1    :  // Copyright 2012 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 the ExplodeBasicBlockSubGraphTransform and
  16    :  // ExplodeBasicBlocksTransform classes. These transforms separate all
  17    :  // of the basic-blocks in a subgraph or block-graph respectively, into
  18    :  // individual code and data blocks. This is primarily a test to exercise
  19    :  // the basic-block motion machinery.
  20    :  
  21    :  #ifndef SYZYGY_PE_TRANSFORMS_EXPLODE_BASIC_BLOCKS_TRANSFORM_H_
  22    :  #define SYZYGY_PE_TRANSFORMS_EXPLODE_BASIC_BLOCKS_TRANSFORM_H_
  23    :  
  24    :  #include "syzygy/block_graph/transforms/iterative_transform.h"
  25    :  #include "syzygy/block_graph/transforms/named_transform.h"
  26    :  
  27    :  namespace pe {
  28    :  namespace transforms {
  29    :  
  30    :  // A BasicBlockSubBlockGraph transform that explodes all basic-blocks in a
  31    :  // basic_block subgraph into individual code or data blocks.
  32    :  class ExplodeBasicBlockSubGraphTransform
  33    :      : public block_graph::transforms::NamedBasicBlockSubGraphTransformImpl<
  34    :            ExplodeBasicBlockSubGraphTransform> {
  35    :   public:
  36    :    typedef block_graph::BlockGraph BlockGraph;
  37    :    typedef block_graph::BasicBlockSubGraph BasicBlockSubGraph;
  38    :  
  39    :    // Initialize a new ExplodeBasicBlockSubGraphTransform instance.
  40    :    explicit ExplodeBasicBlockSubGraphTransform(bool exclude_padding);
  41    :  
  42    :    // @name BasicBlockSubGraphTransformInterface methods.
  43    :    // @{
  44    :    virtual bool TransformBasicBlockSubGraph(
  45    :        BlockGraph* block_graph,
  46    :        BasicBlockSubGraph* basic_block_subgraph) OVERRIDE;
  47    :    // @}
  48    :  
  49    :    // The transform name.
  50    :    static const char kTransformName[];
  51    :  
  52    :    // @name Accessors.
  53    :    // @{
  54  E :    size_t output_code_blocks() const { return output_code_blocks_; }
  55  E :    size_t output_data_blocks() const { return output_data_blocks_; }
  56    :    // @}
  57    :  
  58    :   protected:
  59    :    // A flag for whether padding (and dead code) basic-blocks should be excluded
  60    :    // when reconstituting the exploded blocks.
  61    :    bool exclude_padding_;
  62    :    size_t output_code_blocks_;
  63    :    size_t output_data_blocks_;
  64    :  
  65    :    DISALLOW_COPY_AND_ASSIGN(ExplodeBasicBlockSubGraphTransform);
  66    :  };
  67    :  
  68    :  // A BlockGraph transform that, for every code block which is eligible for
  69    :  // decomposition to basic-blocks, and transforms every basic-blocks in each
  70    :  // code block into an individual code or data block.
  71    :  class ExplodeBasicBlocksTransform
  72    :      : public block_graph::transforms::IterativeTransformImpl<
  73    :            ExplodeBasicBlocksTransform> {
  74    :   public:
  75    :    typedef block_graph::BlockGraph BlockGraph;
  76    :  
  77    :    // Initialize a new ExplodeBasicBlocksTransform instance.
  78    :    ExplodeBasicBlocksTransform();
  79    :  
  80    :    // Explodes each basic code block in @p block referenced by into separate
  81    :    // blocks, then erases @p block from @p block_graph.
  82    :    // @param block_graph The block graph being modified.
  83    :    // @param block The block to explode, this must be in @p block_graph.
  84    :    // @note This method is required by the IterativeTransformImpl parent class.
  85    :    bool OnBlock(BlockGraph* block_graph, BlockGraph::Block* block);
  86    :  
  87    :    // Logs metrics about the performed transform.
  88    :    bool PostBlockGraphIteration(BlockGraph* block_graph,
  89    :                                 BlockGraph::Block* header_block);
  90    :  
  91    :    // @name Accessors.
  92    :    // @{
  93    :    bool exclude_padding() const { return exclude_padding_; }
  94  E :    void set_exclude_padding(bool value) { exclude_padding_ = value; }
  95    :    // @}
  96    :  
  97    :    // The transform name.
  98    :    static const char kTransformName[];
  99    :  
 100    :   protected:
 101    :    // Hooks for unit-testing.
 102    :    virtual bool SkipThisBlock(const BlockGraph::Block* candidate);
 103    :  
 104    :    // A flag for whether padding (and dead code) basic-blocks should be excluded
 105    :    // when reconstituting the exploded blocks.
 106    :    bool exclude_padding_;
 107    :  
 108    :    // Statistics on blocks encountered and generated.
 109    :    size_t non_decomposable_code_blocks_;
 110    :    size_t skipped_code_blocks_;
 111    :    size_t input_code_blocks_;
 112    :    size_t output_code_blocks_;
 113    :    size_t output_data_blocks_;
 114    :  
 115    :    DISALLOW_COPY_AND_ASSIGN(ExplodeBasicBlocksTransform);
 116    :  };
 117    :  
 118    :  }  // namespace transforms
 119    :  }  // namespace pe
 120    :  
 121    :  #endif  // SYZYGY_PE_TRANSFORMS_EXPLODE_BASIC_BLOCKS_TRANSFORM_H_