void Structure::visitChildren(JSCell* cell, SlotVisitor& visitor)
{
Structure* thisObject = jsCast<Structure*>(cell);
ASSERT_GC_OBJECT_INHERITS(thisObject, &s_info);
ASSERT(thisObject->structure()->typeInfo().overridesVisitChildren());
JSCell::visitChildren(thisObject, visitor);
if (thisObject->m_globalObject)
visitor.append(&thisObject->m_globalObject);
if (!thisObject->isObject())
thisObject->m_cachedPrototypeChain.clear();
else {
if (thisObject->m_prototype)
visitor.append(&thisObject->m_prototype);
if (thisObject->m_cachedPrototypeChain)
visitor.append(&thisObject->m_cachedPrototypeChain);
}
if (thisObject->m_previous)
visitor.append(&thisObject->m_previous);
if (thisObject->m_specificValueInPrevious)
visitor.append(&thisObject->m_specificValueInPrevious);
if (thisObject->m_enumerationCache)
visitor.append(&thisObject->m_enumerationCache);
if (thisObject->m_propertyTable) {
PropertyTable::iterator end = thisObject->m_propertyTable->end();
for (PropertyTable::iterator ptr = thisObject->m_propertyTable->begin(); ptr != end; ++ptr) {
if (ptr->specificValue)
visitor.append(&ptr->specificValue);
}
}
}
std::unique_ptr<PolyProtoAccessChain> PolyProtoAccessChain::create(JSGlobalObject* globalObject, JSCell* base, JSObject* target, bool& usesPolyProto)
{
JSCell* current = base;
VM& vm = *base->vm();
bool found = false;
usesPolyProto = false;
std::unique_ptr<PolyProtoAccessChain> result(new PolyProtoAccessChain());
for (unsigned iterationNumber = 0; true; ++iterationNumber) {
Structure* structure = current->structure(vm);
if (!structure->propertyAccessesAreCacheable())
return nullptr;
if (structure->isProxy())
return nullptr;
if (structure->isDictionary()) {
ASSERT(structure->isObject());
if (structure->hasBeenFlattenedBefore())
return nullptr;
structure->flattenDictionaryStructure(vm, asObject(current));
}
// To save memory, we don't include the base in the chain. We let
// AccessCase provide the base to us as needed.
if (iterationNumber)
result->m_chain.append(structure);
else
RELEASE_ASSERT(current == base);
if (current == target) {
found = true;
break;
}
// We only have poly proto if we need to access our prototype via
// the poly proto protocol. If the slot base is the only poly proto
// thing in the chain, and we have a cache hit on it, then we're not
// poly proto.
usesPolyProto |= structure->hasPolyProto();
JSValue prototype = structure->prototypeForLookup(globalObject, current);
if (prototype.isNull())
break;
current = asObject(prototype);
}
if (!found && !!target)
return nullptr;
return result;
}
void Structure::visitChildren(JSCell* cell, SlotVisitor& visitor)
{
Structure* thisObject = jsCast<Structure*>(cell);
ASSERT_GC_OBJECT_INHERITS(thisObject, &s_info);
ASSERT(thisObject->structure()->typeInfo().overridesVisitChildren());
JSCell::visitChildren(thisObject, visitor);
visitor.append(&thisObject->m_globalObject);
if (!thisObject->isObject())
thisObject->m_cachedPrototypeChain.clear();
else {
visitor.append(&thisObject->m_prototype);
visitor.append(&thisObject->m_cachedPrototypeChain);
}
visitor.append(&thisObject->m_previousOrRareData);
visitor.append(&thisObject->m_specificValueInPrevious);
if (thisObject->m_isPinnedPropertyTable) {
ASSERT(thisObject->m_propertyTableUnsafe);
visitor.append(&thisObject->m_propertyTableUnsafe);
} else if (thisObject->m_propertyTableUnsafe)
thisObject->m_propertyTableUnsafe.clear();
}