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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 
     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