1    :  // Copyright 2014 Google Inc. All Rights Reserved.
   2    :  //
   3    :  // Licensed under the Apache License, Version 2.0 (the "License");
   4    :  // you may not use this file except in compliance with the License.
   5    :  // You may obtain a copy of the License at
   6    :  //
   7    :  //     http://www.apache.org/licenses/LICENSE-2.0
   8    :  //
   9    :  // Unless required by applicable law or agreed to in writing, software
  10    :  // distributed under the License is distributed on an "AS IS" BASIS,
  11    :  // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  12    :  // See the License for the specific language governing permissions and
  13    :  // limitations under the License.
  14    :  //
  15    :  // Declares a class for writing an archive of COFF object files to a .lib
  16    :  // file. See ar_reader.h for details of MSVS version of the file format.
  17    :  
  18    :  #ifndef SYZYGY_AR_AR_WRITER_H_
  19    :  #define SYZYGY_AR_AR_WRITER_H_
  20    :  
  21    :  #include <set>
  22    :  
  23    :  #include "base/files/file_path.h"
  24    :  #include "base/memory/scoped_vector.h"
  25    :  #include "syzygy/ar/ar_common.h"
  26    :  
  27    :  namespace ar {
  28    :  
  29    :  // Class for writing an archive of COFF object files. This mimics the behaviour
  30    :  // of lib.exe in that duplicate symbol definitions are ignored but allowed, with
  31    :  // the first definition being the one that is exported to the symbol table.
  32    :  class ArWriter {
  33    :   public:
  34    :    typedef std::pair<ParsedArFileHeader, const DataBuffer*> File;
  35    :    typedef std::vector<File> FileVector;
  36    :  
  37    :    ArWriter();
  38    :  
  39    :    // @returns the current list of files that will be added to the archive.
  40  E :    const FileVector& files() const { return files_; }
  41    :  
  42    :    // @returns the current set of exported symbols.
  43  E :    const SymbolIndexMap& symbols() const { return symbols_; }
  44    :  
  45    :    // Schedules the given object file to be added to the archive.
  46    :    // @param filename The filename that will be associated with the content.
  47    :    // @param timestamp The timestamp to be associated with the file.
  48    :    // @param mode The mode to be associated with the file. In the same format
  49    :    //     as ST_MODE from _wstat.
  50    :    // @param contents The contents of the file. The lifetime of this object
  51    :    //     must exceed the lifetime of the writer.
  52    :    // @param path The file to be added; the filename as specified in @p path
  53    :    //     will be used, and the contents read from disk. Uses the timestamp and
  54    :    //     mode of the file on disk.
  55    :    // @returns true on success, false otherwise.
  56    :    bool AddFile(const base::StringPiece& filename,
  57    :                 const base::Time& timestamp,
  58    :                 uint32 mode,
  59    :                 const DataBuffer* contents);
  60    :    bool AddFile(const base::FilePath& path);
  61    :  
  62    :    // Writes the current set of files to an archive at the specified @p path.
  63    :    // @param path The path of the archive file to be written.
  64    :    // @returns true on success, false otherwise.
  65    :    bool Write(const base::FilePath& path);
  66    :  
  67    :   protected:
  68    :    typedef std::set<std::pair<std::string, size_t>> FileIndexMap;
  69    :    typedef ScopedVector<DataBuffer> ScopedDataBuffers;
  70    :  
  71    :    // Contains a collection of object files and the names with which they
  72    :    // will be committed to the archive.
  73    :    FileVector files_;
  74    :  
  75    :    // A multimap of filenames to their indices in |files_|.
  76    :    FileIndexMap file_index_map_;
  77    :  
  78    :    // Any files whose contents have been read by the writer are stored here.
  79    :    ScopedDataBuffers buffers_;
  80    :  
  81    :    // The collection of symbols exported from the various object files.
  82    :    SymbolIndexMap symbols_;
  83    :  
  84    :    // The collection of weak symbols currently exported from the various object
  85    :    // files. These have to be tracked separately as they can be overridden by
  86    :    // later object files.
  87    :    SymbolIndexMap weak_symbols_;
  88    :  
  89    :   private:
  90    :    DISALLOW_COPY_AND_ASSIGN(ArWriter);
  91    :  };
  92    :  
  93    :  }  // namespace ar
  94    :  
  95    :  #endif  // SYZYGY_AR_AR_WRITER_H_