| // Copyright 2015 the V8 project authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style license that can be |
| // found in the LICENSE file. |
| |
| #include "src/runtime/runtime-utils.h" |
| |
| #include "src/arguments.h" |
| #include "src/elements.h" |
| #include "src/factory.h" |
| #include "src/isolate-inl.h" |
| #include "src/keys.h" |
| #include "src/objects-inl.h" |
| |
| namespace v8 { |
| namespace internal { |
| |
| namespace { |
| |
| // Returns either a FixedArray or, if the given {receiver} has an enum cache |
| // that contains all enumerable properties of the {receiver} and its prototypes |
| // have none, the map of the {receiver}. This is used to speed up the check for |
| // deletions during a for-in. |
| MaybeHandle<HeapObject> Enumerate(Handle<JSReceiver> receiver) { |
| Isolate* const isolate = receiver->GetIsolate(); |
| FastKeyAccumulator accumulator(isolate, receiver, INCLUDE_PROTOS, |
| ENUMERABLE_STRINGS); |
| accumulator.set_filter_proxy_keys(false); |
| // Test if we have an enum cache for {receiver}. |
| if (!accumulator.is_receiver_simple_enum()) { |
| Handle<FixedArray> keys; |
| ASSIGN_RETURN_ON_EXCEPTION(isolate, keys, accumulator.GetKeys(KEEP_NUMBERS), |
| HeapObject); |
| // Test again, since cache may have been built by GetKeys() calls above. |
| if (!accumulator.is_receiver_simple_enum()) return keys; |
| } |
| return handle(receiver->map(), isolate); |
| } |
| |
| // This is a slight modifcation of JSReceiver::HasProperty, dealing with |
| // the oddities of JSProxy in for-in filter. |
| MaybeHandle<Object> HasEnumerableProperty(Isolate* isolate, |
| Handle<JSReceiver> receiver, |
| Handle<Object> key) { |
| bool success = false; |
| Maybe<PropertyAttributes> result = Just(ABSENT); |
| LookupIterator it = |
| LookupIterator::PropertyOrElement(isolate, receiver, key, &success); |
| if (!success) return isolate->factory()->undefined_value(); |
| for (; it.IsFound(); it.Next()) { |
| switch (it.state()) { |
| case LookupIterator::NOT_FOUND: |
| case LookupIterator::TRANSITION: |
| UNREACHABLE(); |
| case LookupIterator::JSPROXY: { |
| // For proxies we have to invoke the [[GetOwnProperty]] trap. |
| result = JSProxy::GetPropertyAttributes(&it); |
| if (result.IsNothing()) return MaybeHandle<Object>(); |
| if (result.FromJust() == ABSENT) { |
| // Continue lookup on the proxy's prototype. |
| Handle<JSProxy> proxy = it.GetHolder<JSProxy>(); |
| Handle<Object> prototype; |
| ASSIGN_RETURN_ON_EXCEPTION(isolate, prototype, |
| JSProxy::GetPrototype(proxy), Object); |
| if (prototype->IsNull()) break; |
| // We already have a stack-check in JSProxy::GetPrototype. |
| return HasEnumerableProperty( |
| isolate, Handle<JSReceiver>::cast(prototype), key); |
| } else if (result.FromJust() & DONT_ENUM) { |
| return isolate->factory()->undefined_value(); |
| } else { |
| return it.GetName(); |
| } |
| } |
| case LookupIterator::INTERCEPTOR: { |
| result = JSObject::GetPropertyAttributesWithInterceptor(&it); |
| if (result.IsNothing()) return MaybeHandle<Object>(); |
| if (result.FromJust() != ABSENT) return it.GetName(); |
| continue; |
| } |
| case LookupIterator::ACCESS_CHECK: { |
| if (it.HasAccess()) continue; |
| result = JSObject::GetPropertyAttributesWithFailedAccessCheck(&it); |
| if (result.IsNothing()) return MaybeHandle<Object>(); |
| if (result.FromJust() != ABSENT) return it.GetName(); |
| return isolate->factory()->undefined_value(); |
| } |
| case LookupIterator::INTEGER_INDEXED_EXOTIC: |
| // TypedArray out-of-bounds access. |
| return isolate->factory()->undefined_value(); |
| case LookupIterator::ACCESSOR: |
| case LookupIterator::DATA: |
| return it.GetName(); |
| } |
| } |
| return isolate->factory()->undefined_value(); |
| } |
| |
| MaybeHandle<Object> Filter(Handle<JSReceiver> receiver, Handle<Object> key) { |
| Isolate* const isolate = receiver->GetIsolate(); |
| return HasEnumerableProperty(isolate, receiver, key); |
| } |
| |
| } // namespace |
| |
| |
| RUNTIME_FUNCTION(Runtime_ForInEnumerate) { |
| HandleScope scope(isolate); |
| DCHECK_EQ(1, args.length()); |
| CONVERT_ARG_HANDLE_CHECKED(JSReceiver, receiver, 0); |
| Handle<HeapObject> result; |
| ASSIGN_RETURN_FAILURE_ON_EXCEPTION(isolate, result, Enumerate(receiver)); |
| return *result; |
| } |
| |
| |
| RUNTIME_FUNCTION_RETURN_TRIPLE(Runtime_ForInPrepare) { |
| HandleScope scope(isolate); |
| DCHECK_EQ(1, args.length()); |
| Handle<JSReceiver> receiver = args.at<JSReceiver>(0); |
| Handle<Object> cache_type; |
| if (!Enumerate(receiver).ToHandle(&cache_type)) { |
| return MakeTriple(isolate->heap()->exception(), nullptr, nullptr); |
| } |
| Handle<FixedArray> cache_array; |
| int cache_length; |
| if (cache_type->IsMap()) { |
| Handle<Map> cache_map = Handle<Map>::cast(cache_type); |
| Handle<DescriptorArray> descriptors(cache_map->instance_descriptors(), |
| isolate); |
| cache_length = cache_map->EnumLength(); |
| if (cache_length && descriptors->HasEnumCache()) { |
| cache_array = handle(descriptors->GetEnumCache(), isolate); |
| } else { |
| cache_array = isolate->factory()->empty_fixed_array(); |
| cache_length = 0; |
| } |
| } else { |
| cache_array = Handle<FixedArray>::cast(cache_type); |
| cache_length = cache_array->length(); |
| cache_type = handle(Smi::FromInt(1), isolate); |
| } |
| return MakeTriple(*cache_type, *cache_array, Smi::FromInt(cache_length)); |
| } |
| |
| |
| RUNTIME_FUNCTION(Runtime_ForInDone) { |
| SealHandleScope scope(isolate); |
| DCHECK_EQ(2, args.length()); |
| CONVERT_SMI_ARG_CHECKED(index, 0); |
| CONVERT_SMI_ARG_CHECKED(length, 1); |
| DCHECK_LE(0, index); |
| DCHECK_LE(index, length); |
| return isolate->heap()->ToBoolean(index == length); |
| } |
| |
| |
| RUNTIME_FUNCTION(Runtime_ForInFilter) { |
| HandleScope scope(isolate); |
| DCHECK_EQ(2, args.length()); |
| CONVERT_ARG_HANDLE_CHECKED(JSReceiver, receiver, 0); |
| CONVERT_ARG_HANDLE_CHECKED(Object, key, 1); |
| Handle<Object> result; |
| ASSIGN_RETURN_FAILURE_ON_EXCEPTION(isolate, result, Filter(receiver, key)); |
| return *result; |
| } |
| |
| |
| RUNTIME_FUNCTION(Runtime_ForInNext) { |
| HandleScope scope(isolate); |
| DCHECK_EQ(4, args.length()); |
| CONVERT_ARG_HANDLE_CHECKED(JSReceiver, receiver, 0); |
| CONVERT_ARG_HANDLE_CHECKED(FixedArray, cache_array, 1); |
| CONVERT_ARG_HANDLE_CHECKED(Object, cache_type, 2); |
| CONVERT_SMI_ARG_CHECKED(index, 3); |
| Handle<Object> key = handle(cache_array->get(index), isolate); |
| // Don't need filtering if expected map still matches that of the receiver. |
| if (receiver->map() == *cache_type) { |
| return *key; |
| } |
| Handle<Object> result; |
| ASSIGN_RETURN_FAILURE_ON_EXCEPTION(isolate, result, Filter(receiver, key)); |
| return *result; |
| } |
| |
| |
| RUNTIME_FUNCTION(Runtime_ForInStep) { |
| SealHandleScope scope(isolate); |
| DCHECK_EQ(1, args.length()); |
| CONVERT_SMI_ARG_CHECKED(index, 0); |
| DCHECK_LE(0, index); |
| DCHECK_LT(index, Smi::kMaxValue); |
| return Smi::FromInt(index + 1); |
| } |
| |
| } // namespace internal |
| } // namespace v8 |