HeaderMap.h revision 7412494982c8b50c90961302c3a718633b2c3ab7 
1//===--- HeaderMap.h - A file that acts like dir of symlinks ----*- 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 HeaderMap interface.
11//
12//===----------------------------------------------------------------------===//
13
14#ifndef LLVM_CLANG_LEX_HEADERMAP_H
15#define LLVM_CLANG_LEX_HEADERMAP_H
16
17namespace llvm {
18  class MemoryBuffer;
19  class StringRef;
20  template <typename T> class SmallVectorImpl;
21}
22namespace clang {
23  class FileEntry;
24  class FileManager;
25  struct HMapBucket;
26  struct HMapHeader;
27
28/// This class represents an Apple concept known as a 'header map'.  To the
29/// #include file resolution process, it basically acts like a directory of
30/// symlinks to files.  Its advantages are that it is dense and more efficient
31/// to create and process than a directory of symlinks.
32class HeaderMap {
33  HeaderMap(const HeaderMap&); // DO NOT IMPLEMENT
34  void operator=(const HeaderMap&); // DO NOT IMPLEMENT
35
36  const llvm::MemoryBuffer *FileBuffer;
37  bool NeedsBSwap;
38
39  HeaderMap(const llvm::MemoryBuffer *File, bool BSwap)
40    : FileBuffer(File), NeedsBSwap(BSwap) {
41  }
42public:
43  ~HeaderMap();
44
45  /// HeaderMap::Create - This attempts to load the specified file as a header
46  /// map.  If it doesn't look like a HeaderMap, it gives up and returns null.
47  static const HeaderMap *Create(const FileEntry *FE, FileManager &FM);
48
49  /// LookupFile - Check to see if the specified relative filename is located in
50  /// this HeaderMap.  If so, open it and return its FileEntry.
51  /// If RawPath is not NULL and the file is found, RawPath will be set to the
52  /// raw path at which the file was found in the file system. For example,
53  /// for a search path ".." and a filename "../file.h" this would be
54  /// "../../file.h".
55  const FileEntry *LookupFile(llvm::StringRef Filename, FileManager &FM) const;
56
57  /// getFileName - Return the filename of the headermap.
58  const char *getFileName() const;
59
60  /// dump - Print the contents of this headermap to stderr.
61  void dump() const;
62
63private:
64  unsigned getEndianAdjustedWord(unsigned X) const;
65  const HMapHeader &getHeader() const;
66  HMapBucket getBucket(unsigned BucketNo) const;
67  const char *getString(unsigned StrTabIdx) const;
68};
69
70} // end namespace clang.
71
72#endif
73