1    :  // Copyright 2013 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    :  // The CoffImageLayoutBuilder is the COFF-specific class for building image
  16    :  // layouts for object files.
  17    :  
  18    :  #ifndef SYZYGY_PE_COFF_IMAGE_LAYOUT_BUILDER_H_
  19    :  #define SYZYGY_PE_COFF_IMAGE_LAYOUT_BUILDER_H_
  20    :  
  21    :  #include <windows.h>
  22    :  #include <map>
  23    :  
  24    :  #include "syzygy/block_graph/block_graph.h"
  25    :  #include "syzygy/block_graph/ordered_block_graph.h"
  26    :  #include "syzygy/pe/image_layout.h"
  27    :  #include "syzygy/pe/pe_coff_image_layout_builder.h"
  28    :  
  29  m :  namespace pe {
  30    :  
  31    :  // A CoffImageLayoutBuilder builds an image layout for a COFF file, mapping
  32    :  // blocks and sections to addresses, updating relocation tables, and fixing
  33    :  // all needed file offset pointers.
  34  m :  class CoffImageLayoutBuilder : public PECoffImageLayoutBuilder {
  35  m :   public:
  36    :    // Construct a new image layout builder that populates the provided image
  37    :    // layout. The image layout must outlive the builder.
  38    :    //
  39    :    // @param image_layout The image layout object to populate.
  40  m :    explicit CoffImageLayoutBuilder(ImageLayout* image_layout);
  41    :  
  42    :    // Lay out the image according to the specified ordering.
  43    :    //
  44    :    // @param ordered_graph the ordered block graph; the underlying block
  45    :    //     graph must match that of the image layout passed to the
  46    :    //     constructor.
  47    :    // @returns true on success, false on failure.
  48  m :    bool LayoutImage(const block_graph::OrderedBlockGraph& ordered_graph);
  49    :  
  50  m :   private:
  51    :    // Lay out the incomplete COFF file header and section table. This
  52    :    // essentially reserves space for these entities, copying over the old
  53    :    // data, assuming the headers block is correctly sized for the expected
  54    :    // number of section header entries, and all old references, in particular
  55    :    // to old relocation tables, have been removed. The contents will need
  56    :    // fixing by the other helper routines, as the information becomes
  57    :    // available.
  58    :    //
  59    :    // @returns true on success, false on failure.
  60  m :    bool LayoutHeaders();
  61    :  
  62    :    // Lay out all section blocks, section by section in the specified order,
  63    :    // as well as the computed relocations for each section, if any; update
  64    :    // the COFF section headers as appropriate.
  65    :    //
  66    :    // @param ordered_graph the ordered block graph.
  67    :    // @returns true on success, false on failure.
  68  m :    bool LayoutSectionBlocks(const OrderedBlockGraph& ordered_graph);
  69    :  
  70    :    // Lay out the symbol and string tables, and update the COFF file header.
  71    :    //
  72    :    // @param ordered_graph the ordered block graph.
  73    :    // @returns true on success, false on failure.
  74  m :    bool LayoutSymbolAndStringTables(const OrderedBlockGraph& ordered_graph);
  75    :  
  76    :    // Remove unmapped relocation blocks, and ensure that no other block is
  77    :    // left unmapped.
  78    :    //
  79    :    // @returns true on success, false on failure.
  80  m :    bool RemoveOldRelocBlocks();
  81    :  
  82    :    // The headers block that contains the file header and section table.
  83  m :    BlockGraph::Block* headers_block_;
  84    :  
  85    :    // The block containing the symbol table.
  86  m :    BlockGraph::Block* symbols_block_;
  87    :  
  88    :    // The block containing the string table.
  89  m :    BlockGraph::Block* strings_block_;
  90    :  
  91  m :    DISALLOW_COPY_AND_ASSIGN(CoffImageLayoutBuilder);
  92  m :  };
  93    :  
  94  m :  }  // namespace pe
  95    :  
  96    :  #endif  // SYZYGY_PE_COFF_IMAGE_LAYOUT_BUILDER_H_