//===--- Module.h - Module description --------------------------*- 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 Module class, which describes a module that has
//  been loaded from an AST file.
//
//===----------------------------------------------------------------------===//

#ifndef LLVM_CLANG_SERIALIZATION_MODULE_H
#define LLVM_CLANG_SERIALIZATION_MODULE_H

#include "clang/Serialization/ASTBitCodes.h"
#include "clang/Serialization/ContinuousRangeMap.h"
#include "clang/Basic/SourceLocation.h"
#include "llvm/ADT/OwningPtr.h"
#include "llvm/ADT/SetVector.h"
#include "llvm/Bitcode/BitstreamReader.h"
#include <string>

namespace clang { 

class DeclContext;
  
namespace serialization {
   
/// \brief Specifies the kind of module that has been loaded.
enum ModuleKind {
  MK_Module,   ///< File is a module proper.
  MK_PCH,      ///< File is a PCH file treated as such.
  MK_Preamble, ///< File is a PCH file treated as the preamble.
  MK_MainFile  ///< File is a PCH file treated as the actual main file.
};

/// \brief Information about the contents of a DeclContext.
struct DeclContextInfo {
  DeclContextInfo() 
    : NameLookupTableData(), LexicalDecls(), NumLexicalDecls() {}
  
  void *NameLookupTableData; // an ASTDeclContextNameLookupTable.
  const KindDeclIDPair *LexicalDecls;
  unsigned NumLexicalDecls;
};

/// \brief Information about a module that has been loaded by the ASTReader.
///
/// Each instance of the Module class corresponds to a single AST file, which 
/// may be a precompiled header, precompiled preamble, a module, or an AST file 
/// of some sort loaded as the main file, all of which are specific formulations of
/// the general notion of a "module". A module may depend on any number of
/// other modules.
class Module {
public:  
  Module(ModuleKind Kind);
  ~Module();
  
  // === General information ===
  
  /// \brief The type of this module.
  ModuleKind Kind;
  
  /// \brief The file name of the module file.
  std::string FileName;
  
  /// \brief Whether this module has been directly imported by the
  /// user.
  bool DirectlyImported;
  
  /// \brief The memory buffer that stores the data associated with
  /// this AST file.
  llvm::OwningPtr<llvm::MemoryBuffer> Buffer;
  
  /// \brief The size of this file, in bits.
  uint64_t SizeInBits;
  
  /// \brief The global bit offset (or base) of this module
  uint64_t GlobalBitOffset;
  
  /// \brief The bitstream reader from which we'll read the AST file.
  llvm::BitstreamReader StreamFile;
  
  /// \brief The main bitstream cursor for the main block.
  llvm::BitstreamCursor Stream;
  
  /// \brief The source location where this module was first imported.
  SourceLocation ImportLoc;
  
  /// \brief The first source location in this module.
  SourceLocation FirstLoc;
  
  // === Source Locations ===
  
  /// \brief Cursor used to read source location entries.
  llvm::BitstreamCursor SLocEntryCursor;
  
  /// \brief The number of source location entries in this AST file.
  unsigned LocalNumSLocEntries;
  
  /// \brief The base ID in the source manager's view of this module.
  int SLocEntryBaseID;
  
  /// \brief The base offset in the source manager's view of this module.
  unsigned SLocEntryBaseOffset;
  
  /// \brief Offsets for all of the source location entries in the
  /// AST file.
  const uint32_t *SLocEntryOffsets;
  
  /// \brief SLocEntries that we're going to preload.
  SmallVector<uint64_t, 4> PreloadSLocEntries;

  /// \brief The number of source location file entries in this AST file.
  unsigned LocalNumSLocFileEntries;
  
  /// \brief Offsets for all of the source location file entries in the
  /// AST file.
  const uint32_t *SLocFileOffsets;
  
  /// \brief Remapping table for source locations in this module.
  ContinuousRangeMap<uint32_t, int, 2> SLocRemap;
  
  // === Identifiers ===
  
  /// \brief The number of identifiers in this AST file.
  unsigned LocalNumIdentifiers;
  
  /// \brief Offsets into the identifier table data.
  ///
  /// This array is indexed by the identifier ID (-1), and provides
  /// the offset into IdentifierTableData where the string data is
  /// stored.
  const uint32_t *IdentifierOffsets;
  
  /// \brief Base identifier ID for identifiers local to this module.
  serialization::IdentID BaseIdentifierID;
  
  /// \brief Remapping table for identifier IDs in this module.
  ContinuousRangeMap<uint32_t, int, 2> IdentifierRemap;
  
  /// \brief Actual data for the on-disk hash table of identifiers.
  ///
  /// This pointer points into a memory buffer, where the on-disk hash
  /// table for identifiers actually lives.
  const char *IdentifierTableData;
  
  /// \brief A pointer to an on-disk hash table of opaque type
  /// IdentifierHashTable.
  void *IdentifierLookupTable;
  
  // === Macros ===
  
  /// \brief The cursor to the start of the preprocessor block, which stores
  /// all of the macro definitions.
  llvm::BitstreamCursor MacroCursor;
  
  /// \brief The offset of the start of the set of defined macros.
  uint64_t MacroStartOffset;
  
  // === Detailed PreprocessingRecord ===
  
  /// \brief The cursor to the start of the (optional) detailed preprocessing 
  /// record block.
  llvm::BitstreamCursor PreprocessorDetailCursor;
  
  /// \brief The offset of the start of the preprocessor detail cursor.
  uint64_t PreprocessorDetailStartOffset;
  
  /// \brief Base preprocessed entity ID for preprocessed entities local to 
  /// this module.
  serialization::PreprocessedEntityID BasePreprocessedEntityID;
  
  /// \brief Remapping table for preprocessed entity IDs in this module.
  ContinuousRangeMap<uint32_t, int, 2> PreprocessedEntityRemap;
  
  const PPEntityOffset *PreprocessedEntityOffsets;
  unsigned NumPreprocessedEntities;
  
  // === Header search information ===
  
  /// \brief The number of local HeaderFileInfo structures.
  unsigned LocalNumHeaderFileInfos;
  
  /// \brief Actual data for the on-disk hash table of header file 
  /// information.
  ///
  /// This pointer points into a memory buffer, where the on-disk hash
  /// table for header file information actually lives.
  const char *HeaderFileInfoTableData;
  
  /// \brief The on-disk hash table that contains information about each of
  /// the header files.
  void *HeaderFileInfoTable;
  
  /// \brief Actual data for the list of framework names used in the header
  /// search information.
  const char *HeaderFileFrameworkStrings;
  
  // === Selectors ===
  
  /// \brief The number of selectors new to this file.
  ///
  /// This is the number of entries in SelectorOffsets.
  unsigned LocalNumSelectors;
  
  /// \brief Offsets into the selector lookup table's data array
  /// where each selector resides.
  const uint32_t *SelectorOffsets;
  
  /// \brief Base selector ID for selectors local to this module.
  serialization::SelectorID BaseSelectorID;
  
  /// \brief Remapping table for selector IDs in this module.
  ContinuousRangeMap<uint32_t, int, 2> SelectorRemap;
  
  /// \brief A pointer to the character data that comprises the selector table
  ///
  /// The SelectorOffsets table refers into this memory.
  const unsigned char *SelectorLookupTableData;
  
  /// \brief A pointer to an on-disk hash table of opaque type
  /// ASTSelectorLookupTable.
  ///
  /// This hash table provides the IDs of all selectors, and the associated
  /// instance and factory methods.
  void *SelectorLookupTable;
  
  // === Declarations ===
  
  /// DeclsCursor - This is a cursor to the start of the DECLS_BLOCK block. It
  /// has read all the abbreviations at the start of the block and is ready to
  /// jump around with these in context.
  llvm::BitstreamCursor DeclsCursor;
  
  /// \brief The number of declarations in this AST file.
  unsigned LocalNumDecls;
  
  /// \brief Offset of each declaration within the bitstream, indexed
  /// by the declaration ID (-1).
  const uint32_t *DeclOffsets;
  
  /// \brief Base declaration ID for declarations local to this module.
  serialization::DeclID BaseDeclID;
  
  /// \brief Remapping table for declaration IDs in this module.
  ContinuousRangeMap<uint32_t, int, 2> DeclRemap;
  
  /// \brief The number of C++ base specifier sets in this AST file.
  unsigned LocalNumCXXBaseSpecifiers;
  
  /// \brief Offset of each C++ base specifier set within the bitstream,
  /// indexed by the C++ base specifier set ID (-1).
  const uint32_t *CXXBaseSpecifiersOffsets;
  
  typedef llvm::DenseMap<const DeclContext *, DeclContextInfo>
  DeclContextInfosMap;
  
  /// \brief Information about the lexical and visible declarations
  /// for each DeclContext.
  DeclContextInfosMap DeclContextInfos;

  typedef llvm::DenseMap<serialization::GlobalDeclID,
             std::pair<serialization::LocalDeclID, serialization::LocalDeclID> >
    ChainedObjCCategoriesMap;
  /// \brief ObjC categories that got chained to an interface from another
  /// module.
  /// Key is the ID of the interface.
  /// Value is a pair of linked category DeclIDs (head category, tail category).
  ChainedObjCCategoriesMap ChainedObjCCategories;
  
  // === Types ===
  
  /// \brief The number of types in this AST file.
  unsigned LocalNumTypes;
  
  /// \brief Offset of each type within the bitstream, indexed by the
  /// type ID, or the representation of a Type*.
  const uint32_t *TypeOffsets;
  
  /// \brief Base type ID for types local to this module as represented in 
  /// the global type ID space.
  serialization::TypeID BaseTypeIndex;
  
  /// \brief Remapping table for type IDs in this module.
  ContinuousRangeMap<uint32_t, int, 2> TypeRemap;
  
  // === Miscellaneous ===
  
  /// \brief Diagnostic IDs and their mappings that the user changed.
  SmallVector<uint64_t, 8> PragmaDiagMappings;
  
  /// \brief The AST stat cache installed for this file, if any.
  ///
  /// The dynamic type of this stat cache is always ASTStatCache
  void *StatCache;
  
  /// \brief List of modules which depend on this module
  llvm::SetVector<Module *> ImportedBy;
  
  /// \brief List of modules which this module depends on
  llvm::SetVector<Module *> Imports;
  
  /// \brief Determine whether this module was directly imported at
  /// any point during translation.
  bool isDirectlyImported() const { return DirectlyImported; }
  
  /// \brief Dump debugging output for this module.
  void dump();
};

} // end namespace serialization

} // end namespace clang

#endif