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 21namespace llvm { 22 class MemoryBuffer; 23} 24namespace 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. 34class 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) {} 43public: 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 67private: 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 77