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 CPU(ARM_THUMB2) |
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 | #if COMPILER(RVCT) |
73 | // RVTC compiler needs C-style cast as it fails with the following error |
74 | // Error: #694: reinterpret_cast cannot cast away const or other type qualifiers |
75 | : m_value((void*)(value)) |
76 | #else |
77 | : m_value(reinterpret_cast<void*>(value)) |
78 | #endif |
79 | { |
80 | ASSERT_VALID_CODE_POINTER(m_value); |
81 | } |
82 | |
83 | void* value() const { return m_value; } |
84 | void* executableAddress() const { return m_value; } |
85 | |
86 | |
87 | private: |
88 | void* m_value; |
89 | }; |
90 | |
91 | // ReturnAddressPtr: |
92 | // |
93 | // ReturnAddressPtr should be used to wrap return addresses generated by processor |
94 | // 'call' instructions exectued in JIT code. We use return addresses to look up |
95 | // exception and optimization information, and to repatch the call instruction |
96 | // that is the source of the return address. |
97 | class ReturnAddressPtr { |
98 | public: |
99 | ReturnAddressPtr() |
100 | : m_value(0) |
101 | { |
102 | } |
103 | |
104 | explicit ReturnAddressPtr(void* value) |
105 | : m_value(value) |
106 | { |
107 | ASSERT_VALID_CODE_POINTER(m_value); |
108 | } |
109 | |
110 | explicit ReturnAddressPtr(FunctionPtr function) |
111 | : m_value(function.value()) |
112 | { |
113 | ASSERT_VALID_CODE_POINTER(m_value); |
114 | } |
115 | |
116 | void* value() const { return m_value; } |
117 | |
118 | private: |
119 | void* m_value; |
120 | }; |
121 | |
122 | // MacroAssemblerCodePtr: |
123 | // |
124 | // MacroAssemblerCodePtr should be used to wrap pointers to JIT generated code. |
125 | class MacroAssemblerCodePtr { |
126 | public: |
127 | MacroAssemblerCodePtr() |
128 | : m_value(0) |
129 | { |
130 | } |
131 | |
132 | explicit MacroAssemblerCodePtr(void* value) |
133 | #if CPU(ARM_THUMB2) |
134 | // Decorate the pointer as a thumb code pointer. |
135 | : m_value(reinterpret_cast<char*>(value) + 1) |
136 | #else |
137 | : m_value(value) |
138 | #endif |
139 | { |
140 | ASSERT_VALID_CODE_POINTER(m_value); |
141 | } |
142 | |
143 | explicit MacroAssemblerCodePtr(ReturnAddressPtr ra) |
144 | : m_value(ra.value()) |
145 | { |
146 | ASSERT_VALID_CODE_POINTER(m_value); |
147 | } |
148 | |
149 | void* executableAddress() const { return m_value; } |
150 | #if CPU(ARM_THUMB2) |
151 | // To use this pointer as a data address remove the decoration. |
152 | void* dataLocation() const { ASSERT_VALID_CODE_POINTER(m_value); return reinterpret_cast<char*>(m_value) - 1; } |
153 | #else |
154 | void* dataLocation() const { ASSERT_VALID_CODE_POINTER(m_value); return m_value; } |
155 | #endif |
156 | |
157 | bool operator!() |
158 | { |
159 | return !m_value; |
160 | } |
161 | |
162 | private: |
163 | void* m_value; |
164 | }; |
165 | |
166 | // MacroAssemblerCodeRef: |
167 | // |
168 | // A reference to a section of JIT generated code. A CodeRef consists of a |
169 | // pointer to the code, and a ref pointer to the pool from within which it |
170 | // was allocated. |
171 | class MacroAssemblerCodeRef { |
172 | public: |
173 | MacroAssemblerCodeRef() |
174 | : m_size(0) |
175 | { |
176 | } |
177 | |
178 | MacroAssemblerCodeRef(void* code, PassRefPtr<ExecutablePool> executablePool, size_t size) |
179 | : m_code(code) |
180 | , m_executablePool(executablePool) |
181 | , m_size(size) |
182 | { |
183 | } |
184 | |
185 | MacroAssemblerCodePtr m_code; |
186 | RefPtr<ExecutablePool> m_executablePool; |
187 | size_t m_size; |
188 | }; |
189 | |
190 | } // namespace JSC |
191 | |
192 | #endif // ENABLE(ASSEMBLER) |
193 | |
194 | #endif // MacroAssemblerCodeRef_h |
195 | |