 : 1)
                                                         << ClassType;
} else if (WarnOnNonAbstractTypes) {
  // Otherwise, if this is not an array delete, it's a bit suspect,
  // but not necessarily wrong.
  Diag(Loc, diag::warn_delete_non_virtual_dtor) << (IsDelete ? 0 : 1)
                                                << ClassType;
}
if (!IsDelete) {
  std::string TypeStr;
  ClassType.getAsStringInternal(TypeStr, getPrintingPolicy());
  Diag(DtorLoc, diag::note_delete_non_virtual)
      << FixItHint::CreateInsertion(DtorLoc, TypeStr + "::");
}
3868}

3870Sema::ConditionResult Sema::ActOnConditionVariable(Decl *ConditionVar,
                                                 SourceLocation StmtLoc,
                                                 ConditionKind CK) {
ExprResult E =
    CheckConditionVariable(cast<VarDecl>(ConditionVar), StmtLoc, CK);
if (E.isInvalid())
  return ConditionError();
return ConditionResult(*this, ConditionVar, MakeFullExpr(E.get(), StmtLoc),
                       CK == ConditionKind::ConstexprIf);
3879}

3881/// Check the use of the given variable as a C++ condition in an if,
3882/// while, do-while, or switch statement.
3883ExprResult Sema::CheckConditionVariable(VarDecl *ConditionVar,
                                      SourceLocation StmtLoc,
                                      ConditionKind CK) {
if (ConditionVar->isInvalidDecl())
  return ExprError();

QualType T = ConditionVar->getType();

// C++ [stmt.select]p2:
//   The declarator shall not specify a function or an array.
if (T->isFunctionType())
  return ExprError(Diag(ConditionVar->getLocation(),
                        diag::err_invalid_use_of_function_type)
                     << ConditionVar->getSourceRange());
else if (T->isArrayType())
  return ExprError(Diag(ConditionVar->getLocation(),
                        diag::err_invalid_use_of_array_type)
                   << ConditionVar->getSourceRange());

ExprResult Condition = BuildDeclRefExpr(
    ConditionVar, ConditionVar->getType().getNonReferenceType(), VK_LValue,
    ConditionVar->getLocation());

switch (CK) {
case ConditionKind::Boolean:
  return CheckBooleanCondition(StmtLoc, Condition.get());

case ConditionKind::ConstexprIf:
  return CheckBooleanCondition(StmtLoc, Condition.get(), true);

case ConditionKind::Switch:
  return CheckSwitchCondition(StmtLoc, Condition.get());
}

llvm_unreachable("unexpected condition kind")__builtin_unreachable();
3918}

3920/// CheckCXXBooleanCondition - Returns true if a conversion to bool is invalid.
3921ExprResult Sema::CheckCXXBooleanCondition(Expr *CondExpr, bool IsConstexpr) {
// C++11 6.4p4:
// The value of a condition that is an initialized declaration in a statement
// other than a switch statement is the value of the declared variable
// implicitly converted to type bool. If that conversion is ill-formed, the
// program is ill-formed.
// The value of a condition that is an expression is the value of the
// expression, implicitly converted to bool.
//
// C++2b 8.5.2p2
// If the if statement is of the form if constexpr, the value of the condition
// is contextually converted to bool and the converted expression shall be
// a constant expression.
//

ExprResult E = PerformContextuallyConvertToBool(CondExpr);
if (!IsConstexpr || E.isInvalid() || E.get()->isValueDependent())
  return E;

// FIXME: Return this value to the caller so they don't need to recompute it.
llvm::APSInt Cond;
E = VerifyIntegerConstantExpression(
    E.get(), &Cond,
    diag::err_constexpr_if_condition_expression_is_not_constant);
return E;
3946}

3948/// Helper function to determine whether this is the (deprecated) C++
3949/// conversion from a string literal to a pointer to non-const char or
3950/// non-const wchar_t (for narrow and wide string literals,
3951/// respectively).
3952bool
3953Sema::IsStringLiteralToNonConstPointerConversion(Expr *From, QualType ToType) {
// Look inside the implicit cast, if it exists.
if (ImplicitCastExpr *Cast = dyn_cast<ImplicitCastExpr>(From))
  From = Cast->getSubExpr();

// A string literal (2.13.4) that is not a wide string literal can
// be converted to an rvalue of type "pointer to char"; a wide
// string literal can be converted to an rvalue of type "pointer
// to wchar_t" (C++ 4.2p2).
if (StringLiteral *StrLit = dyn_cast<StringLiteral>(From->IgnoreParens()))
  if (const PointerType *ToPtrType = ToType->getAs<PointerType>())
    if (const BuiltinType *ToPointeeType
        = ToPtrType->getPointeeType()->getAs<BuiltinType>()) {
      // This conversion is considered only when there is an
      // explicit appropriate pointer target type (C++ 4.2p2).
      if (!ToPtrType->getPointeeType().hasQualifiers()) {
        switch (StrLit->getKind()) {
          case StringLiteral::UTF8:
          case StringLiteral::UTF16:
          case StringLiteral::UTF32:
            // We don't allow UTF literals to be implicitly converted
            break;
          case StringLiteral::Ascii:
            return (ToPointeeType->getKind() == BuiltinType::Char_U ||
                    ToPointeeType->getKind() == BuiltinType::Char_S);
          case StringLiteral::Wide:
            return Context.typesAreCompatible(Context.getWideCharType(),
                                              QualType(ToPointeeType, 0));
        }
      }
    }

return false;
3986}

3988static ExprResult BuildCXXCastArgument(Sema &S,
                                     SourceLocation CastLoc,
                                     QualType Ty,
                                     CastKind Kind,
                                     CXXMethodDecl *Method,
                                     DeclAccessPair FoundDecl,
                                     bool HadMultipleCandidates,
                                     Expr *From) {
switch (Kind) {
default: llvm_unreachable("Unhandled cast kind!")__builtin_unreachable();
case CK_ConstructorConversion: {
  CXXConstructorDecl *Constructor = cast<CXXConstructorDecl>(Method);
  SmallVector<Expr*, 8> ConstructorArgs;

  if (S.RequireNonAbstractType(CastLoc, Ty,
                               diag::err_allocation_of_abstract_type))
    return ExprError();

  if (S.CompleteConstructorCall(Constructor, Ty, From, CastLoc,
                                ConstructorArgs))
    return ExprError();

  S.CheckConstructorAccess(CastLoc, Constructor, FoundDecl,
                           InitializedEntity::InitializeTemporary(Ty));
  if (S.DiagnoseUseOfDecl(Method, CastLoc))
    return ExprError();

  ExprResult Result = S.BuildCXXConstructExpr(
      CastLoc, Ty, FoundDecl, cast<CXXConstructorDecl>(Method),
      ConstructorArgs, HadMultipleCandidates,
      /*ListInit*/ false, /*StdInitListInit*/ false, /*ZeroInit*/ false,
      CXXConstructExpr::CK_Complete, SourceRange());
  if (Result.isInvalid())
    return ExprError();

  return S.MaybeBindToTemporary(Result.getAs<Expr>());
}

case CK_UserDefinedConversion: {
  assert(!From->getType()->isPointerType() && "Arg can't have pointer type!")(static_cast<void> (0));

  S.CheckMemberOperatorAccess(CastLoc, From, /*arg*/ nullptr, FoundDecl);
  if (S.DiagnoseUseOfDecl(Method, CastLoc))
    return ExprError();

  // Create an implicit call expr that calls it.
  CXXConversionDecl *Conv = cast<CXXConversionDecl>(Method);
  ExprResult Result = S.BuildCXXMemberCallExpr(From, FoundDecl, Conv,
                                               HadMultipleCandidates);
  if (Result.isInvalid())
    return ExprError();
  // Record usage of conversion in an implicit cast.
  Result = ImplicitCastExpr::Create(S.Context, Result.get()->getType(),
                                    CK_UserDefinedConversion, Result.get(),
                                    nullptr, Result.get()->getValueKind(),
                                    S.CurFPFeatureOverrides());

  return S.MaybeBindToTemporary(Result.get());
}
}
4048}

4050/// PerformImplicitConversion - Perform an implicit conversion of the
4051/// expression From to the type ToType using the pre-computed implicit
4052/// conversion sequence ICS. Returns the converted
4053/// expression. Action is the kind of conversion we're performing,
4054/// used in the error message.
4055ExprResult
4056Sema::PerformImplicitConversion(Expr *From, QualType ToType,
                              const ImplicitConversionSequence &ICS,
                              AssignmentAction Action,
                              CheckedConversionKind CCK) {
// C++ [over.match.oper]p7: [...] operands of class type are converted [...]
if (CCK == CCK_ForBuiltinOverloadedOp && !From->getType()->isRecordType())
  return From;

switch (ICS.getKind()) {
case ImplicitConversionSequence::StandardConversion: {
  ExprResult Res = PerformImplicitConversion(From, ToType, ICS.Standard,
                                             Action, CCK);
  if (Res.isInvalid())
    return ExprError();
  From = Res.get();
  break;
}

case ImplicitConversionSequence::UserDefinedConversion: {

    FunctionDecl *FD = ICS.UserDefined.ConversionFunction;
    CastKind CastKind;
    QualType BeforeToType;
    assert(FD && "no conversion function for user-defined conversion seq")(static_cast<void> (0));
    if (const CXXConversionDecl *Conv = dyn_cast<CXXConversionDecl>(FD)) {
      CastKind = CK_UserDefinedConversion;

      // If the user-defined conversion is specified by a conversion function,
      // the initial standard conversion sequence converts the source type to
      // the implicit object parameter of the conversion function.
      BeforeToType = Context.getTagDeclType(Conv->getParent());
    } else {
      const CXXConstructorDecl *Ctor = cast<CXXConstructorDecl>(FD);
      CastKind = CK_ConstructorConversion;
      // Do no conversion if dealing with ... for the first conversion.
      if (!ICS.UserDefined.EllipsisConversion) {
        // If the user-defined conversion is specified by a constructor, the
        // initial standard conversion sequence converts the source type to
        // the type required by the argument of the constructor
        BeforeToType = Ctor->getParamDecl(0)->getType().getNonReferenceType();
      }
    }
    // Watch out for ellipsis conversion.
    if (!ICS.UserDefined.EllipsisConversion) {
      ExprResult Res =
        PerformImplicitConversion(From, BeforeToType,
                                  ICS.UserDefined.Before, AA_Converting,
                                  CCK);
      if (Res.isInvalid())
        return ExprError();
      From = Res.get();
    }

    ExprResult CastArg = BuildCXXCastArgument(
        *this, From->getBeginLoc(), ToType.getNonReferenceType(), CastKind,
        cast<CXXMethodDecl>(FD), ICS.UserDefined.FoundConversionFunction,
        ICS.UserDefined.HadMultipleCandidates, From);

    if (CastArg.isInvalid())
      return ExprError();

    From = CastArg.get();

    // C++ [over.match.oper]p7:
    //   [...] the second standard conversion sequence of a user-defined
    //   conversion sequence is not applied.
    if (CCK == CCK_ForBuiltinOverloadedOp)
      return From;

    return PerformImplicitConversion(From, ToType, ICS.UserDefined.After,
                                     AA_Converting, CCK);
}

case ImplicitConversionSequence::AmbiguousConversion:
  ICS.DiagnoseAmbiguousConversion(*this, From->getExprLoc(),
                        PDiag(diag::err_typecheck_ambiguous_condition)
                          << From->getSourceRange());
  return ExprError();

case ImplicitConversionSequence::EllipsisConversion:
  llvm_unreachable("Cannot perform an ellipsis conversion")__builtin_unreachable();

case ImplicitConversionSequence::BadConversion:
  Sema::AssignConvertType ConvTy =
      CheckAssignmentConstraints(From->getExprLoc(), ToType, From->getType());
  bool Diagnosed = DiagnoseAssignmentResult(
      ConvTy == Compatible ? Incompatible : ConvTy, From->getExprLoc(),
      ToType, From->getType(), From, Action);
  assert(Diagnosed && "failed to diagnose bad conversion")(static_cast<void> (0)); (void)Diagnosed;
  return ExprError();
}

// Everything went well.
return From;
4150}

4152/// PerformImplicitConversion - Perform an implicit conversion of the
4153/// expression From to the type ToType by following the standard
4154/// conversion sequence SCS. Returns the converted
4155/// expression. Flavor is the context in which we're performing this
4156/// conversion, for use in error messages.
4157ExprResult
4158Sema::PerformImplicitConversion(Expr *From, QualType ToType,
                              const StandardConversionSequence& SCS,
                              AssignmentAction Action,
                              CheckedConversionKind CCK) {
bool CStyle = (CCK == CCK_CStyleCast || CCK == CCK_FunctionalCast);

// Overall FIXME: we are recomputing too many types here and doing far too
// much extra work. What this means is that we need to keep track of more
// information that is computed when we try the implicit conversion initially,
// so that we don't need to recompute anything here.
QualType FromType = From->getType();

if (SCS.CopyConstructor) {
  // FIXME: When can ToType be a reference type?
  assert(!ToType->isReferenceType())(static_cast<void> (0));
  if (SCS.Second == ICK_Derived_To_Base) {
    SmallVector<Expr*, 8> ConstructorArgs;
    if (CompleteConstructorCall(
            cast<CXXConstructorDecl>(SCS.CopyConstructor), ToType, From,
            /*FIXME:ConstructLoc*/ SourceLocation(), ConstructorArgs))
      return ExprError();
    return BuildCXXConstructExpr(
        /*FIXME:ConstructLoc*/ SourceLocation(), ToType,
        SCS.FoundCopyConstructor, SCS.CopyConstructor,
        ConstructorArgs, /*HadMultipleCandidates*/ false,
        /*ListInit*/ false, /*StdInitListInit*/ false, /*ZeroInit*/ false,
        CXXConstructExpr::CK_Complete, SourceRange());
  }
  return BuildCXXConstructExpr(
      /*FIXME:ConstructLoc*/ SourceLocation(), ToType,
      SCS.FoundCopyConstructor, SCS.CopyConstructor,
      From, /*HadMultipleCandidates*/ false,
      /*ListInit*/ false, /*StdInitListInit*/ false, /*ZeroInit*/ false,
      CXXConstructExpr::CK_Complete, SourceRange());
}

// Resolve overloaded function references.
if (Context.hasSameType(FromType, Context.OverloadTy)) {
  DeclAccessPair Found;
  FunctionDecl *Fn = ResolveAddressOfOverloadedFunction(From, ToType,
                                                        true, Found);
  if (!Fn)
    return ExprError();

  if (DiagnoseUseOfDecl(Fn, From->getBeginLoc()))
    return ExprError();

  From = FixOverloadedFunctionReference(From, Found, Fn);
  FromType = From->getType();
}

// If we're converting to an atomic type, first convert to the corresponding
// non-atomic type.
QualType ToAtomicType;
if (const AtomicType *ToAtomic = ToType->getAs<AtomicType>()) {
  ToAtomicType = ToType;
  ToType = ToAtomic->getValueType();
}

QualType InitialFromType = FromType;
// Perform the first implicit conversion.
switch (SCS.First) {
case ICK_Identity:
  if (const AtomicType *FromAtomic = FromType->getAs<AtomicType>()) {
    FromType = FromAtomic->getValueType().getUnqualifiedType();
    From = ImplicitCastExpr::Create(Context, FromType, CK_AtomicToNonAtomic,
                                    From, /*BasePath=*/nullptr, VK_PRValue,
                                    FPOptionsOverride());
  }
  break;

case ICK_Lvalue_To_Rvalue: {
  assert(From->getObjectKind() != OK_ObjCProperty)(static_cast<void> (0));
  ExprResult FromRes = DefaultLvalueConversion(From);
  if (FromRes.isInvalid())
    return ExprError();

  From = FromRes.get();
  FromType = From->getType();
  break;
}

case ICK_Array_To_Pointer:
  FromType = Context.getArrayDecayedType(FromType);
  From = ImpCastExprToType(From, FromType, CK_ArrayToPointerDecay, VK_PRValue,
                           /*BasePath=*/nullptr, CCK)
             .get();
  break;

case ICK_Function_To_Pointer:
  FromType = Context.getPointerType(FromType);
  From = ImpCastExprToType(From, FromType, CK_FunctionToPointerDecay,
                           VK_PRValue, /*BasePath=*/nullptr, CCK)
             .get();
  break;

default:
  llvm_unreachable("Improper first standard conversion")__builtin_unreachable();
}

// Perform the second implicit conversion
switch (SCS.Second) {
case ICK_Identity:
  // C++ [except.spec]p5:
  //   [For] assignment to and initialization of pointers to functions,
  //   pointers to member functions, and references to functions: the
  //   target entity shall allow at least the exceptions allowed by the
  //   source value in the assignment or initialization.
  switch (Action) {
  case AA_Assigning:
  case AA_Initializing:
    // Note, function argument passing and returning are initialization.
  case AA_Passing:
  case AA_Returning:
  case AA_Sending:
  case AA_Passing_CFAudited:
    if (CheckExceptionSpecCompatibility(From, ToType))
      return ExprError();
    break;

  case AA_Casting:
  case AA_Converting:
    // Casts and implicit conversions are not initialization, so are not
    // checked for exception specification mismatches.
    break;
  }
  // Nothing else to do.
  break;

case ICK_Integral_Promotion:
case ICK_Integral_Conversion:
  if (ToType->isBooleanType()) {
    assert(FromType->castAs<EnumType>()->getDecl()->isFixed() &&(static_cast<void> (0))
           SCS.Second == ICK_Integral_Promotion &&(static_cast<void> (0))
           "only enums with fixed underlying type can promote to bool")(static_cast<void> (0));
    From = ImpCastExprToType(From, ToType, CK_IntegralToBoolean, VK_PRValue,
                             /*BasePath=*/nullptr, CCK)
               .get();
  } else {
    From = ImpCastExprToType(From, ToType, CK_IntegralCast, VK_PRValue,
                             /*BasePath=*/nullptr, CCK)
               .get();
  }
  break;

case ICK_Floating_Promotion:
case ICK_Floating_Conversion:
  From = ImpCastExprToType(From, ToType, CK_FloatingCast, VK_PRValue,
                           /*BasePath=*/nullptr, CCK)
             .get();
  break;

case ICK_Complex_Promotion:
case ICK_Complex_Conversion: {
  QualType FromEl = From->getType()->castAs<ComplexType>()->getElementType();
  QualType ToEl = ToType->castAs<ComplexType>()->getElementType();
  CastKind CK;
  if (FromEl->isRealFloatingType()) {
    if (ToEl->isRealFloatingType())
      CK = CK_FloatingComplexCast;
    else
      CK = CK_FloatingComplexToIntegralComplex;
  } else if (ToEl->isRealFloatingType()) {
    CK = CK_IntegralComplexToFloatingComplex;
  } else {
    CK = CK_IntegralComplexCast;
  }
  From = ImpCastExprToType(From, ToType, CK, VK_PRValue, /*BasePath=*/nullptr,
                           CCK)
             .get();
  break;
}

case ICK_Floating_Integral:
  if (ToType->isRealFloatingType())
    From = ImpCastExprToType(From, ToType, CK_IntegralToFloating, VK_PRValue,
                             /*BasePath=*/nullptr, CCK)
               .get();
  else
    From = ImpCastExprToType(From, ToType, CK_FloatingToIntegral, VK_PRValue,
                             /*BasePath=*/nullptr, CCK)
               .get();
  break;

case ICK_Compatible_Conversion:
  From = ImpCastExprToType(From, ToType, CK_NoOp, From->getValueKind(),
                           /*BasePath=*/nullptr, CCK).get();
  break;

case ICK_Writeback_Conversion:
case ICK_Pointer_Conversion: {
  if (SCS.IncompatibleObjC && Action != AA_Casting) {
    // Diagnose incompatible Objective-C conversions
    if (Action == AA_Initializing || Action == AA_Assigning)
      Diag(From->getBeginLoc(),
           diag::ext_typecheck_convert_incompatible_pointer)
          << ToType << From->getType() << Action << From->getSourceRange()
          << 0;
    else
      Diag(From->getBeginLoc(),
           diag::ext_typecheck_convert_incompatible_pointer)
          << From->getType() << ToType << Action << From->getSourceRange()
          << 0;

    if (From->getType()->isObjCObjectPointerType() &&
        ToType->isObjCObjectPointerType())
      EmitRelatedResultTypeNote(From);
  } else if (getLangOpts().allowsNonTrivialObjCLifetimeQualifiers() &&
             !CheckObjCARCUnavailableWeakConversion(ToType,
                                                    From->getType())) {
    if (Action == AA_Initializing)
      Diag(From->getBeginLoc(), diag::err_arc_weak_unavailable_assign);
    else
      Diag(From->getBeginLoc(), diag::err_arc_convesion_of_weak_unavailable)
          << (Action == AA_Casting) << From->getType() << ToType
          << From->getSourceRange();
  }

  // Defer address space conversion to the third conversion.
  QualType FromPteeType = From->getType()->getPointeeType();
  QualType ToPteeType = ToType->getPointeeType();
  QualType NewToType = ToType;
  if (!FromPteeType.isNull() && !ToPteeType.isNull() &&
      FromPteeType.getAddressSpace() != ToPteeType.getAddressSpace()) {
    NewToType = Context.removeAddrSpaceQualType(ToPteeType);
    NewToType = Context.getAddrSpaceQualType(NewToType,
                                             FromPteeType.getAddressSpace());
    if (ToType->isObjCObjectPointerType())
      NewToType = Context.getObjCObjectPointerType(NewToType);
    else if (ToType->isBlockPointerType())
      NewToType = Context.getBlockPointerType(NewToType);
    else
      NewToType = Context.getPointerType(NewToType);
  }

  CastKind Kind;
  CXXCastPath BasePath;
  if (CheckPointerConversion(From, NewToType, Kind, BasePath, CStyle))
    return ExprError();

  // Make sure we extend blocks if necessary.
  // FIXME: doing this here is really ugly.
  if (Kind == CK_BlockPointerToObjCPointerCast) {
    ExprResult E = From;
    (void) PrepareCastToObjCObjectPointer(E);
    From = E.get();
  }
  if (getLangOpts().allowsNonTrivialObjCLifetimeQualifiers())
    CheckObjCConversion(SourceRange(), NewToType, From, CCK);
  From = ImpCastExprToType(From, NewToType, Kind, VK_PRValue, &BasePath, CCK)
             .get();
  break;
}

case ICK_Pointer_Member: {
  CastKind Kind;
  CXXCastPath BasePath;
  if (CheckMemberPointerConversion(From, ToType, Kind, BasePath, CStyle))
    return ExprError();
  if (CheckExceptionSpecCompatibility(From, ToType))
    return ExprError();

  // We may not have been able to figure out what this member pointer resolved
  // to up until this exact point.  Attempt to lock-in it's inheritance model.
  if (Context.getTargetInfo().getCXXABI().isMicrosoft()) {
    (void)isCompleteType(From->getExprLoc(), From->getType());
    (void)isCompleteType(From->getExprLoc(), ToType);
  }

  From =
      ImpCastExprToType(From, ToType, Kind, VK_PRValue, &BasePath, CCK).get();
  break;
}

case ICK_Boolean_Conversion:
  // Perform half-to-boolean conversion via float.
  if (From->getType()->isHalfType()) {
    From = ImpCastExprToType(From, Context.FloatTy, CK_FloatingCast).get();
    FromType = Context.FloatTy;
  }

  From = ImpCastExprToType(From, Context.BoolTy,
                           ScalarTypeToBooleanCastKind(FromType), VK_PRValue,
                           /*BasePath=*/nullptr, CCK)
             .get();
  break;

case ICK_Derived_To_Base: {
  CXXCastPath BasePath;
  if (CheckDerivedToBaseConversion(
          From->getType(), ToType.getNonReferenceType(), From->getBeginLoc(),
          From->getSourceRange(), &BasePath, CStyle))
    return ExprError();

  From = ImpCastExprToType(From, ToType.getNonReferenceType(),
                    CK_DerivedToBase, From->getValueKind(),
                    &BasePath, CCK).get();
  break;
}

case ICK_Vector_Conversion:
  From = ImpCastExprToType(From, ToType, CK_BitCast, VK_PRValue,
                           /*BasePath=*/nullptr, CCK)
             .get();
  break;

case ICK_SVE_Vector_Conversion:
  From = ImpCastExprToType(From, ToType, CK_BitCast, VK_PRValue,
                           /*BasePath=*/nullptr, CCK)
             .get();
  break;

case ICK_Vector_Splat: {
  // Vector splat from any arithmetic type to a vector.
  Expr *Elem = prepareVectorSplat(ToType, From).get();
  From = ImpCastExprToType(Elem, ToType, CK_VectorSplat, VK_PRValue,
                           /*BasePath=*/nullptr, CCK)
             .get();
  break;
}

case ICK_Complex_Real:
  // Case 1.  x -> _Complex y
  if (const ComplexType *ToComplex = ToType->getAs<ComplexType>()) {
    QualType ElType = ToComplex->getElementType();
    bool isFloatingComplex = ElType->isRealFloatingType();

    // x -> y
    if (Context.hasSameUnqualifiedType(ElType, From->getType())) {
      // do nothing
    } else if (From->getType()->isRealFloatingType()) {
      From = ImpCastExprToType(From, ElType,
              isFloatingComplex ? CK_FloatingCast : CK_FloatingToIntegral).get();
    } else {
      assert(From->getType()->isIntegerType())(static_cast<void> (0));
      From = ImpCastExprToType(From, ElType,
              isFloatingComplex ? CK_IntegralToFloating : CK_IntegralCast).get();
    }
    // y -> _Complex y
    From = ImpCastExprToType(From, ToType,
                 isFloatingComplex ? CK_FloatingRealToComplex
                                   : CK_IntegralRealToComplex).get();

  // Case 2.  _Complex x -> y
  } else {
    auto *FromComplex = From->getType()->castAs<ComplexType>();
    QualType ElType = FromComplex->getElementType();
    bool isFloatingComplex = ElType->isRealFloatingType();

    // _Complex x -> x
    From = ImpCastExprToType(From, ElType,
                             isFloatingComplex ? CK_FloatingComplexToReal
                                               : CK_IntegralComplexToReal,
                             VK_PRValue, /*BasePath=*/nullptr, CCK)
               .get();

    // x -> y
    if (Context.hasSameUnqualifiedType(ElType, ToType)) {
      // do nothing
    } else if (ToType->isRealFloatingType()) {
      From = ImpCastExprToType(From, ToType,
                               isFloatingComplex ? CK_FloatingCast
                                                 : CK_IntegralToFloating,
                               VK_PRValue, /*BasePath=*/nullptr, CCK)
                 .get();
    } else {
      assert(ToType->isIntegerType())(static_cast<void> (0));
      From = ImpCastExprToType(From, ToType,
                               isFloatingComplex ? CK_FloatingToIntegral
                                                 : CK_IntegralCast,
                               VK_PRValue, /*BasePath=*/nullptr, CCK)
                 .get();
    }
  }
  break;

case ICK_Block_Pointer_Conversion: {
  LangAS AddrSpaceL =
      ToType->castAs<BlockPointerType>()->getPointeeType().getAddressSpace();
  LangAS AddrSpaceR =
      FromType->castAs<BlockPointerType>()->getPointeeType().getAddressSpace();
  assert(Qualifiers::isAddressSpaceSupersetOf(AddrSpaceL, AddrSpaceR) &&(static_cast<void> (0))
         "Invalid cast")(static_cast<void> (0));
  CastKind Kind =
      AddrSpaceL != AddrSpaceR ? CK_AddressSpaceConversion : CK_BitCast;
  From = ImpCastExprToType(From, ToType.getUnqualifiedType(), Kind,
                           VK_PRValue, /*BasePath=*/nullptr, CCK)
             .get();
  break;
}

case ICK_TransparentUnionConversion: {
  ExprResult FromRes = From;
  Sema::AssignConvertType ConvTy =
    CheckTransparentUnionArgumentConstraints(ToType, FromRes);
  if (FromRes.isInvalid())
    return ExprError();
  From = FromRes.get();
  assert ((ConvTy == Sema::Compatible) &&(static_cast<void> (0))
          "Improper transparent union conversion")(static_cast<void> (0));
  (void)ConvTy;
  break;
}

case ICK_Zero_Event_Conversion:
case ICK_Zero_Queue_Conversion:
  From = ImpCastExprToType(From, ToType,
                           CK_ZeroToOCLOpaqueType,
                           From->getValueKind()).get();
  break;

case ICK_Lvalue_To_Rvalue:
case ICK_Array_To_Pointer:
case ICK_Function_To_Pointer:
case ICK_Function_Conversion:
case ICK_Qualification:
case ICK_Num_Conversion_Kinds:
case ICK_C_Only_Conversion:
case ICK_Incompatible_Pointer_Conversion:
  llvm_unreachable("Improper second standard conversion")__builtin_unreachable();
}

switch (SCS.Third) {
case ICK_Identity:
  // Nothing to do.
  break;

case ICK_Function_Conversion:
  // If both sides are functions (or pointers/references to them), there could
  // be incompatible exception declarations.
  if (CheckExceptionSpecCompatibility(From, ToType))
    return ExprError();

  From = ImpCastExprToType(From, ToType, CK_NoOp, VK_PRValue,
                           /*BasePath=*/nullptr, CCK)
             .get();
  break;

case ICK_Qualification: {
  ExprValueKind VK = From->getValueKind();
  CastKind CK = CK_NoOp;

  if (ToType->isReferenceType() &&
      ToType->getPointeeType().getAddressSpace() !=
          From->getType().getAddressSpace())
    CK = CK_AddressSpaceConversion;

  if (ToType->isPointerType() &&
      ToType->getPointeeType().getAddressSpace() !=
          From->getType()->getPointeeType().getAddressSpace())
    CK = CK_AddressSpaceConversion;

  From = ImpCastExprToType(From, ToType.getNonLValueExprType(Context), CK, VK,
                           /*BasePath=*/nullptr, CCK)
             .get();

  if (SCS.DeprecatedStringLiteralToCharPtr &&
      !getLangOpts().WritableStrings) {
    Diag(From->getBeginLoc(),
         getLangOpts().CPlusPlus11
             ? diag::ext_deprecated_string_literal_conversion
             : diag::warn_deprecated_string_literal_conversion)
        << ToType.getNonReferenceType();
  }

  break;
}

default:
  llvm_unreachable("Improper third standard conversion")__builtin_unreachable();
}

// If this conversion sequence involved a scalar -> atomic conversion, perform
// that conversion now.
if (!ToAtomicType.isNull()) {
  assert(Context.hasSameType((static_cast<void> (0))
      ToAtomicType->castAs<AtomicType>()->getValueType(), From->getType()))(static_cast<void> (0));
  From = ImpCastExprToType(From, ToAtomicType, CK_NonAtomicToAtomic,
                           VK_PRValue, nullptr, CCK)
             .get();
}

// Materialize a temporary if we're implicitly converting to a reference
// type. This is not required by the C++ rules but is necessary to maintain
// AST invariants.
if (ToType->isReferenceType() && From->isPRValue()) {
  ExprResult Res = TemporaryMaterializationConversion(From);
  if (Res.isInvalid())
    return ExprError();
  From = Res.get();
}

// If this conversion sequence succeeded and involved implicitly converting a
// _Nullable type to a _Nonnull one, complain.
if (!isCast(CCK))
  diagnoseNullableToNonnullConversion(ToType, InitialFromType,
                                      From->getBeginLoc());

return From;
4657}

4659/// Check the completeness of a type in a unary type trait.
4660///
4661/// If the particular type trait requires a complete type, tries to complete
4662/// it. If completing the type fails, a diagnostic is emitted and false
4663/// returned. If completing the type succeeds or no completion was required,
4664/// returns true.
4665static bool CheckUnaryTypeTraitTypeCompleteness(Sema &S, TypeTrait UTT,
                                              SourceLocation Loc,
                                              QualType ArgTy) {
// C++0x [meta.unary.prop]p3:
//   For all of the class templates X declared in this Clause, instantiating
//   that template with a template argument that is a class template
//   specialization may result in the implicit instantiation of the template
//   argument if and only if the semantics of X require that the argument
//   must be a complete type.
// We apply this rule to all the type trait expressions used to implement
// these class templates. We also try to follow any GCC documented behavior
// in these expressions to ensure portability of standard libraries.
switch (UTT) {
default: llvm_unreachable("not a UTT")__builtin_unreachable();
  // is_complete_type somewhat obviously cannot require a complete type.
case UTT_IsCompleteType:
  // Fall-through

  // These traits are modeled on the type predicates in C++0x
  // [meta.unary.cat] and [meta.unary.comp]. They are not specified as
  // requiring a complete type, as whether or not they return true cannot be
  // impacted by the completeness of the type.
case UTT_IsVoid:
case UTT_IsIntegral:
case UTT_IsFloatingPoint:
case UTT_IsArray:
case UTT_IsPointer:
case UTT_IsLvalueReference:
case UTT_IsRvalueReference:
case UTT_IsMemberFunctionPointer:
case UTT_IsMemberObjectPointer:
case UTT_IsEnum:
case UTT_IsUnion:
case UTT_IsClass:
case UTT_IsFunction:
case UTT_IsReference:
case UTT_IsArithmetic:
case UTT_IsFundamental:
case UTT_IsObject:
case UTT_IsScalar:
case UTT_IsCompound:
case UTT_IsMemberPointer:
  // Fall-through

  // These traits are modeled on type predicates in C++0x [meta.unary.prop]
  // which requires some of its traits to have the complete type. However,
  // the completeness of the type cannot impact these traits' semantics, and
  // so they don't require it. This matches the comments on these traits in
  // Table 49.
case UTT_IsConst:
case UTT_IsVolatile:
case UTT_IsSigned:
case UTT_IsUnsigned:

// This type trait always returns false, checking the type is moot.
case UTT_IsInterfaceClass:
  return true;

// C++14 [meta.unary.prop]:
//   If T is a non-union class type, T shall be a complete type.
case UTT_IsEmpty:
case UTT_IsPolymorphic:
case UTT_IsAbstract:
  if (const auto *RD = ArgTy->getAsCXXRecordDecl())
    if (!RD->isUnion())
      return !S.RequireCompleteType(
          Loc, ArgTy, diag::err_incomplete_type_used_in_type_trait_expr);
  return true;

// C++14 [meta.unary.prop]:
//   If T is a class type, T shall be a complete type.
case UTT_IsFinal:
case UTT_IsSealed:
  if (ArgTy->getAsCXXRecordDecl())
    return !S.RequireCompleteType(
        Loc, ArgTy, diag::err_incomplete_type_used_in_type_trait_expr);
  return true;

// C++1z [meta.unary.prop]:
//   remove_all_extents_t<T> shall be a complete type or cv void.
case UTT_IsAggregate:
case UTT_IsTrivial:
case UTT_IsTriviallyCopyable:
case UTT_IsStandardLayout:
case UTT_IsPOD:
case UTT_IsLiteral:
// Per the GCC type traits documentation, T shall be a complete type, cv void,
// or an array of unknown bound. But GCC actually imposes the same constraints
// as above.
case UTT_HasNothrowAssign:
case UTT_HasNothrowMoveAssign:
case UTT_HasNothrowConstructor:
case UTT_HasNothrowCopy:
case UTT_HasTrivialAssign:
case UTT_HasTrivialMoveAssign:
case UTT_HasTrivialDefaultConstructor:
case UTT_HasTrivialMoveConstructor:
case UTT_HasTrivialCopy:
case UTT_HasTrivialDestructor:
case UTT_HasVirtualDestructor:
  ArgTy = QualType(ArgTy->getBaseElementTypeUnsafe(), 0);
  LLVM_FALLTHROUGH[[gnu::fallthrough]];

// C++1z [meta.unary.prop]:
//   T shall be a complete type, cv void, or an array of unknown bound.
case UTT_IsDestructible:
case UTT_IsNothrowDestructible:
case UTT_IsTriviallyDestructible:
case UTT_HasUniqueObjectRepresentations:
  if (ArgTy->isIncompleteArrayType() || ArgTy->isVoidType())
    return true;

  return !S.RequireCompleteType(
      Loc, ArgTy, diag::err_incomplete_type_used_in_type_trait_expr);
}
4780}

4782static bool HasNoThrowOperator(const RecordType *RT, OverloadedOperatorKind Op,
                             Sema &Self, SourceLocation KeyLoc, ASTContext &C,
                             bool (CXXRecordDecl::*HasTrivial)() const,
                             bool (CXXRecordDecl::*HasNonTrivial)() const,
                             bool (CXXMethodDecl::*IsDesiredOp)() const)
4787{
CXXRecordDecl *RD = cast<CXXRecordDecl>(RT->getDecl());
if ((RD->*HasTrivial)() && !(RD->*HasNonTrivial)())
  return true;

DeclarationName Name = C.DeclarationNames.getCXXOperatorName(Op);
DeclarationNameInfo NameInfo(Name, KeyLoc);
LookupResult Res(Self, NameInfo, Sema::LookupOrdinaryName);
if (Self.LookupQualifiedName(Res, RD)) {
  bool FoundOperator = false;
  Res.suppressDiagnostics();
  for (LookupResult::iterator Op = Res.begin(), OpEnd = Res.end();
       Op != OpEnd; ++Op) {
    if (isa<FunctionTemplateDecl>(*Op))
      continue;

    CXXMethodDecl *Operator = cast<CXXMethodDecl>(*Op);
    if((Operator->*IsDesiredOp)()) {
      FoundOperator = true;
      auto *CPT = Operator->getType()->castAs<FunctionProtoType>();
      CPT = Self.ResolveExceptionSpec(KeyLoc, CPT);
      if (!CPT || !CPT->isNothrow())
        return false;
    }
  }
  return FoundOperator;
}
return false;
4815}

4817static bool EvaluateUnaryTypeTrait(Sema &Self, TypeTrait UTT,
                                 SourceLocation KeyLoc, QualType T) {
assert(!T->isDependentType() && "Cannot evaluate traits of dependent type")(static_cast<void> (0));

ASTContext &C = Self.Context;
switch(UTT) {
default: llvm_unreachable("not a UTT")__builtin_unreachable();
  // Type trait expressions corresponding to the primary type category
  // predicates in C++0x [meta.unary.cat].
case UTT_IsVoid:
  return T->isVoidType();
case UTT_IsIntegral:
  return T->isIntegralType(C);
case UTT_IsFloatingPoint:
  return T->isFloatingType();
case UTT_IsArray:
  return T->isArrayType();
case UTT_IsPointer:
  return T->isAnyPointerType();
case UTT_IsLvalueReference:
  return T->isLValueReferenceType();
case UTT_IsRvalueReference:
  return T->isRValueReferenceType();
case UTT_IsMemberFunctionPointer:
  return T->isMemberFunctionPointerType();
case UTT_IsMemberObjectPointer:
  return T->isMemberDataPointerType();
case UTT_IsEnum:
  return T->isEnumeralType();
case UTT_IsUnion:
  return T->isUnionType();
case UTT_IsClass:
  return T->isClassType() || T->isStructureType() || T->isInterfaceType();
case UTT_IsFunction:
  return T->isFunctionType();

  // Type trait expressions which correspond to the convenient composition
  // predicates in C++0x [meta.unary.comp].
case UTT_IsReference:
  return T->isReferenceType();
case UTT_IsArithmetic:
  return T->isArithmeticType() && !T->isEnumeralType();
case UTT_IsFundamental:
  return T->isFundamentalType();
case UTT_IsObject:
  return T->isObjectType();
case UTT_IsScalar:
  // Note: semantic analysis depends on Objective-C lifetime types to be
  // considered scalar types. However, such types do not actually behave
  // like scalar types at run time (since they may require retain/release
  // operations), so we report them as non-scalar.
  if (T->isObjCLifetimeType()) {
    switch (T.getObjCLifetime()) {
    case Qualifiers::OCL_None:
    case Qualifiers::OCL_ExplicitNone:
      return true;

    case Qualifiers::OCL_Strong:
    case Qualifiers::OCL_Weak:
    case Qualifiers::OCL_Autoreleasing:
      return false;
    }
  }

  return T->isScalarType();
case UTT_IsCompound:
  return T->isCompoundType();
case UTT_IsMemberPointer:
  return T->isMemberPointerType();

  // Type trait expressions which correspond to the type property predicates
  // in C++0x [meta.unary.prop].
case UTT_IsConst:
  return T.isConstQualified();
case UTT_IsVolatile:
  return T.isVolatileQualified();
case UTT_IsTrivial:
  return T.isTrivialType(C);
case UTT_IsTriviallyCopyable:
  return T.isTriviallyCopyableType(C);
case UTT_IsStandardLayout:
  return T->isStandardLayoutType();
case UTT_IsPOD:
  return T.isPODType(C);
case UTT_IsLiteral:
  return T->isLiteralType(C);
case UTT_IsEmpty:
  if (const CXXRecordDecl *RD = T->getAsCXXRecordDecl())
    return !RD->isUnion() && RD->isEmpty();
  return false;
case UTT_IsPolymorphic:
  if (const CXXRecordDecl *RD = T->getAsCXXRecordDecl())
    return !RD->isUnion() && RD->isPolymorphic();
  return false;
case UTT_IsAbstract:
  if (const CXXRecordDecl *RD = T->getAsCXXRecordDecl())
    return !RD->isUnion() && RD->isAbstract();
  return false;
case UTT_IsAggregate:
  // Report vector extensions and complex types as aggregates because they
  // support aggregate initialization. GCC mirrors this behavior for vectors
  // but not _Complex.
  return T->isAggregateType() || T->isVectorType() || T->isExtVectorType() ||
         T->isAnyComplexType();
// __is_interface_class only returns true when CL is invoked in /CLR mode and
// even then only when it is used with the 'interface struct ...' syntax
// Clang doesn't support /CLR which makes this type trait moot.
case UTT_IsInterfaceClass:
  return false;
case UTT_IsFinal:
case UTT_IsSealed:
  if (const CXXRecordDecl *RD = T->getAsCXXRecordDecl())
    return RD->hasAttr<FinalAttr>();
  return false;
case UTT_IsSigned:
  // Enum types should always return false.
  // Floating points should always return true.
  return T->isFloatingType() ||
         (T->isSignedIntegerType() && !T->isEnumeralType());
case UTT_IsUnsigned:
  // Enum types should always return false.
  return T->isUnsignedIntegerType() && !T->isEnumeralType();

  // Type trait expressions which query classes regarding their construction,
  // destruction, and copying. Rather than being based directly on the
  // related type predicates in the standard, they are specified by both
  // GCC[1] and the Embarcadero C++ compiler[2], and Clang implements those
  // specifications.
  //
  //   1: http://gcc.gnu/.org/onlinedocs/gcc/Type-Traits.html
  //   2: http://docwiki.embarcadero.com/RADStudio/XE/en/Type_Trait_Functions_(C%2B%2B0x)_Index
  //
  // Note that these builtins do not behave as documented in g++: if a class
  // has both a trivial and a non-trivial special member of a particular kind,
  // they return false! For now, we emulate this behavior.
  // FIXME: This appears to be a g++ bug: more complex cases reveal that it
  // does not correctly compute triviality in the presence of multiple special
  // members of the same kind. Revisit this once the g++ bug is fixed.
case UTT_HasTrivialDefaultConstructor:
  // http://gcc.gnu.org/onlinedocs/gcc/Type-Traits.html:
  //   If __is_pod (type) is true then the trait is true, else if type is
  //   a cv class or union type (or array thereof) with a trivial default
  //   constructor ([class.ctor]) then the trait is true, else it is false.
  if (T.isPODType(C))
    return true;
  if (CXXRecordDecl *RD = C.getBaseElementType(T)->getAsCXXRecordDecl())
    return RD->hasTrivialDefaultConstructor() &&
           !RD->hasNonTrivialDefaultConstructor();
  return false;
case UTT_HasTrivialMoveConstructor:
  //  This trait is implemented by MSVC 2012 and needed to parse the
  //  standard library headers. Specifically this is used as the logic
  //  behind std::is_trivially_move_constructible (20.9.4.3).
  if (T.isPODType(C))
    return true;
  if (CXXRecordDecl *RD = C.getBaseElementType(T)->getAsCXXRecordDecl())
    return RD->hasTrivialMoveConstructor() && !RD->hasNonTrivialMoveConstructor();
  return false;
case UTT_HasTrivialCopy:
  // http://gcc.gnu.org/onlinedocs/gcc/Type-Traits.html:
  //   If __is_pod (type) is true or type is a reference type then
  //   the trait is true, else if type is a cv class or union type
  //   with a trivial copy constructor ([class.copy]) then the trait
  //   is true, else it is false.
  if (T.isPODType(C) || T->isReferenceType())
    return true;
  if (CXXRecordDecl *RD = T->getAsCXXRecordDecl())
    return RD->hasTrivialCopyConstructor() &&
           !RD->hasNonTrivialCopyConstructor();
  return false;
case UTT_HasTrivialMoveAssign:
  //  This trait is implemented by MSVC 2012 and needed to parse the
  //  standard library headers. Specifically it is used as the logic
  //  behind std::is_trivially_move_assignable (20.9.4.3)
  if (T.isPODType(C))
    return true;
  if (CXXRecordDecl *RD = C.getBaseElementType(T)->getAsCXXRecordDecl())
    return RD->hasTrivialMoveAssignment() && !RD->hasNonTrivialMoveAssignment();
  return false;
case UTT_HasTrivialAssign:
  // http://gcc.gnu.org/onlinedocs/gcc/Type-Traits.html:
  //   If type is const qualified or is a reference type then the
  //   trait is false. Otherwise if __is_pod (type) is true then the
  //   trait is true, else if type is a cv class or union type with
  //   a trivial copy assignment ([class.copy]) then the trait is
  //   true, else it is false.
  // Note: the const and reference restrictions are interesting,
  // given that const and reference members don't prevent a class
  // from having a trivial copy assignment operator (but do cause
  // errors if the copy assignment operator is actually used, q.v.
  // [class.copy]p12).

  if (T.isConstQualified())
    return false;
  if (T.isPODType(C))
    return true;
  if (CXXRecordDecl *RD = T->getAsCXXRecordDecl())
    return RD->hasTrivialCopyAssignment() &&
           !RD->hasNonTrivialCopyAssignment();
  return false;
case UTT_IsDestructible:
case UTT_IsTriviallyDestructible:
case UTT_IsNothrowDestructible:
  // C++14 [meta.unary.prop]:
  //   For reference types, is_destructible<T>::value is true.
  if (T->isReferenceType())
    return true;

  // Objective-C++ ARC: autorelease types don't require destruction.
  if (T->isObjCLifetimeType() &&
      T.getObjCLifetime() == Qualifiers::OCL_Autoreleasing)
    return true;

  // C++14 [meta.unary.prop]:
  //   For incomplete types and function types, is_destructible<T>::value is
  //   false.
  if (T->isIncompleteType() || T->isFunctionType())
    return false;

  // A type that requires destruction (via a non-trivial destructor or ARC
  // lifetime semantics) is not trivially-destructible.
  if (UTT == UTT_IsTriviallyDestructible && T.isDestructedType())
    return false;

  // C++14 [meta.unary.prop]:
  //   For object types and given U equal to remove_all_extents_t<T>, if the
  //   expression std::declval<U&>().~U() is well-formed when treated as an
  //   unevaluated operand (Clause 5), then is_destructible<T>::value is true
  if (auto *RD = C.getBaseElementType(T)->getAsCXXRecordDecl()) {
    CXXDestructorDecl *Destructor = Self.LookupDestructor(RD);
    if (!Destructor)
      return false;
    //  C++14 [dcl.fct.def.delete]p2:
    //    A program that refers to a deleted function implicitly or
    //    explicitly, other than to declare it, is ill-formed.
    if (Destructor->isDeleted())
      return false;
    if (C.getLangOpts().AccessControl && Destructor->getAccess() != AS_public)
      return false;
    if (UTT == UTT_IsNothrowDestructible) {
      auto *CPT = Destructor->getType()->castAs<FunctionProtoType>();
      CPT = Self.ResolveExceptionSpec(KeyLoc, CPT);
      if (!CPT || !CPT->isNothrow())
        return false;
    }
  }
  return true;

case UTT_HasTrivialDestructor:
  // http://gcc.gnu.org/onlinedocs/gcc/Type-Traits.html
  //   If __is_pod (type) is true or type is a reference type
  //   then the trait is true, else if type is a cv class or union
  //   type (or array thereof) with a trivial destructor
  //   ([class.dtor]) then the trait is true, else it is
  //   false.
  if (T.isPODType(C) || T->isReferenceType())
    return true;

  // Objective-C++ ARC: autorelease types don't require destruction.
  if (T->isObjCLifetimeType() &&
      T.getObjCLifetime() == Qualifiers::OCL_Autoreleasing)
    return true;

  if (CXXRecordDecl *RD = C.getBaseElementType(T)->getAsCXXRecordDecl())
    return RD->hasTrivialDestructor();
  return false;
// TODO: Propagate nothrowness for implicitly declared special members.
case UTT_HasNothrowAssign:
  // http://gcc.gnu.org/onlinedocs/gcc/Type-Traits.html:
  //   If type is const qualified or is a reference type then the
  //   trait is false. Otherwise if __has_trivial_assign (type)
  //   is true then the trait is true, else if type is a cv class
  //   or union type with copy assignment operators that are known
  //   not to throw an exception then the trait is true, else it is
  //   false.
  if (C.getBaseElementType(T).isConstQualified())
    return false;
  if (T->isReferenceType())
    return false;
  if (T.isPODType(C) || T->isObjCLifetimeType())
    return true;

  if (const RecordType *RT = T->getAs<RecordType>())
    return HasNoThrowOperator(RT, OO_Equal, Self, KeyLoc, C,
                              &CXXRecordDecl::hasTrivialCopyAssignment,
                              &CXXRecordDecl::hasNonTrivialCopyAssignment,
                              &CXXMethodDecl::isCopyAssignmentOperator);
  return false;
case UTT_HasNothrowMoveAssign:
  //  This trait is implemented by MSVC 2012 and needed to parse the
  //  standard library headers. Specifically this is used as the logic
  //  behind std::is_nothrow_move_assignable (20.9.4.3).
  if (T.isPODType(C))
    return true;

  if (const RecordType *RT = C.getBaseElementType(T)->getAs<RecordType>())
    return HasNoThrowOperator(RT, OO_Equal, Self, KeyLoc, C,
                              &CXXRecordDecl::hasTrivialMoveAssignment,
                              &CXXRecordDecl::hasNonTrivialMoveAssignment,
                              &CXXMethodDecl::isMoveAssignmentOperator);
  return false;
case UTT_HasNothrowCopy:
  // http://gcc.gnu.org/onlinedocs/gcc/Type-Traits.html:
  //   If __has_trivial_copy (type) is true then the trait is true, else
  //   if type is a cv class or union type with copy constructors that are
  //   known not to throw an exception then the trait is true, else it is
  //   false.
  if (T.isPODType(C) || T->isReferenceType() || T->isObjCLifetimeType())
    return true;
  if (CXXRecordDecl *RD = T->getAsCXXRecordDecl()) {
    if (RD->hasTrivialCopyConstructor() &&
        !RD->hasNonTrivialCopyConstructor())
      return true;

    bool FoundConstructor = false;
    unsigned FoundTQs;
    for (const auto *ND : Self.LookupConstructors(RD)) {
      // A template constructor is never a copy constructor.
      // FIXME: However, it may actually be selected at the actual overload
      // resolution point.
      if (isa<FunctionTemplateDecl>(ND->getUnderlyingDecl()))
        continue;
      // UsingDecl itself is not a constructor
      if (isa<UsingDecl>(ND))
        continue;
      auto *Constructor = cast<CXXConstructorDecl>(ND->getUnderlyingDecl());
      if (Constructor->isCopyConstructor(FoundTQs)) {
        FoundConstructor = true;
        auto *CPT = Constructor->getType()->castAs<FunctionProtoType>();
        CPT = Self.ResolveExceptionSpec(KeyLoc, CPT);
        if (!CPT)
          return false;
        // TODO: check whether evaluating default arguments can throw.
        // For now, we'll be conservative and assume that they can throw.
        if (!CPT->isNothrow() || CPT->getNumParams() > 1)
          return false;
      }
    }

    return FoundConstructor;
  }
  return false;
case UTT_HasNothrowConstructor:
  // http://gcc.gnu.org/onlinedocs/gcc/Type-Traits.html
  //   If __has_trivial_constructor (type) is true then the trait is
  //   true, else if type is a cv class or union type (or array
  //   thereof) with a default constructor that is known not to
  //   throw an exception then the trait is true, else it is false.
  if (T.isPODType(C) || T->isObjCLifetimeType())
    return true;
  if (CXXRecordDecl *RD = C.getBaseElementType(T)->getAsCXXRecordDecl()) {
    if (RD->hasTrivialDefaultConstructor() &&
        !RD->hasNonTrivialDefaultConstructor())
      return true;

    bool FoundConstructor = false;
    for (const auto *ND : Self.LookupConstructors(RD)) {
      // FIXME: In C++0x, a constructor template can be a default constructor.
      if (isa<FunctionTemplateDecl>(ND->getUnderlyingDecl()))
        continue;
      // UsingDecl itself is not a constructor
      if (isa<UsingDecl>(ND))
        continue;
      auto *Constructor = cast<CXXConstructorDecl>(ND->getUnderlyingDecl());
      if (Constructor->isDefaultConstructor()) {
        FoundConstructor = true;
        auto *CPT = Constructor->getType()->castAs<FunctionProtoType>();
        CPT = Self.ResolveExceptionSpec(KeyLoc, CPT);
        if (!CPT)
          return false;
        // FIXME: check whether evaluating default arguments can throw.
        // For now, we'll be conservative and assume that they can throw.
        if (!CPT->isNothrow() || CPT->getNumParams() > 0)
          return false;
      }
    }
    return FoundConstructor;
  }
  return false;
case UTT_HasVirtualDestructor:
  // http://gcc.gnu.org/onlinedocs/gcc/Type-Traits.html:
  //   If type is a class type with a virtual destructor ([class.dtor])
  //   then the trait is true, else it is false.
  if (CXXRecordDecl *RD = T->getAsCXXRecordDecl())
    if (CXXDestructorDecl *Destructor = Self.LookupDestructor(RD))
      return Destructor->isVirtual();
  return false;

  // These type trait expressions are modeled on the specifications for the
  // Embarcadero C++0x type trait functions:
  //   http://docwiki.embarcadero.com/RADStudio/XE/en/Type_Trait_Functions_(C%2B%2B0x)_Index
case UTT_IsCompleteType:
  // http://docwiki.embarcadero.com/RADStudio/XE/en/Is_complete_type_(typename_T_):
  //   Returns True if and only if T is a complete type at the point of the
  //   function call.
  return !T->isIncompleteType();
case UTT_HasUniqueObjectRepresentations:
  return C.hasUniqueObjectRepresentations(T);
}
5216}

5218static bool EvaluateBinaryTypeTrait(Sema &Self, TypeTrait BTT, QualType LhsT,
                                  QualType RhsT, SourceLocation KeyLoc);

5221static bool evaluateTypeTrait(Sema &S, TypeTrait Kind, SourceLocation KWLoc,
                            ArrayRef<TypeSourceInfo *> Args,
                            SourceLocation RParenLoc) {
if (Kind <= UTT_Last)
  return EvaluateUnaryTypeTrait(S, Kind, KWLoc, Args[0]->getType());

// Evaluate BTT_ReferenceBindsToTemporary alongside the IsConstructible
// traits to avoid duplication.
if (Kind <= BTT_Last && Kind != BTT_ReferenceBindsToTemporary)
  return EvaluateBinaryTypeTrait(S, Kind, Args[0]->getType(),
                                 Args[1]->getType(), RParenLoc);

switch (Kind) {
case clang::BTT_ReferenceBindsToTemporary:
case clang::TT_IsConstructible:
case clang::TT_IsNothrowConstructible:
case clang::TT_IsTriviallyConstructible: {
  // C++11 [meta.unary.prop]:
  //   is_trivially_constructible is defined as:
  //
  //     is_constructible<T, Args...>::value is true and the variable
  //     definition for is_constructible, as defined below, is known to call
  //     no operation that is not trivial.
  //
  //   The predicate condition for a template specialization
  //   is_constructible<T, Args...> shall be satisfied if and only if the
  //   following variable definition would be well-formed for some invented
  //   variable t:
  //
  //     T t(create<Args>()...);
  assert(!Args.empty())(static_cast<void> (0));

  // Precondition: T and all types in the parameter pack Args shall be
  // complete types, (possibly cv-qualified) void, or arrays of
  // unknown bound.
  for (const auto *TSI : Args) {
    QualType ArgTy = TSI->getType();
    if (ArgTy->isVoidType() || ArgTy->isIncompleteArrayType())
      continue;

    if (S.RequireCompleteType(KWLoc, ArgTy,
        diag::err_incomplete_type_used_in_type_trait_expr))
      return false;
  }

  // Make sure the first argument is not incomplete nor a function type.
  QualType T = Args[0]->getType();
  if (T->isIncompleteType() || T->isFunctionType())
    return false;

  // Make sure the first argument is not an abstract type.
  CXXRecordDecl *RD = T->getAsCXXRecordDecl();
  if (RD && RD->isAbstract())
    return false;

  llvm::BumpPtrAllocator OpaqueExprAllocator;
  SmallVector<Expr *, 2> ArgExprs;
  ArgExprs.reserve(Args.size() - 1);
  for (unsigned I = 1, N = Args.size(); I != N; ++I) {
    QualType ArgTy = Args[I]->getType();
    if (ArgTy->isObjectType() || ArgTy->isFunctionType())
      ArgTy = S.Context.getRValueReferenceType(ArgTy);
    ArgExprs.push_back(
        new (OpaqueExprAllocator.Allocate<OpaqueValueExpr>())
            OpaqueValueExpr(Args[I]->getTypeLoc().getBeginLoc(),
                            ArgTy.getNonLValueExprType(S.Context),
                            Expr::getValueKindForType(ArgTy)));
  }

  // Perform the initialization in an unevaluated context within a SFINAE
  // trap at translation unit scope.
  EnterExpressionEvaluationContext Unevaluated(
      S, Sema::ExpressionEvaluationContext::Unevaluated);
  Sema::SFINAETrap SFINAE(S, /*AccessCheckingSFINAE=*/true);
  Sema::ContextRAII TUContext(S, S.Context.getTranslationUnitDecl());
  InitializedEntity To(InitializedEntity::InitializeTemporary(Args[0]));
  InitializationKind InitKind(InitializationKind::CreateDirect(KWLoc, KWLoc,
                                                               RParenLoc));
  InitializationSequence Init(S, To, InitKind, ArgExprs);
  if (Init.Failed())
    return false;

  ExprResult Result = Init.Perform(S, To, InitKind, ArgExprs);
  if (Result.isInvalid() || SFINAE.hasErrorOccurred())
    return false;

  if (Kind == clang::TT_IsConstructible)
    return true;

  if (Kind == clang::BTT_ReferenceBindsToTemporary) {
    if (!T->isReferenceType())
      return false;

    return !Init.isDirectReferenceBinding();
  }

  if (Kind == clang::TT_IsNothrowConstructible)
    return S.canThrow(Result.get()) == CT_Cannot;

  if (Kind == clang::TT_IsTriviallyConstructible) {
    // Under Objective-C ARC and Weak, if the destination has non-trivial
    // Objective-C lifetime, this is a non-trivial construction.
    if (T.getNonReferenceType().hasNonTrivialObjCLifetime())
      return false;

    // The initialization succeeded; now make sure there are no non-trivial
    // calls.
    return !Result.get()->hasNonTrivialCall(S.Context);
  }

  llvm_unreachable("unhandled type trait")__builtin_unreachable();
  return false;
}
  default: llvm_unreachable("not a TT")__builtin_unreachable();
}

return false;
5338}

5340ExprResult Sema::BuildTypeTrait(TypeTrait Kind, SourceLocation KWLoc,
                              ArrayRef<TypeSourceInfo *> Args,
                              SourceLocation RParenLoc) {
QualType ResultType = Context.getLogicalOperationType();

if (Kind <= UTT_Last && !CheckUnaryTypeTraitTypeCompleteness(
                             *this, Kind, KWLoc, Args[0]->getType()))
  return ExprError();

bool Dependent = false;
for (unsigned I = 0, N = Args.size(); I != N; ++I) {
  if (Args[I]->getType()->isDependentType()) {
    Dependent = true;
    break;
  }
}

bool Result = false;
if (!Dependent)
  Result = evaluateTypeTrait(*this, Kind, KWLoc, Args, RParenLoc);

return TypeTraitExpr::Create(Context, ResultType, KWLoc, Kind, Args,
                             RParenLoc, Result);
5363}

5365ExprResult Sema::ActOnTypeTrait(TypeTrait Kind, SourceLocation KWLoc,
                              ArrayRef<ParsedType> Args,
                              SourceLocation RParenLoc) {
SmallVector<TypeSourceInfo *, 4> ConvertedArgs;
ConvertedArgs.reserve(Args.size());

for (unsigned I = 0, N = Args.size(); I != N; ++I) {
  TypeSourceInfo *TInfo;
  QualType T = GetTypeFromParser(Args[I], &TInfo);
  if (!TInfo)
    TInfo = Context.getTrivialTypeSourceInfo(T, KWLoc);

  ConvertedArgs.push_back(TInfo);
}

return BuildTypeTrait(Kind, KWLoc, ConvertedArgs, RParenLoc);
5381}

5383static bool EvaluateBinaryTypeTrait(Sema &Self, TypeTrait BTT, QualType LhsT,
                                  QualType RhsT, SourceLocation KeyLoc) {
assert(!LhsT->isDependentType() && !RhsT->isDependentType() &&(static_cast<void> (0))
       "Cannot evaluate traits of dependent types")(static_cast<void> (0));

switch(BTT) {
case BTT_IsBaseOf: {
  // C++0x [meta.rel]p2
  // Base is a base class of Derived without regard to cv-qualifiers or
  // Base and Derived are not unions and name the same class type without
  // regard to cv-qualifiers.

  const RecordType *lhsRecord = LhsT->getAs<RecordType>();
  const RecordType *rhsRecord = RhsT->getAs<RecordType>();
  if (!rhsRecord || !lhsRecord) {
    const ObjCObjectType *LHSObjTy = LhsT->getAs<ObjCObjectType>();
    const ObjCObjectType *RHSObjTy = RhsT->getAs<ObjCObjectType>();
    if (!LHSObjTy || !RHSObjTy)
      return false;

    ObjCInterfaceDecl *BaseInterface = LHSObjTy->getInterface();
    ObjCInterfaceDecl *DerivedInterface = RHSObjTy->getInterface();
    if (!BaseInterface || !DerivedInterface)
      return false;

    if (Self.RequireCompleteType(
            KeyLoc, RhsT, diag::err_incomplete_type_used_in_type_trait_expr))
      return false;

    return BaseInterface->isSuperClassOf(DerivedInterface);
  }

  assert(Self.Context.hasSameUnqualifiedType(LhsT, RhsT)(static_cast<void> (0))
           == (lhsRecord == rhsRecord))(static_cast<void> (0));

  // Unions are never base classes, and never have base classes.
  // It doesn't matter if they are complete or not. See PR#41843
  if (lhsRecord && lhsRecord->getDecl()->isUnion())
    return false;
  if (rhsRecord && rhsRecord->getDecl()->isUnion())
    return false;

  if (lhsRecord == rhsRecord)
    return true;

  // C++0x [meta.rel]p2:
  //   If Base and Derived are class types and are different types
  //   (ignoring possible cv-qualifiers) then Derived shall be a
  //   complete type.
  if (Self.RequireCompleteType(KeyLoc, RhsT,
                        diag::err_incomplete_type_used_in_type_trait_expr))
    return false;

  return cast<CXXRecordDecl>(rhsRecord->getDecl())
    ->isDerivedFrom(cast<CXXRecordDecl>(lhsRecord->getDecl()));
}
case BTT_IsSame:
  return Self.Context.hasSameType(LhsT, RhsT);
case BTT_TypeCompatible: {
  // GCC ignores cv-qualifiers on arrays for this builtin.
  Qualifiers LhsQuals, RhsQuals;
  QualType Lhs = Self.getASTContext().getUnqualifiedArrayType(LhsT, LhsQuals);
  QualType Rhs = Self.getASTContext().getUnqualifiedArrayType(RhsT, RhsQuals);
  return Self.Context.typesAreCompatible(Lhs, Rhs);
}
case BTT_IsConvertible:
case BTT_IsConvertibleTo: {
  // C++0x [meta.rel]p4:
  //   Given the following function prototype:
  //
  //     template <class T>
  //       typename add_rvalue_reference<T>::type create();
  //
  //   the predicate condition for a template specialization
  //   is_convertible<From, To> shall be satisfied if and only if
  //   the return expression in the following code would be
  //   well-formed, including any implicit conversions to the return
  //   type of the function:
  //
  //     To test() {
  //       return create<From>();
  //     }
  //
  //   Access checking is performed as if in a context unrelated to To and
  //   From. Only the validity of the immediate context of the expression
  //   of the return-statement (including conversions to the return type)
  //   is considered.
  //
  // We model the initialization as a copy-initialization of a temporary
  // of the appropriate type, which for this expression is identical to the
  // return statement (since NRVO doesn't apply).

  // Functions aren't allowed to return function or array types.
  if (RhsT->isFunctionType() || RhsT->isArrayType())
    return false;

  // A return statement in a void function must have void type.
  if (RhsT->isVoidType())
    return LhsT->isVoidType();

  // A function definition requires a complete, non-abstract return type.
  if (!Self.isCompleteType(KeyLoc, RhsT) || Self.isAbstractType(KeyLoc, RhsT))
    return false;

  // Compute the result of add_rvalue_reference.
  if (LhsT->isObjectType() || LhsT->isFunctionType())
    LhsT = Self.Context.getRValueReferenceType(LhsT);

  // Build a fake source and destination for initialization.
  InitializedEntity To(InitializedEntity::InitializeTemporary(RhsT));
  OpaqueValueExpr From(KeyLoc, LhsT.getNonLValueExprType(Self.Context),
                       Expr::getValueKindForType(LhsT));
  Expr *FromPtr = &From;
  InitializationKind Kind(InitializationKind::CreateCopy(KeyLoc,
                                                         SourceLocation()));

  // Perform the initialization in an unevaluated context within a SFINAE
  // trap at translation unit scope.
  EnterExpressionEvaluationContext Unevaluated(
      Self, Sema::ExpressionEvaluationContext::Unevaluated);
  Sema::SFINAETrap SFINAE(Self, /*AccessCheckingSFINAE=*/true);
  Sema::ContextRAII TUContext(Self, Self.Context.getTranslationUnitDecl());
  InitializationSequence Init(Self, To, Kind, FromPtr);
  if (Init.Failed())
    return false;

  ExprResult Result = Init.Perform(Self, To, Kind, FromPtr);
  return !Result.isInvalid() && !SFINAE.hasErrorOccurred();
}

case BTT_IsAssignable:
case BTT_IsNothrowAssignable:
case BTT_IsTriviallyAssignable: {
  // C++11 [meta.unary.prop]p3:
  //   is_trivially_assignable is defined as:
  //     is_assignable<T, U>::value is true and the assignment, as defined by
  //     is_assignable, is known to call no operation that is not trivial
  //
  //   is_assignable is defined as:
  //     The expression declval<T>() = declval<U>() is well-formed when
  //     treated as an unevaluated operand (Clause 5).
  //
  //   For both, T and U shall be complete types, (possibly cv-qualified)
  //   void, or arrays of unknown bound.
  if (!LhsT->isVoidType() && !LhsT->isIncompleteArrayType() &&
      Self.RequireCompleteType(KeyLoc, LhsT,
        diag::err_incomplete_type_used_in_type_trait_expr))
    return false;
  if (!RhsT->isVoidType() && !RhsT->isIncompleteArrayType() &&
      Self.RequireCompleteType(KeyLoc, RhsT,
        diag::err_incomplete_type_used_in_type_trait_expr))
    return false;

  // cv void is never assignable.
  if (LhsT->isVoidType() || RhsT->isVoidType())
    return false;

  // Build expressions that emulate the effect of declval<T>() and
  // declval<U>().
  if (LhsT->isObjectType() || LhsT->isFunctionType())
    LhsT = Self.Context.getRValueReferenceType(LhsT);
  if (RhsT->isObjectType() || RhsT->isFunctionType())
    RhsT = Self.Context.getRValueReferenceType(RhsT);
  OpaqueValueExpr Lhs(KeyLoc, LhsT.getNonLValueExprType(Self.Context),
                      Expr::getValueKindForType(LhsT));
  OpaqueValueExpr Rhs(KeyLoc, RhsT.getNonLValueExprType(Self.Context),
                      Expr::getValueKindForType(RhsT));

  // Attempt the assignment in an unevaluated context within a SFINAE
  // trap at translation unit scope.
  EnterExpressionEvaluationContext Unevaluated(
      Self, Sema::ExpressionEvaluationContext::Unevaluated);
  Sema::SFINAETrap SFINAE(Self, /*AccessCheckingSFINAE=*/true);
  Sema::ContextRAII TUContext(Self, Self.Context.getTranslationUnitDecl());
  ExprResult Result = Self.BuildBinOp(/*S=*/nullptr, KeyLoc, BO_Assign, &Lhs,
                                      &Rhs);
  if (Result.isInvalid())
    return false;

  // Treat the assignment as unused for the purpose of -Wdeprecated-volatile.
  Self.CheckUnusedVolatileAssignment(Result.get());

  if (SFINAE.hasErrorOccurred())
    return false;

  if (BTT == BTT_IsAssignable)
    return true;

  if (BTT == BTT_IsNothrowAssignable)
    return Self.canThrow(Result.get()) == CT_Cannot;

  if (BTT == BTT_IsTriviallyAssignable) {
    // Under Objective-C ARC and Weak, if the destination has non-trivial
    // Objective-C lifetime, this is a non-trivial assignment.
    if (LhsT.getNonReferenceType().hasNonTrivialObjCLifetime())
      return false;

    return !Result.get()->hasNonTrivialCall(Self.Context);
  }

  llvm_unreachable("unhandled type trait")__builtin_unreachable();
  return false;
}
  default: llvm_unreachable("not a BTT")__builtin_unreachable();
}
llvm_unreachable("Unknown type trait or not implemented")__builtin_unreachable();
5589}

5591ExprResult Sema::ActOnArrayTypeTrait(ArrayTypeTrait ATT,
                                   SourceLocation KWLoc,
                                   ParsedType Ty,
                                   Expr* DimExpr,
                                   SourceLocation RParen) {
TypeSourceInfo *TSInfo;
QualType T = GetTypeFromParser(Ty, &TSInfo);
if (!TSInfo)
  TSInfo = Context.getTrivialTypeSourceInfo(T);

return BuildArrayTypeTrait(ATT, KWLoc, TSInfo, DimExpr, RParen);
5602}

5604static uint64_t EvaluateArrayTypeTrait(Sema &Self, ArrayTypeTrait ATT,
                                         QualType T, Expr *DimExpr,
                                         SourceLocation KeyLoc) {
assert(!T->isDependentType() && "Cannot evaluate traits of dependent type")(static_cast<void> (0));

switch(ATT) {
case ATT_ArrayRank:
  if (T->isArrayType()) {
    unsigned Dim = 0;
    while (const ArrayType *AT = Self.Context.getAsArrayType(T)) {
      ++Dim;
      T = AT->getElementType();
    }
    return Dim;
  }
  return 0;

case ATT_ArrayExtent: {
  llvm::APSInt Value;
  uint64_t Dim;
  if (Self.VerifyIntegerConstantExpression(
              DimExpr, &Value, diag::err_dimension_expr_not_constant_integer)
          .isInvalid())
    return 0;
  if (Value.isSigned() && Value.isNegative()) {
    Self.Diag(KeyLoc, diag::err_dimension_expr_not_constant_integer)
      << DimExpr->getSourceRange();
    return 0;
  }
  Dim = Value.getLimitedValue();

  if (T->isArrayType()) {
    unsigned D = 0;
    bool Matched = false;
    while (const ArrayType *AT = Self.Context.getAsArrayType(T)) {
      if (Dim == D) {
        Matched = true;
        break;
      }
      ++D;
      T = AT->getElementType();
    }

    if (Matched && T->isArrayType()) {
      if (const ConstantArrayType *CAT = Self.Context.getAsConstantArrayType(T))
        return CAT->getSize().getLimitedValue();
    }
  }
  return 0;
}
}
llvm_unreachable("Unknown type trait or not implemented")__builtin_unreachable();
5656}

5658ExprResult Sema::BuildArrayTypeTrait(ArrayTypeTrait ATT,
                                   SourceLocation KWLoc,
                                   TypeSourceInfo *TSInfo,
                                   Expr* DimExpr,
                                   SourceLocation RParen) {
QualType T = TSInfo->getType();

// FIXME: This should likely be tracked as an APInt to remove any host
// assumptions about the width of size_t on the target.
uint64_t Value = 0;
if (!T->isDependentType())
  Value = EvaluateArrayTypeTrait(*this, ATT, T, DimExpr, KWLoc);

// While the specification for these traits from the Embarcadero C++
// compiler's documentation says the return type is 'unsigned int', Clang
// returns 'size_t'. On Windows, the primary platform for the Embarcadero
// compiler, there is no difference. On several other platforms this is an
// important distinction.
return new (Context) ArrayTypeTraitExpr(KWLoc, ATT, TSInfo, Value, DimExpr,
                                        RParen, Context.getSizeType());
5678}

5680ExprResult Sema::ActOnExpressionTrait(ExpressionTrait ET,
                                    SourceLocation KWLoc,
                                    Expr *Queried,
                                    SourceLocation RParen) {
// If error parsing the expression, ignore.
if (!Queried)
  return ExprError();

ExprResult Result = BuildExpressionTrait(ET, KWLoc, Queried, RParen);

return Result;
5691}

5693static bool EvaluateExpressionTrait(ExpressionTrait ET, Expr *E) {
switch (ET) {
case ET_IsLValueExpr: return E->isLValue();
case ET_IsRValueExpr:
  return E->isPRValue();
}
llvm_unreachable("Expression trait not covered by switch")__builtin_unreachable();
5700}

5702ExprResult Sema::BuildExpressionTrait(ExpressionTrait ET,
                                    SourceLocation KWLoc,
                                    Expr *Queried,
                                    SourceLocation RParen) {
if (Queried->isTypeDependent()) {
  // Delay type-checking for type-dependent expressions.
} else if (Queried->getType()->isPlaceholderType()) {
  ExprResult PE = CheckPlaceholderExpr(Queried);
  if (PE.isInvalid()) return ExprError();
  return BuildExpressionTrait(ET, KWLoc, PE.get(), RParen);
}

bool Value = EvaluateExpressionTrait(ET, Queried);

return new (Context)
    ExpressionTraitExpr(KWLoc, ET, Queried, Value, RParen, Context.BoolTy);
5718}

5720QualType Sema::CheckPointerToMemberOperands(ExprResult &LHS, ExprResult &RHS,
                                          ExprValueKind &VK,
                                          SourceLocation Loc,
                                          bool isIndirect) {
assert(!LHS.get()->getType()->isPlaceholderType() &&(static_cast<void> (0))
       !RHS.get()->getType()->isPlaceholderType() &&(static_cast<void> (0))
       "placeholders should have been weeded out by now")(static_cast<void> (0));

// The LHS undergoes lvalue conversions if this is ->*, and undergoes the
// temporary materialization conversion otherwise.
if (isIndirect)
  LHS = DefaultLvalueConversion(LHS.get());
else if (LHS.get()->isPRValue())
  LHS = TemporaryMaterializationConversion(LHS.get());
if (LHS.isInvalid())
  return QualType();

// The RHS always undergoes lvalue conversions.
RHS = DefaultLvalueConversion(RHS.get());
if (RHS.isInvalid()) return QualType();

const char *OpSpelling = isIndirect ? "->*" : ".*";
// C++ 5.5p2
//   The binary operator .* [p3: ->*] binds its second operand, which shall
//   be of type "pointer to member of T" (where T is a completely-defined
//   class type) [...]
QualType RHSType = RHS.get()->getType();
const MemberPointerType *MemPtr = RHSType->getAs<MemberPointerType>();
if (!MemPtr) {
  Diag(Loc, diag::err_bad_memptr_rhs)
    << OpSpelling << RHSType << RHS.get()->getSourceRange();
  return QualType();
}

QualType Class(MemPtr->getClass(), 0);

// Note: C++ [expr.mptr.oper]p2-3 says that the class type into which the
// member pointer points must be completely-defined. However, there is no
// reason for this semantic distinction, and the rule is not enforced by
// other compilers. Therefore, we do not check this property, as it is
// likely to be considered a defect.

// C++ 5.5p2
//   [...] to its first operand, which shall be of class T or of a class of
//   which T is an unambiguous and accessible base class. [p3: a pointer to
//   such a class]
QualType LHSType = LHS.get()->getType();
if (isIndirect) {
  if (const PointerType *Ptr = LHSType->getAs<PointerType>())
    LHSType = Ptr->getPointeeType();
  else {
    Diag(Loc, diag::err_bad_memptr_lhs)
      << OpSpelling << 1 << LHSType
      << FixItHint::CreateReplacement(SourceRange(Loc), ".*");
    return QualType();
  }
}

if (!Context.hasSameUnqualifiedType(Class, LHSType)) {
  // If we want to check the hierarchy, we need a complete type.
  if (RequireCompleteType(Loc, LHSType, diag::err_bad_memptr_lhs,
                          OpSpelling, (int)isIndirect)) {
    return QualType();
  }

  if (!IsDerivedFrom(Loc, LHSType, Class)) {
    Diag(Loc, diag::err_bad_memptr_lhs) << OpSpelling
      << (int)isIndirect << LHS.get()->getType();
    return QualType();
  }

  CXXCastPath BasePath;
  if (CheckDerivedToBaseConversion(
          LHSType, Class, Loc,
          SourceRange(LHS.get()->getBeginLoc(), RHS.get()->getEndLoc()),
          &BasePath))
    return QualType();

  // Cast LHS to type of use.
  QualType UseType = Context.getQualifiedType(Class, LHSType.getQualifiers());
  if (isIndirect)
    UseType = Context.getPointerType(UseType);
  ExprValueKind VK = isIndirect ? VK_PRValue : LHS.get()->getValueKind();
  LHS = ImpCastExprToType(LHS.get(), UseType, CK_DerivedToBase, VK,
                          &BasePath);
}

if (isa<CXXScalarValueInitExpr>(RHS.get()->IgnoreParens())) {
  // Diagnose use of pointer-to-member type which when used as
  // the functional cast in a pointer-to-member expression.
  Diag(Loc, diag::err_pointer_to_member_type) << isIndirect;
   return QualType();
}

// C++ 5.5p2
//   The result is an object or a function of the type specified by the
//   second operand.
// The cv qualifiers are the union of those in the pointer and the left side,
// in accordance with 5.5p5 and 5.2.5.
QualType Result = MemPtr->getPointeeType();
Result = Context.getCVRQualifiedType(Result, LHSType.getCVRQualifiers());

// C++0x [expr.mptr.oper]p6:
//   In a .* expression whose object expression is an rvalue, the program is
//   ill-formed if the second operand is a pointer to member function with
//   ref-qualifier &. In a ->* expression or in a .* expression whose object
//   expression is an lvalue, the program is ill-formed if the second operand
//   is a pointer to member function with ref-qualifier &&.
if (const FunctionProtoType *Proto = Result->getAs<FunctionProtoType>()) {
  switch (Proto->getRefQualifier()) {
  case RQ_None:
    // Do nothing
    break;

  case RQ_LValue:
    if (!isIndirect && !LHS.get()->Classify(Context).isLValue()) {
      // C++2a allows functions with ref-qualifier & if their cv-qualifier-seq
      // is (exactly) 'const'.
      if (Proto->isConst() && !Proto->isVolatile())
        Diag(Loc, getLangOpts().CPlusPlus20
                      ? diag::warn_cxx17_compat_pointer_to_const_ref_member_on_rvalue
                      : diag::ext_pointer_to_const_ref_member_on_rvalue);
      else
        Diag(Loc, diag::err_pointer_to_member_oper_value_classify)
            << RHSType << 1 << LHS.get()->getSourceRange();
    }
    break;

  case RQ_RValue:
    if (isIndirect || !LHS.get()->Classify(Context).isRValue())
      Diag(Loc, diag::err_pointer_to_member_oper_value_classify)
        << RHSType << 0 << LHS.get()->getSourceRange();
    break;
  }
}

// C++ [expr.mptr.oper]p6:
//   The result of a .* expression whose second operand is a pointer
//   to a data member is of the same value category as its
//   first operand. The result of a .* expression whose second
//   operand is a pointer to a member function is a prvalue. The
//   result of an ->* expression is an lvalue if its second operand
//   is a pointer to data member and a prvalue otherwise.
if (Result->isFunctionType()) {
  VK = VK_PRValue;
  return Context.BoundMemberTy;
} else if (isIndirect) {
  VK = VK_LValue;
} else {
  VK = LHS.get()->getValueKind();
}

return Result;
5873}

5875/// Try to convert a type to another according to C++11 5.16p3.
5876///
5877/// This is part of the parameter validation for the ? operator. If either
5878/// value operand is a class type, the two operands are attempted to be
5879/// converted to each other. This function does the conversion in one direction.
5880/// It returns true if the program is ill-formed and has already been diagnosed
5881/// as such.
5882static bool TryClassUnification(Sema &Self, Expr *From, Expr *To,
                              SourceLocation QuestionLoc,
                              bool &HaveConversion,
                              QualType &ToType) {
HaveConversion = false;
ToType = To->getType();

InitializationKind Kind =
    InitializationKind::CreateCopy(To->getBeginLoc(), SourceLocation());
// C++11 5.16p3
//   The process for determining whether an operand expression E1 of type T1
//   can be converted to match an operand expression E2 of type T2 is defined
//   as follows:
//   -- If E2 is an lvalue: E1 can be converted to match E2 if E1 can be
//      implicitly converted to type "lvalue reference to T2", subject to the
//      constraint that in the conversion the reference must bind directly to
//      an lvalue.
//   -- If E2 is an xvalue: E1 can be converted to match E2 if E1 can be
//      implicitly converted to the type "rvalue reference to R2", subject to
//      the constraint that the reference must bind directly.
if (To->isGLValue()) {
  QualType T = Self.Context.getReferenceQualifiedType(To);
  InitializedEntity Entity = InitializedEntity::InitializeTemporary(T);

  InitializationSequence InitSeq(Self, Entity, Kind, From);
  if (InitSeq.isDirectReferenceBinding()) {
    ToType = T;
    HaveConversion = true;
    return false;
  }

  if (InitSeq.isAmbiguous())
    return InitSeq.Diagnose(Self, Entity, Kind, From);
}

//   -- If E2 is an rvalue, or if the conversion above cannot be done:
//      -- if E1 and E2 have class type, and the underlying class types are
//         the same or one is a base class of the other:
QualType FTy = From->getType();
QualType TTy = To->getType();
const RecordType *FRec = FTy->getAs<RecordType>();
const RecordType *TRec = TTy->getAs<RecordType>();
bool FDerivedFromT = FRec && TRec && FRec != TRec &&
                     Self.IsDerivedFrom(QuestionLoc, FTy, TTy);
if (FRec && TRec && (FRec == TRec || FDerivedFromT ||
                     Self.IsDerivedFrom(QuestionLoc, TTy, FTy))) {
  //         E1 can be converted to match E2 if the class of T2 is the
  //         same type as, or a base class of, the class of T1, and
  //         [cv2 > cv1].
  if (FRec == TRec || FDerivedFromT) {
    if (TTy.isAtLeastAsQualifiedAs(FTy)) {
      InitializedEntity Entity = InitializedEntity::InitializeTemporary(TTy);
      InitializationSequence InitSeq(Self, Entity, Kind, From);
      if (InitSeq) {
        HaveConversion = true;
        return false;
      }

      if (InitSeq.isAmbiguous())
        return InitSeq.Diagnose(Self, Entity, Kind, From);
    }
  }

  return false;
}

//     -- Otherwise: E1 can be converted to match E2 if E1 can be
//        implicitly converted to the type that expression E2 would have
//        if E2 were converted to an rvalue (or the type it has, if E2 is
//        an rvalue).
//
// This actually refers very narrowly to the lvalue-to-rvalue conversion, not
// to the array-to-pointer or function-to-pointer conversions.
TTy = TTy.getNonLValueExprType(Self.Context);

InitializedEntity Entity = InitializedEntity::InitializeTemporary(TTy);
InitializationSequence InitSeq(Self, Entity, Kind, From);
HaveConversion = !InitSeq.Failed();
ToType = TTy;
if (InitSeq.isAmbiguous())
  return InitSeq.Diagnose(Self, Entity, Kind, From);

return false;
5965}

5967/// Try to find a common type for two according to C++0x 5.16p5.
5968///
5969/// This is part of the parameter validation for the ? operator. If either
5970/// value operand is a class type, overload resolution is used to find a
5971/// conversion to a common type.
5972static bool FindConditionalOverload(Sema &Self, ExprResult &LHS, ExprResult &RHS,
                                  SourceLocation QuestionLoc) {
Expr *Args[2] = { LHS.get(), RHS.get() };
OverloadCandidateSet CandidateSet(QuestionLoc,
                                  OverloadCandidateSet::CSK_Operator);
Self.AddBuiltinOperatorCandidates(OO_Conditional, QuestionLoc, Args,
                                  CandidateSet);

OverloadCandidateSet::iterator Best;
switch (CandidateSet.BestViableFunction(Self, QuestionLoc, Best)) {
  case OR_Success: {
    // We found a match. Perform the conversions on the arguments and move on.
    ExprResult LHSRes = Self.PerformImplicitConversion(
        LHS.get(), Best->BuiltinParamTypes[0], Best->Conversions[0],
        Sema::AA_Converting);
    if (LHSRes.isInvalid())
      break;
    LHS = LHSRes;

    ExprResult RHSRes = Self.PerformImplicitConversion(
        RHS.get(), Best->BuiltinParamTypes[1], Best->Conversions[1],
        Sema::AA_Converting);
    if (RHSRes.isInvalid())
      break;
    RHS = RHSRes;
    if (Best->Function)
      Self.MarkFunctionReferenced(QuestionLoc, Best->Function);
    return false;
  }

  case OR_No_Viable_Function:

    // Emit a better diagnostic if one of the expressions is a null pointer
    // constant and the other is a pointer type. In this case, the user most
    // likely forgot to take the address of the other expression.
    if (Self.DiagnoseConditionalForNull(LHS.get(), RHS.get(), QuestionLoc))
      return true;

    Self.Diag(QuestionLoc, diag::err_typecheck_cond_incompatible_operands)
      << LHS.get()->getType() << RHS.get()->getType()
      << LHS.get()->getSourceRange() << RHS.get()->getSourceRange();
    return true;

  case OR_Ambiguous:
    Self.Diag(QuestionLoc, diag::err_conditional_ambiguous_ovl)
      << LHS.get()->getType() << RHS.get()->getType()
      << LHS.get()->getSourceRange() << RHS.get()->getSourceRange();
    // FIXME: Print the possible common types by printing the return types of
    // the viable candidates.
    break;

  case OR_Deleted:
    llvm_unreachable("Conditional operator has only built-in overloads")__builtin_unreachable();
}
return true;
6027}

6029/// Perform an "extended" implicit conversion as returned by
6030/// TryClassUnification.
6031static bool ConvertForConditional(Sema &Self, ExprResult &E, QualType T) {
InitializedEntity Entity = InitializedEntity::InitializeTemporary(T);
InitializationKind Kind =
    InitializationKind::CreateCopy(E.get()->getBeginLoc(), SourceLocation());
Expr *Arg = E.get();
InitializationSequence InitSeq(Self, Entity, Kind, Arg);
ExprResult Result = InitSeq.Perform(Self, Entity, Kind, Arg);
if (Result.isInvalid())
  return true;

E = Result;
return false;
6043}

6045// Check the condition operand of ?: to see if it is valid for the GCC
6046// extension.
6047static bool isValidVectorForConditionalCondition(ASTContext &Ctx,
                                               QualType CondTy) {
if (!CondTy->isVectorType() && !CondTy->isExtVectorType())
  return false;
const QualType EltTy =
    cast<VectorType>(CondTy.getCanonicalType())->getElementType();
assert(!EltTy->isBooleanType() && !EltTy->isEnumeralType() &&(static_cast<void> (0))
       "Vectors cant be boolean or enum types")(static_cast<void> (0));
return EltTy->isIntegralType(Ctx);
6056}

6058QualType Sema::CheckVectorConditionalTypes(ExprResult &Cond, ExprResult &LHS,
                                         ExprResult &RHS,
                                         SourceLocation QuestionLoc) {
LHS = DefaultFunctionArrayLvalueConversion(LHS.get());
RHS = DefaultFunctionArrayLvalueConversion(RHS.get());

QualType CondType = Cond.get()->getType();
const auto *CondVT = CondType->castAs<VectorType>();
QualType CondElementTy = CondVT->getElementType();
unsigned CondElementCount = CondVT->getNumElements();
QualType LHSType = LHS.get()->getType();
const auto *LHSVT = LHSType->getAs<VectorType>();
QualType RHSType = RHS.get()->getType();
const auto *RHSVT = RHSType->getAs<VectorType>();

QualType ResultType;


if (LHSVT && RHSVT) {
  if (isa<ExtVectorType>(CondVT) != isa<ExtVectorType>(LHSVT)) {
    Diag(QuestionLoc, diag::err_conditional_vector_cond_result_mismatch)
        << /*isExtVector*/ isa<ExtVectorType>(CondVT);
    return {};
  }

  // If both are vector types, they must be the same type.
  if (!Context.hasSameType(LHSType, RHSType)) {
    Diag(QuestionLoc, diag::err_conditional_vector_mismatched)
        << LHSType << RHSType;
    return {};
  }
  ResultType = LHSType;
} else if (LHSVT || RHSVT) {
  ResultType = CheckVectorOperands(
      LHS, RHS, QuestionLoc, /*isCompAssign*/ false, /*AllowBothBool*/ true,
      /*AllowBoolConversions*/ false);
  if (ResultType.isNull())
    return {};
} else {
  // Both are scalar.
  QualType ResultElementTy;
  LHSType = LHSType.getCanonicalType().getUnqualifiedType();
  RHSType = RHSType.getCanonicalType().getUnqualifiedType();

  if (Context.hasSameType(LHSType, RHSType))
    ResultElementTy = LHSType;
  else
    ResultElementTy =
        UsualArithmeticConversions(LHS, RHS, QuestionLoc, ACK_Conditional);

  if (ResultElementTy->isEnumeralType()) {
    Diag(QuestionLoc, diag::err_conditional_vector_operand_type)
        << ResultElementTy;
    return {};
  }
  if (CondType->isExtVectorType())
    ResultType =
        Context.getExtVectorType(ResultElementTy, CondVT->getNumElements());
  else
    ResultType = Context.getVectorType(
        ResultElementTy, CondVT->getNumElements(), VectorType::GenericVector);

  LHS = ImpCastExprToType(LHS.get(), ResultType, CK_VectorSplat);
  RHS = ImpCastExprToType(RHS.get(), ResultType, CK_VectorSplat);
}

assert(!ResultType.isNull() && ResultType->isVectorType() &&(static_cast<void> (0))
       (!CondType->isExtVectorType() || ResultType->isExtVectorType()) &&(static_cast<void> (0))
       "Result should have been a vector type")(static_cast<void> (0));
auto *ResultVectorTy = ResultType->castAs<VectorType>();
QualType ResultElementTy = ResultVectorTy->getElementType();
unsigned ResultElementCount = ResultVectorTy->getNumElements();

if (ResultElementCount != CondElementCount) {
  Diag(QuestionLoc, diag::err_conditional_vector_size) << CondType
                                                       << ResultType;
  return {};
}

if (Context.getTypeSize(ResultElementTy) !=
    Context.getTypeSize(CondElementTy)) {
  Diag(QuestionLoc, diag::err_conditional_vector_element_size) << CondType
                                                               << ResultType;
  return {};
}

return ResultType;
6145}

6147/// Check the operands of ?: under C++ semantics.
6148///
6149/// See C++ [expr.cond]. Note that LHS is never null, even for the GNU x ?: y
6150/// extension. In this case, LHS == Cond. (But they're not aliases.)
6151///
6152/// This function also implements GCC's vector extension and the
6153/// OpenCL/ext_vector_type extension for conditionals. The vector extensions
6154/// permit the use of a?b:c where the type of a is that of a integer vector with
6155/// the same number of elements and size as the vectors of b and c. If one of
6156/// either b or c is a scalar it is implicitly converted to match the type of
6157/// the vector. Otherwise the expression is ill-formed. If both b and c are
6158/// scalars, then b and c are checked and converted to the type of a if
6159/// possible.
6160///
6161/// The expressions are evaluated differently for GCC's and OpenCL's extensions.
6162/// For the GCC extension, the ?: operator is evaluated as
6163///   (a[0] != 0 ? b[0] : c[0], .. , a[n] != 0 ? b[n] : c[n]).
6164/// For the OpenCL extensions, the ?: operator is evaluated as
6165///   (most-significant-bit-set(a[0])  ? b[0] : c[0], .. ,
6166///    most-significant-bit-set(a[n]) ? b[n] : c[n]).
6167QualType Sema::CXXCheckConditionalOperands(ExprResult &Cond, ExprResult &LHS,
                                         ExprResult &RHS, ExprValueKind &VK,
                                         ExprObjectKind &OK,
                                         SourceLocation QuestionLoc) {
// FIXME: Handle C99's complex types, block pointers and Obj-C++ interface
// pointers.

// Assume r-value.
VK = VK_PRValue;
OK = OK_Ordinary;
bool IsVectorConditional =
    isValidVectorForConditionalCondition(Context, Cond.get()->getType());

// C++11 [expr.cond]p1
//   The first expression is contextually converted to bool.
if (!Cond.get()->isTypeDependent()) {
  ExprResult CondRes = IsVectorConditional
                           ? DefaultFunctionArrayLvalueConversion(Cond.get())
                           : CheckCXXBooleanCondition(Cond.get());
  if (CondRes.isInvalid())
    return QualType();
  Cond = CondRes;
} else {
  // To implement C++, the first expression typically doesn't alter the result
  // type of the conditional, however the GCC compatible vector extension
  // changes the result type to be that of the conditional. Since we cannot
  // know if this is a vector extension here, delay the conversion of the
  // LHS/RHS below until later.
  return Context.DependentTy;
}


// Either of the arguments dependent?
if (LHS.get()->isTypeDependent() || RHS.get()->isTypeDependent())
  return Context.DependentTy;

// C++11 [expr.cond]p2
//   If either the second or the third operand has type (cv) void, ...
QualType LTy = LHS.get()->getType();
QualType RTy = RHS.get()->getType();
bool LVoid = LTy->isVoidType();
bool RVoid = RTy->isVoidType();
if (LVoid || RVoid) {
  //   ... one of the following shall hold:
  //   -- The second or the third operand (but not both) is a (possibly
  //      parenthesized) throw-expression; the result is of the type
  //      and value category of the other.
  bool LThrow = isa<CXXThrowExpr>(LHS.get()->IgnoreParenImpCasts());
  bool RThrow = isa<CXXThrowExpr>(RHS.get()->IgnoreParenImpCasts());

  // Void expressions aren't legal in the vector-conditional expressions.
  if (IsVectorConditional) {
    SourceRange DiagLoc =
        LVoid ? LHS.get()->getSourceRange() : RHS.get()->getSourceRange();
    bool IsThrow = LVoid ? LThrow : RThrow;
    Diag(DiagLoc.getBegin(), diag::err_conditional_vector_has_void)
        << DiagLoc << IsThrow;
    return QualType();
  }

  if (LThrow != RThrow) {
    Expr *NonThrow = LThrow ? RHS.get() : LHS.get();
    VK = NonThrow->getValueKind();
    // DR (no number yet): the result is a bit-field if the
    // non-throw-expression operand is a bit-field.
    OK = NonThrow->getObjectKind();
    return NonThrow->getType();
  }

  //   -- Both the second and third operands have type void; the result is of
  //      type void and is a prvalue.
  if (LVoid && RVoid)
    return Context.VoidTy;

  // Neither holds, error.
  Diag(QuestionLoc, diag::err_conditional_void_nonvoid)
    << (LVoid ? RTy : LTy) << (LVoid ? 0 : 1)
    << LHS.get()->getSourceRange() << RHS.get()->getSourceRange();
  return QualType();
}

// Neither is void.
if (IsVectorConditional)
  return CheckVectorConditionalTypes(Cond, LHS, RHS, QuestionLoc);

// C++11 [expr.cond]p3
//   Otherwise, if the second and third operand have different types, and
//   either has (cv) class type [...] an attempt is made to convert each of
//   those operands to the type of the other.
if (!Context.hasSameType(LTy, RTy) &&
    (LTy->isRecordType() || RTy->isRecordType())) {
  // These return true if a single direction is already ambiguous.
  QualType L2RType, R2LType;
  bool HaveL2R, HaveR2L;
  if (TryClassUnification(*this, LHS.get(), RHS.get(), QuestionLoc, HaveL2R, L2RType))
    return QualType();
  if (TryClassUnification(*this, RHS.get(), LHS.get(), QuestionLoc, HaveR2L, R2LType))
    return QualType();

  //   If both can be converted, [...] the program is ill-formed.
  if (HaveL2R && HaveR2L) {
    Diag(QuestionLoc, diag::err_conditional_ambiguous)
      << LTy << RTy << LHS.get()->getSourceRange() << RHS.get()->getSourceRange();
    return QualType();
  }

  //   If exactly one conversion is possible, that conversion is applied to
  //   the chosen operand and the converted operands are used in place of the
  //   original operands for the remainder of this section.
  if (HaveL2R) {
    if (ConvertForConditional(*this, LHS, L2RType) || LHS.isInvalid())
      return QualType();
    LTy = LHS.get()->getType();
  } else if (HaveR2L) {
    if (ConvertForConditional(*this, RHS, R2LType) || RHS.isInvalid())
      return QualType();
    RTy = RHS.get()->getType();
  }
}

// C++11 [expr.cond]p3
//   if both are glvalues of the same value category and the same type except
//   for cv-qualification, an attempt is made to convert each of those
//   operands to the type of the other.
// FIXME:
//   Resolving a defect in P0012R1: we extend this to cover all cases where
//   one of the operands is reference-compatible with the other, in order
//   to support conditionals between functions differing in noexcept. This
//   will similarly cover difference in array bounds after P0388R4.
// FIXME: If LTy and RTy have a composite pointer type, should we convert to
//   that instead?
ExprValueKind LVK = LHS.get()->getValueKind();
ExprValueKind RVK = RHS.get()->getValueKind();
if (!Context.hasSameType(LTy, RTy) && LVK == RVK && LVK != VK_PRValue) {
  // DerivedToBase was already handled by the class-specific case above.
  // FIXME: Should we allow ObjC conversions here?
  const ReferenceConversions AllowedConversions =
      ReferenceConversions::Qualification |
      ReferenceConversions::NestedQualification |
      ReferenceConversions::Function;

  ReferenceConversions RefConv;
  if (CompareReferenceRelationship(QuestionLoc, LTy, RTy, &RefConv) ==
          Ref_Compatible &&
      !(RefConv & ~AllowedConversions) &&
      // [...] subject to the constraint that the reference must bind
      // directly [...]
      !RHS.get()->refersToBitField() && !RHS.get()->refersToVectorElement()) {
    RHS = ImpCastExprToType(RHS.get(), LTy, CK_NoOp, RVK);
    RTy = RHS.get()->getType();
  } else if (CompareReferenceRelationship(QuestionLoc, RTy, LTy, &RefConv) ==
                 Ref_Compatible &&
             !(RefConv & ~AllowedConversions) &&
             !LHS.get()->refersToBitField() &&
             !LHS.get()->refersToVectorElement()) {
    LHS = ImpCastExprToType(LHS.get(), RTy, CK_NoOp, LVK);
    LTy = LHS.get()->getType();
  }
}

// C++11 [expr.cond]p4
//   If the second and third operands are glvalues of the same value
//   category and have the same type, the result is of that type and
//   value category and it is a bit-field if the second or the third
//   operand is a bit-field, or if both are bit-fields.
// We only extend this to bitfields, not to the crazy other kinds of
// l-values.
bool Same = Context.hasSameType(LTy, RTy);
if (Same && LVK == RVK && LVK != VK_PRValue &&
    LHS.get()->isOrdinaryOrBitFieldObject() &&
    RHS.get()->isOrdinaryOrBitFieldObject()) {
  VK = LHS.get()->getValueKind();
  if (LHS.get()->getObjectKind() == OK_BitField ||
      RHS.get()->getObjectKind() == OK_BitField)
    OK = OK_BitField;

  // If we have function pointer types, unify them anyway to unify their
  // exception specifications, if any.
  if (LTy->isFunctionPointerType() || LTy->isMemberFunctionPointerType()) {
    Qualifiers Qs = LTy.getQualifiers();
    LTy = FindCompositePointerType(QuestionLoc, LHS, RHS,
                                   /*ConvertArgs*/false);
    LTy = Context.getQualifiedType(LTy, Qs);

    assert(!LTy.isNull() && "failed to find composite pointer type for "(static_cast<void> (0))
                            "canonically equivalent function ptr types")(static_cast<void> (0));
    assert(Context.hasSameType(LTy, RTy) && "bad composite pointer type")(static_cast<void> (0));
  }

  return LTy;
}

// C++11 [expr.cond]p5
//   Otherwise, the result is a prvalue. If the second and third operands
//   do not have the same type, and either has (cv) class type, ...
if (!Same && (LTy->isRecordType() || RTy->isRecordType())) {
  //   ... overload resolution is used to determine the conversions (if any)
  //   to be applied to the operands. If the overload resolution fails, the
  //   program is ill-formed.
  if (FindConditionalOverload(*this, LHS, RHS, QuestionLoc))
    return QualType();
}

// C++11 [expr.cond]p6
//   Lvalue-to-rvalue, array-to-pointer, and function-to-pointer standard
//   conversions are performed on the second and third operands.
LHS = DefaultFunctionArrayLvalueConversion(LHS.get());
RHS = DefaultFunctionArrayLvalueConversion(RHS.get());
if (LHS.isInvalid() || RHS.isInvalid())
  return QualType();
LTy = LHS.get()->getType();
RTy = RHS.get()->getType();

//   After those conversions, one of the following shall hold:
//   -- The second and third operands have the same type; the result
//      is of that type. If the operands have class type, the result
//      is a prvalue temporary of the result type, which is
//      copy-initialized from either the second operand or the third
//      operand depending on the value of the first operand.
if (Context.getCanonicalType(LTy) == Context.getCanonicalType(RTy)) {
  if (LTy->isRecordType()) {
    // The operands have class type. Make a temporary copy.
    InitializedEntity Entity = InitializedEntity::InitializeTemporary(LTy);

    ExprResult LHSCopy = PerformCopyInitialization(Entity,
                                                   SourceLocation(),
                                                   LHS);
    if (LHSCopy.isInvalid())
      return QualType();

    ExprResult RHSCopy = PerformCopyInitialization(Entity,
                                                   SourceLocation(),
                                                   RHS);
    if (RHSCopy.isInvalid())
      return QualType();

    LHS = LHSCopy;
    RHS = RHSCopy;
  }

  // If we have function pointer types, unify them anyway to unify their
  // exception specifications, if any.
  if (LTy->isFunctionPointerType() || LTy->isMemberFunctionPointerType()) {
    LTy = FindCompositePointerType(QuestionLoc, LHS, RHS);
    assert(!LTy.isNull() && "failed to find composite pointer type for "(static_cast<void> (0))
                            "canonically equivalent function ptr types")(static_cast<void> (0));
  }

  return LTy;
}

// Extension: conditional operator involving vector types.
if (LTy->isVectorType() || RTy->isVectorType())
  return CheckVectorOperands(LHS, RHS, QuestionLoc, /*isCompAssign*/false,
                             /*AllowBothBool*/true,
                             /*AllowBoolConversions*/false);

//   -- The second and third operands have arithmetic or enumeration type;
//      the usual arithmetic conversions are performed to bring them to a
//      common type, and the result is of that type.
if (LTy->isArithmeticType() && RTy->isArithmeticType()) {
  QualType ResTy =
      UsualArithmeticConversions(LHS, RHS, QuestionLoc, ACK_Conditional);
  if (LHS.isInvalid() || RHS.isInvalid())
    return QualType();
  if (ResTy.isNull()) {
    Diag(QuestionLoc,
         diag::err_typecheck_cond_incompatible_operands) << LTy << RTy
      << LHS.get()->getSourceRange() << RHS.get()->getSourceRange();
    return QualType();
  }

  LHS = ImpCastExprToType(LHS.get(), ResTy, PrepareScalarCast(LHS, ResTy));
  RHS = ImpCastExprToType(RHS.get(), ResTy, PrepareScalarCast(RHS, ResTy));

  return ResTy;
}

//   -- The second and third operands have pointer type, or one has pointer
//      type and the other is a null pointer constant, or both are null
//      pointer constants, at least one of which is non-integral; pointer
//      conversions and qualification conversions are performed to bring them
//      to their composite pointer type. The result is of the composite
//      pointer type.
//   -- The second and third operands have pointer to member type, or one has
//      pointer to member type and the other is a null pointer constant;
//      pointer to member conversions and qualification conversions are
//      performed to bring them to a common type, whose cv-qualification
//      shall match the cv-qualification of either the second or the third
//      operand. The result is of the common type.
QualType Composite = FindCompositePointerType(QuestionLoc, LHS, RHS);
if (!Composite.isNull())
  return Composite;

// Similarly, attempt to find composite type of two objective-c pointers.
Composite = FindCompositeObjCPointerType(LHS, RHS, QuestionLoc);
if (LHS.isInvalid() || RHS.isInvalid())
  return QualType();
if (!Composite.isNull())
  return Composite;

// Check if we are using a null with a non-pointer type.
if (DiagnoseConditionalForNull(LHS.get(), RHS.get(), QuestionLoc))
  return QualType();

Diag(QuestionLoc, diag::err_typecheck_cond_incompatible_operands)
  << LHS.get()->getType() << RHS.get()->getType()
  << LHS.get()->getSourceRange() << RHS.get()->getSourceRange();
return QualType();
6476}

6478static FunctionProtoType::ExceptionSpecInfo
6479mergeExceptionSpecs(Sema &S, FunctionProtoType::ExceptionSpecInfo ESI1,
                  FunctionProtoType::ExceptionSpecInfo ESI2,
                  SmallVectorImpl<QualType> &ExceptionTypeStorage) {
ExceptionSpecificationType EST1 = ESI1.Type;
ExceptionSpecificationType EST2 = ESI2.Type;

// If either of them can throw anything, that is the result.
if (EST1 == EST_None) return ESI1;
if (EST2 == EST_None) return ESI2;
if (EST1 == EST_MSAny) return ESI1;
if (EST2 == EST_MSAny) return ESI2;
if (EST1 == EST_NoexceptFalse) return ESI1;
if (EST2 == EST_NoexceptFalse) return ESI2;

// If either of them is non-throwing, the result is the other.
if (EST1 == EST_NoThrow) return ESI2;
if (EST2 == EST_NoThrow) return ESI1;
if (EST1 == EST_DynamicNone) return ESI2;
if (EST2 == EST_DynamicNone) return ESI1;
if (EST1 == EST_BasicNoexcept) return ESI2;
if (EST2 == EST_BasicNoexcept) return ESI1;
if (EST1 == EST_NoexceptTrue) return ESI2;
if (EST2 == EST_NoexceptTrue) return ESI1;

// If we're left with value-dependent computed noexcept expressions, we're
// stuck. Before C++17, we can just drop the exception specification entirely,
// since it's not actually part of the canonical type. And this should never
// happen in C++17, because it would mean we were computing the composite
// pointer type of dependent types, which should never happen.
if (EST1 == EST_DependentNoexcept || EST2 == EST_DependentNoexcept) {
  assert(!S.getLangOpts().CPlusPlus17 &&(static_cast<void> (0))
         "computing composite pointer type of dependent types")(static_cast<void> (0));
  return FunctionProtoType::ExceptionSpecInfo();
}

// Switch over the possibilities so that people adding new values know to
// update this function.
switch (EST1) {
case EST_None:
case EST_DynamicNone:
case EST_MSAny:
case EST_BasicNoexcept:
case EST_DependentNoexcept:
case EST_NoexceptFalse:
case EST_NoexceptTrue:
case EST_NoThrow:
  llvm_unreachable("handled above")__builtin_unreachable();

case EST_Dynamic: {
  // This is the fun case: both exception specifications are dynamic. Form
  // the union of the two lists.
  assert(EST2 == EST_Dynamic && "other cases should already be handled")(static_cast<void> (0));
  llvm::SmallPtrSet<QualType, 8> Found;
  for (auto &Exceptions : {ESI1.Exceptions, ESI2.Exceptions})
    for (QualType E : Exceptions)
      if (Found.insert(S.Context.getCanonicalType(E)).second)
        ExceptionTypeStorage.push_back(E);

  FunctionProtoType::ExceptionSpecInfo Result(EST_Dynamic);
  Result.Exceptions = ExceptionTypeStorage;
  return Result;
}

case EST_Unevaluated:
case EST_Uninstantiated:
case EST_Unparsed:
  llvm_unreachable("shouldn't see unresolved exception specifications here")__builtin_unreachable();
}

llvm_unreachable("invalid ExceptionSpecificationType")__builtin_unreachable();
6549}

6551/// Find a merged pointer type and convert the two expressions to it.
6552///
6553/// This finds the composite pointer type for \p E1 and \p E2 according to
6554/// C++2a [expr.type]p3. It converts both expressions to this type and returns
6555/// it.  It does not emit diagnostics (FIXME: that's not true if \p ConvertArgs
6556/// is \c true).
6557///
6558/// \param Loc The location of the operator requiring these two expressions to
6559/// be converted to the composite pointer type.
6560///
6561/// \param ConvertArgs If \c false, do not convert E1 and E2 to the target type.
6562QualType Sema::FindCompositePointerType(SourceLocation Loc,
                                      Expr *&E1, Expr *&E2,
                                      bool ConvertArgs) {
assert(getLangOpts().CPlusPlus && "This function assumes C++")(static_cast<void> (0));

// C++1z [expr]p14:
//   The composite pointer type of two operands p1 and p2 having types T1
//   and T2
QualType T1 = E1->getType(), T2 = E2->getType();

//   where at least one is a pointer or pointer to member type or
//   std::nullptr_t is:
bool T1IsPointerLike = T1->isAnyPointerType() || T1->isMemberPointerType() ||
                       T1->isNullPtrType();
bool T2IsPointerLike = T2->isAnyPointerType() || T2->isMemberPointerType() ||
                       T2->isNullPtrType();
if (!T1IsPointerLike && !T2IsPointerLike)
  return QualType();

//   - if both p1 and p2 are null pointer constants, std::nullptr_t;
// This can't actually happen, following the standard, but we also use this
// to implement the end of [expr.conv], which hits this case.
//
//   - if either p1 or p2 is a null pointer constant, T2 or T1, respectively;
if (T1IsPointerLike &&
    E2->isNullPointerConstant(Context, Expr::NPC_ValueDependentIsNull)) {
  if (ConvertArgs)
    E2 = ImpCastExprToType(E2, T1, T1->isMemberPointerType()
                                       ? CK_NullToMemberPointer
                                       : CK_NullToPointer).get();
  return T1;
}
if (T2IsPointerLike &&
    E1->isNullPointerConstant(Context, Expr::NPC_ValueDependentIsNull)) {
  if (ConvertArgs)
    E1 = ImpCastExprToType(E1, T2, T2->isMemberPointerType()
                                       ? CK_NullToMemberPointer
                                       : CK_NullToPointer).get();
  return T2;
}

// Now both have to be pointers or member pointers.
if (!T1IsPointerLike || !T2IsPointerLike)
  return QualType();
assert(!T1->isNullPtrType() && !T2->isNullPtrType() &&(static_cast<void> (0))
       "nullptr_t should be a null pointer constant")(static_cast<void> (0));

struct Step {
  enum Kind { Pointer, ObjCPointer, MemberPointer, Array } K;
  // Qualifiers to apply under the step kind.
  Qualifiers Quals;
  /// The class for a pointer-to-member; a constant array type with a bound
  /// (if any) for an array.
  const Type *ClassOrBound;

  Step(Kind K, const Type *ClassOrBound = nullptr)
      : K(K), Quals(), ClassOrBound(ClassOrBound) {}
  QualType rebuild(ASTContext &Ctx, QualType T) const {
    T = Ctx.getQualifiedType(T, Quals);
    switch (K) {
    case Pointer:
      return Ctx.getPointerType(T);
    case MemberPointer:
      return Ctx.getMemberPointerType(T, ClassOrBound);
    case ObjCPointer:
      return Ctx.getObjCObjectPointerType(T);
    case Array:
      if (auto *CAT = cast_or_null<ConstantArrayType>(ClassOrBound))
        return Ctx.getConstantArrayType(T, CAT->getSize(), nullptr,
                                        ArrayType::Normal, 0);
      else
        return Ctx.getIncompleteArrayType(T, ArrayType::Normal, 0);
    }
    llvm_unreachable("unknown step kind")__builtin_unreachable();
  }
};

SmallVector<Step, 8> Steps;

//  - if T1 is "pointer to cv1 C1" and T2 is "pointer to cv2 C2", where C1
//    is reference-related to C2 or C2 is reference-related to C1 (8.6.3),
//    the cv-combined type of T1 and T2 or the cv-combined type of T2 and T1,
//    respectively;
//  - if T1 is "pointer to member of C1 of type cv1 U1" and T2 is "pointer
//    to member of C2 of type cv2 U2" for some non-function type U, where
//    C1 is reference-related to C2 or C2 is reference-related to C1, the
//    cv-combined type of T2 and T1 or the cv-combined type of T1 and T2,
//    respectively;
//  - if T1 and T2 are similar types (4.5), the cv-combined type of T1 and
//    T2;
//
// Dismantle T1 and T2 to simultaneously determine whether they are similar
// and to prepare to form the cv-combined type if so.
QualType Composite1 = T1;
QualType Composite2 = T2;
unsigned NeedConstBefore = 0;
while (true) {
  assert(!Composite1.isNull() && !Composite2.isNull())(static_cast<void> (0));

  Qualifiers Q1, Q2;
  Composite1 = Context.getUnqualifiedArrayType(Composite1, Q1);
  Composite2 = Context.getUnqualifiedArrayType(Composite2, Q2);

  // Top-level qualifiers are ignored. Merge at all lower levels.
  if (!Steps.empty()) {
    // Find the qualifier union: (approximately) the unique minimal set of
    // qualifiers that is compatible with both types.
    Qualifiers Quals = Qualifiers::fromCVRUMask(Q1.getCVRUQualifiers() |
                                                Q2.getCVRUQualifiers());

    // Under one level of pointer or pointer-to-member, we can change to an
    // unambiguous compatible address space.
    if (Q1.getAddressSpace() == Q2.getAddressSpace()) {
      Quals.setAddressSpace(Q1.getAddressSpace());
    } else if (Steps.size() == 1) {
      bool MaybeQ1 = Q1.isAddressSpaceSupersetOf(Q2);
      bool MaybeQ2 = Q2.isAddressSpaceSupersetOf(Q1);
      if (MaybeQ1 == MaybeQ2)
        return QualType(); // No unique best address space.
      Quals.setAddressSpace(MaybeQ1 ? Q1.getAddressSpace()
                                    : Q2.getAddressSpace());
    } else {
      return QualType();
    }

    // FIXME: In C, we merge __strong and none to __strong at the top level.
    if (Q1.getObjCGCAttr() == Q2.getObjCGCAttr())
      Quals.setObjCGCAttr(Q1.getObjCGCAttr());
    else if (T1->isVoidPointerType() || T2->isVoidPointerType())
      assert(Steps.size() == 1)(static_cast<void> (0));
    else
      return QualType();

    // Mismatched lifetime qualifiers never compatibly include each other.
    if (Q1.getObjCLifetime() == Q2.getObjCLifetime())
      Quals.setObjCLifetime(Q1.getObjCLifetime());
    else if (T1->isVoidPointerType() || T2->isVoidPointerType())
      assert(Steps.size() == 1)(static_cast<void> (0));
    else
      return QualType();

    Steps.back().Quals = Quals;
    if (Q1 != Quals || Q2 != Quals)
      NeedConstBefore = Steps.size() - 1;
  }

  // FIXME: Can we unify the following with UnwrapSimilarTypes?
  const PointerType *Ptr1, *Ptr2;
  if ((Ptr1 = Composite1->getAs<PointerType>()) &&
      (Ptr2 = Composite2->getAs<PointerType>())) {
    Composite1 = Ptr1->getPointeeType();
    Composite2 = Ptr2->getPointeeType();
    Steps.emplace_back(Step::Pointer);
    continue;
  }

  const ObjCObjectPointerType *ObjPtr1, *ObjPtr2;
  if ((ObjPtr1 = Composite1->getAs<ObjCObjectPointerType>()) &&
      (ObjPtr2 = Composite2->getAs<ObjCObjectPointerType>())) {
    Composite1 = ObjPtr1->getPointeeType();
    Composite2 = ObjPtr2->getPointeeType();
    Steps.emplace_back(Step::ObjCPointer);
    continue;
  }

  const MemberPointerType *MemPtr1, *MemPtr2;
  if ((MemPtr1 = Composite1->getAs<MemberPointerType>()) &&
      (MemPtr2 = Composite2->getAs<MemberPointerType>())) {
    Composite1 = MemPtr1->getPointeeType();
    Composite2 = MemPtr2->getPointeeType();

    // At the top level, we can perform a base-to-derived pointer-to-member
    // conversion:
    //
    //  - [...] where C1 is reference-related to C2 or C2 is
    //    reference-related to C1
    //
    // (Note that the only kinds of reference-relatedness in scope here are
    // "same type or derived from".) At any other level, the class must
    // exactly match.
    const Type *Class = nullptr;
    QualType Cls1(MemPtr1->getClass(), 0);
    QualType Cls2(MemPtr2->getClass(), 0);
    if (Context.hasSameType(Cls1, Cls2))
      Class = MemPtr1->getClass();
    else if (Steps.empty())
      Class = IsDerivedFrom(Loc, Cls1, Cls2) ? MemPtr1->getClass() :
              IsDerivedFrom(Loc, Cls2, Cls1) ? MemPtr2->getClass() : nullptr;
    if (!Class)
      return QualType();

    Steps.emplace_back(Step::MemberPointer, Class);
    continue;
  }

  // Special case: at the top level, we can decompose an Objective-C pointer
  // and a 'cv void *'. Unify the qualifiers.
  if (Steps.empty() && ((Composite1->isVoidPointerType() &&
                         Composite2->isObjCObjectPointerType()) ||
                        (Composite1->isObjCObjectPointerType() &&
                         Composite2->isVoidPointerType()))) {
    Composite1 = Composite1->getPointeeType();
    Composite2 = Composite2->getPointeeType();
    Steps.emplace_back(Step::Pointer);
    continue;
  }

  // FIXME: arrays

  // FIXME: block pointer types?

  // Cannot unwrap any more types.
  break;
}

//  - if T1 or T2 is "pointer to noexcept function" and the other type is
//    "pointer to function", where the function types are otherwise the same,
//    "pointer to function";
//  - if T1 or T2 is "pointer to member of C1 of type function", the other
//    type is "pointer to member of C2 of type noexcept function", and C1
//    is reference-related to C2 or C2 is reference-related to C1, where
//    the function types are otherwise the same, "pointer to member of C2 of
//    type function" or "pointer to member of C1 of type function",
//    respectively;
//
// We also support 'noreturn' here, so as a Clang extension we generalize the
// above to:
//
//  - [Clang] If T1 and T2 are both of type "pointer to function" or
//    "pointer to member function" and the pointee types can be unified
//    by a function pointer conversion, that conversion is applied
//    before checking the following rules.
//
// We've already unwrapped down to the function types, and we want to merge
// rather than just convert, so do this ourselves rather than calling
// IsFunctionConversion.
//
// FIXME: In order to match the standard wording as closely as possible, we
// currently only do this under a single level of pointers. Ideally, we would
// allow this in general, and set NeedConstBefore to the relevant depth on
// the side(s) where we changed anything. If we permit that, we should also
// consider this conversion when determining type similarity and model it as
// a qualification conversion.
if (Steps.size() == 1) {
  if (auto *FPT1 = Composite1->getAs<FunctionProtoType>()) {
    if (auto *FPT2 = Composite2->getAs<FunctionProtoType>()) {
      FunctionProtoType::ExtProtoInfo EPI1 = FPT1->getExtProtoInfo();
      FunctionProtoType::ExtProtoInfo EPI2 = FPT2->getExtProtoInfo();

      // The result is noreturn if both operands are.
      bool Noreturn =
          EPI1.ExtInfo.getNoReturn() && EPI2.ExtInfo.getNoReturn();
      EPI1.ExtInfo = EPI1.ExtInfo.withNoReturn(Noreturn);
      EPI2.ExtInfo = EPI2.ExtInfo.withNoReturn(Noreturn);

      // The result is nothrow if both operands are.
      SmallVector<QualType, 8> ExceptionTypeStorage;
      EPI1.ExceptionSpec = EPI2.ExceptionSpec =
          mergeExceptionSpecs(*this, EPI1.ExceptionSpec, EPI2.ExceptionSpec,
                              ExceptionTypeStorage);

      Composite1 = Context.getFunctionType(FPT1->getReturnType(),
                                           FPT1->getParamTypes(), EPI1);
      Composite2 = Context.getFunctionType(FPT2->getReturnType(),
                                           FPT2->getParamTypes(), EPI2);
    }
  }
}

// There are some more conversions we can perform under exactly one pointer.
if (Steps.size() == 1 && Steps.front().K == Step::Pointer &&
    !Context.hasSameType(Composite1, Composite2)) {
  //  - if T1 or T2 is "pointer to cv1 void" and the other type is
  //    "pointer to cv2 T", where T is an object type or void,
  //    "pointer to cv12 void", where cv12 is the union of cv1 and cv2;
  if (Composite1->isVoidType() && Composite2->isObjectType())
    Composite2 = Composite1;
  else if (Composite2->isVoidType() && Composite1->isObjectType())
    Composite1 = Composite2;
  //  - if T1 is "pointer to cv1 C1" and T2 is "pointer to cv2 C2", where C1
  //    is reference-related to C2 or C2 is reference-related to C1 (8.6.3),
  //    the cv-combined type of T1 and T2 or the cv-combined type of T2 and
  //    T1, respectively;
  //
  // The "similar type" handling covers all of this except for the "T1 is a
  // base class of T2" case in the definition of reference-related.
  else if (IsDerivedFrom(Loc, Composite1, Composite2))
    Composite1 = Composite2;
  else if (IsDerivedFrom(Loc, Composite2, Composite1))
    Composite2 = Composite1;
}

// At this point, either the inner types are the same or we have failed to
// find a composite pointer type.
if (!Context.hasSameType(Composite1, Composite2))
  return QualType();

// Per C++ [conv.qual]p3, add 'const' to every level before the last
// differing qualifier.
for (unsigned I = 0; I != NeedConstBefore; ++I)
  Steps[I].Quals.addConst();

// Rebuild the composite type.
QualType Composite = Composite1;
for (auto &S : llvm::reverse(Steps))
  Composite = S.rebuild(Context, Composite);

if (ConvertArgs) {
  // Convert the expressions to the composite pointer type.
  InitializedEntity Entity =
      InitializedEntity::InitializeTemporary(Composite);
  InitializationKind Kind =
      InitializationKind::CreateCopy(Loc, SourceLocation());

  InitializationSequence E1ToC(*this, Entity, Kind, E1);
  if (!E1ToC)
    return QualType();

  InitializationSequence E2ToC(*this, Entity, Kind, E2);
  if (!E2ToC)
    return QualType();

  // FIXME: Let the caller know if these fail to avoid duplicate diagnostics.
  ExprResult E1Result = E1ToC.Perform(*this, Entity, Kind, E1);
  if (E1Result.isInvalid())
    return QualType();
  E1 = E1Result.get();

  ExprResult E2Result = E2ToC.Perform(*this, Entity, Kind, E2);
  if (E2Result.isInvalid())
    return QualType();
  E2 = E2Result.get();
}

return Composite;
6897}

6899ExprResult Sema::MaybeBindToTemporary(Expr *E) {
if (!E)
  return ExprError();

assert(!isa<CXXBindTemporaryExpr>(E) && "Double-bound temporary?")(static_cast<void> (0));

// If the result is a glvalue, we shouldn't bind it.
if (E->isGLValue())
  return E;

// In ARC, calls that return a retainable type can return retained,
// in which case we have to insert a consuming cast.
if (getLangOpts().ObjCAutoRefCount &&
    E->getType()->isObjCRetainableType()) {

  bool ReturnsRetained;

  // For actual calls, we compute this by examining the type of the
  // called value.
  if (CallExpr *Call = dyn_cast<CallExpr>(E)) {
    Expr *Callee = Call->getCallee()->IgnoreParens();
    QualType T = Callee->getType();

    if (T == Context.BoundMemberTy) {
      // Handle pointer-to-members.
      if (BinaryOperator *BinOp = dyn_cast<BinaryOperator>(Callee))
        T = BinOp->getRHS()->getType();
      else if (MemberExpr *Mem = dyn_cast<MemberExpr>(Callee))
        T = Mem->getMemberDecl()->getType();
    }

    if (const PointerType *Ptr = T->getAs<PointerType>())
      T = Ptr->getPointeeType();
    else if (const BlockPointerType *Ptr = T->getAs<BlockPointerType>())
      T = Ptr->getPointeeType();
    else if (const MemberPointerType *MemPtr = T->getAs<MemberPointerType>())
      T = MemPtr->getPointeeType();

    auto *FTy = T->castAs<FunctionType>();
    ReturnsRetained = FTy->getExtInfo().getProducesResult();

  // ActOnStmtExpr arranges things so that StmtExprs of retainable
  // type always produce a +1 object.
  } else if (isa<StmtExpr>(E)) {
    ReturnsRetained = true;

  // We hit this case with the lambda conversion-to-block optimization;
  // we don't want any extra casts here.
  } else if (isa<CastExpr>(E) &&
             isa<BlockExpr>(cast<CastExpr>(E)->getSubExpr())) {
    return E;

  // For message sends and property references, we try to find an
  // actual method.  FIXME: we should infer retention by selector in
  // cases where we don't have an actual method.
  } else {
    ObjCMethodDecl *D = nullptr;
    if (ObjCMessageExpr *Send = dyn_cast<ObjCMessageExpr>(E)) {
      D = Send->getMethodDecl();
    } else if (ObjCBoxedExpr *BoxedExpr = dyn_cast<ObjCBoxedExpr>(E)) {
      D = BoxedExpr->getBoxingMethod();
    } else if (ObjCArrayLiteral *ArrayLit = dyn_cast<ObjCArrayLiteral>(E)) {
      // Don't do reclaims if we're using the zero-element array
      // constant.
      if (ArrayLit->getNumElements() == 0 &&
          Context.getLangOpts().ObjCRuntime.hasEmptyCollections())
        return E;

      D = ArrayLit->getArrayWithObjectsMethod();
    } else if (ObjCDictionaryLiteral *DictLit
                                      = dyn_cast<ObjCDictionaryLiteral>(E)) {
      // Don't do reclaims if we're using the zero-element dictionary
      // constant.
      if (DictLit->getNumElements() == 0 &&
          Context.getLangOpts().ObjCRuntime.hasEmptyCollections())
        return E;

      D = DictLit->getDictWithObjectsMethod();
    }

    ReturnsRetained = (D && D->hasAttr<NSReturnsRetainedAttr>());

    // Don't do reclaims on performSelector calls; despite their
    // return type, the invoked method doesn't necessarily actually
    // return an object.
    if (!ReturnsRetained &&
        D && D->getMethodFamily() == OMF_performSelector)
      return E;
  }

  // Don't reclaim an object of Class type.
  if (!ReturnsRetained && E->getType()->isObjCARCImplicitlyUnretainedType())
    return E;

  Cleanup.setExprNeedsCleanups(true);

  CastKind ck = (ReturnsRetained ? CK_ARCConsumeObject
                                 : CK_ARCReclaimReturnedObject);
  return ImplicitCastExpr::Create(Context, E->getType(), ck, E, nullptr,
                                  VK_PRValue, FPOptionsOverride());
}

if (E->getType().isDestructedType() == QualType::DK_nontrivial_c_struct)
  Cleanup.setExprNeedsCleanups(true);

if (!getLangOpts().CPlusPlus)
  return E;

// Search for the base element type (cf. ASTContext::getBaseElementType) with
// a fast path for the common case that the type is directly a RecordType.
const Type *T = Context.getCanonicalType(E->getType().getTypePtr());
const RecordType *RT = nullptr;
while (!RT) {
  switch (T->getTypeClass()) {
  case Type::Record:
    RT = cast<RecordType>(T);
    break;
  case Type::ConstantArray:
  case Type::IncompleteArray:
  case Type::VariableArray:
  case Type::DependentSizedArray:
    T = cast<ArrayType>(T)->getElementType().getTypePtr();
    break;
  default:
    return E;
  }
}

// That should be enough to guarantee that this type is complete, if we're
// not processing a decltype expression.
CXXRecordDecl *RD = cast<CXXRecordDecl>(RT->getDecl());
if (RD->isInvalidDecl() || RD->isDependentContext())
  return E;

bool IsDecltype = ExprEvalContexts.back().ExprContext ==
                  ExpressionEvaluationContextRecord::EK_Decltype;
CXXDestructorDecl *Destructor = IsDecltype ? nullptr : LookupDestructor(RD);

if (Destructor) {
  MarkFunctionReferenced(E->getExprLoc(), Destructor);
  CheckDestructorAccess(E->getExprLoc(), Destructor,
                        PDiag(diag::err_access_dtor_temp)
                          << E->getType());
  if (DiagnoseUseOfDecl(Destructor, E->getExprLoc()))
    return ExprError();

  // If destructor is trivial, we can avoid the extra copy.
  if (Destructor->isTrivial())
    return E;

  // We need a cleanup, but we don't need to remember the temporary.
  Cleanup.setExprNeedsCleanups(true);
}

CXXTemporary *Temp = CXXTemporary::Create(Context, Destructor);
CXXBindTemporaryExpr *Bind = CXXBindTemporaryExpr::Create(Context, Temp, E);

if (IsDecltype)
  ExprEvalContexts.back().DelayedDecltypeBinds.push_back(Bind);

return Bind;
7060}

7062ExprResult
7063Sema::MaybeCreateExprWithCleanups(ExprResult SubExpr) {
if (SubExpr.isInvalid())
  return ExprError();

return MaybeCreateExprWithCleanups(SubExpr.get());
7068}

7070Expr *Sema::MaybeCreateExprWithCleanups(Expr *SubExpr) {
assert(SubExpr && "subexpression can't be null!")(static_cast<void> (0));

CleanupVarDeclMarking();

unsigned FirstCleanup = ExprEvalContexts.back().NumCleanupObjects;
assert(ExprCleanupObjects.size() >= FirstCleanup)(static_cast<void> (0));
assert(Cleanup.exprNeedsCleanups() ||(static_cast<void> (0))
       ExprCleanupObjects.size() == FirstCleanup)(static_cast<void> (0));
if (!Cleanup.exprNeedsCleanups())
  return SubExpr;

auto Cleanups = llvm::makeArrayRef(ExprCleanupObjects.begin() + FirstCleanup,
                                   ExprCleanupObjects.size() - FirstCleanup);

auto *E = ExprWithCleanups::Create(
    Context, SubExpr, Cleanup.cleanupsHaveSideEffects(), Cleanups);
DiscardCleanupsInEvaluationContext();

return E;
7090}

7092Stmt *Sema::MaybeCreateStmtWithCleanups(Stmt *SubStmt) {
assert(SubStmt && "sub-statement can't be null!")(static_cast<void> (0));

CleanupVarDeclMarking();

if (!Cleanup.exprNeedsCleanups())
  return SubStmt;

// FIXME: In order to attach the temporaries, wrap the statement into
// a StmtExpr; currently this is only used for asm statements.
// This is hacky, either create a new CXXStmtWithTemporaries statement or
// a new AsmStmtWithTemporaries.
CompoundStmt *CompStmt = CompoundStmt::Create(
    Context, SubStmt, SourceLocation(), SourceLocation());
Expr *E = new (Context)
    StmtExpr(CompStmt, Context.VoidTy, SourceLocation(), SourceLocation(),
             /*FIXME TemplateDepth=*/0);
return MaybeCreateExprWithCleanups(E);
7110}

7112/// Process the expression contained within a decltype. For such expressions,
7113/// certain semantic checks on temporaries are delayed until this point, and
7114/// are omitted for the 'topmost' call in the decltype expression. If the
7115/// topmost call bound a temporary, strip that temporary off the expression.
7116ExprResult Sema::ActOnDecltypeExpression(Expr *E) {
assert(ExprEvalContexts.back().ExprContext ==(static_cast<void> (0))
           ExpressionEvaluationContextRecord::EK_Decltype &&(static_cast<void> (0))
       "not in a decltype expression")(static_cast<void> (0));

ExprResult Result = CheckPlaceholderExpr(E);
if (Result.isInvalid())
  return ExprError();
E = Result.get();

// C++11 [expr.call]p11:
//   If a function call is a prvalue of object type,
// -- if the function call is either
//   -- the operand of a decltype-specifier, or
//   -- the right operand of a comma operator that is the operand of a
//      decltype-specifier,
//   a temporary object is not introduced for the prvalue.

// Recursively rebuild ParenExprs and comma expressions to strip out the
// outermost CXXBindTemporaryExpr, if any.
if (ParenExpr *PE = dyn_cast<ParenExpr>(E)) {
  ExprResult SubExpr = ActOnDecltypeExpression(PE->getSubExpr());
  if (SubExpr.isInvalid())
    return ExprError();
  if (SubExpr.get() == PE->getSubExpr())
    return E;
  return ActOnParenExpr(PE->getLParen(), PE->getRParen(), SubExpr.get());
}
if (BinaryOperator *BO = dyn_cast<BinaryOperator>(E)) {
  if (BO->getOpcode() == BO_Comma) {
    ExprResult RHS = ActOnDecltypeExpression(BO->getRHS());
    if (RHS.isInvalid())
      return ExprError();
    if (RHS.get() == BO->getRHS())
      return E;
    return BinaryOperator::Create(Context, BO->getLHS(), RHS.get(), BO_Comma,
                                  BO->getType(), BO->getValueKind(),
                                  BO->getObjectKind(), BO->getOperatorLoc(),
                                  BO->getFPFeatures(getLangOpts()));
  }
}

CXXBindTemporaryExpr *TopBind = dyn_cast<CXXBindTemporaryExpr>(E);
CallExpr *TopCall = TopBind ? dyn_cast<CallExpr>(TopBind->getSubExpr())
                            : nullptr;
if (TopCall)
  E = TopCall;
else
  TopBind = nullptr;

// Disable the special decltype handling now.
ExprEvalContexts.back().ExprContext =
    ExpressionEvaluationContextRecord::EK_Other;

Result = CheckUnevaluatedOperand(E);
if (Result.isInvalid())
  return ExprError();
E = Result.get();

// In MS mode, don't perform any extra checking of call return types within a
// decltype expression.
if (getLangOpts().MSVCCompat)
  return E;

// Perform the semantic checks we delayed until this point.
for (unsigned I = 0, N = ExprEvalContexts.back().DelayedDecltypeCalls.size();
     I != N; ++I) {
  CallExpr *Call = ExprEvalContexts.back().DelayedDecltypeCalls[I];
  if (Call == TopCall)
    continue;

  if (CheckCallReturnType(Call->getCallReturnType(Context),
                          Call->getBeginLoc(), Call, Call->getDirectCallee()))
    return ExprError();
}

// Now all relevant types are complete, check the destructors are accessible
// and non-deleted, and annotate them on the temporaries.
for (unsigned I = 0, N = ExprEvalContexts.back().DelayedDecltypeBinds.size();
     I != N; ++I) {
  CXXBindTemporaryExpr *Bind =
    ExprEvalContexts.back().DelayedDecltypeBinds[I];
  if (Bind == TopBind)
    continue;

  CXXTemporary *Temp = Bind->getTemporary();

  CXXRecordDecl *RD =
    Bind->getType()->getBaseElementTypeUnsafe()->getAsCXXRecordDecl();
  CXXDestructorDecl *Destructor = LookupDestructor(RD);
  Temp->setDestructor(Destructor);

  MarkFunctionReferenced(Bind->getExprLoc(), Destructor);
  CheckDestructorAccess(Bind->getExprLoc(), Destructor,
                        PDiag(diag::err_access_dtor_temp)
                          << Bind->getType());
  if (DiagnoseUseOfDecl(Destructor, Bind->getExprLoc()))
    return ExprError();

  // We need a cleanup, but we don't need to remember the temporary.
  Cleanup.setExprNeedsCleanups(true);
}

// Possibly strip off the top CXXBindTemporaryExpr.
return E;
7221}

7223/// Note a set of 'operator->' functions that were used for a member access.
7224static void noteOperatorArrows(Sema &S,
                             ArrayRef<FunctionDecl *> OperatorArrows) {
unsigned SkipStart = OperatorArrows.size(), SkipCount = 0;
// FIXME: Make this configurable?
unsigned Limit = 9;
if (OperatorArrows.size() > Limit) {
  // Produce Limit-1 normal notes and one 'skipping' note.
  SkipStart = (Limit - 1) / 2 + (Limit - 1) % 2;
  SkipCount = OperatorArrows.size() - (Limit - 1);
}

for (unsigned I = 0; I < OperatorArrows.size(); /**/) {
  if (I == SkipStart) {
    S.Diag(OperatorArrows[I]->getLocation(),
           diag::note_operator_arrows_suppressed)
        << SkipCount;
    I += SkipCount;
  } else {
    S.Diag(OperatorArrows[I]->getLocation(), diag::note_operator_arrow_here)
        << OperatorArrows[I]->getCallResultType();
    ++I;
  }
}
7247}

7249ExprResult Sema::ActOnStartCXXMemberReference(Scope *S, Expr *Base,
                                            SourceLocation OpLoc,
                                            tok::TokenKind OpKind,
                                            ParsedType &ObjectType,
                                            bool &MayBePseudoDestructor) {
// Since this might be a postfix expression, get rid of ParenListExprs.
ExprResult Result = MaybeConvertParenListExprToParenExpr(S, Base);
if (Result.isInvalid()) return ExprError();
Base = Result.get();

Result = CheckPlaceholderExpr(Base);
if (Result.isInvalid()) return ExprError();
Base = Result.get();

QualType BaseType = Base->getType();
MayBePseudoDestructor = false;
if (BaseType->isDependentType()) {
  // If we have a pointer to a dependent type and are using the -> operator,
  // the object type is the type that the pointer points to. We might still
  // have enough information about that type to do something useful.
  if (OpKind == tok::arrow)
    if (const PointerType *Ptr = BaseType->getAs<PointerType>())
      BaseType = Ptr->getPointeeType();

  ObjectType = ParsedType::make(BaseType);
  MayBePseudoDestructor = true;
  return Base;
}

// C++ [over.match.oper]p8:
//   [...] When operator->returns, the operator-> is applied  to the value
//   returned, with the original second operand.
if (OpKind == tok::arrow) {
  QualType StartingType = BaseType;
  bool NoArrowOperatorFound = false;
  bool FirstIteration = true;
  FunctionDecl *CurFD = dyn_cast<FunctionDecl>(CurContext);
  // The set of types we've considered so far.
  llvm::SmallPtrSet<CanQualType,8> CTypes;
  SmallVector<FunctionDecl*, 8> OperatorArrows;
  CTypes.insert(Context.getCanonicalType(BaseType));

  while (BaseType->isRecordType()) {
    if (OperatorArrows.size() >= getLangOpts().ArrowDepth) {
      Diag(OpLoc, diag::err_operator_arrow_depth_exceeded)
        << StartingType << getLangOpts().ArrowDepth << Base->getSourceRange();
      noteOperatorArrows(*this, OperatorArrows);
      Diag(OpLoc, diag::note_operator_arrow_depth)
        << getLangOpts().ArrowDepth;
      return ExprError();
    }

    Result = BuildOverloadedArrowExpr(
        S, Base, OpLoc,
        // When in a template specialization and on the first loop iteration,
        // potentially give the default diagnostic (with the fixit in a
        // separate note) instead of having the error reported back to here
        // and giving a diagnostic with a fixit attached to the error itself.
        (FirstIteration && CurFD && CurFD->isFunctionTemplateSpecialization())
            ? nullptr
            : &NoArrowOperatorFound);
    if (Result.isInvalid()) {
      if (NoArrowOperatorFound) {
        if (FirstIteration) {
          Diag(OpLoc, diag::err_typecheck_member_reference_suggestion)
            << BaseType << 1 << Base->getSourceRange()
            << FixItHint::CreateReplacement(OpLoc, ".");
          OpKind = tok::period;
          break;
        }
        Diag(OpLoc, diag::err_typecheck_member_reference_arrow)
          << BaseType << Base->getSourceRange();
        CallExpr *CE = dyn_cast<CallExpr>(Base);
        if (Decl *CD = (CE ? CE->getCalleeDecl() : nullptr)) {
          Diag(CD->getBeginLoc(),
               diag::note_member_reference_arrow_from_operator_arrow);
        }
      }
      return ExprError();
    }
    Base = Result.get();
    if (CXXOperatorCallExpr *OpCall = dyn_cast<CXXOperatorCallExpr>(Base))
      OperatorArrows.push_back(OpCall->getDirectCallee());
    BaseType = Base->getType();
    CanQualType CBaseType = Context.getCanonicalType(BaseType);
    if (!CTypes.insert(CBaseType).second) {
      Diag(OpLoc, diag::err_operator_arrow_circular) << StartingType;
      noteOperatorArrows(*this, OperatorArrows);
      return ExprError();
    }
    FirstIteration = false;
  }

  if (OpKind == tok::arrow) {
    if (BaseType->isPointerType())
      BaseType = BaseType->getPointeeType();
    else if (auto *AT = Context.getAsArrayType(BaseType))
      BaseType = AT->getElementType();
  }
}

// Objective-C properties allow "." access on Objective-C pointer types,
// so adjust the base type to the object type itself.
if (BaseType->isObjCObjectPointerType())
  BaseType = BaseType->getPointeeType();

// C++ [basic.lookup.classref]p2:
//   [...] If the type of the object expression is of pointer to scalar
//   type, the unqualified-id is looked up in the context of the complete
//   postfix-expression.
//
// This also indicates that we could be parsing a pseudo-destructor-name.
// Note that Objective-C class and object types can be pseudo-destructor
// expressions or normal member (ivar or property) access expressions, and
// it's legal for the type to be incomplete if this is a pseudo-destructor
// call.  We'll do more incomplete-type checks later in the lookup process,
// so just skip this check for ObjC types.
if (!BaseType->isRecordType()) {
  ObjectType = ParsedType::make(BaseType);
  MayBePseudoDestructor = true;
  return Base;
}

// The object type must be complete (or dependent), or
// C++11 [expr.prim.general]p3:
//   Unlike the object expression in other contexts, *this is not required to
//   be of complete type for purposes of class member access (5.2.5) outside
//   the member function body.
if (!BaseType->isDependentType() &&
    !isThisOutsideMemberFunctionBody(BaseType) &&
    RequireCompleteType(OpLoc, BaseType, diag::err_incomplete_member_access))
  return ExprError();

// C++ [basic.lookup.classref]p2:
//   If the id-expression in a class member access (5.2.5) is an
//   unqualified-id, and the type of the object expression is of a class
//   type C (or of pointer to a class type C), the unqualified-id is looked
//   up in the scope of class C. [...]
ObjectType = ParsedType::make(BaseType);
return Base;
7389}

7391static bool CheckArrow(Sema &S, QualType &ObjectType, Expr *&Base,
                     tok::TokenKind &OpKind, SourceLocation OpLoc) {
if (Base->hasPlaceholderType()) {
  ExprResult result = S.CheckPlaceholderExpr(Base);
  if (result.isInvalid()) return true;
  Base = result.get();
}
ObjectType = Base->getType();

// C++ [expr.pseudo]p2:
//   The left-hand side of the dot operator shall be of scalar type. The
//   left-hand side of the arrow operator shall be of pointer to scalar type.
//   This scalar type is the object type.
// Note that this is rather different from the normal handling for the
// arrow operator.
if (OpKind == tok::arrow) {
  // The operator requires a prvalue, so perform lvalue conversions.
  // Only do this if we might plausibly end with a pointer, as otherwise
  // this was likely to be intended to be a '.'.
  if (ObjectType->isPointerType() || ObjectType->isArrayType() ||
      ObjectType->isFunctionType()) {
    ExprResult BaseResult = S.DefaultFunctionArrayLvalueConversion(Base);
    if (BaseResult.isInvalid())
      return true;
    Base = BaseResult.get();
    ObjectType = Base->getType();
  }

  if (const PointerType *Ptr = ObjectType->getAs<PointerType>()) {
    ObjectType = Ptr->getPointeeType();
  } else if (!Base->isTypeDependent()) {
    // The user wrote "p->" when they probably meant "p."; fix it.
    S.Diag(OpLoc, diag::err_typecheck_member_reference_suggestion)
      << ObjectType << true
      << FixItHint::CreateReplacement(OpLoc, ".");
    if (S.isSFINAEContext())
      return true;

    OpKind = tok::period;
  }
}

return false;
7434}

7436/// Check if it's ok to try and recover dot pseudo destructor calls on
7437/// pointer objects.
7438static bool
7439canRecoverDotPseudoDestructorCallsOnPointerObjects(Sema &SemaRef,
                                                 QualType DestructedType) {
// If this is a record type, check if its destructor is callable.
if (auto *RD = DestructedType->getAsCXXRecordDecl()) {
  if (RD->hasDefinition())
    if (CXXDestructorDecl *D = SemaRef.LookupDestructor(RD))
      return SemaRef.CanUseDecl(D, /*TreatUnavailableAsInvalid=*/false);
  return false;
}

// Otherwise, check if it's a type for which it's valid to use a pseudo-dtor.
return DestructedType->isDependentType() || DestructedType->isScalarType() ||
       DestructedType->isVectorType();
7452}

7454ExprResult Sema::BuildPseudoDestructorExpr(Expr *Base,
                                         SourceLocation OpLoc,
                                         tok::TokenKind OpKind,
                                         const CXXScopeSpec &SS,
                                         TypeSourceInfo *ScopeTypeInfo,
                                         SourceLocation CCLoc,
                                         SourceLocation TildeLoc,
                                       PseudoDestructorTypeStorage Destructed) {
TypeSourceInfo *DestructedTypeInfo = Destructed.getTypeSourceInfo();

QualType ObjectType;
if (CheckArrow(*this, ObjectType, Base, OpKind, OpLoc))
  return ExprError();

if (!ObjectType->isDependentType() && !ObjectType->isScalarType() &&
    !ObjectType->isVectorType()) {
  if (getLangOpts().MSVCCompat && ObjectType->isVoidType())
    Diag(OpLoc, diag::ext_pseudo_dtor_on_void) << Base->getSourceRange();
  else {
    Diag(OpLoc, diag::err_pseudo_dtor_base_not_scalar)
      << ObjectType << Base->getSourceRange();
    return ExprError();
  }
}

// C++ [expr.pseudo]p2:
//   [...] The cv-unqualified versions of the object type and of the type
//   designated by the pseudo-destructor-name shall be the same type.
if (DestructedTypeInfo) {
  QualType DestructedType = DestructedTypeInfo->getType();
  SourceLocation DestructedTypeStart
    = DestructedTypeInfo->getTypeLoc().getLocalSourceRange().getBegin();
  if (!DestructedType->isDependentType() && !ObjectType->isDependentType()) {
    if (!Context.hasSameUnqualifiedType(DestructedType, ObjectType)) {
      // Detect dot pseudo destructor calls on pointer objects, e.g.:
      //   Foo *foo;
      //   foo.~Foo();
      if (OpKind == tok::period && ObjectType->isPointerType() &&
          Context.hasSameUnqualifiedType(DestructedType,
                                         ObjectType->getPointeeType())) {
        auto Diagnostic =
            Diag(OpLoc, diag::err_typecheck_member_reference_suggestion)
            << ObjectType << /*IsArrow=*/0 << Base->getSourceRange();

        // Issue a fixit only when the destructor is valid.
        if (canRecoverDotPseudoDestructorCallsOnPointerObjects(
                *this, DestructedType))
          Diagnostic << FixItHint::CreateReplacement(OpLoc, "->");

        // Recover by setting the object type to the destructed type and the
        // operator to '->'.
        ObjectType = DestructedType;
        OpKind = tok::arrow;
      } else {
        Diag(DestructedTypeStart, diag::err_pseudo_dtor_type_mismatch)
            << ObjectType << DestructedType << Base->getSourceRange()
            << DestructedTypeInfo->getTypeLoc().getLocalSourceRange();

        // Recover by setting the destructed type to the object type.
        DestructedType = ObjectType;
        DestructedTypeInfo =
            Context.getTrivialTypeSourceInfo(ObjectType, DestructedTypeStart);
        Destructed = PseudoDestructorTypeStorage(DestructedTypeInfo);
      }
    } else if (DestructedType.getObjCLifetime() !=
                                              ObjectType.getObjCLifetime()) {

      if (DestructedType.getObjCLifetime() == Qualifiers::OCL_None) {
        // Okay: just pretend that the user provided the correctly-qualified
        // type.
      } else {
        Diag(DestructedTypeStart, diag::err_arc_pseudo_dtor_inconstant_quals)
          << ObjectType << DestructedType << Base->getSourceRange()
          << DestructedTypeInfo->getTypeLoc().getLocalSourceRange();
      }

      // Recover by setting the destructed type to the object type.
      DestructedType = ObjectType;
      DestructedTypeInfo = Context.getTrivialTypeSourceInfo(ObjectType,
                                                         DestructedTypeStart);
      Destructed = PseudoDestructorTypeStorage(DestructedTypeInfo);
    }
  }
}

// C++ [expr.pseudo]p2:
//   [...] Furthermore, the two type-names in a pseudo-destructor-name of the
//   form
//
//     ::[opt] nested-name-specifier[opt] type-name :: ~ type-name
//
//   shall designate the same scalar type.
if (ScopeTypeInfo) {
  QualType ScopeType = ScopeTypeInfo->getType();
  if (!ScopeType->isDependentType() && !ObjectType->isDependentType() &&
      !Context.hasSameUnqualifiedType(ScopeType, ObjectType)) {

    Diag(ScopeTypeInfo->getTypeLoc().getLocalSourceRange().getBegin(),
         diag::err_pseudo_dtor_type_mismatch)
      << ObjectType << ScopeType << Base->getSourceRange()
      << ScopeTypeInfo->getTypeLoc().getLocalSourceRange();

    ScopeType = QualType();
    ScopeTypeInfo = nullptr;
  }
}

Expr *Result
  = new (Context) CXXPseudoDestructorExpr(Context, Base,
                                          OpKind == tok::arrow, OpLoc,
                                          SS.getWithLocInContext(Context),
                                          ScopeTypeInfo,
                                          CCLoc,
                                          TildeLoc,
                                          Destructed);

return Result;
7571}

7573ExprResult Sema::ActOnPseudoDestructorExpr(Scope *S, Expr *Base,
                                         SourceLocation OpLoc,
                                         tok::TokenKind OpKind,
                                         CXXScopeSpec &SS,
                                         UnqualifiedId &FirstTypeName,
                                         SourceLocation CCLoc,
                                         SourceLocation TildeLoc,
                                         UnqualifiedId &SecondTypeName) {
assert((FirstTypeName.getKind() == UnqualifiedIdKind::IK_TemplateId ||(static_cast<void> (0))
        FirstTypeName.getKind() == UnqualifiedIdKind::IK_Identifier) &&(static_cast<void> (0))
       "Invalid first type name in pseudo-destructor")(static_cast<void> (0));
assert((SecondTypeName.getKind() == UnqualifiedIdKind::IK_TemplateId ||(static_cast<void> (0))
        SecondTypeName.getKind() == UnqualifiedIdKind::IK_Identifier) &&(static_cast<void> (0))
       "Invalid second type name in pseudo-destructor")(static_cast<void> (0));

QualType ObjectType;
if (CheckArrow(*this, ObjectType, Base, OpKind, OpLoc))
  return ExprError();

// Compute the object type that we should use for name lookup purposes. Only
// record types and dependent types matter.
ParsedType ObjectTypePtrForLookup;
if (!SS.isSet()) {
  if (ObjectType->isRecordType())
    ObjectTypePtrForLookup = ParsedType::make(ObjectType);
  else if (ObjectType->isDependentType())
    ObjectTypePtrForLookup = ParsedType::make(Context.DependentTy);
}

// Convert the name of the type being destructed (following the ~) into a
// type (with source-location information).
QualType DestructedType;
TypeSourceInfo *DestructedTypeInfo = nullptr;
PseudoDestructorTypeStorage Destructed;
if (SecondTypeName.getKind() == UnqualifiedIdKind::IK_Identifier) {
  ParsedType T = getTypeName(*SecondTypeName.Identifier,
                             SecondTypeName.StartLocation,
                             S, &SS, true, false, ObjectTypePtrForLookup,
                             /*IsCtorOrDtorName*/true);
  if (!T &&
      ((SS.isSet() && !computeDeclContext(SS, false)) ||
       (!SS.isSet() && ObjectType->isDependentType()))) {
    // The name of the type being destroyed is a dependent name, and we
    // couldn't find anything useful in scope. Just store the identifier and
    // it's location, and we'll perform (qualified) name lookup again at
    // template instantiation time.
    Destructed = PseudoDestructorTypeStorage(SecondTypeName.Identifier,
                                             SecondTypeName.StartLocation);
  } else if (!T) {
    Diag(SecondTypeName.StartLocation,
         diag::err_pseudo_dtor_destructor_non_type)
      << SecondTypeName.Identifier << ObjectType;
    if (isSFINAEContext())
      return ExprError();

    // Recover by assuming we had the right type all along.
    DestructedType = ObjectType;
  } else
    DestructedType = GetTypeFromParser(T, &DestructedTypeInfo);
} else {
  // Resolve the template-id to a type.
  TemplateIdAnnotation *TemplateId = SecondTypeName.TemplateId;
  ASTTemplateArgsPtr TemplateArgsPtr(TemplateId->getTemplateArgs(),
                                     TemplateId->NumArgs);
  TypeResult T = ActOnTemplateIdType(S,
                                     SS,
                                     TemplateId->TemplateKWLoc,
                                     TemplateId->Template,
                                     TemplateId->Name,
                                     TemplateId->TemplateNameLoc,
                                     TemplateId->LAngleLoc,
                                     TemplateArgsPtr,
                                     TemplateId->RAngleLoc,
                                     /*IsCtorOrDtorName*/true);
  if (T.isInvalid() || !T.get()) {
    // Recover by assuming we had the right type all along.
    DestructedType = ObjectType;
  } else
    DestructedType = GetTypeFromParser(T.get(), &DestructedTypeInfo);
}

// If we've performed some kind of recovery, (re-)build the type source
// information.
if (!DestructedType.isNull()) {
  if (!DestructedTypeInfo)
    DestructedTypeInfo = Context.getTrivialTypeSourceInfo(DestructedType,
                                                SecondTypeName.StartLocation);
  Destructed = PseudoDestructorTypeStorage(DestructedTypeInfo);
}

// Convert the name of the scope type (the type prior to '::') into a type.
TypeSourceInfo *ScopeTypeInfo = nullptr;
QualType ScopeType;
if (FirstTypeName.getKind() == UnqualifiedIdKind::IK_TemplateId ||
    FirstTypeName.Identifier) {
  if (FirstTypeName.getKind() == UnqualifiedIdKind::IK_Identifier) {
    ParsedType T = getTypeName(*FirstTypeName.Identifier,
                               FirstTypeName.StartLocation,
                               S, &SS, true, false, ObjectTypePtrForLookup,
                               /*IsCtorOrDtorName*/true);
    if (!T) {
      Diag(FirstTypeName.StartLocation,
           diag::err_pseudo_dtor_destructor_non_type)
        << FirstTypeName.Identifier << ObjectType;

      if (isSFINAEContext())
        return ExprError();

      // Just drop this type. It's unnecessary anyway.
      ScopeType = QualType();
    } else
      ScopeType = GetTypeFromParser(T, &ScopeTypeInfo);
  } else {
    // Resolve the template-id to a type.
    TemplateIdAnnotation *TemplateId = FirstTypeName.TemplateId;
    ASTTemplateArgsPtr TemplateArgsPtr(TemplateId->getTemplateArgs(),
                                       TemplateId->NumArgs);
    TypeResult T = ActOnTemplateIdType(S,
                                       SS,
                                       TemplateId->TemplateKWLoc,
                                       TemplateId->Template,
                                       TemplateId->Name,
                                       TemplateId->TemplateNameLoc,
                                       TemplateId->LAngleLoc,
                                       TemplateArgsPtr,
                                       TemplateId->RAngleLoc,
                                       /*IsCtorOrDtorName*/true);
    if (T.isInvalid() || !T.get()) {
      // Recover by dropping this type.
      ScopeType = QualType();
    } else
      ScopeType = GetTypeFromParser(T.get(), &ScopeTypeInfo);
  }
}

if (!ScopeType.isNull() && !ScopeTypeInfo)
  ScopeTypeInfo = Context.getTrivialTypeSourceInfo(ScopeType,
                                                FirstTypeName.StartLocation);


return BuildPseudoDestructorExpr(Base, OpLoc, OpKind, SS,
                                 ScopeTypeInfo, CCLoc, TildeLoc,
                                 Destructed);
7716}

7718ExprResult Sema::ActOnPseudoDestructorExpr(Scope *S, Expr *Base,
                                         SourceLocation OpLoc,
                                         tok::TokenKind OpKind,
                                         SourceLocation TildeLoc,
                                         const DeclSpec& DS) {
QualType ObjectType;
if (CheckArrow(*this, ObjectType, Base, OpKind, OpLoc))
  return ExprError();

if (DS.getTypeSpecType() == DeclSpec::TST_decltype_auto) {
  Diag(DS.getTypeSpecTypeLoc(), diag::err_decltype_auto_invalid);
  return true;
}

QualType T = BuildDecltypeType(DS.getRepAsExpr(), DS.getTypeSpecTypeLoc(),
                               false);

TypeLocBuilder TLB;
DecltypeTypeLoc DecltypeTL = TLB.push<DecltypeTypeLoc>(T);
DecltypeTL.setNameLoc(DS.getTypeSpecTypeLoc());
TypeSourceInfo *DestructedTypeInfo = TLB.getTypeSourceInfo(Context, T);
PseudoDestructorTypeStorage Destructed(DestructedTypeInfo);

return BuildPseudoDestructorExpr(Base, OpLoc, OpKind, CXXScopeSpec(),
                                 nullptr, SourceLocation(), TildeLoc,
                                 Destructed);
7744}

7746ExprResult Sema::BuildCXXMemberCallExpr(Expr *E, NamedDecl *FoundDecl,
                                      CXXConversionDecl *Method,
                                      bool HadMultipleCandidates) {
// Convert the expression to match the conversion function's implicit object
// parameter.
ExprResult Exp = PerformObjectArgumentInitialization(E, /*Qualifier=*/nullptr,
                                        FoundDecl, Method);
if (Exp.isInvalid())
  return true;

if (Method->getParent()->isLambda() &&
    Method->getConversionType()->isBlockPointerType()) {
  // This is a lambda conversion to block pointer; check if the argument
  // was a LambdaExpr.
  Expr *SubE = E;
  CastExpr *CE = dyn_cast<CastExpr>(SubE);
  if (CE && CE->getCastKind() == CK_NoOp)
    SubE = CE->getSubExpr();
  SubE = SubE->IgnoreParens();
  if (CXXBindTemporaryExpr *BE = dyn_cast<CXXBindTemporaryExpr>(SubE))
    SubE = BE->getSubExpr();
  if (isa<LambdaExpr>(SubE)) {
    // For the conversion to block pointer on a lambda expression, we
    // construct a special BlockLiteral instead; this doesn't really make
    // a difference in ARC, but outside of ARC the resulting block literal
    // follows the normal lifetime rules for block literals instead of being
    // autoreleased.
    PushExpressionEvaluationContext(
        ExpressionEvaluationContext::PotentiallyEvaluated);
    ExprResult BlockExp = BuildBlockForLambdaConversion(
        Exp.get()->getExprLoc(), Exp.get()->getExprLoc(), Method, Exp.get());
    PopExpressionEvaluationContext();

    // FIXME: This note should be produced by a CodeSynthesisContext.
    if (BlockExp.isInvalid())
      Diag(Exp.get()->getExprLoc(), diag::note_lambda_to_block_conv);
    return BlockExp;
  }
}

MemberExpr *ME =
    BuildMemberExpr(Exp.get(), /*IsArrow=*/false, SourceLocation(),
                    NestedNameSpecifierLoc(), SourceLocation(), Method,
                    DeclAccessPair::make(FoundDecl, FoundDecl->getAccess()),
                    HadMultipleCandidates, DeclarationNameInfo(),
                    Context.BoundMemberTy, VK_PRValue, OK_Ordinary);

QualType ResultType = Method->getReturnType();
ExprValueKind VK = Expr::getValueKindForType(ResultType);
ResultType = ResultType.getNonLValueExprType(Context);

CXXMemberCallExpr *CE = CXXMemberCallExpr::Create(
    Context, ME, /*Args=*/{}, ResultType, VK, Exp.get()->getEndLoc(),
    CurFPFeatureOverrides());

if (CheckFunctionCall(Method, CE,
                      Method->getType()->castAs<FunctionProtoType>()))
  return ExprError();

return CheckForImmediateInvocation(CE, CE->getMethodDecl());
7806}

7808ExprResult Sema::BuildCXXNoexceptExpr(SourceLocation KeyLoc, Expr *Operand,
                                    SourceLocation RParen) {
// If the operand is an unresolved lookup expression, the expression is ill-
// formed per [over.over]p1, because overloaded function names cannot be used
// without arguments except in explicit contexts.
ExprResult R = CheckPlaceholderExpr(Operand);
if (R.isInvalid())
  return R;

R = CheckUnevaluatedOperand(R.get());
if (R.isInvalid())
  return ExprError();

Operand = R.get();

if (!inTemplateInstantiation() && !Operand->isInstantiationDependent() &&
    Operand->HasSideEffects(Context, false)) {
  // The expression operand for noexcept is in an unevaluated expression
  // context, so side effects could result in unintended consequences.
  Diag(Operand->getExprLoc(), diag::warn_side_effects_unevaluated_context);
}

CanThrowResult CanThrow = canThrow(Operand);
return new (Context)
    CXXNoexceptExpr(Context.BoolTy, Operand, CanThrow, KeyLoc, RParen);
7833}

7835ExprResult Sema::ActOnNoexceptExpr(SourceLocation KeyLoc, SourceLocation,
                                 Expr *Operand, SourceLocation RParen) {
return BuildCXXNoexceptExpr(KeyLoc, Operand, RParen);
7838}

7840static void MaybeDecrementCount(
  Expr *E, llvm::DenseMap<const VarDecl *, int> &RefsMinusAssignments) {
DeclRefExpr *LHS = nullptr;
if (BinaryOperator *BO = dyn_cast<BinaryOperator>(E)) {
  if (BO->getLHS()->getType()->isDependentType() ||
      BO->getRHS()->getType()->isDependentType()) {
    if (BO->getOpcode() != BO_Assign)
      return;
  } else if (!BO->isAssignmentOp())
    return;
  LHS = dyn_cast<DeclRefExpr>(BO->getLHS());
} else if (CXXOperatorCallExpr *COCE = dyn_cast<CXXOperatorCallExpr>(E)) {
  if (COCE->getOperator() != OO_Equal)
    return;
  LHS = dyn_cast<DeclRefExpr>(COCE->getArg(0));
}
if (!LHS)
  return;
VarDecl *VD = dyn_cast<VarDecl>(LHS->getDecl());
if (!VD)
  return;
auto iter = RefsMinusAssignments.find(VD);
if (iter == RefsMinusAssignments.end())
  return;
iter->getSecond()--;
7865}

7867/// Perform the conversions required for an expression used in a
7868/// context that ignores the result.
7869ExprResult Sema::IgnoredValueConversions(Expr *E) {
MaybeDecrementCount(E, RefsMinusAssignments);

if (E->hasPlaceholderType()) {
  ExprResult result = CheckPlaceholderExpr(E);
  if (result.isInvalid()) return E;
  E = result.get();
}

// C99 6.3.2.1:
//   [Except in specific positions,] an lvalue that does not have
//   array type is converted to the value stored in the
//   designated object (and is no longer an lvalue).
if (E->isPRValue()) {
  // In C, function designators (i.e. expressions of function type)
  // are r-values, but we still want to do function-to-pointer decay
  // on them.  This is both technically correct and convenient for
  // some clients.
  if (!getLangOpts().CPlusPlus && E->getType()->isFunctionType())
    return DefaultFunctionArrayConversion(E);

  return E;
}

if (getLangOpts().CPlusPlus) {
  // The C++11 standard defines the notion of a discarded-value expression;
  // normally, we don't need to do anything to handle it, but if it is a
  // volatile lvalue with a special form, we perform an lvalue-to-rvalue
  // conversion.
  if (getLangOpts().CPlusPlus11 && E->isReadIfDiscardedInCPlusPlus11()) {
    ExprResult Res = DefaultLvalueConversion(E);
    if (Res.isInvalid())
      return E;
    E = Res.get();
  } else {
    // Per C++2a [expr.ass]p5, a volatile assignment is not deprecated if
    // it occurs as a discarded-value expression.
    CheckUnusedVolatileAssignment(E);
  }

  // C++1z:
  //   If the expression is a prvalue after this optional conversion, the
  //   temporary materialization conversion is applied.
  //
  // We skip this step: IR generation is able to synthesize the storage for
  // itself in the aggregate case, and adding the extra node to the AST is
  // just clutter.
  // FIXME: We don't emit lifetime markers for the temporaries due to this.
  // FIXME: Do any other AST consumers care about this?
  return E;
}

// GCC seems to also exclude expressions of incomplete enum type.
if (const EnumType *T = E->getType()->getAs<EnumType>()) {
  if (!T->getDecl()->isComplete()) {
    // FIXME: stupid workaround for a codegen bug!
    E = ImpCastExprToType(E, Context.VoidTy, CK_ToVoid).get();
    return E;
  }
}

ExprResult Res = DefaultFunctionArrayLvalueConversion(E);
if (Res.isInvalid())
  return E;
E = Res.get();

if (!E->getType()->isVoidType())
  RequireCompleteType(E->getExprLoc(), E->getType(),
                      diag::err_incomplete_type);
return E;
7939}

7941ExprResult Sema::CheckUnevaluatedOperand(Expr *E) {
// Per C++2a [expr.ass]p5, a volatile assignment is not deprecated if
// it occurs as an unevaluated operand.
CheckUnusedVolatileAssignment(E);

return E;
7947}

7949// If we can unambiguously determine whether Var can never be used
7950// in a constant expression, return true.
7951//  - if the variable and its initializer are non-dependent, then
7952//    we can unambiguously check if the variable is a constant expression.
7953//  - if the initializer is not value dependent - we can determine whether
7954//    it can be used to initialize a constant expression.  If Init can not
7955//    be used to initialize a constant expression we conclude that Var can
7956//    never be a constant expression.
7957//  - FXIME: if the initializer is dependent, we can still do some analysis and
7958//    identify certain cases unambiguously as non-const by using a Visitor:
7959//      - such as those that involve odr-use of a ParmVarDecl, involve a new
7960//        delete, lambda-expr, dynamic-cast, reinterpret-cast etc...
7961static inline bool VariableCanNeverBeAConstantExpression(VarDecl *Var,
  ASTContext &Context) {
if (isa<ParmVarDecl>(Var)) return true;
const VarDecl *DefVD = nullptr;

// If there is no initializer - this can not be a constant expression.
if (!Var->getAnyInitializer(DefVD)) return true;
assert(DefVD)(static_cast<void> (0));
if (DefVD->isWeak()) return false;
EvaluatedStmt *Eval = DefVD->ensureEvaluatedStmt();

Expr *Init = cast<Expr>(Eval->Value);

if (Var->getType()->isDependentType() || Init->isValueDependent()) {
  // FIXME: Teach the constant evaluator to deal with the non-dependent parts
  // of value-dependent expressions, and use it here to determine whether the
  // initializer is a potential constant expression.
  return false;
}

return !Var->isUsableInConstantExpressions(Context);
7982}

7984/// Check if the current lambda has any potential captures
7985/// that must be captured by any of its enclosing lambdas that are ready to
7986/// capture. If there is a lambda that can capture a nested
7987/// potential-capture, go ahead and do so.  Also, check to see if any
7988/// variables are uncaptureable or do not involve an odr-use so do not
7989/// need to be captured.

7991static void CheckIfAnyEnclosingLambdasMustCaptureAnyPotentialCaptures(
  Expr *const FE, LambdaScopeInfo *const CurrentLSI, Sema &S) {

assert(!S.isUnevaluatedContext())(static_cast<void> (0));
assert(S.CurContext->isDependentContext())(static_cast<void> (0));
7996#ifndef NDEBUG1
DeclContext *DC = S.CurContext;
while (DC && isa<CapturedDecl>(DC))
  DC = DC->getParent();
assert((static_cast<void> (0))
    CurrentLSI->CallOperator == DC &&(static_cast<void> (0))
    "The current call operator must be synchronized with Sema's CurContext")(static_cast<void> (0));
8003#endif // NDEBUG

const bool IsFullExprInstantiationDependent = FE->isInstantiationDependent();

// All the potentially captureable variables in the current nested
// lambda (within a generic outer lambda), must be captured by an
// outer lambda that is enclosed within a non-dependent context.
CurrentLSI->visitPotentialCaptures([&] (VarDecl *Var, Expr *VarExpr) {
  // If the variable is clearly identified as non-odr-used and the full
  // expression is not instantiation dependent, only then do we not
  // need to check enclosing lambda's for speculative captures.
  // For e.g.:
  // Even though 'x' is not odr-used, it should be captured.
  // int test() {
  //   const int x = 10;
  //   auto L = [=](auto a) {
  //     (void) +x + a;
  //   };
  // }
  if (CurrentLSI->isVariableExprMarkedAsNonODRUsed(VarExpr) &&
      !IsFullExprInstantiationDependent)
    return;

  // If we have a capture-capable lambda for the variable, go ahead and
  // capture the variable in that lambda (and all its enclosing lambdas).
  if (const Optional<unsigned> Index =
          getStackIndexOfNearestEnclosingCaptureCapableLambda(
              S.FunctionScopes, Var, S))
    S.MarkCaptureUsedInEnclosingContext(Var, VarExpr->getExprLoc(),
                                        Index.getValue());
  const bool IsVarNeverAConstantExpression =
      VariableCanNeverBeAConstantExpression(Var, S.Context);
  if (!IsFullExprInstantiationDependent || IsVarNeverAConstantExpression) {
    // This full expression is not instantiation dependent or the variable
    // can not be used in a constant expression - which means
    // this variable must be odr-used here, so diagnose a
    // capture violation early, if the variable is un-captureable.
    // This is purely for diagnosing errors early.  Otherwise, this
    // error would get diagnosed when the lambda becomes capture ready.
    QualType CaptureType, DeclRefType;
    SourceLocation ExprLoc = VarExpr->getExprLoc();
    if (S.tryCaptureVariable(Var, ExprLoc, S.TryCapture_Implicit,
                        /*EllipsisLoc*/ SourceLocation(),
                        /*BuildAndDiagnose*/false, CaptureType,
                        DeclRefType, nullptr)) {
      // We will never be able to capture this variable, and we need
      // to be able to in any and all instantiations, so diagnose it.
      S.tryCaptureVariable(Var, ExprLoc, S.TryCapture_Implicit,
                        /*EllipsisLoc*/ SourceLocation(),
                        /*BuildAndDiagnose*/true, CaptureType,
                        DeclRefType, nullptr);
    }
  }
});

// Check if 'this' needs to be captured.
if (CurrentLSI->hasPotentialThisCapture()) {
  // If we have a capture-capable lambda for 'this', go ahead and capture
  // 'this' in that lambda (and all its enclosing lambdas).
  if (const Optional<unsigned> Index =
          getStackIndexOfNearestEnclosingCaptureCapableLambda(
              S.FunctionScopes, /*0 is 'this'*/ nullptr, S)) {
    const unsigned FunctionScopeIndexOfCapturableLambda = Index.getValue();
    S.CheckCXXThisCapture(CurrentLSI->PotentialThisCaptureLocation,
                          /*Explicit*/ false, /*BuildAndDiagnose*/ true,
                          &FunctionScopeIndexOfCapturableLambda);
  }
}

// Reset all the potential captures at the end of each full-expression.
CurrentLSI->clearPotentialCaptures();
8074}

8076static ExprResult attemptRecovery(Sema &SemaRef,
                                const TypoCorrectionConsumer &Consumer,
                                const TypoCorrection &TC) {
LookupResult R(SemaRef, Consumer.getLookupResult().getLookupNameInfo(),
               Consumer.getLookupResult().getLookupKind());
const CXXScopeSpec *SS = Consumer.getSS();
CXXScopeSpec NewSS;

// Use an approprate CXXScopeSpec for building the expr.
if (auto *NNS = TC.getCorrectionSpecifier())
  NewSS.MakeTrivial(SemaRef.Context, NNS, TC.getCorrectionRange());
else if (SS && !TC.WillReplaceSpecifier())
  NewSS = *SS;

if (auto *ND = TC.getFoundDecl()) {
  R.setLookupName(ND->getDeclName());
  R.addDecl(ND);
  if (ND->isCXXClassMember()) {
    // Figure out the correct naming class to add to the LookupResult.
    CXXRecordDecl *Record = nullptr;
    if (auto *NNS = TC.getCorrectionSpecifier())
      Record = NNS->getAsType()->getAsCXXRecordDecl();
    if (!Record)
      Record =
          dyn_cast<CXXRecordDecl>(ND->getDeclContext()->getRedeclContext());
    if (Record)
      R.setNamingClass(Record);

    // Detect and handle the case where the decl might be an implicit
    // member.
    bool MightBeImplicitMember;
    if (!Consumer.isAddressOfOperand())
      MightBeImplicitMember = true;
    else if (!NewSS.isEmpty())
      MightBeImplicitMember = false;
    else if (R.isOverloadedResult())
      MightBeImplicitMember = false;
    else if (R.isUnresolvableResult())
      MightBeImplicitMember = true;
    else
      MightBeImplicitMember = isa<FieldDecl>(ND) ||
                              isa<IndirectFieldDecl>(ND) ||
                              isa<MSPropertyDecl>(ND);

    if (MightBeImplicitMember)
      return SemaRef.BuildPossibleImplicitMemberExpr(
          NewSS, /*TemplateKWLoc*/ SourceLocation(), R,
          /*TemplateArgs*/ nullptr, /*S*/ nullptr);
  } else if (auto *Ivar = dyn_cast<ObjCIvarDecl>(ND)) {
    return SemaRef.LookupInObjCMethod(R, Consumer.getScope(),
                                      Ivar->getIdentifier());
  }
}

return SemaRef.BuildDeclarationNameExpr(NewSS, R, /*NeedsADL*/ false,
                                        /*AcceptInvalidDecl*/ true);
8132}

8134namespace {
8135class FindTypoExprs : public RecursiveASTVisitor<FindTypoExprs> {
llvm::SmallSetVector<TypoExpr *, 2> &TypoExprs;

8138public:
explicit FindTypoExprs(llvm::SmallSetVector<TypoExpr *, 2> &TypoExprs)
    : TypoExprs(TypoExprs) {}
bool VisitTypoExpr(TypoExpr *TE) {
  TypoExprs.insert(TE);
  return true;
}
8145};

8147class TransformTypos : public TreeTransform<TransformTypos> {
typedef TreeTransform<TransformTypos> BaseTransform;

VarDecl *InitDecl; // A decl to avoid as a correction because it is in the
                   // process of being initialized.
llvm::function_ref<ExprResult(Expr *)> ExprFilter;
llvm::SmallSetVector<TypoExpr *, 2> TypoExprs, AmbiguousTypoExprs;
llvm::SmallDenseMap<TypoExpr *, ExprResult, 2> TransformCache;
llvm::SmallDenseMap<OverloadExpr *, Expr *, 4> OverloadResolution;

/// Emit diagnostics for all of the TypoExprs encountered.
///
/// If the TypoExprs were successfully corrected, then the diagnostics should
/// suggest the corrections. Otherwise the diagnostics will not suggest
/// anything (having been passed an empty TypoCorrection).
///
/// If we've failed to correct due to ambiguous corrections, we need to
/// be sure to pass empty corrections and replacements. Otherwise it's
/// possible that the Consumer has a TypoCorrection that failed to ambiguity
/// and we don't want to report those diagnostics.
void EmitAllDiagnostics(bool IsAmbiguous) {
  for (TypoExpr *TE : TypoExprs) {
    auto &State = SemaRef.getTypoExprState(TE);
    if (State.DiagHandler) {
      TypoCorrection TC = IsAmbiguous
          ? TypoCorrection() : State.Consumer->getCurrentCorrection();
      ExprResult Replacement = IsAmbiguous ? ExprError() : TransformCache[TE];

      // Extract the NamedDecl from the transformed TypoExpr and add it to the
      // TypoCorrection, replacing the existing decls. This ensures the right
      // NamedDecl is used in diagnostics e.g. in the case where overload
      // resolution was used to select one from several possible decls that
      // had been stored in the TypoCorrection.
      if (auto *ND = getDeclFromExpr(
              Replacement.isInvalid() ? nullptr : Replacement.get()))
        TC.setCorrectionDecl(ND);

      State.DiagHandler(TC);
    }
    SemaRef.clearDelayedTypo(TE);
  }
}

/// Try to advance the typo correction state of the first unfinished TypoExpr.
/// We allow advancement of the correction stream by removing it from the
/// TransformCache which allows `TransformTypoExpr` to advance during the
/// next transformation attempt.
///
/// Any substitution attempts for the previous TypoExprs (which must have been
/// finished) will need to be retried since it's possible that they will now
/// be invalid given the latest advancement.
///
/// We need to be sure that we're making progress - it's possible that the
/// tree is so malformed that the transform never makes it to the
/// `TransformTypoExpr`.
///
/// Returns true if there are any untried correction combinations.
bool CheckAndAdvanceTypoExprCorrectionStreams() {
  for (auto TE : TypoExprs) {
    auto &State = SemaRef.getTypoExprState(TE);
    TransformCache.erase(TE);
    if (!State.Consumer->hasMadeAnyCorrectionProgress())
      return false;
    if (!State.Consumer->finished())
      return true;
    State.Consumer->resetCorrectionStream();
  }
  return false;
}

NamedDecl *getDeclFromExpr(Expr *E) {
  if (auto *OE = dyn_cast_or_null<OverloadExpr>(E))
    E = OverloadResolution[OE];

  if (!E)
    return nullptr;
  if (auto *DRE = dyn_cast<DeclRefExpr>(E))
    return DRE->getFoundDecl();
  if (auto *ME = dyn_cast<MemberExpr>(E))
    return ME->getFoundDecl();
  // FIXME: Add any other expr types that could be be seen by the delayed typo
  // correction TreeTransform for which the corresponding TypoCorrection could
  // contain multiple decls.
  return nullptr;
}

ExprResult TryTransform(Expr *E) {
  Sema::SFINAETrap Trap(SemaRef);
  ExprResult Res = TransformExpr(E);
  if (Trap.hasErrorOccurred() || Res.isInvalid())
    return ExprError();

  return ExprFilter(Res.get());
}

// Since correcting typos may intoduce new TypoExprs, this function
// checks for new TypoExprs and recurses if it finds any. Note that it will
// only succeed if it is able to correct all typos in the given expression.
ExprResult CheckForRecursiveTypos(ExprResult Res, bool &IsAmbiguous) {
  if (Res.isInvalid()) {
    return Res;
  }
  // Check to see if any new TypoExprs were created. If so, we need to recurse
  // to check their validity.
  Expr *FixedExpr = Res.get();

  auto SavedTypoExprs = std::move(TypoExprs);
  auto SavedAmbiguousTypoExprs = std::move(AmbiguousTypoExprs);
  TypoExprs.clear();
  AmbiguousTypoExprs.clear();

  FindTypoExprs(TypoExprs).TraverseStmt(FixedExpr);
  if (!TypoExprs.empty()) {
    // Recurse to handle newly created TypoExprs. If we're not able to
    // handle them, discard these TypoExprs.
    ExprResult RecurResult =
        RecursiveTransformLoop(FixedExpr, IsAmbiguous);
    if (RecurResult.isInvalid()) {
      Res = ExprError();
      // Recursive corrections didn't work, wipe them away and don't add
      // them to the TypoExprs set. Remove them from Sema's TypoExpr list
      // since we don't want to clear them twice. Note: it's possible the
      // TypoExprs were created recursively and thus won't be in our
      // Sema's TypoExprs - they were created in our `RecursiveTransformLoop`.
      auto &SemaTypoExprs = SemaRef.TypoExprs;
      for (auto TE : TypoExprs) {
        TransformCache.erase(TE);
        SemaRef.clearDelayedTypo(TE);

        auto SI = find(SemaTypoExprs, TE);
        if (SI != SemaTypoExprs.end()) {
          SemaTypoExprs.erase(SI);
        }
      }
    } else {
      // TypoExpr is valid: add newly created TypoExprs since we were
      // able to correct them.
      Res = RecurResult;
      SavedTypoExprs.set_union(TypoExprs);
    }
  }

  TypoExprs = std::move(SavedTypoExprs);
  AmbiguousTypoExprs = std::move(SavedAmbiguousTypoExprs);

  return Res;
}

// Try to transform the given expression, looping through the correction
// candidates with `CheckAndAdvanceTypoExprCorrectionStreams`.
//
// If valid ambiguous typo corrections are seen, `IsAmbiguous` is set to
// true and this method immediately will return an `ExprError`.
ExprResult RecursiveTransformLoop(Expr *E, bool &IsAmbiguous) {
  ExprResult Res;
  auto SavedTypoExprs = std::move(SemaRef.TypoExprs);
  SemaRef.TypoExprs.clear();

  while (true) {
    Res = CheckForRecursiveTypos(TryTransform(E), IsAmbiguous);

    // Recursion encountered an ambiguous correction. This means that our
    // correction itself is ambiguous, so stop now.
    if (IsAmbiguous)
      break;

    // If the transform is still valid after checking for any new typos,
    // it's good to go.
    if (!Res.isInvalid())
      break;

    // The transform was invalid, see if we have any TypoExprs with untried
    // correction candidates.
    if (!CheckAndAdvanceTypoExprCorrectionStreams())
      break;
  }

  // If we found a valid result, double check to make sure it's not ambiguous.
  if (!IsAmbiguous && !Res.isInvalid() && !AmbiguousTypoExprs.empty()) {
    auto SavedTransformCache =
        llvm::SmallDenseMap<TypoExpr *, ExprResult, 2>(TransformCache);

    // Ensure none of the TypoExprs have multiple typo correction candidates
    // with the same edit length that pass all the checks and filters.
    while (!AmbiguousTypoExprs.empty()) {
      auto TE  = AmbiguousTypoExprs.back();

      // TryTransform itself can create new Typos, adding them to the TypoExpr map
      // and invalidating our TypoExprState, so always fetch it instead of storing.
      SemaRef.getTypoExprState(TE).Consumer->saveCurrentPosition();

      TypoCorrection TC = SemaRef.getTypoExprState(TE).Consumer->peekNextCorrection();
      TypoCorrection Next;
      do {
        // Fetch the next correction by erasing the typo from the cache and calling
        // `TryTransform` which will iterate through corrections in
        // `TransformTypoExpr`.
        TransformCache.erase(TE);
        ExprResult AmbigRes = CheckForRecursiveTypos(TryTransform(E), IsAmbiguous);

        if (!AmbigRes.isInvalid() || IsAmbiguous) {
          SemaRef.getTypoExprState(TE).Consumer->resetCorrectionStream();
          SavedTransformCache.erase(TE);
          Res = ExprError();
          IsAmbiguous = true;
          break;
        }
      } while ((Next = SemaRef.getTypoExprState(TE).Consumer->peekNextCorrection()) &&
               Next.getEditDistance(false) == TC.getEditDistance(false));

      if (IsAmbiguous)
        break;

      AmbiguousTypoExprs.remove(TE);
      SemaRef.getTypoExprState(TE).Consumer->restoreSavedPosition();
      TransformCache[TE] = SavedTransformCache[TE];
    }
    TransformCache = std::move(SavedTransformCache);
  }

  // Wipe away any newly created TypoExprs that we don't know about. Since we
  // clear any invalid TypoExprs in `CheckForRecursiveTypos`, this is only
  // possible if a `TypoExpr` is created during a transformation but then
  // fails before we can discover it.
  auto &SemaTypoExprs = SemaRef.TypoExprs;
  for (auto Iterator = SemaTypoExprs.begin(); Iterator != SemaTypoExprs.end();) {
    auto TE = *Iterator;
    auto FI = find(TypoExprs, TE);
    if (FI != TypoExprs.end()) {
      Iterator++;
      continue;
    }
    SemaRef.clearDelayedTypo(TE);
    Iterator = SemaTypoExprs.erase(Iterator);
  }
  SemaRef.TypoExprs = std::move(SavedTypoExprs);

  return Res;
}

8387public:
TransformTypos(Sema &SemaRef, VarDecl *InitDecl, llvm::function_ref<ExprResult(Expr *)> Filter)
    : BaseTransform(SemaRef), InitDecl(InitDecl), ExprFilter(Filter) {}

ExprResult RebuildCallExpr(Expr *Callee, SourceLocation LParenLoc,
                                 MultiExprArg Args,
                                 SourceLocation RParenLoc,
                                 Expr *ExecConfig = nullptr) {
  auto Result = BaseTransform::RebuildCallExpr(Callee, LParenLoc, Args,
                                               RParenLoc, ExecConfig);
  if (auto *OE = dyn_cast<OverloadExpr>(Callee)) {
    if (Result.isUsable()) {
      Expr *ResultCall = Result.get();
      if (auto *BE = dyn_cast<CXXBindTemporaryExpr>(ResultCall))
        ResultCall = BE->getSubExpr();
      if (auto *CE = dyn_cast<CallExpr>(ResultCall))
        OverloadResolution[OE] = CE->getCallee();
    }
  }
  return Result;
}

ExprResult TransformLambdaExpr(LambdaExpr *E) { return Owned(E); }

ExprResult TransformBlockExpr(BlockExpr *E) { return Owned(E); }

ExprResult Transform(Expr *E) {
  bool IsAmbiguous = false;
  ExprResult Res = RecursiveTransformLoop(E, IsAmbiguous);

  if (!Res.isUsable())
    FindTypoExprs(TypoExprs).TraverseStmt(E);

  EmitAllDiagnostics(IsAmbiguous);

  return Res;
}

ExprResult TransformTypoExpr(TypoExpr *E) {
  // If the TypoExpr hasn't been seen before, record it. Otherwise, return the
  // cached transformation result if there is one and the TypoExpr isn't the
  // first one that was encountered.
  auto &CacheEntry = TransformCache[E];
  if (!TypoExprs.insert(E) && !CacheEntry.isUnset()) {
    return CacheEntry;
  }

  auto &State = SemaRef.getTypoExprState(E);
  assert(State.Consumer && "Cannot transform a cleared TypoExpr")(static_cast<void> (0));

  // For the first TypoExpr and an uncached TypoExpr, find the next likely
  // typo correction and return it.
  while (TypoCorrection TC = State.Consumer->getNextCorrection()) {
    if (InitDecl && TC.getFoundDecl() == InitDecl)
      continue;
    // FIXME: If we would typo-correct to an invalid declaration, it's
    // probably best to just suppress all errors from this typo correction.
    ExprResult NE = State.RecoveryHandler ?
        State.RecoveryHandler(SemaRef, E, TC) :
        attemptRecovery(SemaRef, *State.Consumer, TC);
    if (!NE.isInvalid()) {
      // Check whether there may be a second viable correction with the same
      // edit distance; if so, remember this TypoExpr may have an ambiguous
      // correction so it can be more thoroughly vetted later.
      TypoCorrection Next;
      if ((Next = State.Consumer->peekNextCorrection()) &&
          Next.getEditDistance(false) == TC.getEditDistance(false)) {
        AmbiguousTypoExprs.insert(E);
      } else {
        AmbiguousTypoExprs.remove(E);
      }
      assert(!NE.isUnset() &&(static_cast<void> (0))
             "Typo was transformed into a valid-but-null ExprResult")(static_cast<void> (0));
      return CacheEntry = NE;
    }
  }
  return CacheEntry = ExprError();
}
8465};
8466}

8468ExprResult
8469Sema::CorrectDelayedTyposInExpr(Expr *E, VarDecl *InitDecl,
                              bool RecoverUncorrectedTypos,
                              llvm::function_ref<ExprResult(Expr *)> Filter) {
// If the current evaluation context indicates there are uncorrected typos
// and the current expression isn't guaranteed to not have typos, try to
// resolve any TypoExpr nodes that might be in the expression.
if (E && !ExprEvalContexts.empty() && ExprEvalContexts.back().NumTypos &&
    (E->isTypeDependent() || E->isValueDependent() ||
     E->isInstantiationDependent())) {
  auto TyposResolved = DelayedTypos.size();
  auto Result = TransformTypos(*this, InitDecl, Filter).Transform(E);
  TyposResolved -= DelayedTypos.size();
  if (Result.isInvalid() || Result.get() != E) {
    ExprEvalContexts.back().NumTypos -= TyposResolved;
    if (Result.isInvalid() && RecoverUncorrectedTypos) {
      struct TyposReplace : TreeTransform<TyposReplace> {
        TyposReplace(Sema &SemaRef) : TreeTransform(SemaRef) {}
        ExprResult TransformTypoExpr(clang::TypoExpr *E) {
          return this->SemaRef.CreateRecoveryExpr(E->getBeginLoc(),
                                                  E->getEndLoc(), {});
        }
      } TT(*this);
      return TT.TransformExpr(E);
    }
    return Result;
  }
  assert(TyposResolved == 0 && "Corrected typo but got same Expr back?")(static_cast<void> (0));
}
return E;
8498}

8500ExprResult Sema::ActOnFinishFullExpr(Expr *FE, SourceLocation CC,
                                   bool DiscardedValue,
                                   bool IsConstexpr) {
ExprResult FullExpr = FE;

if (!FullExpr.get())
  return ExprError();

if (DiagnoseUnexpandedParameterPack(FullExpr.get()))
  return ExprError();

if (DiscardedValue) {
  // Top-level expressions default to 'id' when we're in a debugger.
  if (getLangOpts().DebuggerCastResultToId &&
      FullExpr.get()->getType() == Context.UnknownAnyTy) {
    FullExpr = forceUnknownAnyToType(FullExpr.get(), Context.getObjCIdType());
    if (FullExpr.isInvalid())
      return ExprError();
  }

  FullExpr = CheckPlaceholderExpr(FullExpr.get());
  if (FullExpr.isInvalid())
    return ExprError();

  FullExpr = IgnoredValueConversions(FullExpr.get());
  if (FullExpr.isInvalid())
    return ExprError();

  DiagnoseUnusedExprResult(FullExpr.get());
}

FullExpr = CorrectDelayedTyposInExpr(FullExpr.get(), /*InitDecl=*/nullptr,
                                     /*RecoverUncorrectedTypos=*/true);
if (FullExpr.isInvalid())
  return ExprError();

CheckCompletedExpr(FullExpr.get(), CC, IsConstexpr);

// At the end of this full expression (which could be a deeply nested
// lambda), if there is a potential capture within the nested lambda,
// have the outer capture-able lambda try and capture it.
// Consider the following code:
// void f(int, int);
// void f(const int&, double);
// void foo() {
//  const int x = 10, y = 20;
//  auto L = [=](auto a) {
//      auto M = [=](auto b) {
//         f(x, b); <-- requires x to be captured by L and M
//         f(y, a); <-- requires y to be captured by L, but not all Ms
//      };
//   };
// }

// FIXME: Also consider what happens for something like this that involves
// the gnu-extension statement-expressions or even lambda-init-captures:
//   void f() {
//     const int n = 0;
//     auto L =  [&](auto a) {
//       +n + ({ 0; a; });
//     };
//   }
//
// Here, we see +n, and then the full-expression 0; ends, so we don't
// capture n (and instead remove it from our list of potential captures),
// and then the full-expression +n + ({ 0; }); ends, but it's too late
// for us to see that we need to capture n after all.

LambdaScopeInfo *const CurrentLSI =
    getCurLambda(/*IgnoreCapturedRegions=*/true);
// FIXME: PR 17877 showed that getCurLambda() can return a valid pointer
// even if CurContext is not a lambda call operator. Refer to that Bug Report
// for an example of the code that might cause this asynchrony.
// By ensuring we are in the context of a lambda's call operator
// we can fix the bug (we only need to check whether we need to capture
// if we are within a lambda's body); but per the comments in that
// PR, a proper fix would entail :
//   "Alternative suggestion:
//   - Add to Sema an integer holding the smallest (outermost) scope
//     index that we are *lexically* within, and save/restore/set to
//     FunctionScopes.size() in InstantiatingTemplate's
//     constructor/destructor.
//  - Teach the handful of places that iterate over FunctionScopes to
//    stop at the outermost enclosing lexical scope."
DeclContext *DC = CurContext;
while (DC && isa<CapturedDecl>(DC))
  DC = DC->getParent();
const bool IsInLambdaDeclContext = isLambdaCallOperator(DC);
if (IsInLambdaDeclContext && CurrentLSI &&
    CurrentLSI->hasPotentialCaptures() && !FullExpr.isInvalid())
  CheckIfAnyEnclosingLambdasMustCaptureAnyPotentialCaptures(FE, CurrentLSI,
                                                            *this);
return MaybeCreateExprWithCleanups(FullExpr);
8593}

8595StmtResult Sema::ActOnFinishFullStmt(Stmt *FullStmt) {
if (!FullStmt) return StmtError();

return MaybeCreateStmtWithCleanups(FullStmt);
8599}

8601Sema::IfExistsResult
8602Sema::CheckMicrosoftIfExistsSymbol(Scope *S,
                                 CXXScopeSpec &SS,
                                 const DeclarationNameInfo &TargetNameInfo) {
DeclarationName TargetName = TargetNameInfo.getName();
if (!TargetName)
  return IER_DoesNotExist;

// If the name itself is dependent, then the result is dependent.
if (TargetName.isDependentName())
  return IER_Dependent;

// Do the redeclaration lookup in the current scope.
LookupResult R(*this, TargetNameInfo, Sema::LookupAnyName,
               Sema::NotForRedeclaration);
LookupParsedName(R, S, &SS);
R.suppressDiagnostics();

switch (R.getResultKind()) {
case LookupResult::Found:
case LookupResult::FoundOverloaded:
case LookupResult::FoundUnresolvedValue:
case LookupResult::Ambiguous:
  return IER_Exists;

case LookupResult::NotFound:
  return IER_DoesNotExist;

case LookupResult::NotFoundInCurrentInstantiation:
  return IER_Dependent;
}

llvm_unreachable("Invalid LookupResult Kind!")__builtin_unreachable();
8634}

8636Sema::IfExistsResult
8637Sema::CheckMicrosoftIfExistsSymbol(Scope *S, SourceLocation KeywordLoc,
                                 bool IsIfExists, CXXScopeSpec &SS,
                                 UnqualifiedId &Name) {
DeclarationNameInfo TargetNameInfo = GetNameFromUnqualifiedId(Name);

// Check for an unexpanded parameter pack.
auto UPPC = IsIfExists ? UPPC_IfExists : UPPC_IfNotExists;
if (DiagnoseUnexpandedParameterPack(SS, UPPC) ||
    DiagnoseUnexpandedParameterPack(TargetNameInfo, UPPC))
  return IER_Error;

return CheckMicrosoftIfExistsSymbol(S, SS, TargetNameInfo);
8649}

8651concepts::Requirement *Sema::ActOnSimpleRequirement(Expr *E) {
return BuildExprRequirement(E, /*IsSimple=*/true,
                            /*NoexceptLoc=*/SourceLocation(),
                            /*ReturnTypeRequirement=*/{});
8655}

8657concepts::Requirement *
8658Sema::ActOnTypeRequirement(SourceLocation TypenameKWLoc, CXXScopeSpec &SS,
                         SourceLocation NameLoc, IdentifierInfo *TypeName,
                         TemplateIdAnnotation *TemplateId) {
assert(((!TypeName && TemplateId) || (TypeName && !TemplateId)) &&(static_cast<void> (0))
       "Exactly one of TypeName and TemplateId must be specified.")(static_cast<void> (0));
TypeSourceInfo *TSI = nullptr;
if (TypeName) {
  QualType T = CheckTypenameType(ETK_Typename, TypenameKWLoc,
                                 SS.getWithLocInContext(Context), *TypeName,
                                 NameLoc, &TSI, /*DeducedTypeContext=*/false);
  if (T.isNull())
    return nullptr;
} else {
  ASTTemplateArgsPtr ArgsPtr(TemplateId->getTemplateArgs(),
                             TemplateId->NumArgs);
  TypeResult T = ActOnTypenameType(CurScope, TypenameKWLoc, SS,
                                   TemplateId->TemplateKWLoc,
                                   TemplateId->Template, TemplateId->Name,
                                   TemplateId->TemplateNameLoc,
                                   TemplateId->LAngleLoc, ArgsPtr,
                                   TemplateId->RAngleLoc);
  if (T.isInvalid())
    return nullptr;
  if (GetTypeFromParser(T.get(), &TSI).isNull())
    return nullptr;
}
return BuildTypeRequirement(TSI);
8685}

8687concepts::Requirement *
8688Sema::ActOnCompoundRequirement(Expr *E, SourceLocation NoexceptLoc) {
return BuildExprRequirement(E, /*IsSimple=*/false, NoexceptLoc,
                            /*ReturnTypeRequirement=*/{});
8691}

8693concepts::Requirement *
8694Sema::ActOnCompoundRequirement(
  Expr *E, SourceLocation NoexceptLoc, CXXScopeSpec &SS,
  TemplateIdAnnotation *TypeConstraint, unsigned Depth) {
// C++2a [expr.prim.req.compound] p1.3.3
//   [..] the expression is deduced against an invented function template
//   F [...] F is a void function template with a single type template
//   parameter T declared with the constrained-parameter. Form a new
//   cv-qualifier-seq cv by taking the union of const and volatile specifiers
//   around the constrained-parameter. F has a single parameter whose
//   type-specifier is cv T followed by the abstract-declarator. [...]
//
// The cv part is done in the calling function - we get the concept with
// arguments and the abstract declarator with the correct CV qualification and
// have to synthesize T and the single parameter of F.
auto &II = Context.Idents.get("expr-type");
auto *TParam = TemplateTypeParmDecl::Create(Context, CurContext,
                                            SourceLocation(),
                                            SourceLocation(), Depth,
                                            /*Index=*/0, &II,
                                            /*Typename=*/true,
                                            /*ParameterPack=*/false,
                                            /*HasTypeConstraint=*/true);

if (BuildTypeConstraint(SS, TypeConstraint, TParam,
                        /*EllpsisLoc=*/SourceLocation(),
                        /*AllowUnexpandedPack=*/true))
  // Just produce a requirement with no type requirements.
  return BuildExprRequirement(E, /*IsSimple=*/false, NoexceptLoc, {});

auto *TPL = TemplateParameterList::Create(Context, SourceLocation(),
                                          SourceLocation(),
                                          ArrayRef<NamedDecl *>(TParam),
                                          SourceLocation(),
                                          /*RequiresClause=*/nullptr);
return BuildExprRequirement(
    E, /*IsSimple=*/false, NoexceptLoc,
    concepts::ExprRequirement::ReturnTypeRequirement(TPL));
8731}

8733concepts::ExprRequirement *
8734Sema::BuildExprRequirement(
  Expr *E, bool IsSimple, SourceLocation NoexceptLoc,
  concepts::ExprRequirement::ReturnTypeRequirement ReturnTypeRequirement) {
auto Status = concepts::ExprRequirement::SS_Satisfied;
ConceptSpecializationExpr *SubstitutedConstraintExpr = nullptr;
if (E->isInstantiationDependent() || ReturnTypeRequirement.isDependent())
  Status = concepts::ExprRequirement::SS_Dependent;
else if (NoexceptLoc.isValid() && canThrow(E) == CanThrowResult::CT_Can)
  Status = concepts::ExprRequirement::SS_NoexceptNotMet;
else if (ReturnTypeRequirement.isSubstitutionFailure())
  Status = concepts::ExprRequirement::SS_TypeRequirementSubstitutionFailure;
else if (ReturnTypeRequirement.isTypeConstraint()) {
  // C++2a [expr.prim.req]p1.3.3
  //     The immediately-declared constraint ([temp]) of decltype((E)) shall
  //     be satisfied.
  TemplateParameterList *TPL =
      ReturnTypeRequirement.getTypeConstraintTemplateParameterList();
  QualType MatchedType =
      Context.getReferenceQualifiedType(E).getCanonicalType();
  llvm::SmallVector<TemplateArgument, 1> Args;
  Args.push_back(TemplateArgument(MatchedType));
  TemplateArgumentList TAL(TemplateArgumentList::OnStack, Args);
  MultiLevelTemplateArgumentList MLTAL(TAL);
  for (unsigned I = 0; I < TPL->getDepth(); ++I)
    MLTAL.addOuterRetainedLevel();
  Expr *IDC =
      cast<TemplateTypeParmDecl>(TPL->getParam(0))->getTypeConstraint()
          ->getImmediatelyDeclaredConstraint();
  ExprResult Constraint = SubstExpr(IDC, MLTAL);
  assert(!Constraint.isInvalid() &&(static_cast<void> (0))
         "Substitution cannot fail as it is simply putting a type template "(static_cast<void> (0))
         "argument into a concept specialization expression's parameter.")(static_cast<void> (0));

  SubstitutedConstraintExpr =
      cast<ConceptSpecializationExpr>(Constraint.get());
  if (!SubstitutedConstraintExpr->isSatisfied())
    Status = concepts::ExprRequirement::SS_ConstraintsNotSatisfied;
}
return new (Context) concepts::ExprRequirement(E, IsSimple, NoexceptLoc,
                                               ReturnTypeRequirement, Status,
                                               SubstitutedConstraintExpr);
8775}

8777concepts::ExprRequirement *
8778Sema::BuildExprRequirement(
  concepts::Requirement::SubstitutionDiagnostic *ExprSubstitutionDiagnostic,
  bool IsSimple, SourceLocation NoexceptLoc,
  concepts::ExprRequirement::ReturnTypeRequirement ReturnTypeRequirement) {
return new (Context) concepts::ExprRequirement(ExprSubstitutionDiagnostic,
                                               IsSimple, NoexceptLoc,
                                               ReturnTypeRequirement);
8785}

8787concepts::TypeRequirement *
8788Sema::BuildTypeRequirement(TypeSourceInfo *Type) {
return new (Context) concepts::TypeRequirement(Type);
8790}

8792concepts::TypeRequirement *
8793Sema::BuildTypeRequirement(
  concepts::Requirement::SubstitutionDiagnostic *SubstDiag) {
return new (Context) concepts::TypeRequirement(SubstDiag);
8796}

8798concepts::Requirement *Sema::ActOnNestedRequirement(Expr *Constraint) {
return BuildNestedRequirement(Constraint);
8800}

8802concepts::NestedRequirement *
8803Sema::BuildNestedRequirement(Expr *Constraint) {
ConstraintSatisfaction Satisfaction;
if (!Constraint->isInstantiationDependent() &&
    CheckConstraintSatisfaction(nullptr, {Constraint}, /*TemplateArgs=*/{},
                                Constraint->getSourceRange(), Satisfaction))
  return nullptr;
return new (Context) concepts::NestedRequirement(Context, Constraint,
                                                 Satisfaction);
8811}

8813concepts::NestedRequirement *
8814Sema::BuildNestedRequirement(
  concepts::Requirement::SubstitutionDiagnostic *SubstDiag) {
return new (Context) concepts::NestedRequirement(SubstDiag);
8817}

8819RequiresExprBodyDecl *
8820Sema::ActOnStartRequiresExpr(SourceLocation RequiresKWLoc,
                           ArrayRef<ParmVarDecl *> LocalParameters,
                           Scope *BodyScope) {
assert(BodyScope)(static_cast<void> (0));

RequiresExprBodyDecl *Body = RequiresExprBodyDecl::Create(Context, CurContext,
                                                          RequiresKWLoc);

PushDeclContext(BodyScope, Body);

for (ParmVarDecl *Param : LocalParameters) {
  if (Param->hasDefaultArg())
    // C++2a [expr.prim.req] p4
    //     [...] A local parameter of a requires-expression shall not have a
    //     default argument. [...]
    Diag(Param->getDefaultArgRange().getBegin(),
         diag::err_requires_expr_local_parameter_default_argument);
  // Ignore default argument and move on

  Param->setDeclContext(Body);
  // If this has an identifier, add it to the scope stack.
  if (Param->getIdentifier()) {
    CheckShadow(BodyScope, Param);
    PushOnScopeChains(Param, BodyScope);
  }
}
return Body;
8847}

8849void Sema::ActOnFinishRequiresExpr() {
assert(CurContext && "DeclContext imbalance!")(static_cast<void> (0));
CurContext = CurContext->getLexicalParent();
assert(CurContext && "Popped translation unit!")(static_cast<void> (0));
8853}

8855ExprResult
8856Sema::ActOnRequiresExpr(SourceLocation RequiresKWLoc,
                      RequiresExprBodyDecl *Body,
                      ArrayRef<ParmVarDecl *> LocalParameters,
                      ArrayRef<concepts::Requirement *> Requirements,
                      SourceLocation ClosingBraceLoc) {
auto *RE = RequiresExpr::Create(Context, RequiresKWLoc, Body, LocalParameters,
                                Requirements, ClosingBraceLoc);
if (DiagnoseUnexpandedParameterPackInRequiresExpr(RE))
  return ExprError();
return RE;
8866}