//===- ASTWriter.h - AST File Writer ----------------------------*- 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 ASTWriter class, which writes an AST file
 
//  containing a serialized representation of a translation unit.
 
//
 
//===----------------------------------------------------------------------===//
 
 
 
#ifndef LLVM_CLANG_SERIALIZATION_ASTWRITER_H
 
#define LLVM_CLANG_SERIALIZATION_ASTWRITER_H
 
 
 
#include "clang/AST/ASTMutationListener.h"
 
#include "clang/AST/Decl.h"
 
#include "clang/AST/Type.h"
 
#include "clang/Basic/LLVM.h"
 
#include "clang/Basic/Module.h"
 
#include "clang/Basic/SourceLocation.h"
 
#include "clang/Sema/Sema.h"
 
#include "clang/Sema/SemaConsumer.h"
 
#include "clang/Serialization/ASTBitCodes.h"
 
#include "clang/Serialization/ASTDeserializationListener.h"
 
#include "clang/Serialization/PCHContainerOperations.h"
 
#include "clang/Serialization/SourceLocationEncoding.h"
 
#include "llvm/ADT/ArrayRef.h"
 
#include "llvm/ADT/DenseMap.h"
 
#include "llvm/ADT/DenseSet.h"
 
#include "llvm/ADT/MapVector.h"
 
#include "llvm/ADT/STLExtras.h"
 
#include "llvm/ADT/SetVector.h"
 
#include "llvm/ADT/SmallVector.h"
 
#include "llvm/ADT/StringRef.h"
 
#include "llvm/Bitstream/BitstreamWriter.h"
 
#include <cassert>
 
#include <cstddef>
 
#include <cstdint>
 
#include <ctime>
 
#include <memory>
 
#include <queue>
 
#include <string>
 
#include <utility>
 
#include <vector>
 
 
 
namespace clang {
 
 
 
class ASTContext;
 
class ASTReader;
 
class Attr;
 
class CXXRecordDecl;
 
class FileEntry;
 
class FPOptionsOverride;
 
class FunctionDecl;
 
class HeaderSearch;
 
class HeaderSearchOptions;
 
class IdentifierResolver;
 
class LangOptions;
 
class MacroDefinitionRecord;
 
class MacroInfo;
 
class Module;
 
class InMemoryModuleCache;
 
class ModuleFileExtension;
 
class ModuleFileExtensionWriter;
 
class NamedDecl;
 
class ObjCInterfaceDecl;
 
class PreprocessingRecord;
 
class Preprocessor;
 
class RecordDecl;
 
class Sema;
 
class SourceManager;
 
class Stmt;
 
class StoredDeclsList;
 
class SwitchCase;
 
class Token;
 
 
 
/// Writes an AST file containing the contents of a translation unit.
 
///
 
/// The ASTWriter class produces a bitstream containing the serialized
 
/// representation of a given abstract syntax tree and its supporting
 
/// data structures. This bitstream can be de-serialized via an
 
/// instance of the ASTReader class.
 
class ASTWriter : public ASTDeserializationListener,
 
                  public ASTMutationListener {
 
public:
 
  friend class ASTDeclWriter;
 
  friend class ASTRecordWriter;
 
 
 
  using RecordData = SmallVector<uint64_t, 64>;
 
  using RecordDataImpl = SmallVectorImpl<uint64_t>;
 
  using RecordDataRef = ArrayRef<uint64_t>;
 
 
 
private:
 
  /// Map that provides the ID numbers of each type within the
 
  /// output stream, plus those deserialized from a chained PCH.
 
  ///
 
  /// The ID numbers of types are consecutive (in order of discovery)
 
  /// and start at 1. 0 is reserved for NULL. When types are actually
 
  /// stored in the stream, the ID number is shifted by 2 bits to
 
  /// allow for the const/volatile qualifiers.
 
  ///
 
  /// Keys in the map never have const/volatile qualifiers.
 
  using TypeIdxMap = llvm::DenseMap<QualType, serialization::TypeIdx,
 
                                    serialization::UnsafeQualTypeDenseMapInfo>;
 
 
 
  using LocSeq = SourceLocationSequence;
 
 
 
  /// The bitstream writer used to emit this precompiled header.
 
  llvm::BitstreamWriter &Stream;
 
 
 
  /// The buffer associated with the bitstream.
 
  const SmallVectorImpl<char> &Buffer;
 
 
 
  /// The PCM manager which manages memory buffers for pcm files.
 
  InMemoryModuleCache &ModuleCache;
 
 
 
  /// The ASTContext we're writing.
 
  ASTContext *Context = nullptr;
 
 
 
  /// The preprocessor we're writing.
 
  Preprocessor *PP = nullptr;
 
 
 
  /// The reader of existing AST files, if we're chaining.
 
  ASTReader *Chain = nullptr;
 
 
 
  /// The module we're currently writing, if any.
 
  Module *WritingModule = nullptr;
 
 
 
  /// The offset of the first bit inside the AST_BLOCK.
 
  uint64_t ASTBlockStartOffset = 0;
 
 
 
  /// The range representing all the AST_BLOCK.
 
  std::pair<uint64_t, uint64_t> ASTBlockRange;
 
 
 
  /// The base directory for any relative paths we emit.
 
  std::string BaseDirectory;
 
 
 
  /// Indicates whether timestamps should be written to the produced
 
  /// module file. This is the case for files implicitly written to the
 
  /// module cache, where we need the timestamps to determine if the module
 
  /// file is up to date, but not otherwise.
 
  bool IncludeTimestamps;
 
 
 
  /// Indicates when the AST writing is actively performing
 
  /// serialization, rather than just queueing updates.
 
  bool WritingAST = false;
 
 
 
  /// Indicates that we are done serializing the collection of decls
 
  /// and types to emit.
 
  bool DoneWritingDeclsAndTypes = false;
 
 
 
  /// Indicates that the AST contained compiler errors.
 
  bool ASTHasCompilerErrors = false;
 
 
 
  /// Mapping from input file entries to the index into the
 
  /// offset table where information about that input file is stored.
 
  llvm::DenseMap<const FileEntry *, uint32_t> InputFileIDs;
 
 
 
  /// Stores a declaration or a type to be written to the AST file.
 
  class DeclOrType {
 
  public:
 
    DeclOrType(Decl *D) : Stored(D), IsType(false) {}
 
    DeclOrType(QualType T) : Stored(T.getAsOpaquePtr()), IsType(true) {}
 
 
 
    bool isType() const { return IsType; }
 
    bool isDecl() const { return !IsType; }
 
 
 
    QualType getType() const {
 
      assert(isType() && "Not a type!");
 
      return QualType::getFromOpaquePtr(Stored);
 
    }
 
 
 
    Decl *getDecl() const {
 
      assert(isDecl() && "Not a decl!");
 
      return static_cast<Decl *>(Stored);
 
    }
 
 
 
  private:
 
    void *Stored;
 
    bool IsType;
 
  };
 
 
 
  /// The declarations and types to emit.
 
  std::queue<DeclOrType> DeclTypesToEmit;
 
 
 
  /// The first ID number we can use for our own declarations.
 
  serialization::DeclID FirstDeclID = serialization::NUM_PREDEF_DECL_IDS;
 
 
 
  /// The decl ID that will be assigned to the next new decl.
 
  serialization::DeclID NextDeclID = FirstDeclID;
 
 
 
  /// Map that provides the ID numbers of each declaration within
 
  /// the output stream, as well as those deserialized from a chained PCH.
 
  ///
 
  /// The ID numbers of declarations are consecutive (in order of
 
  /// discovery) and start at 2. 1 is reserved for the translation
 
  /// unit, while 0 is reserved for NULL.
 
  llvm::DenseMap<const Decl *, serialization::DeclID> DeclIDs;
 
 
 
  /// Offset of each declaration in the bitstream, indexed by
 
  /// the declaration's ID.
 
  std::vector<serialization::DeclOffset> DeclOffsets;
 
 
 
  /// The offset of the DECLTYPES_BLOCK. The offsets in DeclOffsets
 
  /// are relative to this value.
 
  uint64_t DeclTypesBlockStartOffset = 0;
 
 
 
  /// Sorted (by file offset) vector of pairs of file offset/DeclID.
 
  using LocDeclIDsTy =
 
      SmallVector<std::pair<unsigned, serialization::DeclID>, 64>;
 
  struct DeclIDInFileInfo {
 
    LocDeclIDsTy DeclIDs;
 
 
 
    /// Set when the DeclIDs vectors from all files are joined, this
 
    /// indicates the index that this particular vector has in the global one.
 
    unsigned FirstDeclIndex;
 
  };
 
  using FileDeclIDsTy =
 
      llvm::DenseMap<FileID, std::unique_ptr<DeclIDInFileInfo>>;
 
 
 
  /// Map from file SLocEntries to info about the file-level declarations
 
  /// that it contains.
 
  FileDeclIDsTy FileDeclIDs;
 
 
 
  void associateDeclWithFile(const Decl *D, serialization::DeclID);
 
 
 
  /// The first ID number we can use for our own types.
 
  serialization::TypeID FirstTypeID = serialization::NUM_PREDEF_TYPE_IDS;
 
 
 
  /// The type ID that will be assigned to the next new type.
 
  serialization::TypeID NextTypeID = FirstTypeID;
 
 
 
  /// Map that provides the ID numbers of each type within the
 
  /// output stream, plus those deserialized from a chained PCH.
 
  ///
 
  /// The ID numbers of types are consecutive (in order of discovery)
 
  /// and start at 1. 0 is reserved for NULL. When types are actually
 
  /// stored in the stream, the ID number is shifted by 2 bits to
 
  /// allow for the const/volatile qualifiers.
 
  ///
 
  /// Keys in the map never have const/volatile qualifiers.
 
  TypeIdxMap TypeIdxs;
 
 
 
  /// Offset of each type in the bitstream, indexed by
 
  /// the type's ID.
 
  std::vector<serialization::UnderalignedInt64> TypeOffsets;
 
 
 
  /// The first ID number we can use for our own identifiers.
 
  serialization::IdentID FirstIdentID = serialization::NUM_PREDEF_IDENT_IDS;
 
 
 
  /// The identifier ID that will be assigned to the next new identifier.
 
  serialization::IdentID NextIdentID = FirstIdentID;
 
 
 
  /// Map that provides the ID numbers of each identifier in
 
  /// the output stream.
 
  ///
 
  /// The ID numbers for identifiers are consecutive (in order of
 
  /// discovery), starting at 1. An ID of zero refers to a NULL
 
  /// IdentifierInfo.
 
  llvm::MapVector<const IdentifierInfo *, serialization::IdentID> IdentifierIDs;
 
 
 
  /// The first ID number we can use for our own macros.
 
  serialization::MacroID FirstMacroID = serialization::NUM_PREDEF_MACRO_IDS;
 
 
 
  /// The identifier ID that will be assigned to the next new identifier.
 
  serialization::MacroID NextMacroID = FirstMacroID;
 
 
 
  /// Map that provides the ID numbers of each macro.
 
  llvm::DenseMap<MacroInfo *, serialization::MacroID> MacroIDs;
 
 
 
  struct MacroInfoToEmitData {
 
    const IdentifierInfo *Name;
 
    MacroInfo *MI;
 
    serialization::MacroID ID;
 
  };
 
 
 
  /// The macro infos to emit.
 
  std::vector<MacroInfoToEmitData> MacroInfosToEmit;
 
 
 
  llvm::DenseMap<const IdentifierInfo *, uint32_t>
 
      IdentMacroDirectivesOffsetMap;
 
 
 
  /// @name FlushStmt Caches
 
  /// @{
 
 
 
  /// Set of parent Stmts for the currently serializing sub-stmt.
 
  llvm::DenseSet<Stmt *> ParentStmts;
 
 
 
  /// Offsets of sub-stmts already serialized. The offset points
 
  /// just after the stmt record.
 
  llvm::DenseMap<Stmt *, uint64_t> SubStmtEntries;
 
 
 
  /// @}
 
 
 
  /// Offsets of each of the identifier IDs into the identifier
 
  /// table.
 
  std::vector<uint32_t> IdentifierOffsets;
 
 
 
  /// The first ID number we can use for our own submodules.
 
  serialization::SubmoduleID FirstSubmoduleID =
 
      serialization::NUM_PREDEF_SUBMODULE_IDS;
 
 
 
  /// The submodule ID that will be assigned to the next new submodule.
 
  serialization::SubmoduleID NextSubmoduleID = FirstSubmoduleID;
 
 
 
  /// The first ID number we can use for our own selectors.
 
  serialization::SelectorID FirstSelectorID =
 
      serialization::NUM_PREDEF_SELECTOR_IDS;
 
 
 
  /// The selector ID that will be assigned to the next new selector.
 
  serialization::SelectorID NextSelectorID = FirstSelectorID;
 
 
 
  /// Map that provides the ID numbers of each Selector.
 
  llvm::MapVector<Selector, serialization::SelectorID> SelectorIDs;
 
 
 
  /// Offset of each selector within the method pool/selector
 
  /// table, indexed by the Selector ID (-1).
 
  std::vector<uint32_t> SelectorOffsets;
 
 
 
  /// Mapping from macro definitions (as they occur in the preprocessing
 
  /// record) to the macro IDs.
 
  llvm::DenseMap<const MacroDefinitionRecord *,
 
                 serialization::PreprocessedEntityID> MacroDefinitions;
 
 
 
  /// Cache of indices of anonymous declarations within their lexical
 
  /// contexts.
 
  llvm::DenseMap<const Decl *, unsigned> AnonymousDeclarationNumbers;
 
 
 
  /// An update to a Decl.
 
  class DeclUpdate {
 
    /// A DeclUpdateKind.
 
    unsigned Kind;
 
    union {
 
      const Decl *Dcl;
 
      void *Type;
 
      SourceLocation::UIntTy Loc;
 
      unsigned Val;
 
      Module *Mod;
 
      const Attr *Attribute;
 
    };
 
 
 
  public:
 
    DeclUpdate(unsigned Kind) : Kind(Kind), Dcl(nullptr) {}
 
    DeclUpdate(unsigned Kind, const Decl *Dcl) : Kind(Kind), Dcl(Dcl) {}
 
    DeclUpdate(unsigned Kind, QualType Type)
 
        : Kind(Kind), Type(Type.getAsOpaquePtr()) {}
 
    DeclUpdate(unsigned Kind, SourceLocation Loc)
 
        : Kind(Kind), Loc(Loc.getRawEncoding()) {}
 
    DeclUpdate(unsigned Kind, unsigned Val) : Kind(Kind), Val(Val) {}
 
    DeclUpdate(unsigned Kind, Module *M) : Kind(Kind), Mod(M) {}
 
    DeclUpdate(unsigned Kind, const Attr *Attribute)
 
          : Kind(Kind), Attribute(Attribute) {}
 
 
 
    unsigned getKind() const { return Kind; }
 
    const Decl *getDecl() const { return Dcl; }
 
    QualType getType() const { return QualType::getFromOpaquePtr(Type); }
 
 
 
    SourceLocation getLoc() const {
 
      return SourceLocation::getFromRawEncoding(Loc);
 
    }
 
 
 
    unsigned getNumber() const { return Val; }
 
    Module *getModule() const { return Mod; }
 
    const Attr *getAttr() const { return Attribute; }
 
  };
 
 
 
  using UpdateRecord = SmallVector<DeclUpdate, 1>;
 
  using DeclUpdateMap = llvm::MapVector<const Decl *, UpdateRecord>;
 
 
 
  /// Mapping from declarations that came from a chained PCH to the
 
  /// record containing modifications to them.
 
  DeclUpdateMap DeclUpdates;
 
 
 
  using FirstLatestDeclMap = llvm::DenseMap<Decl *, Decl *>;
 
 
 
  /// Map of first declarations from a chained PCH that point to the
 
  /// most recent declarations in another PCH.
 
  FirstLatestDeclMap FirstLatestDecls;
 
 
 
  /// Declarations encountered that might be external
 
  /// definitions.
 
  ///
 
  /// We keep track of external definitions and other 'interesting' declarations
 
  /// as we are emitting declarations to the AST file. The AST file contains a
 
  /// separate record for these declarations, which are provided to the AST
 
  /// consumer by the AST reader. This is behavior is required to properly cope with,
 
  /// e.g., tentative variable definitions that occur within
 
  /// headers. The declarations themselves are stored as declaration
 
  /// IDs, since they will be written out to an EAGERLY_DESERIALIZED_DECLS
 
  /// record.
 
  SmallVector<serialization::DeclID, 16> EagerlyDeserializedDecls;
 
  SmallVector<serialization::DeclID, 16> ModularCodegenDecls;
 
 
 
  /// DeclContexts that have received extensions since their serialized
 
  /// form.
 
  ///
 
  /// For namespaces, when we're chaining and encountering a namespace, we check
 
  /// if its primary namespace comes from the chain. If it does, we add the
 
  /// primary to this set, so that we can write out lexical content updates for
 
  /// it.
 
  llvm::SmallSetVector<const DeclContext *, 16> UpdatedDeclContexts;
 
 
 
  /// Keeps track of declarations that we must emit, even though we're
 
  /// not guaranteed to be able to find them by walking the AST starting at the
 
  /// translation unit.
 
  SmallVector<const Decl *, 16> DeclsToEmitEvenIfUnreferenced;
 
 
 
  /// The set of Objective-C class that have categories we
 
  /// should serialize.
 
  llvm::SetVector<ObjCInterfaceDecl *> ObjCClassesWithCategories;
 
 
 
  /// The set of declarations that may have redeclaration chains that
 
  /// need to be serialized.
 
  llvm::SmallVector<const Decl *, 16> Redeclarations;
 
 
 
  /// A cache of the first local declaration for "interesting"
 
  /// redeclaration chains.
 
  llvm::DenseMap<const Decl *, const Decl *> FirstLocalDeclCache;
 
 
 
  /// Mapping from SwitchCase statements to IDs.
 
  llvm::DenseMap<SwitchCase *, unsigned> SwitchCaseIDs;
 
 
 
  /// The number of statements written to the AST file.
 
  unsigned NumStatements = 0;
 
 
 
  /// The number of macros written to the AST file.
 
  unsigned NumMacros = 0;
 
 
 
  /// The number of lexical declcontexts written to the AST
 
  /// file.
 
  unsigned NumLexicalDeclContexts = 0;
 
 
 
  /// The number of visible declcontexts written to the AST
 
  /// file.
 
  unsigned NumVisibleDeclContexts = 0;
 
 
 
  /// A mapping from each known submodule to its ID number, which will
 
  /// be a positive integer.
 
  llvm::DenseMap<const Module *, unsigned> SubmoduleIDs;
 
 
 
  /// A list of the module file extension writers.
 
  std::vector<std::unique_ptr<ModuleFileExtensionWriter>>
 
      ModuleFileExtensionWriters;
 
 
 
  /// Mapping from a source location entry to whether it is affecting or not.
 
  llvm::BitVector IsSLocAffecting;
 
 
 
  /// Mapping from \c FileID to an index into the FileID adjustment table.
 
  std::vector<FileID> NonAffectingFileIDs;
 
  std::vector<unsigned> NonAffectingFileIDAdjustments;
 
 
 
  /// Mapping from an offset to an index into the offset adjustment table.
 
  std::vector<SourceRange> NonAffectingRanges;
 
  std::vector<SourceLocation::UIntTy> NonAffectingOffsetAdjustments;
 
 
 
  /// Collects input files that didn't affect compilation of the current module,
 
  /// and initializes data structures necessary for leaving those files out
 
  /// during \c SourceManager serialization.
 
  void collectNonAffectingInputFiles();
 
 
 
  /// Returns an adjusted \c FileID, accounting for any non-affecting input
 
  /// files.
 
  FileID getAdjustedFileID(FileID FID) const;
 
  /// Returns an adjusted number of \c FileIDs created within the specified \c
 
  /// FileID, accounting for any non-affecting input files.
 
  unsigned getAdjustedNumCreatedFIDs(FileID FID) const;
 
  /// Returns an adjusted \c SourceLocation, accounting for any non-affecting
 
  /// input files.
 
  SourceLocation getAdjustedLocation(SourceLocation Loc) const;
 
  /// Returns an adjusted \c SourceRange, accounting for any non-affecting input
 
  /// files.
 
  SourceRange getAdjustedRange(SourceRange Range) const;
 
  /// Returns an adjusted \c SourceLocation offset, accounting for any
 
  /// non-affecting input files.
 
  SourceLocation::UIntTy getAdjustedOffset(SourceLocation::UIntTy Offset) const;
 
  /// Returns an adjustment for offset into SourceManager, accounting for any
 
  /// non-affecting input files.
 
  SourceLocation::UIntTy getAdjustment(SourceLocation::UIntTy Offset) const;
 
 
 
  /// Retrieve or create a submodule ID for this module.
 
  unsigned getSubmoduleID(Module *Mod);
 
 
 
  /// Write the given subexpression to the bitstream.
 
  void WriteSubStmt(Stmt *S);
 
 
 
  void WriteBlockInfoBlock();
 
  void WriteControlBlock(Preprocessor &PP, ASTContext &Context,
 
                         StringRef isysroot);
 
 
 
  /// Write out the signature and diagnostic options, and return the signature.
 
  ASTFileSignature writeUnhashedControlBlock(Preprocessor &PP,
 
                                             ASTContext &Context);
 
 
 
  /// Calculate hash of the pcm content.
 
  static std::pair<ASTFileSignature, ASTFileSignature>
 
  createSignature(StringRef AllBytes, StringRef ASTBlockBytes);
 
 
 
  void WriteInputFiles(SourceManager &SourceMgr, HeaderSearchOptions &HSOpts);
 
  void WriteSourceManagerBlock(SourceManager &SourceMgr,
 
                               const Preprocessor &PP);
 
  void writeIncludedFiles(raw_ostream &Out, const Preprocessor &PP);
 
  void WritePreprocessor(const Preprocessor &PP, bool IsModule);
 
  void WriteHeaderSearch(const HeaderSearch &HS);
 
  void WritePreprocessorDetail(PreprocessingRecord &PPRec,
 
                               uint64_t MacroOffsetsBase);
 
  void WriteSubmodules(Module *WritingModule);
 
 
 
  void WritePragmaDiagnosticMappings(const DiagnosticsEngine &Diag,
 
                                     bool isModule);
 
 
 
  unsigned TypeExtQualAbbrev = 0;
 
  void WriteTypeAbbrevs();
 
  void WriteType(QualType T);
 
 
 
  bool isLookupResultExternal(StoredDeclsList &Result, DeclContext *DC);
 
  bool isLookupResultEntirelyExternal(StoredDeclsList &Result, DeclContext *DC);
 
 
 
  void GenerateNameLookupTable(const DeclContext *DC,
 
                               llvm::SmallVectorImpl<char> &LookupTable);
 
  uint64_t WriteDeclContextLexicalBlock(ASTContext &Context, DeclContext *DC);
 
  uint64_t WriteDeclContextVisibleBlock(ASTContext &Context, DeclContext *DC);
 
  void WriteTypeDeclOffsets();
 
  void WriteFileDeclIDsMap();
 
  void WriteComments();
 
  void WriteSelectors(Sema &SemaRef);
 
  void WriteReferencedSelectorsPool(Sema &SemaRef);
 
  void WriteIdentifierTable(Preprocessor &PP, IdentifierResolver &IdResolver,
 
                            bool IsModule);
 
  void WriteDeclUpdatesBlocks(RecordDataImpl &OffsetsRecord);
 
  void WriteDeclContextVisibleUpdate(const DeclContext *DC);
 
  void WriteFPPragmaOptions(const FPOptionsOverride &Opts);
 
  void WriteOpenCLExtensions(Sema &SemaRef);
 
  void WriteCUDAPragmas(Sema &SemaRef);
 
  void WriteObjCCategories();
 
  void WriteLateParsedTemplates(Sema &SemaRef);
 
  void WriteOptimizePragmaOptions(Sema &SemaRef);
 
  void WriteMSStructPragmaOptions(Sema &SemaRef);
 
  void WriteMSPointersToMembersPragmaOptions(Sema &SemaRef);
 
  void WritePackPragmaOptions(Sema &SemaRef);
 
  void WriteFloatControlPragmaOptions(Sema &SemaRef);
 
  void WriteModuleFileExtension(Sema &SemaRef,
 
                                ModuleFileExtensionWriter &Writer);
 
 
 
  unsigned DeclParmVarAbbrev = 0;
 
  unsigned DeclContextLexicalAbbrev = 0;
 
  unsigned DeclContextVisibleLookupAbbrev = 0;
 
  unsigned UpdateVisibleAbbrev = 0;
 
  unsigned DeclRecordAbbrev = 0;
 
  unsigned DeclTypedefAbbrev = 0;
 
  unsigned DeclVarAbbrev = 0;
 
  unsigned DeclFieldAbbrev = 0;
 
  unsigned DeclEnumAbbrev = 0;
 
  unsigned DeclObjCIvarAbbrev = 0;
 
  unsigned DeclCXXMethodAbbrev = 0;
 
 
 
  unsigned DeclRefExprAbbrev = 0;
 
  unsigned CharacterLiteralAbbrev = 0;
 
  unsigned IntegerLiteralAbbrev = 0;
 
  unsigned ExprImplicitCastAbbrev = 0;
 
 
 
  void WriteDeclAbbrevs();
 
  void WriteDecl(ASTContext &Context, Decl *D);
 
 
 
  ASTFileSignature WriteASTCore(Sema &SemaRef, StringRef isysroot,
 
                                Module *WritingModule);
 
 
 
public:
 
  /// Create a new precompiled header writer that outputs to
 
  /// the given bitstream.
 
  ASTWriter(llvm::BitstreamWriter &Stream, SmallVectorImpl<char> &Buffer,
 
            InMemoryModuleCache &ModuleCache,
 
            ArrayRef<std::shared_ptr<ModuleFileExtension>> Extensions,
 
            bool IncludeTimestamps = true);
 
  ~ASTWriter() override;
 
 
 
  ASTContext &getASTContext() const {
 
    assert(Context && "requested AST context when not writing AST");
 
    return *Context;
 
  }
 
 
 
  const LangOptions &getLangOpts() const;
 
 
 
  /// Get a timestamp for output into the AST file. The actual timestamp
 
  /// of the specified file may be ignored if we have been instructed to not
 
  /// include timestamps in the output file.
 
  time_t getTimestampForOutput(const FileEntry *E) const;
 
 
 
  /// Write a precompiled header for the given semantic analysis.
 
  ///
 
  /// \param SemaRef a reference to the semantic analysis object that processed
 
  /// the AST to be written into the precompiled header.
 
  ///
 
  /// \param WritingModule The module that we are writing. If null, we are
 
  /// writing a precompiled header.
 
  ///
 
  /// \param isysroot if non-empty, write a relocatable file whose headers
 
  /// are relative to the given system root. If we're writing a module, its
 
  /// build directory will be used in preference to this if both are available.
 
  ///
 
  /// \return the module signature, which eventually will be a hash of
 
  /// the module but currently is merely a random 32-bit number.
 
  ASTFileSignature WriteAST(Sema &SemaRef, StringRef OutputFile,
 
                            Module *WritingModule, StringRef isysroot,
 
                            bool hasErrors = false,
 
                            bool ShouldCacheASTInMemory = false);
 
 
 
  /// Emit a token.
 
  void AddToken(const Token &Tok, RecordDataImpl &Record);
 
 
 
  /// Emit a AlignPackInfo.
 
  void AddAlignPackInfo(const Sema::AlignPackInfo &Info,
 
                        RecordDataImpl &Record);
 
 
 
  /// Emit a FileID.
 
  void AddFileID(FileID FID, RecordDataImpl &Record);
 
 
 
  /// Emit a source location.
 
  void AddSourceLocation(SourceLocation Loc, RecordDataImpl &Record,
 
                         LocSeq *Seq = nullptr);
 
 
 
  /// Emit a source range.
 
  void AddSourceRange(SourceRange Range, RecordDataImpl &Record,
 
                      LocSeq *Seq = nullptr);
 
 
 
  /// Emit a reference to an identifier.
 
  void AddIdentifierRef(const IdentifierInfo *II, RecordDataImpl &Record);
 
 
 
  /// Get the unique number used to refer to the given selector.
 
  serialization::SelectorID getSelectorRef(Selector Sel);
 
 
 
  /// Get the unique number used to refer to the given identifier.
 
  serialization::IdentID getIdentifierRef(const IdentifierInfo *II);
 
 
 
  /// Get the unique number used to refer to the given macro.
 
  serialization::MacroID getMacroRef(MacroInfo *MI, const IdentifierInfo *Name);
 
 
 
  /// Determine the ID of an already-emitted macro.
 
  serialization::MacroID getMacroID(MacroInfo *MI);
 
 
 
  uint32_t getMacroDirectivesOffset(const IdentifierInfo *Name);
 
 
 
  /// Emit a reference to a type.
 
  void AddTypeRef(QualType T, RecordDataImpl &Record);
 
 
 
  /// Force a type to be emitted and get its ID.
 
  serialization::TypeID GetOrCreateTypeID(QualType T);
 
 
 
  /// Determine the type ID of an already-emitted type.
 
  serialization::TypeID getTypeID(QualType T) const;
 
 
 
  /// Find the first local declaration of a given local redeclarable
 
  /// decl.
 
  const Decl *getFirstLocalDecl(const Decl *D);
 
 
 
  /// Is this a local declaration (that is, one that will be written to
 
  /// our AST file)? This is the case for declarations that are neither imported
 
  /// from another AST file nor predefined.
 
  bool IsLocalDecl(const Decl *D) {
 
    if (D->isFromASTFile())
 
      return false;
 
    auto I = DeclIDs.find(D);
 
    return (I == DeclIDs.end() ||
 
            I->second >= serialization::NUM_PREDEF_DECL_IDS);
 
  };
 
 
 
  /// Emit a reference to a declaration.
 
  void AddDeclRef(const Decl *D, RecordDataImpl &Record);
 
 
 
  /// Force a declaration to be emitted and get its ID.
 
  serialization::DeclID GetDeclRef(const Decl *D);
 
 
 
  /// Determine the declaration ID of an already-emitted
 
  /// declaration.
 
  serialization::DeclID getDeclID(const Decl *D);
 
 
 
  unsigned getAnonymousDeclarationNumber(const NamedDecl *D);
 
 
 
  /// Add a string to the given record.
 
  void AddString(StringRef Str, RecordDataImpl &Record);
 
 
 
  /// Convert a path from this build process into one that is appropriate
 
  /// for emission in the module file.
 
  bool PreparePathForOutput(SmallVectorImpl<char> &Path);
 
 
 
  /// Add a path to the given record.
 
  void AddPath(StringRef Path, RecordDataImpl &Record);
 
 
 
  /// Emit the current record with the given path as a blob.
 
  void EmitRecordWithPath(unsigned Abbrev, RecordDataRef Record,
 
                          StringRef Path);
 
 
 
  /// Add a version tuple to the given record
 
  void AddVersionTuple(const VersionTuple &Version, RecordDataImpl &Record);
 
 
 
  /// Retrieve or create a submodule ID for this module, or return 0 if
 
  /// the submodule is neither local (a submodle of the currently-written module)
 
  /// nor from an imported module.
 
  unsigned getLocalOrImportedSubmoduleID(const Module *Mod);
 
 
 
  /// Note that the identifier II occurs at the given offset
 
  /// within the identifier table.
 
  void SetIdentifierOffset(const IdentifierInfo *II, uint32_t Offset);
 
 
 
  /// Note that the selector Sel occurs at the given offset
 
  /// within the method pool/selector table.
 
  void SetSelectorOffset(Selector Sel, uint32_t Offset);
 
 
 
  /// Record an ID for the given switch-case statement.
 
  unsigned RecordSwitchCaseID(SwitchCase *S);
 
 
 
  /// Retrieve the ID for the given switch-case statement.
 
  unsigned getSwitchCaseID(SwitchCase *S);
 
 
 
  void ClearSwitchCaseIDs();
 
 
 
  unsigned getTypeExtQualAbbrev() const {
 
    return TypeExtQualAbbrev;
 
  }
 
 
 
  unsigned getDeclParmVarAbbrev() const { return DeclParmVarAbbrev; }
 
  unsigned getDeclRecordAbbrev() const { return DeclRecordAbbrev; }
 
  unsigned getDeclTypedefAbbrev() const { return DeclTypedefAbbrev; }
 
  unsigned getDeclVarAbbrev() const { return DeclVarAbbrev; }
 
  unsigned getDeclFieldAbbrev() const { return DeclFieldAbbrev; }
 
  unsigned getDeclEnumAbbrev() const { return DeclEnumAbbrev; }
 
  unsigned getDeclObjCIvarAbbrev() const { return DeclObjCIvarAbbrev; }
 
  unsigned getDeclCXXMethodAbbrev() const { return DeclCXXMethodAbbrev; }
 
 
 
  unsigned getDeclRefExprAbbrev() const { return DeclRefExprAbbrev; }
 
  unsigned getCharacterLiteralAbbrev() const { return CharacterLiteralAbbrev; }
 
  unsigned getIntegerLiteralAbbrev() const { return IntegerLiteralAbbrev; }
 
  unsigned getExprImplicitCastAbbrev() const { return ExprImplicitCastAbbrev; }
 
 
 
  bool hasChain() const { return Chain; }
 
  ASTReader *getChain() const { return Chain; }
 
 
 
  bool isWritingStdCXXNamedModules() const {
 
    return WritingModule && WritingModule->isModulePurview();
 
  }
 
 
 
private:
 
  // ASTDeserializationListener implementation
 
  void ReaderInitialized(ASTReader *Reader) override;
 
  void IdentifierRead(serialization::IdentID ID, IdentifierInfo *II) override;
 
  void MacroRead(serialization::MacroID ID, MacroInfo *MI) override;
 
  void TypeRead(serialization::TypeIdx Idx, QualType T) override;
 
  void SelectorRead(serialization::SelectorID ID, Selector Sel) override;
 
  void MacroDefinitionRead(serialization::PreprocessedEntityID ID,
 
                           MacroDefinitionRecord *MD) override;
 
  void ModuleRead(serialization::SubmoduleID ID, Module *Mod) override;
 
 
 
  // ASTMutationListener implementation.
 
  void CompletedTagDefinition(const TagDecl *D) override;
 
  void AddedVisibleDecl(const DeclContext *DC, const Decl *D) override;
 
  void AddedCXXImplicitMember(const CXXRecordDecl *RD, const Decl *D) override;
 
  void AddedCXXTemplateSpecialization(
 
      const ClassTemplateDecl *TD,
 
      const ClassTemplateSpecializationDecl *D) override;
 
  void AddedCXXTemplateSpecialization(
 
      const VarTemplateDecl *TD,
 
      const VarTemplateSpecializationDecl *D) override;
 
  void AddedCXXTemplateSpecialization(const FunctionTemplateDecl *TD,
 
                                      const FunctionDecl *D) override;
 
  void ResolvedExceptionSpec(const FunctionDecl *FD) override;
 
  void DeducedReturnType(const FunctionDecl *FD, QualType ReturnType) override;
 
  void ResolvedOperatorDelete(const CXXDestructorDecl *DD,
 
                              const FunctionDecl *Delete,
 
                              Expr *ThisArg) override;
 
  void CompletedImplicitDefinition(const FunctionDecl *D) override;
 
  void InstantiationRequested(const ValueDecl *D) override;
 
  void VariableDefinitionInstantiated(const VarDecl *D) override;
 
  void FunctionDefinitionInstantiated(const FunctionDecl *D) override;
 
  void DefaultArgumentInstantiated(const ParmVarDecl *D) override;
 
  void DefaultMemberInitializerInstantiated(const FieldDecl *D) override;
 
  void AddedObjCCategoryToInterface(const ObjCCategoryDecl *CatD,
 
                                    const ObjCInterfaceDecl *IFD) override;
 
  void DeclarationMarkedUsed(const Decl *D) override;
 
  void DeclarationMarkedOpenMPThreadPrivate(const Decl *D) override;
 
  void DeclarationMarkedOpenMPDeclareTarget(const Decl *D,
 
                                            const Attr *Attr) override;
 
  void DeclarationMarkedOpenMPAllocate(const Decl *D, const Attr *A) override;
 
  void RedefinedHiddenDefinition(const NamedDecl *D, Module *M) override;
 
  void AddedAttributeToRecord(const Attr *Attr,
 
                              const RecordDecl *Record) override;
 
};
 
 
 
/// AST and semantic-analysis consumer that generates a
 
/// precompiled header from the parsed source code.
 
class PCHGenerator : public SemaConsumer {
 
  const Preprocessor &PP;
 
  std::string OutputFile;
 
  std::string isysroot;
 
  Sema *SemaPtr;
 
  std::shared_ptr<PCHBuffer> Buffer;
 
  llvm::BitstreamWriter Stream;
 
  ASTWriter Writer;
 
  bool AllowASTWithErrors;
 
  bool ShouldCacheASTInMemory;
 
 
 
protected:
 
  ASTWriter &getWriter() { return Writer; }
 
  const ASTWriter &getWriter() const { return Writer; }
 
  SmallVectorImpl<char> &getPCH() const { return Buffer->Data; }
 
 
 
public:
 
  PCHGenerator(const Preprocessor &PP, InMemoryModuleCache &ModuleCache,
 
               StringRef OutputFile, StringRef isysroot,
 
               std::shared_ptr<PCHBuffer> Buffer,
 
               ArrayRef<std::shared_ptr<ModuleFileExtension>> Extensions,
 
               bool AllowASTWithErrors = false, bool IncludeTimestamps = true,
 
               bool ShouldCacheASTInMemory = false);
 
  ~PCHGenerator() override;
 
 
 
  void InitializeSema(Sema &S) override { SemaPtr = &S; }
 
  void HandleTranslationUnit(ASTContext &Ctx) override;
 
  ASTMutationListener *GetASTMutationListener() override;
 
  ASTDeserializationListener *GetASTDeserializationListener() override;
 
  bool hasEmittedPCH() const { return Buffer->IsComplete; }
 
};
 
 
 
} // namespace clang
 
 
 
#endif // LLVM_CLANG_SERIALIZATION_ASTWRITER_H