jit/JITCode.h

   1 /*
   2  * Copyright (C) 2008, 2012 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) || ENABLE(LLINT)
  30 #include "CallFrame.h"
  31 #include "Disassembler.h"
  32 #include "JITStubs.h"
  33 #include "JSCJSValue.h"
  34 #include "LegacyProfiler.h"
  35 #include "MacroAssemblerCodeRef.h"
  36 #endif
  37
  38 namespace JSC {
  39
  40 #if ENABLE(JIT)
  41     class VM;
  42     class JSStack;
  43 #endif
  44
  45     class JITCode {
  46 #if ENABLE(JIT) || ENABLE(LLINT)
  47         typedef MacroAssemblerCodeRef CodeRef;
  48         typedef MacroAssemblerCodePtr CodePtr;
  49 #else
  50         JITCode() { }
  51 #endif
  52     public:
  53         enum JITType { None, HostCallThunk, InterpreterThunk, BaselineJIT, DFGJIT };
  54
  55         static JITType bottomTierJIT()
  56         {
  57             return BaselineJIT;
  58         }
  59
  60         static JITType topTierJIT()
  61         {
  62             return DFGJIT;
  63         }
  64
  65         static JITType nextTierJIT(JITType jitType)
  66         {
  67             ASSERT_UNUSED(jitType, jitType == BaselineJIT || jitType == DFGJIT);
  68             return DFGJIT;
  69         }
  70
  71         static bool isOptimizingJIT(JITType jitType)
  72         {
  73             return jitType == DFGJIT;
  74         }
  75
  76         static bool isBaselineCode(JITType jitType)
  77         {
  78             return jitType == InterpreterThunk || jitType == BaselineJIT;
  79         }
  80
  81 #if ENABLE(JIT) || ENABLE(LLINT)
  82         JITCode()
  83             : m_jitType(None)
  84         {
  85         }
  86
  87         JITCode(const CodeRef ref, JITType jitType)
  88             : m_ref(ref)
  89             , m_jitType(jitType)
  90         {
  91             ASSERT(jitType != None);
  92         }
  93
  94         bool operator !() const
  95         {
  96             return !m_ref;
  97         }
  98
  99         CodePtr addressForCall()
 100         {
 101             return m_ref.code();
 102         }
 103
 104         void* executableAddressAtOffset(size_t offset) const
 105         {
 106             ASSERT(offset < size());
 107             return reinterpret_cast<char*>(m_ref.code().executableAddress()) + offset;
 108         }
 109
 110         void* executableAddress() const
 111         {
 112             return executableAddressAtOffset(0);
 113         }
 114
 115         void* dataAddressAtOffset(size_t offset) const
 116         {
 117             ASSERT(offset <= size()); // use <= instead of < because it is valid to ask for an address at the exclusive end of the code.
 118             return reinterpret_cast<char*>(m_ref.code().dataLocation()) + offset;
 119         }
 120
 121         // This function returns the offset in bytes of 'pointerIntoCode' into
 122         // this block of code.  The pointer provided must be a pointer into this
 123         // block of code.  It is ASSERTed that no codeblock >4gb in size.
 124         unsigned offsetOf(void* pointerIntoCode)
 125         {
 126             intptr_t result = reinterpret_cast<intptr_t>(pointerIntoCode) - reinterpret_cast<intptr_t>(m_ref.code().executableAddress());
 127             ASSERT(static_cast<intptr_t>(static_cast<unsigned>(result)) == result);
 128             return static_cast<unsigned>(result);
 129         }
 130
 131 #if ENABLE(JIT)
 132         // Execute the code!
 133         inline JSValue execute(JSStack* stack, CallFrame* callFrame, VM* vm)
 134         {
 135             JSValue result = JSValue::decode(ctiTrampoline(m_ref.code().executableAddress(), stack, callFrame, 0, 0, vm));
 136             return vm->exception ? jsNull() : result;
 137         }
 138 #endif
 139
 140         void* start() const
 141         {
 142             return m_ref.code().dataLocation();
 143         }
 144
 145         size_t size() const
 146         {
 147             ASSERT(m_ref.code().executableAddress());
 148             return m_ref.size();
 149         }
 150
 151         bool tryToDisassemble(const char* prefix) const
 152         {
 153             return m_ref.tryToDisassemble(prefix);
 154         }
 155
 156         ExecutableMemoryHandle* getExecutableMemory()
 157         {
 158             return m_ref.executableMemory();
 159         }
 160
 161         JITType jitType() const
 162         {
 163             return m_jitType;
 164         }
 165
 166         // Host functions are a bit special; they have a m_code pointer but they
 167         // do not individully ref the executable pool containing the trampoline.
 168         static JITCode HostFunction(CodeRef code)
 169         {
 170             return JITCode(code, HostCallThunk);
 171         }
 172
 173         void clear()
 174         {
 175             m_ref.~CodeRef();
 176             new (NotNull, &m_ref) CodeRef();
 177         }
 178
 179     private:
 180         JITCode(PassRefPtr<ExecutableMemoryHandle> executableMemory, JITType jitType)
 181             : m_ref(executableMemory)
 182             , m_jitType(jitType)
 183         {
 184         }
 185
 186         CodeRef m_ref;
 187         JITType m_jitType;
 188 #endif // ENABLE(JIT) || ENABLE(LLINT)
 189     };
 190
 191 } // namespace JSC
 192
 193 namespace WTF {
 194
 195 class PrintStream;
 196 void printInternal(PrintStream&, JSC::JITCode::JITType);
 197
 198 } // namespace WTF
 199
 200 #endif