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 CodeLocation_h
27#define CodeLocation_h
28
29#include <wtf/Platform.h>
30
31#include <MacroAssemblerCodeRef.h>
32
33#if ENABLE(ASSEMBLER)
34
35namespace JSC {
36
37class CodeLocationInstruction;
38class CodeLocationLabel;
39class CodeLocationJump;
40class CodeLocationCall;
41class CodeLocationNearCall;
42class CodeLocationDataLabel32;
43class CodeLocationDataLabelPtr;
44
45// The CodeLocation* types are all pretty much do-nothing wrappers around
46// CodePtr (or MacroAssemblerCodePtr, to give it its full name). These
47// classes only exist to provide type-safety when linking and patching code.
48//
49// The one new piece of functionallity introduced by these classes is the
50// ability to create (or put another way, to re-discover) another CodeLocation
51// at an offset from one you already know. When patching code to optimize it
52// we often want to patch a number of instructions that are short, fixed
53// offsets apart. To reduce memory overhead we will only retain a pointer to
54// one of the instructions, and we will use the *AtOffset methods provided by
55// CodeLocationCommon to find the other points in the code to modify.
56class CodeLocationCommon : public MacroAssemblerCodePtr {
57public:
58 CodeLocationInstruction instructionAtOffset(int offset);
59 CodeLocationLabel labelAtOffset(int offset);
60 CodeLocationJump jumpAtOffset(int offset);
61 CodeLocationCall callAtOffset(int offset);
62 CodeLocationNearCall nearCallAtOffset(int offset);
63 CodeLocationDataLabelPtr dataLabelPtrAtOffset(int offset);
64 CodeLocationDataLabel32 dataLabel32AtOffset(int offset);
65
66protected:
67 CodeLocationCommon()
68 {
69 }
70
71 CodeLocationCommon(MacroAssemblerCodePtr location)
72 : MacroAssemblerCodePtr(location)
73 {
74 }
75};
76
77class CodeLocationInstruction : public CodeLocationCommon {
78public:
79 CodeLocationInstruction() {}
80 explicit CodeLocationInstruction(MacroAssemblerCodePtr location)
81 : CodeLocationCommon(location) {}
82 explicit CodeLocationInstruction(void* location)
83 : CodeLocationCommon(MacroAssemblerCodePtr(location)) {}
84};
85
86class CodeLocationLabel : public CodeLocationCommon {
87public:
88 CodeLocationLabel() {}
89 explicit CodeLocationLabel(MacroAssemblerCodePtr location)
90 : CodeLocationCommon(location) {}
91 explicit CodeLocationLabel(void* location)
92 : CodeLocationCommon(MacroAssemblerCodePtr(location)) {}
93};
94
95class CodeLocationJump : public CodeLocationCommon {
96public:
97 CodeLocationJump() {}
98 explicit CodeLocationJump(MacroAssemblerCodePtr location)
99 : CodeLocationCommon(location) {}
100 explicit CodeLocationJump(void* location)
101 : CodeLocationCommon(MacroAssemblerCodePtr(location)) {}
102};
103
104class CodeLocationCall : public CodeLocationCommon {
105public:
106 CodeLocationCall() {}
107 explicit CodeLocationCall(MacroAssemblerCodePtr location)
108 : CodeLocationCommon(location) {}
109 explicit CodeLocationCall(void* location)
110 : CodeLocationCommon(MacroAssemblerCodePtr(location)) {}
111};
112
113class CodeLocationNearCall : public CodeLocationCommon {
114public:
115 CodeLocationNearCall() {}
116 explicit CodeLocationNearCall(MacroAssemblerCodePtr location)
117 : CodeLocationCommon(location) {}
118 explicit CodeLocationNearCall(void* location)
119 : CodeLocationCommon(MacroAssemblerCodePtr(location)) {}
120};
121
122class CodeLocationDataLabel32 : public CodeLocationCommon {
123public:
124 CodeLocationDataLabel32() {}
125 explicit CodeLocationDataLabel32(MacroAssemblerCodePtr location)
126 : CodeLocationCommon(location) {}
127 explicit CodeLocationDataLabel32(void* location)
128 : CodeLocationCommon(MacroAssemblerCodePtr(location)) {}
129};
130
131class CodeLocationDataLabelPtr : public CodeLocationCommon {
132public:
133 CodeLocationDataLabelPtr() {}
134 explicit CodeLocationDataLabelPtr(MacroAssemblerCodePtr location)
135 : CodeLocationCommon(location) {}
136 explicit CodeLocationDataLabelPtr(void* location)
137 : CodeLocationCommon(MacroAssemblerCodePtr(location)) {}
138};
139
140inline CodeLocationInstruction CodeLocationCommon::instructionAtOffset(int offset)
141{
142 ASSERT_VALID_CODE_OFFSET(offset);
143 return CodeLocationInstruction(reinterpret_cast<char*>(dataLocation()) + offset);
144}
145
146inline CodeLocationLabel CodeLocationCommon::labelAtOffset(int offset)
147{
148 ASSERT_VALID_CODE_OFFSET(offset);
149 return CodeLocationLabel(reinterpret_cast<char*>(dataLocation()) + offset);
150}
151
152inline CodeLocationJump CodeLocationCommon::jumpAtOffset(int offset)
153{
154 ASSERT_VALID_CODE_OFFSET(offset);
155 return CodeLocationJump(reinterpret_cast<char*>(dataLocation()) + offset);
156}
157
158inline CodeLocationCall CodeLocationCommon::callAtOffset(int offset)
159{
160 ASSERT_VALID_CODE_OFFSET(offset);
161 return CodeLocationCall(reinterpret_cast<char*>(dataLocation()) + offset);
162}
163
164inline CodeLocationNearCall CodeLocationCommon::nearCallAtOffset(int offset)
165{
166 ASSERT_VALID_CODE_OFFSET(offset);
167 return CodeLocationNearCall(reinterpret_cast<char*>(dataLocation()) + offset);
168}
169
170inline CodeLocationDataLabelPtr CodeLocationCommon::dataLabelPtrAtOffset(int offset)
171{
172 ASSERT_VALID_CODE_OFFSET(offset);
173 return CodeLocationDataLabelPtr(reinterpret_cast<char*>(dataLocation()) + offset);
174}
175
176inline CodeLocationDataLabel32 CodeLocationCommon::dataLabel32AtOffset(int offset)
177{
178 ASSERT_VALID_CODE_OFFSET(offset);
179 return CodeLocationDataLabel32(reinterpret_cast<char*>(dataLocation()) + offset);
180}
181
182} // namespace JSC
183
184#endif // ENABLE(ASSEMBLER)
185
186#endif // CodeLocation_h
187

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