HeaderMap.h revision f56faa01936b9cf909623d7f06e3c2569ca4a78e 
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
17#include "clang/Basic/LLVM.h"
18#include "llvm/Support/Compiler.h"
19
20namespace llvm {
21  class MemoryBuffer;
22}
23namespace clang {
24  class FileEntry;
25  class FileManager;
26  struct HMapBucket;
27  struct HMapHeader;
28
29/// This class represents an Apple concept known as a 'header map'.  To the
30/// \#include file resolution process, it basically acts like a directory of
31/// symlinks to files.  Its advantages are that it is dense and more efficient
32/// to create and process than a directory of symlinks.
33class HeaderMap {
34  HeaderMap(const HeaderMap &) LLVM_DELETED_FUNCTION;
35  void operator=(const HeaderMap &) LLVM_DELETED_FUNCTION;
36
37  const llvm::MemoryBuffer *FileBuffer;
38  bool NeedsBSwap;
39
40  HeaderMap(const llvm::MemoryBuffer *File, bool BSwap)
41    : FileBuffer(File), NeedsBSwap(BSwap) {
42  }
43public:
44  ~HeaderMap();
45
46  /// HeaderMap::Create - This attempts to load the specified file as a header
47  /// map.  If it doesn't look like a HeaderMap, it gives up and returns null.
48  static const HeaderMap *Create(const FileEntry *FE, FileManager &FM);
49
50  /// LookupFile - Check to see if the specified relative filename is located in
51  /// this HeaderMap.  If so, open it and return its FileEntry.
52  /// If RawPath is not NULL and the file is found, RawPath will be set to the
53  /// raw path at which the file was found in the file system. For example,
54  /// for a search path ".." and a filename "../file.h" this would be
55  /// "../../file.h".
56  const FileEntry *LookupFile(StringRef Filename, FileManager &FM) const;
57
58  /// getFileName - Return the filename of the headermap.
59  const char *getFileName() const;
60
61  /// dump - Print the contents of this headermap to stderr.
62  void dump() const;
63
64private:
65  unsigned getEndianAdjustedWord(unsigned X) const;
66  const HMapHeader &getHeader() const;
67  HMapBucket getBucket(unsigned BucketNo) const;
68  const char *getString(unsigned StrTabIdx) const;
69};
70
71} // end namespace clang.
72
73#endif
74