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 "BatchedTransitionOptimizer.h" 25#include "CallFrame.h" 26#include "CustomGetterSetter.h" 27#include "Identifier.h" 28#include "IdentifierInlines.h" 29#include "Intrinsic.h" 30#include "JSGlobalObject.h" 31#include "PropertySlot.h" 32#include "PutPropertySlot.h" 33#include <wtf/Assertions.h> 34 35namespace JSC { 36 struct CompactHashIndex { 37 const int16_t value; 38 const int16_t next; 39 }; 40 41 // FIXME: There is no reason this get function can't be simpler. 42 // ie. typedef JSValue (*GetFunction)(ExecState*, JSObject* baseObject) 43 typedef PropertySlot::GetValueFunc GetFunction; 44 typedef PutPropertySlot::PutValueFunc PutFunction; 45 typedef FunctionExecutable* (*BuiltinGenerator)(VM&); 46 47 // Hash table generated by the create_hash_table script. 48 struct HashTableValue { 49 const char* m_key; // property name 50 unsigned m_attributes; // JSObject attributes 51 Intrinsic m_intrinsic; 52 intptr_t m_value1; 53 intptr_t m_value2; 54 55 unsigned attributes() const { return m_attributes; } 56 57 Intrinsic intrinsic() const { ASSERT(m_attributes & Function); return m_intrinsic; } 58 BuiltinGenerator builtinGenerator() const { ASSERT(m_attributes & Builtin); return reinterpret_cast<BuiltinGenerator>(m_value1); } 59 NativeFunction function() const { ASSERT(m_attributes & Function); return reinterpret_cast<NativeFunction>(m_value1); } 60 unsigned char functionLength() const { ASSERT(m_attributes & Function); return static_cast<unsigned char>(m_value2); } 61 62 GetFunction propertyGetter() const { ASSERT(!(m_attributes & BuiltinOrFunctionOrConstant)); return reinterpret_cast<GetFunction>(m_value1); } 63 PutFunction propertyPutter() const { ASSERT(!(m_attributes & BuiltinOrFunctionOrConstant)); return reinterpret_cast<PutFunction>(m_value2); } 64 65 intptr_t constantInteger() const { ASSERT(m_attributes & ConstantInteger); return m_value1; } 66 67 intptr_t lexerValue() const { ASSERT(!m_attributes); return m_value1; } 68 }; 69 70 struct HashTable { 71 mutable int numberOfValues; 72 int indexMask; 73 bool hasSetterOrReadonlyProperties; 74 75 const HashTableValue* values; // Fixed values generated by script. 76 mutable const char** keys; // Table allocated at runtime. 77 const CompactHashIndex* index; 78 79 ALWAYS_INLINE HashTable copy() const 80 { 81 // Don't copy dynamic table since it's thread specific. 82 HashTable result = { numberOfValues, indexMask, hasSetterOrReadonlyProperties, values, 0, index }; 83 return result; 84 } 85 86 ALWAYS_INLINE void initializeIfNeeded(VM& vm) const 87 { 88 if (!keys) 89 createTable(vm); 90 } 91 92 ALWAYS_INLINE void initializeIfNeeded(ExecState* exec) const 93 { 94 if (!keys) 95 createTable(exec->vm()); 96 } 97 98 JS_EXPORT_PRIVATE void deleteTable() const; 99 100 // Find an entry in the table, and return the entry. 101 ALWAYS_INLINE const HashTableValue* entry(VM& vm, PropertyName identifier) const 102 { 103 initializeIfNeeded(vm); 104 return entry(identifier); 105 } 106 107 ALWAYS_INLINE const HashTableValue* entry(ExecState* exec, PropertyName identifier) const 108 { 109 initializeIfNeeded(exec); 110 return entry(identifier); 111 } 112 113 class ConstIterator { 114 public: 115 ConstIterator(const HashTable* table, int position) 116 : m_table(table) 117 , m_position(position) 118 { 119 skipInvalidKeys(); 120 } 121 122 const HashTableValue* value() 123 { 124 return &m_table->values[m_position]; 125 } 126 127 const char* key() 128 { 129 return m_table->keys[m_position]; 130 } 131 132 const HashTableValue* operator->() 133 { 134 return value(); 135 } 136 137 bool operator!=(const ConstIterator& other) 138 { 139 ASSERT(m_table == other.m_table); 140 return m_position != other.m_position; 141 } 142 143 ConstIterator& operator++() 144 { 145 ASSERT(m_position < m_table->numberOfValues); 146 ++m_position; 147 skipInvalidKeys(); 148 return *this; 149 } 150 151 private: 152 void skipInvalidKeys() 153 { 154 ASSERT(m_position <= m_table->numberOfValues); 155 while (m_position < m_table->numberOfValues && !m_table->keys[m_position]) 156 ++m_position; 157 ASSERT(m_position <= m_table->numberOfValues); 158 } 159 160 const HashTable* m_table; 161 int m_position; 162 }; 163 164 ConstIterator begin(VM& vm) const 165 { 166 initializeIfNeeded(vm); 167 return ConstIterator(this, 0); 168 } 169 ConstIterator end(VM& vm) const 170 { 171 initializeIfNeeded(vm); 172 return ConstIterator(this, numberOfValues); 173 } 174 175 private: 176 ALWAYS_INLINE const HashTableValue* entry(PropertyName propertyName) const 177 { 178 StringImpl* impl = propertyName.uid(); 179 if (!impl) 180 return 0; 181 182 ASSERT(keys); 183 184 int indexEntry = impl->existingHash() & indexMask; 185 int valueIndex = index[indexEntry].value; 186 if (valueIndex == -1) 187 return 0; 188 189 while (true) { 190 if (WTF::equal(impl, keys[valueIndex])) 191 return &values[valueIndex]; 192 193 indexEntry = index[indexEntry].next; 194 if (indexEntry == -1) 195 return nullptr; 196 valueIndex = index[indexEntry].value; 197 ASSERT(valueIndex != -1); 198 }; 199 } 200 201 // Convert the hash table keys to identifiers. 202 JS_EXPORT_PRIVATE void createTable(VM&) const; 203 }; 204 205 JS_EXPORT_PRIVATE bool setUpStaticFunctionSlot(ExecState*, const HashTableValue*, JSObject* thisObject, PropertyName, PropertySlot&); 206 207 /** 208 * This method does it all (looking in the hashtable, checking for function 209 * overrides, creating the function or retrieving from cache, calling 210 * getValueProperty in case of a non-function property, forwarding to parent if 211 * unknown property). 212 */ 213 template <class ThisImp, class ParentImp> 214 inline bool getStaticPropertySlot(ExecState* exec, const HashTable& table, ThisImp* thisObj, PropertyName propertyName, PropertySlot& slot) 215 { 216 const HashTableValue* entry = table.entry(exec, propertyName); 217 218 if (!entry) // not found, forward to parent 219 return ParentImp::getOwnPropertySlot(thisObj, exec, propertyName, slot); 220 221 if (entry->attributes() & BuiltinOrFunction) 222 return setUpStaticFunctionSlot(exec, entry, thisObj, propertyName, slot); 223 224 if (entry->attributes() & ConstantInteger) { 225 slot.setValue(thisObj, entry->attributes(), jsNumber(entry->constantInteger())); 226 return true; 227 } 228 229 slot.setCacheableCustom(thisObj, entry->attributes(), entry->propertyGetter()); 230 return true; 231 } 232 233 /** 234 * Simplified version of getStaticPropertySlot in case there are only functions. 235 * Using this instead of getStaticPropertySlot allows 'this' to avoid implementing 236 * a dummy getValueProperty. 237 */ 238 template <class ParentImp> 239 inline bool getStaticFunctionSlot(ExecState* exec, const HashTable& table, JSObject* thisObj, PropertyName propertyName, PropertySlot& slot) 240 { 241 if (ParentImp::getOwnPropertySlot(thisObj, exec, propertyName, slot)) 242 return true; 243 244 const HashTableValue* entry = table.entry(exec, propertyName); 245 if (!entry) 246 return false; 247 248 return setUpStaticFunctionSlot(exec, entry, thisObj, propertyName, slot); 249 } 250 251 /** 252 * Simplified version of getStaticPropertySlot in case there are no functions, only "values". 253 * Using this instead of getStaticPropertySlot removes the need for a FuncImp class. 254 */ 255 template <class ThisImp, class ParentImp> 256 inline bool getStaticValueSlot(ExecState* exec, const HashTable& table, ThisImp* thisObj, PropertyName propertyName, PropertySlot& slot) 257 { 258 const HashTableValue* entry = table.entry(exec, propertyName); 259 260 if (!entry) // not found, forward to parent 261 return ParentImp::getOwnPropertySlot(thisObj, exec, propertyName, slot); 262 263 ASSERT(!(entry->attributes() & BuiltinOrFunction)); 264 265 if (entry->attributes() & ConstantInteger) { 266 slot.setValue(thisObj, entry->attributes(), jsNumber(entry->constantInteger())); 267 return true; 268 } 269 270 slot.setCacheableCustom(thisObj, entry->attributes(), entry->propertyGetter()); 271 return true; 272 } 273 274 inline void putEntry(ExecState* exec, const HashTableValue* entry, JSObject* base, PropertyName propertyName, JSValue value, PutPropertySlot& slot) 275 { 276 // If this is a function put it as an override property. 277 if (entry->attributes() & BuiltinOrFunction) { 278 if (JSObject* thisObject = jsDynamicCast<JSObject*>(slot.thisValue())) 279 thisObject->putDirect(exec->vm(), propertyName, value); 280 } else if (!(entry->attributes() & ReadOnly)) { 281 entry->propertyPutter()(exec, base, JSValue::encode(slot.thisValue()), JSValue::encode(value)); 282 slot.setCustomProperty(base, entry->propertyPutter()); 283 } else if (slot.isStrictMode()) 284 throwTypeError(exec, StrictModeReadonlyPropertyWriteError); 285 } 286 287 /** 288 * This one is for "put". 289 * It looks up a hash entry for the property to be set. If an entry 290 * is found it sets the value and returns true, else it returns false. 291 */ 292 inline bool lookupPut(ExecState* exec, PropertyName propertyName, JSObject* base, JSValue value, const HashTable& table, PutPropertySlot& slot) 293 { 294 const HashTableValue* entry = table.entry(exec, propertyName); 295 296 if (!entry) 297 return false; 298 299 putEntry(exec, entry, base, propertyName, value, slot); 300 return true; 301 } 302 303 template<unsigned numberOfValues> 304 inline void reifyStaticProperties(VM& vm, const HashTableValue (&values)[numberOfValues], JSObject& thisObj) 305 { 306 BatchedTransitionOptimizer transitionOptimizer(vm, &thisObj); 307 for (auto& value : values) { 308 if (!value.m_key) 309 continue; 310 311 Identifier propertyName(&vm, reinterpret_cast<const LChar*>(value.m_key), strlen(value.m_key)); 312 if (value.attributes() & Builtin) { 313 thisObj.putDirectBuiltinFunction(vm, thisObj.globalObject(), propertyName, value.builtinGenerator()(vm), value.attributes()); 314 continue; 315 } 316 317 if (value.attributes() & Function) { 318 thisObj.putDirectNativeFunction(vm, thisObj.globalObject(), propertyName, value.functionLength(), 319 value.function(), value.intrinsic(), value.attributes()); 320 continue; 321 } 322 323 if (value.attributes() & ConstantInteger) { 324 thisObj.putDirect(vm, propertyName, jsNumber(value.constantInteger()), value.attributes()); 325 continue; 326 } 327 328 if (value.attributes() & Accessor) { 329 RELEASE_ASSERT_NOT_REACHED(); 330 continue; 331 } 332 333 CustomGetterSetter* customGetterSetter = CustomGetterSetter::create(vm, value.propertyGetter(), value.propertyPutter()); 334 thisObj.putDirectCustomAccessor(vm, propertyName, customGetterSetter, value.attributes()); 335 } 336 } 337 338} // namespace JSC 339 340#endif // Lookup_h 341