Пример #1
0
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;
}
Пример #3
0
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();
}