1    :  // Copyright 2012 Google Inc.
   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/block_util.h"
  16    :  
  17    :  namespace block_graph {
  18    :  
  19    :  bool CodeBlockAttributesAreBasicBlockSafe(
  20  E :      const block_graph::BlockGraph::Block* block) {
  21  E :    DCHECK(block != NULL);
  22  E :    DCHECK_EQ(BlockGraph::CODE_BLOCK, block->type());
  23    :  
  24    :    // If the block was built by our toolchain it's inherently safe. This
  25    :    // attribute is used to whitelist a block.
  26  E :    if (block->attributes() & BlockGraph::BUILT_BY_SYZYGY)
  27  E :      return true;
  28    :  
  29    :    // Any of the following attributes make it unsafe to basic-block
  30    :    // decompose the code block.
  31    :    static const BlockGraph::BlockAttributes kInvalidAttributes =
  32    :        BlockGraph::GAP_BLOCK |
  33    :        BlockGraph::PADDING_BLOCK |
  34    :        BlockGraph::HAS_INLINE_ASSEMBLY |
  35    :        BlockGraph::BUILT_BY_UNSUPPORTED_COMPILER |
  36    :        BlockGraph::ERRORED_DISASSEMBLY |
  37    :        BlockGraph::HAS_EXCEPTION_HANDLING |
  38    :        BlockGraph::DISASSEMBLED_PAST_END;
  39  E :    if ((block->attributes() & kInvalidAttributes) != 0)
  40  E :      return false;
  41    :  
  42  E :    return true;
  43  E :  }
  44    :  
  45    :  }  // namespace block_graph