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    :  #include "syzygy/pe/transforms/coff_convert_legacy_code_references_transform.h"
  16    :  
  17    :  namespace pe {
  18    :  namespace transforms {
  19    :  namespace {
  20    :  
  21    :  using block_graph::BlockGraph;
  22    :  
  23    :  // Convert all non-relocation references to equivalent relocation references
  24    :  // in @p block.
  25    :  // @param block the block whose references are to be converted.
  26  E :  void ConvertReferences(BlockGraph::Block* block) {
  27  E :    DCHECK_NE(reinterpret_cast<BlockGraph::Block*>(NULL), block);
  28    :  
  29    :    BlockGraph::Block::ReferenceMap::const_iterator it =
  30  E :        block->references().begin();
  31  E :    for (; it != block->references().end(); ++it) {
  32  E :      if ((it->second.type() & BlockGraph::RELOC_REF_BIT) != 0)
  33  E :        continue;
  34    :      BlockGraph::ReferenceType new_type =
  35    :          static_cast<BlockGraph::ReferenceType>(
  36  E :              it->second.type() | BlockGraph::RELOC_REF_BIT);
  37    :      BlockGraph::Reference ref(new_type,
  38    :                                it->second.size(),
  39    :                                it->second.referenced(),
  40    :                                it->second.offset(),
  41  E :                                it->second.base());
  42    :      // We expect this to return false, as the reference already exists.
  43  E :      CHECK(!block->SetReference(it->first, ref));
  44  E :    }
  45    :    return;
  46  E :  }
  47    :  
  48    :  }  // namespace
  49    :  
  50    :  const char CoffConvertLegacyCodeReferencesTransform::kTransformName[] =
  51    :      "CoffConvertLegacyCodeReferencesTransform";
  52    :  
  53    :  bool CoffConvertLegacyCodeReferencesTransform::TransformBlockGraph(
  54    :      const TransformPolicyInterface* policy,
  55    :      BlockGraph* block_graph,
  56  E :      BlockGraph::Block* /* headers_block */) {
  57  E :    DCHECK_NE(reinterpret_cast<TransformPolicyInterface*>(NULL), policy);
  58  E :    DCHECK_NE(reinterpret_cast<BlockGraph*>(NULL), block_graph);
  59  E :    DCHECK_EQ(BlockGraph::COFF_IMAGE, block_graph->image_format());
  60    :  
  61  E :    BlockGraph::BlockMap::iterator it = block_graph->blocks_mutable().begin();
  62  E :    for (; it != block_graph->blocks_mutable().end(); ++it) {
  63  E :      if (it->second.type() == BlockGraph::CODE_BLOCK)
  64  E :        ConvertReferences(&it->second);
  65  E :    }
  66  E :    return true;
  67  E :  }
  68    :  
  69    :  }  // namespace transforms
  70    :  }  // namespace pe