1/*
2 * Copyright (C) 2009 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 RepatchBuffer_h
27#define RepatchBuffer_h
28
29#include <wtf/Platform.h>
30
31#if ENABLE(ASSEMBLER)
32
33#include <MacroAssembler.h>
34#include <wtf/Noncopyable.h>
35
36namespace JSC {
37
38// RepatchBuffer:
39//
40// This class is used to modify code after code generation has been completed,
41// and after the code has potentially already been executed. This mechanism is
42// used to apply optimizations to the code.
43//
44class RepatchBuffer {
45 typedef MacroAssemblerCodePtr CodePtr;
46
47public:
48 RepatchBuffer(CodeBlock* codeBlock)
49 {
50 JITCode& code = codeBlock->getJITCode();
51 m_start = code.start();
52 m_size = code.size();
53
54 ExecutableAllocator::makeWritable(m_start, m_size);
55 }
56
57 ~RepatchBuffer()
58 {
59 ExecutableAllocator::makeExecutable(m_start, m_size);
60 }
61
62 void relink(CodeLocationJump jump, CodeLocationLabel destination)
63 {
64 MacroAssembler::repatchJump(jump, destination);
65 }
66
67 void relink(CodeLocationCall call, CodeLocationLabel destination)
68 {
69 MacroAssembler::repatchCall(call, destination);
70 }
71
72 void relink(CodeLocationCall call, FunctionPtr destination)
73 {
74 MacroAssembler::repatchCall(call, destination);
75 }
76
77 void relink(CodeLocationNearCall nearCall, CodePtr destination)
78 {
79 MacroAssembler::repatchNearCall(nearCall, destination: CodeLocationLabel(destination));
80 }
81
82 void relink(CodeLocationNearCall nearCall, CodeLocationLabel destination)
83 {
84 MacroAssembler::repatchNearCall(nearCall, destination);
85 }
86
87 void repatch(CodeLocationDataLabel32 dataLabel32, int32_t value)
88 {
89 MacroAssembler::repatchInt32(dataLabel32, value);
90 }
91
92 void repatch(CodeLocationDataLabelPtr dataLabelPtr, void* value)
93 {
94 MacroAssembler::repatchPointer(dataLabelPtr, value);
95 }
96
97 void repatchLoadPtrToLEA(CodeLocationInstruction instruction)
98 {
99 MacroAssembler::repatchLoadPtrToLEA(instruction);
100 }
101
102 void relinkCallerToTrampoline(ReturnAddressPtr returnAddress, CodeLocationLabel label)
103 {
104 relink(call: CodeLocationCall(CodePtr(returnAddress)), destination: label);
105 }
106
107 void relinkCallerToTrampoline(ReturnAddressPtr returnAddress, CodePtr newCalleeFunction)
108 {
109 relinkCallerToTrampoline(returnAddress, label: CodeLocationLabel(newCalleeFunction));
110 }
111
112 void relinkCallerToFunction(ReturnAddressPtr returnAddress, FunctionPtr function)
113 {
114 relink(call: CodeLocationCall(CodePtr(returnAddress)), destination: function);
115 }
116
117 void relinkNearCallerToTrampoline(ReturnAddressPtr returnAddress, CodeLocationLabel label)
118 {
119 relink(nearCall: CodeLocationNearCall(CodePtr(returnAddress)), destination: label);
120 }
121
122 void relinkNearCallerToTrampoline(ReturnAddressPtr returnAddress, CodePtr newCalleeFunction)
123 {
124 relinkNearCallerToTrampoline(returnAddress, label: CodeLocationLabel(newCalleeFunction));
125 }
126
127private:
128 void* m_start;
129 size_t m_size;
130};
131
132} // namespace JSC
133
134#endif // ENABLE(ASSEMBLER)
135
136#endif // RepatchBuffer_h
137

source code of qtscript/src/3rdparty/javascriptcore/JavaScriptCore/assembler/RepatchBuffer.h