clang  3.7.0
HeaderMap.h
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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 #include <memory>
20 
21 namespace llvm {
22  class MemoryBuffer;
23 }
24 namespace clang {
25  class FileEntry;
26  class FileManager;
27  struct HMapBucket;
28  struct HMapHeader;
29 
30 /// This class represents an Apple concept known as a 'header map'. To the
31 /// \#include file resolution process, it basically acts like a directory of
32 /// symlinks to files. Its advantages are that it is dense and more efficient
33 /// to create and process than a directory of symlinks.
34 class HeaderMap {
35  HeaderMap(const HeaderMap &) = delete;
36  void operator=(const HeaderMap &) = delete;
37 
38  std::unique_ptr<const llvm::MemoryBuffer> FileBuffer;
39  bool NeedsBSwap;
40 
41  HeaderMap(std::unique_ptr<const llvm::MemoryBuffer> File, bool BSwap)
42  : FileBuffer(std::move(File)), NeedsBSwap(BSwap) {}
43 public:
44  /// HeaderMap::Create - This attempts to load the specified file as a header
45  /// map. If it doesn't look like a HeaderMap, it gives up and returns null.
46  static const HeaderMap *Create(const FileEntry *FE, FileManager &FM);
47 
48  /// LookupFile - Check to see if the specified relative filename is located in
49  /// this HeaderMap. If so, open it and return its FileEntry.
50  /// If RawPath is not NULL and the file is found, RawPath will be set to the
51  /// raw path at which the file was found in the file system. For example,
52  /// for a search path ".." and a filename "../file.h" this would be
53  /// "../../file.h".
54  const FileEntry *LookupFile(StringRef Filename, FileManager &FM) const;
55 
56  /// If the specified relative filename is located in this HeaderMap return
57  /// the filename it is mapped to, otherwise return an empty StringRef.
58  StringRef lookupFilename(StringRef Filename,
59  SmallVectorImpl<char> &DestPath) const;
60 
61  /// getFileName - Return the filename of the headermap.
62  const char *getFileName() const;
63 
64  /// dump - Print the contents of this headermap to stderr.
65  void dump() const;
66 
67 private:
68  unsigned getEndianAdjustedWord(unsigned X) const;
69  const HMapHeader &getHeader() const;
70  HMapBucket getBucket(unsigned BucketNo) const;
71  const char *getString(unsigned StrTabIdx) const;
72 };
73 
74 } // end namespace clang.
75 
76 #endif
Implements support for file system lookup, file system caching, and directory search management...
Definition: FileManager.h:115
const char * getFileName() const
getFileName - Return the filename of the headermap.
Definition: HeaderMap.cpp:115
const FileEntry * LookupFile(StringRef Filename, FileManager &FM) const
Definition: HeaderMap.cpp:198
static const HeaderMap * Create(const FileEntry *FE, FileManager &FM)
Definition: HeaderMap.cpp:79
void dump() const
dump - Print the contents of this headermap to stderr.
Definition: HeaderMap.cpp:177
Forward-declares and imports various common LLVM datatypes that clang wants to use unqualified...
Cached information about one file (either on disk or in the virtual file system). ...
Definition: FileManager.h:53
X
Definition: SemaDecl.cpp:11429
StringRef lookupFilename(StringRef Filename, SmallVectorImpl< char > &DestPath) const
Definition: HeaderMap.cpp:209