//===- ASTReader.h - AST File Reader ----------------------------*- 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 ASTReader class, which reads AST files.
 
//
 
//===----------------------------------------------------------------------===//
 
 
 
#ifndef LLVM_CLANG_SERIALIZATION_ASTREADER_H
 
#define LLVM_CLANG_SERIALIZATION_ASTREADER_H
 
 
 
#include "clang/AST/Type.h"
 
#include "clang/Basic/Diagnostic.h"
 
#include "clang/Basic/DiagnosticOptions.h"
 
#include "clang/Basic/IdentifierTable.h"
 
#include "clang/Basic/OpenCLOptions.h"
 
#include "clang/Basic/SourceLocation.h"
 
#include "clang/Basic/Version.h"
 
#include "clang/Lex/ExternalPreprocessorSource.h"
 
#include "clang/Lex/HeaderSearch.h"
 
#include "clang/Lex/PreprocessingRecord.h"
 
#include "clang/Lex/PreprocessorOptions.h"
 
#include "clang/Sema/ExternalSemaSource.h"
 
#include "clang/Sema/IdentifierResolver.h"
 
#include "clang/Sema/Sema.h"
 
#include "clang/Serialization/ASTBitCodes.h"
 
#include "clang/Serialization/ContinuousRangeMap.h"
 
#include "clang/Serialization/ModuleFile.h"
 
#include "clang/Serialization/ModuleFileExtension.h"
 
#include "clang/Serialization/ModuleManager.h"
 
#include "clang/Serialization/SourceLocationEncoding.h"
 
#include "llvm/ADT/ArrayRef.h"
 
#include "llvm/ADT/DenseMap.h"
 
#include "llvm/ADT/DenseSet.h"
 
#include "llvm/ADT/IntrusiveRefCntPtr.h"
 
#include "llvm/ADT/MapVector.h"
 
#include "llvm/ADT/STLExtras.h"
 
#include "llvm/ADT/SetVector.h"
 
#include "llvm/ADT/SmallPtrSet.h"
 
#include "llvm/ADT/SmallVector.h"
 
#include "llvm/ADT/StringMap.h"
 
#include "llvm/ADT/StringRef.h"
 
#include "llvm/ADT/iterator.h"
 
#include "llvm/ADT/iterator_range.h"
 
#include "llvm/Bitstream/BitstreamReader.h"
 
#include "llvm/Support/MemoryBuffer.h"
 
#include "llvm/Support/Timer.h"
 
#include "llvm/Support/VersionTuple.h"
 
#include <cassert>
 
#include <cstddef>
 
#include <cstdint>
 
#include <ctime>
 
#include <deque>
 
#include <memory>
 
#include <optional>
 
#include <set>
 
#include <string>
 
#include <utility>
 
#include <vector>
 
 
 
namespace clang {
 
 
 
class ASTConsumer;
 
class ASTContext;
 
class ASTDeserializationListener;
 
class ASTReader;
 
class ASTRecordReader;
 
class CXXTemporary;
 
class Decl;
 
class DeclarationName;
 
class DeclaratorDecl;
 
class DeclContext;
 
class EnumDecl;
 
class Expr;
 
class FieldDecl;
 
class FileEntry;
 
class FileManager;
 
class FileSystemOptions;
 
class FunctionDecl;
 
class GlobalModuleIndex;
 
struct HeaderFileInfo;
 
class HeaderSearchOptions;
 
class LangOptions;
 
class MacroInfo;
 
class InMemoryModuleCache;
 
class NamedDecl;
 
class NamespaceDecl;
 
class ObjCCategoryDecl;
 
class ObjCInterfaceDecl;
 
class PCHContainerReader;
 
class Preprocessor;
 
class PreprocessorOptions;
 
class Sema;
 
class SourceManager;
 
class Stmt;
 
class SwitchCase;
 
class TargetOptions;
 
class Token;
 
class TypedefNameDecl;
 
class ValueDecl;
 
class VarDecl;
 
 
 
/// Abstract interface for callback invocations by the ASTReader.
 
///
 
/// While reading an AST file, the ASTReader will call the methods of the
 
/// listener to pass on specific information. Some of the listener methods can
 
/// return true to indicate to the ASTReader that the information (and
 
/// consequently the AST file) is invalid.
 
class ASTReaderListener {
 
public:
 
  virtual ~ASTReaderListener();
 
 
 
  /// Receives the full Clang version information.
 
  ///
 
  /// \returns true to indicate that the version is invalid. Subclasses should
 
  /// generally defer to this implementation.
 
  virtual bool ReadFullVersionInformation(StringRef FullVersion) {
 
    return FullVersion != getClangFullRepositoryVersion();
 
  }
 
 
 
  virtual void ReadModuleName(StringRef ModuleName) {}
 
  virtual void ReadModuleMapFile(StringRef ModuleMapPath) {}
 
 
 
  /// Receives the language options.
 
  ///
 
  /// \returns true to indicate the options are invalid or false otherwise.
 
  virtual bool ReadLanguageOptions(const LangOptions &LangOpts,
 
                                   bool Complain,
 
                                   bool AllowCompatibleDifferences) {
 
    return false;
 
  }
 
 
 
  /// Receives the target options.
 
  ///
 
  /// \returns true to indicate the target options are invalid, or false
 
  /// otherwise.
 
  virtual bool ReadTargetOptions(const TargetOptions &TargetOpts, bool Complain,
 
                                 bool AllowCompatibleDifferences) {
 
    return false;
 
  }
 
 
 
  /// Receives the diagnostic options.
 
  ///
 
  /// \returns true to indicate the diagnostic options are invalid, or false
 
  /// otherwise.
 
  virtual bool
 
  ReadDiagnosticOptions(IntrusiveRefCntPtr<DiagnosticOptions> DiagOpts,
 
                        bool Complain) {
 
    return false;
 
  }
 
 
 
  /// Receives the file system options.
 
  ///
 
  /// \returns true to indicate the file system options are invalid, or false
 
  /// otherwise.
 
  virtual bool ReadFileSystemOptions(const FileSystemOptions &FSOpts,
 
                                     bool Complain) {
 
    return false;
 
  }
 
 
 
  /// Receives the header search options.
 
  ///
 
  /// \param HSOpts The read header search options. The following fields are
 
  ///               missing and are reported in ReadHeaderSearchPaths():
 
  ///               UserEntries, SystemHeaderPrefixes, VFSOverlayFiles.
 
  ///
 
  /// \returns true to indicate the header search options are invalid, or false
 
  /// otherwise.
 
  virtual bool ReadHeaderSearchOptions(const HeaderSearchOptions &HSOpts,
 
                                       StringRef SpecificModuleCachePath,
 
                                       bool Complain) {
 
    return false;
 
  }
 
 
 
  /// Receives the header search paths.
 
  ///
 
  /// \param HSOpts The read header search paths. Only the following fields are
 
  ///               initialized: UserEntries, SystemHeaderPrefixes,
 
  ///               VFSOverlayFiles. The rest is reported in
 
  ///               ReadHeaderSearchOptions().
 
  ///
 
  /// \returns true to indicate the header search paths are invalid, or false
 
  /// otherwise.
 
  virtual bool ReadHeaderSearchPaths(const HeaderSearchOptions &HSOpts,
 
                                     bool Complain) {
 
    return false;
 
  }
 
 
 
  /// Receives the preprocessor options.
 
  ///
 
  /// \param SuggestedPredefines Can be filled in with the set of predefines
 
  /// that are suggested by the preprocessor options. Typically only used when
 
  /// loading a precompiled header.
 
  ///
 
  /// \returns true to indicate the preprocessor options are invalid, or false
 
  /// otherwise.
 
  virtual bool ReadPreprocessorOptions(const PreprocessorOptions &PPOpts,
 
                                       bool Complain,
 
                                       std::string &SuggestedPredefines) {
 
    return false;
 
  }
 
 
 
  /// Receives __COUNTER__ value.
 
  virtual void ReadCounter(const serialization::ModuleFile &M,
 
                           unsigned Value) {}
 
 
 
  /// This is called for each AST file loaded.
 
  virtual void visitModuleFile(StringRef Filename,
 
                               serialization::ModuleKind Kind) {}
 
 
 
  /// Returns true if this \c ASTReaderListener wants to receive the
 
  /// input files of the AST file via \c visitInputFile, false otherwise.
 
  virtual bool needsInputFileVisitation() { return false; }
 
 
 
  /// Returns true if this \c ASTReaderListener wants to receive the
 
  /// system input files of the AST file via \c visitInputFile, false otherwise.
 
  virtual bool needsSystemInputFileVisitation() { return false; }
 
 
 
  /// if \c needsInputFileVisitation returns true, this is called for
 
  /// each non-system input file of the AST File. If
 
  /// \c needsSystemInputFileVisitation is true, then it is called for all
 
  /// system input files as well.
 
  ///
 
  /// \returns true to continue receiving the next input file, false to stop.
 
  virtual bool visitInputFile(StringRef Filename, bool isSystem,
 
                              bool isOverridden, bool isExplicitModule) {
 
    return true;
 
  }
 
 
 
  /// Returns true if this \c ASTReaderListener wants to receive the
 
  /// imports of the AST file via \c visitImport, false otherwise.
 
  virtual bool needsImportVisitation() const { return false; }
 
 
 
  /// If needsImportVisitation returns \c true, this is called for each
 
  /// AST file imported by this AST file.
 
  virtual void visitImport(StringRef ModuleName, StringRef Filename) {}
 
 
 
  /// Indicates that a particular module file extension has been read.
 
  virtual void readModuleFileExtension(
 
                 const ModuleFileExtensionMetadata &Metadata) {}
 
};
 
 
 
/// Simple wrapper class for chaining listeners.
 
class ChainedASTReaderListener : public ASTReaderListener {
 
  std::unique_ptr<ASTReaderListener> First;
 
  std::unique_ptr<ASTReaderListener> Second;
 
 
 
public:
 
  /// Takes ownership of \p First and \p Second.
 
  ChainedASTReaderListener(std::unique_ptr<ASTReaderListener> First,
 
                           std::unique_ptr<ASTReaderListener> Second)
 
      : First(std::move(First)), Second(std::move(Second)) {}
 
 
 
  std::unique_ptr<ASTReaderListener> takeFirst() { return std::move(First); }
 
  std::unique_ptr<ASTReaderListener> takeSecond() { return std::move(Second); }
 
 
 
  bool ReadFullVersionInformation(StringRef FullVersion) override;
 
  void ReadModuleName(StringRef ModuleName) override;
 
  void ReadModuleMapFile(StringRef ModuleMapPath) override;
 
  bool ReadLanguageOptions(const LangOptions &LangOpts, bool Complain,
 
                           bool AllowCompatibleDifferences) override;
 
  bool ReadTargetOptions(const TargetOptions &TargetOpts, bool Complain,
 
                         bool AllowCompatibleDifferences) override;
 
  bool ReadDiagnosticOptions(IntrusiveRefCntPtr<DiagnosticOptions> DiagOpts,
 
                             bool Complain) override;
 
  bool ReadFileSystemOptions(const FileSystemOptions &FSOpts,
 
                             bool Complain) override;
 
 
 
  bool ReadHeaderSearchOptions(const HeaderSearchOptions &HSOpts,
 
                               StringRef SpecificModuleCachePath,
 
                               bool Complain) override;
 
  bool ReadPreprocessorOptions(const PreprocessorOptions &PPOpts,
 
                               bool Complain,
 
                               std::string &SuggestedPredefines) override;
 
 
 
  void ReadCounter(const serialization::ModuleFile &M, unsigned Value) override;
 
  bool needsInputFileVisitation() override;
 
  bool needsSystemInputFileVisitation() override;
 
  void visitModuleFile(StringRef Filename,
 
                       serialization::ModuleKind Kind) override;
 
  bool visitInputFile(StringRef Filename, bool isSystem,
 
                      bool isOverridden, bool isExplicitModule) override;
 
  void readModuleFileExtension(
 
         const ModuleFileExtensionMetadata &Metadata) override;
 
};
 
 
 
/// ASTReaderListener implementation to validate the information of
 
/// the PCH file against an initialized Preprocessor.
 
class PCHValidator : public ASTReaderListener {
 
  Preprocessor &PP;
 
  ASTReader &Reader;
 
 
 
public:
 
  PCHValidator(Preprocessor &PP, ASTReader &Reader)
 
      : PP(PP), Reader(Reader) {}
 
 
 
  bool ReadLanguageOptions(const LangOptions &LangOpts, bool Complain,
 
                           bool AllowCompatibleDifferences) override;
 
  bool ReadTargetOptions(const TargetOptions &TargetOpts, bool Complain,
 
                         bool AllowCompatibleDifferences) override;
 
  bool ReadDiagnosticOptions(IntrusiveRefCntPtr<DiagnosticOptions> DiagOpts,
 
                             bool Complain) override;
 
  bool ReadPreprocessorOptions(const PreprocessorOptions &PPOpts, bool Complain,
 
                               std::string &SuggestedPredefines) override;
 
  bool ReadHeaderSearchOptions(const HeaderSearchOptions &HSOpts,
 
                               StringRef SpecificModuleCachePath,
 
                               bool Complain) override;
 
  void ReadCounter(const serialization::ModuleFile &M, unsigned Value) override;
 
 
 
private:
 
  void Error(const char *Msg);
 
};
 
 
 
/// ASTReaderListenter implementation to set SuggestedPredefines of
 
/// ASTReader which is required to use a pch file. This is the replacement
 
/// of PCHValidator or SimplePCHValidator when using a pch file without
 
/// validating it.
 
class SimpleASTReaderListener : public ASTReaderListener {
 
  Preprocessor &PP;
 
 
 
public:
 
  SimpleASTReaderListener(Preprocessor &PP) : PP(PP) {}
 
 
 
  bool ReadPreprocessorOptions(const PreprocessorOptions &PPOpts, bool Complain,
 
                               std::string &SuggestedPredefines) override;
 
};
 
 
 
namespace serialization {
 
 
 
class ReadMethodPoolVisitor;
 
 
 
namespace reader {
 
 
 
class ASTIdentifierLookupTrait;
 
 
 
/// The on-disk hash table(s) used for DeclContext name lookup.
 
struct DeclContextLookupTable;
 
 
 
} // namespace reader
 
 
 
} // namespace serialization
 
 
 
/// Reads an AST files chain containing the contents of a translation
 
/// unit.
 
///
 
/// The ASTReader class reads bitstreams (produced by the ASTWriter
 
/// class) containing the serialized representation of a given
 
/// abstract syntax tree and its supporting data structures. An
 
/// instance of the ASTReader can be attached to an ASTContext object,
 
/// which will provide access to the contents of the AST files.
 
///
 
/// The AST reader provides lazy de-serialization of declarations, as
 
/// required when traversing the AST. Only those AST nodes that are
 
/// actually required will be de-serialized.
 
class ASTReader
 
  : public ExternalPreprocessorSource,
 
    public ExternalPreprocessingRecordSource,
 
    public ExternalHeaderFileInfoSource,
 
    public ExternalSemaSource,
 
    public IdentifierInfoLookup,
 
    public ExternalSLocEntrySource
 
{
 
public:
 
  /// Types of AST files.
 
  friend class ASTDeclReader;
 
  friend class ASTIdentifierIterator;
 
  friend class ASTRecordReader;
 
  friend class ASTUnit; // ASTUnit needs to remap source locations.
 
  friend class ASTWriter;
 
  friend class PCHValidator;
 
  friend class serialization::reader::ASTIdentifierLookupTrait;
 
  friend class serialization::ReadMethodPoolVisitor;
 
  friend class TypeLocReader;
 
 
 
  using RecordData = SmallVector<uint64_t, 64>;
 
  using RecordDataImpl = SmallVectorImpl<uint64_t>;
 
 
 
  /// The result of reading the control block of an AST file, which
 
  /// can fail for various reasons.
 
  enum ASTReadResult {
 
    /// The control block was read successfully. Aside from failures,
 
    /// the AST file is safe to read into the current context.
 
    Success,
 
 
 
    /// The AST file itself appears corrupted.
 
    Failure,
 
 
 
    /// The AST file was missing.
 
    Missing,
 
 
 
    /// The AST file is out-of-date relative to its input files,
 
    /// and needs to be regenerated.
 
    OutOfDate,
 
 
 
    /// The AST file was written by a different version of Clang.
 
    VersionMismatch,
 
 
 
    /// The AST file was written with a different language/target
 
    /// configuration.
 
    ConfigurationMismatch,
 
 
 
    /// The AST file has errors.
 
    HadErrors
 
  };
 
 
 
  using ModuleFile = serialization::ModuleFile;
 
  using ModuleKind = serialization::ModuleKind;
 
  using ModuleManager = serialization::ModuleManager;
 
  using ModuleIterator = ModuleManager::ModuleIterator;
 
  using ModuleConstIterator = ModuleManager::ModuleConstIterator;
 
  using ModuleReverseIterator = ModuleManager::ModuleReverseIterator;
 
 
 
private:
 
  using LocSeq = SourceLocationSequence;
 
 
 
  /// The receiver of some callbacks invoked by ASTReader.
 
  std::unique_ptr<ASTReaderListener> Listener;
 
 
 
  /// The receiver of deserialization events.
 
  ASTDeserializationListener *DeserializationListener = nullptr;
 
 
 
  bool OwnsDeserializationListener = false;
 
 
 
  SourceManager &SourceMgr;
 
  FileManager &FileMgr;
 
  const PCHContainerReader &PCHContainerRdr;
 
  DiagnosticsEngine &Diags;
 
 
 
  /// The semantic analysis object that will be processing the
 
  /// AST files and the translation unit that uses it.
 
  Sema *SemaObj = nullptr;
 
 
 
  /// The preprocessor that will be loading the source file.
 
  Preprocessor &PP;
 
 
 
  /// The AST context into which we'll read the AST files.
 
  ASTContext *ContextObj = nullptr;
 
 
 
  /// The AST consumer.
 
  ASTConsumer *Consumer = nullptr;
 
 
 
  /// The module manager which manages modules and their dependencies
 
  ModuleManager ModuleMgr;
 
 
 
  /// A dummy identifier resolver used to merge TU-scope declarations in
 
  /// C, for the cases where we don't have a Sema object to provide a real
 
  /// identifier resolver.
 
  IdentifierResolver DummyIdResolver;
 
 
 
  /// A mapping from extension block names to module file extensions.
 
  llvm::StringMap<std::shared_ptr<ModuleFileExtension>> ModuleFileExtensions;
 
 
 
  /// A timer used to track the time spent deserializing.
 
  std::unique_ptr<llvm::Timer> ReadTimer;
 
 
 
  /// The location where the module file will be considered as
 
  /// imported from. For non-module AST types it should be invalid.
 
  SourceLocation CurrentImportLoc;
 
 
 
  /// The module kind that is currently deserializing.
 
  std::optional<ModuleKind> CurrentDeserializingModuleKind;
 
 
 
  /// The global module index, if loaded.
 
  std::unique_ptr<GlobalModuleIndex> GlobalIndex;
 
 
 
  /// A map of global bit offsets to the module that stores entities
 
  /// at those bit offsets.
 
  ContinuousRangeMap<uint64_t, ModuleFile*, 4> GlobalBitOffsetsMap;
 
 
 
  /// A map of negated SLocEntryIDs to the modules containing them.
 
  ContinuousRangeMap<unsigned, ModuleFile*, 64> GlobalSLocEntryMap;
 
 
 
  using GlobalSLocOffsetMapType =
 
      ContinuousRangeMap<unsigned, ModuleFile *, 64>;
 
 
 
  /// A map of reversed (SourceManager::MaxLoadedOffset - SLocOffset)
 
  /// SourceLocation offsets to the modules containing them.
 
  GlobalSLocOffsetMapType GlobalSLocOffsetMap;
 
 
 
  /// Types that have already been loaded from the chain.
 
  ///
 
  /// When the pointer at index I is non-NULL, the type with
 
  /// ID = (I + 1) << FastQual::Width has already been loaded
 
  std::vector<QualType> TypesLoaded;
 
 
 
  using GlobalTypeMapType =
 
      ContinuousRangeMap<serialization::TypeID, ModuleFile *, 4>;
 
 
 
  /// Mapping from global type IDs to the module in which the
 
  /// type resides along with the offset that should be added to the
 
  /// global type ID to produce a local ID.
 
  GlobalTypeMapType GlobalTypeMap;
 
 
 
  /// Declarations that have already been loaded from the chain.
 
  ///
 
  /// When the pointer at index I is non-NULL, the declaration with ID
 
  /// = I + 1 has already been loaded.
 
  std::vector<Decl *> DeclsLoaded;
 
 
 
  using GlobalDeclMapType =
 
      ContinuousRangeMap<serialization::DeclID, ModuleFile *, 4>;
 
 
 
  /// Mapping from global declaration IDs to the module in which the
 
  /// declaration resides.
 
  GlobalDeclMapType GlobalDeclMap;
 
 
 
  using FileOffset = std::pair<ModuleFile *, uint64_t>;
 
  using FileOffsetsTy = SmallVector<FileOffset, 2>;
 
  using DeclUpdateOffsetsMap =
 
      llvm::DenseMap<serialization::DeclID, FileOffsetsTy>;
 
 
 
  /// Declarations that have modifications residing in a later file
 
  /// in the chain.
 
  DeclUpdateOffsetsMap DeclUpdateOffsets;
 
 
 
  struct PendingUpdateRecord {
 
    Decl *D;
 
    serialization::GlobalDeclID ID;
 
 
 
    // Whether the declaration was just deserialized.
 
    bool JustLoaded;
 
 
 
    PendingUpdateRecord(serialization::GlobalDeclID ID, Decl *D,
 
                        bool JustLoaded)
 
        : D(D), ID(ID), JustLoaded(JustLoaded) {}
 
  };
 
 
 
  /// Declaration updates for already-loaded declarations that we need
 
  /// to apply once we finish processing an import.
 
  llvm::SmallVector<PendingUpdateRecord, 16> PendingUpdateRecords;
 
 
 
  enum class PendingFakeDefinitionKind { NotFake, Fake, FakeLoaded };
 
 
 
  /// The DefinitionData pointers that we faked up for class definitions
 
  /// that we needed but hadn't loaded yet.
 
  llvm::DenseMap<void *, PendingFakeDefinitionKind> PendingFakeDefinitionData;
 
 
 
  /// Exception specification updates that have been loaded but not yet
 
  /// propagated across the relevant redeclaration chain. The map key is the
 
  /// canonical declaration (used only for deduplication) and the value is a
 
  /// declaration that has an exception specification.
 
  llvm::SmallMapVector<Decl *, FunctionDecl *, 4> PendingExceptionSpecUpdates;
 
 
 
  /// Deduced return type updates that have been loaded but not yet propagated
 
  /// across the relevant redeclaration chain. The map key is the canonical
 
  /// declaration and the value is the deduced return type.
 
  llvm::SmallMapVector<FunctionDecl *, QualType, 4> PendingDeducedTypeUpdates;
 
 
 
  /// Declarations that have been imported and have typedef names for
 
  /// linkage purposes.
 
  llvm::DenseMap<std::pair<DeclContext *, IdentifierInfo *>, NamedDecl *>
 
      ImportedTypedefNamesForLinkage;
 
 
 
  /// Mergeable declaration contexts that have anonymous declarations
 
  /// within them, and those anonymous declarations.
 
  llvm::DenseMap<Decl*, llvm::SmallVector<NamedDecl*, 2>>
 
    AnonymousDeclarationsForMerging;
 
 
 
  /// Key used to identify LifetimeExtendedTemporaryDecl for merging,
 
  /// containing the lifetime-extending declaration and the mangling number.
 
  using LETemporaryKey = std::pair<Decl *, unsigned>;
 
 
 
  /// Map of already deserialiazed temporaries.
 
  llvm::DenseMap<LETemporaryKey, LifetimeExtendedTemporaryDecl *>
 
      LETemporaryForMerging;
 
 
 
  struct FileDeclsInfo {
 
    ModuleFile *Mod = nullptr;
 
    ArrayRef<serialization::LocalDeclID> Decls;
 
 
 
    FileDeclsInfo() = default;
 
    FileDeclsInfo(ModuleFile *Mod, ArrayRef<serialization::LocalDeclID> Decls)
 
        : Mod(Mod), Decls(Decls) {}
 
  };
 
 
 
  /// Map from a FileID to the file-level declarations that it contains.
 
  llvm::DenseMap<FileID, FileDeclsInfo> FileDeclIDs;
 
 
 
  /// An array of lexical contents of a declaration context, as a sequence of
 
  /// Decl::Kind, DeclID pairs.
 
  using LexicalContents = ArrayRef<llvm::support::unaligned_uint32_t>;
 
 
 
  /// Map from a DeclContext to its lexical contents.
 
  llvm::DenseMap<const DeclContext*, std::pair<ModuleFile*, LexicalContents>>
 
      LexicalDecls;
 
 
 
  /// Map from the TU to its lexical contents from each module file.
 
  std::vector<std::pair<ModuleFile*, LexicalContents>> TULexicalDecls;
 
 
 
  /// Map from a DeclContext to its lookup tables.
 
  llvm::DenseMap<const DeclContext *,
 
                 serialization::reader::DeclContextLookupTable> Lookups;
 
 
 
  // Updates for visible decls can occur for other contexts than just the
 
  // TU, and when we read those update records, the actual context may not
 
  // be available yet, so have this pending map using the ID as a key. It
 
  // will be realized when the context is actually loaded.
 
  struct PendingVisibleUpdate {
 
    ModuleFile *Mod;
 
    const unsigned char *Data;
 
  };
 
  using DeclContextVisibleUpdates = SmallVector<PendingVisibleUpdate, 1>;
 
 
 
  /// Updates to the visible declarations of declaration contexts that
 
  /// haven't been loaded yet.
 
  llvm::DenseMap<serialization::DeclID, DeclContextVisibleUpdates>
 
      PendingVisibleUpdates;
 
 
 
  /// The set of C++ or Objective-C classes that have forward
 
  /// declarations that have not yet been linked to their definitions.
 
  llvm::SmallPtrSet<Decl *, 4> PendingDefinitions;
 
 
 
  using PendingBodiesMap =
 
      llvm::MapVector<Decl *, uint64_t,
 
                      llvm::SmallDenseMap<Decl *, unsigned, 4>,
 
                      SmallVector<std::pair<Decl *, uint64_t>, 4>>;
 
 
 
  /// Functions or methods that have bodies that will be attached.
 
  PendingBodiesMap PendingBodies;
 
 
 
  /// Definitions for which we have added merged definitions but not yet
 
  /// performed deduplication.
 
  llvm::SetVector<NamedDecl *> PendingMergedDefinitionsToDeduplicate;
 
 
 
  /// Read the record that describes the lexical contents of a DC.
 
  bool ReadLexicalDeclContextStorage(ModuleFile &M,
 
                                     llvm::BitstreamCursor &Cursor,
 
                                     uint64_t Offset, DeclContext *DC);
 
 
 
  /// Read the record that describes the visible contents of a DC.
 
  bool ReadVisibleDeclContextStorage(ModuleFile &M,
 
                                     llvm::BitstreamCursor &Cursor,
 
                                     uint64_t Offset, serialization::DeclID ID);
 
 
 
  /// A vector containing identifiers that have already been
 
  /// loaded.
 
  ///
 
  /// If the pointer at index I is non-NULL, then it refers to the
 
  /// IdentifierInfo for the identifier with ID=I+1 that has already
 
  /// been loaded.
 
  std::vector<IdentifierInfo *> IdentifiersLoaded;
 
 
 
  using GlobalIdentifierMapType =
 
      ContinuousRangeMap<serialization::IdentID, ModuleFile *, 4>;
 
 
 
  /// Mapping from global identifier IDs to the module in which the
 
  /// identifier resides along with the offset that should be added to the
 
  /// global identifier ID to produce a local ID.
 
  GlobalIdentifierMapType GlobalIdentifierMap;
 
 
 
  /// A vector containing macros that have already been
 
  /// loaded.
 
  ///
 
  /// If the pointer at index I is non-NULL, then it refers to the
 
  /// MacroInfo for the identifier with ID=I+1 that has already
 
  /// been loaded.
 
  std::vector<MacroInfo *> MacrosLoaded;
 
 
 
  using LoadedMacroInfo =
 
      std::pair<IdentifierInfo *, serialization::SubmoduleID>;
 
 
 
  /// A set of #undef directives that we have loaded; used to
 
  /// deduplicate the same #undef information coming from multiple module
 
  /// files.
 
  llvm::DenseSet<LoadedMacroInfo> LoadedUndefs;
 
 
 
  using GlobalMacroMapType =
 
      ContinuousRangeMap<serialization::MacroID, ModuleFile *, 4>;
 
 
 
  /// Mapping from global macro IDs to the module in which the
 
  /// macro resides along with the offset that should be added to the
 
  /// global macro ID to produce a local ID.
 
  GlobalMacroMapType GlobalMacroMap;
 
 
 
  /// A vector containing submodules that have already been loaded.
 
  ///
 
  /// This vector is indexed by the Submodule ID (-1). NULL submodule entries
 
  /// indicate that the particular submodule ID has not yet been loaded.
 
  SmallVector<Module *, 2> SubmodulesLoaded;
 
 
 
  using GlobalSubmoduleMapType =
 
      ContinuousRangeMap<serialization::SubmoduleID, ModuleFile *, 4>;
 
 
 
  /// Mapping from global submodule IDs to the module file in which the
 
  /// submodule resides along with the offset that should be added to the
 
  /// global submodule ID to produce a local ID.
 
  GlobalSubmoduleMapType GlobalSubmoduleMap;
 
 
 
  /// A set of hidden declarations.
 
  using HiddenNames = SmallVector<Decl *, 2>;
 
  using HiddenNamesMapType = llvm::DenseMap<Module *, HiddenNames>;
 
 
 
  /// A mapping from each of the hidden submodules to the deserialized
 
  /// declarations in that submodule that could be made visible.
 
  HiddenNamesMapType HiddenNamesMap;
 
 
 
  /// A module import, export, or conflict that hasn't yet been resolved.
 
  struct UnresolvedModuleRef {
 
    /// The file in which this module resides.
 
    ModuleFile *File;
 
 
 
    /// The module that is importing or exporting.
 
    Module *Mod;
 
 
 
    /// The kind of module reference.
 
    enum { Import, Export, Conflict, Affecting } Kind;
 
 
 
    /// The local ID of the module that is being exported.
 
    unsigned ID;
 
 
 
    /// Whether this is a wildcard export.
 
    unsigned IsWildcard : 1;
 
 
 
    /// String data.
 
    StringRef String;
 
  };
 
 
 
  /// The set of module imports and exports that still need to be
 
  /// resolved.
 
  SmallVector<UnresolvedModuleRef, 2> UnresolvedModuleRefs;
 
 
 
  /// A vector containing selectors that have already been loaded.
 
  ///
 
  /// This vector is indexed by the Selector ID (-1). NULL selector
 
  /// entries indicate that the particular selector ID has not yet
 
  /// been loaded.
 
  SmallVector<Selector, 16> SelectorsLoaded;
 
 
 
  using GlobalSelectorMapType =
 
      ContinuousRangeMap<serialization::SelectorID, ModuleFile *, 4>;
 
 
 
  /// Mapping from global selector IDs to the module in which the
 
  /// global selector ID to produce a local ID.
 
  GlobalSelectorMapType GlobalSelectorMap;
 
 
 
  /// The generation number of the last time we loaded data from the
 
  /// global method pool for this selector.
 
  llvm::DenseMap<Selector, unsigned> SelectorGeneration;
 
 
 
  /// Whether a selector is out of date. We mark a selector as out of date
 
  /// if we load another module after the method pool entry was pulled in.
 
  llvm::DenseMap<Selector, bool> SelectorOutOfDate;
 
 
 
  struct PendingMacroInfo {
 
    ModuleFile *M;
 
    /// Offset relative to ModuleFile::MacroOffsetsBase.
 
    uint32_t MacroDirectivesOffset;
 
 
 
    PendingMacroInfo(ModuleFile *M, uint32_t MacroDirectivesOffset)
 
        : M(M), MacroDirectivesOffset(MacroDirectivesOffset) {}
 
  };
 
 
 
  using PendingMacroIDsMap =
 
      llvm::MapVector<IdentifierInfo *, SmallVector<PendingMacroInfo, 2>>;
 
 
 
  /// Mapping from identifiers that have a macro history to the global
 
  /// IDs have not yet been deserialized to the global IDs of those macros.
 
  PendingMacroIDsMap PendingMacroIDs;
 
 
 
  using GlobalPreprocessedEntityMapType =
 
      ContinuousRangeMap<unsigned, ModuleFile *, 4>;
 
 
 
  /// Mapping from global preprocessing entity IDs to the module in
 
  /// which the preprocessed entity resides along with the offset that should be
 
  /// added to the global preprocessing entity ID to produce a local ID.
 
  GlobalPreprocessedEntityMapType GlobalPreprocessedEntityMap;
 
 
 
  using GlobalSkippedRangeMapType =
 
      ContinuousRangeMap<unsigned, ModuleFile *, 4>;
 
 
 
  /// Mapping from global skipped range base IDs to the module in which
 
  /// the skipped ranges reside.
 
  GlobalSkippedRangeMapType GlobalSkippedRangeMap;
 
 
 
  /// \name CodeGen-relevant special data
 
  /// Fields containing data that is relevant to CodeGen.
 
  //@{
 
 
 
  /// The IDs of all declarations that fulfill the criteria of
 
  /// "interesting" decls.
 
  ///
 
  /// This contains the data loaded from all EAGERLY_DESERIALIZED_DECLS blocks
 
  /// in the chain. The referenced declarations are deserialized and passed to
 
  /// the consumer eagerly.
 
  SmallVector<serialization::DeclID, 16> EagerlyDeserializedDecls;
 
 
 
  /// The IDs of all tentative definitions stored in the chain.
 
  ///
 
  /// Sema keeps track of all tentative definitions in a TU because it has to
 
  /// complete them and pass them on to CodeGen. Thus, tentative definitions in
 
  /// the PCH chain must be eagerly deserialized.
 
  SmallVector<serialization::DeclID, 16> TentativeDefinitions;
 
 
 
  /// The IDs of all CXXRecordDecls stored in the chain whose VTables are
 
  /// used.
 
  ///
 
  /// CodeGen has to emit VTables for these records, so they have to be eagerly
 
  /// deserialized.
 
  SmallVector<serialization::DeclID, 64> VTableUses;
 
 
 
  /// A snapshot of the pending instantiations in the chain.
 
  ///
 
  /// This record tracks the instantiations that Sema has to perform at the
 
  /// end of the TU. It consists of a pair of values for every pending
 
  /// instantiation where the first value is the ID of the decl and the second
 
  /// is the instantiation location.
 
  SmallVector<serialization::DeclID, 64> PendingInstantiations;
 
 
 
  //@}
 
 
 
  /// \name DiagnosticsEngine-relevant special data
 
  /// Fields containing data that is used for generating diagnostics
 
  //@{
 
 
 
  /// A snapshot of Sema's unused file-scoped variable tracking, for
 
  /// generating warnings.
 
  SmallVector<serialization::DeclID, 16> UnusedFileScopedDecls;
 
 
 
  /// A list of all the delegating constructors we've seen, to diagnose
 
  /// cycles.
 
  SmallVector<serialization::DeclID, 4> DelegatingCtorDecls;
 
 
 
  /// Method selectors used in a @selector expression. Used for
 
  /// implementation of -Wselector.
 
  SmallVector<serialization::SelectorID, 64> ReferencedSelectorsData;
 
 
 
  /// A snapshot of Sema's weak undeclared identifier tracking, for
 
  /// generating warnings.
 
  SmallVector<serialization::IdentifierID, 64> WeakUndeclaredIdentifiers;
 
 
 
  /// The IDs of type aliases for ext_vectors that exist in the chain.
 
  ///
 
  /// Used by Sema for finding sugared names for ext_vectors in diagnostics.
 
  SmallVector<serialization::DeclID, 4> ExtVectorDecls;
 
 
 
  //@}
 
 
 
  /// \name Sema-relevant special data
 
  /// Fields containing data that is used for semantic analysis
 
  //@{
 
 
 
  /// The IDs of all potentially unused typedef names in the chain.
 
  ///
 
  /// Sema tracks these to emit warnings.
 
  SmallVector<serialization::DeclID, 16> UnusedLocalTypedefNameCandidates;
 
 
 
  /// Our current depth in #pragma cuda force_host_device begin/end
 
  /// macros.
 
  unsigned ForceCUDAHostDeviceDepth = 0;
 
 
 
  /// The IDs of the declarations Sema stores directly.
 
  ///
 
  /// Sema tracks a few important decls, such as namespace std, directly.
 
  SmallVector<serialization::DeclID, 4> SemaDeclRefs;
 
 
 
  /// The IDs of the types ASTContext stores directly.
 
  ///
 
  /// The AST context tracks a few important types, such as va_list, directly.
 
  SmallVector<serialization::TypeID, 16> SpecialTypes;
 
 
 
  /// The IDs of CUDA-specific declarations ASTContext stores directly.
 
  ///
 
  /// The AST context tracks a few important decls, currently cudaConfigureCall,
 
  /// directly.
 
  SmallVector<serialization::DeclID, 2> CUDASpecialDeclRefs;
 
 
 
  /// The floating point pragma option settings.
 
  SmallVector<uint64_t, 1> FPPragmaOptions;
 
 
 
  /// The pragma clang optimize location (if the pragma state is "off").
 
  SourceLocation OptimizeOffPragmaLocation;
 
 
 
  /// The PragmaMSStructKind pragma ms_struct state if set, or -1.
 
  int PragmaMSStructState = -1;
 
 
 
  /// The PragmaMSPointersToMembersKind pragma pointers_to_members state.
 
  int PragmaMSPointersToMembersState = -1;
 
  SourceLocation PointersToMembersPragmaLocation;
 
 
 
  /// The pragma float_control state.
 
  std::optional<FPOptionsOverride> FpPragmaCurrentValue;
 
  SourceLocation FpPragmaCurrentLocation;
 
  struct FpPragmaStackEntry {
 
    FPOptionsOverride Value;
 
    SourceLocation Location;
 
    SourceLocation PushLocation;
 
    StringRef SlotLabel;
 
  };
 
  llvm::SmallVector<FpPragmaStackEntry, 2> FpPragmaStack;
 
  llvm::SmallVector<std::string, 2> FpPragmaStrings;
 
 
 
  /// The pragma align/pack state.
 
  std::optional<Sema::AlignPackInfo> PragmaAlignPackCurrentValue;
 
  SourceLocation PragmaAlignPackCurrentLocation;
 
  struct PragmaAlignPackStackEntry {
 
    Sema::AlignPackInfo Value;
 
    SourceLocation Location;
 
    SourceLocation PushLocation;
 
    StringRef SlotLabel;
 
  };
 
  llvm::SmallVector<PragmaAlignPackStackEntry, 2> PragmaAlignPackStack;
 
  llvm::SmallVector<std::string, 2> PragmaAlignPackStrings;
 
 
 
  /// The OpenCL extension settings.
 
  OpenCLOptions OpenCLExtensions;
 
 
 
  /// Extensions required by an OpenCL type.
 
  llvm::DenseMap<const Type *, std::set<std::string>> OpenCLTypeExtMap;
 
 
 
  /// Extensions required by an OpenCL declaration.
 
  llvm::DenseMap<const Decl *, std::set<std::string>> OpenCLDeclExtMap;
 
 
 
  /// A list of the namespaces we've seen.
 
  SmallVector<serialization::DeclID, 4> KnownNamespaces;
 
 
 
  /// A list of undefined decls with internal linkage followed by the
 
  /// SourceLocation of a matching ODR-use.
 
  SmallVector<serialization::DeclID, 8> UndefinedButUsed;
 
 
 
  /// Delete expressions to analyze at the end of translation unit.
 
  SmallVector<uint64_t, 8> DelayedDeleteExprs;
 
 
 
  // A list of late parsed template function data with their module files.
 
  SmallVector<std::pair<ModuleFile *, SmallVector<uint64_t, 1>>, 4>
 
      LateParsedTemplates;
 
 
 
  /// The IDs of all decls to be checked for deferred diags.
 
  ///
 
  /// Sema tracks these to emit deferred diags.
 
  llvm::SmallSetVector<serialization::DeclID, 4> DeclsToCheckForDeferredDiags;
 
 
 
public:
 
  struct ImportedSubmodule {
 
    serialization::SubmoduleID ID;
 
    SourceLocation ImportLoc;
 
 
 
    ImportedSubmodule(serialization::SubmoduleID ID, SourceLocation ImportLoc)
 
        : ID(ID), ImportLoc(ImportLoc) {}
 
  };
 
 
 
private:
 
  /// A list of modules that were imported by precompiled headers or
 
  /// any other non-module AST file.
 
  SmallVector<ImportedSubmodule, 2> ImportedModules;
 
  //@}
 
 
 
  /// The system include root to be used when loading the
 
  /// precompiled header.
 
  std::string isysroot;
 
 
 
  /// Whether to disable the normal validation performed on precompiled
 
  /// headers and module files when they are loaded.
 
  DisableValidationForModuleKind DisableValidationKind;
 
 
 
  /// Whether to accept an AST file with compiler errors.
 
  bool AllowASTWithCompilerErrors;
 
 
 
  /// Whether to accept an AST file that has a different configuration
 
  /// from the current compiler instance.
 
  bool AllowConfigurationMismatch;
 
 
 
  /// Whether validate system input files.
 
  bool ValidateSystemInputs;
 
 
 
  /// Whether validate headers and module maps using hash based on contents.
 
  bool ValidateASTInputFilesContent;
 
 
 
  /// Whether we are allowed to use the global module index.
 
  bool UseGlobalIndex;
 
 
 
  /// Whether we have tried loading the global module index yet.
 
  bool TriedLoadingGlobalIndex = false;
 
 
 
  ///Whether we are currently processing update records.
 
  bool ProcessingUpdateRecords = false;
 
 
 
  using SwitchCaseMapTy = llvm::DenseMap<unsigned, SwitchCase *>;
 
 
 
  /// Mapping from switch-case IDs in the chain to switch-case statements
 
  ///
 
  /// Statements usually don't have IDs, but switch cases need them, so that the
 
  /// switch statement can refer to them.
 
  SwitchCaseMapTy SwitchCaseStmts;
 
 
 
  SwitchCaseMapTy *CurrSwitchCaseStmts;
 
 
 
  /// The number of source location entries de-serialized from
 
  /// the PCH file.
 
  unsigned NumSLocEntriesRead = 0;
 
 
 
  /// The number of source location entries in the chain.
 
  unsigned TotalNumSLocEntries = 0;
 
 
 
  /// The number of statements (and expressions) de-serialized
 
  /// from the chain.
 
  unsigned NumStatementsRead = 0;
 
 
 
  /// The total number of statements (and expressions) stored
 
  /// in the chain.
 
  unsigned TotalNumStatements = 0;
 
 
 
  /// The number of macros de-serialized from the chain.
 
  unsigned NumMacrosRead = 0;
 
 
 
  /// The total number of macros stored in the chain.
 
  unsigned TotalNumMacros = 0;
 
 
 
  /// The number of lookups into identifier tables.
 
  unsigned NumIdentifierLookups = 0;
 
 
 
  /// The number of lookups into identifier tables that succeed.
 
  unsigned NumIdentifierLookupHits = 0;
 
 
 
  /// The number of selectors that have been read.
 
  unsigned NumSelectorsRead = 0;
 
 
 
  /// The number of method pool entries that have been read.
 
  unsigned NumMethodPoolEntriesRead = 0;
 
 
 
  /// The number of times we have looked up a selector in the method
 
  /// pool.
 
  unsigned NumMethodPoolLookups = 0;
 
 
 
  /// The number of times we have looked up a selector in the method
 
  /// pool and found something.
 
  unsigned NumMethodPoolHits = 0;
 
 
 
  /// The number of times we have looked up a selector in the method
 
  /// pool within a specific module.
 
  unsigned NumMethodPoolTableLookups = 0;
 
 
 
  /// The number of times we have looked up a selector in the method
 
  /// pool within a specific module and found something.
 
  unsigned NumMethodPoolTableHits = 0;
 
 
 
  /// The total number of method pool entries in the selector table.
 
  unsigned TotalNumMethodPoolEntries = 0;
 
 
 
  /// Number of lexical decl contexts read/total.
 
  unsigned NumLexicalDeclContextsRead = 0, TotalLexicalDeclContexts = 0;
 
 
 
  /// Number of visible decl contexts read/total.
 
  unsigned NumVisibleDeclContextsRead = 0, TotalVisibleDeclContexts = 0;
 
 
 
  /// Total size of modules, in bits, currently loaded
 
  uint64_t TotalModulesSizeInBits = 0;
 
 
 
  /// Number of Decl/types that are currently deserializing.
 
  unsigned NumCurrentElementsDeserializing = 0;
 
 
 
  /// Set true while we are in the process of passing deserialized
 
  /// "interesting" decls to consumer inside FinishedDeserializing().
 
  /// This is used as a guard to avoid recursively repeating the process of
 
  /// passing decls to consumer.
 
  bool PassingDeclsToConsumer = false;
 
 
 
  /// The set of identifiers that were read while the AST reader was
 
  /// (recursively) loading declarations.
 
  ///
 
  /// The declarations on the identifier chain for these identifiers will be
 
  /// loaded once the recursive loading has completed.
 
  llvm::MapVector<IdentifierInfo *, SmallVector<uint32_t, 4>>
 
    PendingIdentifierInfos;
 
 
 
  /// The set of lookup results that we have faked in order to support
 
  /// merging of partially deserialized decls but that we have not yet removed.
 
  llvm::SmallMapVector<IdentifierInfo *, SmallVector<NamedDecl*, 2>, 16>
 
    PendingFakeLookupResults;
 
 
 
  /// The generation number of each identifier, which keeps track of
 
  /// the last time we loaded information about this identifier.
 
  llvm::DenseMap<IdentifierInfo *, unsigned> IdentifierGeneration;
 
 
 
  class InterestingDecl {
 
    Decl *D;
 
    bool DeclHasPendingBody;
 
 
 
  public:
 
    InterestingDecl(Decl *D, bool HasBody)
 
        : D(D), DeclHasPendingBody(HasBody) {}
 
 
 
    Decl *getDecl() { return D; }
 
 
 
    /// Whether the declaration has a pending body.
 
    bool hasPendingBody() { return DeclHasPendingBody; }
 
  };
 
 
 
  /// Contains declarations and definitions that could be
 
  /// "interesting" to the ASTConsumer, when we get that AST consumer.
 
  ///
 
  /// "Interesting" declarations are those that have data that may
 
  /// need to be emitted, such as inline function definitions or
 
  /// Objective-C protocols.
 
  std::deque<InterestingDecl> PotentiallyInterestingDecls;
 
 
 
  /// The list of deduced function types that we have not yet read, because
 
  /// they might contain a deduced return type that refers to a local type
 
  /// declared within the function.
 
  SmallVector<std::pair<FunctionDecl *, serialization::TypeID>, 16>
 
      PendingFunctionTypes;
 
 
 
  /// The list of redeclaration chains that still need to be
 
  /// reconstructed, and the local offset to the corresponding list
 
  /// of redeclarations.
 
  SmallVector<std::pair<Decl *, uint64_t>, 16> PendingDeclChains;
 
 
 
  /// The list of canonical declarations whose redeclaration chains
 
  /// need to be marked as incomplete once we're done deserializing things.
 
  SmallVector<Decl *, 16> PendingIncompleteDeclChains;
 
 
 
  /// The Decl IDs for the Sema/Lexical DeclContext of a Decl that has
 
  /// been loaded but its DeclContext was not set yet.
 
  struct PendingDeclContextInfo {
 
    Decl *D;
 
    serialization::GlobalDeclID SemaDC;
 
    serialization::GlobalDeclID LexicalDC;
 
  };
 
 
 
  /// The set of Decls that have been loaded but their DeclContexts are
 
  /// not set yet.
 
  ///
 
  /// The DeclContexts for these Decls will be set once recursive loading has
 
  /// been completed.
 
  std::deque<PendingDeclContextInfo> PendingDeclContextInfos;
 
 
 
  template <typename DeclTy>
 
  using DuplicateObjCDecls = std::pair<DeclTy *, DeclTy *>;
 
 
 
  /// When resolving duplicate ivars from Objective-C extensions we don't error
 
  /// out immediately but check if can merge identical extensions. Not checking
 
  /// extensions for equality immediately because ivar deserialization isn't
 
  /// over yet at that point.
 
  llvm::SmallMapVector<DuplicateObjCDecls<ObjCCategoryDecl>,
 
                       llvm::SmallVector<DuplicateObjCDecls<ObjCIvarDecl>, 4>,
 
                       2>
 
      PendingObjCExtensionIvarRedeclarations;
 
 
 
  /// The set of NamedDecls that have been loaded, but are members of a
 
  /// context that has been merged into another context where the corresponding
 
  /// declaration is either missing or has not yet been loaded.
 
  ///
 
  /// We will check whether the corresponding declaration is in fact missing
 
  /// once recursing loading has been completed.
 
  llvm::SmallVector<NamedDecl *, 16> PendingOdrMergeChecks;
 
 
 
  using DataPointers =
 
      std::pair<CXXRecordDecl *, struct CXXRecordDecl::DefinitionData *>;
 
  using ObjCInterfaceDataPointers =
 
      std::pair<ObjCInterfaceDecl *,
 
                struct ObjCInterfaceDecl::DefinitionData *>;
 
  using ObjCProtocolDataPointers =
 
      std::pair<ObjCProtocolDecl *, struct ObjCProtocolDecl::DefinitionData *>;
 
 
 
  /// Record definitions in which we found an ODR violation.
 
  llvm::SmallDenseMap<CXXRecordDecl *, llvm::SmallVector<DataPointers, 2>, 2>
 
      PendingOdrMergeFailures;
 
 
 
  /// C/ObjC record definitions in which we found an ODR violation.
 
  llvm::SmallDenseMap<RecordDecl *, llvm::SmallVector<RecordDecl *, 2>, 2>
 
      PendingRecordOdrMergeFailures;
 
 
 
  /// Function definitions in which we found an ODR violation.
 
  llvm::SmallDenseMap<FunctionDecl *, llvm::SmallVector<FunctionDecl *, 2>, 2>
 
      PendingFunctionOdrMergeFailures;
 
 
 
  /// Enum definitions in which we found an ODR violation.
 
  llvm::SmallDenseMap<EnumDecl *, llvm::SmallVector<EnumDecl *, 2>, 2>
 
      PendingEnumOdrMergeFailures;
 
 
 
  /// ObjCInterfaceDecl in which we found an ODR violation.
 
  llvm::SmallDenseMap<ObjCInterfaceDecl *,
 
                      llvm::SmallVector<ObjCInterfaceDataPointers, 2>, 2>
 
      PendingObjCInterfaceOdrMergeFailures;
 
 
 
  /// ObjCProtocolDecl in which we found an ODR violation.
 
  llvm::SmallDenseMap<ObjCProtocolDecl *,
 
                      llvm::SmallVector<ObjCProtocolDataPointers, 2>, 2>
 
      PendingObjCProtocolOdrMergeFailures;
 
 
 
  /// DeclContexts in which we have diagnosed an ODR violation.
 
  llvm::SmallPtrSet<DeclContext*, 2> DiagnosedOdrMergeFailures;
 
 
 
  /// The set of Objective-C categories that have been deserialized
 
  /// since the last time the declaration chains were linked.
 
  llvm::SmallPtrSet<ObjCCategoryDecl *, 16> CategoriesDeserialized;
 
 
 
  /// The set of Objective-C class definitions that have already been
 
  /// loaded, for which we will need to check for categories whenever a new
 
  /// module is loaded.
 
  SmallVector<ObjCInterfaceDecl *, 16> ObjCClassesLoaded;
 
 
 
  using KeyDeclsMap =
 
      llvm::DenseMap<Decl *, SmallVector<serialization::DeclID, 2>>;
 
 
 
  /// A mapping from canonical declarations to the set of global
 
  /// declaration IDs for key declaration that have been merged with that
 
  /// canonical declaration. A key declaration is a formerly-canonical
 
  /// declaration whose module did not import any other key declaration for that
 
  /// entity. These are the IDs that we use as keys when finding redecl chains.
 
  KeyDeclsMap KeyDecls;
 
 
 
  /// A mapping from DeclContexts to the semantic DeclContext that we
 
  /// are treating as the definition of the entity. This is used, for instance,
 
  /// when merging implicit instantiations of class templates across modules.
 
  llvm::DenseMap<DeclContext *, DeclContext *> MergedDeclContexts;
 
 
 
  /// A mapping from canonical declarations of enums to their canonical
 
  /// definitions. Only populated when using modules in C++.
 
  llvm::DenseMap<EnumDecl *, EnumDecl *> EnumDefinitions;
 
 
 
  /// A mapping from canonical declarations of records to their canonical
 
  /// definitions. Doesn't cover CXXRecordDecl.
 
  llvm::DenseMap<RecordDecl *, RecordDecl *> RecordDefinitions;
 
 
 
  /// When reading a Stmt tree, Stmt operands are placed in this stack.
 
  SmallVector<Stmt *, 16> StmtStack;
 
 
 
  /// What kind of records we are reading.
 
  enum ReadingKind {
 
    Read_None, Read_Decl, Read_Type, Read_Stmt
 
  };
 
 
 
  /// What kind of records we are reading.
 
  ReadingKind ReadingKind = Read_None;
 
 
 
  /// RAII object to change the reading kind.
 
  class ReadingKindTracker {
 
    ASTReader &Reader;
 
    enum ReadingKind PrevKind;
 
 
 
  public:
 
    ReadingKindTracker(enum ReadingKind newKind, ASTReader &reader)
 
        : Reader(reader), PrevKind(Reader.ReadingKind) {
 
      Reader.ReadingKind = newKind;
 
    }
 
 
 
    ReadingKindTracker(const ReadingKindTracker &) = delete;
 
    ReadingKindTracker &operator=(const ReadingKindTracker &) = delete;
 
    ~ReadingKindTracker() { Reader.ReadingKind = PrevKind; }
 
  };
 
 
 
  /// RAII object to mark the start of processing updates.
 
  class ProcessingUpdatesRAIIObj {
 
    ASTReader &Reader;
 
    bool PrevState;
 
 
 
  public:
 
    ProcessingUpdatesRAIIObj(ASTReader &reader)
 
        : Reader(reader), PrevState(Reader.ProcessingUpdateRecords) {
 
      Reader.ProcessingUpdateRecords = true;
 
    }
 
 
 
    ProcessingUpdatesRAIIObj(const ProcessingUpdatesRAIIObj &) = delete;
 
    ProcessingUpdatesRAIIObj &
 
    operator=(const ProcessingUpdatesRAIIObj &) = delete;
 
    ~ProcessingUpdatesRAIIObj() { Reader.ProcessingUpdateRecords = PrevState; }
 
  };
 
 
 
  /// Suggested contents of the predefines buffer, after this
 
  /// PCH file has been processed.
 
  ///
 
  /// In most cases, this string will be empty, because the predefines
 
  /// buffer computed to build the PCH file will be identical to the
 
  /// predefines buffer computed from the command line. However, when
 
  /// there are differences that the PCH reader can work around, this
 
  /// predefines buffer may contain additional definitions.
 
  std::string SuggestedPredefines;
 
 
 
  llvm::DenseMap<const Decl *, bool> DefinitionSource;
 
 
 
  bool shouldDisableValidationForFile(const serialization::ModuleFile &M) const;
 
 
 
  /// Reads a statement from the specified cursor.
 
  Stmt *ReadStmtFromStream(ModuleFile &F);
 
 
 
  /// Retrieve the stored information about an input file.
 
  serialization::InputFileInfo getInputFileInfo(ModuleFile &F, unsigned ID);
 
 
 
  /// Retrieve the file entry and 'overridden' bit for an input
 
  /// file in the given module file.
 
  serialization::InputFile getInputFile(ModuleFile &F, unsigned ID,
 
                                        bool Complain = true);
 
 
 
public:
 
  void ResolveImportedPath(ModuleFile &M, std::string &Filename);
 
  static void ResolveImportedPath(std::string &Filename, StringRef Prefix);
 
 
 
  /// Returns the first key declaration for the given declaration. This
 
  /// is one that is formerly-canonical (or still canonical) and whose module
 
  /// did not import any other key declaration of the entity.
 
  Decl *getKeyDeclaration(Decl *D) {
 
    D = D->getCanonicalDecl();
 
    if (D->isFromASTFile())
 
      return D;
 
 
 
    auto I = KeyDecls.find(D);
 
    if (I == KeyDecls.end() || I->second.empty())
 
      return D;
 
    return GetExistingDecl(I->second[0]);
 
  }
 
  const Decl *getKeyDeclaration(const Decl *D) {
 
    return getKeyDeclaration(const_cast<Decl*>(D));
 
  }
 
 
 
  /// Run a callback on each imported key declaration of \p D.
 
  template <typename Fn>
 
  void forEachImportedKeyDecl(const Decl *D, Fn Visit) {
 
    D = D->getCanonicalDecl();
 
    if (D->isFromASTFile())
 
      Visit(D);
 
 
 
    auto It = KeyDecls.find(const_cast<Decl*>(D));
 
    if (It != KeyDecls.end())
 
      for (auto ID : It->second)
 
        Visit(GetExistingDecl(ID));
 
  }
 
 
 
  /// Get the loaded lookup tables for \p Primary, if any.
 
  const serialization::reader::DeclContextLookupTable *
 
  getLoadedLookupTables(DeclContext *Primary) const;
 
 
 
private:
 
  struct ImportedModule {
 
    ModuleFile *Mod;
 
    ModuleFile *ImportedBy;
 
    SourceLocation ImportLoc;
 
 
 
    ImportedModule(ModuleFile *Mod,
 
                   ModuleFile *ImportedBy,
 
                   SourceLocation ImportLoc)
 
        : Mod(Mod), ImportedBy(ImportedBy), ImportLoc(ImportLoc) {}
 
  };
 
 
 
  ASTReadResult ReadASTCore(StringRef FileName, ModuleKind Type,
 
                            SourceLocation ImportLoc, ModuleFile *ImportedBy,
 
                            SmallVectorImpl<ImportedModule> &Loaded,
 
                            off_t ExpectedSize, time_t ExpectedModTime,
 
                            ASTFileSignature ExpectedSignature,
 
                            unsigned ClientLoadCapabilities);
 
  ASTReadResult ReadControlBlock(ModuleFile &F,
 
                                 SmallVectorImpl<ImportedModule> &Loaded,
 
                                 const ModuleFile *ImportedBy,
 
                                 unsigned ClientLoadCapabilities);
 
  static ASTReadResult ReadOptionsBlock(
 
      llvm::BitstreamCursor &Stream, unsigned ClientLoadCapabilities,
 
      bool AllowCompatibleConfigurationMismatch, ASTReaderListener &Listener,
 
      std::string &SuggestedPredefines);
 
 
 
  /// Read the unhashed control block.
 
  ///
 
  /// This has no effect on \c F.Stream, instead creating a fresh cursor from
 
  /// \c F.Data and reading ahead.
 
  ASTReadResult readUnhashedControlBlock(ModuleFile &F, bool WasImportedBy,
 
                                         unsigned ClientLoadCapabilities);
 
 
 
  static ASTReadResult
 
  readUnhashedControlBlockImpl(ModuleFile *F, llvm::StringRef StreamData,
 
                               unsigned ClientLoadCapabilities,
 
                               bool AllowCompatibleConfigurationMismatch,
 
                               ASTReaderListener *Listener,
 
                               bool ValidateDiagnosticOptions);
 
 
 
  llvm::Error ReadASTBlock(ModuleFile &F, unsigned ClientLoadCapabilities);
 
  llvm::Error ReadExtensionBlock(ModuleFile &F);
 
  void ReadModuleOffsetMap(ModuleFile &F) const;
 
  void ParseLineTable(ModuleFile &F, const RecordData &Record);
 
  llvm::Error ReadSourceManagerBlock(ModuleFile &F);
 
  llvm::BitstreamCursor &SLocCursorForID(int ID);
 
  SourceLocation getImportLocation(ModuleFile *F);
 
  void readIncludedFiles(ModuleFile &F, StringRef Blob, Preprocessor &PP);
 
  ASTReadResult ReadModuleMapFileBlock(RecordData &Record, ModuleFile &F,
 
                                       const ModuleFile *ImportedBy,
 
                                       unsigned ClientLoadCapabilities);
 
  llvm::Error ReadSubmoduleBlock(ModuleFile &F,
 
                                 unsigned ClientLoadCapabilities);
 
  static bool ParseLanguageOptions(const RecordData &Record, bool Complain,
 
                                   ASTReaderListener &Listener,
 
                                   bool AllowCompatibleDifferences);
 
  static bool ParseTargetOptions(const RecordData &Record, bool Complain,
 
                                 ASTReaderListener &Listener,
 
                                 bool AllowCompatibleDifferences);
 
  static bool ParseDiagnosticOptions(const RecordData &Record, bool Complain,
 
                                     ASTReaderListener &Listener);
 
  static bool ParseFileSystemOptions(const RecordData &Record, bool Complain,
 
                                     ASTReaderListener &Listener);
 
  static bool ParseHeaderSearchOptions(const RecordData &Record, bool Complain,
 
                                       ASTReaderListener &Listener);
 
  static bool ParseHeaderSearchPaths(const RecordData &Record, bool Complain,
 
                                     ASTReaderListener &Listener);
 
  static bool ParsePreprocessorOptions(const RecordData &Record, bool Complain,
 
                                       ASTReaderListener &Listener,
 
                                       std::string &SuggestedPredefines);
 
 
 
  struct RecordLocation {
 
    ModuleFile *F;
 
    uint64_t Offset;
 
 
 
    RecordLocation(ModuleFile *M, uint64_t O) : F(M), Offset(O) {}
 
  };
 
 
 
  QualType readTypeRecord(unsigned Index);
 
  RecordLocation TypeCursorForIndex(unsigned Index);
 
  void LoadedDecl(unsigned Index, Decl *D);
 
  Decl *ReadDeclRecord(serialization::DeclID ID);
 
  void markIncompleteDeclChain(Decl *Canon);
 
 
 
  /// Returns the most recent declaration of a declaration (which must be
 
  /// of a redeclarable kind) that is either local or has already been loaded
 
  /// merged into its redecl chain.
 
  Decl *getMostRecentExistingDecl(Decl *D);
 
 
 
  RecordLocation DeclCursorForID(serialization::DeclID ID,
 
                                 SourceLocation &Location);
 
  void loadDeclUpdateRecords(PendingUpdateRecord &Record);
 
  void loadPendingDeclChain(Decl *D, uint64_t LocalOffset);
 
  void loadObjCCategories(serialization::GlobalDeclID ID, ObjCInterfaceDecl *D,
 
                          unsigned PreviousGeneration = 0);
 
 
 
  RecordLocation getLocalBitOffset(uint64_t GlobalOffset);
 
  uint64_t getGlobalBitOffset(ModuleFile &M, uint64_t LocalOffset);
 
 
 
  /// Returns the first preprocessed entity ID that begins or ends after
 
  /// \arg Loc.
 
  serialization::PreprocessedEntityID
 
  findPreprocessedEntity(SourceLocation Loc, bool EndsAfter) const;
 
 
 
  /// Find the next module that contains entities and return the ID
 
  /// of the first entry.
 
  ///
 
  /// \param SLocMapI points at a chunk of a module that contains no
 
  /// preprocessed entities or the entities it contains are not the
 
  /// ones we are looking for.
 
  serialization::PreprocessedEntityID
 
    findNextPreprocessedEntity(
 
                        GlobalSLocOffsetMapType::const_iterator SLocMapI) const;
 
 
 
  /// Returns (ModuleFile, Local index) pair for \p GlobalIndex of a
 
  /// preprocessed entity.
 
  std::pair<ModuleFile *, unsigned>
 
    getModulePreprocessedEntity(unsigned GlobalIndex);
 
 
 
  /// Returns (begin, end) pair for the preprocessed entities of a
 
  /// particular module.
 
  llvm::iterator_range<PreprocessingRecord::iterator>
 
  getModulePreprocessedEntities(ModuleFile &Mod) const;
 
 
 
  bool canRecoverFromOutOfDate(StringRef ModuleFileName,
 
                               unsigned ClientLoadCapabilities);
 
 
 
public:
 
  class ModuleDeclIterator
 
      : public llvm::iterator_adaptor_base<
 
            ModuleDeclIterator, const serialization::LocalDeclID *,
 
            std::random_access_iterator_tag, const Decl *, ptrdiff_t,
 
            const Decl *, const Decl *> {
 
    ASTReader *Reader = nullptr;
 
    ModuleFile *Mod = nullptr;
 
 
 
  public:
 
    ModuleDeclIterator() : iterator_adaptor_base(nullptr) {}
 
 
 
    ModuleDeclIterator(ASTReader *Reader, ModuleFile *Mod,
 
                       const serialization::LocalDeclID *Pos)
 
        : iterator_adaptor_base(Pos), Reader(Reader), Mod(Mod) {}
 
 
 
    value_type operator*() const {
 
      return Reader->GetDecl(Reader->getGlobalDeclID(*Mod, *I));
 
    }
 
 
 
    value_type operator->() const { return **this; }
 
 
 
    bool operator==(const ModuleDeclIterator &RHS) const {
 
      assert(Reader == RHS.Reader && Mod == RHS.Mod);
 
      return I == RHS.I;
 
    }
 
  };
 
 
 
  llvm::iterator_range<ModuleDeclIterator>
 
  getModuleFileLevelDecls(ModuleFile &Mod);
 
 
 
private:
 
  void PassInterestingDeclsToConsumer();
 
  void PassInterestingDeclToConsumer(Decl *D);
 
 
 
  void finishPendingActions();
 
  void diagnoseOdrViolations();
 
 
 
  void pushExternalDeclIntoScope(NamedDecl *D, DeclarationName Name);
 
 
 
  void addPendingDeclContextInfo(Decl *D,
 
                                 serialization::GlobalDeclID SemaDC,
 
                                 serialization::GlobalDeclID LexicalDC) {
 
    assert(D);
 
    PendingDeclContextInfo Info = { D, SemaDC, LexicalDC };
 
    PendingDeclContextInfos.push_back(Info);
 
  }
 
 
 
  /// Produce an error diagnostic and return true.
 
  ///
 
  /// This routine should only be used for fatal errors that have to
 
  /// do with non-routine failures (e.g., corrupted AST file).
 
  void Error(StringRef Msg) const;
 
  void Error(unsigned DiagID, StringRef Arg1 = StringRef(),
 
             StringRef Arg2 = StringRef(), StringRef Arg3 = StringRef()) const;
 
  void Error(llvm::Error &&Err) const;
 
 
 
public:
 
  /// Load the AST file and validate its contents against the given
 
  /// Preprocessor.
 
  ///
 
  /// \param PP the preprocessor associated with the context in which this
 
  /// precompiled header will be loaded.
 
  ///
 
  /// \param Context the AST context that this precompiled header will be
 
  /// loaded into, if any.
 
  ///
 
  /// \param PCHContainerRdr the PCHContainerOperations to use for loading and
 
  /// creating modules.
 
  ///
 
  /// \param Extensions the list of module file extensions that can be loaded
 
  /// from the AST files.
 
  ///
 
  /// \param isysroot If non-NULL, the system include path specified by the
 
  /// user. This is only used with relocatable PCH files. If non-NULL,
 
  /// a relocatable PCH file will use the default path "/".
 
  ///
 
  /// \param DisableValidationKind If set, the AST reader will suppress most
 
  /// of its regular consistency checking, allowing the use of precompiled
 
  /// headers and module files that cannot be determined to be compatible.
 
  ///
 
  /// \param AllowASTWithCompilerErrors If true, the AST reader will accept an
 
  /// AST file the was created out of an AST with compiler errors,
 
  /// otherwise it will reject it.
 
  ///
 
  /// \param AllowConfigurationMismatch If true, the AST reader will not check
 
  /// for configuration differences between the AST file and the invocation.
 
  ///
 
  /// \param ValidateSystemInputs If true, the AST reader will validate
 
  /// system input files in addition to user input files. This is only
 
  /// meaningful if \p DisableValidation is false.
 
  ///
 
  /// \param UseGlobalIndex If true, the AST reader will try to load and use
 
  /// the global module index.
 
  ///
 
  /// \param ReadTimer If non-null, a timer used to track the time spent
 
  /// deserializing.
 
  ASTReader(Preprocessor &PP, InMemoryModuleCache &ModuleCache,
 
            ASTContext *Context, const PCHContainerReader &PCHContainerRdr,
 
            ArrayRef<std::shared_ptr<ModuleFileExtension>> Extensions,
 
            StringRef isysroot = "",
 
            DisableValidationForModuleKind DisableValidationKind =
 
                DisableValidationForModuleKind::None,
 
            bool AllowASTWithCompilerErrors = false,
 
            bool AllowConfigurationMismatch = false,
 
            bool ValidateSystemInputs = false,
 
            bool ValidateASTInputFilesContent = false,
 
            bool UseGlobalIndex = true,
 
            std::unique_ptr<llvm::Timer> ReadTimer = {});
 
  ASTReader(const ASTReader &) = delete;
 
  ASTReader &operator=(const ASTReader &) = delete;
 
  ~ASTReader() override;
 
 
 
  SourceManager &getSourceManager() const { return SourceMgr; }
 
  FileManager &getFileManager() const { return FileMgr; }
 
  DiagnosticsEngine &getDiags() const { return Diags; }
 
 
 
  /// Flags that indicate what kind of AST loading failures the client
 
  /// of the AST reader can directly handle.
 
  ///
 
  /// When a client states that it can handle a particular kind of failure,
 
  /// the AST reader will not emit errors when producing that kind of failure.
 
  enum LoadFailureCapabilities {
 
    /// The client can't handle any AST loading failures.
 
    ARR_None = 0,
 
 
 
    /// The client can handle an AST file that cannot load because it
 
    /// is missing.
 
    ARR_Missing = 0x1,
 
 
 
    /// The client can handle an AST file that cannot load because it
 
    /// is out-of-date relative to its input files.
 
    ARR_OutOfDate = 0x2,
 
 
 
    /// The client can handle an AST file that cannot load because it
 
    /// was built with a different version of Clang.
 
    ARR_VersionMismatch = 0x4,
 
 
 
    /// The client can handle an AST file that cannot load because it's
 
    /// compiled configuration doesn't match that of the context it was
 
    /// loaded into.
 
    ARR_ConfigurationMismatch = 0x8,
 
 
 
    /// If a module file is marked with errors treat it as out-of-date so the
 
    /// caller can rebuild it.
 
    ARR_TreatModuleWithErrorsAsOutOfDate = 0x10
 
  };
 
 
 
  /// Load the AST file designated by the given file name.
 
  ///
 
  /// \param FileName The name of the AST file to load.
 
  ///
 
  /// \param Type The kind of AST being loaded, e.g., PCH, module, main file,
 
  /// or preamble.
 
  ///
 
  /// \param ImportLoc the location where the module file will be considered as
 
  /// imported from. For non-module AST types it should be invalid.
 
  ///
 
  /// \param ClientLoadCapabilities The set of client load-failure
 
  /// capabilities, represented as a bitset of the enumerators of
 
  /// LoadFailureCapabilities.
 
  ///
 
  /// \param Imported optional out-parameter to append the list of modules
 
  /// that were imported by precompiled headers or any other non-module AST file
 
  ASTReadResult ReadAST(StringRef FileName, ModuleKind Type,
 
                        SourceLocation ImportLoc,
 
                        unsigned ClientLoadCapabilities,
 
                        SmallVectorImpl<ImportedSubmodule> *Imported = nullptr);
 
 
 
  /// Make the entities in the given module and any of its (non-explicit)
 
  /// submodules visible to name lookup.
 
  ///
 
  /// \param Mod The module whose names should be made visible.
 
  ///
 
  /// \param NameVisibility The level of visibility to give the names in the
 
  /// module.  Visibility can only be increased over time.
 
  ///
 
  /// \param ImportLoc The location at which the import occurs.
 
  void makeModuleVisible(Module *Mod,
 
                         Module::NameVisibilityKind NameVisibility,
 
                         SourceLocation ImportLoc);
 
 
 
  /// Make the names within this set of hidden names visible.
 
  void makeNamesVisible(const HiddenNames &Names, Module *Owner);
 
 
 
  /// Note that MergedDef is a redefinition of the canonical definition
 
  /// Def, so Def should be visible whenever MergedDef is.
 
  void mergeDefinitionVisibility(NamedDecl *Def, NamedDecl *MergedDef);
 
 
 
  /// Take the AST callbacks listener.
 
  std::unique_ptr<ASTReaderListener> takeListener() {
 
    return std::move(Listener);
 
  }
 
 
 
  /// Set the AST callbacks listener.
 
  void setListener(std::unique_ptr<ASTReaderListener> Listener) {
 
    this->Listener = std::move(Listener);
 
  }
 
 
 
  /// Add an AST callback listener.
 
  ///
 
  /// Takes ownership of \p L.
 
  void addListener(std::unique_ptr<ASTReaderListener> L) {
 
    if (Listener)
 
      L = std::make_unique<ChainedASTReaderListener>(std::move(L),
 
                                                      std::move(Listener));
 
    Listener = std::move(L);
 
  }
 
 
 
  /// RAII object to temporarily add an AST callback listener.
 
  class ListenerScope {
 
    ASTReader &Reader;
 
    bool Chained = false;
 
 
 
  public:
 
    ListenerScope(ASTReader &Reader, std::unique_ptr<ASTReaderListener> L)
 
        : Reader(Reader) {
 
      auto Old = Reader.takeListener();
 
      if (Old) {
 
        Chained = true;
 
        L = std::make_unique<ChainedASTReaderListener>(std::move(L),
 
                                                        std::move(Old));
 
      }
 
      Reader.setListener(std::move(L));
 
    }
 
 
 
    ~ListenerScope() {
 
      auto New = Reader.takeListener();
 
      if (Chained)
 
        Reader.setListener(static_cast<ChainedASTReaderListener *>(New.get())
 
                               ->takeSecond());
 
    }
 
  };
 
 
 
  /// Set the AST deserialization listener.
 
  void setDeserializationListener(ASTDeserializationListener *Listener,
 
                                  bool TakeOwnership = false);
 
 
 
  /// Get the AST deserialization listener.
 
  ASTDeserializationListener *getDeserializationListener() {
 
    return DeserializationListener;
 
  }
 
 
 
  /// Determine whether this AST reader has a global index.
 
  bool hasGlobalIndex() const { return (bool)GlobalIndex; }
 
 
 
  /// Return global module index.
 
  GlobalModuleIndex *getGlobalIndex() { return GlobalIndex.get(); }
 
 
 
  /// Reset reader for a reload try.
 
  void resetForReload() { TriedLoadingGlobalIndex = false; }
 
 
 
  /// Attempts to load the global index.
 
  ///
 
  /// \returns true if loading the global index has failed for any reason.
 
  bool loadGlobalIndex();
 
 
 
  /// Determine whether we tried to load the global index, but failed,
 
  /// e.g., because it is out-of-date or does not exist.
 
  bool isGlobalIndexUnavailable() const;
 
 
 
  /// Initializes the ASTContext
 
  void InitializeContext();
 
 
 
  /// Update the state of Sema after loading some additional modules.
 
  void UpdateSema();
 
 
 
  /// Add in-memory (virtual file) buffer.
 
  void addInMemoryBuffer(StringRef &FileName,
 
                         std::unique_ptr<llvm::MemoryBuffer> Buffer) {
 
    ModuleMgr.addInMemoryBuffer(FileName, std::move(Buffer));
 
  }
 
 
 
  /// Finalizes the AST reader's state before writing an AST file to
 
  /// disk.
 
  ///
 
  /// This operation may undo temporary state in the AST that should not be
 
  /// emitted.
 
  void finalizeForWriting();
 
 
 
  /// Retrieve the module manager.
 
  ModuleManager &getModuleManager() { return ModuleMgr; }
 
 
 
  /// Retrieve the preprocessor.
 
  Preprocessor &getPreprocessor() const { return PP; }
 
 
 
  /// Retrieve the name of the original source file name for the primary
 
  /// module file.
 
  StringRef getOriginalSourceFile() {
 
    return ModuleMgr.getPrimaryModule().OriginalSourceFileName;
 
  }
 
 
 
  /// Retrieve the name of the original source file name directly from
 
  /// the AST file, without actually loading the AST file.
 
  static std::string
 
  getOriginalSourceFile(const std::string &ASTFileName, FileManager &FileMgr,
 
                        const PCHContainerReader &PCHContainerRdr,
 
                        DiagnosticsEngine &Diags);
 
 
 
  /// Read the control block for the named AST file.
 
  ///
 
  /// \returns true if an error occurred, false otherwise.
 
  static bool readASTFileControlBlock(StringRef Filename, FileManager &FileMgr,
 
                                      const InMemoryModuleCache &ModuleCache,
 
                                      const PCHContainerReader &PCHContainerRdr,
 
                                      bool FindModuleFileExtensions,
 
                                      ASTReaderListener &Listener,
 
                                      bool ValidateDiagnosticOptions);
 
 
 
  /// Determine whether the given AST file is acceptable to load into a
 
  /// translation unit with the given language and target options.
 
  static bool isAcceptableASTFile(StringRef Filename, FileManager &FileMgr,
 
                                  const InMemoryModuleCache &ModuleCache,
 
                                  const PCHContainerReader &PCHContainerRdr,
 
                                  const LangOptions &LangOpts,
 
                                  const TargetOptions &TargetOpts,
 
                                  const PreprocessorOptions &PPOpts,
 
                                  StringRef ExistingModuleCachePath,
 
                                  bool RequireStrictOptionMatches = false);
 
 
 
  /// Returns the suggested contents of the predefines buffer,
 
  /// which contains a (typically-empty) subset of the predefines
 
  /// build prior to including the precompiled header.
 
  const std::string &getSuggestedPredefines() { return SuggestedPredefines; }
 
 
 
  /// Read a preallocated preprocessed entity from the external source.
 
  ///
 
  /// \returns null if an error occurred that prevented the preprocessed
 
  /// entity from being loaded.
 
  PreprocessedEntity *ReadPreprocessedEntity(unsigned Index) override;
 
 
 
  /// Returns a pair of [Begin, End) indices of preallocated
 
  /// preprocessed entities that \p Range encompasses.
 
  std::pair<unsigned, unsigned>
 
      findPreprocessedEntitiesInRange(SourceRange Range) override;
 
 
 
  /// Optionally returns true or false if the preallocated preprocessed
 
  /// entity with index \p Index came from file \p FID.
 
  std::optional<bool> isPreprocessedEntityInFileID(unsigned Index,
 
                                                   FileID FID) override;
 
 
 
  /// Read a preallocated skipped range from the external source.
 
  SourceRange ReadSkippedRange(unsigned Index) override;
 
 
 
  /// Read the header file information for the given file entry.
 
  HeaderFileInfo GetHeaderFileInfo(const FileEntry *FE) override;
 
 
 
  void ReadPragmaDiagnosticMappings(DiagnosticsEngine &Diag);
 
 
 
  /// Returns the number of source locations found in the chain.
 
  unsigned getTotalNumSLocs() const {
 
    return TotalNumSLocEntries;
 
  }
 
 
 
  /// Returns the number of identifiers found in the chain.
 
  unsigned getTotalNumIdentifiers() const {
 
    return static_cast<unsigned>(IdentifiersLoaded.size());
 
  }
 
 
 
  /// Returns the number of macros found in the chain.
 
  unsigned getTotalNumMacros() const {
 
    return static_cast<unsigned>(MacrosLoaded.size());
 
  }
 
 
 
  /// Returns the number of types found in the chain.
 
  unsigned getTotalNumTypes() const {
 
    return static_cast<unsigned>(TypesLoaded.size());
 
  }
 
 
 
  /// Returns the number of declarations found in the chain.
 
  unsigned getTotalNumDecls() const {
 
    return static_cast<unsigned>(DeclsLoaded.size());
 
  }
 
 
 
  /// Returns the number of submodules known.
 
  unsigned getTotalNumSubmodules() const {
 
    return static_cast<unsigned>(SubmodulesLoaded.size());
 
  }
 
 
 
  /// Returns the number of selectors found in the chain.
 
  unsigned getTotalNumSelectors() const {
 
    return static_cast<unsigned>(SelectorsLoaded.size());
 
  }
 
 
 
  /// Returns the number of preprocessed entities known to the AST
 
  /// reader.
 
  unsigned getTotalNumPreprocessedEntities() const {
 
    unsigned Result = 0;
 
    for (const auto &M : ModuleMgr)
 
      Result += M.NumPreprocessedEntities;
 
    return Result;
 
  }
 
 
 
  /// Resolve a type ID into a type, potentially building a new
 
  /// type.
 
  QualType GetType(serialization::TypeID ID);
 
 
 
  /// Resolve a local type ID within a given AST file into a type.
 
  QualType getLocalType(ModuleFile &F, unsigned LocalID);
 
 
 
  /// Map a local type ID within a given AST file into a global type ID.
 
  serialization::TypeID getGlobalTypeID(ModuleFile &F, unsigned LocalID) const;
 
 
 
  /// Read a type from the current position in the given record, which
 
  /// was read from the given AST file.
 
  QualType readType(ModuleFile &F, const RecordData &Record, unsigned &Idx) {
 
    if (Idx >= Record.size())
 
      return {};
 
 
 
    return getLocalType(F, Record[Idx++]);
 
  }
 
 
 
  /// Map from a local declaration ID within a given module to a
 
  /// global declaration ID.
 
  serialization::DeclID getGlobalDeclID(ModuleFile &F,
 
                                      serialization::LocalDeclID LocalID) const;
 
 
 
  /// Returns true if global DeclID \p ID originated from module \p M.
 
  bool isDeclIDFromModule(serialization::GlobalDeclID ID, ModuleFile &M) const;
 
 
 
  /// Retrieve the module file that owns the given declaration, or NULL
 
  /// if the declaration is not from a module file.
 
  ModuleFile *getOwningModuleFile(const Decl *D);
 
 
 
  /// Returns the source location for the decl \p ID.
 
  SourceLocation getSourceLocationForDeclID(serialization::GlobalDeclID ID);
 
 
 
  /// Resolve a declaration ID into a declaration, potentially
 
  /// building a new declaration.
 
  Decl *GetDecl(serialization::DeclID ID);
 
  Decl *GetExternalDecl(uint32_t ID) override;
 
 
 
  /// Resolve a declaration ID into a declaration. Return 0 if it's not
 
  /// been loaded yet.
 
  Decl *GetExistingDecl(serialization::DeclID ID);
 
 
 
  /// Reads a declaration with the given local ID in the given module.
 
  Decl *GetLocalDecl(ModuleFile &F, uint32_t LocalID) {
 
    return GetDecl(getGlobalDeclID(F, LocalID));
 
  }
 
 
 
  /// Reads a declaration with the given local ID in the given module.
 
  ///
 
  /// \returns The requested declaration, casted to the given return type.
 
  template<typename T>
 
  T *GetLocalDeclAs(ModuleFile &F, uint32_t LocalID) {
 
    return cast_or_null<T>(GetLocalDecl(F, LocalID));
 
  }
 
 
 
  /// Map a global declaration ID into the declaration ID used to
 
  /// refer to this declaration within the given module fule.
 
  ///
 
  /// \returns the global ID of the given declaration as known in the given
 
  /// module file.
 
  serialization::DeclID
 
  mapGlobalIDToModuleFileGlobalID(ModuleFile &M,
 
                                  serialization::DeclID GlobalID);
 
 
 
  /// Reads a declaration ID from the given position in a record in the
 
  /// given module.
 
  ///
 
  /// \returns The declaration ID read from the record, adjusted to a global ID.
 
  serialization::DeclID ReadDeclID(ModuleFile &F, const RecordData &Record,
 
                                   unsigned &Idx);
 
 
 
  /// Reads a declaration from the given position in a record in the
 
  /// given module.
 
  Decl *ReadDecl(ModuleFile &F, const RecordData &R, unsigned &I) {
 
    return GetDecl(ReadDeclID(F, R, I));
 
  }
 
 
 
  /// Reads a declaration from the given position in a record in the
 
  /// given module.
 
  ///
 
  /// \returns The declaration read from this location, casted to the given
 
  /// result type.
 
  template<typename T>
 
  T *ReadDeclAs(ModuleFile &F, const RecordData &R, unsigned &I) {
 
    return cast_or_null<T>(GetDecl(ReadDeclID(F, R, I)));
 
  }
 
 
 
  /// If any redeclarations of \p D have been imported since it was
 
  /// last checked, this digs out those redeclarations and adds them to the
 
  /// redeclaration chain for \p D.
 
  void CompleteRedeclChain(const Decl *D) override;
 
 
 
  CXXBaseSpecifier *GetExternalCXXBaseSpecifiers(uint64_t Offset) override;
 
 
 
  /// Resolve the offset of a statement into a statement.
 
  ///
 
  /// This operation will read a new statement from the external
 
  /// source each time it is called, and is meant to be used via a
 
  /// LazyOffsetPtr (which is used by Decls for the body of functions, etc).
 
  Stmt *GetExternalDeclStmt(uint64_t Offset) override;
 
 
 
  /// ReadBlockAbbrevs - Enter a subblock of the specified BlockID with the
 
  /// specified cursor.  Read the abbreviations that are at the top of the block
 
  /// and then leave the cursor pointing into the block.
 
  static llvm::Error ReadBlockAbbrevs(llvm::BitstreamCursor &Cursor,
 
                                      unsigned BlockID,
 
                                      uint64_t *StartOfBlockOffset = nullptr);
 
 
 
  /// Finds all the visible declarations with a given name.
 
  /// The current implementation of this method just loads the entire
 
  /// lookup table as unmaterialized references.
 
  bool FindExternalVisibleDeclsByName(const DeclContext *DC,
 
                                      DeclarationName Name) override;
 
 
 
  /// Read all of the declarations lexically stored in a
 
  /// declaration context.
 
  ///
 
  /// \param DC The declaration context whose declarations will be
 
  /// read.
 
  ///
 
  /// \param IsKindWeWant A predicate indicating which declaration kinds
 
  /// we are interested in.
 
  ///
 
  /// \param Decls Vector that will contain the declarations loaded
 
  /// from the external source. The caller is responsible for merging
 
  /// these declarations with any declarations already stored in the
 
  /// declaration context.
 
  void
 
  FindExternalLexicalDecls(const DeclContext *DC,
 
                           llvm::function_ref<bool(Decl::Kind)> IsKindWeWant,
 
                           SmallVectorImpl<Decl *> &Decls) override;
 
 
 
  /// Get the decls that are contained in a file in the Offset/Length
 
  /// range. \p Length can be 0 to indicate a point at \p Offset instead of
 
  /// a range.
 
  void FindFileRegionDecls(FileID File, unsigned Offset, unsigned Length,
 
                           SmallVectorImpl<Decl *> &Decls) override;
 
 
 
  /// Notify ASTReader that we started deserialization of
 
  /// a decl or type so until FinishedDeserializing is called there may be
 
  /// decls that are initializing. Must be paired with FinishedDeserializing.
 
  void StartedDeserializing() override;
 
 
 
  /// Notify ASTReader that we finished the deserialization of
 
  /// a decl or type. Must be paired with StartedDeserializing.
 
  void FinishedDeserializing() override;
 
 
 
  /// Function that will be invoked when we begin parsing a new
 
  /// translation unit involving this external AST source.
 
  ///
 
  /// This function will provide all of the external definitions to
 
  /// the ASTConsumer.
 
  void StartTranslationUnit(ASTConsumer *Consumer) override;
 
 
 
  /// Print some statistics about AST usage.
 
  void PrintStats() override;
 
 
 
  /// Dump information about the AST reader to standard error.
 
  void dump();
 
 
 
  /// Return the amount of memory used by memory buffers, breaking down
 
  /// by heap-backed versus mmap'ed memory.
 
  void getMemoryBufferSizes(MemoryBufferSizes &sizes) const override;
 
 
 
  /// Initialize the semantic source with the Sema instance
 
  /// being used to perform semantic analysis on the abstract syntax
 
  /// tree.
 
  void InitializeSema(Sema &S) override;
 
 
 
  /// Inform the semantic consumer that Sema is no longer available.
 
  void ForgetSema() override { SemaObj = nullptr; }
 
 
 
  /// Retrieve the IdentifierInfo for the named identifier.
 
  ///
 
  /// This routine builds a new IdentifierInfo for the given identifier. If any
 
  /// declarations with this name are visible from translation unit scope, their
 
  /// declarations will be deserialized and introduced into the declaration
 
  /// chain of the identifier.
 
  IdentifierInfo *get(StringRef Name) override;
 
 
 
  /// Retrieve an iterator into the set of all identifiers
 
  /// in all loaded AST files.
 
  IdentifierIterator *getIdentifiers() override;
 
 
 
  /// Load the contents of the global method pool for a given
 
  /// selector.
 
  void ReadMethodPool(Selector Sel) override;
 
 
 
  /// Load the contents of the global method pool for a given
 
  /// selector if necessary.
 
  void updateOutOfDateSelector(Selector Sel) override;
 
 
 
  /// Load the set of namespaces that are known to the external source,
 
  /// which will be used during typo correction.
 
  void ReadKnownNamespaces(
 
                         SmallVectorImpl<NamespaceDecl *> &Namespaces) override;
 
 
 
  void ReadUndefinedButUsed(
 
      llvm::MapVector<NamedDecl *, SourceLocation> &Undefined) override;
 
 
 
  void ReadMismatchingDeleteExpressions(llvm::MapVector<
 
      FieldDecl *, llvm::SmallVector<std::pair<SourceLocation, bool>, 4>> &
 
                                            Exprs) override;
 
 
 
  void ReadTentativeDefinitions(
 
                            SmallVectorImpl<VarDecl *> &TentativeDefs) override;
 
 
 
  void ReadUnusedFileScopedDecls(
 
                       SmallVectorImpl<const DeclaratorDecl *> &Decls) override;
 
 
 
  void ReadDelegatingConstructors(
 
                         SmallVectorImpl<CXXConstructorDecl *> &Decls) override;
 
 
 
  void ReadExtVectorDecls(SmallVectorImpl<TypedefNameDecl *> &Decls) override;
 
 
 
  void ReadUnusedLocalTypedefNameCandidates(
 
      llvm::SmallSetVector<const TypedefNameDecl *, 4> &Decls) override;
 
 
 
  void ReadDeclsToCheckForDeferredDiags(
 
      llvm::SmallSetVector<Decl *, 4> &Decls) override;
 
 
 
  void ReadReferencedSelectors(
 
           SmallVectorImpl<std::pair<Selector, SourceLocation>> &Sels) override;
 
 
 
  void ReadWeakUndeclaredIdentifiers(
 
           SmallVectorImpl<std::pair<IdentifierInfo *, WeakInfo>> &WI) override;
 
 
 
  void ReadUsedVTables(SmallVectorImpl<ExternalVTableUse> &VTables) override;
 
 
 
  void ReadPendingInstantiations(
 
                  SmallVectorImpl<std::pair<ValueDecl *,
 
                                            SourceLocation>> &Pending) override;
 
 
 
  void ReadLateParsedTemplates(
 
      llvm::MapVector<const FunctionDecl *, std::unique_ptr<LateParsedTemplate>>
 
          &LPTMap) override;
 
 
 
  /// Load a selector from disk, registering its ID if it exists.
 
  void LoadSelector(Selector Sel);
 
 
 
  void SetIdentifierInfo(unsigned ID, IdentifierInfo *II);
 
  void SetGloballyVisibleDecls(IdentifierInfo *II,
 
                               const SmallVectorImpl<uint32_t> &DeclIDs,
 
                               SmallVectorImpl<Decl *> *Decls = nullptr);
 
 
 
  /// Report a diagnostic.
 
  DiagnosticBuilder Diag(unsigned DiagID) const;
 
 
 
  /// Report a diagnostic.
 
  DiagnosticBuilder Diag(SourceLocation Loc, unsigned DiagID) const;
 
 
 
  IdentifierInfo *DecodeIdentifierInfo(serialization::IdentifierID ID);
 
 
 
  IdentifierInfo *readIdentifier(ModuleFile &M, const RecordData &Record,
 
                                 unsigned &Idx) {
 
    return DecodeIdentifierInfo(getGlobalIdentifierID(M, Record[Idx++]));
 
  }
 
 
 
  IdentifierInfo *GetIdentifier(serialization::IdentifierID ID) override {
 
    // Note that we are loading an identifier.
 
    Deserializing AnIdentifier(this);
 
 
 
    return DecodeIdentifierInfo(ID);
 
  }
 
 
 
  IdentifierInfo *getLocalIdentifier(ModuleFile &M, unsigned LocalID);
 
 
 
  serialization::IdentifierID getGlobalIdentifierID(ModuleFile &M,
 
                                                    unsigned LocalID);
 
 
 
  void resolvePendingMacro(IdentifierInfo *II, const PendingMacroInfo &PMInfo);
 
 
 
  /// Retrieve the macro with the given ID.
 
  MacroInfo *getMacro(serialization::MacroID ID);
 
 
 
  /// Retrieve the global macro ID corresponding to the given local
 
  /// ID within the given module file.
 
  serialization::MacroID getGlobalMacroID(ModuleFile &M, unsigned LocalID);
 
 
 
  /// Read the source location entry with index ID.
 
  bool ReadSLocEntry(int ID) override;
 
 
 
  /// Retrieve the module import location and module name for the
 
  /// given source manager entry ID.
 
  std::pair<SourceLocation, StringRef> getModuleImportLoc(int ID) override;
 
 
 
  /// Retrieve the global submodule ID given a module and its local ID
 
  /// number.
 
  serialization::SubmoduleID
 
  getGlobalSubmoduleID(ModuleFile &M, unsigned LocalID);
 
 
 
  /// Retrieve the submodule that corresponds to a global submodule ID.
 
  ///
 
  Module *getSubmodule(serialization::SubmoduleID GlobalID);
 
 
 
  /// Retrieve the module that corresponds to the given module ID.
 
  ///
 
  /// Note: overrides method in ExternalASTSource
 
  Module *getModule(unsigned ID) override;
 
 
 
  /// Retrieve the module file with a given local ID within the specified
 
  /// ModuleFile.
 
  ModuleFile *getLocalModuleFile(ModuleFile &M, unsigned ID);
 
 
 
  /// Get an ID for the given module file.
 
  unsigned getModuleFileID(ModuleFile *M);
 
 
 
  /// Return a descriptor for the corresponding module.
 
  std::optional<ASTSourceDescriptor> getSourceDescriptor(unsigned ID) override;
 
 
 
  ExtKind hasExternalDefinitions(const Decl *D) override;
 
 
 
  /// Retrieve a selector from the given module with its local ID
 
  /// number.
 
  Selector getLocalSelector(ModuleFile &M, unsigned LocalID);
 
 
 
  Selector DecodeSelector(serialization::SelectorID Idx);
 
 
 
  Selector GetExternalSelector(serialization::SelectorID ID) override;
 
  uint32_t GetNumExternalSelectors() override;
 
 
 
  Selector ReadSelector(ModuleFile &M, const RecordData &Record, unsigned &Idx) {
 
    return getLocalSelector(M, Record[Idx++]);
 
  }
 
 
 
  /// Retrieve the global selector ID that corresponds to this
 
  /// the local selector ID in a given module.
 
  serialization::SelectorID getGlobalSelectorID(ModuleFile &F,
 
                                                unsigned LocalID) const;
 
 
 
  /// Read the contents of a CXXCtorInitializer array.
 
  CXXCtorInitializer **GetExternalCXXCtorInitializers(uint64_t Offset) override;
 
 
 
  /// Read a AlignPackInfo from raw form.
 
  Sema::AlignPackInfo ReadAlignPackInfo(uint32_t Raw) const {
 
    return Sema::AlignPackInfo::getFromRawEncoding(Raw);
 
  }
 
 
 
  /// Read a source location from raw form and return it in its
 
  /// originating module file's source location space.
 
  SourceLocation ReadUntranslatedSourceLocation(SourceLocation::UIntTy Raw,
 
                                                LocSeq *Seq = nullptr) const {
 
    return SourceLocationEncoding::decode(Raw, Seq);
 
  }
 
 
 
  /// Read a source location from raw form.
 
  SourceLocation ReadSourceLocation(ModuleFile &ModuleFile,
 
                                    SourceLocation::UIntTy Raw,
 
                                    LocSeq *Seq = nullptr) const {
 
    SourceLocation Loc = ReadUntranslatedSourceLocation(Raw, Seq);
 
    return TranslateSourceLocation(ModuleFile, Loc);
 
  }
 
 
 
  /// Translate a source location from another module file's source
 
  /// location space into ours.
 
  SourceLocation TranslateSourceLocation(ModuleFile &ModuleFile,
 
                                         SourceLocation Loc) const {
 
    if (!ModuleFile.ModuleOffsetMap.empty())
 
      ReadModuleOffsetMap(ModuleFile);
 
    assert(ModuleFile.SLocRemap.find(Loc.getOffset()) !=
 
               ModuleFile.SLocRemap.end() &&
 
           "Cannot find offset to remap.");
 
    SourceLocation::IntTy Remap =
 
        ModuleFile.SLocRemap.find(Loc.getOffset())->second;
 
    return Loc.getLocWithOffset(Remap);
 
  }
 
 
 
  /// Read a source location.
 
  SourceLocation ReadSourceLocation(ModuleFile &ModuleFile,
 
                                    const RecordDataImpl &Record, unsigned &Idx,
 
                                    LocSeq *Seq = nullptr) {
 
    return ReadSourceLocation(ModuleFile, Record[Idx++], Seq);
 
  }
 
 
 
  /// Read a FileID.
 
  FileID ReadFileID(ModuleFile &F, const RecordDataImpl &Record,
 
                    unsigned &Idx) const {
 
    return TranslateFileID(F, FileID::get(Record[Idx++]));
 
  }
 
 
 
  /// Translate a FileID from another module file's FileID space into ours.
 
  FileID TranslateFileID(ModuleFile &F, FileID FID) const {
 
    assert(FID.ID >= 0 && "Reading non-local FileID.");
 
    return FileID::get(F.SLocEntryBaseID + FID.ID - 1);
 
  }
 
 
 
  /// Read a source range.
 
  SourceRange ReadSourceRange(ModuleFile &F, const RecordData &Record,
 
                              unsigned &Idx, LocSeq *Seq = nullptr);
 
 
 
  // Read a string
 
  static std::string ReadString(const RecordData &Record, unsigned &Idx);
 
 
 
  // Skip a string
 
  static void SkipString(const RecordData &Record, unsigned &Idx) {
 
    Idx += Record[Idx] + 1;
 
  }
 
 
 
  // Read a path
 
  std::string ReadPath(ModuleFile &F, const RecordData &Record, unsigned &Idx);
 
 
 
  // Read a path
 
  std::string ReadPath(StringRef BaseDirectory, const RecordData &Record,
 
                       unsigned &Idx);
 
 
 
  // Skip a path
 
  static void SkipPath(const RecordData &Record, unsigned &Idx) {
 
    SkipString(Record, Idx);
 
  }
 
 
 
  /// Read a version tuple.
 
  static VersionTuple ReadVersionTuple(const RecordData &Record, unsigned &Idx);
 
 
 
  CXXTemporary *ReadCXXTemporary(ModuleFile &F, const RecordData &Record,
 
                                 unsigned &Idx);
 
 
 
  /// Reads a statement.
 
  Stmt *ReadStmt(ModuleFile &F);
 
 
 
  /// Reads an expression.
 
  Expr *ReadExpr(ModuleFile &F);
 
 
 
  /// Reads a sub-statement operand during statement reading.
 
  Stmt *ReadSubStmt() {
 
    assert(ReadingKind == Read_Stmt &&
 
           "Should be called only during statement reading!");
 
    // Subexpressions are stored from last to first, so the next Stmt we need
 
    // is at the back of the stack.
 
    assert(!StmtStack.empty() && "Read too many sub-statements!");
 
    return StmtStack.pop_back_val();
 
  }
 
 
 
  /// Reads a sub-expression operand during statement reading.
 
  Expr *ReadSubExpr();
 
 
 
  /// Reads a token out of a record.
 
  Token ReadToken(ModuleFile &M, const RecordDataImpl &Record, unsigned &Idx);
 
 
 
  /// Reads the macro record located at the given offset.
 
  MacroInfo *ReadMacroRecord(ModuleFile &F, uint64_t Offset);
 
 
 
  /// Determine the global preprocessed entity ID that corresponds to
 
  /// the given local ID within the given module.
 
  serialization::PreprocessedEntityID
 
  getGlobalPreprocessedEntityID(ModuleFile &M, unsigned LocalID) const;
 
 
 
  /// Add a macro to deserialize its macro directive history.
 
  ///
 
  /// \param II The name of the macro.
 
  /// \param M The module file.
 
  /// \param MacroDirectivesOffset Offset of the serialized macro directive
 
  /// history.
 
  void addPendingMacro(IdentifierInfo *II, ModuleFile *M,
 
                       uint32_t MacroDirectivesOffset);
 
 
 
  /// Read the set of macros defined by this external macro source.
 
  void ReadDefinedMacros() override;
 
 
 
  /// Update an out-of-date identifier.
 
  void updateOutOfDateIdentifier(IdentifierInfo &II) override;
 
 
 
  /// Note that this identifier is up-to-date.
 
  void markIdentifierUpToDate(IdentifierInfo *II);
 
 
 
  /// Load all external visible decls in the given DeclContext.
 
  void completeVisibleDeclsMap(const DeclContext *DC) override;
 
 
 
  /// Retrieve the AST context that this AST reader supplements.
 
  ASTContext &getContext() {
 
    assert(ContextObj && "requested AST context when not loading AST");
 
    return *ContextObj;
 
  }
 
 
 
  // Contains the IDs for declarations that were requested before we have
 
  // access to a Sema object.
 
  SmallVector<uint64_t, 16> PreloadedDeclIDs;
 
 
 
  /// Retrieve the semantic analysis object used to analyze the
 
  /// translation unit in which the precompiled header is being
 
  /// imported.
 
  Sema *getSema() { return SemaObj; }
 
 
 
  /// Get the identifier resolver used for name lookup / updates
 
  /// in the translation unit scope. We have one of these even if we don't
 
  /// have a Sema object.
 
  IdentifierResolver &getIdResolver();
 
 
 
  /// Retrieve the identifier table associated with the
 
  /// preprocessor.
 
  IdentifierTable &getIdentifierTable();
 
 
 
  /// Record that the given ID maps to the given switch-case
 
  /// statement.
 
  void RecordSwitchCaseID(SwitchCase *SC, unsigned ID);
 
 
 
  /// Retrieve the switch-case statement with the given ID.
 
  SwitchCase *getSwitchCaseWithID(unsigned ID);
 
 
 
  void ClearSwitchCaseIDs();
 
 
 
  /// Cursors for comments blocks.
 
  SmallVector<std::pair<llvm::BitstreamCursor,
 
                        serialization::ModuleFile *>, 8> CommentsCursors;
 
 
 
  /// Loads comments ranges.
 
  void ReadComments() override;
 
 
 
  /// Visit all the input files of the given module file.
 
  void visitInputFiles(serialization::ModuleFile &MF,
 
                       bool IncludeSystem, bool Complain,
 
          llvm::function_ref<void(const serialization::InputFile &IF,
 
                                  bool isSystem)> Visitor);
 
 
 
  /// Visit all the top-level module maps loaded when building the given module
 
  /// file.
 
  void visitTopLevelModuleMaps(serialization::ModuleFile &MF,
 
                               llvm::function_ref<void(FileEntryRef)> Visitor);
 
 
 
  bool isProcessingUpdateRecords() { return ProcessingUpdateRecords; }
 
};
 
 
 
} // namespace clang
 
 
 
#endif // LLVM_CLANG_SERIALIZATION_ASTREADER_H