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 
20 namespace llvm {
21   class MemoryBuffer;
22 }
23 namespace 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.
33 class 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   }
43 public:
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 
64 private:
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