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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 MacroAssemblerCodeRef_h | |
27 | #define MacroAssemblerCodeRef_h | |
28 | ||
29 | #include <wtf/Platform.h> | |
30 | ||
31 | #include "ExecutableAllocator.h" | |
32 | #include "PassRefPtr.h" | |
33 | #include "RefPtr.h" | |
34 | #include "UnusedParam.h" | |
35 | ||
36 | #if ENABLE(ASSEMBLER) | |
37 | ||
38 | // ASSERT_VALID_CODE_POINTER checks that ptr is a non-null pointer, and that it is a valid | |
39 | // instruction address on the platform (for example, check any alignment requirements). | |
40 | #if PLATFORM_ARM_ARCH(7) | |
41 | // ARM/thumb instructions must be 16-bit aligned, but all code pointers to be loaded | |
42 | // into the processor are decorated with the bottom bit set, indicating that this is | |
43 | // thumb code (as oposed to 32-bit traditional ARM). The first test checks for both | |
44 | // decorated and undectorated null, and the second test ensures that the pointer is | |
45 | // decorated. | |
46 | #define ASSERT_VALID_CODE_POINTER(ptr) \ | |
47 | ASSERT(reinterpret_cast<intptr_t>(ptr) & ~1); \ | |
48 | ASSERT(reinterpret_cast<intptr_t>(ptr) & 1) | |
49 | #define ASSERT_VALID_CODE_OFFSET(offset) \ | |
50 | ASSERT(!(offset & 1)) // Must be multiple of 2. | |
51 | #else | |
52 | #define ASSERT_VALID_CODE_POINTER(ptr) \ | |
53 | ASSERT(ptr) | |
54 | #define ASSERT_VALID_CODE_OFFSET(offset) // Anything goes! | |
55 | #endif | |
56 | ||
57 | namespace JSC { | |
58 | ||
59 | // FunctionPtr: | |
60 | // | |
61 | // FunctionPtr should be used to wrap pointers to C/C++ functions in JSC | |
62 | // (particularly, the stub functions). | |
63 | class FunctionPtr { | |
64 | public: | |
65 | FunctionPtr() | |
66 | : m_value(0) | |
67 | { | |
68 | } | |
69 | ||
70 | template<typename FunctionType> | |
71 | explicit FunctionPtr(FunctionType* value) | |
72 | : m_value(reinterpret_cast<void*>(value)) | |
73 | { | |
74 | ASSERT_VALID_CODE_POINTER(m_value); | |
75 | } | |
76 | ||
77 | void* value() const { return m_value; } | |
78 | void* executableAddress() const { return m_value; } | |
79 | ||
80 | ||
81 | private: | |
82 | void* m_value; | |
83 | }; | |
84 | ||
85 | // ReturnAddressPtr: | |
86 | // | |
87 | // ReturnAddressPtr should be used to wrap return addresses generated by processor | |
88 | // 'call' instructions exectued in JIT code. We use return addresses to look up | |
89 | // exception and optimization information, and to repatch the call instruction | |
90 | // that is the source of the return address. | |
91 | class ReturnAddressPtr { | |
92 | public: | |
93 | ReturnAddressPtr() | |
94 | : m_value(0) | |
95 | { | |
96 | } | |
97 | ||
98 | explicit ReturnAddressPtr(void* value) | |
99 | : m_value(value) | |
100 | { | |
101 | ASSERT_VALID_CODE_POINTER(m_value); | |
102 | } | |
103 | ||
104 | explicit ReturnAddressPtr(FunctionPtr function) | |
105 | : m_value(function.value()) | |
106 | { | |
107 | ASSERT_VALID_CODE_POINTER(m_value); | |
108 | } | |
109 | ||
110 | void* value() const { return m_value; } | |
111 | ||
112 | private: | |
113 | void* m_value; | |
114 | }; | |
115 | ||
116 | // MacroAssemblerCodePtr: | |
117 | // | |
118 | // MacroAssemblerCodePtr should be used to wrap pointers to JIT generated code. | |
119 | class MacroAssemblerCodePtr { | |
120 | public: | |
121 | MacroAssemblerCodePtr() | |
122 | : m_value(0) | |
123 | { | |
124 | } | |
125 | ||
126 | explicit MacroAssemblerCodePtr(void* value) | |
127 | #if PLATFORM_ARM_ARCH(7) | |
128 | // Decorate the pointer as a thumb code pointer. | |
129 | : m_value(reinterpret_cast<char*>(value) + 1) | |
130 | #else | |
131 | : m_value(value) | |
132 | #endif | |
133 | { | |
134 | ASSERT_VALID_CODE_POINTER(m_value); | |
135 | } | |
136 | ||
137 | explicit MacroAssemblerCodePtr(ReturnAddressPtr ra) | |
138 | : m_value(ra.value()) | |
139 | { | |
140 | ASSERT_VALID_CODE_POINTER(m_value); | |
141 | } | |
142 | ||
143 | void* executableAddress() const { return m_value; } | |
144 | #if PLATFORM_ARM_ARCH(7) | |
145 | // To use this pointer as a data address remove the decoration. | |
146 | void* dataLocation() const { ASSERT_VALID_CODE_POINTER(m_value); return reinterpret_cast<char*>(m_value) - 1; } | |
147 | #else | |
148 | void* dataLocation() const { ASSERT_VALID_CODE_POINTER(m_value); return m_value; } | |
149 | #endif | |
150 | ||
151 | bool operator!() | |
152 | { | |
153 | return !m_value; | |
154 | } | |
155 | ||
156 | private: | |
157 | void* m_value; | |
158 | }; | |
159 | ||
160 | // MacroAssemblerCodeRef: | |
161 | // | |
162 | // A reference to a section of JIT generated code. A CodeRef consists of a | |
163 | // pointer to the code, and a ref pointer to the pool from within which it | |
164 | // was allocated. | |
165 | class MacroAssemblerCodeRef { | |
166 | public: | |
167 | MacroAssemblerCodeRef() | |
168 | : m_size(0) | |
169 | { | |
170 | } | |
171 | ||
172 | MacroAssemblerCodeRef(void* code, PassRefPtr<ExecutablePool> executablePool, size_t size) | |
173 | : m_code(code) | |
174 | , m_executablePool(executablePool) | |
175 | , m_size(size) | |
176 | { | |
177 | } | |
178 | ||
179 | MacroAssemblerCodePtr m_code; | |
180 | RefPtr<ExecutablePool> m_executablePool; | |
181 | size_t m_size; | |
182 | }; | |
183 | ||
184 | } // namespace JSC | |
185 | ||
186 | #endif // ENABLE(ASSEMBLER) | |
187 | ||
188 | #endif // MacroAssemblerCodeRef_h |