// 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.h"
#include "src/elements.h"
#include "src/factory.h"
#include "src/identity-map.h"
#include "src/isolate-inl.h"
#include "src/objects-inl.h"
#include "src/property-descriptor.h"
#include "src/prototype.h"
namespace v8 {
namespace internal {
KeyAccumulator::~KeyAccumulator() {
for (size_t i = 0; i < elements_.size(); i++) {
delete elements_[i];
}
}
Handle<FixedArray> KeyAccumulator::GetKeys(GetKeysConversion convert) {
if (length_ == 0) {
return isolate_->factory()->empty_fixed_array();
}
// Make sure we have all the lengths collected.
NextPrototype();
if (type_ == OWN_ONLY && !ownProxyKeys_.is_null()) {
return ownProxyKeys_;
}
// Assemble the result array by first adding the element keys and then the
// property keys. We use the total number of String + Symbol keys per level in
// |level_lengths_| and the available element keys in the corresponding bucket
// in |elements_| to deduce the number of keys to take from the
// |string_properties_| and |symbol_properties_| set.
Handle<FixedArray> result = isolate_->factory()->NewFixedArray(length_);
int insertion_index = 0;
int string_properties_index = 0;
int symbol_properties_index = 0;
// String and Symbol lengths always come in pairs:
size_t max_level = level_lengths_.size() / 2;
for (size_t level = 0; level < max_level; level++) {
int num_string_properties = level_lengths_[level * 2];
int num_symbol_properties = level_lengths_[level * 2 + 1];
int num_elements = 0;
if (num_string_properties < 0) {
// If the |num_string_properties| is negative, the current level contains
// properties from a proxy, hence we skip the integer keys in |elements_|
// since proxies define the complete ordering.
num_string_properties = -num_string_properties;
} else if (level < elements_.size()) {
// Add the element indices for this prototype level.
std::vector<uint32_t>* elements = elements_[level];
num_elements = static_cast<int>(elements->size());
for (int i = 0; i < num_elements; i++) {
Handle<Object> key;
if (convert == KEEP_NUMBERS) {
key = isolate_->factory()->NewNumberFromUint(elements->at(i));
} else {
key = isolate_->factory()->Uint32ToString(elements->at(i));
}
result->set(insertion_index, *key);
insertion_index++;
}
}
// Add the string property keys for this prototype level.
for (int i = 0; i < num_string_properties; i++) {
Object* key = string_properties_->KeyAt(string_properties_index);
result->set(insertion_index, key);
insertion_index++;
string_properties_index++;
}
// Add the symbol property keys for this prototype level.
for (int i = 0; i < num_symbol_properties; i++) {
Object* key = symbol_properties_->KeyAt(symbol_properties_index);
result->set(insertion_index, key);
insertion_index++;
symbol_properties_index++;
}
if (FLAG_trace_for_in_enumerate) {
PrintF("| strings=%d symbols=%d elements=%i ", num_string_properties,
num_symbol_properties, num_elements);
}
}
if (FLAG_trace_for_in_enumerate) {
PrintF("|| prototypes=%zu ||\n", max_level);
}
DCHECK_EQ(insertion_index, length_);
return result;
}
namespace {
bool AccumulatorHasKey(std::vector<uint32_t>* sub_elements, uint32_t key) {
return std::binary_search(sub_elements->begin(), sub_elements->end(), key);
}
} // namespace
bool KeyAccumulator::AddKey(Object* key, AddKeyConversion convert) {
return AddKey(handle(key, isolate_), convert);
}
bool KeyAccumulator::AddKey(Handle<Object> key, AddKeyConversion convert) {
if (key->IsSymbol()) {
if (filter_ & SKIP_SYMBOLS) return false;
if (Handle<Symbol>::cast(key)->is_private()) return false;
return AddSymbolKey(key);
}
if (filter_ & SKIP_STRINGS) return false;
// Make sure we do not add keys to a proxy-level (see AddKeysFromProxy).
DCHECK_LE(0, level_string_length_);
// In some cases (e.g. proxies) we might get in String-converted ints which
// should be added to the elements list instead of the properties. For
// proxies we have to convert as well but also respect the original order.
// Therefore we add a converted key to both sides
if (convert == CONVERT_TO_ARRAY_INDEX || convert == PROXY_MAGIC) {
uint32_t index = 0;
int prev_length = length_;
int prev_proto = level_string_length_;
if ((key->IsString() && Handle<String>::cast(key)->AsArrayIndex(&index)) ||
key->ToArrayIndex(&index)) {
bool key_was_added = AddIntegerKey(index);
if (convert == CONVERT_TO_ARRAY_INDEX) return key_was_added;
if (convert == PROXY_MAGIC) {
// If we had an array index (number) and it wasn't added, the key
// already existed before, hence we cannot add it to the properties
// keys as it would lead to duplicate entries.
if (!key_was_added) {
return false;
}
length_ = prev_length;
level_string_length_ = prev_proto;
}
}
}
return AddStringKey(key, convert);
}
bool KeyAccumulator::AddKey(uint32_t key) { return AddIntegerKey(key); }
bool KeyAccumulator::AddIntegerKey(uint32_t key) {
// Make sure we do not add keys to a proxy-level (see AddKeysFromProxy).
// We mark proxy-levels with a negative length
DCHECK_LE(0, level_string_length_);
// Binary search over all but the last level. The last one might not be
// sorted yet.
for (size_t i = 1; i < elements_.size(); i++) {
if (AccumulatorHasKey(elements_[i - 1], key)) return false;
}
elements_.back()->push_back(key);
length_++;
return true;
}
bool KeyAccumulator::AddStringKey(Handle<Object> key,
AddKeyConversion convert) {
if (string_properties_.is_null()) {
string_properties_ = OrderedHashSet::Allocate(isolate_, 16);
}
// TODO(cbruni): remove this conversion once we throw the correct TypeError
// for non-string/symbol elements returned by proxies
if (convert == PROXY_MAGIC && key->IsNumber()) {
key = isolate_->factory()->NumberToString(key);
}
int prev_size = string_properties_->NumberOfElements();
string_properties_ = OrderedHashSet::Add(string_properties_, key);
if (prev_size < string_properties_->NumberOfElements()) {
length_++;
level_string_length_++;
return true;
} else {
return false;
}
}
bool KeyAccumulator::AddSymbolKey(Handle<Object> key) {
if (symbol_properties_.is_null()) {
symbol_properties_ = OrderedHashSet::Allocate(isolate_, 16);
}
int prev_size = symbol_properties_->NumberOfElements();
symbol_properties_ = OrderedHashSet::Add(symbol_properties_, key);
if (prev_size < symbol_properties_->NumberOfElements()) {
length_++;
level_symbol_length_++;
return true;
} else {
return false;
}
}
void KeyAccumulator::AddKeys(Handle<FixedArray> array,
AddKeyConversion convert) {
int add_length = array->length();
if (add_length == 0) return;
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);
}
void KeyAccumulator::AddKeysFromProxy(Handle<JSObject> array_like) {
// Proxies define a complete list of keys with no distinction of
// elements and properties, which breaks the normal assumption for the
// KeyAccumulator.
AddKeys(array_like, PROXY_MAGIC);
// Invert the current length to indicate a present proxy, so we can ignore
// element keys for this level. Otherwise we would not fully respect the order
// given by the proxy.
level_string_length_ = -level_string_length_;
}
MaybeHandle<FixedArray> FilterProxyKeys(Isolate* isolate, Handle<JSProxy> owner,
Handle<FixedArray> keys,
PropertyFilter filter) {
if (filter == ALL_PROPERTIES) {
// Nothing to do.
return keys;
}
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() || !desc.enumerable()) continue; // Skip this key.
}
// Keep this key.
if (store_position != i) {
keys->set(store_position, *key);
}
store_position++;
}
if (store_position == 0) return isolate->factory()->empty_fixed_array();
keys->Shrink(store_position);
return keys;
}
// Returns "nothing" in case of exception, "true" on success.
Maybe<bool> KeyAccumulator::AddKeysFromProxy(Handle<JSProxy> proxy,
Handle<FixedArray> keys) {
if (filter_proxy_keys_) {
ASSIGN_RETURN_ON_EXCEPTION_VALUE(
isolate_, keys, FilterProxyKeys(isolate_, proxy, keys, filter_),
Nothing<bool>());
}
// Proxies define a complete list of keys with no distinction of
// elements and properties, which breaks the normal assumption for the
// KeyAccumulator.
if (type_ == OWN_ONLY) {
ownProxyKeys_ = keys;
level_string_length_ = keys->length();
length_ = level_string_length_;
} else {
AddKeys(keys, PROXY_MAGIC);
}
// Invert the current length to indicate a present proxy, so we can ignore
// element keys for this level. Otherwise we would not fully respect the order
// given by the proxy.
level_string_length_ = -level_string_length_;
return Just(true);
}
void KeyAccumulator::AddElementKeysFromInterceptor(
Handle<JSObject> array_like) {
AddKeys(array_like, CONVERT_TO_ARRAY_INDEX);
// The interceptor might introduce duplicates for the current level, since
// these keys get added after the objects's normal element keys.
SortCurrentElementsListRemoveDuplicates();
}
void KeyAccumulator::SortCurrentElementsListRemoveDuplicates() {
// Sort and remove duplicates from the current elements level and adjust.
// the lengths accordingly.
auto last_level = elements_.back();
size_t nof_removed_keys = last_level->size();
std::sort(last_level->begin(), last_level->end());
last_level->erase(std::unique(last_level->begin(), last_level->end()),
last_level->end());
// Adjust total length by the number of removed duplicates.
nof_removed_keys -= last_level->size();
length_ -= static_cast<int>(nof_removed_keys);
}
void KeyAccumulator::SortCurrentElementsList() {
if (elements_.empty()) return;
auto element_keys = elements_.back();
std::sort(element_keys->begin(), element_keys->end());
}
void KeyAccumulator::NextPrototype() {
// Store the protoLength on the first call of this method.
if (!elements_.empty()) {
level_lengths_.push_back(level_string_length_);
level_lengths_.push_back(level_symbol_length_);
}
elements_.push_back(new std::vector<uint32_t>());
level_string_length_ = 0;
level_symbol_length_ = 0;
}
Maybe<bool> KeyAccumulator::GetKeys_Internal(Handle<JSReceiver> receiver,
Handle<JSReceiver> object,
KeyCollectionType type) {
// Proxies have no hidden prototype and we should not trigger the
// [[GetPrototypeOf]] trap on the last iteration when using
// AdvanceFollowingProxies.
if (type == OWN_ONLY && object->IsJSProxy()) {
MAYBE_RETURN(
JSProxyOwnPropertyKeys(receiver, Handle<JSProxy>::cast(object)),
Nothing<bool>());
return Just(true);
}
PrototypeIterator::WhereToEnd end = type == OWN_ONLY
? PrototypeIterator::END_AT_NON_HIDDEN
: PrototypeIterator::END_AT_NULL;
for (PrototypeIterator iter(isolate_, object,
PrototypeIterator::START_AT_RECEIVER, end);
!iter.IsAtEnd();) {
Handle<JSReceiver> current =
PrototypeIterator::GetCurrent<JSReceiver>(iter);
Maybe<bool> result = Just(false); // Dummy initialization.
if (current->IsJSProxy()) {
result = JSProxyOwnPropertyKeys(receiver, Handle<JSProxy>::cast(current));
} else {
DCHECK(current->IsJSObject());
result =
GetKeysFromJSObject(receiver, Handle<JSObject>::cast(current), type);
}
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 GetKeysFromJSObject.
if (!iter.AdvanceFollowingProxiesIgnoringAccessChecks()) {
return Nothing<bool>();
}
}
return Just(true);
}
namespace {
void TrySettingEmptyEnumCache(JSReceiver* object) {
Map* map = object->map();
DCHECK_EQ(kInvalidEnumCacheSentinel, map->EnumLength());
if (!map->OnlyHasSimpleProperties()) return;
if (map->IsJSProxyMap()) return;
if (map->NumberOfOwnDescriptors() > 0) {
int number_of_enumerable_own_properties =
map->NumberOfDescribedProperties(OWN_DESCRIPTORS, ENUMERABLE_STRINGS);
if (number_of_enumerable_own_properties > 0) return;
}
DCHECK(object->IsJSObject());
map->SetEnumLength(0);
}
bool CheckAndInitalizeSimpleEnumCache(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 (type_ == OWN_ONLY) return;
// Fully walk the prototype chain and find the last prototype with keys.
is_receiver_simple_enum_ = false;
has_empty_prototype_ = true;
JSReceiver* first_non_empty_prototype;
for (PrototypeIterator iter(isolate_, *receiver_); !iter.IsAtEnd();
iter.Advance()) {
JSReceiver* current = iter.GetCurrent<JSReceiver>();
if (CheckAndInitalizeSimpleEnumCache(current)) continue;
has_empty_prototype_ = false;
first_non_empty_prototype = current;
// TODO(cbruni): use the first non-empty prototype.
USE(first_non_empty_prototype);
return;
}
DCHECK(has_empty_prototype_);
is_receiver_simple_enum_ =
receiver_->map()->EnumLength() != kInvalidEnumCacheSentinel &&
!JSObject::cast(*receiver_)->HasEnumerableElements();
}
namespace {
static 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);
}
Handle<FixedArray> GetFastEnumPropertyKeys(Isolate* isolate,
Handle<JSObject> object) {
Handle<Map> map(object->map());
bool cache_enum_length = map->OnlyHasSimpleProperties();
Handle<DescriptorArray> descs =
Handle<DescriptorArray>(map->instance_descriptors(), isolate);
int own_property_count = map->EnumLength();
// If the enum length of the given map is set to kInvalidEnumCache, this
// means that the map itself has never used the present enum cache. The
// first step to using the cache is to set the enum length of the map by
// counting the number of own descriptors that are ENUMERABLE_STRINGS.
if (own_property_count == kInvalidEnumCacheSentinel) {
own_property_count =
map->NumberOfDescribedProperties(OWN_DESCRIPTORS, ENUMERABLE_STRINGS);
} else {
DCHECK(
own_property_count ==
map->NumberOfDescribedProperties(OWN_DESCRIPTORS, ENUMERABLE_STRINGS));
}
if (descs->HasEnumCache()) {
Handle<FixedArray> keys(descs->GetEnumCache(), isolate);
// In case the number of properties required in the enum are actually
// present, we can reuse the enum cache. Otherwise, this means that the
// enum cache was generated for a previous (smaller) version of the
// Descriptor Array. In that case we regenerate the enum cache.
if (own_property_count <= keys->length()) {
isolate->counters()->enum_cache_hits()->Increment();
if (cache_enum_length) map->SetEnumLength(own_property_count);
return ReduceFixedArrayTo(isolate, keys, own_property_count);
}
}
if (descs->IsEmpty()) {
isolate->counters()->enum_cache_hits()->Increment();
if (cache_enum_length) map->SetEnumLength(0);
return isolate->factory()->empty_fixed_array();
}
isolate->counters()->enum_cache_misses()->Increment();
Handle<FixedArray> storage =
isolate->factory()->NewFixedArray(own_property_count);
Handle<FixedArray> indices =
isolate->factory()->NewFixedArray(own_property_count);
int size = map->NumberOfOwnDescriptors();
int index = 0;
for (int i = 0; i < size; i++) {
PropertyDetails details = descs->GetDetails(i);
if (details.IsDontEnum()) continue;
Object* key = descs->GetKey(i);
if (key->IsSymbol()) continue;
storage->set(index, key);
if (!indices.is_null()) {
if (details.type() != DATA) {
indices = Handle<FixedArray>();
} else {
FieldIndex field_index = FieldIndex::ForDescriptor(*map, i);
int load_by_field_index = field_index.GetLoadByFieldIndex();
indices->set(index, Smi::FromInt(load_by_field_index));
}
}
index++;
}
DCHECK(index == storage->length());
DescriptorArray::SetEnumCache(descs, isolate, storage, indices);
if (cache_enum_length) {
map->SetEnumLength(own_property_count);
}
return storage;
}
template <bool fast_properties>
Handle<FixedArray> GetOwnKeysWithElements(Isolate* isolate,
Handle<JSObject> object,
GetKeysConversion convert) {
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::GetEnumPropertyKeys(isolate, object);
}
Handle<FixedArray> 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->length() - keys->length());
}
return result;
}
MaybeHandle<FixedArray> GetOwnKeysWithUninitializedEnumCache(
Isolate* isolate, Handle<JSObject> object) {
// Uninitalized enum cache
Map* map = object->map();
if (object->elements() != isolate->heap()->empty_fixed_array() ||
object->elements() != isolate->heap()->empty_slow_element_dictionary()) {
// 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.
return GetFastEnumPropertyKeys(isolate, object);
}
bool OnlyHasSimpleProperties(Map* map) {
return map->instance_type() > LAST_CUSTOM_ELEMENTS_RECEIVER;
}
} // namespace
MaybeHandle<FixedArray> FastKeyAccumulator::GetKeys(GetKeysConversion convert) {
Handle<FixedArray> keys;
if (GetKeysFast(convert).ToHandle(&keys)) {
return keys;
}
return GetKeysSlow(convert);
}
MaybeHandle<FixedArray> FastKeyAccumulator::GetKeysFast(
GetKeysConversion convert) {
bool own_only = has_empty_prototype_ || type_ == OWN_ONLY;
Map* map = receiver_->map();
if (!own_only || !OnlyHasSimpleProperties(map)) {
return MaybeHandle<FixedArray>();
}
// From this point on we are certiain 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, convert);
}
int enum_length = receiver_->map()->EnumLength();
if (enum_length == kInvalidEnumCacheSentinel) {
Handle<FixedArray> keys;
// Try initializing the enum cache and return own properties.
if (GetOwnKeysWithUninitializedEnumCache(isolate_, object)
.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, convert);
}
MaybeHandle<FixedArray> FastKeyAccumulator::GetKeysSlow(
GetKeysConversion convert) {
return JSReceiver::GetKeys(receiver_, type_, ENUMERABLE_STRINGS, KEEP_NUMBERS,
filter_proxy_keys_);
}
enum IndexedOrNamed { kIndexed, kNamed };
// Returns |true| on success, |nothing| on exception.
template <class Callback, IndexedOrNamed type>
static Maybe<bool> GetKeysFromInterceptor(Handle<JSReceiver> receiver,
Handle<JSObject> object,
KeyAccumulator* accumulator) {
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);
}
PropertyCallbackArguments args(isolate, interceptor->data(), *receiver,
*object, Object::DONT_THROW);
Handle<JSObject> result;
if (!interceptor->enumerator()->IsUndefined()) {
Callback enum_fun = v8::ToCData<Callback>(interceptor->enumerator());
const char* log_tag = type == kIndexed ? "interceptor-indexed-enum"
: "interceptor-named-enum";
LOG(isolate, ApiObjectAccess(log_tag, *object));
result = args.Call(enum_fun);
}
RETURN_VALUE_IF_SCHEDULED_EXCEPTION(isolate, Nothing<bool>());
if (result.is_null()) return Just(true);
DCHECK(result->IsJSArray() || result->HasSloppyArgumentsElements());
// The accumulator takes care of string/symbol filtering.
if (type == kIndexed) {
accumulator->AddElementKeysFromInterceptor(result);
} else {
accumulator->AddKeys(result, DO_NOT_CONVERT);
}
return Just(true);
}
void KeyAccumulator::CollectOwnElementKeys(Handle<JSObject> object) {
if (filter_ & SKIP_STRINGS) return;
ElementsAccessor* accessor = object->GetElementsAccessor();
accessor->CollectElementIndices(object, this, kMaxUInt32, filter_, 0);
}
void KeyAccumulator::CollectOwnPropertyNames(Handle<JSObject> object) {
if (object->HasFastProperties()) {
int real_size = object->map()->NumberOfOwnDescriptors();
Handle<DescriptorArray> descs(object->map()->instance_descriptors(),
isolate_);
for (int i = 0; i < real_size; i++) {
PropertyDetails details = descs->GetDetails(i);
if ((details.attributes() & filter_) != 0) continue;
if (filter_ & ONLY_ALL_CAN_READ) {
if (details.kind() != kAccessor) continue;
Object* accessors = descs->GetValue(i);
if (!accessors->IsAccessorInfo()) continue;
if (!AccessorInfo::cast(accessors)->all_can_read()) continue;
}
Name* key = descs->GetKey(i);
if (key->FilterKey(filter_)) continue;
this->AddKey(key, DO_NOT_CONVERT);
}
} else if (object->IsJSGlobalObject()) {
GlobalDictionary::CollectKeysTo(
handle(object->global_dictionary(), isolate_), this, filter_);
} else {
NameDictionary::CollectKeysTo(
handle(object->property_dictionary(), isolate_), this, filter_);
}
}
// Returns |true| on success, |false| if prototype walking should be stopped,
// |nothing| if an exception was thrown.
Maybe<bool> KeyAccumulator::GetKeysFromJSObject(Handle<JSReceiver> receiver,
Handle<JSObject> object,
KeyCollectionType type) {
this->NextPrototype();
// Check access rights if required.
if (object->IsAccessCheckNeeded() &&
!isolate_->MayAccess(handle(isolate_->context()), object)) {
// The cross-origin spec says that [[Enumerate]] shall return an empty
// iterator when it doesn't have access...
if (type == INCLUDE_PROTOS) {
return Just(false);
}
// ...whereas [[OwnPropertyKeys]] shall return whitelisted properties.
DCHECK_EQ(OWN_ONLY, type);
filter_ = static_cast<PropertyFilter>(filter_ | ONLY_ALL_CAN_READ);
}
this->CollectOwnElementKeys(object);
// Add the element keys from the interceptor.
Maybe<bool> success =
GetKeysFromInterceptor<v8::IndexedPropertyEnumeratorCallback, kIndexed>(
receiver, object, this);
MAYBE_RETURN(success, Nothing<bool>());
if (filter_ == ENUMERABLE_STRINGS) {
Handle<FixedArray> enum_keys =
KeyAccumulator::GetEnumPropertyKeys(isolate_, object);
this->AddKeys(enum_keys, DO_NOT_CONVERT);
} else {
this->CollectOwnPropertyNames(object);
}
// Add the property keys from the interceptor.
success = GetKeysFromInterceptor<v8::GenericNamedPropertyEnumeratorCallback,
kNamed>(receiver, object, this);
MAYBE_RETURN(success, Nothing<bool>());
return Just(true);
}
// static
Handle<FixedArray> KeyAccumulator::GetEnumPropertyKeys(
Isolate* isolate, Handle<JSObject> object) {
if (object->HasFastProperties()) {
return GetFastEnumPropertyKeys(isolate, object);
} else if (object->IsJSGlobalObject()) {
Handle<GlobalDictionary> dictionary(object->global_dictionary(), isolate);
int length = dictionary->NumberOfEnumElements();
if (length == 0) {
return isolate->factory()->empty_fixed_array();
}
Handle<FixedArray> storage = isolate->factory()->NewFixedArray(length);
dictionary->CopyEnumKeysTo(*storage);
return storage;
} else {
Handle<NameDictionary> dictionary(object->property_dictionary(), isolate);
int length = dictionary->NumberOfEnumElements();
if (length == 0) {
return isolate->factory()->empty_fixed_array();
}
Handle<FixedArray> storage = isolate->factory()->NewFixedArray(length);
dictionary->CopyEnumKeysTo(*storage);
return storage;
}
}
// ES6 9.5.12
// Returns |true| on success, |nothing| in case of exception.
Maybe<bool> KeyAccumulator::JSProxyOwnPropertyKeys(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(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()) {
// 6a. Return target.[[OwnPropertyKeys]]().
return this->GetKeys_Internal(receiver, target, OWN_ONLY);
}
// 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::FromInt(0));
} else {
// 14c. Else,
// 14c i. Append key as an element of targetConfigurableKeys.
// (No-op, just keep it in |target_keys|.)
}
}
this->NextPrototype(); // Prepare for accumulating keys.
// 15. If extensibleTarget is true and targetNonconfigurableKeys is empty,
// then:
if (extensible_target && nonconfigurable_keys_length == 0) {
// 15a. Return trapResult.
return this->AddKeysFromProxy(proxy, trap_result);
}
// 16. Let uncheckedResultKeys be a new List which is a copy of trapResult.
Zone set_zone(isolate_->allocator());
const int kPresent = 1;
const int kGone = 0;
IdentityMap<int> unchecked_result_keys(isolate_->heap(), &set_zone);
int unchecked_result_keys_size = 0;
for (int i = 0; i < trap_result->length(); ++i) {
DCHECK(trap_result->get(i)->IsUniqueName());
Object* key = trap_result->get(i);
int* entry = unchecked_result_keys.Get(key);
if (*entry != kPresent) {
*entry = 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* key = target_nonconfigurable_keys->get(i);
// 17a. If key is not an element of uncheckedResultKeys, throw a
// TypeError exception.
int* found = unchecked_result_keys.Find(key);
if (found == nullptr || *found == kGone) {
isolate_->Throw(*isolate_->factory()->NewTypeError(
MessageTemplate::kProxyOwnKeysMissing, handle(key, isolate_)));
return Nothing<bool>();
}
// 17b. Remove key from uncheckedResultKeys.
*found = kGone;
unchecked_result_keys_size--;
}
// 18. If extensibleTarget is true, return trapResult.
if (extensible_target) {
return this->AddKeysFromProxy(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* key = target_configurable_keys->get(i);
if (key->IsSmi()) continue; // Zapped entry, was nonconfigurable.
// 19a. If key is not an element of uncheckedResultKeys, throw a
// TypeError exception.
int* found = unchecked_result_keys.Find(key);
if (found == nullptr || *found == kGone) {
isolate_->Throw(*isolate_->factory()->NewTypeError(
MessageTemplate::kProxyOwnKeysMissing, handle(key, isolate_)));
return Nothing<bool>();
}
// 19b. Remove key from uncheckedResultKeys.
*found = 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 this->AddKeysFromProxy(proxy, trap_result);
}
} // namespace internal
} // namespace v8