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 a simple API for transforming BlockGraphs in situ.
  16    :  
  17    :  #ifndef SYZYGY_BLOCK_GRAPH_TRANSFORM_H_
  18    :  #define SYZYGY_BLOCK_GRAPH_TRANSFORM_H_
  19    :  
  20    :  #include "syzygy/block_graph/basic_block_subgraph.h"
  21    :  #include "syzygy/block_graph/block_graph.h"
  22    :  
  23    :  namespace block_graph {
  24    :  
  25    :  // A BlockGraphTransform is a pure virtual base class defining the transform
  26    :  // API.
  27    :  class BlockGraphTransformInterface {
  28    :   public:
  29  E :    virtual ~BlockGraphTransformInterface() { }
  30    :  
  31    :    // Gets the name of this transform.
  32    :    //
  33    :    // @returns the name of this transform.
  34    :    virtual const char* name() const = 0;
  35    :  
  36    :    // Applies this transform to the provided block graph.
  37    :    //
  38    :    // @param block_graph The block graph to transform.
  39    :    // @param header_block The header block of the block graph to transform.
  40    :    // @returns true on success, false otherwise.
  41    :    virtual bool TransformBlockGraph(BlockGraph* block_graph,
  42    :                                     BlockGraph::Block* header_block) = 0;
  43    :  };
  44    :  
  45    :  // This applies the provided BlockGraphTransform and checks that invariant has
  46    :  // been satisfied; namely, that the header block has not been deleted from the
  47    :  // block graph.
  48    :  //
  49    :  // @param transform the transform to apply.
  50    :  // @param block_graph the block graph to transform.
  51    :  // @param header_block the header block from block_graph.
  52    :  // @returns true on success, false otherwise.
  53    :  bool ApplyBlockGraphTransform(BlockGraphTransformInterface* transform,
  54    :                                BlockGraph* block_graph,
  55    :                                BlockGraph::Block* header_block);
  56    :  
  57    :  // A BasicBlockSubGraphTransform is a pure virtual base class defining the
  58    :  // basic-block transform API.
  59    :  class BasicBlockSubGraphTransformInterface {
  60    :   public:
  61  E :    virtual ~BasicBlockSubGraphTransformInterface() { }
  62    :  
  63    :    // Gets the name of this transform.
  64    :    //
  65    :    // @returns the name of this transform.
  66    :    virtual const char* name() const = 0;
  67    :  
  68    :    // Applies this transform to the provided block.
  69    :    //
  70    :    // @param block_graph the block-graph of which the basic block subgraph
  71    :    //     is a part.
  72    :    // @param basic_block_subgraph the basic block subgraph to be transformed.
  73    :    // @returns true on success, false otherwise.
  74    :    virtual bool TransformBasicBlockSubGraph(
  75    :        BlockGraph* block_graph,
  76    :        BasicBlockSubGraph* basic_block_subgraph) = 0;
  77    :  };
  78    :  
  79    :  // Applies the provided BasicBlockSubGraphTransform to a single block. Takes
  80    :  // care of basic-block decomposing the block, passes it to the transform, and
  81    :  // recomposes the block.
  82    :  //
  83    :  // @param transform the transform to apply.
  84    :  // @param block_graph the block containing the block to be transformed.
  85    :  // @param block the block to be transformed.
  86    :  // @param new_blocks On success, any newly created blocks will be returned
  87    :  //     here. Note that this parameter may be NULL if you are not interested
  88    :  //     in retrieving the set of new blocks.
  89    :  // @pre block must be a code block.
  90    :  // @returns true on success, false otherwise.
  91    :  bool ApplyBasicBlockSubGraphTransform(
  92    :      BasicBlockSubGraphTransformInterface* transform,
  93    :      BlockGraph* block_graph,
  94    :      BlockGraph::Block* block,
  95    :      BlockVector* new_blocks);
  96    :  
  97    :  }  // namespace block_graph
  98    :  
  99    :  #endif  // SYZYGY_BLOCK_GRAPH_TRANSFORM_H_