1    :  // Copyright 2011 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/block_graph/iterate.h"
  16    :  
  17    :  namespace block_graph {
  18    :  
  19    :  bool IterateBlockGraph(const IterationCallback& callback,
  20  E :                         BlockGraph* block_graph) {
  21  E :    DCHECK(block_graph != NULL);
  22    :  
  23  E :    if (block_graph->blocks().size() == 0)
  24  i :      return true;
  25    :  
  26    :    // Get the ID of the last existing block in iterator order.
  27    :    BlockGraph::BlockMap::iterator last_block_it =
  28  E :        block_graph->blocks_mutable().end();
  29  E :    --last_block_it;
  30  E :    BlockGraph::BlockId last_block_id = last_block_it->second.id();
  31    :  
  32    :    // Iterate through all blocks. We stop after having visited the last block
  33    :    // that was pre-existing prior to the iteration.
  34    :    BlockGraph::BlockMap::iterator block_it =
  35  E :        block_graph->blocks_mutable().begin();
  36  E :    BlockGraph::BlockId id = 0;
  37    :    do {
  38    :      // Get the block ID and the next block prior to invoking the callback.
  39    :      // This is because the callback is allowed to delete the current block, and
  40    :      // it may not be valid to use block_it after the callback completes.
  41  E :      id = block_it->second.id();
  42  E :      BlockGraph::BlockMap::iterator next_block_it = block_it;
  43  E :      ++next_block_it;
  44    :  
  45  E :      if (!callback.Run(block_graph, &block_it->second)) {
  46  E :        LOG(ERROR) << "IterateBlocks callback failed for block "
  47    :                   << "\"" << block_it->second.name() << "\".";
  48  E :        return false;
  49    :      }
  50    :  
  51  E :      block_it = next_block_it;
  52  E :    } while (id != last_block_id);
  53    :  
  54  E :    return true;
  55  E :  }
  56    :  
  57    :  }  // namespace block_graph