PTHManager.h revision fdd15602a42bbe26185978ef1e17019f6d969aa7 
1//===--- PTHManager.h - Manager object for PTH processing -------*- C++ -*-===//
2//
3//                     The LLVM Compiler Infrastructure
4//
5// This file is distributed under the University of Illinois Open Source
6// License. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9//
10//  This file defines the PTHManager interface.
11//
12//===----------------------------------------------------------------------===//
13
14#ifndef LLVM_CLANG_PTHMANAGER_H
15#define LLVM_CLANG_PTHMANAGER_H
16
17#include "clang/Lex/PTHLexer.h"
18#include "clang/Basic/LangOptions.h"
19#include "clang/Basic/IdentifierTable.h"
20#include "llvm/ADT/DenseMap.h"
21#include "llvm/Support/Allocator.h"
22#include <string>
23
24namespace llvm {
25  class MemoryBuffer;
26}
27
28namespace clang {
29
30class FileEntry;
31class PTHLexer;
32class DiagnosticsEngine;
33class FileSystemStatCache;
34
35class PTHManager : public IdentifierInfoLookup {
36  friend class PTHLexer;
37
38  /// The memory mapped PTH file.
39  const llvm::MemoryBuffer* Buf;
40
41  /// Alloc - Allocator used for IdentifierInfo objects.
42  llvm::BumpPtrAllocator Alloc;
43
44  /// IdMap - A lazily generated cache mapping from persistent identifiers to
45  ///  IdentifierInfo*.
46  IdentifierInfo** PerIDCache;
47
48  /// FileLookup - Abstract data structure used for mapping between files
49  ///  and token data in the PTH file.
50  void* FileLookup;
51
52  /// IdDataTable - Array representing the mapping from persistent IDs to the
53  ///  data offset within the PTH file containing the information to
54  ///  reconsitute an IdentifierInfo.
55  const unsigned char* const IdDataTable;
56
57  /// SortedIdTable - Abstract data structure mapping from strings to
58  ///  persistent IDs.  This is used by get().
59  void* StringIdLookup;
60
61  /// NumIds - The number of identifiers in the PTH file.
62  const unsigned NumIds;
63
64  /// PP - The Preprocessor object that will use this PTHManager to create
65  ///  PTHLexer objects.
66  Preprocessor* PP;
67
68  /// SpellingBase - The base offset within the PTH memory buffer that
69  ///  contains the cached spellings for literals.
70  const unsigned char* const SpellingBase;
71
72  /// OriginalSourceFile - A null-terminated C-string that specifies the name
73  ///  if the file (if any) that was to used to generate the PTH cache.
74  const char* OriginalSourceFile;
75
76  /// This constructor is intended to only be called by the static 'Create'
77  /// method.
78  PTHManager(const llvm::MemoryBuffer* buf, void* fileLookup,
79             const unsigned char* idDataTable, IdentifierInfo** perIDCache,
80             void* stringIdLookup, unsigned numIds,
81             const unsigned char* spellingBase, const char *originalSourceFile);
82
83  // Do not implement.
84  PTHManager();
85  void operator=(const PTHManager&);
86
87  /// getSpellingAtPTHOffset - Used by PTHLexer classes to get the cached
88  ///  spelling for a token.
89  unsigned getSpellingAtPTHOffset(unsigned PTHOffset, const char*& Buffer);
90
91  /// GetIdentifierInfo - Used to reconstruct IdentifierInfo objects from the
92  ///  PTH file.
93  inline IdentifierInfo* GetIdentifierInfo(unsigned PersistentID) {
94    // Check if the IdentifierInfo has already been resolved.
95    if (IdentifierInfo* II = PerIDCache[PersistentID])
96      return II;
97    return LazilyCreateIdentifierInfo(PersistentID);
98  }
99  IdentifierInfo* LazilyCreateIdentifierInfo(unsigned PersistentID);
100
101public:
102  // The current PTH version.
103  enum { Version = 9 };
104
105  ~PTHManager();
106
107  /// getOriginalSourceFile - Return the full path to the original header
108  ///  file name that was used to generate the PTH cache.
109  const char* getOriginalSourceFile() const {
110    return OriginalSourceFile;
111  }
112
113  /// get - Return the identifier token info for the specified named identifier.
114  ///  Unlike the version in IdentifierTable, this returns a pointer instead
115  ///  of a reference.  If the pointer is NULL then the IdentifierInfo cannot
116  ///  be found.
117  IdentifierInfo *get(StringRef Name);
118
119  /// Create - This method creates PTHManager objects.  The 'file' argument
120  ///  is the name of the PTH file.  This method returns NULL upon failure.
121  static PTHManager *Create(const std::string& file, DiagnosticsEngine &Diags);
122
123  void setPreprocessor(Preprocessor *pp) { PP = pp; }
124
125  /// CreateLexer - Return a PTHLexer that "lexes" the cached tokens for the
126  ///  specified file.  This method returns NULL if no cached tokens exist.
127  ///  It is the responsibility of the caller to 'delete' the returned object.
128  PTHLexer *CreateLexer(FileID FID);
129
130  /// createStatCache - Returns a FileSystemStatCache object for use with
131  ///  FileManager objects.  These objects use the PTH data to speed up
132  ///  calls to stat by memoizing their results from when the PTH file
133  ///  was generated.
134  FileSystemStatCache *createStatCache();
135};
136
137}  // end namespace clang
138
139#endif
140