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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 
     19 namespace llvm {
     20   class MemoryBuffer;
     21 }
     22 namespace clang {
     23   class FileEntry;
     24   class FileManager;
     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.
     32 class 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   }
     42 public:
     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 
     49   /// LookupFile - Check to see if the specified relative filename is located in
     50   /// this HeaderMap.  If so, open it and return its FileEntry.
     51   /// If RawPath is not NULL and the file is found, RawPath will be set to the
     52   /// raw path at which the file was found in the file system. For example,
     53   /// for a search path ".." and a filename "../file.h" this would be
     54   /// "../../file.h".
     55   const FileEntry *LookupFile(StringRef Filename, FileManager &FM) const;
     56 
     57   /// getFileName - Return the filename of the headermap.
     58   const char *getFileName() const;
     59 
     60   /// dump - Print the contents of this headermap to stderr.
     61   void dump() const;
     62 
     63 private:
     64   unsigned getEndianAdjustedWord(unsigned X) const;
     65   const HMapHeader &getHeader() const;
     66   HMapBucket getBucket(unsigned BucketNo) const;
     67   const char *getString(unsigned StrTabIdx) const;
     68 };
     69 
     70 } // end namespace clang.
     71 
     72 #endif
     73