path: root/include/clang/Serialization/ASTWriter.h

//===--- ASTWriter.h - AST File Writer --------------------------*- C++ -*-===//
//
//                     The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
//  This file defines the ASTWriter class, which writes an AST file
//  containing a serialized representation of a translation unit.
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_CLANG_FRONTEND_AST_WRITER_H
#define LLVM_CLANG_FRONTEND_AST_WRITER_H

#include "clang/AST/ASTMutationListener.h"
#include "clang/AST/Decl.h"
#include "clang/AST/DeclarationName.h"
#include "clang/AST/TemplateBase.h"
#include "clang/Sema/SemaConsumer.h"
#include "clang/Serialization/ASTBitCodes.h"
#include "clang/Serialization/ASTDeserializationListener.h"
#include "llvm/ADT/DenseMap.h"
#include "llvm/ADT/DenseSet.h"
#include "llvm/ADT/MapVector.h"
#include "llvm/ADT/SetVector.h"
#include "llvm/ADT/SmallPtrSet.h"
#include "llvm/ADT/SmallVector.h"
#include "llvm/Bitcode/BitstreamWriter.h"
#include <map>
#include <queue>
#include <vector>

namespace llvm {
  class APFloat;
  class APInt;
  class BitstreamWriter;
}

namespace clang {

class ASTContext;
class NestedNameSpecifier;
class CXXBaseSpecifier;
class CXXCtorInitializer;
class FileEntry;
class FPOptions;
class HeaderSearch;
class HeaderSearchOptions;
class IdentifierResolver;
class MacroDefinition;
class MacroDirective;
class MacroInfo;
class OpaqueValueExpr;
class OpenCLOptions;
class ASTReader;
class Module;
class PreprocessedEntity;
class PreprocessingRecord;
class Preprocessor;
class Sema;
class SourceManager;
class SwitchCase;
class TargetInfo;
class VersionTuple;
class ASTUnresolvedSet;

namespace SrcMgr { class SLocEntry; }

/// \brief Writes an AST file containing the contents of a translation unit.
///
/// The ASTWriter class produces a bitstream containing the serialized
/// representation of a given abstract syntax tree and its supporting
/// data structures. This bitstream can be de-serialized via an
/// instance of the ASTReader class.
class ASTWriter : public ASTDeserializationListener,
                  public ASTMutationListener {
public:
  typedef SmallVector<uint64_t, 64> RecordData;
  typedef SmallVectorImpl<uint64_t> RecordDataImpl;

  friend class ASTDeclWriter;
  friend class ASTStmtWriter;
private:
  /// \brief Map that provides the ID numbers of each type within the
  /// output stream, plus those deserialized from a chained PCH.
  ///
  /// The ID numbers of types are consecutive (in order of discovery)
  /// and start at 1. 0 is reserved for NULL. When types are actually
  /// stored in the stream, the ID number is shifted by 2 bits to
  /// allow for the const/volatile qualifiers.
  ///
  /// Keys in the map never have const/volatile qualifiers.
  typedef llvm::DenseMap<QualType, serialization::TypeIdx,
                         serialization::UnsafeQualTypeDenseMapInfo>
    TypeIdxMap;

  /// \brief The bitstream writer used to emit this precompiled header.
  llvm::BitstreamWriter &Stream;

  /// \brief The ASTContext we're writing.
  ASTContext *Context;

  /// \brief The preprocessor we're writing.
  Preprocessor *PP;

  /// \brief The reader of existing AST files, if we're chaining.
  ASTReader *Chain;

  /// \brief The module we're currently writing, if any.
  Module *WritingModule;
                    
  /// \brief Indicates when the AST writing is actively performing
  /// serialization, rather than just queueing updates.
  bool WritingAST;

  /// \brief Indicates that we are done serializing the collection of decls
  /// and types to emit.
  bool DoneWritingDeclsAndTypes;

  /// \brief Indicates that the AST contained compiler errors.
  bool ASTHasCompilerErrors;

  /// \brief Mapping from input file entries to the index into the
  /// offset table where information about that input file is stored.
  llvm::DenseMap<const FileEntry *, uint32_t> InputFileIDs;

  /// \brief Stores a declaration or a type to be written to the AST file.
  class DeclOrType {
  public:
    DeclOrType(Decl *D) : Stored(D), IsType(false) { }
    DeclOrType(QualType T) : Stored(T.getAsOpaquePtr()), IsType(true) { }

    bool isType() const { return IsType; }
    bool isDecl() const { return !IsType; }

    QualType getType() const {
      assert(isType() && "Not a type!");
      return QualType::getFromOpaquePtr(Stored);
    }

    Decl *getDecl() const {
      assert(isDecl() && "Not a decl!");
      return static_cast<Decl *>(Stored);
    }

  private:
    void *Stored;
    bool IsType;
  };

  /// \brief The declarations and types to emit.
  std::queue<DeclOrType> DeclTypesToEmit;

  /// \brief The first ID number we can use for our own declarations.
  serialization::DeclID FirstDeclID;

  /// \brief The decl ID that will be assigned to the next new decl.
  serialization::DeclID NextDeclID;

  /// \brief Map that provides the ID numbers of each declaration within
  /// the output stream, as well as those deserialized from a chained PCH.
  ///
  /// The ID numbers of declarations are consecutive (in order of
  /// discovery) and start at 2. 1 is reserved for the translation
  /// unit, while 0 is reserved for NULL.
  llvm::DenseMap<const Decl *, serialization::DeclID> DeclIDs;

  /// \brief Offset of each declaration in the bitstream, indexed by
  /// the declaration's ID.
  std::vector<serialization::DeclOffset> DeclOffsets;

  /// \brief Sorted (by file offset) vector of pairs of file offset/DeclID.
  typedef SmallVector<std::pair<unsigned, serialization::DeclID>, 64>
    LocDeclIDsTy;
  struct DeclIDInFileInfo {
    LocDeclIDsTy DeclIDs;
    /// \brief Set when the DeclIDs vectors from all files are joined, this
    /// indicates the index that this particular vector has in the global one.
    unsigned FirstDeclIndex;
  };
  typedef llvm::DenseMap<FileID, DeclIDInFileInfo *> FileDeclIDsTy;

  /// \brief Map from file SLocEntries to info about the file-level declarations
  /// that it contains.
  FileDeclIDsTy FileDeclIDs;

  void associateDeclWithFile(const Decl *D, serialization::DeclID);

  /// \brief The first ID number we can use for our own types.
  serialization::TypeID FirstTypeID;

  /// \brief The type ID that will be assigned to the next new type.
  serialization::TypeID NextTypeID;

  /// \brief Map that provides the ID numbers of each type within the
  /// output stream, plus those deserialized from a chained PCH.
  ///
  /// The ID numbers of types are consecutive (in order of discovery)
  /// and start at 1. 0 is reserved for NULL. When types are actually
  /// stored in the stream, the ID number is shifted by 2 bits to
  /// allow for the const/volatile qualifiers.
  ///
  /// Keys in the map never have const/volatile qualifiers.
  TypeIdxMap TypeIdxs;

  /// \brief Offset of each type in the bitstream, indexed by
  /// the type's ID.
  std::vector<uint32_t> TypeOffsets;

  /// \brief The first ID number we can use for our own identifiers.
  serialization::IdentID FirstIdentID;

  /// \brief The identifier ID that will be assigned to the next new identifier.
  serialization::IdentID NextIdentID;

  /// \brief Map that provides the ID numbers of each identifier in
  /// the output stream.
  ///
  /// The ID numbers for identifiers are consecutive (in order of
  /// discovery), starting at 1. An ID of zero refers to a NULL
  /// IdentifierInfo.
  llvm::DenseMap<const IdentifierInfo *, serialization::IdentID> IdentifierIDs;

  /// \brief The first ID number we can use for our own macros.
  serialization::MacroID FirstMacroID;

  /// \brief The identifier ID that will be assigned to the next new identifier.
  serialization::MacroID NextMacroID;

  /// \brief Map that provides the ID numbers of each macro.
  llvm::DenseMap<MacroInfo *, serialization::MacroID> MacroIDs;

  struct MacroInfoToEmitData {
    const IdentifierInfo *Name;
    MacroInfo *MI;
    serialization::MacroID ID;
  };
  /// \brief The macro infos to emit.
  std::vector<MacroInfoToEmitData> MacroInfosToEmit;

  llvm::DenseMap<const IdentifierInfo *, uint64_t> IdentMacroDirectivesOffsetMap;

  /// @name FlushStmt Caches
  /// @{

  /// \brief Set of parent Stmts for the currently serializing sub stmt.
  llvm::DenseSet<Stmt *> ParentStmts;

  /// \brief Offsets of sub stmts already serialized. The offset points
  /// just after the stmt record.