//===- ModuleFile.h - Module file description -------------------*- 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 Module class, which describes a module that has

//  been loaded from an AST file.

//

//===----------------------------------------------------------------------===//

#ifndef LLVM_CLANG_SERIALIZATION_MODULEFILE_H

#define LLVM_CLANG_SERIALIZATION_MODULEFILE_H

#include "clang/Basic/FileManager.h"

#include "clang/Basic/Module.h"

#include "clang/Basic/SourceLocation.h"

#include "clang/Serialization/ASTBitCodes.h"

#include "clang/Serialization/ContinuousRangeMap.h"

#include "clang/Serialization/ModuleFileExtension.h"

#include "llvm/ADT/DenseMap.h"

#include "llvm/ADT/PointerIntPair.h"

#include "llvm/ADT/SetVector.h"

#include "llvm/ADT/SmallVector.h"

#include "llvm/ADT/StringRef.h"

#include "llvm/Bitstream/BitstreamReader.h"

#include "llvm/Support/Endian.h"

#include <cassert>

#include <cstdint>

#include <memory>

#include <string>

#include <vector>

namespace clang {

namespace serialization {

/// Specifies the kind of module that has been loaded.

enum ModuleKind {

  /// File is an implicitly-loaded module.

  MK_ImplicitModule,

  /// File is an explicitly-loaded module.

  MK_ExplicitModule,

  /// File is a PCH file treated as such.

  MK_PCH,

  /// File is a PCH file treated as the preamble.

  MK_Preamble,

  /// File is a PCH file treated as the actual main file.

  MK_MainFile,

  /// File is from a prebuilt module path.

  MK_PrebuiltModule

};

/// The input file that has been loaded from this AST file, along with

/// bools indicating whether this was an overridden buffer or if it was

/// out-of-date or not-found.

class InputFile {

  enum {

    Overridden = 1,

    OutOfDate = 2,

    NotFound = 3

  };

  llvm::PointerIntPair<const FileEntryRef::MapEntry *, 2, unsigned> Val;

public:

  InputFile() = default;

  InputFile(FileEntryRef File, bool isOverridden = false,

            bool isOutOfDate = false) {

    assert(!(isOverridden && isOutOfDate) &&

           "an overridden cannot be out-of-date");

    unsigned intVal = 0;

    if (isOverridden)

      intVal = Overridden;

    else if (isOutOfDate)

      intVal = OutOfDate;

    Val.setPointerAndInt(&File.getMapEntry(), intVal);

  }

  static InputFile getNotFound() {

    InputFile File;

    File.Val.setInt(NotFound);

    return File;

  }

  OptionalFileEntryRefDegradesToFileEntryPtr getFile() const {

    if (auto *P = Val.getPointer())

      return FileEntryRef(*P);

    return None;

  }

  bool isOverridden() const { return Val.getInt() == Overridden; }

  bool isOutOfDate() const { return Val.getInt() == OutOfDate; }

  bool isNotFound() const { return Val.getInt() == NotFound; }

};

/// 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 ModuleFile {

public:

  ModuleFile(ModuleKind Kind, unsigned Generation)

      : Kind(Kind), Generation(Generation) {}

  ~ModuleFile();

  // === General information ===

  /// The index of this module in the list of modules.

  unsigned Index = 0;

  /// The type of this module.

  ModuleKind Kind;

  /// The file name of the module file.

  std::string FileName;

  /// The name of the module.

  std::string ModuleName;

  /// The base directory of the module.

  std::string BaseDirectory;

  std::string getTimestampFilename() const {

    return FileName + ".timestamp";

  }

  /// The original source file name that was used to build the

  /// primary AST file, which may have been modified for

  /// relocatable-pch support.

  std::string OriginalSourceFileName;

  /// The actual original source file name that was used to

  /// build this AST file.

  std::string ActualOriginalSourceFileName;

  /// The file ID for the original source file that was used to

  /// build this AST file.

  FileID OriginalSourceFileID;

  /// The directory that the PCH was originally created in. Used to

  /// allow resolving headers even after headers+PCH was moved to a new path.

  std::string OriginalDir;

  std::string ModuleMapPath;

  /// Whether this precompiled header is a relocatable PCH file.

  bool RelocatablePCH = false;

  /// Whether timestamps are included in this module file.

  bool HasTimestamps = false;

  /// Whether the top-level module has been read from the AST file.

  bool DidReadTopLevelSubmodule = false;

  /// The file entry for the module file.

  OptionalFileEntryRefDegradesToFileEntryPtr File;

  /// The signature of the module file, which may be used instead of the size

  /// and modification time to identify this particular file.

  ASTFileSignature Signature;

  /// The signature of the AST block of the module file, this can be used to

  /// unique module files based on AST contents.

  ASTFileSignature ASTBlockHash;

  /// Whether this module has been directly imported by the

  /// user.

  bool DirectlyImported = false;

  /// The generation of which this module file is a part.

  unsigned Generation;

  /// The memory buffer that stores the data associated with

  /// this AST file, owned by the InMemoryModuleCache.

  llvm::MemoryBuffer *Buffer;

  /// The size of this file, in bits.

  uint64_t SizeInBits = 0;

  /// The global bit offset (or base) of this module

  uint64_t GlobalBitOffset = 0;

  /// The bit offset of the AST block of this module.

  uint64_t ASTBlockStartOffset = 0;

  /// The serialized bitstream data for this file.

  StringRef Data;

  /// The main bitstream cursor for the main block.

  llvm::BitstreamCursor Stream;

  /// The source location where the module was explicitly or implicitly

  /// imported in the local translation unit.

  ///

  /// If module A depends on and imports module B, both modules will have the

  /// same DirectImportLoc, but different ImportLoc (B's ImportLoc will be a

  /// source location inside module A).

  ///

  /// WARNING: This is largely useless. It doesn't tell you when a module was

  /// made visible, just when the first submodule of that module was imported.

  SourceLocation DirectImportLoc;

  /// The source location where this module was first imported.

  SourceLocation ImportLoc;

  /// The first source location in this module.

  SourceLocation FirstLoc;

  /// The list of extension readers that are attached to this module

  /// file.

  std::vector<std::unique_ptr<ModuleFileExtensionReader>> ExtensionReaders;

  /// The module offset map data for this file. If non-empty, the various

  /// ContinuousRangeMaps described below have not yet been populated.

  StringRef ModuleOffsetMap;

  // === Input Files ===

  /// The cursor to the start of the input-files block.

  llvm::BitstreamCursor InputFilesCursor;

  /// Offsets for all of the input file entries in the AST file.

  const llvm::support::unaligned_uint64_t *InputFileOffsets = nullptr;

  /// The input files that have been loaded from this AST file.

  std::vector<InputFile> InputFilesLoaded;

  // All user input files reside at the index range [0, NumUserInputFiles), and

  // system input files reside at [NumUserInputFiles, InputFilesLoaded.size()).

  unsigned NumUserInputFiles = 0;

  /// If non-zero, specifies the time when we last validated input

  /// files.  Zero means we never validated them.

  ///

  /// The time is specified in seconds since the start of the Epoch.

  uint64_t InputFilesValidationTimestamp = 0;

  // === Source Locations ===

  /// Cursor used to read source location entries.

  llvm::BitstreamCursor SLocEntryCursor;

  /// The bit offset to the start of the SOURCE_MANAGER_BLOCK.

  uint64_t SourceManagerBlockStartOffset = 0;

  /// The number of source location entries in this AST file.

  unsigned LocalNumSLocEntries = 0;

  /// The base ID in the source manager's view of this module.

  int SLocEntryBaseID = 0;

  /// The base offset in the source manager's view of this module.

  unsigned SLocEntryBaseOffset = 0;

  /// Base file offset for the offsets in SLocEntryOffsets. Real file offset

  /// for the entry is SLocEntryOffsetsBase + SLocEntryOffsets[i].

  uint64_t SLocEntryOffsetsBase = 0;

  /// Offsets for all of the source location entries in the

  /// AST file.

  const uint32_t *SLocEntryOffsets = nullptr;

  /// SLocEntries that we're going to preload.

  SmallVector<uint64_t, 4> PreloadSLocEntries;

  /// Remapping table for source locations in this module.

  ContinuousRangeMap<uint32_t, int, 2> SLocRemap;

  // === Identifiers ===

  /// The number of identifiers in this AST file.

  unsigned LocalNumIdentifiers = 0;

  /// 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 = nullptr;

  /// Base identifier ID for identifiers local to this module.

  serialization::IdentID BaseIdentifierID = 0;

  /// Remapping table for identifier IDs in this module.

  ContinuousRangeMap<uint32_t, int, 2> IdentifierRemap;

  /// 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 = nullptr;

  /// A pointer to an on-disk hash table of opaque type

  /// IdentifierHashTable.

  void *IdentifierLookupTable = nullptr;

  /// Offsets of identifiers that we're going to preload within

  /// IdentifierTableData.

  std::vector<unsigned> PreloadIdentifierOffsets;

  // === Macros ===

  /// The cursor to the start of the preprocessor block, which stores

  /// all of the macro definitions.

  llvm::BitstreamCursor MacroCursor;

  /// The number of macros in this AST file.

  unsigned LocalNumMacros = 0;

  /// Base file offset for the offsets in MacroOffsets. Real file offset for

  /// the entry is MacroOffsetsBase + MacroOffsets[i].

  uint64_t MacroOffsetsBase = 0;

  /// Offsets of macros in the preprocessor block.

  ///

  /// This array is indexed by the macro ID (-1), and provides

  /// the offset into the preprocessor block where macro definitions are

  /// stored.

  const uint32_t *MacroOffsets = nullptr;

  /// Base macro ID for macros local to this module.

  serialization::MacroID BaseMacroID = 0;

  /// Remapping table for macro IDs in this module.

  ContinuousRangeMap<uint32_t, int, 2> MacroRemap;

  /// The offset of the start of the set of defined macros.

  uint64_t MacroStartOffset = 0;

  // === Detailed PreprocessingRecord ===

  /// The cursor to the start of the (optional) detailed preprocessing

  /// record block.

  llvm::BitstreamCursor PreprocessorDetailCursor;

  /// The offset of the start of the preprocessor detail cursor.

  uint64_t PreprocessorDetailStartOffset = 0;

  /// Base preprocessed entity ID for preprocessed entities local to

  /// this module.

  serialization::PreprocessedEntityID BasePreprocessedEntityID = 0;

  /// Remapping table for preprocessed entity IDs in this module.

  ContinuousRangeMap<uint32_t, int, 2> PreprocessedEntityRemap;

  const PPEntityOffset *PreprocessedEntityOffsets = nullptr;

  unsigned NumPreprocessedEntities = 0;

  /// Base ID for preprocessed skipped ranges local to this module.

  unsigned BasePreprocessedSkippedRangeID = 0;

  const PPSkippedRange *PreprocessedSkippedRangeOffsets = nullptr;

  unsigned NumPreprocessedSkippedRanges = 0;

  // === Header search information ===

  /// The number of local HeaderFileInfo structures.

  unsigned LocalNumHeaderFileInfos = 0;

  /// 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 = nullptr;

  /// The on-disk hash table that contains information about each of

  /// the header files.

  void *HeaderFileInfoTable = nullptr;

  // === Submodule information ===

  /// The number of submodules in this module.

  unsigned LocalNumSubmodules = 0;

  /// Base submodule ID for submodules local to this module.

  serialization::SubmoduleID BaseSubmoduleID = 0;

  /// Remapping table for submodule IDs in this module.

  ContinuousRangeMap<uint32_t, int, 2> SubmoduleRemap;

  // === Selectors ===

  /// The number of selectors new to this file.

  ///

  /// This is the number of entries in SelectorOffsets.

  unsigned LocalNumSelectors = 0;

  /// Offsets into the selector lookup table's data array

  /// where each selector resides.

  const uint32_t *SelectorOffsets = nullptr;

  /// Base selector ID for selectors local to this module.

  serialization::SelectorID BaseSelectorID = 0;

  /// Remapping table for selector IDs in this module.

  ContinuousRangeMap<uint32_t, int, 2> SelectorRemap;

  /// A pointer to the character data that comprises the selector table

  ///

  /// The SelectorOffsets table refers into this memory.

  const unsigned char *SelectorLookupTableData = nullptr;

  /// 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 = nullptr;

  // === Declarations ===

  /// DeclsCursor - This is a cursor to the start of the DECLTYPES_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;

  /// The offset to the start of the DECLTYPES_BLOCK block.

  uint64_t DeclsBlockStartOffset = 0;

  /// The number of declarations in this AST file.

  unsigned LocalNumDecls = 0;

  /// Offset of each declaration within the bitstream, indexed

  /// by the declaration ID (-1).

  const DeclOffset *DeclOffsets = nullptr;

  /// Base declaration ID for declarations local to this module.

  serialization::DeclID BaseDeclID = 0;

  /// Remapping table for declaration IDs in this module.

  ContinuousRangeMap<uint32_t, int, 2> DeclRemap;

  /// Mapping from the module files that this module file depends on

  /// to the base declaration ID for that module as it is understood within this

  /// module.

  ///

  /// This is effectively a reverse global-to-local mapping for declaration

  /// IDs, so that we can interpret a true global ID (for this translation unit)

  /// as a local ID (for this module file).

  llvm::DenseMap<ModuleFile *, serialization::DeclID> GlobalToLocalDeclIDs;

  /// Array of file-level DeclIDs sorted by file.

  const serialization::DeclID *FileSortedDecls = nullptr;

  unsigned NumFileSortedDecls = 0;

  /// Array of category list location information within this

  /// module file, sorted by the definition ID.

  const serialization::ObjCCategoriesInfo *ObjCCategoriesMap = nullptr;

  /// The number of redeclaration info entries in ObjCCategoriesMap.

  unsigned LocalNumObjCCategoriesInMap = 0;

  /// The Objective-C category lists for categories known to this

  /// module.

  SmallVector<uint64_t, 1> ObjCCategories;

  // === Types ===

  /// The number of types in this AST file.

  unsigned LocalNumTypes = 0;

  /// Offset of each type within the bitstream, indexed by the

  /// type ID, or the representation of a Type*.

  const UnderalignedInt64 *TypeOffsets = nullptr;

  /// Base type ID for types local to this module as represented in

  /// the global type ID space.

  serialization::TypeID BaseTypeIndex = 0;

  /// Remapping table for type IDs in this module.

  ContinuousRangeMap<uint32_t, int, 2> TypeRemap;

  // === Miscellaneous ===

  /// Diagnostic IDs and their mappings that the user changed.

  SmallVector<uint64_t, 8> PragmaDiagMappings;

  /// List of modules which depend on this module

  llvm::SetVector<ModuleFile *> ImportedBy;

  /// List of modules which this module depends on

  llvm::SetVector<ModuleFile *> Imports;

  /// Determine whether this module was directly imported at

  /// any point during translation.

  bool isDirectlyImported() const { return DirectlyImported; }

  /// Is this a module file for a module (rather than a PCH or similar).

  bool isModule() const {

    return Kind == MK_ImplicitModule || 
Kind == MK_ExplicitModule655k
 ||

           Kind == MK_PrebuiltModule;

  }

  /// Dump debugging output for this module.

  void dump();

};

} // namespace serialization

} // namespace clang

#endif // LLVM_CLANG_SERIALIZATION_MODULEFILE_H