bool JSGlobalObject::arrayPrototypeChainIsSane()
{
return !hasIndexedProperties(m_arrayPrototype->structure()->indexingType())
&& m_arrayPrototype->prototype() == m_objectPrototype.get()
&& !hasIndexedProperties(m_objectPrototype->structure()->indexingType())
&& m_objectPrototype->prototype().isNull();
}
Structure* PrototypeMap::emptyStructureForPrototypeFromBaseStructure(JSGlobalObject* globalObject, JSObject* prototype, Structure* baseStructure)
{
// We currently do not have inline capacity static analysis for subclasses and all internal function constructors have a default inline capacity of 0.
IndexingType indexingType = baseStructure->indexingType();
if (prototype->structure()->anyObjectInChainMayInterceptIndexedAccesses() && hasIndexedProperties(indexingType))
indexingType = (indexingType & ~IndexingShapeMask) | SlowPutArrayStorageShape;
return createEmptyStructure(globalObject, prototype, baseStructure->typeInfo(), baseStructure->classInfo(), indexingType, 0);
}
inline void StorageStatistics::operator()(JSCell* cell)
{
if (!cell->isObject())
return;
JSObject* object = jsCast<JSObject*>(cell);
if (hasIndexedProperties(object->structure()->indexingType()))
return;
if (object->structure()->isUncacheableDictionary())
return;
++m_objectCount;
if (!object->hasInlineStorage())
++m_objectWithOutOfLineStorageCount;
m_storageSize += object->structure()->totalStorageSize() * sizeof(WriteBarrierBase<Unknown>);
m_storageCapacity += object->structure()->totalStorageCapacity() * sizeof(WriteBarrierBase<Unknown>);
}
void ObjectInitializationScope::verifyPropertiesAreInitialized(JSObject* object)
{
Butterfly* butterfly = object->butterfly();
Structure* structure = object->structure(m_vm);
IndexingType indexingType = structure->indexingType();
unsigned vectorLength = butterfly->vectorLength();
if (UNLIKELY(hasUndecided(indexingType)) || !hasIndexedProperties(indexingType)) {
// Nothing to verify.
} else if (LIKELY(!hasAnyArrayStorage(indexingType))) {
auto data = butterfly->contiguous().data();
for (unsigned i = 0; i < vectorLength; ++i) {
if (isScribbledValue(data[i].get())) {
dataLogLn("Found scribbled value at i = ", i);
ASSERT_NOT_REACHED();
}
}
} else {
ArrayStorage* storage = butterfly->arrayStorage();
for (unsigned i = 0; i < vectorLength; ++i) {
if (isScribbledValue(storage->m_vector[i].get())) {
dataLogLn("Found scribbled value at i = ", i);
ASSERT_NOT_REACHED();
}
}
}
auto isSafeEmptyValueForGCScanning = [] (JSValue value) {
#if USE(JSVALUE64)
return !value;
#else
return !value || !JSValue::encode(value);
#endif
};
for (int64_t i = 0; i < static_cast<int64_t>(structure->outOfLineCapacity()); i++) {
// We rely on properties past the last offset be zero for concurrent GC.
if (i + firstOutOfLineOffset > structure->lastOffset())
ASSERT(isSafeEmptyValueForGCScanning(butterfly->propertyStorage()[-i - 1].get()));
else if (isScribbledValue(butterfly->propertyStorage()[-i - 1].get())) {
dataLogLn("Found scribbled property at i = ", -i - 1);
ASSERT_NOT_REACHED();
}
}
}
JSPropertyNameIterator* JSPropertyNameIterator::create(ExecState* exec, JSObject* o)
{
ASSERT(!o->structure()->enumerationCache() ||
o->structure()->enumerationCache()->cachedStructure() != o->structure() ||
o->structure()->enumerationCache()->cachedPrototypeChain() != o->structure()->prototypeChain(exec));
VM& vm = exec->vm();
PropertyNameArray propertyNames(exec);
o->methodTable()->getPropertyNames(o, exec, propertyNames, ExcludeDontEnumProperties);
size_t numCacheableSlots = 0;
if (!o->structure()->hasNonEnumerableProperties() && !o->structure()->hasGetterSetterProperties()
&& !o->structure()->isUncacheableDictionary() && !o->structure()->typeInfo().overridesGetPropertyNames())
numCacheableSlots = propertyNames.numCacheableSlots();
JSPropertyNameIterator* jsPropertyNameIterator = new (NotNull, allocateCell<JSPropertyNameIterator>(vm.heap)) JSPropertyNameIterator(exec, propertyNames.data(), numCacheableSlots);
jsPropertyNameIterator->finishCreation(vm, propertyNames.data(), o);
if (o->structure()->isDictionary())
return jsPropertyNameIterator;
if (o->structure()->typeInfo().overridesGetPropertyNames())
return jsPropertyNameIterator;
if (hasIndexedProperties(o->indexingType()))
return jsPropertyNameIterator;
size_t count = normalizePrototypeChain(exec, o);
StructureChain* structureChain = o->structure()->prototypeChain(exec);
WriteBarrier<Structure>* structure = structureChain->head();
for (size_t i = 0; i < count; ++i) {
if (structure[i]->typeInfo().overridesGetPropertyNames())
return jsPropertyNameIterator;
}
jsPropertyNameIterator->setCachedPrototypeChain(vm, structureChain);
jsPropertyNameIterator->setCachedStructure(vm, o->structure());
o->structure()->setEnumerationCache(vm, jsPropertyNameIterator);
return jsPropertyNameIterator;
}
EncodedJSValue JSC_HOST_CALL objectConstructorFreeze(ExecState* exec)
{
// 1. If Type(O) is not Object throw a TypeError exception.
JSValue obj = exec->argument(0);
if (!obj.isObject())
return throwVMError(exec, createTypeError(exec, ASCIILiteral("Object.freeze can only be called on Objects.")));
JSObject* object = asObject(obj);
if (isJSFinalObject(object) && !hasIndexedProperties(object->structure()->indexingType())) {
object->freeze(exec->vm());
return JSValue::encode(obj);
}
// 2. For each named own property name P of O,
PropertyNameArray properties(exec);
object->methodTable()->getOwnPropertyNames(object, exec, properties, IncludeDontEnumProperties);
PropertyNameArray::const_iterator end = properties.end();
for (PropertyNameArray::const_iterator iter = properties.begin(); iter != end; ++iter) {
// a. Let desc be the result of calling the [[GetOwnProperty]] internal method of O with P.
PropertyDescriptor desc;
if (!object->methodTable()->getOwnPropertyDescriptor(object, exec, *iter, desc))
continue;
// b. If IsDataDescriptor(desc) is true, then
// i. If desc.[[Writable]] is true, set desc.[[Writable]] to false.
if (desc.isDataDescriptor())
desc.setWritable(false);
// c. If desc.[[Configurable]] is true, set desc.[[Configurable]] to false.
desc.setConfigurable(false);
// d. Call the [[DefineOwnProperty]] internal method of O with P, desc, and true as arguments.
object->methodTable()->defineOwnProperty(object, exec, *iter, desc, true);
if (exec->hadException())
return JSValue::encode(obj);
}
// 3. Set the [[Extensible]] internal property of O to false.
object->preventExtensions(exec->vm());
// 4. Return O.
return JSValue::encode(obj);
}
bool JSGlobalObject::stringPrototypeChainIsSane()
{
return !hasIndexedProperties(m_stringPrototype->structure()->indexingType())
&& m_stringPrototype->prototype() == m_objectPrototype.get()
&& objectPrototypeIsSane();
}
bool JSGlobalObject::objectPrototypeIsSane()
{
return !hasIndexedProperties(m_objectPrototype->structure()->indexingType())
&& m_objectPrototype->prototype().isNull();
}
