//===--- Sema.h - Semantic Analysis & AST Building --------------*- C++ -*-===//
 
//
 
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 
// See https://llvm.org/LICENSE.txt for license information.
 
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 
//
 
//===----------------------------------------------------------------------===//
 
//
 
// This file defines the Sema class, which performs semantic analysis and
 
// builds ASTs.
 
//
 
//===----------------------------------------------------------------------===//
 
 
 
#ifndef LLVM_CLANG_SEMA_SEMA_H
 
#define LLVM_CLANG_SEMA_SEMA_H
 
 
 
#include "clang/AST/ASTConcept.h"
 
#include "clang/AST/ASTFwd.h"
 
#include "clang/AST/Attr.h"
 
#include "clang/AST/Availability.h"
 
#include "clang/AST/ComparisonCategories.h"
 
#include "clang/AST/DeclTemplate.h"
 
#include "clang/AST/DeclarationName.h"
 
#include "clang/AST/Expr.h"
 
#include "clang/AST/ExprCXX.h"
 
#include "clang/AST/ExprConcepts.h"
 
#include "clang/AST/ExprObjC.h"
 
#include "clang/AST/ExprOpenMP.h"
 
#include "clang/AST/ExternalASTSource.h"
 
#include "clang/AST/LocInfoType.h"
 
#include "clang/AST/MangleNumberingContext.h"
 
#include "clang/AST/NSAPI.h"
 
#include "clang/AST/PrettyPrinter.h"
 
#include "clang/AST/StmtCXX.h"
 
#include "clang/AST/StmtOpenMP.h"
 
#include "clang/AST/TypeLoc.h"
 
#include "clang/AST/TypeOrdering.h"
 
#include "clang/Basic/BitmaskEnum.h"
 
#include "clang/Basic/Builtins.h"
 
#include "clang/Basic/DarwinSDKInfo.h"
 
#include "clang/Basic/ExpressionTraits.h"
 
#include "clang/Basic/Module.h"
 
#include "clang/Basic/OpenCLOptions.h"
 
#include "clang/Basic/OpenMPKinds.h"
 
#include "clang/Basic/PragmaKinds.h"
 
#include "clang/Basic/Specifiers.h"
 
#include "clang/Basic/TemplateKinds.h"
 
#include "clang/Basic/TypeTraits.h"
 
#include "clang/Sema/AnalysisBasedWarnings.h"
 
#include "clang/Sema/CleanupInfo.h"
 
#include "clang/Sema/DeclSpec.h"
 
#include "clang/Sema/ExternalSemaSource.h"
 
#include "clang/Sema/IdentifierResolver.h"
 
#include "clang/Sema/ObjCMethodList.h"
 
#include "clang/Sema/Ownership.h"
 
#include "clang/Sema/Scope.h"
 
#include "clang/Sema/SemaConcept.h"
 
#include "clang/Sema/TypoCorrection.h"
 
#include "clang/Sema/Weak.h"
 
#include "llvm/ADT/ArrayRef.h"
 
#include "llvm/ADT/SetVector.h"
 
#include "llvm/ADT/SmallBitVector.h"
 
#include "llvm/ADT/SmallPtrSet.h"
 
#include "llvm/ADT/SmallSet.h"
 
#include "llvm/ADT/SmallVector.h"
 
#include "llvm/ADT/TinyPtrVector.h"
 
#include "llvm/Frontend/OpenMP/OMPConstants.h"
 
#include <deque>
 
#include <memory>
 
#include <optional>
 
#include <string>
 
#include <tuple>
 
#include <vector>
 
 
 
namespace llvm {
 
  class APSInt;
 
  template <typename ValueT, typename ValueInfoT> class DenseSet;
 
  class SmallBitVector;
 
  struct InlineAsmIdentifierInfo;
 
}
 
 
 
namespace 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;
 
 
 
namespace 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;
 
}
 
 
 
namespace threadSafety {
 
  class BeforeSet;
 
  void threadSafetyCleanup(BeforeSet* Cache);
 
}
 
 
 
// FIXME: No way to easily map from TemplateTypeParmTypes to
 
// TemplateTypeParmDecls, so we have this horrible PointerUnion.
 
typedef std::pair<llvm::PointerUnion<const TemplateTypeParmType *, NamedDecl *>,
 
                  SourceLocation>
 
    UnexpandedParameterPack;
 
 
 
/// Describes whether we've seen any nullability information for the given
 
/// file.
 
struct 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;
 
};
 
 
 
/// A mapping from file IDs to a record of whether we've seen nullability
 
/// information in that file.
 
class 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;
 
 
 
public:
 
  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;
 
  }
 
};
 
 
 
/// Tracks expected type during expression parsing, for use in code completion.
 
/// The type is tied to a particular token, all functions that update or consume
 
/// the type take a start location of the token they are looking at as a
 
/// parameter. This avoids updating the type on hot paths in the parser.
 
class PreferredTypeBuilder {
 
public:
 
  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();
 
  }
 
 
 
private:
 
  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;
 
};
 
 
 
/// Sema - This implements semantic analysis and AST building for C.
 
class 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() &&
 
             "should not have found a non-externally-declarable previous decl");
 
      return true;
 
    }
 
    return false;
 
  }
 
  bool shouldLinkPossiblyHiddenDecl(LookupResult &Old, const NamedDecl *New);
 
 
 
  void setupImplicitSpecialMemberType(CXXMethodDecl *SpecialMem,
 
                                      QualType ResultTy,
 
                                      ArrayRef<QualType> Args);
 
 
 
public:
 
  /// 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)
 
  };
 
 
 
  // #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.");
 
    }
 
 
 
    // #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) &&
 
             "Can only push / pop #pragma stack sentinels!");
 
      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;
 
 
 
  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<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;
 
 
 
  public:
 
    DelayedDiagnostics() : CurPool(nullptr) {}
 
 
 
    /// 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);
 
      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");
 
      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() {
 
    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));
 
    }
 
 
 
    void addContextNote(SourceLocation UseLoc) {
 
      assert(!PushedCodeSynthesisContext);
 
 
 
      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::experimental" namespace, where the experimental parts
 
  /// of the standard library resides.
 
  NamespaceDecl *StdExperimentalNamespaceCache;
 
 
 
  /// 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 namespace where coroutine components are defined. In standard,
 
  /// they are defined in std namespace. And in the previous implementation,
 
  /// they are defined in std::experimental namespace.
 
  NamespaceDecl *CoroTraitsNamespaceCache;
 
 
 
  /// 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");
 
      }
 
 
 
      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++2b [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(ValueDecl *VD);
 
 
 
  /// 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;
 
 
 
private:
 
  std::unique_ptr<sema::RISCVIntrinsicManager> RVIntrinsicManager;
 
 
 
  std::optional<std::unique_ptr<DarwinSDKInfo>> CachedDarwinSDKInfo;
 
 
 
  bool WarnedDarwinSDKInfoMissing = false;
 
 
 
public:
 
  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,
 
                          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;
 
    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();
 
  }
 
 
 
  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");
 
    }
 
 
 
    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 };
 
 
 
private:
 
  /// 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;
 
    bool IsPartition = false;
 
    bool ImplicitGlobalModuleFragment = false;
 
    VisibleModuleSet OuterVisibleModules;
 
  };
 
  /// The modules we're currently parsing.
 
  llvm::SmallVector<ModuleScope, 16> ModuleScopes;
 
  /// The global module fragment of the current translation unit.
 
  clang::Module *GlobalModuleFragment = nullptr;
 
 
 
  /// The modules we imported directly.
 
  llvm::SmallPtrSet<clang::Module *, 8> DirectModuleImports;
 
 
 
  /// 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 global module.
 
  Module *PushGlobalModuleFragment(SourceLocation BeginLoc, bool IsImplicit);
 
  /// Leave the scope of the global module.
 
  void PopGlobalModuleFragment();
 
 
 
  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);
 
 
 
public:
 
  /// 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();
 
  }
 
 
 
  bool isModuleDirectlyImported(const Module *M) {
 
    return DirectModuleImports.contains(M);
 
  }
 
 
 
  // Determine whether the module M belongs to the  current TU.
 
  bool isModuleUnitOfCurrentTU(const Module *M) const;
 
 
 
  /// 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(NamedDecl *Def);
 
  bool hasMergedDefinitionInCurrentModule(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()
 
        : ShouldSkip(false), CheckSameAsPrevious(false), Previous(nullptr),
 
          New(nullptr) {}
 
    bool ShouldSkip;
 
    bool CheckSameAsPrevious;
 
    NamedDecl *Previous;
 
    NamedDecl *New;
 
  };
 
 
 
  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);
 
      return Expr;
 
    }
 
 
 
    ParsedType getType() const {
 
      assert(Kind == NC_Type);
 
      return Type;
 
    }
 
 
 
    NamedDecl *getNonTypeDecl() const {
 
      assert(Kind == NC_NonType);
 
      return NonTypeDecl;
 
    }
 
 
 
    TemplateName getTemplateName() const {
 
      assert(Kind == NC_TypeTemplate || Kind == NC_FunctionTemplate ||
 
             Kind == NC_VarTemplate || Kind == NC_Concept ||
 
             Kind == NC_UndeclaredTemplate);
 
      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.");
 
      }
 
    }
 
  };
 
 
 
  /// 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);
 
 
 
private:
 
  /// 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;
 
 
 
public:
 
  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.
 
  };
 
 
 
private:
 
  /// The parser has begun a translation unit to be compiled as a C++20
 
  /// Header Unit, helper for ActOnStartOfTranslationUnit() only.
 
  void HandleStartOfHeaderUnit();
 
 
 
public:
 
  /// 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, NamedDecl *Decl,
 
                             MissingImportKind MIK, bool Recover = true);
 
  void diagnoseMissingImport(SourceLocation Loc, 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);
 
 
 
  /// 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);
 
 
 
  /// 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();
 
 
 
  /// 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);
 
 
 
  /// 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(
 
      NamedDecl *Found, 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() {
 
    // 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;
 
 
 
private:
 
  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);
 
 
 
public:
 
  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(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);
 
 
 
  /// 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;
 
 
 
private:
 
  /// 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);
 
 
 
public:
 
  /// - 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);
 
 
 
private:
 
  /// - 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();
 
  }
 
 
 
public:
 
  /// 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.
 
public:
 
  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(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);
 
 
 
private:
 
  static BinaryOperatorKind ConvertTokenKindToBinaryOpcode(tok::TokenKind Kind);
 
 
 
public:
 
  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();
 
 
 
  NamespaceDecl *lookupStdExperimentalNamespace();
 
  NamespaceDecl *getCachedCoroNamespace() { return CoroTraitsNamespaceCache; }
 
 
 
  CXXRecordDecl *getStdBadAlloc() const;
 
  EnumDecl *getStdAlignValT() const;
 
 
 
private:
 
  // 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);
 
 
 
public:
 
  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) &&
 
             "noexcept(expr) should not be a possible result");
 
      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<std::tuple<bool, unsigned, unsigned, Decl *>> Mangling =
 
          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 ExplicitResultType,
 
                        bool Mutable);
 
 
 
  /// 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);
 
 
 
  /// 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);
 
 
 
  /// \brief This is called after parsing the explicit template parameter list
 
  /// on a lambda (if it exists) in C++2a.
 
  void ActOnLambdaExplicitTemplateParameterList(SourceLocation LAngleLoc,
 
                                                ArrayRef<NamedDecl *> TParams,
 
                                                SourceLocation RAngleLoc,
 
                                                ExprResult RequiresClause);
 
 
 
  /// Introduce the lambda parameters into scope.
 
  void addLambdaParameters(
 
      ArrayRef<LambdaIntroducer::LambdaCapture> Captures,
 
      CXXMethodDecl *CallOperator, Scope *CurScope);
 
 
 
  /// Deduce a block or lambda's return type based on the return
 
  /// statements present in the body.
 
  void deduceClosureReturnType(sema::CapturingScopeInfo &CSI);
 
 
 
  /// 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, Scope *CurScope);
 
 
 
  /// 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);
 
 
 
private:
 
  /// 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);
 
 
 
  /// 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);
 
 
 
private:
 
  // The current stack of constraint satisfactions, so we can exit-early.
 
  using SatisfactionStackEntryTy =
 
      std::pair<const NamedDecl *, llvm::FoldingSetNodeID>;
 
  llvm::SmallVector<SatisfactionStackEntryTy, 10>
 
      SatisfactionStack;
 
 
 
public:
 
  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,
 
                            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 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 *ConstrainedParameter,
 
                            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
 
  };
 
 
 
  bool TemplateParameterListsAreEqual(
 
      const NamedDecl *NewInstFrom, TemplateParameterList *New,
 
      const NamedDecl *OldInstFrom, TemplateParameterList *Old, bool Complain,
 
      TemplateParameterListEqualKind Kind,
 
      SourceLocation TemplateArgLoc = SourceLocation(),
 
      bool PartialOrdering = false);
 
 
 
  bool TemplateParameterListsAreEqual(
 
      TemplateParameterList *New, TemplateParameterList *Old, bool Complain,
 
      TemplateParameterListEqualKind Kind,
 
      SourceLocation TemplateArgLoc = SourceLocation(),
 
      bool PartialOrdering = false) {
 
    return TemplateParameterListsAreEqual(nullptr, New, nullptr, Old, Complain,
 
                                          Kind, TemplateArgLoc,
 
                                          PartialOrdering);
 
  }
 
 
 
  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 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);
 
      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() &&
 
           "Must be in an expression evaluation context");
 
    return ExprEvalContexts.back().isUnevaluated();
 
  }
 
 
 
  bool isConstantEvaluatedContext() const {
 
    assert(!ExprEvalContexts.empty() &&
 
           "Must be in an expression evaluation context");
 
    return ExprEvalContexts.back().isConstantEvaluated();
 
  }
 
 
 
  bool isImmediateFunctionContext() const {
 
    assert(!ExprEvalContexts.empty() &&
 
           "Must be in an expression evaluation context");
 
    return ExprEvalContexts.back().isImmediateFunctionContext();
 
  }
 
 
 
  bool isCheckingDefaultArgumentOrInitializer() const {
 
    assert(!ExprEvalContexts.empty() &&
 
           "Must be in an expression evaluation context");
 
    const ExpressionEvaluationContextRecord &Ctx = ExprEvalContexts.back();
 
    return (Ctx.Context ==
 
            ExpressionEvaluationContext::PotentiallyEvaluatedIfUsed) ||
 
           Ctx.IsCurrentlyCheckingDefaultArgumentOrInitializer;
 
  }
 
 
 
  std::optional<ExpressionEvaluationContextRecord::InitializationContext>
 
  InnermostDeclarationWithDelayedImmediateInvocations() const {
 
    assert(!ExprEvalContexts.empty() &&
 
           "Must be in an expression evaluation context");
 
    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() &&
 
           "Must be in an expression evaluation context");
 
    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;
 
 
 
  class GlobalEagerInstantiationScope {
 
  public:
 
    GlobalEagerInstantiationScope(Sema &S, bool Enabled)
 
        : S(S), Enabled(Enabled) {
 
      if (!Enabled) return;
 
 
 
      SavedPendingInstantiations.swap(S.PendingInstantiations);
 
      SavedVTableUses.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() &&
 
             "VTableUses should be empty before it is discarded.");
 
      S.VTableUses.swap(SavedVTableUses);
 
 
 
      // Restore the set of pending implicit instantiations.
 
      if (S.TUKind != TU_Prefix || !S.LangOpts.PCHInstantiateTemplates) {
 
        assert(S.PendingInstantiations.empty() &&
 
               "PendingInstantiations should be empty before it is discarded.");
 
        S.PendingInstantiations.swap(SavedPendingInstantiations);
 
      } else {
 
        // Template instantiations in the PCH may be delayed until the TU.
 
        S.PendingInstantiations.swap(SavedPendingInstantiations);
 
        S.PendingInstantiations.insert(S.PendingInstantiations.end(),
 
                                       SavedPendingInstantiations.begin(),
 
                                       SavedPendingInstantiations.end());
 
      }
 
    }
 
 
 
  private:
 
    Sema &S;
 
    SmallVector<VTableUse, 16> SavedVTableUses;
 
    std::deque<PendingImplicitInstantiation> SavedPendingInstantiations;
 
    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() &&
 
             "there shouldn't be any pending local implicit instantiations");
 
      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);
 
      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
 
  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);
 
 
 
  /// 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 TS
 
  //
 
  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,
 
                                           NamespaceDecl *&Namespace);
 
  /// Check that the expression co_await promise.final_suspend() shall not be
 
  /// potentially-throwing.
 
  bool checkFinalSuspendNoThrow(const Stmt *FinalSuspend);
 
 
 
  //===--------------------------------------------------------------------===//
 
  // OpenMP directives and clauses.
 
  //
 
private:
 
  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;
 
 
 
public:
 
  /// 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);
 
 
 
private:
 
  /// 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);
 
 
 
public:
 
  /// 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 areMatrixTypesOfTheSameDimension(QualType srcTy, QualType destTy);
 
 
 
  bool areVectorTypesSameSize(QualType srcType, QualType destType);
 
  bool areLaxCompatibleVectorTypes(QualType srcType, QualType destType);
 
  bool isLaxVectorConversion(QualType srcType, QualType destType);
 
  bool areSameVectorElemTypes(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)
 
    };
 
  };
 
  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 ¶mType);
 
 
 
  // 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;
 
    bool HasKnownValue;
 
    bool KnownValue;
 
 
 
    friend class Sema;
 
    ConditionResult(Sema &S, Decl *ConditionVar, FullExprArg Condition,
 
                    bool IsConstexpr)
 
        : ConditionVar(ConditionVar), Condition(Condition), Invalid(false),
 
          HasKnownValue(IsConstexpr && Condition.get() &&
 
                        !Condition.get()->isValueDependent()),
 
          KnownValue(HasKnownValue &&
 
                     !!Condition.get()->EvaluateKnownConstInt(S.Context)) {}
 
    explicit ConditionResult(bool Invalid)
 
        : ConditionVar(nullptr), Condition(nullptr), Invalid(Invalid),
 
          HasKnownValue(false), KnownValue(false) {}
 
 
 
  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 {
 
      if (!HasKnownValue)
 
        return std::nullopt;
 
      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);
 
 
 
private:
 
  unsigned ForceCUDAHostDeviceDepth = 0;
 
 
 
public:
 
  /// 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<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<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<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, 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, FunctionDecl *FD);
 
 
 
  SemaDiagnosticBuilder targetDiag(SourceLocation Loc, unsigned DiagID,
 
                                   FunctionDecl *FD = nullptr);
 
  SemaDiagnosticBuilder targetDiag(SourceLocation Loc,
 
                                   const PartialDiagnostic &PD,
 
                                   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);
 
 
 
public:
 
  /// 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
 
 
 
public:
 
  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);
 
 
 
private:
 
  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 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);
 
 
 
public:
 
  // Used by C++ template instantiation.
 
  ExprResult SemaBuiltinShuffleVector(CallExpr *TheCall);
 
  ExprResult SemaConvertVectorExpr(Expr *E, TypeSourceInfo *TInfo,
 
                                   SourceLocation BuiltinLoc,
 
                                   SourceLocation RParenLoc);
 
 
 
private:
 
  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 PrepareBuiltinElementwiseMathOneArgCall(CallExpr *TheCall);
 
  bool PrepareBuiltinReduceMathOneArgCall(CallExpr *TheCall);
 
 
 
  // Matrix builtin handling.
 
  ExprResult SemaBuiltinMatrixTranspose(CallExpr *TheCall,
 
                                        ExprResult CallResult);
 
  ExprResult SemaBuiltinMatrixColumnMajorLoad(CallExpr *TheCall,
 
                                              ExprResult CallResult);
 
  ExprResult SemaBuiltinMatrixColumnMajorStore(CallExpr *TheCall,
 
                                               ExprResult CallResult);
 
 
 
public:
 
  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);
 
 
 
private:
 
  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);
 
 
 
public:
 
  void CheckFloatComparison(SourceLocation Loc, Expr *LHS, Expr *RHS,
 
                            BinaryOperatorKind Opcode);
 
 
 
private:
 
  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);
 
public:
 
  /// 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;
 
 
 
private:
 
  /// 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;
 
 
 
protected:
 
  friend class Parser;
 
  friend class InitializationSequence;
 
  friend class ASTReader;
 
  friend class ASTDeclReader;
 
  friend class ASTWriter;
 
 
 
public:
 
  /// 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;
 
 
 
private:
 
  int ParsingClassDepth = 0;
 
 
 
  class SavePendingParsedClassStateRAII {
 
  public:
 
    SavePendingParsedClassStateRAII(Sema &S) : S(S) { swapSavedState(); }
 
 
 
    ~SavePendingParsedClassStateRAII() {
 
      assert(S.DelayedOverridingExceptionSpecChecks.empty() &&
 
             "there shouldn't be any pending delayed exception spec checks");
 
      assert(S.DelayedEquivalentExceptionSpecChecks.empty() &&
 
             "there shouldn't be any pending delayed exception spec checks");
 
      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);
 
 
 
public:
 
  /// 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);
 
 
 
  /// Check whether we're allowed to call Callee from the current context.
 
  ///
 
  /// - If the call is never allowed in a semantically-correct program
 
  ///   emits an error and returns false.
 
  ///
 
  /// - If the call is allowed in semantically-correct programs, but only if
 
  ///   it's never codegen'ed, creates a deferred diagnostic to be emitted if
 
  ///   and when the caller is codegen'ed, and returns true.
 
  ///
 
  /// - Otherwise, returns true without emitting any diagnostics.
 
  ///
 
  /// Adds Callee to DeviceCallGraph if we don't know if its caller will be
 
  /// codegen'ed yet.
 
  bool checkSYCLDeviceFunction(SourceLocation Loc, FunctionDecl *Callee);
 
  void deepTypeCheckForSYCLDevice(SourceLocation UsedAt,
 
                                  llvm::DenseSet<QualType> Visited,
 
                                  ValueDecl *DeclToCheck);
 
};
 
 
 
/// RAII object that enters a new expression evaluation context.
 
class EnterExpressionEvaluationContext {
 
  Sema &Actions;
 
  bool Entered = true;
 
 
 
public:
 
  EnterExpressionEvaluationContext(
 
      Sema &Actions, Sema::ExpressionEvaluationContext NewContext,
 
      Decl *LambdaContextDecl = nullptr,
 
      Sema::ExpressionEvaluationContextRecord::ExpressionKind ExprContext =
 
          Sema::ExpressionEvaluationContextRecord::EK_Other,
 
      bool ShouldEnter = true)
 
      : Actions(Actions), Entered(ShouldEnter) {
 
    if (Entered)
 
      Actions.PushExpressionEvaluationContext(NewContext, LambdaContextDecl,
 
                                              ExprContext);
 
  }
 
  EnterExpressionEvaluationContext(
 
      Sema &Actions, Sema::ExpressionEvaluationContext NewContext,
 
      Sema::ReuseLambdaContextDecl_t,
 
      Sema::ExpressionEvaluationContextRecord::ExpressionKind ExprContext =
 
          Sema::ExpressionEvaluationContextRecord::EK_Other)
 
      : Actions(Actions) {
 
    Actions.PushExpressionEvaluationContext(
 
        NewContext, Sema::ReuseLambdaContextDecl, ExprContext);
 
  }
 
 
 
  enum InitListTag { InitList };
 
  EnterExpressionEvaluationContext(Sema &Actions, InitListTag,
 
                                   bool ShouldEnter = true)
 
      : Actions(Actions), Entered(false) {
 
    // In C++11 onwards, narrowing checks are performed on the contents of
 
    // braced-init-lists, even when they occur within unevaluated operands.
 
    // Therefore we still need to instantiate constexpr functions used in such
 
    // a context.
 
    if (ShouldEnter && Actions.isUnevaluatedContext() &&
 
        Actions.getLangOpts().CPlusPlus11) {
 
      Actions.PushExpressionEvaluationContext(
 
          Sema::ExpressionEvaluationContext::UnevaluatedList);
 
      Entered = true;
 
    }
 
  }
 
 
 
  ~EnterExpressionEvaluationContext() {
 
    if (Entered)
 
      Actions.PopExpressionEvaluationContext();
 
  }
 
};
 
 
 
DeductionFailureInfo
 
MakeDeductionFailureInfo(ASTContext &Context, Sema::TemplateDeductionResult TDK,
 
                         sema::TemplateDeductionInfo &Info);
 
 
 
/// Contains a late templated function.
 
/// Will be parsed at the end of the translation unit, used by Sema & Parser.
 
struct LateParsedTemplate {
 
  CachedTokens Toks;
 
  /// The template function declaration to be late parsed.
 
  Decl *D;
 
};
 
 
 
template <>
 
void Sema::PragmaStack<Sema::AlignPackInfo>::Act(SourceLocation PragmaLocation,
 
                                                 PragmaMsStackAction Action,
 
                                                 llvm::StringRef StackSlotLabel,
 
                                                 AlignPackInfo Value);
 
 
 
std::unique_ptr<sema::RISCVIntrinsicManager>
 
CreateRISCVIntrinsicManager(Sema &S);
 
} // end namespace clang
 
 
 
namespace llvm {
 
// Hash a FunctionDeclAndLoc by looking at both its FunctionDecl and its
 
// SourceLocation.
 
template <> struct DenseMapInfo<clang::Sema::FunctionDeclAndLoc> {
 
  using FunctionDeclAndLoc = clang::Sema::FunctionDeclAndLoc;
 
  using FDBaseInfo = DenseMapInfo<clang::CanonicalDeclPtr<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;
 
  }
 
};
 
} // namespace llvm
 
 
 
#endif