/build/source/clang/include/clang/AST/ExprCXX.h

Bug Summary

File:	build/source/clang/include/clang/AST/ExprCXX.h
Warning:	line 4929, column 18 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 -clear-ast-before-backend -disable-llvm-verifier -discard-value-names -main-file-name SemaCoroutine.cpp -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 -ffp-contract=on -fno-rounding-math -mconstructor-aliases -funwind-tables=2 -target-cpu x86-64 -tune-cpu generic -debugger-tuning=gdb -ffunction-sections -fdata-sections -fcoverage-compilation-dir=/build/source/build-llvm -resource-dir /usr/lib/llvm-17/lib/clang/17 -I tools/clang/lib/Sema -I /build/source/clang/lib/Sema -I /build/source/clang/include -I tools/clang/include -I include -I /build/source/llvm/include -D _DEBUG -D _GLIBCXX_ASSERTIONS -D _GNU_SOURCE -D _LIBCPP_ENABLE_ASSERTIONS -D __STDC_CONSTANT_MACROS -D __STDC_FORMAT_MACROS -D __STDC_LIMIT_MACROS -D _FORTIFY_SOURCE=2 -D NDEBUG -U 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-17/lib/clang/17/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 -fmacro-prefix-map=/build/source/build-llvm=build-llvm -fmacro-prefix-map=/build/source/= -fcoverage-prefix-map=/build/source/build-llvm=build-llvm -fcoverage-prefix-map=/build/source/= -O3 -Wno-unused-command-line-argument -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 -Wno-misleading-indentation -std=c++17 -fdeprecated-macro -fdebug-compilation-dir=/build/source/build-llvm -fdebug-prefix-map=/build/source/build-llvm=build-llvm -fdebug-prefix-map=/build/source/= -fdebug-prefix-map=/build/source/build-llvm=build-llvm -fdebug-prefix-map=/build/source/= -ferror-limit 19 -fvisibility-inlines-hidden -stack-protector 2 -fgnuc-version=4.2.1 -fcolor-diagnostics -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-2023-05-10-133810-16478-1 -x c++ /build/source/clang/lib/Sema/SemaCoroutine.cpp

/build/source/clang/lib/Sema/SemaCoroutine.cpp

→

1//===-- SemaCoroutine.cpp - Semantic Analysis for Coroutines --------------===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8//
9//  This file implements semantic analysis for C++ Coroutines.
10//
11//  This file contains references to sections of the Coroutines TS, which
12//  can be found at http://wg21.link/coroutines.
13//
14//===----------------------------------------------------------------------===//

16#include "CoroutineStmtBuilder.h"
17#include "clang/AST/ASTLambda.h"
18#include "clang/AST/Decl.h"
19#include "clang/AST/ExprCXX.h"
20#include "clang/AST/StmtCXX.h"
21#include "clang/Basic/Builtins.h"
22#include "clang/Lex/Preprocessor.h"
23#include "clang/Sema/Initialization.h"
24#include "clang/Sema/Overload.h"
25#include "clang/Sema/ScopeInfo.h"
26#include "clang/Sema/SemaInternal.h"
27#include "llvm/ADT/SmallSet.h"

29using namespace clang;
30using namespace sema;

32static LookupResult lookupMember(Sema &S, const char *Name, CXXRecordDecl *RD,
                               SourceLocation Loc, bool &Res) {
DeclarationName DN = S.PP.getIdentifierInfo(Name);
LookupResult LR(S, DN, Loc, Sema::LookupMemberName);
// Suppress diagnostics when a private member is selected. The same warnings
// will be produced again when building the call.
LR.suppressDiagnostics();
Res = S.LookupQualifiedName(LR, RD);
return LR;
41}

43static bool lookupMember(Sema &S, const char *Name, CXXRecordDecl *RD,
                       SourceLocation Loc) {
bool Res;
lookupMember(S, Name, RD, Loc, Res);
return Res;
48}

50/// Look up the std::coroutine_traits<...>::promise_type for the given
51/// function type.
52static QualType lookupPromiseType(Sema &S, const FunctionDecl *FD,
                                SourceLocation KwLoc) {
const FunctionProtoType *FnType = FD->getType()->castAs<FunctionProtoType>();
const SourceLocation FuncLoc = FD->getLocation();

ClassTemplateDecl *CoroTraits =
    S.lookupCoroutineTraits(KwLoc, FuncLoc);
if (!CoroTraits)
  return QualType();

// Form template argument list for coroutine_traits<R, P1, P2, ...> according
// to [dcl.fct.def.coroutine]3
TemplateArgumentListInfo Args(KwLoc, KwLoc);
auto AddArg = [&](QualType T) {
  Args.addArgument(TemplateArgumentLoc(
      TemplateArgument(T), S.Context.getTrivialTypeSourceInfo(T, KwLoc)));
};
AddArg(FnType->getReturnType());
// If the function is a non-static member function, add the type
// of the implicit object parameter before the formal parameters.
if (auto *MD = dyn_cast<CXXMethodDecl>(FD)) {
  if (MD->isInstance()) {
    // [over.match.funcs]4
    // For non-static member functions, the type of the implicit object
    // parameter is
    //  -- "lvalue reference to cv X" for functions declared without a
    //      ref-qualifier or with the & ref-qualifier
    //  -- "rvalue reference to cv X" for functions declared with the &&
    //      ref-qualifier
    QualType T = MD->getThisType()->castAs<PointerType>()->getPointeeType();
    T = FnType->getRefQualifier() == RQ_RValue
            ? S.Context.getRValueReferenceType(T)
            : S.Context.getLValueReferenceType(T, /*SpelledAsLValue*/ true);
    AddArg(T);
  }
}
for (QualType T : FnType->getParamTypes())
  AddArg(T);

// Build the template-id.
QualType CoroTrait =
    S.CheckTemplateIdType(TemplateName(CoroTraits), KwLoc, Args);
if (CoroTrait.isNull())
  return QualType();
if (S.RequireCompleteType(KwLoc, CoroTrait,
                          diag::err_coroutine_type_missing_specialization))
  return QualType();

auto *RD = CoroTrait->getAsCXXRecordDecl();
assert(RD && "specialization of class template is not a class?")(static_cast <bool> (RD && "specialization of class template is not a class?"
) ? void (0) : __assert_fail ("RD && \"specialization of class template is not a class?\""
, "clang/lib/Sema/SemaCoroutine.cpp", 101, __extension__ __PRETTY_FUNCTION__
));

// Look up the ::promise_type member.
LookupResult R(S, &S.PP.getIdentifierTable().get("promise_type"), KwLoc,
               Sema::LookupOrdinaryName);
S.LookupQualifiedName(R, RD);
auto *Promise = R.getAsSingle<TypeDecl>();
if (!Promise) {
  S.Diag(FuncLoc,
         diag::err_implied_std_coroutine_traits_promise_type_not_found)
      << RD;
  return QualType();
}
// The promise type is required to be a class type.
QualType PromiseType = S.Context.getTypeDeclType(Promise);

auto buildElaboratedType = [&]() {
  auto *NNS = NestedNameSpecifier::Create(S.Context, nullptr, S.getStdNamespace());
  NNS = NestedNameSpecifier::Create(S.Context, NNS, false,
                                    CoroTrait.getTypePtr());
  return S.Context.getElaboratedType(ETK_None, NNS, PromiseType);
};

if (!PromiseType->getAsCXXRecordDecl()) {
  S.Diag(FuncLoc,
         diag::err_implied_std_coroutine_traits_promise_type_not_class)
      << buildElaboratedType();
  return QualType();
}
if (S.RequireCompleteType(FuncLoc, buildElaboratedType(),
                          diag::err_coroutine_promise_type_incomplete))
  return QualType();

return PromiseType;
135}

137/// Look up the std::coroutine_handle<PromiseType>.
138static QualType lookupCoroutineHandleType(Sema &S, QualType PromiseType,
                                        SourceLocation Loc) {
if (PromiseType.isNull())
  return QualType();

NamespaceDecl *CoroNamespace = S.getStdNamespace();
assert(CoroNamespace && "Should already be diagnosed")(static_cast <bool> (CoroNamespace && "Should already be diagnosed"
) ? void (0) : __assert_fail ("CoroNamespace && \"Should already be diagnosed\""
, "clang/lib/Sema/SemaCoroutine.cpp", 144, __extension__ __PRETTY_FUNCTION__
));

LookupResult Result(S, &S.PP.getIdentifierTable().get("coroutine_handle"),
                    Loc, Sema::LookupOrdinaryName);
if (!S.LookupQualifiedName(Result, CoroNamespace)) {
  S.Diag(Loc, diag::err_implied_coroutine_type_not_found)
      << "std::coroutine_handle";
  return QualType();
}

ClassTemplateDecl *CoroHandle = Result.getAsSingle<ClassTemplateDecl>();
if (!CoroHandle) {
  Result.suppressDiagnostics();
  // We found something weird. Complain about the first thing we found.
  NamedDecl *Found = *Result.begin();
  S.Diag(Found->getLocation(), diag::err_malformed_std_coroutine_handle);
  return QualType();
}

// Form template argument list for coroutine_handle<Promise>.
TemplateArgumentListInfo Args(Loc, Loc);
Args.addArgument(TemplateArgumentLoc(
    TemplateArgument(PromiseType),
    S.Context.getTrivialTypeSourceInfo(PromiseType, Loc)));

// Build the template-id.
QualType CoroHandleType =
    S.CheckTemplateIdType(TemplateName(CoroHandle), Loc, Args);
if (CoroHandleType.isNull())
  return QualType();
if (S.RequireCompleteType(Loc, CoroHandleType,
                          diag::err_coroutine_type_missing_specialization))
  return QualType();

return CoroHandleType;
179}

181static bool isValidCoroutineContext(Sema &S, SourceLocation Loc,
                                  StringRef Keyword) {
// [expr.await]p2 dictates that 'co_await' and 'co_yield' must be used within
// a function body.
// FIXME: This also covers [expr.await]p2: "An await-expression shall not
// appear in a default argument." But the diagnostic QoI here could be
// improved to inform the user that default arguments specifically are not
// allowed.
auto *FD = dyn_cast<FunctionDecl>(S.CurContext);
if (!FD) {
  S.Diag(Loc, isa<ObjCMethodDecl>(S.CurContext)
                  ? diag::err_coroutine_objc_method
                  : diag::err_coroutine_outside_function) << Keyword;
  return false;
}

// An enumeration for mapping the diagnostic type to the correct diagnostic
// selection index.
enum InvalidFuncDiag {
  DiagCtor = 0,
  DiagDtor,
  DiagMain,
  DiagConstexpr,
  DiagAutoRet,
  DiagVarargs,
  DiagConsteval,
};
bool Diagnosed = false;
auto DiagInvalid = [&](InvalidFuncDiag ID) {
  S.Diag(Loc, diag::err_coroutine_invalid_func_context) << ID << Keyword;
  Diagnosed = true;
  return false;
};

// Diagnose when a constructor, destructor
// or the function 'main' are declared as a coroutine.
auto *MD = dyn_cast<CXXMethodDecl>(FD);
// [class.ctor]p11: "A constructor shall not be a coroutine."
if (MD && isa<CXXConstructorDecl>(MD))
  return DiagInvalid(DiagCtor);
// [class.dtor]p17: "A destructor shall not be a coroutine."
else if (MD && isa<CXXDestructorDecl>(MD))
  return DiagInvalid(DiagDtor);
// [basic.start.main]p3: "The function main shall not be a coroutine."
else if (FD->isMain())
  return DiagInvalid(DiagMain);

// Emit a diagnostics for each of the following conditions which is not met.
// [expr.const]p2: "An expression e is a core constant expression unless the
// evaluation of e [...] would evaluate one of the following expressions:
// [...] an await-expression [...] a yield-expression."
if (FD->isConstexpr())
  DiagInvalid(FD->isConsteval() ? DiagConsteval : DiagConstexpr);
// [dcl.spec.auto]p15: "A function declared with a return type that uses a
// placeholder type shall not be a coroutine."
if (FD->getReturnType()->isUndeducedType())
  DiagInvalid(DiagAutoRet);
// [dcl.fct.def.coroutine]p1
// The parameter-declaration-clause of the coroutine shall not terminate with
// an ellipsis that is not part of a parameter-declaration.
if (FD->isVariadic())
  DiagInvalid(DiagVarargs);

return !Diagnosed;
245}

247/// Build a call to 'operator co_await' if there is a suitable operator for
248/// the given expression.
249ExprResult Sema::BuildOperatorCoawaitCall(SourceLocation Loc, Expr *E,
                                        UnresolvedLookupExpr *Lookup) {
UnresolvedSet<16> Functions;
Functions.append(Lookup->decls_begin(), Lookup->decls_end());
return CreateOverloadedUnaryOp(Loc, UO_Coawait, Functions, E);
254}

256static ExprResult buildOperatorCoawaitCall(Sema &SemaRef, Scope *S,
                                         SourceLocation Loc, Expr *E) {
ExprResult R = SemaRef.BuildOperatorCoawaitLookupExpr(S, Loc);
if (R.isInvalid())
  return ExprError();
return SemaRef.BuildOperatorCoawaitCall(Loc, E,
                                        cast<UnresolvedLookupExpr>(R.get()));
263}

265static ExprResult buildCoroutineHandle(Sema &S, QualType PromiseType,
                                     SourceLocation Loc) {
QualType CoroHandleType = lookupCoroutineHandleType(S, PromiseType, Loc);
if (CoroHandleType.isNull())
  return ExprError();

DeclContext *LookupCtx = S.computeDeclContext(CoroHandleType);
LookupResult Found(S, &S.PP.getIdentifierTable().get("from_address"), Loc,
                   Sema::LookupOrdinaryName);
if (!S.LookupQualifiedName(Found, LookupCtx)) {
  S.Diag(Loc, diag::err_coroutine_handle_missing_member)
      << "from_address";
  return ExprError();
}

Expr *FramePtr =
    S.BuildBuiltinCallExpr(Loc, Builtin::BI__builtin_coro_frame, {});

CXXScopeSpec SS;
ExprResult FromAddr =
    S.BuildDeclarationNameExpr(SS, Found, /*NeedsADL=*/false);
if (FromAddr.isInvalid())
  return ExprError();

return S.BuildCallExpr(nullptr, FromAddr.get(), Loc, FramePtr, Loc);
290}

292struct ReadySuspendResumeResult {
enum AwaitCallType { ACT_Ready, ACT_Suspend, ACT_Resume };
Expr *Results[3];
OpaqueValueExpr *OpaqueValue;
bool IsInvalid;
297};

299static ExprResult buildMemberCall(Sema &S, Expr *Base, SourceLocation Loc,
                                StringRef Name, MultiExprArg Args) {
DeclarationNameInfo NameInfo(&S.PP.getIdentifierTable().get(Name), Loc);

// FIXME: Fix BuildMemberReferenceExpr to take a const CXXScopeSpec&.
CXXScopeSpec SS;
ExprResult Result = S.BuildMemberReferenceExpr(
    Base, Base->getType(), Loc, /*IsPtr=*/false, SS,
    SourceLocation(), nullptr, NameInfo, /*TemplateArgs=*/nullptr,
    /*Scope=*/nullptr);
if (Result.isInvalid())
  return ExprError();

// We meant exactly what we asked for. No need for typo correction.
if (auto *TE = dyn_cast<TypoExpr>(Result.get())) {
  S.clearDelayedTypo(TE);
  S.Diag(Loc, diag::err_no_member)
      << NameInfo.getName() << Base->getType()->getAsCXXRecordDecl()
      << Base->getSourceRange();
  return ExprError();
}

return S.BuildCallExpr(nullptr, Result.get(), Loc, Args, Loc, nullptr);
322}

324// See if return type is coroutine-handle and if so, invoke builtin coro-resume
325// on its address. This is to enable the support for coroutine-handle
326// returning await_suspend that results in a guaranteed tail call to the target
327// coroutine.
328static Expr *maybeTailCall(Sema &S, QualType RetType, Expr *E,
                         SourceLocation Loc) {
if (RetType->isReferenceType())
  return nullptr;
Type const *T = RetType.getTypePtr();
if (!T->isClassType() && !T->isStructureType())
  return nullptr;

// FIXME: Add convertability check to coroutine_handle<>. Possibly via
// EvaluateBinaryTypeTrait(BTT_IsConvertible, ...) which is at the moment
// a private function in SemaExprCXX.cpp

ExprResult AddressExpr = buildMemberCall(S, E, Loc, "address", std::nullopt);
if (AddressExpr.isInvalid())
  return nullptr;

Expr *JustAddress = AddressExpr.get();

// Check that the type of AddressExpr is void*
if (!JustAddress->getType().getTypePtr()->isVoidPointerType())
  S.Diag(cast<CallExpr>(JustAddress)->getCalleeDecl()->getLocation(),
         diag::warn_coroutine_handle_address_invalid_return_type)
      << JustAddress->getType();

// Clean up temporary objects so that they don't live across suspension points
// unnecessarily. We choose to clean up before the call to
// __builtin_coro_resume so that the cleanup code are not inserted in-between
// the resume call and return instruction, which would interfere with the
// musttail call contract.
JustAddress = S.MaybeCreateExprWithCleanups(JustAddress);
return S.BuildBuiltinCallExpr(Loc, Builtin::BI__builtin_coro_resume,
                              JustAddress);
360}

362/// Build calls to await_ready, await_suspend, and await_resume for a co_await
363/// expression.
364/// The generated AST tries to clean up temporary objects as early as
365/// possible so that they don't live across suspension points if possible.
366/// Having temporary objects living across suspension points unnecessarily can
367/// lead to large frame size, and also lead to memory corruptions if the
368/// coroutine frame is destroyed after coming back from suspension. This is done
369/// by wrapping both the await_ready call and the await_suspend call with
370/// ExprWithCleanups. In the end of this function, we also need to explicitly
371/// set cleanup state so that the CoawaitExpr is also wrapped with an
372/// ExprWithCleanups to clean up the awaiter associated with the co_await
373/// expression.
374static ReadySuspendResumeResult buildCoawaitCalls(Sema &S, VarDecl *CoroPromise,
                                                SourceLocation Loc, Expr *E) {
OpaqueValueExpr *Operand = new (S.Context)
    OpaqueValueExpr(Loc, E->getType(), VK_LValue, E->getObjectKind(), E);

// Assume valid until we see otherwise.
// Further operations are responsible for setting IsInalid to true.
ReadySuspendResumeResult Calls = {{}, Operand, /*IsInvalid=*/false};
31
←
'Calls.IsInvalid' initialized to 0, which participates in a condition later→
32
←
Initializing to a null pointer value→
33
←
'Calls' initialized here→

using ACT = ReadySuspendResumeResult::AwaitCallType;

auto BuildSubExpr = [&](ACT CallType, StringRef Func,
                        MultiExprArg Arg) -> Expr * {
  ExprResult Result = buildMemberCall(S, Operand, Loc, Func, Arg);
  if (Result.isInvalid()) {
    Calls.IsInvalid = true;
    return nullptr;
  }
  Calls.Results[CallType] = Result.get();
  return Result.get();
};

CallExpr *AwaitReady = cast_or_null<CallExpr>(
34
←
Assuming null pointer is passed into cast→
    BuildSubExpr(ACT::ACT_Ready, "await_ready", std::nullopt));
if (!AwaitReady34.1
'AwaitReady' is null
1
'AwaitReady' is null
1
'AwaitReady' is null
)
35
←
Taking true branch→
  return Calls;
36
←
The value 0 is assigned to 'RSS.IsInvalid', which participates in a condition later→
37
←
Storing null pointer value→
if (!AwaitReady->getType()->isDependentType()) {
  // [expr.await]p3 [...]
  // — await-ready is the expression e.await_ready(), contextually converted
  // to bool.
  ExprResult Conv = S.PerformContextuallyConvertToBool(AwaitReady);
  if (Conv.isInvalid()) {
    S.Diag(AwaitReady->getDirectCallee()->getBeginLoc(),
           diag::note_await_ready_no_bool_conversion);
    S.Diag(Loc, diag::note_coroutine_promise_call_implicitly_required)
        << AwaitReady->getDirectCallee() << E->getSourceRange();
    Calls.IsInvalid = true;
  } else
    Calls.Results[ACT::ACT_Ready] = S.MaybeCreateExprWithCleanups(Conv.get());
}

ExprResult CoroHandleRes =
    buildCoroutineHandle(S, CoroPromise->getType(), Loc);
if (CoroHandleRes.isInvalid()) {
  Calls.IsInvalid = true;
  return Calls;
}
Expr *CoroHandle = CoroHandleRes.get();
CallExpr *AwaitSuspend = cast_or_null<CallExpr>(
    BuildSubExpr(ACT::ACT_Suspend, "await_suspend", CoroHandle));
if (!AwaitSuspend)
  return Calls;
if (!AwaitSuspend->getType()->isDependentType()) {
  // [expr.await]p3 [...]
  //   - await-suspend is the expression e.await_suspend(h), which shall be
  //     a prvalue of type void, bool, or std::coroutine_handle<Z> for some
  //     type Z.
  QualType RetType = AwaitSuspend->getCallReturnType(S.Context);

  // Support for coroutine_handle returning await_suspend.
  if (Expr *TailCallSuspend =
          maybeTailCall(S, RetType, AwaitSuspend, Loc))
    // Note that we don't wrap the expression with ExprWithCleanups here
    // because that might interfere with tailcall contract (e.g. inserting
    // clean up instructions in-between tailcall and return). Instead
    // ExprWithCleanups is wrapped within maybeTailCall() prior to the resume
    // call.
    Calls.Results[ACT::ACT_Suspend] = TailCallSuspend;
  else {
    // non-class prvalues always have cv-unqualified types
    if (RetType->isReferenceType() ||
        (!RetType->isBooleanType() && !RetType->isVoidType())) {
      S.Diag(AwaitSuspend->getCalleeDecl()->getLocation(),
             diag::err_await_suspend_invalid_return_type)
          << RetType;
      S.Diag(Loc, diag::note_coroutine_promise_call_implicitly_required)
          << AwaitSuspend->getDirectCallee();
      Calls.IsInvalid = true;
    } else
      Calls.Results[ACT::ACT_Suspend] =
          S.MaybeCreateExprWithCleanups(AwaitSuspend);
  }
}

BuildSubExpr(ACT::ACT_Resume, "await_resume", std::nullopt);

// Make sure the awaiter object gets a chance to be cleaned up.
S.Cleanup.setExprNeedsCleanups(true);

return Calls;
464}

466static ExprResult buildPromiseCall(Sema &S, VarDecl *Promise,
                                 SourceLocation Loc, StringRef Name,
                                 MultiExprArg Args) {

// Form a reference to the promise.
ExprResult PromiseRef = S.BuildDeclRefExpr(
    Promise, Promise->getType().getNonReferenceType(), VK_LValue, Loc);
if (PromiseRef.isInvalid())
  return ExprError();

return buildMemberCall(S, PromiseRef.get(), Loc, Name, Args);
477}

479VarDecl *Sema::buildCoroutinePromise(SourceLocation Loc) {
assert(isa<FunctionDecl>(CurContext) && "not in a function scope")(static_cast <bool> (isa<FunctionDecl>(CurContext
) && "not in a function scope") ? void (0) : __assert_fail
 ("isa<FunctionDecl>(CurContext) && \"not in a function scope\""
, "clang/lib/Sema/SemaCoroutine.cpp", 480, __extension__ __PRETTY_FUNCTION__
));
auto *FD = cast<FunctionDecl>(CurContext);
bool IsThisDependentType = [&] {
  if (auto *MD = dyn_cast_or_null<CXXMethodDecl>(FD))
    return MD->isInstance() && MD->getThisType()->isDependentType();
  else
    return false;
}();

QualType T = FD->getType()->isDependentType() || IsThisDependentType
                 ? Context.DependentTy
                 : lookupPromiseType(*this, FD, Loc);
if (T.isNull())
  return nullptr;

auto *VD = VarDecl::Create(Context, FD, FD->getLocation(), FD->getLocation(),
                           &PP.getIdentifierTable().get("__promise"), T,
                           Context.getTrivialTypeSourceInfo(T, Loc), SC_None);
VD->setImplicit();
CheckVariableDeclarationType(VD);
if (VD->isInvalidDecl())
  return nullptr;

auto *ScopeInfo = getCurFunction();

// Build a list of arguments, based on the coroutine function's arguments,
// that if present will be passed to the promise type's constructor.
llvm::SmallVector<Expr *, 4> CtorArgExprs;

// Add implicit object parameter.
if (auto *MD = dyn_cast<CXXMethodDecl>(FD)) {
  if (MD->isInstance() && !isLambdaCallOperator(MD)) {
    ExprResult ThisExpr = ActOnCXXThis(Loc);
    if (ThisExpr.isInvalid())
      return nullptr;
    ThisExpr = CreateBuiltinUnaryOp(Loc, UO_Deref, ThisExpr.get());
    if (ThisExpr.isInvalid())
      return nullptr;
    CtorArgExprs.push_back(ThisExpr.get());
  }
}

// Add the coroutine function's parameters.
auto &Moves = ScopeInfo->CoroutineParameterMoves;
for (auto *PD : FD->parameters()) {
  if (PD->getType()->isDependentType())
    continue;

  auto RefExpr = ExprEmpty();
  auto Move = Moves.find(PD);
  assert(Move != Moves.end() &&(static_cast <bool> (Move != Moves.end() && "Coroutine function parameter not inserted into move map"
) ? void (0) : __assert_fail ("Move != Moves.end() && \"Coroutine function parameter not inserted into move map\""
, "clang/lib/Sema/SemaCoroutine.cpp", 531, __extension__ __PRETTY_FUNCTION__
))
         "Coroutine function parameter not inserted into move map")(static_cast <bool> (Move != Moves.end() && "Coroutine function parameter not inserted into move map"
) ? void (0) : __assert_fail ("Move != Moves.end() && \"Coroutine function parameter not inserted into move map\""
, "clang/lib/Sema/SemaCoroutine.cpp", 531, __extension__ __PRETTY_FUNCTION__
));
  // If a reference to the function parameter exists in the coroutine
  // frame, use that reference.
  auto *MoveDecl =
      cast<VarDecl>(cast<DeclStmt>(Move->second)->getSingleDecl());
  RefExpr =
      BuildDeclRefExpr(MoveDecl, MoveDecl->getType().getNonReferenceType(),
                       ExprValueKind::VK_LValue, FD->getLocation());
  if (RefExpr.isInvalid())
    return nullptr;
  CtorArgExprs.push_back(RefExpr.get());
}

// If we have a non-zero number of constructor arguments, try to use them.
// Otherwise, fall back to the promise type's default constructor.
if (!CtorArgExprs.empty()) {
  // Create an initialization sequence for the promise type using the
  // constructor arguments, wrapped in a parenthesized list expression.
  Expr *PLE = ParenListExpr::Create(Context, FD->getLocation(),
                                    CtorArgExprs, FD->getLocation());
  InitializedEntity Entity = InitializedEntity::InitializeVariable(VD);
  InitializationKind Kind = InitializationKind::CreateForInit(
      VD->getLocation(), /*DirectInit=*/true, PLE);
  InitializationSequence InitSeq(*this, Entity, Kind, CtorArgExprs,
                                 /*TopLevelOfInitList=*/false,
                                 /*TreatUnavailableAsInvalid=*/false);

  // [dcl.fct.def.coroutine]5.7
  // promise-constructor-arguments is determined as follows: overload
  // resolution is performed on a promise constructor call created by
  // assembling an argument list  q_1 ... q_n . If a viable constructor is
  // found ([over.match.viable]), then promise-constructor-arguments is ( q_1
  // , ...,  q_n ), otherwise promise-constructor-arguments is empty.
  if (InitSeq) {
    ExprResult Result = InitSeq.Perform(*this, Entity, Kind, CtorArgExprs);
    if (Result.isInvalid()) {
      VD->setInvalidDecl();
    } else if (Result.get()) {
      VD->setInit(MaybeCreateExprWithCleanups(Result.get()));
      VD->setInitStyle(VarDecl::CallInit);
      CheckCompleteVariableDeclaration(VD);
    }
  } else
    ActOnUninitializedDecl(VD);
} else
  ActOnUninitializedDecl(VD);

FD->addDecl(VD);
return VD;
580}

582/// Check that this is a context in which a coroutine suspension can appear.
583static FunctionScopeInfo *checkCoroutineContext(Sema &S, SourceLocation Loc,
                                              StringRef Keyword,
                                              bool IsImplicit = false) {
if (!isValidCoroutineContext(S, Loc, Keyword))
  return nullptr;

assert(isa<FunctionDecl>(S.CurContext) && "not in a function scope")(static_cast <bool> (isa<FunctionDecl>(S.CurContext
) && "not in a function scope") ? void (0) : __assert_fail
 ("isa<FunctionDecl>(S.CurContext) && \"not in a function scope\""
, "clang/lib/Sema/SemaCoroutine.cpp", 589, __extension__ __PRETTY_FUNCTION__
));
9
←
Taking false branch→
10
←
Field 'CurContext' is a 'FunctionDecl'→
11
←
'?' condition is true→

auto *ScopeInfo = S.getCurFunction();
12
←
Calling 'Sema::getCurFunction'→
15
←
Returning from 'Sema::getCurFunction'→
assert(ScopeInfo && "missing function scope for function")(static_cast <bool> (ScopeInfo && "missing function scope for function"
) ? void (0) : __assert_fail ("ScopeInfo && \"missing function scope for function\""
, "clang/lib/Sema/SemaCoroutine.cpp", 592, __extension__ __PRETTY_FUNCTION__
));
16
←
Assuming 'ScopeInfo' is non-null→
17
←
'?' condition is true→

if (ScopeInfo->FirstCoroutineStmtLoc.isInvalid() && !IsImplicit)
  ScopeInfo->setFirstCoroutineStmt(Loc, Keyword);

if (ScopeInfo->CoroutinePromise)
18
←
Assuming field 'CoroutinePromise' is null→
19
←
Taking false branch→
  return ScopeInfo;

if (!S.buildCoroutineParameterMoves(Loc))
20
←
Taking false branch→
  return nullptr;

ScopeInfo->CoroutinePromise = S.buildCoroutinePromise(Loc);
if (!ScopeInfo->CoroutinePromise)
21
←
Assuming field 'CoroutinePromise' is non-null→
22
←
Taking false branch→
  return nullptr;

return ScopeInfo;
23
←
Returning pointer (loaded from 'ScopeInfo'), which participates in a condition later→
608}

610/// Recursively check \p E and all its children to see if any call target
611/// (including constructor call) is declared noexcept. Also any value returned
612/// from the call has a noexcept destructor.
613static void checkNoThrow(Sema &S, const Stmt *E,
                       llvm::SmallPtrSetImpl<const Decl *> &ThrowingDecls) {
auto checkDeclNoexcept = [&](const Decl *D, bool IsDtor = false) {
  // In the case of dtor, the call to dtor is implicit and hence we should
  // pass nullptr to canCalleeThrow.
  if (Sema::canCalleeThrow(S, IsDtor ? nullptr : cast<Expr>(E), D)) {
    if (const auto *FD = dyn_cast<FunctionDecl>(D)) {
      // co_await promise.final_suspend() could end up calling
      // __builtin_coro_resume for symmetric transfer if await_suspend()
      // returns a handle. In that case, even __builtin_coro_resume is not
      // declared as noexcept and may throw, it does not throw _into_ the
      // coroutine that just suspended, but rather throws back out from
      // whoever called coroutine_handle::resume(), hence we claim that
      // logically it does not throw.
      if (FD->getBuiltinID() == Builtin::BI__builtin_coro_resume)
        return;
    }
    if (ThrowingDecls.empty()) {
      // [dcl.fct.def.coroutine]p15
      //   The expression co_await promise.final_suspend() shall not be
      //   potentially-throwing ([except.spec]).
      //
      // First time seeing an error, emit the error message.
      S.Diag(cast<FunctionDecl>(S.CurContext)->getLocation(),
             diag::err_coroutine_promise_final_suspend_requires_nothrow);
    }
    ThrowingDecls.insert(D);
  }
};

if (auto *CE = dyn_cast<CXXConstructExpr>(E)) {
  CXXConstructorDecl *Ctor = CE->getConstructor();
  checkDeclNoexcept(Ctor);
  // Check the corresponding destructor of the constructor.
  checkDeclNoexcept(Ctor->getParent()->getDestructor(), /*IsDtor=*/true);
} else if (auto *CE = dyn_cast<CallExpr>(E)) {
  if (CE->isTypeDependent())
    return;

  checkDeclNoexcept(CE->getCalleeDecl());
  QualType ReturnType = CE->getCallReturnType(S.getASTContext());
  // Check the destructor of the call return type, if any.
  if (ReturnType.isDestructedType() ==
      QualType::DestructionKind::DK_cxx_destructor) {
    const auto *T =
        cast<RecordType>(ReturnType.getCanonicalType().getTypePtr());
    checkDeclNoexcept(cast<CXXRecordDecl>(T->getDecl())->getDestructor(),
                      /*IsDtor=*/true);
  }
} else
  for (const auto *Child : E->children()) {
    if (!Child)
      continue;
    checkNoThrow(S, Child, ThrowingDecls);
  }
668}

670bool Sema::checkFinalSuspendNoThrow(const Stmt *FinalSuspend) {
llvm::SmallPtrSet<const Decl *, 4> ThrowingDecls;
// We first collect all declarations that should not throw but not declared
// with noexcept. We then sort them based on the location before printing.
// This is to avoid emitting the same note multiple times on the same
// declaration, and also provide a deterministic order for the messages.
checkNoThrow(*this, FinalSuspend, ThrowingDecls);
auto SortedDecls = llvm::SmallVector<const Decl *, 4>{ThrowingDecls.begin(),
                                                      ThrowingDecls.end()};
sort(SortedDecls, [](const Decl *A, const Decl *B) {
  return A->getEndLoc() < B->getEndLoc();
});
for (const auto *D : SortedDecls) {
  Diag(D->getEndLoc(), diag::note_coroutine_function_declare_noexcept);
}
return ThrowingDecls.empty();
686}

688bool Sema::ActOnCoroutineBodyStart(Scope *SC, SourceLocation KWLoc,
                                 StringRef Keyword) {
if (!checkCoroutineContext(*this, KWLoc, Keyword))
  return false;
auto *ScopeInfo = getCurFunction();
assert(ScopeInfo->CoroutinePromise)(static_cast <bool> (ScopeInfo->CoroutinePromise) ? void
 (0) : __assert_fail ("ScopeInfo->CoroutinePromise", "clang/lib/Sema/SemaCoroutine.cpp"
, 693, __extension__ __PRETTY_FUNCTION__));

// If we have existing coroutine statements then we have already built
// the initial and final suspend points.
if (!ScopeInfo->NeedsCoroutineSuspends)
  return true;

ScopeInfo->setNeedsCoroutineSuspends(false);

auto *Fn = cast<FunctionDecl>(CurContext);
SourceLocation Loc = Fn->getLocation();
// Build the initial suspend point
auto buildSuspends = [&](StringRef Name) mutable -> StmtResult {
  ExprResult Operand = buildPromiseCall(*this, ScopeInfo->CoroutinePromise,
                                        Loc, Name, std::nullopt);
  if (Operand.isInvalid())
    return StmtError();
  ExprResult Suspend =
      buildOperatorCoawaitCall(*this, SC, Loc, Operand.get());
  if (Suspend.isInvalid())
    return StmtError();
  Suspend = BuildResolvedCoawaitExpr(Loc, Operand.get(), Suspend.get(),
                                     /*IsImplicit*/ true);
  Suspend = ActOnFinishFullExpr(Suspend.get(), /*DiscardedValue*/ false);
  if (Suspend.isInvalid()) {
    Diag(Loc, diag::note_coroutine_promise_suspend_implicitly_required)
        << ((Name == "initial_suspend") ? 0 : 1);
    Diag(KWLoc, diag::note_declared_coroutine_here) << Keyword;
    return StmtError();
  }
  return cast<Stmt>(Suspend.get());
};

StmtResult InitSuspend = buildSuspends("initial_suspend");
if (InitSuspend.isInvalid())
  return true;

StmtResult FinalSuspend = buildSuspends("final_suspend");
if (FinalSuspend.isInvalid() || !checkFinalSuspendNoThrow(FinalSuspend.get()))
  return true;

ScopeInfo->setCoroutineSuspends(InitSuspend.get(), FinalSuspend.get());

return true;
737}

739// Recursively walks up the scope hierarchy until either a 'catch' or a function
740// scope is found, whichever comes first.
741static bool isWithinCatchScope(Scope *S) {
// 'co_await' and 'co_yield' keywords are disallowed within catch blocks, but
// lambdas that use 'co_await' are allowed. The loop below ends when a
// function scope is found in order to ensure the following behavior:
//
// void foo() {      // <- function scope
//   try {           //
//     co_await x;   // <- 'co_await' is OK within a function scope
//   } catch {       // <- catch scope
//     co_await x;   // <- 'co_await' is not OK within a catch scope
//     []() {        // <- function scope
//       co_await x; // <- 'co_await' is OK within a function scope
//     }();
//   }
// }
while (S && !S->isFunctionScope()) {
  if (S->isCatchScope())
    return true;
  S = S->getParent();
}
return false;
762}

764// [expr.await]p2, emphasis added: "An await-expression shall appear only in
765// a *potentially evaluated* expression within the compound-statement of a
766// function-body *outside of a handler* [...] A context within a function
767// where an await-expression can appear is called a suspension context of the
768// function."
769static bool checkSuspensionContext(Sema &S, SourceLocation Loc,
                                 StringRef Keyword) {
// First emphasis of [expr.await]p2: must be a potentially evaluated context.
// That is, 'co_await' and 'co_yield' cannot appear in subexpressions of
// \c sizeof.
if (S.isUnevaluatedContext()) {
  S.Diag(Loc, diag::err_coroutine_unevaluated_context) << Keyword;
  return false;
}

// Second emphasis of [expr.await]p2: must be outside of an exception handler.
if (isWithinCatchScope(S.getCurScope())) {
  S.Diag(Loc, diag::err_coroutine_within_handler) << Keyword;
  return false;
}

return true;
786}

788ExprResult Sema::ActOnCoawaitExpr(Scope *S, SourceLocation Loc, Expr *E) {
if (!checkSuspensionContext(*this, Loc, "co_await"))
  return ExprError();

if (!ActOnCoroutineBodyStart(S, Loc, "co_await")) {
  CorrectDelayedTyposInExpr(E);
  return ExprError();
}

if (E->hasPlaceholderType()) {
  ExprResult R = CheckPlaceholderExpr(E);
  if (R.isInvalid()) return ExprError();
  E = R.get();
}
ExprResult Lookup = BuildOperatorCoawaitLookupExpr(S, Loc);
if (Lookup.isInvalid())
  return ExprError();
return BuildUnresolvedCoawaitExpr(Loc, E,
                                 cast<UnresolvedLookupExpr>(Lookup.get()));
807}

809ExprResult Sema::BuildOperatorCoawaitLookupExpr(Scope *S, SourceLocation Loc) {
DeclarationName OpName =
    Context.DeclarationNames.getCXXOperatorName(OO_Coawait);
LookupResult Operators(*this, OpName, SourceLocation(),
                       Sema::LookupOperatorName);
LookupName(Operators, S);

assert(!Operators.isAmbiguous() && "Operator lookup cannot be ambiguous")(static_cast <bool> (!Operators.isAmbiguous() &&
 "Operator lookup cannot be ambiguous") ? void (0) : __assert_fail
 ("!Operators.isAmbiguous() && \"Operator lookup cannot be ambiguous\""
, "clang/lib/Sema/SemaCoroutine.cpp", 816, __extension__ __PRETTY_FUNCTION__
));
const auto &Functions = Operators.asUnresolvedSet();
bool IsOverloaded =
    Functions.size() > 1 ||
    (Functions.size() == 1 && isa<FunctionTemplateDecl>(*Functions.begin()));
Expr *CoawaitOp = UnresolvedLookupExpr::Create(
    Context, /*NamingClass*/ nullptr, NestedNameSpecifierLoc(),
    DeclarationNameInfo(OpName, Loc), /*RequiresADL*/ true, IsOverloaded,
    Functions.begin(), Functions.end());
assert(CoawaitOp)(static_cast <bool> (CoawaitOp) ? void (0) : __assert_fail
 ("CoawaitOp", "clang/lib/Sema/SemaCoroutine.cpp", 825, __extension__
 __PRETTY_FUNCTION__));
return CoawaitOp;
827}

829// Attempts to resolve and build a CoawaitExpr from "raw" inputs, bailing out to
830// DependentCoawaitExpr if needed.
831ExprResult Sema::BuildUnresolvedCoawaitExpr(SourceLocation Loc, Expr *Operand,
                                          UnresolvedLookupExpr *Lookup) {
auto *FSI = checkCoroutineContext(*this, Loc, "co_await");
if (!FSI)
  return ExprError();

if (Operand->hasPlaceholderType()) {
  ExprResult R = CheckPlaceholderExpr(Operand);
  if (R.isInvalid())
    return ExprError();
  Operand = R.get();
}

auto *Promise = FSI->CoroutinePromise;
if (Promise->getType()->isDependentType()) {
  Expr *Res = new (Context)
      DependentCoawaitExpr(Loc, Context.DependentTy, Operand, Lookup);
  return Res;
}

auto *RD = Promise->getType()->getAsCXXRecordDecl();
auto *Transformed = Operand;
if (lookupMember(*this, "await_transform", RD, Loc)) {
  ExprResult R =
      buildPromiseCall(*this, Promise, Loc, "await_transform", Operand);
  if (R.isInvalid()) {
    Diag(Loc,
         diag::note_coroutine_promise_implicit_await_transform_required_here)
        << Operand->getSourceRange();
    return ExprError();
  }
  Transformed = R.get();
}
ExprResult Awaiter = BuildOperatorCoawaitCall(Loc, Transformed, Lookup);
if (Awaiter.isInvalid())
  return ExprError();

return BuildResolvedCoawaitExpr(Loc, Operand, Awaiter.get());
869}

871ExprResult Sema::BuildResolvedCoawaitExpr(SourceLocation Loc, Expr *Operand,
                                        Expr *Awaiter, bool IsImplicit) {
auto *Coroutine = checkCoroutineContext(*this, Loc, "co_await", IsImplicit);
if (!Coroutine)
  return ExprError();

if (Awaiter->hasPlaceholderType()) {
  ExprResult R = CheckPlaceholderExpr(Awaiter);
  if (R.isInvalid()) return ExprError();
  Awaiter = R.get();
}

if (Awaiter->getType()->isDependentType()) {
  Expr *Res = new (Context)
      CoawaitExpr(Loc, Context.DependentTy, Operand, Awaiter, IsImplicit);
  return Res;
}

// If the expression is a temporary, materialize it as an lvalue so that we
// can use it multiple times.
if (Awaiter->isPRValue())
  Awaiter = CreateMaterializeTemporaryExpr(Awaiter->getType(), Awaiter, true);

// The location of the `co_await` token cannot be used when constructing
// the member call expressions since it's before the location of `Expr`, which
// is used as the start of the member call expression.
SourceLocation CallLoc = Awaiter->getExprLoc();

// Build the await_ready, await_suspend, await_resume calls.
ReadySuspendResumeResult RSS =
    buildCoawaitCalls(*this, Coroutine->CoroutinePromise, CallLoc, Awaiter);
if (RSS.IsInvalid)
  return ExprError();

Expr *Res = new (Context)
    CoawaitExpr(Loc, Operand, Awaiter, RSS.Results[0], RSS.Results[1],
                RSS.Results[2], RSS.OpaqueValue, IsImplicit);

return Res;
910}

912ExprResult Sema::ActOnCoyieldExpr(Scope *S, SourceLocation Loc, Expr *E) {
if (!checkSuspensionContext(*this, Loc, "co_yield"))
1
Taking false branch→
  return ExprError();

if (!ActOnCoroutineBodyStart(S, Loc, "co_yield")) {
2
←
Taking false branch→
  CorrectDelayedTyposInExpr(E);
  return ExprError();
}

// Build yield_value call.
ExprResult Awaitable = buildPromiseCall(
    *this, getCurFunction()->CoroutinePromise, Loc, "yield_value", E);
if (Awaitable.isInvalid())
3
←
Assuming the condition is false→
4
←
Taking false branch→
  return ExprError();

// Build 'operator co_await' call.
Awaitable = buildOperatorCoawaitCall(*this, S, Loc, Awaitable.get());
if (Awaitable.isInvalid())
5
←
Assuming the condition is false→
6
←
Taking false branch→
  return ExprError();

return BuildCoyieldExpr(Loc, Awaitable.get());
7
←
Calling 'Sema::BuildCoyieldExpr'→
933}
934ExprResult Sema::BuildCoyieldExpr(SourceLocation Loc, Expr *E) {
auto *Coroutine = checkCoroutineContext(*this, Loc, "co_yield");
8
←
Calling 'checkCoroutineContext'→
24
←
Returning from 'checkCoroutineContext'→
if (!Coroutine24.1
'Coroutine' is non-null
1
'Coroutine' is non-null
1
'Coroutine' is non-null
)
25
←
Taking false branch→
  return ExprError();

if (E->hasPlaceholderType()) {
26
←
Taking false branch→
  ExprResult R = CheckPlaceholderExpr(E);
  if (R.isInvalid()) return ExprError();
  E = R.get();
}

Expr *Operand = E;

if (E->getType()->isDependentType()) {
27
←
Assuming the condition is false→
28
←
Taking false branch→
  Expr *Res = new (Context) CoyieldExpr(Loc, Context.DependentTy, Operand, E);
  return Res;
}

// If the expression is a temporary, materialize it as an lvalue so that we
// can use it multiple times.
if (E->isPRValue())
29
←
Taking false branch→
  E = CreateMaterializeTemporaryExpr(E->getType(), E, true);

// Build the await_ready, await_suspend, await_resume calls.
ReadySuspendResumeResult RSS = buildCoawaitCalls(
30
←
Calling 'buildCoawaitCalls'→
38
←
Returning from 'buildCoawaitCalls'→
    *this, Coroutine->CoroutinePromise, Loc, E);
if (RSS.IsInvalid38.1
Field 'IsInvalid' is false
1
Field 'IsInvalid' is false
1
Field 'IsInvalid' is false
)
39
←
Taking false branch→
  return ExprError();

Expr *Res =
    new (Context) CoyieldExpr(Loc, Operand, E, RSS.Results[0], RSS.Results[1],
41
←
Calling constructor for 'CoyieldExpr'→
                              RSS.Results[2], RSS.OpaqueValue);
40
←
Passing null pointer value via 6th parameter 'Resume'→

return Res;
968}

970StmtResult Sema::ActOnCoreturnStmt(Scope *S, SourceLocation Loc, Expr *E) {
if (!ActOnCoroutineBodyStart(S, Loc, "co_return")) {
  CorrectDelayedTyposInExpr(E);
  return StmtError();
}
return BuildCoreturnStmt(Loc, E);
976}

978StmtResult Sema::BuildCoreturnStmt(SourceLocation Loc, Expr *E,
                                 bool IsImplicit) {
auto *FSI = checkCoroutineContext(*this, Loc, "co_return", IsImplicit);
if (!FSI)
  return StmtError();

if (E && E->hasPlaceholderType() &&
    !E->hasPlaceholderType(BuiltinType::Overload)) {
  ExprResult R = CheckPlaceholderExpr(E);
  if (R.isInvalid()) return StmtError();
  E = R.get();
}

VarDecl *Promise = FSI->CoroutinePromise;
ExprResult PC;
if (E && (isa<InitListExpr>(E) || !E->getType()->isVoidType())) {
  getNamedReturnInfo(E, SimplerImplicitMoveMode::ForceOn);
  PC = buildPromiseCall(*this, Promise, Loc, "return_value", E);
} else {
  E = MakeFullDiscardedValueExpr(E).get();
  PC = buildPromiseCall(*this, Promise, Loc, "return_void", std::nullopt);
}
if (PC.isInvalid())
  return StmtError();

Expr *PCE = ActOnFinishFullExpr(PC.get(), /*DiscardedValue*/ false).get();

Stmt *Res = new (Context) CoreturnStmt(Loc, E, PCE, IsImplicit);
return Res;
1007}

1009/// Look up the std::nothrow object.
1010static Expr *buildStdNoThrowDeclRef(Sema &S, SourceLocation Loc) {
NamespaceDecl *Std = S.getStdNamespace();
assert(Std && "Should already be diagnosed")(static_cast <bool> (Std && "Should already be diagnosed"
) ? void (0) : __assert_fail ("Std && \"Should already be diagnosed\""
, "clang/lib/Sema/SemaCoroutine.cpp", 1012, __extension__ __PRETTY_FUNCTION__
));

LookupResult Result(S, &S.PP.getIdentifierTable().get("nothrow"), Loc,
                    Sema::LookupOrdinaryName);
if (!S.LookupQualifiedName(Result, Std)) {
  // <coroutine> is not requred to include <new>, so we couldn't omit
  // the check here.
  S.Diag(Loc, diag::err_implicit_coroutine_std_nothrow_type_not_found);
  return nullptr;
}

auto *VD = Result.getAsSingle<VarDecl>();
if (!VD) {
  Result.suppressDiagnostics();
  // We found something weird. Complain about the first thing we found.
  NamedDecl *Found = *Result.begin();
  S.Diag(Found->getLocation(), diag::err_malformed_std_nothrow);
  return nullptr;
}

ExprResult DR = S.BuildDeclRefExpr(VD, VD->getType(), VK_LValue, Loc);
if (DR.isInvalid())
  return nullptr;

return DR.get();
1037}

1039static TypeSourceInfo *getTypeSourceInfoForStdAlignValT(Sema &S,
                                                      SourceLocation Loc) {
EnumDecl *StdAlignValT = S.getStdAlignValT();
QualType StdAlignValDecl = S.Context.getTypeDeclType(StdAlignValT);
return S.Context.getTrivialTypeSourceInfo(StdAlignValDecl);
1044}

1046// Find an appropriate delete for the promise.
1047static bool findDeleteForPromise(Sema &S, SourceLocation Loc, QualType PromiseType,
                               FunctionDecl *&OperatorDelete) {
DeclarationName DeleteName =
    S.Context.DeclarationNames.getCXXOperatorName(OO_Delete);

auto *PointeeRD = PromiseType->getAsCXXRecordDecl();
assert(PointeeRD && "PromiseType must be a CxxRecordDecl type")(static_cast <bool> (PointeeRD && "PromiseType must be a CxxRecordDecl type"
) ? void (0) : __assert_fail ("PointeeRD && \"PromiseType must be a CxxRecordDecl type\""
, "clang/lib/Sema/SemaCoroutine.cpp", 1053, __extension__ __PRETTY_FUNCTION__
));

const bool Overaligned = S.getLangOpts().CoroAlignedAllocation;

// [dcl.fct.def.coroutine]p12
// The deallocation function's name is looked up by searching for it in the
// scope of the promise type. If nothing is found, a search is performed in
// the global scope.
if (S.FindDeallocationFunction(Loc, PointeeRD, DeleteName, OperatorDelete,
                               /*Diagnose*/ true, /*WantSize*/ true,
                               /*WantAligned*/ Overaligned))
  return false;

// [dcl.fct.def.coroutine]p12
//   If both a usual deallocation function with only a pointer parameter and a
//   usual deallocation function with both a pointer parameter and a size
//   parameter are found, then the selected deallocation function shall be the
//   one with two parameters. Otherwise, the selected deallocation function
//   shall be the function with one parameter.
if (!OperatorDelete) {
  // Look for a global declaration.
  // Coroutines can always provide their required size.
  const bool CanProvideSize = true;
  // Sema::FindUsualDeallocationFunction will try to find the one with two
  // parameters first. It will return the deallocation function with one
  // parameter if failed.
  OperatorDelete = S.FindUsualDeallocationFunction(Loc, CanProvideSize,
                                                   Overaligned, DeleteName);

  if (!OperatorDelete)
    return false;
}

S.MarkFunctionReferenced(Loc, OperatorDelete);
return true;
1088}


1091void Sema::CheckCompletedCoroutineBody(FunctionDecl *FD, Stmt *&Body) {
FunctionScopeInfo *Fn = getCurFunction();
assert(Fn && Fn->isCoroutine() && "not a coroutine")(static_cast <bool> (Fn && Fn->isCoroutine()
 && "not a coroutine") ? void (0) : __assert_fail ("Fn && Fn->isCoroutine() && \"not a coroutine\""
, "clang/lib/Sema/SemaCoroutine.cpp", 1093, __extension__ __PRETTY_FUNCTION__
));
if (!Body) {
  assert(FD->isInvalidDecl() &&(static_cast <bool> (FD->isInvalidDecl() && "a null body is only allowed for invalid declarations"
) ? void (0) : __assert_fail ("FD->isInvalidDecl() && \"a null body is only allowed for invalid declarations\""
, "clang/lib/Sema/SemaCoroutine.cpp", 1096, __extension__ __PRETTY_FUNCTION__
))
         "a null body is only allowed for invalid declarations")(static_cast <bool> (FD->isInvalidDecl() && "a null body is only allowed for invalid declarations"
) ? void (0) : __assert_fail ("FD->isInvalidDecl() && \"a null body is only allowed for invalid declarations\""
, "clang/lib/Sema/SemaCoroutine.cpp", 1096, __extension__ __PRETTY_FUNCTION__
));
  return;
}
// We have a function that uses coroutine keywords, but we failed to build
// the promise type.
if (!Fn->CoroutinePromise)
  return FD->setInvalidDecl();

if (isa<CoroutineBodyStmt>(Body)) {
  // Nothing todo. the body is already a transformed coroutine body statement.
  return;
}

// The always_inline attribute doesn't reliably apply to a coroutine,
// because the coroutine will be split into pieces and some pieces
// might be called indirectly, as in a virtual call. Even the ramp
// function cannot be inlined at -O0, due to pipeline ordering
// problems (see https://llvm.org/PR53413). Tell the user about it.
if (FD->hasAttr<AlwaysInlineAttr>())
  Diag(FD->getLocation(), diag::warn_always_inline_coroutine);

// [stmt.return.coroutine]p1:
//   A coroutine shall not enclose a return statement ([stmt.return]).
if (Fn->FirstReturnLoc.isValid()) {
  assert(Fn->FirstCoroutineStmtLoc.isValid() &&(static_cast <bool> (Fn->FirstCoroutineStmtLoc.isValid
() && "first coroutine location not set") ? void (0) :
 __assert_fail ("Fn->FirstCoroutineStmtLoc.isValid() && \"first coroutine location not set\""
, "clang/lib/Sema/SemaCoroutine.cpp", 1121, __extension__ __PRETTY_FUNCTION__
))
                 "first coroutine location not set")(static_cast <bool> (Fn->FirstCoroutineStmtLoc.isValid
() && "first coroutine location not set") ? void (0) :
 __assert_fail ("Fn->FirstCoroutineStmtLoc.isValid() && \"first coroutine location not set\""
, "clang/lib/Sema/SemaCoroutine.cpp", 1121, __extension__ __PRETTY_FUNCTION__
));
  Diag(Fn->FirstReturnLoc, diag::err_return_in_coroutine);
  Diag(Fn->FirstCoroutineStmtLoc, diag::note_declared_coroutine_here)
          << Fn->getFirstCoroutineStmtKeyword();
}

// Coroutines will get splitted into pieces. The GNU address of label
// extension wouldn't be meaningful in coroutines.
for (AddrLabelExpr *ALE : Fn->AddrLabels)
  Diag(ALE->getBeginLoc(), diag::err_coro_invalid_addr_of_label);

CoroutineStmtBuilder Builder(*this, *FD, *Fn, Body);
if (Builder.isInvalid() || !Builder.buildStatements())
  return FD->setInvalidDecl();

// Build body for the coroutine wrapper statement.
Body = CoroutineBodyStmt::Create(Context, Builder);
1138}

1140static CompoundStmt *buildCoroutineBody(Stmt *Body, ASTContext &Context) {
if (auto *CS = dyn_cast<CompoundStmt>(Body))
  return CS;

// The body of the coroutine may be a try statement if it is in
// 'function-try-block' syntax. Here we wrap it into a compound
// statement for consistency.
assert(isa<CXXTryStmt>(Body) && "Unimaged coroutine body type")(static_cast <bool> (isa<CXXTryStmt>(Body) &&
 "Unimaged coroutine body type") ? void (0) : __assert_fail (
"isa<CXXTryStmt>(Body) && \"Unimaged coroutine body type\""
, "clang/lib/Sema/SemaCoroutine.cpp", 1147, __extension__ __PRETTY_FUNCTION__
));
return CompoundStmt::Create(Context, {Body}, FPOptionsOverride(),
                            SourceLocation(), SourceLocation());
1150}

1152CoroutineStmtBuilder::CoroutineStmtBuilder(Sema &S, FunctionDecl &FD,
                                         sema::FunctionScopeInfo &Fn,
                                         Stmt *Body)
  : S(S), FD(FD), Fn(Fn), Loc(FD.getLocation()),
    IsPromiseDependentType(
        !Fn.CoroutinePromise ||
        Fn.CoroutinePromise->getType()->isDependentType()) {
this->Body = buildCoroutineBody(Body, S.getASTContext());

for (auto KV : Fn.CoroutineParameterMoves)
  this->ParamMovesVector.push_back(KV.second);
this->ParamMoves = this->ParamMovesVector;

if (!IsPromiseDependentType) {
  PromiseRecordDecl = Fn.CoroutinePromise->getType()->getAsCXXRecordDecl();
  assert(PromiseRecordDecl && "Type should have already been checked")(static_cast <bool> (PromiseRecordDecl && "Type should have already been checked"
) ? void (0) : __assert_fail ("PromiseRecordDecl && \"Type should have already been checked\""
, "clang/lib/Sema/SemaCoroutine.cpp", 1167, __extension__ __PRETTY_FUNCTION__
));
}
this->IsValid = makePromiseStmt() && makeInitialAndFinalSuspend();
1170}

1172bool CoroutineStmtBuilder::buildStatements() {
assert(this->IsValid && "coroutine already invalid")(static_cast <bool> (this->IsValid && "coroutine already invalid"
) ? void (0) : __assert_fail ("this->IsValid && \"coroutine already invalid\""
, "clang/lib/Sema/SemaCoroutine.cpp", 1173, __extension__ __PRETTY_FUNCTION__
));
this->IsValid = makeReturnObject();
if (this->IsValid && !IsPromiseDependentType)
  buildDependentStatements();
return this->IsValid;
1178}

1180bool CoroutineStmtBuilder::buildDependentStatements() {
assert(this->IsValid && "coroutine already invalid")(static_cast <bool> (this->IsValid && "coroutine already invalid"
) ? void (0) : __assert_fail ("this->IsValid && \"coroutine already invalid\""
, "clang/lib/Sema/SemaCoroutine.cpp", 1181, __extension__ __PRETTY_FUNCTION__
));
assert(!this->IsPromiseDependentType &&(static_cast <bool> (!this->IsPromiseDependentType &&
 "coroutine cannot have a dependent promise type") ? void (0)
 : __assert_fail ("!this->IsPromiseDependentType && \"coroutine cannot have a dependent promise type\""
, "clang/lib/Sema/SemaCoroutine.cpp", 1183, __extension__ __PRETTY_FUNCTION__
))
       "coroutine cannot have a dependent promise type")(static_cast <bool> (!this->IsPromiseDependentType &&
 "coroutine cannot have a dependent promise type") ? void (0)
 : __assert_fail ("!this->IsPromiseDependentType && \"coroutine cannot have a dependent promise type\""
, "clang/lib/Sema/SemaCoroutine.cpp", 1183, __extension__ __PRETTY_FUNCTION__
));
this->IsValid = makeOnException() && makeOnFallthrough() &&
                makeGroDeclAndReturnStmt() && makeReturnOnAllocFailure() &&
                makeNewAndDeleteExpr();
return this->IsValid;
1188}

1190bool CoroutineStmtBuilder::makePromiseStmt() {
// Form a declaration statement for the promise declaration, so that AST
// visitors can more easily find it.
StmtResult PromiseStmt =
    S.ActOnDeclStmt(S.ConvertDeclToDeclGroup(Fn.CoroutinePromise), Loc, Loc);
if (PromiseStmt.isInvalid())
  return false;

this->Promise = PromiseStmt.get();
return true;
1200}

1202bool CoroutineStmtBuilder::makeInitialAndFinalSuspend() {
if (Fn.hasInvalidCoroutineSuspends())
  return false;
this->InitialSuspend = cast<Expr>(Fn.CoroutineSuspends.first);
this->FinalSuspend = cast<Expr>(Fn.CoroutineSuspends.second);
return true;
1208}

1210static bool diagReturnOnAllocFailure(Sema &S, Expr *E,
                                   CXXRecordDecl *PromiseRecordDecl,
                                   FunctionScopeInfo &Fn) {
auto Loc = E->getExprLoc();
if (auto *DeclRef = dyn_cast_or_null<DeclRefExpr>(E)) {
  auto *Decl = DeclRef->getDecl();
  if (CXXMethodDecl *Method = dyn_cast_or_null<CXXMethodDecl>(Decl)) {
    if (Method->isStatic())
      return true;
    else
      Loc = Decl->getLocation();
  }
}

S.Diag(
    Loc,
    diag::err_coroutine_promise_get_return_object_on_allocation_failure)
    << PromiseRecordDecl;
S.Diag(Fn.FirstCoroutineStmtLoc, diag::note_declared_coroutine_here)
    << Fn.getFirstCoroutineStmtKeyword();
return false;
1231}

1233bool CoroutineStmtBuilder::makeReturnOnAllocFailure() {
assert(!IsPromiseDependentType &&(static_cast <bool> (!IsPromiseDependentType &&
 "cannot make statement while the promise type is dependent")
 ? void (0) : __assert_fail ("!IsPromiseDependentType && \"cannot make statement while the promise type is dependent\""
, "clang/lib/Sema/SemaCoroutine.cpp", 1235, __extension__ __PRETTY_FUNCTION__
))
       "cannot make statement while the promise type is dependent")(static_cast <bool> (!IsPromiseDependentType &&
 "cannot make statement while the promise type is dependent")
 ? void (0) : __assert_fail ("!IsPromiseDependentType && \"cannot make statement while the promise type is dependent\""
, "clang/lib/Sema/SemaCoroutine.cpp", 1235, __extension__ __PRETTY_FUNCTION__
));

// [dcl.fct.def.coroutine]p10
//   If a search for the name get_return_object_on_allocation_failure in
// the scope of the promise type ([class.member.lookup]) finds any
// declarations, then the result of a call to an allocation function used to
// obtain storage for the coroutine state is assumed to return nullptr if it
// fails to obtain storage, ... If the allocation function returns nullptr,
// ... and the return value is obtained by a call to
// T::get_return_object_on_allocation_failure(), where T is the
// promise type.
DeclarationName DN =
    S.PP.getIdentifierInfo("get_return_object_on_allocation_failure");
LookupResult Found(S, DN, Loc, Sema::LookupMemberName);
if (!S.LookupQualifiedName(Found, PromiseRecordDecl))
  return true;

CXXScopeSpec SS;
ExprResult DeclNameExpr =
    S.BuildDeclarationNameExpr(SS, Found, /*NeedsADL=*/false);
if (DeclNameExpr.isInvalid())
  return false;

if (!diagReturnOnAllocFailure(S, DeclNameExpr.get(), PromiseRecordDecl, Fn))
  return false;

ExprResult ReturnObjectOnAllocationFailure =
    S.BuildCallExpr(nullptr, DeclNameExpr.get(), Loc, {}, Loc);
if (ReturnObjectOnAllocationFailure.isInvalid())
  return false;

StmtResult ReturnStmt =
    S.BuildReturnStmt(Loc, ReturnObjectOnAllocationFailure.get());
if (ReturnStmt.isInvalid()) {
  S.Diag(Found.getFoundDecl()->getLocation(), diag::note_member_declared_here)
      << DN;
  S.Diag(Fn.FirstCoroutineStmtLoc, diag::note_declared_coroutine_here)
      << Fn.getFirstCoroutineStmtKeyword();
  return false;
}

this->ReturnStmtOnAllocFailure = ReturnStmt.get();
return true;
1278}

1280// Collect placement arguments for allocation function of coroutine FD.
1281// Return true if we collect placement arguments succesfully. Return false,
1282// otherwise.
1283static bool collectPlacementArgs(Sema &S, FunctionDecl &FD, SourceLocation Loc,
                               SmallVectorImpl<Expr *> &PlacementArgs) {
if (auto *MD = dyn_cast<CXXMethodDecl>(&FD)) {
  if (MD->isInstance() && !isLambdaCallOperator(MD)) {
    ExprResult ThisExpr = S.ActOnCXXThis(Loc);
    if (ThisExpr.isInvalid())
      return false;
    ThisExpr = S.CreateBuiltinUnaryOp(Loc, UO_Deref, ThisExpr.get());
    if (ThisExpr.isInvalid())
      return false;
    PlacementArgs.push_back(ThisExpr.get());
  }
}

for (auto *PD : FD.parameters()) {
  if (PD->getType()->isDependentType())
    continue;

  // Build a reference to the parameter.
  auto PDLoc = PD->getLocation();
  ExprResult PDRefExpr =
      S.BuildDeclRefExpr(PD, PD->getOriginalType().getNonReferenceType(),
                         ExprValueKind::VK_LValue, PDLoc);
  if (PDRefExpr.isInvalid())
    return false;

  PlacementArgs.push_back(PDRefExpr.get());
}

return true;
1313}

1315bool CoroutineStmtBuilder::makeNewAndDeleteExpr() {
// Form and check allocation and deallocation calls.
assert(!IsPromiseDependentType &&(static_cast <bool> (!IsPromiseDependentType &&
 "cannot make statement while the promise type is dependent")
 ? void (0) : __assert_fail ("!IsPromiseDependentType && \"cannot make statement while the promise type is dependent\""
, "clang/lib/Sema/SemaCoroutine.cpp", 1318, __extension__ __PRETTY_FUNCTION__
))
       "cannot make statement while the promise type is dependent")(static_cast <bool> (!IsPromiseDependentType &&
 "cannot make statement while the promise type is dependent")
 ? void (0) : __assert_fail ("!IsPromiseDependentType && \"cannot make statement while the promise type is dependent\""
, "clang/lib/Sema/SemaCoroutine.cpp", 1318, __extension__ __PRETTY_FUNCTION__
));
QualType PromiseType = Fn.CoroutinePromise->getType();

if (S.RequireCompleteType(Loc, PromiseType, diag::err_incomplete_type))
  return false;

const bool RequiresNoThrowAlloc = ReturnStmtOnAllocFailure != nullptr;

// According to [dcl.fct.def.coroutine]p9, Lookup allocation functions using a
// parameter list composed of the requested size of the coroutine state being
// allocated, followed by the coroutine function's arguments. If a matching
// allocation function exists, use it. Otherwise, use an allocation function
// that just takes the requested size.
//
// [dcl.fct.def.coroutine]p9
//   An implementation may need to allocate additional storage for a
//   coroutine.
// This storage is known as the coroutine state and is obtained by calling a
// non-array allocation function ([basic.stc.dynamic.allocation]). The
// allocation function's name is looked up by searching for it in the scope of
// the promise type.
// - If any declarations are found, overload resolution is performed on a
// function call created by assembling an argument list. The first argument is
// the amount of space requested, and has type std::size_t. The
// lvalues p1 ... pn are the succeeding arguments.
//
// ...where "p1 ... pn" are defined earlier as:
//
// [dcl.fct.def.coroutine]p3
//   The promise type of a coroutine is `std::coroutine_traits<R, P1, ...,
//   Pn>`
// , where R is the return type of the function, and `P1, ..., Pn` are the
// sequence of types of the non-object function parameters, preceded by the
// type of the object parameter ([dcl.fct]) if the coroutine is a non-static
// member function. [dcl.fct.def.coroutine]p4 In the following, p_i is an
// lvalue of type P_i, where p1 denotes the object parameter and p_i+1 denotes
// the i-th non-object function parameter for a non-static member function,
// and p_i denotes the i-th function parameter otherwise. For a non-static
// member function, q_1 is an lvalue that denotes *this; any other q_i is an
// lvalue that denotes the parameter copy corresponding to p_i.

FunctionDecl *OperatorNew = nullptr;
SmallVector<Expr *, 1> PlacementArgs;

const bool PromiseContainsNew = [this, &PromiseType]() -> bool {
  DeclarationName NewName =
      S.getASTContext().DeclarationNames.getCXXOperatorName(OO_New);
  LookupResult R(S, NewName, Loc, Sema::LookupOrdinaryName);

  if (PromiseType->isRecordType())
    S.LookupQualifiedName(R, PromiseType->getAsCXXRecordDecl());

  return !R.empty() && !R.isAmbiguous();
}();

// Helper function to indicate whether the last lookup found the aligned
// allocation function.
bool PassAlignment = S.getLangOpts().CoroAlignedAllocation;
auto LookupAllocationFunction = [&](Sema::AllocationFunctionScope NewScope =
                                        Sema::AFS_Both,
                                    bool WithoutPlacementArgs = false,
                                    bool ForceNonAligned = false) {
  // [dcl.fct.def.coroutine]p9
  //   The allocation function's name is looked up by searching for it in the
  // scope of the promise type.
  // - If any declarations are found, ...
  // - If no declarations are found in the scope of the promise type, a search
  // is performed in the global scope.
  if (NewScope == Sema::AFS_Both)
    NewScope = PromiseContainsNew ? Sema::AFS_Class : Sema::AFS_Global;

  PassAlignment = !ForceNonAligned && S.getLangOpts().CoroAlignedAllocation;
  FunctionDecl *UnusedResult = nullptr;
  S.FindAllocationFunctions(Loc, SourceRange(), NewScope,
                            /*DeleteScope*/ Sema::AFS_Both, PromiseType,
                            /*isArray*/ false, PassAlignment,
                            WithoutPlacementArgs ? MultiExprArg{}
                                                 : PlacementArgs,
                            OperatorNew, UnusedResult, /*Diagnose*/ false);
};

// We don't expect to call to global operator new with (size, p0, …, pn).
// So if we choose to lookup the allocation function in global scope, we
// shouldn't lookup placement arguments.
if (PromiseContainsNew && !collectPlacementArgs(S, FD, Loc, PlacementArgs))
  return false;

LookupAllocationFunction();

if (PromiseContainsNew && !PlacementArgs.empty()) {
  // [dcl.fct.def.coroutine]p9
  //   If no viable function is found ([over.match.viable]), overload
  //   resolution
  // is performed again on a function call created by passing just the amount
  // of space required as an argument of type std::size_t.
  //
  // Proposed Change of [dcl.fct.def.coroutine]p9 in P2014R0:
  //   Otherwise, overload resolution is performed again on a function call
  //   created
  // by passing the amount of space requested as an argument of type
  // std::size_t as the first argument, and the requested alignment as
  // an argument of type std:align_val_t as the second argument.
  if (!OperatorNew ||
      (S.getLangOpts().CoroAlignedAllocation && !PassAlignment))
    LookupAllocationFunction(/*NewScope*/ Sema::AFS_Class,
                             /*WithoutPlacementArgs*/ true);
}

// Proposed Change of [dcl.fct.def.coroutine]p12 in P2014R0:
//   Otherwise, overload resolution is performed again on a function call
//   created
// by passing the amount of space requested as an argument of type
// std::size_t as the first argument, and the lvalues p1 ... pn as the
// succeeding arguments. Otherwise, overload resolution is performed again
// on a function call created by passing just the amount of space required as
// an argument of type std::size_t.
//
// So within the proposed change in P2014RO, the priority order of aligned
// allocation functions wiht promise_type is:
//
//    void* operator new( std::size_t, std::align_val_t, placement_args... );
//    void* operator new( std::size_t, std::align_val_t);
//    void* operator new( std::size_t, placement_args... );
//    void* operator new( std::size_t);

// Helper variable to emit warnings.
bool FoundNonAlignedInPromise = false;
if (PromiseContainsNew && S.getLangOpts().CoroAlignedAllocation)
  if (!OperatorNew || !PassAlignment) {
    FoundNonAlignedInPromise = OperatorNew;

    LookupAllocationFunction(/*NewScope*/ Sema::AFS_Class,
                             /*WithoutPlacementArgs*/ false,
                             /*ForceNonAligned*/ true);

    if (!OperatorNew && !PlacementArgs.empty())
      LookupAllocationFunction(/*NewScope*/ Sema::AFS_Class,
                               /*WithoutPlacementArgs*/ true,
                               /*ForceNonAligned*/ true);
  }

bool IsGlobalOverload =
    OperatorNew && !isa<CXXRecordDecl>(OperatorNew->getDeclContext());
// If we didn't find a class-local new declaration and non-throwing new
// was is required then we need to lookup the non-throwing global operator
// instead.
if (RequiresNoThrowAlloc && (!OperatorNew || IsGlobalOverload)) {
  auto *StdNoThrow = buildStdNoThrowDeclRef(S, Loc);
  if (!StdNoThrow)
    return false;
  PlacementArgs = {StdNoThrow};
  OperatorNew = nullptr;
  LookupAllocationFunction(Sema::AFS_Global);
}

// If we found a non-aligned allocation function in the promise_type,
// it indicates the user forgot to update the allocation function. Let's emit
// a warning here.
if (FoundNonAlignedInPromise) {
  S.Diag(OperatorNew->getLocation(),
         diag::warn_non_aligned_allocation_function)
      << &FD;
}

if (!OperatorNew) {
  if (PromiseContainsNew)
    S.Diag(Loc, diag::err_coroutine_unusable_new) << PromiseType << &FD;
  else if (RequiresNoThrowAlloc)
    S.Diag(Loc, diag::err_coroutine_unfound_nothrow_new)
        << &FD << S.getLangOpts().CoroAlignedAllocation;

  return false;
}

if (RequiresNoThrowAlloc) {
  const auto *FT = OperatorNew->getType()->castAs<FunctionProtoType>();
  if (!FT->isNothrow(/*ResultIfDependent*/ false)) {
    S.Diag(OperatorNew->getLocation(),
           diag::err_coroutine_promise_new_requires_nothrow)
        << OperatorNew;
    S.Diag(Loc, diag::note_coroutine_promise_call_implicitly_required)
        << OperatorNew;
    return false;
  }
}

FunctionDecl *OperatorDelete = nullptr;
if (!findDeleteForPromise(S, Loc, PromiseType, OperatorDelete)) {
  // FIXME: We should add an error here. According to:
  // [dcl.fct.def.coroutine]p12
  //   If no usual deallocation function is found, the program is ill-formed.
  return false;
}

Expr *FramePtr =
    S.BuildBuiltinCallExpr(Loc, Builtin::BI__builtin_coro_frame, {});

Expr *FrameSize =
    S.BuildBuiltinCallExpr(Loc, Builtin::BI__builtin_coro_size, {});

Expr *FrameAlignment = nullptr;

if (S.getLangOpts().CoroAlignedAllocation) {
  FrameAlignment =
      S.BuildBuiltinCallExpr(Loc, Builtin::BI__builtin_coro_align, {});

  TypeSourceInfo *AlignValTy = getTypeSourceInfoForStdAlignValT(S, Loc);
  if (!AlignValTy)
    return false;

  FrameAlignment = S.BuildCXXNamedCast(Loc, tok::kw_static_cast, AlignValTy,
                                       FrameAlignment, SourceRange(Loc, Loc),
                                       SourceRange(Loc, Loc))
                       .get();
}

// Make new call.
ExprResult NewRef =
    S.BuildDeclRefExpr(OperatorNew, OperatorNew->getType(), VK_LValue, Loc);
if (NewRef.isInvalid())
  return false;

SmallVector<Expr *, 2> NewArgs(1, FrameSize);
if (S.getLangOpts().CoroAlignedAllocation && PassAlignment)
  NewArgs.push_back(FrameAlignment);

if (OperatorNew->getNumParams() > NewArgs.size())
  llvm::append_range(NewArgs, PlacementArgs);

ExprResult NewExpr =
    S.BuildCallExpr(S.getCurScope(), NewRef.get(), Loc, NewArgs, Loc);
NewExpr = S.ActOnFinishFullExpr(NewExpr.get(), /*DiscardedValue*/ false);
if (NewExpr.isInvalid())
  return false;

// Make delete call.

QualType OpDeleteQualType = OperatorDelete->getType();

ExprResult DeleteRef =
    S.BuildDeclRefExpr(OperatorDelete, OpDeleteQualType, VK_LValue, Loc);
if (DeleteRef.isInvalid())
  return false;

Expr *CoroFree =
    S.BuildBuiltinCallExpr(Loc, Builtin::BI__builtin_coro_free, {FramePtr});

SmallVector<Expr *, 2> DeleteArgs{CoroFree};

// [dcl.fct.def.coroutine]p12
//   The selected deallocation function shall be called with the address of
//   the block of storage to be reclaimed as its first argument. If a
//   deallocation function with a parameter of type std::size_t is
//   used, the size of the block is passed as the corresponding argument.
const auto *OpDeleteType =
    OpDeleteQualType.getTypePtr()->castAs<FunctionProtoType>();
if (OpDeleteType->getNumParams() > DeleteArgs.size() &&
    S.getASTContext().hasSameUnqualifiedType(
        OpDeleteType->getParamType(DeleteArgs.size()), FrameSize->getType()))
  DeleteArgs.push_back(FrameSize);

// Proposed Change of [dcl.fct.def.coroutine]p12 in P2014R0:
//   If deallocation function lookup finds a usual deallocation function with
//   a pointer parameter, size parameter and alignment parameter then this
//   will be the selected deallocation function, otherwise if lookup finds a
//   usual deallocation function with both a pointer parameter and a size
//   parameter, then this will be the selected deallocation function.
//   Otherwise, if lookup finds a usual deallocation function with only a
//   pointer parameter, then this will be the selected deallocation
//   function.
//
// So we are not forced to pass alignment to the deallocation function.
if (S.getLangOpts().CoroAlignedAllocation &&
    OpDeleteType->getNumParams() > DeleteArgs.size() &&
    S.getASTContext().hasSameUnqualifiedType(
        OpDeleteType->getParamType(DeleteArgs.size()),
        FrameAlignment->getType()))
  DeleteArgs.push_back(FrameAlignment);

ExprResult DeleteExpr =
    S.BuildCallExpr(S.getCurScope(), DeleteRef.get(), Loc, DeleteArgs, Loc);
DeleteExpr =
    S.ActOnFinishFullExpr(DeleteExpr.get(), /*DiscardedValue*/ false);
if (DeleteExpr.isInvalid())
  return false;

this->Allocate = NewExpr.get();
this->Deallocate = DeleteExpr.get();

return true;
1608}

1610bool CoroutineStmtBuilder::makeOnFallthrough() {
assert(!IsPromiseDependentType &&(static_cast <bool> (!IsPromiseDependentType &&
 "cannot make statement while the promise type is dependent")
 ? void (0) : __assert_fail ("!IsPromiseDependentType && \"cannot make statement while the promise type is dependent\""
, "clang/lib/Sema/SemaCoroutine.cpp", 1612, __extension__ __PRETTY_FUNCTION__
))
       "cannot make statement while the promise type is dependent")(static_cast <bool> (!IsPromiseDependentType &&
 "cannot make statement while the promise type is dependent")
 ? void (0) : __assert_fail ("!IsPromiseDependentType && \"cannot make statement while the promise type is dependent\""
, "clang/lib/Sema/SemaCoroutine.cpp", 1612, __extension__ __PRETTY_FUNCTION__
));

// [dcl.fct.def.coroutine]/p6
// If searches for the names return_void and return_value in the scope of
// the promise type each find any declarations, the program is ill-formed.
// [Note 1: If return_void is found, flowing off the end of a coroutine is
// equivalent to a co_return with no operand. Otherwise, flowing off the end
// of a coroutine results in undefined behavior ([stmt.return.coroutine]). —
// end note]
bool HasRVoid, HasRValue;
LookupResult LRVoid =
    lookupMember(S, "return_void", PromiseRecordDecl, Loc, HasRVoid);
LookupResult LRValue =
    lookupMember(S, "return_value", PromiseRecordDecl, Loc, HasRValue);

StmtResult Fallthrough;
if (HasRVoid && HasRValue) {
  // FIXME Improve this diagnostic
  S.Diag(FD.getLocation(),
         diag::err_coroutine_promise_incompatible_return_functions)
      << PromiseRecordDecl;
  S.Diag(LRVoid.getRepresentativeDecl()->getLocation(),
         diag::note_member_first_declared_here)
      << LRVoid.getLookupName();
  S.Diag(LRValue.getRepresentativeDecl()->getLocation(),
         diag::note_member_first_declared_here)
      << LRValue.getLookupName();
  return false;
} else if (!HasRVoid && !HasRValue) {
  // We need to set 'Fallthrough'. Otherwise the other analysis part might
  // think the coroutine has defined a return_value method. So it might emit
  // **false** positive warning. e.g.,
  //
  //    promise_without_return_func foo() {
  //        co_await something();
  //    }
  //
  // Then AnalysisBasedWarning would emit a warning about `foo()` lacking a
  // co_return statements, which isn't correct.
  Fallthrough = S.ActOnNullStmt(PromiseRecordDecl->getLocation());
  if (Fallthrough.isInvalid())
    return false;
} else if (HasRVoid) {
  Fallthrough = S.BuildCoreturnStmt(FD.getLocation(), nullptr,
                                    /*IsImplicit*/false);
  Fallthrough = S.ActOnFinishFullStmt(Fallthrough.get());
  if (Fallthrough.isInvalid())
    return false;
}

this->OnFallthrough = Fallthrough.get();
return true;
1664}

1666bool CoroutineStmtBuilder::makeOnException() {
// Try to form 'p.unhandled_exception();'
assert(!IsPromiseDependentType &&(static_cast <bool> (!IsPromiseDependentType &&
 "cannot make statement while the promise type is dependent")
 ? void (0) : __assert_fail ("!IsPromiseDependentType && \"cannot make statement while the promise type is dependent\""
, "clang/lib/Sema/SemaCoroutine.cpp", 1669, __extension__ __PRETTY_FUNCTION__
))
       "cannot make statement while the promise type is dependent")(static_cast <bool> (!IsPromiseDependentType &&
 "cannot make statement while the promise type is dependent")
 ? void (0) : __assert_fail ("!IsPromiseDependentType && \"cannot make statement while the promise type is dependent\""
, "clang/lib/Sema/SemaCoroutine.cpp", 1669, __extension__ __PRETTY_FUNCTION__
));

const bool RequireUnhandledException = S.getLangOpts().CXXExceptions;

if (!lookupMember(S, "unhandled_exception", PromiseRecordDecl, Loc)) {
  auto DiagID =
      RequireUnhandledException
          ? diag::err_coroutine_promise_unhandled_exception_required
          : diag::
                warn_coroutine_promise_unhandled_exception_required_with_exceptions;
  S.Diag(Loc, DiagID) << PromiseRecordDecl;
  S.Diag(PromiseRecordDecl->getLocation(), diag::note_defined_here)
      << PromiseRecordDecl;
  return !RequireUnhandledException;
}

// If exceptions are disabled, don't try to build OnException.
if (!S.getLangOpts().CXXExceptions)
  return true;

ExprResult UnhandledException = buildPromiseCall(
    S, Fn.CoroutinePromise, Loc, "unhandled_exception", std::nullopt);
UnhandledException = S.ActOnFinishFullExpr(UnhandledException.get(), Loc,
                                           /*DiscardedValue*/ false);
if (UnhandledException.isInvalid())
  return false;

// Since the body of the coroutine will be wrapped in try-catch, it will
// be incompatible with SEH __try if present in a function.
if (!S.getLangOpts().Borland && Fn.FirstSEHTryLoc.isValid()) {
  S.Diag(Fn.FirstSEHTryLoc, diag::err_seh_in_a_coroutine_with_cxx_exceptions);
  S.Diag(Fn.FirstCoroutineStmtLoc, diag::note_declared_coroutine_here)
      << Fn.getFirstCoroutineStmtKeyword();
  return false;
}

this->OnException = UnhandledException.get();
return true;
1707}

1709bool CoroutineStmtBuilder::makeReturnObject() {
// [dcl.fct.def.coroutine]p7
// The expression promise.get_return_object() is used to initialize the
// returned reference or prvalue result object of a call to a coroutine.
ExprResult ReturnObject = buildPromiseCall(S, Fn.CoroutinePromise, Loc,
                                           "get_return_object", std::nullopt);
if (ReturnObject.isInvalid())
  return false;

this->ReturnValue = ReturnObject.get();
return true;
1720}

1722static void noteMemberDeclaredHere(Sema &S, Expr *E, FunctionScopeInfo &Fn) {
if (auto *MbrRef = dyn_cast<CXXMemberCallExpr>(E)) {
  auto *MethodDecl = MbrRef->getMethodDecl();
  S.Diag(MethodDecl->getLocation(), diag::note_member_declared_here)
      << MethodDecl;
}
S.Diag(Fn.FirstCoroutineStmtLoc, diag::note_declared_coroutine_here)
    << Fn.getFirstCoroutineStmtKeyword();
1730}

1732bool CoroutineStmtBuilder::makeGroDeclAndReturnStmt() {
assert(!IsPromiseDependentType &&(static_cast <bool> (!IsPromiseDependentType &&
 "cannot make statement while the promise type is dependent")
 ? void (0) : __assert_fail ("!IsPromiseDependentType && \"cannot make statement while the promise type is dependent\""
, "clang/lib/Sema/SemaCoroutine.cpp", 1734, __extension__ __PRETTY_FUNCTION__
))
       "cannot make statement while the promise type is dependent")(static_cast <bool> (!IsPromiseDependentType &&
 "cannot make statement while the promise type is dependent")
 ? void (0) : __assert_fail ("!IsPromiseDependentType && \"cannot make statement while the promise type is dependent\""
, "clang/lib/Sema/SemaCoroutine.cpp", 1734, __extension__ __PRETTY_FUNCTION__
));
assert(this->ReturnValue && "ReturnValue must be already formed")(static_cast <bool> (this->ReturnValue && "ReturnValue must be already formed"
) ? void (0) : __assert_fail ("this->ReturnValue && \"ReturnValue must be already formed\""
, "clang/lib/Sema/SemaCoroutine.cpp", 1735, __extension__ __PRETTY_FUNCTION__
));

QualType const GroType = this->ReturnValue->getType();
assert(!GroType->isDependentType() &&(static_cast <bool> (!GroType->isDependentType() &&
 "get_return_object type must no longer be dependent") ? void
 (0) : __assert_fail ("!GroType->isDependentType() && \"get_return_object type must no longer be dependent\""
, "clang/lib/Sema/SemaCoroutine.cpp", 1739, __extension__ __PRETTY_FUNCTION__
))
       "get_return_object type must no longer be dependent")(static_cast <bool> (!GroType->isDependentType() &&
 "get_return_object type must no longer be dependent") ? void
 (0) : __assert_fail ("!GroType->isDependentType() && \"get_return_object type must no longer be dependent\""
, "clang/lib/Sema/SemaCoroutine.cpp", 1739, __extension__ __PRETTY_FUNCTION__
));

QualType const FnRetType = FD.getReturnType();
assert(!FnRetType->isDependentType() &&(static_cast <bool> (!FnRetType->isDependentType() &&
 "get_return_object type must no longer be dependent") ? void
 (0) : __assert_fail ("!FnRetType->isDependentType() && \"get_return_object type must no longer be dependent\""
, "clang/lib/Sema/SemaCoroutine.cpp", 1743, __extension__ __PRETTY_FUNCTION__
))
       "get_return_object type must no longer be dependent")(static_cast <bool> (!FnRetType->isDependentType() &&
 "get_return_object type must no longer be dependent") ? void
 (0) : __assert_fail ("!FnRetType->isDependentType() && \"get_return_object type must no longer be dependent\""
, "clang/lib/Sema/SemaCoroutine.cpp", 1743, __extension__ __PRETTY_FUNCTION__
));

// The call to get_­return_­object is sequenced before the call to
// initial_­suspend and is invoked at most once, but there are caveats
// regarding on whether the prvalue result object may be initialized
// directly/eager or delayed, depending on the types involved.
//
// More info at https://github.com/cplusplus/papers/issues/1414
bool GroMatchesRetType = S.getASTContext().hasSameType(GroType, FnRetType);

if (FnRetType->isVoidType()) {
  ExprResult Res =
      S.ActOnFinishFullExpr(this->ReturnValue, Loc, /*DiscardedValue*/ false);
  if (Res.isInvalid())
    return false;

  if (!GroMatchesRetType)
    this->ResultDecl = Res.get();
  return true;
}

if (GroType->isVoidType()) {
  // Trigger a nice error message.
  InitializedEntity Entity =
      InitializedEntity::InitializeResult(Loc, FnRetType);
  S.PerformCopyInitialization(Entity, SourceLocation(), ReturnValue);
  noteMemberDeclaredHere(S, ReturnValue, Fn);
  return false;
}

StmtResult ReturnStmt;
clang::VarDecl *GroDecl = nullptr;
if (GroMatchesRetType) {
  ReturnStmt = S.BuildReturnStmt(Loc, ReturnValue);
} else {
  GroDecl = VarDecl::Create(
      S.Context, &FD, FD.getLocation(), FD.getLocation(),
      &S.PP.getIdentifierTable().get("__coro_gro"), GroType,
      S.Context.getTrivialTypeSourceInfo(GroType, Loc), SC_None);
  GroDecl->setImplicit();

  S.CheckVariableDeclarationType(GroDecl);
  if (GroDecl->isInvalidDecl())
    return false;

  InitializedEntity Entity = InitializedEntity::InitializeVariable(GroDecl);
  ExprResult Res =
      S.PerformCopyInitialization(Entity, SourceLocation(), ReturnValue);
  if (Res.isInvalid())
    return false;

  Res = S.ActOnFinishFullExpr(Res.get(), /*DiscardedValue*/ false);
  if (Res.isInvalid())
    return false;

  S.AddInitializerToDecl(GroDecl, Res.get(),
                         /*DirectInit=*/false);

  S.FinalizeDeclaration(GroDecl);

  // Form a declaration statement for the return declaration, so that AST
  // visitors can more easily find it.
  StmtResult GroDeclStmt =
      S.ActOnDeclStmt(S.ConvertDeclToDeclGroup(GroDecl), Loc, Loc);
  if (GroDeclStmt.isInvalid())
    return false;

  this->ResultDecl = GroDeclStmt.get();

  ExprResult declRef = S.BuildDeclRefExpr(GroDecl, GroType, VK_LValue, Loc);
  if (declRef.isInvalid())
    return false;

  ReturnStmt = S.BuildReturnStmt(Loc, declRef.get());
}

if (ReturnStmt.isInvalid()) {
  noteMemberDeclaredHere(S, ReturnValue, Fn);
  return false;
}

if (!GroMatchesRetType &&
    cast<clang::ReturnStmt>(ReturnStmt.get())->getNRVOCandidate() == GroDecl)
  GroDecl->setNRVOVariable(true);

this->ReturnStmt = ReturnStmt.get();
return true;
1830}

1832// Create a static_cast\<T&&>(expr).
1833static Expr *castForMoving(Sema &S, Expr *E, QualType T = QualType()) {
if (T.isNull())
  T = E->getType();
QualType TargetType = S.BuildReferenceType(
    T, /*SpelledAsLValue*/ false, SourceLocation(), DeclarationName());
SourceLocation ExprLoc = E->getBeginLoc();
TypeSourceInfo *TargetLoc =
    S.Context.getTrivialTypeSourceInfo(TargetType, ExprLoc);

return S
    .BuildCXXNamedCast(ExprLoc, tok::kw_static_cast, TargetLoc, E,
                       SourceRange(ExprLoc, ExprLoc), E->getSourceRange())
    .get();
1846}

1848/// Build a variable declaration for move parameter.
1849static VarDecl *buildVarDecl(Sema &S, SourceLocation Loc, QualType Type,
                           IdentifierInfo *II) {
TypeSourceInfo *TInfo = S.Context.getTrivialTypeSourceInfo(Type, Loc);
VarDecl *Decl = VarDecl::Create(S.Context, S.CurContext, Loc, Loc, II, Type,
                                TInfo, SC_None);
Decl->setImplicit();
return Decl;
1856}

1858// Build statements that move coroutine function parameters to the coroutine
1859// frame, and store them on the function scope info.
1860bool Sema::buildCoroutineParameterMoves(SourceLocation Loc) {
assert(isa<FunctionDecl>(CurContext) && "not in a function scope")(static_cast <bool> (isa<FunctionDecl>(CurContext
) && "not in a function scope") ? void (0) : __assert_fail
 ("isa<FunctionDecl>(CurContext) && \"not in a function scope\""
, "clang/lib/Sema/SemaCoroutine.cpp", 1861, __extension__ __PRETTY_FUNCTION__
));
auto *FD = cast<FunctionDecl>(CurContext);

auto *ScopeInfo = getCurFunction();
if (!ScopeInfo->CoroutineParameterMoves.empty())
  return false;

// [dcl.fct.def.coroutine]p13
//   When a coroutine is invoked, after initializing its parameters
//   ([expr.call]), a copy is created for each coroutine parameter. For a
//   parameter of type cv T, the copy is a variable of type cv T with
//   automatic storage duration that is direct-initialized from an xvalue of
//   type T referring to the parameter.
for (auto *PD : FD->parameters()) {
  if (PD->getType()->isDependentType())
    continue;

  ExprResult PDRefExpr =
      BuildDeclRefExpr(PD, PD->getType().getNonReferenceType(),
                       ExprValueKind::VK_LValue, Loc); // FIXME: scope?
  if (PDRefExpr.isInvalid())
    return false;

  Expr *CExpr = nullptr;
  if (PD->getType()->getAsCXXRecordDecl() ||
      PD->getType()->isRValueReferenceType())
    CExpr = castForMoving(*this, PDRefExpr.get());
  else
    CExpr = PDRefExpr.get();
  // [dcl.fct.def.coroutine]p13
  //   The initialization and destruction of each parameter copy occurs in the
  //   context of the called coroutine.
  auto *D = buildVarDecl(*this, Loc, PD->getType(), PD->getIdentifier());
  AddInitializerToDecl(D, CExpr, /*DirectInit=*/true);

  // Convert decl to a statement.
  StmtResult Stmt = ActOnDeclStmt(ConvertDeclToDeclGroup(D), Loc, Loc);
  if (Stmt.isInvalid())
    return false;

  ScopeInfo->CoroutineParameterMoves.insert(std::make_pair(PD, Stmt.get()));
}
return true;
1904}

1906StmtResult Sema::BuildCoroutineBodyStmt(CoroutineBodyStmt::CtorArgs Args) {
CoroutineBodyStmt *Res = CoroutineBodyStmt::Create(Context, Args);
if (!Res)
  return StmtError();
return Res;
1911}

1913ClassTemplateDecl *Sema::lookupCoroutineTraits(SourceLocation KwLoc,
                                             SourceLocation FuncLoc) {
if (StdCoroutineTraitsCache)
  return StdCoroutineTraitsCache;

IdentifierInfo const &TraitIdent =
    PP.getIdentifierTable().get("coroutine_traits");

NamespaceDecl *StdSpace = getStdNamespace();
LookupResult Result(*this, &TraitIdent, FuncLoc, LookupOrdinaryName);
bool Found = StdSpace && LookupQualifiedName(Result, StdSpace);

if (!Found) {
  // The goggles, we found nothing!
  Diag(KwLoc, diag::err_implied_coroutine_type_not_found)
      << "std::coroutine_traits";
  return nullptr;
}

// coroutine_traits is required to be a class template.
StdCoroutineTraitsCache = Result.getAsSingle<ClassTemplateDecl>();
if (!StdCoroutineTraitsCache) {
  Result.suppressDiagnostics();
  NamedDecl *Found = *Result.begin();
  Diag(Found->getLocation(), diag::err_malformed_std_coroutine_traits);
  return nullptr;
}

return StdCoroutineTraitsCache;
1942}

←

/build/source/clang/include/clang/Sema/Sema.h

→

1//===--- Sema.h - Semantic Analysis & AST Building --------------*- C++ -*-===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8//
9// This file defines the Sema class, which performs semantic analysis and
10// builds ASTs.
11//
12//===----------------------------------------------------------------------===//

14#ifndef LLVM_CLANG_SEMA_SEMA_H
15#define LLVM_CLANG_SEMA_SEMA_H

17#include "clang/AST/ASTConcept.h"
18#include "clang/AST/ASTFwd.h"
19#include "clang/AST/Attr.h"
20#include "clang/AST/Availability.h"
21#include "clang/AST/ComparisonCategories.h"
22#include "clang/AST/DeclTemplate.h"
23#include "clang/AST/DeclarationName.h"
24#include "clang/AST/Expr.h"
25#include "clang/AST/ExprCXX.h"
26#include "clang/AST/ExprConcepts.h"
27#include "clang/AST/ExprObjC.h"
28#include "clang/AST/ExprOpenMP.h"
29#include "clang/AST/ExternalASTSource.h"
30#include "clang/AST/LocInfoType.h"
31#include "clang/AST/MangleNumberingContext.h"
32#include "clang/AST/NSAPI.h"
33#include "clang/AST/PrettyPrinter.h"
34#include "clang/AST/StmtCXX.h"
35#include "clang/AST/StmtOpenMP.h"
36#include "clang/AST/TypeLoc.h"
37#include "clang/AST/TypeOrdering.h"
38#include "clang/Basic/BitmaskEnum.h"
39#include "clang/Basic/Builtins.h"
40#include "clang/Basic/DarwinSDKInfo.h"
41#include "clang/Basic/ExpressionTraits.h"
42#include "clang/Basic/Module.h"
43#include "clang/Basic/OpenCLOptions.h"
44#include "clang/Basic/OpenMPKinds.h"
45#include "clang/Basic/PragmaKinds.h"
46#include "clang/Basic/Specifiers.h"
47#include "clang/Basic/TemplateKinds.h"
48#include "clang/Basic/TypeTraits.h"
49#include "clang/Sema/AnalysisBasedWarnings.h"
50#include "clang/Sema/CleanupInfo.h"
51#include "clang/Sema/DeclSpec.h"
52#include "clang/Sema/ExternalSemaSource.h"
53#include "clang/Sema/IdentifierResolver.h"
54#include "clang/Sema/ObjCMethodList.h"
55#include "clang/Sema/Ownership.h"
56#include "clang/Sema/Scope.h"
57#include "clang/Sema/SemaConcept.h"
58#include "clang/Sema/TypoCorrection.h"
59#include "clang/Sema/Weak.h"
60#include "llvm/ADT/ArrayRef.h"
61#include "llvm/ADT/SetVector.h"
62#include "llvm/ADT/SmallBitVector.h"
63#include "llvm/ADT/SmallPtrSet.h"
64#include "llvm/ADT/SmallSet.h"
65#include "llvm/ADT/SmallVector.h"
66#include "llvm/ADT/TinyPtrVector.h"
67#include "llvm/Frontend/OpenMP/OMPConstants.h"
68#include <deque>
69#include <memory>
70#include <optional>
71#include <string>
72#include <tuple>
73#include <vector>

75namespace llvm {
class APSInt;
template <typename ValueT, typename ValueInfoT> class DenseSet;
class SmallBitVector;
struct InlineAsmIdentifierInfo;
80}

82namespace clang {
class ADLResult;
class ASTConsumer;
class ASTContext;
class ASTMutationListener;
class ASTReader;
class ASTWriter;
class ArrayType;
class ParsedAttr;
class BindingDecl;
class BlockDecl;
class CapturedDecl;
class CXXBasePath;
class CXXBasePaths;
class CXXBindTemporaryExpr;
typedef SmallVector<CXXBaseSpecifier*, 4> CXXCastPath;
class CXXConstructorDecl;
class CXXConversionDecl;
class CXXDeleteExpr;
class CXXDestructorDecl;
class CXXFieldCollector;
class CXXMemberCallExpr;
class CXXMethodDecl;
class CXXScopeSpec;
class CXXTemporary;
class CXXTryStmt;
class CallExpr;
class ClassTemplateDecl;
class ClassTemplatePartialSpecializationDecl;
class ClassTemplateSpecializationDecl;
class VarTemplatePartialSpecializationDecl;
class CodeCompleteConsumer;
class CodeCompletionAllocator;
class CodeCompletionTUInfo;
class CodeCompletionResult;
class CoroutineBodyStmt;
class Decl;
class DeclAccessPair;
class DeclContext;
class DeclRefExpr;
class DeclaratorDecl;
class DeducedTemplateArgument;
class DependentDiagnostic;
class DesignatedInitExpr;
class Designation;
class EnableIfAttr;
class EnumConstantDecl;
class Expr;
class ExtVectorType;
class FormatAttr;
class FriendDecl;
class FunctionDecl;
class FunctionProtoType;
class FunctionTemplateDecl;
class ImplicitConversionSequence;
typedef MutableArrayRef<ImplicitConversionSequence> ConversionSequenceList;
class InitListExpr;
class InitializationKind;
class InitializationSequence;
class InitializedEntity;
class IntegerLiteral;
class LabelStmt;
class LambdaExpr;
class LangOptions;
class LocalInstantiationScope;
class LookupResult;
class MacroInfo;
typedef ArrayRef<std::pair<IdentifierInfo *, SourceLocation>> ModuleIdPath;
class ModuleLoader;
class MultiLevelTemplateArgumentList;
class NamedDecl;
class ObjCCategoryDecl;
class ObjCCategoryImplDecl;
class ObjCCompatibleAliasDecl;
class ObjCContainerDecl;
class ObjCImplDecl;
class ObjCImplementationDecl;
class ObjCInterfaceDecl;
class ObjCIvarDecl;
template <class T> class ObjCList;
class ObjCMessageExpr;
class ObjCMethodDecl;
class ObjCPropertyDecl;
class ObjCProtocolDecl;
class OMPThreadPrivateDecl;
class OMPRequiresDecl;
class OMPDeclareReductionDecl;
class OMPDeclareSimdDecl;
class OMPClause;
struct OMPVarListLocTy;
struct OverloadCandidate;
enum class OverloadCandidateParamOrder : char;
enum OverloadCandidateRewriteKind : unsigned;
class OverloadCandidateSet;
class OverloadExpr;
class ParenListExpr;
class ParmVarDecl;
class Preprocessor;
class PseudoDestructorTypeStorage;
class PseudoObjectExpr;
class QualType;
class StandardConversionSequence;
class Stmt;
class StringLiteral;
class SwitchStmt;
class TemplateArgument;
class TemplateArgumentList;
class TemplateArgumentLoc;
class TemplateDecl;
class TemplateInstantiationCallback;
class TemplateParameterList;
class TemplatePartialOrderingContext;
class TemplateTemplateParmDecl;
class Token;
class TypeAliasDecl;
class TypedefDecl;
class TypedefNameDecl;
class TypeLoc;
class TypoCorrectionConsumer;
class UnqualifiedId;
class UnresolvedLookupExpr;
class UnresolvedMemberExpr;
class UnresolvedSetImpl;
class UnresolvedSetIterator;
class UsingDecl;
class UsingShadowDecl;
class ValueDecl;
class VarDecl;
class VarTemplateSpecializationDecl;
class VisibilityAttr;
class VisibleDeclConsumer;
class IndirectFieldDecl;
struct DeductionFailureInfo;
class TemplateSpecCandidateSet;

217namespace sema {
class AccessedEntity;
class BlockScopeInfo;
class Capture;
class CapturedRegionScopeInfo;
class CapturingScopeInfo;
class CompoundScopeInfo;
class DelayedDiagnostic;
class DelayedDiagnosticPool;
class FunctionScopeInfo;
class LambdaScopeInfo;
class PossiblyUnreachableDiag;
class RISCVIntrinsicManager;
class SemaPPCallbacks;
class TemplateDeductionInfo;
232}

234namespace threadSafety {
class BeforeSet;
void threadSafetyCleanup(BeforeSet* Cache);
237}

239// FIXME: No way to easily map from TemplateTypeParmTypes to
240// TemplateTypeParmDecls, so we have this horrible PointerUnion.
241typedef std::pair<llvm::PointerUnion<const TemplateTypeParmType *, NamedDecl *>,
                SourceLocation>
  UnexpandedParameterPack;

245/// Describes whether we've seen any nullability information for the given
246/// file.
247struct FileNullability {
/// The first pointer declarator (of any pointer kind) in the file that does
/// not have a corresponding nullability annotation.
SourceLocation PointerLoc;

/// The end location for the first pointer declarator in the file. Used for
/// placing fix-its.
SourceLocation PointerEndLoc;

/// Which kind of pointer declarator we saw.
uint8_t PointerKind;

/// Whether we saw any type nullability annotations in the given file.
bool SawTypeNullability = false;
261};

263/// A mapping from file IDs to a record of whether we've seen nullability
264/// information in that file.
265class FileNullabilityMap {
/// A mapping from file IDs to the nullability information for each file ID.
llvm::DenseMap<FileID, FileNullability> Map;

/// A single-element cache based on the file ID.
struct {
  FileID File;
  FileNullability Nullability;
} Cache;

275public:
FileNullability &operator[](FileID file) {
  // Check the single-element cache.
  if (file == Cache.File)
    return Cache.Nullability;

  // It's not in the single-element cache; flush the cache if we have one.
  if (!Cache.File.isInvalid()) {
    Map[Cache.File] = Cache.Nullability;
  }

  // Pull this entry into the cache.
  Cache.File = file;
  Cache.Nullability = Map[file];
  return Cache.Nullability;
}
291};

293/// Tracks expected type during expression parsing, for use in code completion.
294/// The type is tied to a particular token, all functions that update or consume
295/// the type take a start location of the token they are looking at as a
296/// parameter. This avoids updating the type on hot paths in the parser.
297class PreferredTypeBuilder {
298public:
PreferredTypeBuilder(bool Enabled) : Enabled(Enabled) {}

void enterCondition(Sema &S, SourceLocation Tok);
void enterReturn(Sema &S, SourceLocation Tok);
void enterVariableInit(SourceLocation Tok, Decl *D);
/// Handles e.g. BaseType{ .D = Tok...
void enterDesignatedInitializer(SourceLocation Tok, QualType BaseType,
                                const Designation &D);
/// Computing a type for the function argument may require running
/// overloading, so we postpone its computation until it is actually needed.
///
/// Clients should be very careful when using this function, as it stores a
/// function_ref, clients should make sure all calls to get() with the same
/// location happen while function_ref is alive.
///
/// The callback should also emit signature help as a side-effect, but only
/// if the completion point has been reached.
void enterFunctionArgument(SourceLocation Tok,
                           llvm::function_ref<QualType()> ComputeType);

void enterParenExpr(SourceLocation Tok, SourceLocation LParLoc);
void enterUnary(Sema &S, SourceLocation Tok, tok::TokenKind OpKind,
                SourceLocation OpLoc);
void enterBinary(Sema &S, SourceLocation Tok, Expr *LHS, tok::TokenKind Op);
void enterMemAccess(Sema &S, SourceLocation Tok, Expr *Base);
void enterSubscript(Sema &S, SourceLocation Tok, Expr *LHS);
/// Handles all type casts, including C-style cast, C++ casts, etc.
void enterTypeCast(SourceLocation Tok, QualType CastType);

/// Get the expected type associated with this location, if any.
///
/// If the location is a function argument, determining the expected type
/// involves considering all function overloads and the arguments so far.
/// In this case, signature help for these function overloads will be reported
/// as a side-effect (only if the completion point has been reached).
QualType get(SourceLocation Tok) const {
  if (!Enabled || Tok != ExpectedLoc)
    return QualType();
  if (!Type.isNull())
    return Type;
  if (ComputeType)
    return ComputeType();
  return QualType();
}

344private:
bool Enabled;
/// Start position of a token for which we store expected type.
SourceLocation ExpectedLoc;
/// Expected type for a token starting at ExpectedLoc.
QualType Type;
/// A function to compute expected type at ExpectedLoc. It is only considered
/// if Type is null.
llvm::function_ref<QualType()> ComputeType;
353};

355/// Sema - This implements semantic analysis and AST building for C.
356class Sema final {
Sema(const Sema &) = delete;
void operator=(const Sema &) = delete;

///Source of additional semantic information.
IntrusiveRefCntPtr<ExternalSemaSource> ExternalSource;

static bool mightHaveNonExternalLinkage(const DeclaratorDecl *FD);

/// Determine whether two declarations should be linked together, given that
/// the old declaration might not be visible and the new declaration might
/// not have external linkage.
bool shouldLinkPossiblyHiddenDecl(const NamedDecl *Old,
                                  const NamedDecl *New) {
  if (isVisible(Old))
   return true;
  // See comment in below overload for why it's safe to compute the linkage
  // of the new declaration here.
  if (New->isExternallyDeclarable()) {
    assert(Old->isExternallyDeclarable() &&(static_cast <bool> (Old->isExternallyDeclarable() &&
 "should not have found a non-externally-declarable previous decl"
) ? void (0) : __assert_fail ("Old->isExternallyDeclarable() && \"should not have found a non-externally-declarable previous decl\""
, "clang/include/clang/Sema/Sema.h", 376, __extension__ __PRETTY_FUNCTION__
))
           "should not have found a non-externally-declarable previous decl")(static_cast <bool> (Old->isExternallyDeclarable() &&
 "should not have found a non-externally-declarable previous decl"
) ? void (0) : __assert_fail ("Old->isExternallyDeclarable() && \"should not have found a non-externally-declarable previous decl\""
, "clang/include/clang/Sema/Sema.h", 376, __extension__ __PRETTY_FUNCTION__
));
    return true;
  }
  return false;
}
bool shouldLinkPossiblyHiddenDecl(LookupResult &Old, const NamedDecl *New);

void setupImplicitSpecialMemberType(CXXMethodDecl *SpecialMem,
                                    QualType ResultTy,
                                    ArrayRef<QualType> Args);

387public:
/// The maximum alignment, same as in llvm::Value. We duplicate them here
/// because that allows us not to duplicate the constants in clang code,
/// which we must to since we can't directly use the llvm constants.
/// The value is verified against llvm here: lib/CodeGen/CGDecl.cpp
///
/// This is the greatest alignment value supported by load, store, and alloca
/// instructions, and global values.
static const unsigned MaxAlignmentExponent = 32;
static const uint64_t MaximumAlignment = 1ull << MaxAlignmentExponent;

typedef OpaquePtr<DeclGroupRef> DeclGroupPtrTy;
typedef OpaquePtr<TemplateName> TemplateTy;
typedef OpaquePtr<QualType> TypeTy;

OpenCLOptions OpenCLFeatures;
FPOptions CurFPFeatures;

const LangOptions &LangOpts;
Preprocessor &PP;
ASTContext &Context;
ASTConsumer &Consumer;
DiagnosticsEngine &Diags;
SourceManager &SourceMgr;

/// Flag indicating whether or not to collect detailed statistics.
bool CollectStats;

/// Code-completion consumer.
CodeCompleteConsumer *CodeCompleter;

/// CurContext - This is the current declaration context of parsing.
DeclContext *CurContext;

/// Generally null except when we temporarily switch decl contexts,
/// like in \see ActOnObjCTemporaryExitContainerContext.
DeclContext *OriginalLexicalContext;

/// VAListTagName - The declaration name corresponding to __va_list_tag.
/// This is used as part of a hack to omit that class from ADL results.
DeclarationName VAListTagName;

bool MSStructPragmaOn; // True when \#pragma ms_struct on

/// Controls member pointer representation format under the MS ABI.
LangOptions::PragmaMSPointersToMembersKind
    MSPointerToMemberRepresentationMethod;

/// Stack of active SEH __finally scopes.  Can be empty.
SmallVector<Scope*, 2> CurrentSEHFinally;

/// Source location for newly created implicit MSInheritanceAttrs
SourceLocation ImplicitMSInheritanceAttrLoc;

/// Holds TypoExprs that are created from `createDelayedTypo`. This is used by
/// `TransformTypos` in order to keep track of any TypoExprs that are created
/// recursively during typo correction and wipe them away if the correction
/// fails.
llvm::SmallVector<TypoExpr *, 2> TypoExprs;

/// pragma clang section kind
enum PragmaClangSectionKind {
  PCSK_Invalid      = 0,
  PCSK_BSS          = 1,
  PCSK_Data         = 2,
  PCSK_Rodata       = 3,
  PCSK_Text         = 4,
  PCSK_Relro        = 5
 };

enum PragmaClangSectionAction {
  PCSA_Set     = 0,
  PCSA_Clear   = 1
};

struct PragmaClangSection {
  std::string SectionName;
  bool Valid = false;
  SourceLocation PragmaLocation;
};

 PragmaClangSection PragmaClangBSSSection;
 PragmaClangSection PragmaClangDataSection;
 PragmaClangSection PragmaClangRodataSection;
 PragmaClangSection PragmaClangRelroSection;
 PragmaClangSection PragmaClangTextSection;

enum PragmaMsStackAction {
  PSK_Reset     = 0x0,                // #pragma ()
  PSK_Set       = 0x1,                // #pragma (value)
  PSK_Push      = 0x2,                // #pragma (push[, id])
  PSK_Pop       = 0x4,                // #pragma (pop[, id])
  PSK_Show      = 0x8,                // #pragma (show) -- only for "pack"!
  PSK_Push_Set  = PSK_Push | PSK_Set, // #pragma (push[, id], value)
  PSK_Pop_Set   = PSK_Pop | PSK_Set,  // #pragma (pop[, id], value)
};

struct PragmaPackInfo {
  PragmaMsStackAction Action;
  StringRef SlotLabel;
  Token Alignment;
};

// #pragma pack and align.
class AlignPackInfo {
public:
  // `Native` represents default align mode, which may vary based on the
  // platform.
  enum Mode : unsigned char { Native, Natural, Packed, Mac68k };

  // #pragma pack info constructor
  AlignPackInfo(AlignPackInfo::Mode M, unsigned Num, bool IsXL)
      : PackAttr(true), AlignMode(M), PackNumber(Num), XLStack(IsXL) {
    assert(Num == PackNumber && "The pack number has been truncated.")(static_cast <bool> (Num == PackNumber && "The pack number has been truncated."
) ? void (0) : __assert_fail ("Num == PackNumber && \"The pack number has been truncated.\""
, "clang/include/clang/Sema/Sema.h", 500, __extension__ __PRETTY_FUNCTION__
));
  }

  // #pragma align info constructor
  AlignPackInfo(AlignPackInfo::Mode M, bool IsXL)
      : PackAttr(false), AlignMode(M),
        PackNumber(M == Packed ? 1 : UninitPackVal), XLStack(IsXL) {}

  explicit AlignPackInfo(bool IsXL) : AlignPackInfo(Native, IsXL) {}

  AlignPackInfo() : AlignPackInfo(Native, false) {}

  // When a AlignPackInfo itself cannot be used, this returns an 32-bit
  // integer encoding for it. This should only be passed to
  // AlignPackInfo::getFromRawEncoding, it should not be inspected directly.
  static uint32_t getRawEncoding(const AlignPackInfo &Info) {
    std::uint32_t Encoding{};
    if (Info.IsXLStack())
      Encoding |= IsXLMask;

    Encoding |= static_cast<uint32_t>(Info.getAlignMode()) << 1;

    if (Info.IsPackAttr())
      Encoding |= PackAttrMask;

    Encoding |= static_cast<uint32_t>(Info.getPackNumber()) << 4;

    return Encoding;
  }

  static AlignPackInfo getFromRawEncoding(unsigned Encoding) {
    bool IsXL = static_cast<bool>(Encoding & IsXLMask);
    AlignPackInfo::Mode M =
        static_cast<AlignPackInfo::Mode>((Encoding & AlignModeMask) >> 1);
    int PackNumber = (Encoding & PackNumMask) >> 4;

    if (Encoding & PackAttrMask)
      return AlignPackInfo(M, PackNumber, IsXL);

    return AlignPackInfo(M, IsXL);
  }

  bool IsPackAttr() const { return PackAttr; }

  bool IsAlignAttr() const { return !PackAttr; }

  Mode getAlignMode() const { return AlignMode; }

  unsigned getPackNumber() const { return PackNumber; }

  bool IsPackSet() const {
    // #pragma align, #pragma pack(), and #pragma pack(0) do not set the pack
    // attriute on a decl.
    return PackNumber != UninitPackVal && PackNumber != 0;
  }

  bool IsXLStack() const { return XLStack; }

  bool operator==(const AlignPackInfo &Info) const {
    return std::tie(AlignMode, PackNumber, PackAttr, XLStack) ==
           std::tie(Info.AlignMode, Info.PackNumber, Info.PackAttr,
                    Info.XLStack);
  }

  bool operator!=(const AlignPackInfo &Info) const {
    return !(*this == Info);
  }

private:
  /// \brief True if this is a pragma pack attribute,
  ///         not a pragma align attribute.
  bool PackAttr;

  /// \brief The alignment mode that is in effect.
  Mode AlignMode;

  /// \brief The pack number of the stack.
  unsigned char PackNumber;

  /// \brief True if it is a XL #pragma align/pack stack.
  bool XLStack;

  /// \brief Uninitialized pack value.
  static constexpr unsigned char UninitPackVal = -1;

  // Masks to encode and decode an AlignPackInfo.
  static constexpr uint32_t IsXLMask{0x0000'0001};
  static constexpr uint32_t AlignModeMask{0x0000'0006};
  static constexpr uint32_t PackAttrMask{0x00000'0008};
  static constexpr uint32_t PackNumMask{0x0000'01F0};
};

template<typename ValueType>
struct PragmaStack {
  struct Slot {
    llvm::StringRef StackSlotLabel;
    ValueType Value;
    SourceLocation PragmaLocation;
    SourceLocation PragmaPushLocation;
    Slot(llvm::StringRef StackSlotLabel, ValueType Value,
         SourceLocation PragmaLocation, SourceLocation PragmaPushLocation)
        : StackSlotLabel(StackSlotLabel), Value(Value),
          PragmaLocation(PragmaLocation),
          PragmaPushLocation(PragmaPushLocation) {}
  };

  void Act(SourceLocation PragmaLocation, PragmaMsStackAction Action,
           llvm::StringRef StackSlotLabel, ValueType Value) {
    if (Action == PSK_Reset) {
      CurrentValue = DefaultValue;
      CurrentPragmaLocation = PragmaLocation;
      return;
    }
    if (Action & PSK_Push)
      Stack.emplace_back(StackSlotLabel, CurrentValue, CurrentPragmaLocation,
                         PragmaLocation);
    else if (Action & PSK_Pop) {
      if (!StackSlotLabel.empty()) {
        // If we've got a label, try to find it and jump there.
        auto I = llvm::find_if(llvm::reverse(Stack), [&](const Slot &x) {
          return x.StackSlotLabel == StackSlotLabel;
        });
        // If we found the label so pop from there.
        if (I != Stack.rend()) {
          CurrentValue = I->Value;
          CurrentPragmaLocation = I->PragmaLocation;
          Stack.erase(std::prev(I.base()), Stack.end());
        }
      } else if (!Stack.empty()) {
        // We do not have a label, just pop the last entry.
        CurrentValue = Stack.back().Value;
        CurrentPragmaLocation = Stack.back().PragmaLocation;
        Stack.pop_back();
      }
    }
    if (Action & PSK_Set) {
      CurrentValue = Value;
      CurrentPragmaLocation = PragmaLocation;
    }
  }

  // MSVC seems to add artificial slots to #pragma stacks on entering a C++
  // method body to restore the stacks on exit, so it works like this:
  //
  //   struct S {
  //     #pragma <name>(push, InternalPragmaSlot, <current_pragma_value>)
  //     void Method {}
  //     #pragma <name>(pop, InternalPragmaSlot)
  //   };
  //
  // It works even with #pragma vtordisp, although MSVC doesn't support
  //   #pragma vtordisp(push [, id], n)
  // syntax.
  //
  // Push / pop a named sentinel slot.
  void SentinelAction(PragmaMsStackAction Action, StringRef Label) {
    assert((Action == PSK_Push || Action == PSK_Pop) &&(static_cast <bool> ((Action == PSK_Push || Action == PSK_Pop
) && "Can only push / pop #pragma stack sentinels!") ?
 void (0) : __assert_fail ("(Action == PSK_Push || Action == PSK_Pop) && \"Can only push / pop #pragma stack sentinels!\""
, "clang/include/clang/Sema/Sema.h", 657, __extension__ __PRETTY_FUNCTION__
))
           "Can only push / pop #pragma stack sentinels!")(static_cast <bool> ((Action == PSK_Push || Action == PSK_Pop
) && "Can only push / pop #pragma stack sentinels!") ?
 void (0) : __assert_fail ("(Action == PSK_Push || Action == PSK_Pop) && \"Can only push / pop #pragma stack sentinels!\""
, "clang/include/clang/Sema/Sema.h", 657, __extension__ __PRETTY_FUNCTION__
));
    Act(CurrentPragmaLocation, Action, Label, CurrentValue);
  }

  // Constructors.
  explicit PragmaStack(const ValueType &Default)
      : DefaultValue(Default), CurrentValue(Default) {}

  bool hasValue() const { return CurrentValue != DefaultValue; }

  SmallVector<Slot, 2> Stack;
  ValueType DefaultValue; // Value used for PSK_Reset action.
  ValueType CurrentValue;
  SourceLocation CurrentPragmaLocation;
};
// FIXME: We should serialize / deserialize these if they occur in a PCH (but
// we shouldn't do so if they're in a module).

/// Whether to insert vtordisps prior to virtual bases in the Microsoft
/// C++ ABI.  Possible values are 0, 1, and 2, which mean:
///
/// 0: Suppress all vtordisps
/// 1: Insert vtordisps in the presence of vbase overrides and non-trivial
///    structors
/// 2: Always insert vtordisps to support RTTI on partially constructed
///    objects
PragmaStack<MSVtorDispMode> VtorDispStack;
PragmaStack<AlignPackInfo> AlignPackStack;
// The current #pragma align/pack values and locations at each #include.
struct AlignPackIncludeState {
  AlignPackInfo CurrentValue;
  SourceLocation CurrentPragmaLocation;
  bool HasNonDefaultValue, ShouldWarnOnInclude;
};
SmallVector<AlignPackIncludeState, 8> AlignPackIncludeStack;
// Segment #pragmas.
PragmaStack<StringLiteral *> DataSegStack;
PragmaStack<StringLiteral *> BSSSegStack;
PragmaStack<StringLiteral *> ConstSegStack;
PragmaStack<StringLiteral *> CodeSegStack;

// #pragma strict_gs_check.
PragmaStack<bool> StrictGuardStackCheckStack;

// This stack tracks the current state of Sema.CurFPFeatures.
PragmaStack<FPOptionsOverride> FpPragmaStack;
FPOptionsOverride CurFPFeatureOverrides() {
  FPOptionsOverride result;
  if (!FpPragmaStack.hasValue()) {
    result = FPOptionsOverride();
  } else {
    result = FpPragmaStack.CurrentValue;
  }
  return result;
}

// RAII object to push / pop sentinel slots for all MS #pragma stacks.
// Actions should be performed only if we enter / exit a C++ method body.
class PragmaStackSentinelRAII {
public:
  PragmaStackSentinelRAII(Sema &S, StringRef SlotLabel, bool ShouldAct);
  ~PragmaStackSentinelRAII();

private:
  Sema &S;
  StringRef SlotLabel;
  bool ShouldAct;
};

/// A mapping that describes the nullability we've seen in each header file.
FileNullabilityMap NullabilityMap;

/// Last section used with #pragma init_seg.
StringLiteral *CurInitSeg;
SourceLocation CurInitSegLoc;

/// Sections used with #pragma alloc_text.
llvm::StringMap<std::tuple<StringRef, SourceLocation>> FunctionToSectionMap;

/// VisContext - Manages the stack for \#pragma GCC visibility.
void *VisContext; // Really a "PragmaVisStack*"

/// This an attribute introduced by \#pragma clang attribute.
struct PragmaAttributeEntry {
  SourceLocation Loc;
  ParsedAttr *Attribute;
  SmallVector<attr::SubjectMatchRule, 4> MatchRules;
  bool IsUsed;
};

/// A push'd group of PragmaAttributeEntries.
struct PragmaAttributeGroup {
  /// The location of the push attribute.
  SourceLocation Loc;
  /// The namespace of this push group.
  const IdentifierInfo *Namespace;
  SmallVector<PragmaAttributeEntry, 2> Entries;
};

SmallVector<PragmaAttributeGroup, 2> PragmaAttributeStack;

/// The declaration that is currently receiving an attribute from the
/// #pragma attribute stack.
const Decl *PragmaAttributeCurrentTargetDecl;

/// This represents the last location of a "#pragma clang optimize off"
/// directive if such a directive has not been closed by an "on" yet. If
/// optimizations are currently "on", this is set to an invalid location.
SourceLocation OptimizeOffPragmaLocation;

/// The "on" or "off" argument passed by \#pragma optimize, that denotes
/// whether the optimizations in the list passed to the pragma should be
/// turned off or on. This boolean is true by default because command line
/// options are honored when `#pragma optimize("", on)`.
/// (i.e. `ModifyFnAttributeMSPragmaOptimze()` does nothing)
bool MSPragmaOptimizeIsOn = true;

/// Set of no-builtin functions listed by \#pragma function.
llvm::SmallSetVector<StringRef, 4> MSFunctionNoBuiltins;

/// Flag indicating if Sema is building a recovery call expression.
///
/// This flag is used to avoid building recovery call expressions
/// if Sema is already doing so, which would cause infinite recursions.
bool IsBuildingRecoveryCallExpr;

/// Used to control the generation of ExprWithCleanups.
CleanupInfo Cleanup;

/// ExprCleanupObjects - This is the stack of objects requiring
/// cleanup that are created by the current full expression.
SmallVector<ExprWithCleanups::CleanupObject, 8> ExprCleanupObjects;

/// Store a set of either DeclRefExprs or MemberExprs that contain a reference
/// to a variable (constant) that may or may not be odr-used in this Expr, and
/// we won't know until all lvalue-to-rvalue and discarded value conversions
/// have been applied to all subexpressions of the enclosing full expression.
/// This is cleared at the end of each full expression.
using MaybeODRUseExprSet = llvm::SetVector<Expr *, SmallVector<Expr *, 4>,
                                           llvm::SmallPtrSet<Expr *, 4>>;
MaybeODRUseExprSet MaybeODRUseExprs;

std::unique_ptr<sema::FunctionScopeInfo> CachedFunctionScope;

/// Stack containing information about each of the nested
/// function, block, and method scopes that are currently active.
SmallVector<sema::FunctionScopeInfo *, 4> FunctionScopes;

/// The index of the first FunctionScope that corresponds to the current
/// context.
unsigned FunctionScopesStart = 0;

/// Track the number of currently active capturing scopes.
unsigned CapturingFunctionScopes = 0;

ArrayRef<sema::FunctionScopeInfo*> getFunctionScopes() const {
  return llvm::ArrayRef(FunctionScopes.begin() + FunctionScopesStart,
                        FunctionScopes.end());
}

/// Stack containing information needed when in C++2a an 'auto' is encountered
/// in a function declaration parameter type specifier in order to invent a
/// corresponding template parameter in the enclosing abbreviated function
/// template. This information is also present in LambdaScopeInfo, stored in
/// the FunctionScopes stack.
SmallVector<InventedTemplateParameterInfo, 4> InventedParameterInfos;

/// The index of the first InventedParameterInfo that refers to the current
/// context.
unsigned InventedParameterInfosStart = 0;

ArrayRef<InventedTemplateParameterInfo> getInventedParameterInfos() const {
  return llvm::ArrayRef(InventedParameterInfos.begin() +
                            InventedParameterInfosStart,
                        InventedParameterInfos.end());
}

typedef LazyVector<TypedefNameDecl *, ExternalSemaSource,
                   &ExternalSemaSource::ReadExtVectorDecls, 2, 2>
  ExtVectorDeclsType;

/// ExtVectorDecls - This is a list all the extended vector types. This allows
/// us to associate a raw vector type with one of the ext_vector type names.
/// This is only necessary for issuing pretty diagnostics.
ExtVectorDeclsType ExtVectorDecls;

/// FieldCollector - Collects CXXFieldDecls during parsing of C++ classes.
std::unique_ptr<CXXFieldCollector> FieldCollector;

typedef llvm::SmallSetVector<const NamedDecl *, 16> NamedDeclSetType;

/// Set containing all declared private fields that are not used.
NamedDeclSetType UnusedPrivateFields;

/// Set containing all typedefs that are likely unused.
llvm::SmallSetVector<const TypedefNameDecl *, 4>
    UnusedLocalTypedefNameCandidates;

/// Delete-expressions to be analyzed at the end of translation unit
///
/// This list contains class members, and locations of delete-expressions
/// that could not be proven as to whether they mismatch with new-expression
/// used in initializer of the field.
typedef std::pair<SourceLocation, bool> DeleteExprLoc;
typedef llvm::SmallVector<DeleteExprLoc, 4> DeleteLocs;
llvm::MapVector<FieldDecl *, DeleteLocs> DeleteExprs;

typedef llvm::SmallPtrSet<const CXXRecordDecl*, 8> RecordDeclSetTy;

/// PureVirtualClassDiagSet - a set of class declarations which we have
/// emitted a list of pure virtual functions. Used to prevent emitting the
/// same list more than once.
std::unique_ptr<RecordDeclSetTy> PureVirtualClassDiagSet;

/// ParsingInitForAutoVars - a set of declarations with auto types for which
/// we are currently parsing the initializer.
llvm::SmallPtrSet<const Decl*, 4> ParsingInitForAutoVars;

/// Look for a locally scoped extern "C" declaration by the given name.
NamedDecl *findLocallyScopedExternCDecl(DeclarationName Name);

typedef LazyVector<VarDecl *, ExternalSemaSource,
                   &ExternalSemaSource::ReadTentativeDefinitions, 2, 2>
  TentativeDefinitionsType;

/// All the tentative definitions encountered in the TU.
TentativeDefinitionsType TentativeDefinitions;

/// All the external declarations encoutered and used in the TU.
SmallVector<VarDecl *, 4> ExternalDeclarations;

typedef LazyVector<const DeclaratorDecl *, ExternalSemaSource,
                   &ExternalSemaSource::ReadUnusedFileScopedDecls, 2, 2>
  UnusedFileScopedDeclsType;

/// The set of file scoped decls seen so far that have not been used
/// and must warn if not used. Only contains the first declaration.
UnusedFileScopedDeclsType UnusedFileScopedDecls;

typedef LazyVector<CXXConstructorDecl *, ExternalSemaSource,
                   &ExternalSemaSource::ReadDelegatingConstructors, 2, 2>
  DelegatingCtorDeclsType;

/// All the delegating constructors seen so far in the file, used for
/// cycle detection at the end of the TU.
DelegatingCtorDeclsType DelegatingCtorDecls;

/// All the overriding functions seen during a class definition
/// that had their exception spec checks delayed, plus the overridden
/// function.
SmallVector<std::pair<const CXXMethodDecl*, const CXXMethodDecl*>, 2>
  DelayedOverridingExceptionSpecChecks;

/// All the function redeclarations seen during a class definition that had
/// their exception spec checks delayed, plus the prior declaration they
/// should be checked against. Except during error recovery, the new decl
/// should always be a friend declaration, as that's the only valid way to
/// redeclare a special member before its class is complete.
SmallVector<std::pair<FunctionDecl*, FunctionDecl*>, 2>
  DelayedEquivalentExceptionSpecChecks;

typedef llvm::MapVector<const FunctionDecl *,
                        std::unique_ptr<LateParsedTemplate>>
    LateParsedTemplateMapT;
LateParsedTemplateMapT LateParsedTemplateMap;

/// Callback to the parser to parse templated functions when needed.
typedef void LateTemplateParserCB(void *P, LateParsedTemplate &LPT);
typedef void LateTemplateParserCleanupCB(void *P);
LateTemplateParserCB *LateTemplateParser;
LateTemplateParserCleanupCB *LateTemplateParserCleanup;
void *OpaqueParser;

void SetLateTemplateParser(LateTemplateParserCB *LTP,
                           LateTemplateParserCleanupCB *LTPCleanup,
                           void *P) {
  LateTemplateParser = LTP;
  LateTemplateParserCleanup = LTPCleanup;
  OpaqueParser = P;
}

class DelayedDiagnostics;

class DelayedDiagnosticsState {
  sema::DelayedDiagnosticPool *SavedPool;
  friend class Sema::DelayedDiagnostics;
};
typedef DelayedDiagnosticsState ParsingDeclState;
typedef DelayedDiagnosticsState ProcessingContextState;

/// A class which encapsulates the logic for delaying diagnostics
/// during parsing and other processing.
class DelayedDiagnostics {
  /// The current pool of diagnostics into which delayed
  /// diagnostics should go.
  sema::DelayedDiagnosticPool *CurPool = nullptr;

public:
  DelayedDiagnostics() = default;

  /// Adds a delayed diagnostic.
  void add(const sema::DelayedDiagnostic &diag); // in DelayedDiagnostic.h

  /// Determines whether diagnostics should be delayed.
  bool shouldDelayDiagnostics() { return CurPool != nullptr; }

  /// Returns the current delayed-diagnostics pool.
  sema::DelayedDiagnosticPool *getCurrentPool() const {
    return CurPool;
  }

  /// Enter a new scope.  Access and deprecation diagnostics will be
  /// collected in this pool.
  DelayedDiagnosticsState push(sema::DelayedDiagnosticPool &pool) {
    DelayedDiagnosticsState state;
    state.SavedPool = CurPool;
    CurPool = &pool;
    return state;
  }

  /// Leave a delayed-diagnostic state that was previously pushed.
  /// Do not emit any of the diagnostics.  This is performed as part
  /// of the bookkeeping of popping a pool "properly".
  void popWithoutEmitting(DelayedDiagnosticsState state) {
    CurPool = state.SavedPool;
  }

  /// Enter a new scope where access and deprecation diagnostics are
  /// not delayed.
  DelayedDiagnosticsState pushUndelayed() {
    DelayedDiagnosticsState state;
    state.SavedPool = CurPool;
    CurPool = nullptr;
    return state;
  }

  /// Undo a previous pushUndelayed().
  void popUndelayed(DelayedDiagnosticsState state) {
    assert(CurPool == nullptr)(static_cast <bool> (CurPool == nullptr) ? void (0) : __assert_fail
 ("CurPool == nullptr", "clang/include/clang/Sema/Sema.h", 995
, __extension__ __PRETTY_FUNCTION__));
    CurPool = state.SavedPool;
  }
} DelayedDiagnostics;

/// A RAII object to temporarily push a declaration context.
class ContextRAII {
private:
  Sema &S;
  DeclContext *SavedContext;
  ProcessingContextState SavedContextState;
  QualType SavedCXXThisTypeOverride;
  unsigned SavedFunctionScopesStart;
  unsigned SavedInventedParameterInfosStart;

public:
  ContextRAII(Sema &S, DeclContext *ContextToPush, bool NewThisContext = true)
    : S(S), SavedContext(S.CurContext),
      SavedContextState(S.DelayedDiagnostics.pushUndelayed()),
      SavedCXXThisTypeOverride(S.CXXThisTypeOverride),
      SavedFunctionScopesStart(S.FunctionScopesStart),
      SavedInventedParameterInfosStart(S.InventedParameterInfosStart)
  {
    assert(ContextToPush && "pushing null context")(static_cast <bool> (ContextToPush && "pushing null context"
) ? void (0) : __assert_fail ("ContextToPush && \"pushing null context\""
, "clang/include/clang/Sema/Sema.h", 1018, __extension__ __PRETTY_FUNCTION__
));
    S.CurContext = ContextToPush;
    if (NewThisContext)
      S.CXXThisTypeOverride = QualType();
    // Any saved FunctionScopes do not refer to this context.
    S.FunctionScopesStart = S.FunctionScopes.size();
    S.InventedParameterInfosStart = S.InventedParameterInfos.size();
  }

  void pop() {
    if (!SavedContext) return;
    S.CurContext = SavedContext;
    S.DelayedDiagnostics.popUndelayed(SavedContextState);
    S.CXXThisTypeOverride = SavedCXXThisTypeOverride;
    S.FunctionScopesStart = SavedFunctionScopesStart;
    S.InventedParameterInfosStart = SavedInventedParameterInfosStart;
    SavedContext = nullptr;
  }

  ~ContextRAII() {
    pop();
  }
};

/// Whether the AST is currently being rebuilt to correct immediate
/// invocations. Immediate invocation candidates and references to consteval
/// functions aren't tracked when this is set.
bool RebuildingImmediateInvocation = false;

/// Used to change context to isConstantEvaluated without pushing a heavy
/// ExpressionEvaluationContextRecord object.
bool isConstantEvaluatedOverride;

bool isConstantEvaluated() const {
  return ExprEvalContexts.back().isConstantEvaluated() ||
         isConstantEvaluatedOverride;
}

/// RAII object to handle the state changes required to synthesize
/// a function body.
class SynthesizedFunctionScope {
  Sema &S;
  Sema::ContextRAII SavedContext;
  bool PushedCodeSynthesisContext = false;

public:
  SynthesizedFunctionScope(Sema &S, DeclContext *DC)
      : S(S), SavedContext(S, DC) {
    S.PushFunctionScope();
    S.PushExpressionEvaluationContext(
        Sema::ExpressionEvaluationContext::PotentiallyEvaluated);
    if (auto *FD = dyn_cast<FunctionDecl>(DC))
      FD->setWillHaveBody(true);
    else
      assert(isa<ObjCMethodDecl>(DC))(static_cast <bool> (isa<ObjCMethodDecl>(DC)) ? void
 (0) : __assert_fail ("isa<ObjCMethodDecl>(DC)", "clang/include/clang/Sema/Sema.h"
, 1072, __extension__ __PRETTY_FUNCTION__));
  }

  void addContextNote(SourceLocation UseLoc) {
    assert(!PushedCodeSynthesisContext)(static_cast <bool> (!PushedCodeSynthesisContext) ? void
 (0) : __assert_fail ("!PushedCodeSynthesisContext", "clang/include/clang/Sema/Sema.h"
, 1076, __extension__ __PRETTY_FUNCTION__));

    Sema::CodeSynthesisContext Ctx;
    Ctx.Kind = Sema::CodeSynthesisContext::DefiningSynthesizedFunction;
    Ctx.PointOfInstantiation = UseLoc;
    Ctx.Entity = cast<Decl>(S.CurContext);
    S.pushCodeSynthesisContext(Ctx);

    PushedCodeSynthesisContext = true;
  }

  ~SynthesizedFunctionScope() {
    if (PushedCodeSynthesisContext)
      S.popCodeSynthesisContext();
    if (auto *FD = dyn_cast<FunctionDecl>(S.CurContext))
      FD->setWillHaveBody(false);
    S.PopExpressionEvaluationContext();
    S.PopFunctionScopeInfo();
  }
};

/// WeakUndeclaredIdentifiers - Identifiers contained in \#pragma weak before
/// declared. Rare. May alias another identifier, declared or undeclared.
///
/// For aliases, the target identifier is used as a key for eventual
/// processing when the target is declared. For the single-identifier form,
/// the sole identifier is used as the key. Each entry is a `SetVector`
/// (ordered by parse order) of aliases (identified by the alias name) in case
/// of multiple aliases to the same undeclared identifier.
llvm::MapVector<
    IdentifierInfo *,
    llvm::SetVector<
        WeakInfo, llvm::SmallVector<WeakInfo, 1u>,
        llvm::SmallDenseSet<WeakInfo, 2u, WeakInfo::DenseMapInfoByAliasOnly>>>
    WeakUndeclaredIdentifiers;

/// ExtnameUndeclaredIdentifiers - Identifiers contained in
/// \#pragma redefine_extname before declared.  Used in Solaris system headers
/// to define functions that occur in multiple standards to call the version
/// in the currently selected standard.
llvm::DenseMap<IdentifierInfo*,AsmLabelAttr*> ExtnameUndeclaredIdentifiers;


/// Load weak undeclared identifiers from the external source.
void LoadExternalWeakUndeclaredIdentifiers();

/// WeakTopLevelDecl - Translation-unit scoped declarations generated by
/// \#pragma weak during processing of other Decls.
/// I couldn't figure out a clean way to generate these in-line, so
/// we store them here and handle separately -- which is a hack.
/// It would be best to refactor this.
SmallVector<Decl*,2> WeakTopLevelDecl;

IdentifierResolver IdResolver;

/// Translation Unit Scope - useful to Objective-C actions that need
/// to lookup file scope declarations in the "ordinary" C decl namespace.
/// For example, user-defined classes, built-in "id" type, etc.
Scope *TUScope;

/// The C++ "std" namespace, where the standard library resides.
LazyDeclPtr StdNamespace;

/// The C++ "std::bad_alloc" class, which is defined by the C++
/// standard library.
LazyDeclPtr StdBadAlloc;

/// The C++ "std::align_val_t" enum class, which is defined by the C++
/// standard library.
LazyDeclPtr StdAlignValT;

/// The C++ "std::initializer_list" template, which is defined in
/// \<initializer_list>.
ClassTemplateDecl *StdInitializerList;

/// The C++ "std::coroutine_traits" template, which is defined in
/// \<coroutine_traits>
ClassTemplateDecl *StdCoroutineTraitsCache;

/// The C++ "type_info" declaration, which is defined in \<typeinfo>.
RecordDecl *CXXTypeInfoDecl;

/// The MSVC "_GUID" struct, which is defined in MSVC header files.
RecordDecl *MSVCGuidDecl;

/// The C++ "std::source_location::__impl" struct, defined in
/// \<source_location>.
RecordDecl *StdSourceLocationImplDecl;

/// Caches identifiers/selectors for NSFoundation APIs.
std::unique_ptr<NSAPI> NSAPIObj;

/// The declaration of the Objective-C NSNumber class.
ObjCInterfaceDecl *NSNumberDecl;

/// The declaration of the Objective-C NSValue class.
ObjCInterfaceDecl *NSValueDecl;

/// Pointer to NSNumber type (NSNumber *).
QualType NSNumberPointer;

/// Pointer to NSValue type (NSValue *).
QualType NSValuePointer;

/// The Objective-C NSNumber methods used to create NSNumber literals.
ObjCMethodDecl *NSNumberLiteralMethods[NSAPI::NumNSNumberLiteralMethods];

/// The declaration of the Objective-C NSString class.
ObjCInterfaceDecl *NSStringDecl;

/// Pointer to NSString type (NSString *).
QualType NSStringPointer;

/// The declaration of the stringWithUTF8String: method.
ObjCMethodDecl *StringWithUTF8StringMethod;

/// The declaration of the valueWithBytes:objCType: method.
ObjCMethodDecl *ValueWithBytesObjCTypeMethod;

/// The declaration of the Objective-C NSArray class.
ObjCInterfaceDecl *NSArrayDecl;

/// The declaration of the arrayWithObjects:count: method.
ObjCMethodDecl *ArrayWithObjectsMethod;

/// The declaration of the Objective-C NSDictionary class.
ObjCInterfaceDecl *NSDictionaryDecl;

/// The declaration of the dictionaryWithObjects:forKeys:count: method.
ObjCMethodDecl *DictionaryWithObjectsMethod;

/// id<NSCopying> type.
QualType QIDNSCopying;

/// will hold 'respondsToSelector:'
Selector RespondsToSelectorSel;

/// A flag to remember whether the implicit forms of operator new and delete
/// have been declared.
bool GlobalNewDeleteDeclared;

/// Describes how the expressions currently being parsed are
/// evaluated at run-time, if at all.
enum class ExpressionEvaluationContext {
  /// The current expression and its subexpressions occur within an
  /// unevaluated operand (C++11 [expr]p7), such as the subexpression of
  /// \c sizeof, where the type of the expression may be significant but
  /// no code will be generated to evaluate the value of the expression at
  /// run time.
  Unevaluated,

  /// The current expression occurs within a braced-init-list within
  /// an unevaluated operand. This is mostly like a regular unevaluated
  /// context, except that we still instantiate constexpr functions that are
  /// referenced here so that we can perform narrowing checks correctly.
  UnevaluatedList,

  /// The current expression occurs within a discarded statement.
  /// This behaves largely similarly to an unevaluated operand in preventing
  /// definitions from being required, but not in other ways.
  DiscardedStatement,

  /// The current expression occurs within an unevaluated
  /// operand that unconditionally permits abstract references to
  /// fields, such as a SIZE operator in MS-style inline assembly.
  UnevaluatedAbstract,

  /// The current context is "potentially evaluated" in C++11 terms,
  /// but the expression is evaluated at compile-time (like the values of
  /// cases in a switch statement).
  ConstantEvaluated,

  /// In addition of being constant evaluated, the current expression
  /// occurs in an immediate function context - either a consteval function
  /// or a consteval if function.
  ImmediateFunctionContext,

  /// The current expression is potentially evaluated at run time,
  /// which means that code may be generated to evaluate the value of the
  /// expression at run time.
  PotentiallyEvaluated,

  /// The current expression is potentially evaluated, but any
  /// declarations referenced inside that expression are only used if
  /// in fact the current expression is used.
  ///
  /// This value is used when parsing default function arguments, for which
  /// we would like to provide diagnostics (e.g., passing non-POD arguments
  /// through varargs) but do not want to mark declarations as "referenced"
  /// until the default argument is used.
  PotentiallyEvaluatedIfUsed
};

using ImmediateInvocationCandidate = llvm::PointerIntPair<ConstantExpr *, 1>;

/// Data structure used to record current or nested
/// expression evaluation contexts.
struct ExpressionEvaluationContextRecord {
  /// The expression evaluation context.
  ExpressionEvaluationContext Context;

  /// Whether the enclosing context needed a cleanup.
  CleanupInfo ParentCleanup;

  /// The number of active cleanup objects when we entered
  /// this expression evaluation context.
  unsigned NumCleanupObjects;

  /// The number of typos encountered during this expression evaluation
  /// context (i.e. the number of TypoExprs created).
  unsigned NumTypos;

  MaybeODRUseExprSet SavedMaybeODRUseExprs;

  /// The lambdas that are present within this context, if it
  /// is indeed an unevaluated context.
  SmallVector<LambdaExpr *, 2> Lambdas;

  /// The declaration that provides context for lambda expressions
  /// and block literals if the normal declaration context does not
  /// suffice, e.g., in a default function argument.
  Decl *ManglingContextDecl;

  /// If we are processing a decltype type, a set of call expressions
  /// for which we have deferred checking the completeness of the return type.
  SmallVector<CallExpr *, 8> DelayedDecltypeCalls;

  /// If we are processing a decltype type, a set of temporary binding
  /// expressions for which we have deferred checking the destructor.
  SmallVector<CXXBindTemporaryExpr *, 8> DelayedDecltypeBinds;

  llvm::SmallPtrSet<const Expr *, 8> PossibleDerefs;

  /// Expressions appearing as the LHS of a volatile assignment in this
  /// context. We produce a warning for these when popping the context if
  /// they are not discarded-value expressions nor unevaluated operands.
  SmallVector<Expr*, 2> VolatileAssignmentLHSs;

  /// Set of candidates for starting an immediate invocation.
  llvm::SmallVector<ImmediateInvocationCandidate, 4> ImmediateInvocationCandidates;

  /// Set of DeclRefExprs referencing a consteval function when used in a
  /// context not already known to be immediately invoked.
  llvm::SmallPtrSet<DeclRefExpr *, 4> ReferenceToConsteval;

  /// \brief Describes whether we are in an expression constext which we have
  /// to handle differently.
  enum ExpressionKind {
    EK_Decltype, EK_TemplateArgument, EK_Other
  } ExprContext;

  // A context can be nested in both a discarded statement context and
  // an immediate function context, so they need to be tracked independently.
  bool InDiscardedStatement;
  bool InImmediateFunctionContext;

  bool IsCurrentlyCheckingDefaultArgumentOrInitializer = false;

  // When evaluating immediate functions in the initializer of a default
  // argument or default member initializer, this is the declaration whose
  // default initializer is being evaluated and the location of the call
  // or constructor definition.
  struct InitializationContext {
    InitializationContext(SourceLocation Loc, ValueDecl *Decl,
                          DeclContext *Context)
        : Loc(Loc), Decl(Decl), Context(Context) {
      assert(Decl && Context && "invalid initialization context")(static_cast <bool> (Decl && Context &&
 "invalid initialization context") ? void (0) : __assert_fail
 ("Decl && Context && \"invalid initialization context\""
, "clang/include/clang/Sema/Sema.h", 1342, __extension__ __PRETTY_FUNCTION__
));
    }

    SourceLocation Loc;
    ValueDecl *Decl = nullptr;
    DeclContext *Context = nullptr;
  };
  std::optional<InitializationContext> DelayedDefaultInitializationContext;

  ExpressionEvaluationContextRecord(ExpressionEvaluationContext Context,
                                    unsigned NumCleanupObjects,
                                    CleanupInfo ParentCleanup,
                                    Decl *ManglingContextDecl,
                                    ExpressionKind ExprContext)
      : Context(Context), ParentCleanup(ParentCleanup),
        NumCleanupObjects(NumCleanupObjects), NumTypos(0),
        ManglingContextDecl(ManglingContextDecl), ExprContext(ExprContext),
        InDiscardedStatement(false), InImmediateFunctionContext(false) {}

  bool isUnevaluated() const {
    return Context == ExpressionEvaluationContext::Unevaluated ||
           Context == ExpressionEvaluationContext::UnevaluatedAbstract ||
           Context == ExpressionEvaluationContext::UnevaluatedList;
  }

  bool isConstantEvaluated() const {
    return Context == ExpressionEvaluationContext::ConstantEvaluated ||
           Context == ExpressionEvaluationContext::ImmediateFunctionContext;
  }

  bool isImmediateFunctionContext() const {
    return Context == ExpressionEvaluationContext::ImmediateFunctionContext ||
           (Context == ExpressionEvaluationContext::DiscardedStatement &&
            InImmediateFunctionContext) ||
           // C++23 [expr.const]p14:
           // An expression or conversion is in an immediate function
           // context if it is potentially evaluated and either:
           //   * its innermost enclosing non-block scope is a function
           //     parameter scope of an immediate function, or
           //   * its enclosing statement is enclosed by the compound-
           //     statement of a consteval if statement.
           (Context == ExpressionEvaluationContext::PotentiallyEvaluated &&
            InImmediateFunctionContext);
  }

  bool isDiscardedStatementContext() const {
    return Context == ExpressionEvaluationContext::DiscardedStatement ||
           (Context ==
                ExpressionEvaluationContext::ImmediateFunctionContext &&
            InDiscardedStatement);
  }
};

/// A stack of expression evaluation contexts.
SmallVector<ExpressionEvaluationContextRecord, 8> ExprEvalContexts;

// Set of failed immediate invocations to avoid double diagnosing.
llvm::SmallPtrSet<ConstantExpr *, 4> FailedImmediateInvocations;

/// Emit a warning for all pending noderef expressions that we recorded.
void WarnOnPendingNoDerefs(ExpressionEvaluationContextRecord &Rec);

/// Compute the mangling number context for a lambda expression or
/// block literal. Also return the extra mangling decl if any.
///
/// \param DC - The DeclContext containing the lambda expression or
/// block literal.
std::tuple<MangleNumberingContext *, Decl *>
getCurrentMangleNumberContext(const DeclContext *DC);


/// SpecialMemberOverloadResult - The overloading result for a special member
/// function.
///
/// This is basically a wrapper around PointerIntPair. The lowest bits of the
/// integer are used to determine whether overload resolution succeeded.
class SpecialMemberOverloadResult {
public:
  enum Kind {
    NoMemberOrDeleted,
    Ambiguous,
    Success
  };

private:
  llvm::PointerIntPair<CXXMethodDecl *, 2> Pair;

public:
  SpecialMemberOverloadResult() {}
  SpecialMemberOverloadResult(CXXMethodDecl *MD)
      : Pair(MD, MD->isDeleted() ? NoMemberOrDeleted : Success) {}

  CXXMethodDecl *getMethod() const { return Pair.getPointer(); }
  void setMethod(CXXMethodDecl *MD) { Pair.setPointer(MD); }

  Kind getKind() const { return static_cast<Kind>(Pair.getInt()); }
  void setKind(Kind K) { Pair.setInt(K); }
};

class SpecialMemberOverloadResultEntry
    : public llvm::FastFoldingSetNode,
      public SpecialMemberOverloadResult {
public:
  SpecialMemberOverloadResultEntry(const llvm::FoldingSetNodeID &ID)
    : FastFoldingSetNode(ID)
  {}
};

/// A cache of special member function overload resolution results
/// for C++ records.
llvm::FoldingSet<SpecialMemberOverloadResultEntry> SpecialMemberCache;

/// A cache of the flags available in enumerations with the flag_bits
/// attribute.
mutable llvm::DenseMap<const EnumDecl*, llvm::APInt> FlagBitsCache;

/// The kind of translation unit we are processing.
///
/// When we're processing a complete translation unit, Sema will perform
/// end-of-translation-unit semantic tasks (such as creating
/// initializers for tentative definitions in C) once parsing has
/// completed. Modules and precompiled headers perform different kinds of
/// checks.
const TranslationUnitKind TUKind;

llvm::BumpPtrAllocator BumpAlloc;

/// The number of SFINAE diagnostics that have been trapped.
unsigned NumSFINAEErrors;

typedef llvm::DenseMap<ParmVarDecl *, llvm::TinyPtrVector<ParmVarDecl *>>
  UnparsedDefaultArgInstantiationsMap;

/// A mapping from parameters with unparsed default arguments to the
/// set of instantiations of each parameter.
///
/// This mapping is a temporary data structure used when parsing
/// nested class templates or nested classes of class templates,
/// where we might end up instantiating an inner class before the
/// default arguments of its methods have been parsed.
UnparsedDefaultArgInstantiationsMap UnparsedDefaultArgInstantiations;

// Contains the locations of the beginning of unparsed default
// argument locations.
llvm::DenseMap<ParmVarDecl *, SourceLocation> UnparsedDefaultArgLocs;

/// UndefinedInternals - all the used, undefined objects which require a
/// definition in this translation unit.
llvm::MapVector<NamedDecl *, SourceLocation> UndefinedButUsed;

/// Determine if VD, which must be a variable or function, is an external
/// symbol that nonetheless can't be referenced from outside this translation
/// unit because its type has no linkage and it's not extern "C".
bool isExternalWithNoLinkageType(const ValueDecl *VD) const;

/// Obtain a sorted list of functions that are undefined but ODR-used.
void getUndefinedButUsed(
    SmallVectorImpl<std::pair<NamedDecl *, SourceLocation> > &Undefined);

/// Retrieves list of suspicious delete-expressions that will be checked at
/// the end of translation unit.
const llvm::MapVector<FieldDecl *, DeleteLocs> &
getMismatchingDeleteExpressions() const;

class GlobalMethodPool {
public:
  using Lists = std::pair<ObjCMethodList, ObjCMethodList>;
  using iterator = llvm::DenseMap<Selector, Lists>::iterator;
  iterator begin() { return Methods.begin(); }
  iterator end() { return Methods.end(); }
  iterator find(Selector Sel) { return Methods.find(Sel); }
  std::pair<iterator, bool> insert(std::pair<Selector, Lists> &&Val) {
    return Methods.insert(Val);
  }
  int count(Selector Sel) const { return Methods.count(Sel); }
  bool empty() const { return Methods.empty(); }

private:
  llvm::DenseMap<Selector, Lists> Methods;
};

/// Method Pool - allows efficient lookup when typechecking messages to "id".
/// We need to maintain a list, since selectors can have differing signatures
/// across classes. In Cocoa, this happens to be extremely uncommon (only 1%
/// of selectors are "overloaded").
/// At the head of the list it is recorded whether there were 0, 1, or >= 2
/// methods inside categories with a particular selector.
GlobalMethodPool MethodPool;

/// Method selectors used in a \@selector expression. Used for implementation
/// of -Wselector.
llvm::MapVector<Selector, SourceLocation> ReferencedSelectors;

/// List of SourceLocations where 'self' is implicitly retained inside a
/// block.
llvm::SmallVector<std::pair<SourceLocation, const BlockDecl *>, 1>
    ImplicitlyRetainedSelfLocs;

/// Kinds of C++ special members.
enum CXXSpecialMember {
  CXXDefaultConstructor,
  CXXCopyConstructor,
  CXXMoveConstructor,
  CXXCopyAssignment,
  CXXMoveAssignment,
  CXXDestructor,
  CXXInvalid
};

typedef llvm::PointerIntPair<CXXRecordDecl *, 3, CXXSpecialMember>
    SpecialMemberDecl;

/// The C++ special members which we are currently in the process of
/// declaring. If this process recursively triggers the declaration of the
/// same special member, we should act as if it is not yet declared.
llvm::SmallPtrSet<SpecialMemberDecl, 4> SpecialMembersBeingDeclared;

/// Kinds of defaulted comparison operator functions.
enum class DefaultedComparisonKind : unsigned char {
  /// This is not a defaultable comparison operator.
  None,
  /// This is an operator== that should be implemented as a series of
  /// subobject comparisons.
  Equal,
  /// This is an operator<=> that should be implemented as a series of
  /// subobject comparisons.
  ThreeWay,
  /// This is an operator!= that should be implemented as a rewrite in terms
  /// of a == comparison.
  NotEqual,
  /// This is an <, <=, >, or >= that should be implemented as a rewrite in
  /// terms of a <=> comparison.
  Relational,
};

/// The function definitions which were renamed as part of typo-correction
/// to match their respective declarations. We want to keep track of them
/// to ensure that we don't emit a "redefinition" error if we encounter a
/// correctly named definition after the renamed definition.
llvm::SmallPtrSet<const NamedDecl *, 4> TypoCorrectedFunctionDefinitions;

/// Stack of types that correspond to the parameter entities that are
/// currently being copy-initialized. Can be empty.
llvm::SmallVector<QualType, 4> CurrentParameterCopyTypes;

void ReadMethodPool(Selector Sel);
void updateOutOfDateSelector(Selector Sel);

/// Private Helper predicate to check for 'self'.
bool isSelfExpr(Expr *RExpr);
bool isSelfExpr(Expr *RExpr, const ObjCMethodDecl *Method);

/// Cause the active diagnostic on the DiagosticsEngine to be
/// emitted. This is closely coupled to the SemaDiagnosticBuilder class and
/// should not be used elsewhere.
void EmitCurrentDiagnostic(unsigned DiagID);

/// Records and restores the CurFPFeatures state on entry/exit of compound
/// statements.
class FPFeaturesStateRAII {
public:
  FPFeaturesStateRAII(Sema &S);
  ~FPFeaturesStateRAII();
  FPOptionsOverride getOverrides() { return OldOverrides; }

private:
  Sema& S;
  FPOptions OldFPFeaturesState;
  FPOptionsOverride OldOverrides;
  LangOptions::FPEvalMethodKind OldEvalMethod;
  SourceLocation OldFPPragmaLocation;
};

void addImplicitTypedef(StringRef Name, QualType T);

bool WarnedStackExhausted = false;

/// Increment when we find a reference; decrement when we find an ignored
/// assignment.  Ultimately the value is 0 if every reference is an ignored
/// assignment.
llvm::DenseMap<const VarDecl *, int> RefsMinusAssignments;

/// Indicate RISC-V vector builtin functions enabled or not.
bool DeclareRISCVVBuiltins = false;

/// Indicate RISC-V Sifive vector builtin functions enabled or not.
bool DeclareRISCVVectorBuiltins = false;

1630private:
std::unique_ptr<sema::RISCVIntrinsicManager> RVIntrinsicManager;

std::optional<std::unique_ptr<DarwinSDKInfo>> CachedDarwinSDKInfo;

bool WarnedDarwinSDKInfoMissing = false;

1637public:
Sema(Preprocessor &pp, ASTContext &ctxt, ASTConsumer &consumer,
     TranslationUnitKind TUKind = TU_Complete,
     CodeCompleteConsumer *CompletionConsumer = nullptr);
~Sema();

/// Perform initialization that occurs after the parser has been
/// initialized but before it parses anything.
void Initialize();

/// This virtual key function only exists to limit the emission of debug info
/// describing the Sema class. GCC and Clang only emit debug info for a class
/// with a vtable when the vtable is emitted. Sema is final and not
/// polymorphic, but the debug info size savings are so significant that it is
/// worth adding a vtable just to take advantage of this optimization.
virtual void anchor();

const LangOptions &getLangOpts() const { return LangOpts; }
OpenCLOptions &getOpenCLOptions() { return OpenCLFeatures; }
FPOptions     &getCurFPFeatures() { return CurFPFeatures; }

DiagnosticsEngine &getDiagnostics() const { return Diags; }
SourceManager &getSourceManager() const { return SourceMgr; }
Preprocessor &getPreprocessor() const { return PP; }
ASTContext &getASTContext() const { return Context; }
ASTConsumer &getASTConsumer() const { return Consumer; }
ASTMutationListener *getASTMutationListener() const;
ExternalSemaSource *getExternalSource() const { return ExternalSource.get(); }

DarwinSDKInfo *getDarwinSDKInfoForAvailabilityChecking(SourceLocation Loc,
                                                       StringRef Platform);
DarwinSDKInfo *getDarwinSDKInfoForAvailabilityChecking();

///Registers an external source. If an external source already exists,
/// creates a multiplex external source and appends to it.
///
///\param[in] E - A non-null external sema source.
///
void addExternalSource(ExternalSemaSource *E);

void PrintStats() const;

/// Warn that the stack is nearly exhausted.
void warnStackExhausted(SourceLocation Loc);

/// Run some code with "sufficient" stack space. (Currently, at least 256K is
/// guaranteed). Produces a warning if we're low on stack space and allocates
/// more in that case. Use this in code that may recurse deeply (for example,
/// in template instantiation) to avoid stack overflow.
void runWithSufficientStackSpace(SourceLocation Loc,
                                 llvm::function_ref<void()> Fn);

/// Helper class that creates diagnostics with optional
/// template instantiation stacks.
///
/// This class provides a wrapper around the basic DiagnosticBuilder
/// class that emits diagnostics. ImmediateDiagBuilder is
/// responsible for emitting the diagnostic (as DiagnosticBuilder
/// does) and, if the diagnostic comes from inside a template
/// instantiation, printing the template instantiation stack as
/// well.
class ImmediateDiagBuilder : public DiagnosticBuilder {
  Sema &SemaRef;
  unsigned DiagID;

public:
  ImmediateDiagBuilder(DiagnosticBuilder &DB, Sema &SemaRef, unsigned DiagID)
      : DiagnosticBuilder(DB), SemaRef(SemaRef), DiagID(DiagID) {}
  ImmediateDiagBuilder(DiagnosticBuilder &&DB, Sema &SemaRef, unsigned DiagID)
      : DiagnosticBuilder(DB), SemaRef(SemaRef), DiagID(DiagID) {}

  // This is a cunning lie. DiagnosticBuilder actually performs move
  // construction in its copy constructor (but due to varied uses, it's not
  // possible to conveniently express this as actual move construction). So
  // the default copy ctor here is fine, because the base class disables the
  // source anyway, so the user-defined ~ImmediateDiagBuilder is a safe no-op
  // in that case anwyay.
  ImmediateDiagBuilder(const ImmediateDiagBuilder &) = default;

  ~ImmediateDiagBuilder() {
    // If we aren't active, there is nothing to do.
    if (!isActive()) return;

    // Otherwise, we need to emit the diagnostic. First clear the diagnostic
    // builder itself so it won't emit the diagnostic in its own destructor.
    //
    // This seems wasteful, in that as written the DiagnosticBuilder dtor will
    // do its own needless checks to see if the diagnostic needs to be
    // emitted. However, because we take care to ensure that the builder
    // objects never escape, a sufficiently smart compiler will be able to
    // eliminate that code.
    Clear();

    // Dispatch to Sema to emit the diagnostic.
    SemaRef.EmitCurrentDiagnostic(DiagID);
  }

  /// Teach operator<< to produce an object of the correct type.
  template <typename T>
  friend const ImmediateDiagBuilder &
  operator<<(const ImmediateDiagBuilder &Diag, const T &Value) {
    const DiagnosticBuilder &BaseDiag = Diag;
    BaseDiag << Value;
    return Diag;
  }

  // It is necessary to limit this to rvalue reference to avoid calling this
  // function with a bitfield lvalue argument since non-const reference to
  // bitfield is not allowed.
  template <typename T,
            typename = std::enable_if_t<!std::is_lvalue_reference<T>::value>>
  const ImmediateDiagBuilder &operator<<(T &&V) const {
    const DiagnosticBuilder &BaseDiag = *this;
    BaseDiag << std::move(V);
    return *this;
  }
};

/// A generic diagnostic builder for errors which may or may not be deferred.
///
/// In CUDA, there exist constructs (e.g. variable-length arrays, try/catch)
/// which are not allowed to appear inside __device__ functions and are
/// allowed to appear in __host__ __device__ functions only if the host+device
/// function is never codegen'ed.
///
/// To handle this, we use the notion of "deferred diagnostics", where we
/// attach a diagnostic to a FunctionDecl that's emitted iff it's codegen'ed.
///
/// This class lets you emit either a regular diagnostic, a deferred
/// diagnostic, or no diagnostic at all, according to an argument you pass to
/// its constructor, thus simplifying the process of creating these "maybe
/// deferred" diagnostics.
class SemaDiagnosticBuilder {
public:
  enum Kind {
    /// Emit no diagnostics.
    K_Nop,
    /// Emit the diagnostic immediately (i.e., behave like Sema::Diag()).
    K_Immediate,
    /// Emit the diagnostic immediately, and, if it's a warning or error, also
    /// emit a call stack showing how this function can be reached by an a
    /// priori known-emitted function.
    K_ImmediateWithCallStack,
    /// Create a deferred diagnostic, which is emitted only if the function
    /// it's attached to is codegen'ed.  Also emit a call stack as with
    /// K_ImmediateWithCallStack.
    K_Deferred
  };

  SemaDiagnosticBuilder(Kind K, SourceLocation Loc, unsigned DiagID,
                        const FunctionDecl *Fn, Sema &S);
  SemaDiagnosticBuilder(SemaDiagnosticBuilder &&D);
  SemaDiagnosticBuilder(const SemaDiagnosticBuilder &) = default;
  ~SemaDiagnosticBuilder();

  bool isImmediate() const { return ImmediateDiag.has_value(); }

  /// Convertible to bool: True if we immediately emitted an error, false if
  /// we didn't emit an error or we created a deferred error.
  ///
  /// Example usage:
  ///
  ///   if (SemaDiagnosticBuilder(...) << foo << bar)
  ///     return ExprError();
  ///
  /// But see CUDADiagIfDeviceCode() and CUDADiagIfHostCode() -- you probably
  /// want to use these instead of creating a SemaDiagnosticBuilder yourself.
  operator bool() const { return isImmediate(); }

  template <typename T>
  friend const SemaDiagnosticBuilder &
  operator<<(const SemaDiagnosticBuilder &Diag, const T &Value) {
    if (Diag.ImmediateDiag)
      *Diag.ImmediateDiag << Value;
    else if (Diag.PartialDiagId)
      Diag.S.DeviceDeferredDiags[Diag.Fn][*Diag.PartialDiagId].second
          << Value;
    return Diag;
  }

  // It is necessary to limit this to rvalue reference to avoid calling this
  // function with a bitfield lvalue argument since non-const reference to
  // bitfield is not allowed.
  template <typename T,
            typename = std::enable_if_t<!std::is_lvalue_reference<T>::value>>
  const SemaDiagnosticBuilder &operator<<(T &&V) const {
    if (ImmediateDiag)
      *ImmediateDiag << std::move(V);
    else if (PartialDiagId)
      S.DeviceDeferredDiags[Fn][*PartialDiagId].second << std::move(V);
    return *this;
  }

  friend const SemaDiagnosticBuilder &
  operator<<(const SemaDiagnosticBuilder &Diag, const PartialDiagnostic &PD) {
    if (Diag.ImmediateDiag)
      PD.Emit(*Diag.ImmediateDiag);
    else if (Diag.PartialDiagId)
      Diag.S.DeviceDeferredDiags[Diag.Fn][*Diag.PartialDiagId].second = PD;
    return Diag;
  }

  void AddFixItHint(const FixItHint &Hint) const {
    if (ImmediateDiag)
      ImmediateDiag->AddFixItHint(Hint);
    else if (PartialDiagId)
      S.DeviceDeferredDiags[Fn][*PartialDiagId].second.AddFixItHint(Hint);
  }

  friend ExprResult ExprError(const SemaDiagnosticBuilder &) {
    return ExprError();
  }
  friend StmtResult StmtError(const SemaDiagnosticBuilder &) {
    return StmtError();
  }
  operator ExprResult() const { return ExprError(); }
  operator StmtResult() const { return StmtError(); }
  operator TypeResult() const { return TypeError(); }
  operator DeclResult() const { return DeclResult(true); }
  operator MemInitResult() const { return MemInitResult(true); }

private:
  Sema &S;
  SourceLocation Loc;
  unsigned DiagID;
  const FunctionDecl *Fn;
  bool ShowCallStack;

  // Invariant: At most one of these Optionals has a value.
  // FIXME: Switch these to a Variant once that exists.
  std::optional<ImmediateDiagBuilder> ImmediateDiag;
  std::optional<unsigned> PartialDiagId;
};

/// Is the last error level diagnostic immediate. This is used to determined
/// whether the next info diagnostic should be immediate.
bool IsLastErrorImmediate = true;

/// Emit a diagnostic.
SemaDiagnosticBuilder Diag(SourceLocation Loc, unsigned DiagID,
                           bool DeferHint = false);

/// Emit a partial diagnostic.
SemaDiagnosticBuilder Diag(SourceLocation Loc, const PartialDiagnostic &PD,
                           bool DeferHint = false);

/// Build a partial diagnostic.
PartialDiagnostic PDiag(unsigned DiagID = 0); // in SemaInternal.h

/// Whether deferrable diagnostics should be deferred.
bool DeferDiags = false;

/// RAII class to control scope of DeferDiags.
class DeferDiagsRAII {
  Sema &S;
  bool SavedDeferDiags = false;

public:
  DeferDiagsRAII(Sema &S, bool DeferDiags)
      : S(S), SavedDeferDiags(S.DeferDiags) {
    S.DeferDiags = DeferDiags;
  }
  ~DeferDiagsRAII() { S.DeferDiags = SavedDeferDiags; }
};

/// Whether uncompilable error has occurred. This includes error happens
/// in deferred diagnostics.
bool hasUncompilableErrorOccurred() const;

bool findMacroSpelling(SourceLocation &loc, StringRef name);

/// Get a string to suggest for zero-initialization of a type.
std::string
getFixItZeroInitializerForType(QualType T, SourceLocation Loc) const;
std::string getFixItZeroLiteralForType(QualType T, SourceLocation Loc) const;

/// Calls \c Lexer::getLocForEndOfToken()
SourceLocation getLocForEndOfToken(SourceLocation Loc, unsigned Offset = 0);

/// Retrieve the module loader associated with the preprocessor.
ModuleLoader &getModuleLoader() const;

/// Invent a new identifier for parameters of abbreviated templates.
IdentifierInfo *
InventAbbreviatedTemplateParameterTypeName(IdentifierInfo *ParamName,
                                           unsigned Index);

void emitAndClearUnusedLocalTypedefWarnings();

private:
  /// Function or variable declarations to be checked for whether the deferred
  /// diagnostics should be emitted.
  llvm::SmallSetVector<Decl *, 4> DeclsToCheckForDeferredDiags;

public:
// Emit all deferred diagnostics.
void emitDeferredDiags();

enum TUFragmentKind {
  /// The global module fragment, between 'module;' and a module-declaration.
  Global,
  /// A normal translation unit fragment. For a non-module unit, this is the
  /// entire translation unit. Otherwise, it runs from the module-declaration
  /// to the private-module-fragment (if any) or the end of the TU (if not).
  Normal,
  /// The private module fragment, between 'module :private;' and the end of
  /// the translation unit.
  Private
};

void ActOnStartOfTranslationUnit();
void ActOnEndOfTranslationUnit();
void ActOnEndOfTranslationUnitFragment(TUFragmentKind Kind);

void CheckDelegatingCtorCycles();

Scope *getScopeForContext(DeclContext *Ctx);

void PushFunctionScope();
void PushBlockScope(Scope *BlockScope, BlockDecl *Block);
sema::LambdaScopeInfo *PushLambdaScope();

/// This is used to inform Sema what the current TemplateParameterDepth
/// is during Parsing.  Currently it is used to pass on the depth
/// when parsing generic lambda 'auto' parameters.
void RecordParsingTemplateParameterDepth(unsigned Depth);

void PushCapturedRegionScope(Scope *RegionScope, CapturedDecl *CD,
                             RecordDecl *RD, CapturedRegionKind K,
                             unsigned OpenMPCaptureLevel = 0);

/// Custom deleter to allow FunctionScopeInfos to be kept alive for a short
/// time after they've been popped.
class PoppedFunctionScopeDeleter {
  Sema *Self;

public:
  explicit PoppedFunctionScopeDeleter(Sema *Self) : Self(Self) {}
  void operator()(sema::FunctionScopeInfo *Scope) const;
};

using PoppedFunctionScopePtr =
    std::unique_ptr<sema::FunctionScopeInfo, PoppedFunctionScopeDeleter>;

PoppedFunctionScopePtr
PopFunctionScopeInfo(const sema::AnalysisBasedWarnings::Policy *WP = nullptr,
                     const Decl *D = nullptr,
                     QualType BlockType = QualType());

sema::FunctionScopeInfo *getCurFunction() const {
  return FunctionScopes.empty() ? nullptr : FunctionScopes.back();
13
←
'?' condition is false→
14
←
Returning pointer, which participates in a condition later→
}

sema::FunctionScopeInfo *getEnclosingFunction() const;

void setFunctionHasBranchIntoScope();
void setFunctionHasBranchProtectedScope();
void setFunctionHasIndirectGoto();
void setFunctionHasMustTail();

void PushCompoundScope(bool IsStmtExpr);
void PopCompoundScope();

sema::CompoundScopeInfo &getCurCompoundScope() const;

bool hasAnyUnrecoverableErrorsInThisFunction() const;

/// Retrieve the current block, if any.
sema::BlockScopeInfo *getCurBlock();

/// Get the innermost lambda enclosing the current location, if any. This
/// looks through intervening non-lambda scopes such as local functions and
/// blocks.
sema::LambdaScopeInfo *getEnclosingLambda() const;

/// Retrieve the current lambda scope info, if any.
/// \param IgnoreNonLambdaCapturingScope true if should find the top-most
/// lambda scope info ignoring all inner capturing scopes that are not
/// lambda scopes.
sema::LambdaScopeInfo *
getCurLambda(bool IgnoreNonLambdaCapturingScope = false);

/// Retrieve the current generic lambda info, if any.
sema::LambdaScopeInfo *getCurGenericLambda();

/// Retrieve the current captured region, if any.
sema::CapturedRegionScopeInfo *getCurCapturedRegion();

/// Retrieve the current function, if any, that should be analyzed for
/// potential availability violations.
sema::FunctionScopeInfo *getCurFunctionAvailabilityContext();

/// WeakTopLevelDeclDecls - access to \#pragma weak-generated Decls
SmallVectorImpl<Decl *> &WeakTopLevelDecls() { return WeakTopLevelDecl; }

/// Called before parsing a function declarator belonging to a function
/// declaration.
void ActOnStartFunctionDeclarationDeclarator(Declarator &D,
                                             unsigned TemplateParameterDepth);

/// Called after parsing a function declarator belonging to a function
/// declaration.
void ActOnFinishFunctionDeclarationDeclarator(Declarator &D);

void ActOnComment(SourceRange Comment);

//===--------------------------------------------------------------------===//
// Type Analysis / Processing: SemaType.cpp.
//

QualType BuildQualifiedType(QualType T, SourceLocation Loc, Qualifiers Qs,
                            const DeclSpec *DS = nullptr);
QualType BuildQualifiedType(QualType T, SourceLocation Loc, unsigned CVRA,
                            const DeclSpec *DS = nullptr);
QualType BuildPointerType(QualType T,
                          SourceLocation Loc, DeclarationName Entity);
QualType BuildReferenceType(QualType T, bool LValueRef,
                            SourceLocation Loc, DeclarationName Entity);
QualType BuildArrayType(QualType T, ArrayType::ArraySizeModifier ASM,
                        Expr *ArraySize, unsigned Quals,
                        SourceRange Brackets, DeclarationName Entity);
QualType BuildVectorType(QualType T, Expr *VecSize, SourceLocation AttrLoc);
QualType BuildExtVectorType(QualType T, Expr *ArraySize,
                            SourceLocation AttrLoc);
QualType BuildMatrixType(QualType T, Expr *NumRows, Expr *NumColumns,
                         SourceLocation AttrLoc);

QualType BuildAddressSpaceAttr(QualType &T, LangAS ASIdx, Expr *AddrSpace,
                               SourceLocation AttrLoc);

/// Same as above, but constructs the AddressSpace index if not provided.
QualType BuildAddressSpaceAttr(QualType &T, Expr *AddrSpace,
                               SourceLocation AttrLoc);

bool CheckQualifiedFunctionForTypeId(QualType T, SourceLocation Loc);

bool CheckFunctionReturnType(QualType T, SourceLocation Loc);

/// Build a function type.
///
/// This routine checks the function type according to C++ rules and
/// under the assumption that the result type and parameter types have
/// just been instantiated from a template. It therefore duplicates
/// some of the behavior of GetTypeForDeclarator, but in a much
/// simpler form that is only suitable for this narrow use case.
///
/// \param T The return type of the function.
///
/// \param ParamTypes The parameter types of the function. This array
/// will be modified to account for adjustments to the types of the
/// function parameters.
///
/// \param Loc The location of the entity whose type involves this
/// function type or, if there is no such entity, the location of the
/// type that will have function type.
///
/// \param Entity The name of the entity that involves the function
/// type, if known.
///
/// \param EPI Extra information about the function type. Usually this will
/// be taken from an existing function with the same prototype.
///
/// \returns A suitable function type, if there are no errors. The
/// unqualified type will always be a FunctionProtoType.
/// Otherwise, returns a NULL type.
QualType BuildFunctionType(QualType T,
                           MutableArrayRef<QualType> ParamTypes,
                           SourceLocation Loc, DeclarationName Entity,
                           const FunctionProtoType::ExtProtoInfo &EPI);

QualType BuildMemberPointerType(QualType T, QualType Class,
                                SourceLocation Loc,
                                DeclarationName Entity);
QualType BuildBlockPointerType(QualType T,
                               SourceLocation Loc, DeclarationName Entity);
QualType BuildParenType(QualType T);
QualType BuildAtomicType(QualType T, SourceLocation Loc);
QualType BuildReadPipeType(QualType T,
                       SourceLocation Loc);
QualType BuildWritePipeType(QualType T,
                       SourceLocation Loc);
QualType BuildBitIntType(bool IsUnsigned, Expr *BitWidth, SourceLocation Loc);

TypeSourceInfo *GetTypeForDeclarator(Declarator &D, Scope *S);
TypeSourceInfo *GetTypeForDeclaratorCast(Declarator &D, QualType FromTy);

/// Package the given type and TSI into a ParsedType.
ParsedType CreateParsedType(QualType T, TypeSourceInfo *TInfo);
DeclarationNameInfo GetNameForDeclarator(Declarator &D);
DeclarationNameInfo GetNameFromUnqualifiedId(const UnqualifiedId &Name);
static QualType GetTypeFromParser(ParsedType Ty,
                                  TypeSourceInfo **TInfo = nullptr);
CanThrowResult canThrow(const Stmt *E);
/// Determine whether the callee of a particular function call can throw.
/// E, D and Loc are all optional.
static CanThrowResult canCalleeThrow(Sema &S, const Expr *E, const Decl *D,
                                     SourceLocation Loc = SourceLocation());
const FunctionProtoType *ResolveExceptionSpec(SourceLocation Loc,
                                              const FunctionProtoType *FPT);
void UpdateExceptionSpec(FunctionDecl *FD,
                         const FunctionProtoType::ExceptionSpecInfo &ESI);
bool CheckSpecifiedExceptionType(QualType &T, SourceRange Range);
bool CheckDistantExceptionSpec(QualType T);
bool CheckEquivalentExceptionSpec(FunctionDecl *Old, FunctionDecl *New);
bool CheckEquivalentExceptionSpec(
    const FunctionProtoType *Old, SourceLocation OldLoc,
    const FunctionProtoType *New, SourceLocation NewLoc);
bool CheckEquivalentExceptionSpec(
    const PartialDiagnostic &DiagID, const PartialDiagnostic & NoteID,
    const FunctionProtoType *Old, SourceLocation OldLoc,
    const FunctionProtoType *New, SourceLocation NewLoc);
bool handlerCanCatch(QualType HandlerType, QualType ExceptionType);
bool CheckExceptionSpecSubset(const PartialDiagnostic &DiagID,
                              const PartialDiagnostic &NestedDiagID,
                              const PartialDiagnostic &NoteID,
                              const PartialDiagnostic &NoThrowDiagID,
                              const FunctionProtoType *Superset,
                              SourceLocation SuperLoc,
                              const FunctionProtoType *Subset,
                              SourceLocation SubLoc);
bool CheckParamExceptionSpec(const PartialDiagnostic &NestedDiagID,
                             const PartialDiagnostic &NoteID,
                             const FunctionProtoType *Target,
                             SourceLocation TargetLoc,
                             const FunctionProtoType *Source,
                             SourceLocation SourceLoc);

TypeResult ActOnTypeName(Scope *S, Declarator &D);

/// The parser has parsed the context-sensitive type 'instancetype'
/// in an Objective-C message declaration. Return the appropriate type.
ParsedType ActOnObjCInstanceType(SourceLocation Loc);

/// Abstract class used to diagnose incomplete types.
struct TypeDiagnoser {
  TypeDiagnoser() {}

  virtual void diagnose(Sema &S, SourceLocation Loc, QualType T) = 0;
  virtual ~TypeDiagnoser() {}
};

static int getPrintable(int I) { return I; }
static unsigned getPrintable(unsigned I) { return I; }
static bool getPrintable(bool B) { return B; }
static const char * getPrintable(const char *S) { return S; }
static StringRef getPrintable(StringRef S) { return S; }
static const std::string &getPrintable(const std::string &S) { return S; }
static const IdentifierInfo *getPrintable(const IdentifierInfo *II) {
  return II;
}
static DeclarationName getPrintable(DeclarationName N) { return N; }
static QualType getPrintable(QualType T) { return T; }
static SourceRange getPrintable(SourceRange R) { return R; }
static SourceRange getPrintable(SourceLocation L) { return L; }
static SourceRange getPrintable(const Expr *E) { return E->getSourceRange(); }
static SourceRange getPrintable(TypeLoc TL) { return TL.getSourceRange();}

template <typename... Ts> class BoundTypeDiagnoser : public TypeDiagnoser {
protected:
  unsigned DiagID;
  std::tuple<const Ts &...> Args;

  template <std::size_t... Is>
  void emit(const SemaDiagnosticBuilder &DB,
            std::index_sequence<Is...>) const {
    // Apply all tuple elements to the builder in order.
    bool Dummy[] = {false, (DB << getPrintable(std::get<Is>(Args)))...};
    (void)Dummy;
  }

public:
  BoundTypeDiagnoser(unsigned DiagID, const Ts &...Args)
      : TypeDiagnoser(), DiagID(DiagID), Args(Args...) {
    assert(DiagID != 0 && "no diagnostic for type diagnoser")(static_cast <bool> (DiagID != 0 && "no diagnostic for type diagnoser"
) ? void (0) : __assert_fail ("DiagID != 0 && \"no diagnostic for type diagnoser\""
, "clang/include/clang/Sema/Sema.h", 2210, __extension__ __PRETTY_FUNCTION__
));
  }

  void diagnose(Sema &S, SourceLocation Loc, QualType T) override {
    const SemaDiagnosticBuilder &DB = S.Diag(Loc, DiagID);
    emit(DB, std::index_sequence_for<Ts...>());
    DB << T;
  }
};

/// Do a check to make sure \p Name looks like a legal argument for the
/// swift_name attribute applied to decl \p D.  Raise a diagnostic if the name
/// is invalid for the given declaration.
///
/// \p AL is used to provide caret diagnostics in case of a malformed name.
///
/// \returns true if the name is a valid swift name for \p D, false otherwise.
bool DiagnoseSwiftName(Decl *D, StringRef Name, SourceLocation Loc,
                       const ParsedAttr &AL, bool IsAsync);

/// A derivative of BoundTypeDiagnoser for which the diagnostic's type
/// parameter is preceded by a 0/1 enum that is 1 if the type is sizeless.
/// For example, a diagnostic with no other parameters would generally have
/// the form "...%select{incomplete|sizeless}0 type %1...".
template <typename... Ts>
class SizelessTypeDiagnoser : public BoundTypeDiagnoser<Ts...> {
public:
  SizelessTypeDiagnoser(unsigned DiagID, const Ts &... Args)
      : BoundTypeDiagnoser<Ts...>(DiagID, Args...) {}

  void diagnose(Sema &S, SourceLocation Loc, QualType T) override {
    const SemaDiagnosticBuilder &DB = S.Diag(Loc, this->DiagID);
    this->emit(DB, std::index_sequence_for<Ts...>());
    DB << T->isSizelessType() << T;
  }
};

enum class CompleteTypeKind {
  /// Apply the normal rules for complete types.  In particular,
  /// treat all sizeless types as incomplete.
  Normal,

  /// Relax the normal rules for complete types so that they include
  /// sizeless built-in types.
  AcceptSizeless,

  // FIXME: Eventually we should flip the default to Normal and opt in
  // to AcceptSizeless rather than opt out of it.
  Default = AcceptSizeless
};

enum class AcceptableKind { Visible, Reachable };

2263private:
/// Methods for marking which expressions involve dereferencing a pointer
/// marked with the 'noderef' attribute. Expressions are checked bottom up as
/// they are parsed, meaning that a noderef pointer may not be accessed. For
/// example, in `&*p` where `p` is a noderef pointer, we will first parse the
/// `*p`, but need to check that `address of` is called on it. This requires
/// keeping a container of all pending expressions and checking if the address
/// of them are eventually taken.
void CheckSubscriptAccessOfNoDeref(const ArraySubscriptExpr *E);
void CheckAddressOfNoDeref(const Expr *E);
void CheckMemberAccessOfNoDeref(const MemberExpr *E);

bool RequireCompleteTypeImpl(SourceLocation Loc, QualType T,
                             CompleteTypeKind Kind, TypeDiagnoser *Diagnoser);

struct ModuleScope {
  SourceLocation BeginLoc;
  clang::Module *Module = nullptr;
  bool ModuleInterface = false;
  VisibleModuleSet OuterVisibleModules;
};
/// The modules we're currently parsing.
llvm::SmallVector<ModuleScope, 16> ModuleScopes;

/// For an interface unit, this is the implicitly imported interface unit.
clang::Module *ThePrimaryInterface = nullptr;

/// The explicit global module fragment of the current translation unit.
/// The explicit Global Module Fragment, as specified in C++
/// [module.global.frag].
clang::Module *TheGlobalModuleFragment = nullptr;

/// The implicit global module fragments of the current translation unit.
/// We would only create at most two implicit global module fragments to
/// avoid performance penalties when there are many language linkage
/// exports.
///
/// The contents in the implicit global module fragment can't be discarded
/// no matter if it is exported or not.
clang::Module *TheImplicitGlobalModuleFragment = nullptr;
clang::Module *TheExportedImplicitGlobalModuleFragment = nullptr;

/// Namespace definitions that we will export when they finish.
llvm::SmallPtrSet<const NamespaceDecl*, 8> DeferredExportedNamespaces;

/// In a C++ standard module, inline declarations require a definition to be
/// present at the end of a definition domain.  This set holds the decls to
/// be checked at the end of the TU.
llvm::SmallPtrSet<const FunctionDecl *, 8> PendingInlineFuncDecls;

/// Helper function to judge if we are in module purview.
/// Return false if we are not in a module.
bool isCurrentModulePurview() const {
  return getCurrentModule() ? getCurrentModule()->isModulePurview() : false;
}

/// Enter the scope of the explicit global module fragment.
Module *PushGlobalModuleFragment(SourceLocation BeginLoc);
/// Leave the scope of the explicit global module fragment.
void PopGlobalModuleFragment();

/// Enter the scope of an implicit global module fragment.
Module *PushImplicitGlobalModuleFragment(SourceLocation BeginLoc,
                                         bool IsExported);
/// Leave the scope of an implicit global module fragment.
void PopImplicitGlobalModuleFragment();

VisibleModuleSet VisibleModules;

/// Cache for module units which is usable for current module.
llvm::DenseSet<const Module *> UsableModuleUnitsCache;

bool isUsableModule(const Module *M);

bool isAcceptableSlow(const NamedDecl *D, AcceptableKind Kind);

2339public:
/// Get the module unit whose scope we are currently within.
Module *getCurrentModule() const {
  return ModuleScopes.empty() ? nullptr : ModuleScopes.back().Module;
}

/// Is the module scope we are an interface?
bool currentModuleIsInterface() const {
  return ModuleScopes.empty() ? false : ModuleScopes.back().ModuleInterface;
}

/// Is the module scope we are in a C++ Header Unit?
bool currentModuleIsHeaderUnit() const {
  return ModuleScopes.empty() ? false
                              : ModuleScopes.back().Module->isHeaderUnit();
}

/// Get the module owning an entity.
Module *getOwningModule(const Decl *Entity) {
  return Entity->getOwningModule();
}

/// Make a merged definition of an existing hidden definition \p ND
/// visible at the specified location.
void makeMergedDefinitionVisible(NamedDecl *ND);

bool isModuleVisible(const Module *M, bool ModulePrivate = false);

// When loading a non-modular PCH files, this is used to restore module
// visibility.
void makeModuleVisible(Module *Mod, SourceLocation ImportLoc) {
  VisibleModules.setVisible(Mod, ImportLoc);
}

/// Determine whether a declaration is visible to name lookup.
bool isVisible(const NamedDecl *D) {
  return D->isUnconditionallyVisible() ||
         isAcceptableSlow(D, AcceptableKind::Visible);
}

/// Determine whether a declaration is reachable.
bool isReachable(const NamedDecl *D) {
  // All visible declarations are reachable.
  return D->isUnconditionallyVisible() ||
         isAcceptableSlow(D, AcceptableKind::Reachable);
}

/// Determine whether a declaration is acceptable (visible/reachable).
bool isAcceptable(const NamedDecl *D, AcceptableKind Kind) {
  return Kind == AcceptableKind::Visible ? isVisible(D) : isReachable(D);
}

/// Determine whether any declaration of an entity is visible.
bool
hasVisibleDeclaration(const NamedDecl *D,
                      llvm::SmallVectorImpl<Module *> *Modules = nullptr) {
  return isVisible(D) || hasVisibleDeclarationSlow(D, Modules);
}

bool hasVisibleDeclarationSlow(const NamedDecl *D,
                               llvm::SmallVectorImpl<Module *> *Modules);
/// Determine whether any declaration of an entity is reachable.
bool
hasReachableDeclaration(const NamedDecl *D,
                        llvm::SmallVectorImpl<Module *> *Modules = nullptr) {
  return isReachable(D) || hasReachableDeclarationSlow(D, Modules);
}
bool hasReachableDeclarationSlow(
    const NamedDecl *D, llvm::SmallVectorImpl<Module *> *Modules = nullptr);

bool hasVisibleMergedDefinition(const NamedDecl *Def);
bool hasMergedDefinitionInCurrentModule(const NamedDecl *Def);

/// Determine if \p D and \p Suggested have a structurally compatible
/// layout as described in C11 6.2.7/1.
bool hasStructuralCompatLayout(Decl *D, Decl *Suggested);

/// Determine if \p D has a visible definition. If not, suggest a declaration
/// that should be made visible to expose the definition.
bool hasVisibleDefinition(NamedDecl *D, NamedDecl **Suggested,
                          bool OnlyNeedComplete = false);
bool hasVisibleDefinition(const NamedDecl *D) {
  NamedDecl *Hidden;
  return hasVisibleDefinition(const_cast<NamedDecl*>(D), &Hidden);
}

/// Determine if \p D has a reachable definition. If not, suggest a
/// declaration that should be made reachable to expose the definition.
bool hasReachableDefinition(NamedDecl *D, NamedDecl **Suggested,
                            bool OnlyNeedComplete = false);
bool hasReachableDefinition(NamedDecl *D) {
  NamedDecl *Hidden;
  return hasReachableDefinition(D, &Hidden);
}

bool hasAcceptableDefinition(NamedDecl *D, NamedDecl **Suggested,
                             AcceptableKind Kind,
                             bool OnlyNeedComplete = false);
bool hasAcceptableDefinition(NamedDecl *D, AcceptableKind Kind) {
  NamedDecl *Hidden;
  return hasAcceptableDefinition(D, &Hidden, Kind);
}

/// Determine if the template parameter \p D has a visible default argument.
bool
hasVisibleDefaultArgument(const NamedDecl *D,
                          llvm::SmallVectorImpl<Module *> *Modules = nullptr);
/// Determine if the template parameter \p D has a reachable default argument.
bool hasReachableDefaultArgument(
    const NamedDecl *D, llvm::SmallVectorImpl<Module *> *Modules = nullptr);
/// Determine if the template parameter \p D has a reachable default argument.
bool hasAcceptableDefaultArgument(const NamedDecl *D,
                                  llvm::SmallVectorImpl<Module *> *Modules,
                                  Sema::AcceptableKind Kind);

/// Determine if there is a visible declaration of \p D that is an explicit
/// specialization declaration for a specialization of a template. (For a
/// member specialization, use hasVisibleMemberSpecialization.)
bool hasVisibleExplicitSpecialization(
    const NamedDecl *D, llvm::SmallVectorImpl<Module *> *Modules = nullptr);
/// Determine if there is a reachable declaration of \p D that is an explicit
/// specialization declaration for a specialization of a template. (For a
/// member specialization, use hasReachableMemberSpecialization.)
bool hasReachableExplicitSpecialization(
    const NamedDecl *D, llvm::SmallVectorImpl<Module *> *Modules = nullptr);

/// Determine if there is a visible declaration of \p D that is a member
/// specialization declaration (as opposed to an instantiated declaration).
bool hasVisibleMemberSpecialization(
    const NamedDecl *D, llvm::SmallVectorImpl<Module *> *Modules = nullptr);
/// Determine if there is a reachable declaration of \p D that is a member
/// specialization declaration (as opposed to an instantiated declaration).
bool hasReachableMemberSpecialization(
    const NamedDecl *D, llvm::SmallVectorImpl<Module *> *Modules = nullptr);

/// Determine if \p A and \p B are equivalent internal linkage declarations
/// from different modules, and thus an ambiguity error can be downgraded to
/// an extension warning.
bool isEquivalentInternalLinkageDeclaration(const NamedDecl *A,
                                            const NamedDecl *B);
void diagnoseEquivalentInternalLinkageDeclarations(
    SourceLocation Loc, const NamedDecl *D,
    ArrayRef<const NamedDecl *> Equiv);

bool isUsualDeallocationFunction(const CXXMethodDecl *FD);

// Check whether the size of array element of type \p EltTy is a multiple of
// its alignment and return false if it isn't.
bool checkArrayElementAlignment(QualType EltTy, SourceLocation Loc);

bool isCompleteType(SourceLocation Loc, QualType T,
                    CompleteTypeKind Kind = CompleteTypeKind::Default) {
  return !RequireCompleteTypeImpl(Loc, T, Kind, nullptr);
}
bool RequireCompleteType(SourceLocation Loc, QualType T,
                         CompleteTypeKind Kind, TypeDiagnoser &Diagnoser);
bool RequireCompleteType(SourceLocation Loc, QualType T,
                         CompleteTypeKind Kind, unsigned DiagID);

bool RequireCompleteType(SourceLocation Loc, QualType T,
                         TypeDiagnoser &Diagnoser) {
  return RequireCompleteType(Loc, T, CompleteTypeKind::Default, Diagnoser);
}
bool RequireCompleteType(SourceLocation Loc, QualType T, unsigned DiagID) {
  return RequireCompleteType(Loc, T, CompleteTypeKind::Default, DiagID);
}

template <typename... Ts>
bool RequireCompleteType(SourceLocation Loc, QualType T, unsigned DiagID,
                         const Ts &...Args) {
  BoundTypeDiagnoser<Ts...> Diagnoser(DiagID, Args...);
  return RequireCompleteType(Loc, T, Diagnoser);
}

template <typename... Ts>
bool RequireCompleteSizedType(SourceLocation Loc, QualType T, unsigned DiagID,
                              const Ts &... Args) {
  SizelessTypeDiagnoser<Ts...> Diagnoser(DiagID, Args...);
  return RequireCompleteType(Loc, T, CompleteTypeKind::Normal, Diagnoser);
}

/// Get the type of expression E, triggering instantiation to complete the
/// type if necessary -- that is, if the expression refers to a templated
/// static data member of incomplete array type.
///
/// May still return an incomplete type if instantiation was not possible or
/// if the type is incomplete for a different reason. Use
/// RequireCompleteExprType instead if a diagnostic is expected for an
/// incomplete expression type.
QualType getCompletedType(Expr *E);

void completeExprArrayBound(Expr *E);
bool RequireCompleteExprType(Expr *E, CompleteTypeKind Kind,
                             TypeDiagnoser &Diagnoser);
bool RequireCompleteExprType(Expr *E, unsigned DiagID);

template <typename... Ts>
bool RequireCompleteExprType(Expr *E, unsigned DiagID, const Ts &...Args) {
  BoundTypeDiagnoser<Ts...> Diagnoser(DiagID, Args...);
  return RequireCompleteExprType(E, CompleteTypeKind::Default, Diagnoser);
}

template <typename... Ts>
bool RequireCompleteSizedExprType(Expr *E, unsigned DiagID,
                                  const Ts &... Args) {
  SizelessTypeDiagnoser<Ts...> Diagnoser(DiagID, Args...);
  return RequireCompleteExprType(E, CompleteTypeKind::Normal, Diagnoser);
}

bool RequireLiteralType(SourceLocation Loc, QualType T,
                        TypeDiagnoser &Diagnoser);
bool RequireLiteralType(SourceLocation Loc, QualType T, unsigned DiagID);

template <typename... Ts>
bool RequireLiteralType(SourceLocation Loc, QualType T, unsigned DiagID,
                        const Ts &...Args) {
  BoundTypeDiagnoser<Ts...> Diagnoser(DiagID, Args...);
  return RequireLiteralType(Loc, T, Diagnoser);
}

QualType getElaboratedType(ElaboratedTypeKeyword Keyword,
                           const CXXScopeSpec &SS, QualType T,
                           TagDecl *OwnedTagDecl = nullptr);

// Returns the underlying type of a decltype with the given expression.
QualType getDecltypeForExpr(Expr *E);

QualType BuildTypeofExprType(Expr *E, TypeOfKind Kind);
/// If AsUnevaluated is false, E is treated as though it were an evaluated
/// context, such as when building a type for decltype(auto).
QualType BuildDecltypeType(Expr *E, bool AsUnevaluated = true);

using UTTKind = UnaryTransformType::UTTKind;
QualType BuildUnaryTransformType(QualType BaseType, UTTKind UKind,
                                 SourceLocation Loc);
QualType BuiltinEnumUnderlyingType(QualType BaseType, SourceLocation Loc);
QualType BuiltinAddPointer(QualType BaseType, SourceLocation Loc);
QualType BuiltinRemovePointer(QualType BaseType, SourceLocation Loc);
QualType BuiltinDecay(QualType BaseType, SourceLocation Loc);
QualType BuiltinAddReference(QualType BaseType, UTTKind UKind,
                             SourceLocation Loc);
QualType BuiltinRemoveExtent(QualType BaseType, UTTKind UKind,
                             SourceLocation Loc);
QualType BuiltinRemoveReference(QualType BaseType, UTTKind UKind,
                                SourceLocation Loc);
QualType BuiltinChangeCVRQualifiers(QualType BaseType, UTTKind UKind,
                                    SourceLocation Loc);
QualType BuiltinChangeSignedness(QualType BaseType, UTTKind UKind,
                                 SourceLocation Loc);

//===--------------------------------------------------------------------===//
// Symbol table / Decl tracking callbacks: SemaDecl.cpp.
//

struct SkipBodyInfo {
  SkipBodyInfo() = default;
  bool ShouldSkip = false;
  bool CheckSameAsPrevious = false;
  NamedDecl *Previous = nullptr;
  NamedDecl *New = nullptr;
};

DeclGroupPtrTy ConvertDeclToDeclGroup(Decl *Ptr, Decl *OwnedType = nullptr);

void DiagnoseUseOfUnimplementedSelectors();

bool isSimpleTypeSpecifier(tok::TokenKind Kind) const;

ParsedType getTypeName(const IdentifierInfo &II, SourceLocation NameLoc,
                       Scope *S, CXXScopeSpec *SS = nullptr,
                       bool isClassName = false, bool HasTrailingDot = false,
                       ParsedType ObjectType = nullptr,
                       bool IsCtorOrDtorName = false,
                       bool WantNontrivialTypeSourceInfo = false,
                       bool IsClassTemplateDeductionContext = true,
                       ImplicitTypenameContext AllowImplicitTypename =
                           ImplicitTypenameContext::No,
                       IdentifierInfo **CorrectedII = nullptr);
TypeSpecifierType isTagName(IdentifierInfo &II, Scope *S);
bool isMicrosoftMissingTypename(const CXXScopeSpec *SS, Scope *S);
void DiagnoseUnknownTypeName(IdentifierInfo *&II,
                             SourceLocation IILoc,
                             Scope *S,
                             CXXScopeSpec *SS,
                             ParsedType &SuggestedType,
                             bool IsTemplateName = false);

/// Attempt to behave like MSVC in situations where lookup of an unqualified
/// type name has failed in a dependent context. In these situations, we
/// automatically form a DependentTypeName that will retry lookup in a related
/// scope during instantiation.
ParsedType ActOnMSVCUnknownTypeName(const IdentifierInfo &II,
                                    SourceLocation NameLoc,
                                    bool IsTemplateTypeArg);

/// Describes the result of the name lookup and resolution performed
/// by \c ClassifyName().
enum NameClassificationKind {
  /// This name is not a type or template in this context, but might be
  /// something else.
  NC_Unknown,
  /// Classification failed; an error has been produced.
  NC_Error,
  /// The name has been typo-corrected to a keyword.
  NC_Keyword,
  /// The name was classified as a type.
  NC_Type,
  /// The name was classified as a specific non-type, non-template
  /// declaration. ActOnNameClassifiedAsNonType should be called to
  /// convert the declaration to an expression.
  NC_NonType,
  /// The name was classified as an ADL-only function name.
  /// ActOnNameClassifiedAsUndeclaredNonType should be called to convert the
  /// result to an expression.
  NC_UndeclaredNonType,
  /// The name denotes a member of a dependent type that could not be
  /// resolved. ActOnNameClassifiedAsDependentNonType should be called to
  /// convert the result to an expression.
  NC_DependentNonType,
  /// The name was classified as an overload set, and an expression
  /// representing that overload set has been formed.
  /// ActOnNameClassifiedAsOverloadSet should be called to form a suitable
  /// expression referencing the overload set.
  NC_OverloadSet,
  /// The name was classified as a template whose specializations are types.
  NC_TypeTemplate,
  /// The name was classified as a variable template name.
  NC_VarTemplate,
  /// The name was classified as a function template name.
  NC_FunctionTemplate,
  /// The name was classified as an ADL-only function template name.
  NC_UndeclaredTemplate,
  /// The name was classified as a concept name.
  NC_Concept,
};

class NameClassification {
  NameClassificationKind Kind;
  union {
    ExprResult Expr;
    NamedDecl *NonTypeDecl;
    TemplateName Template;
    ParsedType Type;
  };

  explicit NameClassification(NameClassificationKind Kind) : Kind(Kind) {}

public:
  NameClassification(ParsedType Type) : Kind(NC_Type), Type(Type) {}

  NameClassification(const IdentifierInfo *Keyword) : Kind(NC_Keyword) {}

  static NameClassification Error() {
    return NameClassification(NC_Error);
  }

  static NameClassification Unknown() {
    return NameClassification(NC_Unknown);
  }

  static NameClassification OverloadSet(ExprResult E) {
    NameClassification Result(NC_OverloadSet);
    Result.Expr = E;
    return Result;
  }

  static NameClassification NonType(NamedDecl *D) {
    NameClassification Result(NC_NonType);
    Result.NonTypeDecl = D;
    return Result;
  }

  static NameClassification UndeclaredNonType() {
    return NameClassification(NC_UndeclaredNonType);
  }

  static NameClassification DependentNonType() {
    return NameClassification(NC_DependentNonType);
  }

  static NameClassification TypeTemplate(TemplateName Name) {
    NameClassification Result(NC_TypeTemplate);
    Result.Template = Name;
    return Result;
  }

  static NameClassification VarTemplate(TemplateName Name) {
    NameClassification Result(NC_VarTemplate);
    Result.Template = Name;
    return Result;
  }

  static NameClassification FunctionTemplate(TemplateName Name) {
    NameClassification Result(NC_FunctionTemplate);
    Result.Template = Name;
    return Result;
  }

  static NameClassification Concept(TemplateName Name) {
    NameClassification Result(NC_Concept);
    Result.Template = Name;
    return Result;
  }

  static NameClassification UndeclaredTemplate(TemplateName Name) {
    NameClassification Result(NC_UndeclaredTemplate);
    Result.Template = Name;
    return Result;
  }

  NameClassificationKind getKind() const { return Kind; }

  ExprResult getExpression() const {
    assert(Kind == NC_OverloadSet)(static_cast <bool> (Kind == NC_OverloadSet) ? void (0)
 : __assert_fail ("Kind == NC_OverloadSet", "clang/include/clang/Sema/Sema.h"
, 2752, __extension__ __PRETTY_FUNCTION__));
    return Expr;
  }

  ParsedType getType() const {
    assert(Kind == NC_Type)(static_cast <bool> (Kind == NC_Type) ? void (0) : __assert_fail
 ("Kind == NC_Type", "clang/include/clang/Sema/Sema.h", 2757,
 __extension__ __PRETTY_FUNCTION__));
    return Type;
  }

  NamedDecl *getNonTypeDecl() const {
    assert(Kind == NC_NonType)(static_cast <bool> (Kind == NC_NonType) ? void (0) : __assert_fail
 ("Kind == NC_NonType", "clang/include/clang/Sema/Sema.h", 2762
, __extension__ __PRETTY_FUNCTION__));
    return NonTypeDecl;
  }

  TemplateName getTemplateName() const {
    assert(Kind == NC_TypeTemplate || Kind == NC_FunctionTemplate ||(static_cast <bool> (Kind == NC_TypeTemplate || Kind ==
 NC_FunctionTemplate || Kind == NC_VarTemplate || Kind == NC_Concept
 || Kind == NC_UndeclaredTemplate) ? void (0) : __assert_fail
 ("Kind == NC_TypeTemplate || Kind == NC_FunctionTemplate || Kind == NC_VarTemplate || Kind == NC_Concept || Kind == NC_UndeclaredTemplate"
, "clang/include/clang/Sema/Sema.h", 2769, __extension__ __PRETTY_FUNCTION__
))
           Kind == NC_VarTemplate || Kind == NC_Concept ||(static_cast <bool> (Kind == NC_TypeTemplate || Kind ==
 NC_FunctionTemplate || Kind == NC_VarTemplate || Kind == NC_Concept
 || Kind == NC_UndeclaredTemplate) ? void (0) : __assert_fail
 ("Kind == NC_TypeTemplate || Kind == NC_FunctionTemplate || Kind == NC_VarTemplate || Kind == NC_Concept || Kind == NC_UndeclaredTemplate"
, "clang/include/clang/Sema/Sema.h", 2769, __extension__ __PRETTY_FUNCTION__
))
           Kind == NC_UndeclaredTemplate)(static_cast <bool> (Kind == NC_TypeTemplate || Kind ==
 NC_FunctionTemplate || Kind == NC_VarTemplate || Kind == NC_Concept
 || Kind == NC_UndeclaredTemplate) ? void (0) : __assert_fail
 ("Kind == NC_TypeTemplate || Kind == NC_FunctionTemplate || Kind == NC_VarTemplate || Kind == NC_Concept || Kind == NC_UndeclaredTemplate"
, "clang/include/clang/Sema/Sema.h", 2769, __extension__ __PRETTY_FUNCTION__
));
    return Template;
  }

  TemplateNameKind getTemplateNameKind() const {
    switch (Kind) {
    case NC_TypeTemplate:
      return TNK_Type_template;
    case NC_FunctionTemplate:
      return TNK_Function_template;
    case NC_VarTemplate:
      return TNK_Var_template;
    case NC_Concept:
      return TNK_Concept_template;
    case NC_UndeclaredTemplate:
      return TNK_Undeclared_template;
    default:
      llvm_unreachable("unsupported name classification.")::llvm::llvm_unreachable_internal("unsupported name classification."
, "clang/include/clang/Sema/Sema.h", 2786);
    }
  }
};

/// Perform name lookup on the given name, classifying it based on
/// the results of name lookup and the following token.
///
/// This routine is used by the parser to resolve identifiers and help direct
/// parsing. When the identifier cannot be found, this routine will attempt
/// to correct the typo and classify based on the resulting name.
///
/// \param S The scope in which we're performing name lookup.
///
/// \param SS The nested-name-specifier that precedes the name.
///
/// \param Name The identifier. If typo correction finds an alternative name,
/// this pointer parameter will be updated accordingly.
///
/// \param NameLoc The location of the identifier.
///
/// \param NextToken The token following the identifier. Used to help
/// disambiguate the name.
///
/// \param CCC The correction callback, if typo correction is desired.
NameClassification ClassifyName(Scope *S, CXXScopeSpec &SS,
                                IdentifierInfo *&Name, SourceLocation NameLoc,
                                const Token &NextToken,
                                CorrectionCandidateCallback *CCC = nullptr);

/// Act on the result of classifying a name as an undeclared (ADL-only)
/// non-type declaration.
ExprResult ActOnNameClassifiedAsUndeclaredNonType(IdentifierInfo *Name,
                                                  SourceLocation NameLoc);
/// Act on the result of classifying a name as an undeclared member of a
/// dependent base class.
ExprResult ActOnNameClassifiedAsDependentNonType(const CXXScopeSpec &SS,
                                                 IdentifierInfo *Name,
                                                 SourceLocation NameLoc,
                                                 bool IsAddressOfOperand);
/// Act on the result of classifying a name as a specific non-type
/// declaration.
ExprResult ActOnNameClassifiedAsNonType(Scope *S, const CXXScopeSpec &SS,
                                        NamedDecl *Found,
                                        SourceLocation NameLoc,
                                        const Token &NextToken);
/// Act on the result of classifying a name as an overload set.
ExprResult ActOnNameClassifiedAsOverloadSet(Scope *S, Expr *OverloadSet);

/// Describes the detailed kind of a template name. Used in diagnostics.
enum class TemplateNameKindForDiagnostics {
  ClassTemplate,
  FunctionTemplate,
  VarTemplate,
  AliasTemplate,
  TemplateTemplateParam,
  Concept,
  DependentTemplate
};
TemplateNameKindForDiagnostics
getTemplateNameKindForDiagnostics(TemplateName Name);

/// Determine whether it's plausible that E was intended to be a
/// template-name.
bool mightBeIntendedToBeTemplateName(ExprResult E, bool &Dependent) {
  if (!getLangOpts().CPlusPlus || E.isInvalid())
    return false;
  Dependent = false;
  if (auto *DRE = dyn_cast<DeclRefExpr>(E.get()))
    return !DRE->hasExplicitTemplateArgs();
  if (auto *ME = dyn_cast<MemberExpr>(E.get()))
    return !ME->hasExplicitTemplateArgs();
  Dependent = true;
  if (auto *DSDRE = dyn_cast<DependentScopeDeclRefExpr>(E.get()))
    return !DSDRE->hasExplicitTemplateArgs();
  if (auto *DSME = dyn_cast<CXXDependentScopeMemberExpr>(E.get()))
    return !DSME->hasExplicitTemplateArgs();
  // Any additional cases recognized here should also be handled by
  // diagnoseExprIntendedAsTemplateName.
  return false;
}
void diagnoseExprIntendedAsTemplateName(Scope *S, ExprResult TemplateName,
                                        SourceLocation Less,
                                        SourceLocation Greater);

void warnOnReservedIdentifier(const NamedDecl *D);

Decl *ActOnDeclarator(Scope *S, Declarator &D);

NamedDecl *HandleDeclarator(Scope *S, Declarator &D,
                            MultiTemplateParamsArg TemplateParameterLists);
bool tryToFixVariablyModifiedVarType(TypeSourceInfo *&TInfo,
                                     QualType &T, SourceLocation Loc,
                                     unsigned FailedFoldDiagID);
void RegisterLocallyScopedExternCDecl(NamedDecl *ND, Scope *S);
bool DiagnoseClassNameShadow(DeclContext *DC, DeclarationNameInfo Info);
bool diagnoseQualifiedDeclaration(CXXScopeSpec &SS, DeclContext *DC,
                                  DeclarationName Name, SourceLocation Loc,
                                  bool IsTemplateId);
void
diagnoseIgnoredQualifiers(unsigned DiagID, unsigned Quals,
                          SourceLocation FallbackLoc,
                          SourceLocation ConstQualLoc = SourceLocation(),
                          SourceLocation VolatileQualLoc = SourceLocation(),
                          SourceLocation RestrictQualLoc = SourceLocation(),
                          SourceLocation AtomicQualLoc = SourceLocation(),
                          SourceLocation UnalignedQualLoc = SourceLocation());

static bool adjustContextForLocalExternDecl(DeclContext *&DC);
void DiagnoseFunctionSpecifiers(const DeclSpec &DS);
NamedDecl *getShadowedDeclaration(const TypedefNameDecl *D,
                                  const LookupResult &R);
NamedDecl *getShadowedDeclaration(const VarDecl *D, const LookupResult &R);
NamedDecl *getShadowedDeclaration(const BindingDecl *D,
                                  const LookupResult &R);
void CheckShadow(NamedDecl *D, NamedDecl *ShadowedDecl,
                 const LookupResult &R);
void CheckShadow(Scope *S, VarDecl *D);

/// Warn if 'E', which is an expression that is about to be modified, refers
/// to a shadowing declaration.
void CheckShadowingDeclModification(Expr *E, SourceLocation Loc);

void DiagnoseShadowingLambdaDecls(const sema::LambdaScopeInfo *LSI);

2911private:
/// Map of current shadowing declarations to shadowed declarations. Warn if
/// it looks like the user is trying to modify the shadowing declaration.
llvm::DenseMap<const NamedDecl *, const NamedDecl *> ShadowingDecls;

2916public:
void CheckCastAlign(Expr *Op, QualType T, SourceRange TRange);
void handleTagNumbering(const TagDecl *Tag, Scope *TagScope);
void setTagNameForLinkagePurposes(TagDecl *TagFromDeclSpec,
                                  TypedefNameDecl *NewTD);
void CheckTypedefForVariablyModifiedType(Scope *S, TypedefNameDecl *D);
NamedDecl* ActOnTypedefDeclarator(Scope* S, Declarator& D, DeclContext* DC,
                                  TypeSourceInfo *TInfo,
                                  LookupResult &Previous);
NamedDecl* ActOnTypedefNameDecl(Scope* S, DeclContext* DC, TypedefNameDecl *D,
                                LookupResult &Previous, bool &Redeclaration);
NamedDecl *ActOnVariableDeclarator(
    Scope *S, Declarator &D, DeclContext *DC, TypeSourceInfo *TInfo,
    LookupResult &Previous, MultiTemplateParamsArg TemplateParamLists,
    bool &AddToScope, ArrayRef<BindingDecl *> Bindings = std::nullopt);
NamedDecl *
ActOnDecompositionDeclarator(Scope *S, Declarator &D,
                             MultiTemplateParamsArg TemplateParamLists);
// Returns true if the variable declaration is a redeclaration
bool CheckVariableDeclaration(VarDecl *NewVD, LookupResult &Previous);
void CheckVariableDeclarationType(VarDecl *NewVD);
bool DeduceVariableDeclarationType(VarDecl *VDecl, bool DirectInit,
                                   Expr *Init);
void CheckCompleteVariableDeclaration(VarDecl *VD);
void CheckCompleteDecompositionDeclaration(DecompositionDecl *DD);
void MaybeSuggestAddingStaticToDecl(const FunctionDecl *D);

NamedDecl* ActOnFunctionDeclarator(Scope* S, Declarator& D, DeclContext* DC,
                                   TypeSourceInfo *TInfo,
                                   LookupResult &Previous,
                                   MultiTemplateParamsArg TemplateParamLists,
                                   bool &AddToScope);
bool AddOverriddenMethods(CXXRecordDecl *DC, CXXMethodDecl *MD);

enum class CheckConstexprKind {
  /// Diagnose issues that are non-constant or that are extensions.
  Diagnose,
  /// Identify whether this function satisfies the formal rules for constexpr
  /// functions in the current lanugage mode (with no extensions).
  CheckValid
};

bool CheckConstexprFunctionDefinition(const FunctionDecl *FD,
                                      CheckConstexprKind Kind);

void DiagnoseHiddenVirtualMethods(CXXMethodDecl *MD);
void FindHiddenVirtualMethods(CXXMethodDecl *MD,
                        SmallVectorImpl<CXXMethodDecl*> &OverloadedMethods);
void NoteHiddenVirtualMethods(CXXMethodDecl *MD,
                        SmallVectorImpl<CXXMethodDecl*> &OverloadedMethods);
// Returns true if the function declaration is a redeclaration
bool CheckFunctionDeclaration(Scope *S,
                              FunctionDecl *NewFD, LookupResult &Previous,
                              bool IsMemberSpecialization, bool DeclIsDefn);
bool shouldLinkDependentDeclWithPrevious(Decl *D, Decl *OldDecl);
bool canFullyTypeCheckRedeclaration(ValueDecl *NewD, ValueDecl *OldD,
                                    QualType NewT, QualType OldT);
void CheckMain(FunctionDecl *FD, const DeclSpec &D);
void CheckMSVCRTEntryPoint(FunctionDecl *FD);
void CheckHLSLEntryPoint(FunctionDecl *FD);
Attr *getImplicitCodeSegOrSectionAttrForFunction(const FunctionDecl *FD,
                                                 bool IsDefinition);
void CheckFunctionOrTemplateParamDeclarator(Scope *S, Declarator &D);
Decl *ActOnParamDeclarator(Scope *S, Declarator &D);
ParmVarDecl *BuildParmVarDeclForTypedef(DeclContext *DC,
                                        SourceLocation Loc,
                                        QualType T);
ParmVarDecl *CheckParameter(DeclContext *DC, SourceLocation StartLoc,
                            SourceLocation NameLoc, IdentifierInfo *Name,
                            QualType T, TypeSourceInfo *TSInfo,
                            StorageClass SC);
void ActOnParamDefaultArgument(Decl *param,
                               SourceLocation EqualLoc,
                               Expr *defarg);
void ActOnParamUnparsedDefaultArgument(Decl *param, SourceLocation EqualLoc,
                                       SourceLocation ArgLoc);
void ActOnParamDefaultArgumentError(Decl *param, SourceLocation EqualLoc);
ExprResult ConvertParamDefaultArgument(ParmVarDecl *Param, Expr *DefaultArg,
                                       SourceLocation EqualLoc);
void SetParamDefaultArgument(ParmVarDecl *Param, Expr *DefaultArg,
                             SourceLocation EqualLoc);

// Contexts where using non-trivial C union types can be disallowed. This is
// passed to err_non_trivial_c_union_in_invalid_context.
enum NonTrivialCUnionContext {
  // Function parameter.
  NTCUC_FunctionParam,
  // Function return.
  NTCUC_FunctionReturn,
  // Default-initialized object.
  NTCUC_DefaultInitializedObject,
  // Variable with automatic storage duration.
  NTCUC_AutoVar,
  // Initializer expression that might copy from another object.
  NTCUC_CopyInit,
  // Assignment.
  NTCUC_Assignment,
  // Compound literal.
  NTCUC_CompoundLiteral,
  // Block capture.
  NTCUC_BlockCapture,
  // lvalue-to-rvalue conversion of volatile type.
  NTCUC_LValueToRValueVolatile,
};

/// Emit diagnostics if the initializer or any of its explicit or
/// implicitly-generated subexpressions require copying or
/// default-initializing a type that is or contains a C union type that is
/// non-trivial to copy or default-initialize.
void checkNonTrivialCUnionInInitializer(const Expr *Init, SourceLocation Loc);

// These flags are passed to checkNonTrivialCUnion.
enum NonTrivialCUnionKind {
  NTCUK_Init = 0x1,
  NTCUK_Destruct = 0x2,
  NTCUK_Copy = 0x4,
};

/// Emit diagnostics if a non-trivial C union type or a struct that contains
/// a non-trivial C union is used in an invalid context.
void checkNonTrivialCUnion(QualType QT, SourceLocation Loc,
                           NonTrivialCUnionContext UseContext,
                           unsigned NonTrivialKind);

void AddInitializerToDecl(Decl *dcl, Expr *init, bool DirectInit);
void ActOnUninitializedDecl(Decl *dcl);
void ActOnInitializerError(Decl *Dcl);

void ActOnPureSpecifier(Decl *D, SourceLocation PureSpecLoc);
void ActOnCXXForRangeDecl(Decl *D);
StmtResult ActOnCXXForRangeIdentifier(Scope *S, SourceLocation IdentLoc,
                                      IdentifierInfo *Ident,
                                      ParsedAttributes &Attrs);
void SetDeclDeleted(Decl *dcl, SourceLocation DelLoc);
void SetDeclDefaulted(Decl *dcl, SourceLocation DefaultLoc);
void CheckStaticLocalForDllExport(VarDecl *VD);
void CheckThreadLocalForLargeAlignment(VarDecl *VD);
void FinalizeDeclaration(Decl *D);
DeclGroupPtrTy FinalizeDeclaratorGroup(Scope *S, const DeclSpec &DS,
                                       ArrayRef<Decl *> Group);
DeclGroupPtrTy BuildDeclaratorGroup(MutableArrayRef<Decl *> Group);

/// Should be called on all declarations that might have attached
/// documentation comments.
void ActOnDocumentableDecl(Decl *D);
void ActOnDocumentableDecls(ArrayRef<Decl *> Group);

enum class FnBodyKind {
  /// C++ [dcl.fct.def.general]p1
  /// function-body:
  ///   ctor-initializer[opt] compound-statement
  ///   function-try-block
  Other,
  ///   = default ;
  Default,
  ///   = delete ;
  Delete
};

void ActOnFinishKNRParamDeclarations(Scope *S, Declarator &D,
                                     SourceLocation LocAfterDecls);
void CheckForFunctionRedefinition(
    FunctionDecl *FD, const FunctionDecl *EffectiveDefinition = nullptr,
    SkipBodyInfo *SkipBody = nullptr);
Decl *ActOnStartOfFunctionDef(Scope *S, Declarator &D,
                              MultiTemplateParamsArg TemplateParamLists,
                              SkipBodyInfo *SkipBody = nullptr,
                              FnBodyKind BodyKind = FnBodyKind::Other);
Decl *ActOnStartOfFunctionDef(Scope *S, Decl *D,
                              SkipBodyInfo *SkipBody = nullptr,
                              FnBodyKind BodyKind = FnBodyKind::Other);
void SetFunctionBodyKind(Decl *D, SourceLocation Loc, FnBodyKind BodyKind);
void ActOnStartTrailingRequiresClause(Scope *S, Declarator &D);
ExprResult ActOnFinishTrailingRequiresClause(ExprResult ConstraintExpr);
ExprResult ActOnRequiresClause(ExprResult ConstraintExpr);
void ActOnStartOfObjCMethodDef(Scope *S, Decl *D);
bool isObjCMethodDecl(Decl *D) {
  return D && isa<ObjCMethodDecl>(D);
}

/// Determine whether we can delay parsing the body of a function or
/// function template until it is used, assuming we don't care about emitting
/// code for that function.
///
/// This will be \c false if we may need the body of the function in the
/// middle of parsing an expression (where it's impractical to switch to
/// parsing a different function), for instance, if it's constexpr in C++11
/// or has an 'auto' return type in C++14. These cases are essentially bugs.
bool canDelayFunctionBody(const Declarator &D);

/// Determine whether we can skip parsing the body of a function
/// definition, assuming we don't care about analyzing its body or emitting
/// code for that function.
///
/// This will be \c false only if we may need the body of the function in
/// order to parse the rest of the program (for instance, if it is
/// \c constexpr in C++11 or has an 'auto' return type in C++14).
bool canSkipFunctionBody(Decl *D);

/// Determine whether \param D is function like (function or function
/// template) for parsing.
bool isDeclaratorFunctionLike(Declarator &D);

void computeNRVO(Stmt *Body, sema::FunctionScopeInfo *Scope);
Decl *ActOnFinishFunctionBody(Decl *Decl, Stmt *Body);
Decl *ActOnFinishFunctionBody(Decl *Decl, Stmt *Body, bool IsInstantiation);
Decl *ActOnSkippedFunctionBody(Decl *Decl);
void ActOnFinishInlineFunctionDef(FunctionDecl *D);

/// ActOnFinishDelayedAttribute - Invoked when we have finished parsing an
/// attribute for which parsing is delayed.
void ActOnFinishDelayedAttribute(Scope *S, Decl *D, ParsedAttributes &Attrs);

/// Diagnose any unused parameters in the given sequence of
/// ParmVarDecl pointers.
void DiagnoseUnusedParameters(ArrayRef<ParmVarDecl *> Parameters);

/// Diagnose whether the size of parameters or return value of a
/// function or obj-c method definition is pass-by-value and larger than a
/// specified threshold.
void
DiagnoseSizeOfParametersAndReturnValue(ArrayRef<ParmVarDecl *> Parameters,
                                       QualType ReturnTy, NamedDecl *D);

void DiagnoseInvalidJumps(Stmt *Body);
Decl *ActOnFileScopeAsmDecl(Expr *expr,
                            SourceLocation AsmLoc,
                            SourceLocation RParenLoc);

Decl *ActOnTopLevelStmtDecl(Stmt *Statement);

/// Handle a C++11 empty-declaration and attribute-declaration.
Decl *ActOnEmptyDeclaration(Scope *S, const ParsedAttributesView &AttrList,
                            SourceLocation SemiLoc);

enum class ModuleDeclKind {
  Interface,               ///< 'export module X;'
  Implementation,          ///< 'module X;'
  PartitionInterface,      ///< 'export module X:Y;'
  PartitionImplementation, ///< 'module X:Y;'
};

/// An enumeration to represent the transition of states in parsing module
/// fragments and imports.  If we are not parsing a C++20 TU, or we find
/// an error in state transition, the state is set to NotACXX20Module.
enum class ModuleImportState {
  FirstDecl,      ///< Parsing the first decl in a TU.
  GlobalFragment, ///< after 'module;' but before 'module X;'
  ImportAllowed,  ///< after 'module X;' but before any non-import decl.
  ImportFinished, ///< after any non-import decl.
  PrivateFragmentImportAllowed,  ///< after 'module :private;' but before any
                                 ///< non-import decl.
  PrivateFragmentImportFinished, ///< after 'module :private;' but a
                                 ///< non-import decl has already been seen.
  NotACXX20Module ///< Not a C++20 TU, or an invalid state was found.
};

3173private:
/// The parser has begun a translation unit to be compiled as a C++20
/// Header Unit, helper for ActOnStartOfTranslationUnit() only.
void HandleStartOfHeaderUnit();

3178public:
/// The parser has processed a module-declaration that begins the definition
/// of a module interface or implementation.
DeclGroupPtrTy ActOnModuleDecl(SourceLocation StartLoc,
                               SourceLocation ModuleLoc, ModuleDeclKind MDK,
                               ModuleIdPath Path, ModuleIdPath Partition,
                               ModuleImportState &ImportState);

/// The parser has processed a global-module-fragment declaration that begins
/// the definition of the global module fragment of the current module unit.
/// \param ModuleLoc The location of the 'module' keyword.
DeclGroupPtrTy ActOnGlobalModuleFragmentDecl(SourceLocation ModuleLoc);

/// The parser has processed a private-module-fragment declaration that begins
/// the definition of the private module fragment of the current module unit.
/// \param ModuleLoc The location of the 'module' keyword.
/// \param PrivateLoc The location of the 'private' keyword.
DeclGroupPtrTy ActOnPrivateModuleFragmentDecl(SourceLocation ModuleLoc,
                                              SourceLocation PrivateLoc);

/// The parser has processed a module import declaration.
///
/// \param StartLoc The location of the first token in the declaration. This
///        could be the location of an '@', 'export', or 'import'.
/// \param ExportLoc The location of the 'export' keyword, if any.
/// \param ImportLoc The location of the 'import' keyword.
/// \param Path The module toplevel name as an access path.
/// \param IsPartition If the name is for a partition.
DeclResult ActOnModuleImport(SourceLocation StartLoc,
                             SourceLocation ExportLoc,
                             SourceLocation ImportLoc, ModuleIdPath Path,
                             bool IsPartition = false);
DeclResult ActOnModuleImport(SourceLocation StartLoc,
                             SourceLocation ExportLoc,
                             SourceLocation ImportLoc, Module *M,
                             ModuleIdPath Path = {});

/// The parser has processed a module import translated from a
/// #include or similar preprocessing directive.
void ActOnModuleInclude(SourceLocation DirectiveLoc, Module *Mod);
void BuildModuleInclude(SourceLocation DirectiveLoc, Module *Mod);

/// The parsed has entered a submodule.
void ActOnModuleBegin(SourceLocation DirectiveLoc, Module *Mod);
/// The parser has left a submodule.
void ActOnModuleEnd(SourceLocation DirectiveLoc, Module *Mod);

/// Create an implicit import of the given module at the given
/// source location, for error recovery, if possible.
///
/// This routine is typically used when an entity found by name lookup
/// is actually hidden within a module that we know about but the user
/// has forgotten to import.
void createImplicitModuleImportForErrorRecovery(SourceLocation Loc,
                                                Module *Mod);

/// Kinds of missing import. Note, the values of these enumerators correspond
/// to %select values in diagnostics.
enum class MissingImportKind {
  Declaration,
  Definition,
  DefaultArgument,
  ExplicitSpecialization,
  PartialSpecialization
};

/// Diagnose that the specified declaration needs to be visible but
/// isn't, and suggest a module import that would resolve the problem.
void diagnoseMissingImport(SourceLocation Loc, const NamedDecl *Decl,
                           MissingImportKind MIK, bool Recover = true);
void diagnoseMissingImport(SourceLocation Loc, const NamedDecl *Decl,
                           SourceLocation DeclLoc, ArrayRef<Module *> Modules,
                           MissingImportKind MIK, bool Recover);

Decl *ActOnStartExportDecl(Scope *S, SourceLocation ExportLoc,
                           SourceLocation LBraceLoc);
Decl *ActOnFinishExportDecl(Scope *S, Decl *ExportDecl,
                            SourceLocation RBraceLoc);

/// We've found a use of a templated declaration that would trigger an
/// implicit instantiation. Check that any relevant explicit specializations
/// and partial specializations are visible/reachable, and diagnose if not.
void checkSpecializationVisibility(SourceLocation Loc, NamedDecl *Spec);
void checkSpecializationReachability(SourceLocation Loc, NamedDecl *Spec);

/// Retrieve a suitable printing policy for diagnostics.
PrintingPolicy getPrintingPolicy() const {
  return getPrintingPolicy(Context, PP);
}

/// Retrieve a suitable printing policy for diagnostics.
static PrintingPolicy getPrintingPolicy(const ASTContext &Ctx,
                                        const Preprocessor &PP);

/// Scope actions.
void ActOnPopScope(SourceLocation Loc, Scope *S);
void ActOnTranslationUnitScope(Scope *S);

Decl *ParsedFreeStandingDeclSpec(Scope *S, AccessSpecifier AS, DeclSpec &DS,
                                 const ParsedAttributesView &DeclAttrs,
                                 RecordDecl *&AnonRecord);
Decl *ParsedFreeStandingDeclSpec(Scope *S, AccessSpecifier AS, DeclSpec &DS,
                                 const ParsedAttributesView &DeclAttrs,
                                 MultiTemplateParamsArg TemplateParams,
                                 bool IsExplicitInstantiation,
                                 RecordDecl *&AnonRecord);

Decl *BuildAnonymousStructOrUnion(Scope *S, DeclSpec &DS,
                                  AccessSpecifier AS,
                                  RecordDecl *Record,
                                  const PrintingPolicy &Policy);

Decl *BuildMicrosoftCAnonymousStruct(Scope *S, DeclSpec &DS,
                                     RecordDecl *Record);

/// Common ways to introduce type names without a tag for use in diagnostics.
/// Keep in sync with err_tag_reference_non_tag.
enum NonTagKind {
  NTK_NonStruct,
  NTK_NonClass,
  NTK_NonUnion,
  NTK_NonEnum,
  NTK_Typedef,
  NTK_TypeAlias,
  NTK_Template,
  NTK_TypeAliasTemplate,
  NTK_TemplateTemplateArgument,
};

/// Given a non-tag type declaration, returns an enum useful for indicating
/// what kind of non-tag type this is.
NonTagKind getNonTagTypeDeclKind(const Decl *D, TagTypeKind TTK);

bool isAcceptableTagRedeclaration(const TagDecl *Previous,
                                  TagTypeKind NewTag, bool isDefinition,
                                  SourceLocation NewTagLoc,
                                  const IdentifierInfo *Name);

enum TagUseKind {
  TUK_Reference,   // Reference to a tag:  'struct foo *X;'
  TUK_Declaration, // Fwd decl of a tag:   'struct foo;'
  TUK_Definition,  // Definition of a tag: 'struct foo { int X; } Y;'
  TUK_Friend       // Friend declaration:  'friend struct foo;'
};

enum OffsetOfKind {
  // Not parsing a type within __builtin_offsetof.
  OOK_Outside,
  // Parsing a type within __builtin_offsetof.
  OOK_Builtin,
  // Parsing a type within macro "offsetof", defined in __buitin_offsetof
  // To improve our diagnostic message.
  OOK_Macro,
};

DeclResult ActOnTag(Scope *S, unsigned TagSpec, TagUseKind TUK,
                    SourceLocation KWLoc, CXXScopeSpec &SS,
                    IdentifierInfo *Name, SourceLocation NameLoc,
                    const ParsedAttributesView &Attr, AccessSpecifier AS,
                    SourceLocation ModulePrivateLoc,
                    MultiTemplateParamsArg TemplateParameterLists,
                    bool &OwnedDecl, bool &IsDependent,
                    SourceLocation ScopedEnumKWLoc,
                    bool ScopedEnumUsesClassTag, TypeResult UnderlyingType,
                    bool IsTypeSpecifier, bool IsTemplateParamOrArg,
                    OffsetOfKind OOK, SkipBodyInfo *SkipBody = nullptr);

DeclResult ActOnTemplatedFriendTag(Scope *S, SourceLocation FriendLoc,
                                   unsigned TagSpec, SourceLocation TagLoc,
                                   CXXScopeSpec &SS, IdentifierInfo *Name,
                                   SourceLocation NameLoc,
                                   const ParsedAttributesView &Attr,
                                   MultiTemplateParamsArg TempParamLists);

TypeResult ActOnDependentTag(Scope *S,
                             unsigned TagSpec,
                             TagUseKind TUK,
                             const CXXScopeSpec &SS,
                             IdentifierInfo *Name,
                             SourceLocation TagLoc,
                             SourceLocation NameLoc);

void ActOnDefs(Scope *S, Decl *TagD, SourceLocation DeclStart,
               IdentifierInfo *ClassName,
               SmallVectorImpl<Decl *> &Decls);
Decl *ActOnField(Scope *S, Decl *TagD, SourceLocation DeclStart,
                 Declarator &D, Expr *BitfieldWidth);

FieldDecl *HandleField(Scope *S, RecordDecl *TagD, SourceLocation DeclStart,
                       Declarator &D, Expr *BitfieldWidth,
                       InClassInitStyle InitStyle,
                       AccessSpecifier AS);
MSPropertyDecl *HandleMSProperty(Scope *S, RecordDecl *TagD,
                                 SourceLocation DeclStart, Declarator &D,
                                 Expr *BitfieldWidth,
                                 InClassInitStyle InitStyle,
                                 AccessSpecifier AS,
                                 const ParsedAttr &MSPropertyAttr);

FieldDecl *CheckFieldDecl(DeclarationName Name, QualType T,
                          TypeSourceInfo *TInfo,
                          RecordDecl *Record, SourceLocation Loc,
                          bool Mutable, Expr *BitfieldWidth,
                          InClassInitStyle InitStyle,
                          SourceLocation TSSL,
                          AccessSpecifier AS, NamedDecl *PrevDecl,
                          Declarator *D = nullptr);

bool CheckNontrivialField(FieldDecl *FD);
void DiagnoseNontrivial(const CXXRecordDecl *Record, CXXSpecialMember CSM);

enum TrivialABIHandling {
  /// The triviality of a method unaffected by "trivial_abi".
  TAH_IgnoreTrivialABI,

  /// The triviality of a method affected by "trivial_abi".
  TAH_ConsiderTrivialABI
};

bool SpecialMemberIsTrivial(CXXMethodDecl *MD, CXXSpecialMember CSM,
                            TrivialABIHandling TAH = TAH_IgnoreTrivialABI,
                            bool Diagnose = false);

/// For a defaulted function, the kind of defaulted function that it is.
class DefaultedFunctionKind {
  CXXSpecialMember SpecialMember : 8;
  DefaultedComparisonKind Comparison : 8;

public:
  DefaultedFunctionKind()
      : SpecialMember(CXXInvalid), Comparison(DefaultedComparisonKind::None) {
  }
  DefaultedFunctionKind(CXXSpecialMember CSM)
      : SpecialMember(CSM), Comparison(DefaultedComparisonKind::None) {}
  DefaultedFunctionKind(DefaultedComparisonKind Comp)
      : SpecialMember(CXXInvalid), Comparison(Comp) {}

  bool isSpecialMember() const { return SpecialMember != CXXInvalid; }
  bool isComparison() const {
    return Comparison != DefaultedComparisonKind::None;
  }

  explicit operator bool() const {
    return isSpecialMember() || isComparison();
  }

  CXXSpecialMember asSpecialMember() const { return SpecialMember; }
  DefaultedComparisonKind asComparison() const { return Comparison; }

  /// Get the index of this function kind for use in diagnostics.
  unsigned getDiagnosticIndex() const {
    static_assert(CXXInvalid > CXXDestructor,
                  "invalid should have highest index");
    static_assert((unsigned)DefaultedComparisonKind::None == 0,
                  "none should be equal to zero");
    return SpecialMember + (unsigned)Comparison;
  }
};

DefaultedFunctionKind getDefaultedFunctionKind(const FunctionDecl *FD);

CXXSpecialMember getSpecialMember(const CXXMethodDecl *MD) {
  return getDefaultedFunctionKind(MD).asSpecialMember();
}
DefaultedComparisonKind getDefaultedComparisonKind(const FunctionDecl *FD) {
  return getDefaultedFunctionKind(FD).asComparison();
}

void ActOnLastBitfield(SourceLocation DeclStart,
                       SmallVectorImpl<Decl *> &AllIvarDecls);
Decl *ActOnIvar(Scope *S, SourceLocation DeclStart,
                Declarator &D, Expr *BitfieldWidth,
                tok::ObjCKeywordKind visibility);

// This is used for both record definitions and ObjC interface declarations.
void ActOnFields(Scope *S, SourceLocation RecLoc, Decl *TagDecl,
                 ArrayRef<Decl *> Fields, SourceLocation LBrac,
                 SourceLocation RBrac, const ParsedAttributesView &AttrList);

/// ActOnTagStartDefinition - Invoked when we have entered the
/// scope of a tag's definition (e.g., for an enumeration, class,
/// struct, or union).
void ActOnTagStartDefinition(Scope *S, Decl *TagDecl);

/// Perform ODR-like check for C/ObjC when merging tag types from modules.
/// Differently from C++, actually parse the body and reject / error out
/// in case of a structural mismatch.
bool ActOnDuplicateDefinition(Decl *Prev, SkipBodyInfo &SkipBody);

/// Check ODR hashes for C/ObjC when merging types from modules.
/// Differently from C++, actually parse the body and reject in case
/// of a mismatch.
template <typename T,
          typename = std::enable_if_t<std::is_base_of<NamedDecl, T>::value>>
bool ActOnDuplicateODRHashDefinition(T *Duplicate, T *Previous) {
  if (Duplicate->getODRHash() != Previous->getODRHash())
    return false;

  // Make the previous decl visible.
  makeMergedDefinitionVisible(Previous);
  return true;
}

typedef void *SkippedDefinitionContext;

/// Invoked when we enter a tag definition that we're skipping.
SkippedDefinitionContext ActOnTagStartSkippedDefinition(Scope *S, Decl *TD);

void ActOnObjCContainerStartDefinition(ObjCContainerDecl *IDecl);

/// ActOnStartCXXMemberDeclarations - Invoked when we have parsed a
/// C++ record definition's base-specifiers clause and are starting its
/// member declarations.
void ActOnStartCXXMemberDeclarations(Scope *S, Decl *TagDecl,
                                     SourceLocation FinalLoc,
                                     bool IsFinalSpelledSealed,
                                     bool IsAbstract,
                                     SourceLocation LBraceLoc);

/// ActOnTagFinishDefinition - Invoked once we have finished parsing
/// the definition of a tag (enumeration, class, struct, or union).
void ActOnTagFinishDefinition(Scope *S, Decl *TagDecl,
                              SourceRange BraceRange);

void ActOnTagFinishSkippedDefinition(SkippedDefinitionContext Context);

void ActOnObjCContainerFinishDefinition();

/// Invoked when we must temporarily exit the objective-c container
/// scope for parsing/looking-up C constructs.
///
/// Must be followed by a call to \see ActOnObjCReenterContainerContext
void ActOnObjCTemporaryExitContainerContext(ObjCContainerDecl *ObjCCtx);
void ActOnObjCReenterContainerContext(ObjCContainerDecl *ObjCCtx);

/// ActOnTagDefinitionError - Invoked when there was an unrecoverable
/// error parsing the definition of a tag.
void ActOnTagDefinitionError(Scope *S, Decl *TagDecl);

EnumConstantDecl *CheckEnumConstant(EnumDecl *Enum,
                                    EnumConstantDecl *LastEnumConst,
                                    SourceLocation IdLoc,
                                    IdentifierInfo *Id,
                                    Expr *val);
bool CheckEnumUnderlyingType(TypeSourceInfo *TI);
bool CheckEnumRedeclaration(SourceLocation EnumLoc, bool IsScoped,
                            QualType EnumUnderlyingTy, bool IsFixed,
                            const EnumDecl *Prev);

/// Determine whether the body of an anonymous enumeration should be skipped.
/// \param II The name of the first enumerator.
SkipBodyInfo shouldSkipAnonEnumBody(Scope *S, IdentifierInfo *II,
                                    SourceLocation IILoc);

Decl *ActOnEnumConstant(Scope *S, Decl *EnumDecl, Decl *LastEnumConstant,
                        SourceLocation IdLoc, IdentifierInfo *Id,
                        const ParsedAttributesView &Attrs,
                        SourceLocation EqualLoc, Expr *Val);
void ActOnEnumBody(SourceLocation EnumLoc, SourceRange BraceRange,
                   Decl *EnumDecl, ArrayRef<Decl *> Elements, Scope *S,
                   const ParsedAttributesView &Attr);

/// Set the current declaration context until it gets popped.
void PushDeclContext(Scope *S, DeclContext *DC);
void PopDeclContext();

/// EnterDeclaratorContext - Used when we must lookup names in the context
/// of a declarator's nested name specifier.
void EnterDeclaratorContext(Scope *S, DeclContext *DC);
void ExitDeclaratorContext(Scope *S);

/// Enter a template parameter scope, after it's been associated with a particular
/// DeclContext. Causes lookup within the scope to chain through enclosing contexts
/// in the correct order.
void EnterTemplatedContext(Scope *S, DeclContext *DC);

/// Push the parameters of D, which must be a function, into scope.
void ActOnReenterFunctionContext(Scope* S, Decl* D);
void ActOnExitFunctionContext();

/// If \p AllowLambda is true, treat lambda as function.
DeclContext *getFunctionLevelDeclContext(bool AllowLambda = false) const;

/// Returns a pointer to the innermost enclosing function, or nullptr if the
/// current context is not inside a function. If \p AllowLambda is true,
/// this can return the call operator of an enclosing lambda, otherwise
/// lambdas are skipped when looking for an enclosing function.
FunctionDecl *getCurFunctionDecl(bool AllowLambda = false) const;

/// getCurMethodDecl - If inside of a method body, this returns a pointer to
/// the method decl for the method being parsed.  If we're currently
/// in a 'block', this returns the containing context.
ObjCMethodDecl *getCurMethodDecl();

/// getCurFunctionOrMethodDecl - Return the Decl for the current ObjC method
/// or C function we're in, otherwise return null.  If we're currently
/// in a 'block', this returns the containing context.
NamedDecl *getCurFunctionOrMethodDecl() const;

/// Add this decl to the scope shadowed decl chains.
void PushOnScopeChains(NamedDecl *D, Scope *S, bool AddToContext = true);

/// isDeclInScope - If 'Ctx' is a function/method, isDeclInScope returns true
/// if 'D' is in Scope 'S', otherwise 'S' is ignored and isDeclInScope returns
/// true if 'D' belongs to the given declaration context.
///
/// \param AllowInlineNamespace If \c true, allow the declaration to be in the
///        enclosing namespace set of the context, rather than contained
///        directly within it.
bool isDeclInScope(NamedDecl *D, DeclContext *Ctx, Scope *S = nullptr,
                   bool AllowInlineNamespace = false) const;

/// Finds the scope corresponding to the given decl context, if it
/// happens to be an enclosing scope.  Otherwise return NULL.
static Scope *getScopeForDeclContext(Scope *S, DeclContext *DC);

/// Subroutines of ActOnDeclarator().
TypedefDecl *ParseTypedefDecl(Scope *S, Declarator &D, QualType T,
                              TypeSourceInfo *TInfo);
bool isIncompatibleTypedef(TypeDecl *Old, TypedefNameDecl *New);

/// Describes the kind of merge to perform for availability
/// attributes (including "deprecated", "unavailable", and "availability").
enum AvailabilityMergeKind {
  /// Don't merge availability attributes at all.
  AMK_None,
  /// Merge availability attributes for a redeclaration, which requires
  /// an exact match.
  AMK_Redeclaration,
  /// Merge availability attributes for an override, which requires
  /// an exact match or a weakening of constraints.
  AMK_Override,
  /// Merge availability attributes for an implementation of
  /// a protocol requirement.
  AMK_ProtocolImplementation,
  /// Merge availability attributes for an implementation of
  /// an optional protocol requirement.
  AMK_OptionalProtocolImplementation
};

/// Describes the kind of priority given to an availability attribute.
///
/// The sum of priorities deteremines the final priority of the attribute.
/// The final priority determines how the attribute will be merged.
/// An attribute with a lower priority will always remove higher priority
/// attributes for the specified platform when it is being applied. An
/// attribute with a higher priority will not be applied if the declaration
/// already has an availability attribute with a lower priority for the
/// specified platform. The final prirority values are not expected to match
/// the values in this enumeration, but instead should be treated as a plain
/// integer value. This enumeration just names the priority weights that are
/// used to calculate that final vaue.
enum AvailabilityPriority : int {
  /// The availability attribute was specified explicitly next to the
  /// declaration.
  AP_Explicit = 0,

  /// The availability attribute was applied using '#pragma clang attribute'.
  AP_PragmaClangAttribute = 1,

  /// The availability attribute for a specific platform was inferred from
  /// an availability attribute for another platform.
  AP_InferredFromOtherPlatform = 2
};

/// Attribute merging methods. Return true if a new attribute was added.
AvailabilityAttr *
mergeAvailabilityAttr(NamedDecl *D, const AttributeCommonInfo &CI,
                      IdentifierInfo *Platform, bool Implicit,
                      VersionTuple Introduced, VersionTuple Deprecated,
                      VersionTuple Obsoleted, bool IsUnavailable,
                      StringRef Message, bool IsStrict, StringRef Replacement,
                      AvailabilityMergeKind AMK, int Priority);
TypeVisibilityAttr *
mergeTypeVisibilityAttr(Decl *D, const AttributeCommonInfo &CI,
                        TypeVisibilityAttr::VisibilityType Vis);
VisibilityAttr *mergeVisibilityAttr(Decl *D, const AttributeCommonInfo &CI,
                                    VisibilityAttr::VisibilityType Vis);
UuidAttr *mergeUuidAttr(Decl *D, const AttributeCommonInfo &CI,
                        StringRef UuidAsWritten, MSGuidDecl *GuidDecl);
DLLImportAttr *mergeDLLImportAttr(Decl *D, const AttributeCommonInfo &CI);
DLLExportAttr *mergeDLLExportAttr(Decl *D, const AttributeCommonInfo &CI);
MSInheritanceAttr *mergeMSInheritanceAttr(Decl *D,
                                          const AttributeCommonInfo &CI,
                                          bool BestCase,
                                          MSInheritanceModel Model);
ErrorAttr *mergeErrorAttr(Decl *D, const AttributeCommonInfo &CI,
                          StringRef NewUserDiagnostic);
FormatAttr *mergeFormatAttr(Decl *D, const AttributeCommonInfo &CI,
                            IdentifierInfo *Format, int FormatIdx,
                            int FirstArg);
SectionAttr *mergeSectionAttr(Decl *D, const AttributeCommonInfo &CI,
                              StringRef Name);
CodeSegAttr *mergeCodeSegAttr(Decl *D, const AttributeCommonInfo &CI,
                              StringRef Name);
AlwaysInlineAttr *mergeAlwaysInlineAttr(Decl *D,
                                        const AttributeCommonInfo &CI,
                                        const IdentifierInfo *Ident);
MinSizeAttr *mergeMinSizeAttr(Decl *D, const AttributeCommonInfo &CI);
SwiftNameAttr *mergeSwiftNameAttr(Decl *D, const SwiftNameAttr &SNA,
                                  StringRef Name);
OptimizeNoneAttr *mergeOptimizeNoneAttr(Decl *D,
                                        const AttributeCommonInfo &CI);
InternalLinkageAttr *mergeInternalLinkageAttr(Decl *D, const ParsedAttr &AL);
InternalLinkageAttr *mergeInternalLinkageAttr(Decl *D,
                                              const InternalLinkageAttr &AL);
WebAssemblyImportNameAttr *mergeImportNameAttr(
    Decl *D, const WebAssemblyImportNameAttr &AL);
WebAssemblyImportModuleAttr *mergeImportModuleAttr(
    Decl *D, const WebAssemblyImportModuleAttr &AL);
EnforceTCBAttr *mergeEnforceTCBAttr(Decl *D, const EnforceTCBAttr &AL);
EnforceTCBLeafAttr *mergeEnforceTCBLeafAttr(Decl *D,
                                            const EnforceTCBLeafAttr &AL);
BTFDeclTagAttr *mergeBTFDeclTagAttr(Decl *D, const BTFDeclTagAttr &AL);
HLSLNumThreadsAttr *mergeHLSLNumThreadsAttr(Decl *D,
                                            const AttributeCommonInfo &AL,
                                            int X, int Y, int Z);
HLSLShaderAttr *mergeHLSLShaderAttr(Decl *D, const AttributeCommonInfo &AL,
                                    HLSLShaderAttr::ShaderType ShaderType);

void mergeDeclAttributes(NamedDecl *New, Decl *Old,
                         AvailabilityMergeKind AMK = AMK_Redeclaration);
void MergeTypedefNameDecl(Scope *S, TypedefNameDecl *New,
                          LookupResult &OldDecls);
bool MergeFunctionDecl(FunctionDecl *New, NamedDecl *&Old, Scope *S,
                       bool MergeTypeWithOld, bool NewDeclIsDefn);
bool MergeCompatibleFunctionDecls(FunctionDecl *New, FunctionDecl *Old,
                                  Scope *S, bool MergeTypeWithOld);
void mergeObjCMethodDecls(ObjCMethodDecl *New, ObjCMethodDecl *Old);
void MergeVarDecl(VarDecl *New, LookupResult &Previous);
void MergeVarDeclTypes(VarDecl *New, VarDecl *Old, bool MergeTypeWithOld);
void MergeVarDeclExceptionSpecs(VarDecl *New, VarDecl *Old);
bool checkVarDeclRedefinition(VarDecl *OldDefn, VarDecl *NewDefn);
void notePreviousDefinition(const NamedDecl *Old, SourceLocation New);
bool MergeCXXFunctionDecl(FunctionDecl *New, FunctionDecl *Old, Scope *S);

// AssignmentAction - This is used by all the assignment diagnostic functions
// to represent what is actually causing the operation
enum AssignmentAction {
  AA_Assigning,
  AA_Passing,
  AA_Returning,
  AA_Converting,
  AA_Initializing,
  AA_Sending,
  AA_Casting,
  AA_Passing_CFAudited
};

/// C++ Overloading.
enum OverloadKind {
  /// This is a legitimate overload: the existing declarations are
  /// functions or function templates with different signatures.
  Ovl_Overload,

  /// This is not an overload because the signature exactly matches
  /// an existing declaration.
  Ovl_Match,

  /// This is not an overload because the lookup results contain a
  /// non-function.
  Ovl_NonFunction
};
OverloadKind CheckOverload(Scope *S,
                           FunctionDecl *New,
                           const LookupResult &OldDecls,
                           NamedDecl *&OldDecl,
                           bool UseMemberUsingDeclRules);
bool IsOverload(FunctionDecl *New, FunctionDecl *Old,
                bool UseMemberUsingDeclRules, bool ConsiderCudaAttrs = true,
                bool ConsiderRequiresClauses = true);

// Calculates whether the expression Constraint depends on an enclosing
// template, for the purposes of [temp.friend] p9.
// TemplateDepth is the 'depth' of the friend function, which is used to
// compare whether a declaration reference is referring to a containing
// template, or just the current friend function. A 'lower' TemplateDepth in
// the AST refers to a 'containing' template. As the constraint is
// uninstantiated, this is relative to the 'top' of the TU.
bool
ConstraintExpressionDependsOnEnclosingTemplate(const FunctionDecl *Friend,
                                               unsigned TemplateDepth,
                                               const Expr *Constraint);

// Calculates whether the friend function depends on an enclosing template for
// the purposes of [temp.friend] p9.
bool FriendConstraintsDependOnEnclosingTemplate(const FunctionDecl *FD);

// Calculates whether two constraint expressions are equal irrespective of a
// difference in 'depth'. This takes a pair of optional 'NamedDecl's 'Old' and
// 'New', which are the "source" of the constraint, since this is necessary
// for figuring out the relative 'depth' of the constraint. The depth of the
// 'primary template' and the 'instantiated from' templates aren't necessarily
// the same, such as a case when one is a 'friend' defined in a class.
bool AreConstraintExpressionsEqual(const NamedDecl *Old,
                                   const Expr *OldConstr,
                                   const NamedDecl *New,
                                   const Expr *NewConstr);

enum class AllowedExplicit {
  /// Allow no explicit functions to be used.
  None,
  /// Allow explicit conversion functions but not explicit constructors.
  Conversions,
  /// Allow both explicit conversion functions and explicit constructors.
  All
};

ImplicitConversionSequence
TryImplicitConversion(Expr *From, QualType ToType,
                      bool SuppressUserConversions,
                      AllowedExplicit AllowExplicit,
                      bool InOverloadResolution,
                      bool CStyle,
                      bool AllowObjCWritebackConversion);

bool IsIntegralPromotion(Expr *From, QualType FromType, QualType ToType);
bool IsFloatingPointPromotion(QualType FromType, QualType ToType);
bool IsComplexPromotion(QualType FromType, QualType ToType);
bool IsPointerConversion(Expr *From, QualType FromType, QualType ToType,
                         bool InOverloadResolution,
                         QualType& ConvertedType, bool &IncompatibleObjC);
bool isObjCPointerConversion(QualType FromType, QualType ToType,
                             QualType& ConvertedType, bool &IncompatibleObjC);
bool isObjCWritebackConversion(QualType FromType, QualType ToType,
                               QualType &ConvertedType);
bool IsBlockPointerConversion(QualType FromType, QualType ToType,
                              QualType& ConvertedType);
bool FunctionParamTypesAreEqual(const FunctionProtoType *OldType,
                                const FunctionProtoType *NewType,
                                unsigned *ArgPos = nullptr,
                                bool Reversed = false);
void HandleFunctionTypeMismatch(PartialDiagnostic &PDiag,
                                QualType FromType, QualType ToType);

void maybeExtendBlockObject(ExprResult &E);
CastKind PrepareCastToObjCObjectPointer(ExprResult &E);
bool CheckPointerConversion(Expr *From, QualType ToType,
                            CastKind &Kind,
                            CXXCastPath& BasePath,
                            bool IgnoreBaseAccess,
                            bool Diagnose = true);
bool IsMemberPointerConversion(Expr *From, QualType FromType, QualType ToType,
                               bool InOverloadResolution,
                               QualType &ConvertedType);
bool CheckMemberPointerConversion(Expr *From, QualType ToType,
                                  CastKind &Kind,
                                  CXXCastPath &BasePath,
                                  bool IgnoreBaseAccess);
bool IsQualificationConversion(QualType FromType, QualType ToType,
                               bool CStyle, bool &ObjCLifetimeConversion);
bool IsFunctionConversion(QualType FromType, QualType ToType,
                          QualType &ResultTy);
bool DiagnoseMultipleUserDefinedConversion(Expr *From, QualType ToType);
bool isSameOrCompatibleFunctionType(QualType Param, QualType Arg);

bool CanPerformAggregateInitializationForOverloadResolution(
    const InitializedEntity &Entity, InitListExpr *From);

bool IsStringInit(Expr *Init, const ArrayType *AT);

bool CanPerformCopyInitialization(const InitializedEntity &Entity,
                                  ExprResult Init);
ExprResult PerformCopyInitialization(const InitializedEntity &Entity,
                                     SourceLocation EqualLoc,
                                     ExprResult Init,
                                     bool TopLevelOfInitList = false,
                                     bool AllowExplicit = false);
ExprResult PerformObjectArgumentInitialization(Expr *From,
                                               NestedNameSpecifier *Qualifier,
                                               NamedDecl *FoundDecl,
                                               CXXMethodDecl *Method);

/// Check that the lifetime of the initializer (and its subobjects) is
/// sufficient for initializing the entity, and perform lifetime extension
/// (when permitted) if not.
void checkInitializerLifetime(const InitializedEntity &Entity, Expr *Init);

ExprResult PerformContextuallyConvertToBool(Expr *From);
ExprResult PerformContextuallyConvertToObjCPointer(Expr *From);

/// Contexts in which a converted constant expression is required.
enum CCEKind {
  CCEK_CaseValue,    ///< Expression in a case label.
  CCEK_Enumerator,   ///< Enumerator value with fixed underlying type.
  CCEK_TemplateArg,  ///< Value of a non-type template parameter.
  CCEK_ArrayBound,   ///< Array bound in array declarator or new-expression.
  CCEK_ExplicitBool, ///< Condition in an explicit(bool) specifier.
  CCEK_Noexcept      ///< Condition in a noexcept(bool) specifier.
};
ExprResult CheckConvertedConstantExpression(Expr *From, QualType T,
                                            llvm::APSInt &Value, CCEKind CCE);
ExprResult CheckConvertedConstantExpression(Expr *From, QualType T,
                                            APValue &Value, CCEKind CCE,
                                            NamedDecl *Dest = nullptr);

/// Abstract base class used to perform a contextual implicit
/// conversion from an expression to any type passing a filter.
class ContextualImplicitConverter {
public:
  bool Suppress;
  bool SuppressConversion;

  ContextualImplicitConverter(bool Suppress = false,
                              bool SuppressConversion = false)
      : Suppress(Suppress), SuppressConversion(SuppressConversion) {}

  /// Determine whether the specified type is a valid destination type
  /// for this conversion.
  virtual bool match(QualType T) = 0;

  /// Emits a diagnostic complaining that the expression does not have
  /// integral or enumeration type.
  virtual SemaDiagnosticBuilder
  diagnoseNoMatch(Sema &S, SourceLocation Loc, QualType T) = 0;

  /// Emits a diagnostic when the expression has incomplete class type.
  virtual SemaDiagnosticBuilder
  diagnoseIncomplete(Sema &S, SourceLocation Loc, QualType T) = 0;

  /// Emits a diagnostic when the only matching conversion function
  /// is explicit.
  virtual SemaDiagnosticBuilder diagnoseExplicitConv(
      Sema &S, SourceLocation Loc, QualType T, QualType ConvTy) = 0;

  /// Emits a note for the explicit conversion function.
  virtual SemaDiagnosticBuilder
  noteExplicitConv(Sema &S, CXXConversionDecl *Conv, QualType ConvTy) = 0;

  /// Emits a diagnostic when there are multiple possible conversion
  /// functions.
  virtual SemaDiagnosticBuilder
  diagnoseAmbiguous(Sema &S, SourceLocation Loc, QualType T) = 0;

  /// Emits a note for one of the candidate conversions.
  virtual SemaDiagnosticBuilder
  noteAmbiguous(Sema &S, CXXConversionDecl *Conv, QualType ConvTy) = 0;

  /// Emits a diagnostic when we picked a conversion function
  /// (for cases when we are not allowed to pick a conversion function).
  virtual SemaDiagnosticBuilder diagnoseConversion(
      Sema &S, SourceLocation Loc, QualType T, QualType ConvTy) = 0;

  virtual ~ContextualImplicitConverter() {}
};

class ICEConvertDiagnoser : public ContextualImplicitConverter {
  bool AllowScopedEnumerations;

public:
  ICEConvertDiagnoser(bool AllowScopedEnumerations,
                      bool Suppress, bool SuppressConversion)
      : ContextualImplicitConverter(Suppress, SuppressConversion),
        AllowScopedEnumerations(AllowScopedEnumerations) {}

  /// Match an integral or (possibly scoped) enumeration type.
  bool match(QualType T) override;

  SemaDiagnosticBuilder
  diagnoseNoMatch(Sema &S, SourceLocation Loc, QualType T) override {
    return diagnoseNotInt(S, Loc, T);
  }

  /// Emits a diagnostic complaining that the expression does not have
  /// integral or enumeration type.
  virtual SemaDiagnosticBuilder
  diagnoseNotInt(Sema &S, SourceLocation Loc, QualType T) = 0;
};

/// Perform a contextual implicit conversion.
ExprResult PerformContextualImplicitConversion(
    SourceLocation Loc, Expr *FromE, ContextualImplicitConverter &Converter);


enum ObjCSubscriptKind {
  OS_Array,
  OS_Dictionary,
  OS_Error
};
ObjCSubscriptKind CheckSubscriptingKind(Expr *FromE);

// Note that LK_String is intentionally after the other literals, as
// this is used for diagnostics logic.
enum ObjCLiteralKind {
  LK_Array,
  LK_Dictionary,
  LK_Numeric,
  LK_Boxed,
  LK_String,
  LK_Block,
  LK_None
};
ObjCLiteralKind CheckLiteralKind(Expr *FromE);

ExprResult PerformObjectMemberConversion(Expr *From,
                                         NestedNameSpecifier *Qualifier,
                                         NamedDecl *FoundDecl,
                                         NamedDecl *Member);

// Members have to be NamespaceDecl* or TranslationUnitDecl*.
// TODO: make this is a typesafe union.
typedef llvm::SmallSetVector<DeclContext   *, 16> AssociatedNamespaceSet;
typedef llvm::SmallSetVector<CXXRecordDecl *, 16> AssociatedClassSet;

using ADLCallKind = CallExpr::ADLCallKind;

void AddOverloadCandidate(
    FunctionDecl *Function, DeclAccessPair FoundDecl, ArrayRef<Expr *> Args,
    OverloadCandidateSet &CandidateSet, bool SuppressUserConversions = false,
    bool PartialOverloading = false, bool AllowExplicit = true,
    bool AllowExplicitConversion = false,
    ADLCallKind IsADLCandidate = ADLCallKind::NotADL,
    ConversionSequenceList EarlyConversions = std::nullopt,
    OverloadCandidateParamOrder PO = {});
void AddFunctionCandidates(const UnresolvedSetImpl &Functions,
                    ArrayRef<Expr *> Args,
                    OverloadCandidateSet &CandidateSet,
                    TemplateArgumentListInfo *ExplicitTemplateArgs = nullptr,
                    bool SuppressUserConversions = false,
                    bool PartialOverloading = false,
                    bool FirstArgumentIsBase = false);
void AddMethodCandidate(DeclAccessPair FoundDecl,
                        QualType ObjectType,
                        Expr::Classification ObjectClassification,
                        ArrayRef<Expr *> Args,
                        OverloadCandidateSet& CandidateSet,
                        bool SuppressUserConversion = false,
                        OverloadCandidateParamOrder PO = {});
void
AddMethodCandidate(CXXMethodDecl *Method, DeclAccessPair FoundDecl,
                   CXXRecordDecl *ActingContext, QualType ObjectType,
                   Expr::Classification ObjectClassification,
                   ArrayRef<Expr *> Args, OverloadCandidateSet &CandidateSet,
                   bool SuppressUserConversions = false,
                   bool PartialOverloading = false,
                   ConversionSequenceList EarlyConversions = std::nullopt,
                   OverloadCandidateParamOrder PO = {});
void AddMethodTemplateCandidate(FunctionTemplateDecl *MethodTmpl,
                                DeclAccessPair FoundDecl,
                                CXXRecordDecl *ActingContext,
                               TemplateArgumentListInfo *ExplicitTemplateArgs,
                                QualType ObjectType,
                                Expr::Classification ObjectClassification,
                                ArrayRef<Expr *> Args,
                                OverloadCandidateSet& CandidateSet,
                                bool SuppressUserConversions = false,
                                bool PartialOverloading = false,
                                OverloadCandidateParamOrder PO = {});
void AddTemplateOverloadCandidate(
    FunctionTemplateDecl *FunctionTemplate, DeclAccessPair FoundDecl,
    TemplateArgumentListInfo *ExplicitTemplateArgs, ArrayRef<Expr *> Args,
    OverloadCandidateSet &CandidateSet, bool SuppressUserConversions = false,
    bool PartialOverloading = false, bool AllowExplicit = true,
    ADLCallKind IsADLCandidate = ADLCallKind::NotADL,
    OverloadCandidateParamOrder PO = {});
bool CheckNonDependentConversions(
    FunctionTemplateDecl *FunctionTemplate, ArrayRef<QualType> ParamTypes,
    ArrayRef<Expr *> Args, OverloadCandidateSet &CandidateSet,
    ConversionSequenceList &Conversions, bool SuppressUserConversions,
    CXXRecordDecl *ActingContext = nullptr, QualType ObjectType = QualType(),
    Expr::Classification ObjectClassification = {},
    OverloadCandidateParamOrder PO = {});
void AddConversionCandidate(
    CXXConversionDecl *Conversion, DeclAccessPair FoundDecl,
    CXXRecordDecl *ActingContext, Expr *From, QualType ToType,
    OverloadCandidateSet &CandidateSet, bool AllowObjCConversionOnExplicit,
    bool AllowExplicit, bool AllowResultConversion = true);
void AddTemplateConversionCandidate(
    FunctionTemplateDecl *FunctionTemplate, DeclAccessPair FoundDecl,
    CXXRecordDecl *ActingContext, Expr *From, QualType ToType,
    OverloadCandidateSet &CandidateSet, bool AllowObjCConversionOnExplicit,
    bool AllowExplicit, bool AllowResultConversion = true);
void AddSurrogateCandidate(CXXConversionDecl *Conversion,
                           DeclAccessPair FoundDecl,
                           CXXRecordDecl *ActingContext,
                           const FunctionProtoType *Proto,
                           Expr *Object, ArrayRef<Expr *> Args,
                           OverloadCandidateSet& CandidateSet);
void AddNonMemberOperatorCandidates(
    const UnresolvedSetImpl &Functions, ArrayRef<Expr *> Args,
    OverloadCandidateSet &CandidateSet,
    TemplateArgumentListInfo *ExplicitTemplateArgs = nullptr);
void AddMemberOperatorCandidates(OverloadedOperatorKind Op,
                                 SourceLocation OpLoc, ArrayRef<Expr *> Args,
                                 OverloadCandidateSet &CandidateSet,
                                 OverloadCandidateParamOrder PO = {});
void AddBuiltinCandidate(QualType *ParamTys, ArrayRef<Expr *> Args,
                         OverloadCandidateSet& CandidateSet,
                         bool IsAssignmentOperator = false,
                         unsigned NumContextualBoolArguments = 0);
void AddBuiltinOperatorCandidates(OverloadedOperatorKind Op,
                                  SourceLocation OpLoc, ArrayRef<Expr *> Args,
                                  OverloadCandidateSet& CandidateSet);
void AddArgumentDependentLookupCandidates(DeclarationName Name,
                                          SourceLocation Loc,
                                          ArrayRef<Expr *> Args,
                              TemplateArgumentListInfo *ExplicitTemplateArgs,
                                          OverloadCandidateSet& CandidateSet,
                                          bool PartialOverloading = false);

// Emit as a 'note' the specific overload candidate
void NoteOverloadCandidate(
    const NamedDecl *Found, const FunctionDecl *Fn,
    OverloadCandidateRewriteKind RewriteKind = OverloadCandidateRewriteKind(),
    QualType DestType = QualType(), bool TakingAddress = false);

// Emit as a series of 'note's all template and non-templates identified by
// the expression Expr
void NoteAllOverloadCandidates(Expr *E, QualType DestType = QualType(),
                               bool TakingAddress = false);

/// Check the enable_if expressions on the given function. Returns the first
/// failing attribute, or NULL if they were all successful.
EnableIfAttr *CheckEnableIf(FunctionDecl *Function, SourceLocation CallLoc,
                            ArrayRef<Expr *> Args,
                            bool MissingImplicitThis = false);

/// Find the failed Boolean condition within a given Boolean
/// constant expression, and describe it with a string.
std::pair<Expr *, std::string> findFailedBooleanCondition(Expr *Cond);

/// Emit diagnostics for the diagnose_if attributes on Function, ignoring any
/// non-ArgDependent DiagnoseIfAttrs.
///
/// Argument-dependent diagnose_if attributes should be checked each time a
/// function is used as a direct callee of a function call.
///
/// Returns true if any errors were emitted.
bool diagnoseArgDependentDiagnoseIfAttrs(const FunctionDecl *Function,
                                         const Expr *ThisArg,
                                         ArrayRef<const Expr *> Args,
                                         SourceLocation Loc);

/// Emit diagnostics for the diagnose_if attributes on Function, ignoring any
/// ArgDependent DiagnoseIfAttrs.
///
/// Argument-independent diagnose_if attributes should be checked on every use
/// of a function.
///
/// Returns true if any errors were emitted.
bool diagnoseArgIndependentDiagnoseIfAttrs(const NamedDecl *ND,
                                           SourceLocation Loc);

/// Returns whether the given function's address can be taken or not,
/// optionally emitting a diagnostic if the address can't be taken.
///
/// Returns false if taking the address of the function is illegal.
bool checkAddressOfFunctionIsAvailable(const FunctionDecl *Function,
                                       bool Complain = false,
                                       SourceLocation Loc = SourceLocation());

// [PossiblyAFunctionType]  -->   [Return]
// NonFunctionType --> NonFunctionType
// R (A) --> R(A)
// R (*)(A) --> R (A)
// R (&)(A) --> R (A)
// R (S::*)(A) --> R (A)
QualType ExtractUnqualifiedFunctionType(QualType PossiblyAFunctionType);

FunctionDecl *
ResolveAddressOfOverloadedFunction(Expr *AddressOfExpr,
                                   QualType TargetType,
                                   bool Complain,
                                   DeclAccessPair &Found,
                                   bool *pHadMultipleCandidates = nullptr);

FunctionDecl *
resolveAddressOfSingleOverloadCandidate(Expr *E, DeclAccessPair &FoundResult);

bool resolveAndFixAddressOfSingleOverloadCandidate(
    ExprResult &SrcExpr, bool DoFunctionPointerConversion = false);

FunctionDecl *
ResolveSingleFunctionTemplateSpecialization(OverloadExpr *ovl,
                                            bool Complain = false,
                                            DeclAccessPair *Found = nullptr);

bool ResolveAndFixSingleFunctionTemplateSpecialization(
    ExprResult &SrcExpr, bool DoFunctionPointerConversion = false,
    bool Complain = false, SourceRange OpRangeForComplaining = SourceRange(),
    QualType DestTypeForComplaining = QualType(),
    unsigned DiagIDForComplaining = 0);

Expr *FixOverloadedFunctionReference(Expr *E,
                                     DeclAccessPair FoundDecl,
                                     FunctionDecl *Fn);
ExprResult FixOverloadedFunctionReference(ExprResult,
                                          DeclAccessPair FoundDecl,
                                          FunctionDecl *Fn);

void AddOverloadedCallCandidates(UnresolvedLookupExpr *ULE,
                                 ArrayRef<Expr *> Args,
                                 OverloadCandidateSet &CandidateSet,
                                 bool PartialOverloading = false);
void AddOverloadedCallCandidates(
    LookupResult &R, TemplateArgumentListInfo *ExplicitTemplateArgs,
    ArrayRef<Expr *> Args, OverloadCandidateSet &CandidateSet);

// An enum used to represent the different possible results of building a
// range-based for loop.
enum ForRangeStatus {
  FRS_Success,
  FRS_NoViableFunction,
  FRS_DiagnosticIssued
};

ForRangeStatus BuildForRangeBeginEndCall(SourceLocation Loc,
                                         SourceLocation RangeLoc,
                                         const DeclarationNameInfo &NameInfo,
                                         LookupResult &MemberLookup,
                                         OverloadCandidateSet *CandidateSet,
                                         Expr *Range, ExprResult *CallExpr);

ExprResult BuildOverloadedCallExpr(Scope *S, Expr *Fn,
                                   UnresolvedLookupExpr *ULE,
                                   SourceLocation LParenLoc,
                                   MultiExprArg Args,
                                   SourceLocation RParenLoc,
                                   Expr *ExecConfig,
                                   bool AllowTypoCorrection=true,
                                   bool CalleesAddressIsTaken=false);

bool buildOverloadedCallSet(Scope *S, Expr *Fn, UnresolvedLookupExpr *ULE,
                            MultiExprArg Args, SourceLocation RParenLoc,
                            OverloadCandidateSet *CandidateSet,
                            ExprResult *Result);

ExprResult CreateUnresolvedLookupExpr(CXXRecordDecl *NamingClass,
                                      NestedNameSpecifierLoc NNSLoc,
                                      DeclarationNameInfo DNI,
                                      const UnresolvedSetImpl &Fns,
                                      bool PerformADL = true);

ExprResult CreateOverloadedUnaryOp(SourceLocation OpLoc,
                                   UnaryOperatorKind Opc,
                                   const UnresolvedSetImpl &Fns,
                                   Expr *input, bool RequiresADL = true);

void LookupOverloadedBinOp(OverloadCandidateSet &CandidateSet,
                           OverloadedOperatorKind Op,
                           const UnresolvedSetImpl &Fns,
                           ArrayRef<Expr *> Args, bool RequiresADL = true);
ExprResult CreateOverloadedBinOp(SourceLocation OpLoc,
                                 BinaryOperatorKind Opc,
                                 const UnresolvedSetImpl &Fns,
                                 Expr *LHS, Expr *RHS,
                                 bool RequiresADL = true,
                                 bool AllowRewrittenCandidates = true,
                                 FunctionDecl *DefaultedFn = nullptr);
ExprResult BuildSynthesizedThreeWayComparison(SourceLocation OpLoc,
                                              const UnresolvedSetImpl &Fns,
                                              Expr *LHS, Expr *RHS,
                                              FunctionDecl *DefaultedFn);

ExprResult CreateOverloadedArraySubscriptExpr(SourceLocation LLoc,
                                              SourceLocation RLoc, Expr *Base,
                                              MultiExprArg Args);

ExprResult BuildCallToMemberFunction(Scope *S, Expr *MemExpr,
                                     SourceLocation LParenLoc,
                                     MultiExprArg Args,
                                     SourceLocation RParenLoc,
                                     Expr *ExecConfig = nullptr,
                                     bool IsExecConfig = false,
                                     bool AllowRecovery = false);
ExprResult
BuildCallToObjectOfClassType(Scope *S, Expr *Object, SourceLocation LParenLoc,
                             MultiExprArg Args,
                             SourceLocation RParenLoc);

ExprResult BuildOverloadedArrowExpr(Scope *S, Expr *Base,
                                    SourceLocation OpLoc,
                                    bool *NoArrowOperatorFound = nullptr);

/// CheckCallReturnType - Checks that a call expression's return type is
/// complete. Returns true on failure. The location passed in is the location
/// that best represents the call.
bool CheckCallReturnType(QualType ReturnType, SourceLocation Loc,
                         CallExpr *CE, FunctionDecl *FD);

/// Helpers for dealing with blocks and functions.
bool CheckParmsForFunctionDef(ArrayRef<ParmVarDecl *> Parameters,
                              bool CheckParameterNames);
void CheckCXXDefaultArguments(FunctionDecl *FD);
void CheckExtraCXXDefaultArguments(Declarator &D);
Scope *getNonFieldDeclScope(Scope *S);

/// \name Name lookup
///
/// These routines provide name lookup that is used during semantic
/// analysis to resolve the various kinds of names (identifiers,
/// overloaded operator names, constructor names, etc.) into zero or
/// more declarations within a particular scope. The major entry
/// points are LookupName, which performs unqualified name lookup,
/// and LookupQualifiedName, which performs qualified name lookup.
///
/// All name lookup is performed based on some specific criteria,
/// which specify what names will be visible to name lookup and how
/// far name lookup should work. These criteria are important both
/// for capturing language semantics (certain lookups will ignore
/// certain names, for example) and for performance, since name
/// lookup is often a bottleneck in the compilation of C++. Name
/// lookup criteria is specified via the LookupCriteria enumeration.
///
/// The results of name lookup can vary based on the kind of name
/// lookup performed, the current language, and the translation
/// unit. In C, for example, name lookup will either return nothing
/// (no entity found) or a single declaration. In C++, name lookup
/// can additionally refer to a set of overloaded functions or
/// result in an ambiguity. All of the possible results of name
/// lookup are captured by the LookupResult class, which provides
/// the ability to distinguish among them.
//@{

/// Describes the kind of name lookup to perform.
enum LookupNameKind {
  /// Ordinary name lookup, which finds ordinary names (functions,
  /// variables, typedefs, etc.) in C and most kinds of names
  /// (functions, variables, members, types, etc.) in C++.
  LookupOrdinaryName = 0,
  /// Tag name lookup, which finds the names of enums, classes,
  /// structs, and unions.
  LookupTagName,
  /// Label name lookup.
  LookupLabel,
  /// Member name lookup, which finds the names of
  /// class/struct/union members.
  LookupMemberName,
  /// Look up of an operator name (e.g., operator+) for use with
  /// operator overloading. This lookup is similar to ordinary name
  /// lookup, but will ignore any declarations that are class members.
  LookupOperatorName,
  /// Look up a name following ~ in a destructor name. This is an ordinary
  /// lookup, but prefers tags to typedefs.
  LookupDestructorName,
  /// Look up of a name that precedes the '::' scope resolution
  /// operator in C++. This lookup completely ignores operator, object,
  /// function, and enumerator names (C++ [basic.lookup.qual]p1).
  LookupNestedNameSpecifierName,
  /// Look up a namespace name within a C++ using directive or
  /// namespace alias definition, ignoring non-namespace names (C++
  /// [basic.lookup.udir]p1).
  LookupNamespaceName,
  /// Look up all declarations in a scope with the given name,
  /// including resolved using declarations.  This is appropriate
  /// for checking redeclarations for a using declaration.
  LookupUsingDeclName,
  /// Look up an ordinary name that is going to be redeclared as a
  /// name with linkage. This lookup ignores any declarations that
  /// are outside of the current scope unless they have linkage. See
  /// C99 6.2.2p4-5 and C++ [basic.link]p6.
  LookupRedeclarationWithLinkage,
  /// Look up a friend of a local class. This lookup does not look
  /// outside the innermost non-class scope. See C++11 [class.friend]p11.
  LookupLocalFriendName,
  /// Look up the name of an Objective-C protocol.
  LookupObjCProtocolName,
  /// Look up implicit 'self' parameter of an objective-c method.
  LookupObjCImplicitSelfParam,
  /// Look up the name of an OpenMP user-defined reduction operation.
  LookupOMPReductionName,
  /// Look up the name of an OpenMP user-defined mapper.
  LookupOMPMapperName,
  /// Look up any declaration with any name.
  LookupAnyName
};

/// Specifies whether (or how) name lookup is being performed for a
/// redeclaration (vs. a reference).
enum RedeclarationKind {
  /// The lookup is a reference to this name that is not for the
  /// purpose of redeclaring the name.
  NotForRedeclaration = 0,
  /// The lookup results will be used for redeclaration of a name,
  /// if an entity by that name already exists and is visible.
  ForVisibleRedeclaration,
  /// The lookup results will be used for redeclaration of a name
  /// with external linkage; non-visible lookup results with external linkage
  /// may also be found.
  ForExternalRedeclaration
};

RedeclarationKind forRedeclarationInCurContext() const {
  // A declaration with an owning module for linkage can never link against
  // anything that is not visible. We don't need to check linkage here; if
  // the context has internal linkage, redeclaration lookup won't find things
  // from other TUs, and we can't safely compute linkage yet in general.
  if (cast<Decl>(CurContext)
          ->getOwningModuleForLinkage(/*IgnoreLinkage*/true))
    return ForVisibleRedeclaration;
  return ForExternalRedeclaration;
}

/// The possible outcomes of name lookup for a literal operator.
enum LiteralOperatorLookupResult {
  /// The lookup resulted in an error.
  LOLR_Error,
  /// The lookup found no match but no diagnostic was issued.
  LOLR_ErrorNoDiagnostic,
  /// The lookup found a single 'cooked' literal operator, which
  /// expects a normal literal to be built and passed to it.
  LOLR_Cooked,
  /// The lookup found a single 'raw' literal operator, which expects
  /// a string literal containing the spelling of the literal token.
  LOLR_Raw,
  /// The lookup found an overload set of literal operator templates,
  /// which expect the characters of the spelling of the literal token to be
  /// passed as a non-type template argument pack.
  LOLR_Template,
  /// The lookup found an overload set of literal operator templates,
  /// which expect the character type and characters of the spelling of the
  /// string literal token to be passed as template arguments.
  LOLR_StringTemplatePack,
};

SpecialMemberOverloadResult LookupSpecialMember(CXXRecordDecl *D,
                                                CXXSpecialMember SM,
                                                bool ConstArg,
                                                bool VolatileArg,
                                                bool RValueThis,
                                                bool ConstThis,
                                                bool VolatileThis);

typedef std::function<void(const TypoCorrection &)> TypoDiagnosticGenerator;
typedef std::function<ExprResult(Sema &, TypoExpr *, TypoCorrection)>
    TypoRecoveryCallback;

4405private:
bool CppLookupName(LookupResult &R, Scope *S);

struct TypoExprState {
  std::unique_ptr<TypoCorrectionConsumer> Consumer;
  TypoDiagnosticGenerator DiagHandler;
  TypoRecoveryCallback RecoveryHandler;
  TypoExprState();
  TypoExprState(TypoExprState &&other) noexcept;
  TypoExprState &operator=(TypoExprState &&other) noexcept;
};

/// The set of unhandled TypoExprs and their associated state.
llvm::MapVector<TypoExpr *, TypoExprState> DelayedTypos;

/// Creates a new TypoExpr AST node.
TypoExpr *createDelayedTypo(std::unique_ptr<TypoCorrectionConsumer> TCC,
                            TypoDiagnosticGenerator TDG,
                            TypoRecoveryCallback TRC, SourceLocation TypoLoc);

// The set of known/encountered (unique, canonicalized) NamespaceDecls.
//
// The boolean value will be true to indicate that the namespace was loaded
// from an AST/PCH file, or false otherwise.
llvm::MapVector<NamespaceDecl*, bool> KnownNamespaces;

/// Whether we have already loaded known namespaces from an extenal
/// source.
bool LoadedExternalKnownNamespaces;

/// Helper for CorrectTypo and CorrectTypoDelayed used to create and
/// populate a new TypoCorrectionConsumer. Returns nullptr if typo correction
/// should be skipped entirely.
std::unique_ptr<TypoCorrectionConsumer>
makeTypoCorrectionConsumer(const DeclarationNameInfo &Typo,
                           Sema::LookupNameKind LookupKind, Scope *S,
                           CXXScopeSpec *SS,
                           CorrectionCandidateCallback &CCC,
                           DeclContext *MemberContext, bool EnteringContext,
                           const ObjCObjectPointerType *OPT,
                           bool ErrorRecovery);

4447public:
const TypoExprState &getTypoExprState(TypoExpr *TE) const;

/// Clears the state of the given TypoExpr.
void clearDelayedTypo(TypoExpr *TE);

/// Look up a name, looking for a single declaration.  Return
/// null if the results were absent, ambiguous, or overloaded.
///
/// It is preferable to use the elaborated form and explicitly handle
/// ambiguity and overloaded.
NamedDecl *LookupSingleName(Scope *S, DeclarationName Name,
                            SourceLocation Loc,
                            LookupNameKind NameKind,
                            RedeclarationKind Redecl
                              = NotForRedeclaration);
bool LookupBuiltin(LookupResult &R);
void LookupNecessaryTypesForBuiltin(Scope *S, unsigned ID);
bool LookupName(LookupResult &R, Scope *S, bool AllowBuiltinCreation = false,
                bool ForceNoCPlusPlus = false);
bool LookupQualifiedName(LookupResult &R, DeclContext *LookupCtx,
                         bool InUnqualifiedLookup = false);
bool LookupQualifiedName(LookupResult &R, DeclContext *LookupCtx,
                         CXXScopeSpec &SS);
bool LookupParsedName(LookupResult &R, Scope *S, CXXScopeSpec *SS,
                      bool AllowBuiltinCreation = false,
                      bool EnteringContext = false);
ObjCProtocolDecl *LookupProtocol(IdentifierInfo *II, SourceLocation IdLoc,
                                 RedeclarationKind Redecl
                                   = NotForRedeclaration);
bool LookupInSuper(LookupResult &R, CXXRecordDecl *Class);

void LookupOverloadedOperatorName(OverloadedOperatorKind Op, Scope *S,
                                  UnresolvedSetImpl &Functions);

LabelDecl *LookupOrCreateLabel(IdentifierInfo *II, SourceLocation IdentLoc,
                               SourceLocation GnuLabelLoc = SourceLocation());

DeclContextLookupResult LookupConstructors(CXXRecordDecl *Class);
CXXConstructorDecl *LookupDefaultConstructor(CXXRecordDecl *Class);
CXXConstructorDecl *LookupCopyingConstructor(CXXRecordDecl *Class,
                                             unsigned Quals);
CXXMethodDecl *LookupCopyingAssignment(CXXRecordDecl *Class, unsigned Quals,
                                       bool RValueThis, unsigned ThisQuals);
CXXConstructorDecl *LookupMovingConstructor(CXXRecordDecl *Class,
                                            unsigned Quals);
CXXMethodDecl *LookupMovingAssignment(CXXRecordDecl *Class, unsigned Quals,
                                      bool RValueThis, unsigned ThisQuals);
CXXDestructorDecl *LookupDestructor(CXXRecordDecl *Class);

bool checkLiteralOperatorId(const CXXScopeSpec &SS, const UnqualifiedId &Id,
                            bool IsUDSuffix);
LiteralOperatorLookupResult
LookupLiteralOperator(Scope *S, LookupResult &R, ArrayRef<QualType> ArgTys,
                      bool AllowRaw, bool AllowTemplate,
                      bool AllowStringTemplate, bool DiagnoseMissing,
                      StringLiteral *StringLit = nullptr);
bool isKnownName(StringRef name);

/// Status of the function emission on the CUDA/HIP/OpenMP host/device attrs.
enum class FunctionEmissionStatus {
  Emitted,
  CUDADiscarded,     // Discarded due to CUDA/HIP hostness
  OMPDiscarded,      // Discarded due to OpenMP hostness
  TemplateDiscarded, // Discarded due to uninstantiated templates
  Unknown,
};
FunctionEmissionStatus getEmissionStatus(const FunctionDecl *Decl,
                                         bool Final = false);

// Whether the callee should be ignored in CUDA/HIP/OpenMP host/device check.
bool shouldIgnoreInHostDeviceCheck(FunctionDecl *Callee);

void ArgumentDependentLookup(DeclarationName Name, SourceLocation Loc,
                             ArrayRef<Expr *> Args, ADLResult &Functions);

void LookupVisibleDecls(Scope *S, LookupNameKind Kind,
                        VisibleDeclConsumer &Consumer,
                        bool IncludeGlobalScope = true,
                        bool LoadExternal = true);
void LookupVisibleDecls(DeclContext *Ctx, LookupNameKind Kind,
                        VisibleDeclConsumer &Consumer,
                        bool IncludeGlobalScope = true,
                        bool IncludeDependentBases = false,
                        bool LoadExternal = true);

enum CorrectTypoKind {
  CTK_NonError,     // CorrectTypo used in a non error recovery situation.
  CTK_ErrorRecovery // CorrectTypo used in normal error recovery.
};

TypoCorrection CorrectTypo(const DeclarationNameInfo &Typo,
                           Sema::LookupNameKind LookupKind,
                           Scope *S, CXXScopeSpec *SS,
                           CorrectionCandidateCallback &CCC,
                           CorrectTypoKind Mode,
                           DeclContext *MemberContext = nullptr,
                           bool EnteringContext = false,
                           const ObjCObjectPointerType *OPT = nullptr,
                           bool RecordFailure = true);

TypoExpr *CorrectTypoDelayed(const DeclarationNameInfo &Typo,
                             Sema::LookupNameKind LookupKind, Scope *S,
                             CXXScopeSpec *SS,
                             CorrectionCandidateCallback &CCC,
                             TypoDiagnosticGenerator TDG,
                             TypoRecoveryCallback TRC, CorrectTypoKind Mode,
                             DeclContext *MemberContext = nullptr,
                             bool EnteringContext = false,
                             const ObjCObjectPointerType *OPT = nullptr);

/// Process any TypoExprs in the given Expr and its children,
/// generating diagnostics as appropriate and returning a new Expr if there
/// were typos that were all successfully corrected and ExprError if one or
/// more typos could not be corrected.
///
/// \param E The Expr to check for TypoExprs.
///
/// \param InitDecl A VarDecl to avoid because the Expr being corrected is its
/// initializer.
///
/// \param RecoverUncorrectedTypos If true, when typo correction fails, it
/// will rebuild the given Expr with all TypoExprs degraded to RecoveryExprs.
///
/// \param Filter A function applied to a newly rebuilt Expr to determine if
/// it is an acceptable/usable result from a single combination of typo
/// corrections. As long as the filter returns ExprError, different
/// combinations of corrections will be tried until all are exhausted.
ExprResult CorrectDelayedTyposInExpr(
    Expr *E, VarDecl *InitDecl = nullptr,
    bool RecoverUncorrectedTypos = false,
    llvm::function_ref<ExprResult(Expr *)> Filter =
        [](Expr *E) -> ExprResult { return E; });

ExprResult CorrectDelayedTyposInExpr(
    ExprResult ER, VarDecl *InitDecl = nullptr,
    bool RecoverUncorrectedTypos = false,
    llvm::function_ref<ExprResult(Expr *)> Filter =
        [](Expr *E) -> ExprResult { return E; }) {
  return ER.isInvalid()
             ? ER
             : CorrectDelayedTyposInExpr(ER.get(), InitDecl,
                                         RecoverUncorrectedTypos, Filter);
}

void diagnoseTypo(const TypoCorrection &Correction,
                  const PartialDiagnostic &TypoDiag,
                  bool ErrorRecovery = true);

void diagnoseTypo(const TypoCorrection &Correction,
                  const PartialDiagnostic &TypoDiag,
                  const PartialDiagnostic &PrevNote,
                  bool ErrorRecovery = true);

void MarkTypoCorrectedFunctionDefinition(const NamedDecl *F);

void FindAssociatedClassesAndNamespaces(SourceLocation InstantiationLoc,
                                        ArrayRef<Expr *> Args,
                                 AssociatedNamespaceSet &AssociatedNamespaces,
                                 AssociatedClassSet &AssociatedClasses);

void FilterLookupForScope(LookupResult &R, DeclContext *Ctx, Scope *S,
                          bool ConsiderLinkage, bool AllowInlineNamespace);

bool CheckRedeclarationModuleOwnership(NamedDecl *New, NamedDecl *Old);
bool CheckRedeclarationExported(NamedDecl *New, NamedDecl *Old);
bool CheckRedeclarationInModule(NamedDecl *New, NamedDecl *Old);
bool IsRedefinitionInModule(const NamedDecl *New,
                               const NamedDecl *Old) const;

void DiagnoseAmbiguousLookup(LookupResult &Result);
//@}

/// Attempts to produce a RecoveryExpr after some AST node cannot be created.
ExprResult CreateRecoveryExpr(SourceLocation Begin, SourceLocation End,
                              ArrayRef<Expr *> SubExprs,
                              QualType T = QualType());

ObjCInterfaceDecl *getObjCInterfaceDecl(IdentifierInfo *&Id,
                                        SourceLocation IdLoc,
                                        bool TypoCorrection = false);
FunctionDecl *CreateBuiltin(IdentifierInfo *II, QualType Type, unsigned ID,
                            SourceLocation Loc);
NamedDecl *LazilyCreateBuiltin(IdentifierInfo *II, unsigned ID,
                               Scope *S, bool ForRedeclaration,
                               SourceLocation Loc);
NamedDecl *ImplicitlyDefineFunction(SourceLocation Loc, IdentifierInfo &II,
                                    Scope *S);
void AddKnownFunctionAttributesForReplaceableGlobalAllocationFunction(
    FunctionDecl *FD);
void AddKnownFunctionAttributes(FunctionDecl *FD);

// More parsing and symbol table subroutines.

void ProcessPragmaWeak(Scope *S, Decl *D);
// Decl attributes - this routine is the top level dispatcher.
void ProcessDeclAttributes(Scope *S, Decl *D, const Declarator &PD);
// Helper for delayed processing of attributes.
void ProcessDeclAttributeDelayed(Decl *D,
                                 const ParsedAttributesView &AttrList);

// Options for ProcessDeclAttributeList().
struct ProcessDeclAttributeOptions {
  ProcessDeclAttributeOptions()
      : IncludeCXX11Attributes(true), IgnoreTypeAttributes(false) {}

  ProcessDeclAttributeOptions WithIncludeCXX11Attributes(bool Val) {
    ProcessDeclAttributeOptions Result = *this;
    Result.IncludeCXX11Attributes = Val;
    return Result;
  }

  ProcessDeclAttributeOptions WithIgnoreTypeAttributes(bool Val) {
    ProcessDeclAttributeOptions Result = *this;
    Result.IgnoreTypeAttributes = Val;
    return Result;
  }

  // Should C++11 attributes be processed?
  bool IncludeCXX11Attributes;

  // Should any type attributes encountered be ignored?
  // If this option is false, a diagnostic will be emitted for any type
  // attributes of a kind that does not "slide" from the declaration to
  // the decl-specifier-seq.
  bool IgnoreTypeAttributes;
};

void ProcessDeclAttributeList(Scope *S, Decl *D,
                              const ParsedAttributesView &AttrList,
                              const ProcessDeclAttributeOptions &Options =
                                  ProcessDeclAttributeOptions());
bool ProcessAccessDeclAttributeList(AccessSpecDecl *ASDecl,
                                 const ParsedAttributesView &AttrList);

void checkUnusedDeclAttributes(Declarator &D);

/// Handles semantic checking for features that are common to all attributes,
/// such as checking whether a parameter was properly specified, or the
/// correct number of arguments were passed, etc. Returns true if the
/// attribute has been diagnosed.
bool checkCommonAttributeFeatures(const Decl *D, const ParsedAttr &A,
                                  bool SkipArgCountCheck = false);
bool checkCommonAttributeFeatures(const Stmt *S, const ParsedAttr &A,
                                  bool SkipArgCountCheck = false);

/// Determine if type T is a valid subject for a nonnull and similar
/// attributes. By default, we look through references (the behavior used by
/// nonnull), but if the second parameter is true, then we treat a reference
/// type as valid.
bool isValidPointerAttrType(QualType T, bool RefOkay = false);

bool CheckRegparmAttr(const ParsedAttr &attr, unsigned &value);
bool CheckCallingConvAttr(const ParsedAttr &attr, CallingConv &CC,
                          const FunctionDecl *FD = nullptr);
bool CheckAttrTarget(const ParsedAttr &CurrAttr);
bool CheckAttrNoArgs(const ParsedAttr &CurrAttr);
bool checkStringLiteralArgumentAttr(const AttributeCommonInfo &CI,
                                    const Expr *E, StringRef &Str,
                                    SourceLocation *ArgLocation = nullptr);
bool checkStringLiteralArgumentAttr(const ParsedAttr &Attr, unsigned ArgNum,
                                    StringRef &Str,
                                    SourceLocation *ArgLocation = nullptr);
llvm::Error isValidSectionSpecifier(StringRef Str);
bool checkSectionName(SourceLocation LiteralLoc, StringRef Str);
bool checkTargetAttr(SourceLocation LiteralLoc, StringRef Str);
bool checkTargetVersionAttr(SourceLocation LiteralLoc, StringRef &Str,
                            bool &isDefault);
bool
checkTargetClonesAttrString(SourceLocation LiteralLoc, StringRef Str,
                            const StringLiteral *Literal, bool &HasDefault,
                            bool &HasCommas, bool &HasNotDefault,
                            SmallVectorImpl<SmallString<64>> &StringsBuffer);
bool checkMSInheritanceAttrOnDefinition(
    CXXRecordDecl *RD, SourceRange Range, bool BestCase,
    MSInheritanceModel SemanticSpelling);

void CheckAlignasUnderalignment(Decl *D);

bool CheckNoInlineAttr(const Stmt *OrigSt, const Stmt *CurSt,
                       const AttributeCommonInfo &A);
bool CheckAlwaysInlineAttr(const Stmt *OrigSt, const Stmt *CurSt,
                           const AttributeCommonInfo &A);

/// Adjust the calling convention of a method to be the ABI default if it
/// wasn't specified explicitly.  This handles method types formed from
/// function type typedefs and typename template arguments.
void adjustMemberFunctionCC(QualType &T, bool IsStatic, bool IsCtorOrDtor,
                            SourceLocation Loc);

// Check if there is an explicit attribute, but only look through parens.
// The intent is to look for an attribute on the current declarator, but not
// one that came from a typedef.
bool hasExplicitCallingConv(QualType T);

/// Get the outermost AttributedType node that sets a calling convention.
/// Valid types should not have multiple attributes with different CCs.
const AttributedType *getCallingConvAttributedType(QualType T) const;

/// Process the attributes before creating an attributed statement. Returns
/// the semantic attributes that have been processed.
void ProcessStmtAttributes(Stmt *Stmt, const ParsedAttributes &InAttrs,
                           SmallVectorImpl<const Attr *> &OutAttrs);

void WarnConflictingTypedMethods(ObjCMethodDecl *Method,
                                 ObjCMethodDecl *MethodDecl,
                                 bool IsProtocolMethodDecl);

void CheckConflictingOverridingMethod(ObjCMethodDecl *Method,
                                 ObjCMethodDecl *Overridden,
                                 bool IsProtocolMethodDecl);

/// WarnExactTypedMethods - This routine issues a warning if method
/// implementation declaration matches exactly that of its declaration.
void WarnExactTypedMethods(ObjCMethodDecl *Method,
                           ObjCMethodDecl *MethodDecl,
                           bool IsProtocolMethodDecl);

typedef llvm::SmallPtrSet<Selector, 8> SelectorSet;

/// CheckImplementationIvars - This routine checks if the instance variables
/// listed in the implelementation match those listed in the interface.
void CheckImplementationIvars(ObjCImplementationDecl *ImpDecl,
                              ObjCIvarDecl **Fields, unsigned nIvars,
                              SourceLocation Loc);

/// ImplMethodsVsClassMethods - This is main routine to warn if any method
/// remains unimplemented in the class or category \@implementation.
void ImplMethodsVsClassMethods(Scope *S, ObjCImplDecl* IMPDecl,
                               ObjCContainerDecl* IDecl,
                               bool IncompleteImpl = false);

/// DiagnoseUnimplementedProperties - This routine warns on those properties
/// which must be implemented by this implementation.
void DiagnoseUnimplementedProperties(Scope *S, ObjCImplDecl* IMPDecl,
                                     ObjCContainerDecl *CDecl,
                                     bool SynthesizeProperties);

/// Diagnose any null-resettable synthesized setters.
void diagnoseNullResettableSynthesizedSetters(const ObjCImplDecl *impDecl);

/// DefaultSynthesizeProperties - This routine default synthesizes all
/// properties which must be synthesized in the class's \@implementation.
void DefaultSynthesizeProperties(Scope *S, ObjCImplDecl *IMPDecl,
                                 ObjCInterfaceDecl *IDecl,
                                 SourceLocation AtEnd);
void DefaultSynthesizeProperties(Scope *S, Decl *D, SourceLocation AtEnd);

/// IvarBacksCurrentMethodAccessor - This routine returns 'true' if 'IV' is
/// an ivar synthesized for 'Method' and 'Method' is a property accessor
/// declared in class 'IFace'.
bool IvarBacksCurrentMethodAccessor(ObjCInterfaceDecl *IFace,
                                    ObjCMethodDecl *Method, ObjCIvarDecl *IV);

/// DiagnoseUnusedBackingIvarInAccessor - Issue an 'unused' warning if ivar which
/// backs the property is not used in the property's accessor.
void DiagnoseUnusedBackingIvarInAccessor(Scope *S,
                                         const ObjCImplementationDecl *ImplD);

/// GetIvarBackingPropertyAccessor - If method is a property setter/getter and
/// it property has a backing ivar, returns this ivar; otherwise, returns NULL.
/// It also returns ivar's property on success.
ObjCIvarDecl *GetIvarBackingPropertyAccessor(const ObjCMethodDecl *Method,
                                             const ObjCPropertyDecl *&PDecl) const;

/// Called by ActOnProperty to handle \@property declarations in
/// class extensions.
ObjCPropertyDecl *HandlePropertyInClassExtension(Scope *S,
                    SourceLocation AtLoc,
                    SourceLocation LParenLoc,
                    FieldDeclarator &FD,
                    Selector GetterSel,
                    SourceLocation GetterNameLoc,
                    Selector SetterSel,
                    SourceLocation SetterNameLoc,
                    const bool isReadWrite,
                    unsigned &Attributes,
                    const unsigned AttributesAsWritten,
                    QualType T,
                    TypeSourceInfo *TSI,
                    tok::ObjCKeywordKind MethodImplKind);

/// Called by ActOnProperty and HandlePropertyInClassExtension to
/// handle creating the ObjcPropertyDecl for a category or \@interface.
ObjCPropertyDecl *CreatePropertyDecl(Scope *S,
                                     ObjCContainerDecl *CDecl,
                                     SourceLocation AtLoc,
                                     SourceLocation LParenLoc,
                                     FieldDeclarator &FD,
                                     Selector GetterSel,
                                     SourceLocation GetterNameLoc,
                                     Selector SetterSel,
                                     SourceLocation SetterNameLoc,
                                     const bool isReadWrite,
                                     const unsigned Attributes,
                                     const unsigned AttributesAsWritten,
                                     QualType T,
                                     TypeSourceInfo *TSI,
                                     tok::ObjCKeywordKind MethodImplKind,
                                     DeclContext *lexicalDC = nullptr);

/// AtomicPropertySetterGetterRules - This routine enforces the rule (via
/// warning) when atomic property has one but not the other user-declared
/// setter or getter.
void AtomicPropertySetterGetterRules(ObjCImplDecl* IMPDecl,
                                     ObjCInterfaceDecl* IDecl);

void DiagnoseOwningPropertyGetterSynthesis(const ObjCImplementationDecl *D);

void DiagnoseMissingDesignatedInitOverrides(
                                        const ObjCImplementationDecl *ImplD,
                                        const ObjCInterfaceDecl *IFD);

void DiagnoseDuplicateIvars(ObjCInterfaceDecl *ID, ObjCInterfaceDecl *SID);

enum MethodMatchStrategy {
  MMS_loose,
  MMS_strict
};

/// MatchTwoMethodDeclarations - Checks if two methods' type match and returns
/// true, or false, accordingly.
bool MatchTwoMethodDeclarations(const ObjCMethodDecl *Method,
                                const ObjCMethodDecl *PrevMethod,
                                MethodMatchStrategy strategy = MMS_strict);

/// MatchAllMethodDeclarations - Check methods declaraed in interface or
/// or protocol against those declared in their implementations.
void MatchAllMethodDeclarations(const SelectorSet &InsMap,
                                const SelectorSet &ClsMap,
                                SelectorSet &InsMapSeen,
                                SelectorSet &ClsMapSeen,
                                ObjCImplDecl* IMPDecl,
                                ObjCContainerDecl* IDecl,
                                bool &IncompleteImpl,
                                bool ImmediateClass,
                                bool WarnCategoryMethodImpl=false);

/// CheckCategoryVsClassMethodMatches - Checks that methods implemented in
/// category matches with those implemented in its primary class and
/// warns each time an exact match is found.
void CheckCategoryVsClassMethodMatches(ObjCCategoryImplDecl *CatIMP);

/// Add the given method to the list of globally-known methods.
void addMethodToGlobalList(ObjCMethodList *List, ObjCMethodDecl *Method);

/// Returns default addr space for method qualifiers.
LangAS getDefaultCXXMethodAddrSpace() const;

4896private:
/// AddMethodToGlobalPool - Add an instance or factory method to the global
/// pool. See descriptoin of AddInstanceMethodToGlobalPool.
void AddMethodToGlobalPool(ObjCMethodDecl *Method, bool impl, bool instance);

/// LookupMethodInGlobalPool - Returns the instance or factory method and
/// optionally warns if there are multiple signatures.
ObjCMethodDecl *LookupMethodInGlobalPool(Selector Sel, SourceRange R,
                                         bool receiverIdOrClass,
                                         bool instance);

4907public:
/// - Returns instance or factory methods in global method pool for
/// given selector. It checks the desired kind first, if none is found, and
/// parameter checkTheOther is set, it then checks the other kind. If no such
/// method or only one method is found, function returns false; otherwise, it
/// returns true.
bool
CollectMultipleMethodsInGlobalPool(Selector Sel,
                                   SmallVectorImpl<ObjCMethodDecl*>& Methods,
                                   bool InstanceFirst, bool CheckTheOther,
                                   const ObjCObjectType *TypeBound = nullptr);

bool
AreMultipleMethodsInGlobalPool(Selector Sel, ObjCMethodDecl *BestMethod,
                               SourceRange R, bool receiverIdOrClass,
                               SmallVectorImpl<ObjCMethodDecl*>& Methods);

void
DiagnoseMultipleMethodInGlobalPool(SmallVectorImpl<ObjCMethodDecl*> &Methods,
                                   Selector Sel, SourceRange R,
                                   bool receiverIdOrClass);

4929private:
/// - Returns a selector which best matches given argument list or
/// nullptr if none could be found
ObjCMethodDecl *SelectBestMethod(Selector Sel, MultiExprArg Args,
                                 bool IsInstance,
                                 SmallVectorImpl<ObjCMethodDecl*>& Methods);


/// Record the typo correction failure and return an empty correction.
TypoCorrection FailedCorrection(IdentifierInfo *Typo, SourceLocation TypoLoc,
                                bool RecordFailure = true) {
  if (RecordFailure)
    TypoCorrectionFailures[Typo].insert(TypoLoc);
  return TypoCorrection();
}

4945public:
/// AddInstanceMethodToGlobalPool - All instance methods in a translation
/// unit are added to a global pool. This allows us to efficiently associate
/// a selector with a method declaraation for purposes of typechecking
/// messages sent to "id" (where the class of the object is unknown).
void AddInstanceMethodToGlobalPool(ObjCMethodDecl *Method, bool impl=false) {
  AddMethodToGlobalPool(Method, impl, /*instance*/true);
}

/// AddFactoryMethodToGlobalPool - Same as above, but for factory methods.
void AddFactoryMethodToGlobalPool(ObjCMethodDecl *Method, bool impl=false) {
  AddMethodToGlobalPool(Method, impl, /*instance*/false);
}

/// AddAnyMethodToGlobalPool - Add any method, instance or factory to global
/// pool.
void AddAnyMethodToGlobalPool(Decl *D);

/// LookupInstanceMethodInGlobalPool - Returns the method and warns if
/// there are multiple signatures.
ObjCMethodDecl *LookupInstanceMethodInGlobalPool(Selector Sel, SourceRange R,
                                                 bool receiverIdOrClass=false) {
  return LookupMethodInGlobalPool(Sel, R, receiverIdOrClass,
                                  /*instance*/true);
}

/// LookupFactoryMethodInGlobalPool - Returns the method and warns if
/// there are multiple signatures.
ObjCMethodDecl *LookupFactoryMethodInGlobalPool(Selector Sel, SourceRange R,
                                                bool receiverIdOrClass=false) {
  return LookupMethodInGlobalPool(Sel, R, receiverIdOrClass,
                                  /*instance*/false);
}

const ObjCMethodDecl *SelectorsForTypoCorrection(Selector Sel,
                            QualType ObjectType=QualType());
/// LookupImplementedMethodInGlobalPool - Returns the method which has an
/// implementation.
ObjCMethodDecl *LookupImplementedMethodInGlobalPool(Selector Sel);

/// CollectIvarsToConstructOrDestruct - Collect those ivars which require
/// initialization.
void CollectIvarsToConstructOrDestruct(ObjCInterfaceDecl *OI,
                                SmallVectorImpl<ObjCIvarDecl*> &Ivars);

//===--------------------------------------------------------------------===//
// Statement Parsing Callbacks: SemaStmt.cpp.
4992public:
class FullExprArg {
public:
  FullExprArg() : E(nullptr) { }
  FullExprArg(Sema &actions) : E(nullptr) { }

  ExprResult release() {
    return E;
  }

  Expr *get() const { return E; }

  Expr *operator->() {
    return E;
  }

private:
  // FIXME: No need to make the entire Sema class a friend when it's just
  // Sema::MakeFullExpr that needs access to the constructor below.
  friend class Sema;

  explicit FullExprArg(Expr *expr) : E(expr) {}

  Expr *E;
};

FullExprArg MakeFullExpr(Expr *Arg) {
  return MakeFullExpr(Arg, Arg ? Arg->getExprLoc() : SourceLocation());
}
FullExprArg MakeFullExpr(Expr *Arg, SourceLocation CC) {
  return FullExprArg(
      ActOnFinishFullExpr(Arg, CC, /*DiscardedValue*/ false).get());
}
FullExprArg MakeFullDiscardedValueExpr(Expr *Arg) {
  ExprResult FE =
      ActOnFinishFullExpr(Arg, Arg ? Arg->getExprLoc() : SourceLocation(),
                          /*DiscardedValue*/ true);
  return FullExprArg(FE.get());
}

StmtResult ActOnExprStmt(ExprResult Arg, bool DiscardedValue = true);
StmtResult ActOnExprStmtError();

StmtResult ActOnNullStmt(SourceLocation SemiLoc,
                         bool HasLeadingEmptyMacro = false);

void ActOnStartOfCompoundStmt(bool IsStmtExpr);
void ActOnAfterCompoundStatementLeadingPragmas();
void ActOnFinishOfCompoundStmt();
StmtResult ActOnCompoundStmt(SourceLocation L, SourceLocation R,
                             ArrayRef<Stmt *> Elts, bool isStmtExpr);

/// A RAII object to enter scope of a compound statement.
class CompoundScopeRAII {
public:
  CompoundScopeRAII(Sema &S, bool IsStmtExpr = false) : S(S) {
    S.ActOnStartOfCompoundStmt(IsStmtExpr);
  }

  ~CompoundScopeRAII() {
    S.ActOnFinishOfCompoundStmt();
  }

private:
  Sema &S;
};

/// An RAII helper that pops function a function scope on exit.
struct FunctionScopeRAII {
  Sema &S;
  bool Active;
  FunctionScopeRAII(Sema &S) : S(S), Active(true) {}
  ~FunctionScopeRAII() {
    if (Active)
      S.PopFunctionScopeInfo();
  }
  void disable() { Active = false; }
};

StmtResult ActOnDeclStmt(DeclGroupPtrTy Decl,
                                 SourceLocation StartLoc,
                                 SourceLocation EndLoc);
void ActOnForEachDeclStmt(DeclGroupPtrTy Decl);
StmtResult ActOnForEachLValueExpr(Expr *E);
ExprResult ActOnCaseExpr(SourceLocation CaseLoc, ExprResult Val);
StmtResult ActOnCaseStmt(SourceLocation CaseLoc, ExprResult LHS,
                         SourceLocation DotDotDotLoc, ExprResult RHS,
                         SourceLocation ColonLoc);
void ActOnCaseStmtBody(Stmt *CaseStmt, Stmt *SubStmt);

StmtResult ActOnDefaultStmt(SourceLocation DefaultLoc,
                                    SourceLocation ColonLoc,
                                    Stmt *SubStmt, Scope *CurScope);
StmtResult ActOnLabelStmt(SourceLocation IdentLoc, LabelDecl *TheDecl,
                          SourceLocation ColonLoc, Stmt *SubStmt);

StmtResult BuildAttributedStmt(SourceLocation AttrsLoc,
                               ArrayRef<const Attr *> Attrs, Stmt *SubStmt);
StmtResult ActOnAttributedStmt(const ParsedAttributes &AttrList,
                               Stmt *SubStmt);

class ConditionResult;

StmtResult ActOnIfStmt(SourceLocation IfLoc, IfStatementKind StatementKind,
                       SourceLocation LParenLoc, Stmt *InitStmt,
                       ConditionResult Cond, SourceLocation RParenLoc,
                       Stmt *ThenVal, SourceLocation ElseLoc, Stmt *ElseVal);
StmtResult BuildIfStmt(SourceLocation IfLoc, IfStatementKind StatementKind,
                       SourceLocation LParenLoc, Stmt *InitStmt,
                       ConditionResult Cond, SourceLocation RParenLoc,
                       Stmt *ThenVal, SourceLocation ElseLoc, Stmt *ElseVal);
StmtResult ActOnStartOfSwitchStmt(SourceLocation SwitchLoc,
                                  SourceLocation LParenLoc, Stmt *InitStmt,
                                  ConditionResult Cond,
                                  SourceLocation RParenLoc);
StmtResult ActOnFinishSwitchStmt(SourceLocation SwitchLoc,
                                         Stmt *Switch, Stmt *Body);
StmtResult ActOnWhileStmt(SourceLocation WhileLoc, SourceLocation LParenLoc,
                          ConditionResult Cond, SourceLocation RParenLoc,
                          Stmt *Body);
StmtResult ActOnDoStmt(SourceLocation DoLoc, Stmt *Body,
                       SourceLocation WhileLoc, SourceLocation CondLParen,
                       Expr *Cond, SourceLocation CondRParen);

StmtResult ActOnForStmt(SourceLocation ForLoc,
                        SourceLocation LParenLoc,
                        Stmt *First,
                        ConditionResult Second,
                        FullExprArg Third,
                        SourceLocation RParenLoc,
                        Stmt *Body);
ExprResult CheckObjCForCollectionOperand(SourceLocation forLoc,
                                         Expr *collection);
StmtResult ActOnObjCForCollectionStmt(SourceLocation ForColLoc,
                                      Stmt *First, Expr *collection,
                                      SourceLocation RParenLoc);
StmtResult FinishObjCForCollectionStmt(Stmt *ForCollection, Stmt *Body);

enum BuildForRangeKind {
  /// Initial building of a for-range statement.
  BFRK_Build,
  /// Instantiation or recovery rebuild of a for-range statement. Don't
  /// attempt any typo-correction.
  BFRK_Rebuild,
  /// Determining whether a for-range statement could be built. Avoid any
  /// unnecessary or irreversible actions.
  BFRK_Check
};

StmtResult ActOnCXXForRangeStmt(Scope *S, SourceLocation ForLoc,
                                SourceLocation CoawaitLoc,
                                Stmt *InitStmt,
                                Stmt *LoopVar,
                                SourceLocation ColonLoc, Expr *Collection,
                                SourceLocation RParenLoc,
                                BuildForRangeKind Kind);
StmtResult BuildCXXForRangeStmt(SourceLocation ForLoc,
                                SourceLocation CoawaitLoc,
                                Stmt *InitStmt,
                                SourceLocation ColonLoc,
                                Stmt *RangeDecl, Stmt *Begin, Stmt *End,
                                Expr *Cond, Expr *Inc,
                                Stmt *LoopVarDecl,
                                SourceLocation RParenLoc,
                                BuildForRangeKind Kind);
StmtResult FinishCXXForRangeStmt(Stmt *ForRange, Stmt *Body);

StmtResult ActOnGotoStmt(SourceLocation GotoLoc,
                         SourceLocation LabelLoc,
                         LabelDecl *TheDecl);
StmtResult ActOnIndirectGotoStmt(SourceLocation GotoLoc,
                                 SourceLocation StarLoc,
                                 Expr *DestExp);
StmtResult ActOnContinueStmt(SourceLocation ContinueLoc, Scope *CurScope);
StmtResult ActOnBreakStmt(SourceLocation BreakLoc, Scope *CurScope);

void ActOnCapturedRegionStart(SourceLocation Loc, Scope *CurScope,
                              CapturedRegionKind Kind, unsigned NumParams);
typedef std::pair<StringRef, QualType> CapturedParamNameType;
void ActOnCapturedRegionStart(SourceLocation Loc, Scope *CurScope,
                              CapturedRegionKind Kind,
                              ArrayRef<CapturedParamNameType> Params,
                              unsigned OpenMPCaptureLevel = 0);
StmtResult ActOnCapturedRegionEnd(Stmt *S);
void ActOnCapturedRegionError();
RecordDecl *CreateCapturedStmtRecordDecl(CapturedDecl *&CD,
                                         SourceLocation Loc,
                                         unsigned NumParams);

struct NamedReturnInfo {
  const VarDecl *Candidate;

  enum Status : uint8_t { None, MoveEligible, MoveEligibleAndCopyElidable };
  Status S;

  bool isMoveEligible() const { return S != None; };
  bool isCopyElidable() const { return S == MoveEligibleAndCopyElidable; }
};
enum class SimplerImplicitMoveMode { ForceOff, Normal, ForceOn };
NamedReturnInfo getNamedReturnInfo(
    Expr *&E, SimplerImplicitMoveMode Mode = SimplerImplicitMoveMode::Normal);
NamedReturnInfo getNamedReturnInfo(const VarDecl *VD);
const VarDecl *getCopyElisionCandidate(NamedReturnInfo &Info,
                                       QualType ReturnType);

ExprResult
PerformMoveOrCopyInitialization(const InitializedEntity &Entity,
                                const NamedReturnInfo &NRInfo, Expr *Value,
                                bool SupressSimplerImplicitMoves = false);

StmtResult ActOnReturnStmt(SourceLocation ReturnLoc, Expr *RetValExp,
                           Scope *CurScope);
StmtResult BuildReturnStmt(SourceLocation ReturnLoc, Expr *RetValExp,
                           bool AllowRecovery = false);
StmtResult ActOnCapScopeReturnStmt(SourceLocation ReturnLoc, Expr *RetValExp,
                                   NamedReturnInfo &NRInfo,
                                   bool SupressSimplerImplicitMoves);

StmtResult ActOnGCCAsmStmt(SourceLocation AsmLoc, bool IsSimple,
                           bool IsVolatile, unsigned NumOutputs,
                           unsigned NumInputs, IdentifierInfo **Names,
                           MultiExprArg Constraints, MultiExprArg Exprs,
                           Expr *AsmString, MultiExprArg Clobbers,
                           unsigned NumLabels,
                           SourceLocation RParenLoc);

void FillInlineAsmIdentifierInfo(Expr *Res,
                                 llvm::InlineAsmIdentifierInfo &Info);
ExprResult LookupInlineAsmIdentifier(CXXScopeSpec &SS,
                                     SourceLocation TemplateKWLoc,
                                     UnqualifiedId &Id,
                                     bool IsUnevaluatedContext);
bool LookupInlineAsmField(StringRef Base, StringRef Member,
                          unsigned &Offset, SourceLocation AsmLoc);
ExprResult LookupInlineAsmVarDeclField(Expr *RefExpr, StringRef Member,
                                       SourceLocation AsmLoc);
StmtResult ActOnMSAsmStmt(SourceLocation AsmLoc, SourceLocation LBraceLoc,
                          ArrayRef<Token> AsmToks,
                          StringRef AsmString,
                          unsigned NumOutputs, unsigned NumInputs,
                          ArrayRef<StringRef> Constraints,
                          ArrayRef<StringRef> Clobbers,
                          ArrayRef<Expr*> Exprs,
                          SourceLocation EndLoc);
LabelDecl *GetOrCreateMSAsmLabel(StringRef ExternalLabelName,
                                 SourceLocation Location,
                                 bool AlwaysCreate);

VarDecl *BuildObjCExceptionDecl(TypeSourceInfo *TInfo, QualType ExceptionType,
                                SourceLocation StartLoc,
                                SourceLocation IdLoc, IdentifierInfo *Id,
                                bool Invalid = false);

Decl *ActOnObjCExceptionDecl(Scope *S, Declarator &D);

StmtResult ActOnObjCAtCatchStmt(SourceLocation AtLoc, SourceLocation RParen,
                                Decl *Parm, Stmt *Body);

StmtResult ActOnObjCAtFinallyStmt(SourceLocation AtLoc, Stmt *Body);

StmtResult ActOnObjCAtTryStmt(SourceLocation AtLoc, Stmt *Try,
                              MultiStmtArg Catch, Stmt *Finally);

StmtResult BuildObjCAtThrowStmt(SourceLocation AtLoc, Expr *Throw);
StmtResult ActOnObjCAtThrowStmt(SourceLocation AtLoc, Expr *Throw,
                                Scope *CurScope);
ExprResult ActOnObjCAtSynchronizedOperand(SourceLocation atLoc,
                                          Expr *operand);
StmtResult ActOnObjCAtSynchronizedStmt(SourceLocation AtLoc,
                                       Expr *SynchExpr,
                                       Stmt *SynchBody);

StmtResult ActOnObjCAutoreleasePoolStmt(SourceLocation AtLoc, Stmt *Body);

VarDecl *BuildExceptionDeclaration(Scope *S, TypeSourceInfo *TInfo,
                                   SourceLocation StartLoc,
                                   SourceLocation IdLoc,
                                   IdentifierInfo *Id);

Decl *ActOnExceptionDeclarator(Scope *S, Declarator &D);

StmtResult ActOnCXXCatchBlock(SourceLocation CatchLoc,
                              Decl *ExDecl, Stmt *HandlerBlock);
StmtResult ActOnCXXTryBlock(SourceLocation TryLoc, Stmt *TryBlock,
                            ArrayRef<Stmt *> Handlers);

StmtResult ActOnSEHTryBlock(bool IsCXXTry, // try (true) or __try (false) ?
                            SourceLocation TryLoc, Stmt *TryBlock,
                            Stmt *Handler);
StmtResult ActOnSEHExceptBlock(SourceLocation Loc,
                               Expr *FilterExpr,
                               Stmt *Block);
void ActOnStartSEHFinallyBlock();
void ActOnAbortSEHFinallyBlock();
StmtResult ActOnFinishSEHFinallyBlock(SourceLocation Loc, Stmt *Block);
StmtResult ActOnSEHLeaveStmt(SourceLocation Loc, Scope *CurScope);

void DiagnoseReturnInConstructorExceptionHandler(CXXTryStmt *TryBlock);

bool ShouldWarnIfUnusedFileScopedDecl(const DeclaratorDecl *D) const;

/// If it's a file scoped decl that must warn if not used, keep track
/// of it.
void MarkUnusedFileScopedDecl(const DeclaratorDecl *D);

typedef llvm::function_ref<void(SourceLocation Loc, PartialDiagnostic PD)>
    DiagReceiverTy;

/// DiagnoseUnusedExprResult - If the statement passed in is an expression
/// whose result is unused, warn.
void DiagnoseUnusedExprResult(const Stmt *S, unsigned DiagID);
void DiagnoseUnusedNestedTypedefs(const RecordDecl *D);
void DiagnoseUnusedNestedTypedefs(const RecordDecl *D,
                                  DiagReceiverTy DiagReceiver);
void DiagnoseUnusedDecl(const NamedDecl *ND);
void DiagnoseUnusedDecl(const NamedDecl *ND, DiagReceiverTy DiagReceiver);

/// If VD is set but not otherwise used, diagnose, for a parameter or a
/// variable.
void DiagnoseUnusedButSetDecl(const VarDecl *VD, DiagReceiverTy DiagReceiver);

/// Emit \p DiagID if statement located on \p StmtLoc has a suspicious null
/// statement as a \p Body, and it is located on the same line.
///
/// This helps prevent bugs due to typos, such as:
///     if (condition);
///       do_stuff();
void DiagnoseEmptyStmtBody(SourceLocation StmtLoc,
                           const Stmt *Body,
                           unsigned DiagID);

/// Warn if a for/while loop statement \p S, which is followed by
/// \p PossibleBody, has a suspicious null statement as a body.
void DiagnoseEmptyLoopBody(const Stmt *S,
                           const Stmt *PossibleBody);

/// Warn if a value is moved to itself.
void DiagnoseSelfMove(const Expr *LHSExpr, const Expr *RHSExpr,
                      SourceLocation OpLoc);

/// Returns a field in a CXXRecordDecl that has the same name as the decl \p
/// SelfAssigned when inside a CXXMethodDecl.
const FieldDecl *
getSelfAssignmentClassMemberCandidate(const ValueDecl *SelfAssigned);

/// Warn if we're implicitly casting from a _Nullable pointer type to a
/// _Nonnull one.
void diagnoseNullableToNonnullConversion(QualType DstType, QualType SrcType,
                                         SourceLocation Loc);

/// Warn when implicitly casting 0 to nullptr.
void diagnoseZeroToNullptrConversion(CastKind Kind, const Expr *E);

ParsingDeclState PushParsingDeclaration(sema::DelayedDiagnosticPool &pool) {
  return DelayedDiagnostics.push(pool);
}
void PopParsingDeclaration(ParsingDeclState state, Decl *decl);

typedef ProcessingContextState ParsingClassState;
ParsingClassState PushParsingClass() {
  ParsingClassDepth++;
  return DelayedDiagnostics.pushUndelayed();
}
void PopParsingClass(ParsingClassState state) {
  ParsingClassDepth--;
  DelayedDiagnostics.popUndelayed(state);
}

void redelayDiagnostics(sema::DelayedDiagnosticPool &pool);

void DiagnoseAvailabilityOfDecl(NamedDecl *D, ArrayRef<SourceLocation> Locs,
                                const ObjCInterfaceDecl *UnknownObjCClass,
                                bool ObjCPropertyAccess,
                                bool AvoidPartialAvailabilityChecks = false,
                                ObjCInterfaceDecl *ClassReceiver = nullptr);

bool makeUnavailableInSystemHeader(SourceLocation loc,
                                   UnavailableAttr::ImplicitReason reason);

/// Issue any -Wunguarded-availability warnings in \c FD
void DiagnoseUnguardedAvailabilityViolations(Decl *FD);

void handleDelayedAvailabilityCheck(sema::DelayedDiagnostic &DD, Decl *Ctx);

//===--------------------------------------------------------------------===//
// Expression Parsing Callbacks: SemaExpr.cpp.

bool CanUseDecl(NamedDecl *D, bool TreatUnavailableAsInvalid);
// A version of DiagnoseUseOfDecl that should be used if overload resolution
// has been used to find this declaration, which means we don't have to bother
// checking the trailing requires clause.
bool DiagnoseUseOfOverloadedDecl(NamedDecl *D, SourceLocation Loc) {
  return DiagnoseUseOfDecl(
      D, Loc, /*UnknownObjCClass=*/nullptr, /*ObjCPropertyAccess=*/false,
      /*AvoidPartialAvailabilityChecks=*/false, /*ClassReceiver=*/nullptr,
      /*SkipTrailingRequiresClause=*/true);
}

bool DiagnoseUseOfDecl(NamedDecl *D, ArrayRef<SourceLocation> Locs,
                       const ObjCInterfaceDecl *UnknownObjCClass = nullptr,
                       bool ObjCPropertyAccess = false,
                       bool AvoidPartialAvailabilityChecks = false,
                       ObjCInterfaceDecl *ClassReciever = nullptr,
                       bool SkipTrailingRequiresClause = false);
void NoteDeletedFunction(FunctionDecl *FD);
void NoteDeletedInheritingConstructor(CXXConstructorDecl *CD);
bool DiagnosePropertyAccessorMismatch(ObjCPropertyDecl *PD,
                                      ObjCMethodDecl *Getter,
                                      SourceLocation Loc);
void DiagnoseSentinelCalls(NamedDecl *D, SourceLocation Loc,
                           ArrayRef<Expr *> Args);

void PushExpressionEvaluationContext(
    ExpressionEvaluationContext NewContext, Decl *LambdaContextDecl = nullptr,
    ExpressionEvaluationContextRecord::ExpressionKind Type =
        ExpressionEvaluationContextRecord::EK_Other);
enum ReuseLambdaContextDecl_t { ReuseLambdaContextDecl };
void PushExpressionEvaluationContext(
    ExpressionEvaluationContext NewContext, ReuseLambdaContextDecl_t,
    ExpressionEvaluationContextRecord::ExpressionKind Type =
        ExpressionEvaluationContextRecord::EK_Other);
void PopExpressionEvaluationContext();

void DiscardCleanupsInEvaluationContext();

ExprResult TransformToPotentiallyEvaluated(Expr *E);
TypeSourceInfo *TransformToPotentiallyEvaluated(TypeSourceInfo *TInfo);
ExprResult HandleExprEvaluationContextForTypeof(Expr *E);

ExprResult CheckUnevaluatedOperand(Expr *E);
void CheckUnusedVolatileAssignment(Expr *E);

ExprResult ActOnConstantExpression(ExprResult Res);

// Functions for marking a declaration referenced.  These functions also
// contain the relevant logic for marking if a reference to a function or
// variable is an odr-use (in the C++11 sense).  There are separate variants
// for expressions referring to a decl; these exist because odr-use marking
// needs to be delayed for some constant variables when we build one of the
// named expressions.
//
// MightBeOdrUse indicates whether the use could possibly be an odr-use, and
// should usually be true. This only needs to be set to false if the lack of
// odr-use cannot be determined from the current context (for instance,
// because the name denotes a virtual function and was written without an
// explicit nested-name-specifier).
void MarkAnyDeclReferenced(SourceLocation Loc, Decl *D, bool MightBeOdrUse);
void MarkFunctionReferenced(SourceLocation Loc, FunctionDecl *Func,
                            bool MightBeOdrUse = true);
void MarkVariableReferenced(SourceLocation Loc, VarDecl *Var);
void MarkDeclRefReferenced(DeclRefExpr *E, const Expr *Base = nullptr);
void MarkMemberReferenced(MemberExpr *E);
void MarkFunctionParmPackReferenced(FunctionParmPackExpr *E);
void MarkCaptureUsedInEnclosingContext(ValueDecl *Capture, SourceLocation Loc,
                                       unsigned CapturingScopeIndex);

ExprResult CheckLValueToRValueConversionOperand(Expr *E);
void CleanupVarDeclMarking();

enum TryCaptureKind {
  TryCapture_Implicit, TryCapture_ExplicitByVal, TryCapture_ExplicitByRef
};

/// Try to capture the given variable.
///
/// \param Var The variable to capture.
///
/// \param Loc The location at which the capture occurs.
///
/// \param Kind The kind of capture, which may be implicit (for either a
/// block or a lambda), or explicit by-value or by-reference (for a lambda).
///
/// \param EllipsisLoc The location of the ellipsis, if one is provided in
/// an explicit lambda capture.
///
/// \param BuildAndDiagnose Whether we are actually supposed to add the
/// captures or diagnose errors. If false, this routine merely check whether
/// the capture can occur without performing the capture itself or complaining
/// if the variable cannot be captured.
///
/// \param CaptureType Will be set to the type of the field used to capture
/// this variable in the innermost block or lambda. Only valid when the
/// variable can be captured.
///
/// \param DeclRefType Will be set to the type of a reference to the capture
/// from within the current scope. Only valid when the variable can be
/// captured.
///
/// \param FunctionScopeIndexToStopAt If non-null, it points to the index
/// of the FunctionScopeInfo stack beyond which we do not attempt to capture.
/// This is useful when enclosing lambdas must speculatively capture
/// variables that may or may not be used in certain specializations of
/// a nested generic lambda.
///
/// \returns true if an error occurred (i.e., the variable cannot be
/// captured) and false if the capture succeeded.
bool tryCaptureVariable(ValueDecl *Var, SourceLocation Loc,
                        TryCaptureKind Kind, SourceLocation EllipsisLoc,
                        bool BuildAndDiagnose, QualType &CaptureType,
                        QualType &DeclRefType,
                        const unsigned *const FunctionScopeIndexToStopAt);

/// Try to capture the given variable.
bool tryCaptureVariable(ValueDecl *Var, SourceLocation Loc,
                        TryCaptureKind Kind = TryCapture_Implicit,
                        SourceLocation EllipsisLoc = SourceLocation());

/// Checks if the variable must be captured.
bool NeedToCaptureVariable(ValueDecl *Var, SourceLocation Loc);

/// Given a variable, determine the type that a reference to that
/// variable will have in the given scope.
QualType getCapturedDeclRefType(ValueDecl *Var, SourceLocation Loc);

/// Mark all of the declarations referenced within a particular AST node as
/// referenced. Used when template instantiation instantiates a non-dependent
/// type -- entities referenced by the type are now referenced.
void MarkDeclarationsReferencedInType(SourceLocation Loc, QualType T);
void MarkDeclarationsReferencedInExpr(
    Expr *E, bool SkipLocalVariables = false,
    ArrayRef<const Expr *> StopAt = std::nullopt);

/// Try to recover by turning the given expression into a
/// call.  Returns true if recovery was attempted or an error was
/// emitted; this may also leave the ExprResult invalid.
bool tryToRecoverWithCall(ExprResult &E, const PartialDiagnostic &PD,
                          bool ForceComplain = false,
                          bool (*IsPlausibleResult)(QualType) = nullptr);

/// Figure out if an expression could be turned into a call.
bool tryExprAsCall(Expr &E, QualType &ZeroArgCallReturnTy,
                   UnresolvedSetImpl &NonTemplateOverloads);

/// Try to convert an expression \p E to type \p Ty. Returns the result of the
/// conversion.
ExprResult tryConvertExprToType(Expr *E, QualType Ty);

/// Conditionally issue a diagnostic based on the statements's reachability
/// analysis.
///
/// \param Stmts If Stmts is non-empty, delay reporting the diagnostic until
/// the function body is parsed, and then do a basic reachability analysis to
/// determine if the statement is reachable. If it is unreachable, the
/// diagnostic will not be emitted.
bool DiagIfReachable(SourceLocation Loc, ArrayRef<const Stmt *> Stmts,
                     const PartialDiagnostic &PD);

/// Conditionally issue a diagnostic based on the current
/// evaluation context.
///
/// \param Statement If Statement is non-null, delay reporting the
/// diagnostic until the function body is parsed, and then do a basic
/// reachability analysis to determine if the statement is reachable.
/// If it is unreachable, the diagnostic will not be emitted.
bool DiagRuntimeBehavior(SourceLocation Loc, const Stmt *Statement,
                         const PartialDiagnostic &PD);
/// Similar, but diagnostic is only produced if all the specified statements
/// are reachable.
bool DiagRuntimeBehavior(SourceLocation Loc, ArrayRef<const Stmt*> Stmts,
                         const PartialDiagnostic &PD);

// Primary Expressions.
SourceRange getExprRange(Expr *E) const;

ExprResult ActOnIdExpression(
    Scope *S, CXXScopeSpec &SS, SourceLocation TemplateKWLoc,
    UnqualifiedId &Id, bool HasTrailingLParen, bool IsAddressOfOperand,
    CorrectionCandidateCallback *CCC = nullptr,
    bool IsInlineAsmIdentifier = false, Token *KeywordReplacement = nullptr);

void DecomposeUnqualifiedId(const UnqualifiedId &Id,
                            TemplateArgumentListInfo &Buffer,
                            DeclarationNameInfo &NameInfo,
                            const TemplateArgumentListInfo *&TemplateArgs);

bool DiagnoseDependentMemberLookup(const LookupResult &R);

bool
DiagnoseEmptyLookup(Scope *S, CXXScopeSpec &SS, LookupResult &R,
                    CorrectionCandidateCallback &CCC,
                    TemplateArgumentListInfo *ExplicitTemplateArgs = nullptr,
                    ArrayRef<Expr *> Args = std::nullopt,
                    TypoExpr **Out = nullptr);

DeclResult LookupIvarInObjCMethod(LookupResult &Lookup, Scope *S,
                                  IdentifierInfo *II);
ExprResult BuildIvarRefExpr(Scope *S, SourceLocation Loc, ObjCIvarDecl *IV);

ExprResult LookupInObjCMethod(LookupResult &LookUp, Scope *S,
                              IdentifierInfo *II,
                              bool AllowBuiltinCreation=false);

ExprResult ActOnDependentIdExpression(const CXXScopeSpec &SS,
                                      SourceLocation TemplateKWLoc,
                                      const DeclarationNameInfo &NameInfo,
                                      bool isAddressOfOperand,
                              const TemplateArgumentListInfo *TemplateArgs);

/// If \p D cannot be odr-used in the current expression evaluation context,
/// return a reason explaining why. Otherwise, return NOUR_None.
NonOdrUseReason getNonOdrUseReasonInCurrentContext(ValueDecl *D);

DeclRefExpr *BuildDeclRefExpr(ValueDecl *D, QualType Ty, ExprValueKind VK,
                              SourceLocation Loc,
                              const CXXScopeSpec *SS = nullptr);
DeclRefExpr *
BuildDeclRefExpr(ValueDecl *D, QualType Ty, ExprValueKind VK,
                 const DeclarationNameInfo &NameInfo,
                 const CXXScopeSpec *SS = nullptr,
                 NamedDecl *FoundD = nullptr,
                 SourceLocation TemplateKWLoc = SourceLocation(),
                 const TemplateArgumentListInfo *TemplateArgs = nullptr);
DeclRefExpr *
BuildDeclRefExpr(ValueDecl *D, QualType Ty, ExprValueKind VK,
                 const DeclarationNameInfo &NameInfo,
                 NestedNameSpecifierLoc NNS,
                 NamedDecl *FoundD = nullptr,
                 SourceLocation TemplateKWLoc = SourceLocation(),
                 const TemplateArgumentListInfo *TemplateArgs = nullptr);

ExprResult
BuildAnonymousStructUnionMemberReference(
    const CXXScopeSpec &SS,
    SourceLocation nameLoc,
    IndirectFieldDecl *indirectField,
    DeclAccessPair FoundDecl = DeclAccessPair::make(nullptr, AS_none),
    Expr *baseObjectExpr = nullptr,
    SourceLocation opLoc = SourceLocation());

ExprResult BuildPossibleImplicitMemberExpr(
    const CXXScopeSpec &SS, SourceLocation TemplateKWLoc, LookupResult &R,
    const TemplateArgumentListInfo *TemplateArgs, const Scope *S,
    UnresolvedLookupExpr *AsULE = nullptr);
ExprResult BuildImplicitMemberExpr(const CXXScopeSpec &SS,
                                   SourceLocation TemplateKWLoc,
                                   LookupResult &R,
                              const TemplateArgumentListInfo *TemplateArgs,
                                   bool IsDefiniteInstance,
                                   const Scope *S);
bool UseArgumentDependentLookup(const CXXScopeSpec &SS,
                                const LookupResult &R,
                                bool HasTrailingLParen);

ExprResult
BuildQualifiedDeclarationNameExpr(CXXScopeSpec &SS,
                                  const DeclarationNameInfo &NameInfo,
                                  bool IsAddressOfOperand, const Scope *S,
                                  TypeSourceInfo **RecoveryTSI = nullptr);

ExprResult BuildDependentDeclRefExpr(const CXXScopeSpec &SS,
                                     SourceLocation TemplateKWLoc,
                              const DeclarationNameInfo &NameInfo,
                              const TemplateArgumentListInfo *TemplateArgs);

ExprResult BuildDeclarationNameExpr(const CXXScopeSpec &SS,
                                    LookupResult &R,
                                    bool NeedsADL,
                                    bool AcceptInvalidDecl = false);
ExprResult BuildDeclarationNameExpr(
    const CXXScopeSpec &SS, const DeclarationNameInfo &NameInfo, NamedDecl *D,
    NamedDecl *FoundD = nullptr,
    const TemplateArgumentListInfo *TemplateArgs = nullptr,
    bool AcceptInvalidDecl = false);

ExprResult BuildLiteralOperatorCall(LookupResult &R,
                    DeclarationNameInfo &SuffixInfo,
                    ArrayRef<Expr *> Args,
                    SourceLocation LitEndLoc,
                    TemplateArgumentListInfo *ExplicitTemplateArgs = nullptr);

ExprResult BuildPredefinedExpr(SourceLocation Loc,
                               PredefinedExpr::IdentKind IK);
ExprResult ActOnPredefinedExpr(SourceLocation Loc, tok::TokenKind Kind);
ExprResult ActOnIntegerConstant(SourceLocation Loc, uint64_t Val);

ExprResult BuildSYCLUniqueStableNameExpr(SourceLocation OpLoc,
                                         SourceLocation LParen,
                                         SourceLocation RParen,
                                         TypeSourceInfo *TSI);
ExprResult ActOnSYCLUniqueStableNameExpr(SourceLocation OpLoc,
                                         SourceLocation LParen,
                                         SourceLocation RParen,
                                         ParsedType ParsedTy);

bool CheckLoopHintExpr(Expr *E, SourceLocation Loc);

ExprResult ActOnNumericConstant(const Token &Tok, Scope *UDLScope = nullptr);
ExprResult ActOnCharacterConstant(const Token &Tok,
                                  Scope *UDLScope = nullptr);
ExprResult ActOnParenExpr(SourceLocation L, SourceLocation R, Expr *E);
ExprResult ActOnParenListExpr(SourceLocation L,
                              SourceLocation R,
                              MultiExprArg Val);

/// ActOnStringLiteral - The specified tokens were lexed as pasted string
/// fragments (e.g. "foo" "bar" L"baz").
ExprResult ActOnStringLiteral(ArrayRef<Token> StringToks,
                              Scope *UDLScope = nullptr);

ExprResult ActOnGenericSelectionExpr(SourceLocation KeyLoc,
                                     SourceLocation DefaultLoc,
                                     SourceLocation RParenLoc,
                                     Expr *ControllingExpr,
                                     ArrayRef<ParsedType> ArgTypes,
                                     ArrayRef<Expr *> ArgExprs);
ExprResult CreateGenericSelectionExpr(SourceLocation KeyLoc,
                                      SourceLocation DefaultLoc,
                                      SourceLocation RParenLoc,
                                      Expr *ControllingExpr,
                                      ArrayRef<TypeSourceInfo *> Types,
                                      ArrayRef<Expr *> Exprs);

// Binary/Unary Operators.  'Tok' is the token for the operator.
ExprResult CreateBuiltinUnaryOp(SourceLocation OpLoc, UnaryOperatorKind Opc,
                                Expr *InputExpr, bool IsAfterAmp = false);
ExprResult BuildUnaryOp(Scope *S, SourceLocation OpLoc, UnaryOperatorKind Opc,
                        Expr *Input, bool IsAfterAmp = false);
ExprResult ActOnUnaryOp(Scope *S, SourceLocation OpLoc, tok::TokenKind Op,
                        Expr *Input, bool IsAfterAmp = false);

bool isQualifiedMemberAccess(Expr *E);
QualType CheckAddressOfOperand(ExprResult &Operand, SourceLocation OpLoc);

bool CheckTypeTraitArity(unsigned Arity, SourceLocation Loc, size_t N);

ExprResult CreateUnaryExprOrTypeTraitExpr(TypeSourceInfo *TInfo,
                                          SourceLocation OpLoc,
                                          UnaryExprOrTypeTrait ExprKind,
                                          SourceRange R);
ExprResult CreateUnaryExprOrTypeTraitExpr(Expr *E, SourceLocation OpLoc,
                                          UnaryExprOrTypeTrait ExprKind);
ExprResult
  ActOnUnaryExprOrTypeTraitExpr(SourceLocation OpLoc,
                                UnaryExprOrTypeTrait ExprKind,
                                bool IsType, void *TyOrEx,
                                SourceRange ArgRange);

ExprResult CheckPlaceholderExpr(Expr *E);
bool CheckVecStepExpr(Expr *E);

bool CheckUnaryExprOrTypeTraitOperand(Expr *E, UnaryExprOrTypeTrait ExprKind);
bool CheckUnaryExprOrTypeTraitOperand(QualType ExprType, SourceLocation OpLoc,
                                      SourceRange ExprRange,
                                      UnaryExprOrTypeTrait ExprKind);
ExprResult ActOnSizeofParameterPackExpr(Scope *S,
                                        SourceLocation OpLoc,
                                        IdentifierInfo &Name,
                                        SourceLocation NameLoc,
                                        SourceLocation RParenLoc);
ExprResult ActOnPostfixUnaryOp(Scope *S, SourceLocation OpLoc,
                               tok::TokenKind Kind, Expr *Input);

ExprResult ActOnArraySubscriptExpr(Scope *S, Expr *Base, SourceLocation LLoc,
                                   MultiExprArg ArgExprs,
                                   SourceLocation RLoc);
ExprResult CreateBuiltinArraySubscriptExpr(Expr *Base, SourceLocation LLoc,
                                           Expr *Idx, SourceLocation RLoc);

ExprResult CreateBuiltinMatrixSubscriptExpr(Expr *Base, Expr *RowIdx,
                                            Expr *ColumnIdx,
                                            SourceLocation RBLoc);

ExprResult ActOnOMPArraySectionExpr(Expr *Base, SourceLocation LBLoc,
                                    Expr *LowerBound,
                                    SourceLocation ColonLocFirst,
                                    SourceLocation ColonLocSecond,
                                    Expr *Length, Expr *Stride,
                                    SourceLocation RBLoc);
ExprResult ActOnOMPArrayShapingExpr(Expr *Base, SourceLocation LParenLoc,
                                    SourceLocation RParenLoc,
                                    ArrayRef<Expr *> Dims,
                                    ArrayRef<SourceRange> Brackets);

/// Data structure for iterator expression.
struct OMPIteratorData {
  IdentifierInfo *DeclIdent = nullptr;
  SourceLocation DeclIdentLoc;
  ParsedType Type;
  OMPIteratorExpr::IteratorRange Range;
  SourceLocation AssignLoc;
  SourceLocation ColonLoc;
  SourceLocation SecColonLoc;
};

ExprResult ActOnOMPIteratorExpr(Scope *S, SourceLocation IteratorKwLoc,
                                SourceLocation LLoc, SourceLocation RLoc,
                                ArrayRef<OMPIteratorData> Data);

// This struct is for use by ActOnMemberAccess to allow
// BuildMemberReferenceExpr to be able to reinvoke ActOnMemberAccess after
// changing the access operator from a '.' to a '->' (to see if that is the
// change needed to fix an error about an unknown member, e.g. when the class
// defines a custom operator->).
struct ActOnMemberAccessExtraArgs {
  Scope *S;
  UnqualifiedId &Id;
  Decl *ObjCImpDecl;
};

ExprResult BuildMemberReferenceExpr(
    Expr *Base, QualType BaseType, SourceLocation OpLoc, bool IsArrow,
    CXXScopeSpec &SS, SourceLocation TemplateKWLoc,
    NamedDecl *FirstQualifierInScope, const DeclarationNameInfo &NameInfo,
    const TemplateArgumentListInfo *TemplateArgs,
    const Scope *S,
    ActOnMemberAccessExtraArgs *ExtraArgs = nullptr);

ExprResult
BuildMemberReferenceExpr(Expr *Base, QualType BaseType, SourceLocation OpLoc,
                         bool IsArrow, const CXXScopeSpec &SS,
                         SourceLocation TemplateKWLoc,
                         NamedDecl *FirstQualifierInScope, LookupResult &R,
                         const TemplateArgumentListInfo *TemplateArgs,
                         const Scope *S,
                         bool SuppressQualifierCheck = false,
                         ActOnMemberAccessExtraArgs *ExtraArgs = nullptr);

ExprResult BuildFieldReferenceExpr(Expr *BaseExpr, bool IsArrow,
                                   SourceLocation OpLoc,
                                   const CXXScopeSpec &SS, FieldDecl *Field,
                                   DeclAccessPair FoundDecl,
                                   const DeclarationNameInfo &MemberNameInfo);

ExprResult PerformMemberExprBaseConversion(Expr *Base, bool IsArrow);

bool CheckQualifiedMemberReference(Expr *BaseExpr, QualType BaseType,
                                   const CXXScopeSpec &SS,
                                   const LookupResult &R);

ExprResult ActOnDependentMemberExpr(Expr *Base, QualType BaseType,
                                    bool IsArrow, SourceLocation OpLoc,
                                    const CXXScopeSpec &SS,
                                    SourceLocation TemplateKWLoc,
                                    NamedDecl *FirstQualifierInScope,
                             const DeclarationNameInfo &NameInfo,
                             const TemplateArgumentListInfo *TemplateArgs);

ExprResult ActOnMemberAccessExpr(Scope *S, Expr *Base,
                                 SourceLocation OpLoc,
                                 tok::TokenKind OpKind,
                                 CXXScopeSpec &SS,
                                 SourceLocation TemplateKWLoc,
                                 UnqualifiedId &Member,
                                 Decl *ObjCImpDecl);

MemberExpr *
BuildMemberExpr(Expr *Base, bool IsArrow, SourceLocation OpLoc,
                const CXXScopeSpec *SS, SourceLocation TemplateKWLoc,
                ValueDecl *Member, DeclAccessPair FoundDecl,
                bool HadMultipleCandidates,
                const DeclarationNameInfo &MemberNameInfo, QualType Ty,
                ExprValueKind VK, ExprObjectKind OK,
                const TemplateArgumentListInfo *TemplateArgs = nullptr);
MemberExpr *
BuildMemberExpr(Expr *Base, bool IsArrow, SourceLocation OpLoc,
                NestedNameSpecifierLoc NNS, SourceLocation TemplateKWLoc,
                ValueDecl *Member, DeclAccessPair FoundDecl,
                bool HadMultipleCandidates,
                const DeclarationNameInfo &MemberNameInfo, QualType Ty,
                ExprValueKind VK, ExprObjectKind OK,
                const TemplateArgumentListInfo *TemplateArgs = nullptr);

void ActOnDefaultCtorInitializers(Decl *CDtorDecl);
bool ConvertArgumentsForCall(CallExpr *Call, Expr *Fn,
                             FunctionDecl *FDecl,
                             const FunctionProtoType *Proto,
                             ArrayRef<Expr *> Args,
                             SourceLocation RParenLoc,
                             bool ExecConfig = false);
void CheckStaticArrayArgument(SourceLocation CallLoc,
                              ParmVarDecl *Param,
                              const Expr *ArgExpr);

/// ActOnCallExpr - Handle a call to Fn with the specified array of arguments.
/// This provides the location of the left/right parens and a list of comma
/// locations.
ExprResult ActOnCallExpr(Scope *S, Expr *Fn, SourceLocation LParenLoc,
                         MultiExprArg ArgExprs, SourceLocation RParenLoc,
                         Expr *ExecConfig = nullptr);
ExprResult BuildCallExpr(Scope *S, Expr *Fn, SourceLocation LParenLoc,
                         MultiExprArg ArgExprs, SourceLocation RParenLoc,
                         Expr *ExecConfig = nullptr,
                         bool IsExecConfig = false,
                         bool AllowRecovery = false);
Expr *BuildBuiltinCallExpr(SourceLocation Loc, Builtin::ID Id,
                           MultiExprArg CallArgs);
enum class AtomicArgumentOrder { API, AST };
ExprResult
BuildAtomicExpr(SourceRange CallRange, SourceRange ExprRange,
                SourceLocation RParenLoc, MultiExprArg Args,
                AtomicExpr::AtomicOp Op,
                AtomicArgumentOrder ArgOrder = AtomicArgumentOrder::API);
ExprResult
BuildResolvedCallExpr(Expr *Fn, NamedDecl *NDecl, SourceLocation LParenLoc,
                      ArrayRef<Expr *> Arg, SourceLocation RParenLoc,
                      Expr *Config = nullptr, bool IsExecConfig = false,
                      ADLCallKind UsesADL = ADLCallKind::NotADL);

ExprResult ActOnCUDAExecConfigExpr(Scope *S, SourceLocation LLLLoc,
                                   MultiExprArg ExecConfig,
                                   SourceLocation GGGLoc);

ExprResult ActOnCastExpr(Scope *S, SourceLocation LParenLoc,
                         Declarator &D, ParsedType &Ty,
                         SourceLocation RParenLoc, Expr *CastExpr);
ExprResult BuildCStyleCastExpr(SourceLocation LParenLoc,
                               TypeSourceInfo *Ty,
                               SourceLocation RParenLoc,
                               Expr *Op);
CastKind PrepareScalarCast(ExprResult &src, QualType destType);

/// Build an altivec or OpenCL literal.
ExprResult BuildVectorLiteral(SourceLocation LParenLoc,
                              SourceLocation RParenLoc, Expr *E,
                              TypeSourceInfo *TInfo);

ExprResult MaybeConvertParenListExprToParenExpr(Scope *S, Expr *ME);

ExprResult ActOnCompoundLiteral(SourceLocation LParenLoc,
                                ParsedType Ty,
                                SourceLocation RParenLoc,
                                Expr *InitExpr);

ExprResult BuildCompoundLiteralExpr(SourceLocation LParenLoc,
                                    TypeSourceInfo *TInfo,
                                    SourceLocation RParenLoc,
                                    Expr *LiteralExpr);

ExprResult ActOnInitList(SourceLocation LBraceLoc,
                         MultiExprArg InitArgList,
                         SourceLocation RBraceLoc);

ExprResult BuildInitList(SourceLocation LBraceLoc,
                         MultiExprArg InitArgList,
                         SourceLocation RBraceLoc);

ExprResult ActOnDesignatedInitializer(Designation &Desig,
                                      SourceLocation EqualOrColonLoc,
                                      bool GNUSyntax,
                                      ExprResult Init);

5933private:
static BinaryOperatorKind ConvertTokenKindToBinaryOpcode(tok::TokenKind Kind);

5936public:
ExprResult ActOnBinOp(Scope *S, SourceLocation TokLoc,
                      tok::TokenKind Kind, Expr *LHSExpr, Expr *RHSExpr);
ExprResult BuildBinOp(Scope *S, SourceLocation OpLoc,
                      BinaryOperatorKind Opc, Expr *LHSExpr, Expr *RHSExpr);
ExprResult CreateBuiltinBinOp(SourceLocation OpLoc, BinaryOperatorKind Opc,
                              Expr *LHSExpr, Expr *RHSExpr);
void LookupBinOp(Scope *S, SourceLocation OpLoc, BinaryOperatorKind Opc,
                 UnresolvedSetImpl &Functions);

void DiagnoseCommaOperator(const Expr *LHS, SourceLocation Loc);

/// ActOnConditionalOp - Parse a ?: operation.  Note that 'LHS' may be null
/// in the case of a the GNU conditional expr extension.
ExprResult ActOnConditionalOp(SourceLocation QuestionLoc,
                              SourceLocation ColonLoc,
                              Expr *CondExpr, Expr *LHSExpr, Expr *RHSExpr);

/// ActOnAddrLabel - Parse the GNU address of label extension: "&&foo".
ExprResult ActOnAddrLabel(SourceLocation OpLoc, SourceLocation LabLoc,
                          LabelDecl *TheDecl);

void ActOnStartStmtExpr();
ExprResult ActOnStmtExpr(Scope *S, SourceLocation LPLoc, Stmt *SubStmt,
                         SourceLocation RPLoc);
ExprResult BuildStmtExpr(SourceLocation LPLoc, Stmt *SubStmt,
                         SourceLocation RPLoc, unsigned TemplateDepth);
// Handle the final expression in a statement expression.
ExprResult ActOnStmtExprResult(ExprResult E);
void ActOnStmtExprError();

// __builtin_offsetof(type, identifier(.identifier|[expr])*)
struct OffsetOfComponent {
  SourceLocation LocStart, LocEnd;
  bool isBrackets;  // true if [expr], false if .ident
  union {
    IdentifierInfo *IdentInfo;
    Expr *E;
  } U;
};

/// __builtin_offsetof(type, a.b[123][456].c)
ExprResult BuildBuiltinOffsetOf(SourceLocation BuiltinLoc,
                                TypeSourceInfo *TInfo,
                                ArrayRef<OffsetOfComponent> Components,
                                SourceLocation RParenLoc);
ExprResult ActOnBuiltinOffsetOf(Scope *S,
                                SourceLocation BuiltinLoc,
                                SourceLocation TypeLoc,
                                ParsedType ParsedArgTy,
                                ArrayRef<OffsetOfComponent> Components,
                                SourceLocation RParenLoc);

// __builtin_choose_expr(constExpr, expr1, expr2)
ExprResult ActOnChooseExpr(SourceLocation BuiltinLoc,
                           Expr *CondExpr, Expr *LHSExpr,
                           Expr *RHSExpr, SourceLocation RPLoc);

// __builtin_va_arg(expr, type)
ExprResult ActOnVAArg(SourceLocation BuiltinLoc, Expr *E, ParsedType Ty,
                      SourceLocation RPLoc);
ExprResult BuildVAArgExpr(SourceLocation BuiltinLoc, Expr *E,
                          TypeSourceInfo *TInfo, SourceLocation RPLoc);

// __builtin_LINE(), __builtin_FUNCTION(), __builtin_FILE(),
// __builtin_COLUMN(), __builtin_source_location()
ExprResult ActOnSourceLocExpr(SourceLocExpr::IdentKind Kind,
                              SourceLocation BuiltinLoc,
                              SourceLocation RPLoc);

// Build a potentially resolved SourceLocExpr.
ExprResult BuildSourceLocExpr(SourceLocExpr::IdentKind Kind,
                              QualType ResultTy, SourceLocation BuiltinLoc,
                              SourceLocation RPLoc,
                              DeclContext *ParentContext);

// __null
ExprResult ActOnGNUNullExpr(SourceLocation TokenLoc);

bool CheckCaseExpression(Expr *E);

/// Describes the result of an "if-exists" condition check.
enum IfExistsResult {
  /// The symbol exists.
  IER_Exists,

  /// The symbol does not exist.
  IER_DoesNotExist,

  /// The name is a dependent name, so the results will differ
  /// from one instantiation to the next.
  IER_Dependent,

  /// An error occurred.
  IER_Error
};

IfExistsResult
CheckMicrosoftIfExistsSymbol(Scope *S, CXXScopeSpec &SS,
                             const DeclarationNameInfo &TargetNameInfo);

IfExistsResult
CheckMicrosoftIfExistsSymbol(Scope *S, SourceLocation KeywordLoc,
                             bool IsIfExists, CXXScopeSpec &SS,
                             UnqualifiedId &Name);

StmtResult BuildMSDependentExistsStmt(SourceLocation KeywordLoc,
                                      bool IsIfExists,
                                      NestedNameSpecifierLoc QualifierLoc,
                                      DeclarationNameInfo NameInfo,
                                      Stmt *Nested);
StmtResult ActOnMSDependentExistsStmt(SourceLocation KeywordLoc,
                                      bool IsIfExists,
                                      CXXScopeSpec &SS, UnqualifiedId &Name,
                                      Stmt *Nested);

//===------------------------- "Block" Extension ------------------------===//

/// ActOnBlockStart - This callback is invoked when a block literal is
/// started.
void ActOnBlockStart(SourceLocation CaretLoc, Scope *CurScope);

/// ActOnBlockArguments - This callback allows processing of block arguments.
/// If there are no arguments, this is still invoked.
void ActOnBlockArguments(SourceLocation CaretLoc, Declarator &ParamInfo,
                         Scope *CurScope);

/// ActOnBlockError - If there is an error parsing a block, this callback
/// is invoked to pop the information about the block from the action impl.
void ActOnBlockError(SourceLocation CaretLoc, Scope *CurScope);

/// ActOnBlockStmtExpr - This is called when the body of a block statement
/// literal was successfully completed.  ^(int x){...}
ExprResult ActOnBlockStmtExpr(SourceLocation CaretLoc, Stmt *Body,
                              Scope *CurScope);

//===---------------------------- Clang Extensions ----------------------===//

/// __builtin_convertvector(...)
ExprResult ActOnConvertVectorExpr(Expr *E, ParsedType ParsedDestTy,
                                  SourceLocation BuiltinLoc,
                                  SourceLocation RParenLoc);

//===---------------------------- OpenCL Features -----------------------===//

/// __builtin_astype(...)
ExprResult ActOnAsTypeExpr(Expr *E, ParsedType ParsedDestTy,
                           SourceLocation BuiltinLoc,
                           SourceLocation RParenLoc);
ExprResult BuildAsTypeExpr(Expr *E, QualType DestTy,
                           SourceLocation BuiltinLoc,
                           SourceLocation RParenLoc);

//===---------------------------- HLSL Features -------------------------===//
Decl *ActOnStartHLSLBuffer(Scope *BufferScope, bool CBuffer,
                           SourceLocation KwLoc, IdentifierInfo *Ident,
                           SourceLocation IdentLoc, SourceLocation LBrace);
void ActOnFinishHLSLBuffer(Decl *Dcl, SourceLocation RBrace);

//===---------------------------- C++ Features --------------------------===//

// Act on C++ namespaces
Decl *ActOnStartNamespaceDef(Scope *S, SourceLocation InlineLoc,
                             SourceLocation NamespaceLoc,
                             SourceLocation IdentLoc, IdentifierInfo *Ident,
                             SourceLocation LBrace,
                             const ParsedAttributesView &AttrList,
                             UsingDirectiveDecl *&UsingDecl, bool IsNested);
void ActOnFinishNamespaceDef(Decl *Dcl, SourceLocation RBrace);

NamespaceDecl *getStdNamespace() const;
NamespaceDecl *getOrCreateStdNamespace();

CXXRecordDecl *getStdBadAlloc() const;
EnumDecl *getStdAlignValT() const;

6112private:
// A cache representing if we've fully checked the various comparison category
// types stored in ASTContext. The bit-index corresponds to the integer value
// of a ComparisonCategoryType enumerator.
llvm::SmallBitVector FullyCheckedComparisonCategories;

ValueDecl *tryLookupCtorInitMemberDecl(CXXRecordDecl *ClassDecl,
                                       CXXScopeSpec &SS,
                                       ParsedType TemplateTypeTy,
                                       IdentifierInfo *MemberOrBase);

6123public:
enum class ComparisonCategoryUsage {
  /// The '<=>' operator was used in an expression and a builtin operator
  /// was selected.
  OperatorInExpression,
  /// A defaulted 'operator<=>' needed the comparison category. This
  /// typically only applies to 'std::strong_ordering', due to the implicit
  /// fallback return value.
  DefaultedOperator,
};

/// Lookup the specified comparison category types in the standard
///   library, an check the VarDecls possibly returned by the operator<=>
///   builtins for that type.
///
/// \return The type of the comparison category type corresponding to the
///   specified Kind, or a null type if an error occurs
QualType CheckComparisonCategoryType(ComparisonCategoryType Kind,
                                     SourceLocation Loc,
                                     ComparisonCategoryUsage Usage);

/// Tests whether Ty is an instance of std::initializer_list and, if
/// it is and Element is not NULL, assigns the element type to Element.
bool isStdInitializerList(QualType Ty, QualType *Element);

/// Looks for the std::initializer_list template and instantiates it
/// with Element, or emits an error if it's not found.
///
/// \returns The instantiated template, or null on error.
QualType BuildStdInitializerList(QualType Element, SourceLocation Loc);

/// Determine whether Ctor is an initializer-list constructor, as
/// defined in [dcl.init.list]p2.
bool isInitListConstructor(const FunctionDecl *Ctor);

Decl *ActOnUsingDirective(Scope *CurScope, SourceLocation UsingLoc,
                          SourceLocation NamespcLoc, CXXScopeSpec &SS,
                          SourceLocation IdentLoc,
                          IdentifierInfo *NamespcName,
                          const ParsedAttributesView &AttrList);

void PushUsingDirective(Scope *S, UsingDirectiveDecl *UDir);

Decl *ActOnNamespaceAliasDef(Scope *CurScope,
                             SourceLocation NamespaceLoc,
                             SourceLocation AliasLoc,
                             IdentifierInfo *Alias,
                             CXXScopeSpec &SS,
                             SourceLocation IdentLoc,
                             IdentifierInfo *Ident);

void FilterUsingLookup(Scope *S, LookupResult &lookup);
void HideUsingShadowDecl(Scope *S, UsingShadowDecl *Shadow);
bool CheckUsingShadowDecl(BaseUsingDecl *BUD, NamedDecl *Target,
                          const LookupResult &PreviousDecls,
                          UsingShadowDecl *&PrevShadow);
UsingShadowDecl *BuildUsingShadowDecl(Scope *S, BaseUsingDecl *BUD,
                                      NamedDecl *Target,
                                      UsingShadowDecl *PrevDecl);

bool CheckUsingDeclRedeclaration(SourceLocation UsingLoc,
                                 bool HasTypenameKeyword,
                                 const CXXScopeSpec &SS,
                                 SourceLocation NameLoc,
                                 const LookupResult &Previous);
bool CheckUsingDeclQualifier(SourceLocation UsingLoc, bool HasTypename,
                             const CXXScopeSpec &SS,
                             const DeclarationNameInfo &NameInfo,
                             SourceLocation NameLoc,
                             const LookupResult *R = nullptr,
                             const UsingDecl *UD = nullptr);

NamedDecl *BuildUsingDeclaration(
    Scope *S, AccessSpecifier AS, SourceLocation UsingLoc,
    bool HasTypenameKeyword, SourceLocation TypenameLoc, CXXScopeSpec &SS,
    DeclarationNameInfo NameInfo, SourceLocation EllipsisLoc,
    const ParsedAttributesView &AttrList, bool IsInstantiation,
    bool IsUsingIfExists);
NamedDecl *BuildUsingEnumDeclaration(Scope *S, AccessSpecifier AS,
                                     SourceLocation UsingLoc,
                                     SourceLocation EnumLoc,
                                     SourceLocation NameLoc,
                                     TypeSourceInfo *EnumType, EnumDecl *ED);
NamedDecl *BuildUsingPackDecl(NamedDecl *InstantiatedFrom,
                              ArrayRef<NamedDecl *> Expansions);

bool CheckInheritingConstructorUsingDecl(UsingDecl *UD);

/// Given a derived-class using shadow declaration for a constructor and the
/// correspnding base class constructor, find or create the implicit
/// synthesized derived class constructor to use for this initialization.
CXXConstructorDecl *
findInheritingConstructor(SourceLocation Loc, CXXConstructorDecl *BaseCtor,
                          ConstructorUsingShadowDecl *DerivedShadow);

Decl *ActOnUsingDeclaration(Scope *CurScope, AccessSpecifier AS,
                            SourceLocation UsingLoc,
                            SourceLocation TypenameLoc, CXXScopeSpec &SS,
                            UnqualifiedId &Name, SourceLocation EllipsisLoc,
                            const ParsedAttributesView &AttrList);
Decl *ActOnUsingEnumDeclaration(Scope *CurScope, AccessSpecifier AS,
                                SourceLocation UsingLoc,
                                SourceLocation EnumLoc,
                                SourceLocation IdentLoc, IdentifierInfo &II,
                                CXXScopeSpec *SS = nullptr);
Decl *ActOnAliasDeclaration(Scope *CurScope, AccessSpecifier AS,
                            MultiTemplateParamsArg TemplateParams,
                            SourceLocation UsingLoc, UnqualifiedId &Name,
                            const ParsedAttributesView &AttrList,
                            TypeResult Type, Decl *DeclFromDeclSpec);

/// BuildCXXConstructExpr - Creates a complete call to a constructor,
/// including handling of its default argument expressions.
///
/// \param ConstructKind - a CXXConstructExpr::ConstructionKind
ExprResult
BuildCXXConstructExpr(SourceLocation ConstructLoc, QualType DeclInitType,
                      NamedDecl *FoundDecl,
                      CXXConstructorDecl *Constructor, MultiExprArg Exprs,
                      bool HadMultipleCandidates, bool IsListInitialization,
                      bool IsStdInitListInitialization,
                      bool RequiresZeroInit, unsigned ConstructKind,
                      SourceRange ParenRange);

/// Build a CXXConstructExpr whose constructor has already been resolved if
/// it denotes an inherited constructor.
ExprResult
BuildCXXConstructExpr(SourceLocation ConstructLoc, QualType DeclInitType,
                      CXXConstructorDecl *Constructor, bool Elidable,
                      MultiExprArg Exprs,
                      bool HadMultipleCandidates, bool IsListInitialization,
                      bool IsStdInitListInitialization,
                      bool RequiresZeroInit, unsigned ConstructKind,
                      SourceRange ParenRange);

// FIXME: Can we remove this and have the above BuildCXXConstructExpr check if
// the constructor can be elidable?
ExprResult
BuildCXXConstructExpr(SourceLocation ConstructLoc, QualType DeclInitType,
                      NamedDecl *FoundDecl,
                      CXXConstructorDecl *Constructor, bool Elidable,
                      MultiExprArg Exprs, bool HadMultipleCandidates,
                      bool IsListInitialization,
                      bool IsStdInitListInitialization, bool RequiresZeroInit,
                      unsigned ConstructKind, SourceRange ParenRange);

ExprResult ConvertMemberDefaultInitExpression(FieldDecl *FD, Expr *InitExpr,
                                              SourceLocation InitLoc);

ExprResult BuildCXXDefaultInitExpr(SourceLocation Loc, FieldDecl *Field);


/// Instantiate or parse a C++ default argument expression as necessary.
/// Return true on error.
bool CheckCXXDefaultArgExpr(SourceLocation CallLoc, FunctionDecl *FD,
                            ParmVarDecl *Param, Expr *Init = nullptr,
                            bool SkipImmediateInvocations = true);

/// BuildCXXDefaultArgExpr - Creates a CXXDefaultArgExpr, instantiating
/// the default expr if needed.
ExprResult BuildCXXDefaultArgExpr(SourceLocation CallLoc, FunctionDecl *FD,
                                  ParmVarDecl *Param, Expr *Init = nullptr);

/// FinalizeVarWithDestructor - Prepare for calling destructor on the
/// constructed variable.
void FinalizeVarWithDestructor(VarDecl *VD, const RecordType *DeclInitType);

/// Helper class that collects exception specifications for
/// implicitly-declared special member functions.
class ImplicitExceptionSpecification {
  // Pointer to allow copying
  Sema *Self;
  // We order exception specifications thus:
  // noexcept is the most restrictive, but is only used in C++11.
  // throw() comes next.
  // Then a throw(collected exceptions)
  // Finally no specification, which is expressed as noexcept(false).
  // throw(...) is used instead if any called function uses it.
  ExceptionSpecificationType ComputedEST;
  llvm::SmallPtrSet<CanQualType, 4> ExceptionsSeen;
  SmallVector<QualType, 4> Exceptions;

  void ClearExceptions() {
    ExceptionsSeen.clear();
    Exceptions.clear();
  }

public:
  explicit ImplicitExceptionSpecification(Sema &Self)
    : Self(&Self), ComputedEST(EST_BasicNoexcept) {
    if (!Self.getLangOpts().CPlusPlus11)
      ComputedEST = EST_DynamicNone;
  }

  /// Get the computed exception specification type.
  ExceptionSpecificationType getExceptionSpecType() const {
    assert(!isComputedNoexcept(ComputedEST) &&(static_cast <bool> (!isComputedNoexcept(ComputedEST) &&
 "noexcept(expr) should not be a possible result") ? void (0)
 : __assert_fail ("!isComputedNoexcept(ComputedEST) && \"noexcept(expr) should not be a possible result\""
, "clang/include/clang/Sema/Sema.h", 6320, __extension__ __PRETTY_FUNCTION__
))
           "noexcept(expr) should not be a possible result")(static_cast <bool> (!isComputedNoexcept(ComputedEST) &&
 "noexcept(expr) should not be a possible result") ? void (0)
 : __assert_fail ("!isComputedNoexcept(ComputedEST) && \"noexcept(expr) should not be a possible result\""
, "clang/include/clang/Sema/Sema.h", 6320, __extension__ __PRETTY_FUNCTION__
));
    return ComputedEST;
  }

  /// The number of exceptions in the exception specification.
  unsigned size() const { return Exceptions.size(); }

  /// The set of exceptions in the exception specification.
  const QualType *data() const { return Exceptions.data(); }

  /// Integrate another called method into the collected data.
  void CalledDecl(SourceLocation CallLoc, const CXXMethodDecl *Method);

  /// Integrate an invoked expression into the collected data.
  void CalledExpr(Expr *E) { CalledStmt(E); }

  /// Integrate an invoked statement into the collected data.
  void CalledStmt(Stmt *S);

  /// Overwrite an EPI's exception specification with this
  /// computed exception specification.
  FunctionProtoType::ExceptionSpecInfo getExceptionSpec() const {
    FunctionProtoType::ExceptionSpecInfo ESI;
    ESI.Type = getExceptionSpecType();
    if (ESI.Type == EST_Dynamic) {
      ESI.Exceptions = Exceptions;
    } else if (ESI.Type == EST_None) {
      /// C++11 [except.spec]p14:
      ///   The exception-specification is noexcept(false) if the set of
      ///   potential exceptions of the special member function contains "any"
      ESI.Type = EST_NoexceptFalse;
      ESI.NoexceptExpr = Self->ActOnCXXBoolLiteral(SourceLocation(),
                                                   tok::kw_false).get();
    }
    return ESI;
  }
};

/// Evaluate the implicit exception specification for a defaulted
/// special member function.
void EvaluateImplicitExceptionSpec(SourceLocation Loc, FunctionDecl *FD);

/// Check the given noexcept-specifier, convert its expression, and compute
/// the appropriate ExceptionSpecificationType.
ExprResult ActOnNoexceptSpec(Expr *NoexceptExpr,
                             ExceptionSpecificationType &EST);

/// Check the given exception-specification and update the
/// exception specification information with the results.
void checkExceptionSpecification(bool IsTopLevel,
                                 ExceptionSpecificationType EST,
                                 ArrayRef<ParsedType> DynamicExceptions,
                                 ArrayRef<SourceRange> DynamicExceptionRanges,
                                 Expr *NoexceptExpr,
                                 SmallVectorImpl<QualType> &Exceptions,
                                 FunctionProtoType::ExceptionSpecInfo &ESI);

/// Determine if we're in a case where we need to (incorrectly) eagerly
/// parse an exception specification to work around a libstdc++ bug.
bool isLibstdcxxEagerExceptionSpecHack(const Declarator &D);

/// Add an exception-specification to the given member function
/// (or member function template). The exception-specification was parsed
/// after the method itself was declared.
void actOnDelayedExceptionSpecification(Decl *Method,
       ExceptionSpecificationType EST,
       SourceRange SpecificationRange,
       ArrayRef<ParsedType> DynamicExceptions,
       ArrayRef<SourceRange> DynamicExceptionRanges,
       Expr *NoexceptExpr);

class InheritedConstructorInfo;

/// Determine if a special member function should have a deleted
/// definition when it is defaulted.
bool ShouldDeleteSpecialMember(CXXMethodDecl *MD, CXXSpecialMember CSM,
                               InheritedConstructorInfo *ICI = nullptr,
                               bool Diagnose = false);

/// Produce notes explaining why a defaulted function was defined as deleted.
void DiagnoseDeletedDefaultedFunction(FunctionDecl *FD);

/// Declare the implicit default constructor for the given class.
///
/// \param ClassDecl The class declaration into which the implicit
/// default constructor will be added.
///
/// \returns The implicitly-declared default constructor.
CXXConstructorDecl *DeclareImplicitDefaultConstructor(
                                                   CXXRecordDecl *ClassDecl);

/// DefineImplicitDefaultConstructor - Checks for feasibility of
/// defining this constructor as the default constructor.
void DefineImplicitDefaultConstructor(SourceLocation CurrentLocation,
                                      CXXConstructorDecl *Constructor);

/// Declare the implicit destructor for the given class.
///
/// \param ClassDecl The class declaration into which the implicit
/// destructor will be added.
///
/// \returns The implicitly-declared destructor.
CXXDestructorDecl *DeclareImplicitDestructor(CXXRecordDecl *ClassDecl);

/// DefineImplicitDestructor - Checks for feasibility of
/// defining this destructor as the default destructor.
void DefineImplicitDestructor(SourceLocation CurrentLocation,
                              CXXDestructorDecl *Destructor);

/// Build an exception spec for destructors that don't have one.
///
/// C++11 says that user-defined destructors with no exception spec get one
/// that looks as if the destructor was implicitly declared.
void AdjustDestructorExceptionSpec(CXXDestructorDecl *Destructor);

/// Define the specified inheriting constructor.
void DefineInheritingConstructor(SourceLocation UseLoc,
                                 CXXConstructorDecl *Constructor);

/// Declare the implicit copy constructor for the given class.
///
/// \param ClassDecl The class declaration into which the implicit
/// copy constructor will be added.
///
/// \returns The implicitly-declared copy constructor.
CXXConstructorDecl *DeclareImplicitCopyConstructor(CXXRecordDecl *ClassDecl);

/// DefineImplicitCopyConstructor - Checks for feasibility of
/// defining this constructor as the copy constructor.
void DefineImplicitCopyConstructor(SourceLocation CurrentLocation,
                                   CXXConstructorDecl *Constructor);

/// Declare the implicit move constructor for the given class.
///
/// \param ClassDecl The Class declaration into which the implicit
/// move constructor will be added.
///
/// \returns The implicitly-declared move constructor, or NULL if it wasn't
/// declared.
CXXConstructorDecl *DeclareImplicitMoveConstructor(CXXRecordDecl *ClassDecl);

/// DefineImplicitMoveConstructor - Checks for feasibility of
/// defining this constructor as the move constructor.
void DefineImplicitMoveConstructor(SourceLocation CurrentLocation,
                                   CXXConstructorDecl *Constructor);

/// Declare the implicit copy assignment operator for the given class.
///
/// \param ClassDecl The class declaration into which the implicit
/// copy assignment operator will be added.
///
/// \returns The implicitly-declared copy assignment operator.
CXXMethodDecl *DeclareImplicitCopyAssignment(CXXRecordDecl *ClassDecl);

/// Defines an implicitly-declared copy assignment operator.
void DefineImplicitCopyAssignment(SourceLocation CurrentLocation,
                                  CXXMethodDecl *MethodDecl);

/// Declare the implicit move assignment operator for the given class.
///
/// \param ClassDecl The Class declaration into which the implicit
/// move assignment operator will be added.
///
/// \returns The implicitly-declared move assignment operator, or NULL if it
/// wasn't declared.
CXXMethodDecl *DeclareImplicitMoveAssignment(CXXRecordDecl *ClassDecl);

/// Defines an implicitly-declared move assignment operator.
void DefineImplicitMoveAssignment(SourceLocation CurrentLocation,
                                  CXXMethodDecl *MethodDecl);

/// Force the declaration of any implicitly-declared members of this
/// class.
void ForceDeclarationOfImplicitMembers(CXXRecordDecl *Class);

/// Check a completed declaration of an implicit special member.
void CheckImplicitSpecialMemberDeclaration(Scope *S, FunctionDecl *FD);

/// Determine whether the given function is an implicitly-deleted
/// special member function.
bool isImplicitlyDeleted(FunctionDecl *FD);

/// Check whether 'this' shows up in the type of a static member
/// function after the (naturally empty) cv-qualifier-seq would be.
///
/// \returns true if an error occurred.
bool checkThisInStaticMemberFunctionType(CXXMethodDecl *Method);

/// Whether this' shows up in the exception specification of a static
/// member function.
bool checkThisInStaticMemberFunctionExceptionSpec(CXXMethodDecl *Method);

/// Check whether 'this' shows up in the attributes of the given
/// static member function.
///
/// \returns true if an error occurred.
bool checkThisInStaticMemberFunctionAttributes(CXXMethodDecl *Method);

/// MaybeBindToTemporary - If the passed in expression has a record type with
/// a non-trivial destructor, this will return CXXBindTemporaryExpr. Otherwise
/// it simply returns the passed in expression.
ExprResult MaybeBindToTemporary(Expr *E);

/// Wrap the expression in a ConstantExpr if it is a potential immediate
/// invocation.
ExprResult CheckForImmediateInvocation(ExprResult E, FunctionDecl *Decl);

bool CompleteConstructorCall(CXXConstructorDecl *Constructor,
                             QualType DeclInitType, MultiExprArg ArgsPtr,
                             SourceLocation Loc,
                             SmallVectorImpl<Expr *> &ConvertedArgs,
                             bool AllowExplicit = false,
                             bool IsListInitialization = false);

ParsedType getInheritingConstructorName(CXXScopeSpec &SS,
                                        SourceLocation NameLoc,
                                        IdentifierInfo &Name);

ParsedType getConstructorName(IdentifierInfo &II, SourceLocation NameLoc,
                              Scope *S, CXXScopeSpec &SS,
                              bool EnteringContext);
ParsedType getDestructorName(SourceLocation TildeLoc,
                             IdentifierInfo &II, SourceLocation NameLoc,
                             Scope *S, CXXScopeSpec &SS,
                             ParsedType ObjectType,
                             bool EnteringContext);

ParsedType getDestructorTypeForDecltype(const DeclSpec &DS,
                                        ParsedType ObjectType);

// Checks that reinterpret casts don't have undefined behavior.
void CheckCompatibleReinterpretCast(QualType SrcType, QualType DestType,
                                    bool IsDereference, SourceRange Range);

// Checks that the vector type should be initialized from a scalar
// by splatting the value rather than populating a single element.
// This is the case for AltiVecVector types as well as with
// AltiVecPixel and AltiVecBool when -faltivec-src-compat=xl is specified.
bool ShouldSplatAltivecScalarInCast(const VectorType *VecTy);

// Checks if the -faltivec-src-compat=gcc option is specified.
// If so, AltiVecVector, AltiVecBool and AltiVecPixel types are
// treated the same way as they are when trying to initialize
// these vectors on gcc (an error is emitted).
bool CheckAltivecInitFromScalar(SourceRange R, QualType VecTy,
                                QualType SrcTy);

/// ActOnCXXNamedCast - Parse
/// {dynamic,static,reinterpret,const,addrspace}_cast's.
ExprResult ActOnCXXNamedCast(SourceLocation OpLoc,
                             tok::TokenKind Kind,
                             SourceLocation LAngleBracketLoc,
                             Declarator &D,
                             SourceLocation RAngleBracketLoc,
                             SourceLocation LParenLoc,
                             Expr *E,
                             SourceLocation RParenLoc);

ExprResult BuildCXXNamedCast(SourceLocation OpLoc,
                             tok::TokenKind Kind,
                             TypeSourceInfo *Ty,
                             Expr *E,
                             SourceRange AngleBrackets,
                             SourceRange Parens);

ExprResult ActOnBuiltinBitCastExpr(SourceLocation KWLoc, Declarator &Dcl,
                                   ExprResult Operand,
                                   SourceLocation RParenLoc);

ExprResult BuildBuiltinBitCastExpr(SourceLocation KWLoc, TypeSourceInfo *TSI,
                                   Expr *Operand, SourceLocation RParenLoc);

ExprResult BuildCXXTypeId(QualType TypeInfoType,
                          SourceLocation TypeidLoc,
                          TypeSourceInfo *Operand,
                          SourceLocation RParenLoc);
ExprResult BuildCXXTypeId(QualType TypeInfoType,
                          SourceLocation TypeidLoc,
                          Expr *Operand,
                          SourceLocation RParenLoc);

/// ActOnCXXTypeid - Parse typeid( something ).
ExprResult ActOnCXXTypeid(SourceLocation OpLoc,
                          SourceLocation LParenLoc, bool isType,
                          void *TyOrExpr,
                          SourceLocation RParenLoc);

ExprResult BuildCXXUuidof(QualType TypeInfoType,
                          SourceLocation TypeidLoc,
                          TypeSourceInfo *Operand,
                          SourceLocation RParenLoc);
ExprResult BuildCXXUuidof(QualType TypeInfoType,
                          SourceLocation TypeidLoc,
                          Expr *Operand,
                          SourceLocation RParenLoc);

/// ActOnCXXUuidof - Parse __uuidof( something ).
ExprResult ActOnCXXUuidof(SourceLocation OpLoc,
                          SourceLocation LParenLoc, bool isType,
                          void *TyOrExpr,
                          SourceLocation RParenLoc);

/// Handle a C++1z fold-expression: ( expr op ... op expr ).
ExprResult ActOnCXXFoldExpr(Scope *S, SourceLocation LParenLoc, Expr *LHS,
                            tok::TokenKind Operator,
                            SourceLocation EllipsisLoc, Expr *RHS,
                            SourceLocation RParenLoc);
ExprResult BuildCXXFoldExpr(UnresolvedLookupExpr *Callee,
                            SourceLocation LParenLoc, Expr *LHS,
                            BinaryOperatorKind Operator,
                            SourceLocation EllipsisLoc, Expr *RHS,
                            SourceLocation RParenLoc,
                            std::optional<unsigned> NumExpansions);
ExprResult BuildEmptyCXXFoldExpr(SourceLocation EllipsisLoc,
                                 BinaryOperatorKind Operator);

//// ActOnCXXThis -  Parse 'this' pointer.
ExprResult ActOnCXXThis(SourceLocation loc);

/// Build a CXXThisExpr and mark it referenced in the current context.
Expr *BuildCXXThisExpr(SourceLocation Loc, QualType Type, bool IsImplicit);
void MarkThisReferenced(CXXThisExpr *This);

/// Try to retrieve the type of the 'this' pointer.
///
/// \returns The type of 'this', if possible. Otherwise, returns a NULL type.
QualType getCurrentThisType();

/// When non-NULL, the C++ 'this' expression is allowed despite the
/// current context not being a non-static member function. In such cases,
/// this provides the type used for 'this'.
QualType CXXThisTypeOverride;

/// RAII object used to temporarily allow the C++ 'this' expression
/// to be used, with the given qualifiers on the current class type.
class CXXThisScopeRAII {
  Sema &S;
  QualType OldCXXThisTypeOverride;
  bool Enabled;

public:
  /// Introduce a new scope where 'this' may be allowed (when enabled),
  /// using the given declaration (which is either a class template or a
  /// class) along with the given qualifiers.
  /// along with the qualifiers placed on '*this'.
  CXXThisScopeRAII(Sema &S, Decl *ContextDecl, Qualifiers CXXThisTypeQuals,
                   bool Enabled = true);

  ~CXXThisScopeRAII();
};

/// Make sure the value of 'this' is actually available in the current
/// context, if it is a potentially evaluated context.
///
/// \param Loc The location at which the capture of 'this' occurs.
///
/// \param Explicit Whether 'this' is explicitly captured in a lambda
/// capture list.
///
/// \param FunctionScopeIndexToStopAt If non-null, it points to the index
/// of the FunctionScopeInfo stack beyond which we do not attempt to capture.
/// This is useful when enclosing lambdas must speculatively capture
/// 'this' that may or may not be used in certain specializations of
/// a nested generic lambda (depending on whether the name resolves to
/// a non-static member function or a static function).
/// \return returns 'true' if failed, 'false' if success.
bool CheckCXXThisCapture(SourceLocation Loc, bool Explicit = false,
    bool BuildAndDiagnose = true,
    const unsigned *const FunctionScopeIndexToStopAt = nullptr,
    bool ByCopy = false);

/// Determine whether the given type is the type of *this that is used
/// outside of the body of a member function for a type that is currently
/// being defined.
bool isThisOutsideMemberFunctionBody(QualType BaseType);

/// ActOnCXXBoolLiteral - Parse {true,false} literals.
ExprResult ActOnCXXBoolLiteral(SourceLocation OpLoc, tok::TokenKind Kind);


/// ActOnObjCBoolLiteral - Parse {__objc_yes,__objc_no} literals.
ExprResult ActOnObjCBoolLiteral(SourceLocation OpLoc, tok::TokenKind Kind);

ExprResult
ActOnObjCAvailabilityCheckExpr(llvm::ArrayRef<AvailabilitySpec> AvailSpecs,
                               SourceLocation AtLoc, SourceLocation RParen);

/// ActOnCXXNullPtrLiteral - Parse 'nullptr'.
ExprResult ActOnCXXNullPtrLiteral(SourceLocation Loc);

//// ActOnCXXThrow -  Parse throw expressions.
ExprResult ActOnCXXThrow(Scope *S, SourceLocation OpLoc, Expr *expr);
ExprResult BuildCXXThrow(SourceLocation OpLoc, Expr *Ex,
                         bool IsThrownVarInScope);
bool CheckCXXThrowOperand(SourceLocation ThrowLoc, QualType ThrowTy, Expr *E);

/// ActOnCXXTypeConstructExpr - Parse construction of a specified type.
/// Can be interpreted either as function-style casting ("int(x)")
/// or class type construction ("ClassType(x,y,z)")
/// or creation of a value-initialized type ("int()").
ExprResult ActOnCXXTypeConstructExpr(ParsedType TypeRep,
                                     SourceLocation LParenOrBraceLoc,
                                     MultiExprArg Exprs,
                                     SourceLocation RParenOrBraceLoc,
                                     bool ListInitialization);

ExprResult BuildCXXTypeConstructExpr(TypeSourceInfo *Type,
                                     SourceLocation LParenLoc,
                                     MultiExprArg Exprs,
                                     SourceLocation RParenLoc,
                                     bool ListInitialization);

/// ActOnCXXNew - Parsed a C++ 'new' expression.
ExprResult ActOnCXXNew(SourceLocation StartLoc, bool UseGlobal,
                       SourceLocation PlacementLParen,
                       MultiExprArg PlacementArgs,
                       SourceLocation PlacementRParen,
                       SourceRange TypeIdParens, Declarator &D,
                       Expr *Initializer);
ExprResult
BuildCXXNew(SourceRange Range, bool UseGlobal, SourceLocation PlacementLParen,
            MultiExprArg PlacementArgs, SourceLocation PlacementRParen,
            SourceRange TypeIdParens, QualType AllocType,
            TypeSourceInfo *AllocTypeInfo, std::optional<Expr *> ArraySize,
            SourceRange DirectInitRange, Expr *Initializer);

/// Determine whether \p FD is an aligned allocation or deallocation
/// function that is unavailable.
bool isUnavailableAlignedAllocationFunction(const FunctionDecl &FD) const;

/// Produce diagnostics if \p FD is an aligned allocation or deallocation
/// function that is unavailable.
void diagnoseUnavailableAlignedAllocation(const FunctionDecl &FD,
                                          SourceLocation Loc);

bool CheckAllocatedType(QualType AllocType, SourceLocation Loc,
                        SourceRange R);

/// The scope in which to find allocation functions.
enum AllocationFunctionScope {
  /// Only look for allocation functions in the global scope.
  AFS_Global,
  /// Only look for allocation functions in the scope of the
  /// allocated class.
  AFS_Class,
  /// Look for allocation functions in both the global scope
  /// and in the scope of the allocated class.
  AFS_Both
};

/// Finds the overloads of operator new and delete that are appropriate
/// for the allocation.
bool FindAllocationFunctions(SourceLocation StartLoc, SourceRange Range,
                             AllocationFunctionScope NewScope,
                             AllocationFunctionScope DeleteScope,
                             QualType AllocType, bool IsArray,
                             bool &PassAlignment, MultiExprArg PlaceArgs,
                             FunctionDecl *&OperatorNew,
                             FunctionDecl *&OperatorDelete,
                             bool Diagnose = true);
void DeclareGlobalNewDelete();
void DeclareGlobalAllocationFunction(DeclarationName Name, QualType Return,
                                     ArrayRef<QualType> Params);

bool FindDeallocationFunction(SourceLocation StartLoc, CXXRecordDecl *RD,
                              DeclarationName Name, FunctionDecl *&Operator,
                              bool Diagnose = true, bool WantSize = false,
                              bool WantAligned = false);
FunctionDecl *FindUsualDeallocationFunction(SourceLocation StartLoc,
                                            bool CanProvideSize,
                                            bool Overaligned,
                                            DeclarationName Name);
FunctionDecl *FindDeallocationFunctionForDestructor(SourceLocation StartLoc,
                                                    CXXRecordDecl *RD);

/// ActOnCXXDelete - Parsed a C++ 'delete' expression
ExprResult ActOnCXXDelete(SourceLocation StartLoc,
                          bool UseGlobal, bool ArrayForm,
                          Expr *Operand);
void CheckVirtualDtorCall(CXXDestructorDecl *dtor, SourceLocation Loc,
                          bool IsDelete, bool CallCanBeVirtual,
                          bool WarnOnNonAbstractTypes,
                          SourceLocation DtorLoc);

ExprResult ActOnNoexceptExpr(SourceLocation KeyLoc, SourceLocation LParen,
                             Expr *Operand, SourceLocation RParen);
ExprResult BuildCXXNoexceptExpr(SourceLocation KeyLoc, Expr *Operand,
                                SourceLocation RParen);

/// Parsed one of the type trait support pseudo-functions.
ExprResult ActOnTypeTrait(TypeTrait Kind, SourceLocation KWLoc,
                          ArrayRef<ParsedType> Args,
                          SourceLocation RParenLoc);
ExprResult BuildTypeTrait(TypeTrait Kind, SourceLocation KWLoc,
                          ArrayRef<TypeSourceInfo *> Args,
                          SourceLocation RParenLoc);

/// ActOnArrayTypeTrait - Parsed one of the binary type trait support
/// pseudo-functions.
ExprResult ActOnArrayTypeTrait(ArrayTypeTrait ATT,
                               SourceLocation KWLoc,
                               ParsedType LhsTy,
                               Expr *DimExpr,
                               SourceLocation RParen);

ExprResult BuildArrayTypeTrait(ArrayTypeTrait ATT,
                               SourceLocation KWLoc,
                               TypeSourceInfo *TSInfo,
                               Expr *DimExpr,
                               SourceLocation RParen);

/// ActOnExpressionTrait - Parsed one of the unary type trait support
/// pseudo-functions.
ExprResult ActOnExpressionTrait(ExpressionTrait OET,
                                SourceLocation KWLoc,
                                Expr *Queried,
                                SourceLocation RParen);

ExprResult BuildExpressionTrait(ExpressionTrait OET,
                                SourceLocation KWLoc,
                                Expr *Queried,
                                SourceLocation RParen);

ExprResult ActOnStartCXXMemberReference(Scope *S,
                                        Expr *Base,
                                        SourceLocation OpLoc,
                                        tok::TokenKind OpKind,
                                        ParsedType &ObjectType,
                                        bool &MayBePseudoDestructor);

ExprResult BuildPseudoDestructorExpr(Expr *Base,
                                     SourceLocation OpLoc,
                                     tok::TokenKind OpKind,
                                     const CXXScopeSpec &SS,
                                     TypeSourceInfo *ScopeType,
                                     SourceLocation CCLoc,
                                     SourceLocation TildeLoc,
                                   PseudoDestructorTypeStorage DestroyedType);

ExprResult ActOnPseudoDestructorExpr(Scope *S, Expr *Base,
                                     SourceLocation OpLoc,
                                     tok::TokenKind OpKind,
                                     CXXScopeSpec &SS,
                                     UnqualifiedId &FirstTypeName,
                                     SourceLocation CCLoc,
                                     SourceLocation TildeLoc,
                                     UnqualifiedId &SecondTypeName);

ExprResult ActOnPseudoDestructorExpr(Scope *S, Expr *Base,
                                     SourceLocation OpLoc,
                                     tok::TokenKind OpKind,
                                     SourceLocation TildeLoc,
                                     const DeclSpec& DS);

/// MaybeCreateExprWithCleanups - If the current full-expression
/// requires any cleanups, surround it with a ExprWithCleanups node.
/// Otherwise, just returns the passed-in expression.
Expr *MaybeCreateExprWithCleanups(Expr *SubExpr);
Stmt *MaybeCreateStmtWithCleanups(Stmt *SubStmt);
ExprResult MaybeCreateExprWithCleanups(ExprResult SubExpr);

MaterializeTemporaryExpr *
CreateMaterializeTemporaryExpr(QualType T, Expr *Temporary,
                               bool BoundToLvalueReference);

ExprResult ActOnFinishFullExpr(Expr *Expr, bool DiscardedValue) {
  return ActOnFinishFullExpr(
      Expr, Expr ? Expr->getExprLoc() : SourceLocation(), DiscardedValue);
}
ExprResult ActOnFinishFullExpr(Expr *Expr, SourceLocation CC,
                               bool DiscardedValue, bool IsConstexpr = false,
                               bool IsTemplateArgument = false);
StmtResult ActOnFinishFullStmt(Stmt *Stmt);

// Marks SS invalid if it represents an incomplete type.
bool RequireCompleteDeclContext(CXXScopeSpec &SS, DeclContext *DC);
// Complete an enum decl, maybe without a scope spec.
bool RequireCompleteEnumDecl(EnumDecl *D, SourceLocation L,
                             CXXScopeSpec *SS = nullptr);

DeclContext *computeDeclContext(QualType T);
DeclContext *computeDeclContext(const CXXScopeSpec &SS,
                                bool EnteringContext = false);
bool isDependentScopeSpecifier(const CXXScopeSpec &SS);
CXXRecordDecl *getCurrentInstantiationOf(NestedNameSpecifier *NNS);

/// The parser has parsed a global nested-name-specifier '::'.
///
/// \param CCLoc The location of the '::'.
///
/// \param SS The nested-name-specifier, which will be updated in-place
/// to reflect the parsed nested-name-specifier.
///
/// \returns true if an error occurred, false otherwise.
bool ActOnCXXGlobalScopeSpecifier(SourceLocation CCLoc, CXXScopeSpec &SS);

/// The parser has parsed a '__super' nested-name-specifier.
///
/// \param SuperLoc The location of the '__super' keyword.
///
/// \param ColonColonLoc The location of the '::'.
///
/// \param SS The nested-name-specifier, which will be updated in-place
/// to reflect the parsed nested-name-specifier.
///
/// \returns true if an error occurred, false otherwise.
bool ActOnSuperScopeSpecifier(SourceLocation SuperLoc,
                              SourceLocation ColonColonLoc, CXXScopeSpec &SS);

bool isAcceptableNestedNameSpecifier(const NamedDecl *SD,
                                     bool *CanCorrect = nullptr);
NamedDecl *FindFirstQualifierInScope(Scope *S, NestedNameSpecifier *NNS);

/// Keeps information about an identifier in a nested-name-spec.
///
struct NestedNameSpecInfo {
  /// The type of the object, if we're parsing nested-name-specifier in
  /// a member access expression.
  ParsedType ObjectType;

  /// The identifier preceding the '::'.
  IdentifierInfo *Identifier;

  /// The location of the identifier.
  SourceLocation IdentifierLoc;

  /// The location of the '::'.
  SourceLocation CCLoc;

  /// Creates info object for the most typical case.
  NestedNameSpecInfo(IdentifierInfo *II, SourceLocation IdLoc,
           SourceLocation ColonColonLoc, ParsedType ObjectType = ParsedType())
    : ObjectType(ObjectType), Identifier(II), IdentifierLoc(IdLoc),
      CCLoc(ColonColonLoc) {
  }

  NestedNameSpecInfo(IdentifierInfo *II, SourceLocation IdLoc,
                     SourceLocation ColonColonLoc, QualType ObjectType)
    : ObjectType(ParsedType::make(ObjectType)), Identifier(II),
      IdentifierLoc(IdLoc), CCLoc(ColonColonLoc) {
  }
};

bool isNonTypeNestedNameSpecifier(Scope *S, CXXScopeSpec &SS,
                                  NestedNameSpecInfo &IdInfo);

bool BuildCXXNestedNameSpecifier(Scope *S,
                                 NestedNameSpecInfo &IdInfo,
                                 bool EnteringContext,
                                 CXXScopeSpec &SS,
                                 NamedDecl *ScopeLookupResult,
                                 bool ErrorRecoveryLookup,
                                 bool *IsCorrectedToColon = nullptr,
                                 bool OnlyNamespace = false);

/// The parser has parsed a nested-name-specifier 'identifier::'.
///
/// \param S The scope in which this nested-name-specifier occurs.
///
/// \param IdInfo Parser information about an identifier in the
/// nested-name-spec.
///
/// \param EnteringContext Whether we're entering the context nominated by
/// this nested-name-specifier.
///
/// \param SS The nested-name-specifier, which is both an input
/// parameter (the nested-name-specifier before this type) and an
/// output parameter (containing the full nested-name-specifier,
/// including this new type).
///
/// \param IsCorrectedToColon If not null, suggestions to replace '::' -> ':'
/// are allowed.  The bool value pointed by this parameter is set to 'true'
/// if the identifier is treated as if it was followed by ':', not '::'.
///
/// \param OnlyNamespace If true, only considers namespaces in lookup.
///
/// \returns true if an error occurred, false otherwise.
bool ActOnCXXNestedNameSpecifier(Scope *S,
                                 NestedNameSpecInfo &IdInfo,
                                 bool EnteringContext,
                                 CXXScopeSpec &SS,
                                 bool *IsCorrectedToColon = nullptr,
                                 bool OnlyNamespace = false);

ExprResult ActOnDecltypeExpression(Expr *E);

bool ActOnCXXNestedNameSpecifierDecltype(CXXScopeSpec &SS,
                                         const DeclSpec &DS,
                                         SourceLocation ColonColonLoc);

bool IsInvalidUnlessNestedName(Scope *S, CXXScopeSpec &SS,
                               NestedNameSpecInfo &IdInfo,
                               bool EnteringContext);

/// The parser has parsed a nested-name-specifier
/// 'template[opt] template-name < template-args >::'.
///
/// \param S The scope in which this nested-name-specifier occurs.
///
/// \param SS The nested-name-specifier, which is both an input
/// parameter (the nested-name-specifier before this type) and an
/// output parameter (containing the full nested-name-specifier,
/// including this new type).
///
/// \param TemplateKWLoc the location of the 'template' keyword, if any.
/// \param TemplateName the template name.
/// \param TemplateNameLoc The location of the template name.
/// \param LAngleLoc The location of the opening angle bracket  ('<').
/// \param TemplateArgs The template arguments.
/// \param RAngleLoc The location of the closing angle bracket  ('>').
/// \param CCLoc The location of the '::'.
///
/// \param EnteringContext Whether we're entering the context of the
/// nested-name-specifier.
///
///
/// \returns true if an error occurred, false otherwise.
bool ActOnCXXNestedNameSpecifier(Scope *S,
                                 CXXScopeSpec &SS,
                                 SourceLocation TemplateKWLoc,
                                 TemplateTy TemplateName,
                                 SourceLocation TemplateNameLoc,
                                 SourceLocation LAngleLoc,
                                 ASTTemplateArgsPtr TemplateArgs,
                                 SourceLocation RAngleLoc,
                                 SourceLocation CCLoc,
                                 bool EnteringContext);

/// Given a C++ nested-name-specifier, produce an annotation value
/// that the parser can use later to reconstruct the given
/// nested-name-specifier.
///
/// \param SS A nested-name-specifier.
///
/// \returns A pointer containing all of the information in the
/// nested-name-specifier \p SS.
void *SaveNestedNameSpecifierAnnotation(CXXScopeSpec &SS);

/// Given an annotation pointer for a nested-name-specifier, restore
/// the nested-name-specifier structure.
///
/// \param Annotation The annotation pointer, produced by
/// \c SaveNestedNameSpecifierAnnotation().
///
/// \param AnnotationRange The source range corresponding to the annotation.
///
/// \param SS The nested-name-specifier that will be updated with the contents
/// of the annotation pointer.
void RestoreNestedNameSpecifierAnnotation(void *Annotation,
                                          SourceRange AnnotationRange,
                                          CXXScopeSpec &SS);

bool ShouldEnterDeclaratorScope(Scope *S, const CXXScopeSpec &SS);

/// ActOnCXXEnterDeclaratorScope - Called when a C++ scope specifier (global
/// scope or nested-name-specifier) is parsed, part of a declarator-id.
/// After this method is called, according to [C++ 3.4.3p3], names should be
/// looked up in the declarator-id's scope, until the declarator is parsed and
/// ActOnCXXExitDeclaratorScope is called.
/// The 'SS' should be a non-empty valid CXXScopeSpec.
bool ActOnCXXEnterDeclaratorScope(Scope *S, CXXScopeSpec &SS);

/// ActOnCXXExitDeclaratorScope - Called when a declarator that previously
/// invoked ActOnCXXEnterDeclaratorScope(), is finished. 'SS' is the same
/// CXXScopeSpec that was passed to ActOnCXXEnterDeclaratorScope as well.
/// Used to indicate that names should revert to being looked up in the
/// defining scope.
void ActOnCXXExitDeclaratorScope(Scope *S, const CXXScopeSpec &SS);

/// ActOnCXXEnterDeclInitializer - Invoked when we are about to parse an
/// initializer for the declaration 'Dcl'.
/// After this method is called, according to [C++ 3.4.1p13], if 'Dcl' is a
/// static data member of class X, names should be looked up in the scope of
/// class X.
void ActOnCXXEnterDeclInitializer(Scope *S, Decl *Dcl);

/// ActOnCXXExitDeclInitializer - Invoked after we are finished parsing an
/// initializer for the declaration 'Dcl'.
void ActOnCXXExitDeclInitializer(Scope *S, Decl *Dcl);

/// Create a new lambda closure type.
CXXRecordDecl *createLambdaClosureType(SourceRange IntroducerRange,
                                       TypeSourceInfo *Info,
                                       unsigned LambdaDependencyKind,
                                       LambdaCaptureDefault CaptureDefault);

/// Start the definition of a lambda expression.
CXXMethodDecl *
startLambdaDefinition(CXXRecordDecl *Class, SourceRange IntroducerRange,
                      TypeSourceInfo *MethodType, SourceLocation EndLoc,
                      ArrayRef<ParmVarDecl *> Params,
                      ConstexprSpecKind ConstexprKind, StorageClass SC,
                      Expr *TrailingRequiresClause);

/// Number lambda for linkage purposes if necessary.
void handleLambdaNumbering(CXXRecordDecl *Class, CXXMethodDecl *Method,
                           std::optional<CXXRecordDecl::LambdaNumbering>
                               NumberingOverride = std::nullopt);

/// Endow the lambda scope info with the relevant properties.
void buildLambdaScope(sema::LambdaScopeInfo *LSI, CXXMethodDecl *CallOperator,
                      SourceRange IntroducerRange,
                      LambdaCaptureDefault CaptureDefault,
                      SourceLocation CaptureDefaultLoc, bool ExplicitParams,
                      bool Mutable);

CXXMethodDecl *CreateLambdaCallOperator(SourceRange IntroducerRange,
                                        CXXRecordDecl *Class);
void CompleteLambdaCallOperator(
    CXXMethodDecl *Method, SourceLocation LambdaLoc,
    SourceLocation CallOperatorLoc, Expr *TrailingRequiresClause,
    TypeSourceInfo *MethodTyInfo, ConstexprSpecKind ConstexprKind,
    StorageClass SC, ArrayRef<ParmVarDecl *> Params,
    bool HasExplicitResultType);

/// Perform initialization analysis of the init-capture and perform
/// any implicit conversions such as an lvalue-to-rvalue conversion if
/// not being used to initialize a reference.
ParsedType actOnLambdaInitCaptureInitialization(
    SourceLocation Loc, bool ByRef, SourceLocation EllipsisLoc,
    IdentifierInfo *Id, LambdaCaptureInitKind InitKind, Expr *&Init) {
  return ParsedType::make(buildLambdaInitCaptureInitialization(
      Loc, ByRef, EllipsisLoc, std::nullopt, Id,
      InitKind != LambdaCaptureInitKind::CopyInit, Init));
}
QualType buildLambdaInitCaptureInitialization(
    SourceLocation Loc, bool ByRef, SourceLocation EllipsisLoc,
    std::optional<unsigned> NumExpansions, IdentifierInfo *Id,
    bool DirectInit, Expr *&Init);

/// Create a dummy variable within the declcontext of the lambda's
///  call operator, for name lookup purposes for a lambda init capture.
///
///  CodeGen handles emission of lambda captures, ignoring these dummy
///  variables appropriately.
VarDecl *createLambdaInitCaptureVarDecl(
    SourceLocation Loc, QualType InitCaptureType, SourceLocation EllipsisLoc,
    IdentifierInfo *Id, unsigned InitStyle, Expr *Init, DeclContext *DeclCtx);

/// Add an init-capture to a lambda scope.
void addInitCapture(sema::LambdaScopeInfo *LSI, VarDecl *Var,
                    bool isReferenceType);

/// Note that we have finished the explicit captures for the
/// given lambda.
void finishLambdaExplicitCaptures(sema::LambdaScopeInfo *LSI);

/// Deduce a block or lambda's return type based on the return
/// statements present in the body.
void deduceClosureReturnType(sema::CapturingScopeInfo &CSI);

/// Once the Lambdas capture are known, we can start to create the closure,
/// call operator method, and keep track of the captures.
/// We do the capture lookup here, but they are not actually captured until
/// after we know what the qualifiers of the call operator are.
void ActOnLambdaExpressionAfterIntroducer(LambdaIntroducer &Intro,
                                          Scope *CurContext);

/// This is called after parsing the explicit template parameter list
/// on a lambda (if it exists) in C++2a.
void ActOnLambdaExplicitTemplateParameterList(LambdaIntroducer &Intro,
                                              SourceLocation LAngleLoc,
                                              ArrayRef<NamedDecl *> TParams,
                                              SourceLocation RAngleLoc,
                                              ExprResult RequiresClause);

void ActOnLambdaClosureQualifiers(LambdaIntroducer &Intro,
                                  SourceLocation MutableLoc);

void ActOnLambdaClosureParameters(
    Scope *LambdaScope,
    MutableArrayRef<DeclaratorChunk::ParamInfo> ParamInfo);

/// ActOnStartOfLambdaDefinition - This is called just before we start
/// parsing the body of a lambda; it analyzes the explicit captures and
/// arguments, and sets up various data-structures for the body of the
/// lambda.
void ActOnStartOfLambdaDefinition(LambdaIntroducer &Intro,
                                  Declarator &ParamInfo, const DeclSpec &DS);

/// ActOnLambdaError - If there is an error parsing a lambda, this callback
/// is invoked to pop the information about the lambda.
void ActOnLambdaError(SourceLocation StartLoc, Scope *CurScope,
                      bool IsInstantiation = false);

/// ActOnLambdaExpr - This is called when the body of a lambda expression
/// was successfully completed.
ExprResult ActOnLambdaExpr(SourceLocation StartLoc, Stmt *Body,
                           Scope *CurScope);

/// Does copying/destroying the captured variable have side effects?
bool CaptureHasSideEffects(const sema::Capture &From);

/// Diagnose if an explicit lambda capture is unused. Returns true if a
/// diagnostic is emitted.
bool DiagnoseUnusedLambdaCapture(SourceRange CaptureRange,
                                 const sema::Capture &From);

/// Build a FieldDecl suitable to hold the given capture.
FieldDecl *BuildCaptureField(RecordDecl *RD, const sema::Capture &Capture);

/// Initialize the given capture with a suitable expression.
ExprResult BuildCaptureInit(const sema::Capture &Capture,
                            SourceLocation ImplicitCaptureLoc,
                            bool IsOpenMPMapping = false);

/// Complete a lambda-expression having processed and attached the
/// lambda body.
ExprResult BuildLambdaExpr(SourceLocation StartLoc, SourceLocation EndLoc,
                           sema::LambdaScopeInfo *LSI);

/// Get the return type to use for a lambda's conversion function(s) to
/// function pointer type, given the type of the call operator.
QualType
getLambdaConversionFunctionResultType(const FunctionProtoType *CallOpType,
                                      CallingConv CC);

/// Define the "body" of the conversion from a lambda object to a
/// function pointer.
///
/// This routine doesn't actually define a sensible body; rather, it fills
/// in the initialization expression needed to copy the lambda object into
/// the block, and IR generation actually generates the real body of the
/// block pointer conversion.
void DefineImplicitLambdaToFunctionPointerConversion(
       SourceLocation CurrentLoc, CXXConversionDecl *Conv);

/// Define the "body" of the conversion from a lambda object to a
/// block pointer.
///
/// This routine doesn't actually define a sensible body; rather, it fills
/// in the initialization expression needed to copy the lambda object into
/// the block, and IR generation actually generates the real body of the
/// block pointer conversion.
void DefineImplicitLambdaToBlockPointerConversion(SourceLocation CurrentLoc,
                                                  CXXConversionDecl *Conv);

ExprResult BuildBlockForLambdaConversion(SourceLocation CurrentLocation,
                                         SourceLocation ConvLocation,
                                         CXXConversionDecl *Conv,
                                         Expr *Src);

/// Check whether the given expression is a valid constraint expression.
/// A diagnostic is emitted if it is not, false is returned, and
/// PossibleNonPrimary will be set to true if the failure might be due to a
/// non-primary expression being used as an atomic constraint.
bool CheckConstraintExpression(const Expr *CE, Token NextToken = Token(),
                               bool *PossibleNonPrimary = nullptr,
                               bool IsTrailingRequiresClause = false);

7270private:
/// Caches pairs of template-like decls whose associated constraints were
/// checked for subsumption and whether or not the first's constraints did in
/// fact subsume the second's.
llvm::DenseMap<std::pair<NamedDecl *, NamedDecl *>, bool> SubsumptionCache;
/// Caches the normalized associated constraints of declarations (concepts or
/// constrained declarations). If an error occurred while normalizing the
/// associated constraints of the template or concept, nullptr will be cached
/// here.
llvm::DenseMap<NamedDecl *, NormalizedConstraint *>
    NormalizationCache;

llvm::ContextualFoldingSet<ConstraintSatisfaction, const ASTContext &>
    SatisfactionCache;

/// Introduce the instantiated function parameters into the local
/// instantiation scope, and set the parameter names to those used
/// in the template.
bool addInstantiatedParametersToScope(
    FunctionDecl *Function, const FunctionDecl *PatternDecl,
    LocalInstantiationScope &Scope,
    const MultiLevelTemplateArgumentList &TemplateArgs);

/// Introduce the instantiated captures of the lambda into the local
/// instantiation scope.
bool addInstantiatedCapturesToScope(
    FunctionDecl *Function, const FunctionDecl *PatternDecl,
    LocalInstantiationScope &Scope,
    const MultiLevelTemplateArgumentList &TemplateArgs);

/// used by SetupConstraintCheckingTemplateArgumentsAndScope to recursively(in
/// the case of lambdas) set up the LocalInstantiationScope of the current
/// function.
bool SetupConstraintScope(
    FunctionDecl *FD, std::optional<ArrayRef<TemplateArgument>> TemplateArgs,
    MultiLevelTemplateArgumentList MLTAL, LocalInstantiationScope &Scope);

/// Used during constraint checking, sets up the constraint template argument
/// lists, and calls SetupConstraintScope to set up the
/// LocalInstantiationScope to have the proper set of ParVarDecls configured.
std::optional<MultiLevelTemplateArgumentList>
SetupConstraintCheckingTemplateArgumentsAndScope(
    FunctionDecl *FD, std::optional<ArrayRef<TemplateArgument>> TemplateArgs,
    LocalInstantiationScope &Scope);

7315private:
// The current stack of constraint satisfactions, so we can exit-early.
using SatisfactionStackEntryTy =
    std::pair<const NamedDecl *, llvm::FoldingSetNodeID>;
llvm::SmallVector<SatisfactionStackEntryTy, 10>
    SatisfactionStack;

7322public:
void PushSatisfactionStackEntry(const NamedDecl *D,
                                const llvm::FoldingSetNodeID &ID) {
  const NamedDecl *Can = cast<NamedDecl>(D->getCanonicalDecl());
  SatisfactionStack.emplace_back(Can, ID);
}

void PopSatisfactionStackEntry() { SatisfactionStack.pop_back(); }

bool SatisfactionStackContains(const NamedDecl *D,
                               const llvm::FoldingSetNodeID &ID) const {
  const NamedDecl *Can = cast<NamedDecl>(D->getCanonicalDecl());
  return llvm::find(SatisfactionStack,
                    SatisfactionStackEntryTy{Can, ID}) !=
         SatisfactionStack.end();
}

// Resets the current SatisfactionStack for cases where we are instantiating
// constraints as a 'side effect' of normal instantiation in a way that is not
// indicative of recursive definition.
class SatisfactionStackResetRAII {
  llvm::SmallVector<SatisfactionStackEntryTy, 10>
      BackupSatisfactionStack;
  Sema &SemaRef;

public:
  SatisfactionStackResetRAII(Sema &S) : SemaRef(S) {
    SemaRef.SwapSatisfactionStack(BackupSatisfactionStack);
  }

  ~SatisfactionStackResetRAII() {
    SemaRef.SwapSatisfactionStack(BackupSatisfactionStack);
  }
};

void SwapSatisfactionStack(
    llvm::SmallVectorImpl<SatisfactionStackEntryTy> &NewSS) {
  SatisfactionStack.swap(NewSS);
}

const NormalizedConstraint *
getNormalizedAssociatedConstraints(
    NamedDecl *ConstrainedDecl, ArrayRef<const Expr *> AssociatedConstraints);

/// \brief Check whether the given declaration's associated constraints are
/// at least as constrained than another declaration's according to the
/// partial ordering of constraints.
///
/// \param Result If no error occurred, receives the result of true if D1 is
/// at least constrained than D2, and false otherwise.
///
/// \returns true if an error occurred, false otherwise.
bool IsAtLeastAsConstrained(NamedDecl *D1, MutableArrayRef<const Expr *> AC1,
                            NamedDecl *D2, MutableArrayRef<const Expr *> AC2,
                            bool &Result);

/// If D1 was not at least as constrained as D2, but would've been if a pair
/// of atomic constraints involved had been declared in a concept and not
/// repeated in two separate places in code.
/// \returns true if such a diagnostic was emitted, false otherwise.
bool MaybeEmitAmbiguousAtomicConstraintsDiagnostic(NamedDecl *D1,
    ArrayRef<const Expr *> AC1, NamedDecl *D2, ArrayRef<const Expr *> AC2);

/// \brief Check whether the given list of constraint expressions are
/// satisfied (as if in a 'conjunction') given template arguments.
/// \param Template the template-like entity that triggered the constraints
/// check (either a concept or a constrained entity).
/// \param ConstraintExprs a list of constraint expressions, treated as if
/// they were 'AND'ed together.
/// \param TemplateArgLists the list of template arguments to substitute into
/// the constraint expression.
/// \param TemplateIDRange The source range of the template id that
/// caused the constraints check.
/// \param Satisfaction if true is returned, will contain details of the
/// satisfaction, with enough information to diagnose an unsatisfied
/// expression.
/// \returns true if an error occurred and satisfaction could not be checked,
/// false otherwise.
bool CheckConstraintSatisfaction(
    const NamedDecl *Template, ArrayRef<const Expr *> ConstraintExprs,
    const MultiLevelTemplateArgumentList &TemplateArgLists,
    SourceRange TemplateIDRange, ConstraintSatisfaction &Satisfaction) {
  llvm::SmallVector<Expr *, 4> Converted;
  return CheckConstraintSatisfaction(Template, ConstraintExprs, Converted,
                                     TemplateArgLists, TemplateIDRange,
                                     Satisfaction);
}

/// \brief Check whether the given list of constraint expressions are
/// satisfied (as if in a 'conjunction') given template arguments.
/// Additionally, takes an empty list of Expressions which is populated with
/// the instantiated versions of the ConstraintExprs.
/// \param Template the template-like entity that triggered the constraints
/// check (either a concept or a constrained entity).
/// \param ConstraintExprs a list of constraint expressions, treated as if
/// they were 'AND'ed together.
/// \param ConvertedConstraints a out parameter that will get populated with
/// the instantiated version of the ConstraintExprs if we successfully checked
/// satisfaction.
/// \param TemplateArgList the multi-level list of template arguments to
/// substitute into the constraint expression. This should be relative to the
/// top-level (hence multi-level), since we need to instantiate fully at the
/// time of checking.
/// \param TemplateIDRange The source range of the template id that
/// caused the constraints check.
/// \param Satisfaction if true is returned, will contain details of the
/// satisfaction, with enough information to diagnose an unsatisfied
/// expression.
/// \returns true if an error occurred and satisfaction could not be checked,
/// false otherwise.
bool CheckConstraintSatisfaction(
    const NamedDecl *Template, ArrayRef<const Expr *> ConstraintExprs,
    llvm::SmallVectorImpl<Expr *> &ConvertedConstraints,
    const MultiLevelTemplateArgumentList &TemplateArgList,
    SourceRange TemplateIDRange, ConstraintSatisfaction &Satisfaction);

/// \brief Check whether the given non-dependent constraint expression is
/// satisfied. Returns false and updates Satisfaction with the satisfaction
/// verdict if successful, emits a diagnostic and returns true if an error
/// occurred and satisfaction could not be determined.
///
/// \returns true if an error occurred, false otherwise.
bool CheckConstraintSatisfaction(const Expr *ConstraintExpr,
                                 ConstraintSatisfaction &Satisfaction);

/// Check whether the given function decl's trailing requires clause is
/// satisfied, if any. Returns false and updates Satisfaction with the
/// satisfaction verdict if successful, emits a diagnostic and returns true if
/// an error occurred and satisfaction could not be determined.
///
/// \returns true if an error occurred, false otherwise.
bool CheckFunctionConstraints(const FunctionDecl *FD,
                              ConstraintSatisfaction &Satisfaction,
                              SourceLocation UsageLoc = SourceLocation(),
                              bool ForOverloadResolution = false);

/// \brief Ensure that the given template arguments satisfy the constraints
/// associated with the given template, emitting a diagnostic if they do not.
///
/// \param Template The template to which the template arguments are being
/// provided.
///
/// \param TemplateArgs The converted, canonicalized template arguments.
///
/// \param TemplateIDRange The source range of the template id that
/// caused the constraints check.
///
/// \returns true if the constrains are not satisfied or could not be checked
/// for satisfaction, false if the constraints are satisfied.
bool EnsureTemplateArgumentListConstraints(
    TemplateDecl *Template,
    const MultiLevelTemplateArgumentList &TemplateArgs,
    SourceRange TemplateIDRange);

/// \brief Emit diagnostics explaining why a constraint expression was deemed
/// unsatisfied.
/// \param First whether this is the first time an unsatisfied constraint is
/// diagnosed for this error.
void
DiagnoseUnsatisfiedConstraint(const ConstraintSatisfaction &Satisfaction,
                              bool First = true);

/// \brief Emit diagnostics explaining why a constraint expression was deemed
/// unsatisfied.
void
DiagnoseUnsatisfiedConstraint(const ASTConstraintSatisfaction &Satisfaction,
                              bool First = true);

// ParseObjCStringLiteral - Parse Objective-C string literals.
ExprResult ParseObjCStringLiteral(SourceLocation *AtLocs,
                                  ArrayRef<Expr *> Strings);

ExprResult BuildObjCStringLiteral(SourceLocation AtLoc, StringLiteral *S);

/// BuildObjCNumericLiteral - builds an ObjCBoxedExpr AST node for the
/// numeric literal expression. Type of the expression will be "NSNumber *"
/// or "id" if NSNumber is unavailable.
ExprResult BuildObjCNumericLiteral(SourceLocation AtLoc, Expr *Number);
ExprResult ActOnObjCBoolLiteral(SourceLocation AtLoc, SourceLocation ValueLoc,
                                bool Value);
ExprResult BuildObjCArrayLiteral(SourceRange SR, MultiExprArg Elements);

/// BuildObjCBoxedExpr - builds an ObjCBoxedExpr AST node for the
/// '@' prefixed parenthesized expression. The type of the expression will
/// either be "NSNumber *", "NSString *" or "NSValue *" depending on the type
/// of ValueType, which is allowed to be a built-in numeric type, "char *",
/// "const char *" or C structure with attribute 'objc_boxable'.
ExprResult BuildObjCBoxedExpr(SourceRange SR, Expr *ValueExpr);

ExprResult BuildObjCSubscriptExpression(SourceLocation RB, Expr *BaseExpr,
                                        Expr *IndexExpr,
                                        ObjCMethodDecl *getterMethod,
                                        ObjCMethodDecl *setterMethod);

ExprResult BuildObjCDictionaryLiteral(SourceRange SR,
                             MutableArrayRef<ObjCDictionaryElement> Elements);

ExprResult BuildObjCEncodeExpression(SourceLocation AtLoc,
                                TypeSourceInfo *EncodedTypeInfo,
                                SourceLocation RParenLoc);
ExprResult BuildCXXMemberCallExpr(Expr *Exp, NamedDecl *FoundDecl,
                                  CXXConversionDecl *Method,
                                  bool HadMultipleCandidates);

ExprResult ParseObjCEncodeExpression(SourceLocation AtLoc,
                                     SourceLocation EncodeLoc,
                                     SourceLocation LParenLoc,
                                     ParsedType Ty,
                                     SourceLocation RParenLoc);

/// ParseObjCSelectorExpression - Build selector expression for \@selector
ExprResult ParseObjCSelectorExpression(Selector Sel,
                                       SourceLocation AtLoc,
                                       SourceLocation SelLoc,
                                       SourceLocation LParenLoc,
                                       SourceLocation RParenLoc,
                                       bool WarnMultipleSelectors);

/// ParseObjCProtocolExpression - Build protocol expression for \@protocol
ExprResult ParseObjCProtocolExpression(IdentifierInfo * ProtocolName,
                                       SourceLocation AtLoc,
                                       SourceLocation ProtoLoc,
                                       SourceLocation LParenLoc,
                                       SourceLocation ProtoIdLoc,
                                       SourceLocation RParenLoc);

//===--------------------------------------------------------------------===//
// C++ Declarations
//
Decl *ActOnStartLinkageSpecification(Scope *S,
                                     SourceLocation ExternLoc,
                                     Expr *LangStr,
                                     SourceLocation LBraceLoc);
Decl *ActOnFinishLinkageSpecification(Scope *S,
                                      Decl *LinkageSpec,
                                      SourceLocation RBraceLoc);


//===--------------------------------------------------------------------===//
// C++ Classes
//
CXXRecordDecl *getCurrentClass(Scope *S, const CXXScopeSpec *SS);
bool isCurrentClassName(const IdentifierInfo &II, Scope *S,
                        const CXXScopeSpec *SS = nullptr);
bool isCurrentClassNameTypo(IdentifierInfo *&II, const CXXScopeSpec *SS);

bool ActOnAccessSpecifier(AccessSpecifier Access, SourceLocation ASLoc,
                          SourceLocation ColonLoc,
                          const ParsedAttributesView &Attrs);

NamedDecl *ActOnCXXMemberDeclarator(Scope *S, AccessSpecifier AS,
                               Declarator &D,
                               MultiTemplateParamsArg TemplateParameterLists,
                               Expr *BitfieldWidth, const VirtSpecifiers &VS,
                               InClassInitStyle InitStyle);

void ActOnStartCXXInClassMemberInitializer();
void ActOnFinishCXXInClassMemberInitializer(Decl *VarDecl,
                                            SourceLocation EqualLoc,
                                            Expr *Init);

MemInitResult ActOnMemInitializer(Decl *ConstructorD,
                                  Scope *S,
                                  CXXScopeSpec &SS,
                                  IdentifierInfo *MemberOrBase,
                                  ParsedType TemplateTypeTy,
                                  const DeclSpec &DS,
                                  SourceLocation IdLoc,
                                  SourceLocation LParenLoc,
                                  ArrayRef<Expr *> Args,
                                  SourceLocation RParenLoc,
                                  SourceLocation EllipsisLoc);

MemInitResult ActOnMemInitializer(Decl *ConstructorD,
                                  Scope *S,
                                  CXXScopeSpec &SS,
                                  IdentifierInfo *MemberOrBase,
                                  ParsedType TemplateTypeTy,
                                  const DeclSpec &DS,
                                  SourceLocation IdLoc,
                                  Expr *InitList,
                                  SourceLocation EllipsisLoc);

MemInitResult BuildMemInitializer(Decl *ConstructorD,
                                  Scope *S,
                                  CXXScopeSpec &SS,
                                  IdentifierInfo *MemberOrBase,
                                  ParsedType TemplateTypeTy,
                                  const DeclSpec &DS,
                                  SourceLocation IdLoc,
                                  Expr *Init,
                                  SourceLocation EllipsisLoc);

MemInitResult BuildMemberInitializer(ValueDecl *Member,
                                     Expr *Init,
                                     SourceLocation IdLoc);

MemInitResult BuildBaseInitializer(QualType BaseType,
                                   TypeSourceInfo *BaseTInfo,
                                   Expr *Init,
                                   CXXRecordDecl *ClassDecl,
                                   SourceLocation EllipsisLoc);

MemInitResult BuildDelegatingInitializer(TypeSourceInfo *TInfo,
                                         Expr *Init,
                                         CXXRecordDecl *ClassDecl);

bool SetDelegatingInitializer(CXXConstructorDecl *Constructor,
                              CXXCtorInitializer *Initializer);

bool SetCtorInitializers(
    CXXConstructorDecl *Constructor, bool AnyErrors,
    ArrayRef<CXXCtorInitializer *> Initializers = std::nullopt);

void SetIvarInitializers(ObjCImplementationDecl *ObjCImplementation);


/// MarkBaseAndMemberDestructorsReferenced - Given a record decl,
/// mark all the non-trivial destructors of its members and bases as
/// referenced.
void MarkBaseAndMemberDestructorsReferenced(SourceLocation Loc,
                                            CXXRecordDecl *Record);

/// Mark destructors of virtual bases of this class referenced. In the Itanium
/// C++ ABI, this is done when emitting a destructor for any non-abstract
/// class. In the Microsoft C++ ABI, this is done any time a class's
/// destructor is referenced.
void MarkVirtualBaseDestructorsReferenced(
    SourceLocation Location, CXXRecordDecl *ClassDecl,
    llvm::SmallPtrSetImpl<const RecordType *> *DirectVirtualBases = nullptr);

/// Do semantic checks to allow the complete destructor variant to be emitted
/// when the destructor is defined in another translation unit. In the Itanium
/// C++ ABI, destructor variants are emitted together. In the MS C++ ABI, they
/// can be emitted in separate TUs. To emit the complete variant, run a subset
/// of the checks performed when emitting a regular destructor.
void CheckCompleteDestructorVariant(SourceLocation CurrentLocation,
                                    CXXDestructorDecl *Dtor);

/// The list of classes whose vtables have been used within
/// this translation unit, and the source locations at which the
/// first use occurred.
typedef std::pair<CXXRecordDecl*, SourceLocation> VTableUse;

/// The list of vtables that are required but have not yet been
/// materialized.
SmallVector<VTableUse, 16> VTableUses;

/// The set of classes whose vtables have been used within
/// this translation unit, and a bit that will be true if the vtable is
/// required to be emitted (otherwise, it should be emitted only if needed
/// by code generation).
llvm::DenseMap<CXXRecordDecl *, bool> VTablesUsed;

/// Load any externally-stored vtable uses.
void LoadExternalVTableUses();

/// Note that the vtable for the given class was used at the
/// given location.
void MarkVTableUsed(SourceLocation Loc, CXXRecordDecl *Class,
                    bool DefinitionRequired = false);

/// Mark the exception specifications of all virtual member functions
/// in the given class as needed.
void MarkVirtualMemberExceptionSpecsNeeded(SourceLocation Loc,
                                           const CXXRecordDecl *RD);

/// MarkVirtualMembersReferenced - Will mark all members of the given
/// CXXRecordDecl referenced.
void MarkVirtualMembersReferenced(SourceLocation Loc, const CXXRecordDecl *RD,
                                  bool ConstexprOnly = false);

/// Define all of the vtables that have been used in this
/// translation unit and reference any virtual members used by those
/// vtables.
///
/// \returns true if any work was done, false otherwise.
bool DefineUsedVTables();

void AddImplicitlyDeclaredMembersToClass(CXXRecordDecl *ClassDecl);

void ActOnMemInitializers(Decl *ConstructorDecl,
                          SourceLocation ColonLoc,
                          ArrayRef<CXXCtorInitializer*> MemInits,
                          bool AnyErrors);

/// Check class-level dllimport/dllexport attribute. The caller must
/// ensure that referenceDLLExportedClassMethods is called some point later
/// when all outer classes of Class are complete.
void checkClassLevelDLLAttribute(CXXRecordDecl *Class);
void checkClassLevelCodeSegAttribute(CXXRecordDecl *Class);

void referenceDLLExportedClassMethods();

void propagateDLLAttrToBaseClassTemplate(
    CXXRecordDecl *Class, Attr *ClassAttr,
    ClassTemplateSpecializationDecl *BaseTemplateSpec,
    SourceLocation BaseLoc);

/// Add gsl::Pointer attribute to std::container::iterator
/// \param ND The declaration that introduces the name
/// std::container::iterator. \param UnderlyingRecord The record named by ND.
void inferGslPointerAttribute(NamedDecl *ND, CXXRecordDecl *UnderlyingRecord);

/// Add [[gsl::Owner]] and [[gsl::Pointer]] attributes for std:: types.
void inferGslOwnerPointerAttribute(CXXRecordDecl *Record);

/// Add [[gsl::Pointer]] attributes for std:: types.
void inferGslPointerAttribute(TypedefNameDecl *TD);

void CheckCompletedCXXClass(Scope *S, CXXRecordDecl *Record);

/// Check that the C++ class annoated with "trivial_abi" satisfies all the
/// conditions that are needed for the attribute to have an effect.
void checkIllFormedTrivialABIStruct(CXXRecordDecl &RD);

void ActOnFinishCXXMemberSpecification(Scope *S, SourceLocation RLoc,
                                       Decl *TagDecl, SourceLocation LBrac,
                                       SourceLocation RBrac,
                                       const ParsedAttributesView &AttrList);
void ActOnFinishCXXMemberDecls();
void ActOnFinishCXXNonNestedClass();

void ActOnReenterCXXMethodParameter(Scope *S, ParmVarDecl *Param);
unsigned ActOnReenterTemplateScope(Decl *Template,
                                   llvm::function_ref<Scope *()> EnterScope);
void ActOnStartDelayedMemberDeclarations(Scope *S, Decl *Record);
void ActOnStartDelayedCXXMethodDeclaration(Scope *S, Decl *Method);
void ActOnDelayedCXXMethodParameter(Scope *S, Decl *Param);
void ActOnFinishDelayedMemberDeclarations(Scope *S, Decl *Record);
void ActOnFinishDelayedCXXMethodDeclaration(Scope *S, Decl *Method);
void ActOnFinishDelayedMemberInitializers(Decl *Record);
void MarkAsLateParsedTemplate(FunctionDecl *FD, Decl *FnD,
                              CachedTokens &Toks);
void UnmarkAsLateParsedTemplate(FunctionDecl *FD);
bool IsInsideALocalClassWithinATemplateFunction();

Decl *ActOnStaticAssertDeclaration(SourceLocation StaticAssertLoc,
                                   Expr *AssertExpr,
                                   Expr *AssertMessageExpr,
                                   SourceLocation RParenLoc);
Decl *BuildStaticAssertDeclaration(SourceLocation StaticAssertLoc,
                                   Expr *AssertExpr,
                                   StringLiteral *AssertMessageExpr,
                                   SourceLocation RParenLoc,
                                   bool Failed);
void DiagnoseStaticAssertDetails(const Expr *E);

FriendDecl *CheckFriendTypeDecl(SourceLocation LocStart,
                                SourceLocation FriendLoc,
                                TypeSourceInfo *TSInfo);
Decl *ActOnFriendTypeDecl(Scope *S, const DeclSpec &DS,
                          MultiTemplateParamsArg TemplateParams);
NamedDecl *ActOnFriendFunctionDecl(Scope *S, Declarator &D,
                                   MultiTemplateParamsArg TemplateParams);

QualType CheckConstructorDeclarator(Declarator &D, QualType R,
                                    StorageClass& SC);
void CheckConstructor(CXXConstructorDecl *Constructor);
QualType CheckDestructorDeclarator(Declarator &D, QualType R,
                                   StorageClass& SC);
bool CheckDestructor(CXXDestructorDecl *Destructor);
void CheckConversionDeclarator(Declarator &D, QualType &R,
                               StorageClass& SC);
Decl *ActOnConversionDeclarator(CXXConversionDecl *Conversion);
void CheckDeductionGuideDeclarator(Declarator &D, QualType &R,
                                   StorageClass &SC);
void CheckDeductionGuideTemplate(FunctionTemplateDecl *TD);

void CheckExplicitlyDefaultedFunction(Scope *S, FunctionDecl *MD);

bool CheckExplicitlyDefaultedSpecialMember(CXXMethodDecl *MD,
                                           CXXSpecialMember CSM,
                                           SourceLocation DefaultLoc);
void CheckDelayedMemberExceptionSpecs();

bool CheckExplicitlyDefaultedComparison(Scope *S, FunctionDecl *MD,
                                        DefaultedComparisonKind DCK);
void DeclareImplicitEqualityComparison(CXXRecordDecl *RD,
                                       FunctionDecl *Spaceship);
void DefineDefaultedComparison(SourceLocation Loc, FunctionDecl *FD,
                               DefaultedComparisonKind DCK);

//===--------------------------------------------------------------------===//
// C++ Derived Classes
//

/// ActOnBaseSpecifier - Parsed a base specifier
CXXBaseSpecifier *CheckBaseSpecifier(CXXRecordDecl *Class,
                                     SourceRange SpecifierRange,
                                     bool Virtual, AccessSpecifier Access,
                                     TypeSourceInfo *TInfo,
                                     SourceLocation EllipsisLoc);

BaseResult ActOnBaseSpecifier(Decl *classdecl, SourceRange SpecifierRange,
                              const ParsedAttributesView &Attrs, bool Virtual,
                              AccessSpecifier Access, ParsedType basetype,
                              SourceLocation BaseLoc,
                              SourceLocation EllipsisLoc);

bool AttachBaseSpecifiers(CXXRecordDecl *Class,
                          MutableArrayRef<CXXBaseSpecifier *> Bases);
void ActOnBaseSpecifiers(Decl *ClassDecl,
                         MutableArrayRef<CXXBaseSpecifier *> Bases);

bool IsDerivedFrom(SourceLocation Loc, QualType Derived, QualType Base);
bool IsDerivedFrom(SourceLocation Loc, QualType Derived, QualType Base,
                   CXXBasePaths &Paths);

// FIXME: I don't like this name.
void BuildBasePathArray(const CXXBasePaths &Paths, CXXCastPath &BasePath);

bool CheckDerivedToBaseConversion(QualType Derived, QualType Base,
                                  SourceLocation Loc, SourceRange Range,
                                  CXXCastPath *BasePath = nullptr,
                                  bool IgnoreAccess = false);
bool CheckDerivedToBaseConversion(QualType Derived, QualType Base,
                                  unsigned InaccessibleBaseID,
                                  unsigned AmbiguousBaseConvID,
                                  SourceLocation Loc, SourceRange Range,
                                  DeclarationName Name,
                                  CXXCastPath *BasePath,
                                  bool IgnoreAccess = false);

std::string getAmbiguousPathsDisplayString(CXXBasePaths &Paths);

bool CheckOverridingFunctionAttributes(const CXXMethodDecl *New,
                                       const CXXMethodDecl *Old);

/// CheckOverridingFunctionReturnType - Checks whether the return types are
/// covariant, according to C++ [class.virtual]p5.
bool CheckOverridingFunctionReturnType(const CXXMethodDecl *New,
                                       const CXXMethodDecl *Old);

/// CheckOverridingFunctionExceptionSpec - Checks whether the exception
/// spec is a subset of base spec.
bool CheckOverridingFunctionExceptionSpec(const CXXMethodDecl *New,
                                          const CXXMethodDecl *Old);

bool CheckPureMethod(CXXMethodDecl *Method, SourceRange InitRange);

/// CheckOverrideControl - Check C++11 override control semantics.
void CheckOverrideControl(NamedDecl *D);

/// DiagnoseAbsenceOfOverrideControl - Diagnose if 'override' keyword was
/// not used in the declaration of an overriding method.
void DiagnoseAbsenceOfOverrideControl(NamedDecl *D, bool Inconsistent);

/// CheckForFunctionMarkedFinal - Checks whether a virtual member function
/// overrides a virtual member function marked 'final', according to
/// C++11 [class.virtual]p4.
bool CheckIfOverriddenFunctionIsMarkedFinal(const CXXMethodDecl *New,
                                            const CXXMethodDecl *Old);


//===--------------------------------------------------------------------===//
// C++ Access Control
//

enum AccessResult {
  AR_accessible,
  AR_inaccessible,
  AR_dependent,
  AR_delayed
};

bool SetMemberAccessSpecifier(NamedDecl *MemberDecl,
                              NamedDecl *PrevMemberDecl,
                              AccessSpecifier LexicalAS);

AccessResult CheckUnresolvedMemberAccess(UnresolvedMemberExpr *E,
                                         DeclAccessPair FoundDecl);
AccessResult CheckUnresolvedLookupAccess(UnresolvedLookupExpr *E,
                                         DeclAccessPair FoundDecl);
AccessResult CheckAllocationAccess(SourceLocation OperatorLoc,
                                   SourceRange PlacementRange,
                                   CXXRecordDecl *NamingClass,
                                   DeclAccessPair FoundDecl,
                                   bool Diagnose = true);
AccessResult CheckConstructorAccess(SourceLocation Loc,
                                    CXXConstructorDecl *D,
                                    DeclAccessPair FoundDecl,
                                    const InitializedEntity &Entity,
                                    bool IsCopyBindingRefToTemp = false);
AccessResult CheckConstructorAccess(SourceLocation Loc,
                                    CXXConstructorDecl *D,
                                    DeclAccessPair FoundDecl,
                                    const InitializedEntity &Entity,
                                    const PartialDiagnostic &PDiag);
AccessResult CheckDestructorAccess(SourceLocation Loc,
                                   CXXDestructorDecl *Dtor,
                                   const PartialDiagnostic &PDiag,
                                   QualType objectType = QualType());
AccessResult CheckFriendAccess(NamedDecl *D);
AccessResult CheckMemberAccess(SourceLocation UseLoc,
                               CXXRecordDecl *NamingClass,
                               DeclAccessPair Found);
AccessResult
CheckStructuredBindingMemberAccess(SourceLocation UseLoc,
                                   CXXRecordDecl *DecomposedClass,
                                   DeclAccessPair Field);
AccessResult CheckMemberOperatorAccess(SourceLocation Loc, Expr *ObjectExpr,
                                       const SourceRange &,
                                       DeclAccessPair FoundDecl);
AccessResult CheckMemberOperatorAccess(SourceLocation Loc,
                                       Expr *ObjectExpr,
                                       Expr *ArgExpr,
                                       DeclAccessPair FoundDecl);
AccessResult CheckMemberOperatorAccess(SourceLocation Loc, Expr *ObjectExpr,
                                       ArrayRef<Expr *> ArgExprs,
                                       DeclAccessPair FoundDecl);
AccessResult CheckAddressOfMemberAccess(Expr *OvlExpr,
                                        DeclAccessPair FoundDecl);
AccessResult CheckBaseClassAccess(SourceLocation AccessLoc,
                                  QualType Base, QualType Derived,
                                  const CXXBasePath &Path,
                                  unsigned DiagID,
                                  bool ForceCheck = false,
                                  bool ForceUnprivileged = false);
void CheckLookupAccess(const LookupResult &R);
bool IsSimplyAccessible(NamedDecl *Decl, CXXRecordDecl *NamingClass,
                        QualType BaseType);
bool isMemberAccessibleForDeletion(CXXRecordDecl *NamingClass,
                                   DeclAccessPair Found, QualType ObjectType,
                                   SourceLocation Loc,
                                   const PartialDiagnostic &Diag);
bool isMemberAccessibleForDeletion(CXXRecordDecl *NamingClass,
                                   DeclAccessPair Found,
                                   QualType ObjectType) {
  return isMemberAccessibleForDeletion(NamingClass, Found, ObjectType,
                                       SourceLocation(), PDiag());
}

void HandleDependentAccessCheck(const DependentDiagnostic &DD,
                       const MultiLevelTemplateArgumentList &TemplateArgs);
void PerformDependentDiagnostics(const DeclContext *Pattern,
                      const MultiLevelTemplateArgumentList &TemplateArgs);

void HandleDelayedAccessCheck(sema::DelayedDiagnostic &DD, Decl *Ctx);

/// When true, access checking violations are treated as SFINAE
/// failures rather than hard errors.
bool AccessCheckingSFINAE;

enum AbstractDiagSelID {
  AbstractNone = -1,
  AbstractReturnType,
  AbstractParamType,
  AbstractVariableType,
  AbstractFieldType,
  AbstractIvarType,
  AbstractSynthesizedIvarType,
  AbstractArrayType
};

bool isAbstractType(SourceLocation Loc, QualType T);
bool RequireNonAbstractType(SourceLocation Loc, QualType T,
                            TypeDiagnoser &Diagnoser);
template <typename... Ts>
bool RequireNonAbstractType(SourceLocation Loc, QualType T, unsigned DiagID,
                            const Ts &...Args) {
  BoundTypeDiagnoser<Ts...> Diagnoser(DiagID, Args...);
  return RequireNonAbstractType(Loc, T, Diagnoser);
}

void DiagnoseAbstractType(const CXXRecordDecl *RD);

//===--------------------------------------------------------------------===//
// C++ Overloaded Operators [C++ 13.5]
//

bool CheckOverloadedOperatorDeclaration(FunctionDecl *FnDecl);

bool CheckLiteralOperatorDeclaration(FunctionDecl *FnDecl);

//===--------------------------------------------------------------------===//
// C++ Templates [C++ 14]
//
void FilterAcceptableTemplateNames(LookupResult &R,
                                   bool AllowFunctionTemplates = true,
                                   bool AllowDependent = true);
bool hasAnyAcceptableTemplateNames(LookupResult &R,
                                   bool AllowFunctionTemplates = true,
                                   bool AllowDependent = true,
                                   bool AllowNonTemplateFunctions = false);
/// Try to interpret the lookup result D as a template-name.
///
/// \param D A declaration found by name lookup.
/// \param AllowFunctionTemplates Whether function templates should be
///        considered valid results.
/// \param AllowDependent Whether unresolved using declarations (that might
///        name templates) should be considered valid results.
static NamedDecl *getAsTemplateNameDecl(NamedDecl *D,
                                        bool AllowFunctionTemplates = true,
                                        bool AllowDependent = true);

enum TemplateNameIsRequiredTag { TemplateNameIsRequired };
/// Whether and why a template name is required in this lookup.
class RequiredTemplateKind {
public:
  /// Template name is required if TemplateKWLoc is valid.
  RequiredTemplateKind(SourceLocation TemplateKWLoc = SourceLocation())
      : TemplateKW(TemplateKWLoc) {}
  /// Template name is unconditionally required.
  RequiredTemplateKind(TemplateNameIsRequiredTag) {}

  SourceLocation getTemplateKeywordLoc() const {
    return TemplateKW.value_or(SourceLocation());
  }
  bool hasTemplateKeyword() const { return getTemplateKeywordLoc().isValid(); }
  bool isRequired() const { return TemplateKW != SourceLocation(); }
  explicit operator bool() const { return isRequired(); }

private:
  std::optional<SourceLocation> TemplateKW;
};

enum class AssumedTemplateKind {
  /// This is not assumed to be a template name.
  None,
  /// This is assumed to be a template name because lookup found nothing.
  FoundNothing,
  /// This is assumed to be a template name because lookup found one or more
  /// functions (but no function templates).
  FoundFunctions,
};
bool LookupTemplateName(
    LookupResult &R, Scope *S, CXXScopeSpec &SS, QualType ObjectType,
    bool EnteringContext, bool &MemberOfUnknownSpecialization,
    RequiredTemplateKind RequiredTemplate = SourceLocation(),
    AssumedTemplateKind *ATK = nullptr, bool AllowTypoCorrection = true);

TemplateNameKind isTemplateName(Scope *S,
                                CXXScopeSpec &SS,
                                bool hasTemplateKeyword,
                                const UnqualifiedId &Name,
                                ParsedType ObjectType,
                                bool EnteringContext,
                                TemplateTy &Template,
                                bool &MemberOfUnknownSpecialization,
                                bool Disambiguation = false);

/// Try to resolve an undeclared template name as a type template.
///
/// Sets II to the identifier corresponding to the template name, and updates
/// Name to a corresponding (typo-corrected) type template name and TNK to
/// the corresponding kind, if possible.
void ActOnUndeclaredTypeTemplateName(Scope *S, TemplateTy &Name,
                                     TemplateNameKind &TNK,
                                     SourceLocation NameLoc,
                                     IdentifierInfo *&II);

bool resolveAssumedTemplateNameAsType(Scope *S, TemplateName &Name,
                                      SourceLocation NameLoc,
                                      bool Diagnose = true);

/// Determine whether a particular identifier might be the name in a C++1z
/// deduction-guide declaration.
bool isDeductionGuideName(Scope *S, const IdentifierInfo &Name,
                          SourceLocation NameLoc, CXXScopeSpec &SS,
                          ParsedTemplateTy *Template = nullptr);

bool DiagnoseUnknownTemplateName(const IdentifierInfo &II,
                                 SourceLocation IILoc,
                                 Scope *S,
                                 const CXXScopeSpec *SS,
                                 TemplateTy &SuggestedTemplate,
                                 TemplateNameKind &SuggestedKind);

bool DiagnoseUninstantiableTemplate(SourceLocation PointOfInstantiation,
                                    NamedDecl *Instantiation,
                                    bool InstantiatedFromMember,
                                    const NamedDecl *Pattern,
                                    const NamedDecl *PatternDef,
                                    TemplateSpecializationKind TSK,
                                    bool Complain = true);

void DiagnoseTemplateParameterShadow(SourceLocation Loc, Decl *PrevDecl);
TemplateDecl *AdjustDeclIfTemplate(Decl *&Decl);

NamedDecl *ActOnTypeParameter(Scope *S, bool Typename,
                              SourceLocation EllipsisLoc,
                              SourceLocation KeyLoc,
                              IdentifierInfo *ParamName,
                              SourceLocation ParamNameLoc,
                              unsigned Depth, unsigned Position,
                              SourceLocation EqualLoc,
                              ParsedType DefaultArg, bool HasTypeConstraint);

bool CheckTypeConstraint(TemplateIdAnnotation *TypeConstraint);

bool ActOnTypeConstraint(const CXXScopeSpec &SS,
                         TemplateIdAnnotation *TypeConstraint,
                         TemplateTypeParmDecl *ConstrainedParameter,
                         SourceLocation EllipsisLoc);
bool BuildTypeConstraint(const CXXScopeSpec &SS,
                         TemplateIdAnnotation *TypeConstraint,
                         TemplateTypeParmDecl *ConstrainedParameter,
                         SourceLocation EllipsisLoc,
                         bool AllowUnexpandedPack);

bool AttachTypeConstraint(NestedNameSpecifierLoc NS,
                          DeclarationNameInfo NameInfo,
                          ConceptDecl *NamedConcept,
                          const TemplateArgumentListInfo *TemplateArgs,
                          TemplateTypeParmDecl *ConstrainedParameter,
                          SourceLocation EllipsisLoc);

bool AttachTypeConstraint(AutoTypeLoc TL,
                          NonTypeTemplateParmDecl *NewConstrainedParm,
                          NonTypeTemplateParmDecl *OrigConstrainedParm,
                          SourceLocation EllipsisLoc);

bool RequireStructuralType(QualType T, SourceLocation Loc);

QualType CheckNonTypeTemplateParameterType(TypeSourceInfo *&TSI,
                                           SourceLocation Loc);
QualType CheckNonTypeTemplateParameterType(QualType T, SourceLocation Loc);

NamedDecl *ActOnNonTypeTemplateParameter(Scope *S, Declarator &D,
                                    unsigned Depth,
                                    unsigned Position,
                                    SourceLocation EqualLoc,
                                    Expr *DefaultArg);
NamedDecl *ActOnTemplateTemplateParameter(Scope *S,
                                     SourceLocation TmpLoc,
                                     TemplateParameterList *Params,
                                     SourceLocation EllipsisLoc,
                                     IdentifierInfo *ParamName,
                                     SourceLocation ParamNameLoc,
                                     unsigned Depth,
                                     unsigned Position,
                                     SourceLocation EqualLoc,
                                     ParsedTemplateArgument DefaultArg);

TemplateParameterList *
ActOnTemplateParameterList(unsigned Depth,
                           SourceLocation ExportLoc,
                           SourceLocation TemplateLoc,
                           SourceLocation LAngleLoc,
                           ArrayRef<NamedDecl *> Params,
                           SourceLocation RAngleLoc,
                           Expr *RequiresClause);

/// The context in which we are checking a template parameter list.
enum TemplateParamListContext {
  TPC_ClassTemplate,
  TPC_VarTemplate,
  TPC_FunctionTemplate,
  TPC_ClassTemplateMember,
  TPC_FriendClassTemplate,
  TPC_FriendFunctionTemplate,
  TPC_FriendFunctionTemplateDefinition,
  TPC_TypeAliasTemplate
};

bool CheckTemplateParameterList(TemplateParameterList *NewParams,
                                TemplateParameterList *OldParams,
                                TemplateParamListContext TPC,
                                SkipBodyInfo *SkipBody = nullptr);
TemplateParameterList *MatchTemplateParametersToScopeSpecifier(
    SourceLocation DeclStartLoc, SourceLocation DeclLoc,
    const CXXScopeSpec &SS, TemplateIdAnnotation *TemplateId,
    ArrayRef<TemplateParameterList *> ParamLists,
    bool IsFriend, bool &IsMemberSpecialization, bool &Invalid,
    bool SuppressDiagnostic = false);

DeclResult CheckClassTemplate(
    Scope *S, unsigned TagSpec, TagUseKind TUK, SourceLocation KWLoc,
    CXXScopeSpec &SS, IdentifierInfo *Name, SourceLocation NameLoc,
    const ParsedAttributesView &Attr, TemplateParameterList *TemplateParams,
    AccessSpecifier AS, SourceLocation ModulePrivateLoc,
    SourceLocation FriendLoc, unsigned NumOuterTemplateParamLists,
    TemplateParameterList **OuterTemplateParamLists,
    SkipBodyInfo *SkipBody = nullptr);

TemplateArgumentLoc getTrivialTemplateArgumentLoc(const TemplateArgument &Arg,
                                                  QualType NTTPType,
                                                  SourceLocation Loc);

/// Get a template argument mapping the given template parameter to itself,
/// e.g. for X in \c template<int X>, this would return an expression template
/// argument referencing X.
TemplateArgumentLoc getIdentityTemplateArgumentLoc(NamedDecl *Param,
                                                   SourceLocation Location);

void translateTemplateArguments(const ASTTemplateArgsPtr &In,
                                TemplateArgumentListInfo &Out);

ParsedTemplateArgument ActOnTemplateTypeArgument(TypeResult ParsedType);

void NoteAllFoundTemplates(TemplateName Name);

QualType CheckTemplateIdType(TemplateName Template,
                             SourceLocation TemplateLoc,
                            TemplateArgumentListInfo &TemplateArgs);

TypeResult
ActOnTemplateIdType(Scope *S, CXXScopeSpec &SS, SourceLocation TemplateKWLoc,
                    TemplateTy Template, IdentifierInfo *TemplateII,
                    SourceLocation TemplateIILoc, SourceLocation LAngleLoc,
                    ASTTemplateArgsPtr TemplateArgs, SourceLocation RAngleLoc,
                    bool IsCtorOrDtorName = false, bool IsClassName = false,
                    ImplicitTypenameContext AllowImplicitTypename =
                        ImplicitTypenameContext::No);

/// Parsed an elaborated-type-specifier that refers to a template-id,
/// such as \c class T::template apply<U>.
TypeResult ActOnTagTemplateIdType(TagUseKind TUK,
                                  TypeSpecifierType TagSpec,
                                  SourceLocation TagLoc,
                                  CXXScopeSpec &SS,
                                  SourceLocation TemplateKWLoc,
                                  TemplateTy TemplateD,
                                  SourceLocation TemplateLoc,
                                  SourceLocation LAngleLoc,
                                  ASTTemplateArgsPtr TemplateArgsIn,
                                  SourceLocation RAngleLoc);

DeclResult ActOnVarTemplateSpecialization(
    Scope *S, Declarator &D, TypeSourceInfo *DI,
    SourceLocation TemplateKWLoc, TemplateParameterList *TemplateParams,
    StorageClass SC, bool IsPartialSpecialization);

/// Get the specialization of the given variable template corresponding to
/// the specified argument list, or a null-but-valid result if the arguments
/// are dependent.
DeclResult CheckVarTemplateId(VarTemplateDecl *Template,
                              SourceLocation TemplateLoc,
                              SourceLocation TemplateNameLoc,
                              const TemplateArgumentListInfo &TemplateArgs);

/// Form a reference to the specialization of the given variable template
/// corresponding to the specified argument list, or a null-but-valid result
/// if the arguments are dependent.
ExprResult CheckVarTemplateId(const CXXScopeSpec &SS,
                              const DeclarationNameInfo &NameInfo,
                              VarTemplateDecl *Template,
                              SourceLocation TemplateLoc,
                              const TemplateArgumentListInfo *TemplateArgs);

ExprResult
CheckConceptTemplateId(const CXXScopeSpec &SS,
                       SourceLocation TemplateKWLoc,
                       const DeclarationNameInfo &ConceptNameInfo,
                       NamedDecl *FoundDecl, ConceptDecl *NamedConcept,
                       const TemplateArgumentListInfo *TemplateArgs);

void diagnoseMissingTemplateArguments(TemplateName Name, SourceLocation Loc);

ExprResult BuildTemplateIdExpr(const CXXScopeSpec &SS,
                               SourceLocation TemplateKWLoc,
                               LookupResult &R,
                               bool RequiresADL,
                             const TemplateArgumentListInfo *TemplateArgs);

ExprResult BuildQualifiedTemplateIdExpr(CXXScopeSpec &SS,
                                        SourceLocation TemplateKWLoc,
                             const DeclarationNameInfo &NameInfo,
                             const TemplateArgumentListInfo *TemplateArgs);

TemplateNameKind ActOnTemplateName(
    Scope *S, CXXScopeSpec &SS, SourceLocation TemplateKWLoc,
    const UnqualifiedId &Name, ParsedType ObjectType, bool EnteringContext,
    TemplateTy &Template, bool AllowInjectedClassName = false);

DeclResult ActOnClassTemplateSpecialization(
    Scope *S, unsigned TagSpec, TagUseKind TUK, SourceLocation KWLoc,
    SourceLocation ModulePrivateLoc, CXXScopeSpec &SS,
    TemplateIdAnnotation &TemplateId, const ParsedAttributesView &Attr,
    MultiTemplateParamsArg TemplateParameterLists,
    SkipBodyInfo *SkipBody = nullptr);

bool CheckTemplatePartialSpecializationArgs(SourceLocation Loc,
                                            TemplateDecl *PrimaryTemplate,
                                            unsigned NumExplicitArgs,
                                            ArrayRef<TemplateArgument> Args);
void CheckTemplatePartialSpecialization(
    ClassTemplatePartialSpecializationDecl *Partial);
void CheckTemplatePartialSpecialization(
    VarTemplatePartialSpecializationDecl *Partial);

Decl *ActOnTemplateDeclarator(Scope *S,
                              MultiTemplateParamsArg TemplateParameterLists,
                              Declarator &D);

bool
CheckSpecializationInstantiationRedecl(SourceLocation NewLoc,
                                       TemplateSpecializationKind NewTSK,
                                       NamedDecl *PrevDecl,
                                       TemplateSpecializationKind PrevTSK,
                                       SourceLocation PrevPtOfInstantiation,
                                       bool &SuppressNew);

bool CheckDependentFunctionTemplateSpecialization(FunctionDecl *FD,
                  const TemplateArgumentListInfo &ExplicitTemplateArgs,
                                                  LookupResult &Previous);

bool CheckFunctionTemplateSpecialization(
    FunctionDecl *FD, TemplateArgumentListInfo *ExplicitTemplateArgs,
    LookupResult &Previous, bool QualifiedFriend = false);
bool CheckMemberSpecialization(NamedDecl *Member, LookupResult &Previous);
void CompleteMemberSpecialization(NamedDecl *Member, LookupResult &Previous);

DeclResult ActOnExplicitInstantiation(
    Scope *S, SourceLocation ExternLoc, SourceLocation TemplateLoc,
    unsigned TagSpec, SourceLocation KWLoc, const CXXScopeSpec &SS,
    TemplateTy Template, SourceLocation TemplateNameLoc,
    SourceLocation LAngleLoc, ASTTemplateArgsPtr TemplateArgs,
    SourceLocation RAngleLoc, const ParsedAttributesView &Attr);

DeclResult ActOnExplicitInstantiation(Scope *S, SourceLocation ExternLoc,
                                      SourceLocation TemplateLoc,
                                      unsigned TagSpec, SourceLocation KWLoc,
                                      CXXScopeSpec &SS, IdentifierInfo *Name,
                                      SourceLocation NameLoc,
                                      const ParsedAttributesView &Attr);

DeclResult ActOnExplicitInstantiation(Scope *S,
                                      SourceLocation ExternLoc,
                                      SourceLocation TemplateLoc,
                                      Declarator &D);

TemplateArgumentLoc SubstDefaultTemplateArgumentIfAvailable(
    TemplateDecl *Template, SourceLocation TemplateLoc,
    SourceLocation RAngleLoc, Decl *Param,
    ArrayRef<TemplateArgument> SugaredConverted,
    ArrayRef<TemplateArgument> CanonicalConverted, bool &HasDefaultArg);

/// Specifies the context in which a particular template
/// argument is being checked.
enum CheckTemplateArgumentKind {
  /// The template argument was specified in the code or was
  /// instantiated with some deduced template arguments.
  CTAK_Specified,

  /// The template argument was deduced via template argument
  /// deduction.
  CTAK_Deduced,

  /// The template argument was deduced from an array bound
  /// via template argument deduction.
  CTAK_DeducedFromArrayBound
};

bool
CheckTemplateArgument(NamedDecl *Param, TemplateArgumentLoc &Arg,
                      NamedDecl *Template, SourceLocation TemplateLoc,
                      SourceLocation RAngleLoc, unsigned ArgumentPackIndex,
                      SmallVectorImpl<TemplateArgument> &SugaredConverted,
                      SmallVectorImpl<TemplateArgument> &CanonicalConverted,
                      CheckTemplateArgumentKind CTAK);

/// Check that the given template arguments can be provided to
/// the given template, converting the arguments along the way.
///
/// \param Template The template to which the template arguments are being
/// provided.
///
/// \param TemplateLoc The location of the template name in the source.
///
/// \param TemplateArgs The list of template arguments. If the template is
/// a template template parameter, this function may extend the set of
/// template arguments to also include substituted, defaulted template
/// arguments.
///
/// \param PartialTemplateArgs True if the list of template arguments is
/// intentionally partial, e.g., because we're checking just the initial
/// set of template arguments.
///
/// \param Converted Will receive the converted, canonicalized template
/// arguments.
///
/// \param UpdateArgsWithConversions If \c true, update \p TemplateArgs to
/// contain the converted forms of the template arguments as written.
/// Otherwise, \p TemplateArgs will not be modified.
///
/// \param ConstraintsNotSatisfied If provided, and an error occurred, will
/// receive true if the cause for the error is the associated constraints of
/// the template not being satisfied by the template arguments.
///
/// \returns true if an error occurred, false otherwise.
bool CheckTemplateArgumentList(
    TemplateDecl *Template, SourceLocation TemplateLoc,
    TemplateArgumentListInfo &TemplateArgs, bool PartialTemplateArgs,
    SmallVectorImpl<TemplateArgument> &SugaredConverted,
    SmallVectorImpl<TemplateArgument> &CanonicalConverted,
    bool UpdateArgsWithConversions = true,
    bool *ConstraintsNotSatisfied = nullptr);

bool CheckTemplateTypeArgument(
    TemplateTypeParmDecl *Param, TemplateArgumentLoc &Arg,
    SmallVectorImpl<TemplateArgument> &SugaredConverted,
    SmallVectorImpl<TemplateArgument> &CanonicalConverted);

bool CheckTemplateArgument(TypeSourceInfo *Arg);
ExprResult CheckTemplateArgument(NonTypeTemplateParmDecl *Param,
                                 QualType InstantiatedParamType, Expr *Arg,
                                 TemplateArgument &SugaredConverted,
                                 TemplateArgument &CanonicalConverted,
                                 CheckTemplateArgumentKind CTAK);
bool CheckTemplateTemplateArgument(TemplateTemplateParmDecl *Param,
                                   TemplateParameterList *Params,
                                   TemplateArgumentLoc &Arg);

ExprResult
BuildExpressionFromDeclTemplateArgument(const TemplateArgument &Arg,
                                        QualType ParamType,
                                        SourceLocation Loc);
ExprResult
BuildExpressionFromIntegralTemplateArgument(const TemplateArgument &Arg,
                                            SourceLocation Loc);

/// Enumeration describing how template parameter lists are compared
/// for equality.
enum TemplateParameterListEqualKind {
  /// We are matching the template parameter lists of two templates
  /// that might be redeclarations.
  ///
  /// \code
  /// template<typename T> struct X;
  /// template<typename T> struct X;
  /// \endcode
  TPL_TemplateMatch,

  /// We are matching the template parameter lists of two template
  /// template parameters as part of matching the template parameter lists
  /// of two templates that might be redeclarations.
  ///
  /// \code
  /// template<template<int I> class TT> struct X;
  /// template<template<int Value> class Other> struct X;
  /// \endcode
  TPL_TemplateTemplateParmMatch,

  /// We are matching the template parameter lists of a template
  /// template argument against the template parameter lists of a template
  /// template parameter.
  ///
  /// \code
  /// template<template<int Value> class Metafun> struct X;
  /// template<int Value> struct integer_c;
  /// X<integer_c> xic;
  /// \endcode
  TPL_TemplateTemplateArgumentMatch,

  /// We are determining whether the template-parameters are equivalent
  /// according to C++ [temp.over.link]/6. This comparison does not consider
  /// constraints.
  ///
  /// \code
  /// template<C1 T> void f(T);
  /// template<C2 T> void f(T);
  /// \endcode
  TPL_TemplateParamsEquivalent,
};

bool TemplateParameterListsAreEqual(
    const NamedDecl *NewInstFrom, TemplateParameterList *New,
    const NamedDecl *OldInstFrom, TemplateParameterList *Old, bool Complain,
    TemplateParameterListEqualKind Kind,
    SourceLocation TemplateArgLoc = SourceLocation());

bool TemplateParameterListsAreEqual(
    TemplateParameterList *New, TemplateParameterList *Old, bool Complain,
    TemplateParameterListEqualKind Kind,
    SourceLocation TemplateArgLoc = SourceLocation()) {
  return TemplateParameterListsAreEqual(nullptr, New, nullptr, Old, Complain,
                                        Kind, TemplateArgLoc);
}

bool CheckTemplateDeclScope(Scope *S, TemplateParameterList *TemplateParams);

/// Called when the parser has parsed a C++ typename
/// specifier, e.g., "typename T::type".
///
/// \param S The scope in which this typename type occurs.
/// \param TypenameLoc the location of the 'typename' keyword
/// \param SS the nested-name-specifier following the typename (e.g., 'T::').
/// \param II the identifier we're retrieving (e.g., 'type' in the example).
/// \param IdLoc the location of the identifier.
/// \param IsImplicitTypename context where T::type refers to a type.
TypeResult ActOnTypenameType(
    Scope *S, SourceLocation TypenameLoc, const CXXScopeSpec &SS,
    const IdentifierInfo &II, SourceLocation IdLoc,
    ImplicitTypenameContext IsImplicitTypename = ImplicitTypenameContext::No);

/// Called when the parser has parsed a C++ typename
/// specifier that ends in a template-id, e.g.,
/// "typename MetaFun::template apply<T1, T2>".
///
/// \param S The scope in which this typename type occurs.
/// \param TypenameLoc the location of the 'typename' keyword
/// \param SS the nested-name-specifier following the typename (e.g., 'T::').
/// \param TemplateLoc the location of the 'template' keyword, if any.
/// \param TemplateName The template name.
/// \param TemplateII The identifier used to name the template.
/// \param TemplateIILoc The location of the template name.
/// \param LAngleLoc The location of the opening angle bracket  ('<').
/// \param TemplateArgs The template arguments.
/// \param RAngleLoc The location of the closing angle bracket  ('>').
TypeResult
ActOnTypenameType(Scope *S, SourceLocation TypenameLoc,
                  const CXXScopeSpec &SS,
                  SourceLocation TemplateLoc,
                  TemplateTy TemplateName,
                  IdentifierInfo *TemplateII,
                  SourceLocation TemplateIILoc,
                  SourceLocation LAngleLoc,
                  ASTTemplateArgsPtr TemplateArgs,
                  SourceLocation RAngleLoc);

QualType CheckTypenameType(ElaboratedTypeKeyword Keyword,
                           SourceLocation KeywordLoc,
                           NestedNameSpecifierLoc QualifierLoc,
                           const IdentifierInfo &II,
                           SourceLocation IILoc,
                           TypeSourceInfo **TSI,
                           bool DeducedTSTContext);

QualType CheckTypenameType(ElaboratedTypeKeyword Keyword,
                           SourceLocation KeywordLoc,
                           NestedNameSpecifierLoc QualifierLoc,
                           const IdentifierInfo &II,
                           SourceLocation IILoc,
                           bool DeducedTSTContext = true);


TypeSourceInfo *RebuildTypeInCurrentInstantiation(TypeSourceInfo *T,
                                                  SourceLocation Loc,
                                                  DeclarationName Name);
bool RebuildNestedNameSpecifierInCurrentInstantiation(CXXScopeSpec &SS);

ExprResult RebuildExprInCurrentInstantiation(Expr *E);
bool RebuildTemplateParamsInCurrentInstantiation(
                                              TemplateParameterList *Params);

std::string
getTemplateArgumentBindingsText(const TemplateParameterList *Params,
                                const TemplateArgumentList &Args);

std::string
getTemplateArgumentBindingsText(const TemplateParameterList *Params,
                                const TemplateArgument *Args,
                                unsigned NumArgs);

//===--------------------------------------------------------------------===//
// C++ Concepts
//===--------------------------------------------------------------------===//
Decl *ActOnConceptDefinition(
    Scope *S, MultiTemplateParamsArg TemplateParameterLists,
    IdentifierInfo *Name, SourceLocation NameLoc, Expr *ConstraintExpr);

void CheckConceptRedefinition(ConceptDecl *NewDecl, LookupResult &Previous,
                              bool &AddToScope);

RequiresExprBodyDecl *
ActOnStartRequiresExpr(SourceLocation RequiresKWLoc,
                       ArrayRef<ParmVarDecl *> LocalParameters,
                       Scope *BodyScope);
void ActOnFinishRequiresExpr();
concepts::Requirement *ActOnSimpleRequirement(Expr *E);
concepts::Requirement *ActOnTypeRequirement(
    SourceLocation TypenameKWLoc, CXXScopeSpec &SS, SourceLocation NameLoc,
    IdentifierInfo *TypeName, TemplateIdAnnotation *TemplateId);
concepts::Requirement *ActOnCompoundRequirement(Expr *E,
                                                SourceLocation NoexceptLoc);
concepts::Requirement *
ActOnCompoundRequirement(
    Expr *E, SourceLocation NoexceptLoc, CXXScopeSpec &SS,
    TemplateIdAnnotation *TypeConstraint, unsigned Depth);
concepts::Requirement *ActOnNestedRequirement(Expr *Constraint);
concepts::ExprRequirement *
BuildExprRequirement(
    Expr *E, bool IsSatisfied, SourceLocation NoexceptLoc,
    concepts::ExprRequirement::ReturnTypeRequirement ReturnTypeRequirement);
concepts::ExprRequirement *
BuildExprRequirement(
    concepts::Requirement::SubstitutionDiagnostic *ExprSubstDiag,
    bool IsSatisfied, SourceLocation NoexceptLoc,
    concepts::ExprRequirement::ReturnTypeRequirement ReturnTypeRequirement);
concepts::TypeRequirement *BuildTypeRequirement(TypeSourceInfo *Type);
concepts::TypeRequirement *
BuildTypeRequirement(
    concepts::Requirement::SubstitutionDiagnostic *SubstDiag);
concepts::NestedRequirement *BuildNestedRequirement(Expr *E);
concepts::NestedRequirement *
BuildNestedRequirement(StringRef InvalidConstraintEntity,
                       const ASTConstraintSatisfaction &Satisfaction);
ExprResult ActOnRequiresExpr(SourceLocation RequiresKWLoc,
                             RequiresExprBodyDecl *Body,
                             ArrayRef<ParmVarDecl *> LocalParameters,
                             ArrayRef<concepts::Requirement *> Requirements,
                             SourceLocation ClosingBraceLoc);

//===--------------------------------------------------------------------===//
// C++ Variadic Templates (C++0x [temp.variadic])
//===--------------------------------------------------------------------===//

/// Determine whether an unexpanded parameter pack might be permitted in this
/// location. Useful for error recovery.
bool isUnexpandedParameterPackPermitted();

/// The context in which an unexpanded parameter pack is
/// being diagnosed.
///
/// Note that the values of this enumeration line up with the first
/// argument to the \c err_unexpanded_parameter_pack diagnostic.
enum UnexpandedParameterPackContext {
  /// An arbitrary expression.
  UPPC_Expression = 0,

  /// The base type of a class type.
  UPPC_BaseType,

  /// The type of an arbitrary declaration.
  UPPC_DeclarationType,

  /// The type of a data member.
  UPPC_DataMemberType,

  /// The size of a bit-field.
  UPPC_BitFieldWidth,

  /// The expression in a static assertion.
  UPPC_StaticAssertExpression,

  /// The fixed underlying type of an enumeration.
  UPPC_FixedUnderlyingType,

  /// The enumerator value.
  UPPC_EnumeratorValue,

  /// A using declaration.
  UPPC_UsingDeclaration,

  /// A friend declaration.
  UPPC_FriendDeclaration,

  /// A declaration qualifier.
  UPPC_DeclarationQualifier,

  /// An initializer.
  UPPC_Initializer,

  /// A default argument.
  UPPC_DefaultArgument,

  /// The type of a non-type template parameter.
  UPPC_NonTypeTemplateParameterType,

  /// The type of an exception.
  UPPC_ExceptionType,

  /// Partial specialization.
  UPPC_PartialSpecialization,

  /// Microsoft __if_exists.
  UPPC_IfExists,

  /// Microsoft __if_not_exists.
  UPPC_IfNotExists,

  /// Lambda expression.
  UPPC_Lambda,

  /// Block expression.
  UPPC_Block,

  /// A type constraint.
  UPPC_TypeConstraint,

  // A requirement in a requires-expression.
  UPPC_Requirement,

  // A requires-clause.
  UPPC_RequiresClause,
};

/// Diagnose unexpanded parameter packs.
///
/// \param Loc The location at which we should emit the diagnostic.
///
/// \param UPPC The context in which we are diagnosing unexpanded
/// parameter packs.
///
/// \param Unexpanded the set of unexpanded parameter packs.
///
/// \returns true if an error occurred, false otherwise.
bool DiagnoseUnexpandedParameterPacks(SourceLocation Loc,
                                      UnexpandedParameterPackContext UPPC,
                                ArrayRef<UnexpandedParameterPack> Unexpanded);

/// If the given type contains an unexpanded parameter pack,
/// diagnose the error.
///
/// \param Loc The source location where a diagnostc should be emitted.
///
/// \param T The type that is being checked for unexpanded parameter
/// packs.
///
/// \returns true if an error occurred, false otherwise.
bool DiagnoseUnexpandedParameterPack(SourceLocation Loc, TypeSourceInfo *T,
                                     UnexpandedParameterPackContext UPPC);

/// If the given expression contains an unexpanded parameter
/// pack, diagnose the error.
///
/// \param E The expression that is being checked for unexpanded
/// parameter packs.
///
/// \returns true if an error occurred, false otherwise.
bool DiagnoseUnexpandedParameterPack(Expr *E,
                     UnexpandedParameterPackContext UPPC = UPPC_Expression);

/// If the given requirees-expression contains an unexpanded reference to one
/// of its own parameter packs, diagnose the error.
///
/// \param RE The requiress-expression that is being checked for unexpanded
/// parameter packs.
///
/// \returns true if an error occurred, false otherwise.
bool DiagnoseUnexpandedParameterPackInRequiresExpr(RequiresExpr *RE);

/// If the given nested-name-specifier contains an unexpanded
/// parameter pack, diagnose the error.
///
/// \param SS The nested-name-specifier that is being checked for
/// unexpanded parameter packs.
///
/// \returns true if an error occurred, false otherwise.
bool DiagnoseUnexpandedParameterPack(const CXXScopeSpec &SS,
                                     UnexpandedParameterPackContext UPPC);

/// If the given name contains an unexpanded parameter pack,
/// diagnose the error.
///
/// \param NameInfo The name (with source location information) that
/// is being checked for unexpanded parameter packs.
///
/// \returns true if an error occurred, false otherwise.
bool DiagnoseUnexpandedParameterPack(const DeclarationNameInfo &NameInfo,
                                     UnexpandedParameterPackContext UPPC);

/// If the given template name contains an unexpanded parameter pack,
/// diagnose the error.
///
/// \param Loc The location of the template name.
///
/// \param Template The template name that is being checked for unexpanded
/// parameter packs.
///
/// \returns true if an error occurred, false otherwise.
bool DiagnoseUnexpandedParameterPack(SourceLocation Loc,
                                     TemplateName Template,
                                     UnexpandedParameterPackContext UPPC);

/// If the given template argument contains an unexpanded parameter
/// pack, diagnose the error.
///
/// \param Arg The template argument that is being checked for unexpanded
/// parameter packs.
///
/// \returns true if an error occurred, false otherwise.
bool DiagnoseUnexpandedParameterPack(TemplateArgumentLoc Arg,
                                     UnexpandedParameterPackContext UPPC);

/// Collect the set of unexpanded parameter packs within the given
/// template argument.
///
/// \param Arg The template argument that will be traversed to find
/// unexpanded parameter packs.
void collectUnexpandedParameterPacks(TemplateArgument Arg,
                 SmallVectorImpl<UnexpandedParameterPack> &Unexpanded);

/// Collect the set of unexpanded parameter packs within the given
/// template argument.
///
/// \param Arg The template argument that will be traversed to find
/// unexpanded parameter packs.
void collectUnexpandedParameterPacks(TemplateArgumentLoc Arg,
                  SmallVectorImpl<UnexpandedParameterPack> &Unexpanded);

/// Collect the set of unexpanded parameter packs within the given
/// type.
///
/// \param T The type that will be traversed to find
/// unexpanded parameter packs.
void collectUnexpandedParameterPacks(QualType T,
                 SmallVectorImpl<UnexpandedParameterPack> &Unexpanded);

/// Collect the set of unexpanded parameter packs within the given
/// type.
///
/// \param TL The type that will be traversed to find
/// unexpanded parameter packs.
void collectUnexpandedParameterPacks(TypeLoc TL,
                 SmallVectorImpl<UnexpandedParameterPack> &Unexpanded);

/// Collect the set of unexpanded parameter packs within the given
/// nested-name-specifier.
///
/// \param NNS The nested-name-specifier that will be traversed to find
/// unexpanded parameter packs.
void collectUnexpandedParameterPacks(NestedNameSpecifierLoc NNS,
                       SmallVectorImpl<UnexpandedParameterPack> &Unexpanded);

/// Collect the set of unexpanded parameter packs within the given
/// name.
///
/// \param NameInfo The name that will be traversed to find
/// unexpanded parameter packs.
void collectUnexpandedParameterPacks(const DeclarationNameInfo &NameInfo,
                       SmallVectorImpl<UnexpandedParameterPack> &Unexpanded);

/// Invoked when parsing a template argument followed by an
/// ellipsis, which creates a pack expansion.
///
/// \param Arg The template argument preceding the ellipsis, which
/// may already be invalid.
///
/// \param EllipsisLoc The location of the ellipsis.
ParsedTemplateArgument ActOnPackExpansion(const ParsedTemplateArgument &Arg,
                                          SourceLocation EllipsisLoc);

/// Invoked when parsing a type followed by an ellipsis, which
/// creates a pack expansion.
///
/// \param Type The type preceding the ellipsis, which will become
/// the pattern of the pack expansion.
///
/// \param EllipsisLoc The location of the ellipsis.
TypeResult ActOnPackExpansion(ParsedType Type, SourceLocation EllipsisLoc);

/// Construct a pack expansion type from the pattern of the pack
/// expansion.
TypeSourceInfo *CheckPackExpansion(TypeSourceInfo *Pattern,
                                   SourceLocation EllipsisLoc,
                                   std::optional<unsigned> NumExpansions);

/// Construct a pack expansion type from the pattern of the pack
/// expansion.
QualType CheckPackExpansion(QualType Pattern, SourceRange PatternRange,
                            SourceLocation EllipsisLoc,
                            std::optional<unsigned> NumExpansions);

/// Invoked when parsing an expression followed by an ellipsis, which
/// creates a pack expansion.
///
/// \param Pattern The expression preceding the ellipsis, which will become
/// the pattern of the pack expansion.
///
/// \param EllipsisLoc The location of the ellipsis.
ExprResult ActOnPackExpansion(Expr *Pattern, SourceLocation EllipsisLoc);

/// Invoked when parsing an expression followed by an ellipsis, which
/// creates a pack expansion.
///
/// \param Pattern The expression preceding the ellipsis, which will become
/// the pattern of the pack expansion.
///
/// \param EllipsisLoc The location of the ellipsis.
ExprResult CheckPackExpansion(Expr *Pattern, SourceLocation EllipsisLoc,
                              std::optional<unsigned> NumExpansions);

/// Determine whether we could expand a pack expansion with the
/// given set of parameter packs into separate arguments by repeatedly
/// transforming the pattern.
///
/// \param EllipsisLoc The location of the ellipsis that identifies the
/// pack expansion.
///
/// \param PatternRange The source range that covers the entire pattern of
/// the pack expansion.
///
/// \param Unexpanded The set of unexpanded parameter packs within the
/// pattern.
///
/// \param ShouldExpand Will be set to \c true if the transformer should
/// expand the corresponding pack expansions into separate arguments. When
/// set, \c NumExpansions must also be set.
///
/// \param RetainExpansion Whether the caller should add an unexpanded
/// pack expansion after all of the expanded arguments. This is used
/// when extending explicitly-specified template argument packs per
/// C++0x [temp.arg.explicit]p9.
///
/// \param NumExpansions The number of separate arguments that will be in
/// the expanded form of the corresponding pack expansion. This is both an
/// input and an output parameter, which can be set by the caller if the
/// number of expansions is known a priori (e.g., due to a prior substitution)
/// and will be set by the callee when the number of expansions is known.
/// The callee must set this value when \c ShouldExpand is \c true; it may
/// set this value in other cases.
///
/// \returns true if an error occurred (e.g., because the parameter packs
/// are to be instantiated with arguments of different lengths), false
/// otherwise. If false, \c ShouldExpand (and possibly \c NumExpansions)
/// must be set.
bool CheckParameterPacksForExpansion(
    SourceLocation EllipsisLoc, SourceRange PatternRange,
    ArrayRef<UnexpandedParameterPack> Unexpanded,
    const MultiLevelTemplateArgumentList &TemplateArgs, bool &ShouldExpand,
    bool &RetainExpansion, std::optional<unsigned> &NumExpansions);

/// Determine the number of arguments in the given pack expansion
/// type.
///
/// This routine assumes that the number of arguments in the expansion is
/// consistent across all of the unexpanded parameter packs in its pattern.
///
/// Returns an empty Optional if the type can't be expanded.
std::optional<unsigned> getNumArgumentsInExpansion(
    QualType T, const MultiLevelTemplateArgumentList &TemplateArgs);

/// Determine whether the given declarator contains any unexpanded
/// parameter packs.
///
/// This routine is used by the parser to disambiguate function declarators
/// with an ellipsis prior to the ')', e.g.,
///
/// \code
///   void f(T...);
/// \endcode
///
/// To determine whether we have an (unnamed) function parameter pack or
/// a variadic function.
///
/// \returns true if the declarator contains any unexpanded parameter packs,
/// false otherwise.
bool containsUnexpandedParameterPacks(Declarator &D);

/// Returns the pattern of the pack expansion for a template argument.
///
/// \param OrigLoc The template argument to expand.
///
/// \param Ellipsis Will be set to the location of the ellipsis.
///
/// \param NumExpansions Will be set to the number of expansions that will
/// be generated from this pack expansion, if known a priori.
TemplateArgumentLoc getTemplateArgumentPackExpansionPattern(
    TemplateArgumentLoc OrigLoc, SourceLocation &Ellipsis,
    std::optional<unsigned> &NumExpansions) const;

/// Given a template argument that contains an unexpanded parameter pack, but
/// which has already been substituted, attempt to determine the number of
/// elements that will be produced once this argument is fully-expanded.
///
/// This is intended for use when transforming 'sizeof...(Arg)' in order to
/// avoid actually expanding the pack where possible.
std::optional<unsigned> getFullyPackExpandedSize(TemplateArgument Arg);

//===--------------------------------------------------------------------===//
// C++ Template Argument Deduction (C++ [temp.deduct])
//===--------------------------------------------------------------------===//

/// Adjust the type \p ArgFunctionType to match the calling convention,
/// noreturn, and optionally the exception specification of \p FunctionType.
/// Deduction often wants to ignore these properties when matching function
/// types.
QualType adjustCCAndNoReturn(QualType ArgFunctionType, QualType FunctionType,
                             bool AdjustExceptionSpec = false);

/// Describes the result of template argument deduction.
///
/// The TemplateDeductionResult enumeration describes the result of
/// template argument deduction, as returned from
/// DeduceTemplateArguments(). The separate TemplateDeductionInfo
/// structure provides additional information about the results of
/// template argument deduction, e.g., the deduced template argument
/// list (if successful) or the specific template parameters or
/// deduced arguments that were involved in the failure.
enum TemplateDeductionResult {
  /// Template argument deduction was successful.
  TDK_Success = 0,
  /// The declaration was invalid; do nothing.
  TDK_Invalid,
  /// Template argument deduction exceeded the maximum template
  /// instantiation depth (which has already been diagnosed).
  TDK_InstantiationDepth,
  /// Template argument deduction did not deduce a value
  /// for every template parameter.
  TDK_Incomplete,
  /// Template argument deduction did not deduce a value for every
  /// expansion of an expanded template parameter pack.
  TDK_IncompletePack,
  /// Template argument deduction produced inconsistent
  /// deduced values for the given template parameter.
  TDK_Inconsistent,
  /// Template argument deduction failed due to inconsistent
  /// cv-qualifiers on a template parameter type that would
  /// otherwise be deduced, e.g., we tried to deduce T in "const T"
  /// but were given a non-const "X".
  TDK_Underqualified,
  /// Substitution of the deduced template argument values
  /// resulted in an error.
  TDK_SubstitutionFailure,
  /// After substituting deduced template arguments, a dependent
  /// parameter type did not match the corresponding argument.
  TDK_DeducedMismatch,
  /// After substituting deduced template arguments, an element of
  /// a dependent parameter type did not match the corresponding element
  /// of the corresponding argument (when deducing from an initializer list).
  TDK_DeducedMismatchNested,
  /// A non-depnedent component of the parameter did not match the
  /// corresponding component of the argument.
  TDK_NonDeducedMismatch,
  /// When performing template argument deduction for a function
  /// template, there were too many call arguments.
  TDK_TooManyArguments,
  /// When performing template argument deduction for a function
  /// template, there were too few call arguments.
  TDK_TooFewArguments,
  /// The explicitly-specified template arguments were not valid
  /// template arguments for the given template.
  TDK_InvalidExplicitArguments,
  /// Checking non-dependent argument conversions failed.
  TDK_NonDependentConversionFailure,
  /// The deduced arguments did not satisfy the constraints associated
  /// with the template.
  TDK_ConstraintsNotSatisfied,
  /// Deduction failed; that's all we know.
  TDK_MiscellaneousDeductionFailure,
  /// CUDA Target attributes do not match.
  TDK_CUDATargetMismatch,
  /// Some error which was already diagnosed.
  TDK_AlreadyDiagnosed
};

TemplateDeductionResult
DeduceTemplateArguments(ClassTemplatePartialSpecializationDecl *Partial,
                        const TemplateArgumentList &TemplateArgs,
                        sema::TemplateDeductionInfo &Info);

TemplateDeductionResult
DeduceTemplateArguments(VarTemplatePartialSpecializationDecl *Partial,
                        const TemplateArgumentList &TemplateArgs,
                        sema::TemplateDeductionInfo &Info);

TemplateDeductionResult SubstituteExplicitTemplateArguments(
    FunctionTemplateDecl *FunctionTemplate,
    TemplateArgumentListInfo &ExplicitTemplateArgs,
    SmallVectorImpl<DeducedTemplateArgument> &Deduced,
    SmallVectorImpl<QualType> &ParamTypes, QualType *FunctionType,
    sema::TemplateDeductionInfo &Info);

/// brief A function argument from which we performed template argument
// deduction for a call.
struct OriginalCallArg {
  OriginalCallArg(QualType OriginalParamType, bool DecomposedParam,
                  unsigned ArgIdx, QualType OriginalArgType)
      : OriginalParamType(OriginalParamType),
        DecomposedParam(DecomposedParam), ArgIdx(ArgIdx),
        OriginalArgType(OriginalArgType) {}

  QualType OriginalParamType;
  bool DecomposedParam;
  unsigned ArgIdx;
  QualType OriginalArgType;
};

TemplateDeductionResult FinishTemplateArgumentDeduction(
    FunctionTemplateDecl *FunctionTemplate,
    SmallVectorImpl<DeducedTemplateArgument> &Deduced,
    unsigned NumExplicitlySpecified, FunctionDecl *&Specialization,
    sema::TemplateDeductionInfo &Info,
    SmallVectorImpl<OriginalCallArg> const *OriginalCallArgs = nullptr,
    bool PartialOverloading = false,
    llvm::function_ref<bool()> CheckNonDependent = []{ return false; });

TemplateDeductionResult DeduceTemplateArguments(
    FunctionTemplateDecl *FunctionTemplate,
    TemplateArgumentListInfo *ExplicitTemplateArgs, ArrayRef<Expr *> Args,
    FunctionDecl *&Specialization, sema::TemplateDeductionInfo &Info,
    bool PartialOverloading,
    llvm::function_ref<bool(ArrayRef<QualType>)> CheckNonDependent);

TemplateDeductionResult
DeduceTemplateArguments(FunctionTemplateDecl *FunctionTemplate,
                        TemplateArgumentListInfo *ExplicitTemplateArgs,
                        QualType ArgFunctionType,
                        FunctionDecl *&Specialization,
                        sema::TemplateDeductionInfo &Info,
                        bool IsAddressOfFunction = false);

TemplateDeductionResult
DeduceTemplateArguments(FunctionTemplateDecl *FunctionTemplate,
                        QualType ToType,
                        CXXConversionDecl *&Specialization,
                        sema::TemplateDeductionInfo &Info);

TemplateDeductionResult
DeduceTemplateArguments(FunctionTemplateDecl *FunctionTemplate,
                        TemplateArgumentListInfo *ExplicitTemplateArgs,
                        FunctionDecl *&Specialization,
                        sema::TemplateDeductionInfo &Info,
                        bool IsAddressOfFunction = false);

/// Substitute Replacement for \p auto in \p TypeWithAuto
QualType SubstAutoType(QualType TypeWithAuto, QualType Replacement);
/// Substitute Replacement for auto in TypeWithAuto
TypeSourceInfo* SubstAutoTypeSourceInfo(TypeSourceInfo *TypeWithAuto,
                                        QualType Replacement);

// Substitute auto in TypeWithAuto for a Dependent auto type
QualType SubstAutoTypeDependent(QualType TypeWithAuto);

// Substitute auto in TypeWithAuto for a Dependent auto type
TypeSourceInfo *
SubstAutoTypeSourceInfoDependent(TypeSourceInfo *TypeWithAuto);

/// Completely replace the \c auto in \p TypeWithAuto by
/// \p Replacement. This does not retain any \c auto type sugar.
QualType ReplaceAutoType(QualType TypeWithAuto, QualType Replacement);
TypeSourceInfo *ReplaceAutoTypeSourceInfo(TypeSourceInfo *TypeWithAuto,
                                          QualType Replacement);

TemplateDeductionResult DeduceAutoType(TypeLoc AutoTypeLoc, Expr *Initializer,
                                       QualType &Result,
                                       sema::TemplateDeductionInfo &Info,
                                       bool DependentDeduction = false,
                                       bool IgnoreConstraints = false);
void DiagnoseAutoDeductionFailure(VarDecl *VDecl, Expr *Init);
bool DeduceReturnType(FunctionDecl *FD, SourceLocation Loc,
                      bool Diagnose = true);

/// Declare implicit deduction guides for a class template if we've
/// not already done so.
void DeclareImplicitDeductionGuides(TemplateDecl *Template,
                                    SourceLocation Loc);

QualType DeduceTemplateSpecializationFromInitializer(
    TypeSourceInfo *TInfo, const InitializedEntity &Entity,
    const InitializationKind &Kind, MultiExprArg Init);

QualType deduceVarTypeFromInitializer(VarDecl *VDecl, DeclarationName Name,
                                      QualType Type, TypeSourceInfo *TSI,
                                      SourceRange Range, bool DirectInit,
                                      Expr *Init);

TypeLoc getReturnTypeLoc(FunctionDecl *FD) const;

bool DeduceFunctionTypeFromReturnExpr(FunctionDecl *FD,
                                      SourceLocation ReturnLoc, Expr *RetExpr,
                                      const AutoType *AT);

FunctionTemplateDecl *getMoreSpecializedTemplate(
    FunctionTemplateDecl *FT1, FunctionTemplateDecl *FT2, SourceLocation Loc,
    TemplatePartialOrderingContext TPOC, unsigned NumCallArguments1,
    unsigned NumCallArguments2, bool Reversed = false);
UnresolvedSetIterator
getMostSpecialized(UnresolvedSetIterator SBegin, UnresolvedSetIterator SEnd,
                   TemplateSpecCandidateSet &FailedCandidates,
                   SourceLocation Loc,
                   const PartialDiagnostic &NoneDiag,
                   const PartialDiagnostic &AmbigDiag,
                   const PartialDiagnostic &CandidateDiag,
                   bool Complain = true, QualType TargetType = QualType());

ClassTemplatePartialSpecializationDecl *
getMoreSpecializedPartialSpecialization(
                                ClassTemplatePartialSpecializationDecl *PS1,
                                ClassTemplatePartialSpecializationDecl *PS2,
                                SourceLocation Loc);

bool isMoreSpecializedThanPrimary(ClassTemplatePartialSpecializationDecl *T,
                                  sema::TemplateDeductionInfo &Info);

VarTemplatePartialSpecializationDecl *getMoreSpecializedPartialSpecialization(
    VarTemplatePartialSpecializationDecl *PS1,
    VarTemplatePartialSpecializationDecl *PS2, SourceLocation Loc);

bool isMoreSpecializedThanPrimary(VarTemplatePartialSpecializationDecl *T,
                                  sema::TemplateDeductionInfo &Info);

bool isTemplateTemplateParameterAtLeastAsSpecializedAs(
    TemplateParameterList *PParam, TemplateDecl *AArg, SourceLocation Loc);

void MarkUsedTemplateParameters(const Expr *E, bool OnlyDeduced,
                                unsigned Depth, llvm::SmallBitVector &Used);

void MarkUsedTemplateParameters(const TemplateArgumentList &TemplateArgs,
                                bool OnlyDeduced,
                                unsigned Depth,
                                llvm::SmallBitVector &Used);
void MarkDeducedTemplateParameters(
                                const FunctionTemplateDecl *FunctionTemplate,
                                llvm::SmallBitVector &Deduced) {
  return MarkDeducedTemplateParameters(Context, FunctionTemplate, Deduced);
}
static void MarkDeducedTemplateParameters(ASTContext &Ctx,
                                const FunctionTemplateDecl *FunctionTemplate,
                                llvm::SmallBitVector &Deduced);

//===--------------------------------------------------------------------===//
// C++ Template Instantiation
//

MultiLevelTemplateArgumentList
getTemplateInstantiationArgs(const NamedDecl *D, bool Final = false,
                             const TemplateArgumentList *Innermost = nullptr,
                             bool RelativeToPrimary = false,
                             const FunctionDecl *Pattern = nullptr,
                             bool ForConstraintInstantiation = false,
                             bool SkipForSpecialization = false);

/// A context in which code is being synthesized (where a source location
/// alone is not sufficient to identify the context). This covers template
/// instantiation and various forms of implicitly-generated functions.
struct CodeSynthesisContext {
  /// The kind of template instantiation we are performing
  enum SynthesisKind {
    /// We are instantiating a template declaration. The entity is
    /// the declaration we're instantiating (e.g., a CXXRecordDecl).
    TemplateInstantiation,

    /// We are instantiating a default argument for a template
    /// parameter. The Entity is the template parameter whose argument is
    /// being instantiated, the Template is the template, and the
    /// TemplateArgs/NumTemplateArguments provide the template arguments as
    /// specified.
    DefaultTemplateArgumentInstantiation,

    /// We are instantiating a default argument for a function.
    /// The Entity is the ParmVarDecl, and TemplateArgs/NumTemplateArgs
    /// provides the template arguments as specified.
    DefaultFunctionArgumentInstantiation,

    /// We are substituting explicit template arguments provided for
    /// a function template. The entity is a FunctionTemplateDecl.
    ExplicitTemplateArgumentSubstitution,

    /// We are substituting template argument determined as part of
    /// template argument deduction for either a class template
    /// partial specialization or a function template. The
    /// Entity is either a {Class|Var}TemplatePartialSpecializationDecl or
    /// a TemplateDecl.
    DeducedTemplateArgumentSubstitution,

    /// We are substituting into a lambda expression.
    LambdaExpressionSubstitution,

    /// We are substituting prior template arguments into a new
    /// template parameter. The template parameter itself is either a
    /// NonTypeTemplateParmDecl or a TemplateTemplateParmDecl.
    PriorTemplateArgumentSubstitution,

    /// We are checking the validity of a default template argument that
    /// has been used when naming a template-id.
    DefaultTemplateArgumentChecking,

    /// We are computing the exception specification for a defaulted special
    /// member function.
    ExceptionSpecEvaluation,

    /// We are instantiating the exception specification for a function
    /// template which was deferred until it was needed.
    ExceptionSpecInstantiation,

    /// We are instantiating a requirement of a requires expression.
    RequirementInstantiation,

    /// We are checking the satisfaction of a nested requirement of a requires
    /// expression.
    NestedRequirementConstraintsCheck,

    /// We are declaring an implicit special member function.
    DeclaringSpecialMember,

    /// We are declaring an implicit 'operator==' for a defaulted
    /// 'operator<=>'.
    DeclaringImplicitEqualityComparison,

    /// We are defining a synthesized function (such as a defaulted special
    /// member).
    DefiningSynthesizedFunction,

    // We are checking the constraints associated with a constrained entity or
    // the constraint expression of a concept. This includes the checks that
    // atomic constraints have the type 'bool' and that they can be constant
    // evaluated.
    ConstraintsCheck,

    // We are substituting template arguments into a constraint expression.
    ConstraintSubstitution,

    // We are normalizing a constraint expression.
    ConstraintNormalization,

    // Instantiating a Requires Expression parameter clause.
    RequirementParameterInstantiation,

    // We are substituting into the parameter mapping of an atomic constraint
    // during normalization.
    ParameterMappingSubstitution,

    /// We are rewriting a comparison operator in terms of an operator<=>.
    RewritingOperatorAsSpaceship,

    /// We are initializing a structured binding.
    InitializingStructuredBinding,

    /// We are marking a class as __dllexport.
    MarkingClassDllexported,

    /// We are building an implied call from __builtin_dump_struct. The
    /// arguments are in CallArgs.
    BuildingBuiltinDumpStructCall,

    /// Added for Template instantiation observation.
    /// Memoization means we are _not_ instantiating a template because
    /// it is already instantiated (but we entered a context where we
    /// would have had to if it was not already instantiated).
    Memoization
  } Kind;

  /// Was the enclosing context a non-instantiation SFINAE context?
  bool SavedInNonInstantiationSFINAEContext;

  /// The point of instantiation or synthesis within the source code.
  SourceLocation PointOfInstantiation;

  /// The entity that is being synthesized.
  Decl *Entity;

  /// The template (or partial specialization) in which we are
  /// performing the instantiation, for substitutions of prior template
  /// arguments.
  NamedDecl *Template;

  union {
    /// The list of template arguments we are substituting, if they
    /// are not part of the entity.
    const TemplateArgument *TemplateArgs;

    /// The list of argument expressions in a synthesized call.
    const Expr *const *CallArgs;
  };

  // FIXME: Wrap this union around more members, or perhaps store the
  // kind-specific members in the RAII object owning the context.
  union {
    /// The number of template arguments in TemplateArgs.
    unsigned NumTemplateArgs;

    /// The number of expressions in CallArgs.
    unsigned NumCallArgs;

    /// The special member being declared or defined.
    CXXSpecialMember SpecialMember;
  };

  ArrayRef<TemplateArgument> template_arguments() const {
    assert(Kind != DeclaringSpecialMember)(static_cast <bool> (Kind != DeclaringSpecialMember) ? void
 (0) : __assert_fail ("Kind != DeclaringSpecialMember", "clang/include/clang/Sema/Sema.h"
, 9375, __extension__ __PRETTY_FUNCTION__));
    return {TemplateArgs, NumTemplateArgs};
  }

  /// The template deduction info object associated with the
  /// substitution or checking of explicit or deduced template arguments.
  sema::TemplateDeductionInfo *DeductionInfo;

  /// The source range that covers the construct that cause
  /// the instantiation, e.g., the template-id that causes a class
  /// template instantiation.
  SourceRange InstantiationRange;

  CodeSynthesisContext()
      : Kind(TemplateInstantiation),
        SavedInNonInstantiationSFINAEContext(false), Entity(nullptr),
        Template(nullptr), TemplateArgs(nullptr), NumTemplateArgs(0),
        DeductionInfo(nullptr) {}

  /// Determines whether this template is an actual instantiation
  /// that should be counted toward the maximum instantiation depth.
  bool isInstantiationRecord() const;
};

/// List of active code synthesis contexts.
///
/// This vector is treated as a stack. As synthesis of one entity requires
/// synthesis of another, additional contexts are pushed onto the stack.
SmallVector<CodeSynthesisContext, 16> CodeSynthesisContexts;

/// Specializations whose definitions are currently being instantiated.
llvm::DenseSet<std::pair<Decl *, unsigned>> InstantiatingSpecializations;

/// Non-dependent types used in templates that have already been instantiated
/// by some template instantiation.
llvm::DenseSet<QualType> InstantiatedNonDependentTypes;

/// Extra modules inspected when performing a lookup during a template
/// instantiation. Computed lazily.
SmallVector<Module*, 16> CodeSynthesisContextLookupModules;

/// Cache of additional modules that should be used for name lookup
/// within the current template instantiation. Computed lazily; use
/// getLookupModules() to get a complete set.
llvm::DenseSet<Module*> LookupModulesCache;

/// Get the set of additional modules that should be checked during
/// name lookup. A module and its imports become visible when instanting a
/// template defined within it.
llvm::DenseSet<Module*> &getLookupModules();

/// Map from the most recent declaration of a namespace to the most
/// recent visible declaration of that namespace.
llvm::DenseMap<NamedDecl*, NamedDecl*> VisibleNamespaceCache;

/// Whether we are in a SFINAE context that is not associated with
/// template instantiation.
///
/// This is used when setting up a SFINAE trap (\c see SFINAETrap) outside
/// of a template instantiation or template argument deduction.
bool InNonInstantiationSFINAEContext;

/// The number of \p CodeSynthesisContexts that are not template
/// instantiations and, therefore, should not be counted as part of the
/// instantiation depth.
///
/// When the instantiation depth reaches the user-configurable limit
/// \p LangOptions::InstantiationDepth we will abort instantiation.
// FIXME: Should we have a similar limit for other forms of synthesis?
unsigned NonInstantiationEntries;

/// The depth of the context stack at the point when the most recent
/// error or warning was produced.
///
/// This value is used to suppress printing of redundant context stacks
/// when there are multiple errors or warnings in the same instantiation.
// FIXME: Does this belong in Sema? It's tough to implement it anywhere else.
unsigned LastEmittedCodeSynthesisContextDepth = 0;

/// The template instantiation callbacks to trace or track
/// instantiations (objects can be chained).
///
/// This callbacks is used to print, trace or track template
/// instantiations as they are being constructed.
std::vector<std::unique_ptr<TemplateInstantiationCallback>>
    TemplateInstCallbacks;

/// The current index into pack expansion arguments that will be
/// used for substitution of parameter packs.
///
/// The pack expansion index will be -1 to indicate that parameter packs
/// should be instantiated as themselves. Otherwise, the index specifies
/// which argument within the parameter pack will be used for substitution.
int ArgumentPackSubstitutionIndex;

/// RAII object used to change the argument pack substitution index
/// within a \c Sema object.
///
/// See \c ArgumentPackSubstitutionIndex for more information.
class ArgumentPackSubstitutionIndexRAII {
  Sema &Self;
  int OldSubstitutionIndex;

public:
  ArgumentPackSubstitutionIndexRAII(Sema &Self, int NewSubstitutionIndex)
    : Self(Self), OldSubstitutionIndex(Self.ArgumentPackSubstitutionIndex) {
    Self.ArgumentPackSubstitutionIndex = NewSubstitutionIndex;
  }

  ~ArgumentPackSubstitutionIndexRAII() {
    Self.ArgumentPackSubstitutionIndex = OldSubstitutionIndex;
  }
};

friend class ArgumentPackSubstitutionRAII;

/// For each declaration that involved template argument deduction, the
/// set of diagnostics that were suppressed during that template argument
/// deduction.
///
/// FIXME: Serialize this structure to the AST file.
typedef llvm::DenseMap<Decl *, SmallVector<PartialDiagnosticAt, 1> >
  SuppressedDiagnosticsMap;
SuppressedDiagnosticsMap SuppressedDiagnostics;

/// A stack object to be created when performing template
/// instantiation.
///
/// Construction of an object of type \c InstantiatingTemplate
/// pushes the current instantiation onto the stack of active
/// instantiations. If the size of this stack exceeds the maximum
/// number of recursive template instantiations, construction
/// produces an error and evaluates true.
///
/// Destruction of this object will pop the named instantiation off
/// the stack.
struct InstantiatingTemplate {
  /// Note that we are instantiating a class template,
  /// function template, variable template, alias template,
  /// or a member thereof.
  InstantiatingTemplate(Sema &SemaRef, SourceLocation PointOfInstantiation,
                        Decl *Entity,
                        SourceRange InstantiationRange = SourceRange());

  struct ExceptionSpecification {};
  /// Note that we are instantiating an exception specification
  /// of a function template.
  InstantiatingTemplate(Sema &SemaRef, SourceLocation PointOfInstantiation,
                        FunctionDecl *Entity, ExceptionSpecification,
                        SourceRange InstantiationRange = SourceRange());

  /// Note that we are instantiating a default argument in a
  /// template-id.
  InstantiatingTemplate(Sema &SemaRef, SourceLocation PointOfInstantiation,
                        TemplateParameter Param, TemplateDecl *Template,
                        ArrayRef<TemplateArgument> TemplateArgs,
                        SourceRange InstantiationRange = SourceRange());

  /// Note that we are substituting either explicitly-specified or
  /// deduced template arguments during function template argument deduction.
  InstantiatingTemplate(Sema &SemaRef, SourceLocation PointOfInstantiation,
                        FunctionTemplateDecl *FunctionTemplate,
                        ArrayRef<TemplateArgument> TemplateArgs,
                        CodeSynthesisContext::SynthesisKind Kind,
                        sema::TemplateDeductionInfo &DeductionInfo,
                        SourceRange InstantiationRange = SourceRange());

  /// Note that we are instantiating as part of template
  /// argument deduction for a class template declaration.
  InstantiatingTemplate(Sema &SemaRef, SourceLocation PointOfInstantiation,
                        TemplateDecl *Template,
                        ArrayRef<TemplateArgument> TemplateArgs,
                        sema::TemplateDeductionInfo &DeductionInfo,
                        SourceRange InstantiationRange = SourceRange());

  /// Note that we are instantiating as part of template
  /// argument deduction for a class template partial
  /// specialization.
  InstantiatingTemplate(Sema &SemaRef, SourceLocation PointOfInstantiation,
                        ClassTemplatePartialSpecializationDecl *PartialSpec,
                        ArrayRef<TemplateArgument> TemplateArgs,
                        sema::TemplateDeductionInfo &DeductionInfo,
                        SourceRange InstantiationRange = SourceRange());

  /// Note that we are instantiating as part of template
  /// argument deduction for a variable template partial
  /// specialization.
  InstantiatingTemplate(Sema &SemaRef, SourceLocation PointOfInstantiation,
                        VarTemplatePartialSpecializationDecl *PartialSpec,
                        ArrayRef<TemplateArgument> TemplateArgs,
                        sema::TemplateDeductionInfo &DeductionInfo,
                        SourceRange InstantiationRange = SourceRange());

  /// Note that we are instantiating a default argument for a function
  /// parameter.
  InstantiatingTemplate(Sema &SemaRef, SourceLocation PointOfInstantiation,
                        ParmVarDecl *Param,
                        ArrayRef<TemplateArgument> TemplateArgs,
                        SourceRange InstantiationRange = SourceRange());

  /// Note that we are substituting prior template arguments into a
  /// non-type parameter.
  InstantiatingTemplate(Sema &SemaRef, SourceLocation PointOfInstantiation,
                        NamedDecl *Template,
                        NonTypeTemplateParmDecl *Param,
                        ArrayRef<TemplateArgument> TemplateArgs,
                        SourceRange InstantiationRange);

  /// Note that we are substituting prior template arguments into a
  /// template template parameter.
  InstantiatingTemplate(Sema &SemaRef, SourceLocation PointOfInstantiation,
                        NamedDecl *Template,
                        TemplateTemplateParmDecl *Param,
                        ArrayRef<TemplateArgument> TemplateArgs,
                        SourceRange InstantiationRange);

  /// Note that we are checking the default template argument
  /// against the template parameter for a given template-id.
  InstantiatingTemplate(Sema &SemaRef, SourceLocation PointOfInstantiation,
                        TemplateDecl *Template,
                        NamedDecl *Param,
                        ArrayRef<TemplateArgument> TemplateArgs,
                        SourceRange InstantiationRange);

  struct ConstraintsCheck {};
  /// \brief Note that we are checking the constraints associated with some
  /// constrained entity (a concept declaration or a template with associated
  /// constraints).
  InstantiatingTemplate(Sema &SemaRef, SourceLocation PointOfInstantiation,
                        ConstraintsCheck, NamedDecl *Template,
                        ArrayRef<TemplateArgument> TemplateArgs,
                        SourceRange InstantiationRange);

  struct ConstraintSubstitution {};
  /// \brief Note that we are checking a constraint expression associated
  /// with a template declaration or as part of the satisfaction check of a
  /// concept.
  InstantiatingTemplate(Sema &SemaRef, SourceLocation PointOfInstantiation,
                        ConstraintSubstitution, NamedDecl *Template,
                        sema::TemplateDeductionInfo &DeductionInfo,
                        SourceRange InstantiationRange);

  struct ConstraintNormalization {};
  /// \brief Note that we are normalizing a constraint expression.
  InstantiatingTemplate(Sema &SemaRef, SourceLocation PointOfInstantiation,
                        ConstraintNormalization, NamedDecl *Template,
                        SourceRange InstantiationRange);

  struct ParameterMappingSubstitution {};
  /// \brief Note that we are subtituting into the parameter mapping of an
  /// atomic constraint during constraint normalization.
  InstantiatingTemplate(Sema &SemaRef, SourceLocation PointOfInstantiation,
                        ParameterMappingSubstitution, NamedDecl *Template,
                        SourceRange InstantiationRange);

  /// \brief Note that we are substituting template arguments into a part of
  /// a requirement of a requires expression.
  InstantiatingTemplate(Sema &SemaRef, SourceLocation PointOfInstantiation,
                        concepts::Requirement *Req,
                        sema::TemplateDeductionInfo &DeductionInfo,
                        SourceRange InstantiationRange = SourceRange());

  /// \brief Note that we are checking the satisfaction of the constraint
  /// expression inside of a nested requirement.
  InstantiatingTemplate(Sema &SemaRef, SourceLocation PointOfInstantiation,
                        concepts::NestedRequirement *Req, ConstraintsCheck,
                        SourceRange InstantiationRange = SourceRange());

  /// \brief Note that we are checking a requires clause.
  InstantiatingTemplate(Sema &SemaRef, SourceLocation PointOfInstantiation,
                        const RequiresExpr *E,
                        sema::TemplateDeductionInfo &DeductionInfo,
                        SourceRange InstantiationRange);
  /// Note that we have finished instantiating this template.
  void Clear();

  ~InstantiatingTemplate() { Clear(); }

  /// Determines whether we have exceeded the maximum
  /// recursive template instantiations.
  bool isInvalid() const { return Invalid; }

  /// Determine whether we are already instantiating this
  /// specialization in some surrounding active instantiation.
  bool isAlreadyInstantiating() const { return AlreadyInstantiating; }

private:
  Sema &SemaRef;
  bool Invalid;
  bool AlreadyInstantiating;
  bool CheckInstantiationDepth(SourceLocation PointOfInstantiation,
                               SourceRange InstantiationRange);

  InstantiatingTemplate(
      Sema &SemaRef, CodeSynthesisContext::SynthesisKind Kind,
      SourceLocation PointOfInstantiation, SourceRange InstantiationRange,
      Decl *Entity, NamedDecl *Template = nullptr,
      ArrayRef<TemplateArgument> TemplateArgs = std::nullopt,
      sema::TemplateDeductionInfo *DeductionInfo = nullptr);

  InstantiatingTemplate(const InstantiatingTemplate&) = delete;

  InstantiatingTemplate&
  operator=(const InstantiatingTemplate&) = delete;
};

void pushCodeSynthesisContext(CodeSynthesisContext Ctx);
void popCodeSynthesisContext();

/// Determine whether we are currently performing template instantiation.
bool inTemplateInstantiation() const {
  return CodeSynthesisContexts.size() > NonInstantiationEntries;
}

void PrintContextStack() {
  if (!CodeSynthesisContexts.empty() &&
      CodeSynthesisContexts.size() != LastEmittedCodeSynthesisContextDepth) {
    PrintInstantiationStack();
    LastEmittedCodeSynthesisContextDepth = CodeSynthesisContexts.size();
  }
  if (PragmaAttributeCurrentTargetDecl)
    PrintPragmaAttributeInstantiationPoint();
}
void PrintInstantiationStack();

void PrintPragmaAttributeInstantiationPoint();

/// Determines whether we are currently in a context where
/// template argument substitution failures are not considered
/// errors.
///
/// \returns An empty \c Optional if we're not in a SFINAE context.
/// Otherwise, contains a pointer that, if non-NULL, contains the nearest
/// template-deduction context object, which can be used to capture
/// diagnostics that will be suppressed.
std::optional<sema::TemplateDeductionInfo *> isSFINAEContext() const;

/// Determines whether we are currently in a context that
/// is not evaluated as per C++ [expr] p5.
bool isUnevaluatedContext() const {
  assert(!ExprEvalContexts.empty() &&(static_cast <bool> (!ExprEvalContexts.empty() &&
 "Must be in an expression evaluation context") ? void (0) : __assert_fail
 ("!ExprEvalContexts.empty() && \"Must be in an expression evaluation context\""
, "clang/include/clang/Sema/Sema.h", 9716, __extension__ __PRETTY_FUNCTION__
))
         "Must be in an expression evaluation context")(static_cast <bool> (!ExprEvalContexts.empty() &&
 "Must be in an expression evaluation context") ? void (0) : __assert_fail
 ("!ExprEvalContexts.empty() && \"Must be in an expression evaluation context\""
, "clang/include/clang/Sema/Sema.h", 9716, __extension__ __PRETTY_FUNCTION__
));
  return ExprEvalContexts.back().isUnevaluated();
}

bool isConstantEvaluatedContext() const {
  assert(!ExprEvalContexts.empty() &&(static_cast <bool> (!ExprEvalContexts.empty() &&
 "Must be in an expression evaluation context") ? void (0) : __assert_fail
 ("!ExprEvalContexts.empty() && \"Must be in an expression evaluation context\""
, "clang/include/clang/Sema/Sema.h", 9722, __extension__ __PRETTY_FUNCTION__
))
         "Must be in an expression evaluation context")(static_cast <bool> (!ExprEvalContexts.empty() &&
 "Must be in an expression evaluation context") ? void (0) : __assert_fail
 ("!ExprEvalContexts.empty() && \"Must be in an expression evaluation context\""
, "clang/include/clang/Sema/Sema.h", 9722, __extension__ __PRETTY_FUNCTION__
));
  return ExprEvalContexts.back().isConstantEvaluated();
}

bool isImmediateFunctionContext() const {
  assert(!ExprEvalContexts.empty() &&(static_cast <bool> (!ExprEvalContexts.empty() &&
 "Must be in an expression evaluation context") ? void (0) : __assert_fail
 ("!ExprEvalContexts.empty() && \"Must be in an expression evaluation context\""
, "clang/include/clang/Sema/Sema.h", 9728, __extension__ __PRETTY_FUNCTION__
))
         "Must be in an expression evaluation context")(static_cast <bool> (!ExprEvalContexts.empty() &&
 "Must be in an expression evaluation context") ? void (0) : __assert_fail
 ("!ExprEvalContexts.empty() && \"Must be in an expression evaluation context\""
, "clang/include/clang/Sema/Sema.h", 9728, __extension__ __PRETTY_FUNCTION__
));
  return ExprEvalContexts.back().isImmediateFunctionContext();
}

bool isCheckingDefaultArgumentOrInitializer() const {
  assert(!ExprEvalContexts.empty() &&(static_cast <bool> (!ExprEvalContexts.empty() &&
 "Must be in an expression evaluation context") ? void (0) : __assert_fail
 ("!ExprEvalContexts.empty() && \"Must be in an expression evaluation context\""
, "clang/include/clang/Sema/Sema.h", 9734, __extension__ __PRETTY_FUNCTION__
))
         "Must be in an expression evaluation context")(static_cast <bool> (!ExprEvalContexts.empty() &&
 "Must be in an expression evaluation context") ? void (0) : __assert_fail
 ("!ExprEvalContexts.empty() && \"Must be in an expression evaluation context\""
, "clang/include/clang/Sema/Sema.h", 9734, __extension__ __PRETTY_FUNCTION__
));
  const ExpressionEvaluationContextRecord &Ctx = ExprEvalContexts.back();
  return (Ctx.Context ==
          ExpressionEvaluationContext::PotentiallyEvaluatedIfUsed) ||
         Ctx.IsCurrentlyCheckingDefaultArgumentOrInitializer;
}

std::optional<ExpressionEvaluationContextRecord::InitializationContext>
InnermostDeclarationWithDelayedImmediateInvocations() const {
  assert(!ExprEvalContexts.empty() &&(static_cast <bool> (!ExprEvalContexts.empty() &&
 "Must be in an expression evaluation context") ? void (0) : __assert_fail
 ("!ExprEvalContexts.empty() && \"Must be in an expression evaluation context\""
, "clang/include/clang/Sema/Sema.h", 9744, __extension__ __PRETTY_FUNCTION__
))
         "Must be in an expression evaluation context")(static_cast <bool> (!ExprEvalContexts.empty() &&
 "Must be in an expression evaluation context") ? void (0) : __assert_fail
 ("!ExprEvalContexts.empty() && \"Must be in an expression evaluation context\""
, "clang/include/clang/Sema/Sema.h", 9744, __extension__ __PRETTY_FUNCTION__
));
  for (const auto &Ctx : llvm::reverse(ExprEvalContexts)) {
    if (Ctx.Context == ExpressionEvaluationContext::PotentiallyEvaluated &&
        Ctx.DelayedDefaultInitializationContext)
      return Ctx.DelayedDefaultInitializationContext;
    if (Ctx.isConstantEvaluated() || Ctx.isImmediateFunctionContext() ||
        Ctx.isUnevaluated())
      break;
  }
  return std::nullopt;
}

std::optional<ExpressionEvaluationContextRecord::InitializationContext>
OutermostDeclarationWithDelayedImmediateInvocations() const {
  assert(!ExprEvalContexts.empty() &&(static_cast <bool> (!ExprEvalContexts.empty() &&
 "Must be in an expression evaluation context") ? void (0) : __assert_fail
 ("!ExprEvalContexts.empty() && \"Must be in an expression evaluation context\""
, "clang/include/clang/Sema/Sema.h", 9759, __extension__ __PRETTY_FUNCTION__
))
         "Must be in an expression evaluation context")(static_cast <bool> (!ExprEvalContexts.empty() &&
 "Must be in an expression evaluation context") ? void (0) : __assert_fail
 ("!ExprEvalContexts.empty() && \"Must be in an expression evaluation context\""
, "clang/include/clang/Sema/Sema.h", 9759, __extension__ __PRETTY_FUNCTION__
));
  std::optional<ExpressionEvaluationContextRecord::InitializationContext> Res;
  for (auto &Ctx : llvm::reverse(ExprEvalContexts)) {
    if (Ctx.Context == ExpressionEvaluationContext::PotentiallyEvaluated &&
        !Ctx.DelayedDefaultInitializationContext && Res)
      break;
    if (Ctx.isConstantEvaluated() || Ctx.isImmediateFunctionContext() ||
        Ctx.isUnevaluated())
      break;
    Res = Ctx.DelayedDefaultInitializationContext;
  }
  return Res;
}

/// RAII class used to determine whether SFINAE has
/// trapped any errors that occur during template argument
/// deduction.
class SFINAETrap {
  Sema &SemaRef;
  unsigned PrevSFINAEErrors;
  bool PrevInNonInstantiationSFINAEContext;
  bool PrevAccessCheckingSFINAE;
  bool PrevLastDiagnosticIgnored;

public:
  explicit SFINAETrap(Sema &SemaRef, bool AccessCheckingSFINAE = false)
    : SemaRef(SemaRef), PrevSFINAEErrors(SemaRef.NumSFINAEErrors),
      PrevInNonInstantiationSFINAEContext(
                                    SemaRef.InNonInstantiationSFINAEContext),
      PrevAccessCheckingSFINAE(SemaRef.AccessCheckingSFINAE),
      PrevLastDiagnosticIgnored(
          SemaRef.getDiagnostics().isLastDiagnosticIgnored())
  {
    if (!SemaRef.isSFINAEContext())
      SemaRef.InNonInstantiationSFINAEContext = true;
    SemaRef.AccessCheckingSFINAE = AccessCheckingSFINAE;
  }

  ~SFINAETrap() {
    SemaRef.NumSFINAEErrors = PrevSFINAEErrors;
    SemaRef.InNonInstantiationSFINAEContext
      = PrevInNonInstantiationSFINAEContext;
    SemaRef.AccessCheckingSFINAE = PrevAccessCheckingSFINAE;
    SemaRef.getDiagnostics().setLastDiagnosticIgnored(
        PrevLastDiagnosticIgnored);
  }

  /// Determine whether any SFINAE errors have been trapped.
  bool hasErrorOccurred() const {
    return SemaRef.NumSFINAEErrors > PrevSFINAEErrors;
  }
};

/// RAII class used to indicate that we are performing provisional
/// semantic analysis to determine the validity of a construct, so
/// typo-correction and diagnostics in the immediate context (not within
/// implicitly-instantiated templates) should be suppressed.
class TentativeAnalysisScope {
  Sema &SemaRef;
  // FIXME: Using a SFINAETrap for this is a hack.
  SFINAETrap Trap;
  bool PrevDisableTypoCorrection;
public:
  explicit TentativeAnalysisScope(Sema &SemaRef)
      : SemaRef(SemaRef), Trap(SemaRef, true),
        PrevDisableTypoCorrection(SemaRef.DisableTypoCorrection) {
    SemaRef.DisableTypoCorrection = true;
  }
  ~TentativeAnalysisScope() {
    SemaRef.DisableTypoCorrection = PrevDisableTypoCorrection;
  }
};

/// The current instantiation scope used to store local
/// variables.
LocalInstantiationScope *CurrentInstantiationScope;

/// Tracks whether we are in a context where typo correction is
/// disabled.
bool DisableTypoCorrection;

/// The number of typos corrected by CorrectTypo.
unsigned TyposCorrected;

typedef llvm::SmallSet<SourceLocation, 2> SrcLocSet;
typedef llvm::DenseMap<IdentifierInfo *, SrcLocSet> IdentifierSourceLocations;

/// A cache containing identifiers for which typo correction failed and
/// their locations, so that repeated attempts to correct an identifier in a
/// given location are ignored if typo correction already failed for it.
IdentifierSourceLocations TypoCorrectionFailures;

/// Worker object for performing CFG-based warnings.
sema::AnalysisBasedWarnings AnalysisWarnings;
threadSafety::BeforeSet *ThreadSafetyDeclCache;

/// An entity for which implicit template instantiation is required.
///
/// The source location associated with the declaration is the first place in
/// the source code where the declaration was "used". It is not necessarily
/// the point of instantiation (which will be either before or after the
/// namespace-scope declaration that triggered this implicit instantiation),
/// However, it is the location that diagnostics should generally refer to,
/// because users will need to know what code triggered the instantiation.
typedef std::pair<ValueDecl *, SourceLocation> PendingImplicitInstantiation;

/// The queue of implicit template instantiations that are required
/// but have not yet been performed.
std::deque<PendingImplicitInstantiation> PendingInstantiations;

/// Queue of implicit template instantiations that cannot be performed
/// eagerly.
SmallVector<PendingImplicitInstantiation, 1> LateParsedInstantiations;

SmallVector<SmallVector<VTableUse, 16>, 8> SavedVTableUses;
SmallVector<std::deque<PendingImplicitInstantiation>, 8>
    SavedPendingInstantiations;

class GlobalEagerInstantiationScope {
public:
  GlobalEagerInstantiationScope(Sema &S, bool Enabled)
      : S(S), Enabled(Enabled) {
    if (!Enabled) return;

    S.SavedPendingInstantiations.emplace_back();
    S.SavedPendingInstantiations.back().swap(S.PendingInstantiations);

    S.SavedVTableUses.emplace_back();
    S.SavedVTableUses.back().swap(S.VTableUses);
  }

  void perform() {
    if (Enabled) {
      S.DefineUsedVTables();
      S.PerformPendingInstantiations();
    }
  }

  ~GlobalEagerInstantiationScope() {
    if (!Enabled) return;

    // Restore the set of pending vtables.
    assert(S.VTableUses.empty() &&(static_cast <bool> (S.VTableUses.empty() && "VTableUses should be empty before it is discarded."
) ? void (0) : __assert_fail ("S.VTableUses.empty() && \"VTableUses should be empty before it is discarded.\""
, "clang/include/clang/Sema/Sema.h", 9902, __extension__ __PRETTY_FUNCTION__
))
           "VTableUses should be empty before it is discarded.")(static_cast <bool> (S.VTableUses.empty() && "VTableUses should be empty before it is discarded."
) ? void (0) : __assert_fail ("S.VTableUses.empty() && \"VTableUses should be empty before it is discarded.\""
, "clang/include/clang/Sema/Sema.h", 9902, __extension__ __PRETTY_FUNCTION__
));
    S.VTableUses.swap(S.SavedVTableUses.back());
    S.SavedVTableUses.pop_back();

    // Restore the set of pending implicit instantiations.
    if (S.TUKind != TU_Prefix || !S.LangOpts.PCHInstantiateTemplates) {
      assert(S.PendingInstantiations.empty() &&(static_cast <bool> (S.PendingInstantiations.empty() &&
 "PendingInstantiations should be empty before it is discarded."
) ? void (0) : __assert_fail ("S.PendingInstantiations.empty() && \"PendingInstantiations should be empty before it is discarded.\""
, "clang/include/clang/Sema/Sema.h", 9909, __extension__ __PRETTY_FUNCTION__
))
             "PendingInstantiations should be empty before it is discarded.")(static_cast <bool> (S.PendingInstantiations.empty() &&
 "PendingInstantiations should be empty before it is discarded."
) ? void (0) : __assert_fail ("S.PendingInstantiations.empty() && \"PendingInstantiations should be empty before it is discarded.\""
, "clang/include/clang/Sema/Sema.h", 9909, __extension__ __PRETTY_FUNCTION__
));
      S.PendingInstantiations.swap(S.SavedPendingInstantiations.back());
      S.SavedPendingInstantiations.pop_back();
    } else {
      // Template instantiations in the PCH may be delayed until the TU.
      S.PendingInstantiations.swap(S.SavedPendingInstantiations.back());
      S.PendingInstantiations.insert(
          S.PendingInstantiations.end(),
          S.SavedPendingInstantiations.back().begin(),
          S.SavedPendingInstantiations.back().end());
      S.SavedPendingInstantiations.pop_back();
    }
  }

private:
  Sema &S;
  bool Enabled;
};

/// The queue of implicit template instantiations that are required
/// and must be performed within the current local scope.
///
/// This queue is only used for member functions of local classes in
/// templates, which must be instantiated in the same scope as their
/// enclosing function, so that they can reference function-local
/// types, static variables, enumerators, etc.
std::deque<PendingImplicitInstantiation> PendingLocalImplicitInstantiations;

class LocalEagerInstantiationScope {
public:
  LocalEagerInstantiationScope(Sema &S) : S(S) {
    SavedPendingLocalImplicitInstantiations.swap(
        S.PendingLocalImplicitInstantiations);
  }

  void perform() { S.PerformPendingInstantiations(/*LocalOnly=*/true); }

  ~LocalEagerInstantiationScope() {
    assert(S.PendingLocalImplicitInstantiations.empty() &&(static_cast <bool> (S.PendingLocalImplicitInstantiations
.empty() && "there shouldn't be any pending local implicit instantiations"
) ? void (0) : __assert_fail ("S.PendingLocalImplicitInstantiations.empty() && \"there shouldn't be any pending local implicit instantiations\""
, "clang/include/clang/Sema/Sema.h", 9948, __extension__ __PRETTY_FUNCTION__
))
           "there shouldn't be any pending local implicit instantiations")(static_cast <bool> (S.PendingLocalImplicitInstantiations
.empty() && "there shouldn't be any pending local implicit instantiations"
) ? void (0) : __assert_fail ("S.PendingLocalImplicitInstantiations.empty() && \"there shouldn't be any pending local implicit instantiations\""
, "clang/include/clang/Sema/Sema.h", 9948, __extension__ __PRETTY_FUNCTION__
));
    SavedPendingLocalImplicitInstantiations.swap(
        S.PendingLocalImplicitInstantiations);
  }

private:
  Sema &S;
  std::deque<PendingImplicitInstantiation>
      SavedPendingLocalImplicitInstantiations;
};

/// A helper class for building up ExtParameterInfos.
class ExtParameterInfoBuilder {
  SmallVector<FunctionProtoType::ExtParameterInfo, 16> Infos;
  bool HasInteresting = false;

public:
  /// Set the ExtParameterInfo for the parameter at the given index,
  ///
  void set(unsigned index, FunctionProtoType::ExtParameterInfo info) {
    assert(Infos.size() <= index)(static_cast <bool> (Infos.size() <= index) ? void (
0) : __assert_fail ("Infos.size() <= index", "clang/include/clang/Sema/Sema.h"
, 9968, __extension__ __PRETTY_FUNCTION__));
    Infos.resize(index);
    Infos.push_back(info);

    if (!HasInteresting)
      HasInteresting = (info != FunctionProtoType::ExtParameterInfo());
  }

  /// Return a pointer (suitable for setting in an ExtProtoInfo) to the
  /// ExtParameterInfo array we've built up.
  const FunctionProtoType::ExtParameterInfo *
  getPointerOrNull(unsigned numParams) {
    if (!HasInteresting) return nullptr;
    Infos.resize(numParams);
    return Infos.data();
  }
};

void PerformPendingInstantiations(bool LocalOnly = false);

TypeSourceInfo *SubstType(TypeSourceInfo *T,
                          const MultiLevelTemplateArgumentList &TemplateArgs,
                          SourceLocation Loc, DeclarationName Entity,
                          bool AllowDeducedTST = false);

QualType SubstType(QualType T,
                   const MultiLevelTemplateArgumentList &TemplateArgs,
                   SourceLocation Loc, DeclarationName Entity);

TypeSourceInfo *SubstType(TypeLoc TL,
                          const MultiLevelTemplateArgumentList &TemplateArgs,
                          SourceLocation Loc, DeclarationName Entity);

TypeSourceInfo *SubstFunctionDeclType(
    TypeSourceInfo *T, const MultiLevelTemplateArgumentList &TemplateArgs,
    SourceLocation Loc, DeclarationName Entity, CXXRecordDecl *ThisContext,
    Qualifiers ThisTypeQuals, bool EvaluateConstraints = true);
void SubstExceptionSpec(FunctionDecl *New, const FunctionProtoType *Proto,
                        const MultiLevelTemplateArgumentList &Args);
bool SubstExceptionSpec(SourceLocation Loc,
                        FunctionProtoType::ExceptionSpecInfo &ESI,
                        SmallVectorImpl<QualType> &ExceptionStorage,
                        const MultiLevelTemplateArgumentList &Args);
ParmVarDecl *
SubstParmVarDecl(ParmVarDecl *D,
                 const MultiLevelTemplateArgumentList &TemplateArgs,
                 int indexAdjustment, std::optional<unsigned> NumExpansions,
                 bool ExpectParameterPack, bool EvaluateConstraints = true);
bool SubstParmTypes(SourceLocation Loc, ArrayRef<ParmVarDecl *> Params,
                    const FunctionProtoType::ExtParameterInfo *ExtParamInfos,
                    const MultiLevelTemplateArgumentList &TemplateArgs,
                    SmallVectorImpl<QualType> &ParamTypes,
                    SmallVectorImpl<ParmVarDecl *> *OutParams,
                    ExtParameterInfoBuilder &ParamInfos);
bool SubstDefaultArgument(SourceLocation Loc, ParmVarDecl *Param,
                          const MultiLevelTemplateArgumentList &TemplateArgs,
                          bool ForCallExpr = false);
ExprResult SubstExpr(Expr *E,
                     const MultiLevelTemplateArgumentList &TemplateArgs);

// A RAII type used by the TemplateDeclInstantiator and TemplateInstantiator
// to disable constraint evaluation, then restore the state.
template <typename InstTy> struct ConstraintEvalRAII {
  InstTy &TI;
  bool OldValue;

  ConstraintEvalRAII(InstTy &TI)
      : TI(TI), OldValue(TI.getEvaluateConstraints()) {
    TI.setEvaluateConstraints(false);
  }
  ~ConstraintEvalRAII() { TI.setEvaluateConstraints(OldValue); }
};

// Unlike the above, this evaluates constraints, which should only happen at
// 'constraint checking' time.
ExprResult
SubstConstraintExpr(Expr *E,
                    const MultiLevelTemplateArgumentList &TemplateArgs);

/// Substitute the given template arguments into a list of
/// expressions, expanding pack expansions if required.
///
/// \param Exprs The list of expressions to substitute into.
///
/// \param IsCall Whether this is some form of call, in which case
/// default arguments will be dropped.
///
/// \param TemplateArgs The set of template arguments to substitute.
///
/// \param Outputs Will receive all of the substituted arguments.
///
/// \returns true if an error occurred, false otherwise.
bool SubstExprs(ArrayRef<Expr *> Exprs, bool IsCall,
                const MultiLevelTemplateArgumentList &TemplateArgs,
                SmallVectorImpl<Expr *> &Outputs);

StmtResult SubstStmt(Stmt *S,
                     const MultiLevelTemplateArgumentList &TemplateArgs);

TemplateParameterList *
SubstTemplateParams(TemplateParameterList *Params, DeclContext *Owner,
                    const MultiLevelTemplateArgumentList &TemplateArgs,
                    bool EvaluateConstraints = true);

bool
SubstTemplateArguments(ArrayRef<TemplateArgumentLoc> Args,
                       const MultiLevelTemplateArgumentList &TemplateArgs,
                       TemplateArgumentListInfo &Outputs);

Decl *SubstDecl(Decl *D, DeclContext *Owner,
                const MultiLevelTemplateArgumentList &TemplateArgs);

/// Substitute the name and return type of a defaulted 'operator<=>' to form
/// an implicit 'operator=='.
FunctionDecl *SubstSpaceshipAsEqualEqual(CXXRecordDecl *RD,
                                         FunctionDecl *Spaceship);

ExprResult SubstInitializer(Expr *E,
                     const MultiLevelTemplateArgumentList &TemplateArgs,
                     bool CXXDirectInit);

bool
SubstBaseSpecifiers(CXXRecordDecl *Instantiation,
                    CXXRecordDecl *Pattern,
                    const MultiLevelTemplateArgumentList &TemplateArgs);

bool
InstantiateClass(SourceLocation PointOfInstantiation,
                 CXXRecordDecl *Instantiation, CXXRecordDecl *Pattern,
                 const MultiLevelTemplateArgumentList &TemplateArgs,
                 TemplateSpecializationKind TSK,
                 bool Complain = true);

bool InstantiateEnum(SourceLocation PointOfInstantiation,
                     EnumDecl *Instantiation, EnumDecl *Pattern,
                     const MultiLevelTemplateArgumentList &TemplateArgs,
                     TemplateSpecializationKind TSK);

bool InstantiateInClassInitializer(
    SourceLocation PointOfInstantiation, FieldDecl *Instantiation,
    FieldDecl *Pattern, const MultiLevelTemplateArgumentList &TemplateArgs);

struct LateInstantiatedAttribute {
  const Attr *TmplAttr;
  LocalInstantiationScope *Scope;
  Decl *NewDecl;

  LateInstantiatedAttribute(const Attr *A, LocalInstantiationScope *S,
                            Decl *D)
    : TmplAttr(A), Scope(S), NewDecl(D)
  { }
};
typedef SmallVector<LateInstantiatedAttribute, 16> LateInstantiatedAttrVec;

void InstantiateAttrs(const MultiLevelTemplateArgumentList &TemplateArgs,
                      const Decl *Pattern, Decl *Inst,
                      LateInstantiatedAttrVec *LateAttrs = nullptr,
                      LocalInstantiationScope *OuterMostScope = nullptr);
void updateAttrsForLateParsedTemplate(const Decl *Pattern, Decl *Inst);

void
InstantiateAttrsForDecl(const MultiLevelTemplateArgumentList &TemplateArgs,
                        const Decl *Pattern, Decl *Inst,
                        LateInstantiatedAttrVec *LateAttrs = nullptr,
                        LocalInstantiationScope *OuterMostScope = nullptr);

void InstantiateDefaultCtorDefaultArgs(CXXConstructorDecl *Ctor);

bool usesPartialOrExplicitSpecialization(
    SourceLocation Loc, ClassTemplateSpecializationDecl *ClassTemplateSpec);

bool
InstantiateClassTemplateSpecialization(SourceLocation PointOfInstantiation,
                         ClassTemplateSpecializationDecl *ClassTemplateSpec,
                         TemplateSpecializationKind TSK,
                         bool Complain = true);

void InstantiateClassMembers(SourceLocation PointOfInstantiation,
                             CXXRecordDecl *Instantiation,
                          const MultiLevelTemplateArgumentList &TemplateArgs,
                             TemplateSpecializationKind TSK);

void InstantiateClassTemplateSpecializationMembers(
                                        SourceLocation PointOfInstantiation,
                         ClassTemplateSpecializationDecl *ClassTemplateSpec,
                                              TemplateSpecializationKind TSK);

NestedNameSpecifierLoc
SubstNestedNameSpecifierLoc(NestedNameSpecifierLoc NNS,
                         const MultiLevelTemplateArgumentList &TemplateArgs);

DeclarationNameInfo
SubstDeclarationNameInfo(const DeclarationNameInfo &NameInfo,
                         const MultiLevelTemplateArgumentList &TemplateArgs);
TemplateName
SubstTemplateName(NestedNameSpecifierLoc QualifierLoc, TemplateName Name,
                  SourceLocation Loc,
                  const MultiLevelTemplateArgumentList &TemplateArgs);

bool SubstTypeConstraint(TemplateTypeParmDecl *Inst, const TypeConstraint *TC,
                         const MultiLevelTemplateArgumentList &TemplateArgs,
                         bool EvaluateConstraint);

bool InstantiateDefaultArgument(SourceLocation CallLoc, FunctionDecl *FD,
                                ParmVarDecl *Param);
void InstantiateExceptionSpec(SourceLocation PointOfInstantiation,
                              FunctionDecl *Function);
bool CheckInstantiatedFunctionTemplateConstraints(
    SourceLocation PointOfInstantiation, FunctionDecl *Decl,
    ArrayRef<TemplateArgument> TemplateArgs,
    ConstraintSatisfaction &Satisfaction);
FunctionDecl *InstantiateFunctionDeclaration(FunctionTemplateDecl *FTD,
                                             const TemplateArgumentList *Args,
                                             SourceLocation Loc);
void InstantiateFunctionDefinition(SourceLocation PointOfInstantiation,
                                   FunctionDecl *Function,
                                   bool Recursive = false,
                                   bool DefinitionRequired = false,
                                   bool AtEndOfTU = false);
VarTemplateSpecializationDecl *BuildVarTemplateInstantiation(
    VarTemplateDecl *VarTemplate, VarDecl *FromVar,
    const TemplateArgumentList &TemplateArgList,
    const TemplateArgumentListInfo &TemplateArgsInfo,
    SmallVectorImpl<TemplateArgument> &Converted,
    SourceLocation PointOfInstantiation,
    LateInstantiatedAttrVec *LateAttrs = nullptr,
    LocalInstantiationScope *StartingScope = nullptr);
VarTemplateSpecializationDecl *CompleteVarTemplateSpecializationDecl(
    VarTemplateSpecializationDecl *VarSpec, VarDecl *PatternDecl,
    const MultiLevelTemplateArgumentList &TemplateArgs);
void
BuildVariableInstantiation(VarDecl *NewVar, VarDecl *OldVar,
                           const MultiLevelTemplateArgumentList &TemplateArgs,
                           LateInstantiatedAttrVec *LateAttrs,
                           DeclContext *Owner,
                           LocalInstantiationScope *StartingScope,
                           bool InstantiatingVarTemplate = false,
                           VarTemplateSpecializationDecl *PrevVTSD = nullptr);

void InstantiateVariableInitializer(
    VarDecl *Var, VarDecl *OldVar,
    const MultiLevelTemplateArgumentList &TemplateArgs);
void InstantiateVariableDefinition(SourceLocation PointOfInstantiation,
                                   VarDecl *Var, bool Recursive = false,
                                   bool DefinitionRequired = false,
                                   bool AtEndOfTU = false);

void InstantiateMemInitializers(CXXConstructorDecl *New,
                                const CXXConstructorDecl *Tmpl,
                          const MultiLevelTemplateArgumentList &TemplateArgs);

NamedDecl *FindInstantiatedDecl(SourceLocation Loc, NamedDecl *D,
                        const MultiLevelTemplateArgumentList &TemplateArgs,
                        bool FindingInstantiatedContext = false);
DeclContext *FindInstantiatedContext(SourceLocation Loc, DeclContext *DC,
                        const MultiLevelTemplateArgumentList &TemplateArgs);

// Objective-C declarations.
enum ObjCContainerKind {
  OCK_None = -1,
  OCK_Interface = 0,
  OCK_Protocol,
  OCK_Category,
  OCK_ClassExtension,
  OCK_Implementation,
  OCK_CategoryImplementation
};
ObjCContainerKind getObjCContainerKind() const;

DeclResult actOnObjCTypeParam(Scope *S,
                              ObjCTypeParamVariance variance,
                              SourceLocation varianceLoc,
                              unsigned index,
                              IdentifierInfo *paramName,
                              SourceLocation paramLoc,
                              SourceLocation colonLoc,
                              ParsedType typeBound);

ObjCTypeParamList *actOnObjCTypeParamList(Scope *S, SourceLocation lAngleLoc,
                                          ArrayRef<Decl *> typeParams,
                                          SourceLocation rAngleLoc);
void popObjCTypeParamList(Scope *S, ObjCTypeParamList *typeParamList);

ObjCInterfaceDecl *ActOnStartClassInterface(
    Scope *S, SourceLocation AtInterfaceLoc, IdentifierInfo *ClassName,
    SourceLocation ClassLoc, ObjCTypeParamList *typeParamList,
    IdentifierInfo *SuperName, SourceLocation SuperLoc,
    ArrayRef<ParsedType> SuperTypeArgs, SourceRange SuperTypeArgsRange,
    Decl *const *ProtoRefs, unsigned NumProtoRefs,
    const SourceLocation *ProtoLocs, SourceLocation EndProtoLoc,
    const ParsedAttributesView &AttrList, SkipBodyInfo *SkipBody);

void ActOnSuperClassOfClassInterface(Scope *S,
                                     SourceLocation AtInterfaceLoc,
                                     ObjCInterfaceDecl *IDecl,
                                     IdentifierInfo *ClassName,
                                     SourceLocation ClassLoc,
                                     IdentifierInfo *SuperName,
                                     SourceLocation SuperLoc,
                                     ArrayRef<ParsedType> SuperTypeArgs,
                                     SourceRange SuperTypeArgsRange);

void ActOnTypedefedProtocols(SmallVectorImpl<Decl *> &ProtocolRefs,
                             SmallVectorImpl<SourceLocation> &ProtocolLocs,
                             IdentifierInfo *SuperName,
                             SourceLocation SuperLoc);

Decl *ActOnCompatibilityAlias(
                  SourceLocation AtCompatibilityAliasLoc,
                  IdentifierInfo *AliasName,  SourceLocation AliasLocation,
                  IdentifierInfo *ClassName, SourceLocation ClassLocation);

bool CheckForwardProtocolDeclarationForCircularDependency(
  IdentifierInfo *PName,
  SourceLocation &PLoc, SourceLocation PrevLoc,
  const ObjCList<ObjCProtocolDecl> &PList);

ObjCProtocolDecl *ActOnStartProtocolInterface(
    SourceLocation AtProtoInterfaceLoc, IdentifierInfo *ProtocolName,
    SourceLocation ProtocolLoc, Decl *const *ProtoRefNames,
    unsigned NumProtoRefs, const SourceLocation *ProtoLocs,
    SourceLocation EndProtoLoc, const ParsedAttributesView &AttrList,
    SkipBodyInfo *SkipBody);

ObjCCategoryDecl *ActOnStartCategoryInterface(
    SourceLocation AtInterfaceLoc, IdentifierInfo *ClassName,
    SourceLocation ClassLoc, ObjCTypeParamList *typeParamList,
    IdentifierInfo *CategoryName, SourceLocation CategoryLoc,
    Decl *const *ProtoRefs, unsigned NumProtoRefs,
    const SourceLocation *ProtoLocs, SourceLocation EndProtoLoc,
    const ParsedAttributesView &AttrList);

ObjCImplementationDecl *ActOnStartClassImplementation(
    SourceLocation AtClassImplLoc, IdentifierInfo *ClassName,
    SourceLocation ClassLoc, IdentifierInfo *SuperClassname,
    SourceLocation SuperClassLoc, const ParsedAttributesView &AttrList);

ObjCCategoryImplDecl *ActOnStartCategoryImplementation(
    SourceLocation AtCatImplLoc, IdentifierInfo *ClassName,
    SourceLocation ClassLoc, IdentifierInfo *CatName, SourceLocation CatLoc,
    const ParsedAttributesView &AttrList);

DeclGroupPtrTy ActOnFinishObjCImplementation(Decl *ObjCImpDecl,
                                             ArrayRef<Decl *> Decls);

DeclGroupPtrTy ActOnForwardClassDeclaration(SourceLocation Loc,
                 IdentifierInfo **IdentList,
                 SourceLocation *IdentLocs,
                 ArrayRef<ObjCTypeParamList *> TypeParamLists,
                 unsigned NumElts);

DeclGroupPtrTy
ActOnForwardProtocolDeclaration(SourceLocation AtProtoclLoc,
                                ArrayRef<IdentifierLocPair> IdentList,
                                const ParsedAttributesView &attrList);

void FindProtocolDeclaration(bool WarnOnDeclarations, bool ForObjCContainer,
                             ArrayRef<IdentifierLocPair> ProtocolId,
                             SmallVectorImpl<Decl *> &Protocols);

void DiagnoseTypeArgsAndProtocols(IdentifierInfo *ProtocolId,
                                  SourceLocation ProtocolLoc,
                                  IdentifierInfo *TypeArgId,
                                  SourceLocation TypeArgLoc,
                                  bool SelectProtocolFirst = false);

/// Given a list of identifiers (and their locations), resolve the
/// names to either Objective-C protocol qualifiers or type
/// arguments, as appropriate.
void actOnObjCTypeArgsOrProtocolQualifiers(
       Scope *S,
       ParsedType baseType,
       SourceLocation lAngleLoc,
       ArrayRef<IdentifierInfo *> identifiers,
       ArrayRef<SourceLocation> identifierLocs,
       SourceLocation rAngleLoc,
       SourceLocation &typeArgsLAngleLoc,
       SmallVectorImpl<ParsedType> &typeArgs,
       SourceLocation &typeArgsRAngleLoc,
       SourceLocation &protocolLAngleLoc,
       SmallVectorImpl<Decl *> &protocols,
       SourceLocation &protocolRAngleLoc,
       bool warnOnIncompleteProtocols);

/// Build a an Objective-C protocol-qualified 'id' type where no
/// base type was specified.
TypeResult actOnObjCProtocolQualifierType(
             SourceLocation lAngleLoc,
             ArrayRef<Decl *> protocols,
             ArrayRef<SourceLocation> protocolLocs,
             SourceLocation rAngleLoc);

/// Build a specialized and/or protocol-qualified Objective-C type.
TypeResult actOnObjCTypeArgsAndProtocolQualifiers(
             Scope *S,
             SourceLocation Loc,
             ParsedType BaseType,
             SourceLocation TypeArgsLAngleLoc,
             ArrayRef<ParsedType> TypeArgs,
             SourceLocation TypeArgsRAngleLoc,
             SourceLocation ProtocolLAngleLoc,
             ArrayRef<Decl *> Protocols,
             ArrayRef<SourceLocation> ProtocolLocs,
             SourceLocation ProtocolRAngleLoc);

/// Build an Objective-C type parameter type.
QualType BuildObjCTypeParamType(const ObjCTypeParamDecl *Decl,
                                SourceLocation ProtocolLAngleLoc,
                                ArrayRef<ObjCProtocolDecl *> Protocols,
                                ArrayRef<SourceLocation> ProtocolLocs,
                                SourceLocation ProtocolRAngleLoc,
                                bool FailOnError = false);

/// Build an Objective-C object pointer type.
QualType BuildObjCObjectType(
    QualType BaseType, SourceLocation Loc, SourceLocation TypeArgsLAngleLoc,
    ArrayRef<TypeSourceInfo *> TypeArgs, SourceLocation TypeArgsRAngleLoc,
    SourceLocation ProtocolLAngleLoc, ArrayRef<ObjCProtocolDecl *> Protocols,
    ArrayRef<SourceLocation> ProtocolLocs, SourceLocation ProtocolRAngleLoc,
    bool FailOnError, bool Rebuilding);

/// Ensure attributes are consistent with type.
/// \param [in, out] Attributes The attributes to check; they will
/// be modified to be consistent with \p PropertyTy.
void CheckObjCPropertyAttributes(Decl *PropertyPtrTy,
                                 SourceLocation Loc,
                                 unsigned &Attributes,
                                 bool propertyInPrimaryClass);

/// Process the specified property declaration and create decls for the
/// setters and getters as needed.
/// \param property The property declaration being processed
void ProcessPropertyDecl(ObjCPropertyDecl *property);


void DiagnosePropertyMismatch(ObjCPropertyDecl *Property,
                              ObjCPropertyDecl *SuperProperty,
                              const IdentifierInfo *Name,
                              bool OverridingProtocolProperty);

void DiagnoseClassExtensionDupMethods(ObjCCategoryDecl *CAT,
                                      ObjCInterfaceDecl *ID);

Decl *ActOnAtEnd(Scope *S, SourceRange AtEnd,
                 ArrayRef<Decl *> allMethods = std::nullopt,
                 ArrayRef<DeclGroupPtrTy> allTUVars = std::nullopt);

Decl *ActOnProperty(Scope *S, SourceLocation AtLoc,
                    SourceLocation LParenLoc,
                    FieldDeclarator &FD, ObjCDeclSpec &ODS,
                    Selector GetterSel, Selector SetterSel,
                    tok::ObjCKeywordKind MethodImplKind,
                    DeclContext *lexicalDC = nullptr);

Decl *ActOnPropertyImplDecl(Scope *S,
                            SourceLocation AtLoc,
                            SourceLocation PropertyLoc,
                            bool ImplKind,
                            IdentifierInfo *PropertyId,
                            IdentifierInfo *PropertyIvar,
                            SourceLocation PropertyIvarLoc,
                            ObjCPropertyQueryKind QueryKind);

enum ObjCSpecialMethodKind {
  OSMK_None,
  OSMK_Alloc,
  OSMK_New,
  OSMK_Copy,
  OSMK_RetainingInit,
  OSMK_NonRetainingInit
};

struct ObjCArgInfo {
  IdentifierInfo *Name;
  SourceLocation NameLoc;
  // The Type is null if no type was specified, and the DeclSpec is invalid
  // in this case.
  ParsedType Type;
  ObjCDeclSpec DeclSpec;

  /// ArgAttrs - Attribute list for this argument.
  ParsedAttributesView ArgAttrs;
};

Decl *ActOnMethodDeclaration(
    Scope *S,
    SourceLocation BeginLoc, // location of the + or -.
    SourceLocation EndLoc,   // location of the ; or {.
    tok::TokenKind MethodType, ObjCDeclSpec &ReturnQT, ParsedType ReturnType,
    ArrayRef<SourceLocation> SelectorLocs, Selector Sel,
    // optional arguments. The number of types/arguments is obtained
    // from the Sel.getNumArgs().
    ObjCArgInfo *ArgInfo, DeclaratorChunk::ParamInfo *CParamInfo,
    unsigned CNumArgs, // c-style args
    const ParsedAttributesView &AttrList, tok::ObjCKeywordKind MethodImplKind,
    bool isVariadic, bool MethodDefinition);

ObjCMethodDecl *LookupMethodInQualifiedType(Selector Sel,
                                            const ObjCObjectPointerType *OPT,
                                            bool IsInstance);
ObjCMethodDecl *LookupMethodInObjectType(Selector Sel, QualType Ty,
                                         bool IsInstance);

bool CheckARCMethodDecl(ObjCMethodDecl *method);
bool inferObjCARCLifetime(ValueDecl *decl);

void deduceOpenCLAddressSpace(ValueDecl *decl);

ExprResult
HandleExprPropertyRefExpr(const ObjCObjectPointerType *OPT,
                          Expr *BaseExpr,
                          SourceLocation OpLoc,
                          DeclarationName MemberName,
                          SourceLocation MemberLoc,
                          SourceLocation SuperLoc, QualType SuperType,
                          bool Super);

ExprResult
ActOnClassPropertyRefExpr(IdentifierInfo &receiverName,
                          IdentifierInfo &propertyName,
                          SourceLocation receiverNameLoc,
                          SourceLocation propertyNameLoc);

ObjCMethodDecl *tryCaptureObjCSelf(SourceLocation Loc);

/// Describes the kind of message expression indicated by a message
/// send that starts with an identifier.
enum ObjCMessageKind {
  /// The message is sent to 'super'.
  ObjCSuperMessage,
  /// The message is an instance message.
  ObjCInstanceMessage,
  /// The message is a class message, and the identifier is a type
  /// name.
  ObjCClassMessage
};

ObjCMessageKind getObjCMessageKind(Scope *S,
                                   IdentifierInfo *Name,
                                   SourceLocation NameLoc,
                                   bool IsSuper,
                                   bool HasTrailingDot,
                                   ParsedType &ReceiverType);

ExprResult ActOnSuperMessage(Scope *S, SourceLocation SuperLoc,
                             Selector Sel,
                             SourceLocation LBracLoc,
                             ArrayRef<SourceLocation> SelectorLocs,
                             SourceLocation RBracLoc,
                             MultiExprArg Args);

ExprResult BuildClassMessage(TypeSourceInfo *ReceiverTypeInfo,
                             QualType ReceiverType,
                             SourceLocation SuperLoc,
                             Selector Sel,
                             ObjCMethodDecl *Method,
                             SourceLocation LBracLoc,
                             ArrayRef<SourceLocation> SelectorLocs,
                             SourceLocation RBracLoc,
                             MultiExprArg Args,
                             bool isImplicit = false);

ExprResult BuildClassMessageImplicit(QualType ReceiverType,
                                     bool isSuperReceiver,
                                     SourceLocation Loc,
                                     Selector Sel,
                                     ObjCMethodDecl *Method,
                                     MultiExprArg Args);

ExprResult ActOnClassMessage(Scope *S,
                             ParsedType Receiver,
                             Selector Sel,
                             SourceLocation LBracLoc,
                             ArrayRef<SourceLocation> SelectorLocs,
                             SourceLocation RBracLoc,
                             MultiExprArg Args);

ExprResult BuildInstanceMessage(Expr *Receiver,
                                QualType ReceiverType,
                                SourceLocation SuperLoc,
                                Selector Sel,
                                ObjCMethodDecl *Method,
                                SourceLocation LBracLoc,
                                ArrayRef<SourceLocation> SelectorLocs,
                                SourceLocation RBracLoc,
                                MultiExprArg Args,
                                bool isImplicit = false);

ExprResult BuildInstanceMessageImplicit(Expr *Receiver,
                                        QualType ReceiverType,
                                        SourceLocation Loc,
                                        Selector Sel,
                                        ObjCMethodDecl *Method,
                                        MultiExprArg Args);

ExprResult ActOnInstanceMessage(Scope *S,
                                Expr *Receiver,
                                Selector Sel,
                                SourceLocation LBracLoc,
                                ArrayRef<SourceLocation> SelectorLocs,
                                SourceLocation RBracLoc,
                                MultiExprArg Args);

ExprResult BuildObjCBridgedCast(SourceLocation LParenLoc,
                                ObjCBridgeCastKind Kind,
                                SourceLocation BridgeKeywordLoc,
                                TypeSourceInfo *TSInfo,
                                Expr *SubExpr);

ExprResult ActOnObjCBridgedCast(Scope *S,
                                SourceLocation LParenLoc,
                                ObjCBridgeCastKind Kind,
                                SourceLocation BridgeKeywordLoc,
                                ParsedType Type,
                                SourceLocation RParenLoc,
                                Expr *SubExpr);

void CheckTollFreeBridgeCast(QualType castType, Expr *castExpr);

void CheckObjCBridgeRelatedCast(QualType castType, Expr *castExpr);

bool CheckTollFreeBridgeStaticCast(QualType castType, Expr *castExpr,
                                   CastKind &Kind);

bool checkObjCBridgeRelatedComponents(SourceLocation Loc,
                                      QualType DestType, QualType SrcType,
                                      ObjCInterfaceDecl *&RelatedClass,
                                      ObjCMethodDecl *&ClassMethod,
                                      ObjCMethodDecl *&InstanceMethod,
                                      TypedefNameDecl *&TDNDecl,
                                      bool CfToNs, bool Diagnose = true);

bool CheckObjCBridgeRelatedConversions(SourceLocation Loc,
                                       QualType DestType, QualType SrcType,
                                       Expr *&SrcExpr, bool Diagnose = true);

bool CheckConversionToObjCLiteral(QualType DstType, Expr *&SrcExpr,
                                  bool Diagnose = true);

bool checkInitMethod(ObjCMethodDecl *method, QualType receiverTypeIfCall);

/// Check whether the given new method is a valid override of the
/// given overridden method, and set any properties that should be inherited.
void CheckObjCMethodOverride(ObjCMethodDecl *NewMethod,
                             const ObjCMethodDecl *Overridden);

/// Describes the compatibility of a result type with its method.
enum ResultTypeCompatibilityKind {
  RTC_Compatible,
  RTC_Incompatible,
  RTC_Unknown
};

void CheckObjCMethodDirectOverrides(ObjCMethodDecl *method,
                                    ObjCMethodDecl *overridden);

void CheckObjCMethodOverrides(ObjCMethodDecl *ObjCMethod,
                              ObjCInterfaceDecl *CurrentClass,
                              ResultTypeCompatibilityKind RTC);

enum PragmaOptionsAlignKind {
  POAK_Native,  // #pragma options align=native
  POAK_Natural, // #pragma options align=natural
  POAK_Packed,  // #pragma options align=packed
  POAK_Power,   // #pragma options align=power
  POAK_Mac68k,  // #pragma options align=mac68k
  POAK_Reset    // #pragma options align=reset
};

/// ActOnPragmaClangSection - Called on well formed \#pragma clang section
void ActOnPragmaClangSection(SourceLocation PragmaLoc,
                             PragmaClangSectionAction Action,
                             PragmaClangSectionKind SecKind, StringRef SecName);

/// ActOnPragmaOptionsAlign - Called on well formed \#pragma options align.
void ActOnPragmaOptionsAlign(PragmaOptionsAlignKind Kind,
                             SourceLocation PragmaLoc);

/// ActOnPragmaPack - Called on well formed \#pragma pack(...).
void ActOnPragmaPack(SourceLocation PragmaLoc, PragmaMsStackAction Action,
                     StringRef SlotLabel, Expr *Alignment);

enum class PragmaAlignPackDiagnoseKind {
  NonDefaultStateAtInclude,
  ChangedStateAtExit
};

void DiagnoseNonDefaultPragmaAlignPack(PragmaAlignPackDiagnoseKind Kind,
                                       SourceLocation IncludeLoc);
void DiagnoseUnterminatedPragmaAlignPack();

/// ActOnPragmaMSStrictGuardStackCheck - Called on well formed \#pragma
/// strict_gs_check.
void ActOnPragmaMSStrictGuardStackCheck(SourceLocation PragmaLocation,
                                        PragmaMsStackAction Action,
                                        bool Value);

/// ActOnPragmaMSStruct - Called on well formed \#pragma ms_struct [on|off].
void ActOnPragmaMSStruct(PragmaMSStructKind Kind);

/// ActOnPragmaMSComment - Called on well formed
/// \#pragma comment(kind, "arg").
void ActOnPragmaMSComment(SourceLocation CommentLoc, PragmaMSCommentKind Kind,
                          StringRef Arg);

/// ActOnPragmaMSPointersToMembers - called on well formed \#pragma
/// pointers_to_members(representation method[, general purpose
/// representation]).
void ActOnPragmaMSPointersToMembers(
    LangOptions::PragmaMSPointersToMembersKind Kind,
    SourceLocation PragmaLoc);

/// Called on well formed \#pragma vtordisp().
void ActOnPragmaMSVtorDisp(PragmaMsStackAction Action,
                           SourceLocation PragmaLoc,
                           MSVtorDispMode Value);

enum PragmaSectionKind {
  PSK_DataSeg,
  PSK_BSSSeg,
  PSK_ConstSeg,
  PSK_CodeSeg,
};

bool UnifySection(StringRef SectionName, int SectionFlags,
                  NamedDecl *TheDecl);
bool UnifySection(StringRef SectionName,
                  int SectionFlags,
                  SourceLocation PragmaSectionLocation);

/// Called on well formed \#pragma bss_seg/data_seg/const_seg/code_seg.
void ActOnPragmaMSSeg(SourceLocation PragmaLocation,
                      PragmaMsStackAction Action,
                      llvm::StringRef StackSlotLabel,
                      StringLiteral *SegmentName,
                      llvm::StringRef PragmaName);

/// Called on well formed \#pragma section().
void ActOnPragmaMSSection(SourceLocation PragmaLocation,
                          int SectionFlags, StringLiteral *SegmentName);

/// Called on well-formed \#pragma init_seg().
void ActOnPragmaMSInitSeg(SourceLocation PragmaLocation,
                          StringLiteral *SegmentName);

/// Called on well-formed \#pragma alloc_text().
void ActOnPragmaMSAllocText(
    SourceLocation PragmaLocation, StringRef Section,
    const SmallVector<std::tuple<IdentifierInfo *, SourceLocation>>
        &Functions);

/// Called on #pragma clang __debug dump II
void ActOnPragmaDump(Scope *S, SourceLocation Loc, IdentifierInfo *II);

/// Called on #pragma clang __debug dump E
void ActOnPragmaDump(Expr *E);

/// ActOnPragmaDetectMismatch - Call on well-formed \#pragma detect_mismatch
void ActOnPragmaDetectMismatch(SourceLocation Loc, StringRef Name,
                               StringRef Value);

/// Are precise floating point semantics currently enabled?
bool isPreciseFPEnabled() {
  return !CurFPFeatures.getAllowFPReassociate() &&
         !CurFPFeatures.getNoSignedZero() &&
         !CurFPFeatures.getAllowReciprocal() &&
         !CurFPFeatures.getAllowApproxFunc();
}

void ActOnPragmaFPEvalMethod(SourceLocation Loc,
                             LangOptions::FPEvalMethodKind Value);

/// ActOnPragmaFloatControl - Call on well-formed \#pragma float_control
void ActOnPragmaFloatControl(SourceLocation Loc, PragmaMsStackAction Action,
                             PragmaFloatControlKind Value);

/// ActOnPragmaUnused - Called on well-formed '\#pragma unused'.
void ActOnPragmaUnused(const Token &Identifier,
                       Scope *curScope,
                       SourceLocation PragmaLoc);

/// ActOnPragmaVisibility - Called on well formed \#pragma GCC visibility... .
void ActOnPragmaVisibility(const IdentifierInfo* VisType,
                           SourceLocation PragmaLoc);

NamedDecl *DeclClonePragmaWeak(NamedDecl *ND, const IdentifierInfo *II,
                               SourceLocation Loc);
void DeclApplyPragmaWeak(Scope *S, NamedDecl *ND, const WeakInfo &W);

/// ActOnPragmaWeakID - Called on well formed \#pragma weak ident.
void ActOnPragmaWeakID(IdentifierInfo* WeakName,
                       SourceLocation PragmaLoc,
                       SourceLocation WeakNameLoc);

/// ActOnPragmaRedefineExtname - Called on well formed
/// \#pragma redefine_extname oldname newname.
void ActOnPragmaRedefineExtname(IdentifierInfo* WeakName,
                                IdentifierInfo* AliasName,
                                SourceLocation PragmaLoc,
                                SourceLocation WeakNameLoc,
                                SourceLocation AliasNameLoc);

/// ActOnPragmaWeakAlias - Called on well formed \#pragma weak ident = ident.
void ActOnPragmaWeakAlias(IdentifierInfo* WeakName,
                          IdentifierInfo* AliasName,
                          SourceLocation PragmaLoc,
                          SourceLocation WeakNameLoc,
                          SourceLocation AliasNameLoc);

/// ActOnPragmaFPContract - Called on well formed
/// \#pragma {STDC,OPENCL} FP_CONTRACT and
/// \#pragma clang fp contract
void ActOnPragmaFPContract(SourceLocation Loc, LangOptions::FPModeKind FPC);

/// Called on well formed
/// \#pragma clang fp reassociate
void ActOnPragmaFPReassociate(SourceLocation Loc, bool IsEnabled);

/// ActOnPragmaFenvAccess - Called on well formed
/// \#pragma STDC FENV_ACCESS
void ActOnPragmaFEnvAccess(SourceLocation Loc, bool IsEnabled);

/// Called on well formed '\#pragma clang fp' that has option 'exceptions'.
void ActOnPragmaFPExceptions(SourceLocation Loc,
                             LangOptions::FPExceptionModeKind);

/// Called to set constant rounding mode for floating point operations.
void ActOnPragmaFEnvRound(SourceLocation Loc, llvm::RoundingMode);

/// Called to set exception behavior for floating point operations.
void setExceptionMode(SourceLocation Loc, LangOptions::FPExceptionModeKind);

/// AddAlignmentAttributesForRecord - Adds any needed alignment attributes to
/// a the record decl, to handle '\#pragma pack' and '\#pragma options align'.
void AddAlignmentAttributesForRecord(RecordDecl *RD);

/// AddMsStructLayoutForRecord - Adds ms_struct layout attribute to record.
void AddMsStructLayoutForRecord(RecordDecl *RD);

/// PushNamespaceVisibilityAttr - Note that we've entered a
/// namespace with a visibility attribute.
void PushNamespaceVisibilityAttr(const VisibilityAttr *Attr,
                                 SourceLocation Loc);

/// AddPushedVisibilityAttribute - If '\#pragma GCC visibility' was used,
/// add an appropriate visibility attribute.
void AddPushedVisibilityAttribute(Decl *RD);

/// PopPragmaVisibility - Pop the top element of the visibility stack; used
/// for '\#pragma GCC visibility' and visibility attributes on namespaces.
void PopPragmaVisibility(bool IsNamespaceEnd, SourceLocation EndLoc);

/// FreeVisContext - Deallocate and null out VisContext.
void FreeVisContext();

/// AddCFAuditedAttribute - Check whether we're currently within
/// '\#pragma clang arc_cf_code_audited' and, if so, consider adding
/// the appropriate attribute.
void AddCFAuditedAttribute(Decl *D);

void ActOnPragmaAttributeAttribute(ParsedAttr &Attribute,
                                   SourceLocation PragmaLoc,
                                   attr::ParsedSubjectMatchRuleSet Rules);
void ActOnPragmaAttributeEmptyPush(SourceLocation PragmaLoc,
                                   const IdentifierInfo *Namespace);

/// Called on well-formed '\#pragma clang attribute pop'.
void ActOnPragmaAttributePop(SourceLocation PragmaLoc,
                             const IdentifierInfo *Namespace);

/// Adds the attributes that have been specified using the
/// '\#pragma clang attribute push' directives to the given declaration.
void AddPragmaAttributes(Scope *S, Decl *D);

void DiagnoseUnterminatedPragmaAttribute();

/// Called on well formed \#pragma clang optimize.
void ActOnPragmaOptimize(bool On, SourceLocation PragmaLoc);

/// #pragma optimize("[optimization-list]", on | off).
void ActOnPragmaMSOptimize(SourceLocation Loc, bool IsOn);

/// Call on well formed \#pragma function.
void
ActOnPragmaMSFunction(SourceLocation Loc,
                      const llvm::SmallVectorImpl<StringRef> &NoBuiltins);

/// Get the location for the currently active "\#pragma clang optimize
/// off". If this location is invalid, then the state of the pragma is "on".
SourceLocation getOptimizeOffPragmaLocation() const {
  return OptimizeOffPragmaLocation;
}

/// Only called on function definitions; if there is a pragma in scope
/// with the effect of a range-based optnone, consider marking the function
/// with attribute optnone.
void AddRangeBasedOptnone(FunctionDecl *FD);

/// Only called on function definitions; if there is a `#pragma alloc_text`
/// that decides which code section the function should be in, add
/// attribute section to the function.
void AddSectionMSAllocText(FunctionDecl *FD);

/// Adds the 'optnone' attribute to the function declaration if there
/// are no conflicts; Loc represents the location causing the 'optnone'
/// attribute to be added (usually because of a pragma).
void AddOptnoneAttributeIfNoConflicts(FunctionDecl *FD, SourceLocation Loc);

/// Only called on function definitions; if there is a MSVC #pragma optimize
/// in scope, consider changing the function's attributes based on the
/// optimization list passed to the pragma.
void ModifyFnAttributesMSPragmaOptimize(FunctionDecl *FD);

/// Only called on function definitions; if there is a pragma in scope
/// with the effect of a range-based no_builtin, consider marking the function
/// with attribute no_builtin.
void AddImplicitMSFunctionNoBuiltinAttr(FunctionDecl *FD);

/// AddAlignedAttr - Adds an aligned attribute to a particular declaration.
void AddAlignedAttr(Decl *D, const AttributeCommonInfo &CI, Expr *E,
                    bool IsPackExpansion);
void AddAlignedAttr(Decl *D, const AttributeCommonInfo &CI, TypeSourceInfo *T,
                    bool IsPackExpansion);

/// AddAssumeAlignedAttr - Adds an assume_aligned attribute to a particular
/// declaration.
void AddAssumeAlignedAttr(Decl *D, const AttributeCommonInfo &CI, Expr *E,
                          Expr *OE);

/// AddAllocAlignAttr - Adds an alloc_align attribute to a particular
/// declaration.
void AddAllocAlignAttr(Decl *D, const AttributeCommonInfo &CI,
                       Expr *ParamExpr);

/// AddAlignValueAttr - Adds an align_value attribute to a particular
/// declaration.
void AddAlignValueAttr(Decl *D, const AttributeCommonInfo &CI, Expr *E);

/// AddAnnotationAttr - Adds an annotation Annot with Args arguments to D.
void AddAnnotationAttr(Decl *D, const AttributeCommonInfo &CI,
                       StringRef Annot, MutableArrayRef<Expr *> Args);

/// ConstantFoldAttrArgs - Folds attribute arguments into ConstantExprs
/// (unless they are value dependent or type dependent). Returns false
/// and emits a diagnostic if one or more of the arguments could not be
/// folded into a constant.
bool ConstantFoldAttrArgs(const AttributeCommonInfo &CI,
                          MutableArrayRef<Expr *> Args);

/// AddLaunchBoundsAttr - Adds a launch_bounds attribute to a particular
/// declaration.
void AddLaunchBoundsAttr(Decl *D, const AttributeCommonInfo &CI,
                         Expr *MaxThreads, Expr *MinBlocks);

/// AddModeAttr - Adds a mode attribute to a particular declaration.
void AddModeAttr(Decl *D, const AttributeCommonInfo &CI, IdentifierInfo *Name,
                 bool InInstantiation = false);

void AddParameterABIAttr(Decl *D, const AttributeCommonInfo &CI,
                         ParameterABI ABI);

enum class RetainOwnershipKind {NS, CF, OS};
void AddXConsumedAttr(Decl *D, const AttributeCommonInfo &CI,
                      RetainOwnershipKind K, bool IsTemplateInstantiation);

/// addAMDGPUFlatWorkGroupSizeAttr - Adds an amdgpu_flat_work_group_size
/// attribute to a particular declaration.
void addAMDGPUFlatWorkGroupSizeAttr(Decl *D, const AttributeCommonInfo &CI,
                                    Expr *Min, Expr *Max);

/// addAMDGPUWavePersEUAttr - Adds an amdgpu_waves_per_eu attribute to a
/// particular declaration.
void addAMDGPUWavesPerEUAttr(Decl *D, const AttributeCommonInfo &CI,
                             Expr *Min, Expr *Max);

bool checkNSReturnsRetainedReturnType(SourceLocation loc, QualType type);

//===--------------------------------------------------------------------===//
// C++ Coroutines
//
bool ActOnCoroutineBodyStart(Scope *S, SourceLocation KwLoc,
                             StringRef Keyword);
ExprResult ActOnCoawaitExpr(Scope *S, SourceLocation KwLoc, Expr *E);
ExprResult ActOnCoyieldExpr(Scope *S, SourceLocation KwLoc, Expr *E);
StmtResult ActOnCoreturnStmt(Scope *S, SourceLocation KwLoc, Expr *E);

ExprResult BuildOperatorCoawaitLookupExpr(Scope *S, SourceLocation Loc);
ExprResult BuildOperatorCoawaitCall(SourceLocation Loc, Expr *E,
                                    UnresolvedLookupExpr *Lookup);
ExprResult BuildResolvedCoawaitExpr(SourceLocation KwLoc, Expr *Operand,
                                    Expr *Awaiter, bool IsImplicit = false);
ExprResult BuildUnresolvedCoawaitExpr(SourceLocation KwLoc, Expr *Operand,
                                      UnresolvedLookupExpr *Lookup);
ExprResult BuildCoyieldExpr(SourceLocation KwLoc, Expr *E);
StmtResult BuildCoreturnStmt(SourceLocation KwLoc, Expr *E,
                             bool IsImplicit = false);
StmtResult BuildCoroutineBodyStmt(CoroutineBodyStmt::CtorArgs);
bool buildCoroutineParameterMoves(SourceLocation Loc);
VarDecl *buildCoroutinePromise(SourceLocation Loc);
void CheckCompletedCoroutineBody(FunctionDecl *FD, Stmt *&Body);
/// Lookup 'coroutine_traits' in std namespace and std::experimental
/// namespace. The namespace found is recorded in Namespace.
ClassTemplateDecl *lookupCoroutineTraits(SourceLocation KwLoc,
                                         SourceLocation FuncLoc);
/// Check that the expression co_await promise.final_suspend() shall not be
/// potentially-throwing.
bool checkFinalSuspendNoThrow(const Stmt *FinalSuspend);

//===--------------------------------------------------------------------===//
// OpenMP directives and clauses.
//
10979private:
void *VarDataSharingAttributesStack;

struct DeclareTargetContextInfo {
  struct MapInfo {
    OMPDeclareTargetDeclAttr::MapTypeTy MT;
    SourceLocation Loc;
  };
  /// Explicitly listed variables and functions in a 'to' or 'link' clause.
  llvm::DenseMap<NamedDecl *, MapInfo> ExplicitlyMapped;

  /// The 'device_type' as parsed from the clause.
  OMPDeclareTargetDeclAttr::DevTypeTy DT = OMPDeclareTargetDeclAttr::DT_Any;

  /// The directive kind, `begin declare target` or `declare target`.
  OpenMPDirectiveKind Kind;

  /// The directive with indirect clause.
  std::optional<Expr *> Indirect;

  /// The directive location.
  SourceLocation Loc;

  DeclareTargetContextInfo(OpenMPDirectiveKind Kind, SourceLocation Loc)
      : Kind(Kind), Loc(Loc) {}
};

/// Number of nested '#pragma omp declare target' directives.
SmallVector<DeclareTargetContextInfo, 4> DeclareTargetNesting;

/// Initialization of data-sharing attributes stack.
void InitDataSharingAttributesStack();
void DestroyDataSharingAttributesStack();
ExprResult
VerifyPositiveIntegerConstantInClause(Expr *Op, OpenMPClauseKind CKind,
                                      bool StrictlyPositive = true,
                                      bool SuppressExprDiags = false);
/// Returns OpenMP nesting level for current directive.
unsigned getOpenMPNestingLevel() const;

/// Adjusts the function scopes index for the target-based regions.
void adjustOpenMPTargetScopeIndex(unsigned &FunctionScopesIndex,
                                  unsigned Level) const;

/// Returns the number of scopes associated with the construct on the given
/// OpenMP level.
int getNumberOfConstructScopes(unsigned Level) const;

/// Push new OpenMP function region for non-capturing function.
void pushOpenMPFunctionRegion();

/// Pop OpenMP function region for non-capturing function.
void popOpenMPFunctionRegion(const sema::FunctionScopeInfo *OldFSI);

/// Analyzes and checks a loop nest for use by a loop transformation.
///
/// \param Kind          The loop transformation directive kind.
/// \param NumLoops      How many nested loops the directive is expecting.
/// \param AStmt         Associated statement of the transformation directive.
/// \param LoopHelpers   [out] The loop analysis result.
/// \param Body          [out] The body code nested in \p NumLoops loop.
/// \param OriginalInits [out] Collection of statements and declarations that
///                      must have been executed/declared before entering the
///                      loop.
///
/// \return Whether there was any error.
bool checkTransformableLoopNest(
    OpenMPDirectiveKind Kind, Stmt *AStmt, int NumLoops,
    SmallVectorImpl<OMPLoopBasedDirective::HelperExprs> &LoopHelpers,
    Stmt *&Body,
    SmallVectorImpl<SmallVector<llvm::PointerUnion<Stmt *, Decl *>, 0>>
        &OriginalInits);

/// Helper to keep information about the current `omp begin/end declare
/// variant` nesting.
struct OMPDeclareVariantScope {
  /// The associated OpenMP context selector.
  OMPTraitInfo *TI;

  /// The associated OpenMP context selector mangling.
  std::string NameSuffix;

  OMPDeclareVariantScope(OMPTraitInfo &TI);
};

/// Return the OMPTraitInfo for the surrounding scope, if any.
OMPTraitInfo *getOMPTraitInfoForSurroundingScope() {
  return OMPDeclareVariantScopes.empty() ? nullptr
                                         : OMPDeclareVariantScopes.back().TI;
}

/// The current `omp begin/end declare variant` scopes.
SmallVector<OMPDeclareVariantScope, 4> OMPDeclareVariantScopes;

/// The current `omp begin/end assumes` scopes.
SmallVector<AssumptionAttr *, 4> OMPAssumeScoped;

/// All `omp assumes` we encountered so far.
SmallVector<AssumptionAttr *, 4> OMPAssumeGlobal;

11079public:
/// The declarator \p D defines a function in the scope \p S which is nested
/// in an `omp begin/end declare variant` scope. In this method we create a
/// declaration for \p D and rename \p D according to the OpenMP context
/// selector of the surrounding scope. Return all base functions in \p Bases.
void ActOnStartOfFunctionDefinitionInOpenMPDeclareVariantScope(
    Scope *S, Declarator &D, MultiTemplateParamsArg TemplateParameterLists,
    SmallVectorImpl<FunctionDecl *> &Bases);

/// Register \p D as specialization of all base functions in \p Bases in the
/// current `omp begin/end declare variant` scope.
void ActOnFinishedFunctionDefinitionInOpenMPDeclareVariantScope(
    Decl *D, SmallVectorImpl<FunctionDecl *> &Bases);

/// Act on \p D, a function definition inside of an `omp [begin/end] assumes`.
void ActOnFinishedFunctionDefinitionInOpenMPAssumeScope(Decl *D);

/// Can we exit an OpenMP declare variant scope at the moment.
bool isInOpenMPDeclareVariantScope() const {
  return !OMPDeclareVariantScopes.empty();
}

/// Given the potential call expression \p Call, determine if there is a
/// specialization via the OpenMP declare variant mechanism available. If
/// there is, return the specialized call expression, otherwise return the
/// original \p Call.
ExprResult ActOnOpenMPCall(ExprResult Call, Scope *Scope,
                           SourceLocation LParenLoc, MultiExprArg ArgExprs,
                           SourceLocation RParenLoc, Expr *ExecConfig);

/// Handle a `omp begin declare variant`.
void ActOnOpenMPBeginDeclareVariant(SourceLocation Loc, OMPTraitInfo &TI);

/// Handle a `omp end declare variant`.
void ActOnOpenMPEndDeclareVariant();

/// Checks if the variant/multiversion functions are compatible.
bool areMultiversionVariantFunctionsCompatible(
    const FunctionDecl *OldFD, const FunctionDecl *NewFD,
    const PartialDiagnostic &NoProtoDiagID,
    const PartialDiagnosticAt &NoteCausedDiagIDAt,
    const PartialDiagnosticAt &NoSupportDiagIDAt,
    const PartialDiagnosticAt &DiffDiagIDAt, bool TemplatesSupported,
    bool ConstexprSupported, bool CLinkageMayDiffer);

/// Function tries to capture lambda's captured variables in the OpenMP region
/// before the original lambda is captured.
void tryCaptureOpenMPLambdas(ValueDecl *V);

/// Return true if the provided declaration \a VD should be captured by
/// reference.
/// \param Level Relative level of nested OpenMP construct for that the check
/// is performed.
/// \param OpenMPCaptureLevel Capture level within an OpenMP construct.
bool isOpenMPCapturedByRef(const ValueDecl *D, unsigned Level,
                           unsigned OpenMPCaptureLevel) const;

/// Check if the specified variable is used in one of the private
/// clauses (private, firstprivate, lastprivate, reduction etc.) in OpenMP
/// constructs.
VarDecl *isOpenMPCapturedDecl(ValueDecl *D, bool CheckScopeInfo = false,
                              unsigned StopAt = 0);

/// The member expression(this->fd) needs to be rebuilt in the template
/// instantiation to generate private copy for OpenMP when default
/// clause is used. The function will return true if default
/// cluse is used.
bool isOpenMPRebuildMemberExpr(ValueDecl *D);

ExprResult getOpenMPCapturedExpr(VarDecl *Capture, ExprValueKind VK,
                                 ExprObjectKind OK, SourceLocation Loc);

/// If the current region is a loop-based region, mark the start of the loop
/// construct.
void startOpenMPLoop();

/// If the current region is a range loop-based region, mark the start of the
/// loop construct.
void startOpenMPCXXRangeFor();

/// Check if the specified variable is used in 'private' clause.
/// \param Level Relative level of nested OpenMP construct for that the check
/// is performed.
OpenMPClauseKind isOpenMPPrivateDecl(ValueDecl *D, unsigned Level,
                                     unsigned CapLevel) const;

/// Sets OpenMP capture kind (OMPC_private, OMPC_firstprivate, OMPC_map etc.)
/// for \p FD based on DSA for the provided corresponding captured declaration
/// \p D.
void setOpenMPCaptureKind(FieldDecl *FD, const ValueDecl *D, unsigned Level);

/// Check if the specified variable is captured  by 'target' directive.
/// \param Level Relative level of nested OpenMP construct for that the check
/// is performed.
bool isOpenMPTargetCapturedDecl(const ValueDecl *D, unsigned Level,
                                unsigned CaptureLevel) const;

/// Check if the specified global variable must be captured  by outer capture
/// regions.
/// \param Level Relative level of nested OpenMP construct for that
/// the check is performed.
bool isOpenMPGlobalCapturedDecl(ValueDecl *D, unsigned Level,
                                unsigned CaptureLevel) const;

ExprResult PerformOpenMPImplicitIntegerConversion(SourceLocation OpLoc,
                                                  Expr *Op);
/// Called on start of new data sharing attribute block.
void StartOpenMPDSABlock(OpenMPDirectiveKind K,
                         const DeclarationNameInfo &DirName, Scope *CurScope,
                         SourceLocation Loc);
/// Start analysis of clauses.
void StartOpenMPClause(OpenMPClauseKind K);
/// End analysis of clauses.
void EndOpenMPClause();
/// Called on end of data sharing attribute block.
void EndOpenMPDSABlock(Stmt *CurDirective);

/// Check if the current region is an OpenMP loop region and if it is,
/// mark loop control variable, used in \p Init for loop initialization, as
/// private by default.
/// \param Init First part of the for loop.
void ActOnOpenMPLoopInitialization(SourceLocation ForLoc, Stmt *Init);

/// Called on well-formed '\#pragma omp metadirective' after parsing
/// of the  associated statement.
StmtResult ActOnOpenMPMetaDirective(ArrayRef<OMPClause *> Clauses,
                                    Stmt *AStmt, SourceLocation StartLoc,
                                    SourceLocation EndLoc);

// OpenMP directives and clauses.
/// Called on correct id-expression from the '#pragma omp
/// threadprivate'.
ExprResult ActOnOpenMPIdExpression(Scope *CurScope, CXXScopeSpec &ScopeSpec,
                                   const DeclarationNameInfo &Id,
                                   OpenMPDirectiveKind Kind);
/// Called on well-formed '#pragma omp threadprivate'.
DeclGroupPtrTy ActOnOpenMPThreadprivateDirective(
                                   SourceLocation Loc,
                                   ArrayRef<Expr *> VarList);
/// Builds a new OpenMPThreadPrivateDecl and checks its correctness.
OMPThreadPrivateDecl *CheckOMPThreadPrivateDecl(SourceLocation Loc,
                                                ArrayRef<Expr *> VarList);
/// Called on well-formed '#pragma omp allocate'.
DeclGroupPtrTy ActOnOpenMPAllocateDirective(SourceLocation Loc,
                                            ArrayRef<Expr *> VarList,
                                            ArrayRef<OMPClause *> Clauses,
                                            DeclContext *Owner = nullptr);

/// Called on well-formed '#pragma omp [begin] assume[s]'.
void ActOnOpenMPAssumesDirective(SourceLocation Loc,
                                 OpenMPDirectiveKind DKind,
                                 ArrayRef<std::string> Assumptions,
                                 bool SkippedClauses);

/// Check if there is an active global `omp begin assumes` directive.
bool isInOpenMPAssumeScope() const { return !OMPAssumeScoped.empty(); }

/// Check if there is an active global `omp assumes` directive.
bool hasGlobalOpenMPAssumes() const { return !OMPAssumeGlobal.empty(); }

/// Called on well-formed '#pragma omp end assumes'.
void ActOnOpenMPEndAssumesDirective();

/// Called on well-formed '#pragma omp requires'.
DeclGroupPtrTy ActOnOpenMPRequiresDirective(SourceLocation Loc,
                                            ArrayRef<OMPClause *> ClauseList);
/// Check restrictions on Requires directive
OMPRequiresDecl *CheckOMPRequiresDecl(SourceLocation Loc,
                                      ArrayRef<OMPClause *> Clauses);
/// Check if the specified type is allowed to be used in 'omp declare
/// reduction' construct.
QualType ActOnOpenMPDeclareReductionType(SourceLocation TyLoc,
                                         TypeResult ParsedType);
/// Called on start of '#pragma omp declare reduction'.
DeclGroupPtrTy ActOnOpenMPDeclareReductionDirectiveStart(
    Scope *S, DeclContext *DC, DeclarationName Name,
    ArrayRef<std::pair<QualType, SourceLocation>> ReductionTypes,
    AccessSpecifier AS, Decl *PrevDeclInScope = nullptr);
/// Initialize declare reduction construct initializer.
void ActOnOpenMPDeclareReductionCombinerStart(Scope *S, Decl *D);
/// Finish current declare reduction construct initializer.
void ActOnOpenMPDeclareReductionCombinerEnd(Decl *D, Expr *Combiner);
/// Initialize declare reduction construct initializer.
/// \return omp_priv variable.
VarDecl *ActOnOpenMPDeclareReductionInitializerStart(Scope *S, Decl *D);
/// Finish current declare reduction construct initializer.
void ActOnOpenMPDeclareReductionInitializerEnd(Decl *D, Expr *Initializer,
                                               VarDecl *OmpPrivParm);
/// Called at the end of '#pragma omp declare reduction'.
DeclGroupPtrTy ActOnOpenMPDeclareReductionDirectiveEnd(
    Scope *S, DeclGroupPtrTy DeclReductions, bool IsValid);

/// Check variable declaration in 'omp declare mapper' construct.
TypeResult ActOnOpenMPDeclareMapperVarDecl(Scope *S, Declarator &D);
/// Check if the specified type is allowed to be used in 'omp declare
/// mapper' construct.
QualType ActOnOpenMPDeclareMapperType(SourceLocation TyLoc,
                                      TypeResult ParsedType);
/// Called on start of '#pragma omp declare mapper'.
DeclGroupPtrTy ActOnOpenMPDeclareMapperDirective(
    Scope *S, DeclContext *DC, DeclarationName Name, QualType MapperType,
    SourceLocation StartLoc, DeclarationName VN, AccessSpecifier AS,
    Expr *MapperVarRef, ArrayRef<OMPClause *> Clauses,
    Decl *PrevDeclInScope = nullptr);
/// Build the mapper variable of '#pragma omp declare mapper'.
ExprResult ActOnOpenMPDeclareMapperDirectiveVarDecl(Scope *S,
                                                    QualType MapperType,
                                                    SourceLocation StartLoc,
                                                    DeclarationName VN);
void ActOnOpenMPIteratorVarDecl(VarDecl *VD);
bool isOpenMPDeclareMapperVarDeclAllowed(const VarDecl *VD) const;
const ValueDecl *getOpenMPDeclareMapperVarName() const;

/// Called on the start of target region i.e. '#pragma omp declare target'.
bool ActOnStartOpenMPDeclareTargetContext(DeclareTargetContextInfo &DTCI);

/// Called at the end of target region i.e. '#pragma omp end declare target'.
const DeclareTargetContextInfo ActOnOpenMPEndDeclareTargetDirective();

/// Called once a target context is completed, that can be when a
/// '#pragma omp end declare target' was encountered or when a
/// '#pragma omp declare target' without declaration-definition-seq was
/// encountered.
void ActOnFinishedOpenMPDeclareTargetContext(DeclareTargetContextInfo &DTCI);

/// Report unterminated 'omp declare target' or 'omp begin declare target' at
/// the end of a compilation unit.
void DiagnoseUnterminatedOpenMPDeclareTarget();

/// Searches for the provided declaration name for OpenMP declare target
/// directive.
NamedDecl *lookupOpenMPDeclareTargetName(Scope *CurScope,
                                         CXXScopeSpec &ScopeSpec,
                                         const DeclarationNameInfo &Id);

/// Called on correct id-expression from the '#pragma omp declare target'.
void ActOnOpenMPDeclareTargetName(NamedDecl *ND, SourceLocation Loc,
                                  OMPDeclareTargetDeclAttr::MapTypeTy MT,
                                  DeclareTargetContextInfo &DTCI);

/// Check declaration inside target region.
void
checkDeclIsAllowedInOpenMPTarget(Expr *E, Decl *D,
                                 SourceLocation IdLoc = SourceLocation());
/// Finishes analysis of the deferred functions calls that may be declared as
/// host/nohost during device/host compilation.
void finalizeOpenMPDelayedAnalysis(const FunctionDecl *Caller,
                                   const FunctionDecl *Callee,
                                   SourceLocation Loc);

/// Return true if currently in OpenMP task with untied clause context.
bool isInOpenMPTaskUntiedContext() const;

/// Return true inside OpenMP declare target region.
bool isInOpenMPDeclareTargetContext() const {
  return !DeclareTargetNesting.empty();
}
/// Return true inside OpenMP target region.
bool isInOpenMPTargetExecutionDirective() const;

/// Return the number of captured regions created for an OpenMP directive.
static int getOpenMPCaptureLevels(OpenMPDirectiveKind Kind);

/// Initialization of captured region for OpenMP region.
void ActOnOpenMPRegionStart(OpenMPDirectiveKind DKind, Scope *CurScope);

/// Called for syntactical loops (ForStmt or CXXForRangeStmt) associated to
/// an OpenMP loop directive.
StmtResult ActOnOpenMPCanonicalLoop(Stmt *AStmt);

/// Process a canonical OpenMP loop nest that can either be a canonical
/// literal loop (ForStmt or CXXForRangeStmt), or the generated loop of an
/// OpenMP loop transformation construct.
StmtResult ActOnOpenMPLoopnest(Stmt *AStmt);

/// End of OpenMP region.
///
/// \param S Statement associated with the current OpenMP region.
/// \param Clauses List of clauses for the current OpenMP region.
///
/// \returns Statement for finished OpenMP region.
StmtResult ActOnOpenMPRegionEnd(StmtResult S, ArrayRef<OMPClause *> Clauses);
StmtResult ActOnOpenMPExecutableDirective(
    OpenMPDirectiveKind Kind, const DeclarationNameInfo &DirName,
    OpenMPDirectiveKind CancelRegion, ArrayRef<OMPClause *> Clauses,
    Stmt *AStmt, SourceLocation StartLoc, SourceLocation EndLoc);
/// Called on well-formed '\#pragma omp parallel' after parsing
/// of the  associated statement.
StmtResult ActOnOpenMPParallelDirective(ArrayRef<OMPClause *> Clauses,
                                        Stmt *AStmt,
                                        SourceLocation StartLoc,
                                        SourceLocation EndLoc);
using VarsWithInheritedDSAType =
    llvm::SmallDenseMap<const ValueDecl *, const Expr *, 4>;
/// Called on well-formed '\#pragma omp simd' after parsing
/// of the associated statement.
StmtResult
ActOnOpenMPSimdDirective(ArrayRef<OMPClause *> Clauses, Stmt *AStmt,
                         SourceLocation StartLoc, SourceLocation EndLoc,
                         VarsWithInheritedDSAType &VarsWithImplicitDSA);
/// Called on well-formed '#pragma omp tile' after parsing of its clauses and
/// the associated statement.
StmtResult ActOnOpenMPTileDirective(ArrayRef<OMPClause *> Clauses,
                                    Stmt *AStmt, SourceLocation StartLoc,
                                    SourceLocation EndLoc);
/// Called on well-formed '#pragma omp unroll' after parsing of its clauses
/// and the associated statement.
StmtResult ActOnOpenMPUnrollDirective(ArrayRef<OMPClause *> Clauses,
                                      Stmt *AStmt, SourceLocation StartLoc,
                                      SourceLocation EndLoc);
/// Called on well-formed '\#pragma omp for' after parsing
/// of the associated statement.
StmtResult
ActOnOpenMPForDirective(ArrayRef<OMPClause *> Clauses, Stmt *AStmt,
                        SourceLocation StartLoc, SourceLocation EndLoc,
                        VarsWithInheritedDSAType &VarsWithImplicitDSA);
/// Called on well-formed '\#pragma omp for simd' after parsing
/// of the associated statement.
StmtResult
ActOnOpenMPForSimdDirective(ArrayRef<OMPClause *> Clauses, Stmt *AStmt,
                            SourceLocation StartLoc, SourceLocation EndLoc,
                            VarsWithInheritedDSAType &VarsWithImplicitDSA);
/// Called on well-formed '\#pragma omp sections' after parsing
/// of the associated statement.
StmtResult ActOnOpenMPSectionsDirective(ArrayRef<OMPClause *> Clauses,
                                        Stmt *AStmt, SourceLocation StartLoc,
                                        SourceLocation EndLoc);
/// Called on well-formed '\#pragma omp section' after parsing of the
/// associated statement.
StmtResult ActOnOpenMPSectionDirective(Stmt *AStmt, SourceLocation StartLoc,
                                       SourceLocation EndLoc);
/// Called on well-formed '\#pragma omp single' after parsing of the
/// associated statement.
StmtResult ActOnOpenMPSingleDirective(ArrayRef<OMPClause *> Clauses,
                                      Stmt *AStmt, SourceLocation StartLoc,
                                      SourceLocation EndLoc);
/// Called on well-formed '\#pragma omp master' after parsing of the
/// associated statement.
StmtResult ActOnOpenMPMasterDirective(Stmt *AStmt, SourceLocation StartLoc,
                                      SourceLocation EndLoc);
/// Called on well-formed '\#pragma omp critical' after parsing of the
/// associated statement.
StmtResult ActOnOpenMPCriticalDirective(const DeclarationNameInfo &DirName,
                                        ArrayRef<OMPClause *> Clauses,
                                        Stmt *AStmt, SourceLocation StartLoc,
                                        SourceLocation EndLoc);
/// Called on well-formed '\#pragma omp parallel for' after parsing
/// of the  associated statement.
StmtResult ActOnOpenMPParallelForDirective(
    ArrayRef<OMPClause *> Clauses, Stmt *AStmt, SourceLocation StartLoc,
    SourceLocation EndLoc, VarsWithInheritedDSAType &VarsWithImplicitDSA);
/// Called on well-formed '\#pragma omp parallel for simd' after
/// parsing of the  associated statement.
StmtResult ActOnOpenMPParallelForSimdDirective(
    ArrayRef<OMPClause *> Clauses, Stmt *AStmt, SourceLocation StartLoc,
    SourceLocation EndLoc, VarsWithInheritedDSAType &VarsWithImplicitDSA);
/// Called on well-formed '\#pragma omp parallel master' after
/// parsing of the  associated statement.
StmtResult ActOnOpenMPParallelMasterDirective(ArrayRef<OMPClause *> Clauses,
                                              Stmt *AStmt,
                                              SourceLocation StartLoc,
                                              SourceLocation EndLoc);
/// Called on well-formed '\#pragma omp parallel masked' after
/// parsing of the associated statement.
StmtResult ActOnOpenMPParallelMaskedDirective(ArrayRef<OMPClause *> Clauses,
                                              Stmt *AStmt,
                                              SourceLocation StartLoc,
                                              SourceLocation EndLoc);
/// Called on well-formed '\#pragma omp parallel sections' after
/// parsing of the  associated statement.
StmtResult ActOnOpenMPParallelSectionsDirective(ArrayRef<OMPClause *> Clauses,
                                                Stmt *AStmt,
                                                SourceLocation StartLoc,
                                                SourceLocation EndLoc);
/// Called on well-formed '\#pragma omp task' after parsing of the
/// associated statement.
StmtResult ActOnOpenMPTaskDirective(ArrayRef<OMPClause *> Clauses,
                                    Stmt *AStmt, SourceLocation StartLoc,
                                    SourceLocation EndLoc);
/// Called on well-formed '\#pragma omp taskyield'.
StmtResult ActOnOpenMPTaskyieldDirective(SourceLocation StartLoc,
                                         SourceLocation EndLoc);
/// Called on well-formed '\#pragma omp error'.
/// Error direcitive is allowed in both declared and excutable contexts.
/// Adding InExContext to identify which context is called from.
StmtResult ActOnOpenMPErrorDirective(ArrayRef<OMPClause *> Clauses,
                                     SourceLocation StartLoc,
                                     SourceLocation EndLoc,
                                     bool InExContext = true);
/// Called on well-formed '\#pragma omp barrier'.
StmtResult ActOnOpenMPBarrierDirective(SourceLocation StartLoc,
                                       SourceLocation EndLoc);
/// Called on well-formed '\#pragma omp taskwait'.
StmtResult ActOnOpenMPTaskwaitDirective(ArrayRef<OMPClause *> Clauses,
                                        SourceLocation StartLoc,
                                        SourceLocation EndLoc);
/// Called on well-formed '\#pragma omp taskgroup'.
StmtResult ActOnOpenMPTaskgroupDirective(ArrayRef<OMPClause *> Clauses,
                                         Stmt *AStmt, SourceLocation StartLoc,
                                         SourceLocation EndLoc);
/// Called on well-formed '\#pragma omp flush'.
StmtResult ActOnOpenMPFlushDirective(ArrayRef<OMPClause *> Clauses,
                                     SourceLocation StartLoc,
                                     SourceLocation EndLoc);
/// Called on well-formed '\#pragma omp depobj'.
StmtResult ActOnOpenMPDepobjDirective(ArrayRef<OMPClause *> Clauses,
                                      SourceLocation StartLoc,
                                      SourceLocation EndLoc);
/// Called on well-formed '\#pragma omp scan'.
StmtResult ActOnOpenMPScanDirective(ArrayRef<OMPClause *> Clauses,
                                    SourceLocation StartLoc,
                                    SourceLocation EndLoc);
/// Called on well-formed '\#pragma omp ordered' after parsing of the
/// associated statement.
StmtResult ActOnOpenMPOrderedDirective(ArrayRef<OMPClause *> Clauses,
                                       Stmt *AStmt, SourceLocation StartLoc,
                                       SourceLocation EndLoc);
/// Called on well-formed '\#pragma omp atomic' after parsing of the
/// associated statement.
StmtResult ActOnOpenMPAtomicDirective(ArrayRef<OMPClause *> Clauses,
                                      Stmt *AStmt, SourceLocation StartLoc,
                                      SourceLocation EndLoc);
/// Called on well-formed '\#pragma omp target' after parsing of the
/// associated statement.
StmtResult ActOnOpenMPTargetDirective(ArrayRef<OMPClause *> Clauses,
                                      Stmt *AStmt, SourceLocation StartLoc,
                                      SourceLocation EndLoc);
/// Called on well-formed '\#pragma omp target data' after parsing of
/// the associated statement.
StmtResult ActOnOpenMPTargetDataDirective(ArrayRef<OMPClause *> Clauses,
                                          Stmt *AStmt, SourceLocation StartLoc,
                                          SourceLocation EndLoc);
/// Called on well-formed '\#pragma omp target enter data' after
/// parsing of the associated statement.
StmtResult ActOnOpenMPTargetEnterDataDirective(ArrayRef<OMPClause *> Clauses,
                                               SourceLocation StartLoc,
                                               SourceLocation EndLoc,
                                               Stmt *AStmt);
/// Called on well-formed '\#pragma omp target exit data' after
/// parsing of the associated statement.
StmtResult ActOnOpenMPTargetExitDataDirective(ArrayRef<OMPClause *> Clauses,
                                              SourceLocation StartLoc,
                                              SourceLocation EndLoc,
                                              Stmt *AStmt);
/// Called on well-formed '\#pragma omp target parallel' after
/// parsing of the associated statement.
StmtResult ActOnOpenMPTargetParallelDirective(ArrayRef<OMPClause *> Clauses,
                                              Stmt *AStmt,
                                              SourceLocation StartLoc,
                                              SourceLocation EndLoc);
/// Called on well-formed '\#pragma omp target parallel for' after
/// parsing of the  associated statement.
StmtResult ActOnOpenMPTargetParallelForDirective(
    ArrayRef<OMPClause *> Clauses, Stmt *AStmt, SourceLocation StartLoc,
    SourceLocation EndLoc, VarsWithInheritedDSAType &VarsWithImplicitDSA);
/// Called on well-formed '\#pragma omp teams' after parsing of the
/// associated statement.
StmtResult ActOnOpenMPTeamsDirective(ArrayRef<OMPClause *> Clauses,
                                     Stmt *AStmt, SourceLocation StartLoc,
                                     SourceLocation EndLoc);
/// Called on well-formed '\#pragma omp teams loop' after parsing of the
/// associated statement.
StmtResult ActOnOpenMPTeamsGenericLoopDirective(
    ArrayRef<OMPClause *> Clauses, Stmt *AStmt, SourceLocation StartLoc,
    SourceLocation EndLoc, VarsWithInheritedDSAType &VarsWithImplicitDSA);
/// Called on well-formed '\#pragma omp target teams loop' after parsing of
/// the associated statement.
StmtResult ActOnOpenMPTargetTeamsGenericLoopDirective(
    ArrayRef<OMPClause *> Clauses, Stmt *AStmt, SourceLocation StartLoc,
    SourceLocation EndLoc, VarsWithInheritedDSAType &VarsWithImplicitDSA);
/// Called on well-formed '\#pragma omp parallel loop' after parsing of the
/// associated statement.
StmtResult ActOnOpenMPParallelGenericLoopDirective(
    ArrayRef<OMPClause *> Clauses, Stmt *AStmt, SourceLocation StartLoc,
    SourceLocation EndLoc, VarsWithInheritedDSAType &VarsWithImplicitDSA);
/// Called on well-formed '\#pragma omp target parallel loop' after parsing
/// of the associated statement.
StmtResult ActOnOpenMPTargetParallelGenericLoopDirective(
    ArrayRef<OMPClause *> Clauses, Stmt *AStmt, SourceLocation StartLoc,
    SourceLocation EndLoc, VarsWithInheritedDSAType &VarsWithImplicitDSA);
/// Called on well-formed '\#pragma omp cancellation point'.
StmtResult
ActOnOpenMPCancellationPointDirective(SourceLocation StartLoc,
                                      SourceLocation EndLoc,
                                      OpenMPDirectiveKind CancelRegion);
/// Called on well-formed '\#pragma omp cancel'.
StmtResult ActOnOpenMPCancelDirective(ArrayRef<OMPClause *> Clauses,
                                      SourceLocation StartLoc,
                                      SourceLocation EndLoc,
                                      OpenMPDirectiveKind CancelRegion);
/// Called on well-formed '\#pragma omp taskloop' after parsing of the
/// associated statement.
StmtResult
ActOnOpenMPTaskLoopDirective(ArrayRef<OMPClause *> Clauses, Stmt *AStmt,
                             SourceLocation StartLoc, SourceLocation EndLoc,
                             VarsWithInheritedDSAType &VarsWithImplicitDSA);
/// Called on well-formed '\#pragma omp taskloop simd' after parsing of
/// the associated statement.
StmtResult ActOnOpenMPTaskLoopSimdDirective(
    ArrayRef<OMPClause *> Clauses, Stmt *AStmt, SourceLocation StartLoc,
    SourceLocation EndLoc, VarsWithInheritedDSAType &VarsWithImplicitDSA);
/// Called on well-formed '\#pragma omp master taskloop' after parsing of the
/// associated statement.
StmtResult ActOnOpenMPMasterTaskLoopDirective(
    ArrayRef<OMPClause *> Clauses, Stmt *AStmt, SourceLocation StartLoc,
    SourceLocation EndLoc, VarsWithInheritedDSAType &VarsWithImplicitDSA);
/// Called on well-formed '\#pragma omp master taskloop simd' after parsing of
/// the associated statement.
StmtResult ActOnOpenMPMasterTaskLoopSimdDirective(
    ArrayRef<OMPClause *> Clauses, Stmt *AStmt, SourceLocation StartLoc,
    SourceLocation EndLoc, VarsWithInheritedDSAType &VarsWithImplicitDSA);
/// Called on well-formed '\#pragma omp parallel master taskloop' after
/// parsing of the associated statement.
StmtResult ActOnOpenMPParallelMasterTaskLoopDirective(
    ArrayRef<OMPClause *> Clauses, Stmt *AStmt, SourceLocation StartLoc,
    SourceLocation EndLoc, VarsWithInheritedDSAType &VarsWithImplicitDSA);
/// Called on well-formed '\#pragma omp parallel master taskloop simd' after
/// parsing of the associated statement.
StmtResult ActOnOpenMPParallelMasterTaskLoopSimdDirective(
    ArrayRef<OMPClause *> Clauses, Stmt *AStmt, SourceLocation StartLoc,
    SourceLocation EndLoc, VarsWithInheritedDSAType &VarsWithImplicitDSA);
/// Called on well-formed '\#pragma omp masked taskloop' after parsing of the
/// associated statement.
StmtResult ActOnOpenMPMaskedTaskLoopDirective(
    ArrayRef<OMPClause *> Clauses, Stmt *AStmt, SourceLocation StartLoc,
    SourceLocation EndLoc, VarsWithInheritedDSAType &VarsWithImplicitDSA);
/// Called on well-formed '\#pragma omp masked taskloop simd' after parsing of
/// the associated statement.
StmtResult ActOnOpenMPMaskedTaskLoopSimdDirective(
    ArrayRef<OMPClause *> Clauses, Stmt *AStmt, SourceLocation StartLoc,
    SourceLocation EndLoc, VarsWithInheritedDSAType &VarsWithImplicitDSA);
/// Called on well-formed '\#pragma omp parallel masked taskloop' after
/// parsing of the associated statement.
StmtResult ActOnOpenMPParallelMaskedTaskLoopDirective(
    ArrayRef<OMPClause *> Clauses, Stmt *AStmt, SourceLocation StartLoc,
    SourceLocation EndLoc, VarsWithInheritedDSAType &VarsWithImplicitDSA);
/// Called on well-formed '\#pragma omp parallel masked taskloop simd' after
/// parsing of the associated statement.
StmtResult ActOnOpenMPParallelMaskedTaskLoopSimdDirective(
    ArrayRef<OMPClause *> Clauses, Stmt *AStmt, SourceLocation StartLoc,
    SourceLocation EndLoc, VarsWithInheritedDSAType &VarsWithImplicitDSA);
/// Called on well-formed '\#pragma omp distribute' after parsing
/// of the associated statement.
StmtResult
ActOnOpenMPDistributeDirective(ArrayRef<OMPClause *> Clauses, Stmt *AStmt,
                               SourceLocation StartLoc, SourceLocation EndLoc,
                               VarsWithInheritedDSAType &VarsWithImplicitDSA);
/// Called on well-formed '\#pragma omp target update'.
StmtResult ActOnOpenMPTargetUpdateDirective(ArrayRef<OMPClause *> Clauses,
                                            SourceLocation StartLoc,
                                            SourceLocation EndLoc,
                                            Stmt *AStmt);
/// Called on well-formed '\#pragma omp distribute parallel for' after
/// parsing of the associated statement.
StmtResult ActOnOpenMPDistributeParallelForDirective(
    ArrayRef<OMPClause *> Clauses, Stmt *AStmt, SourceLocation StartLoc,
    SourceLocation EndLoc, VarsWithInheritedDSAType &VarsWithImplicitDSA);
/// Called on well-formed '\#pragma omp distribute parallel for simd'
/// after parsing of the associated statement.
StmtResult ActOnOpenMPDistributeParallelForSimdDirective(
    ArrayRef<OMPClause *> Clauses, Stmt *AStmt, SourceLocation StartLoc,
    SourceLocation EndLoc, VarsWithInheritedDSAType &VarsWithImplicitDSA);
/// Called on well-formed '\#pragma omp distribute simd' after
/// parsing of the associated statement.
StmtResult ActOnOpenMPDistributeSimdDirective(
    ArrayRef<OMPClause *> Clauses, Stmt *AStmt, SourceLocation StartLoc,
    SourceLocation EndLoc, VarsWithInheritedDSAType &VarsWithImplicitDSA);
/// Called on well-formed '\#pragma omp target parallel for simd' after
/// parsing of the associated statement.
StmtResult ActOnOpenMPTargetParallelForSimdDirective(
    ArrayRef<OMPClause *> Clauses, Stmt *AStmt, SourceLocation StartLoc,
    SourceLocation EndLoc, VarsWithInheritedDSAType &VarsWithImplicitDSA);
/// Called on well-formed '\#pragma omp target simd' after parsing of
/// the associated statement.
StmtResult
ActOnOpenMPTargetSimdDirective(ArrayRef<OMPClause *> Clauses, Stmt *AStmt,
                               SourceLocation StartLoc, SourceLocation EndLoc,
                               VarsWithInheritedDSAType &VarsWithImplicitDSA);
/// Called on well-formed '\#pragma omp teams distribute' after parsing of
/// the associated statement.
StmtResult ActOnOpenMPTeamsDistributeDirective(
    ArrayRef<OMPClause *> Clauses, Stmt *AStmt, SourceLocation StartLoc,
    SourceLocation EndLoc, VarsWithInheritedDSAType &VarsWithImplicitDSA);
/// Called on well-formed '\#pragma omp teams distribute simd' after parsing
/// of the associated statement.
StmtResult ActOnOpenMPTeamsDistributeSimdDirective(
    ArrayRef<OMPClause *> Clauses, Stmt *AStmt, SourceLocation StartLoc,
    SourceLocation EndLoc, VarsWithInheritedDSAType &VarsWithImplicitDSA);
/// Called on well-formed '\#pragma omp teams distribute parallel for simd'
/// after parsing of the associated statement.
StmtResult ActOnOpenMPTeamsDistributeParallelForSimdDirective(
    ArrayRef<OMPClause *> Clauses, Stmt *AStmt, SourceLocation StartLoc,
    SourceLocation EndLoc, VarsWithInheritedDSAType &VarsWithImplicitDSA);
/// Called on well-formed '\#pragma omp teams distribute parallel for'
/// after parsing of the associated statement.
StmtResult ActOnOpenMPTeamsDistributeParallelForDirective(
    ArrayRef<OMPClause *> Clauses, Stmt *AStmt, SourceLocation StartLoc,
    SourceLocation EndLoc, VarsWithInheritedDSAType &VarsWithImplicitDSA);
/// Called on well-formed '\#pragma omp target teams' after parsing of the
/// associated statement.
StmtResult ActOnOpenMPTargetTeamsDirective(ArrayRef<OMPClause *> Clauses,
                                           Stmt *AStmt,
                                           SourceLocation StartLoc,
                                           SourceLocation EndLoc);
/// Called on well-formed '\#pragma omp target teams distribute' after parsing
/// of the associated statement.
StmtResult ActOnOpenMPTargetTeamsDistributeDirective(
    ArrayRef<OMPClause *> Clauses, Stmt *AStmt, SourceLocation StartLoc,
    SourceLocation EndLoc, VarsWithInheritedDSAType &VarsWithImplicitDSA);
/// Called on well-formed '\#pragma omp target teams distribute parallel for'
/// after parsing of the associated statement.
StmtResult ActOnOpenMPTargetTeamsDistributeParallelForDirective(
    ArrayRef<OMPClause *> Clauses, Stmt *AStmt, SourceLocation StartLoc,
    SourceLocation EndLoc, VarsWithInheritedDSAType &VarsWithImplicitDSA);
/// Called on well-formed '\#pragma omp target teams distribute parallel for
/// simd' after parsing of the associated statement.
StmtResult ActOnOpenMPTargetTeamsDistributeParallelForSimdDirective(
    ArrayRef<OMPClause *> Clauses, Stmt *AStmt, SourceLocation StartLoc,
    SourceLocation EndLoc, VarsWithInheritedDSAType &VarsWithImplicitDSA);
/// Called on well-formed '\#pragma omp target teams distribute simd' after
/// parsing of the associated statement.
StmtResult ActOnOpenMPTargetTeamsDistributeSimdDirective(
    ArrayRef<OMPClause *> Clauses, Stmt *AStmt, SourceLocation StartLoc,
    SourceLocation EndLoc, VarsWithInheritedDSAType &VarsWithImplicitDSA);
/// Called on well-formed '\#pragma omp interop'.
StmtResult ActOnOpenMPInteropDirective(ArrayRef<OMPClause *> Clauses,
                                       SourceLocation StartLoc,
                                       SourceLocation EndLoc);
/// Called on well-formed '\#pragma omp dispatch' after parsing of the
// /associated statement.
StmtResult ActOnOpenMPDispatchDirective(ArrayRef<OMPClause *> Clauses,
                                        Stmt *AStmt, SourceLocation StartLoc,
                                        SourceLocation EndLoc);
/// Called on well-formed '\#pragma omp masked' after parsing of the
// /associated statement.
StmtResult ActOnOpenMPMaskedDirective(ArrayRef<OMPClause *> Clauses,
                                      Stmt *AStmt, SourceLocation StartLoc,
                                      SourceLocation EndLoc);

/// Called on well-formed '\#pragma omp loop' after parsing of the
/// associated statement.
StmtResult ActOnOpenMPGenericLoopDirective(
    ArrayRef<OMPClause *> Clauses, Stmt *AStmt, SourceLocation StartLoc,
    SourceLocation EndLoc, VarsWithInheritedDSAType &VarsWithImplicitDSA);

/// Checks correctness of linear modifiers.
bool CheckOpenMPLinearModifier(OpenMPLinearClauseKind LinKind,
                               SourceLocation LinLoc);
/// Checks that the specified declaration matches requirements for the linear
/// decls.
bool CheckOpenMPLinearDecl(const ValueDecl *D, SourceLocation ELoc,
                           OpenMPLinearClauseKind LinKind, QualType Type,
                           bool IsDeclareSimd = false);

/// Called on well-formed '\#pragma omp declare simd' after parsing of
/// the associated method/function.
DeclGroupPtrTy ActOnOpenMPDeclareSimdDirective(
    DeclGroupPtrTy DG, OMPDeclareSimdDeclAttr::BranchStateTy BS,
    Expr *Simdlen, ArrayRef<Expr *> Uniforms, ArrayRef<Expr *> Aligneds,
    ArrayRef<Expr *> Alignments, ArrayRef<Expr *> Linears,
    ArrayRef<unsigned> LinModifiers, ArrayRef<Expr *> Steps, SourceRange SR);

/// Checks '\#pragma omp declare variant' variant function and original
/// functions after parsing of the associated method/function.
/// \param DG Function declaration to which declare variant directive is
/// applied to.
/// \param VariantRef Expression that references the variant function, which
/// must be used instead of the original one, specified in \p DG.
/// \param TI The trait info object representing the match clause.
/// \param NumAppendArgs The number of omp_interop_t arguments to account for
/// in checking.
/// \returns std::nullopt, if the function/variant function are not compatible
/// with the pragma, pair of original function/variant ref expression
/// otherwise.
std::optional<std::pair<FunctionDecl *, Expr *>>
checkOpenMPDeclareVariantFunction(DeclGroupPtrTy DG, Expr *VariantRef,
                                  OMPTraitInfo &TI, unsigned NumAppendArgs,
                                  SourceRange SR);

/// Called on well-formed '\#pragma omp declare variant' after parsing of
/// the associated method/function.
/// \param FD Function declaration to which declare variant directive is
/// applied to.
/// \param VariantRef Expression that references the variant function, which
/// must be used instead of the original one, specified in \p DG.
/// \param TI The context traits associated with the function variant.
/// \param AdjustArgsNothing The list of 'nothing' arguments.
/// \param AdjustArgsNeedDevicePtr The list of 'need_device_ptr' arguments.
/// \param AppendArgs The list of 'append_args' arguments.
/// \param AdjustArgsLoc The Location of an 'adjust_args' clause.
/// \param AppendArgsLoc The Location of an 'append_args' clause.
/// \param SR The SourceRange of the 'declare variant' directive.
void ActOnOpenMPDeclareVariantDirective(
    FunctionDecl *FD, Expr *VariantRef, OMPTraitInfo &TI,
    ArrayRef<Expr *> AdjustArgsNothing,
    ArrayRef<Expr *> AdjustArgsNeedDevicePtr,
    ArrayRef<OMPInteropInfo> AppendArgs, SourceLocation AdjustArgsLoc,
    SourceLocation AppendArgsLoc, SourceRange SR);

OMPClause *ActOnOpenMPSingleExprClause(OpenMPClauseKind Kind,
                                       Expr *Expr,
                                       SourceLocation StartLoc,
                                       SourceLocation LParenLoc,
                                       SourceLocation EndLoc);
/// Called on well-formed 'allocator' clause.
OMPClause *ActOnOpenMPAllocatorClause(Expr *Allocator,
                                      SourceLocation StartLoc,
                                      SourceLocation LParenLoc,
                                      SourceLocation EndLoc);
/// Called on well-formed 'if' clause.
OMPClause *ActOnOpenMPIfClause(OpenMPDirectiveKind NameModifier,
                               Expr *Condition, SourceLocation StartLoc,
                               SourceLocation LParenLoc,
                               SourceLocation NameModifierLoc,
                               SourceLocation ColonLoc,
                               SourceLocation EndLoc);
/// Called on well-formed 'final' clause.
OMPClause *ActOnOpenMPFinalClause(Expr *Condition, SourceLocation StartLoc,
                                  SourceLocation LParenLoc,
                                  SourceLocation EndLoc);
/// Called on well-formed 'num_threads' clause.
OMPClause *ActOnOpenMPNumThreadsClause(Expr *NumThreads,
                                       SourceLocation StartLoc,
                                       SourceLocation LParenLoc,
                                       SourceLocation EndLoc);
/// Called on well-formed 'align' clause.
OMPClause *ActOnOpenMPAlignClause(Expr *Alignment, SourceLocation StartLoc,
                                  SourceLocation LParenLoc,
                                  SourceLocation EndLoc);
/// Called on well-formed 'safelen' clause.
OMPClause *ActOnOpenMPSafelenClause(Expr *Length,
                                    SourceLocation StartLoc,
                                    SourceLocation LParenLoc,
                                    SourceLocation EndLoc);
/// Called on well-formed 'simdlen' clause.
OMPClause *ActOnOpenMPSimdlenClause(Expr *Length, SourceLocation StartLoc,
                                    SourceLocation LParenLoc,
                                    SourceLocation EndLoc);
/// Called on well-form 'sizes' clause.
OMPClause *ActOnOpenMPSizesClause(ArrayRef<Expr *> SizeExprs,
                                  SourceLocation StartLoc,
                                  SourceLocation LParenLoc,
                                  SourceLocation EndLoc);
/// Called on well-form 'full' clauses.
OMPClause *ActOnOpenMPFullClause(SourceLocation StartLoc,
                                 SourceLocation EndLoc);
/// Called on well-form 'partial' clauses.
OMPClause *ActOnOpenMPPartialClause(Expr *FactorExpr, SourceLocation StartLoc,
                                    SourceLocation LParenLoc,
                                    SourceLocation EndLoc);
/// Called on well-formed 'collapse' clause.
OMPClause *ActOnOpenMPCollapseClause(Expr *NumForLoops,
                                     SourceLocation StartLoc,
                                     SourceLocation LParenLoc,
                                     SourceLocation EndLoc);
/// Called on well-formed 'ordered' clause.
OMPClause *
ActOnOpenMPOrderedClause(SourceLocation StartLoc, SourceLocation EndLoc,
                         SourceLocation LParenLoc = SourceLocation(),
                         Expr *NumForLoops = nullptr);
/// Called on well-formed 'grainsize' clause.
OMPClause *ActOnOpenMPGrainsizeClause(OpenMPGrainsizeClauseModifier Modifier,
                                      Expr *Size, SourceLocation StartLoc,
                                      SourceLocation LParenLoc,
                                      SourceLocation ModifierLoc,
                                      SourceLocation EndLoc);
/// Called on well-formed 'num_tasks' clause.
OMPClause *ActOnOpenMPNumTasksClause(OpenMPNumTasksClauseModifier Modifier,
                                     Expr *NumTasks, SourceLocation StartLoc,
                                     SourceLocation LParenLoc,
                                     SourceLocation ModifierLoc,
                                     SourceLocation EndLoc);
/// Called on well-formed 'hint' clause.
OMPClause *ActOnOpenMPHintClause(Expr *Hint, SourceLocation StartLoc,
                                 SourceLocation LParenLoc,
                                 SourceLocation EndLoc);
/// Called on well-formed 'detach' clause.
OMPClause *ActOnOpenMPDetachClause(Expr *Evt, SourceLocation StartLoc,
                                   SourceLocation LParenLoc,
                                   SourceLocation EndLoc);

OMPClause *ActOnOpenMPSimpleClause(OpenMPClauseKind Kind,
                                   unsigned Argument,
                                   SourceLocation ArgumentLoc,
                                   SourceLocation StartLoc,
                                   SourceLocation LParenLoc,
                                   SourceLocation EndLoc);
/// Called on well-formed 'when' clause.
OMPClause *ActOnOpenMPWhenClause(OMPTraitInfo &TI, SourceLocation StartLoc,
                                 SourceLocation LParenLoc,
                                 SourceLocation EndLoc);
/// Called on well-formed 'default' clause.
OMPClause *ActOnOpenMPDefaultClause(llvm::omp::DefaultKind Kind,
                                    SourceLocation KindLoc,
                                    SourceLocation StartLoc,
                                    SourceLocation LParenLoc,
                                    SourceLocation EndLoc);
/// Called on well-formed 'proc_bind' clause.
OMPClause *ActOnOpenMPProcBindClause(llvm::omp::ProcBindKind Kind,
                                     SourceLocation KindLoc,
                                     SourceLocation StartLoc,
                                     SourceLocation LParenLoc,
                                     SourceLocation EndLoc);
/// Called on well-formed 'order' clause.
OMPClause *ActOnOpenMPOrderClause(OpenMPOrderClauseModifier Modifier,
                                  OpenMPOrderClauseKind Kind,
                                  SourceLocation StartLoc,
                                  SourceLocation LParenLoc,
                                  SourceLocation MLoc, SourceLocation KindLoc,
                                  SourceLocation EndLoc);
/// Called on well-formed 'update' clause.
OMPClause *ActOnOpenMPUpdateClause(OpenMPDependClauseKind Kind,
                                   SourceLocation KindLoc,
                                   SourceLocation StartLoc,
                                   SourceLocation LParenLoc,
                                   SourceLocation EndLoc);

OMPClause *ActOnOpenMPSingleExprWithArgClause(
    OpenMPClauseKind Kind, ArrayRef<unsigned> Arguments, Expr *Expr,
    SourceLocation StartLoc, SourceLocation LParenLoc,
    ArrayRef<SourceLocation> ArgumentsLoc, SourceLocation DelimLoc,
    SourceLocation EndLoc);
/// Called on well-formed 'schedule' clause.
OMPClause *ActOnOpenMPScheduleClause(
    OpenMPScheduleClauseModifier M1, OpenMPScheduleClauseModifier M2,
    OpenMPScheduleClauseKind Kind, Expr *ChunkSize, SourceLocation StartLoc,
    SourceLocation LParenLoc, SourceLocation M1Loc, SourceLocation M2Loc,
    SourceLocation KindLoc, SourceLocation CommaLoc, SourceLocation EndLoc);

OMPClause *ActOnOpenMPClause(OpenMPClauseKind Kind, SourceLocation StartLoc,
                             SourceLocation EndLoc);
/// Called on well-formed 'nowait' clause.
OMPClause *ActOnOpenMPNowaitClause(SourceLocation StartLoc,
                                   SourceLocation EndLoc);
/// Called on well-formed 'untied' clause.
OMPClause *ActOnOpenMPUntiedClause(SourceLocation StartLoc,
                                   SourceLocation EndLoc);
/// Called on well-formed 'mergeable' clause.
OMPClause *ActOnOpenMPMergeableClause(SourceLocation StartLoc,
                                      SourceLocation EndLoc);
/// Called on well-formed 'read' clause.
OMPClause *ActOnOpenMPReadClause(SourceLocation StartLoc,
                                 SourceLocation EndLoc);
/// Called on well-formed 'write' clause.
OMPClause *ActOnOpenMPWriteClause(SourceLocation StartLoc,
                                  SourceLocation EndLoc);
/// Called on well-formed 'update' clause.
OMPClause *ActOnOpenMPUpdateClause(SourceLocation StartLoc,
                                   SourceLocation EndLoc);
/// Called on well-formed 'capture' clause.
OMPClause *ActOnOpenMPCaptureClause(SourceLocation StartLoc,
                                    SourceLocation EndLoc);
/// Called on well-formed 'compare' clause.
OMPClause *ActOnOpenMPCompareClause(SourceLocation StartLoc,
                                    SourceLocation EndLoc);
/// Called on well-formed 'seq_cst' clause.
OMPClause *ActOnOpenMPSeqCstClause(SourceLocation StartLoc,
                                   SourceLocation EndLoc);
/// Called on well-formed 'acq_rel' clause.
OMPClause *ActOnOpenMPAcqRelClause(SourceLocation StartLoc,
                                   SourceLocation EndLoc);
/// Called on well-formed 'acquire' clause.
OMPClause *ActOnOpenMPAcquireClause(SourceLocation StartLoc,
                                    SourceLocation EndLoc);
/// Called on well-formed 'release' clause.
OMPClause *ActOnOpenMPReleaseClause(SourceLocation StartLoc,
                                    SourceLocation EndLoc);
/// Called on well-formed 'relaxed' clause.
OMPClause *ActOnOpenMPRelaxedClause(SourceLocation StartLoc,
                                    SourceLocation EndLoc);

/// Called on well-formed 'init' clause.
OMPClause *
ActOnOpenMPInitClause(Expr *InteropVar, OMPInteropInfo &InteropInfo,
                      SourceLocation StartLoc, SourceLocation LParenLoc,
                      SourceLocation VarLoc, SourceLocation EndLoc);

/// Called on well-formed 'use' clause.
OMPClause *ActOnOpenMPUseClause(Expr *InteropVar, SourceLocation StartLoc,
                                SourceLocation LParenLoc,
                                SourceLocation VarLoc, SourceLocation EndLoc);

/// Called on well-formed 'destroy' clause.
OMPClause *ActOnOpenMPDestroyClause(Expr *InteropVar, SourceLocation StartLoc,
                                    SourceLocation LParenLoc,
                                    SourceLocation VarLoc,
                                    SourceLocation EndLoc);
/// Called on well-formed 'novariants' clause.
OMPClause *ActOnOpenMPNovariantsClause(Expr *Condition,
                                       SourceLocation StartLoc,
                                       SourceLocation LParenLoc,
                                       SourceLocation EndLoc);
/// Called on well-formed 'nocontext' clause.
OMPClause *ActOnOpenMPNocontextClause(Expr *Condition,
                                      SourceLocation StartLoc,
                                      SourceLocation LParenLoc,
                                      SourceLocation EndLoc);
/// Called on well-formed 'filter' clause.
OMPClause *ActOnOpenMPFilterClause(Expr *ThreadID, SourceLocation StartLoc,
                                   SourceLocation LParenLoc,
                                   SourceLocation EndLoc);
/// Called on well-formed 'threads' clause.
OMPClause *ActOnOpenMPThreadsClause(SourceLocation StartLoc,
                                    SourceLocation EndLoc);
/// Called on well-formed 'simd' clause.
OMPClause *ActOnOpenMPSIMDClause(SourceLocation StartLoc,
                                 SourceLocation EndLoc);
/// Called on well-formed 'nogroup' clause.
OMPClause *ActOnOpenMPNogroupClause(SourceLocation StartLoc,
                                    SourceLocation EndLoc);
/// Called on well-formed 'unified_address' clause.
OMPClause *ActOnOpenMPUnifiedAddressClause(SourceLocation StartLoc,
                                           SourceLocation EndLoc);

/// Called on well-formed 'unified_address' clause.
OMPClause *ActOnOpenMPUnifiedSharedMemoryClause(SourceLocation StartLoc,
                                                SourceLocation EndLoc);

/// Called on well-formed 'reverse_offload' clause.
OMPClause *ActOnOpenMPReverseOffloadClause(SourceLocation StartLoc,
                                           SourceLocation EndLoc);

/// Called on well-formed 'dynamic_allocators' clause.
OMPClause *ActOnOpenMPDynamicAllocatorsClause(SourceLocation StartLoc,
                                              SourceLocation EndLoc);

/// Called on well-formed 'atomic_default_mem_order' clause.
OMPClause *ActOnOpenMPAtomicDefaultMemOrderClause(
    OpenMPAtomicDefaultMemOrderClauseKind Kind, SourceLocation KindLoc,
    SourceLocation StartLoc, SourceLocation LParenLoc, SourceLocation EndLoc);

/// Called on well-formed 'at' clause.
OMPClause *ActOnOpenMPAtClause(OpenMPAtClauseKind Kind,
                               SourceLocation KindLoc,
                               SourceLocation StartLoc,
                               SourceLocation LParenLoc,
                               SourceLocation EndLoc);

/// Called on well-formed 'severity' clause.
OMPClause *ActOnOpenMPSeverityClause(OpenMPSeverityClauseKind Kind,
                                     SourceLocation KindLoc,
                                     SourceLocation StartLoc,
                                     SourceLocation LParenLoc,
                                     SourceLocation EndLoc);

/// Called on well-formed 'message' clause.
/// passing string for message.
OMPClause *ActOnOpenMPMessageClause(Expr *MS, SourceLocation StartLoc,
                                    SourceLocation LParenLoc,
                                    SourceLocation EndLoc);

/// Data used for processing a list of variables in OpenMP clauses.
struct OpenMPVarListDataTy final {
  Expr *DepModOrTailExpr = nullptr;
  Expr *IteratorExpr = nullptr;
  SourceLocation ColonLoc;
  SourceLocation RLoc;
  CXXScopeSpec ReductionOrMapperIdScopeSpec;
  DeclarationNameInfo ReductionOrMapperId;
  int ExtraModifier = -1; ///< Additional modifier for linear, map, depend or
                          ///< lastprivate clause.
  SmallVector<OpenMPMapModifierKind, NumberOfOMPMapClauseModifiers>
      MapTypeModifiers;
  SmallVector<SourceLocation, NumberOfOMPMapClauseModifiers>
      MapTypeModifiersLoc;
  SmallVector<OpenMPMotionModifierKind, NumberOfOMPMotionModifiers>
      MotionModifiers;
  SmallVector<SourceLocation, NumberOfOMPMotionModifiers> MotionModifiersLoc;
  bool IsMapTypeImplicit = false;
  SourceLocation ExtraModifierLoc;
  SourceLocation OmpAllMemoryLoc;
};

OMPClause *ActOnOpenMPVarListClause(OpenMPClauseKind Kind,
                                    ArrayRef<Expr *> Vars,
                                    const OMPVarListLocTy &Locs,
                                    OpenMPVarListDataTy &Data);
/// Called on well-formed 'inclusive' clause.
OMPClause *ActOnOpenMPInclusiveClause(ArrayRef<Expr *> VarList,
                                      SourceLocation StartLoc,
                                      SourceLocation LParenLoc,
                                      SourceLocation EndLoc);
/// Called on well-formed 'exclusive' clause.
OMPClause *ActOnOpenMPExclusiveClause(ArrayRef<Expr *> VarList,
                                      SourceLocation StartLoc,
                                      SourceLocation LParenLoc,
                                      SourceLocation EndLoc);
/// Called on well-formed 'allocate' clause.
OMPClause *
ActOnOpenMPAllocateClause(Expr *Allocator, ArrayRef<Expr *> VarList,
                          SourceLocation StartLoc, SourceLocation ColonLoc,
                          SourceLocation LParenLoc, SourceLocation EndLoc);
/// Called on well-formed 'private' clause.
OMPClause *ActOnOpenMPPrivateClause(ArrayRef<Expr *> VarList,
                                    SourceLocation StartLoc,
                                    SourceLocation LParenLoc,
                                    SourceLocation EndLoc);
/// Called on well-formed 'firstprivate' clause.
OMPClause *ActOnOpenMPFirstprivateClause(ArrayRef<Expr *> VarList,
                                         SourceLocation StartLoc,
                                         SourceLocation LParenLoc,
                                         SourceLocation EndLoc);
/// Called on well-formed 'lastprivate' clause.
OMPClause *ActOnOpenMPLastprivateClause(
    ArrayRef<Expr *> VarList, OpenMPLastprivateModifier LPKind,
    SourceLocation LPKindLoc, SourceLocation ColonLoc,
    SourceLocation StartLoc, SourceLocation LParenLoc, SourceLocation EndLoc);
/// Called on well-formed 'shared' clause.
OMPClause *ActOnOpenMPSharedClause(ArrayRef<Expr *> VarList,
                                   SourceLocation StartLoc,
                                   SourceLocation LParenLoc,
                                   SourceLocation EndLoc);
/// Called on well-formed 'reduction' clause.
OMPClause *ActOnOpenMPReductionClause(
    ArrayRef<Expr *> VarList, OpenMPReductionClauseModifier Modifier,
    SourceLocation StartLoc, SourceLocation LParenLoc,
    SourceLocation ModifierLoc, SourceLocation ColonLoc,
    SourceLocation EndLoc, CXXScopeSpec &ReductionIdScopeSpec,
    const DeclarationNameInfo &ReductionId,
    ArrayRef<Expr *> UnresolvedReductions = std::nullopt);
/// Called on well-formed 'task_reduction' clause.
OMPClause *ActOnOpenMPTaskReductionClause(
    ArrayRef<Expr *> VarList, SourceLocation StartLoc,
    SourceLocation LParenLoc, SourceLocation ColonLoc, SourceLocation EndLoc,
    CXXScopeSpec &ReductionIdScopeSpec,
    const DeclarationNameInfo &ReductionId,
    ArrayRef<Expr *> UnresolvedReductions = std::nullopt);
/// Called on well-formed 'in_reduction' clause.
OMPClause *ActOnOpenMPInReductionClause(
    ArrayRef<Expr *> VarList, SourceLocation StartLoc,
    SourceLocation LParenLoc, SourceLocation ColonLoc, SourceLocation EndLoc,
    CXXScopeSpec &ReductionIdScopeSpec,
    const DeclarationNameInfo &ReductionId,
    ArrayRef<Expr *> UnresolvedReductions = std::nullopt);
/// Called on well-formed 'linear' clause.
OMPClause *
ActOnOpenMPLinearClause(ArrayRef<Expr *> VarList, Expr *Step,
                        SourceLocation StartLoc, SourceLocation LParenLoc,
                        OpenMPLinearClauseKind LinKind, SourceLocation LinLoc,
                        SourceLocation ColonLoc, SourceLocation EndLoc);
/// Called on well-formed 'aligned' clause.
OMPClause *ActOnOpenMPAlignedClause(ArrayRef<Expr *> VarList,
                                    Expr *Alignment,
                                    SourceLocation StartLoc,
                                    SourceLocation LParenLoc,
                                    SourceLocation ColonLoc,
                                    SourceLocation EndLoc);
/// Called on well-formed 'copyin' clause.
OMPClause *ActOnOpenMPCopyinClause(ArrayRef<Expr *> VarList,
                                   SourceLocation StartLoc,
                                   SourceLocation LParenLoc,
                                   SourceLocation EndLoc);
/// Called on well-formed 'copyprivate' clause.
OMPClause *ActOnOpenMPCopyprivateClause(ArrayRef<Expr *> VarList,
                                        SourceLocation StartLoc,
                                        SourceLocation LParenLoc,
                                        SourceLocation EndLoc);
/// Called on well-formed 'flush' pseudo clause.
OMPClause *ActOnOpenMPFlushClause(ArrayRef<Expr *> VarList,
                                  SourceLocation StartLoc,
                                  SourceLocation LParenLoc,
                                  SourceLocation EndLoc);
/// Called on well-formed 'depobj' pseudo clause.
OMPClause *ActOnOpenMPDepobjClause(Expr *Depobj, SourceLocation StartLoc,
                                   SourceLocation LParenLoc,
                                   SourceLocation EndLoc);
/// Called on well-formed 'depend' clause.
OMPClause *ActOnOpenMPDependClause(const OMPDependClause::DependDataTy &Data,
                                   Expr *DepModifier,
                                   ArrayRef<Expr *> VarList,
                                   SourceLocation StartLoc,
                                   SourceLocation LParenLoc,
                                   SourceLocation EndLoc);
/// Called on well-formed 'device' clause.
OMPClause *ActOnOpenMPDeviceClause(OpenMPDeviceClauseModifier Modifier,
                                   Expr *Device, SourceLocation StartLoc,
                                   SourceLocation LParenLoc,
                                   SourceLocation ModifierLoc,
                                   SourceLocation EndLoc);
/// Called on well-formed 'map' clause.
OMPClause *ActOnOpenMPMapClause(
    Expr *IteratorModifier, ArrayRef<OpenMPMapModifierKind> MapTypeModifiers,
    ArrayRef<SourceLocation> MapTypeModifiersLoc,
    CXXScopeSpec &MapperIdScopeSpec, DeclarationNameInfo &MapperId,
    OpenMPMapClauseKind MapType, bool IsMapTypeImplicit,
    SourceLocation MapLoc, SourceLocation ColonLoc, ArrayRef<Expr *> VarList,
    const OMPVarListLocTy &Locs, bool NoDiagnose = false,
    ArrayRef<Expr *> UnresolvedMappers = std::nullopt);
/// Called on well-formed 'num_teams' clause.
OMPClause *ActOnOpenMPNumTeamsClause(Expr *NumTeams, SourceLocation StartLoc,
                                     SourceLocation LParenLoc,
                                     SourceLocation EndLoc);
/// Called on well-formed 'thread_limit' clause.
OMPClause *ActOnOpenMPThreadLimitClause(Expr *ThreadLimit,
                                        SourceLocation StartLoc,
                                        SourceLocation LParenLoc,
                                        SourceLocation EndLoc);
/// Called on well-formed 'priority' clause.
OMPClause *ActOnOpenMPPriorityClause(Expr *Priority, SourceLocation StartLoc,
                                     SourceLocation LParenLoc,
                                     SourceLocation EndLoc);
/// Called on well-formed 'dist_schedule' clause.
OMPClause *ActOnOpenMPDistScheduleClause(
    OpenMPDistScheduleClauseKind Kind, Expr *ChunkSize,
    SourceLocation StartLoc, SourceLocation LParenLoc, SourceLocation KindLoc,
    SourceLocation CommaLoc, SourceLocation EndLoc);
/// Called on well-formed 'defaultmap' clause.
OMPClause *ActOnOpenMPDefaultmapClause(
    OpenMPDefaultmapClauseModifier M, OpenMPDefaultmapClauseKind Kind,
    SourceLocation StartLoc, SourceLocation LParenLoc, SourceLocation MLoc,
    SourceLocation KindLoc, SourceLocation EndLoc);
/// Called on well-formed 'to' clause.
OMPClause *
ActOnOpenMPToClause(ArrayRef<OpenMPMotionModifierKind> MotionModifiers,
                    ArrayRef<SourceLocation> MotionModifiersLoc,
                    CXXScopeSpec &MapperIdScopeSpec,
                    DeclarationNameInfo &MapperId, SourceLocation ColonLoc,
                    ArrayRef<Expr *> VarList, const OMPVarListLocTy &Locs,
                    ArrayRef<Expr *> UnresolvedMappers = std::nullopt);
/// Called on well-formed 'from' clause.
OMPClause *
ActOnOpenMPFromClause(ArrayRef<OpenMPMotionModifierKind> MotionModifiers,
                      ArrayRef<SourceLocation> MotionModifiersLoc,
                      CXXScopeSpec &MapperIdScopeSpec,
                      DeclarationNameInfo &MapperId, SourceLocation ColonLoc,
                      ArrayRef<Expr *> VarList, const OMPVarListLocTy &Locs,
                      ArrayRef<Expr *> UnresolvedMappers = std::nullopt);
/// Called on well-formed 'use_device_ptr' clause.
OMPClause *ActOnOpenMPUseDevicePtrClause(ArrayRef<Expr *> VarList,
                                         const OMPVarListLocTy &Locs);
/// Called on well-formed 'use_device_addr' clause.
OMPClause *ActOnOpenMPUseDeviceAddrClause(ArrayRef<Expr *> VarList,
                                          const OMPVarListLocTy &Locs);
/// Called on well-formed 'is_device_ptr' clause.
OMPClause *ActOnOpenMPIsDevicePtrClause(ArrayRef<Expr *> VarList,
                                        const OMPVarListLocTy &Locs);
/// Called on well-formed 'has_device_addr' clause.
OMPClause *ActOnOpenMPHasDeviceAddrClause(ArrayRef<Expr *> VarList,
                                          const OMPVarListLocTy &Locs);
/// Called on well-formed 'nontemporal' clause.
OMPClause *ActOnOpenMPNontemporalClause(ArrayRef<Expr *> VarList,
                                        SourceLocation StartLoc,
                                        SourceLocation LParenLoc,
                                        SourceLocation EndLoc);

/// Data for list of allocators.
struct UsesAllocatorsData {
  /// Allocator.
  Expr *Allocator = nullptr;
  /// Allocator traits.
  Expr *AllocatorTraits = nullptr;
  /// Locations of '(' and ')' symbols.
  SourceLocation LParenLoc, RParenLoc;
};
/// Called on well-formed 'uses_allocators' clause.
OMPClause *ActOnOpenMPUsesAllocatorClause(SourceLocation StartLoc,
                                          SourceLocation LParenLoc,
                                          SourceLocation EndLoc,
                                          ArrayRef<UsesAllocatorsData> Data);
/// Called on well-formed 'affinity' clause.
OMPClause *ActOnOpenMPAffinityClause(SourceLocation StartLoc,
                                     SourceLocation LParenLoc,
                                     SourceLocation ColonLoc,
                                     SourceLocation EndLoc, Expr *Modifier,
                                     ArrayRef<Expr *> Locators);
/// Called on a well-formed 'bind' clause.
OMPClause *ActOnOpenMPBindClause(OpenMPBindClauseKind Kind,
                                 SourceLocation KindLoc,
                                 SourceLocation StartLoc,
                                 SourceLocation LParenLoc,
                                 SourceLocation EndLoc);

/// Called on a well-formed 'ompx_dyn_cgroup_mem' clause.
OMPClause *ActOnOpenMPXDynCGroupMemClause(Expr *Size, SourceLocation StartLoc,
                                          SourceLocation LParenLoc,
                                          SourceLocation EndLoc);

/// The kind of conversion being performed.
enum CheckedConversionKind {
  /// An implicit conversion.
  CCK_ImplicitConversion,
  /// A C-style cast.
  CCK_CStyleCast,
  /// A functional-style cast.
  CCK_FunctionalCast,
  /// A cast other than a C-style cast.
  CCK_OtherCast,
  /// A conversion for an operand of a builtin overloaded operator.
  CCK_ForBuiltinOverloadedOp
};

static bool isCast(CheckedConversionKind CCK) {
  return CCK == CCK_CStyleCast || CCK == CCK_FunctionalCast ||
         CCK == CCK_OtherCast;
}

/// ImpCastExprToType - If Expr is not of type 'Type', insert an implicit
/// cast.  If there is already an implicit cast, merge into the existing one.
/// If isLvalue, the result of the cast is an lvalue.
ExprResult
ImpCastExprToType(Expr *E, QualType Type, CastKind CK,
                  ExprValueKind VK = VK_PRValue,
                  const CXXCastPath *BasePath = nullptr,
                  CheckedConversionKind CCK = CCK_ImplicitConversion);

/// ScalarTypeToBooleanCastKind - Returns the cast kind corresponding
/// to the conversion from scalar type ScalarTy to the Boolean type.
static CastKind ScalarTypeToBooleanCastKind(QualType ScalarTy);

/// IgnoredValueConversions - Given that an expression's result is
/// syntactically ignored, perform any conversions that are
/// required.
ExprResult IgnoredValueConversions(Expr *E);

// UsualUnaryConversions - promotes integers (C99 6.3.1.1p2) and converts
// functions and arrays to their respective pointers (C99 6.3.2.1).
ExprResult UsualUnaryConversions(Expr *E);

/// CallExprUnaryConversions - a special case of an unary conversion
/// performed on a function designator of a call expression.
ExprResult CallExprUnaryConversions(Expr *E);

// DefaultFunctionArrayConversion - converts functions and arrays
// to their respective pointers (C99 6.3.2.1).
ExprResult DefaultFunctionArrayConversion(Expr *E, bool Diagnose = true);

// DefaultFunctionArrayLvalueConversion - converts functions and
// arrays to their respective pointers and performs the
// lvalue-to-rvalue conversion.
ExprResult DefaultFunctionArrayLvalueConversion(Expr *E,
                                                bool Diagnose = true);

// DefaultLvalueConversion - performs lvalue-to-rvalue conversion on
// the operand. This function is a no-op if the operand has a function type
// or an array type.
ExprResult DefaultLvalueConversion(Expr *E);

// DefaultArgumentPromotion (C99 6.5.2.2p6). Used for function calls that
// do not have a prototype. Integer promotions are performed on each
// argument, and arguments that have type float are promoted to double.
ExprResult DefaultArgumentPromotion(Expr *E);

/// If \p E is a prvalue denoting an unmaterialized temporary, materialize
/// it as an xvalue. In C++98, the result will still be a prvalue, because
/// we don't have xvalues there.
ExprResult TemporaryMaterializationConversion(Expr *E);

// Used for emitting the right warning by DefaultVariadicArgumentPromotion
enum VariadicCallType {
  VariadicFunction,
  VariadicBlock,
  VariadicMethod,
  VariadicConstructor,
  VariadicDoesNotApply
};

VariadicCallType getVariadicCallType(FunctionDecl *FDecl,
                                     const FunctionProtoType *Proto,
                                     Expr *Fn);

// Used for determining in which context a type is allowed to be passed to a
// vararg function.
enum VarArgKind {
  VAK_Valid,
  VAK_ValidInCXX11,
  VAK_Undefined,
  VAK_MSVCUndefined,
  VAK_Invalid
};

// Determines which VarArgKind fits an expression.
VarArgKind isValidVarArgType(const QualType &Ty);

/// Check to see if the given expression is a valid argument to a variadic
/// function, issuing a diagnostic if not.
void checkVariadicArgument(const Expr *E, VariadicCallType CT);

/// Check whether the given statement can have musttail applied to it,
/// issuing a diagnostic and returning false if not. In the success case,
/// the statement is rewritten to remove implicit nodes from the return
/// value.
bool checkAndRewriteMustTailAttr(Stmt *St, const Attr &MTA);

12362private:
/// Check whether the given statement can have musttail applied to it,
/// issuing a diagnostic and returning false if not.
bool checkMustTailAttr(const Stmt *St, const Attr &MTA);

12367public:
/// Check to see if a given expression could have '.c_str()' called on it.
bool hasCStrMethod(const Expr *E);

/// GatherArgumentsForCall - Collector argument expressions for various
/// form of call prototypes.
bool GatherArgumentsForCall(SourceLocation CallLoc, FunctionDecl *FDecl,
                            const FunctionProtoType *Proto,
                            unsigned FirstParam, ArrayRef<Expr *> Args,
                            SmallVectorImpl<Expr *> &AllArgs,
                            VariadicCallType CallType = VariadicDoesNotApply,
                            bool AllowExplicit = false,
                            bool IsListInitialization = false);

// DefaultVariadicArgumentPromotion - Like DefaultArgumentPromotion, but
// will create a runtime trap if the resulting type is not a POD type.
ExprResult DefaultVariadicArgumentPromotion(Expr *E, VariadicCallType CT,
                                            FunctionDecl *FDecl);

/// Context in which we're performing a usual arithmetic conversion.
enum ArithConvKind {
  /// An arithmetic operation.
  ACK_Arithmetic,
  /// A bitwise operation.
  ACK_BitwiseOp,
  /// A comparison.
  ACK_Comparison,
  /// A conditional (?:) operator.
  ACK_Conditional,
  /// A compound assignment expression.
  ACK_CompAssign,
};

// UsualArithmeticConversions - performs the UsualUnaryConversions on it's
// operands and then handles various conversions that are common to binary
// operators (C99 6.3.1.8). If both operands aren't arithmetic, this
// routine returns the first non-arithmetic type found. The client is
// responsible for emitting appropriate error diagnostics.
QualType UsualArithmeticConversions(ExprResult &LHS, ExprResult &RHS,
                                    SourceLocation Loc, ArithConvKind ACK);

/// AssignConvertType - All of the 'assignment' semantic checks return this
/// enum to indicate whether the assignment was allowed.  These checks are
/// done for simple assignments, as well as initialization, return from
/// function, argument passing, etc.  The query is phrased in terms of a
/// source and destination type.
enum AssignConvertType {
  /// Compatible - the types are compatible according to the standard.
  Compatible,

  /// PointerToInt - The assignment converts a pointer to an int, which we
  /// accept as an extension.
  PointerToInt,

  /// IntToPointer - The assignment converts an int to a pointer, which we
  /// accept as an extension.
  IntToPointer,

  /// FunctionVoidPointer - The assignment is between a function pointer and
  /// void*, which the standard doesn't allow, but we accept as an extension.
  FunctionVoidPointer,

  /// IncompatiblePointer - The assignment is between two pointers types that
  /// are not compatible, but we accept them as an extension.
  IncompatiblePointer,

  /// IncompatibleFunctionPointer - The assignment is between two function
  /// pointers types that are not compatible, but we accept them as an
  /// extension.
  IncompatibleFunctionPointer,

  /// IncompatibleFunctionPointerStrict - The assignment is between two
  /// function pointer types that are not identical, but are compatible,
  /// unless compiled with -fsanitize=cfi, in which case the type mismatch
  /// may trip an indirect call runtime check.
  IncompatibleFunctionPointerStrict,

  /// IncompatiblePointerSign - The assignment is between two pointers types
  /// which point to integers which have a different sign, but are otherwise
  /// identical. This is a subset of the above, but broken out because it's by
  /// far the most common case of incompatible pointers.
  IncompatiblePointerSign,

  /// CompatiblePointerDiscardsQualifiers - The assignment discards
  /// c/v/r qualifiers, which we accept as an extension.
  CompatiblePointerDiscardsQualifiers,

  /// IncompatiblePointerDiscardsQualifiers - The assignment
  /// discards qualifiers that we don't permit to be discarded,
  /// like address spaces.
  IncompatiblePointerDiscardsQualifiers,

  /// IncompatibleNestedPointerAddressSpaceMismatch - The assignment
  /// changes address spaces in nested pointer types which is not allowed.
  /// For instance, converting __private int ** to __generic int ** is
  /// illegal even though __private could be converted to __generic.
  IncompatibleNestedPointerAddressSpaceMismatch,

  /// IncompatibleNestedPointerQualifiers - The assignment is between two
  /// nested pointer types, and the qualifiers other than the first two
  /// levels differ e.g. char ** -> const char **, but we accept them as an
  /// extension.
  IncompatibleNestedPointerQualifiers,

  /// IncompatibleVectors - The assignment is between two vector types that
  /// have the same size, which we accept as an extension.
  IncompatibleVectors,

  /// IntToBlockPointer - The assignment converts an int to a block
  /// pointer. We disallow this.
  IntToBlockPointer,

  /// IncompatibleBlockPointer - The assignment is between two block
  /// pointers types that are not compatible.
  IncompatibleBlockPointer,

  /// IncompatibleObjCQualifiedId - The assignment is between a qualified
  /// id type and something else (that is incompatible with it). For example,
  /// "id <XXX>" = "Foo *", where "Foo *" doesn't implement the XXX protocol.
  IncompatibleObjCQualifiedId,

  /// IncompatibleObjCWeakRef - Assigning a weak-unavailable object to an
  /// object with __weak qualifier.
  IncompatibleObjCWeakRef,

  /// Incompatible - We reject this conversion outright, it is invalid to
  /// represent it in the AST.
  Incompatible
};

/// DiagnoseAssignmentResult - Emit a diagnostic, if required, for the
/// assignment conversion type specified by ConvTy.  This returns true if the
/// conversion was invalid or false if the conversion was accepted.
bool DiagnoseAssignmentResult(AssignConvertType ConvTy,
                              SourceLocation Loc,
                              QualType DstType, QualType SrcType,
                              Expr *SrcExpr, AssignmentAction Action,
                              bool *Complained = nullptr);

/// IsValueInFlagEnum - Determine if a value is allowed as part of a flag
/// enum. If AllowMask is true, then we also allow the complement of a valid
/// value, to be used as a mask.
bool IsValueInFlagEnum(const EnumDecl *ED, const llvm::APInt &Val,
                       bool AllowMask) const;

/// DiagnoseAssignmentEnum - Warn if assignment to enum is a constant
/// integer not in the range of enum values.
void DiagnoseAssignmentEnum(QualType DstType, QualType SrcType,
                            Expr *SrcExpr);

/// CheckAssignmentConstraints - Perform type checking for assignment,
/// argument passing, variable initialization, and function return values.
/// C99 6.5.16.
AssignConvertType CheckAssignmentConstraints(SourceLocation Loc,
                                             QualType LHSType,
                                             QualType RHSType);

/// Check assignment constraints and optionally prepare for a conversion of
/// the RHS to the LHS type. The conversion is prepared for if ConvertRHS
/// is true.
AssignConvertType CheckAssignmentConstraints(QualType LHSType,
                                             ExprResult &RHS,
                                             CastKind &Kind,
                                             bool ConvertRHS = true);

/// Check assignment constraints for an assignment of RHS to LHSType.
///
/// \param LHSType The destination type for the assignment.
/// \param RHS The source expression for the assignment.
/// \param Diagnose If \c true, diagnostics may be produced when checking
///        for assignability. If a diagnostic is produced, \p RHS will be
///        set to ExprError(). Note that this function may still return
///        without producing a diagnostic, even for an invalid assignment.
/// \param DiagnoseCFAudited If \c true, the target is a function parameter
///        in an audited Core Foundation API and does not need to be checked
///        for ARC retain issues.
/// \param ConvertRHS If \c true, \p RHS will be updated to model the
///        conversions necessary to perform the assignment. If \c false,
///        \p Diagnose must also be \c false.
AssignConvertType CheckSingleAssignmentConstraints(
    QualType LHSType, ExprResult &RHS, bool Diagnose = true,
    bool DiagnoseCFAudited = false, bool ConvertRHS = true);

// If the lhs type is a transparent union, check whether we
// can initialize the transparent union with the given expression.
AssignConvertType CheckTransparentUnionArgumentConstraints(QualType ArgType,
                                                           ExprResult &RHS);

bool IsStringLiteralToNonConstPointerConversion(Expr *From, QualType ToType);

bool CheckExceptionSpecCompatibility(Expr *From, QualType ToType);

ExprResult PerformImplicitConversion(Expr *From, QualType ToType,
                                     AssignmentAction Action,
                                     bool AllowExplicit = false);
ExprResult PerformImplicitConversion(Expr *From, QualType ToType,
                                     const ImplicitConversionSequence& ICS,
                                     AssignmentAction Action,
                                     CheckedConversionKind CCK
                                        = CCK_ImplicitConversion);
ExprResult PerformImplicitConversion(Expr *From, QualType ToType,
                                     const StandardConversionSequence& SCS,
                                     AssignmentAction Action,
                                     CheckedConversionKind CCK);

ExprResult PerformQualificationConversion(
    Expr *E, QualType Ty, ExprValueKind VK = VK_PRValue,
    CheckedConversionKind CCK = CCK_ImplicitConversion);

/// the following "Check" methods will return a valid/converted QualType
/// or a null QualType (indicating an error diagnostic was issued).

/// type checking binary operators (subroutines of CreateBuiltinBinOp).
QualType InvalidOperands(SourceLocation Loc, ExprResult &LHS,
                         ExprResult &RHS);
QualType InvalidLogicalVectorOperands(SourceLocation Loc, ExprResult &LHS,
                               ExprResult &RHS);
QualType CheckPointerToMemberOperands( // C++ 5.5
  ExprResult &LHS, ExprResult &RHS, ExprValueKind &VK,
  SourceLocation OpLoc, bool isIndirect);
QualType CheckMultiplyDivideOperands( // C99 6.5.5
  ExprResult &LHS, ExprResult &RHS, SourceLocation Loc, bool IsCompAssign,
  bool IsDivide);
QualType CheckRemainderOperands( // C99 6.5.5
  ExprResult &LHS, ExprResult &RHS, SourceLocation Loc,
  bool IsCompAssign = false);
QualType CheckAdditionOperands( // C99 6.5.6
  ExprResult &LHS, ExprResult &RHS, SourceLocation Loc,
  BinaryOperatorKind Opc, QualType* CompLHSTy = nullptr);
QualType CheckSubtractionOperands( // C99 6.5.6
  ExprResult &LHS, ExprResult &RHS, SourceLocation Loc,
  QualType* CompLHSTy = nullptr);
QualType CheckShiftOperands( // C99 6.5.7
  ExprResult &LHS, ExprResult &RHS, SourceLocation Loc,
  BinaryOperatorKind Opc, bool IsCompAssign = false);
void CheckPtrComparisonWithNullChar(ExprResult &E, ExprResult &NullE);
QualType CheckCompareOperands( // C99 6.5.8/9
    ExprResult &LHS, ExprResult &RHS, SourceLocation Loc,
    BinaryOperatorKind Opc);
QualType CheckBitwiseOperands( // C99 6.5.[10...12]
    ExprResult &LHS, ExprResult &RHS, SourceLocation Loc,
    BinaryOperatorKind Opc);
QualType CheckLogicalOperands( // C99 6.5.[13,14]
  ExprResult &LHS, ExprResult &RHS, SourceLocation Loc,
  BinaryOperatorKind Opc);
// CheckAssignmentOperands is used for both simple and compound assignment.
// For simple assignment, pass both expressions and a null converted type.
// For compound assignment, pass both expressions and the converted type.
QualType CheckAssignmentOperands( // C99 6.5.16.[1,2]
    Expr *LHSExpr, ExprResult &RHS, SourceLocation Loc, QualType CompoundType,
    BinaryOperatorKind Opc);

ExprResult checkPseudoObjectIncDec(Scope *S, SourceLocation OpLoc,
                                   UnaryOperatorKind Opcode, Expr *Op);
ExprResult checkPseudoObjectAssignment(Scope *S, SourceLocation OpLoc,
                                       BinaryOperatorKind Opcode,
                                       Expr *LHS, Expr *RHS);
ExprResult checkPseudoObjectRValue(Expr *E);
Expr *recreateSyntacticForm(PseudoObjectExpr *E);

QualType CheckConditionalOperands( // C99 6.5.15
  ExprResult &Cond, ExprResult &LHS, ExprResult &RHS,
  ExprValueKind &VK, ExprObjectKind &OK, SourceLocation QuestionLoc);
QualType CXXCheckConditionalOperands( // C++ 5.16
  ExprResult &cond, ExprResult &lhs, ExprResult &rhs,
  ExprValueKind &VK, ExprObjectKind &OK, SourceLocation questionLoc);
QualType CheckVectorConditionalTypes(ExprResult &Cond, ExprResult &LHS,
                                     ExprResult &RHS,
                                     SourceLocation QuestionLoc);

QualType CheckSizelessVectorConditionalTypes(ExprResult &Cond,
                                             ExprResult &LHS, ExprResult &RHS,
                                             SourceLocation QuestionLoc);
QualType FindCompositePointerType(SourceLocation Loc, Expr *&E1, Expr *&E2,
                                  bool ConvertArgs = true);
QualType FindCompositePointerType(SourceLocation Loc,
                                  ExprResult &E1, ExprResult &E2,
                                  bool ConvertArgs = true) {
  Expr *E1Tmp = E1.get(), *E2Tmp = E2.get();
  QualType Composite =
      FindCompositePointerType(Loc, E1Tmp, E2Tmp, ConvertArgs);
  E1 = E1Tmp;
  E2 = E2Tmp;
  return Composite;
}

QualType FindCompositeObjCPointerType(ExprResult &LHS, ExprResult &RHS,
                                      SourceLocation QuestionLoc);

bool DiagnoseConditionalForNull(Expr *LHSExpr, Expr *RHSExpr,
                                SourceLocation QuestionLoc);

void DiagnoseAlwaysNonNullPointer(Expr *E,
                                  Expr::NullPointerConstantKind NullType,
                                  bool IsEqual, SourceRange Range);

/// type checking for vector binary operators.
QualType CheckVectorOperands(ExprResult &LHS, ExprResult &RHS,
                             SourceLocation Loc, bool IsCompAssign,
                             bool AllowBothBool, bool AllowBoolConversion,
                             bool AllowBoolOperation, bool ReportInvalid);
QualType GetSignedVectorType(QualType V);
QualType GetSignedSizelessVectorType(QualType V);
QualType CheckVectorCompareOperands(ExprResult &LHS, ExprResult &RHS,
                                    SourceLocation Loc,
                                    BinaryOperatorKind Opc);
QualType CheckSizelessVectorCompareOperands(ExprResult &LHS, ExprResult &RHS,
                                            SourceLocation Loc,
                                            BinaryOperatorKind Opc);
QualType CheckVectorLogicalOperands(ExprResult &LHS, ExprResult &RHS,
                                    SourceLocation Loc);

// type checking for sizeless vector binary operators.
QualType CheckSizelessVectorOperands(ExprResult &LHS, ExprResult &RHS,
                                     SourceLocation Loc, bool IsCompAssign,
                                     ArithConvKind OperationKind);

/// Type checking for matrix binary operators.
QualType CheckMatrixElementwiseOperands(ExprResult &LHS, ExprResult &RHS,
                                        SourceLocation Loc,
                                        bool IsCompAssign);
QualType CheckMatrixMultiplyOperands(ExprResult &LHS, ExprResult &RHS,
                                     SourceLocation Loc, bool IsCompAssign);

bool isValidSveBitcast(QualType srcType, QualType destType);
bool isValidRVVBitcast(QualType srcType, QualType destType);

bool areMatrixTypesOfTheSameDimension(QualType srcTy, QualType destTy);

bool areVectorTypesSameSize(QualType srcType, QualType destType);
bool areLaxCompatibleVectorTypes(QualType srcType, QualType destType);
bool isLaxVectorConversion(QualType srcType, QualType destType);
bool anyAltivecTypes(QualType srcType, QualType destType);

/// type checking declaration initializers (C99 6.7.8)
bool CheckForConstantInitializer(Expr *e, QualType t);

// type checking C++ declaration initializers (C++ [dcl.init]).

/// ReferenceCompareResult - Expresses the result of comparing two
/// types (cv1 T1 and cv2 T2) to determine their compatibility for the
/// purposes of initialization by reference (C++ [dcl.init.ref]p4).
enum ReferenceCompareResult {
  /// Ref_Incompatible - The two types are incompatible, so direct
  /// reference binding is not possible.
  Ref_Incompatible = 0,
  /// Ref_Related - The two types are reference-related, which means
  /// that their unqualified forms (T1 and T2) are either the same
  /// or T1 is a base class of T2.
  Ref_Related,
  /// Ref_Compatible - The two types are reference-compatible.
  Ref_Compatible
};

// Fake up a scoped enumeration that still contextually converts to bool.
struct ReferenceConversionsScope {
  /// The conversions that would be performed on an lvalue of type T2 when
  /// binding a reference of type T1 to it, as determined when evaluating
  /// whether T1 is reference-compatible with T2.
  enum ReferenceConversions {
    Qualification = 0x1,
    NestedQualification = 0x2,
    Function = 0x4,
    DerivedToBase = 0x8,
    ObjC = 0x10,
    ObjCLifetime = 0x20,

    LLVM_MARK_AS_BITMASK_ENUM(/*LargestValue=*/ObjCLifetime)LLVM_BITMASK_LARGEST_ENUMERATOR = ObjCLifetime
  };
};
using ReferenceConversions = ReferenceConversionsScope::ReferenceConversions;

ReferenceCompareResult
CompareReferenceRelationship(SourceLocation Loc, QualType T1, QualType T2,
                             ReferenceConversions *Conv = nullptr);

ExprResult checkUnknownAnyCast(SourceRange TypeRange, QualType CastType,
                               Expr *CastExpr, CastKind &CastKind,
                               ExprValueKind &VK, CXXCastPath &Path);

/// Force an expression with unknown-type to an expression of the
/// given type.
ExprResult forceUnknownAnyToType(Expr *E, QualType ToType);

/// Type-check an expression that's being passed to an
/// __unknown_anytype parameter.
ExprResult checkUnknownAnyArg(SourceLocation callLoc,
                              Expr *result, QualType &paramType);

// CheckMatrixCast - Check type constraints for matrix casts.
// We allow casting between matrixes of the same dimensions i.e. when they
// have the same number of rows and column. Returns true if the cast is
// invalid.
bool CheckMatrixCast(SourceRange R, QualType DestTy, QualType SrcTy,
                     CastKind &Kind);

// CheckVectorCast - check type constraints for vectors.
// Since vectors are an extension, there are no C standard reference for this.
// We allow casting between vectors and integer datatypes of the same size.
// returns true if the cast is invalid
bool CheckVectorCast(SourceRange R, QualType VectorTy, QualType Ty,
                     CastKind &Kind);

/// Prepare `SplattedExpr` for a vector splat operation, adding
/// implicit casts if necessary.
ExprResult prepareVectorSplat(QualType VectorTy, Expr *SplattedExpr);

// CheckExtVectorCast - check type constraints for extended vectors.
// Since vectors are an extension, there are no C standard reference for this.
// We allow casting between vectors and integer datatypes of the same size,
// or vectors and the element type of that vector.
// returns the cast expr
ExprResult CheckExtVectorCast(SourceRange R, QualType DestTy, Expr *CastExpr,
                              CastKind &Kind);

ExprResult BuildCXXFunctionalCastExpr(TypeSourceInfo *TInfo, QualType Type,
                                      SourceLocation LParenLoc,
                                      Expr *CastExpr,
                                      SourceLocation RParenLoc);

enum ARCConversionResult { ACR_okay, ACR_unbridged, ACR_error };

/// Checks for invalid conversions and casts between
/// retainable pointers and other pointer kinds for ARC and Weak.
ARCConversionResult CheckObjCConversion(SourceRange castRange,
                                        QualType castType, Expr *&op,
                                        CheckedConversionKind CCK,
                                        bool Diagnose = true,
                                        bool DiagnoseCFAudited = false,
                                        BinaryOperatorKind Opc = BO_PtrMemD
                                        );

Expr *stripARCUnbridgedCast(Expr *e);
void diagnoseARCUnbridgedCast(Expr *e);

bool CheckObjCARCUnavailableWeakConversion(QualType castType,
                                           QualType ExprType);

/// checkRetainCycles - Check whether an Objective-C message send
/// might create an obvious retain cycle.
void checkRetainCycles(ObjCMessageExpr *msg);
void checkRetainCycles(Expr *receiver, Expr *argument);
void checkRetainCycles(VarDecl *Var, Expr *Init);

/// checkUnsafeAssigns - Check whether +1 expr is being assigned
/// to weak/__unsafe_unretained type.
bool checkUnsafeAssigns(SourceLocation Loc, QualType LHS, Expr *RHS);

/// checkUnsafeExprAssigns - Check whether +1 expr is being assigned
/// to weak/__unsafe_unretained expression.
void checkUnsafeExprAssigns(SourceLocation Loc, Expr *LHS, Expr *RHS);

/// CheckMessageArgumentTypes - Check types in an Obj-C message send.
/// \param Method - May be null.
/// \param [out] ReturnType - The return type of the send.
/// \return true iff there were any incompatible types.
bool CheckMessageArgumentTypes(const Expr *Receiver, QualType ReceiverType,
                               MultiExprArg Args, Selector Sel,
                               ArrayRef<SourceLocation> SelectorLocs,
                               ObjCMethodDecl *Method, bool isClassMessage,
                               bool isSuperMessage, SourceLocation lbrac,
                               SourceLocation rbrac, SourceRange RecRange,
                               QualType &ReturnType, ExprValueKind &VK);

/// Determine the result of a message send expression based on
/// the type of the receiver, the method expected to receive the message,
/// and the form of the message send.
QualType getMessageSendResultType(const Expr *Receiver, QualType ReceiverType,
                                  ObjCMethodDecl *Method, bool isClassMessage,
                                  bool isSuperMessage);

/// If the given expression involves a message send to a method
/// with a related result type, emit a note describing what happened.
void EmitRelatedResultTypeNote(const Expr *E);

/// Given that we had incompatible pointer types in a return
/// statement, check whether we're in a method with a related result
/// type, and if so, emit a note describing what happened.
void EmitRelatedResultTypeNoteForReturn(QualType destType);

class ConditionResult {
  Decl *ConditionVar;
  FullExprArg Condition;
  bool Invalid;
  std::optional<bool> KnownValue;

  friend class Sema;
  ConditionResult(Sema &S, Decl *ConditionVar, FullExprArg Condition,
                  bool IsConstexpr)
      : ConditionVar(ConditionVar), Condition(Condition), Invalid(false) {
    if (IsConstexpr && Condition.get()) {
      if (std::optional<llvm::APSInt> Val =
              Condition.get()->getIntegerConstantExpr(S.Context)) {
        KnownValue = !!(*Val);
      }
    }
  }
  explicit ConditionResult(bool Invalid)
      : ConditionVar(nullptr), Condition(nullptr), Invalid(Invalid),
        KnownValue(std::nullopt) {}

public:
  ConditionResult() : ConditionResult(false) {}
  bool isInvalid() const { return Invalid; }
  std::pair<VarDecl *, Expr *> get() const {
    return std::make_pair(cast_or_null<VarDecl>(ConditionVar),
                          Condition.get());
  }
  std::optional<bool> getKnownValue() const { return KnownValue; }
};
static ConditionResult ConditionError() { return ConditionResult(true); }

enum class ConditionKind {
  Boolean,     ///< A boolean condition, from 'if', 'while', 'for', or 'do'.
  ConstexprIf, ///< A constant boolean condition from 'if constexpr'.
  Switch       ///< An integral condition for a 'switch' statement.
};
QualType PreferredConditionType(ConditionKind K) const {
  return K == ConditionKind::Switch ? Context.IntTy : Context.BoolTy;
}

ConditionResult ActOnCondition(Scope *S, SourceLocation Loc, Expr *SubExpr,
                               ConditionKind CK, bool MissingOK = false);

ConditionResult ActOnConditionVariable(Decl *ConditionVar,
                                       SourceLocation StmtLoc,
                                       ConditionKind CK);

DeclResult ActOnCXXConditionDeclaration(Scope *S, Declarator &D);

ExprResult CheckConditionVariable(VarDecl *ConditionVar,
                                  SourceLocation StmtLoc,
                                  ConditionKind CK);
ExprResult CheckSwitchCondition(SourceLocation SwitchLoc, Expr *Cond);

/// CheckBooleanCondition - Diagnose problems involving the use of
/// the given expression as a boolean condition (e.g. in an if
/// statement).  Also performs the standard function and array
/// decays, possibly changing the input variable.
///
/// \param Loc - A location associated with the condition, e.g. the
/// 'if' keyword.
/// \return true iff there were any errors
ExprResult CheckBooleanCondition(SourceLocation Loc, Expr *E,
                                 bool IsConstexpr = false);

/// ActOnExplicitBoolSpecifier - Build an ExplicitSpecifier from an expression
/// found in an explicit(bool) specifier.
ExplicitSpecifier ActOnExplicitBoolSpecifier(Expr *E);

/// tryResolveExplicitSpecifier - Attempt to resolve the explict specifier.
/// Returns true if the explicit specifier is now resolved.
bool tryResolveExplicitSpecifier(ExplicitSpecifier &ExplicitSpec);

/// DiagnoseAssignmentAsCondition - Given that an expression is
/// being used as a boolean condition, warn if it's an assignment.
void DiagnoseAssignmentAsCondition(Expr *E);

/// Redundant parentheses over an equality comparison can indicate
/// that the user intended an assignment used as condition.
void DiagnoseEqualityWithExtraParens(ParenExpr *ParenE);

/// CheckCXXBooleanCondition - Returns true if conversion to bool is invalid.
ExprResult CheckCXXBooleanCondition(Expr *CondExpr, bool IsConstexpr = false);

/// ConvertIntegerToTypeWarnOnOverflow - Convert the specified APInt to have
/// the specified width and sign.  If an overflow occurs, detect it and emit
/// the specified diagnostic.
void ConvertIntegerToTypeWarnOnOverflow(llvm::APSInt &OldVal,
                                        unsigned NewWidth, bool NewSign,
                                        SourceLocation Loc, unsigned DiagID);

/// Checks that the Objective-C declaration is declared in the global scope.
/// Emits an error and marks the declaration as invalid if it's not declared
/// in the global scope.
bool CheckObjCDeclScope(Decl *D);

/// Abstract base class used for diagnosing integer constant
/// expression violations.
class VerifyICEDiagnoser {
public:
  bool Suppress;

  VerifyICEDiagnoser(bool Suppress = false) : Suppress(Suppress) { }

  virtual SemaDiagnosticBuilder
  diagnoseNotICEType(Sema &S, SourceLocation Loc, QualType T);
  virtual SemaDiagnosticBuilder diagnoseNotICE(Sema &S,
                                               SourceLocation Loc) = 0;
  virtual SemaDiagnosticBuilder diagnoseFold(Sema &S, SourceLocation Loc);
  virtual ~VerifyICEDiagnoser() {}
};

enum AllowFoldKind {
  NoFold,
  AllowFold,
};

/// VerifyIntegerConstantExpression - Verifies that an expression is an ICE,
/// and reports the appropriate diagnostics. Returns false on success.
/// Can optionally return the value of the expression.
ExprResult VerifyIntegerConstantExpression(Expr *E, llvm::APSInt *Result,
                                           VerifyICEDiagnoser &Diagnoser,
                                           AllowFoldKind CanFold = NoFold);
ExprResult VerifyIntegerConstantExpression(Expr *E, llvm::APSInt *Result,
                                           unsigned DiagID,
                                           AllowFoldKind CanFold = NoFold);
ExprResult VerifyIntegerConstantExpression(Expr *E,
                                           llvm::APSInt *Result = nullptr,
                                           AllowFoldKind CanFold = NoFold);
ExprResult VerifyIntegerConstantExpression(Expr *E,
                                           AllowFoldKind CanFold = NoFold) {
  return VerifyIntegerConstantExpression(E, nullptr, CanFold);
}

/// VerifyBitField - verifies that a bit field expression is an ICE and has
/// the correct width, and that the field type is valid.
/// Returns false on success.
ExprResult VerifyBitField(SourceLocation FieldLoc, IdentifierInfo *FieldName,
                          QualType FieldTy, bool IsMsStruct, Expr *BitWidth);

12988private:
unsigned ForceCUDAHostDeviceDepth = 0;

12991public:
/// Increments our count of the number of times we've seen a pragma forcing
/// functions to be __host__ __device__.  So long as this count is greater
/// than zero, all functions encountered will be __host__ __device__.
void PushForceCUDAHostDevice();

/// Decrements our count of the number of times we've seen a pragma forcing
/// functions to be __host__ __device__.  Returns false if the count is 0
/// before incrementing, so you can emit an error.
bool PopForceCUDAHostDevice();

/// Diagnostics that are emitted only if we discover that the given function
/// must be codegen'ed.  Because handling these correctly adds overhead to
/// compilation, this is currently only enabled for CUDA compilations.
llvm::DenseMap<CanonicalDeclPtr<const FunctionDecl>,
               std::vector<PartialDiagnosticAt>>
    DeviceDeferredDiags;

/// A pair of a canonical FunctionDecl and a SourceLocation.  When used as the
/// key in a hashtable, both the FD and location are hashed.
struct FunctionDeclAndLoc {
  CanonicalDeclPtr<const FunctionDecl> FD;
  SourceLocation Loc;
};

/// FunctionDecls and SourceLocations for which CheckCUDACall has emitted a
/// (maybe deferred) "bad call" diagnostic.  We use this to avoid emitting the
/// same deferred diag twice.
llvm::DenseSet<FunctionDeclAndLoc> LocsWithCUDACallDiags;

/// An inverse call graph, mapping known-emitted functions to one of their
/// known-emitted callers (plus the location of the call).
///
/// Functions that we can tell a priori must be emitted aren't added to this
/// map.
llvm::DenseMap</* Callee = */ CanonicalDeclPtr<const FunctionDecl>,
               /* Caller = */ FunctionDeclAndLoc>
    DeviceKnownEmittedFns;

/// Creates a SemaDiagnosticBuilder that emits the diagnostic if the current
/// context is "used as device code".
///
/// - If CurContext is a __host__ function, does not emit any diagnostics
///   unless \p EmitOnBothSides is true.
/// - If CurContext is a __device__ or __global__ function, emits the
///   diagnostics immediately.
/// - If CurContext is a __host__ __device__ function and we are compiling for
///   the device, creates a diagnostic which is emitted if and when we realize
///   that the function will be codegen'ed.
///
/// Example usage:
///
///  // Variable-length arrays are not allowed in CUDA device code.
///  if (CUDADiagIfDeviceCode(Loc, diag::err_cuda_vla) << CurrentCUDATarget())
///    return ExprError();
///  // Otherwise, continue parsing as normal.
SemaDiagnosticBuilder CUDADiagIfDeviceCode(SourceLocation Loc,
                                           unsigned DiagID);

/// Creates a SemaDiagnosticBuilder that emits the diagnostic if the current
/// context is "used as host code".
///
/// Same as CUDADiagIfDeviceCode, with "host" and "device" switched.
SemaDiagnosticBuilder CUDADiagIfHostCode(SourceLocation Loc, unsigned DiagID);

/// Creates a SemaDiagnosticBuilder that emits the diagnostic if the current
/// context is "used as device code".
///
/// - If CurContext is a `declare target` function or it is known that the
/// function is emitted for the device, emits the diagnostics immediately.
/// - If CurContext is a non-`declare target` function and we are compiling
///   for the device, creates a diagnostic which is emitted if and when we
///   realize that the function will be codegen'ed.
///
/// Example usage:
///
///  // Variable-length arrays are not allowed in NVPTX device code.
///  if (diagIfOpenMPDeviceCode(Loc, diag::err_vla_unsupported))
///    return ExprError();
///  // Otherwise, continue parsing as normal.
SemaDiagnosticBuilder diagIfOpenMPDeviceCode(SourceLocation Loc,
                                             unsigned DiagID,
                                             const FunctionDecl *FD);

/// Creates a SemaDiagnosticBuilder that emits the diagnostic if the current
/// context is "used as host code".
///
/// - If CurContext is a `declare target` function or it is known that the
/// function is emitted for the host, emits the diagnostics immediately.
/// - If CurContext is a non-host function, just ignore it.
///
/// Example usage:
///
///  // Variable-length arrays are not allowed in NVPTX device code.
///  if (diagIfOpenMPHostode(Loc, diag::err_vla_unsupported))
///    return ExprError();
///  // Otherwise, continue parsing as normal.
SemaDiagnosticBuilder diagIfOpenMPHostCode(SourceLocation Loc,
                                           unsigned DiagID,
                                           const FunctionDecl *FD);

SemaDiagnosticBuilder targetDiag(SourceLocation Loc, unsigned DiagID,
                                 const FunctionDecl *FD = nullptr);
SemaDiagnosticBuilder targetDiag(SourceLocation Loc,
                                 const PartialDiagnostic &PD,
                                 const FunctionDecl *FD = nullptr) {
  return targetDiag(Loc, PD.getDiagID(), FD) << PD;
}

/// Check if the type is allowed to be used for the current target.
void checkTypeSupport(QualType Ty, SourceLocation Loc,
                      ValueDecl *D = nullptr);

enum CUDAFunctionTarget {
  CFT_Device,
  CFT_Global,
  CFT_Host,
  CFT_HostDevice,
  CFT_InvalidTarget
};

/// Determines whether the given function is a CUDA device/host/kernel/etc.
/// function.
///
/// Use this rather than examining the function's attributes yourself -- you
/// will get it wrong.  Returns CFT_Host if D is null.
CUDAFunctionTarget IdentifyCUDATarget(const FunctionDecl *D,
                                      bool IgnoreImplicitHDAttr = false);
CUDAFunctionTarget IdentifyCUDATarget(const ParsedAttributesView &Attrs);

enum CUDAVariableTarget {
  CVT_Device,  /// Emitted on device side with a shadow variable on host side
  CVT_Host,    /// Emitted on host side only
  CVT_Both,    /// Emitted on both sides with different addresses
  CVT_Unified, /// Emitted as a unified address, e.g. managed variables
};
/// Determines whether the given variable is emitted on host or device side.
CUDAVariableTarget IdentifyCUDATarget(const VarDecl *D);

/// Gets the CUDA target for the current context.
CUDAFunctionTarget CurrentCUDATarget() {
  return IdentifyCUDATarget(dyn_cast<FunctionDecl>(CurContext));
}

static bool isCUDAImplicitHostDeviceFunction(const FunctionDecl *D);

// CUDA function call preference. Must be ordered numerically from
// worst to best.
enum CUDAFunctionPreference {
  CFP_Never,      // Invalid caller/callee combination.
  CFP_WrongSide,  // Calls from host-device to host or device
                  // function that do not match current compilation
                  // mode.
  CFP_HostDevice, // Any calls to host/device functions.
  CFP_SameSide,   // Calls from host-device to host or device
                  // function matching current compilation mode.
  CFP_Native,     // host-to-host or device-to-device calls.
};

/// Identifies relative preference of a given Caller/Callee
/// combination, based on their host/device attributes.
/// \param Caller function which needs address of \p Callee.
///               nullptr in case of global context.
/// \param Callee target function
///
/// \returns preference value for particular Caller/Callee combination.
CUDAFunctionPreference IdentifyCUDAPreference(const FunctionDecl *Caller,
                                              const FunctionDecl *Callee);

/// Determines whether Caller may invoke Callee, based on their CUDA
/// host/device attributes.  Returns false if the call is not allowed.
///
/// Note: Will return true for CFP_WrongSide calls.  These may appear in
/// semantically correct CUDA programs, but only if they're never codegen'ed.
bool IsAllowedCUDACall(const FunctionDecl *Caller,
                       const FunctionDecl *Callee) {
  return IdentifyCUDAPreference(Caller, Callee) != CFP_Never;
}

/// May add implicit CUDAHostAttr and CUDADeviceAttr attributes to FD,
/// depending on FD and the current compilation settings.
void maybeAddCUDAHostDeviceAttrs(FunctionDecl *FD,
                                 const LookupResult &Previous);

/// May add implicit CUDAConstantAttr attribute to VD, depending on VD
/// and current compilation settings.
void MaybeAddCUDAConstantAttr(VarDecl *VD);

13179public:
/// Check whether we're allowed to call Callee from the current context.
///
/// - If the call is never allowed in a semantically-correct program
///   (CFP_Never), emits an error and returns false.
///
/// - If the call is allowed in semantically-correct programs, but only if
///   it's never codegen'ed (CFP_WrongSide), creates a deferred diagnostic to
///   be emitted if and when the caller is codegen'ed, and returns true.
///
///   Will only create deferred diagnostics for a given SourceLocation once,
///   so you can safely call this multiple times without generating duplicate
///   deferred errors.
///
/// - Otherwise, returns true without emitting any diagnostics.
bool CheckCUDACall(SourceLocation Loc, FunctionDecl *Callee);

void CUDACheckLambdaCapture(CXXMethodDecl *D, const sema::Capture &Capture);

/// Set __device__ or __host__ __device__ attributes on the given lambda
/// operator() method.
///
/// CUDA lambdas by default is host device function unless it has explicit
/// host or device attribute.
void CUDASetLambdaAttrs(CXXMethodDecl *Method);

/// Finds a function in \p Matches with highest calling priority
/// from \p Caller context and erases all functions with lower
/// calling priority.
void EraseUnwantedCUDAMatches(
    const FunctionDecl *Caller,
    SmallVectorImpl<std::pair<DeclAccessPair, FunctionDecl *>> &Matches);

/// Given a implicit special member, infer its CUDA target from the
/// calls it needs to make to underlying base/field special members.
/// \param ClassDecl the class for which the member is being created.
/// \param CSM the kind of special member.
/// \param MemberDecl the special member itself.
/// \param ConstRHS true if this is a copy operation with a const object on
///        its RHS.
/// \param Diagnose true if this call should emit diagnostics.
/// \return true if there was an error inferring.
/// The result of this call is implicit CUDA target attribute(s) attached to
/// the member declaration.
bool inferCUDATargetForImplicitSpecialMember(CXXRecordDecl *ClassDecl,
                                             CXXSpecialMember CSM,
                                             CXXMethodDecl *MemberDecl,
                                             bool ConstRHS,
                                             bool Diagnose);

/// \return true if \p CD can be considered empty according to CUDA
/// (E.2.3.1 in CUDA 7.5 Programming guide).
bool isEmptyCudaConstructor(SourceLocation Loc, CXXConstructorDecl *CD);
bool isEmptyCudaDestructor(SourceLocation Loc, CXXDestructorDecl *CD);

// \brief Checks that initializers of \p Var satisfy CUDA restrictions. In
// case of error emits appropriate diagnostic and invalidates \p Var.
//
// \details CUDA allows only empty constructors as initializers for global
// variables (see E.2.3.1, CUDA 7.5). The same restriction also applies to all
// __shared__ variables whether they are local or not (they all are implicitly
// static in CUDA). One exception is that CUDA allows constant initializers
// for __constant__ and __device__ variables.
void checkAllowedCUDAInitializer(VarDecl *VD);

/// Check whether NewFD is a valid overload for CUDA. Emits
/// diagnostics and invalidates NewFD if not.
void checkCUDATargetOverload(FunctionDecl *NewFD,
                             const LookupResult &Previous);
/// Copies target attributes from the template TD to the function FD.
void inheritCUDATargetAttrs(FunctionDecl *FD, const FunctionTemplateDecl &TD);

/// Returns the name of the launch configuration function.  This is the name
/// of the function that will be called to configure kernel call, with the
/// parameters specified via <<<>>>.
std::string getCudaConfigureFuncName() const;

/// \name Code completion
//@{
/// Describes the context in which code completion occurs.
enum ParserCompletionContext {
  /// Code completion occurs at top-level or namespace context.
  PCC_Namespace,
  /// Code completion occurs within a class, struct, or union.
  PCC_Class,
  /// Code completion occurs within an Objective-C interface, protocol,
  /// or category.
  PCC_ObjCInterface,
  /// Code completion occurs within an Objective-C implementation or
  /// category implementation
  PCC_ObjCImplementation,
  /// Code completion occurs within the list of instance variables
  /// in an Objective-C interface, protocol, category, or implementation.
  PCC_ObjCInstanceVariableList,
  /// Code completion occurs following one or more template
  /// headers.
  PCC_Template,
  /// Code completion occurs following one or more template
  /// headers within a class.
  PCC_MemberTemplate,
  /// Code completion occurs within an expression.
  PCC_Expression,
  /// Code completion occurs within a statement, which may
  /// also be an expression or a declaration.
  PCC_Statement,
  /// Code completion occurs at the beginning of the
  /// initialization statement (or expression) in a for loop.
  PCC_ForInit,
  /// Code completion occurs within the condition of an if,
  /// while, switch, or for statement.
  PCC_Condition,
  /// Code completion occurs within the body of a function on a
  /// recovery path, where we do not have a specific handle on our position
  /// in the grammar.
  PCC_RecoveryInFunction,
  /// Code completion occurs where only a type is permitted.
  PCC_Type,
  /// Code completion occurs in a parenthesized expression, which
  /// might also be a type cast.
  PCC_ParenthesizedExpression,
  /// Code completion occurs within a sequence of declaration
  /// specifiers within a function, method, or block.
  PCC_LocalDeclarationSpecifiers
};

void CodeCompleteModuleImport(SourceLocation ImportLoc, ModuleIdPath Path);
void CodeCompleteOrdinaryName(Scope *S,
                              ParserCompletionContext CompletionContext);
void CodeCompleteDeclSpec(Scope *S, DeclSpec &DS,
                          bool AllowNonIdentifiers,
                          bool AllowNestedNameSpecifiers);

struct CodeCompleteExpressionData;
void CodeCompleteExpression(Scope *S,
                            const CodeCompleteExpressionData &Data);
void CodeCompleteExpression(Scope *S, QualType PreferredType,
                            bool IsParenthesized = false);
void CodeCompleteMemberReferenceExpr(Scope *S, Expr *Base, Expr *OtherOpBase,
                                     SourceLocation OpLoc, bool IsArrow,
                                     bool IsBaseExprStatement,
                                     QualType PreferredType);
void CodeCompletePostfixExpression(Scope *S, ExprResult LHS,
                                   QualType PreferredType);
void CodeCompleteTag(Scope *S, unsigned TagSpec);
void CodeCompleteTypeQualifiers(DeclSpec &DS);
void CodeCompleteFunctionQualifiers(DeclSpec &DS, Declarator &D,
                                    const VirtSpecifiers *VS = nullptr);
void CodeCompleteBracketDeclarator(Scope *S);
void CodeCompleteCase(Scope *S);
enum class AttributeCompletion {
  Attribute,
  Scope,
  None,
};
void CodeCompleteAttribute(
    AttributeCommonInfo::Syntax Syntax,
    AttributeCompletion Completion = AttributeCompletion::Attribute,
    const IdentifierInfo *Scope = nullptr);
/// Determines the preferred type of the current function argument, by
/// examining the signatures of all possible overloads.
/// Returns null if unknown or ambiguous, or if code completion is off.
///
/// If the code completion point has been reached, also reports the function
/// signatures that were considered.
///
/// FIXME: rename to GuessCallArgumentType to reduce confusion.
QualType ProduceCallSignatureHelp(Expr *Fn, ArrayRef<Expr *> Args,
                                  SourceLocation OpenParLoc);
QualType ProduceConstructorSignatureHelp(QualType Type, SourceLocation Loc,
                                         ArrayRef<Expr *> Args,
                                         SourceLocation OpenParLoc,
                                         bool Braced);
QualType ProduceCtorInitMemberSignatureHelp(
    Decl *ConstructorDecl, CXXScopeSpec SS, ParsedType TemplateTypeTy,
    ArrayRef<Expr *> ArgExprs, IdentifierInfo *II, SourceLocation OpenParLoc,
    bool Braced);
QualType ProduceTemplateArgumentSignatureHelp(
    TemplateTy, ArrayRef<ParsedTemplateArgument>, SourceLocation LAngleLoc);
void CodeCompleteInitializer(Scope *S, Decl *D);
/// Trigger code completion for a record of \p BaseType. \p InitExprs are
/// expressions in the initializer list seen so far and \p D is the current
/// Designation being parsed.
void CodeCompleteDesignator(const QualType BaseType,
                            llvm::ArrayRef<Expr *> InitExprs,
                            const Designation &D);
void CodeCompleteAfterIf(Scope *S, bool IsBracedThen);

void CodeCompleteQualifiedId(Scope *S, CXXScopeSpec &SS, bool EnteringContext,
                             bool IsUsingDeclaration, QualType BaseType,
                             QualType PreferredType);
void CodeCompleteUsing(Scope *S);
void CodeCompleteUsingDirective(Scope *S);
void CodeCompleteNamespaceDecl(Scope *S);
void CodeCompleteNamespaceAliasDecl(Scope *S);
void CodeCompleteOperatorName(Scope *S);
void CodeCompleteConstructorInitializer(
                              Decl *Constructor,
                              ArrayRef<CXXCtorInitializer *> Initializers);

void CodeCompleteLambdaIntroducer(Scope *S, LambdaIntroducer &Intro,
                                  bool AfterAmpersand);
void CodeCompleteAfterFunctionEquals(Declarator &D);

void CodeCompleteObjCAtDirective(Scope *S);
void CodeCompleteObjCAtVisibility(Scope *S);
void CodeCompleteObjCAtStatement(Scope *S);
void CodeCompleteObjCAtExpression(Scope *S);
void CodeCompleteObjCPropertyFlags(Scope *S, ObjCDeclSpec &ODS);
void CodeCompleteObjCPropertyGetter(Scope *S);
void CodeCompleteObjCPropertySetter(Scope *S);
void CodeCompleteObjCPassingType(Scope *S, ObjCDeclSpec &DS,
                                 bool IsParameter);
void CodeCompleteObjCMessageReceiver(Scope *S);
void CodeCompleteObjCSuperMessage(Scope *S, SourceLocation SuperLoc,
                                  ArrayRef<IdentifierInfo *> SelIdents,
                                  bool AtArgumentExpression);
void CodeCompleteObjCClassMessage(Scope *S, ParsedType Receiver,
                                  ArrayRef<IdentifierInfo *> SelIdents,
                                  bool AtArgumentExpression,
                                  bool IsSuper = false);
void CodeCompleteObjCInstanceMessage(Scope *S, Expr *Receiver,
                                     ArrayRef<IdentifierInfo *> SelIdents,
                                     bool AtArgumentExpression,
                                     ObjCInterfaceDecl *Super = nullptr);
void CodeCompleteObjCForCollection(Scope *S,
                                   DeclGroupPtrTy IterationVar);
void CodeCompleteObjCSelector(Scope *S,
                              ArrayRef<IdentifierInfo *> SelIdents);
void CodeCompleteObjCProtocolReferences(
                                       ArrayRef<IdentifierLocPair> Protocols);
void CodeCompleteObjCProtocolDecl(Scope *S);
void CodeCompleteObjCInterfaceDecl(Scope *S);
void CodeCompleteObjCSuperclass(Scope *S,
                                IdentifierInfo *ClassName,
                                SourceLocation ClassNameLoc);
void CodeCompleteObjCImplementationDecl(Scope *S);
void CodeCompleteObjCInterfaceCategory(Scope *S,
                                       IdentifierInfo *ClassName,
                                       SourceLocation ClassNameLoc);
void CodeCompleteObjCImplementationCategory(Scope *S,
                                            IdentifierInfo *ClassName,
                                            SourceLocation ClassNameLoc);
void CodeCompleteObjCPropertyDefinition(Scope *S);
void CodeCompleteObjCPropertySynthesizeIvar(Scope *S,
                                            IdentifierInfo *PropertyName);
void CodeCompleteObjCMethodDecl(Scope *S,
                                std::optional<bool> IsInstanceMethod,
                                ParsedType ReturnType);
void CodeCompleteObjCMethodDeclSelector(Scope *S,
                                        bool IsInstanceMethod,
                                        bool AtParameterName,
                                        ParsedType ReturnType,
                                        ArrayRef<IdentifierInfo *> SelIdents);
void CodeCompleteObjCClassPropertyRefExpr(Scope *S, IdentifierInfo &ClassName,
                                          SourceLocation ClassNameLoc,
                                          bool IsBaseExprStatement);
void CodeCompletePreprocessorDirective(bool InConditional);
void CodeCompleteInPreprocessorConditionalExclusion(Scope *S);
void CodeCompletePreprocessorMacroName(bool IsDefinition);
void CodeCompletePreprocessorExpression();
void CodeCompletePreprocessorMacroArgument(Scope *S,
                                           IdentifierInfo *Macro,
                                           MacroInfo *MacroInfo,
                                           unsigned Argument);
void CodeCompleteIncludedFile(llvm::StringRef Dir, bool IsAngled);
void CodeCompleteNaturalLanguage();
void CodeCompleteAvailabilityPlatformName();
void GatherGlobalCodeCompletions(CodeCompletionAllocator &Allocator,
                                 CodeCompletionTUInfo &CCTUInfo,
                SmallVectorImpl<CodeCompletionResult> &Results);
//@}

//===--------------------------------------------------------------------===//
// Extra semantic analysis beyond the C type system

13454public:
SourceLocation getLocationOfStringLiteralByte(const StringLiteral *SL,
                                              unsigned ByteNo) const;

enum FormatArgumentPassingKind {
  FAPK_Fixed,    // values to format are fixed (no C-style variadic arguments)
  FAPK_Variadic, // values to format are passed as variadic arguments
  FAPK_VAList,   // values to format are passed in a va_list
};

// Used to grab the relevant information from a FormatAttr and a
// FunctionDeclaration.
struct FormatStringInfo {
  unsigned FormatIdx;
  unsigned FirstDataArg;
  FormatArgumentPassingKind ArgPassingKind;
};

static bool getFormatStringInfo(const FormatAttr *Format, bool IsCXXMember,
                                bool IsVariadic, FormatStringInfo *FSI);

13475private:
void CheckArrayAccess(const Expr *BaseExpr, const Expr *IndexExpr,
                      const ArraySubscriptExpr *ASE = nullptr,
                      bool AllowOnePastEnd = true, bool IndexNegated = false);
void CheckArrayAccess(const Expr *E);

bool CheckFunctionCall(FunctionDecl *FDecl, CallExpr *TheCall,
                       const FunctionProtoType *Proto);
bool CheckObjCMethodCall(ObjCMethodDecl *Method, SourceLocation loc,
                         ArrayRef<const Expr *> Args);
bool CheckPointerCall(NamedDecl *NDecl, CallExpr *TheCall,
                      const FunctionProtoType *Proto);
bool CheckOtherCall(CallExpr *TheCall, const FunctionProtoType *Proto);
void CheckConstructorCall(FunctionDecl *FDecl, QualType ThisType,
                          ArrayRef<const Expr *> Args,
                          const FunctionProtoType *Proto, SourceLocation Loc);

void checkAIXMemberAlignment(SourceLocation Loc, const Expr *Arg);

void CheckArgAlignment(SourceLocation Loc, NamedDecl *FDecl,
                       StringRef ParamName, QualType ArgTy, QualType ParamTy);

void checkCall(NamedDecl *FDecl, const FunctionProtoType *Proto,
               const Expr *ThisArg, ArrayRef<const Expr *> Args,
               bool IsMemberFunction, SourceLocation Loc, SourceRange Range,
               VariadicCallType CallType);

bool CheckObjCString(Expr *Arg);
ExprResult CheckOSLogFormatStringArg(Expr *Arg);

ExprResult CheckBuiltinFunctionCall(FunctionDecl *FDecl,
                                    unsigned BuiltinID, CallExpr *TheCall);

bool CheckTSBuiltinFunctionCall(const TargetInfo &TI, unsigned BuiltinID,
                                CallExpr *TheCall);

void checkFortifiedBuiltinMemoryFunction(FunctionDecl *FD, CallExpr *TheCall);

bool CheckARMBuiltinExclusiveCall(unsigned BuiltinID, CallExpr *TheCall,
                                  unsigned MaxWidth);
bool CheckNeonBuiltinFunctionCall(const TargetInfo &TI, unsigned BuiltinID,
                                  CallExpr *TheCall);
bool CheckMVEBuiltinFunctionCall(unsigned BuiltinID, CallExpr *TheCall);
bool CheckSVEBuiltinFunctionCall(unsigned BuiltinID, CallExpr *TheCall);
bool CheckCDEBuiltinFunctionCall(const TargetInfo &TI, unsigned BuiltinID,
                                 CallExpr *TheCall);
bool CheckARMCoprocessorImmediate(const TargetInfo &TI, const Expr *CoprocArg,
                                  bool WantCDE);
bool CheckARMBuiltinFunctionCall(const TargetInfo &TI, unsigned BuiltinID,
                                 CallExpr *TheCall);

bool CheckAArch64BuiltinFunctionCall(const TargetInfo &TI, unsigned BuiltinID,
                                     CallExpr *TheCall);
bool CheckBPFBuiltinFunctionCall(unsigned BuiltinID, CallExpr *TheCall);
bool CheckHexagonBuiltinFunctionCall(unsigned BuiltinID, CallExpr *TheCall);
bool CheckHexagonBuiltinArgument(unsigned BuiltinID, CallExpr *TheCall);
bool CheckMipsBuiltinFunctionCall(const TargetInfo &TI, unsigned BuiltinID,
                                  CallExpr *TheCall);
bool CheckMipsBuiltinCpu(const TargetInfo &TI, unsigned BuiltinID,
                         CallExpr *TheCall);
bool CheckMipsBuiltinArgument(unsigned BuiltinID, CallExpr *TheCall);
bool CheckSystemZBuiltinFunctionCall(unsigned BuiltinID, CallExpr *TheCall);
bool CheckX86BuiltinRoundingOrSAE(unsigned BuiltinID, CallExpr *TheCall);
bool CheckX86BuiltinGatherScatterScale(unsigned BuiltinID, CallExpr *TheCall);
bool CheckX86BuiltinTileArguments(unsigned BuiltinID, CallExpr *TheCall);
bool CheckX86BuiltinTileArgumentsRange(CallExpr *TheCall,
                                       ArrayRef<int> ArgNums);
bool CheckX86BuiltinTileDuplicate(CallExpr *TheCall, ArrayRef<int> ArgNums);
bool CheckX86BuiltinTileRangeAndDuplicate(CallExpr *TheCall,
                                          ArrayRef<int> ArgNums);
bool CheckX86BuiltinFunctionCall(const TargetInfo &TI, unsigned BuiltinID,
                                 CallExpr *TheCall);
bool CheckPPCBuiltinFunctionCall(const TargetInfo &TI, unsigned BuiltinID,
                                 CallExpr *TheCall);
bool CheckAMDGCNBuiltinFunctionCall(unsigned BuiltinID, CallExpr *TheCall);
bool CheckRISCVLMUL(CallExpr *TheCall, unsigned ArgNum);
bool CheckRISCVBuiltinFunctionCall(const TargetInfo &TI, unsigned BuiltinID,
                                   CallExpr *TheCall);
bool CheckLoongArchBuiltinFunctionCall(const TargetInfo &TI,
                                       unsigned BuiltinID, CallExpr *TheCall);
bool CheckWebAssemblyBuiltinFunctionCall(const TargetInfo &TI,
                                         unsigned BuiltinID,
                                         CallExpr *TheCall);

bool SemaBuiltinVAStart(unsigned BuiltinID, CallExpr *TheCall);
bool SemaBuiltinVAStartARMMicrosoft(CallExpr *Call);
bool SemaBuiltinUnorderedCompare(CallExpr *TheCall);
bool SemaBuiltinFPClassification(CallExpr *TheCall, unsigned NumArgs);
bool SemaBuiltinComplex(CallExpr *TheCall);
bool SemaBuiltinVSX(CallExpr *TheCall);
bool SemaBuiltinOSLogFormat(CallExpr *TheCall);
bool SemaValueIsRunOfOnes(CallExpr *TheCall, unsigned ArgNum);

13568public:
// Used by C++ template instantiation.
ExprResult SemaBuiltinShuffleVector(CallExpr *TheCall);
ExprResult SemaConvertVectorExpr(Expr *E, TypeSourceInfo *TInfo,
                                 SourceLocation BuiltinLoc,
                                 SourceLocation RParenLoc);

13575private:
bool SemaBuiltinPrefetch(CallExpr *TheCall);
bool SemaBuiltinAllocaWithAlign(CallExpr *TheCall);
bool SemaBuiltinArithmeticFence(CallExpr *TheCall);
bool SemaBuiltinAssume(CallExpr *TheCall);
bool SemaBuiltinAssumeAligned(CallExpr *TheCall);
bool SemaBuiltinLongjmp(CallExpr *TheCall);
bool SemaBuiltinSetjmp(CallExpr *TheCall);
ExprResult SemaBuiltinAtomicOverloaded(ExprResult TheCallResult);
ExprResult SemaBuiltinNontemporalOverloaded(ExprResult TheCallResult);
ExprResult SemaAtomicOpsOverloaded(ExprResult TheCallResult,
                                   AtomicExpr::AtomicOp Op);
ExprResult SemaBuiltinOperatorNewDeleteOverloaded(ExprResult TheCallResult,
                                                  bool IsDelete);
bool SemaBuiltinConstantArg(CallExpr *TheCall, int ArgNum,
                            llvm::APSInt &Result);
bool SemaBuiltinConstantArgRange(CallExpr *TheCall, int ArgNum, int Low,
                                 int High, bool RangeIsError = true);
bool SemaBuiltinConstantArgMultiple(CallExpr *TheCall, int ArgNum,
                                    unsigned Multiple);
bool SemaBuiltinConstantArgPower2(CallExpr *TheCall, int ArgNum);
bool SemaBuiltinConstantArgShiftedByte(CallExpr *TheCall, int ArgNum,
                                       unsigned ArgBits);
bool SemaBuiltinConstantArgShiftedByteOrXXFF(CallExpr *TheCall, int ArgNum,
                                             unsigned ArgBits);
bool SemaBuiltinARMSpecialReg(unsigned BuiltinID, CallExpr *TheCall,
                              int ArgNum, unsigned ExpectedFieldNum,
                              bool AllowName);
bool SemaBuiltinARMMemoryTaggingCall(unsigned BuiltinID, CallExpr *TheCall);
bool SemaBuiltinPPCMMACall(CallExpr *TheCall, unsigned BuiltinID,
                           const char *TypeDesc);

bool CheckPPCMMAType(QualType Type, SourceLocation TypeLoc);

bool SemaBuiltinElementwiseMath(CallExpr *TheCall);
bool SemaBuiltinElementwiseTernaryMath(CallExpr *TheCall);
bool PrepareBuiltinElementwiseMathOneArgCall(CallExpr *TheCall);
bool PrepareBuiltinReduceMathOneArgCall(CallExpr *TheCall);

bool SemaBuiltinNonDeterministicValue(CallExpr *TheCall);

// Matrix builtin handling.
ExprResult SemaBuiltinMatrixTranspose(CallExpr *TheCall,
                                      ExprResult CallResult);
ExprResult SemaBuiltinMatrixColumnMajorLoad(CallExpr *TheCall,
                                            ExprResult CallResult);
ExprResult SemaBuiltinMatrixColumnMajorStore(CallExpr *TheCall,
                                             ExprResult CallResult);

// WebAssembly builtin handling.
bool BuiltinWasmRefNullExtern(CallExpr *TheCall);
bool BuiltinWasmRefNullFunc(CallExpr *TheCall);

13628public:
enum FormatStringType {
  FST_Scanf,
  FST_Printf,
  FST_NSString,
  FST_Strftime,
  FST_Strfmon,
  FST_Kprintf,
  FST_FreeBSDKPrintf,
  FST_OSTrace,
  FST_OSLog,
  FST_Unknown
};
static FormatStringType GetFormatStringType(const FormatAttr *Format);

bool FormatStringHasSArg(const StringLiteral *FExpr);

static bool GetFormatNSStringIdx(const FormatAttr *Format, unsigned &Idx);

13647private:
bool CheckFormatArguments(const FormatAttr *Format,
                          ArrayRef<const Expr *> Args, bool IsCXXMember,
                          VariadicCallType CallType, SourceLocation Loc,
                          SourceRange Range,
                          llvm::SmallBitVector &CheckedVarArgs);
bool CheckFormatArguments(ArrayRef<const Expr *> Args,
                          FormatArgumentPassingKind FAPK, unsigned format_idx,
                          unsigned firstDataArg, FormatStringType Type,
                          VariadicCallType CallType, SourceLocation Loc,
                          SourceRange range,
                          llvm::SmallBitVector &CheckedVarArgs);

void CheckAbsoluteValueFunction(const CallExpr *Call,
                                const FunctionDecl *FDecl);

void CheckMaxUnsignedZero(const CallExpr *Call, const FunctionDecl *FDecl);

void CheckMemaccessArguments(const CallExpr *Call,
                             unsigned BId,
                             IdentifierInfo *FnName);

void CheckStrlcpycatArguments(const CallExpr *Call,
                              IdentifierInfo *FnName);

void CheckStrncatArguments(const CallExpr *Call,
                           IdentifierInfo *FnName);

void CheckFreeArguments(const CallExpr *E);

void CheckReturnValExpr(Expr *RetValExp, QualType lhsType,
                        SourceLocation ReturnLoc,
                        bool isObjCMethod = false,
                        const AttrVec *Attrs = nullptr,
                        const FunctionDecl *FD = nullptr);

13683public:
void CheckFloatComparison(SourceLocation Loc, Expr *LHS, Expr *RHS,
                          BinaryOperatorKind Opcode);

13687private:
void CheckImplicitConversions(Expr *E, SourceLocation CC = SourceLocation());
void CheckBoolLikeConversion(Expr *E, SourceLocation CC);
void CheckForIntOverflow(Expr *E);
void CheckUnsequencedOperations(const Expr *E);

/// Perform semantic checks on a completed expression. This will either
/// be a full-expression or a default argument expression.
void CheckCompletedExpr(Expr *E, SourceLocation CheckLoc = SourceLocation(),
                        bool IsConstexpr = false);

void CheckBitFieldInitialization(SourceLocation InitLoc, FieldDecl *Field,
                                 Expr *Init);

/// Check if there is a field shadowing.
void CheckShadowInheritedFields(const SourceLocation &Loc,
                                DeclarationName FieldName,
                                const CXXRecordDecl *RD,
                                bool DeclIsField = true);

/// Check if the given expression contains 'break' or 'continue'
/// statement that produces control flow different from GCC.
void CheckBreakContinueBinding(Expr *E);

/// Check whether receiver is mutable ObjC container which
/// attempts to add itself into the container
void CheckObjCCircularContainer(ObjCMessageExpr *Message);

void CheckTCBEnforcement(const SourceLocation CallExprLoc,
                         const NamedDecl *Callee);

void AnalyzeDeleteExprMismatch(const CXXDeleteExpr *DE);
void AnalyzeDeleteExprMismatch(FieldDecl *Field, SourceLocation DeleteLoc,
                               bool DeleteWasArrayForm);
13721public:
/// Register a magic integral constant to be used as a type tag.
void RegisterTypeTagForDatatype(const IdentifierInfo *ArgumentKind,
                                uint64_t MagicValue, QualType Type,
                                bool LayoutCompatible, bool MustBeNull);

struct TypeTagData {
  TypeTagData() {}

  TypeTagData(QualType Type, bool LayoutCompatible, bool MustBeNull) :
      Type(Type), LayoutCompatible(LayoutCompatible),
      MustBeNull(MustBeNull)
  {}

  QualType Type;

  /// If true, \c Type should be compared with other expression's types for
  /// layout-compatibility.
  unsigned LayoutCompatible : 1;
  unsigned MustBeNull : 1;
};

/// A pair of ArgumentKind identifier and magic value.  This uniquely
/// identifies the magic value.
typedef std::pair<const IdentifierInfo *, uint64_t> TypeTagMagicValue;

13747private:
/// A map from magic value to type information.
std::unique_ptr<llvm::DenseMap<TypeTagMagicValue, TypeTagData>>
    TypeTagForDatatypeMagicValues;

/// Peform checks on a call of a function with argument_with_type_tag
/// or pointer_with_type_tag attributes.
void CheckArgumentWithTypeTag(const ArgumentWithTypeTagAttr *Attr,
                              const ArrayRef<const Expr *> ExprArgs,
                              SourceLocation CallSiteLoc);

/// Check if we are taking the address of a packed field
/// as this may be a problem if the pointer value is dereferenced.
void CheckAddressOfPackedMember(Expr *rhs);

/// The parser's current scope.
///
/// The parser maintains this state here.
Scope *CurScope;

mutable IdentifierInfo *Ident_super;
mutable IdentifierInfo *Ident___float128;

/// Nullability type specifiers.
IdentifierInfo *Ident__Nonnull = nullptr;
IdentifierInfo *Ident__Nullable = nullptr;
IdentifierInfo *Ident__Nullable_result = nullptr;
IdentifierInfo *Ident__Null_unspecified = nullptr;

IdentifierInfo *Ident_NSError = nullptr;

/// The handler for the FileChanged preprocessor events.
///
/// Used for diagnostics that implement custom semantic analysis for #include
/// directives, like -Wpragma-pack.
sema::SemaPPCallbacks *SemaPPCallbackHandler;

13784protected:
friend class Parser;
friend class InitializationSequence;
friend class ASTReader;
friend class ASTDeclReader;
friend class ASTWriter;

13791public:
/// Retrieve the keyword associated
IdentifierInfo *getNullabilityKeyword(NullabilityKind nullability);

/// The struct behind the CFErrorRef pointer.
RecordDecl *CFError = nullptr;
bool isCFError(RecordDecl *D);

/// Retrieve the identifier "NSError".
IdentifierInfo *getNSErrorIdent();

/// Retrieve the parser's current scope.
///
/// This routine must only be used when it is certain that semantic analysis
/// and the parser are in precisely the same context, which is not the case
/// when, e.g., we are performing any kind of template instantiation.
/// Therefore, the only safe places to use this scope are in the parser
/// itself and in routines directly invoked from the parser and *never* from
/// template substitution or instantiation.
Scope *getCurScope() const { return CurScope; }

void incrementMSManglingNumber() const {
  return CurScope->incrementMSManglingNumber();
}

IdentifierInfo *getSuperIdentifier() const;
IdentifierInfo *getFloat128Identifier() const;

ObjCContainerDecl *getObjCDeclContext() const;

DeclContext *getCurLexicalContext() const {
  return OriginalLexicalContext ? OriginalLexicalContext : CurContext;
}

const DeclContext *getCurObjCLexicalContext() const {
  const DeclContext *DC = getCurLexicalContext();
  // A category implicitly has the attribute of the interface.
  if (const ObjCCategoryDecl *CatD = dyn_cast<ObjCCategoryDecl>(DC))
    DC = CatD->getClassInterface();
  return DC;
}

/// Determine the number of levels of enclosing template parameters. This is
/// only usable while parsing. Note that this does not include dependent
/// contexts in which no template parameters have yet been declared, such as
/// in a terse function template or generic lambda before the first 'auto' is
/// encountered.
unsigned getTemplateDepth(Scope *S) const;

/// To be used for checking whether the arguments being passed to
/// function exceeds the number of parameters expected for it.
static bool TooManyArguments(size_t NumParams, size_t NumArgs,
                             bool PartialOverloading = false) {
  // We check whether we're just after a comma in code-completion.
  if (NumArgs > 0 && PartialOverloading)
    return NumArgs + 1 > NumParams; // If so, we view as an extra argument.
  return NumArgs > NumParams;
}

// Emitting members of dllexported classes is delayed until the class
// (including field initializers) is fully parsed.
SmallVector<CXXRecordDecl*, 4> DelayedDllExportClasses;
SmallVector<CXXMethodDecl*, 4> DelayedDllExportMemberFunctions;

13855private:
int ParsingClassDepth = 0;

class SavePendingParsedClassStateRAII {
public:
  SavePendingParsedClassStateRAII(Sema &S) : S(S) { swapSavedState(); }

  ~SavePendingParsedClassStateRAII() {
    assert(S.DelayedOverridingExceptionSpecChecks.empty() &&(static_cast <bool> (S.DelayedOverridingExceptionSpecChecks
.empty() && "there shouldn't be any pending delayed exception spec checks"
) ? void (0) : __assert_fail ("S.DelayedOverridingExceptionSpecChecks.empty() && \"there shouldn't be any pending delayed exception spec checks\""
, "clang/include/clang/Sema/Sema.h", 13864, __extension__ __PRETTY_FUNCTION__
))
           "there shouldn't be any pending delayed exception spec checks")(static_cast <bool> (S.DelayedOverridingExceptionSpecChecks
.empty() && "there shouldn't be any pending delayed exception spec checks"
) ? void (0) : __assert_fail ("S.DelayedOverridingExceptionSpecChecks.empty() && \"there shouldn't be any pending delayed exception spec checks\""
, "clang/include/clang/Sema/Sema.h", 13864, __extension__ __PRETTY_FUNCTION__
));
    assert(S.DelayedEquivalentExceptionSpecChecks.empty() &&(static_cast <bool> (S.DelayedEquivalentExceptionSpecChecks
.empty() && "there shouldn't be any pending delayed exception spec checks"
) ? void (0) : __assert_fail ("S.DelayedEquivalentExceptionSpecChecks.empty() && \"there shouldn't be any pending delayed exception spec checks\""
, "clang/include/clang/Sema/Sema.h", 13866, __extension__ __PRETTY_FUNCTION__
))
           "there shouldn't be any pending delayed exception spec checks")(static_cast <bool> (S.DelayedEquivalentExceptionSpecChecks
.empty() && "there shouldn't be any pending delayed exception spec checks"
) ? void (0) : __assert_fail ("S.DelayedEquivalentExceptionSpecChecks.empty() && \"there shouldn't be any pending delayed exception spec checks\""
, "clang/include/clang/Sema/Sema.h", 13866, __extension__ __PRETTY_FUNCTION__
));
    swapSavedState();
  }

private:
  Sema &S;
  decltype(DelayedOverridingExceptionSpecChecks)
      SavedOverridingExceptionSpecChecks;
  decltype(DelayedEquivalentExceptionSpecChecks)
      SavedEquivalentExceptionSpecChecks;

  void swapSavedState() {
    SavedOverridingExceptionSpecChecks.swap(
        S.DelayedOverridingExceptionSpecChecks);
    SavedEquivalentExceptionSpecChecks.swap(
        S.DelayedEquivalentExceptionSpecChecks);
  }
};

/// Helper class that collects misaligned member designations and
/// their location info for delayed diagnostics.
struct MisalignedMember {
  Expr *E;
  RecordDecl *RD;
  ValueDecl *MD;
  CharUnits Alignment;

  MisalignedMember() : E(), RD(), MD() {}
  MisalignedMember(Expr *E, RecordDecl *RD, ValueDecl *MD,
                   CharUnits Alignment)
      : E(E), RD(RD), MD(MD), Alignment(Alignment) {}
  explicit MisalignedMember(Expr *E)
      : MisalignedMember(E, nullptr, nullptr, CharUnits()) {}

  bool operator==(const MisalignedMember &m) { return this->E == m.E; }
};
/// Small set of gathered accesses to potentially misaligned members
/// due to the packed attribute.
SmallVector<MisalignedMember, 4> MisalignedMembers;

/// Adds an expression to the set of gathered misaligned members.
void AddPotentialMisalignedMembers(Expr *E, RecordDecl *RD, ValueDecl *MD,
                                   CharUnits Alignment);

13910public:
/// Diagnoses the current set of gathered accesses. This typically
/// happens at full expression level. The set is cleared after emitting the
/// diagnostics.
void DiagnoseMisalignedMembers();

/// This function checks if the expression is in the sef of potentially
/// misaligned members and it is converted to some pointer type T with lower
/// or equal alignment requirements. If so it removes it. This is used when
/// we do not want to diagnose such misaligned access (e.g. in conversions to
/// void*).
void DiscardMisalignedMemberAddress(const Type *T, Expr *E);

/// This function calls Action when it determines that E designates a
/// misaligned member due to the packed attribute. This is used to emit
/// local diagnostics like in reference binding.
void RefersToMemberWithReducedAlignment(
    Expr *E,
    llvm::function_ref<void(Expr *, RecordDecl *, FieldDecl *, CharUnits)>
        Action);

/// Describes the reason a calling convention specification was ignored, used
/// for diagnostics.
enum class CallingConventionIgnoredReason {
  ForThisTarget = 0,
  VariadicFunction,
  ConstructorDestructor,
  BuiltinFunction
};
/// Creates a SemaDiagnosticBuilder that emits the diagnostic if the current
/// context is "used as device code".
///
/// - If CurLexicalContext is a kernel function or it is known that the
///   function will be emitted for the device, emits the diagnostics
///   immediately.
/// - If CurLexicalContext is a function and we are compiling
///   for the device, but we don't know that this function will be codegen'ed
///   for devive yet, creates a diagnostic which is emitted if and when we
///   realize that the function will be codegen'ed.
///
/// Example usage:
///
/// Diagnose __float128 type usage only from SYCL device code if the current
/// target doesn't support it
/// if (!S.Context.getTargetInfo().hasFloat128Type() &&
///     S.getLangOpts().SYCLIsDevice)
///   SYCLDiagIfDeviceCode(Loc, diag::err_type_unsupported) << "__float128";
SemaDiagnosticBuilder SYCLDiagIfDeviceCode(SourceLocation Loc,
                                           unsigned DiagID);

void deepTypeCheckForSYCLDevice(SourceLocation UsedAt,
                                llvm::DenseSet<QualType> Visited,
                                ValueDecl *DeclToCheck);
13963};

13965DeductionFailureInfo
13966MakeDeductionFailureInfo(ASTContext &Context, Sema::TemplateDeductionResult TDK,
                       sema::TemplateDeductionInfo &Info);

13969/// Contains a late templated function.
13970/// Will be parsed at the end of the translation unit, used by Sema & Parser.
13971struct LateParsedTemplate {
CachedTokens Toks;
/// The template function declaration to be late parsed.
Decl *D;
13975};

13977template <>
13978void Sema::PragmaStack<Sema::AlignPackInfo>::Act(SourceLocation PragmaLocation,
                                               PragmaMsStackAction Action,
                                               llvm::StringRef StackSlotLabel,
                                               AlignPackInfo Value);

13983std::unique_ptr<sema::RISCVIntrinsicManager>
13984CreateRISCVIntrinsicManager(Sema &S);
13985} // end namespace clang

13987namespace llvm {
13988// Hash a FunctionDeclAndLoc by looking at both its FunctionDecl and its
13989// SourceLocation.
13990template <> struct DenseMapInfo<clang::Sema::FunctionDeclAndLoc> {
using FunctionDeclAndLoc = clang::Sema::FunctionDeclAndLoc;
using FDBaseInfo =
    DenseMapInfo<clang::CanonicalDeclPtr<const clang::FunctionDecl>>;

static FunctionDeclAndLoc getEmptyKey() {
  return {FDBaseInfo::getEmptyKey(), clang::SourceLocation()};
}

static FunctionDeclAndLoc getTombstoneKey() {
  return {FDBaseInfo::getTombstoneKey(), clang::SourceLocation()};
}

static unsigned getHashValue(const FunctionDeclAndLoc &FDL) {
  return hash_combine(FDBaseInfo::getHashValue(FDL.FD),
                      FDL.Loc.getHashValue());
}

static bool isEqual(const FunctionDeclAndLoc &LHS,
                    const FunctionDeclAndLoc &RHS) {
  return LHS.FD == RHS.FD && LHS.Loc == RHS.Loc;
}
14012};
14013} // namespace llvm

14015#endif

←

/build/source/clang/include/clang/AST/ExprCXX.h

1//===- ExprCXX.h - Classes for representing expressions ---------*- C++ -*-===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8//
9/// \file
10/// Defines the clang::Expr interface and subclasses for C++ expressions.
11//
12//===----------------------------------------------------------------------===//

14#ifndef LLVM_CLANG_AST_EXPRCXX_H
15#define LLVM_CLANG_AST_EXPRCXX_H

17#include "clang/AST/ASTConcept.h"
18#include "clang/AST/ComputeDependence.h"
19#include "clang/AST/Decl.h"
20#include "clang/AST/DeclBase.h"
21#include "clang/AST/DeclCXX.h"
22#include "clang/AST/DeclTemplate.h"
23#include "clang/AST/DeclarationName.h"
24#include "clang/AST/DependenceFlags.h"
25#include "clang/AST/Expr.h"
26#include "clang/AST/NestedNameSpecifier.h"
27#include "clang/AST/OperationKinds.h"
28#include "clang/AST/Stmt.h"
29#include "clang/AST/StmtCXX.h"
30#include "clang/AST/TemplateBase.h"
31#include "clang/AST/Type.h"
32#include "clang/AST/UnresolvedSet.h"
33#include "clang/Basic/ExceptionSpecificationType.h"
34#include "clang/Basic/ExpressionTraits.h"
35#include "clang/Basic/LLVM.h"
36#include "clang/Basic/Lambda.h"
37#include "clang/Basic/LangOptions.h"
38#include "clang/Basic/OperatorKinds.h"
39#include "clang/Basic/SourceLocation.h"
40#include "clang/Basic/Specifiers.h"
41#include "clang/Basic/TypeTraits.h"
42#include "llvm/ADT/ArrayRef.h"
43#include "llvm/ADT/PointerUnion.h"
44#include "llvm/ADT/StringRef.h"
45#include "llvm/ADT/iterator_range.h"
46#include "llvm/Support/Casting.h"
47#include "llvm/Support/Compiler.h"
48#include "llvm/Support/TrailingObjects.h"
49#include <cassert>
50#include <cstddef>
51#include <cstdint>
52#include <memory>
53#include <optional>

55namespace clang {

57class ASTContext;
58class DeclAccessPair;
59class IdentifierInfo;
60class LambdaCapture;
61class NonTypeTemplateParmDecl;
62class TemplateParameterList;

64//===--------------------------------------------------------------------===//
65// C++ Expressions.
66//===--------------------------------------------------------------------===//

68/// A call to an overloaded operator written using operator
69/// syntax.
70///
71/// Represents a call to an overloaded operator written using operator
72/// syntax, e.g., "x + y" or "*p". While semantically equivalent to a
73/// normal call, this AST node provides better information about the
74/// syntactic representation of the call.
75///
76/// In a C++ template, this expression node kind will be used whenever
77/// any of the arguments are type-dependent. In this case, the
78/// function itself will be a (possibly empty) set of functions and
79/// function templates that were found by name lookup at template
80/// definition time.
81class CXXOperatorCallExpr final : public CallExpr {
friend class ASTStmtReader;
friend class ASTStmtWriter;

SourceRange Range;

// CXXOperatorCallExpr has some trailing objects belonging
// to CallExpr. See CallExpr for the details.

SourceRange getSourceRangeImpl() const LLVM_READONLY__attribute__((__pure__));

CXXOperatorCallExpr(OverloadedOperatorKind OpKind, Expr *Fn,
                    ArrayRef<Expr *> Args, QualType Ty, ExprValueKind VK,
                    SourceLocation OperatorLoc, FPOptionsOverride FPFeatures,
                    ADLCallKind UsesADL);

CXXOperatorCallExpr(unsigned NumArgs, bool HasFPFeatures, EmptyShell Empty);

99public:
static CXXOperatorCallExpr *
Create(const ASTContext &Ctx, OverloadedOperatorKind OpKind, Expr *Fn,
       ArrayRef<Expr *> Args, QualType Ty, ExprValueKind VK,
       SourceLocation OperatorLoc, FPOptionsOverride FPFeatures,
       ADLCallKind UsesADL = NotADL);

static CXXOperatorCallExpr *CreateEmpty(const ASTContext &Ctx,
                                        unsigned NumArgs, bool HasFPFeatures,
                                        EmptyShell Empty);

/// Returns the kind of overloaded operator that this expression refers to.
OverloadedOperatorKind getOperator() const {
  return static_cast<OverloadedOperatorKind>(
      CXXOperatorCallExprBits.OperatorKind);
}

static bool isAssignmentOp(OverloadedOperatorKind Opc) {
  return Opc == OO_Equal || Opc == OO_StarEqual || Opc == OO_SlashEqual ||
         Opc == OO_PercentEqual || Opc == OO_PlusEqual ||
         Opc == OO_MinusEqual || Opc == OO_LessLessEqual ||
         Opc == OO_GreaterGreaterEqual || Opc == OO_AmpEqual ||
         Opc == OO_CaretEqual || Opc == OO_PipeEqual;
}
bool isAssignmentOp() const { return isAssignmentOp(getOperator()); }

static bool isComparisonOp(OverloadedOperatorKind Opc) {
  switch (Opc) {
  case OO_EqualEqual:
  case OO_ExclaimEqual:
  case OO_Greater:
  case OO_GreaterEqual:
  case OO_Less:
  case OO_LessEqual:
  case OO_Spaceship:
    return true;
  default:
    return false;
  }
}
bool isComparisonOp() const { return isComparisonOp(getOperator()); }

/// Is this written as an infix binary operator?
bool isInfixBinaryOp() const;

/// Returns the location of the operator symbol in the expression.
///
/// When \c getOperator()==OO_Call, this is the location of the right
/// parentheses; when \c getOperator()==OO_Subscript, this is the location
/// of the right bracket.
SourceLocation getOperatorLoc() const { return getRParenLoc(); }

SourceLocation getExprLoc() const LLVM_READONLY__attribute__((__pure__)) {
  OverloadedOperatorKind Operator = getOperator();
  return (Operator < OO_Plus || Operator >= OO_Arrow ||
          Operator == OO_PlusPlus || Operator == OO_MinusMinus)
             ? getBeginLoc()
             : getOperatorLoc();
}

SourceLocation getBeginLoc() const { return Range.getBegin(); }
SourceLocation getEndLoc() const { return Range.getEnd(); }
SourceRange getSourceRange() const { return Range; }

static bool classof(const Stmt *T) {
  return T->getStmtClass() == CXXOperatorCallExprClass;
}
166};

168/// Represents a call to a member function that
169/// may be written either with member call syntax (e.g., "obj.func()"
170/// or "objptr->func()") or with normal function-call syntax
171/// ("func()") within a member function that ends up calling a member
172/// function. The callee in either case is a MemberExpr that contains
173/// both the object argument and the member function, while the
174/// arguments are the arguments within the parentheses (not including
175/// the object argument).
176class CXXMemberCallExpr final : public CallExpr {
// CXXMemberCallExpr has some trailing objects belonging
// to CallExpr. See CallExpr for the details.

CXXMemberCallExpr(Expr *Fn, ArrayRef<Expr *> Args, QualType Ty,
                  ExprValueKind VK, SourceLocation RP,
                  FPOptionsOverride FPOptions, unsigned MinNumArgs);

CXXMemberCallExpr(unsigned NumArgs, bool HasFPFeatures, EmptyShell Empty);

186public:
static CXXMemberCallExpr *Create(const ASTContext &Ctx, Expr *Fn,
                                 ArrayRef<Expr *> Args, QualType Ty,
                                 ExprValueKind VK, SourceLocation RP,
                                 FPOptionsOverride FPFeatures,
                                 unsigned MinNumArgs = 0);

static CXXMemberCallExpr *CreateEmpty(const ASTContext &Ctx, unsigned NumArgs,
                                      bool HasFPFeatures, EmptyShell Empty);

/// Retrieve the implicit object argument for the member call.
///
/// For example, in "x.f(5)", this returns the sub-expression "x".
Expr *getImplicitObjectArgument() const;

/// Retrieve the type of the object argument.
///
/// Note that this always returns a non-pointer type.
QualType getObjectType() const;

/// Retrieve the declaration of the called method.
CXXMethodDecl *getMethodDecl() const;

/// Retrieve the CXXRecordDecl for the underlying type of
/// the implicit object argument.
///
/// Note that this is may not be the same declaration as that of the class
/// context of the CXXMethodDecl which this function is calling.
/// FIXME: Returns 0 for member pointer call exprs.
CXXRecordDecl *getRecordDecl() const;

SourceLocation getExprLoc() const LLVM_READONLY__attribute__((__pure__)) {
  SourceLocation CLoc = getCallee()->getExprLoc();
  if (CLoc.isValid())
    return CLoc;

  return getBeginLoc();
}

static bool classof(const Stmt *T) {
  return T->getStmtClass() == CXXMemberCallExprClass;
}
228};

230/// Represents a call to a CUDA kernel function.
231class CUDAKernelCallExpr final : public CallExpr {
friend class ASTStmtReader;

enum { CONFIG, END_PREARG };

// CUDAKernelCallExpr has some trailing objects belonging
// to CallExpr. See CallExpr for the details.

CUDAKernelCallExpr(Expr *Fn, CallExpr *Config, ArrayRef<Expr *> Args,
                   QualType Ty, ExprValueKind VK, SourceLocation RP,
                   FPOptionsOverride FPFeatures, unsigned MinNumArgs);

CUDAKernelCallExpr(unsigned NumArgs, bool HasFPFeatures, EmptyShell Empty);

245public:
static CUDAKernelCallExpr *Create(const ASTContext &Ctx, Expr *Fn,
                                  CallExpr *Config, ArrayRef<Expr *> Args,
                                  QualType Ty, ExprValueKind VK,
                                  SourceLocation RP,
                                  FPOptionsOverride FPFeatures,
                                  unsigned MinNumArgs = 0);

static CUDAKernelCallExpr *CreateEmpty(const ASTContext &Ctx,
                                       unsigned NumArgs, bool HasFPFeatures,
                                       EmptyShell Empty);

const CallExpr *getConfig() const {
  return cast_or_null<CallExpr>(getPreArg(CONFIG));
}
CallExpr *getConfig() { return cast_or_null<CallExpr>(getPreArg(CONFIG)); }

static bool classof(const Stmt *T) {
  return T->getStmtClass() == CUDAKernelCallExprClass;
}
265};

267/// A rewritten comparison expression that was originally written using
268/// operator syntax.
269///
270/// In C++20, the following rewrites are performed:
271/// - <tt>a == b</tt> -> <tt>b == a</tt>
272/// - <tt>a != b</tt> -> <tt>!(a == b)</tt>
273/// - <tt>a != b</tt> -> <tt>!(b == a)</tt>
274/// - For \c \@ in \c <, \c <=, \c >, \c >=, \c <=>:
275///   - <tt>a @ b</tt> -> <tt>(a <=> b) @ 0</tt>
276///   - <tt>a @ b</tt> -> <tt>0 @ (b <=> a)</tt>
277///
278/// This expression provides access to both the original syntax and the
279/// rewritten expression.
280///
281/// Note that the rewritten calls to \c ==, \c <=>, and \c \@ are typically
282/// \c CXXOperatorCallExprs, but could theoretically be \c BinaryOperators.
283class CXXRewrittenBinaryOperator : public Expr {
friend class ASTStmtReader;

/// The rewritten semantic form.
Stmt *SemanticForm;

289public:
CXXRewrittenBinaryOperator(Expr *SemanticForm, bool IsReversed)
    : Expr(CXXRewrittenBinaryOperatorClass, SemanticForm->getType(),
           SemanticForm->getValueKind(), SemanticForm->getObjectKind()),
      SemanticForm(SemanticForm) {
  CXXRewrittenBinaryOperatorBits.IsReversed = IsReversed;
  setDependence(computeDependence(this));
}
CXXRewrittenBinaryOperator(EmptyShell Empty)
    : Expr(CXXRewrittenBinaryOperatorClass, Empty), SemanticForm() {}

/// Get an equivalent semantic form for this expression.
Expr *getSemanticForm() { return cast<Expr>(SemanticForm); }
const Expr *getSemanticForm() const { return cast<Expr>(SemanticForm); }

struct DecomposedForm {
  /// The original opcode, prior to rewriting.
  BinaryOperatorKind Opcode;
  /// The original left-hand side.
  const Expr *LHS;
  /// The original right-hand side.
  const Expr *RHS;
  /// The inner \c == or \c <=> operator expression.
  const Expr *InnerBinOp;
};

/// Decompose this operator into its syntactic form.
DecomposedForm getDecomposedForm() const LLVM_READONLY__attribute__((__pure__));

/// Determine whether this expression was rewritten in reverse form.
bool isReversed() const { return CXXRewrittenBinaryOperatorBits.IsReversed; }

BinaryOperatorKind getOperator() const { return getDecomposedForm().Opcode; }
BinaryOperatorKind getOpcode() const { return getOperator(); }
static StringRef getOpcodeStr(BinaryOperatorKind Op) {
  return BinaryOperator::getOpcodeStr(Op);
}
StringRef getOpcodeStr() const {
  return BinaryOperator::getOpcodeStr(getOpcode());
}
bool isComparisonOp() const { return true; }
bool isAssignmentOp() const { return false; }

const Expr *getLHS() const { return getDecomposedForm().LHS; }
const Expr *getRHS() const { return getDecomposedForm().RHS; }

SourceLocation getOperatorLoc() const LLVM_READONLY__attribute__((__pure__)) {
  return getDecomposedForm().InnerBinOp->getExprLoc();
}
SourceLocation getExprLoc() const LLVM_READONLY__attribute__((__pure__)) { return getOperatorLoc(); }

/// Compute the begin and end locations from the decomposed form.
/// The locations of the semantic form are not reliable if this is
/// a reversed expression.
//@{
SourceLocation getBeginLoc() const LLVM_READONLY__attribute__((__pure__)) {
  return getDecomposedForm().LHS->getBeginLoc();
}
SourceLocation getEndLoc() const LLVM_READONLY__attribute__((__pure__)) {
  return getDecomposedForm().RHS->getEndLoc();
}
SourceRange getSourceRange() const LLVM_READONLY__attribute__((__pure__)) {
  DecomposedForm DF = getDecomposedForm();
  return SourceRange(DF.LHS->getBeginLoc(), DF.RHS->getEndLoc());
}
//@}

child_range children() {
  return child_range(&SemanticForm, &SemanticForm + 1);
}

static bool classof(const Stmt *T) {
  return T->getStmtClass() == CXXRewrittenBinaryOperatorClass;
}
363};

365/// Abstract class common to all of the C++ "named"/"keyword" casts.
366///
367/// This abstract class is inherited by all of the classes
368/// representing "named" casts: CXXStaticCastExpr for \c static_cast,
369/// CXXDynamicCastExpr for \c dynamic_cast, CXXReinterpretCastExpr for
370/// reinterpret_cast, CXXConstCastExpr for \c const_cast and
371/// CXXAddrspaceCastExpr for addrspace_cast (in OpenCL).
372class CXXNamedCastExpr : public ExplicitCastExpr {
373private:
// the location of the casting op
SourceLocation Loc;

// the location of the right parenthesis
SourceLocation RParenLoc;

// range for '<' '>'
SourceRange AngleBrackets;

383protected:
friend class ASTStmtReader;

CXXNamedCastExpr(StmtClass SC, QualType ty, ExprValueKind VK, CastKind kind,
                 Expr *op, unsigned PathSize, bool HasFPFeatures,
                 TypeSourceInfo *writtenTy, SourceLocation l,
                 SourceLocation RParenLoc, SourceRange AngleBrackets)
    : ExplicitCastExpr(SC, ty, VK, kind, op, PathSize, HasFPFeatures,
                       writtenTy),
      Loc(l), RParenLoc(RParenLoc), AngleBrackets(AngleBrackets) {}

explicit CXXNamedCastExpr(StmtClass SC, EmptyShell Shell, unsigned PathSize,
                          bool HasFPFeatures)
    : ExplicitCastExpr(SC, Shell, PathSize, HasFPFeatures) {}

398public:
const char *getCastName() const;

/// Retrieve the location of the cast operator keyword, e.g.,
/// \c static_cast.
SourceLocation getOperatorLoc() const { return Loc; }

/// Retrieve the location of the closing parenthesis.
SourceLocation getRParenLoc() const { return RParenLoc; }

SourceLocation getBeginLoc() const LLVM_READONLY__attribute__((__pure__)) { return Loc; }
SourceLocation getEndLoc() const LLVM_READONLY__attribute__((__pure__)) { return RParenLoc; }
SourceRange getAngleBrackets() const LLVM_READONLY__attribute__((__pure__)) { return AngleBrackets; }

static bool classof(const Stmt *T) {
  switch (T->getStmtClass()) {
  case CXXStaticCastExprClass:
  case CXXDynamicCastExprClass:
  case CXXReinterpretCastExprClass:
  case CXXConstCastExprClass:
  case CXXAddrspaceCastExprClass:
    return true;
  default:
    return false;
  }
}
424};

426/// A C++ \c static_cast expression (C++ [expr.static.cast]).
427///
428/// This expression node represents a C++ static cast, e.g.,
429/// \c static_cast<int>(1.0).
430class CXXStaticCastExpr final
  : public CXXNamedCastExpr,
    private llvm::TrailingObjects<CXXStaticCastExpr, CXXBaseSpecifier *,
                                  FPOptionsOverride> {
CXXStaticCastExpr(QualType ty, ExprValueKind vk, CastKind kind, Expr *op,
                  unsigned pathSize, TypeSourceInfo *writtenTy,
                  FPOptionsOverride FPO, SourceLocation l,
                  SourceLocation RParenLoc, SourceRange AngleBrackets)
    : CXXNamedCastExpr(CXXStaticCastExprClass, ty, vk, kind, op, pathSize,
                       FPO.requiresTrailingStorage(), writtenTy, l, RParenLoc,
                       AngleBrackets) {
  if (hasStoredFPFeatures())
    *getTrailingFPFeatures() = FPO;
}

explicit CXXStaticCastExpr(EmptyShell Empty, unsigned PathSize,
                           bool HasFPFeatures)
    : CXXNamedCastExpr(CXXStaticCastExprClass, Empty, PathSize,
                       HasFPFeatures) {}

unsigned numTrailingObjects(OverloadToken<CXXBaseSpecifier *>) const {
  return path_size();
}

454public:
friend class CastExpr;
friend TrailingObjects;

static CXXStaticCastExpr *
Create(const ASTContext &Context, QualType T, ExprValueKind VK, CastKind K,
       Expr *Op, const CXXCastPath *Path, TypeSourceInfo *Written,
       FPOptionsOverride FPO, SourceLocation L, SourceLocation RParenLoc,
       SourceRange AngleBrackets);
static CXXStaticCastExpr *CreateEmpty(const ASTContext &Context,
                                      unsigned PathSize, bool hasFPFeatures);

static bool classof(const Stmt *T) {
  return T->getStmtClass() == CXXStaticCastExprClass;
}
469};

471/// A C++ @c dynamic_cast expression (C++ [expr.dynamic.cast]).
472///
473/// This expression node represents a dynamic cast, e.g.,
474/// \c dynamic_cast<Derived*>(BasePtr). Such a cast may perform a run-time
475/// check to determine how to perform the type conversion.
476class CXXDynamicCastExpr final
  : public CXXNamedCastExpr,
    private llvm::TrailingObjects<CXXDynamicCastExpr, CXXBaseSpecifier *> {
CXXDynamicCastExpr(QualType ty, ExprValueKind VK, CastKind kind, Expr *op,
                   unsigned pathSize, TypeSourceInfo *writtenTy,
                   SourceLocation l, SourceLocation RParenLoc,
                   SourceRange AngleBrackets)
    : CXXNamedCastExpr(CXXDynamicCastExprClass, ty, VK, kind, op, pathSize,
                       /*HasFPFeatures*/ false, writtenTy, l, RParenLoc,
                       AngleBrackets) {}

explicit CXXDynamicCastExpr(EmptyShell Empty, unsigned pathSize)
    : CXXNamedCastExpr(CXXDynamicCastExprClass, Empty, pathSize,
                       /*HasFPFeatures*/ false) {}

491public:
friend class CastExpr;
friend TrailingObjects;

static CXXDynamicCastExpr *Create(const ASTContext &Context, QualType T,
                                  ExprValueKind VK, CastKind Kind, Expr *Op,
                                  const CXXCastPath *Path,
                                  TypeSourceInfo *Written, SourceLocation L,
                                  SourceLocation RParenLoc,
                                  SourceRange AngleBrackets);

static CXXDynamicCastExpr *CreateEmpty(const ASTContext &Context,
                                       unsigned pathSize);

bool isAlwaysNull() const;

static bool classof(const Stmt *T) {
  return T->getStmtClass() == CXXDynamicCastExprClass;
}
510};

512/// A C++ @c reinterpret_cast expression (C++ [expr.reinterpret.cast]).
513///
514/// This expression node represents a reinterpret cast, e.g.,
515/// @c reinterpret_cast<int>(VoidPtr).
516///
517/// A reinterpret_cast provides a differently-typed view of a value but
518/// (in Clang, as in most C++ implementations) performs no actual work at
519/// run time.
520class CXXReinterpretCastExpr final
  : public CXXNamedCastExpr,
    private llvm::TrailingObjects<CXXReinterpretCastExpr,
                                  CXXBaseSpecifier *> {
CXXReinterpretCastExpr(QualType ty, ExprValueKind vk, CastKind kind, Expr *op,
                       unsigned pathSize, TypeSourceInfo *writtenTy,
                       SourceLocation l, SourceLocation RParenLoc,
                       SourceRange AngleBrackets)
    : CXXNamedCastExpr(CXXReinterpretCastExprClass, ty, vk, kind, op,
                       pathSize, /*HasFPFeatures*/ false, writtenTy, l,
                       RParenLoc, AngleBrackets) {}

CXXReinterpretCastExpr(EmptyShell Empty, unsigned pathSize)
    : CXXNamedCastExpr(CXXReinterpretCastExprClass, Empty, pathSize,
                       /*HasFPFeatures*/ false) {}

536public:
friend class CastExpr;
friend TrailingObjects;

static CXXReinterpretCastExpr *Create(const ASTContext &Context, QualType T,
                                      ExprValueKind VK, CastKind Kind,
                                      Expr *Op, const CXXCastPath *Path,
                               TypeSourceInfo *WrittenTy, SourceLocation L,
                                      SourceLocation RParenLoc,
                                      SourceRange AngleBrackets);
static CXXReinterpretCastExpr *CreateEmpty(const ASTContext &Context,
                                           unsigned pathSize);

static bool classof(const Stmt *T) {
  return T->getStmtClass() == CXXReinterpretCastExprClass;
}
552};

554/// A C++ \c const_cast expression (C++ [expr.const.cast]).
555///
556/// This expression node represents a const cast, e.g.,
557/// \c const_cast<char*>(PtrToConstChar).
558///
559/// A const_cast can remove type qualifiers but does not change the underlying
560/// value.
561class CXXConstCastExpr final
  : public CXXNamedCastExpr,
    private llvm::TrailingObjects<CXXConstCastExpr, CXXBaseSpecifier *> {
CXXConstCastExpr(QualType ty, ExprValueKind VK, Expr *op,
                 TypeSourceInfo *writtenTy, SourceLocation l,
                 SourceLocation RParenLoc, SourceRange AngleBrackets)
    : CXXNamedCastExpr(CXXConstCastExprClass, ty, VK, CK_NoOp, op, 0,
                       /*HasFPFeatures*/ false, writtenTy, l, RParenLoc,
                       AngleBrackets) {}

explicit CXXConstCastExpr(EmptyShell Empty)
    : CXXNamedCastExpr(CXXConstCastExprClass, Empty, 0,
                       /*HasFPFeatures*/ false) {}

575public:
friend class CastExpr;
friend TrailingObjects;

static CXXConstCastExpr *Create(const ASTContext &Context, QualType T,
                                ExprValueKind VK, Expr *Op,
                                TypeSourceInfo *WrittenTy, SourceLocation L,
                                SourceLocation RParenLoc,
                                SourceRange AngleBrackets);
static CXXConstCastExpr *CreateEmpty(const ASTContext &Context);

static bool classof(const Stmt *T) {
  return T->getStmtClass() == CXXConstCastExprClass;
}
589};

591/// A C++ addrspace_cast expression (currently only enabled for OpenCL).
592///
593/// This expression node represents a cast between pointers to objects in
594/// different address spaces e.g.,
595/// \c addrspace_cast<global int*>(PtrToGenericInt).
596///
597/// A addrspace_cast can cast address space type qualifiers but does not change
598/// the underlying value.
599class CXXAddrspaceCastExpr final
  : public CXXNamedCastExpr,
    private llvm::TrailingObjects<CXXAddrspaceCastExpr, CXXBaseSpecifier *> {
CXXAddrspaceCastExpr(QualType ty, ExprValueKind VK, CastKind Kind, Expr *op,
                     TypeSourceInfo *writtenTy, SourceLocation l,
                     SourceLocation RParenLoc, SourceRange AngleBrackets)
    : CXXNamedCastExpr(CXXAddrspaceCastExprClass, ty, VK, Kind, op, 0,
                       /*HasFPFeatures*/ false, writtenTy, l, RParenLoc,
                       AngleBrackets) {}

explicit CXXAddrspaceCastExpr(EmptyShell Empty)
    : CXXNamedCastExpr(CXXAddrspaceCastExprClass, Empty, 0,
                       /*HasFPFeatures*/ false) {}

613public:
friend class CastExpr;
friend TrailingObjects;

static CXXAddrspaceCastExpr *
Create(const ASTContext &Context, QualType T, ExprValueKind VK, CastKind Kind,
       Expr *Op, TypeSourceInfo *WrittenTy, SourceLocation L,
       SourceLocation RParenLoc, SourceRange AngleBrackets);
static CXXAddrspaceCastExpr *CreateEmpty(const ASTContext &Context);

static bool classof(const Stmt *T) {
  return T->getStmtClass() == CXXAddrspaceCastExprClass;
}
626};

628/// A call to a literal operator (C++11 [over.literal])
629/// written as a user-defined literal (C++11 [lit.ext]).
630///
631/// Represents a user-defined literal, e.g. "foo"_bar or 1.23_xyz. While this
632/// is semantically equivalent to a normal call, this AST node provides better
633/// information about the syntactic representation of the literal.
634///
635/// Since literal operators are never found by ADL and can only be declared at
636/// namespace scope, a user-defined literal is never dependent.
637class UserDefinedLiteral final : public CallExpr {
friend class ASTStmtReader;
friend class ASTStmtWriter;

/// The location of a ud-suffix within the literal.
SourceLocation UDSuffixLoc;

// UserDefinedLiteral has some trailing objects belonging
// to CallExpr. See CallExpr for the details.

UserDefinedLiteral(Expr *Fn, ArrayRef<Expr *> Args, QualType Ty,
                   ExprValueKind VK, SourceLocation LitEndLoc,
                   SourceLocation SuffixLoc, FPOptionsOverride FPFeatures);

UserDefinedLiteral(unsigned NumArgs, bool HasFPFeatures, EmptyShell Empty);

653public:
static UserDefinedLiteral *Create(const ASTContext &Ctx, Expr *Fn,
                                  ArrayRef<Expr *> Args, QualType Ty,
                                  ExprValueKind VK, SourceLocation LitEndLoc,
                                  SourceLocation SuffixLoc,
                                  FPOptionsOverride FPFeatures);

static UserDefinedLiteral *CreateEmpty(const ASTContext &Ctx,
                                       unsigned NumArgs, bool HasFPOptions,
                                       EmptyShell Empty);

/// The kind of literal operator which is invoked.
enum LiteralOperatorKind {
  /// Raw form: operator "" X (const char *)
  LOK_Raw,

  /// Raw form: operator "" X<cs...> ()
  LOK_Template,

  /// operator "" X (unsigned long long)
  LOK_Integer,

  /// operator "" X (long double)
  LOK_Floating,

  /// operator "" X (const CharT *, size_t)
  LOK_String,

  /// operator "" X (CharT)
  LOK_Character
};

/// Returns the kind of literal operator invocation
/// which this expression represents.
LiteralOperatorKind getLiteralOperatorKind() const;

/// If this is not a raw user-defined literal, get the
/// underlying cooked literal (representing the literal with the suffix
/// removed).
Expr *getCookedLiteral();
const Expr *getCookedLiteral() const {
  return const_cast<UserDefinedLiteral*>(this)->getCookedLiteral();
}

SourceLocation getBeginLoc() const {
  if (getLiteralOperatorKind() == LOK_Template)
    return getRParenLoc();
  return getArg(0)->getBeginLoc();
}

SourceLocation getEndLoc() const { return getRParenLoc(); }

/// Returns the location of a ud-suffix in the expression.
///
/// For a string literal, there may be multiple identical suffixes. This
/// returns the first.
SourceLocation getUDSuffixLoc() const { return UDSuffixLoc; }

/// Returns the ud-suffix specified for this literal.
const IdentifierInfo *getUDSuffix() const;

static bool classof(const Stmt *S) {
  return S->getStmtClass() == UserDefinedLiteralClass;
}
717};

719/// A boolean literal, per ([C++ lex.bool] Boolean literals).
720class CXXBoolLiteralExpr : public Expr {
721public:
CXXBoolLiteralExpr(bool Val, QualType Ty, SourceLocation Loc)
    : Expr(CXXBoolLiteralExprClass, Ty, VK_PRValue, OK_Ordinary) {
  CXXBoolLiteralExprBits.Value = Val;
  CXXBoolLiteralExprBits.Loc = Loc;
  setDependence(ExprDependence::None);
}

explicit CXXBoolLiteralExpr(EmptyShell Empty)
    : Expr(CXXBoolLiteralExprClass, Empty) {}

static CXXBoolLiteralExpr *Create(const ASTContext &C, bool Val, QualType Ty,
                                  SourceLocation Loc) {
  return new (C) CXXBoolLiteralExpr(Val, Ty, Loc);
}

bool getValue() const { return CXXBoolLiteralExprBits.Value; }
void setValue(bool V) { CXXBoolLiteralExprBits.Value = V; }

SourceLocation getBeginLoc() const { return getLocation(); }
SourceLocation getEndLoc() const { return getLocation(); }

SourceLocation getLocation() const { return CXXBoolLiteralExprBits.Loc; }
void setLocation(SourceLocation L) { CXXBoolLiteralExprBits.Loc = L; }

static bool classof(const Stmt *T) {
  return T->getStmtClass() == CXXBoolLiteralExprClass;
}

// Iterators
child_range children() {
  return child_range(child_iterator(), child_iterator());
}

const_child_range children() const {
  return const_child_range(const_child_iterator(), const_child_iterator());
}
758};

760/// The null pointer literal (C++11 [lex.nullptr])
761///
762/// Introduced in C++11, the only literal of type \c nullptr_t is \c nullptr.
763/// This also implements the null pointer literal in C2x (C2x 6.4.1) which is
764/// intended to have the same semantics as the feature in C++.
765class CXXNullPtrLiteralExpr : public Expr {
766public:
CXXNullPtrLiteralExpr(QualType Ty, SourceLocation Loc)
    : Expr(CXXNullPtrLiteralExprClass, Ty, VK_PRValue, OK_Ordinary) {
  CXXNullPtrLiteralExprBits.Loc = Loc;
  setDependence(ExprDependence::None);
}

explicit CXXNullPtrLiteralExpr(EmptyShell Empty)
    : Expr(CXXNullPtrLiteralExprClass, Empty) {}

SourceLocation getBeginLoc() const { return getLocation(); }
SourceLocation getEndLoc() const { return getLocation(); }

SourceLocation getLocation() const { return CXXNullPtrLiteralExprBits.Loc; }
void setLocation(SourceLocation L) { CXXNullPtrLiteralExprBits.Loc = L; }

static bool classof(const Stmt *T) {
  return T->getStmtClass() == CXXNullPtrLiteralExprClass;
}

child_range children() {
  return child_range(child_iterator(), child_iterator());
}

const_child_range children() const {
  return const_child_range(const_child_iterator(), const_child_iterator());
}
793};

795/// Implicit construction of a std::initializer_list<T> object from an
796/// array temporary within list-initialization (C++11 [dcl.init.list]p5).
797class CXXStdInitializerListExpr : public Expr {
Stmt *SubExpr = nullptr;

CXXStdInitializerListExpr(EmptyShell Empty)
    : Expr(CXXStdInitializerListExprClass, Empty) {}

803public:
friend class ASTReader;
friend class ASTStmtReader;

CXXStdInitializerListExpr(QualType Ty, Expr *SubExpr)
    : Expr(CXXStdInitializerListExprClass, Ty, VK_PRValue, OK_Ordinary),
      SubExpr(SubExpr) {
  setDependence(computeDependence(this));
}

Expr *getSubExpr() { return static_cast<Expr*>(SubExpr); }
const Expr *getSubExpr() const { return static_cast<const Expr*>(SubExpr); }

SourceLocation getBeginLoc() const LLVM_READONLY__attribute__((__pure__)) {
  return SubExpr->getBeginLoc();
}

SourceLocation getEndLoc() const LLVM_READONLY__attribute__((__pure__)) {
  return SubExpr->getEndLoc();
}

/// Retrieve the source range of the expression.
SourceRange getSourceRange() const LLVM_READONLY__attribute__((__pure__)) {
  return SubExpr->getSourceRange();
}

static bool classof(const Stmt *S) {
  return S->getStmtClass() == CXXStdInitializerListExprClass;
}

child_range children() { return child_range(&SubExpr, &SubExpr + 1); }

const_child_range children() const {
  return const_child_range(&SubExpr, &SubExpr + 1);
}
838};

840/// A C++ \c typeid expression (C++ [expr.typeid]), which gets
841/// the \c type_info that corresponds to the supplied type, or the (possibly
842/// dynamic) type of the supplied expression.
843///
844/// This represents code like \c typeid(int) or \c typeid(*objPtr)
845class CXXTypeidExpr : public Expr {
friend class ASTStmtReader;

848private:
llvm::PointerUnion<Stmt *, TypeSourceInfo *> Operand;
SourceRange Range;

852public:
CXXTypeidExpr(QualType Ty, TypeSourceInfo *Operand, SourceRange R)
    : Expr(CXXTypeidExprClass, Ty, VK_LValue, OK_Ordinary), Operand(Operand),
      Range(R) {
  setDependence(computeDependence(this));
}

CXXTypeidExpr(QualType Ty, Expr *Operand, SourceRange R)
    : Expr(CXXTypeidExprClass, Ty, VK_LValue, OK_Ordinary), Operand(Operand),
      Range(R) {
  setDependence(computeDependence(this));
}

CXXTypeidExpr(EmptyShell Empty, bool isExpr)
    : Expr(CXXTypeidExprClass, Empty) {
  if (isExpr)
    Operand = (Expr*)nullptr;
  else
    Operand = (TypeSourceInfo*)nullptr;
}

/// Determine whether this typeid has a type operand which is potentially
/// evaluated, per C++11 [expr.typeid]p3.
bool isPotentiallyEvaluated() const;

/// Best-effort check if the expression operand refers to a most derived
/// object. This is not a strong guarantee.
bool isMostDerived(ASTContext &Context) const;

bool isTypeOperand() const { return Operand.is<TypeSourceInfo *>(); }

/// Retrieves the type operand of this typeid() expression after
/// various required adjustments (removing reference types, cv-qualifiers).
QualType getTypeOperand(ASTContext &Context) const;

/// Retrieve source information for the type operand.
TypeSourceInfo *getTypeOperandSourceInfo() const {
  assert(isTypeOperand() && "Cannot call getTypeOperand for typeid(expr)")(static_cast <bool> (isTypeOperand() && "Cannot call getTypeOperand for typeid(expr)"
) ? void (0) : __assert_fail ("isTypeOperand() && \"Cannot call getTypeOperand for typeid(expr)\""
, "clang/include/clang/AST/ExprCXX.h", 889, __extension__ __PRETTY_FUNCTION__
));
  return Operand.get<TypeSourceInfo *>();
}
Expr *getExprOperand() const {
  assert(!isTypeOperand() && "Cannot call getExprOperand for typeid(type)")(static_cast <bool> (!isTypeOperand() && "Cannot call getExprOperand for typeid(type)"
) ? void (0) : __assert_fail ("!isTypeOperand() && \"Cannot call getExprOperand for typeid(type)\""
, "clang/include/clang/AST/ExprCXX.h", 893, __extension__ __PRETTY_FUNCTION__
));
  return static_cast<Expr*>(Operand.get<Stmt *>());
}

SourceLocation getBeginLoc() const LLVM_READONLY__attribute__((__pure__)) { return Range.getBegin(); }
SourceLocation getEndLoc() const LLVM_READONLY__attribute__((__pure__)) { return Range.getEnd(); }
SourceRange getSourceRange() const LLVM_READONLY__attribute__((__pure__)) { return Range; }
void setSourceRange(SourceRange R) { Range = R; }

static bool classof(const Stmt *T) {
  return T->getStmtClass() == CXXTypeidExprClass;
}

// Iterators
child_range children() {
  if (isTypeOperand())
    return child_range(child_iterator(), child_iterator());
  auto **begin = reinterpret_cast<Stmt **>(&Operand);
  return child_range(begin, begin + 1);
}

const_child_range children() const {
  if (isTypeOperand())
    return const_child_range(const_child_iterator(), const_child_iterator());

  auto **begin =
      reinterpret_cast<Stmt **>(&const_cast<CXXTypeidExpr *>(this)->Operand);
  return const_child_range(begin, begin + 1);
}
922};

924/// A member reference to an MSPropertyDecl.
925///
926/// This expression always has pseudo-object type, and therefore it is
927/// typically not encountered in a fully-typechecked expression except
928/// within the syntactic form of a PseudoObjectExpr.
929class MSPropertyRefExpr : public Expr {
Expr *BaseExpr;
MSPropertyDecl *TheDecl;
SourceLocation MemberLoc;
bool IsArrow;
NestedNameSpecifierLoc QualifierLoc;

936public:
friend class ASTStmtReader;

MSPropertyRefExpr(Expr *baseExpr, MSPropertyDecl *decl, bool isArrow,
                  QualType ty, ExprValueKind VK,
                  NestedNameSpecifierLoc qualifierLoc, SourceLocation nameLoc)
    : Expr(MSPropertyRefExprClass, ty, VK, OK_Ordinary), BaseExpr(baseExpr),
      TheDecl(decl), MemberLoc(nameLoc), IsArrow(isArrow),
      QualifierLoc(qualifierLoc) {
  setDependence(computeDependence(this));
}

MSPropertyRefExpr(EmptyShell Empty) : Expr(MSPropertyRefExprClass, Empty) {}

SourceRange getSourceRange() const LLVM_READONLY__attribute__((__pure__)) {
  return SourceRange(getBeginLoc(), getEndLoc());
}

bool isImplicitAccess() const {
  return getBaseExpr() && getBaseExpr()->isImplicitCXXThis();
}

SourceLocation getBeginLoc() const {
  if (!isImplicitAccess())
    return BaseExpr->getBeginLoc();
  else if (QualifierLoc)
    return QualifierLoc.getBeginLoc();
  else
      return MemberLoc;
}

SourceLocation getEndLoc() const { return getMemberLoc(); }

child_range children() {
  return child_range((Stmt**)&BaseExpr, (Stmt**)&BaseExpr + 1);
}

const_child_range children() const {
  auto Children = const_cast<MSPropertyRefExpr *>(this)->children();
  return const_child_range(Children.begin(), Children.end());
}

static bool classof(const Stmt *T) {
  return T->getStmtClass() == MSPropertyRefExprClass;
}

Expr *getBaseExpr() const { return BaseExpr; }
MSPropertyDecl *getPropertyDecl() const { return TheDecl; }
bool isArrow() const { return IsArrow; }
SourceLocation getMemberLoc() const { return MemberLoc; }
NestedNameSpecifierLoc getQualifierLoc() const { return QualifierLoc; }
987};

989/// MS property subscript expression.
990/// MSVC supports 'property' attribute and allows to apply it to the
991/// declaration of an empty array in a class or structure definition.
992/// For example:
993/// \code
994/// __declspec(property(get=GetX, put=PutX)) int x[];
995/// \endcode
996/// The above statement indicates that x[] can be used with one or more array
997/// indices. In this case, i=p->x[a][b] will be turned into i=p->GetX(a, b), and
998/// p->x[a][b] = i will be turned into p->PutX(a, b, i).
999/// This is a syntactic pseudo-object expression.
1000class MSPropertySubscriptExpr : public Expr {
friend class ASTStmtReader;

enum { BASE_EXPR, IDX_EXPR, NUM_SUBEXPRS = 2 };

Stmt *SubExprs[NUM_SUBEXPRS];
SourceLocation RBracketLoc;

void setBase(Expr *Base) { SubExprs[BASE_EXPR] = Base; }
void setIdx(Expr *Idx) { SubExprs[IDX_EXPR] = Idx; }

1011public:
MSPropertySubscriptExpr(Expr *Base, Expr *Idx, QualType Ty, ExprValueKind VK,
                        ExprObjectKind OK, SourceLocation RBracketLoc)
    : Expr(MSPropertySubscriptExprClass, Ty, VK, OK),
      RBracketLoc(RBracketLoc) {
  SubExprs[BASE_EXPR] = Base;
  SubExprs[IDX_EXPR] = Idx;
  setDependence(computeDependence(this));
}

/// Create an empty array subscript expression.
explicit MSPropertySubscriptExpr(EmptyShell Shell)
    : Expr(MSPropertySubscriptExprClass, Shell) {}

Expr *getBase() { return cast<Expr>(SubExprs[BASE_EXPR]); }
const Expr *getBase() const { return cast<Expr>(SubExprs[BASE_EXPR]); }

Expr *getIdx() { return cast<Expr>(SubExprs[IDX_EXPR]); }
const Expr *getIdx() const { return cast<Expr>(SubExprs[IDX_EXPR]); }

SourceLocation getBeginLoc() const LLVM_READONLY__attribute__((__pure__)) {
  return getBase()->getBeginLoc();
}

SourceLocation getEndLoc() const LLVM_READONLY__attribute__((__pure__)) { return RBracketLoc; }

SourceLocation getRBracketLoc() const { return RBracketLoc; }
void setRBracketLoc(SourceLocation L) { RBracketLoc = L; }

SourceLocation getExprLoc() const LLVM_READONLY__attribute__((__pure__)) {
  return getBase()->getExprLoc();
}

static bool classof(const Stmt *T) {
  return T->getStmtClass() == MSPropertySubscriptExprClass;
}

// Iterators
child_range children() {
  return child_range(&SubExprs[0], &SubExprs[0] + NUM_SUBEXPRS);
}

const_child_range children() const {
  return const_child_range(&SubExprs[0], &SubExprs[0] + NUM_SUBEXPRS);
}
1056};

1058/// A Microsoft C++ @c __uuidof expression, which gets
1059/// the _GUID that corresponds to the supplied type or expression.
1060///
1061/// This represents code like @c __uuidof(COMTYPE) or @c __uuidof(*comPtr)
1062class CXXUuidofExpr : public Expr {
friend class ASTStmtReader;

1065private:
llvm::PointerUnion<Stmt *, TypeSourceInfo *> Operand;
MSGuidDecl *Guid;
SourceRange Range;

1070public:
CXXUuidofExpr(QualType Ty, TypeSourceInfo *Operand, MSGuidDecl *Guid,
              SourceRange R)
    : Expr(CXXUuidofExprClass, Ty, VK_LValue, OK_Ordinary), Operand(Operand),
      Guid(Guid), Range(R) {
  setDependence(computeDependence(this));
}

CXXUuidofExpr(QualType Ty, Expr *Operand, MSGuidDecl *Guid, SourceRange R)
    : Expr(CXXUuidofExprClass, Ty, VK_LValue, OK_Ordinary), Operand(Operand),
      Guid(Guid), Range(R) {
  setDependence(computeDependence(this));
}

CXXUuidofExpr(EmptyShell Empty, bool isExpr)
  : Expr(CXXUuidofExprClass, Empty) {
  if (isExpr)
    Operand = (Expr*)nullptr;
  else
    Operand = (TypeSourceInfo*)nullptr;
}

bool isTypeOperand() const { return Operand.is<TypeSourceInfo *>(); }

/// Retrieves the type operand of this __uuidof() expression after
/// various required adjustments (removing reference types, cv-qualifiers).
QualType getTypeOperand(ASTContext &Context) const;

/// Retrieve source information for the type operand.
TypeSourceInfo *getTypeOperandSourceInfo() const {
  assert(isTypeOperand() && "Cannot call getTypeOperand for __uuidof(expr)")(static_cast <bool> (isTypeOperand() && "Cannot call getTypeOperand for __uuidof(expr)"
) ? void (0) : __assert_fail ("isTypeOperand() && \"Cannot call getTypeOperand for __uuidof(expr)\""
, "clang/include/clang/AST/ExprCXX.h", 1100, __extension__ __PRETTY_FUNCTION__
));
  return Operand.get<TypeSourceInfo *>();
}
Expr *getExprOperand() const {
  assert(!isTypeOperand() && "Cannot call getExprOperand for __uuidof(type)")(static_cast <bool> (!isTypeOperand() && "Cannot call getExprOperand for __uuidof(type)"
) ? void (0) : __assert_fail ("!isTypeOperand() && \"Cannot call getExprOperand for __uuidof(type)\""
, "clang/include/clang/AST/ExprCXX.h", 1104, __extension__ __PRETTY_FUNCTION__
));
  return static_cast<Expr*>(Operand.get<Stmt *>());
}

MSGuidDecl *getGuidDecl() const { return Guid; }

SourceLocation getBeginLoc() const LLVM_READONLY__attribute__((__pure__)) { return Range.getBegin(); }
SourceLocation getEndLoc() const LLVM_READONLY__attribute__((__pure__)) { return Range.getEnd(); }
SourceRange getSourceRange() const LLVM_READONLY__attribute__((__pure__)) { return Range; }
void setSourceRange(SourceRange R) { Range = R; }

static bool classof(const Stmt *T) {
  return T->getStmtClass() == CXXUuidofExprClass;
}

// Iterators
child_range children() {
  if (isTypeOperand())
    return child_range(child_iterator(), child_iterator());
  auto **begin = reinterpret_cast<Stmt **>(&Operand);
  return child_range(begin, begin + 1);
}

const_child_range children() const {
  if (isTypeOperand())
    return const_child_range(const_child_iterator(), const_child_iterator());
  auto **begin =
      reinterpret_cast<Stmt **>(&const_cast<CXXUuidofExpr *>(this)->Operand);
  return const_child_range(begin, begin + 1);
}
1134};

1136/// Represents the \c this expression in C++.
1137///
1138/// This is a pointer to the object on which the current member function is
1139/// executing (C++ [expr.prim]p3). Example:
1140///
1141/// \code
1142/// class Foo {
1143/// public:
1144///   void bar();
1145///   void test() { this->bar(); }
1146/// };
1147/// \endcode
1148class CXXThisExpr : public Expr {
1149public:
CXXThisExpr(SourceLocation L, QualType Ty, bool IsImplicit)
    : Expr(CXXThisExprClass, Ty, VK_PRValue, OK_Ordinary) {
  CXXThisExprBits.IsImplicit = IsImplicit;
  CXXThisExprBits.Loc = L;
  setDependence(computeDependence(this));
}

CXXThisExpr(EmptyShell Empty) : Expr(CXXThisExprClass, Empty) {}

SourceLocation getLocation() const { return CXXThisExprBits.Loc; }
void setLocation(SourceLocation L) { CXXThisExprBits.Loc = L; }

SourceLocation getBeginLoc() const { return getLocation(); }
SourceLocation getEndLoc() const { return getLocation(); }

bool isImplicit() const { return CXXThisExprBits.IsImplicit; }
void setImplicit(bool I) { CXXThisExprBits.IsImplicit = I; }

static bool classof(const Stmt *T) {
  return T->getStmtClass() == CXXThisExprClass;
}

// Iterators
child_range children() {
  return child_range(child_iterator(), child_iterator());
}

const_child_range children() const {
  return const_child_range(const_child_iterator(), const_child_iterator());
}
1180};

1182/// A C++ throw-expression (C++ [except.throw]).
1183///
1184/// This handles 'throw' (for re-throwing the current exception) and
1185/// 'throw' assignment-expression.  When assignment-expression isn't
1186/// present, Op will be null.
1187class CXXThrowExpr : public Expr {
friend class ASTStmtReader;

/// The optional expression in the throw statement.
Stmt *Operand;

1193public:
// \p Ty is the void type which is used as the result type of the
// expression. The \p Loc is the location of the throw keyword.
// \p Operand is the expression in the throw statement, and can be
// null if not present.
CXXThrowExpr(Expr *Operand, QualType Ty, SourceLocation Loc,
             bool IsThrownVariableInScope)
    : Expr(CXXThrowExprClass, Ty, VK_PRValue, OK_Ordinary), Operand(Operand) {
  CXXThrowExprBits.ThrowLoc = Loc;
  CXXThrowExprBits.IsThrownVariableInScope = IsThrownVariableInScope;
  setDependence(computeDependence(this));
}
CXXThrowExpr(EmptyShell Empty) : Expr(CXXThrowExprClass, Empty) {}

const Expr *getSubExpr() const { return cast_or_null<Expr>(Operand); }
Expr *getSubExpr() { return cast_or_null<Expr>(Operand); }

SourceLocation getThrowLoc() const { return CXXThrowExprBits.ThrowLoc; }

/// Determines whether the variable thrown by this expression (if any!)
/// is within the innermost try block.
///
/// This information is required to determine whether the NRVO can apply to
/// this variable.
bool isThrownVariableInScope() const {
  return CXXThrowExprBits.IsThrownVariableInScope;
}

SourceLocation getBeginLoc() const { return getThrowLoc(); }
SourceLocation getEndLoc() const LLVM_READONLY__attribute__((__pure__)) {
  if (!getSubExpr())
    return getThrowLoc();
  return getSubExpr()->getEndLoc();
}

static bool classof(const Stmt *T) {
  return T->getStmtClass() == CXXThrowExprClass;
}

// Iterators
child_range children() {
  return child_range(&Operand, Operand ? &Operand + 1 : &Operand);
}

const_child_range children() const {
  return const_child_range(&Operand, Operand ? &Operand + 1 : &Operand);
}
1240};

1242/// A default argument (C++ [dcl.fct.default]).
1243///
1244/// This wraps up a function call argument that was created from the
1245/// corresponding parameter's default argument, when the call did not
1246/// explicitly supply arguments for all of the parameters.
1247class CXXDefaultArgExpr final
  : public Expr,
    private llvm::TrailingObjects<CXXDefaultArgExpr, Expr *> {
friend class ASTStmtReader;
friend class ASTReader;
friend TrailingObjects;

/// The parameter whose default is being used.
ParmVarDecl *Param;

/// The context where the default argument expression was used.
DeclContext *UsedContext;

CXXDefaultArgExpr(StmtClass SC, SourceLocation Loc, ParmVarDecl *Param,
                  Expr *RewrittenExpr, DeclContext *UsedContext)
    : Expr(SC,
           Param->hasUnparsedDefaultArg()
               ? Param->getType().getNonReferenceType()
               : Param->getDefaultArg()->getType(),
           Param->getDefaultArg()->getValueKind(),
           Param->getDefaultArg()->getObjectKind()),
      Param(Param), UsedContext(UsedContext) {
  CXXDefaultArgExprBits.Loc = Loc;
  CXXDefaultArgExprBits.HasRewrittenInit = RewrittenExpr != nullptr;
  if (RewrittenExpr)
    *getTrailingObjects<Expr *>() = RewrittenExpr;
  setDependence(computeDependence(this));
}

CXXDefaultArgExpr(EmptyShell Empty, bool HasRewrittenInit)
    : Expr(CXXDefaultArgExprClass, Empty) {
  CXXDefaultArgExprBits.HasRewrittenInit = HasRewrittenInit;
}

1281public:
static CXXDefaultArgExpr *CreateEmpty(const ASTContext &C,
                                      bool HasRewrittenInit);

// \p Param is the parameter whose default argument is used by this
// expression.
static CXXDefaultArgExpr *Create(const ASTContext &C, SourceLocation Loc,
                                 ParmVarDecl *Param, Expr *RewrittenExpr,
                                 DeclContext *UsedContext);
// Retrieve the parameter that the argument was created from.
const ParmVarDecl *getParam() const { return Param; }
ParmVarDecl *getParam() { return Param; }

bool hasRewrittenInit() const {
  return CXXDefaultArgExprBits.HasRewrittenInit;
}

// Retrieve the argument to the function call.
Expr *getExpr();
const Expr *getExpr() const {
  return const_cast<CXXDefaultArgExpr *>(this)->getExpr();
}

Expr *getRewrittenExpr() {
  return hasRewrittenInit() ? *getTrailingObjects<Expr *>() : nullptr;
}

const Expr *getRewrittenExpr() const {
  return const_cast<CXXDefaultArgExpr *>(this)->getRewrittenExpr();
}

// Retrieve the rewritten init expression (for an init expression containing
// immediate calls) with the top level FullExpr and ConstantExpr stripped off.
Expr *getAdjustedRewrittenExpr();
const Expr *getAdjustedRewrittenExpr() const {
  return const_cast<CXXDefaultArgExpr *>(this)->getAdjustedRewrittenExpr();
}

const DeclContext *getUsedContext() const { return UsedContext; }
DeclContext *getUsedContext() { return UsedContext; }

/// Retrieve the location where this default argument was actually used.
SourceLocation getUsedLocation() const { return CXXDefaultArgExprBits.Loc; }

/// Default argument expressions have no representation in the
/// source, so they have an empty source range.
SourceLocation getBeginLoc() const { return SourceLocation(); }
SourceLocation getEndLoc() const { return SourceLocation(); }

SourceLocation getExprLoc() const { return getUsedLocation(); }

static bool classof(const Stmt *T) {
  return T->getStmtClass() == CXXDefaultArgExprClass;
}

// Iterators
child_range children() {
  return child_range(child_iterator(), child_iterator());
}

const_child_range children() const {
  return const_child_range(const_child_iterator(), const_child_iterator());
}
1344};

1346/// A use of a default initializer in a constructor or in aggregate
1347/// initialization.
1348///
1349/// This wraps a use of a C++ default initializer (technically,
1350/// a brace-or-equal-initializer for a non-static data member) when it
1351/// is implicitly used in a mem-initializer-list in a constructor
1352/// (C++11 [class.base.init]p8) or in aggregate initialization
1353/// (C++1y [dcl.init.aggr]p7).
1354class CXXDefaultInitExpr final
  : public Expr,
    private llvm::TrailingObjects<CXXDefaultInitExpr, Expr *> {

friend class ASTStmtReader;
friend class ASTReader;
friend TrailingObjects;
/// The field whose default is being used.
FieldDecl *Field;

/// The context where the default initializer expression was used.
DeclContext *UsedContext;

CXXDefaultInitExpr(const ASTContext &Ctx, SourceLocation Loc,
                   FieldDecl *Field, QualType Ty, DeclContext *UsedContext,
                   Expr *RewrittenInitExpr);

CXXDefaultInitExpr(EmptyShell Empty, bool HasRewrittenInit)
    : Expr(CXXDefaultInitExprClass, Empty) {
  CXXDefaultInitExprBits.HasRewrittenInit = HasRewrittenInit;
}

1376public:
static CXXDefaultInitExpr *CreateEmpty(const ASTContext &C,
                                       bool HasRewrittenInit);
/// \p Field is the non-static data member whose default initializer is used
/// by this expression.
static CXXDefaultInitExpr *Create(const ASTContext &Ctx, SourceLocation Loc,
                                  FieldDecl *Field, DeclContext *UsedContext,
                                  Expr *RewrittenInitExpr);

bool hasRewrittenInit() const {
  return CXXDefaultInitExprBits.HasRewrittenInit;
}

/// Get the field whose initializer will be used.
FieldDecl *getField() { return Field; }
const FieldDecl *getField() const { return Field; }

/// Get the initialization expression that will be used.
Expr *getExpr();
const Expr *getExpr() const {
  return const_cast<CXXDefaultInitExpr *>(this)->getExpr();
}

/// Retrieve the initializing expression with evaluated immediate calls, if
/// any.
const Expr *getRewrittenExpr() const {
  assert(hasRewrittenInit() && "expected a rewritten init expression")(static_cast <bool> (hasRewrittenInit() && "expected a rewritten init expression"
) ? void (0) : __assert_fail ("hasRewrittenInit() && \"expected a rewritten init expression\""
, "clang/include/clang/AST/ExprCXX.h", 1402, __extension__ __PRETTY_FUNCTION__
));
  return *getTrailingObjects<Expr *>();
}

/// Retrieve the initializing expression with evaluated immediate calls, if
/// any.
Expr *getRewrittenExpr() {
  assert(hasRewrittenInit() && "expected a rewritten init expression")(static_cast <bool> (hasRewrittenInit() && "expected a rewritten init expression"
) ? void (0) : __assert_fail ("hasRewrittenInit() && \"expected a rewritten init expression\""
, "clang/include/clang/AST/ExprCXX.h", 1409, __extension__ __PRETTY_FUNCTION__
));
  return *getTrailingObjects<Expr *>();
}

const DeclContext *getUsedContext() const { return UsedContext; }
DeclContext *getUsedContext() { return UsedContext; }

/// Retrieve the location where this default initializer expression was
/// actually used.
SourceLocation getUsedLocation() const { return getBeginLoc(); }

SourceLocation getBeginLoc() const { return CXXDefaultInitExprBits.Loc; }
SourceLocation getEndLoc() const { return CXXDefaultInitExprBits.Loc; }

static bool classof(const Stmt *T) {
  return T->getStmtClass() == CXXDefaultInitExprClass;
}

// Iterators
child_range children() {
  return child_range(child_iterator(), child_iterator());
}

const_child_range children() const {
  return const_child_range(const_child_iterator(), const_child_iterator());
}
1435};

1437/// Represents a C++ temporary.
1438class CXXTemporary {
/// The destructor that needs to be called.
const CXXDestructorDecl *Destructor;

explicit CXXTemporary(const CXXDestructorDecl *destructor)
    : Destructor(destructor) {}

1445public:
static CXXTemporary *Create(const ASTContext &C,
                            const CXXDestructorDecl *Destructor);

const CXXDestructorDecl *getDestructor() const { return Destructor; }

void setDestructor(const CXXDestructorDecl *Dtor) {
  Destructor = Dtor;
}
1454};

1456/// Represents binding an expression to a temporary.
1457///
1458/// This ensures the destructor is called for the temporary. It should only be
1459/// needed for non-POD, non-trivially destructable class types. For example:
1460///
1461/// \code
1462///   struct S {
1463///     S() { }  // User defined constructor makes S non-POD.
1464///     ~S() { } // User defined destructor makes it non-trivial.
1465///   };
1466///   void test() {
1467///     const S &s_ref = S(); // Requires a CXXBindTemporaryExpr.
1468///   }
1469/// \endcode
1470class CXXBindTemporaryExpr : public Expr {
CXXTemporary *Temp = nullptr;
Stmt *SubExpr = nullptr;

CXXBindTemporaryExpr(CXXTemporary *temp, Expr *SubExpr)
    : Expr(CXXBindTemporaryExprClass, SubExpr->getType(), VK_PRValue,
           OK_Ordinary),
      Temp(temp), SubExpr(SubExpr) {
  setDependence(computeDependence(this));
}

1481public:
CXXBindTemporaryExpr(EmptyShell Empty)
    : Expr(CXXBindTemporaryExprClass, Empty) {}

static CXXBindTemporaryExpr *Create(const ASTContext &C, CXXTemporary *Temp,
                                    Expr* SubExpr);

CXXTemporary *getTemporary() { return Temp; }
const CXXTemporary *getTemporary() const { return Temp; }
void setTemporary(CXXTemporary *T) { Temp = T; }

const Expr *getSubExpr() const { return cast<Expr>(SubExpr); }
Expr *getSubExpr() { return cast<Expr>(SubExpr); }
void setSubExpr(Expr *E) { SubExpr = E; }

SourceLocation getBeginLoc() const LLVM_READONLY__attribute__((__pure__)) {
  return SubExpr->getBeginLoc();
}

SourceLocation getEndLoc() const LLVM_READONLY__attribute__((__pure__)) {
  return SubExpr->getEndLoc();
}

// Implement isa/cast/dyncast/etc.
static bool classof(const Stmt *T) {
  return T->getStmtClass() == CXXBindTemporaryExprClass;
}

// Iterators
child_range children() { return child_range(&SubExpr, &SubExpr + 1); }

const_child_range children() const {
  return const_child_range(&SubExpr, &SubExpr + 1);
}
1515};

1517/// Represents a call to a C++ constructor.
1518class CXXConstructExpr : public Expr {
friend class ASTStmtReader;

1521public:
enum ConstructionKind {
  CK_Complete,
  CK_NonVirtualBase,
  CK_VirtualBase,
  CK_Delegating
};

1529private:
/// A pointer to the constructor which will be ultimately called.
CXXConstructorDecl *Constructor;

SourceRange ParenOrBraceRange;

/// The number of arguments.
unsigned NumArgs;

// We would like to stash the arguments of the constructor call after
// CXXConstructExpr. However CXXConstructExpr is used as a base class of
// CXXTemporaryObjectExpr which makes the use of llvm::TrailingObjects
// impossible.
//
// Instead we manually stash the trailing object after the full object
// containing CXXConstructExpr (that is either CXXConstructExpr or
// CXXTemporaryObjectExpr).
//
// The trailing objects are:
//
// * An array of getNumArgs() "Stmt *" for the arguments of the
//   constructor call.

/// Return a pointer to the start of the trailing arguments.
/// Defined just after CXXTemporaryObjectExpr.
inline Stmt **getTrailingArgs();
const Stmt *const *getTrailingArgs() const {
  return const_cast<CXXConstructExpr *>(this)->getTrailingArgs();
}

1559protected:
/// Build a C++ construction expression.
CXXConstructExpr(StmtClass SC, QualType Ty, SourceLocation Loc,
                 CXXConstructorDecl *Ctor, bool Elidable,
                 ArrayRef<Expr *> Args, bool HadMultipleCandidates,
                 bool ListInitialization, bool StdInitListInitialization,
                 bool ZeroInitialization, ConstructionKind ConstructKind,
                 SourceRange ParenOrBraceRange);

/// Build an empty C++ construction expression.
CXXConstructExpr(StmtClass SC, EmptyShell Empty, unsigned NumArgs);

/// Return the size in bytes of the trailing objects. Used by
/// CXXTemporaryObjectExpr to allocate the right amount of storage.
static unsigned sizeOfTrailingObjects(unsigned NumArgs) {
  return NumArgs * sizeof(Stmt *);
}

1577public:
/// Create a C++ construction expression.
static CXXConstructExpr *
Create(const ASTContext &Ctx, QualType Ty, SourceLocation Loc,
       CXXConstructorDecl *Ctor, bool Elidable, ArrayRef<Expr *> Args,
       bool HadMultipleCandidates, bool ListInitialization,
       bool StdInitListInitialization, bool ZeroInitialization,
       ConstructionKind ConstructKind, SourceRange ParenOrBraceRange);

/// Create an empty C++ construction expression.
static CXXConstructExpr *CreateEmpty(const ASTContext &Ctx, unsigned NumArgs);

/// Get the constructor that this expression will (ultimately) call.
CXXConstructorDecl *getConstructor() const { return Constructor; }

SourceLocation getLocation() const { return CXXConstructExprBits.Loc; }
void setLocation(SourceLocation Loc) { CXXConstructExprBits.Loc = Loc; }

/// Whether this construction is elidable.
bool isElidable() const { return CXXConstructExprBits.Elidable; }
void setElidable(bool E) { CXXConstructExprBits.Elidable = E; }

/// Whether the referred constructor was resolved from
/// an overloaded set having size greater than 1.
bool hadMultipleCandidates() const {
  return CXXConstructExprBits.HadMultipleCandidates;
}
void setHadMultipleCandidates(bool V) {
  CXXConstructExprBits.HadMultipleCandidates = V;
}

/// Whether this constructor call was written as list-initialization.
bool isListInitialization() const {
  return CXXConstructExprBits.ListInitialization;
}
void setListInitialization(bool V) {
  CXXConstructExprBits.ListInitialization = V;
}

/// Whether this constructor call was written as list-initialization,
/// but was interpreted as forming a std::initializer_list<T> from the list
/// and passing that as a single constructor argument.
/// See C++11 [over.match.list]p1 bullet 1.
bool isStdInitListInitialization() const {
  return CXXConstructExprBits.StdInitListInitialization;
}
void setStdInitListInitialization(bool V) {
  CXXConstructExprBits.StdInitListInitialization = V;
}

/// Whether this construction first requires
/// zero-initialization before the initializer is called.
bool requiresZeroInitialization() const {
  return CXXConstructExprBits.ZeroInitialization;
}
void setRequiresZeroInitialization(bool ZeroInit) {
  CXXConstructExprBits.ZeroInitialization = ZeroInit;
}

/// Determine whether this constructor is actually constructing
/// a base class (rather than a complete object).
ConstructionKind getConstructionKind() const {
  return static_cast<ConstructionKind>(CXXConstructExprBits.ConstructionKind);
}
void setConstructionKind(ConstructionKind CK) {
  CXXConstructExprBits.ConstructionKind = CK;
}

using arg_iterator = ExprIterator;
using const_arg_iterator = ConstExprIterator;
using arg_range = llvm::iterator_range<arg_iterator>;
using const_arg_range = llvm::iterator_range<const_arg_iterator>;

arg_range arguments() { return arg_range(arg_begin(), arg_end()); }
const_arg_range arguments() const {
  return const_arg_range(arg_begin(), arg_end());
}

arg_iterator arg_begin() { return getTrailingArgs(); }
arg_iterator arg_end() { return arg_begin() + getNumArgs(); }
const_arg_iterator arg_begin() const { return getTrailingArgs(); }
const_arg_iterator arg_end() const { return arg_begin() + getNumArgs(); }

Expr **getArgs() { return reinterpret_cast<Expr **>(getTrailingArgs()); }
const Expr *const *getArgs() const {
  return reinterpret_cast<const Expr *const *>(getTrailingArgs());
}

/// Return the number of arguments to the constructor call.
unsigned getNumArgs() const { return NumArgs; }

/// Return the specified argument.
Expr *getArg(unsigned Arg) {
  assert(Arg < getNumArgs() && "Arg access out of range!")(static_cast <bool> (Arg < getNumArgs() && "Arg access out of range!"
) ? void (0) : __assert_fail ("Arg < getNumArgs() && \"Arg access out of range!\""
, "clang/include/clang/AST/ExprCXX.h", 1670, __extension__ __PRETTY_FUNCTION__
));
  return getArgs()[Arg];
}
const Expr *getArg(unsigned Arg) const {
  assert(Arg < getNumArgs() && "Arg access out of range!")(static_cast <bool> (Arg < getNumArgs() && "Arg access out of range!"
) ? void (0) : __assert_fail ("Arg < getNumArgs() && \"Arg access out of range!\""
, "clang/include/clang/AST/ExprCXX.h", 1674, __extension__ __PRETTY_FUNCTION__
));
  return getArgs()[Arg];
}

/// Set the specified argument.
void setArg(unsigned Arg, Expr *ArgExpr) {
  assert(Arg < getNumArgs() && "Arg access out of range!")(static_cast <bool> (Arg < getNumArgs() && "Arg access out of range!"
) ? void (0) : __assert_fail ("Arg < getNumArgs() && \"Arg access out of range!\""
, "clang/include/clang/AST/ExprCXX.h", 1680, __extension__ __PRETTY_FUNCTION__
));
  getArgs()[Arg] = ArgExpr;
}

SourceLocation getBeginLoc() const LLVM_READONLY__attribute__((__pure__));
SourceLocation getEndLoc() const LLVM_READONLY__attribute__((__pure__));
SourceRange getParenOrBraceRange() const { return ParenOrBraceRange; }
void setParenOrBraceRange(SourceRange Range) { ParenOrBraceRange = Range; }

static bool classof(const Stmt *T) {
  return T->getStmtClass() == CXXConstructExprClass ||
         T->getStmtClass() == CXXTemporaryObjectExprClass;
}

// Iterators
child_range children() {
  return child_range(getTrailingArgs(), getTrailingArgs() + getNumArgs());
}

const_child_range children() const {
  auto Children = const_cast<CXXConstructExpr *>(this)->children();
  return const_child_range(Children.begin(), Children.end());
}
1703};

1705/// Represents a call to an inherited base class constructor from an
1706/// inheriting constructor. This call implicitly forwards the arguments from
1707/// the enclosing context (an inheriting constructor) to the specified inherited
1708/// base class constructor.
1709class CXXInheritedCtorInitExpr : public Expr {
1710private:
CXXConstructorDecl *Constructor = nullptr;

/// The location of the using declaration.
SourceLocation Loc;

/// Whether this is the construction of a virtual base.
unsigned ConstructsVirtualBase : 1;

/// Whether the constructor is inherited from a virtual base class of the
/// class that we construct.
unsigned InheritedFromVirtualBase : 1;

1723public:
friend class ASTStmtReader;

/// Construct a C++ inheriting construction expression.
CXXInheritedCtorInitExpr(SourceLocation Loc, QualType T,
                         CXXConstructorDecl *Ctor, bool ConstructsVirtualBase,
                         bool InheritedFromVirtualBase)
    : Expr(CXXInheritedCtorInitExprClass, T, VK_PRValue, OK_Ordinary),
      Constructor(Ctor), Loc(Loc),
      ConstructsVirtualBase(ConstructsVirtualBase),
      InheritedFromVirtualBase(InheritedFromVirtualBase) {
  assert(!T->isDependentType())(static_cast <bool> (!T->isDependentType()) ? void (
0) : __assert_fail ("!T->isDependentType()", "clang/include/clang/AST/ExprCXX.h"
, 1734, __extension__ __PRETTY_FUNCTION__));
  setDependence(ExprDependence::None);
}

/// Construct an empty C++ inheriting construction expression.
explicit CXXInheritedCtorInitExpr(EmptyShell Empty)
    : Expr(CXXInheritedCtorInitExprClass, Empty),
      ConstructsVirtualBase(false), InheritedFromVirtualBase(false) {}

/// Get the constructor that this expression will call.
CXXConstructorDecl *getConstructor() const { return Constructor; }

/// Determine whether this constructor is actually constructing
/// a base class (rather than a complete object).
bool constructsVBase() const { return ConstructsVirtualBase; }
CXXConstructExpr::ConstructionKind getConstructionKind() const {
  return ConstructsVirtualBase ? CXXConstructExpr::CK_VirtualBase
                               : CXXConstructExpr::CK_NonVirtualBase;
}

/// Determine whether the inherited constructor is inherited from a
/// virtual base of the object we construct. If so, we are not responsible
/// for calling the inherited constructor (the complete object constructor
/// does that), and so we don't need to pass any arguments.
bool inheritedFromVBase() const { return InheritedFromVirtualBase; }

SourceLocation getLocation() const LLVM_READONLY__attribute__((__pure__)) { return Loc; }
SourceLocation getBeginLoc() const LLVM_READONLY__attribute__((__pure__)) { return Loc; }
SourceLocation getEndLoc() const LLVM_READONLY__attribute__((__pure__)) { return Loc; }

static bool classof(const Stmt *T) {
  return T->getStmtClass() == CXXInheritedCtorInitExprClass;
}

child_range children() {
  return child_range(child_iterator(), child_iterator());
}

const_child_range children() const {
  return const_child_range(const_child_iterator(), const_child_iterator());
}
1775};

1777/// Represents an explicit C++ type conversion that uses "functional"
1778/// notation (C++ [expr.type.conv]).
1779///
1780/// Example:
1781/// \code
1782///   x = int(0.5);
1783/// \endcode
1784class CXXFunctionalCastExpr final
  : public ExplicitCastExpr,
    private llvm::TrailingObjects<CXXFunctionalCastExpr, CXXBaseSpecifier *,
                                  FPOptionsOverride> {
SourceLocation LParenLoc;
SourceLocation RParenLoc;

CXXFunctionalCastExpr(QualType ty, ExprValueKind VK,
                      TypeSourceInfo *writtenTy, CastKind kind,
                      Expr *castExpr, unsigned pathSize,
                      FPOptionsOverride FPO, SourceLocation lParenLoc,
                      SourceLocation rParenLoc)
    : ExplicitCastExpr(CXXFunctionalCastExprClass, ty, VK, kind, castExpr,
                       pathSize, FPO.requiresTrailingStorage(), writtenTy),
      LParenLoc(lParenLoc), RParenLoc(rParenLoc) {
  if (hasStoredFPFeatures())
    *getTrailingFPFeatures() = FPO;
}

explicit CXXFunctionalCastExpr(EmptyShell Shell, unsigned PathSize,
                               bool HasFPFeatures)
    : ExplicitCastExpr(CXXFunctionalCastExprClass, Shell, PathSize,
                       HasFPFeatures) {}

unsigned numTrailingObjects(OverloadToken<CXXBaseSpecifier *>) const {
  return path_size();
}

1812public:
friend class CastExpr;
friend TrailingObjects;

static CXXFunctionalCastExpr *
Create(const ASTContext &Context, QualType T, ExprValueKind VK,
       TypeSourceInfo *Written, CastKind Kind, Expr *Op,
       const CXXCastPath *Path, FPOptionsOverride FPO, SourceLocation LPLoc,
       SourceLocation RPLoc);
static CXXFunctionalCastExpr *
CreateEmpty(const ASTContext &Context, unsigned PathSize, bool HasFPFeatures);

SourceLocation getLParenLoc() const { return LParenLoc; }
void setLParenLoc(SourceLocation L) { LParenLoc = L; }
SourceLocation getRParenLoc() const { return RParenLoc; }
void setRParenLoc(SourceLocation L) { RParenLoc = L; }

/// Determine whether this expression models list-initialization.
bool isListInitialization() const { return LParenLoc.isInvalid(); }

SourceLocation getBeginLoc() const LLVM_READONLY__attribute__((__pure__));
SourceLocation getEndLoc() const LLVM_READONLY__attribute__((__pure__));

static bool classof(const Stmt *T) {
  return T->getStmtClass() == CXXFunctionalCastExprClass;
}
1838};

1840/// Represents a C++ functional cast expression that builds a
1841/// temporary object.
1842///
1843/// This expression type represents a C++ "functional" cast
1844/// (C++[expr.type.conv]) with N != 1 arguments that invokes a
1845/// constructor to build a temporary object. With N == 1 arguments the
1846/// functional cast expression will be represented by CXXFunctionalCastExpr.
1847/// Example:
1848/// \code
1849/// struct X { X(int, float); }
1850///
1851/// X create_X() {
1852///   return X(1, 3.14f); // creates a CXXTemporaryObjectExpr
1853/// };
1854/// \endcode
1855class CXXTemporaryObjectExpr final : public CXXConstructExpr {
friend class ASTStmtReader;

// CXXTemporaryObjectExpr has some trailing objects belonging
// to CXXConstructExpr. See the comment inside CXXConstructExpr
// for more details.

TypeSourceInfo *TSI;

CXXTemporaryObjectExpr(CXXConstructorDecl *Cons, QualType Ty,
                       TypeSourceInfo *TSI, ArrayRef<Expr *> Args,
                       SourceRange ParenOrBraceRange,
                       bool HadMultipleCandidates, bool ListInitialization,
                       bool StdInitListInitialization,
                       bool ZeroInitialization);

CXXTemporaryObjectExpr(EmptyShell Empty, unsigned NumArgs);

1873public:
static CXXTemporaryObjectExpr *
Create(const ASTContext &Ctx, CXXConstructorDecl *Cons, QualType Ty,
       TypeSourceInfo *TSI, ArrayRef<Expr *> Args,
       SourceRange ParenOrBraceRange, bool HadMultipleCandidates,
       bool ListInitialization, bool StdInitListInitialization,
       bool ZeroInitialization);

static CXXTemporaryObjectExpr *CreateEmpty(const ASTContext &Ctx,
                                           unsigned NumArgs);

TypeSourceInfo *getTypeSourceInfo() const { return TSI; }

SourceLocation getBeginLoc() const LLVM_READONLY__attribute__((__pure__));
SourceLocation getEndLoc() const LLVM_READONLY__attribute__((__pure__));

static bool classof(const Stmt *T) {
  return T->getStmtClass() == CXXTemporaryObjectExprClass;
}
1892};

1894Stmt **CXXConstructExpr::getTrailingArgs() {
if (auto *E = dyn_cast<CXXTemporaryObjectExpr>(this))
  return reinterpret_cast<Stmt **>(E + 1);
assert((getStmtClass() == CXXConstructExprClass) &&(static_cast <bool> ((getStmtClass() == CXXConstructExprClass
) && "Unexpected class deriving from CXXConstructExpr!"
) ? void (0) : __assert_fail ("(getStmtClass() == CXXConstructExprClass) && \"Unexpected class deriving from CXXConstructExpr!\""
, "clang/include/clang/AST/ExprCXX.h", 1898, __extension__ __PRETTY_FUNCTION__
))
       "Unexpected class deriving from CXXConstructExpr!")(static_cast <bool> ((getStmtClass() == CXXConstructExprClass
) && "Unexpected class deriving from CXXConstructExpr!"
) ? void (0) : __assert_fail ("(getStmtClass() == CXXConstructExprClass) && \"Unexpected class deriving from CXXConstructExpr!\""
, "clang/include/clang/AST/ExprCXX.h", 1898, __extension__ __PRETTY_FUNCTION__
));
return reinterpret_cast<Stmt **>(this + 1);
1900}

1902/// A C++ lambda expression, which produces a function object
1903/// (of unspecified type) that can be invoked later.
1904///
1905/// Example:
1906/// \code
1907/// void low_pass_filter(std::vector<double> &values, double cutoff) {
1908///   values.erase(std::remove_if(values.begin(), values.end(),
1909///                               [=](double value) { return value > cutoff; });
1910/// }
1911/// \endcode
1912///
1913/// C++11 lambda expressions can capture local variables, either by copying
1914/// the values of those local variables at the time the function
1915/// object is constructed (not when it is called!) or by holding a
1916/// reference to the local variable. These captures can occur either
1917/// implicitly or can be written explicitly between the square
1918/// brackets ([...]) that start the lambda expression.
1919///
1920/// C++1y introduces a new form of "capture" called an init-capture that
1921/// includes an initializing expression (rather than capturing a variable),
1922/// and which can never occur implicitly.
1923class LambdaExpr final : public Expr,
                       private llvm::TrailingObjects<LambdaExpr, Stmt *> {
// LambdaExpr has some data stored in LambdaExprBits.

/// The source range that covers the lambda introducer ([...]).
SourceRange IntroducerRange;

/// The source location of this lambda's capture-default ('=' or '&').
SourceLocation CaptureDefaultLoc;

/// The location of the closing brace ('}') that completes
/// the lambda.
///
/// The location of the brace is also available by looking up the
/// function call operator in the lambda class. However, it is
/// stored here to improve the performance of getSourceRange(), and
/// to avoid having to deserialize the function call operator from a
/// module file just to determine the source range.
SourceLocation ClosingBrace;

/// Construct a lambda expression.
LambdaExpr(QualType T, SourceRange IntroducerRange,
           LambdaCaptureDefault CaptureDefault,
           SourceLocation CaptureDefaultLoc, bool ExplicitParams,
           bool ExplicitResultType, ArrayRef<Expr *> CaptureInits,
           SourceLocation ClosingBrace, bool ContainsUnexpandedParameterPack);

/// Construct an empty lambda expression.
LambdaExpr(EmptyShell Empty, unsigned NumCaptures);

Stmt **getStoredStmts() { return getTrailingObjects<Stmt *>(); }
Stmt *const *getStoredStmts() const { return getTrailingObjects<Stmt *>(); }

void initBodyIfNeeded() const;

1958public:
friend class ASTStmtReader;
friend class ASTStmtWriter;
friend TrailingObjects;

/// Construct a new lambda expression.
static LambdaExpr *
Create(const ASTContext &C, CXXRecordDecl *Class, SourceRange IntroducerRange,
       LambdaCaptureDefault CaptureDefault, SourceLocation CaptureDefaultLoc,
       bool ExplicitParams, bool ExplicitResultType,
       ArrayRef<Expr *> CaptureInits, SourceLocation ClosingBrace,
       bool ContainsUnexpandedParameterPack);

/// Construct a new lambda expression that will be deserialized from
/// an external source.
static LambdaExpr *CreateDeserialized(const ASTContext &C,
                                      unsigned NumCaptures);

/// Determine the default capture kind for this lambda.
LambdaCaptureDefault getCaptureDefault() const {
  return static_cast<LambdaCaptureDefault>(LambdaExprBits.CaptureDefault);
}

/// Retrieve the location of this lambda's capture-default, if any.
SourceLocation getCaptureDefaultLoc() const { return CaptureDefaultLoc; }

/// Determine whether one of this lambda's captures is an init-capture.
bool isInitCapture(const LambdaCapture *Capture) const;

/// An iterator that walks over the captures of the lambda,
/// both implicit and explicit.
using capture_iterator = const LambdaCapture *;

/// An iterator over a range of lambda captures.
using capture_range = llvm::iterator_range<capture_iterator>;

/// Retrieve this lambda's captures.
capture_range captures() const;

/// Retrieve an iterator pointing to the first lambda capture.
capture_iterator capture_begin() const;

/// Retrieve an iterator pointing past the end of the
/// sequence of lambda captures.
capture_iterator capture_end() const;

/// Determine the number of captures in this lambda.
unsigned capture_size() const { return LambdaExprBits.NumCaptures; }

/// Retrieve this lambda's explicit captures.
capture_range explicit_captures() const;

/// Retrieve an iterator pointing to the first explicit
/// lambda capture.
capture_iterator explicit_capture_begin() const;

/// Retrieve an iterator pointing past the end of the sequence of
/// explicit lambda captures.
capture_iterator explicit_capture_end() const;

/// Retrieve this lambda's implicit captures.
capture_range implicit_captures() const;

/// Retrieve an iterator pointing to the first implicit
/// lambda capture.
capture_iterator implicit_capture_begin() const;

/// Retrieve an iterator pointing past the end of the sequence of
/// implicit lambda captures.
capture_iterator implicit_capture_end() const;

/// Iterator that walks over the capture initialization
/// arguments.
using capture_init_iterator = Expr **;

/// Const iterator that walks over the capture initialization
/// arguments.
/// FIXME: This interface is prone to being used incorrectly.
using const_capture_init_iterator = Expr *const *;

/// Retrieve the initialization expressions for this lambda's captures.
llvm::iterator_range<capture_init_iterator> capture_inits() {
  return llvm::make_range(capture_init_begin(), capture_init_end());
}

/// Retrieve the initialization expressions for this lambda's captures.
llvm::iterator_range<const_capture_init_iterator> capture_inits() const {
  return llvm::make_range(capture_init_begin(), capture_init_end());
}

/// Retrieve the first initialization argument for this
/// lambda expression (which initializes the first capture field).
capture_init_iterator capture_init_begin() {
  return reinterpret_cast<Expr **>(getStoredStmts());
}

/// Retrieve the first initialization argument for this
/// lambda expression (which initializes the first capture field).
const_capture_init_iterator capture_init_begin() const {
  return reinterpret_cast<Expr *const *>(getStoredStmts());
}

/// Retrieve the iterator pointing one past the last
/// initialization argument for this lambda expression.
capture_init_iterator capture_init_end() {
  return capture_init_begin() + capture_size();
}

/// Retrieve the iterator pointing one past the last
/// initialization argument for this lambda expression.
const_capture_init_iterator capture_init_end() const {
  return capture_init_begin() + capture_size();
}

/// Retrieve the source range covering the lambda introducer,
/// which contains the explicit capture list surrounded by square
/// brackets ([...]).
SourceRange getIntroducerRange() const { return IntroducerRange; }

/// Retrieve the class that corresponds to the lambda.
///
/// This is the "closure type" (C++1y [expr.prim.lambda]), and stores the
/// captures in its fields and provides the various operations permitted
/// on a lambda (copying, calling).
CXXRecordDecl *getLambdaClass() const;

/// Retrieve the function call operator associated with this
/// lambda expression.
CXXMethodDecl *getCallOperator() const;

/// Retrieve the function template call operator associated with this
/// lambda expression.
FunctionTemplateDecl *getDependentCallOperator() const;

/// If this is a generic lambda expression, retrieve the template
/// parameter list associated with it, or else return null.
TemplateParameterList *getTemplateParameterList() const;

/// Get the template parameters were explicitly specified (as opposed to being
/// invented by use of an auto parameter).
ArrayRef<NamedDecl *> getExplicitTemplateParameters() const;

/// Get the trailing requires clause, if any.
Expr *getTrailingRequiresClause() const;

/// Whether this is a generic lambda.
bool isGenericLambda() const { return getTemplateParameterList(); }

/// Retrieve the body of the lambda. This will be most of the time
/// a \p CompoundStmt, but can also be \p CoroutineBodyStmt wrapping
/// a \p CompoundStmt. Note that unlike functions, lambda-expressions
/// cannot have a function-try-block.
Stmt *getBody() const;

/// Retrieve the \p CompoundStmt representing the body of the lambda.
/// This is a convenience function for callers who do not need
/// to handle node(s) which may wrap a \p CompoundStmt.
const CompoundStmt *getCompoundStmtBody() const;
CompoundStmt *getCompoundStmtBody() {
  const auto *ConstThis = this;
  return const_cast<CompoundStmt *>(ConstThis->getCompoundStmtBody());
}

/// Determine whether the lambda is mutable, meaning that any
/// captures values can be modified.
bool isMutable() const;

/// Determine whether this lambda has an explicit parameter
/// list vs. an implicit (empty) parameter list.
bool hasExplicitParameters() const { return LambdaExprBits.ExplicitParams; }

/// Whether this lambda had its result type explicitly specified.
bool hasExplicitResultType() const {
  return LambdaExprBits.ExplicitResultType;
}

static bool classof(const Stmt *T) {
  return T->getStmtClass() == LambdaExprClass;
}

SourceLocation getBeginLoc() const LLVM_READONLY__attribute__((__pure__)) {
  return IntroducerRange.getBegin();
}

SourceLocation getEndLoc() const LLVM_READONLY__attribute__((__pure__)) { return ClosingBrace; }

/// Includes the captures and the body of the lambda.
child_range children();
const_child_range children() const;
2147};

2149/// An expression "T()" which creates a value-initialized rvalue of type
2150/// T, which is a non-class type.  See (C++98 [5.2.3p2]).
2151class CXXScalarValueInitExpr : public Expr {
friend class ASTStmtReader;

TypeSourceInfo *TypeInfo;

2156public:
/// Create an explicitly-written scalar-value initialization
/// expression.
CXXScalarValueInitExpr(QualType Type, TypeSourceInfo *TypeInfo,
                       SourceLocation RParenLoc)
    : Expr(CXXScalarValueInitExprClass, Type, VK_PRValue, OK_Ordinary),
      TypeInfo(TypeInfo) {
  CXXScalarValueInitExprBits.RParenLoc = RParenLoc;
  setDependence(computeDependence(this));
}

explicit CXXScalarValueInitExpr(EmptyShell Shell)
    : Expr(CXXScalarValueInitExprClass, Shell) {}

TypeSourceInfo *getTypeSourceInfo() const {
  return TypeInfo;
}

SourceLocation getRParenLoc() const {
  return CXXScalarValueInitExprBits.RParenLoc;
}

SourceLocation getBeginLoc() const LLVM_READONLY__attribute__((__pure__));
SourceLocation getEndLoc() const { return getRParenLoc(); }

static bool classof(const Stmt *T) {
  return T->getStmtClass() == CXXScalarValueInitExprClass;
}

// Iterators
child_range children() {
  return child_range(child_iterator(), child_iterator());
}

const_child_range children() const {
  return const_child_range(const_child_iterator(), const_child_iterator());
}
2193};

2195/// Represents a new-expression for memory allocation and constructor
2196/// calls, e.g: "new CXXNewExpr(foo)".
2197class CXXNewExpr final
  : public Expr,
    private llvm::TrailingObjects<CXXNewExpr, Stmt *, SourceRange> {
friend class ASTStmtReader;
friend class ASTStmtWriter;
friend TrailingObjects;

/// Points to the allocation function used.
FunctionDecl *OperatorNew;

/// Points to the deallocation function used in case of error. May be null.
FunctionDecl *OperatorDelete;

/// The allocated type-source information, as written in the source.
TypeSourceInfo *AllocatedTypeInfo;

/// Range of the entire new expression.
SourceRange Range;

/// Source-range of a paren-delimited initializer.
SourceRange DirectInitRange;

// CXXNewExpr is followed by several optional trailing objects.
// They are in order:
//
// * An optional "Stmt *" for the array size expression.
//    Present if and ony if isArray().
//
// * An optional "Stmt *" for the init expression.
//    Present if and only if hasInitializer().
//
// * An array of getNumPlacementArgs() "Stmt *" for the placement new
//   arguments, if any.
//
// * An optional SourceRange for the range covering the parenthesized type-id
//    if the allocated type was expressed as a parenthesized type-id.
//    Present if and only if isParenTypeId().
unsigned arraySizeOffset() const { return 0; }
unsigned initExprOffset() const { return arraySizeOffset() + isArray(); }
unsigned placementNewArgsOffset() const {
  return initExprOffset() + hasInitializer();
}

unsigned numTrailingObjects(OverloadToken<Stmt *>) const {
  return isArray() + hasInitializer() + getNumPlacementArgs();
}

unsigned numTrailingObjects(OverloadToken<SourceRange>) const {
  return isParenTypeId();
}

2248public:
enum InitializationStyle {
  /// New-expression has no initializer as written.
  NoInit,

  /// New-expression has a C++98 paren-delimited initializer.
  CallInit,

  /// New-expression has a C++11 list-initializer.
  ListInit
};

2260private:
/// Build a c++ new expression.
CXXNewExpr(bool IsGlobalNew, FunctionDecl *OperatorNew,
           FunctionDecl *OperatorDelete, bool ShouldPassAlignment,
           bool UsualArrayDeleteWantsSize, ArrayRef<Expr *> PlacementArgs,
           SourceRange TypeIdParens, std::optional<Expr *> ArraySize,
           InitializationStyle InitializationStyle, Expr *Initializer,
           QualType Ty, TypeSourceInfo *AllocatedTypeInfo, SourceRange Range,
           SourceRange DirectInitRange);

/// Build an empty c++ new expression.
CXXNewExpr(EmptyShell Empty, bool IsArray, unsigned NumPlacementArgs,
           bool IsParenTypeId);

2274public:
/// Create a c++ new expression.
static CXXNewExpr *
Create(const ASTContext &Ctx, bool IsGlobalNew, FunctionDecl *OperatorNew,
       FunctionDecl *OperatorDelete, bool ShouldPassAlignment,
       bool UsualArrayDeleteWantsSize, ArrayRef<Expr *> PlacementArgs,
       SourceRange TypeIdParens, std::optional<Expr *> ArraySize,
       InitializationStyle InitializationStyle, Expr *Initializer,
       QualType Ty, TypeSourceInfo *AllocatedTypeInfo, SourceRange Range,
       SourceRange DirectInitRange);

/// Create an empty c++ new expression.
static CXXNewExpr *CreateEmpty(const ASTContext &Ctx, bool IsArray,
                               bool HasInit, unsigned NumPlacementArgs,
                               bool IsParenTypeId);

QualType getAllocatedType() const {
  return getType()->castAs<PointerType>()->getPointeeType();
}

TypeSourceInfo *getAllocatedTypeSourceInfo() const {
  return AllocatedTypeInfo;
}

/// True if the allocation result needs to be null-checked.
///
/// C++11 [expr.new]p13:
///   If the allocation function returns null, initialization shall
///   not be done, the deallocation function shall not be called,
///   and the value of the new-expression shall be null.
///
/// C++ DR1748:
///   If the allocation function is a reserved placement allocation
///   function that returns null, the behavior is undefined.
///
/// An allocation function is not allowed to return null unless it
/// has a non-throwing exception-specification.  The '03 rule is
/// identical except that the definition of a non-throwing
/// exception specification is just "is it throw()?".
bool shouldNullCheckAllocation() const;

FunctionDecl *getOperatorNew() const { return OperatorNew; }
void setOperatorNew(FunctionDecl *D) { OperatorNew = D; }
FunctionDecl *getOperatorDelete() const { return OperatorDelete; }
void setOperatorDelete(FunctionDecl *D) { OperatorDelete = D; }

bool isArray() const { return CXXNewExprBits.IsArray; }

/// This might return std::nullopt even if isArray() returns true,
/// since there might not be an array size expression.
/// If the result is not std::nullopt, it will never wrap a nullptr.
std::optional<Expr *> getArraySize() {
  if (!isArray())
    return std::nullopt;

  if (auto *Result =
          cast_or_null<Expr>(getTrailingObjects<Stmt *>()[arraySizeOffset()]))
    return Result;

  return std::nullopt;
}

/// This might return std::nullopt even if isArray() returns true,
/// since there might not be an array size expression.
/// If the result is not std::nullopt, it will never wrap a nullptr.
std::optional<const Expr *> getArraySize() const {
  if (!isArray())
    return std::nullopt;

  if (auto *Result =
          cast_or_null<Expr>(getTrailingObjects<Stmt *>()[arraySizeOffset()]))
    return Result;

  return std::nullopt;
}

unsigned getNumPlacementArgs() const {
  return CXXNewExprBits.NumPlacementArgs;
}

Expr **getPlacementArgs() {
  return reinterpret_cast<Expr **>(getTrailingObjects<Stmt *>() +
                                   placementNewArgsOffset());
}

Expr *getPlacementArg(unsigned I) {
  assert((I < getNumPlacementArgs()) && "Index out of range!")(static_cast <bool> ((I < getNumPlacementArgs()) &&
 "Index out of range!") ? void (0) : __assert_fail ("(I < getNumPlacementArgs()) && \"Index out of range!\""
, "clang/include/clang/AST/ExprCXX.h", 2360, __extension__ __PRETTY_FUNCTION__
));
  return getPlacementArgs()[I];
}
const Expr *getPlacementArg(unsigned I) const {
  return const_cast<CXXNewExpr *>(this)->getPlacementArg(I);
}

bool isParenTypeId() const { return CXXNewExprBits.IsParenTypeId; }
SourceRange getTypeIdParens() const {
  return isParenTypeId() ? getTrailingObjects<SourceRange>()[0]
                         : SourceRange();
}

bool isGlobalNew() const { return CXXNewExprBits.IsGlobalNew; }

/// Whether this new-expression has any initializer at all.
bool hasInitializer() const {
  return CXXNewExprBits.StoredInitializationStyle > 0;
}

/// The kind of initializer this new-expression has.
InitializationStyle getInitializationStyle() const {
  if (CXXNewExprBits.StoredInitializationStyle == 0)
    return NoInit;
  return static_cast<InitializationStyle>(
      CXXNewExprBits.StoredInitializationStyle - 1);
}

/// The initializer of this new-expression.
Expr *getInitializer() {
  return hasInitializer()
             ? cast<Expr>(getTrailingObjects<Stmt *>()[initExprOffset()])
             : nullptr;
}
const Expr *getInitializer() const {
  return hasInitializer()
             ? cast<Expr>(getTrailingObjects<Stmt *>()[initExprOffset()])
             : nullptr;
}

/// Returns the CXXConstructExpr from this new-expression, or null.
const CXXConstructExpr *getConstructExpr() const {
  return dyn_cast_or_null<CXXConstructExpr>(getInitializer());
}

/// Indicates whether the required alignment should be implicitly passed to
/// the allocation function.
bool passAlignment() const { return CXXNewExprBits.ShouldPassAlignment; }

/// Answers whether the usual array deallocation function for the
/// allocated type expects the size of the allocation as a
/// parameter.
bool doesUsualArrayDeleteWantSize() const {
  return CXXNewExprBits.UsualArrayDeleteWantsSize;
}

using arg_iterator = ExprIterator;
using const_arg_iterator = ConstExprIterator;

llvm::iterator_range<arg_iterator> placement_arguments() {
  return llvm::make_range(placement_arg_begin(), placement_arg_end());
}

llvm::iterator_range<const_arg_iterator> placement_arguments() const {
  return llvm::make_range(placement_arg_begin(), placement_arg_end());
}

arg_iterator placement_arg_begin() {
  return getTrailingObjects<Stmt *>() + placementNewArgsOffset();
}
arg_iterator placement_arg_end() {
  return placement_arg_begin() + getNumPlacementArgs();
}
const_arg_iterator placement_arg_begin() const {
  return getTrailingObjects<Stmt *>() + placementNewArgsOffset();
}
const_arg_iterator placement_arg_end() const {
  return placement_arg_begin() + getNumPlacementArgs();
}

using raw_arg_iterator = Stmt **;

raw_arg_iterator raw_arg_begin() { return getTrailingObjects<Stmt *>(); }
raw_arg_iterator raw_arg_end() {
  return raw_arg_begin() + numTrailingObjects(OverloadToken<Stmt *>());
}
const_arg_iterator raw_arg_begin() const {
  return getTrailingObjects<Stmt *>();
}
const_arg_iterator raw_arg_end() const {
  return raw_arg_begin() + numTrailingObjects(OverloadToken<Stmt *>());
}

SourceLocation getBeginLoc() const { return Range.getBegin(); }
SourceLocation getEndLoc() const { return Range.getEnd(); }

SourceRange getDirectInitRange() const { return DirectInitRange; }
SourceRange getSourceRange() const { return Range; }

static bool classof(const Stmt *T) {
  return T->getStmtClass() == CXXNewExprClass;
}

// Iterators
child_range children() { return child_range(raw_arg_begin(), raw_arg_end()); }

const_child_range children() const {
  return const_child_range(const_cast<CXXNewExpr *>(this)->children());
}
2469};

2471/// Represents a \c delete expression for memory deallocation and
2472/// destructor calls, e.g. "delete[] pArray".
2473class CXXDeleteExpr : public Expr {
friend class ASTStmtReader;

/// Points to the operator delete overload that is used. Could be a member.
FunctionDecl *OperatorDelete = nullptr;

/// The pointer expression to be deleted.
Stmt *Argument = nullptr;

2482public:
CXXDeleteExpr(QualType Ty, bool GlobalDelete, bool ArrayForm,
              bool ArrayFormAsWritten, bool UsualArrayDeleteWantsSize,
              FunctionDecl *OperatorDelete, Expr *Arg, SourceLocation Loc)
    : Expr(CXXDeleteExprClass, Ty, VK_PRValue, OK_Ordinary),
      OperatorDelete(OperatorDelete), Argument(Arg) {
  CXXDeleteExprBits.GlobalDelete = GlobalDelete;
  CXXDeleteExprBits.ArrayForm = ArrayForm;
  CXXDeleteExprBits.ArrayFormAsWritten = ArrayFormAsWritten;
  CXXDeleteExprBits.UsualArrayDeleteWantsSize = UsualArrayDeleteWantsSize;
  CXXDeleteExprBits.Loc = Loc;
  setDependence(computeDependence(this));
}

explicit CXXDeleteExpr(EmptyShell Shell) : Expr(CXXDeleteExprClass, Shell) {}

bool isGlobalDelete() const { return CXXDeleteExprBits.GlobalDelete; }
bool isArrayForm() const { return CXXDeleteExprBits.ArrayForm; }
bool isArrayFormAsWritten() const {
  return CXXDeleteExprBits.ArrayFormAsWritten;
}

/// Answers whether the usual array deallocation function for the
/// allocated type expects the size of the allocation as a
/// parameter.  This can be true even if the actual deallocation
/// function that we're using doesn't want a size.
bool doesUsualArrayDeleteWantSize() const {
  return CXXDeleteExprBits.UsualArrayDeleteWantsSize;
}

FunctionDecl *getOperatorDelete() const { return OperatorDelete; }

Expr *getArgument() { return cast<Expr>(Argument); }
const Expr *getArgument() const { return cast<Expr>(Argument); }

/// Retrieve the type being destroyed.
///
/// If the type being destroyed is a dependent type which may or may not
/// be a pointer, return an invalid type.
QualType getDestroyedType() const;

SourceLocation getBeginLoc() const { return CXXDeleteExprBits.Loc; }
SourceLocation getEndLoc() const LLVM_READONLY__attribute__((__pure__)) {
  return Argument->getEndLoc();
}

static bool classof(const Stmt *T) {
  return T->getStmtClass() == CXXDeleteExprClass;
}

// Iterators
child_range children() { return child_range(&Argument, &Argument + 1); }

const_child_range children() const {
  return const_child_range(&Argument, &Argument + 1);
}
2538};

2540/// Stores the type being destroyed by a pseudo-destructor expression.
2541class PseudoDestructorTypeStorage {
/// Either the type source information or the name of the type, if
/// it couldn't be resolved due to type-dependence.
llvm::PointerUnion<TypeSourceInfo *, IdentifierInfo *> Type;

/// The starting source location of the pseudo-destructor type.
SourceLocation Location;

2549public:
PseudoDestructorTypeStorage() = default;

PseudoDestructorTypeStorage(IdentifierInfo *II, SourceLocation Loc)
    : Type(II), Location(Loc) {}

PseudoDestructorTypeStorage(TypeSourceInfo *Info);

TypeSourceInfo *getTypeSourceInfo() const {
  return Type.dyn_cast<TypeSourceInfo *>();
}

IdentifierInfo *getIdentifier() const {
  return Type.dyn_cast<IdentifierInfo *>();
}

SourceLocation getLocation() const { return Location; }
2566};

2568/// Represents a C++ pseudo-destructor (C++ [expr.pseudo]).
2569///
2570/// A pseudo-destructor is an expression that looks like a member access to a
2571/// destructor of a scalar type, except that scalar types don't have
2572/// destructors. For example:
2573///
2574/// \code
2575/// typedef int T;
2576/// void f(int *p) {
2577///   p->T::~T();
2578/// }
2579/// \endcode
2580///
2581/// Pseudo-destructors typically occur when instantiating templates such as:
2582///
2583/// \code
2584/// template<typename T>
2585/// void destroy(T* ptr) {
2586///   ptr->T::~T();
2587/// }
2588/// \endcode
2589///
2590/// for scalar types. A pseudo-destructor expression has no run-time semantics
2591/// beyond evaluating the base expression.
2592class CXXPseudoDestructorExpr : public Expr {
friend class ASTStmtReader;

/// The base expression (that is being destroyed).
Stmt *Base = nullptr;

/// Whether the operator was an arrow ('->'); otherwise, it was a
/// period ('.').
bool IsArrow : 1;

/// The location of the '.' or '->' operator.
SourceLocation OperatorLoc;

/// The nested-name-specifier that follows the operator, if present.
NestedNameSpecifierLoc QualifierLoc;

/// The type that precedes the '::' in a qualified pseudo-destructor
/// expression.
TypeSourceInfo *ScopeType = nullptr;

/// The location of the '::' in a qualified pseudo-destructor
/// expression.
SourceLocation ColonColonLoc;

/// The location of the '~'.
SourceLocation TildeLoc;

/// The type being destroyed, or its name if we were unable to
/// resolve the name.
PseudoDestructorTypeStorage DestroyedType;

2623public:
CXXPseudoDestructorExpr(const ASTContext &Context,
                        Expr *Base, bool isArrow, SourceLocation OperatorLoc,
                        NestedNameSpecifierLoc QualifierLoc,
                        TypeSourceInfo *ScopeType,
                        SourceLocation ColonColonLoc,
                        SourceLocation TildeLoc,
                        PseudoDestructorTypeStorage DestroyedType);

explicit CXXPseudoDestructorExpr(EmptyShell Shell)
    : Expr(CXXPseudoDestructorExprClass, Shell), IsArrow(false) {}

Expr *getBase() const { return cast<Expr>(Base); }

/// Determines whether this member expression actually had
/// a C++ nested-name-specifier prior to the name of the member, e.g.,
/// x->Base::foo.
bool hasQualifier() const { return QualifierLoc.hasQualifier(); }

/// Retrieves the nested-name-specifier that qualifies the type name,
/// with source-location information.
NestedNameSpecifierLoc getQualifierLoc() const { return QualifierLoc; }

/// If the member name was qualified, retrieves the
/// nested-name-specifier that precedes the member name. Otherwise, returns
/// null.
NestedNameSpecifier *getQualifier() const {
  return QualifierLoc.getNestedNameSpecifier();
}

/// Determine whether this pseudo-destructor expression was written
/// using an '->' (otherwise, it used a '.').
bool isArrow() const { return IsArrow; }

/// Retrieve the location of the '.' or '->' operator.
SourceLocation getOperatorLoc() const { return OperatorLoc; }

/// Retrieve the scope type in a qualified pseudo-destructor
/// expression.
///
/// Pseudo-destructor expressions can have extra qualification within them
/// that is not part of the nested-name-specifier, e.g., \c p->T::~T().
/// Here, if the object type of the expression is (or may be) a scalar type,
/// \p T may also be a scalar type and, therefore, cannot be part of a
/// nested-name-specifier. It is stored as the "scope type" of the pseudo-
/// destructor expression.
TypeSourceInfo *getScopeTypeInfo() const { return ScopeType; }

/// Retrieve the location of the '::' in a qualified pseudo-destructor
/// expression.
SourceLocation getColonColonLoc() const { return ColonColonLoc; }

/// Retrieve the location of the '~'.
SourceLocation getTildeLoc() const { return TildeLoc; }

/// Retrieve the source location information for the type
/// being destroyed.
///
/// This type-source information is available for non-dependent
/// pseudo-destructor expressions and some dependent pseudo-destructor
/// expressions. Returns null if we only have the identifier for a
/// dependent pseudo-destructor expression.
TypeSourceInfo *getDestroyedTypeInfo() const {
  return DestroyedType.getTypeSourceInfo();
}

/// In a dependent pseudo-destructor expression for which we do not
/// have full type information on the destroyed type, provides the name
/// of the destroyed type.
IdentifierInfo *getDestroyedTypeIdentifier() const {
  return DestroyedType.getIdentifier();
}

/// Retrieve the type being destroyed.
QualType getDestroyedType() const;

/// Retrieve the starting location of the type being destroyed.
SourceLocation getDestroyedTypeLoc() const {
  return DestroyedType.getLocation();
}

/// Set the name of destroyed type for a dependent pseudo-destructor
/// expression.
void setDestroyedType(IdentifierInfo *II, SourceLocation Loc) {
  DestroyedType = PseudoDestructorTypeStorage(II, Loc);
}

/// Set the destroyed type.
void setDestroyedType(TypeSourceInfo *Info) {
  DestroyedType = PseudoDestructorTypeStorage(Info);
}

SourceLocation getBeginLoc() const LLVM_READONLY__attribute__((__pure__)) {
  return Base->getBeginLoc();
}
SourceLocation getEndLoc() const LLVM_READONLY__attribute__((__pure__));

static bool classof(const Stmt *T) {
  return T->getStmtClass() == CXXPseudoDestructorExprClass;
}

// Iterators
child_range children() { return child_range(&Base, &Base + 1); }

const_child_range children() const {
  return const_child_range(&Base, &Base + 1);
}
2730};

2732/// A type trait used in the implementation of various C++11 and
2733/// Library TR1 trait templates.
2734///
2735/// \code
2736///   __is_pod(int) == true
2737///   __is_enum(std::string) == false
2738///   __is_trivially_constructible(vector<int>, int*, int*)
2739/// \endcode
2740class TypeTraitExpr final
  : public Expr,
    private llvm::TrailingObjects<TypeTraitExpr, TypeSourceInfo *> {
/// The location of the type trait keyword.
SourceLocation Loc;

///  The location of the closing parenthesis.
SourceLocation RParenLoc;

// Note: The TypeSourceInfos for the arguments are allocated after the
// TypeTraitExpr.

TypeTraitExpr(QualType T, SourceLocation Loc, TypeTrait Kind,
              ArrayRef<TypeSourceInfo *> Args,
              SourceLocation RParenLoc,
              bool Value);

TypeTraitExpr(EmptyShell Empty) : Expr(TypeTraitExprClass, Empty) {}

size_t numTrailingObjects(OverloadToken<TypeSourceInfo *>) const {
  return getNumArgs();
}

2763public:
friend class ASTStmtReader;
friend class ASTStmtWriter;
friend TrailingObjects;

/// Create a new type trait expression.
static TypeTraitExpr *Create(const ASTContext &C, QualType T,
                             SourceLocation Loc, TypeTrait Kind,
                             ArrayRef<TypeSourceInfo *> Args,
                             SourceLocation RParenLoc,
                             bool Value);

static TypeTraitExpr *CreateDeserialized(const ASTContext &C,
                                         unsigned NumArgs);

/// Determine which type trait this expression uses.
TypeTrait getTrait() const {
  return static_cast<TypeTrait>(TypeTraitExprBits.Kind);
}

bool getValue() const {
  assert(!isValueDependent())(static_cast <bool> (!isValueDependent()) ? void (0) : __assert_fail
 ("!isValueDependent()", "clang/include/clang/AST/ExprCXX.h",
 2784, __extension__ __PRETTY_FUNCTION__));
  return TypeTraitExprBits.Value;
}

/// Determine the number of arguments to this type trait.
unsigned getNumArgs() const { return TypeTraitExprBits.NumArgs; }

/// Retrieve the Ith argument.
TypeSourceInfo *getArg(unsigned I) const {
  assert(I < getNumArgs() && "Argument out-of-range")(static_cast <bool> (I < getNumArgs() && "Argument out-of-range"
) ? void (0) : __assert_fail ("I < getNumArgs() && \"Argument out-of-range\""
, "clang/include/clang/AST/ExprCXX.h", 2793, __extension__ __PRETTY_FUNCTION__
));
  return getArgs()[I];
}

/// Retrieve the argument types.
ArrayRef<TypeSourceInfo *> getArgs() const {
  return llvm::ArrayRef(getTrailingObjects<TypeSourceInfo *>(), getNumArgs());
}

SourceLocation getBeginLoc() const LLVM_READONLY__attribute__((__pure__)) { return Loc; }
SourceLocation getEndLoc() const LLVM_READONLY__attribute__((__pure__)) { return RParenLoc; }

static bool classof(const Stmt *T) {
  return T->getStmtClass() == TypeTraitExprClass;
}

// Iterators
child_range children() {
  return child_range(child_iterator(), child_iterator());
}

const_child_range children() const {
  return const_child_range(const_child_iterator(), const_child_iterator());
}
2817};

2819/// An Embarcadero array type trait, as used in the implementation of
2820/// __array_rank and __array_extent.
2821///
2822/// Example:
2823/// \code
2824///   __array_rank(int[10][20]) == 2
2825///   __array_extent(int, 1)    == 20
2826/// \endcode
2827class ArrayTypeTraitExpr : public Expr {
/// The trait. An ArrayTypeTrait enum in MSVC compat unsigned.
unsigned ATT : 2;

/// The value of the type trait. Unspecified if dependent.
uint64_t Value = 0;

/// The array dimension being queried, or -1 if not used.
Expr *Dimension;

/// The location of the type trait keyword.
SourceLocation Loc;

/// The location of the closing paren.
SourceLocation RParen;

/// The type being queried.
TypeSourceInfo *QueriedType = nullptr;

2846public:
friend class ASTStmtReader;

ArrayTypeTraitExpr(SourceLocation loc, ArrayTypeTrait att,
                   TypeSourceInfo *queried, uint64_t value, Expr *dimension,
                   SourceLocation rparen, QualType ty)
    : Expr(ArrayTypeTraitExprClass, ty, VK_PRValue, OK_Ordinary), ATT(att),
      Value(value), Dimension(dimension), Loc(loc), RParen(rparen),
      QueriedType(queried) {
  assert(att <= ATT_Last && "invalid enum value!")(static_cast <bool> (att <= ATT_Last && "invalid enum value!"
) ? void (0) : __assert_fail ("att <= ATT_Last && \"invalid enum value!\""
, "clang/include/clang/AST/ExprCXX.h", 2855, __extension__ __PRETTY_FUNCTION__
));
  assert(static_cast<unsigned>(att) == ATT && "ATT overflow!")(static_cast <bool> (static_cast<unsigned>(att) ==
 ATT && "ATT overflow!") ? void (0) : __assert_fail (
"static_cast<unsigned>(att) == ATT && \"ATT overflow!\""
, "clang/include/clang/AST/ExprCXX.h", 2856, __extension__ __PRETTY_FUNCTION__
));
  setDependence(computeDependence(this));
}

explicit ArrayTypeTraitExpr(EmptyShell Empty)
    : Expr(ArrayTypeTraitExprClass, Empty), ATT(0) {}

SourceLocation getBeginLoc() const LLVM_READONLY__attribute__((__pure__)) { return Loc; }
SourceLocation getEndLoc() const LLVM_READONLY__attribute__((__pure__)) { return RParen; }

ArrayTypeTrait getTrait() const { return static_cast<ArrayTypeTrait>(ATT); }

QualType getQueriedType() const { return QueriedType->getType(); }

TypeSourceInfo *getQueriedTypeSourceInfo() const { return QueriedType; }

uint64_t getValue() const { assert(!isTypeDependent())(static_cast <bool> (!isTypeDependent()) ? void (0) : __assert_fail
 ("!isTypeDependent()", "clang/include/clang/AST/ExprCXX.h", 2872
, __extension__ __PRETTY_FUNCTION__)); return Value; }

Expr *getDimensionExpression() const { return Dimension; }

static bool classof(const Stmt *T) {
  return T->getStmtClass() == ArrayTypeTraitExprClass;
}

// Iterators
child_range children() {
  return child_range(child_iterator(), child_iterator());
}

const_child_range children() const {
  return const_child_range(const_child_iterator(), const_child_iterator());
}
2888};

2890/// An expression trait intrinsic.
2891///
2892/// Example:
2893/// \code
2894///   __is_lvalue_expr(std::cout) == true
2895///   __is_lvalue_expr(1) == false
2896/// \endcode
2897class ExpressionTraitExpr : public Expr {
/// The trait. A ExpressionTrait enum in MSVC compatible unsigned.
unsigned ET : 31;

/// The value of the type trait. Unspecified if dependent.
unsigned Value : 1;

/// The location of the type trait keyword.
SourceLocation Loc;

/// The location of the closing paren.
SourceLocation RParen;

/// The expression being queried.
Expr* QueriedExpression = nullptr;

2913public:
friend class ASTStmtReader;

ExpressionTraitExpr(SourceLocation loc, ExpressionTrait et, Expr *queried,
                    bool value, SourceLocation rparen, QualType resultType)
    : Expr(ExpressionTraitExprClass, resultType, VK_PRValue, OK_Ordinary),
      ET(et), Value(value), Loc(loc), RParen(rparen),
      QueriedExpression(queried) {
  assert(et <= ET_Last && "invalid enum value!")(static_cast <bool> (et <= ET_Last && "invalid enum value!"
) ? void (0) : __assert_fail ("et <= ET_Last && \"invalid enum value!\""
, "clang/include/clang/AST/ExprCXX.h", 2921, __extension__ __PRETTY_FUNCTION__
));
  assert(static_cast<unsigned>(et) == ET && "ET overflow!")(static_cast <bool> (static_cast<unsigned>(et) ==
 ET && "ET overflow!") ? void (0) : __assert_fail ("static_cast<unsigned>(et) == ET && \"ET overflow!\""
, "clang/include/clang/AST/ExprCXX.h", 2922, __extension__ __PRETTY_FUNCTION__
));
  setDependence(computeDependence(this));
}

explicit ExpressionTraitExpr(EmptyShell Empty)
    : Expr(ExpressionTraitExprClass, Empty), ET(0), Value(false) {}

SourceLocation getBeginLoc() const LLVM_READONLY__attribute__((__pure__)) { return Loc; }
SourceLocation getEndLoc() const LLVM_READONLY__attribute__((__pure__)) { return RParen; }

ExpressionTrait getTrait() const { return static_cast<ExpressionTrait>(ET); }

Expr *getQueriedExpression() const { return QueriedExpression; }

bool getValue() const { return Value; }

static bool classof(const Stmt *T) {
  return T->getStmtClass() == ExpressionTraitExprClass;
}

// Iterators
child_range children() {
  return child_range(child_iterator(), child_iterator());
}

const_child_range children() const {
  return const_child_range(const_child_iterator(), const_child_iterator());
}
2950};

2952/// A reference to an overloaded function set, either an
2953/// \c UnresolvedLookupExpr or an \c UnresolvedMemberExpr.
2954class OverloadExpr : public Expr {
friend class ASTStmtReader;
friend class ASTStmtWriter;

/// The common name of these declarations.
DeclarationNameInfo NameInfo;

/// The nested-name-specifier that qualifies the name, if any.
NestedNameSpecifierLoc QualifierLoc;

2964protected:
OverloadExpr(StmtClass SC, const ASTContext &Context,
             NestedNameSpecifierLoc QualifierLoc,
             SourceLocation TemplateKWLoc,
             const DeclarationNameInfo &NameInfo,
             const TemplateArgumentListInfo *TemplateArgs,
             UnresolvedSetIterator Begin, UnresolvedSetIterator End,
             bool KnownDependent, bool KnownInstantiationDependent,
             bool KnownContainsUnexpandedParameterPack);

OverloadExpr(StmtClass SC, EmptyShell Empty, unsigned NumResults,
             bool HasTemplateKWAndArgsInfo);

/// Return the results. Defined after UnresolvedMemberExpr.
inline DeclAccessPair *getTrailingResults();
const DeclAccessPair *getTrailingResults() const {
  return const_cast<OverloadExpr *>(this)->getTrailingResults();
}

/// Return the optional template keyword and arguments info.
/// Defined after UnresolvedMemberExpr.
inline ASTTemplateKWAndArgsInfo *getTrailingASTTemplateKWAndArgsInfo();
const ASTTemplateKWAndArgsInfo *getTrailingASTTemplateKWAndArgsInfo() const {
  return const_cast<OverloadExpr *>(this)
      ->getTrailingASTTemplateKWAndArgsInfo();
}

/// Return the optional template arguments. Defined after
/// UnresolvedMemberExpr.
inline TemplateArgumentLoc *getTrailingTemplateArgumentLoc();
const TemplateArgumentLoc *getTrailingTemplateArgumentLoc() const {
  return const_cast<OverloadExpr *>(this)->getTrailingTemplateArgumentLoc();
}

bool hasTemplateKWAndArgsInfo() const {
  return OverloadExprBits.HasTemplateKWAndArgsInfo;
}

3002public:
struct FindResult {
  OverloadExpr *Expression;
  bool IsAddressOfOperand;
  bool HasFormOfMemberPointer;
};

/// Finds the overloaded expression in the given expression \p E of
/// OverloadTy.
///
/// \return the expression (which must be there) and true if it has
/// the particular form of a member pointer expression
static FindResult find(Expr *E) {
  assert(E->getType()->isSpecificBuiltinType(BuiltinType::Overload))(static_cast <bool> (E->getType()->isSpecificBuiltinType
(BuiltinType::Overload)) ? void (0) : __assert_fail ("E->getType()->isSpecificBuiltinType(BuiltinType::Overload)"
, "clang/include/clang/AST/ExprCXX.h", 3015, __extension__ __PRETTY_FUNCTION__
));

  FindResult Result;

  E = E->IgnoreParens();
  if (isa<UnaryOperator>(E)) {
    assert(cast<UnaryOperator>(E)->getOpcode() == UO_AddrOf)(static_cast <bool> (cast<UnaryOperator>(E)->getOpcode
() == UO_AddrOf) ? void (0) : __assert_fail ("cast<UnaryOperator>(E)->getOpcode() == UO_AddrOf"
, "clang/include/clang/AST/ExprCXX.h", 3021, __extension__ __PRETTY_FUNCTION__
));
    E = cast<UnaryOperator>(E)->getSubExpr();
    auto *Ovl = cast<OverloadExpr>(E->IgnoreParens());

    Result.HasFormOfMemberPointer = (E == Ovl && Ovl->getQualifier());
    Result.IsAddressOfOperand = true;
    Result.Expression = Ovl;
  } else {
    Result.HasFormOfMemberPointer = false;
    Result.IsAddressOfOperand = false;
    Result.Expression = cast<OverloadExpr>(E);
  }

  return Result;
}

/// Gets the naming class of this lookup, if any.
/// Defined after UnresolvedMemberExpr.
inline CXXRecordDecl *getNamingClass();
const CXXRecordDecl *getNamingClass() const {
  return const_cast<OverloadExpr *>(this)->getNamingClass();
}

using decls_iterator = UnresolvedSetImpl::iterator;

decls_iterator decls_begin() const {
  return UnresolvedSetIterator(getTrailingResults());
}
decls_iterator decls_end() const {
  return UnresolvedSetIterator(getTrailingResults() + getNumDecls());
}
llvm::iterator_range<decls_iterator> decls() const {
  return llvm::make_range(decls_begin(), decls_end());
}

/// Gets the number of declarations in the unresolved set.
unsigned getNumDecls() const { return OverloadExprBits.NumResults; }

/// Gets the full name info.
const DeclarationNameInfo &getNameInfo() const { return NameInfo; }

/// Gets the name looked up.
DeclarationName getName() const { return NameInfo.getName(); }

/// Gets the location of the name.
SourceLocation getNameLoc() const { return NameInfo.getLoc(); }

/// Fetches the nested-name qualifier, if one was given.
NestedNameSpecifier *getQualifier() const {
  return QualifierLoc.getNestedNameSpecifier();
}

/// Fetches the nested-name qualifier with source-location
/// information, if one was given.
NestedNameSpecifierLoc getQualifierLoc() const { return QualifierLoc; }

/// Retrieve the location of the template keyword preceding
/// this name, if any.
SourceLocation getTemplateKeywordLoc() const {
  if (!hasTemplateKWAndArgsInfo())
    return SourceLocation();
  return getTrailingASTTemplateKWAndArgsInfo()->TemplateKWLoc;
}

/// Retrieve the location of the left angle bracket starting the
/// explicit template argument list following the name, if any.
SourceLocation getLAngleLoc() const {
  if (!hasTemplateKWAndArgsInfo())
    return SourceLocation();
  return getTrailingASTTemplateKWAndArgsInfo()->LAngleLoc;
}

/// Retrieve the location of the right angle bracket ending the
/// explicit template argument list following the name, if any.
SourceLocation getRAngleLoc() const {
  if (!hasTemplateKWAndArgsInfo())
    return SourceLocation();
  return getTrailingASTTemplateKWAndArgsInfo()->RAngleLoc;
}

/// Determines whether the name was preceded by the template keyword.
bool hasTemplateKeyword() const { return getTemplateKeywordLoc().isValid(); }

/// Determines whether this expression had explicit template arguments.
bool hasExplicitTemplateArgs() const { return getLAngleLoc().isValid(); }

TemplateArgumentLoc const *getTemplateArgs() const {
  if (!hasExplicitTemplateArgs())
    return nullptr;
  return const_cast<OverloadExpr *>(this)->getTrailingTemplateArgumentLoc();
}

unsigned getNumTemplateArgs() const {
  if (!hasExplicitTemplateArgs())
    return 0;

  return getTrailingASTTemplateKWAndArgsInfo()->NumTemplateArgs;
}

ArrayRef<TemplateArgumentLoc> template_arguments() const {
  return {getTemplateArgs(), getNumTemplateArgs()};
}

/// Copies the template arguments into the given structure.
void copyTemplateArgumentsInto(TemplateArgumentListInfo &List) const {
  if (hasExplicitTemplateArgs())
    getTrailingASTTemplateKWAndArgsInfo()->copyInto(getTemplateArgs(), List);
}

static bool classof(const Stmt *T) {
  return T->getStmtClass() == UnresolvedLookupExprClass ||
         T->getStmtClass() == UnresolvedMemberExprClass;
}
3134};

3136/// A reference to a name which we were able to look up during
3137/// parsing but could not resolve to a specific declaration.
3138///
3139/// This arises in several ways:
3140///   * we might be waiting for argument-dependent lookup;
3141///   * the name might resolve to an overloaded function;
3142/// and eventually:
3143///   * the lookup might have included a function template.
3144///
3145/// These never include UnresolvedUsingValueDecls, which are always class
3146/// members and therefore appear only in UnresolvedMemberLookupExprs.
3147class UnresolvedLookupExpr final
  : public OverloadExpr,
    private llvm::TrailingObjects<UnresolvedLookupExpr, DeclAccessPair,
                                  ASTTemplateKWAndArgsInfo,
                                  TemplateArgumentLoc> {
friend class ASTStmtReader;
friend class OverloadExpr;
friend TrailingObjects;

/// The naming class (C++ [class.access.base]p5) of the lookup, if
/// any.  This can generally be recalculated from the context chain,
/// but that can be fairly expensive for unqualified lookups.
CXXRecordDecl *NamingClass;

// UnresolvedLookupExpr is followed by several trailing objects.
// They are in order:
//
// * An array of getNumResults() DeclAccessPair for the results. These are
//   undesugared, which is to say, they may include UsingShadowDecls.
//   Access is relative to the naming class.
//
// * An optional ASTTemplateKWAndArgsInfo for the explicitly specified
//   template keyword and arguments. Present if and only if
//   hasTemplateKWAndArgsInfo().
//
// * An array of getNumTemplateArgs() TemplateArgumentLoc containing
//   location information for the explicitly specified template arguments.

UnresolvedLookupExpr(const ASTContext &Context, CXXRecordDecl *NamingClass,
                     NestedNameSpecifierLoc QualifierLoc,
                     SourceLocation TemplateKWLoc,
                     const DeclarationNameInfo &NameInfo, bool RequiresADL,
                     bool Overloaded,
                     const TemplateArgumentListInfo *TemplateArgs,
                     UnresolvedSetIterator Begin, UnresolvedSetIterator End);

UnresolvedLookupExpr(EmptyShell Empty, unsigned NumResults,
                     bool HasTemplateKWAndArgsInfo);

unsigned numTrailingObjects(OverloadToken<DeclAccessPair>) const {
  return getNumDecls();
}

unsigned numTrailingObjects(OverloadToken<ASTTemplateKWAndArgsInfo>) const {
  return hasTemplateKWAndArgsInfo();
}

3194public:
static UnresolvedLookupExpr *
Create(const ASTContext &Context, CXXRecordDecl *NamingClass,
       NestedNameSpecifierLoc QualifierLoc,
       const DeclarationNameInfo &NameInfo, bool RequiresADL, bool Overloaded,
       UnresolvedSetIterator Begin, UnresolvedSetIterator End);

static UnresolvedLookupExpr *
Create(const ASTContext &Context, CXXRecordDecl *NamingClass,
       NestedNameSpecifierLoc QualifierLoc, SourceLocation TemplateKWLoc,
       const DeclarationNameInfo &NameInfo, bool RequiresADL,
       const TemplateArgumentListInfo *Args, UnresolvedSetIterator Begin,
       UnresolvedSetIterator End);

static UnresolvedLookupExpr *CreateEmpty(const ASTContext &Context,
                                         unsigned NumResults,
                                         bool HasTemplateKWAndArgsInfo,
                                         unsigned NumTemplateArgs);

/// True if this declaration should be extended by
/// argument-dependent lookup.
bool requiresADL() const { return UnresolvedLookupExprBits.RequiresADL; }

/// True if this lookup is overloaded.
bool isOverloaded() const { return UnresolvedLookupExprBits.Overloaded; }

/// Gets the 'naming class' (in the sense of C++0x
/// [class.access.base]p5) of the lookup.  This is the scope
/// that was looked in to find these results.
CXXRecordDecl *getNamingClass() { return NamingClass; }
const CXXRecordDecl *getNamingClass() const { return NamingClass; }

SourceLocation getBeginLoc() const LLVM_READONLY__attribute__((__pure__)) {
  if (NestedNameSpecifierLoc l = getQualifierLoc())
    return l.getBeginLoc();
  return getNameInfo().getBeginLoc();
}

SourceLocation getEndLoc() const LLVM_READONLY__attribute__((__pure__)) {
  if (hasExplicitTemplateArgs())
    return getRAngleLoc();
  return getNameInfo().getEndLoc();
}

child_range children() {
  return child_range(child_iterator(), child_iterator());
}

const_child_range children() const {
  return const_child_range(const_child_iterator(), const_child_iterator());
}

static bool classof(const Stmt *T) {
  return T->getStmtClass() == UnresolvedLookupExprClass;
}
3249};

3251/// A qualified reference to a name whose declaration cannot
3252/// yet be resolved.
3253///
3254/// DependentScopeDeclRefExpr is similar to DeclRefExpr in that
3255/// it expresses a reference to a declaration such as
3256/// X<T>::value. The difference, however, is that an
3257/// DependentScopeDeclRefExpr node is used only within C++ templates when
3258/// the qualification (e.g., X<T>::) refers to a dependent type. In
3259/// this case, X<T>::value cannot resolve to a declaration because the
3260/// declaration will differ from one instantiation of X<T> to the
3261/// next. Therefore, DependentScopeDeclRefExpr keeps track of the
3262/// qualifier (X<T>::) and the name of the entity being referenced
3263/// ("value"). Such expressions will instantiate to a DeclRefExpr once the
3264/// declaration can be found.
3265class DependentScopeDeclRefExpr final
  : public Expr,
    private llvm::TrailingObjects<DependentScopeDeclRefExpr,
                                  ASTTemplateKWAndArgsInfo,
                                  TemplateArgumentLoc> {
friend class ASTStmtReader;
friend class ASTStmtWriter;
friend TrailingObjects;

/// The nested-name-specifier that qualifies this unresolved
/// declaration name.
NestedNameSpecifierLoc QualifierLoc;

/// The name of the entity we will be referencing.
DeclarationNameInfo NameInfo;

DependentScopeDeclRefExpr(QualType Ty, NestedNameSpecifierLoc QualifierLoc,
                          SourceLocation TemplateKWLoc,
                          const DeclarationNameInfo &NameInfo,
                          const TemplateArgumentListInfo *Args);

size_t numTrailingObjects(OverloadToken<ASTTemplateKWAndArgsInfo>) const {
  return hasTemplateKWAndArgsInfo();
}

bool hasTemplateKWAndArgsInfo() const {
  return DependentScopeDeclRefExprBits.HasTemplateKWAndArgsInfo;
}

3294public:
static DependentScopeDeclRefExpr *
Create(const ASTContext &Context, NestedNameSpecifierLoc QualifierLoc,
       SourceLocation TemplateKWLoc, const DeclarationNameInfo &NameInfo,
       const TemplateArgumentListInfo *TemplateArgs);

static DependentScopeDeclRefExpr *CreateEmpty(const ASTContext &Context,
                                              bool HasTemplateKWAndArgsInfo,
                                              unsigned NumTemplateArgs);

/// Retrieve the name that this expression refers to.
const DeclarationNameInfo &getNameInfo() const { return NameInfo; }

/// Retrieve the name that this expression refers to.
DeclarationName getDeclName() const { return NameInfo.getName(); }

/// Retrieve the location of the name within the expression.
///
/// For example, in "X<T>::value" this is the location of "value".
SourceLocation getLocation() const { return NameInfo.getLoc(); }

/// Retrieve the nested-name-specifier that qualifies the
/// name, with source location information.
NestedNameSpecifierLoc getQualifierLoc() const { return QualifierLoc; }

/// Retrieve the nested-name-specifier that qualifies this
/// declaration.
NestedNameSpecifier *getQualifier() const {
  return QualifierLoc.getNestedNameSpecifier();
}

/// Retrieve the location of the template keyword preceding
/// this name, if any.
SourceLocation getTemplateKeywordLoc() const {
  if (!hasTemplateKWAndArgsInfo())
    return SourceLocation();
  return getTrailingObjects<ASTTemplateKWAndArgsInfo>()->TemplateKWLoc;
}

/// Retrieve the location of the left angle bracket starting the
/// explicit template argument list following the name, if any.
SourceLocation getLAngleLoc() const {
  if (!hasTemplateKWAndArgsInfo())
    return SourceLocation();
  return getTrailingObjects<ASTTemplateKWAndArgsInfo>()->LAngleLoc;
}

/// Retrieve the location of the right angle bracket ending the
/// explicit template argument list following the name, if any.
SourceLocation getRAngleLoc() const {
  if (!hasTemplateKWAndArgsInfo())
    return SourceLocation();
  return getTrailingObjects<ASTTemplateKWAndArgsInfo>()->RAngleLoc;
}

/// Determines whether the name was preceded by the template keyword.
bool hasTemplateKeyword() const { return getTemplateKeywordLoc().isValid(); }

/// Determines whether this lookup had explicit template arguments.
bool hasExplicitTemplateArgs() const { return getLAngleLoc().isValid(); }

/// Copies the template arguments (if present) into the given
/// structure.
void copyTemplateArgumentsInto(TemplateArgumentListInfo &List) const {
  if (hasExplicitTemplateArgs())
    getTrailingObjects<ASTTemplateKWAndArgsInfo>()->copyInto(
        getTrailingObjects<TemplateArgumentLoc>(), List);
}

TemplateArgumentLoc const *getTemplateArgs() const {
  if (!hasExplicitTemplateArgs())
    return nullptr;

  return getTrailingObjects<TemplateArgumentLoc>();
}

unsigned getNumTemplateArgs() const {
  if (!hasExplicitTemplateArgs())
    return 0;

  return getTrailingObjects<ASTTemplateKWAndArgsInfo>()->NumTemplateArgs;
}

ArrayRef<TemplateArgumentLoc> template_arguments() const {
  return {getTemplateArgs(), getNumTemplateArgs()};
}

/// Note: getBeginLoc() is the start of the whole DependentScopeDeclRefExpr,
/// and differs from getLocation().getStart().
SourceLocation getBeginLoc() const LLVM_READONLY__attribute__((__pure__)) {
  return QualifierLoc.getBeginLoc();
}

SourceLocation getEndLoc() const LLVM_READONLY__attribute__((__pure__)) {
  if (hasExplicitTemplateArgs())
    return getRAngleLoc();
  return getLocation();
}

static bool classof(const Stmt *T) {
  return T->getStmtClass() == DependentScopeDeclRefExprClass;
}

child_range children() {
  return child_range(child_iterator(), child_iterator());
}

const_child_range children() const {
  return const_child_range(const_child_iterator(), const_child_iterator());
}
3404};

3406/// Represents an expression -- generally a full-expression -- that
3407/// introduces cleanups to be run at the end of the sub-expression's
3408/// evaluation.  The most common source of expression-introduced
3409/// cleanups is temporary objects in C++, but several other kinds of
3410/// expressions can create cleanups, including basically every
3411/// call in ARC that returns an Objective-C pointer.
3412///
3413/// This expression also tracks whether the sub-expression contains a
3414/// potentially-evaluated block literal.  The lifetime of a block
3415/// literal is the extent of the enclosing scope.
3416class ExprWithCleanups final
  : public FullExpr,
    private llvm::TrailingObjects<
        ExprWithCleanups,
        llvm::PointerUnion<BlockDecl *, CompoundLiteralExpr *>> {
3421public:
/// The type of objects that are kept in the cleanup.
/// It's useful to remember the set of blocks and block-scoped compound
/// literals; we could also remember the set of temporaries, but there's
/// currently no need.
using CleanupObject = llvm::PointerUnion<BlockDecl *, CompoundLiteralExpr *>;

3428private:
friend class ASTStmtReader;
friend TrailingObjects;

ExprWithCleanups(EmptyShell, unsigned NumObjects);
ExprWithCleanups(Expr *SubExpr, bool CleanupsHaveSideEffects,
                 ArrayRef<CleanupObject> Objects);

3436public:
static ExprWithCleanups *Create(const ASTContext &C, EmptyShell empty,
                                unsigned numObjects);

static ExprWithCleanups *Create(const ASTContext &C, Expr *subexpr,
                                bool CleanupsHaveSideEffects,
                                ArrayRef<CleanupObject> objects);

ArrayRef<CleanupObject> getObjects() const {
  return llvm::ArrayRef(getTrailingObjects<CleanupObject>(), getNumObjects());
}

unsigned getNumObjects() const { return ExprWithCleanupsBits.NumObjects; }

CleanupObject getObject(unsigned i) const {
  assert(i < getNumObjects() && "Index out of range")(static_cast <bool> (i < getNumObjects() && "Index out of range"
) ? void (0) : __assert_fail ("i < getNumObjects() && \"Index out of range\""
, "clang/include/clang/AST/ExprCXX.h", 3451, __extension__ __PRETTY_FUNCTION__
));
  return getObjects()[i];
}

bool cleanupsHaveSideEffects() const {
  return ExprWithCleanupsBits.CleanupsHaveSideEffects;
}

SourceLocation getBeginLoc() const LLVM_READONLY__attribute__((__pure__)) {
  return SubExpr->getBeginLoc();
}

SourceLocation getEndLoc() const LLVM_READONLY__attribute__((__pure__)) {
  return SubExpr->getEndLoc();
}

// Implement isa/cast/dyncast/etc.
static bool classof(const Stmt *T) {
  return T->getStmtClass() == ExprWithCleanupsClass;
}

// Iterators
child_range children() { return child_range(&SubExpr, &SubExpr + 1); }

const_child_range children() const {
  return const_child_range(&SubExpr, &SubExpr + 1);
}
3478};

3480/// Describes an explicit type conversion that uses functional
3481/// notion but could not be resolved because one or more arguments are
3482/// type-dependent.
3483///
3484/// The explicit type conversions expressed by
3485/// CXXUnresolvedConstructExpr have the form <tt>T(a1, a2, ..., aN)</tt>,
3486/// where \c T is some type and \c a1, \c a2, ..., \c aN are values, and
3487/// either \c T is a dependent type or one or more of the <tt>a</tt>'s is
3488/// type-dependent. For example, this would occur in a template such
3489/// as:
3490///
3491/// \code
3492///   template<typename T, typename A1>
3493///   inline T make_a(const A1& a1) {
3494///     return T(a1);
3495///   }
3496/// \endcode
3497///
3498/// When the returned expression is instantiated, it may resolve to a
3499/// constructor call, conversion function call, or some kind of type
3500/// conversion.
3501class CXXUnresolvedConstructExpr final
  : public Expr,
    private llvm::TrailingObjects<CXXUnresolvedConstructExpr, Expr *> {
friend class ASTStmtReader;
friend TrailingObjects;

/// The type being constructed, and whether the construct expression models
/// list initialization or not.
llvm::PointerIntPair<TypeSourceInfo *, 1> TypeAndInitForm;

/// The location of the left parentheses ('(').
SourceLocation LParenLoc;

/// The location of the right parentheses (')').
SourceLocation RParenLoc;

CXXUnresolvedConstructExpr(QualType T, TypeSourceInfo *TSI,
                           SourceLocation LParenLoc, ArrayRef<Expr *> Args,
                           SourceLocation RParenLoc, bool IsListInit);

CXXUnresolvedConstructExpr(EmptyShell Empty, unsigned NumArgs)
    : Expr(CXXUnresolvedConstructExprClass, Empty) {
  CXXUnresolvedConstructExprBits.NumArgs = NumArgs;
}

3526public:
static CXXUnresolvedConstructExpr *
Create(const ASTContext &Context, QualType T, TypeSourceInfo *TSI,
       SourceLocation LParenLoc, ArrayRef<Expr *> Args,
       SourceLocation RParenLoc, bool IsListInit);

static CXXUnresolvedConstructExpr *CreateEmpty(const ASTContext &Context,
                                               unsigned NumArgs);

/// Retrieve the type that is being constructed, as specified
/// in the source code.
QualType getTypeAsWritten() const { return getTypeSourceInfo()->getType(); }

/// Retrieve the type source information for the type being
/// constructed.
TypeSourceInfo *getTypeSourceInfo() const {
  return TypeAndInitForm.getPointer();
}

/// Retrieve the location of the left parentheses ('(') that
/// precedes the argument list.
SourceLocation getLParenLoc() const { return LParenLoc; }
void setLParenLoc(SourceLocation L) { LParenLoc = L; }

/// Retrieve the location of the right parentheses (')') that
/// follows the argument list.
SourceLocation getRParenLoc() const { return RParenLoc; }
void setRParenLoc(SourceLocation L) { RParenLoc = L; }

/// Determine whether this expression models list-initialization.
/// If so, there will be exactly one subexpression, which will be
/// an InitListExpr.
bool isListInitialization() const { return TypeAndInitForm.getInt(); }

/// Retrieve the number of arguments.
unsigned getNumArgs() const { return CXXUnresolvedConstructExprBits.NumArgs; }

using arg_iterator = Expr **;
using arg_range = llvm::iterator_range<arg_iterator>;

arg_iterator arg_begin() { return getTrailingObjects<Expr *>(); }
arg_iterator arg_end() { return arg_begin() + getNumArgs(); }
arg_range arguments() { return arg_range(arg_begin(), arg_end()); }

using const_arg_iterator = const Expr* const *;
using const_arg_range = llvm::iterator_range<const_arg_iterator>;

const_arg_iterator arg_begin() const { return getTrailingObjects<Expr *>(); }
const_arg_iterator arg_end() const { return arg_begin() + getNumArgs(); }
const_arg_range arguments() const {
  return const_arg_range(arg_begin(), arg_end());
}

Expr *getArg(unsigned I) {
  assert(I < getNumArgs() && "Argument index out-of-range")(static_cast <bool> (I < getNumArgs() && "Argument index out-of-range"
) ? void (0) : __assert_fail ("I < getNumArgs() && \"Argument index out-of-range\""
, "clang/include/clang/AST/ExprCXX.h", 3580, __extension__ __PRETTY_FUNCTION__
));
  return arg_begin()[I];
}

const Expr *getArg(unsigned I) const {
  assert(I < getNumArgs() && "Argument index out-of-range")(static_cast <bool> (I < getNumArgs() && "Argument index out-of-range"
) ? void (0) : __assert_fail ("I < getNumArgs() && \"Argument index out-of-range\""
, "clang/include/clang/AST/ExprCXX.h", 3585, __extension__ __PRETTY_FUNCTION__
));
  return arg_begin()[I];
}

void setArg(unsigned I, Expr *E) {
  assert(I < getNumArgs() && "Argument index out-of-range")(static_cast <bool> (I < getNumArgs() && "Argument index out-of-range"
) ? void (0) : __assert_fail ("I < getNumArgs() && \"Argument index out-of-range\""
, "clang/include/clang/AST/ExprCXX.h", 3590, __extension__ __PRETTY_FUNCTION__
));
  arg_begin()[I] = E;
}

SourceLocation getBeginLoc() const LLVM_READONLY__attribute__((__pure__));
SourceLocation getEndLoc() const LLVM_READONLY__attribute__((__pure__)) {
  if (!RParenLoc.isValid() && getNumArgs() > 0)
    return getArg(getNumArgs() - 1)->getEndLoc();
  return RParenLoc;
}

static bool classof(const Stmt *T) {
  return T->getStmtClass() == CXXUnresolvedConstructExprClass;
}

// Iterators
child_range children() {
  auto **begin = reinterpret_cast<Stmt **>(arg_begin());
  return child_range(begin, begin + getNumArgs());
}

const_child_range children() const {
  auto **begin = reinterpret_cast<Stmt **>(
      const_cast<CXXUnresolvedConstructExpr *>(this)->arg_begin());
  return const_child_range(begin, begin + getNumArgs());
}
3616};

3618/// Represents a C++ member access expression where the actual
3619/// member referenced could not be resolved because the base
3620/// expression or the member name was dependent.
3621///
3622/// Like UnresolvedMemberExprs, these can be either implicit or
3623/// explicit accesses.  It is only possible to get one of these with
3624/// an implicit access if a qualifier is provided.
3625class CXXDependentScopeMemberExpr final
  : public Expr,
    private llvm::TrailingObjects<CXXDependentScopeMemberExpr,
                                  ASTTemplateKWAndArgsInfo,
                                  TemplateArgumentLoc, NamedDecl *> {
friend class ASTStmtReader;
friend class ASTStmtWriter;
friend TrailingObjects;

/// The expression for the base pointer or class reference,
/// e.g., the \c x in x.f.  Can be null in implicit accesses.
Stmt *Base;

/// The type of the base expression.  Never null, even for
/// implicit accesses.
QualType BaseType;

/// The nested-name-specifier that precedes the member name, if any.
/// FIXME: This could be in principle store as a trailing object.
/// However the performance impact of doing so should be investigated first.
NestedNameSpecifierLoc QualifierLoc;

/// The member to which this member expression refers, which
/// can be name, overloaded operator, or destructor.
///
/// FIXME: could also be a template-id
DeclarationNameInfo MemberNameInfo;

// CXXDependentScopeMemberExpr is followed by several trailing objects,
// some of which optional. They are in order:
//
// * An optional ASTTemplateKWAndArgsInfo for the explicitly specified
//   template keyword and arguments. Present if and only if
//   hasTemplateKWAndArgsInfo().
//
// * An array of getNumTemplateArgs() TemplateArgumentLoc containing location
//   information for the explicitly specified template arguments.
//
// * An optional NamedDecl *. In a qualified member access expression such
//   as t->Base::f, this member stores the resolves of name lookup in the
//   context of the member access expression, to be used at instantiation
//   time. Present if and only if hasFirstQualifierFoundInScope().

bool hasTemplateKWAndArgsInfo() const {
  return CXXDependentScopeMemberExprBits.HasTemplateKWAndArgsInfo;
}

bool hasFirstQualifierFoundInScope() const {
  return CXXDependentScopeMemberExprBits.HasFirstQualifierFoundInScope;
}

unsigned numTrailingObjects(OverloadToken<ASTTemplateKWAndArgsInfo>) const {
  return hasTemplateKWAndArgsInfo();
}

unsigned numTrailingObjects(OverloadToken<TemplateArgumentLoc>) const {
  return getNumTemplateArgs();
}

unsigned numTrailingObjects(OverloadToken<NamedDecl *>) const {
  return hasFirstQualifierFoundInScope();
}

CXXDependentScopeMemberExpr(const ASTContext &Ctx, Expr *Base,
                            QualType BaseType, bool IsArrow,
                            SourceLocation OperatorLoc,
                            NestedNameSpecifierLoc QualifierLoc,
                            SourceLocation TemplateKWLoc,
                            NamedDecl *FirstQualifierFoundInScope,
                            DeclarationNameInfo MemberNameInfo,
                            const TemplateArgumentListInfo *TemplateArgs);

CXXDependentScopeMemberExpr(EmptyShell Empty, bool HasTemplateKWAndArgsInfo,
                            bool HasFirstQualifierFoundInScope);

3700public:
static CXXDependentScopeMemberExpr *
Create(const ASTContext &Ctx, Expr *Base, QualType BaseType, bool IsArrow,
       SourceLocation OperatorLoc, NestedNameSpecifierLoc QualifierLoc,
       SourceLocation TemplateKWLoc, NamedDecl *FirstQualifierFoundInScope,
       DeclarationNameInfo MemberNameInfo,
       const TemplateArgumentListInfo *TemplateArgs);

static CXXDependentScopeMemberExpr *
CreateEmpty(const ASTContext &Ctx, bool HasTemplateKWAndArgsInfo,
            unsigned NumTemplateArgs, bool HasFirstQualifierFoundInScope);

/// True if this is an implicit access, i.e. one in which the
/// member being accessed was not written in the source.  The source
/// location of the operator is invalid in this case.
bool isImplicitAccess() const {
  if (!Base)
    return true;
  return cast<Expr>(Base)->isImplicitCXXThis();
}

/// Retrieve the base object of this member expressions,
/// e.g., the \c x in \c x.m.
Expr *getBase() const {
  assert(!isImplicitAccess())(static_cast <bool> (!isImplicitAccess()) ? void (0) : __assert_fail
 ("!isImplicitAccess()", "clang/include/clang/AST/ExprCXX.h",
 3724, __extension__ __PRETTY_FUNCTION__));
  return cast<Expr>(Base);
}

QualType getBaseType() const { return BaseType; }

/// Determine whether this member expression used the '->'
/// operator; otherwise, it used the '.' operator.
bool isArrow() const { return CXXDependentScopeMemberExprBits.IsArrow; }

/// Retrieve the location of the '->' or '.' operator.
SourceLocation getOperatorLoc() const {
  return CXXDependentScopeMemberExprBits.OperatorLoc;
}

/// Retrieve the nested-name-specifier that qualifies the member name.
NestedNameSpecifier *getQualifier() const {
  return QualifierLoc.getNestedNameSpecifier();
}

/// Retrieve the nested-name-specifier that qualifies the member
/// name, with source location information.
NestedNameSpecifierLoc getQualifierLoc() const { return QualifierLoc; }

/// Retrieve the first part of the nested-name-specifier that was
/// found in the scope of the member access expression when the member access
/// was initially parsed.
///
/// This function only returns a useful result when member access expression
/// uses a qualified member name, e.g., "x.Base::f". Here, the declaration
/// returned by this function describes what was found by unqualified name
/// lookup for the identifier "Base" within the scope of the member access
/// expression itself. At template instantiation time, this information is
/// combined with the results of name lookup into the type of the object
/// expression itself (the class type of x).
NamedDecl *getFirstQualifierFoundInScope() const {
  if (!hasFirstQualifierFoundInScope())
    return nullptr;
  return *getTrailingObjects<NamedDecl *>();
}

/// Retrieve the name of the member that this expression refers to.
const DeclarationNameInfo &getMemberNameInfo() const {
  return MemberNameInfo;
}

/// Retrieve the name of the member that this expression refers to.
DeclarationName getMember() const { return MemberNameInfo.getName(); }

// Retrieve the location of the name of the member that this
// expression refers to.
SourceLocation getMemberLoc() const { return MemberNameInfo.getLoc(); }

/// Retrieve the location of the template keyword preceding the
/// member name, if any.
SourceLocation getTemplateKeywordLoc() const {
  if (!hasTemplateKWAndArgsInfo())
    return SourceLocation();
  return getTrailingObjects<ASTTemplateKWAndArgsInfo>()->TemplateKWLoc;
}

/// Retrieve the location of the left angle bracket starting the
/// explicit template argument list following the member name, if any.
SourceLocation getLAngleLoc() const {
  if (!hasTemplateKWAndArgsInfo())
    return SourceLocation();
  return getTrailingObjects<ASTTemplateKWAndArgsInfo>()->LAngleLoc;
}

/// Retrieve the location of the right angle bracket ending the
/// explicit template argument list following the member name, if any.
SourceLocation getRAngleLoc() const {
  if (!hasTemplateKWAndArgsInfo())
    return SourceLocation();
  return getTrailingObjects<ASTTemplateKWAndArgsInfo>()->RAngleLoc;
}

/// Determines whether the member name was preceded by the template keyword.
bool hasTemplateKeyword() const { return getTemplateKeywordLoc().isValid(); }

/// Determines whether this member expression actually had a C++
/// template argument list explicitly specified, e.g., x.f<int>.
bool hasExplicitTemplateArgs() const { return getLAngleLoc().isValid(); }

/// Copies the template arguments (if present) into the given
/// structure.
void copyTemplateArgumentsInto(TemplateArgumentListInfo &List) const {
  if (hasExplicitTemplateArgs())
    getTrailingObjects<ASTTemplateKWAndArgsInfo>()->copyInto(
        getTrailingObjects<TemplateArgumentLoc>(), List);
}

/// Retrieve the template arguments provided as part of this
/// template-id.
const TemplateArgumentLoc *getTemplateArgs() const {
  if (!hasExplicitTemplateArgs())
    return nullptr;

  return getTrailingObjects<TemplateArgumentLoc>();
}

/// Retrieve the number of template arguments provided as part of this
/// template-id.
unsigned getNumTemplateArgs() const {
  if (!hasExplicitTemplateArgs())
    return 0;

  return getTrailingObjects<ASTTemplateKWAndArgsInfo>()->NumTemplateArgs;
}

ArrayRef<TemplateArgumentLoc> template_arguments() const {
  return {getTemplateArgs(), getNumTemplateArgs()};
}

SourceLocation getBeginLoc() const LLVM_READONLY__attribute__((__pure__)) {
  if (!isImplicitAccess())
    return Base->getBeginLoc();
  if (getQualifier())
    return getQualifierLoc().getBeginLoc();
  return MemberNameInfo.getBeginLoc();
}

SourceLocation getEndLoc() const LLVM_READONLY__attribute__((__pure__)) {
  if (hasExplicitTemplateArgs())
    return getRAngleLoc();
  return MemberNameInfo.getEndLoc();
}

static bool classof(const Stmt *T) {
  return T->getStmtClass() == CXXDependentScopeMemberExprClass;
}

// Iterators
child_range children() {
  if (isImplicitAccess())
    return child_range(child_iterator(), child_iterator());
  return child_range(&Base, &Base + 1);
}

const_child_range children() const {
  if (isImplicitAccess())
    return const_child_range(const_child_iterator(), const_child_iterator());
  return const_child_range(&Base, &Base + 1);
}
3868};

3870/// Represents a C++ member access expression for which lookup
3871/// produced a set of overloaded functions.
3872///
3873/// The member access may be explicit or implicit:
3874/// \code
3875///    struct A {
3876///      int a, b;
3877///      int explicitAccess() { return this->a + this->A::b; }
3878///      int implicitAccess() { return a + A::b; }
3879///    };
3880/// \endcode
3881///
3882/// In the final AST, an explicit access always becomes a MemberExpr.
3883/// An implicit access may become either a MemberExpr or a
3884/// DeclRefExpr, depending on whether the member is static.
3885class UnresolvedMemberExpr final
  : public OverloadExpr,
    private llvm::TrailingObjects<UnresolvedMemberExpr, DeclAccessPair,
                                  ASTTemplateKWAndArgsInfo,
                                  TemplateArgumentLoc> {
friend class ASTStmtReader;
friend class OverloadExpr;
friend TrailingObjects;

/// The expression for the base pointer or class reference,
/// e.g., the \c x in x.f.
///
/// This can be null if this is an 'unbased' member expression.
Stmt *Base;

/// The type of the base expression; never null.
QualType BaseType;

/// The location of the '->' or '.' operator.
SourceLocation OperatorLoc;

// UnresolvedMemberExpr is followed by several trailing objects.
// They are in order:
//
// * An array of getNumResults() DeclAccessPair for the results. These are
//   undesugared, which is to say, they may include UsingShadowDecls.
//   Access is relative to the naming class.
//
// * An optional ASTTemplateKWAndArgsInfo for the explicitly specified
//   template keyword and arguments. Present if and only if
//   hasTemplateKWAndArgsInfo().
//
// * An array of getNumTemplateArgs() TemplateArgumentLoc containing
//   location information for the explicitly specified template arguments.

UnresolvedMemberExpr(const ASTContext &Context, bool HasUnresolvedUsing,
                     Expr *Base, QualType BaseType, bool IsArrow,
                     SourceLocation OperatorLoc,
                     NestedNameSpecifierLoc QualifierLoc,
                     SourceLocation TemplateKWLoc,
                     const DeclarationNameInfo &MemberNameInfo,
                     const TemplateArgumentListInfo *TemplateArgs,
                     UnresolvedSetIterator Begin, UnresolvedSetIterator End);

UnresolvedMemberExpr(EmptyShell Empty, unsigned NumResults,
                     bool HasTemplateKWAndArgsInfo);

unsigned numTrailingObjects(OverloadToken<DeclAccessPair>) const {
  return getNumDecls();
}

unsigned numTrailingObjects(OverloadToken<ASTTemplateKWAndArgsInfo>) const {
  return hasTemplateKWAndArgsInfo();
}

3940public:
static UnresolvedMemberExpr *
Create(const ASTContext &Context, bool HasUnresolvedUsing, Expr *Base,
       QualType BaseType, bool IsArrow, SourceLocation OperatorLoc,
       NestedNameSpecifierLoc QualifierLoc, SourceLocation TemplateKWLoc,
       const DeclarationNameInfo &MemberNameInfo,
       const TemplateArgumentListInfo *TemplateArgs,
       UnresolvedSetIterator Begin, UnresolvedSetIterator End);

static UnresolvedMemberExpr *CreateEmpty(const ASTContext &Context,
                                         unsigned NumResults,
                                         bool HasTemplateKWAndArgsInfo,
                                         unsigned NumTemplateArgs);

/// True if this is an implicit access, i.e., one in which the
/// member being accessed was not written in the source.
///
/// The source location of the operator is invalid in this case.
bool isImplicitAccess() const;

/// Retrieve the base object of this member expressions,
/// e.g., the \c x in \c x.m.
Expr *getBase() {
  assert(!isImplicitAccess())(static_cast <bool> (!isImplicitAccess()) ? void (0) : __assert_fail
 ("!isImplicitAccess()", "clang/include/clang/AST/ExprCXX.h",
 3963, __extension__ __PRETTY_FUNCTION__));
  return cast<Expr>(Base);
}
const Expr *getBase() const {
  assert(!isImplicitAccess())(static_cast <bool> (!isImplicitAccess()) ? void (0) : __assert_fail
 ("!isImplicitAccess()", "clang/include/clang/AST/ExprCXX.h",
 3967, __extension__ __PRETTY_FUNCTION__));
  return cast<Expr>(Base);
}

QualType getBaseType() const { return BaseType; }

/// Determine whether the lookup results contain an unresolved using
/// declaration.
bool hasUnresolvedUsing() const {
  return UnresolvedMemberExprBits.HasUnresolvedUsing;
}

/// Determine whether this member expression used the '->'
/// operator; otherwise, it used the '.' operator.
bool isArrow() const { return UnresolvedMemberExprBits.IsArrow; }

/// Retrieve the location of the '->' or '.' operator.
SourceLocation getOperatorLoc() const { return OperatorLoc; }

/// Retrieve the naming class of this lookup.
CXXRecordDecl *getNamingClass();
const CXXRecordDecl *getNamingClass() const {
  return const_cast<UnresolvedMemberExpr *>(this)->getNamingClass();
}

/// Retrieve the full name info for the member that this expression
/// refers to.
const DeclarationNameInfo &getMemberNameInfo() const { return getNameInfo(); }

/// Retrieve the name of the member that this expression refers to.
DeclarationName getMemberName() const { return getName(); }

/// Retrieve the location of the name of the member that this
/// expression refers to.
SourceLocation getMemberLoc() const { return getNameLoc(); }

/// Return the preferred location (the member name) for the arrow when
/// diagnosing a problem with this expression.
SourceLocation getExprLoc() const LLVM_READONLY__attribute__((__pure__)) { return getMemberLoc(); }

SourceLocation getBeginLoc() const LLVM_READONLY__attribute__((__pure__)) {
  if (!isImplicitAccess())
    return Base->getBeginLoc();
  if (NestedNameSpecifierLoc l = getQualifierLoc())
    return l.getBeginLoc();
  return getMemberNameInfo().getBeginLoc();
}

SourceLocation getEndLoc() const LLVM_READONLY__attribute__((__pure__)) {
  if (hasExplicitTemplateArgs())
    return getRAngleLoc();
  return getMemberNameInfo().getEndLoc();
}

static bool classof(const Stmt *T) {
  return T->getStmtClass() == UnresolvedMemberExprClass;
}

// Iterators
child_range children() {
  if (isImplicitAccess())
    return child_range(child_iterator(), child_iterator());
  return child_range(&Base, &Base + 1);
}

const_child_range children() const {
  if (isImplicitAccess())
    return const_child_range(const_child_iterator(), const_child_iterator());
  return const_child_range(&Base, &Base + 1);
}
4037};

4039DeclAccessPair *OverloadExpr::getTrailingResults() {
if (auto *ULE = dyn_cast<UnresolvedLookupExpr>(this))
  return ULE->getTrailingObjects<DeclAccessPair>();
return cast<UnresolvedMemberExpr>(this)->getTrailingObjects<DeclAccessPair>();
4043}

4045ASTTemplateKWAndArgsInfo *OverloadExpr::getTrailingASTTemplateKWAndArgsInfo() {
if (!hasTemplateKWAndArgsInfo())
  return nullptr;

if (auto *ULE = dyn_cast<UnresolvedLookupExpr>(this))
  return ULE->getTrailingObjects<ASTTemplateKWAndArgsInfo>();
return cast<UnresolvedMemberExpr>(this)
    ->getTrailingObjects<ASTTemplateKWAndArgsInfo>();
4053}

4055TemplateArgumentLoc *OverloadExpr::getTrailingTemplateArgumentLoc() {
if (auto *ULE = dyn_cast<UnresolvedLookupExpr>(this))
  return ULE->getTrailingObjects<TemplateArgumentLoc>();
return cast<UnresolvedMemberExpr>(this)
    ->getTrailingObjects<TemplateArgumentLoc>();
4060}

4062CXXRecordDecl *OverloadExpr::getNamingClass() {
if (auto *ULE = dyn_cast<UnresolvedLookupExpr>(this))
  return ULE->getNamingClass();
return cast<UnresolvedMemberExpr>(this)->getNamingClass();
4066}

4068/// Represents a C++11 noexcept expression (C++ [expr.unary.noexcept]).
4069///
4070/// The noexcept expression tests whether a given expression might throw. Its
4071/// result is a boolean constant.
4072class CXXNoexceptExpr : public Expr {
friend class ASTStmtReader;

Stmt *Operand;
SourceRange Range;

4078public:
CXXNoexceptExpr(QualType Ty, Expr *Operand, CanThrowResult Val,
                SourceLocation Keyword, SourceLocation RParen)
    : Expr(CXXNoexceptExprClass, Ty, VK_PRValue, OK_Ordinary),
      Operand(Operand), Range(Keyword, RParen) {
  CXXNoexceptExprBits.Value = Val == CT_Cannot;
  setDependence(computeDependence(this, Val));
}

CXXNoexceptExpr(EmptyShell Empty) : Expr(CXXNoexceptExprClass, Empty) {}

Expr *getOperand() const { return static_cast<Expr *>(Operand); }

SourceLocation getBeginLoc() const { return Range.getBegin(); }
SourceLocation getEndLoc() const { return Range.getEnd(); }
SourceRange getSourceRange() const { return Range; }

bool getValue() const { return CXXNoexceptExprBits.Value; }

static bool classof(const Stmt *T) {
  return T->getStmtClass() == CXXNoexceptExprClass;
}

// Iterators
child_range children() { return child_range(&Operand, &Operand + 1); }

const_child_range children() const {
  return const_child_range(&Operand, &Operand + 1);
}
4107};

4109/// Represents a C++11 pack expansion that produces a sequence of
4110/// expressions.
4111///
4112/// A pack expansion expression contains a pattern (which itself is an
4113/// expression) followed by an ellipsis. For example:
4114///
4115/// \code
4116/// template<typename F, typename ...Types>
4117/// void forward(F f, Types &&...args) {
4118///   f(static_cast<Types&&>(args)...);
4119/// }
4120/// \endcode
4121///
4122/// Here, the argument to the function object \c f is a pack expansion whose
4123/// pattern is \c static_cast<Types&&>(args). When the \c forward function
4124/// template is instantiated, the pack expansion will instantiate to zero or
4125/// or more function arguments to the function object \c f.
4126class PackExpansionExpr : public Expr {
friend class ASTStmtReader;
friend class ASTStmtWriter;

SourceLocation EllipsisLoc;

/// The number of expansions that will be produced by this pack
/// expansion expression, if known.
///
/// When zero, the number of expansions is not known. Otherwise, this value
/// is the number of expansions + 1.
unsigned NumExpansions;

Stmt *Pattern;

4141public:
PackExpansionExpr(QualType T, Expr *Pattern, SourceLocation EllipsisLoc,
                  std::optional<unsigned> NumExpansions)
    : Expr(PackExpansionExprClass, T, Pattern->getValueKind(),
           Pattern->getObjectKind()),
      EllipsisLoc(EllipsisLoc),
      NumExpansions(NumExpansions ? *NumExpansions + 1 : 0),
      Pattern(Pattern) {
  setDependence(computeDependence(this));
}

PackExpansionExpr(EmptyShell Empty) : Expr(PackExpansionExprClass, Empty) {}

/// Retrieve the pattern of the pack expansion.
Expr *getPattern() { return reinterpret_cast<Expr *>(Pattern); }

/// Retrieve the pattern of the pack expansion.
const Expr *getPattern() const { return reinterpret_cast<Expr *>(Pattern); }

/// Retrieve the location of the ellipsis that describes this pack
/// expansion.
SourceLocation getEllipsisLoc() const { return EllipsisLoc; }

/// Determine the number of expansions that will be produced when
/// this pack expansion is instantiated, if already known.
std::optional<unsigned> getNumExpansions() const {
  if (NumExpansions)
    return NumExpansions - 1;

  return std::nullopt;
}

SourceLocation getBeginLoc() const LLVM_READONLY__attribute__((__pure__)) {
  return Pattern->getBeginLoc();
}

SourceLocation getEndLoc() const LLVM_READONLY__attribute__((__pure__)) { return EllipsisLoc; }

static bool classof(const Stmt *T) {
  return T->getStmtClass() == PackExpansionExprClass;
}

// Iterators
child_range children() {
  return child_range(&Pattern, &Pattern + 1);
}

const_child_range children() const {
  return const_child_range(&Pattern, &Pattern + 1);
}
4191};

4193/// Represents an expression that computes the length of a parameter
4194/// pack.
4195///
4196/// \code
4197/// template<typename ...Types>
4198/// struct count {
4199///   static const unsigned value = sizeof...(Types);
4200/// };
4201/// \endcode
4202class SizeOfPackExpr final
  : public Expr,
    private llvm::TrailingObjects<SizeOfPackExpr, TemplateArgument> {
friend class ASTStmtReader;
friend class ASTStmtWriter;
friend TrailingObjects;

/// The location of the \c sizeof keyword.
SourceLocation OperatorLoc;

/// The location of the name of the parameter pack.
SourceLocation PackLoc;

/// The location of the closing parenthesis.
SourceLocation RParenLoc;

/// The length of the parameter pack, if known.
///
/// When this expression is not value-dependent, this is the length of
/// the pack. When the expression was parsed rather than instantiated
/// (and thus is value-dependent), this is zero.
///
/// After partial substitution into a sizeof...(X) expression (for instance,
/// within an alias template or during function template argument deduction),
/// we store a trailing array of partially-substituted TemplateArguments,
/// and this is the length of that array.
unsigned Length;

/// The parameter pack.
NamedDecl *Pack = nullptr;

/// Create an expression that computes the length of
/// the given parameter pack.
SizeOfPackExpr(QualType SizeType, SourceLocation OperatorLoc, NamedDecl *Pack,
               SourceLocation PackLoc, SourceLocation RParenLoc,
               std::optional<unsigned> Length,
               ArrayRef<TemplateArgument> PartialArgs)
    : Expr(SizeOfPackExprClass, SizeType, VK_PRValue, OK_Ordinary),
      OperatorLoc(OperatorLoc), PackLoc(PackLoc), RParenLoc(RParenLoc),
      Length(Length ? *Length : PartialArgs.size()), Pack(Pack) {
  assert((!Length || PartialArgs.empty()) &&(static_cast <bool> ((!Length || PartialArgs.empty()) &&
 "have partial args for non-dependent sizeof... expression") ?
 void (0) : __assert_fail ("(!Length || PartialArgs.empty()) && \"have partial args for non-dependent sizeof... expression\""
, "clang/include/clang/AST/ExprCXX.h", 4243, __extension__ __PRETTY_FUNCTION__
))
         "have partial args for non-dependent sizeof... expression")(static_cast <bool> ((!Length || PartialArgs.empty()) &&
 "have partial args for non-dependent sizeof... expression") ?
 void (0) : __assert_fail ("(!Length || PartialArgs.empty()) && \"have partial args for non-dependent sizeof... expression\""
, "clang/include/clang/AST/ExprCXX.h", 4243, __extension__ __PRETTY_FUNCTION__
));
  auto *Args = getTrailingObjects<TemplateArgument>();
  std::uninitialized_copy(PartialArgs.begin(), PartialArgs.end(), Args);
  setDependence(Length ? ExprDependence::None
                       : ExprDependence::ValueInstantiation);
}

/// Create an empty expression.
SizeOfPackExpr(EmptyShell Empty, unsigned NumPartialArgs)
    : Expr(SizeOfPackExprClass, Empty), Length(NumPartialArgs) {}

4254public:
static SizeOfPackExpr *
Create(ASTContext &Context, SourceLocation OperatorLoc, NamedDecl *Pack,
       SourceLocation PackLoc, SourceLocation RParenLoc,
       std::optional<unsigned> Length = std::nullopt,
       ArrayRef<TemplateArgument> PartialArgs = std::nullopt);
static SizeOfPackExpr *CreateDeserialized(ASTContext &Context,
                                          unsigned NumPartialArgs);

/// Determine the location of the 'sizeof' keyword.
SourceLocation getOperatorLoc() const { return OperatorLoc; }

/// Determine the location of the parameter pack.
SourceLocation getPackLoc() const { return PackLoc; }

/// Determine the location of the right parenthesis.
SourceLocation getRParenLoc() const { return RParenLoc; }

/// Retrieve the parameter pack.
NamedDecl *getPack() const { return Pack; }

/// Retrieve the length of the parameter pack.
///
/// This routine may only be invoked when the expression is not
/// value-dependent.
unsigned getPackLength() const {
  assert(!isValueDependent() &&(static_cast <bool> (!isValueDependent() && "Cannot get the length of a value-dependent pack size expression"
) ? void (0) : __assert_fail ("!isValueDependent() && \"Cannot get the length of a value-dependent pack size expression\""
, "clang/include/clang/AST/ExprCXX.h", 4281, __extension__ __PRETTY_FUNCTION__
))
         "Cannot get the length of a value-dependent pack size expression")(static_cast <bool> (!isValueDependent() && "Cannot get the length of a value-dependent pack size expression"
) ? void (0) : __assert_fail ("!isValueDependent() && \"Cannot get the length of a value-dependent pack size expression\""
, "clang/include/clang/AST/ExprCXX.h", 4281, __extension__ __PRETTY_FUNCTION__
));
  return Length;
}

/// Determine whether this represents a partially-substituted sizeof...
/// expression, such as is produced for:
///
///   template<typename ...Ts> using X = int[sizeof...(Ts)];
///   template<typename ...Us> void f(X<Us..., 1, 2, 3, Us...>);
bool isPartiallySubstituted() const {
  return isValueDependent() && Length;
}

/// Get
ArrayRef<TemplateArgument> getPartialArguments() const {
  assert(isPartiallySubstituted())(static_cast <bool> (isPartiallySubstituted()) ? void (
0) : __assert_fail ("isPartiallySubstituted()", "clang/include/clang/AST/ExprCXX.h"
, 4296, __extension__ __PRETTY_FUNCTION__));
  const auto *Args = getTrailingObjects<TemplateArgument>();
  return llvm::ArrayRef(Args, Args + Length);
}

SourceLocation getBeginLoc() const LLVM_READONLY__attribute__((__pure__)) { return OperatorLoc; }
SourceLocation getEndLoc() const LLVM_READONLY__attribute__((__pure__)) { return RParenLoc; }

static bool classof(const Stmt *T) {
  return T->getStmtClass() == SizeOfPackExprClass;
}

// Iterators
child_range children() {
  return child_range(child_iterator(), child_iterator());
}

const_child_range children() const {
  return const_child_range(const_child_iterator(), const_child_iterator());
}
4316};

4318/// Represents a reference to a non-type template parameter
4319/// that has been substituted with a template argument.
4320class SubstNonTypeTemplateParmExpr : public Expr {
friend class ASTReader;
friend class ASTStmtReader;

/// The replacement expression.
Stmt *Replacement;

/// The associated declaration and a flag indicating if it was a reference
/// parameter. For class NTTPs, we can't determine that based on the value
/// category alone.
llvm::PointerIntPair<Decl *, 1, bool> AssociatedDeclAndRef;

unsigned Index : 15;
unsigned PackIndex : 16;

explicit SubstNonTypeTemplateParmExpr(EmptyShell Empty)
    : Expr(SubstNonTypeTemplateParmExprClass, Empty) {}

4338public:
SubstNonTypeTemplateParmExpr(QualType Ty, ExprValueKind ValueKind,
                             SourceLocation Loc, Expr *Replacement,
                             Decl *AssociatedDecl, unsigned Index,
                             std::optional<unsigned> PackIndex, bool RefParam)
    : Expr(SubstNonTypeTemplateParmExprClass, Ty, ValueKind, OK_Ordinary),
      Replacement(Replacement),
      AssociatedDeclAndRef(AssociatedDecl, RefParam), Index(Index),
      PackIndex(PackIndex ? *PackIndex + 1 : 0) {
  assert(AssociatedDecl != nullptr)(static_cast <bool> (AssociatedDecl != nullptr) ? void (
0) : __assert_fail ("AssociatedDecl != nullptr", "clang/include/clang/AST/ExprCXX.h"
, 4347, __extension__ __PRETTY_FUNCTION__));
  SubstNonTypeTemplateParmExprBits.NameLoc = Loc;
  setDependence(computeDependence(this));
}

SourceLocation getNameLoc() const {
  return SubstNonTypeTemplateParmExprBits.NameLoc;
}
SourceLocation getBeginLoc() const { return getNameLoc(); }
SourceLocation getEndLoc() const { return getNameLoc(); }

Expr *getReplacement() const { return cast<Expr>(Replacement); }

/// A template-like entity which owns the whole pattern being substituted.
/// This will own a set of template parameters.
Decl *getAssociatedDecl() const { return AssociatedDeclAndRef.getPointer(); }

/// Returns the index of the replaced parameter in the associated declaration.
/// This should match the result of `getParameter()->getIndex()`.
unsigned getIndex() const { return Index; }

std::optional<unsigned> getPackIndex() const {
  if (PackIndex == 0)
    return std::nullopt;
  return PackIndex - 1;
}

NonTypeTemplateParmDecl *getParameter() const;

bool isReferenceParameter() const { return AssociatedDeclAndRef.getInt(); }

/// Determine the substituted type of the template parameter.
QualType getParameterType(const ASTContext &Ctx) const;

static bool classof(const Stmt *s) {
  return s->getStmtClass() == SubstNonTypeTemplateParmExprClass;
}

// Iterators
child_range children() { return child_range(&Replacement, &Replacement + 1); }

const_child_range children() const {
  return const_child_range(&Replacement, &Replacement + 1);
}
4391};

4393/// Represents a reference to a non-type template parameter pack that
4394/// has been substituted with a non-template argument pack.
4395///
4396/// When a pack expansion in the source code contains multiple parameter packs
4397/// and those parameter packs correspond to different levels of template
4398/// parameter lists, this node is used to represent a non-type template
4399/// parameter pack from an outer level, which has already had its argument pack
4400/// substituted but that still lives within a pack expansion that itself
4401/// could not be instantiated. When actually performing a substitution into
4402/// that pack expansion (e.g., when all template parameters have corresponding
4403/// arguments), this type will be replaced with the appropriate underlying
4404/// expression at the current pack substitution index.
4405class SubstNonTypeTemplateParmPackExpr : public Expr {
friend class ASTReader;
friend class ASTStmtReader;

/// The non-type template parameter pack itself.
Decl *AssociatedDecl;

/// A pointer to the set of template arguments that this
/// parameter pack is instantiated with.
const TemplateArgument *Arguments;

/// The number of template arguments in \c Arguments.
unsigned NumArguments : 16;

unsigned Index : 16;

/// The location of the non-type template parameter pack reference.
SourceLocation NameLoc;

explicit SubstNonTypeTemplateParmPackExpr(EmptyShell Empty)
    : Expr(SubstNonTypeTemplateParmPackExprClass, Empty) {}

4427public:
SubstNonTypeTemplateParmPackExpr(QualType T, ExprValueKind ValueKind,
                                 SourceLocation NameLoc,
                                 const TemplateArgument &ArgPack,
                                 Decl *AssociatedDecl, unsigned Index);

/// A template-like entity which owns the whole pattern being substituted.
/// This will own a set of template parameters.
Decl *getAssociatedDecl() const { return AssociatedDecl; }

/// Returns the index of the replaced parameter in the associated declaration.
/// This should match the result of `getParameterPack()->getIndex()`.
unsigned getIndex() const { return Index; }

/// Retrieve the non-type template parameter pack being substituted.
NonTypeTemplateParmDecl *getParameterPack() const;

/// Retrieve the location of the parameter pack name.
SourceLocation getParameterPackLocation() const { return NameLoc; }

/// Retrieve the template argument pack containing the substituted
/// template arguments.
TemplateArgument getArgumentPack() const;

SourceLocation getBeginLoc() const LLVM_READONLY__attribute__((__pure__)) { return NameLoc; }
SourceLocation getEndLoc() const LLVM_READONLY__attribute__((__pure__)) { return NameLoc; }

static bool classof(const Stmt *T) {
  return T->getStmtClass() == SubstNonTypeTemplateParmPackExprClass;
}

// Iterators
child_range children() {
  return child_range(child_iterator(), child_iterator());
}

const_child_range children() const {
  return const_child_range(const_child_iterator(), const_child_iterator());
}
4466};

4468/// Represents a reference to a function parameter pack or init-capture pack
4469/// that has been substituted but not yet expanded.
4470///
4471/// When a pack expansion contains multiple parameter packs at different levels,
4472/// this node is used to represent a function parameter pack at an outer level
4473/// which we have already substituted to refer to expanded parameters, but where
4474/// the containing pack expansion cannot yet be expanded.
4475///
4476/// \code
4477/// template<typename...Ts> struct S {
4478///   template<typename...Us> auto f(Ts ...ts) -> decltype(g(Us(ts)...));
4479/// };
4480/// template struct S<int, int>;
4481/// \endcode
4482class FunctionParmPackExpr final
  : public Expr,
    private llvm::TrailingObjects<FunctionParmPackExpr, VarDecl *> {
friend class ASTReader;
friend class ASTStmtReader;
friend TrailingObjects;

/// The function parameter pack which was referenced.
VarDecl *ParamPack;

/// The location of the function parameter pack reference.
SourceLocation NameLoc;

/// The number of expansions of this pack.
unsigned NumParameters;

FunctionParmPackExpr(QualType T, VarDecl *ParamPack,
                     SourceLocation NameLoc, unsigned NumParams,
                     VarDecl *const *Params);

4502public:
static FunctionParmPackExpr *Create(const ASTContext &Context, QualType T,
                                    VarDecl *ParamPack,
                                    SourceLocation NameLoc,
                                    ArrayRef<VarDecl *> Params);
static FunctionParmPackExpr *CreateEmpty(const ASTContext &Context,
                                         unsigned NumParams);

/// Get the parameter pack which this expression refers to.
VarDecl *getParameterPack() const { return ParamPack; }

/// Get the location of the parameter pack.
SourceLocation getParameterPackLocation() const { return NameLoc; }

/// Iterators over the parameters which the parameter pack expanded
/// into.
using iterator = VarDecl * const *;
iterator begin() const { return getTrailingObjects<VarDecl *>(); }
iterator end() const { return begin() + NumParameters; }

/// Get the number of parameters in this parameter pack.
unsigned getNumExpansions() const { return NumParameters; }

/// Get an expansion of the parameter pack by index.
VarDecl *getExpansion(unsigned I) const { return begin()[I]; }

SourceLocation getBeginLoc() const LLVM_READONLY__attribute__((__pure__)) { return NameLoc; }
SourceLocation getEndLoc() const LLVM_READONLY__attribute__((__pure__)) { return NameLoc; }

static bool classof(const Stmt *T) {
  return T->getStmtClass() == FunctionParmPackExprClass;
}

child_range children() {
  return child_range(child_iterator(), child_iterator());
}

const_child_range children() const {
  return const_child_range(const_child_iterator(), const_child_iterator());
}
4542};

4544/// Represents a prvalue temporary that is written into memory so that
4545/// a reference can bind to it.
4546///
4547/// Prvalue expressions are materialized when they need to have an address
4548/// in memory for a reference to bind to. This happens when binding a
4549/// reference to the result of a conversion, e.g.,
4550///
4551/// \code
4552/// const int &r = 1.0;
4553/// \endcode
4554///
4555/// Here, 1.0 is implicitly converted to an \c int. That resulting \c int is
4556/// then materialized via a \c MaterializeTemporaryExpr, and the reference
4557/// binds to the temporary. \c MaterializeTemporaryExprs are always glvalues
4558/// (either an lvalue or an xvalue, depending on the kind of reference binding
4559/// to it), maintaining the invariant that references always bind to glvalues.
4560///
4561/// Reference binding and copy-elision can both extend the lifetime of a
4562/// temporary. When either happens, the expression will also track the
4563/// declaration which is responsible for the lifetime extension.
4564class MaterializeTemporaryExpr : public Expr {
4565private:
friend class ASTStmtReader;
friend class ASTStmtWriter;

llvm::PointerUnion<Stmt *, LifetimeExtendedTemporaryDecl *> State;

4571public:
MaterializeTemporaryExpr(QualType T, Expr *Temporary,
                         bool BoundToLvalueReference,
                         LifetimeExtendedTemporaryDecl *MTD = nullptr);

MaterializeTemporaryExpr(EmptyShell Empty)
    : Expr(MaterializeTemporaryExprClass, Empty) {}

/// Retrieve the temporary-generating subexpression whose value will
/// be materialized into a glvalue.
Expr *getSubExpr() const {
  return cast<Expr>(
      State.is<Stmt *>()
          ? State.get<Stmt *>()
          : State.get<LifetimeExtendedTemporaryDecl *>()->getTemporaryExpr());
}

/// Retrieve the storage duration for the materialized temporary.
StorageDuration getStorageDuration() const {
  return State.is<Stmt *>() ? SD_FullExpression
                            : State.get<LifetimeExtendedTemporaryDecl *>()
                                  ->getStorageDuration();
}

/// Get the storage for the constant value of a materialized temporary
/// of static storage duration.
APValue *getOrCreateValue(bool MayCreate) const {
  assert(State.is<LifetimeExtendedTemporaryDecl *>() &&(static_cast <bool> (State.is<LifetimeExtendedTemporaryDecl
 *>() && "the temporary has not been lifetime extended"
) ? void (0) : __assert_fail ("State.is<LifetimeExtendedTemporaryDecl *>() && \"the temporary has not been lifetime extended\""
, "clang/include/clang/AST/ExprCXX.h", 4599, __extension__ __PRETTY_FUNCTION__
))
         "the temporary has not been lifetime extended")(static_cast <bool> (State.is<LifetimeExtendedTemporaryDecl
 *>() && "the temporary has not been lifetime extended"
) ? void (0) : __assert_fail ("State.is<LifetimeExtendedTemporaryDecl *>() && \"the temporary has not been lifetime extended\""
, "clang/include/clang/AST/ExprCXX.h", 4599, __extension__ __PRETTY_FUNCTION__
));
  return State.get<LifetimeExtendedTemporaryDecl *>()->getOrCreateValue(
      MayCreate);
}

LifetimeExtendedTemporaryDecl *getLifetimeExtendedTemporaryDecl() {
  return State.dyn_cast<LifetimeExtendedTemporaryDecl *>();
}
const LifetimeExtendedTemporaryDecl *
getLifetimeExtendedTemporaryDecl() const {
  return State.dyn_cast<LifetimeExtendedTemporaryDecl *>();
}

/// Get the declaration which triggered the lifetime-extension of this
/// temporary, if any.
ValueDecl *getExtendingDecl() {
  return State.is<Stmt *>() ? nullptr
                            : State.get<LifetimeExtendedTemporaryDecl *>()
                                  ->getExtendingDecl();
}
const ValueDecl *getExtendingDecl() const {
  return const_cast<MaterializeTemporaryExpr *>(this)->getExtendingDecl();
}

void setExtendingDecl(ValueDecl *ExtendedBy, unsigned ManglingNumber);

unsigned getManglingNumber() const {
  return State.is<Stmt *>() ? 0
                            : State.get<LifetimeExtendedTemporaryDecl *>()
                                  ->getManglingNumber();
}

/// Determine whether this materialized temporary is bound to an
/// lvalue reference; otherwise, it's bound to an rvalue reference.
bool isBoundToLvalueReference() const { return isLValue(); }

/// Determine whether this temporary object is usable in constant
/// expressions, as specified in C++20 [expr.const]p4.
bool isUsableInConstantExpressions(const ASTContext &Context) const;

SourceLocation getBeginLoc() const LLVM_READONLY__attribute__((__pure__)) {
  return getSubExpr()->getBeginLoc();
}

SourceLocation getEndLoc() const LLVM_READONLY__attribute__((__pure__)) {
  return getSubExpr()->getEndLoc();
}

static bool classof(const Stmt *T) {
  return T->getStmtClass() == MaterializeTemporaryExprClass;
}

// Iterators
child_range children() {
  return State.is<Stmt *>()
             ? child_range(State.getAddrOfPtr1(), State.getAddrOfPtr1() + 1)
             : State.get<LifetimeExtendedTemporaryDecl *>()->childrenExpr();
}

const_child_range children() const {
  return State.is<Stmt *>()
             ? const_child_range(State.getAddrOfPtr1(),
                                 State.getAddrOfPtr1() + 1)
             : const_cast<const LifetimeExtendedTemporaryDecl *>(
                   State.get<LifetimeExtendedTemporaryDecl *>())
                   ->childrenExpr();
}
4666};

4668/// Represents a folding of a pack over an operator.
4669///
4670/// This expression is always dependent and represents a pack expansion of the
4671/// forms:
4672///
4673///    ( expr op ... )
4674///    ( ... op expr )
4675///    ( expr op ... op expr )
4676class CXXFoldExpr : public Expr {
friend class ASTStmtReader;
friend class ASTStmtWriter;

enum SubExpr { Callee, LHS, RHS, Count };

SourceLocation LParenLoc;
SourceLocation EllipsisLoc;
SourceLocation RParenLoc;
// When 0, the number of expansions is not known. Otherwise, this is one more
// than the number of expansions.
unsigned NumExpansions;
Stmt *SubExprs[SubExpr::Count];
BinaryOperatorKind Opcode;

4691public:
CXXFoldExpr(QualType T, UnresolvedLookupExpr *Callee,
            SourceLocation LParenLoc, Expr *LHS, BinaryOperatorKind Opcode,
            SourceLocation EllipsisLoc, Expr *RHS, SourceLocation RParenLoc,
            std::optional<unsigned> NumExpansions)
    : Expr(CXXFoldExprClass, T, VK_PRValue, OK_Ordinary),
      LParenLoc(LParenLoc), EllipsisLoc(EllipsisLoc), RParenLoc(RParenLoc),
      NumExpansions(NumExpansions ? *NumExpansions + 1 : 0), Opcode(Opcode) {
  SubExprs[SubExpr::Callee] = Callee;
  SubExprs[SubExpr::LHS] = LHS;
  SubExprs[SubExpr::RHS] = RHS;
  setDependence(computeDependence(this));
}

CXXFoldExpr(EmptyShell Empty) : Expr(CXXFoldExprClass, Empty) {}

UnresolvedLookupExpr *getCallee() const {
  return static_cast<UnresolvedLookupExpr *>(SubExprs[SubExpr::Callee]);
}
Expr *getLHS() const { return static_cast<Expr*>(SubExprs[SubExpr::LHS]); }
Expr *getRHS() const { return static_cast<Expr*>(SubExprs[SubExpr::RHS]); }

/// Does this produce a right-associated sequence of operators?
bool isRightFold() const {
  return getLHS() && getLHS()->containsUnexpandedParameterPack();
}

/// Does this produce a left-associated sequence of operators?
bool isLeftFold() const { return !isRightFold(); }

/// Get the pattern, that is, the operand that contains an unexpanded pack.
Expr *getPattern() const { return isLeftFold() ? getRHS() : getLHS(); }

/// Get the operand that doesn't contain a pack, for a binary fold.
Expr *getInit() const { return isLeftFold() ? getLHS() : getRHS(); }

SourceLocation getLParenLoc() const { return LParenLoc; }
SourceLocation getRParenLoc() const { return RParenLoc; }
SourceLocation getEllipsisLoc() const { return EllipsisLoc; }
BinaryOperatorKind getOperator() const { return Opcode; }

std::optional<unsigned> getNumExpansions() const {
  if (NumExpansions)
    return NumExpansions - 1;
  return std::nullopt;
}

SourceLocation getBeginLoc() const LLVM_READONLY__attribute__((__pure__)) {
  if (LParenLoc.isValid())
    return LParenLoc;
  if (isLeftFold())
    return getEllipsisLoc();
  return getLHS()->getBeginLoc();
}

SourceLocation getEndLoc() const LLVM_READONLY__attribute__((__pure__)) {
  if (RParenLoc.isValid())
    return RParenLoc;
  if (isRightFold())
    return getEllipsisLoc();
  return getRHS()->getEndLoc();
}

static bool classof(const Stmt *T) {
  return T->getStmtClass() == CXXFoldExprClass;
}

// Iterators
child_range children() {
  return child_range(SubExprs, SubExprs + SubExpr::Count);
}

const_child_range children() const {
  return const_child_range(SubExprs, SubExprs + SubExpr::Count);
}
4766};

4768/// Represents a list-initialization with parenthesis.
4769///
4770/// As per P0960R3, this is a C++20 feature that allows aggregate to
4771/// be initialized with a parenthesized list of values:
4772/// ```
4773/// struct A {
4774///   int a;
4775///   double b;
4776/// };
4777///
4778/// void foo() {
4779///   A a1(0);        // Well-formed in C++20
4780///   A a2(1.5, 1.0); // Well-formed in C++20
4781/// }
4782/// ```
4783/// It has some sort of similiarity to braced
4784/// list-initialization, with some differences such as
4785/// it allows narrowing conversion whilst braced
4786/// list-initialization doesn't.
4787/// ```
4788/// struct A {
4789///   char a;
4790/// };
4791/// void foo() {
4792///   A a(1.5); // Well-formed in C++20
4793///   A b{1.5}; // Ill-formed !
4794/// }
4795/// ```
4796class CXXParenListInitExpr final
  : public Expr,
    private llvm::TrailingObjects<CXXParenListInitExpr, Expr *> {
friend class TrailingObjects;
friend class ASTStmtReader;
friend class ASTStmtWriter;

unsigned NumExprs;
unsigned NumUserSpecifiedExprs;
SourceLocation InitLoc, LParenLoc, RParenLoc;
llvm::PointerUnion<Expr *, FieldDecl *> ArrayFillerOrUnionFieldInit;

CXXParenListInitExpr(ArrayRef<Expr *> Args, QualType T,
                     unsigned NumUserSpecifiedExprs, SourceLocation InitLoc,
                     SourceLocation LParenLoc, SourceLocation RParenLoc)
    : Expr(CXXParenListInitExprClass, T, getValueKindForType(T), OK_Ordinary),
      NumExprs(Args.size()), NumUserSpecifiedExprs(NumUserSpecifiedExprs),
      InitLoc(InitLoc), LParenLoc(LParenLoc), RParenLoc(RParenLoc) {
  std::copy(Args.begin(), Args.end(), getTrailingObjects<Expr *>());
  assert(NumExprs >= NumUserSpecifiedExprs &&(static_cast <bool> (NumExprs >= NumUserSpecifiedExprs
 && "number of user specified inits is greater than the number of "
 "passed inits") ? void (0) : __assert_fail ("NumExprs >= NumUserSpecifiedExprs && \"number of user specified inits is greater than the number of \" \"passed inits\""
, "clang/include/clang/AST/ExprCXX.h", 4817, __extension__ __PRETTY_FUNCTION__
))
         "number of user specified inits is greater than the number of "(static_cast <bool> (NumExprs >= NumUserSpecifiedExprs
 && "number of user specified inits is greater than the number of "
 "passed inits") ? void (0) : __assert_fail ("NumExprs >= NumUserSpecifiedExprs && \"number of user specified inits is greater than the number of \" \"passed inits\""
, "clang/include/clang/AST/ExprCXX.h", 4817, __extension__ __PRETTY_FUNCTION__
))
         "passed inits")(static_cast <bool> (NumExprs >= NumUserSpecifiedExprs
 && "number of user specified inits is greater than the number of "
 "passed inits") ? void (0) : __assert_fail ("NumExprs >= NumUserSpecifiedExprs && \"number of user specified inits is greater than the number of \" \"passed inits\""
, "clang/include/clang/AST/ExprCXX.h", 4817, __extension__ __PRETTY_FUNCTION__
));
  setDependence(computeDependence(this));
}

size_t numTrailingObjects(OverloadToken<Expr *>) const { return NumExprs; }

4823public:
static CXXParenListInitExpr *
Create(ASTContext &C, ArrayRef<Expr *> Args, QualType T,
       unsigned NumUserSpecifiedExprs, SourceLocation InitLoc,
       SourceLocation LParenLoc, SourceLocation RParenLoc);

static CXXParenListInitExpr *CreateEmpty(ASTContext &C, unsigned numExprs,
                                         EmptyShell Empty);

explicit CXXParenListInitExpr(EmptyShell Empty, unsigned NumExprs)
    : Expr(CXXParenListInitExprClass, Empty), NumExprs(NumExprs),
      NumUserSpecifiedExprs(0) {}

void updateDependence() { setDependence(computeDependence(this)); }

ArrayRef<Expr *> getInitExprs() {
  return ArrayRef(getTrailingObjects<Expr *>(), NumExprs);
}

const ArrayRef<Expr *> getInitExprs() const {
  return ArrayRef(getTrailingObjects<Expr *>(), NumExprs);
}

ArrayRef<Expr *> getUserSpecifiedInitExprs() {
  return ArrayRef(getTrailingObjects<Expr *>(), NumUserSpecifiedExprs);
}

const ArrayRef<Expr *> getUserSpecifiedInitExprs() const {
  return ArrayRef(getTrailingObjects<Expr *>(), NumUserSpecifiedExprs);
}

SourceLocation getBeginLoc() const LLVM_READONLY__attribute__((__pure__)) { return LParenLoc; }

SourceLocation getEndLoc() const LLVM_READONLY__attribute__((__pure__)) { return RParenLoc; }

SourceLocation getInitLoc() const LLVM_READONLY__attribute__((__pure__)) { return InitLoc; }

SourceRange getSourceRange() const LLVM_READONLY__attribute__((__pure__)) {
  return SourceRange(getBeginLoc(), getEndLoc());
}

void setArrayFiller(Expr *E) { ArrayFillerOrUnionFieldInit = E; }

Expr *getArrayFiller() {
  return ArrayFillerOrUnionFieldInit.dyn_cast<Expr *>();
}

const Expr *getArrayFiller() const {
  return ArrayFillerOrUnionFieldInit.dyn_cast<Expr *>();
}

void setInitializedFieldInUnion(FieldDecl *FD) {
  ArrayFillerOrUnionFieldInit = FD;
}

FieldDecl *getInitializedFieldInUnion() {
  return ArrayFillerOrUnionFieldInit.dyn_cast<FieldDecl *>();
}

const FieldDecl *getInitializedFieldInUnion() const {
  return ArrayFillerOrUnionFieldInit.dyn_cast<FieldDecl *>();
}

child_range children() {
  Stmt **Begin = reinterpret_cast<Stmt **>(getTrailingObjects<Expr *>());
  return child_range(Begin, Begin + NumExprs);
}

const_child_range children() const {
  Stmt *const *Begin =
      reinterpret_cast<Stmt *const *>(getTrailingObjects<Expr *>());
  return const_child_range(Begin, Begin + NumExprs);
}

static bool classof(const Stmt *T) {
  return T->getStmtClass() == CXXParenListInitExprClass;
}
4900};

4902/// Represents an expression that might suspend coroutine execution;
4903/// either a co_await or co_yield expression.
4904///
4905/// Evaluation of this expression first evaluates its 'ready' expression. If
4906/// that returns 'false':
4907///  -- execution of the coroutine is suspended
4908///  -- the 'suspend' expression is evaluated
4909///     -- if the 'suspend' expression returns 'false', the coroutine is
4910///        resumed
4911///     -- otherwise, control passes back to the resumer.
4912/// If the coroutine is not suspended, or when it is resumed, the 'resume'
4913/// expression is evaluated, and its result is the result of the overall
4914/// expression.
4915class CoroutineSuspendExpr : public Expr {
friend class ASTStmtReader;

SourceLocation KeywordLoc;

enum SubExpr { Operand, Common, Ready, Suspend, Resume, Count };

Stmt *SubExprs[SubExpr::Count];
OpaqueValueExpr *OpaqueValue = nullptr;

4925public:
CoroutineSuspendExpr(StmtClass SC, SourceLocation KeywordLoc, Expr *Operand,
                     Expr *Common, Expr *Ready, Expr *Suspend, Expr *Resume,
                     OpaqueValueExpr *OpaqueValue)
    : Expr(SC, Resume->getType(), Resume->getValueKind(),
44
←
Called C++ object pointer is null
           Resume->getObjectKind()),
      KeywordLoc(KeywordLoc), OpaqueValue(OpaqueValue) {
  SubExprs[SubExpr::Operand] = Operand;
  SubExprs[SubExpr::Common] = Common;
  SubExprs[SubExpr::Ready] = Ready;
  SubExprs[SubExpr::Suspend] = Suspend;
  SubExprs[SubExpr::Resume] = Resume;
  setDependence(computeDependence(this));
}

CoroutineSuspendExpr(StmtClass SC, SourceLocation KeywordLoc, QualType Ty,
                     Expr *Operand, Expr *Common)
    : Expr(SC, Ty, VK_PRValue, OK_Ordinary), KeywordLoc(KeywordLoc) {
  assert(Common->isTypeDependent() && Ty->isDependentType() &&(static_cast <bool> (Common->isTypeDependent() &&
 Ty->isDependentType() && "wrong constructor for non-dependent co_await/co_yield expression"
) ? void (0) : __assert_fail ("Common->isTypeDependent() && Ty->isDependentType() && \"wrong constructor for non-dependent co_await/co_yield expression\""
, "clang/include/clang/AST/ExprCXX.h", 4944, __extension__ __PRETTY_FUNCTION__
))
         "wrong constructor for non-dependent co_await/co_yield expression")(static_cast <bool> (Common->isTypeDependent() &&
 Ty->isDependentType() && "wrong constructor for non-dependent co_await/co_yield expression"
) ? void (0) : __assert_fail ("Common->isTypeDependent() && Ty->isDependentType() && \"wrong constructor for non-dependent co_await/co_yield expression\""
, "clang/include/clang/AST/ExprCXX.h", 4944, __extension__ __PRETTY_FUNCTION__
));
  SubExprs[SubExpr::Operand] = Operand;
  SubExprs[SubExpr::Common] = Common;
  SubExprs[SubExpr::Ready] = nullptr;
  SubExprs[SubExpr::Suspend] = nullptr;
  SubExprs[SubExpr::Resume] = nullptr;
  setDependence(computeDependence(this));
}

CoroutineSuspendExpr(StmtClass SC, EmptyShell Empty) : Expr(SC, Empty) {
  SubExprs[SubExpr::Operand] = nullptr;
  SubExprs[SubExpr::Common] = nullptr;
  SubExprs[SubExpr::Ready] = nullptr;
  SubExprs[SubExpr::Suspend] = nullptr;
  SubExprs[SubExpr::Resume] = nullptr;
}

Expr *getCommonExpr() const {
  return static_cast<Expr*>(SubExprs[SubExpr::Common]);
}

/// getOpaqueValue - Return the opaque value placeholder.
OpaqueValueExpr *getOpaqueValue() const { return OpaqueValue; }

Expr *getReadyExpr() const {
  return static_cast<Expr*>(SubExprs[SubExpr::Ready]);
}

Expr *getSuspendExpr() const {
  return static_cast<Expr*>(SubExprs[SubExpr::Suspend]);
}

Expr *getResumeExpr() const {
  return static_cast<Expr*>(SubExprs[SubExpr::Resume]);
}

// The syntactic operand written in the code
Expr *getOperand() const {
  return static_cast<Expr *>(SubExprs[SubExpr::Operand]);
}

SourceLocation getKeywordLoc() const { return KeywordLoc; }

SourceLocation getBeginLoc() const LLVM_READONLY__attribute__((__pure__)) { return KeywordLoc; }

SourceLocation getEndLoc() const LLVM_READONLY__attribute__((__pure__)) {
  return getOperand()->getEndLoc();
}

child_range children() {
  return child_range(SubExprs, SubExprs + SubExpr::Count);
}

const_child_range children() const {
  return const_child_range(SubExprs, SubExprs + SubExpr::Count);
}

static bool classof(const Stmt *T) {
  return T->getStmtClass() == CoawaitExprClass ||
         T->getStmtClass() == CoyieldExprClass;
}
5005};

5007/// Represents a 'co_await' expression.
5008class CoawaitExpr : public CoroutineSuspendExpr {
friend class ASTStmtReader;

5011public:
CoawaitExpr(SourceLocation CoawaitLoc, Expr *Operand, Expr *Common,
            Expr *Ready, Expr *Suspend, Expr *Resume,
            OpaqueValueExpr *OpaqueValue, bool IsImplicit = false)
    : CoroutineSuspendExpr(CoawaitExprClass, CoawaitLoc, Operand, Common,
                           Ready, Suspend, Resume, OpaqueValue) {
  CoawaitBits.IsImplicit = IsImplicit;
}

CoawaitExpr(SourceLocation CoawaitLoc, QualType Ty, Expr *Operand,
            Expr *Common, bool IsImplicit = false)
    : CoroutineSuspendExpr(CoawaitExprClass, CoawaitLoc, Ty, Operand,
                           Common) {
  CoawaitBits.IsImplicit = IsImplicit;
}

CoawaitExpr(EmptyShell Empty)
    : CoroutineSuspendExpr(CoawaitExprClass, Empty) {}

bool isImplicit() const { return CoawaitBits.IsImplicit; }
void setIsImplicit(bool value = true) { CoawaitBits.IsImplicit = value; }

static bool classof(const Stmt *T) {
  return T->getStmtClass() == CoawaitExprClass;
}
5036};

5038/// Represents a 'co_await' expression while the type of the promise
5039/// is dependent.
5040class DependentCoawaitExpr : public Expr {
friend class ASTStmtReader;

SourceLocation KeywordLoc;
Stmt *SubExprs[2];

5046public:
DependentCoawaitExpr(SourceLocation KeywordLoc, QualType Ty, Expr *Op,
                     UnresolvedLookupExpr *OpCoawait)
    : Expr(DependentCoawaitExprClass, Ty, VK_PRValue, OK_Ordinary),
      KeywordLoc(KeywordLoc) {
  // NOTE: A co_await expression is dependent on the coroutines promise
  // type and may be dependent even when the `Op` expression is not.
  assert(Ty->isDependentType() &&(static_cast <bool> (Ty->isDependentType() &&
 "wrong constructor for non-dependent co_await/co_yield expression"
) ? void (0) : __assert_fail ("Ty->isDependentType() && \"wrong constructor for non-dependent co_await/co_yield expression\""
, "clang/include/clang/AST/ExprCXX.h", 5054, __extension__ __PRETTY_FUNCTION__
))
         "wrong constructor for non-dependent co_await/co_yield expression")(static_cast <bool> (Ty->isDependentType() &&
 "wrong constructor for non-dependent co_await/co_yield expression"
) ? void (0) : __assert_fail ("Ty->isDependentType() && \"wrong constructor for non-dependent co_await/co_yield expression\""
, "clang/include/clang/AST/ExprCXX.h", 5054, __extension__ __PRETTY_FUNCTION__
));
  SubExprs[0] = Op;
  SubExprs[1] = OpCoawait;
  setDependence(computeDependence(this));
}

DependentCoawaitExpr(EmptyShell Empty)
    : Expr(DependentCoawaitExprClass, Empty) {}

Expr *getOperand() const { return cast<Expr>(SubExprs[0]); }

UnresolvedLookupExpr *getOperatorCoawaitLookup() const {
  return cast<UnresolvedLookupExpr>(SubExprs[1]);
}

SourceLocation getKeywordLoc() const { return KeywordLoc; }

SourceLocation getBeginLoc() const LLVM_READONLY__attribute__((__pure__)) { return KeywordLoc; }

SourceLocation getEndLoc() const LLVM_READONLY__attribute__((__pure__)) {
  return getOperand()->getEndLoc();
}

child_range children() { return child_range(SubExprs, SubExprs + 2); }

const_child_range children() const {
  return const_child_range(SubExprs, SubExprs + 2);
}

static bool classof(const Stmt *T) {
  return T->getStmtClass() == DependentCoawaitExprClass;
}
5086};

5088/// Represents a 'co_yield' expression.
5089class CoyieldExpr : public CoroutineSuspendExpr {
friend class ASTStmtReader;

5092public:
CoyieldExpr(SourceLocation CoyieldLoc, Expr *Operand, Expr *Common,
            Expr *Ready, Expr *Suspend, Expr *Resume,
            OpaqueValueExpr *OpaqueValue)
    : CoroutineSuspendExpr(CoyieldExprClass, CoyieldLoc, Operand, Common,
43
←
Calling constructor for 'CoroutineSuspendExpr'→
                           Ready, Suspend, Resume, OpaqueValue) {}
42
←
Passing null pointer value via 7th parameter 'Resume'→
CoyieldExpr(SourceLocation CoyieldLoc, QualType Ty, Expr *Operand,
            Expr *Common)
    : CoroutineSuspendExpr(CoyieldExprClass, CoyieldLoc, Ty, Operand,
                           Common) {}
CoyieldExpr(EmptyShell Empty)
    : CoroutineSuspendExpr(CoyieldExprClass, Empty) {}

static bool classof(const Stmt *T) {
  return T->getStmtClass() == CoyieldExprClass;
}
5108};

5110/// Represents a C++2a __builtin_bit_cast(T, v) expression. Used to implement
5111/// std::bit_cast. These can sometimes be evaluated as part of a constant
5112/// expression, but otherwise CodeGen to a simple memcpy in general.
5113class BuiltinBitCastExpr final
  : public ExplicitCastExpr,
    private llvm::TrailingObjects<BuiltinBitCastExpr, CXXBaseSpecifier *> {
friend class ASTStmtReader;
friend class CastExpr;
friend TrailingObjects;

SourceLocation KWLoc;
SourceLocation RParenLoc;

5123public:
BuiltinBitCastExpr(QualType T, ExprValueKind VK, CastKind CK, Expr *SrcExpr,
                   TypeSourceInfo *DstType, SourceLocation KWLoc,
                   SourceLocation RParenLoc)
    : ExplicitCastExpr(BuiltinBitCastExprClass, T, VK, CK, SrcExpr, 0, false,
                       DstType),
      KWLoc(KWLoc), RParenLoc(RParenLoc) {}
BuiltinBitCastExpr(EmptyShell Empty)
    : ExplicitCastExpr(BuiltinBitCastExprClass, Empty, 0, false) {}

SourceLocation getBeginLoc() const LLVM_READONLY__attribute__((__pure__)) { return KWLoc; }
SourceLocation getEndLoc() const LLVM_READONLY__attribute__((__pure__)) { return RParenLoc; }

static bool classof(const Stmt *T) {
  return T->getStmtClass() == BuiltinBitCastExprClass;
}
5139};

5141} // namespace clang

5143#endif // LLVM_CLANG_AST_EXPRCXX_H