text: /*
   * Copyright (C) 2008, 2012 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 JITCode_h
  #define JITCode_h
  
  #if ENABLE(JIT) || ENABLE(LLINT)
  #include "CallFrame.h"
  #include "Disassembler.h"
  #include "JITStubs.h"
  #include "JSCJSValue.h"
  #include "LegacyProfiler.h"
  #include "MacroAssemblerCodeRef.h"
  #endif
  
  namespace JSC {
  
  #if ENABLE(JIT)
      class VM;
      class JSStack;
  #endif
      
      class JITCode {
  #if ENABLE(JIT) || ENABLE(LLINT)
          typedef MacroAssemblerCodeRef CodeRef;
          typedef MacroAssemblerCodePtr CodePtr;
  #else
          JITCode() { }
  #endif
      public:
          enum JITType { None, HostCallThunk, InterpreterThunk, BaselineJIT, DFGJIT };
          
          static JITType bottomTierJIT()
          {
              return BaselineJIT;
          }
          
          static JITType topTierJIT()
          {
              return DFGJIT;
          }
          
          static JITType nextTierJIT(JITType jitType)
          {
              ASSERT_UNUSED(jitType, jitType == BaselineJIT || jitType == DFGJIT);
              return DFGJIT;
          }
          
          static bool isOptimizingJIT(JITType jitType)
          {
              return jitType == DFGJIT;
          }
          
          static bool isBaselineCode(JITType jitType)
          {
              return jitType == InterpreterThunk || jitType == BaselineJIT;
          }
          
  #if ENABLE(JIT) || ENABLE(LLINT)
          JITCode()
              : m_jitType(None)
          {
          }
  
          JITCode(const CodeRef ref, JITType jitType)
              : m_ref(ref)
              , m_jitType(jitType)
          {
              ASSERT(jitType != None);
          }
          
          bool operator !() const
          {
              return !m_ref;
          }
  
          CodePtr addressForCall()
          {
              return m_ref.code();
          }
  
          void* executableAddressAtOffset(size_t offset) const
          {
              ASSERT(offset < size());
              return reinterpret_cast<char*>(m_ref.code().executableAddress()) + offset;
          }
          
          void* executableAddress() const
          {
              return executableAddressAtOffset(0);
          }
          
          void* dataAddressAtOffset(size_t offset) const
          {
              ASSERT(offset <= size()); // use <= instead of < because it is valid to ask for an address at the exclusive end of the code.
              return reinterpret_cast<char*>(m_ref.code().dataLocation()) + offset;
          }
  
          // This function returns the offset in bytes of 'pointerIntoCode' into
          // this block of code.  The pointer provided must be a pointer into this
          // block of code.  It is ASSERTed that no codeblock >4gb in size.
          unsigned offsetOf(void* pointerIntoCode)
          {
              intptr_t result = reinterpret_cast<intptr_t>(pointerIntoCode) - reinterpret_cast<intptr_t>(m_ref.code().executableAddress());
              ASSERT(static_cast<intptr_t>(static_cast<unsigned>(result)) == result);
              return static_cast<unsigned>(result);
          }
  
  #if ENABLE(JIT)
          // Execute the code!
          inline JSValue execute(JSStack* stack, CallFrame* callFrame, VM* vm)
          {
              JSValue result = JSValue::decode(ctiTrampoline(m_ref.code().executableAddress(), stack, callFrame, 0, 0, vm));
              return vm->exception ? jsNull() : result;
          }
  #endif
  
          void* start() const
          {
              return m_ref.code().dataLocation();
          }
  
          size_t size() const
          {
              ASSERT(m_ref.code().executableAddress());
              return m_ref.size();
          }
          
          bool tryToDisassemble(const char* prefix) const
          {
              return m_ref.tryToDisassemble(prefix);
          }
  
          ExecutableMemoryHandle* getExecutableMemory()
          {
              return m_ref.executableMemory();
          }
          
          JITType jitType() const
          {
              return m_jitType;
          }
  
          // Host functions are a bit special; they have a m_code pointer but they
          // do not individully ref the executable pool containing the trampoline.
          static JITCode HostFunction(CodeRef code)
          {
              return JITCode(code, HostCallThunk);
          }
  
          void clear()
          {
              m_ref.~CodeRef();
              new (NotNull, &m_ref) CodeRef();
          }
  
      private:
          JITCode(PassRefPtr<ExecutableMemoryHandle> executableMemory, JITType jitType)
              : m_ref(executableMemory)
              , m_jitType(jitType)
          {
          }
  
          CodeRef m_ref;
          JITType m_jitType;
  #endif // ENABLE(JIT) || ENABLE(LLINT)
      };
  
  } // namespace JSC
  
  namespace WTF {
  
  class PrintStream;
  void printInternal(PrintStream&, JSC::JITCode::JITType);
  
  } // namespace WTF
  
  #endif
  