qtdeclarative/src/qml/jsruntime/qv4objectiterator.cpp

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#include "qv4objectiterator_p.h"
#include "qv4object_p.h"
#include "qv4stringobject_p.h"
#include "qv4identifier_p.h"
#include "qv4argumentsobject_p.h"
#include "qv4string_p.h"
#include "qv4iterator_p.h"
#include "qv4propertykey_p.h"

using namespace QV4;

void ForInIteratorPrototype::init(ExecutionEngine *)
{
    defineDefaultProperty(QStringLiteral("next"), method_next, 0);
}

void ObjectIterator::init(const Object *o)
{
    object->setM(o ? o->m() : nullptr);
    current->setM(o ? o->m() : nullptr);

    if (object->as<ArgumentsObject>()) {
        Scope scope(engine);
        Scoped<ArgumentsObject> (scope, object->asReturnedValue())->fullyCreate();
    }
}

void ObjectIterator::next(Value *name, uint *index, Property *pd, PropertyAttributes *attrs)
{
    name->setM(nullptr);
    *index = UINT_MAX;

    if (!object->as<Object>()) {
        *attrs = PropertyAttributes();
        return;
    }
    Scope scope(engine);
    ScopedObject o(scope);
    ScopedString n(scope);

    while (1) {
        Object *co = current->objectValue();
        if (!co)
            break;

        while (1) {
            co->advanceIterator(this, name, index, pd, attrs);
            if (attrs->isEmpty())
                break;
            // check the property is not already defined earlier in the proto chain
            if (co->heapObject() != object->heapObject()) {
                o = object->as<Object>();
                n = *name;
                bool shadowed = false;
                while (o->d() != current->heapObject()) {
                    PropertyKey id = n ? (n->toPropertyKey()) : PropertyKey::fromArrayIndex(*index);
                    if (id.isValid() && o->getOwnProperty(id) != Attr_Invalid) {
                        shadowed = true;
                        break;
                    }
                    o = o->getPrototypeOf();
                }
                if (shadowed)
                    continue;
            }
            return;
        }

        if (flags & WithProtoChain)
            current->setM(co->getPrototypeOf());
        else
            current->setM(nullptr);

        arrayIndex = 0;
        memberIndex = 0;
    }
    *attrs = PropertyAttributes();
}

ReturnedValue ObjectIterator::nextPropertyName(Value *value)
{
    Object *o = object->objectValue();
    if (!o)
        return Encode::null();

    PropertyAttributes attrs;
    uint index;
    Scope scope(engine);
    ScopedProperty p(scope);
    ScopedString name(scope);
    next(name.getRef(), &index, p, &attrs);
    if (attrs.isEmpty())
        return Encode::null();

    *value = o->getValue(p->value, attrs);

    if (!!name)
        return name->asReturnedValue();
    Q_ASSERT(index < UINT_MAX);
    return Encode(index);
}

ReturnedValue ObjectIterator::nextPropertyNameAsString(Value *value)
{
    Object *o = object->objectValue();
    if (!o)
        return Encode::null();

    PropertyAttributes attrs;
    uint index;
    Scope scope(engine);
    ScopedProperty p(scope);
    ScopedString name(scope);
    next(name.getRef(), &index, p, &attrs);
    if (attrs.isEmpty())
        return Encode::null();

    *value = o->getValue(p->value, attrs);

    if (!!name)
        return name->asReturnedValue();
    Q_ASSERT(index < UINT_MAX);
    return Encode(engine->newString(QString::number(index)));
}

ReturnedValue ObjectIterator::nextPropertyNameAsString()
{
    if (!object->as<Object>())
        return Encode::null();

    PropertyAttributes attrs;
    uint index;
    Scope scope(engine);
    ScopedProperty p(scope);
    ScopedString name(scope);
    next(name.getRef(), &index, p, &attrs);
    if (attrs.isEmpty())
        return Encode::null();

    if (!!name)
        return name->asReturnedValue();
    Q_ASSERT(index < UINT_MAX);
    return Encode(engine->newString(QString::number(index)));
}


DEFINE_OBJECT_VTABLE(ForInIteratorObject);

void Heap::ForInIteratorObject::markObjects(Heap::Base *that, MarkStack *markStack)
{
    ForInIteratorObject *o = static_cast<ForInIteratorObject *>(that);
    o->object->mark(markStack);
    o->workArea[0].mark(markStack);
    o->workArea[1].mark(markStack);
    Object::markObjects(that, markStack);
}

void Heap::ForInIteratorObject::destroy()
{
    delete iterator;
}

ReturnedValue ForInIteratorPrototype::method_next(const FunctionObject *b, const Value *thisObject, const Value *, int)
{
    const ForInIteratorObject *forIn = static_cast<const ForInIteratorObject *>(thisObject);
    Q_ASSERT(forIn);
    Scope scope(b);

    ScopedPropertyKey key(scope, forIn->nextProperty());
    bool done = false;
    if (!key->isValid())
        done = true;
    ScopedStringOrSymbol s(scope, key->toStringOrSymbol(scope.engine));
    return IteratorPrototype::createIterResultObject(scope.engine, s, done);
}


PropertyKey ForInIteratorObject::nextProperty() const
{
    if (!d()->current)
        return PropertyKey::invalid();

    Scope scope(this);
    ScopedObject c(scope, d()->current);
    ScopedObject o(scope);
    ScopedPropertyKey key(scope);
    PropertyAttributes attrs;

    while (1) {
        while (1) {
            key = d()->iterator->next(c, nullptr, &attrs);
            if (!key->isValid())
                break;
            if (!attrs.isEnumerable() || key->isSymbol())
                continue;
            // check the property is not already defined earlier in the proto chain
            if (d()->current != d()->object) {
                o = d()->object;
                bool shadowed = false;
                while (o->d() != c->heapObject()) {
                    if (o->getOwnProperty(key) != Attr_Invalid) {
                        shadowed = true;
                        break;
                    }
                    o = o->getPrototypeOf();
                }
                if (shadowed)
                    continue;
            }
            return key;
        }

        c = c->getPrototypeOf();
        d()->current.set(scope.engine, c->d());
        if (!c)
            break;
        delete d()->iterator;
        d()->iterator = c->ownPropertyKeys();
    }
    return PropertyKey::invalid();
}