1    :  // Copyright 2015 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    :  // This defines BufferSerializer that can be used with the Assembler to assemble
  16    :  // into a memory buffer.
  17    :  
  18    :  #ifndef SYZYGY_ASSM_BUFFER_SERIALIZER_H_
  19    :  #define SYZYGY_ASSM_BUFFER_SERIALIZER_H_
  20    :  
  21    :  #include "syzygy/assm/assembler.h"
  22    :  
  23    :  namespace assm {
  24    :  
  25    :  // An InstructionSerializer class that assembles instructions into a memory
  26    :  // buffer.
  27    :  // The assembler should also be created using the desired target location to
  28    :  // make correct references. The buffer passed in the constructor arguments is
  29    :  // used for bounds checking in DCHECK mode.
  30    :  class BufferSerializer : public AssemblerImpl::InstructionSerializer {
  31    :   public:
  32    :    // Creates a BufferSerializer object.
  33    :    // @param buffer A pointer to the buffer.
  34    :    // @param size The size of the buffer.
  35  E :    BufferSerializer(uint8* buffer, size_t size)
  36    :        : buffer_(buffer), size_(size) { }
  37    :  
  38    :    // @name Accessors.
  39    :    // @{
  40    :    uint8* buffer() const { return buffer_; }
  41    :    size_t size() const { return size_; }
  42    :    // @}
  43    :  
  44    :    // @name Implementation of the InstructionSerializer interface.
  45    :    // @{
  46    :    typedef assm::AssemblerImpl::ReferenceInfo ReferenceInfo;
  47    :    void AppendInstruction(uint32 location,
  48    :                           const uint8* bytes,
  49    :                           size_t num_bytes,
  50    :                           const ReferenceInfo* refs,
  51  E :                           size_t num_refs) override {
  52  E :      uint8* write_location = static_cast<uint8*>(0) + location;
  53  E :      DCHECK_GE(write_location, buffer_);
  54  E :      DCHECK_LE(write_location + num_bytes, buffer_ + size_);
  55    :  
  56  E :      ::memcpy(write_location, bytes, num_bytes);
  57  E :    }
  58    :    bool FinalizeLabel(uint32 location,
  59    :                       const uint8* bytes,
  60  i :                       size_t num_bytes) override {
  61  i :      return false;  // No label support.
  62  i :    }
  63    :    // @}
  64    :  
  65    :   private:
  66    :    uint8* buffer_;
  67    :    size_t size_;
  68    :  };
  69    :  
  70    :  }  // namespace assm
  71    :  
  72    :  #endif  // SYZYGY_ASSM_BUFFER_SERIALIZER_H_