1 | /* |
2 | * Copyright (C) 1999-2000 Harri Porten (porten@kde.org) |
3 | * Copyright (C) 2003, 2006, 2007, 2008, 2009 Apple Inc. All rights reserved. |
4 | * |
5 | * This library is free software; you can redistribute it and/or |
6 | * modify it under the terms of the GNU Lesser General Public |
7 | * License as published by the Free Software Foundation; either |
8 | * version 2 of the License, or (at your option) any later version. |
9 | * |
10 | * This library is distributed in the hope that it will be useful, |
11 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
12 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
13 | * Lesser General Public License for more details. |
14 | * |
15 | * You should have received a copy of the GNU Lesser General Public |
16 | * License along with this library; if not, write to the Free Software |
17 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
18 | * |
19 | */ |
20 | |
21 | #ifndef Lookup_h |
22 | #define Lookup_h |
23 | |
24 | #include "CallFrame.h" |
25 | #include "Identifier.h" |
26 | #include "JSGlobalObject.h" |
27 | #include "JSObject.h" |
28 | #include "PropertySlot.h" |
29 | #include <stdio.h> |
30 | #include <wtf/Assertions.h> |
31 | |
32 | // Bug #26843: Work around Metrowerks compiler bug |
33 | #if COMPILER(WINSCW) |
34 | #define JSC_CONST_HASHTABLE |
35 | #else |
36 | #define JSC_CONST_HASHTABLE const |
37 | #endif |
38 | |
39 | namespace JSC { |
40 | |
41 | // Hash table generated by the create_hash_table script. |
42 | struct HashTableValue { |
43 | const char* key; // property name |
44 | unsigned char attributes; // JSObject attributes |
45 | intptr_t value1; |
46 | intptr_t value2; |
47 | }; |
48 | |
49 | // FIXME: There is no reason this get function can't be simpler. |
50 | // ie. typedef JSValue (*GetFunction)(ExecState*, JSObject* baseObject) |
51 | typedef PropertySlot::GetValueFunc GetFunction; |
52 | typedef void (*PutFunction)(ExecState*, JSObject* baseObject, JSValue value); |
53 | |
54 | class HashEntry : public FastAllocBase { |
55 | public: |
56 | void initialize(UString::Rep* key, unsigned char attributes, intptr_t v1, intptr_t v2) |
57 | { |
58 | m_key = key; |
59 | m_attributes = attributes; |
60 | m_u.store.value1 = v1; |
61 | m_u.store.value2 = v2; |
62 | m_next = 0; |
63 | } |
64 | |
65 | void setKey(UString::Rep* key) { m_key = key; } |
66 | UString::Rep* key() const { return m_key; } |
67 | |
68 | unsigned char attributes() const { return m_attributes; } |
69 | |
70 | NativeFunction function() const { ASSERT(m_attributes & Function); return m_u.function.functionValue; } |
71 | unsigned char functionLength() const { ASSERT(m_attributes & Function); return static_cast<unsigned char>(m_u.function.length); } |
72 | |
73 | GetFunction propertyGetter() const { ASSERT(!(m_attributes & Function)); return m_u.property.get; } |
74 | PutFunction propertyPutter() const { ASSERT(!(m_attributes & Function)); return m_u.property.put; } |
75 | |
76 | intptr_t lexerValue() const { ASSERT(!m_attributes); return m_u.lexer.value; } |
77 | |
78 | void setNext(HashEntry *next) { m_next = next; } |
79 | HashEntry* next() const { return m_next; } |
80 | |
81 | private: |
82 | UString::Rep* m_key; |
83 | unsigned char m_attributes; // JSObject attributes |
84 | |
85 | union { |
86 | struct { |
87 | intptr_t value1; |
88 | intptr_t value2; |
89 | } store; |
90 | struct { |
91 | NativeFunction functionValue; |
92 | intptr_t length; // number of arguments for function |
93 | } function; |
94 | struct { |
95 | GetFunction get; |
96 | PutFunction put; |
97 | } property; |
98 | struct { |
99 | intptr_t value; |
100 | intptr_t unused; |
101 | } lexer; |
102 | } m_u; |
103 | |
104 | HashEntry* m_next; |
105 | }; |
106 | |
107 | struct HashTable { |
108 | |
109 | int compactSize; |
110 | int compactHashSizeMask; |
111 | |
112 | const HashTableValue* values; // Fixed values generated by script. |
113 | mutable const HashEntry* table; // Table allocated at runtime. |
114 | |
115 | ALWAYS_INLINE void initializeIfNeeded(JSGlobalData* globalData) const |
116 | { |
117 | if (!table) |
118 | createTable(globalData); |
119 | } |
120 | |
121 | ALWAYS_INLINE void initializeIfNeeded(ExecState* exec) const |
122 | { |
123 | if (!table) |
124 | createTable(&exec->globalData()); |
125 | } |
126 | |
127 | void deleteTable() const; |
128 | |
129 | // Find an entry in the table, and return the entry. |
130 | ALWAYS_INLINE const HashEntry* entry(JSGlobalData* globalData, const Identifier& identifier) const |
131 | { |
132 | initializeIfNeeded(globalData); |
133 | return entry(identifier); |
134 | } |
135 | |
136 | ALWAYS_INLINE const HashEntry* entry(ExecState* exec, const Identifier& identifier) const |
137 | { |
138 | initializeIfNeeded(exec); |
139 | return entry(identifier); |
140 | } |
141 | |
142 | private: |
143 | ALWAYS_INLINE const HashEntry* entry(const Identifier& identifier) const |
144 | { |
145 | ASSERT(table); |
146 | |
147 | const HashEntry* entry = &table[identifier.ustring().rep()->existingHash() & compactHashSizeMask]; |
148 | |
149 | if (!entry->key()) |
150 | return 0; |
151 | |
152 | do { |
153 | if (entry->key() == identifier.ustring().rep()) |
154 | return entry; |
155 | entry = entry->next(); |
156 | } while (entry); |
157 | |
158 | return 0; |
159 | } |
160 | |
161 | // Convert the hash table keys to identifiers. |
162 | void createTable(JSGlobalData*) const; |
163 | }; |
164 | |
165 | void setUpStaticFunctionSlot(ExecState*, const HashEntry*, JSObject* thisObject, const Identifier& propertyName, PropertySlot&); |
166 | |
167 | /** |
168 | * This method does it all (looking in the hashtable, checking for function |
169 | * overrides, creating the function or retrieving from cache, calling |
170 | * getValueProperty in case of a non-function property, forwarding to parent if |
171 | * unknown property). |
172 | */ |
173 | template <class ThisImp, class ParentImp> |
174 | inline bool getStaticPropertySlot(ExecState* exec, const HashTable* table, ThisImp* thisObj, const Identifier& propertyName, PropertySlot& slot) |
175 | { |
176 | const HashEntry* entry = table->entry(exec, identifier: propertyName); |
177 | |
178 | if (!entry) // not found, forward to parent |
179 | return thisObj->ParentImp::getOwnPropertySlot(exec, propertyName, slot); |
180 | |
181 | if (entry->attributes() & Function) |
182 | setUpStaticFunctionSlot(exec, entry, thisObj, propertyName, slot); |
183 | else |
184 | slot.setCustom(slotBase: thisObj, getValue: entry->propertyGetter()); |
185 | |
186 | return true; |
187 | } |
188 | |
189 | template <class ThisImp, class ParentImp> |
190 | inline bool getStaticPropertyDescriptor(ExecState* exec, const HashTable* table, ThisImp* thisObj, const Identifier& propertyName, PropertyDescriptor& descriptor) |
191 | { |
192 | const HashEntry* entry = table->entry(exec, identifier: propertyName); |
193 | |
194 | if (!entry) // not found, forward to parent |
195 | return thisObj->ParentImp::getOwnPropertyDescriptor(exec, propertyName, descriptor); |
196 | |
197 | PropertySlot slot; |
198 | if (entry->attributes() & Function) |
199 | setUpStaticFunctionSlot(exec, entry, thisObj, propertyName, slot); |
200 | else |
201 | slot.setCustom(slotBase: thisObj, getValue: entry->propertyGetter()); |
202 | |
203 | descriptor.setDescriptor(value: slot.getValue(exec, propertyName), attributes: entry->attributes()); |
204 | return true; |
205 | } |
206 | |
207 | /** |
208 | * Simplified version of getStaticPropertySlot in case there are only functions. |
209 | * Using this instead of getStaticPropertySlot allows 'this' to avoid implementing |
210 | * a dummy getValueProperty. |
211 | */ |
212 | template <class ParentImp> |
213 | inline bool getStaticFunctionSlot(ExecState* exec, const HashTable* table, JSObject* thisObj, const Identifier& propertyName, PropertySlot& slot) |
214 | { |
215 | if (static_cast<ParentImp*>(thisObj)->ParentImp::getOwnPropertySlot(exec, propertyName, slot)) |
216 | return true; |
217 | |
218 | const HashEntry* entry = table->entry(exec, identifier: propertyName); |
219 | if (!entry) |
220 | return false; |
221 | |
222 | setUpStaticFunctionSlot(exec, entry, thisObject: thisObj, propertyName, slot); |
223 | return true; |
224 | } |
225 | |
226 | /** |
227 | * Simplified version of getStaticPropertyDescriptor in case there are only functions. |
228 | * Using this instead of getStaticPropertyDescriptor allows 'this' to avoid implementing |
229 | * a dummy getValueProperty. |
230 | */ |
231 | template <class ParentImp> |
232 | inline bool getStaticFunctionDescriptor(ExecState* exec, const HashTable* table, JSObject* thisObj, const Identifier& propertyName, PropertyDescriptor& descriptor) |
233 | { |
234 | if (static_cast<ParentImp*>(thisObj)->ParentImp::getOwnPropertyDescriptor(exec, propertyName, descriptor)) |
235 | return true; |
236 | |
237 | const HashEntry* entry = table->entry(exec, identifier: propertyName); |
238 | if (!entry) |
239 | return false; |
240 | |
241 | PropertySlot slot; |
242 | setUpStaticFunctionSlot(exec, entry, thisObject: thisObj, propertyName, slot); |
243 | descriptor.setDescriptor(value: slot.getValue(exec, propertyName), attributes: entry->attributes()); |
244 | return true; |
245 | } |
246 | |
247 | /** |
248 | * Simplified version of getStaticPropertySlot in case there are no functions, only "values". |
249 | * Using this instead of getStaticPropertySlot removes the need for a FuncImp class. |
250 | */ |
251 | template <class ThisImp, class ParentImp> |
252 | inline bool getStaticValueSlot(ExecState* exec, const HashTable* table, ThisImp* thisObj, const Identifier& propertyName, PropertySlot& slot) |
253 | { |
254 | const HashEntry* entry = table->entry(exec, identifier: propertyName); |
255 | |
256 | if (!entry) // not found, forward to parent |
257 | return thisObj->ParentImp::getOwnPropertySlot(exec, propertyName, slot); |
258 | |
259 | ASSERT(!(entry->attributes() & Function)); |
260 | |
261 | slot.setCustom(slotBase: thisObj, getValue: entry->propertyGetter()); |
262 | return true; |
263 | } |
264 | |
265 | /** |
266 | * Simplified version of getStaticPropertyDescriptor in case there are no functions, only "values". |
267 | * Using this instead of getStaticPropertyDescriptor removes the need for a FuncImp class. |
268 | */ |
269 | template <class ThisImp, class ParentImp> |
270 | inline bool getStaticValueDescriptor(ExecState* exec, const HashTable* table, ThisImp* thisObj, const Identifier& propertyName, PropertyDescriptor& descriptor) |
271 | { |
272 | const HashEntry* entry = table->entry(exec, identifier: propertyName); |
273 | |
274 | if (!entry) // not found, forward to parent |
275 | return thisObj->ParentImp::getOwnPropertyDescriptor(exec, propertyName, descriptor); |
276 | |
277 | ASSERT(!(entry->attributes() & Function)); |
278 | PropertySlot slot; |
279 | slot.setCustom(slotBase: thisObj, getValue: entry->propertyGetter()); |
280 | descriptor.setDescriptor(value: slot.getValue(exec, propertyName), attributes: entry->attributes()); |
281 | return true; |
282 | } |
283 | |
284 | /** |
285 | * This one is for "put". |
286 | * It looks up a hash entry for the property to be set. If an entry |
287 | * is found it sets the value and returns true, else it returns false. |
288 | */ |
289 | template <class ThisImp> |
290 | inline bool lookupPut(ExecState* exec, const Identifier& propertyName, JSValue value, const HashTable* table, ThisImp* thisObj) |
291 | { |
292 | const HashEntry* entry = table->entry(exec, identifier: propertyName); |
293 | |
294 | if (!entry) |
295 | return false; |
296 | |
297 | if (entry->attributes() & Function) { // function: put as override property |
298 | if (LIKELY(value.isCell())) |
299 | thisObj->putDirectFunction(propertyName, value.asCell()); |
300 | else |
301 | thisObj->putDirect(propertyName, value); |
302 | } else if (!(entry->attributes() & ReadOnly)) |
303 | entry->propertyPutter()(exec, thisObj, value); |
304 | |
305 | return true; |
306 | } |
307 | |
308 | /** |
309 | * This one is for "put". |
310 | * It calls lookupPut<ThisImp>() to set the value. If that call |
311 | * returns false (meaning no entry in the hash table was found), |
312 | * then it calls put() on the ParentImp class. |
313 | */ |
314 | template <class ThisImp, class ParentImp> |
315 | inline void lookupPut(ExecState* exec, const Identifier& propertyName, JSValue value, const HashTable* table, ThisImp* thisObj, PutPropertySlot& slot) |
316 | { |
317 | if (!lookupPut<ThisImp>(exec, propertyName, value, table, thisObj)) |
318 | thisObj->ParentImp::put(exec, propertyName, value, slot); // not found: forward to parent |
319 | } |
320 | |
321 | } // namespace JSC |
322 | |
323 | #endif // Lookup_h |
324 | |