JSPropertyNameEnumerator.cpp [plain text]
#include "config.h"
#include "JSPropertyNameEnumerator.h"
#include "JSObjectInlines.h"
namespace JSC {
const ClassInfo JSPropertyNameEnumerator::s_info = { "JSPropertyNameEnumerator", nullptr, nullptr, nullptr, CREATE_METHOD_TABLE(JSPropertyNameEnumerator) };
JSPropertyNameEnumerator* JSPropertyNameEnumerator::create(VM& vm, Structure* structure, uint32_t indexedLength, uint32_t numberStructureProperties, PropertyNameArray&& propertyNames)
{
unsigned propertyNamesSize = propertyNames.size();
unsigned propertyNamesBufferSizeInBytes = (Checked<unsigned>(propertyNamesSize) * sizeof(WriteBarrier<JSString>)).unsafeGet();
WriteBarrier<JSString>* propertyNamesBuffer = nullptr;
if (propertyNamesBufferSizeInBytes) {
propertyNamesBuffer = static_cast<WriteBarrier<JSString>*>(vm.jsValueGigacageAuxiliarySpace.allocateNonVirtual(vm, propertyNamesBufferSizeInBytes, nullptr, AllocationFailureMode::Assert));
for (unsigned i = 0; i < propertyNamesSize; ++i)
propertyNamesBuffer[i].clear();
}
JSPropertyNameEnumerator* enumerator = new (NotNull, allocateCell<JSPropertyNameEnumerator>(vm.heap)) JSPropertyNameEnumerator(vm, structure, indexedLength, numberStructureProperties, propertyNamesBuffer, propertyNamesSize);
enumerator->finishCreation(vm, propertyNames.releaseData());
return enumerator;
}
JSPropertyNameEnumerator::JSPropertyNameEnumerator(VM& vm, Structure* structure, uint32_t indexedLength, uint32_t numberStructureProperties, WriteBarrier<JSString>* propertyNamesBuffer, unsigned propertyNamesSize)
: JSCell(vm, vm.propertyNameEnumeratorStructure.get())
, m_propertyNames(vm, this, propertyNamesBuffer)
, m_cachedStructureID(structure ? structure->id() : 0)
, m_indexedLength(indexedLength)
, m_endStructurePropertyIndex(numberStructureProperties)
, m_endGenericPropertyIndex(propertyNamesSize)
, m_cachedInlineCapacity(structure ? structure->inlineCapacity() : 0)
{
}
void JSPropertyNameEnumerator::finishCreation(VM& vm, RefPtr<PropertyNameArrayData>&& identifiers)
{
Base::finishCreation(vm);
PropertyNameArrayData::PropertyNameVector& vector = identifiers->propertyNameVector();
ASSERT(m_endGenericPropertyIndex == vector.size());
for (unsigned i = 0; i < vector.size(); ++i) {
const Identifier& identifier = vector[i];
m_propertyNames.get()[i].set(vm, this, jsString(vm, identifier.string()));
}
}
void JSPropertyNameEnumerator::visitChildren(JSCell* cell, SlotVisitor& visitor)
{
JSPropertyNameEnumerator* thisObject = jsCast<JSPropertyNameEnumerator*>(cell);
ASSERT_GC_OBJECT_INHERITS(thisObject, info());
Base::visitChildren(cell, visitor);
if (auto* propertyNames = thisObject->m_propertyNames.get()) {
visitor.markAuxiliary(propertyNames);
visitor.append(propertyNames, propertyNames + thisObject->sizeOfPropertyNames());
}
visitor.append(thisObject->m_prototypeChain);
if (thisObject->cachedStructureID()) {
VM& vm = visitor.vm();
visitor.appendUnbarriered(vm.getStructure(thisObject->cachedStructureID()));
}
}
void getEnumerablePropertyNames(JSGlobalObject* globalObject, JSObject* base, PropertyNameArray& propertyNames, uint32_t& indexedLength, uint32_t& structurePropertyCount)
{
VM& vm = globalObject->vm();
auto scope = DECLARE_THROW_SCOPE(vm);
auto getOwnPropertyNames = [&](JSObject* object) {
auto mode = DontEnumPropertiesMode::Exclude;
if (object->type() == ProxyObjectType) {
mode = DontEnumPropertiesMode::Include;
}
object->methodTable(vm)->getOwnPropertyNames(object, globalObject, propertyNames, mode);
};
Structure* structure = base->structure(vm);
if (structure->canAccessPropertiesQuicklyForEnumeration() && indexedLength == base->getArrayLength()) {
base->methodTable(vm)->getOwnSpecialPropertyNames(base, globalObject, propertyNames, DontEnumPropertiesMode::Exclude);
RETURN_IF_EXCEPTION(scope, void());
base->getNonReifiedStaticPropertyNames(vm, propertyNames, DontEnumPropertiesMode::Exclude);
unsigned nonStructurePropertyCount = propertyNames.size();
structure->getPropertyNamesFromStructure(vm, propertyNames, DontEnumPropertiesMode::Exclude);
scope.assertNoException();
if (!nonStructurePropertyCount)
structurePropertyCount = propertyNames.size();
} else {
getOwnPropertyNames(base);
RETURN_IF_EXCEPTION(scope, void());
indexedLength = 0;
}
JSObject* object = base;
unsigned prototypeCount = 0;
while (true) {
JSValue prototype = object->getPrototype(vm, globalObject);
RETURN_IF_EXCEPTION(scope, void());
if (prototype.isNull())
break;
if (UNLIKELY(++prototypeCount > JSObject::maximumPrototypeChainDepth)) {
throwStackOverflowError(globalObject, scope);
return;
}
object = asObject(prototype);
getOwnPropertyNames(object);
RETURN_IF_EXCEPTION(scope, void());
}
}
}