bool
ArrayPushDense(JSContext *cx, HandleArrayObject obj, HandleValue v, uint32_t *length)
{
if (MOZ_LIKELY(obj->lengthIsWritable())) {
uint32_t idx = obj->length();
NativeObject::EnsureDenseResult result = obj->ensureDenseElements(cx, idx, 1);
if (result == NativeObject::ED_FAILED)
return false;
if (result == NativeObject::ED_OK) {
obj->setDenseElement(idx, v);
MOZ_ASSERT(idx < INT32_MAX);
*length = idx + 1;
obj->setLengthInt32(*length);
return true;
}
}
JS::AutoValueArray<3> argv(cx);
argv[0].setUndefined();
argv[1].setObject(*obj);
argv[2].set(v);
if (!js::array_push(cx, 1, argv.begin()))
return false;
*length = argv[0].toInt32();
return true;
}
bool
MapIteratorObject::next(JSContext* cx, Handle<MapIteratorObject*> mapIterator,
HandleArrayObject resultPairObj)
{
MOZ_ASSERT(resultPairObj->getDenseInitializedLength() == 2);
ValueMap::Range* range = MapIteratorObjectRange(mapIterator);
if (!range || range->empty()) {
js_delete(range);
mapIterator->setReservedSlot(RangeSlot, PrivateValue(nullptr));
return true;
}
switch (mapIterator->kind()) {
case MapObject::Keys:
resultPairObj->setDenseElementWithType(cx, 0, range->front().key.get());
break;
case MapObject::Values:
resultPairObj->setDenseElementWithType(cx, 1, range->front().value);
break;
case MapObject::Entries: {
resultPairObj->setDenseElementWithType(cx, 0, range->front().key.get());
resultPairObj->setDenseElementWithType(cx, 1, range->front().value);
break;
}
}
range->popFront();
return false;
}
bool
SetIteratorObject::next(Handle<SetIteratorObject*> setIterator, HandleArrayObject resultObj,
JSContext* cx)
{
// Check invariants for inlined _GetNextSetEntryForIterator.
// The array should be tenured, so that post-barrier can be done simply.
MOZ_ASSERT(resultObj->isTenured());
// The array elements should be fixed.
MOZ_ASSERT(resultObj->hasFixedElements());
MOZ_ASSERT(resultObj->getDenseInitializedLength() == 1);
MOZ_ASSERT(resultObj->getDenseCapacity() >= 1);
ValueSet::Range* range = SetIteratorObjectRange(setIterator);
if (!range || range->empty()) {
js_delete(range);
setIterator->setReservedSlot(RangeSlot, PrivateValue(nullptr));
return true;
}
resultObj->setDenseElementWithType(cx, 0, range->front().get());
range->popFront();
return false;
}
bool
MapIteratorObject::next(JSContext* cx, Handle<MapIteratorObject*> mapIterator,
HandleArrayObject resultPairObj)
{
// Check invariants for inlined _GetNextMapEntryForIterator.
// The array should be tenured, so that post-barrier can be done simply.
MOZ_ASSERT(resultPairObj->isTenured());
// The array elements should be fixed.
MOZ_ASSERT(resultPairObj->hasFixedElements());
MOZ_ASSERT(resultPairObj->getDenseInitializedLength() == 2);
MOZ_ASSERT(resultPairObj->getDenseCapacity() >= 2);
ValueMap::Range* range = MapIteratorObjectRange(mapIterator);
if (!range || range->empty()) {
js_delete(range);
mapIterator->setReservedSlot(RangeSlot, PrivateValue(nullptr));
return true;
}
switch (mapIterator->kind()) {
case MapObject::Keys:
resultPairObj->setDenseElementWithType(cx, 0, range->front().key.get());
break;
case MapObject::Values:
resultPairObj->setDenseElementWithType(cx, 1, range->front().value);
break;
case MapObject::Entries: {
resultPairObj->setDenseElementWithType(cx, 0, range->front().key.get());
resultPairObj->setDenseElementWithType(cx, 1, range->front().value);
break;
}
}
range->popFront();
return false;
}
bool
js::ForOfPIC::Chain::tryOptimizeArray(JSContext *cx, HandleArrayObject array, bool *optimized)
{
MOZ_ASSERT(optimized);
*optimized = false;
if (!initialized_) {
// If PIC is not initialized, initialize it.
if (!initialize(cx))
return false;
} else if (!disabled_ && !isArrayStateStillSane()) {
// Otherwise, if array state is no longer sane, reinitialize.
reset(cx);
if (!initialize(cx))
return false;
}
MOZ_ASSERT(initialized_);
// If PIC is disabled, don't bother trying to optimize.
if (disabled_)
return true;
// By the time we get here, we should have a sane array state to work with.
MOZ_ASSERT(isArrayStateStillSane());
// Check if stub already exists.
ForOfPIC::Stub *stub = isArrayOptimized(&array->as<ArrayObject>());
if (stub) {
*optimized = true;
return true;
}
// If the number of stubs is about to exceed the limit, throw away entire
// existing cache before adding new stubs. We shouldn't really have heavy
// churn on these.
if (numStubs() >= MAX_STUBS)
eraseChain();
// Ensure array's prototype is the actual Array.prototype
if (!isOptimizableArray(array))
return true;
// Ensure array doesn't define '@@iterator' directly.
if (array->lookup(cx, cx->names().std_iterator))
return true;
// Good to optimize now, create stub to add.
RootedShape shape(cx, array->lastProperty());
stub = cx->new_<Stub>(shape);
if (!stub)
return false;
// Add the stub.
addStub(stub);
*optimized = true;
return true;
}