// 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-inl.h" #include "src/elements.h" #include "src/heap/factory.h" #include "src/isolate-inl.h" #include "src/keys.h" #include "src/objects-inl.h" #include "src/objects/module.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(Isolate* isolate, Handle<JSReceiver> receiver) { JSObject::MakePrototypesFast(receiver, kStartAtReceiver, isolate); FastKeyAccumulator accumulator(isolate, receiver, KeyCollectionMode::kIncludePrototypes, ENUMERABLE_STRINGS, true); // 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(GetKeysConversion::kConvertToString), HeapObject); // Test again, since cache may have been built by GetKeys() calls above. if (!accumulator.is_receiver_simple_enum()) return keys; } DCHECK(!receiver->IsJSModuleNamespace()); return handle(receiver->map(), isolate); } // This is a slight modifcation of JSReceiver::HasProperty, dealing with // the oddities of JSProxy and JSModuleNamespace 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(isolate)) { return isolate->factory()->undefined_value(); } // 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: { if (it.GetHolder<Object>()->IsJSModuleNamespace()) { result = JSModuleNamespace::GetPropertyAttributes(&it); if (result.IsNothing()) return MaybeHandle<Object>(); DCHECK_EQ(0, result.FromJust() & DONT_ENUM); } return it.GetName(); } case LookupIterator::DATA: return it.GetName(); } } return isolate->factory()->undefined_value(); } } // namespace RUNTIME_FUNCTION(Runtime_ForInEnumerate) { HandleScope scope(isolate); DCHECK_EQ(1, args.length()); CONVERT_ARG_HANDLE_CHECKED(JSReceiver, receiver, 0); RETURN_RESULT_OR_FAILURE(isolate, Enumerate(isolate, receiver)); } RUNTIME_FUNCTION(Runtime_ForInHasProperty) { 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, HasEnumerableProperty(isolate, receiver, key)); return isolate->heap()->ToBoolean(!result->IsUndefined(isolate)); } } // namespace internal } // namespace v8