// Copyright 2013 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/keys.h"
#include "src/api-arguments-inl.h"
#include "src/elements-inl.h"
#include "src/handles-inl.h"
#include "src/heap/factory.h"
#include "src/identity-map.h"
#include "src/isolate-inl.h"
#include "src/objects-inl.h"
#include "src/objects/api-callbacks.h"
#include "src/objects/hash-table-inl.h"
#include "src/objects/module-inl.h"
#include "src/property-descriptor.h"
#include "src/prototype.h"
namespace v8 {
namespace internal {
KeyAccumulator::~KeyAccumulator() {
}
namespace {
static bool ContainsOnlyValidKeys(Handle<FixedArray> array) {
int len = array->length();
for (int i = 0; i < len; i++) {
Object* e = array->get(i);
if (!(e->IsName() || e->IsNumber())) return false;
}
return true;
}
} // namespace
// static
MaybeHandle<FixedArray> KeyAccumulator::GetKeys(
Handle<JSReceiver> object, KeyCollectionMode mode, PropertyFilter filter,
GetKeysConversion keys_conversion, bool is_for_in, bool skip_indices) {
Isolate* isolate = object->GetIsolate();
FastKeyAccumulator accumulator(isolate, object, mode, filter, is_for_in,
skip_indices);
return accumulator.GetKeys(keys_conversion);
}
Handle<FixedArray> KeyAccumulator::GetKeys(GetKeysConversion convert) {
if (keys_.is_null()) {
return isolate_->factory()->empty_fixed_array();
}
if (mode_ == KeyCollectionMode::kOwnOnly &&
keys_->map() == ReadOnlyRoots(isolate_).fixed_array_map()) {
return Handle<FixedArray>::cast(keys_);
}
USE(ContainsOnlyValidKeys);
Handle<FixedArray> result =
OrderedHashSet::ConvertToKeysArray(isolate(), keys(), convert);
DCHECK(ContainsOnlyValidKeys(result));
return result;
}
Handle<OrderedHashSet> KeyAccumulator::keys() {
return Handle<OrderedHashSet>::cast(keys_);
}
void KeyAccumulator::AddKey(Object* key, AddKeyConversion convert) {
AddKey(handle(key, isolate_), convert);
}
void KeyAccumulator::AddKey(Handle<Object> key, AddKeyConversion convert) {
if (key->IsSymbol()) {
if (filter_ & SKIP_SYMBOLS) return;
if (Handle<Symbol>::cast(key)->is_private()) return;
} else if (filter_ & SKIP_STRINGS) {
return;
}
if (IsShadowed(key)) return;
if (keys_.is_null()) {
keys_ = OrderedHashSet::Allocate(isolate_, 16);
}
uint32_t index;
if (convert == CONVERT_TO_ARRAY_INDEX && key->IsString() &&
Handle<String>::cast(key)->AsArrayIndex(&index)) {
key = isolate_->factory()->NewNumberFromUint(index);
}
Handle<OrderedHashSet> new_set = OrderedHashSet::Add(isolate(), keys(), key);
if (*new_set != *keys_) {
// The keys_ Set is converted directly to a FixedArray in GetKeys which can
// be left-trimmer. Hence the previous Set should not keep a pointer to the
// new one.
keys_->set(OrderedHashTableBase::kNextTableIndex, Smi::kZero);
keys_ = new_set;
}
}
void KeyAccumulator::AddKeys(Handle<FixedArray> array,
AddKeyConversion convert) {
int add_length = array->length();
for (int i = 0; i < add_length; i++) {
Handle<Object> current(array->get(i), isolate_);
AddKey(current, convert);
}
}
void KeyAccumulator::AddKeys(Handle<JSObject> array_like,
AddKeyConversion convert) {
DCHECK(array_like->IsJSArray() || array_like->HasSloppyArgumentsElements());
ElementsAccessor* accessor = array_like->GetElementsAccessor();
accessor->AddElementsToKeyAccumulator(array_like, this, convert);
}
MaybeHandle<FixedArray> FilterProxyKeys(KeyAccumulator* accumulator,
Handle<JSProxy> owner,
Handle<FixedArray> keys,
PropertyFilter filter) {
if (filter == ALL_PROPERTIES) {
// Nothing to do.
return keys;
}
Isolate* isolate = accumulator->isolate();
int store_position = 0;
for (int i = 0; i < keys->length(); ++i) {
Handle<Name> key(Name::cast(keys->get(i)), isolate);
if (key->FilterKey(filter)) continue; // Skip this key.
if (filter & ONLY_ENUMERABLE) {
PropertyDescriptor desc;
Maybe<bool> found =
JSProxy::GetOwnPropertyDescriptor(isolate, owner, key, &desc);
MAYBE_RETURN(found, MaybeHandle<FixedArray>());
if (!found.FromJust()) continue;
if (!desc.enumerable()) {
accumulator->AddShadowingKey(key);
continue;
}
}
// Keep this key.
if (store_position != i) {
keys->set(store_position, *key);
}
store_position++;
}
return FixedArray::ShrinkOrEmpty(isolate, keys, store_position);
}
// Returns "nothing" in case of exception, "true" on success.
Maybe<bool> KeyAccumulator::AddKeysFromJSProxy(Handle<JSProxy> proxy,
Handle<FixedArray> keys) {
// Postpone the enumerable check for for-in to the ForInFilter step.
if (!is_for_in_) {
ASSIGN_RETURN_ON_EXCEPTION_VALUE(
isolate_, keys, FilterProxyKeys(this, proxy, keys, filter_),
Nothing<bool>());
if (mode_ == KeyCollectionMode::kOwnOnly) {
// If we collect only the keys from a JSProxy do not sort or deduplicate.
keys_ = keys;
return Just(true);
}
}
AddKeys(keys, is_for_in_ ? CONVERT_TO_ARRAY_INDEX : DO_NOT_CONVERT);
return Just(true);
}
Maybe<bool> KeyAccumulator::CollectKeys(Handle<JSReceiver> receiver,
Handle<JSReceiver> object) {
// Proxies have no hidden prototype and we should not trigger the
// [[GetPrototypeOf]] trap on the last iteration when using
// AdvanceFollowingProxies.
if (mode_ == KeyCollectionMode::kOwnOnly && object->IsJSProxy()) {
MAYBE_RETURN(CollectOwnJSProxyKeys(receiver, Handle<JSProxy>::cast(object)),
Nothing<bool>());
return Just(true);
}
PrototypeIterator::WhereToEnd end = mode_ == KeyCollectionMode::kOwnOnly
? PrototypeIterator::END_AT_NON_HIDDEN
: PrototypeIterator::END_AT_NULL;
for (PrototypeIterator iter(isolate_, object, kStartAtReceiver, end);
!iter.IsAtEnd();) {
// Start the shadow checks only after the first prototype has added
// shadowing keys.
if (HasShadowingKeys()) skip_shadow_check_ = false;
Handle<JSReceiver> current =
PrototypeIterator::GetCurrent<JSReceiver>(iter);
Maybe<bool> result = Just(false); // Dummy initialization.
if (current->IsJSProxy()) {
result = CollectOwnJSProxyKeys(receiver, Handle<JSProxy>::cast(current));
} else {
DCHECK(current->IsJSObject());
result = CollectOwnKeys(receiver, Handle<JSObject>::cast(current));
}
MAYBE_RETURN(result, Nothing<bool>());
if (!result.FromJust()) break; // |false| means "stop iterating".
// Iterate through proxies but ignore access checks for the ALL_CAN_READ
// case on API objects for OWN_ONLY keys handled in CollectOwnKeys.
if (!iter.AdvanceFollowingProxiesIgnoringAccessChecks()) {
return Nothing<bool>();
}
if (!last_non_empty_prototype_.is_null() &&
*last_non_empty_prototype_ == *current) {
break;
}
}
return Just(true);
}
bool KeyAccumulator::HasShadowingKeys() { return !shadowing_keys_.is_null(); }
bool KeyAccumulator::IsShadowed(Handle<Object> key) {
if (!HasShadowingKeys() || skip_shadow_check_) return false;
return shadowing_keys_->Has(isolate_, key);
}
void KeyAccumulator::AddShadowingKey(Object* key) {
if (mode_ == KeyCollectionMode::kOwnOnly) return;
AddShadowingKey(handle(key, isolate_));
}
void KeyAccumulator::AddShadowingKey(Handle<Object> key) {
if (mode_ == KeyCollectionMode::kOwnOnly) return;
if (shadowing_keys_.is_null()) {
shadowing_keys_ = ObjectHashSet::New(isolate_, 16);
}
shadowing_keys_ = ObjectHashSet::Add(isolate(), shadowing_keys_, key);
}
namespace {
void TrySettingEmptyEnumCache(JSReceiver* object) {
Map* map = object->map();
DCHECK_EQ(kInvalidEnumCacheSentinel, map->EnumLength());
if (!map->OnlyHasSimpleProperties()) return;
if (map->IsJSProxyMap()) return;
if (map->NumberOfEnumerableProperties() > 0) return;
DCHECK(object->IsJSObject());
map->SetEnumLength(0);
}
bool CheckAndInitalizeEmptyEnumCache(JSReceiver* object) {
if (object->map()->EnumLength() == kInvalidEnumCacheSentinel) {
TrySettingEmptyEnumCache(object);
}
if (object->map()->EnumLength() != 0) return false;
DCHECK(object->IsJSObject());
return !JSObject::cast(object)->HasEnumerableElements();
}
} // namespace
void FastKeyAccumulator::Prepare() {
DisallowHeapAllocation no_gc;
// Directly go for the fast path for OWN_ONLY keys.
if (mode_ == KeyCollectionMode::kOwnOnly) return;
// Fully walk the prototype chain and find the last prototype with keys.
is_receiver_simple_enum_ = false;
has_empty_prototype_ = true;
JSReceiver* last_prototype = nullptr;
for (PrototypeIterator iter(isolate_, *receiver_); !iter.IsAtEnd();
iter.Advance()) {
JSReceiver* current = iter.GetCurrent<JSReceiver>();
bool has_no_properties = CheckAndInitalizeEmptyEnumCache(current);
if (has_no_properties) continue;
last_prototype = current;
has_empty_prototype_ = false;
}
if (has_empty_prototype_) {
is_receiver_simple_enum_ =
receiver_->map()->EnumLength() != kInvalidEnumCacheSentinel &&
!JSObject::cast(*receiver_)->HasEnumerableElements();
} else if (last_prototype != nullptr) {
last_non_empty_prototype_ = handle(last_prototype, isolate_);
}
}
namespace {
Handle<FixedArray> ReduceFixedArrayTo(Isolate* isolate,
Handle<FixedArray> array, int length) {
DCHECK_LE(length, array->length());
if (array->length() == length) return array;
return isolate->factory()->CopyFixedArrayUpTo(array, length);
}
// Initializes and directly returns the enume cache. Users of this function
// have to make sure to never directly leak the enum cache.
Handle<FixedArray> GetFastEnumPropertyKeys(Isolate* isolate,
Handle<JSObject> object) {
Handle<Map> map(object->map(), isolate);
Handle<FixedArray> keys(map->instance_descriptors()->GetEnumCache()->keys(),
isolate);
// Check if the {map} has a valid enum length, which implies that it
// must have a valid enum cache as well.
int enum_length = map->EnumLength();
if (enum_length != kInvalidEnumCacheSentinel) {
DCHECK(map->OnlyHasSimpleProperties());
DCHECK_LE(enum_length, keys->length());
DCHECK_EQ(enum_length, map->NumberOfEnumerableProperties());
isolate->counters()->enum_cache_hits()->Increment();
return ReduceFixedArrayTo(isolate, keys, enum_length);
}
// Determine the actual number of enumerable properties of the {map}.
enum_length = map->NumberOfEnumerableProperties();
// Check if there's already a shared enum cache on the {map}s
// DescriptorArray with sufficient number of entries.
if (enum_length <= keys->length()) {
if (map->OnlyHasSimpleProperties()) map->SetEnumLength(enum_length);
isolate->counters()->enum_cache_hits()->Increment();
return ReduceFixedArrayTo(isolate, keys, enum_length);
}
Handle<DescriptorArray> descriptors =
Handle<DescriptorArray>(map->instance_descriptors(), isolate);
isolate->counters()->enum_cache_misses()->Increment();
int nod = map->NumberOfOwnDescriptors();
// Create the keys array.
int index = 0;
bool fields_only = true;
keys = isolate->factory()->NewFixedArray(enum_length);
for (int i = 0; i < nod; i++) {
DisallowHeapAllocation no_gc;
PropertyDetails details = descriptors->GetDetails(i);
if (details.IsDontEnum()) continue;
Object* key = descriptors->GetKey(i);
if (key->IsSymbol()) continue;
keys->set(index, key);
if (details.location() != kField) fields_only = false;
index++;
}
DCHECK_EQ(index, keys->length());
// Optionally also create the indices array.
Handle<FixedArray> indices = isolate->factory()->empty_fixed_array();
if (fields_only) {
indices = isolate->factory()->NewFixedArray(enum_length);
index = 0;
for (int i = 0; i < nod; i++) {
DisallowHeapAllocation no_gc;
PropertyDetails details = descriptors->GetDetails(i);
if (details.IsDontEnum()) continue;
Object* key = descriptors->GetKey(i);
if (key->IsSymbol()) continue;
DCHECK_EQ(kData, details.kind());
DCHECK_EQ(kField, details.location());
FieldIndex field_index = FieldIndex::ForDescriptor(*map, i);
indices->set(index, Smi::FromInt(field_index.GetLoadByFieldIndex()));
index++;
}
DCHECK_EQ(index, indices->length());
}
DescriptorArray::SetEnumCache(descriptors, isolate, keys, indices);
if (map->OnlyHasSimpleProperties()) map->SetEnumLength(enum_length);
return keys;
}
template <bool fast_properties>
MaybeHandle<FixedArray> GetOwnKeysWithElements(Isolate* isolate,
Handle<JSObject> object,
GetKeysConversion convert,
bool skip_indices) {
Handle<FixedArray> keys;
ElementsAccessor* accessor = object->GetElementsAccessor();
if (fast_properties) {
keys = GetFastEnumPropertyKeys(isolate, object);
} else {
// TODO(cbruni): preallocate big enough array to also hold elements.
keys = KeyAccumulator::GetOwnEnumPropertyKeys(isolate, object);
}
MaybeHandle<FixedArray> result;
if (skip_indices) {
result = keys;
} else {
result =
accessor->PrependElementIndices(object, keys, convert, ONLY_ENUMERABLE);
}
if (FLAG_trace_for_in_enumerate) {
PrintF("| strings=%d symbols=0 elements=%u || prototypes>=1 ||\n",
keys->length(), result.ToHandleChecked()->length() - keys->length());
}
return result;
}
} // namespace
MaybeHandle<FixedArray> FastKeyAccumulator::GetKeys(
GetKeysConversion keys_conversion) {
if (filter_ == ENUMERABLE_STRINGS) {
Handle<FixedArray> keys;
if (GetKeysFast(keys_conversion).ToHandle(&keys)) {
return keys;
}
if (isolate_->has_pending_exception()) return MaybeHandle<FixedArray>();
}
return GetKeysSlow(keys_conversion);
}
MaybeHandle<FixedArray> FastKeyAccumulator::GetKeysFast(
GetKeysConversion keys_conversion) {
bool own_only = has_empty_prototype_ || mode_ == KeyCollectionMode::kOwnOnly;
Map* map = receiver_->map();
if (!own_only || map->IsCustomElementsReceiverMap()) {
return MaybeHandle<FixedArray>();
}
// From this point on we are certain to only collect own keys.
DCHECK(receiver_->IsJSObject());
Handle<JSObject> object = Handle<JSObject>::cast(receiver_);
// Do not try to use the enum-cache for dict-mode objects.
if (map->is_dictionary_map()) {
return GetOwnKeysWithElements<false>(isolate_, object, keys_conversion,
skip_indices_);
}
int enum_length = receiver_->map()->EnumLength();
if (enum_length == kInvalidEnumCacheSentinel) {
Handle<FixedArray> keys;
// Try initializing the enum cache and return own properties.
if (GetOwnKeysWithUninitializedEnumCache().ToHandle(&keys)) {
if (FLAG_trace_for_in_enumerate) {
PrintF("| strings=%d symbols=0 elements=0 || prototypes>=1 ||\n",
keys->length());
}
is_receiver_simple_enum_ =
object->map()->EnumLength() != kInvalidEnumCacheSentinel;
return keys;
}
}
// The properties-only case failed because there were probably elements on the
// receiver.
return GetOwnKeysWithElements<true>(isolate_, object, keys_conversion,
skip_indices_);
}
MaybeHandle<FixedArray>
FastKeyAccumulator::GetOwnKeysWithUninitializedEnumCache() {
Handle<JSObject> object = Handle<JSObject>::cast(receiver_);
// Uninitalized enum cache
Map* map = object->map();
if (object->elements()->length() != 0) {
// Assume that there are elements.
return MaybeHandle<FixedArray>();
}
int number_of_own_descriptors = map->NumberOfOwnDescriptors();
if (number_of_own_descriptors == 0) {
map->SetEnumLength(0);
return isolate_->factory()->empty_fixed_array();
}
// We have no elements but possibly enumerable property keys, hence we can
// directly initialize the enum cache.
Handle<FixedArray> keys = GetFastEnumPropertyKeys(isolate_, object);
if (is_for_in_) return keys;
// Do not leak the enum cache as it might end up as an elements backing store.
return isolate_->factory()->CopyFixedArray(keys);
}
MaybeHandle<FixedArray> FastKeyAccumulator::GetKeysSlow(
GetKeysConversion keys_conversion) {
KeyAccumulator accumulator(isolate_, mode_, filter_);
accumulator.set_is_for_in(is_for_in_);
accumulator.set_skip_indices(skip_indices_);
accumulator.set_last_non_empty_prototype(last_non_empty_prototype_);
MAYBE_RETURN(accumulator.CollectKeys(receiver_, receiver_),
MaybeHandle<FixedArray>());
return accumulator.GetKeys(keys_conversion);
}
namespace {
enum IndexedOrNamed { kIndexed, kNamed };
void FilterForEnumerableProperties(Handle<JSReceiver> receiver,
Handle<JSObject> object,
Handle<InterceptorInfo> interceptor,
KeyAccumulator* accumulator,
Handle<JSObject> result,
IndexedOrNamed type) {
DCHECK(result->IsJSArray() || result->HasSloppyArgumentsElements());
ElementsAccessor* accessor = result->GetElementsAccessor();
uint32_t length = accessor->GetCapacity(*result, result->elements());
for (uint32_t i = 0; i < length; i++) {
if (!accessor->HasEntry(*result, i)) continue;
// args are invalid after args.Call(), create a new one in every iteration.
PropertyCallbackArguments args(accumulator->isolate(), interceptor->data(),
*receiver, *object, kDontThrow);
Handle<Object> element = accessor->Get(result, i);
Handle<Object> attributes;
if (type == kIndexed) {
uint32_t number;
CHECK(element->ToUint32(&number));
attributes = args.CallIndexedQuery(interceptor, number);
} else {
CHECK(element->IsName());
attributes =
args.CallNamedQuery(interceptor, Handle<Name>::cast(element));
}
if (!attributes.is_null()) {
int32_t value;
CHECK(attributes->ToInt32(&value));
if ((value & DONT_ENUM) == 0) {
accumulator->AddKey(element, DO_NOT_CONVERT);
}
}
}
}
// Returns |true| on success, |nothing| on exception.
Maybe<bool> CollectInterceptorKeysInternal(Handle<JSReceiver> receiver,
Handle<JSObject> object,
Handle<InterceptorInfo> interceptor,
KeyAccumulator* accumulator,
IndexedOrNamed type) {
Isolate* isolate = accumulator->isolate();
PropertyCallbackArguments enum_args(isolate, interceptor->data(), *receiver,
*object, kDontThrow);
Handle<JSObject> result;
if (!interceptor->enumerator()->IsUndefined(isolate)) {
if (type == kIndexed) {
result = enum_args.CallIndexedEnumerator(interceptor);
} else {
DCHECK_EQ(type, kNamed);
result = enum_args.CallNamedEnumerator(interceptor);
}
}
RETURN_VALUE_IF_SCHEDULED_EXCEPTION(isolate, Nothing<bool>());
if (result.is_null()) return Just(true);
if ((accumulator->filter() & ONLY_ENUMERABLE) &&
!interceptor->query()->IsUndefined(isolate)) {
FilterForEnumerableProperties(receiver, object, interceptor, accumulator,
result, type);
} else {
accumulator->AddKeys(
result, type == kIndexed ? CONVERT_TO_ARRAY_INDEX : DO_NOT_CONVERT);
}
return Just(true);
}
Maybe<bool> CollectInterceptorKeys(Handle<JSReceiver> receiver,
Handle<JSObject> object,
KeyAccumulator* accumulator,
IndexedOrNamed type) {
Isolate* isolate = accumulator->isolate();
if (type == kIndexed) {
if (!object->HasIndexedInterceptor()) return Just(true);
} else {
if (!object->HasNamedInterceptor()) return Just(true);
}
Handle<InterceptorInfo> interceptor(type == kIndexed
? object->GetIndexedInterceptor()
: object->GetNamedInterceptor(),
isolate);
if ((accumulator->filter() & ONLY_ALL_CAN_READ) &&
!interceptor->all_can_read()) {
return Just(true);
}
return CollectInterceptorKeysInternal(receiver, object, interceptor,
accumulator, type);
}
} // namespace
Maybe<bool> KeyAccumulator::CollectOwnElementIndices(
Handle<JSReceiver> receiver, Handle<JSObject> object) {
if (filter_ & SKIP_STRINGS || skip_indices_) return Just(true);
ElementsAccessor* accessor = object->GetElementsAccessor();
accessor->CollectElementIndices(object, this);
return CollectInterceptorKeys(receiver, object, this, kIndexed);
}
namespace {
template <bool skip_symbols>
int CollectOwnPropertyNamesInternal(Handle<JSObject> object,
KeyAccumulator* keys,
Handle<DescriptorArray> descs,
int start_index, int limit) {
int first_skipped = -1;
PropertyFilter filter = keys->filter();
KeyCollectionMode mode = keys->mode();
for (int i = start_index; i < limit; i++) {
bool is_shadowing_key = false;
PropertyDetails details = descs->GetDetails(i);
if ((details.attributes() & filter) != 0) {
if (mode == KeyCollectionMode::kIncludePrototypes) {
is_shadowing_key = true;
} else {
continue;
}
}
if (filter & ONLY_ALL_CAN_READ) {
if (details.kind() != kAccessor) continue;
Object* accessors = descs->GetStrongValue(i);
if (!accessors->IsAccessorInfo()) continue;
if (!AccessorInfo::cast(accessors)->all_can_read()) continue;
}
Name* key = descs->GetKey(i);
if (skip_symbols == key->IsSymbol()) {
if (first_skipped == -1) first_skipped = i;
continue;
}
if (key->FilterKey(keys->filter())) continue;
if (is_shadowing_key) {
keys->AddShadowingKey(key);
} else {
keys->AddKey(key, DO_NOT_CONVERT);
}
}
return first_skipped;
}
template <class T>
Handle<FixedArray> GetOwnEnumPropertyDictionaryKeys(Isolate* isolate,
KeyCollectionMode mode,
KeyAccumulator* accumulator,
Handle<JSObject> object,
T* raw_dictionary) {
Handle<T> dictionary(raw_dictionary, isolate);
int length = dictionary->NumberOfEnumerableProperties();
if (length == 0) {
return isolate->factory()->empty_fixed_array();
}
Handle<FixedArray> storage = isolate->factory()->NewFixedArray(length);
T::CopyEnumKeysTo(isolate, dictionary, storage, mode, accumulator);
return storage;
}
} // namespace
Maybe<bool> KeyAccumulator::CollectOwnPropertyNames(Handle<JSReceiver> receiver,
Handle<JSObject> object) {
if (filter_ == ENUMERABLE_STRINGS) {
Handle<FixedArray> enum_keys;
if (object->HasFastProperties()) {
enum_keys = KeyAccumulator::GetOwnEnumPropertyKeys(isolate_, object);
// If the number of properties equals the length of enumerable properties
// we do not have to filter out non-enumerable ones
Map* map = object->map();
int nof_descriptors = map->NumberOfOwnDescriptors();
if (enum_keys->length() != nof_descriptors) {
Handle<DescriptorArray> descs =
Handle<DescriptorArray>(map->instance_descriptors(), isolate_);
for (int i = 0; i < nof_descriptors; i++) {
PropertyDetails details = descs->GetDetails(i);
if (!details.IsDontEnum()) continue;
Object* key = descs->GetKey(i);
this->AddShadowingKey(key);
}
}
} else if (object->IsJSGlobalObject()) {
enum_keys = GetOwnEnumPropertyDictionaryKeys(
isolate_, mode_, this, object,
JSGlobalObject::cast(*object)->global_dictionary());
} else {
enum_keys = GetOwnEnumPropertyDictionaryKeys(
isolate_, mode_, this, object, object->property_dictionary());
}
if (object->IsJSModuleNamespace()) {
// Simulate [[GetOwnProperty]] for establishing enumerability, which
// throws for uninitialized exports.
for (int i = 0, n = enum_keys->length(); i < n; ++i) {
Handle<String> key(String::cast(enum_keys->get(i)), isolate_);
if (Handle<JSModuleNamespace>::cast(object)
->GetExport(isolate(), key)
.is_null()) {
return Nothing<bool>();
}
}
}
AddKeys(enum_keys, DO_NOT_CONVERT);
} else {
if (object->HasFastProperties()) {
int limit = object->map()->NumberOfOwnDescriptors();
Handle<DescriptorArray> descs(object->map()->instance_descriptors(),
isolate_);
// First collect the strings,
int first_symbol =
CollectOwnPropertyNamesInternal<true>(object, this, descs, 0, limit);
// then the symbols.
if (first_symbol != -1) {
CollectOwnPropertyNamesInternal<false>(object, this, descs,
first_symbol, limit);
}
} else if (object->IsJSGlobalObject()) {
GlobalDictionary::CollectKeysTo(
handle(JSGlobalObject::cast(*object)->global_dictionary(), isolate_),
this);
} else {
NameDictionary::CollectKeysTo(
handle(object->property_dictionary(), isolate_), this);
}
}
// Add the property keys from the interceptor.
return CollectInterceptorKeys(receiver, object, this, kNamed);
}
Maybe<bool> KeyAccumulator::CollectAccessCheckInterceptorKeys(
Handle<AccessCheckInfo> access_check_info, Handle<JSReceiver> receiver,
Handle<JSObject> object) {
if (!skip_indices_) {
MAYBE_RETURN((CollectInterceptorKeysInternal(
receiver, object,
handle(InterceptorInfo::cast(
access_check_info->indexed_interceptor()),
isolate_),
this, kIndexed)),
Nothing<bool>());
}
MAYBE_RETURN(
(CollectInterceptorKeysInternal(
receiver, object,
handle(InterceptorInfo::cast(access_check_info->named_interceptor()),
isolate_),
this, kNamed)),
Nothing<bool>());
return Just(true);
}
// Returns |true| on success, |false| if prototype walking should be stopped,
// |nothing| if an exception was thrown.
Maybe<bool> KeyAccumulator::CollectOwnKeys(Handle<JSReceiver> receiver,
Handle<JSObject> object) {
// Check access rights if required.
if (object->IsAccessCheckNeeded() &&
!isolate_->MayAccess(handle(isolate_->context(), isolate_), object)) {
// The cross-origin spec says that [[Enumerate]] shall return an empty
// iterator when it doesn't have access...
if (mode_ == KeyCollectionMode::kIncludePrototypes) {
return Just(false);
}
// ...whereas [[OwnPropertyKeys]] shall return whitelisted properties.
DCHECK_EQ(KeyCollectionMode::kOwnOnly, mode_);
Handle<AccessCheckInfo> access_check_info;
{
DisallowHeapAllocation no_gc;
AccessCheckInfo* maybe_info = AccessCheckInfo::Get(isolate_, object);
if (maybe_info) access_check_info = handle(maybe_info, isolate_);
}
// We always have both kinds of interceptors or none.
if (!access_check_info.is_null() &&
access_check_info->named_interceptor()) {
MAYBE_RETURN(CollectAccessCheckInterceptorKeys(access_check_info,
receiver, object),
Nothing<bool>());
return Just(false);
}
filter_ = static_cast<PropertyFilter>(filter_ | ONLY_ALL_CAN_READ);
}
MAYBE_RETURN(CollectOwnElementIndices(receiver, object), Nothing<bool>());
MAYBE_RETURN(CollectOwnPropertyNames(receiver, object), Nothing<bool>());
return Just(true);
}
// static
Handle<FixedArray> KeyAccumulator::GetOwnEnumPropertyKeys(
Isolate* isolate, Handle<JSObject> object) {
if (object->HasFastProperties()) {
return GetFastEnumPropertyKeys(isolate, object);
} else if (object->IsJSGlobalObject()) {
return GetOwnEnumPropertyDictionaryKeys(
isolate, KeyCollectionMode::kOwnOnly, nullptr, object,
JSGlobalObject::cast(*object)->global_dictionary());
} else {
return GetOwnEnumPropertyDictionaryKeys(
isolate, KeyCollectionMode::kOwnOnly, nullptr, object,
object->property_dictionary());
}
}
namespace {
class NameComparator {
public:
explicit NameComparator(Isolate* isolate) : isolate_(isolate) {}
bool operator()(uint32_t hash1, uint32_t hash2, const Handle<Name>& key1,
const Handle<Name>& key2) const {
return Name::Equals(isolate_, key1, key2);
}
private:
Isolate* isolate_;
};
} // namespace
// ES6 9.5.12
// Returns |true| on success, |nothing| in case of exception.
Maybe<bool> KeyAccumulator::CollectOwnJSProxyKeys(Handle<JSReceiver> receiver,
Handle<JSProxy> proxy) {
STACK_CHECK(isolate_, Nothing<bool>());
// 1. Let handler be the value of the [[ProxyHandler]] internal slot of O.
Handle<Object> handler(proxy->handler(), isolate_);
// 2. If handler is null, throw a TypeError exception.
// 3. Assert: Type(handler) is Object.
if (proxy->IsRevoked()) {
isolate_->Throw(*isolate_->factory()->NewTypeError(
MessageTemplate::kProxyRevoked, isolate_->factory()->ownKeys_string()));
return Nothing<bool>();
}
// 4. Let target be the value of the [[ProxyTarget]] internal slot of O.
Handle<JSReceiver> target(JSReceiver::cast(proxy->target()), isolate_);
// 5. Let trap be ? GetMethod(handler, "ownKeys").
Handle<Object> trap;
ASSIGN_RETURN_ON_EXCEPTION_VALUE(
isolate_, trap, Object::GetMethod(Handle<JSReceiver>::cast(handler),
isolate_->factory()->ownKeys_string()),
Nothing<bool>());
// 6. If trap is undefined, then
if (trap->IsUndefined(isolate_)) {
// 6a. Return target.[[OwnPropertyKeys]]().
return CollectOwnJSProxyTargetKeys(proxy, target);
}
// 7. Let trapResultArray be Call(trap, handler, «target»).
Handle<Object> trap_result_array;
Handle<Object> args[] = {target};
ASSIGN_RETURN_ON_EXCEPTION_VALUE(
isolate_, trap_result_array,
Execution::Call(isolate_, trap, handler, arraysize(args), args),
Nothing<bool>());
// 8. Let trapResult be ? CreateListFromArrayLike(trapResultArray,
// «String, Symbol»).
Handle<FixedArray> trap_result;
ASSIGN_RETURN_ON_EXCEPTION_VALUE(
isolate_, trap_result,
Object::CreateListFromArrayLike(isolate_, trap_result_array,
ElementTypes::kStringAndSymbol),
Nothing<bool>());
// 9. Let extensibleTarget be ? IsExtensible(target).
Maybe<bool> maybe_extensible = JSReceiver::IsExtensible(target);
MAYBE_RETURN(maybe_extensible, Nothing<bool>());
bool extensible_target = maybe_extensible.FromJust();
// 10. Let targetKeys be ? target.[[OwnPropertyKeys]]().
Handle<FixedArray> target_keys;
ASSIGN_RETURN_ON_EXCEPTION_VALUE(isolate_, target_keys,
JSReceiver::OwnPropertyKeys(target),
Nothing<bool>());
// 11. (Assert)
// 12. Let targetConfigurableKeys be an empty List.
// To save memory, we're re-using target_keys and will modify it in-place.
Handle<FixedArray> target_configurable_keys = target_keys;
// 13. Let targetNonconfigurableKeys be an empty List.
Handle<FixedArray> target_nonconfigurable_keys =
isolate_->factory()->NewFixedArray(target_keys->length());
int nonconfigurable_keys_length = 0;
// 14. Repeat, for each element key of targetKeys:
for (int i = 0; i < target_keys->length(); ++i) {
// 14a. Let desc be ? target.[[GetOwnProperty]](key).
PropertyDescriptor desc;
Maybe<bool> found = JSReceiver::GetOwnPropertyDescriptor(
isolate_, target, handle(target_keys->get(i), isolate_), &desc);
MAYBE_RETURN(found, Nothing<bool>());
// 14b. If desc is not undefined and desc.[[Configurable]] is false, then
if (found.FromJust() && !desc.configurable()) {
// 14b i. Append key as an element of targetNonconfigurableKeys.
target_nonconfigurable_keys->set(nonconfigurable_keys_length,
target_keys->get(i));
nonconfigurable_keys_length++;
// The key was moved, null it out in the original list.
target_keys->set(i, Smi::kZero);
} else {
// 14c. Else,
// 14c i. Append key as an element of targetConfigurableKeys.
// (No-op, just keep it in |target_keys|.)
}
}
// 15. If extensibleTarget is true and targetNonconfigurableKeys is empty,
// then:
if (extensible_target && nonconfigurable_keys_length == 0) {
// 15a. Return trapResult.
return AddKeysFromJSProxy(proxy, trap_result);
}
// 16. Let uncheckedResultKeys be a new List which is a copy of trapResult.
Zone set_zone(isolate_->allocator(), ZONE_NAME);
ZoneAllocationPolicy alloc(&set_zone);
const int kPresent = 1;
const int kGone = 0;
base::TemplateHashMapImpl<Handle<Name>, int, NameComparator,
ZoneAllocationPolicy>
unchecked_result_keys(ZoneHashMap::kDefaultHashMapCapacity,
NameComparator(isolate_), alloc);
int unchecked_result_keys_size = 0;
for (int i = 0; i < trap_result->length(); ++i) {
Handle<Name> key(Name::cast(trap_result->get(i)), isolate_);
auto entry = unchecked_result_keys.LookupOrInsert(key, key->Hash(), alloc);
if (entry->value != kPresent) {
entry->value = kPresent;
unchecked_result_keys_size++;
}
}
// 17. Repeat, for each key that is an element of targetNonconfigurableKeys:
for (int i = 0; i < nonconfigurable_keys_length; ++i) {
Object* raw_key = target_nonconfigurable_keys->get(i);
Handle<Name> key(Name::cast(raw_key), isolate_);
// 17a. If key is not an element of uncheckedResultKeys, throw a
// TypeError exception.
auto found = unchecked_result_keys.Lookup(key, key->Hash());
if (found == nullptr || found->value == kGone) {
isolate_->Throw(*isolate_->factory()->NewTypeError(
MessageTemplate::kProxyOwnKeysMissing, key));
return Nothing<bool>();
}
// 17b. Remove key from uncheckedResultKeys.
found->value = kGone;
unchecked_result_keys_size--;
}
// 18. If extensibleTarget is true, return trapResult.
if (extensible_target) {
return AddKeysFromJSProxy(proxy, trap_result);
}
// 19. Repeat, for each key that is an element of targetConfigurableKeys:
for (int i = 0; i < target_configurable_keys->length(); ++i) {
Object* raw_key = target_configurable_keys->get(i);
if (raw_key->IsSmi()) continue; // Zapped entry, was nonconfigurable.
Handle<Name> key(Name::cast(raw_key), isolate_);
// 19a. If key is not an element of uncheckedResultKeys, throw a
// TypeError exception.
auto found = unchecked_result_keys.Lookup(key, key->Hash());
if (found == nullptr || found->value == kGone) {
isolate_->Throw(*isolate_->factory()->NewTypeError(
MessageTemplate::kProxyOwnKeysMissing, key));
return Nothing<bool>();
}
// 19b. Remove key from uncheckedResultKeys.
found->value = kGone;
unchecked_result_keys_size--;
}
// 20. If uncheckedResultKeys is not empty, throw a TypeError exception.
if (unchecked_result_keys_size != 0) {
DCHECK_GT(unchecked_result_keys_size, 0);
isolate_->Throw(*isolate_->factory()->NewTypeError(
MessageTemplate::kProxyOwnKeysNonExtensible));
return Nothing<bool>();
}
// 21. Return trapResult.
return AddKeysFromJSProxy(proxy, trap_result);
}
Maybe<bool> KeyAccumulator::CollectOwnJSProxyTargetKeys(
Handle<JSProxy> proxy, Handle<JSReceiver> target) {
// TODO(cbruni): avoid creating another KeyAccumulator
Handle<FixedArray> keys;
ASSIGN_RETURN_ON_EXCEPTION_VALUE(
isolate_, keys,
KeyAccumulator::GetKeys(
target, KeyCollectionMode::kOwnOnly, ALL_PROPERTIES,
GetKeysConversion::kConvertToString, is_for_in_, skip_indices_),
Nothing<bool>());
Maybe<bool> result = AddKeysFromJSProxy(proxy, keys);
return result;
}
} // namespace internal
} // namespace v8