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
35 namespace JSC {
36
37 class CodeLocationInstruction;
38 class CodeLocationLabel;
39 class CodeLocationJump;
40 class CodeLocationCall;
41 class CodeLocationNearCall;
42 class CodeLocationDataLabel32;
43 class 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.
56 class CodeLocationCommon : public MacroAssemblerCodePtr {
57 public:
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
66 protected:
CodeLocationCommon()67 CodeLocationCommon()
68 {
69 }
70
CodeLocationCommon(MacroAssemblerCodePtr location)71 CodeLocationCommon(MacroAssemblerCodePtr location)
72 : MacroAssemblerCodePtr(location)
73 {
74 }
75 };
76
77 class CodeLocationInstruction : public CodeLocationCommon {
78 public:
CodeLocationInstruction()79 CodeLocationInstruction() {}
CodeLocationInstruction(MacroAssemblerCodePtr location)80 explicit CodeLocationInstruction(MacroAssemblerCodePtr location)
81 : CodeLocationCommon(location) {}
CodeLocationInstruction(void * location)82 explicit CodeLocationInstruction(void* location)
83 : CodeLocationCommon(MacroAssemblerCodePtr(location)) {}
84 };
85
86 class CodeLocationLabel : public CodeLocationCommon {
87 public:
CodeLocationLabel()88 CodeLocationLabel() {}
CodeLocationLabel(MacroAssemblerCodePtr location)89 explicit CodeLocationLabel(MacroAssemblerCodePtr location)
90 : CodeLocationCommon(location) {}
CodeLocationLabel(void * location)91 explicit CodeLocationLabel(void* location)
92 : CodeLocationCommon(MacroAssemblerCodePtr(location)) {}
93 };
94
95 class CodeLocationJump : public CodeLocationCommon {
96 public:
CodeLocationJump()97 CodeLocationJump() {}
CodeLocationJump(MacroAssemblerCodePtr location)98 explicit CodeLocationJump(MacroAssemblerCodePtr location)
99 : CodeLocationCommon(location) {}
CodeLocationJump(void * location)100 explicit CodeLocationJump(void* location)
101 : CodeLocationCommon(MacroAssemblerCodePtr(location)) {}
102 };
103
104 class CodeLocationCall : public CodeLocationCommon {
105 public:
CodeLocationCall()106 CodeLocationCall() {}
CodeLocationCall(MacroAssemblerCodePtr location)107 explicit CodeLocationCall(MacroAssemblerCodePtr location)
108 : CodeLocationCommon(location) {}
CodeLocationCall(void * location)109 explicit CodeLocationCall(void* location)
110 : CodeLocationCommon(MacroAssemblerCodePtr(location)) {}
111 };
112
113 class CodeLocationNearCall : public CodeLocationCommon {
114 public:
CodeLocationNearCall()115 CodeLocationNearCall() {}
CodeLocationNearCall(MacroAssemblerCodePtr location)116 explicit CodeLocationNearCall(MacroAssemblerCodePtr location)
117 : CodeLocationCommon(location) {}
CodeLocationNearCall(void * location)118 explicit CodeLocationNearCall(void* location)
119 : CodeLocationCommon(MacroAssemblerCodePtr(location)) {}
120 };
121
122 class CodeLocationDataLabel32 : public CodeLocationCommon {
123 public:
CodeLocationDataLabel32()124 CodeLocationDataLabel32() {}
CodeLocationDataLabel32(MacroAssemblerCodePtr location)125 explicit CodeLocationDataLabel32(MacroAssemblerCodePtr location)
126 : CodeLocationCommon(location) {}
CodeLocationDataLabel32(void * location)127 explicit CodeLocationDataLabel32(void* location)
128 : CodeLocationCommon(MacroAssemblerCodePtr(location)) {}
129 };
130
131 class CodeLocationDataLabelPtr : public CodeLocationCommon {
132 public:
CodeLocationDataLabelPtr()133 CodeLocationDataLabelPtr() {}
CodeLocationDataLabelPtr(MacroAssemblerCodePtr location)134 explicit CodeLocationDataLabelPtr(MacroAssemblerCodePtr location)
135 : CodeLocationCommon(location) {}
CodeLocationDataLabelPtr(void * location)136 explicit CodeLocationDataLabelPtr(void* location)
137 : CodeLocationCommon(MacroAssemblerCodePtr(location)) {}
138 };
139
instructionAtOffset(int offset)140 inline CodeLocationInstruction CodeLocationCommon::instructionAtOffset(int offset)
141 {
142 ASSERT_VALID_CODE_OFFSET(offset);
143 return CodeLocationInstruction(reinterpret_cast<char*>(dataLocation()) + offset);
144 }
145
labelAtOffset(int offset)146 inline CodeLocationLabel CodeLocationCommon::labelAtOffset(int offset)
147 {
148 ASSERT_VALID_CODE_OFFSET(offset);
149 return CodeLocationLabel(reinterpret_cast<char*>(dataLocation()) + offset);
150 }
151
jumpAtOffset(int offset)152 inline CodeLocationJump CodeLocationCommon::jumpAtOffset(int offset)
153 {
154 ASSERT_VALID_CODE_OFFSET(offset);
155 return CodeLocationJump(reinterpret_cast<char*>(dataLocation()) + offset);
156 }
157
callAtOffset(int offset)158 inline CodeLocationCall CodeLocationCommon::callAtOffset(int offset)
159 {
160 ASSERT_VALID_CODE_OFFSET(offset);
161 return CodeLocationCall(reinterpret_cast<char*>(dataLocation()) + offset);
162 }
163
nearCallAtOffset(int offset)164 inline CodeLocationNearCall CodeLocationCommon::nearCallAtOffset(int offset)
165 {
166 ASSERT_VALID_CODE_OFFSET(offset);
167 return CodeLocationNearCall(reinterpret_cast<char*>(dataLocation()) + offset);
168 }
169
dataLabelPtrAtOffset(int offset)170 inline CodeLocationDataLabelPtr CodeLocationCommon::dataLabelPtrAtOffset(int offset)
171 {
172 ASSERT_VALID_CODE_OFFSET(offset);
173 return CodeLocationDataLabelPtr(reinterpret_cast<char*>(dataLocation()) + offset);
174 }
175
dataLabel32AtOffset(int offset)176 inline 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