1 | /* |
2 | * Copyright (C) 2005, 2007, 2008 Apple Inc. All rights reserved. |
3 | * |
4 | * This library is free software; you can redistribute it and/or |
5 | * modify it under the terms of the GNU Library General Public |
6 | * License as published by the Free Software Foundation; either |
7 | * version 2 of the License, or (at your option) any later version. |
8 | * |
9 | * This library is distributed in the hope that it will be useful, |
10 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
11 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
12 | * Library General Public License for more details. |
13 | * |
14 | * You should have received a copy of the GNU Library General Public License |
15 | * along with this library; see the file COPYING.LIB. If not, write to |
16 | * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, |
17 | * Boston, MA 02110-1301, USA. |
18 | * |
19 | */ |
20 | |
21 | #ifndef PropertySlot_h |
22 | #define PropertySlot_h |
23 | |
24 | #include "Identifier.h" |
25 | #include "JSValue.h" |
26 | #include "Register.h" |
27 | #include <wtf/Assertions.h> |
28 | #include <wtf/NotFound.h> |
29 | |
30 | namespace JSC { |
31 | |
32 | class ExecState; |
33 | class JSObject; |
34 | |
35 | #define JSC_VALUE_SLOT_MARKER 0 |
36 | #define JSC_REGISTER_SLOT_MARKER reinterpret_cast<GetValueFunc>(1) |
37 | |
38 | class PropertySlot { |
39 | public: |
40 | PropertySlot() |
41 | { |
42 | clearBase(); |
43 | clearOffset(); |
44 | clearValue(); |
45 | } |
46 | |
47 | explicit PropertySlot(const JSValue base) |
48 | : m_slotBase(base) |
49 | { |
50 | clearOffset(); |
51 | clearValue(); |
52 | } |
53 | |
54 | typedef JSValue (*GetValueFunc)(ExecState*, const Identifier&, const PropertySlot&); |
55 | |
56 | JSValue getValue(ExecState* exec, const Identifier& propertyName) const |
57 | { |
58 | if (m_getValue == JSC_VALUE_SLOT_MARKER) |
59 | return *m_data.valueSlot; |
60 | if (m_getValue == JSC_REGISTER_SLOT_MARKER) |
61 | return (*m_data.registerSlot).jsValue(); |
62 | return m_getValue(exec, propertyName, *this); |
63 | } |
64 | |
65 | JSValue getValue(ExecState* exec, unsigned propertyName) const |
66 | { |
67 | if (m_getValue == JSC_VALUE_SLOT_MARKER) |
68 | return *m_data.valueSlot; |
69 | if (m_getValue == JSC_REGISTER_SLOT_MARKER) |
70 | return (*m_data.registerSlot).jsValue(); |
71 | return m_getValue(exec, Identifier::from(exec, y: propertyName), *this); |
72 | } |
73 | |
74 | bool isCacheable() const { return m_offset != WTF::notFound; } |
75 | size_t cachedOffset() const |
76 | { |
77 | ASSERT(isCacheable()); |
78 | return m_offset; |
79 | } |
80 | |
81 | void setValueSlot(JSValue* valueSlot) |
82 | { |
83 | ASSERT(valueSlot); |
84 | clearBase(); |
85 | clearOffset(); |
86 | m_getValue = JSC_VALUE_SLOT_MARKER; |
87 | m_data.valueSlot = valueSlot; |
88 | } |
89 | |
90 | void setValueSlot(JSValue slotBase, JSValue* valueSlot) |
91 | { |
92 | ASSERT(valueSlot); |
93 | m_getValue = JSC_VALUE_SLOT_MARKER; |
94 | m_slotBase = slotBase; |
95 | m_data.valueSlot = valueSlot; |
96 | } |
97 | |
98 | void setValueSlot(JSValue slotBase, JSValue* valueSlot, size_t offset) |
99 | { |
100 | ASSERT(valueSlot); |
101 | m_getValue = JSC_VALUE_SLOT_MARKER; |
102 | m_slotBase = slotBase; |
103 | m_data.valueSlot = valueSlot; |
104 | m_offset = offset; |
105 | } |
106 | |
107 | void setValue(JSValue value) |
108 | { |
109 | ASSERT(value); |
110 | clearBase(); |
111 | clearOffset(); |
112 | m_getValue = JSC_VALUE_SLOT_MARKER; |
113 | m_value = value; |
114 | m_data.valueSlot = &m_value; |
115 | } |
116 | |
117 | void setRegisterSlot(Register* registerSlot) |
118 | { |
119 | ASSERT(registerSlot); |
120 | clearBase(); |
121 | clearOffset(); |
122 | m_getValue = JSC_REGISTER_SLOT_MARKER; |
123 | m_data.registerSlot = registerSlot; |
124 | } |
125 | |
126 | void setCustom(JSValue slotBase, GetValueFunc getValue) |
127 | { |
128 | ASSERT(slotBase); |
129 | ASSERT(getValue); |
130 | m_getValue = getValue; |
131 | m_slotBase = slotBase; |
132 | } |
133 | |
134 | void setCustomIndex(JSValue slotBase, unsigned index, GetValueFunc getValue) |
135 | { |
136 | ASSERT(slotBase); |
137 | ASSERT(getValue); |
138 | m_getValue = getValue; |
139 | m_slotBase = slotBase; |
140 | m_data.index = index; |
141 | } |
142 | |
143 | void setGetterSlot(JSObject* getterFunc) |
144 | { |
145 | ASSERT(getterFunc); |
146 | m_getValue = functionGetter; |
147 | m_data.getterFunc = getterFunc; |
148 | } |
149 | |
150 | void setUndefined() |
151 | { |
152 | setValue(jsUndefined()); |
153 | } |
154 | |
155 | JSValue slotBase() const |
156 | { |
157 | return m_slotBase; |
158 | } |
159 | |
160 | void setBase(JSValue base) |
161 | { |
162 | ASSERT(m_slotBase); |
163 | ASSERT(base); |
164 | m_slotBase = base; |
165 | } |
166 | |
167 | void clearBase() |
168 | { |
169 | #ifndef NDEBUG |
170 | m_slotBase = JSValue(); |
171 | #endif |
172 | } |
173 | |
174 | void clearValue() |
175 | { |
176 | #ifndef NDEBUG |
177 | m_value = JSValue(); |
178 | #endif |
179 | } |
180 | |
181 | void clearOffset() |
182 | { |
183 | // Clear offset even in release builds, in case this PropertySlot has been used before. |
184 | // (For other data members, we don't need to clear anything because reuse would meaningfully overwrite them.) |
185 | m_offset = WTF::notFound; |
186 | } |
187 | |
188 | unsigned index() const { return m_data.index; } |
189 | |
190 | private: |
191 | static JSValue functionGetter(ExecState*, const Identifier&, const PropertySlot&); |
192 | |
193 | GetValueFunc m_getValue; |
194 | |
195 | JSValue m_slotBase; |
196 | union { |
197 | JSObject* getterFunc; |
198 | JSValue* valueSlot; |
199 | Register* registerSlot; |
200 | unsigned index; |
201 | } m_data; |
202 | |
203 | JSValue m_value; |
204 | |
205 | size_t m_offset; |
206 | }; |
207 | |
208 | } // namespace JSC |
209 | |
210 | #endif // PropertySlot_h |
211 | |