blob: e7bfd039de84f8f7937720aea77d658a581b912b [file] [log] [blame]
// Copyright 2011 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/objects/property-descriptor.h"
#include "src/execution/isolate-inl.h"
#include "src/heap/factory.h"
#include "src/heap/heap-inl.h" // For ToBoolean. TODO(jkummerow): Drop.
#include "src/init/bootstrapper.h"
#include "src/objects/lookup.h"
#include "src/objects/objects-inl.h"
#include "src/objects/property-descriptor-object-inl.h"
namespace v8 {
namespace internal {
namespace {
// Helper function for ToPropertyDescriptor. Comments describe steps for
// "enumerable", other properties are handled the same way.
// Returns false if an exception was thrown.
bool GetPropertyIfPresent(Handle<JSReceiver> receiver, Handle<String> name,
Handle<Object>* value) {
LookupIterator it(receiver->GetIsolate(), receiver, name, receiver);
// 4. Let hasEnumerable be HasProperty(Obj, "enumerable").
Maybe<bool> has_property = JSReceiver::HasProperty(&it);
// 5. ReturnIfAbrupt(hasEnumerable).
if (has_property.IsNothing()) return false;
// 6. If hasEnumerable is true, then
if (has_property.FromJust() == true) {
// 6a. Let enum be ToBoolean(Get(Obj, "enumerable")).
// 6b. ReturnIfAbrupt(enum).
if (!Object::GetProperty(&it).ToHandle(value)) return false;
}
return true;
}
// Helper function for ToPropertyDescriptor. Handles the case of "simple"
// objects: nothing on the prototype chain, just own fast data properties.
// Must not have observable side effects, because the slow path will restart
// the entire conversion!
bool ToPropertyDescriptorFastPath(Isolate* isolate, Handle<JSReceiver> obj,
PropertyDescriptor* desc) {
if (!obj->IsJSObject()) return false;
Handle<Map> map(Handle<JSObject>::cast(obj)->map(), isolate);
if (map->instance_type() != JS_OBJECT_TYPE) return false;
if (map->is_access_check_needed()) return false;
if (map->prototype() != *isolate->initial_object_prototype()) return false;
// During bootstrapping, the object_function_prototype_map hasn't been
// set up yet.
if (isolate->bootstrapper()->IsActive()) return false;
if (JSObject::cast(map->prototype()).map() !=
isolate->native_context()->object_function_prototype_map()) {
return false;
}
// TODO(jkummerow): support dictionary properties?
if (map->is_dictionary_map()) return false;
Handle<DescriptorArray> descs =
Handle<DescriptorArray>(map->instance_descriptors(kRelaxedLoad), isolate);
for (InternalIndex i : map->IterateOwnDescriptors()) {
PropertyDetails details = descs->GetDetails(i);
Handle<Object> value;
if (details.location() == kField) {
if (details.kind() == kData) {
value = JSObject::FastPropertyAt(Handle<JSObject>::cast(obj),
details.representation(),
FieldIndex::ForDescriptor(*map, i));
} else {
DCHECK_EQ(kAccessor, details.kind());
// Bail out to slow path.
return false;
}
} else {
DCHECK_EQ(kDescriptor, details.location());
if (details.kind() == kData) {
value = handle(descs->GetStrongValue(i), isolate);
} else {
DCHECK_EQ(kAccessor, details.kind());
// Bail out to slow path.
return false;
}
}
Name key = descs->GetKey(i);
ReadOnlyRoots roots(isolate);
if (key == roots.enumerable_string()) {
desc->set_enumerable(value->BooleanValue(isolate));
} else if (key == roots.configurable_string()) {
desc->set_configurable(value->BooleanValue(isolate));
} else if (key == roots.value_string()) {
desc->set_value(value);
} else if (key == roots.writable_string()) {
desc->set_writable(value->BooleanValue(isolate));
} else if (key == roots.get_string()) {
// Bail out to slow path to throw an exception if necessary.
if (!value->IsCallable()) return false;
desc->set_get(value);
} else if (key == roots.set_string()) {
// Bail out to slow path to throw an exception if necessary.
if (!value->IsCallable()) return false;
desc->set_set(value);
}
}
if ((desc->has_get() || desc->has_set()) &&
(desc->has_value() || desc->has_writable())) {
// Bail out to slow path to throw an exception.
return false;
}
return true;
}
void CreateDataProperty(Handle<JSObject> object, Handle<String> name,
Handle<Object> value) {
LookupIterator it(object->GetIsolate(), object, name, object,
LookupIterator::OWN_SKIP_INTERCEPTOR);
Maybe<bool> result = JSObject::CreateDataProperty(&it, value);
CHECK(result.IsJust() && result.FromJust());
}
} // namespace
// ES6 6.2.4.4 "FromPropertyDescriptor"
Handle<Object> PropertyDescriptor::ToObject(Isolate* isolate) {
DCHECK(!(PropertyDescriptor::IsAccessorDescriptor(this) &&
PropertyDescriptor::IsDataDescriptor(this)));
Factory* factory = isolate->factory();
if (IsRegularAccessorProperty()) {
// Fast case for regular accessor properties.
Handle<JSObject> result = factory->NewJSObjectFromMap(
isolate->accessor_property_descriptor_map());
result->InObjectPropertyAtPut(JSAccessorPropertyDescriptor::kGetIndex,
*get());
result->InObjectPropertyAtPut(JSAccessorPropertyDescriptor::kSetIndex,
*set());
result->InObjectPropertyAtPut(
JSAccessorPropertyDescriptor::kEnumerableIndex,
isolate->heap()->ToBoolean(enumerable()));
result->InObjectPropertyAtPut(
JSAccessorPropertyDescriptor::kConfigurableIndex,
isolate->heap()->ToBoolean(configurable()));
return result;
}
if (IsRegularDataProperty()) {
// Fast case for regular data properties.
Handle<JSObject> result =
factory->NewJSObjectFromMap(isolate->data_property_descriptor_map());
result->InObjectPropertyAtPut(JSDataPropertyDescriptor::kValueIndex,
*value());
result->InObjectPropertyAtPut(JSDataPropertyDescriptor::kWritableIndex,
isolate->heap()->ToBoolean(writable()));
result->InObjectPropertyAtPut(JSDataPropertyDescriptor::kEnumerableIndex,
isolate->heap()->ToBoolean(enumerable()));
result->InObjectPropertyAtPut(JSDataPropertyDescriptor::kConfigurableIndex,
isolate->heap()->ToBoolean(configurable()));
return result;
}
Handle<JSObject> result = factory->NewJSObject(isolate->object_function());
if (has_value()) {
CreateDataProperty(result, factory->value_string(), value());
}
if (has_writable()) {
CreateDataProperty(result, factory->writable_string(),
factory->ToBoolean(writable()));
}
if (has_get()) {
CreateDataProperty(result, factory->get_string(), get());
}
if (has_set()) {
CreateDataProperty(result, factory->set_string(), set());
}
if (has_enumerable()) {
CreateDataProperty(result, factory->enumerable_string(),
factory->ToBoolean(enumerable()));
}
if (has_configurable()) {
CreateDataProperty(result, factory->configurable_string(),
factory->ToBoolean(configurable()));
}
return result;
}
// ES6 6.2.4.5
// Returns false in case of exception.
// static
bool PropertyDescriptor::ToPropertyDescriptor(Isolate* isolate,
Handle<Object> obj,
PropertyDescriptor* desc) {
// 1. ReturnIfAbrupt(Obj).
// 2. If Type(Obj) is not Object, throw a TypeError exception.
if (!obj->IsJSReceiver()) {
isolate->Throw(*isolate->factory()->NewTypeError(
MessageTemplate::kPropertyDescObject, obj));
return false;
}
// 3. Let desc be a new Property Descriptor that initially has no fields.
DCHECK(desc->is_empty());
Handle<JSReceiver> receiver = Handle<JSReceiver>::cast(obj);
if (ToPropertyDescriptorFastPath(isolate, receiver, desc)) {
return true;
}
// enumerable?
Handle<Object> enumerable;
// 4 through 6b.
if (!GetPropertyIfPresent(receiver, isolate->factory()->enumerable_string(),
&enumerable)) {
return false;
}
// 6c. Set the [[Enumerable]] field of desc to enum.
if (!enumerable.is_null()) {
desc->set_enumerable(enumerable->BooleanValue(isolate));
}
// configurable?
Handle<Object> configurable;
// 7 through 9b.
if (!GetPropertyIfPresent(receiver, isolate->factory()->configurable_string(),
&configurable)) {
return false;
}
// 9c. Set the [[Configurable]] field of desc to conf.
if (!configurable.is_null()) {
desc->set_configurable(configurable->BooleanValue(isolate));
}
// value?
Handle<Object> value;
// 10 through 12b.
if (!GetPropertyIfPresent(receiver, isolate->factory()->value_string(),
&value)) {
return false;
}
// 12c. Set the [[Value]] field of desc to value.
if (!value.is_null()) desc->set_value(value);
// writable?
Handle<Object> writable;
// 13 through 15b.
if (!GetPropertyIfPresent(receiver, isolate->factory()->writable_string(),
&writable)) {
return false;
}
// 15c. Set the [[Writable]] field of desc to writable.
if (!writable.is_null()) desc->set_writable(writable->BooleanValue(isolate));
// getter?
Handle<Object> getter;
// 16 through 18b.
if (!GetPropertyIfPresent(receiver, isolate->factory()->get_string(),
&getter)) {
return false;
}
if (!getter.is_null()) {
// 18c. If IsCallable(getter) is false and getter is not undefined,
// throw a TypeError exception.
if (!getter->IsCallable() && !getter->IsUndefined(isolate)) {
isolate->Throw(*isolate->factory()->NewTypeError(
MessageTemplate::kObjectGetterCallable, getter));
return false;
}
// 18d. Set the [[Get]] field of desc to getter.
desc->set_get(getter);
}
// setter?
Handle<Object> setter;
// 19 through 21b.
if (!GetPropertyIfPresent(receiver, isolate->factory()->set_string(),
&setter)) {
return false;
}
if (!setter.is_null()) {
// 21c. If IsCallable(setter) is false and setter is not undefined,
// throw a TypeError exception.
if (!setter->IsCallable() && !setter->IsUndefined(isolate)) {
isolate->Throw(*isolate->factory()->NewTypeError(
MessageTemplate::kObjectSetterCallable, setter));
return false;
}
// 21d. Set the [[Set]] field of desc to setter.
desc->set_set(setter);
}
// 22. If either desc.[[Get]] or desc.[[Set]] is present, then
// 22a. If either desc.[[Value]] or desc.[[Writable]] is present,
// throw a TypeError exception.
if ((desc->has_get() || desc->has_set()) &&
(desc->has_value() || desc->has_writable())) {
isolate->Throw(*isolate->factory()->NewTypeError(
MessageTemplate::kValueAndAccessor, obj));
return false;
}
// 23. Return desc.
return true;
}
// ES6 6.2.4.6
// static
void PropertyDescriptor::CompletePropertyDescriptor(Isolate* isolate,
PropertyDescriptor* desc) {
// 1. ReturnIfAbrupt(Desc).
// 2. Assert: Desc is a Property Descriptor.
// 3. Let like be Record{
// [[Value]]: undefined, [[Writable]]: false,
// [[Get]]: undefined, [[Set]]: undefined,
// [[Enumerable]]: false, [[Configurable]]: false}.
// 4. If either IsGenericDescriptor(Desc) or IsDataDescriptor(Desc) is true,
// then:
if (!IsAccessorDescriptor(desc)) {
// 4a. If Desc does not have a [[Value]] field, set Desc.[[Value]] to
// like.[[Value]].
if (!desc->has_value()) {
desc->set_value(isolate->factory()->undefined_value());
}
// 4b. If Desc does not have a [[Writable]] field, set Desc.[[Writable]]
// to like.[[Writable]].
if (!desc->has_writable()) desc->set_writable(false);
} else {
// 5. Else,
// 5a. If Desc does not have a [[Get]] field, set Desc.[[Get]] to
// like.[[Get]].
if (!desc->has_get()) {
desc->set_get(isolate->factory()->undefined_value());
}
// 5b. If Desc does not have a [[Set]] field, set Desc.[[Set]] to
// like.[[Set]].
if (!desc->has_set()) {
desc->set_set(isolate->factory()->undefined_value());
}
}
// 6. If Desc does not have an [[Enumerable]] field, set
// Desc.[[Enumerable]] to like.[[Enumerable]].
if (!desc->has_enumerable()) desc->set_enumerable(false);
// 7. If Desc does not have a [[Configurable]] field, set
// Desc.[[Configurable]] to like.[[Configurable]].
if (!desc->has_configurable()) desc->set_configurable(false);
// 8. Return Desc.
}
Handle<PropertyDescriptorObject> PropertyDescriptor::ToPropertyDescriptorObject(
Isolate* isolate) {
Handle<PropertyDescriptorObject> obj =
isolate->factory()->NewPropertyDescriptorObject();
int flags =
PropertyDescriptorObject::IsEnumerableBit::encode(enumerable_) |
PropertyDescriptorObject::HasEnumerableBit::encode(has_enumerable_) |
PropertyDescriptorObject::IsConfigurableBit::encode(configurable_) |
PropertyDescriptorObject::HasConfigurableBit::encode(has_configurable_) |
PropertyDescriptorObject::IsWritableBit::encode(writable_) |
PropertyDescriptorObject::HasWritableBit::encode(has_writable_) |
PropertyDescriptorObject::HasValueBit::encode(has_value()) |
PropertyDescriptorObject::HasGetBit::encode(has_get()) |
PropertyDescriptorObject::HasSetBit::encode(has_set());
obj->set_flags(flags);
if (has_value()) obj->set_value(*value_);
if (has_get()) obj->set_get(*get_);
if (has_set()) obj->set_set(*set_);
return obj;
}
} // namespace internal
} // namespace v8