static inline PropertyIteratorObject*
VectorToKeyIterator(JSContext* cx, HandleObject obj, AutoIdVector& keys, uint32_t numGuards)
{
if (obj->isSingleton() && !JSObject::setIteratedSingleton(cx, obj))
return nullptr;
MarkObjectGroupFlags(cx, obj, OBJECT_FLAG_ITERATED);
Rooted<PropertyIteratorObject*> iterobj(cx, NewPropertyIteratorObject(cx));
if (!iterobj)
return nullptr;
NativeIterator* ni = NativeIterator::allocateIterator(cx, numGuards, keys.length());
if (!ni)
return nullptr;
iterobj->setNativeIterator(ni);
ni->init(obj, iterobj, numGuards, 0);
if (!ni->initProperties(cx, iterobj, keys))
return nullptr;
if (numGuards) {
// Fill in the guard array from scratch. Also recompute the guard key
// as we might have reshaped the object (see for instance the
// setIteratedSingleton call above) or GC might have moved shapes and
// groups in memory.
JSObject* pobj = obj;
size_t ind = 0;
uint32_t key = 0;
do {
ReceiverGuard guard(pobj);
ni->guard_array[ind++].init(guard);
key = mozilla::AddToHash(key, guard.hash());
// The one caller of this method that passes |numGuards > 0|, does
// so only if the entire chain consists of cacheable objects (that
// necessarily have static prototypes).
pobj = pobj->staticPrototype();
} while (pobj);
ni->guard_key = key;
MOZ_ASSERT(ind == numGuards);
}
RegisterEnumerator(cx, ni);
return iterobj;
}
// Mainly used for .. in over null/undefined
JSObject*
js::NewEmptyPropertyIterator(JSContext* cx)
{
Rooted<PropertyIteratorObject*> iterobj(cx, NewPropertyIteratorObject(cx));
if (!iterobj)
return nullptr;
AutoIdVector keys(cx); // Empty
NativeIterator* ni = NativeIterator::allocateIterator(cx, 0, keys.length());
if (!ni)
return nullptr;
iterobj->setNativeIterator(ni);
ni->init(nullptr, iterobj, 0, 0);
if (!ni->initProperties(cx, iterobj, keys))
return nullptr;
RegisterEnumerator(cx, ni);
return iterobj;
}
