jit/JITCode.h

   1 /*
   2  * Copyright (C) 2008 Apple Inc. All rights reserved.
   3  *
   4  * Redistribution and use in source and binary forms, with or without
   5  * modification, are permitted provided that the following conditions
   6  * are met:
   7  * 1. Redistributions of source code must retain the above copyright
   8  *    notice, this list of conditions and the following disclaimer.
   9  * 2. Redistributions in binary form must reproduce the above copyright
  10  *    notice, this list of conditions and the following disclaimer in the
  11  *    documentation and/or other materials provided with the distribution.
  12  *
  13  * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
  14  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  15  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  16  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE INC. OR
  17  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
  18  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
  19  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
  20  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
  21  * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  22  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  23  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  24  */
  25
  26 #ifndef JITCode_h
  27 #define JITCode_h
  28
  29 #if ENABLE(JIT)
  30 #include "CallFrame.h"
  31 #include "JSValue.h"
  32 #include "MacroAssemblerCodeRef.h"
  33 #include "Profiler.h"
  34 #endif
  35
  36 namespace JSC {
  37
  38 #if ENABLE(JIT)
  39     class JSGlobalData;
  40     class RegisterFile;
  41 #endif
  42
  43     class JITCode {
  44 #if ENABLE(JIT)
  45         typedef MacroAssemblerCodeRef CodeRef;
  46         typedef MacroAssemblerCodePtr CodePtr;
  47 #else
  48         JITCode() { }
  49 #endif
  50     public:
  51         enum JITType { None, HostCallThunk, InterpreterThunk, BaselineJIT, DFGJIT };
  52
  53         static JITType bottomTierJIT()
  54         {
  55             return BaselineJIT;
  56         }
  57
  58         static JITType topTierJIT()
  59         {
  60             return DFGJIT;
  61         }
  62
  63         static JITType nextTierJIT(JITType jitType)
  64         {
  65             ASSERT_UNUSED(jitType, jitType == BaselineJIT || jitType == DFGJIT);
  66             return DFGJIT;
  67         }
  68
  69         static bool isOptimizingJIT(JITType jitType)
  70         {
  71             return jitType == DFGJIT;
  72         }
  73
  74         static bool isBaselineCode(JITType jitType)
  75         {
  76             return jitType == InterpreterThunk || jitType == BaselineJIT;
  77         }
  78
  79 #if ENABLE(JIT)
  80         JITCode()
  81             : m_jitType(None)
  82         {
  83         }
  84
  85         JITCode(const CodeRef ref, JITType jitType)
  86             : m_ref(ref)
  87             , m_jitType(jitType)
  88         {
  89             ASSERT(jitType != None);
  90         }
  91
  92         bool operator !() const
  93         {
  94             return !m_ref;
  95         }
  96
  97         CodePtr addressForCall()
  98         {
  99             return m_ref.code();
 100         }
 101
 102         void* executableAddressAtOffset(size_t offset) const
 103         {
 104             ASSERT(offset < size());
 105             return reinterpret_cast<char*>(m_ref.code().executableAddress()) + offset;
 106         }
 107
 108         void* dataAddressAtOffset(size_t offset) const
 109         {
 110             ASSERT(offset < size());
 111             return reinterpret_cast<char*>(m_ref.code().dataLocation()) + offset;
 112         }
 113
 114         // This function returns the offset in bytes of 'pointerIntoCode' into
 115         // this block of code.  The pointer provided must be a pointer into this
 116         // block of code.  It is ASSERTed that no codeblock >4gb in size.
 117         unsigned offsetOf(void* pointerIntoCode)
 118         {
 119             intptr_t result = reinterpret_cast<intptr_t>(pointerIntoCode) - reinterpret_cast<intptr_t>(m_ref.code().executableAddress());
 120             ASSERT(static_cast<intptr_t>(static_cast<unsigned>(result)) == result);
 121             return static_cast<unsigned>(result);
 122         }
 123
 124         // Execute the code!
 125         inline JSValue execute(RegisterFile* registerFile, CallFrame* callFrame, JSGlobalData* globalData)
 126         {
 127             JSValue result = JSValue::decode(ctiTrampoline(m_ref.code().executableAddress(), registerFile, callFrame, 0, Profiler::enabledProfilerReference(), globalData));
 128             return globalData->exception ? jsNull() : result;
 129         }
 130
 131         void* start() const
 132         {
 133             return m_ref.code().dataLocation();
 134         }
 135
 136         size_t size() const
 137         {
 138             ASSERT(m_ref.code().executableAddress());
 139             return m_ref.size();
 140         }
 141
 142         ExecutableMemoryHandle* getExecutableMemory()
 143         {
 144             return m_ref.executableMemory();
 145         }
 146
 147         JITType jitType()
 148         {
 149             return m_jitType;
 150         }
 151
 152         // Host functions are a bit special; they have a m_code pointer but they
 153         // do not individully ref the executable pool containing the trampoline.
 154         static JITCode HostFunction(CodeRef code)
 155         {
 156             return JITCode(code, HostCallThunk);
 157         }
 158
 159         void clear()
 160         {
 161             m_ref.~CodeRef();
 162             new (NotNull, &m_ref) CodeRef();
 163         }
 164
 165     private:
 166         JITCode(PassRefPtr<ExecutableMemoryHandle> executableMemory, JITType jitType)
 167             : m_ref(executableMemory)
 168             , m_jitType(jitType)
 169         {
 170         }
 171
 172         CodeRef m_ref;
 173         JITType m_jitType;
 174 #endif // ENABLE(JIT)
 175     };
 176
 177 };
 178
 179 #endif