text: /*
   * Copyright (C) 2009 Apple Inc. All rights reserved.
   *
   * Redistribution and use in source and binary forms, with or without
   * modification, are permitted provided that the following conditions
   * are met:
   * 1. Redistributions of source code must retain the above copyright
   *    notice, this list of conditions and the following disclaimer.
   * 2. Redistributions in binary form must reproduce the above copyright
   *    notice, this list of conditions and the following disclaimer in the
   *    documentation and/or other materials provided with the distribution.
   *
   * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
   * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
   * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
   * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE INC. OR
   * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
   * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
   * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
   * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
   * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
   * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
   * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 
   */
  
  #ifndef RepatchBuffer_h
  #define RepatchBuffer_h
  
  #include "assembler/wtf/Platform.h"
  
  #if ENABLE_ASSEMBLER
  
  #include <assembler/MacroAssembler.h>
  #include <moco/MocoStubs.h> //MOCO
  
  namespace JSC {
  
  // RepatchBuffer:
  //
  // This class is used to modify code after code generation has been completed,
  // and after the code has potentially already been executed.  This mechanism is
  // used to apply optimizations to the code.
  //
  class RepatchBuffer {
      typedef MacroAssemblerCodePtr CodePtr;
  
  public:
      RepatchBuffer(void *start, size_t size, bool mprot = true)
      : m_start(start), m_size(size), mprot(mprot)
      {
          ExecutableAllocator::makeWritable(m_start, m_size);
      }
  
      RepatchBuffer(CodeBlock* codeBlock)
      {
          JITCode& code = codeBlock->getJITCode();
          m_start = code.start();
          m_size = code.size();
          mprot = true;
  
          if (mprot)
              ExecutableAllocator::makeWritable(m_start, m_size);
      }
  
      ~RepatchBuffer()
      {
          if (mprot)
              ExecutableAllocator::makeExecutable(m_start, m_size);
      }
  
      void relink(CodeLocationJump jump, CodeLocationLabel destination)
      {
          MacroAssembler::repatchJump(jump, destination);
      }
  
      void relink(CodeLocationCall call, CodeLocationLabel destination)
      {
          MacroAssembler::repatchCall(call, destination);
      }
  
      void relink(CodeLocationCall call, FunctionPtr destination)
      {
          MacroAssembler::repatchCall(call, destination);
      }
  
      void relink(CodeLocationNearCall nearCall, CodePtr destination)
      {
          MacroAssembler::repatchNearCall(nearCall, CodeLocationLabel(destination));
      }
  
      void relink(CodeLocationNearCall nearCall, CodeLocationLabel destination)
      {
          MacroAssembler::repatchNearCall(nearCall, destination);
      }
  
      void repatch(CodeLocationDataLabel32 dataLabel32, int32_t value)
      {
          MacroAssembler::repatchInt32(dataLabel32, value);
      }
  
      void repatch(CodeLocationDataLabelPtr dataLabelPtr, void* value)
      {
          MacroAssembler::repatchPointer(dataLabelPtr, value);
      }
  
      void repatchLoadPtrToLEA(CodeLocationInstruction instruction)
      {
          MacroAssembler::repatchLoadPtrToLEA(instruction);
      }
  
      void repatchLEAToLoadPtr(CodeLocationInstruction instruction)
      {
          MacroAssembler::repatchLEAToLoadPtr(instruction);
      }
  
      void relinkCallerToTrampoline(ReturnAddressPtr returnAddress, CodeLocationLabel label)
      {
          relink(CodeLocationCall(CodePtr(returnAddress)), label);
      }
      
      void relinkCallerToTrampoline(ReturnAddressPtr returnAddress, CodePtr newCalleeFunction)
      {
          relinkCallerToTrampoline(returnAddress, CodeLocationLabel(newCalleeFunction));
      }
  
      void relinkCallerToFunction(ReturnAddressPtr returnAddress, FunctionPtr function)
      {
          relink(CodeLocationCall(CodePtr(returnAddress)), function);
      }
      
      void relinkNearCallerToTrampoline(ReturnAddressPtr returnAddress, CodeLocationLabel label)
      {
          relink(CodeLocationNearCall(CodePtr(returnAddress)), label);
      }
      
      void relinkNearCallerToTrampoline(ReturnAddressPtr returnAddress, CodePtr newCalleeFunction)
      {
          relinkNearCallerToTrampoline(returnAddress, CodeLocationLabel(newCalleeFunction));
      }
  
  protected:
      void* m_start;
      size_t m_size;
      bool mprot;
  };
  
  } // namespace JSC
  
  #endif // ENABLE(ASSEMBLER)
  
  #endif // RepatchBuffer_h
  