HeaderMap.h revision 389db16c63eec6ecfa9b235155252d8da766e94e
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} 21namespace clang { 22 class FileEntry; 23 class FileManager; 24 class FileSystemOptions; 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 const FileSystemOptions &FSOpts); 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 const FileEntry *LookupFile(llvm::StringRef Filename, FileManager &FM, 53 const FileSystemOptions &FileSystemOpts) const; 54 55 /// getFileName - Return the filename of the headermap. 56 const char *getFileName() const; 57 58 /// dump - Print the contents of this headermap to stderr. 59 void dump() const; 60 61private: 62 unsigned getEndianAdjustedWord(unsigned X) const; 63 const HMapHeader &getHeader() const; 64 HMapBucket getBucket(unsigned BucketNo) const; 65 const char *getString(unsigned StrTabIdx) const; 66}; 67 68} // end namespace clang. 69 70#endif 71