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

//===- ASTBitCodes.h - Enum values for the PCH bitcode format ---*- C++ -*-===//
//
//                     The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This header defines Bitcode enum values for Clang serialized AST files.
//
// The enum values defined in this file should be considered permanent.  If
// new features are added, they should have values added at the end of the
// respective lists.
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_CLANG_FRONTEND_PCHBITCODES_H
#define LLVM_CLANG_FRONTEND_PCHBITCODES_H

#include "clang/AST/Type.h"
#include "llvm/Bitcode/BitCodes.h"
#include "llvm/Support/DataTypes.h"
#include "llvm/ADT/DenseMap.h"

namespace clang {
  namespace serialization {
    /// \brief AST file major version number supported by this version of
    /// Clang.
    ///
    /// Whenever the AST file format changes in a way that makes it
    /// incompatible with previous versions (such that a reader
    /// designed for the previous version could not support reading
    /// the new version), this number should be increased.
    ///
    /// Version 4 of AST files also requires that the version control branch and
    /// revision match exactly, since there is no backward compatibility of
    /// AST files at this time.
    const unsigned VERSION_MAJOR = 4;

    /// \brief AST file minor version number supported by this version of
    /// Clang.
    ///
    /// Whenever the AST format changes in a way that is still
    /// compatible with previous versions (such that a reader designed
    /// for the previous version could still support reading the new
    /// version by ignoring new kinds of subblocks), this number
    /// should be increased.
    const unsigned VERSION_MINOR = 0;

    /// \brief An ID number that refers to an identifier in an AST file.
    /// 
    /// The ID numbers of identifiers are consecutive (in order of discovery)
    /// and start at 1. 0 is reserved for NULL.
    typedef uint32_t IdentifierID;
    
    /// \brief An ID number that refers to a declaration in an AST file.
    ///
    /// The ID numbers of declarations are consecutive (in order of
    /// discovery), with values below NUM_PREDEF_DECL_IDS being reserved. 
    /// At the start of a chain of precompiled headers, declaration ID 1 is 
    /// used for the translation unit declaration.
    typedef uint32_t DeclID;

    /// \brief a Decl::Kind/DeclID pair.
    typedef std::pair<uint32_t, DeclID> KindDeclIDPair;

    /// \brief An ID number that refers to a type in an AST file.
    ///
    /// The ID of a type is partitioned into two parts: the lower
    /// three bits are used to store the const/volatile/restrict
    /// qualifiers (as with QualType) and the upper bits provide a
    /// type index. The type index values are partitioned into two
    /// sets. The values below NUM_PREDEF_TYPE_IDs are predefined type
    /// IDs (based on the PREDEF_TYPE_*_ID constants), with 0 as a
    /// placeholder for "no type". Values from NUM_PREDEF_TYPE_IDs are
    /// other types that have serialized representations.
    typedef uint32_t TypeID;

    /// \brief A type index; the type ID with the qualifier bits removed.
    class TypeIdx {
      uint32_t Idx;
    public:
      TypeIdx() : Idx(0) { }
      explicit TypeIdx(uint32_t index) : Idx(index) { }

      uint32_t getIndex() const { return Idx; }
      TypeID asTypeID(unsigned FastQuals) const {
        if (Idx == uint32_t(-1))
          return TypeID(-1);
        
        return (Idx << Qualifiers::FastWidth) | FastQuals;
      }
      static TypeIdx fromTypeID(TypeID ID) {
        if (ID == TypeID(-1))
          return TypeIdx(-1);
        
        return TypeIdx(ID >> Qualifiers::FastWidth);
      }
    };

    /// A structure for putting "fast"-unqualified QualTypes into a
    /// DenseMap.  This uses the standard pointer hash function.
    struct UnsafeQualTypeDenseMapInfo {
      static inline bool isEqual(QualType A, QualType B) { return A == B; }
      static inline QualType getEmptyKey() {
        return QualType::getFromOpaquePtr((void*) 1);
      }
      static inline QualType getTombstoneKey() {
        return QualType::getFromOpaquePtr((void*) 2);
      }
      static inline unsigned getHashValue(QualType T) {
        assert(!T.getLocalFastQualifiers() && 
               "hash invalid for types with fast quals");
        uintptr_t v = reinterpret_cast<uintptr_t>(T.getAsOpaquePtr());
        return (unsigned(v) >> 4) ^ (unsigned(v) >> 9);
      }
    };

    /// \brief An ID number that refers to an identifier in an AST file.
    typedef uint32_t IdentID;

    /// \brief An ID number that refers to a macro in an AST file.
    typedef uint32_t MacroID;

    /// \brief An ID number that refers to an ObjC selctor in an AST file.
    typedef uint32_t SelectorID;

    /// \brief An ID number that refers to a set of CXXBaseSpecifiers in an 
    /// AST file.
    typedef uint32_t CXXBaseSpecifiersID;
    
    /// \brief An ID number that refers to an entity in the detailed
    /// preprocessing record.
    typedef uint32_t PreprocessedEntityID;
    
    /// \brief Describes the various kinds of blocks that occur within
    /// an AST file.
    enum BlockIDs {
      /// \brief The AST block, which acts as a container around the
      /// full AST block.
      AST_BLOCK_ID = llvm::bitc::FIRST_APPLICATION_BLOCKID,

      /// \brief The block containing information about the source
      /// manager.
      SOURCE_MANAGER_BLOCK_ID,

      /// \brief The block con