bool
GetPropIRGenerator::tryAttachDenseElementHole(HandleObject obj, ObjOperandId objId,
ValOperandId indexId)
{
MOZ_ASSERT(idVal_.isInt32());
if (idVal_.toInt32() < 0)
return false;
if (!obj->isNative() || !CanAttachDenseElementHole(obj))
return false;
// Guard on the shape, to prevent non-dense elements from appearing.
writer.guardShape(objId, obj->as<NativeObject>().lastProperty());
if (obj->hasUncacheableProto()) {
// If the shape does not imply the proto, emit an explicit proto guard.
writer.guardProto(objId, obj->staticPrototype());
}
JSObject* pobj = obj->staticPrototype();
while (pobj) {
ObjOperandId protoId = writer.loadObject(pobj);
// Non-singletons with uncacheable protos can change their proto
// without a shape change, so also guard on the group (which determines
// the proto) in this case.
if (pobj->hasUncacheableProto() && !pobj->isSingleton())
writer.guardGroup(protoId, pobj->group());
// Make sure the shape matches, to avoid non-dense elements or anything
// else that is being checked by CanAttachDenseElementHole.
writer.guardShape(protoId, pobj->as<NativeObject>().lastProperty());
// Also make sure there are no dense elements.
writer.guardNoDenseElements(protoId);
pobj = pobj->staticPrototype();
}
Int32OperandId int32IndexId = writer.guardIsInt32(indexId);
writer.loadDenseElementHoleResult(objId, int32IndexId);
writer.typeMonitorResult();
return true;
}
bool
GetPropIRGenerator::tryAttachDOMProxyUnshadowed(HandleObject obj, ObjOperandId objId, HandleId id)
{
MOZ_ASSERT(IsCacheableDOMProxy(obj));
RootedObject checkObj(cx_, obj->staticPrototype());
RootedNativeObject holder(cx_);
RootedShape shape(cx_);
NativeGetPropCacheability canCache = CanAttachNativeGetProp(cx_, checkObj, id, &holder, &shape,
pc_, engine_,
isTemporarilyUnoptimizable_);
if (canCache == CanAttachNone)
return false;
maybeEmitIdGuard(id);
writer.guardShape(objId, obj->maybeShape());
// Guard that our expando object hasn't started shadowing this property.
CheckDOMProxyExpandoDoesNotShadow(writer, obj, id, objId);
if (holder) {
// Found the property on the prototype chain. Treat it like a native
// getprop.
GeneratePrototypeGuards(writer, obj, holder, objId);
// Guard on the holder of the property.
ObjOperandId holderId = writer.loadObject(holder);
writer.guardShape(holderId, holder->lastProperty());
if (canCache == CanAttachReadSlot) {
EmitLoadSlotResult(writer, holderId, holder, shape);
writer.typeMonitorResult();
} else {
// EmitCallGetterResultNoGuards expects |obj| to be the object the
// property is on to do some checks. Since we actually looked at
// checkObj, and no extra guards will be generated, we can just
// pass that instead.
MOZ_ASSERT(canCache == CanAttachCallGetter);
EmitCallGetterResultNoGuards(writer, checkObj, holder, shape, objId);
}
} else {
// Property was not found on the prototype chain. Deoptimize down to
// proxy get call.
writer.callProxyGetResult(objId, id);
writer.typeMonitorResult();
}
return true;
}
static inline bool
Enumerate(JSContext* cx, HandleObject pobj, jsid id,
bool enumerable, unsigned flags, Maybe<IdSet>& ht, AutoIdVector* props)
{
if (CheckForDuplicates) {
if (!ht) {
ht.emplace(cx);
// Most of the time there are only a handful of entries.
if (!ht->init(5))
return false;
}
// If we've already seen this, we definitely won't add it.
IdSet::AddPtr p = ht->lookupForAdd(id);
if (MOZ_UNLIKELY(!!p))
return true;
// It's not necessary to add properties to the hash table at the end of
// the prototype chain, but custom enumeration behaviors might return
// duplicated properties, so always add in such cases.
if (pobj->is<ProxyObject>() ||
pobj->staticPrototype() ||
pobj->getClass()->getNewEnumerate())
{
if (!ht->add(p, id))
return false;
}
}
if (!enumerable && !(flags & JSITER_HIDDEN))
return true;
// Symbol-keyed properties and nonenumerable properties are skipped unless
// the caller specifically asks for them. A caller can also filter out
// non-symbols by asking for JSITER_SYMBOLSONLY.
if (JSID_IS_SYMBOL(id) ? !(flags & JSITER_SYMBOLS) : (flags & JSITER_SYMBOLSONLY))
return true;
return props->append(id);
}