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