1  /*
  2   *  Copyright (C) 1999-2001 Harri Porten (porten@kde.org)
  3   *  Copyright (C) 2004-2019 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  #include "config.h"
 22  #include "StringObject.h"
 23  
 24  #include "JSCInlines.h"
 25  #include "PropertyNameArray.h"
 26  #include "TypeError.h"
 27  
 28  namespace JSC {
 29  
 30  STATIC_ASSERT_IS_TRIVIALLY_DESTRUCTIBLE(StringObject);
 31  
 32  const ClassInfo StringObject::s_info = { "String", &Base::s_info, nullptr, nullptr, CREATE_METHOD_TABLE(StringObject) };
 33  
 34  StringObject::StringObject(VM& vm, Structure* structure)
 35      : Base(vm, structure)
 36  {
 37  }
 38  
 39  void StringObject::finishCreation(VM& vm, JSString* string)
 40  {
 41      Base::finishCreation(vm);
 42      ASSERT(inherits(vm, info()));
 43      setInternalValue(vm, string);
 44      ASSERT_WITH_MESSAGE(type() == StringObjectType || type() == DerivedStringObjectType, "Instance inheriting StringObject should have DerivedStringObjectType");
 45  }
 46  
 47  bool StringObject::getOwnPropertySlot(JSObject* cell, JSGlobalObject* globalObject, PropertyName propertyName, PropertySlot& slot)
 48  {
 49      StringObject* thisObject = jsCast<StringObject*>(cell);
 50      if (thisObject->internalValue()->getStringPropertySlot(globalObject, propertyName, slot))
 51          return true;
 52      return JSObject::getOwnPropertySlot(thisObject, globalObject, propertyName, slot);
 53  }
 54      
 55  bool StringObject::getOwnPropertySlotByIndex(JSObject* object, JSGlobalObject* globalObject, unsigned propertyName, PropertySlot& slot)
 56  {
 57      StringObject* thisObject = jsCast<StringObject*>(object);
 58      if (thisObject->internalValue()->getStringPropertySlot(globalObject, propertyName, slot))
 59          return true;    
 60      VM& vm = globalObject->vm();
 61      return JSObject::getOwnPropertySlot(thisObject, globalObject, Identifier::from(vm, propertyName), slot);
 62  }
 63  
 64  bool StringObject::put(JSCell* cell, JSGlobalObject* globalObject, PropertyName propertyName, JSValue value, PutPropertySlot& slot)
 65  {
 66      VM& vm = globalObject->vm();
 67      auto scope = DECLARE_THROW_SCOPE(vm);
 68  
 69      StringObject* thisObject = jsCast<StringObject*>(cell);
 70  
 71      if (UNLIKELY(isThisValueAltered(slot, thisObject))) 
 72          RELEASE_AND_RETURN(scope, ordinarySetSlow(globalObject, thisObject, propertyName, value, slot.thisValue(), slot.isStrictMode()));
 73  
 74      if (propertyName == vm.propertyNames->length)
 75          return typeError(globalObject, scope, slot.isStrictMode(), ReadonlyPropertyWriteError);
 76      if (Optional<uint32_t> index = parseIndex(propertyName)) 
 77          RELEASE_AND_RETURN(scope, putByIndex(cell, globalObject, index.value(), value, slot.isStrictMode()));
 78      RELEASE_AND_RETURN(scope, JSObject::put(cell, globalObject, propertyName, value, slot));
 79  }
 80  
 81  bool StringObject::putByIndex(JSCell* cell, JSGlobalObject* globalObject, unsigned propertyName, JSValue value, bool shouldThrow)
 82  {
 83      VM& vm = globalObject->vm();
 84      auto scope = DECLARE_THROW_SCOPE(vm);
 85  
 86      StringObject* thisObject = jsCast<StringObject*>(cell);
 87      if (thisObject->internalValue()->canGetIndex(propertyName))
 88          return typeError(globalObject, scope, shouldThrow, ReadonlyPropertyWriteError);
 89      RELEASE_AND_RETURN(scope, JSObject::putByIndex(cell, globalObject, propertyName, value, shouldThrow));
 90  }
 91  
 92  static bool isStringOwnProperty(JSGlobalObject* globalObject, StringObject* object, PropertyName propertyName)
 93  {
 94      VM& vm = globalObject->vm();
 95      if (propertyName == vm.propertyNames->length)
 96          return true;
 97      if (Optional<uint32_t> index = parseIndex(propertyName)) {
 98          if (object->internalValue()->canGetIndex(index.value()))
 99              return true;
100      }
101      return false;
102  }
103  
104  bool StringObject::defineOwnProperty(JSObject* object, JSGlobalObject* globalObject, PropertyName propertyName, const PropertyDescriptor& descriptor, bool throwException)
105  {
106      VM& vm = globalObject->vm();
107      auto scope = DECLARE_THROW_SCOPE(vm);
108      StringObject* thisObject = jsCast<StringObject*>(object);
109  
110      if (isStringOwnProperty(globalObject, thisObject, propertyName)) {
111          // The current PropertyDescriptor is always
112          // PropertyDescriptor{[[Value]]: value, [[Writable]]: false, [[Enumerable]]: true, [[Configurable]]: false}.
113          // This ensures that any property descriptor cannot change the existing one.
114          // Here, simply return the result of validateAndApplyPropertyDescriptor.
115          // https://tc39.github.io/ecma262/#sec-string-exotic-objects-getownproperty-p
116          PropertyDescriptor current;
117          bool isCurrentDefined = thisObject->getOwnPropertyDescriptor(globalObject, propertyName, current);
118          EXCEPTION_ASSERT(!scope.exception() == isCurrentDefined);
119          RETURN_IF_EXCEPTION(scope, false);
120          bool isExtensible = thisObject->isExtensible(globalObject);
121          RETURN_IF_EXCEPTION(scope, false);
122          RELEASE_AND_RETURN(scope, validateAndApplyPropertyDescriptor(globalObject, nullptr, propertyName, isExtensible, descriptor, isCurrentDefined, current, throwException));
123      }
124  
125      RELEASE_AND_RETURN(scope, Base::defineOwnProperty(object, globalObject, propertyName, descriptor, throwException));
126  }
127  
128  bool StringObject::deleteProperty(JSCell* cell, JSGlobalObject* globalObject, PropertyName propertyName, DeletePropertySlot& slot)
129  {
130      VM& vm = globalObject->vm();
131      StringObject* thisObject = jsCast<StringObject*>(cell);
132      if (propertyName == vm.propertyNames->length)
133          return false;
134      Optional<uint32_t> index = parseIndex(propertyName);
135      if (index && thisObject->internalValue()->canGetIndex(index.value()))
136          return false;
137      return JSObject::deleteProperty(thisObject, globalObject, propertyName, slot);
138  }
139  
140  bool StringObject::deletePropertyByIndex(JSCell* cell, JSGlobalObject* globalObject, unsigned i)
141  {
142      StringObject* thisObject = jsCast<StringObject*>(cell);
143      if (thisObject->internalValue()->canGetIndex(i))
144          return false;
145      return JSObject::deletePropertyByIndex(thisObject, globalObject, i);
146  }
147  
148  void StringObject::getOwnPropertyNames(JSObject* object, JSGlobalObject* globalObject, PropertyNameArray& propertyNames, DontEnumPropertiesMode mode)
149  {
150      VM& vm = globalObject->vm();
151      StringObject* thisObject = jsCast<StringObject*>(object);
152      if (propertyNames.includeStringProperties()) {
153          int size = thisObject->internalValue()->length();
154          for (int i = 0; i < size; ++i)
155              propertyNames.add(Identifier::from(vm, i));
156          thisObject->getOwnIndexedPropertyNames(globalObject, propertyNames, mode);
157      }
158      if (mode == DontEnumPropertiesMode::Include)
159          propertyNames.add(vm.propertyNames->length);
160      thisObject->getOwnNonIndexPropertyNames(globalObject, propertyNames, mode);
161  }
162  
163  String StringObject::toStringName(const JSObject*, JSGlobalObject*)
164  {
165      return "String"_s;
166  }
167  
168  StringObject* constructString(VM& vm, JSGlobalObject* globalObject, JSValue string)
169  {
170      StringObject* object = StringObject::create(vm, globalObject->stringObjectStructure());
171      object->setInternalValue(vm, string);
172      return object;
173  }
174  
175  } // namespace JSC