| // Copyright 2016 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/builtins/builtins.h" |
| #include "src/builtins/builtins-utils.h" |
| |
| #include "src/code-factory.h" |
| #include "src/code-stub-assembler.h" |
| #include "src/contexts.h" |
| #include "src/counters.h" |
| #include "src/elements.h" |
| #include "src/isolate.h" |
| #include "src/lookup.h" |
| #include "src/objects-inl.h" |
| #include "src/prototype.h" |
| |
| namespace v8 { |
| namespace internal { |
| |
| namespace { |
| |
| inline bool ClampedToInteger(Isolate* isolate, Object* object, int* out) { |
| // This is an extended version of ECMA-262 7.1.11 handling signed values |
| // Try to convert object to a number and clamp values to [kMinInt, kMaxInt] |
| if (object->IsSmi()) { |
| *out = Smi::ToInt(object); |
| return true; |
| } else if (object->IsHeapNumber()) { |
| double value = HeapNumber::cast(object)->value(); |
| if (std::isnan(value)) { |
| *out = 0; |
| } else if (value > kMaxInt) { |
| *out = kMaxInt; |
| } else if (value < kMinInt) { |
| *out = kMinInt; |
| } else { |
| *out = static_cast<int>(value); |
| } |
| return true; |
| } else if (object->IsNullOrUndefined(isolate)) { |
| *out = 0; |
| return true; |
| } else if (object->IsBoolean()) { |
| *out = object->IsTrue(isolate); |
| return true; |
| } |
| return false; |
| } |
| |
| inline bool IsJSArrayFastElementMovingAllowed(Isolate* isolate, |
| JSArray* receiver) { |
| return JSObject::PrototypeHasNoElements(isolate, receiver); |
| } |
| |
| inline bool HasSimpleElements(JSObject* current) { |
| return current->map()->instance_type() > LAST_CUSTOM_ELEMENTS_RECEIVER && |
| !current->GetElementsAccessor()->HasAccessors(current); |
| } |
| |
| inline bool HasOnlySimpleReceiverElements(Isolate* isolate, |
| JSObject* receiver) { |
| // Check that we have no accessors on the receiver's elements. |
| if (!HasSimpleElements(receiver)) return false; |
| return JSObject::PrototypeHasNoElements(isolate, receiver); |
| } |
| |
| inline bool HasOnlySimpleElements(Isolate* isolate, JSReceiver* receiver) { |
| DisallowHeapAllocation no_gc; |
| PrototypeIterator iter(isolate, receiver, kStartAtReceiver); |
| for (; !iter.IsAtEnd(); iter.Advance()) { |
| if (iter.GetCurrent()->IsJSProxy()) return false; |
| JSObject* current = iter.GetCurrent<JSObject>(); |
| if (!HasSimpleElements(current)) return false; |
| } |
| return true; |
| } |
| |
| // Returns |false| if not applicable. |
| MUST_USE_RESULT |
| inline bool EnsureJSArrayWithWritableFastElements(Isolate* isolate, |
| Handle<Object> receiver, |
| BuiltinArguments* args, |
| int first_added_arg) { |
| if (!receiver->IsJSArray()) return false; |
| Handle<JSArray> array = Handle<JSArray>::cast(receiver); |
| ElementsKind origin_kind = array->GetElementsKind(); |
| if (IsDictionaryElementsKind(origin_kind)) return false; |
| if (!array->map()->is_extensible()) return false; |
| if (args == nullptr) return true; |
| |
| // If there may be elements accessors in the prototype chain, the fast path |
| // cannot be used if there arguments to add to the array. |
| if (!IsJSArrayFastElementMovingAllowed(isolate, *array)) return false; |
| |
| // Adding elements to the array prototype would break code that makes sure |
| // it has no elements. Handle that elsewhere. |
| if (isolate->IsAnyInitialArrayPrototype(array)) return false; |
| |
| // Need to ensure that the arguments passed in args can be contained in |
| // the array. |
| int args_length = args->length(); |
| if (first_added_arg >= args_length) return true; |
| |
| if (IsObjectElementsKind(origin_kind)) return true; |
| ElementsKind target_kind = origin_kind; |
| { |
| DisallowHeapAllocation no_gc; |
| for (int i = first_added_arg; i < args_length; i++) { |
| Object* arg = (*args)[i]; |
| if (arg->IsHeapObject()) { |
| if (arg->IsHeapNumber()) { |
| target_kind = PACKED_DOUBLE_ELEMENTS; |
| } else { |
| target_kind = PACKED_ELEMENTS; |
| break; |
| } |
| } |
| } |
| } |
| if (target_kind != origin_kind) { |
| // Use a short-lived HandleScope to avoid creating several copies of the |
| // elements handle which would cause issues when left-trimming later-on. |
| HandleScope scope(isolate); |
| JSObject::TransitionElementsKind(array, target_kind); |
| } |
| return true; |
| } |
| |
| MUST_USE_RESULT static Object* CallJsIntrinsic(Isolate* isolate, |
| Handle<JSFunction> function, |
| BuiltinArguments args) { |
| HandleScope handleScope(isolate); |
| int argc = args.length() - 1; |
| ScopedVector<Handle<Object>> argv(argc); |
| for (int i = 0; i < argc; ++i) { |
| argv[i] = args.at(i + 1); |
| } |
| RETURN_RESULT_OR_FAILURE( |
| isolate, |
| Execution::Call(isolate, function, args.receiver(), argc, argv.start())); |
| } |
| } // namespace |
| |
| BUILTIN(ArrayPush) { |
| HandleScope scope(isolate); |
| Handle<Object> receiver = args.receiver(); |
| if (!EnsureJSArrayWithWritableFastElements(isolate, receiver, &args, 1)) { |
| return CallJsIntrinsic(isolate, isolate->array_push(), args); |
| } |
| // Fast Elements Path |
| int to_add = args.length() - 1; |
| Handle<JSArray> array = Handle<JSArray>::cast(receiver); |
| int len = Smi::ToInt(array->length()); |
| if (to_add == 0) return Smi::FromInt(len); |
| |
| // Currently fixed arrays cannot grow too big, so we should never hit this. |
| DCHECK_LE(to_add, Smi::kMaxValue - Smi::ToInt(array->length())); |
| |
| if (JSArray::HasReadOnlyLength(array)) { |
| return CallJsIntrinsic(isolate, isolate->array_push(), args); |
| } |
| |
| ElementsAccessor* accessor = array->GetElementsAccessor(); |
| int new_length = accessor->Push(array, &args, to_add); |
| return Smi::FromInt(new_length); |
| } |
| |
| BUILTIN(ArrayPop) { |
| HandleScope scope(isolate); |
| Handle<Object> receiver = args.receiver(); |
| if (!EnsureJSArrayWithWritableFastElements(isolate, receiver, nullptr, 0)) { |
| return CallJsIntrinsic(isolate, isolate->array_pop(), args); |
| } |
| |
| Handle<JSArray> array = Handle<JSArray>::cast(receiver); |
| |
| uint32_t len = static_cast<uint32_t>(Smi::ToInt(array->length())); |
| if (len == 0) return isolate->heap()->undefined_value(); |
| |
| if (JSArray::HasReadOnlyLength(array)) { |
| return CallJsIntrinsic(isolate, isolate->array_pop(), args); |
| } |
| |
| Handle<Object> result; |
| if (IsJSArrayFastElementMovingAllowed(isolate, JSArray::cast(*receiver))) { |
| // Fast Elements Path |
| result = array->GetElementsAccessor()->Pop(array); |
| } else { |
| // Use Slow Lookup otherwise |
| uint32_t new_length = len - 1; |
| ASSIGN_RETURN_FAILURE_ON_EXCEPTION( |
| isolate, result, JSReceiver::GetElement(isolate, array, new_length)); |
| JSArray::SetLength(array, new_length); |
| } |
| return *result; |
| } |
| |
| BUILTIN(ArrayShift) { |
| HandleScope scope(isolate); |
| Heap* heap = isolate->heap(); |
| Handle<Object> receiver = args.receiver(); |
| if (!EnsureJSArrayWithWritableFastElements(isolate, receiver, nullptr, 0) || |
| !IsJSArrayFastElementMovingAllowed(isolate, JSArray::cast(*receiver))) { |
| return CallJsIntrinsic(isolate, isolate->array_shift(), args); |
| } |
| Handle<JSArray> array = Handle<JSArray>::cast(receiver); |
| |
| int len = Smi::ToInt(array->length()); |
| if (len == 0) return heap->undefined_value(); |
| |
| if (JSArray::HasReadOnlyLength(array)) { |
| return CallJsIntrinsic(isolate, isolate->array_shift(), args); |
| } |
| |
| Handle<Object> first = array->GetElementsAccessor()->Shift(array); |
| return *first; |
| } |
| |
| BUILTIN(ArrayUnshift) { |
| HandleScope scope(isolate); |
| Handle<Object> receiver = args.receiver(); |
| if (!EnsureJSArrayWithWritableFastElements(isolate, receiver, &args, 1)) { |
| return CallJsIntrinsic(isolate, isolate->array_unshift(), args); |
| } |
| Handle<JSArray> array = Handle<JSArray>::cast(receiver); |
| int to_add = args.length() - 1; |
| if (to_add == 0) return array->length(); |
| |
| // Currently fixed arrays cannot grow too big, so we should never hit this. |
| DCHECK_LE(to_add, Smi::kMaxValue - Smi::ToInt(array->length())); |
| |
| if (JSArray::HasReadOnlyLength(array)) { |
| return CallJsIntrinsic(isolate, isolate->array_unshift(), args); |
| } |
| |
| ElementsAccessor* accessor = array->GetElementsAccessor(); |
| int new_length = accessor->Unshift(array, &args, to_add); |
| return Smi::FromInt(new_length); |
| } |
| |
| BUILTIN(ArraySlice) { |
| HandleScope scope(isolate); |
| Handle<Object> receiver = args.receiver(); |
| int len = -1; |
| int relative_start = 0; |
| int relative_end = 0; |
| |
| if (receiver->IsJSArray()) { |
| DisallowHeapAllocation no_gc; |
| JSArray* array = JSArray::cast(*receiver); |
| if (V8_UNLIKELY(!array->HasFastElements() || |
| !IsJSArrayFastElementMovingAllowed(isolate, array) || |
| !isolate->IsArraySpeciesLookupChainIntact() || |
| // If this is a subclass of Array, then call out to JS |
| !array->HasArrayPrototype(isolate))) { |
| AllowHeapAllocation allow_allocation; |
| return CallJsIntrinsic(isolate, isolate->array_slice(), args); |
| } |
| len = Smi::ToInt(array->length()); |
| } else if (receiver->IsJSObject() && |
| JSSloppyArgumentsObject::GetSloppyArgumentsLength( |
| isolate, Handle<JSObject>::cast(receiver), &len)) { |
| // Array.prototype.slice.call(arguments, ...) is quite a common idiom |
| // (notably more than 50% of invocations in Web apps). |
| // Treat it in C++ as well. |
| DCHECK(JSObject::cast(*receiver)->HasFastElements() || |
| JSObject::cast(*receiver)->HasFastArgumentsElements()); |
| } else { |
| AllowHeapAllocation allow_allocation; |
| return CallJsIntrinsic(isolate, isolate->array_slice(), args); |
| } |
| DCHECK_LE(0, len); |
| int argument_count = args.length() - 1; |
| // Note carefully chosen defaults---if argument is missing, |
| // it's undefined which gets converted to 0 for relative_start |
| // and to len for relative_end. |
| relative_start = 0; |
| relative_end = len; |
| if (argument_count > 0) { |
| DisallowHeapAllocation no_gc; |
| if (!ClampedToInteger(isolate, args[1], &relative_start)) { |
| AllowHeapAllocation allow_allocation; |
| return CallJsIntrinsic(isolate, isolate->array_slice(), args); |
| } |
| if (argument_count > 1) { |
| Object* end_arg = args[2]; |
| // slice handles the end_arg specially |
| if (end_arg->IsUndefined(isolate)) { |
| relative_end = len; |
| } else if (!ClampedToInteger(isolate, end_arg, &relative_end)) { |
| AllowHeapAllocation allow_allocation; |
| return CallJsIntrinsic(isolate, isolate->array_slice(), args); |
| } |
| } |
| } |
| |
| // ECMAScript 232, 3rd Edition, Section 15.4.4.10, step 6. |
| uint32_t actual_start = (relative_start < 0) ? Max(len + relative_start, 0) |
| : Min(relative_start, len); |
| |
| // ECMAScript 232, 3rd Edition, Section 15.4.4.10, step 8. |
| uint32_t actual_end = |
| (relative_end < 0) ? Max(len + relative_end, 0) : Min(relative_end, len); |
| |
| Handle<JSObject> object = Handle<JSObject>::cast(receiver); |
| ElementsAccessor* accessor = object->GetElementsAccessor(); |
| return *accessor->Slice(object, actual_start, actual_end); |
| } |
| |
| BUILTIN(ArraySplice) { |
| HandleScope scope(isolate); |
| Handle<Object> receiver = args.receiver(); |
| if (V8_UNLIKELY( |
| !EnsureJSArrayWithWritableFastElements(isolate, receiver, &args, 3) || |
| // If this is a subclass of Array, then call out to JS. |
| !Handle<JSArray>::cast(receiver)->HasArrayPrototype(isolate) || |
| // If anything with @@species has been messed with, call out to JS. |
| !isolate->IsArraySpeciesLookupChainIntact())) { |
| return CallJsIntrinsic(isolate, isolate->array_splice(), args); |
| } |
| Handle<JSArray> array = Handle<JSArray>::cast(receiver); |
| |
| int argument_count = args.length() - 1; |
| int relative_start = 0; |
| if (argument_count > 0) { |
| DisallowHeapAllocation no_gc; |
| if (!ClampedToInteger(isolate, args[1], &relative_start)) { |
| AllowHeapAllocation allow_allocation; |
| return CallJsIntrinsic(isolate, isolate->array_splice(), args); |
| } |
| } |
| int len = Smi::ToInt(array->length()); |
| // clip relative start to [0, len] |
| int actual_start = (relative_start < 0) ? Max(len + relative_start, 0) |
| : Min(relative_start, len); |
| |
| int actual_delete_count; |
| if (argument_count == 1) { |
| // SpiderMonkey, TraceMonkey and JSC treat the case where no delete count is |
| // given as a request to delete all the elements from the start. |
| // And it differs from the case of undefined delete count. |
| // This does not follow ECMA-262, but we do the same for compatibility. |
| DCHECK_GE(len - actual_start, 0); |
| actual_delete_count = len - actual_start; |
| } else { |
| int delete_count = 0; |
| DisallowHeapAllocation no_gc; |
| if (argument_count > 1) { |
| if (!ClampedToInteger(isolate, args[2], &delete_count)) { |
| AllowHeapAllocation allow_allocation; |
| return CallJsIntrinsic(isolate, isolate->array_splice(), args); |
| } |
| } |
| actual_delete_count = Min(Max(delete_count, 0), len - actual_start); |
| } |
| |
| int add_count = (argument_count > 1) ? (argument_count - 2) : 0; |
| int new_length = len - actual_delete_count + add_count; |
| |
| if (new_length != len && JSArray::HasReadOnlyLength(array)) { |
| AllowHeapAllocation allow_allocation; |
| return CallJsIntrinsic(isolate, isolate->array_splice(), args); |
| } |
| ElementsAccessor* accessor = array->GetElementsAccessor(); |
| Handle<JSArray> result_array = accessor->Splice( |
| array, actual_start, actual_delete_count, &args, add_count); |
| return *result_array; |
| } |
| |
| // Array Concat ------------------------------------------------------------- |
| |
| namespace { |
| |
| /** |
| * A simple visitor visits every element of Array's. |
| * The backend storage can be a fixed array for fast elements case, |
| * or a dictionary for sparse array. Since Dictionary is a subtype |
| * of FixedArray, the class can be used by both fast and slow cases. |
| * The second parameter of the constructor, fast_elements, specifies |
| * whether the storage is a FixedArray or Dictionary. |
| * |
| * An index limit is used to deal with the situation that a result array |
| * length overflows 32-bit non-negative integer. |
| */ |
| class ArrayConcatVisitor { |
| public: |
| ArrayConcatVisitor(Isolate* isolate, Handle<HeapObject> storage, |
| bool fast_elements) |
| : isolate_(isolate), |
| storage_(isolate->global_handles()->Create(*storage)), |
| index_offset_(0u), |
| bit_field_( |
| FastElementsField::encode(fast_elements) | |
| ExceedsLimitField::encode(false) | |
| IsFixedArrayField::encode(storage->IsFixedArray()) | |
| HasSimpleElementsField::encode(storage->IsFixedArray() || |
| storage->map()->instance_type() > |
| LAST_CUSTOM_ELEMENTS_RECEIVER)) { |
| DCHECK(!(this->fast_elements() && !is_fixed_array())); |
| } |
| |
| ~ArrayConcatVisitor() { clear_storage(); } |
| |
| MUST_USE_RESULT bool visit(uint32_t i, Handle<Object> elm) { |
| uint32_t index = index_offset_ + i; |
| |
| if (i >= JSObject::kMaxElementCount - index_offset_) { |
| set_exceeds_array_limit(true); |
| // Exception hasn't been thrown at this point. Return true to |
| // break out, and caller will throw. !visit would imply that |
| // there is already a pending exception. |
| return true; |
| } |
| |
| if (!is_fixed_array()) { |
| LookupIterator it(isolate_, storage_, index, LookupIterator::OWN); |
| MAYBE_RETURN(JSReceiver::CreateDataProperty(&it, elm, kThrowOnError), |
| false); |
| return true; |
| } |
| |
| if (fast_elements()) { |
| if (index < static_cast<uint32_t>(storage_fixed_array()->length())) { |
| storage_fixed_array()->set(index, *elm); |
| return true; |
| } |
| // Our initial estimate of length was foiled, possibly by |
| // getters on the arrays increasing the length of later arrays |
| // during iteration. |
| // This shouldn't happen in anything but pathological cases. |
| SetDictionaryMode(); |
| // Fall-through to dictionary mode. |
| } |
| DCHECK(!fast_elements()); |
| Handle<NumberDictionary> dict(NumberDictionary::cast(*storage_)); |
| // The object holding this backing store has just been allocated, so |
| // it cannot yet be used as a prototype. |
| Handle<JSObject> not_a_prototype_holder; |
| Handle<NumberDictionary> result = |
| NumberDictionary::Set(dict, index, elm, not_a_prototype_holder); |
| if (!result.is_identical_to(dict)) { |
| // Dictionary needed to grow. |
| clear_storage(); |
| set_storage(*result); |
| } |
| return true; |
| } |
| |
| void increase_index_offset(uint32_t delta) { |
| if (JSObject::kMaxElementCount - index_offset_ < delta) { |
| index_offset_ = JSObject::kMaxElementCount; |
| } else { |
| index_offset_ += delta; |
| } |
| // If the initial length estimate was off (see special case in visit()), |
| // but the array blowing the limit didn't contain elements beyond the |
| // provided-for index range, go to dictionary mode now. |
| if (fast_elements() && |
| index_offset_ > |
| static_cast<uint32_t>(FixedArrayBase::cast(*storage_)->length())) { |
| SetDictionaryMode(); |
| } |
| } |
| |
| bool exceeds_array_limit() const { |
| return ExceedsLimitField::decode(bit_field_); |
| } |
| |
| Handle<JSArray> ToArray() { |
| DCHECK(is_fixed_array()); |
| Handle<JSArray> array = isolate_->factory()->NewJSArray(0); |
| Handle<Object> length = |
| isolate_->factory()->NewNumber(static_cast<double>(index_offset_)); |
| Handle<Map> map = JSObject::GetElementsTransitionMap( |
| array, fast_elements() ? HOLEY_ELEMENTS : DICTIONARY_ELEMENTS); |
| array->set_length(*length); |
| array->set_elements(*storage_fixed_array()); |
| array->synchronized_set_map(*map); |
| return array; |
| } |
| |
| MUST_USE_RESULT MaybeHandle<JSReceiver> ToJSReceiver() { |
| DCHECK(!is_fixed_array()); |
| Handle<JSReceiver> result = Handle<JSReceiver>::cast(storage_); |
| Handle<Object> length = |
| isolate_->factory()->NewNumber(static_cast<double>(index_offset_)); |
| RETURN_ON_EXCEPTION( |
| isolate_, |
| JSReceiver::SetProperty(result, isolate_->factory()->length_string(), |
| length, LanguageMode::kStrict), |
| JSReceiver); |
| return result; |
| } |
| bool has_simple_elements() const { |
| return HasSimpleElementsField::decode(bit_field_); |
| } |
| |
| private: |
| // Convert storage to dictionary mode. |
| void SetDictionaryMode() { |
| DCHECK(fast_elements() && is_fixed_array()); |
| Handle<FixedArray> current_storage = storage_fixed_array(); |
| Handle<NumberDictionary> slow_storage( |
| NumberDictionary::New(isolate_, current_storage->length())); |
| uint32_t current_length = static_cast<uint32_t>(current_storage->length()); |
| FOR_WITH_HANDLE_SCOPE( |
| isolate_, uint32_t, i = 0, i, i < current_length, i++, { |
| Handle<Object> element(current_storage->get(i), isolate_); |
| if (!element->IsTheHole(isolate_)) { |
| // The object holding this backing store has just been allocated, so |
| // it cannot yet be used as a prototype. |
| Handle<JSObject> not_a_prototype_holder; |
| Handle<NumberDictionary> new_storage = NumberDictionary::Set( |
| slow_storage, i, element, not_a_prototype_holder); |
| if (!new_storage.is_identical_to(slow_storage)) { |
| slow_storage = loop_scope.CloseAndEscape(new_storage); |
| } |
| } |
| }); |
| clear_storage(); |
| set_storage(*slow_storage); |
| set_fast_elements(false); |
| } |
| |
| inline void clear_storage() { GlobalHandles::Destroy(storage_.location()); } |
| |
| inline void set_storage(FixedArray* storage) { |
| DCHECK(is_fixed_array()); |
| DCHECK(has_simple_elements()); |
| storage_ = isolate_->global_handles()->Create(storage); |
| } |
| |
| class FastElementsField : public BitField<bool, 0, 1> {}; |
| class ExceedsLimitField : public BitField<bool, 1, 1> {}; |
| class IsFixedArrayField : public BitField<bool, 2, 1> {}; |
| class HasSimpleElementsField : public BitField<bool, 3, 1> {}; |
| |
| bool fast_elements() const { return FastElementsField::decode(bit_field_); } |
| void set_fast_elements(bool fast) { |
| bit_field_ = FastElementsField::update(bit_field_, fast); |
| } |
| void set_exceeds_array_limit(bool exceeds) { |
| bit_field_ = ExceedsLimitField::update(bit_field_, exceeds); |
| } |
| bool is_fixed_array() const { return IsFixedArrayField::decode(bit_field_); } |
| Handle<FixedArray> storage_fixed_array() { |
| DCHECK(is_fixed_array()); |
| DCHECK(has_simple_elements()); |
| return Handle<FixedArray>::cast(storage_); |
| } |
| |
| Isolate* isolate_; |
| Handle<Object> storage_; // Always a global handle. |
| // Index after last seen index. Always less than or equal to |
| // JSObject::kMaxElementCount. |
| uint32_t index_offset_; |
| uint32_t bit_field_; |
| }; |
| |
| uint32_t EstimateElementCount(Handle<JSArray> array) { |
| DisallowHeapAllocation no_gc; |
| uint32_t length = static_cast<uint32_t>(array->length()->Number()); |
| int element_count = 0; |
| switch (array->GetElementsKind()) { |
| case PACKED_SMI_ELEMENTS: |
| case HOLEY_SMI_ELEMENTS: |
| case PACKED_ELEMENTS: |
| case HOLEY_ELEMENTS: { |
| // Fast elements can't have lengths that are not representable by |
| // a 32-bit signed integer. |
| DCHECK_GE(static_cast<int32_t>(FixedArray::kMaxLength), 0); |
| int fast_length = static_cast<int>(length); |
| Isolate* isolate = array->GetIsolate(); |
| FixedArray* elements = FixedArray::cast(array->elements()); |
| for (int i = 0; i < fast_length; i++) { |
| if (!elements->get(i)->IsTheHole(isolate)) element_count++; |
| } |
| break; |
| } |
| case PACKED_DOUBLE_ELEMENTS: |
| case HOLEY_DOUBLE_ELEMENTS: { |
| // Fast elements can't have lengths that are not representable by |
| // a 32-bit signed integer. |
| DCHECK_GE(static_cast<int32_t>(FixedDoubleArray::kMaxLength), 0); |
| int fast_length = static_cast<int>(length); |
| if (array->elements()->IsFixedArray()) { |
| DCHECK_EQ(FixedArray::cast(array->elements())->length(), 0); |
| break; |
| } |
| FixedDoubleArray* elements = FixedDoubleArray::cast(array->elements()); |
| for (int i = 0; i < fast_length; i++) { |
| if (!elements->is_the_hole(i)) element_count++; |
| } |
| break; |
| } |
| case DICTIONARY_ELEMENTS: { |
| NumberDictionary* dictionary = NumberDictionary::cast(array->elements()); |
| Isolate* isolate = dictionary->GetIsolate(); |
| int capacity = dictionary->Capacity(); |
| for (int i = 0; i < capacity; i++) { |
| Object* key = dictionary->KeyAt(i); |
| if (dictionary->IsKey(isolate, key)) { |
| element_count++; |
| } |
| } |
| break; |
| } |
| #define TYPED_ARRAY_CASE(Type, type, TYPE, ctype, size) case TYPE##_ELEMENTS: |
| |
| TYPED_ARRAYS(TYPED_ARRAY_CASE) |
| #undef TYPED_ARRAY_CASE |
| // External arrays are always dense. |
| return length; |
| case NO_ELEMENTS: |
| return 0; |
| case FAST_SLOPPY_ARGUMENTS_ELEMENTS: |
| case SLOW_SLOPPY_ARGUMENTS_ELEMENTS: |
| case FAST_STRING_WRAPPER_ELEMENTS: |
| case SLOW_STRING_WRAPPER_ELEMENTS: |
| UNREACHABLE(); |
| } |
| // As an estimate, we assume that the prototype doesn't contain any |
| // inherited elements. |
| return element_count; |
| } |
| |
| void CollectElementIndices(Handle<JSObject> object, uint32_t range, |
| std::vector<uint32_t>* indices) { |
| Isolate* isolate = object->GetIsolate(); |
| ElementsKind kind = object->GetElementsKind(); |
| switch (kind) { |
| case PACKED_SMI_ELEMENTS: |
| case PACKED_ELEMENTS: |
| case HOLEY_SMI_ELEMENTS: |
| case HOLEY_ELEMENTS: { |
| DisallowHeapAllocation no_gc; |
| FixedArray* elements = FixedArray::cast(object->elements()); |
| uint32_t length = static_cast<uint32_t>(elements->length()); |
| if (range < length) length = range; |
| for (uint32_t i = 0; i < length; i++) { |
| if (!elements->get(i)->IsTheHole(isolate)) { |
| indices->push_back(i); |
| } |
| } |
| break; |
| } |
| case HOLEY_DOUBLE_ELEMENTS: |
| case PACKED_DOUBLE_ELEMENTS: { |
| if (object->elements()->IsFixedArray()) { |
| DCHECK_EQ(object->elements()->length(), 0); |
| break; |
| } |
| Handle<FixedDoubleArray> elements( |
| FixedDoubleArray::cast(object->elements())); |
| uint32_t length = static_cast<uint32_t>(elements->length()); |
| if (range < length) length = range; |
| for (uint32_t i = 0; i < length; i++) { |
| if (!elements->is_the_hole(i)) { |
| indices->push_back(i); |
| } |
| } |
| break; |
| } |
| case DICTIONARY_ELEMENTS: { |
| DisallowHeapAllocation no_gc; |
| NumberDictionary* dict = NumberDictionary::cast(object->elements()); |
| uint32_t capacity = dict->Capacity(); |
| FOR_WITH_HANDLE_SCOPE(isolate, uint32_t, j = 0, j, j < capacity, j++, { |
| Object* k = dict->KeyAt(j); |
| if (!dict->IsKey(isolate, k)) continue; |
| DCHECK(k->IsNumber()); |
| uint32_t index = static_cast<uint32_t>(k->Number()); |
| if (index < range) { |
| indices->push_back(index); |
| } |
| }); |
| break; |
| } |
| #define TYPED_ARRAY_CASE(Type, type, TYPE, ctype, size) case TYPE##_ELEMENTS: |
| |
| TYPED_ARRAYS(TYPED_ARRAY_CASE) |
| #undef TYPED_ARRAY_CASE |
| { |
| uint32_t length = static_cast<uint32_t>( |
| FixedArrayBase::cast(object->elements())->length()); |
| if (range <= length) { |
| length = range; |
| // We will add all indices, so we might as well clear it first |
| // and avoid duplicates. |
| indices->clear(); |
| } |
| for (uint32_t i = 0; i < length; i++) { |
| indices->push_back(i); |
| } |
| if (length == range) return; // All indices accounted for already. |
| break; |
| } |
| case FAST_SLOPPY_ARGUMENTS_ELEMENTS: |
| case SLOW_SLOPPY_ARGUMENTS_ELEMENTS: { |
| DisallowHeapAllocation no_gc; |
| FixedArrayBase* elements = object->elements(); |
| JSObject* raw_object = *object; |
| ElementsAccessor* accessor = object->GetElementsAccessor(); |
| for (uint32_t i = 0; i < range; i++) { |
| if (accessor->HasElement(raw_object, i, elements)) { |
| indices->push_back(i); |
| } |
| } |
| break; |
| } |
| case FAST_STRING_WRAPPER_ELEMENTS: |
| case SLOW_STRING_WRAPPER_ELEMENTS: { |
| DCHECK(object->IsJSValue()); |
| Handle<JSValue> js_value = Handle<JSValue>::cast(object); |
| DCHECK(js_value->value()->IsString()); |
| Handle<String> string(String::cast(js_value->value()), isolate); |
| uint32_t length = static_cast<uint32_t>(string->length()); |
| uint32_t i = 0; |
| uint32_t limit = Min(length, range); |
| for (; i < limit; i++) { |
| indices->push_back(i); |
| } |
| ElementsAccessor* accessor = object->GetElementsAccessor(); |
| for (; i < range; i++) { |
| if (accessor->HasElement(*object, i)) { |
| indices->push_back(i); |
| } |
| } |
| break; |
| } |
| case NO_ELEMENTS: |
| break; |
| } |
| |
| PrototypeIterator iter(isolate, object); |
| if (!iter.IsAtEnd()) { |
| // The prototype will usually have no inherited element indices, |
| // but we have to check. |
| CollectElementIndices(PrototypeIterator::GetCurrent<JSObject>(iter), range, |
| indices); |
| } |
| } |
| |
| bool IterateElementsSlow(Isolate* isolate, Handle<JSReceiver> receiver, |
| uint32_t length, ArrayConcatVisitor* visitor) { |
| FOR_WITH_HANDLE_SCOPE(isolate, uint32_t, i = 0, i, i < length, ++i, { |
| Maybe<bool> maybe = JSReceiver::HasElement(receiver, i); |
| if (maybe.IsNothing()) return false; |
| if (maybe.FromJust()) { |
| Handle<Object> element_value; |
| ASSIGN_RETURN_ON_EXCEPTION_VALUE( |
| isolate, element_value, JSReceiver::GetElement(isolate, receiver, i), |
| false); |
| if (!visitor->visit(i, element_value)) return false; |
| } |
| }); |
| visitor->increase_index_offset(length); |
| return true; |
| } |
| /** |
| * A helper function that visits "array" elements of a JSReceiver in numerical |
| * order. |
| * |
| * The visitor argument called for each existing element in the array |
| * with the element index and the element's value. |
| * Afterwards it increments the base-index of the visitor by the array |
| * length. |
| * Returns false if any access threw an exception, otherwise true. |
| */ |
| bool IterateElements(Isolate* isolate, Handle<JSReceiver> receiver, |
| ArrayConcatVisitor* visitor) { |
| uint32_t length = 0; |
| |
| if (receiver->IsJSArray()) { |
| Handle<JSArray> array = Handle<JSArray>::cast(receiver); |
| length = static_cast<uint32_t>(array->length()->Number()); |
| } else { |
| Handle<Object> val; |
| ASSIGN_RETURN_ON_EXCEPTION_VALUE( |
| isolate, val, Object::GetLengthFromArrayLike(isolate, receiver), false); |
| // TODO(caitp): Support larger element indexes (up to 2^53-1). |
| if (!val->ToUint32(&length)) { |
| length = 0; |
| } |
| // TODO(cbruni): handle other element kind as well |
| return IterateElementsSlow(isolate, receiver, length, visitor); |
| } |
| |
| if (!HasOnlySimpleElements(isolate, *receiver) || |
| !visitor->has_simple_elements()) { |
| return IterateElementsSlow(isolate, receiver, length, visitor); |
| } |
| Handle<JSObject> array = Handle<JSObject>::cast(receiver); |
| |
| switch (array->GetElementsKind()) { |
| case PACKED_SMI_ELEMENTS: |
| case PACKED_ELEMENTS: |
| case HOLEY_SMI_ELEMENTS: |
| case HOLEY_ELEMENTS: { |
| // Run through the elements FixedArray and use HasElement and GetElement |
| // to check the prototype for missing elements. |
| Handle<FixedArray> elements(FixedArray::cast(array->elements())); |
| int fast_length = static_cast<int>(length); |
| DCHECK(fast_length <= elements->length()); |
| FOR_WITH_HANDLE_SCOPE(isolate, int, j = 0, j, j < fast_length, j++, { |
| Handle<Object> element_value(elements->get(j), isolate); |
| if (!element_value->IsTheHole(isolate)) { |
| if (!visitor->visit(j, element_value)) return false; |
| } else { |
| Maybe<bool> maybe = JSReceiver::HasElement(array, j); |
| if (maybe.IsNothing()) return false; |
| if (maybe.FromJust()) { |
| // Call GetElement on array, not its prototype, or getters won't |
| // have the correct receiver. |
| ASSIGN_RETURN_ON_EXCEPTION_VALUE( |
| isolate, element_value, |
| JSReceiver::GetElement(isolate, array, j), false); |
| if (!visitor->visit(j, element_value)) return false; |
| } |
| } |
| }); |
| break; |
| } |
| case HOLEY_DOUBLE_ELEMENTS: |
| case PACKED_DOUBLE_ELEMENTS: { |
| // Empty array is FixedArray but not FixedDoubleArray. |
| if (length == 0) break; |
| // Run through the elements FixedArray and use HasElement and GetElement |
| // to check the prototype for missing elements. |
| if (array->elements()->IsFixedArray()) { |
| DCHECK_EQ(array->elements()->length(), 0); |
| break; |
| } |
| Handle<FixedDoubleArray> elements( |
| FixedDoubleArray::cast(array->elements())); |
| int fast_length = static_cast<int>(length); |
| DCHECK(fast_length <= elements->length()); |
| FOR_WITH_HANDLE_SCOPE(isolate, int, j = 0, j, j < fast_length, j++, { |
| if (!elements->is_the_hole(j)) { |
| double double_value = elements->get_scalar(j); |
| Handle<Object> element_value = |
| isolate->factory()->NewNumber(double_value); |
| if (!visitor->visit(j, element_value)) return false; |
| } else { |
| Maybe<bool> maybe = JSReceiver::HasElement(array, j); |
| if (maybe.IsNothing()) return false; |
| if (maybe.FromJust()) { |
| // Call GetElement on array, not its prototype, or getters won't |
| // have the correct receiver. |
| Handle<Object> element_value; |
| ASSIGN_RETURN_ON_EXCEPTION_VALUE( |
| isolate, element_value, |
| JSReceiver::GetElement(isolate, array, j), false); |
| if (!visitor->visit(j, element_value)) return false; |
| } |
| } |
| }); |
| break; |
| } |
| |
| case DICTIONARY_ELEMENTS: { |
| Handle<NumberDictionary> dict(array->element_dictionary()); |
| std::vector<uint32_t> indices; |
| indices.reserve(dict->Capacity() / 2); |
| |
| // Collect all indices in the object and the prototypes less |
| // than length. This might introduce duplicates in the indices list. |
| CollectElementIndices(array, length, &indices); |
| std::sort(indices.begin(), indices.end()); |
| size_t n = indices.size(); |
| FOR_WITH_HANDLE_SCOPE(isolate, size_t, j = 0, j, j < n, (void)0, { |
| uint32_t index = indices[j]; |
| Handle<Object> element; |
| ASSIGN_RETURN_ON_EXCEPTION_VALUE( |
| isolate, element, JSReceiver::GetElement(isolate, array, index), |
| false); |
| if (!visitor->visit(index, element)) return false; |
| // Skip to next different index (i.e., omit duplicates). |
| do { |
| j++; |
| } while (j < n && indices[j] == index); |
| }); |
| break; |
| } |
| case FAST_SLOPPY_ARGUMENTS_ELEMENTS: |
| case SLOW_SLOPPY_ARGUMENTS_ELEMENTS: { |
| FOR_WITH_HANDLE_SCOPE( |
| isolate, uint32_t, index = 0, index, index < length, index++, { |
| Handle<Object> element; |
| ASSIGN_RETURN_ON_EXCEPTION_VALUE( |
| isolate, element, JSReceiver::GetElement(isolate, array, index), |
| false); |
| if (!visitor->visit(index, element)) return false; |
| }); |
| break; |
| } |
| case NO_ELEMENTS: |
| break; |
| #define TYPED_ARRAY_CASE(Type, type, TYPE, ctype, size) case TYPE##_ELEMENTS: |
| TYPED_ARRAYS(TYPED_ARRAY_CASE) |
| #undef TYPED_ARRAY_CASE |
| return IterateElementsSlow(isolate, receiver, length, visitor); |
| case FAST_STRING_WRAPPER_ELEMENTS: |
| case SLOW_STRING_WRAPPER_ELEMENTS: |
| // |array| is guaranteed to be an array or typed array. |
| UNREACHABLE(); |
| break; |
| } |
| visitor->increase_index_offset(length); |
| return true; |
| } |
| |
| static Maybe<bool> IsConcatSpreadable(Isolate* isolate, Handle<Object> obj) { |
| HandleScope handle_scope(isolate); |
| if (!obj->IsJSReceiver()) return Just(false); |
| if (!isolate->IsIsConcatSpreadableLookupChainIntact(JSReceiver::cast(*obj))) { |
| // Slow path if @@isConcatSpreadable has been used. |
| Handle<Symbol> key(isolate->factory()->is_concat_spreadable_symbol()); |
| Handle<Object> value; |
| MaybeHandle<Object> maybeValue = |
| i::Runtime::GetObjectProperty(isolate, obj, key); |
| if (!maybeValue.ToHandle(&value)) return Nothing<bool>(); |
| if (!value->IsUndefined(isolate)) return Just(value->BooleanValue()); |
| } |
| return Object::IsArray(obj); |
| } |
| |
| Object* Slow_ArrayConcat(BuiltinArguments* args, Handle<Object> species, |
| Isolate* isolate) { |
| int argument_count = args->length(); |
| |
| bool is_array_species = *species == isolate->context()->array_function(); |
| |
| // Pass 1: estimate the length and number of elements of the result. |
| // The actual length can be larger if any of the arguments have getters |
| // that mutate other arguments (but will otherwise be precise). |
| // The number of elements is precise if there are no inherited elements. |
| |
| ElementsKind kind = PACKED_SMI_ELEMENTS; |
| |
| uint32_t estimate_result_length = 0; |
| uint32_t estimate_nof = 0; |
| FOR_WITH_HANDLE_SCOPE(isolate, int, i = 0, i, i < argument_count, i++, { |
| Handle<Object> obj((*args)[i], isolate); |
| uint32_t length_estimate; |
| uint32_t element_estimate; |
| if (obj->IsJSArray()) { |
| Handle<JSArray> array(Handle<JSArray>::cast(obj)); |
| length_estimate = static_cast<uint32_t>(array->length()->Number()); |
| if (length_estimate != 0) { |
| ElementsKind array_kind = |
| GetPackedElementsKind(array->GetElementsKind()); |
| kind = GetMoreGeneralElementsKind(kind, array_kind); |
| } |
| element_estimate = EstimateElementCount(array); |
| } else { |
| if (obj->IsHeapObject()) { |
| kind = GetMoreGeneralElementsKind( |
| kind, obj->IsNumber() ? PACKED_DOUBLE_ELEMENTS : PACKED_ELEMENTS); |
| } |
| length_estimate = 1; |
| element_estimate = 1; |
| } |
| // Avoid overflows by capping at kMaxElementCount. |
| if (JSObject::kMaxElementCount - estimate_result_length < length_estimate) { |
| estimate_result_length = JSObject::kMaxElementCount; |
| } else { |
| estimate_result_length += length_estimate; |
| } |
| if (JSObject::kMaxElementCount - estimate_nof < element_estimate) { |
| estimate_nof = JSObject::kMaxElementCount; |
| } else { |
| estimate_nof += element_estimate; |
| } |
| }); |
| |
| // If estimated number of elements is more than half of length, a |
| // fixed array (fast case) is more time and space-efficient than a |
| // dictionary. |
| bool fast_case = is_array_species && |
| (estimate_nof * 2) >= estimate_result_length && |
| isolate->IsIsConcatSpreadableLookupChainIntact(); |
| |
| if (fast_case && kind == PACKED_DOUBLE_ELEMENTS) { |
| Handle<FixedArrayBase> storage = |
| isolate->factory()->NewFixedDoubleArray(estimate_result_length); |
| int j = 0; |
| bool failure = false; |
| if (estimate_result_length > 0) { |
| Handle<FixedDoubleArray> double_storage = |
| Handle<FixedDoubleArray>::cast(storage); |
| for (int i = 0; i < argument_count; i++) { |
| Handle<Object> obj((*args)[i], isolate); |
| if (obj->IsSmi()) { |
| double_storage->set(j, Smi::ToInt(*obj)); |
| j++; |
| } else if (obj->IsNumber()) { |
| double_storage->set(j, obj->Number()); |
| j++; |
| } else { |
| DisallowHeapAllocation no_gc; |
| JSArray* array = JSArray::cast(*obj); |
| uint32_t length = static_cast<uint32_t>(array->length()->Number()); |
| switch (array->GetElementsKind()) { |
| case HOLEY_DOUBLE_ELEMENTS: |
| case PACKED_DOUBLE_ELEMENTS: { |
| // Empty array is FixedArray but not FixedDoubleArray. |
| if (length == 0) break; |
| FixedDoubleArray* elements = |
| FixedDoubleArray::cast(array->elements()); |
| for (uint32_t i = 0; i < length; i++) { |
| if (elements->is_the_hole(i)) { |
| // TODO(jkummerow/verwaest): We could be a bit more clever |
| // here: Check if there are no elements/getters on the |
| // prototype chain, and if so, allow creation of a holey |
| // result array. |
| // Same thing below (holey smi case). |
| failure = true; |
| break; |
| } |
| double double_value = elements->get_scalar(i); |
| double_storage->set(j, double_value); |
| j++; |
| } |
| break; |
| } |
| case HOLEY_SMI_ELEMENTS: |
| case PACKED_SMI_ELEMENTS: { |
| Object* the_hole = isolate->heap()->the_hole_value(); |
| FixedArray* elements(FixedArray::cast(array->elements())); |
| for (uint32_t i = 0; i < length; i++) { |
| Object* element = elements->get(i); |
| if (element == the_hole) { |
| failure = true; |
| break; |
| } |
| int32_t int_value = Smi::ToInt(element); |
| double_storage->set(j, int_value); |
| j++; |
| } |
| break; |
| } |
| case HOLEY_ELEMENTS: |
| case PACKED_ELEMENTS: |
| case DICTIONARY_ELEMENTS: |
| case NO_ELEMENTS: |
| DCHECK_EQ(0u, length); |
| break; |
| default: |
| UNREACHABLE(); |
| } |
| } |
| if (failure) break; |
| } |
| } |
| if (!failure) { |
| return *isolate->factory()->NewJSArrayWithElements(storage, kind, j); |
| } |
| // In case of failure, fall through. |
| } |
| |
| Handle<HeapObject> storage; |
| if (fast_case) { |
| // The backing storage array must have non-existing elements to preserve |
| // holes across concat operations. |
| storage = |
| isolate->factory()->NewFixedArrayWithHoles(estimate_result_length); |
| } else if (is_array_species) { |
| storage = NumberDictionary::New(isolate, estimate_nof); |
| } else { |
| DCHECK(species->IsConstructor()); |
| Handle<Object> length(Smi::kZero, isolate); |
| Handle<Object> storage_object; |
| ASSIGN_RETURN_FAILURE_ON_EXCEPTION( |
| isolate, storage_object, |
| Execution::New(isolate, species, species, 1, &length)); |
| storage = Handle<HeapObject>::cast(storage_object); |
| } |
| |
| ArrayConcatVisitor visitor(isolate, storage, fast_case); |
| |
| for (int i = 0; i < argument_count; i++) { |
| Handle<Object> obj((*args)[i], isolate); |
| Maybe<bool> spreadable = IsConcatSpreadable(isolate, obj); |
| MAYBE_RETURN(spreadable, isolate->heap()->exception()); |
| if (spreadable.FromJust()) { |
| Handle<JSReceiver> object = Handle<JSReceiver>::cast(obj); |
| if (!IterateElements(isolate, object, &visitor)) { |
| return isolate->heap()->exception(); |
| } |
| } else { |
| if (!visitor.visit(0, obj)) return isolate->heap()->exception(); |
| visitor.increase_index_offset(1); |
| } |
| } |
| |
| if (visitor.exceeds_array_limit()) { |
| THROW_NEW_ERROR_RETURN_FAILURE( |
| isolate, NewRangeError(MessageTemplate::kInvalidArrayLength)); |
| } |
| |
| if (is_array_species) { |
| return *visitor.ToArray(); |
| } else { |
| RETURN_RESULT_OR_FAILURE(isolate, visitor.ToJSReceiver()); |
| } |
| } |
| |
| bool IsSimpleArray(Isolate* isolate, Handle<JSArray> obj) { |
| DisallowHeapAllocation no_gc; |
| Map* map = obj->map(); |
| // If there is only the 'length' property we are fine. |
| if (map->prototype() == |
| isolate->native_context()->initial_array_prototype() && |
| map->NumberOfOwnDescriptors() == 1) { |
| return true; |
| } |
| // TODO(cbruni): slower lookup for array subclasses and support slow |
| // @@IsConcatSpreadable lookup. |
| return false; |
| } |
| |
| MaybeHandle<JSArray> Fast_ArrayConcat(Isolate* isolate, |
| BuiltinArguments* args) { |
| if (!isolate->IsIsConcatSpreadableLookupChainIntact()) { |
| return MaybeHandle<JSArray>(); |
| } |
| // We shouldn't overflow when adding another len. |
| const int kHalfOfMaxInt = 1 << (kBitsPerInt - 2); |
| STATIC_ASSERT(FixedArray::kMaxLength < kHalfOfMaxInt); |
| STATIC_ASSERT(FixedDoubleArray::kMaxLength < kHalfOfMaxInt); |
| USE(kHalfOfMaxInt); |
| |
| int n_arguments = args->length(); |
| int result_len = 0; |
| { |
| DisallowHeapAllocation no_gc; |
| // Iterate through all the arguments performing checks |
| // and calculating total length. |
| for (int i = 0; i < n_arguments; i++) { |
| Object* arg = (*args)[i]; |
| if (!arg->IsJSArray()) return MaybeHandle<JSArray>(); |
| if (!HasOnlySimpleReceiverElements(isolate, JSObject::cast(arg))) { |
| return MaybeHandle<JSArray>(); |
| } |
| // TODO(cbruni): support fast concatenation of DICTIONARY_ELEMENTS. |
| if (!JSObject::cast(arg)->HasFastElements()) { |
| return MaybeHandle<JSArray>(); |
| } |
| Handle<JSArray> array(JSArray::cast(arg), isolate); |
| if (!IsSimpleArray(isolate, array)) { |
| return MaybeHandle<JSArray>(); |
| } |
| // The Array length is guaranted to be <= kHalfOfMaxInt thus we won't |
| // overflow. |
| result_len += Smi::ToInt(array->length()); |
| DCHECK_GE(result_len, 0); |
| // Throw an Error if we overflow the FixedArray limits |
| if (FixedDoubleArray::kMaxLength < result_len || |
| FixedArray::kMaxLength < result_len) { |
| AllowHeapAllocation gc; |
| THROW_NEW_ERROR(isolate, |
| NewRangeError(MessageTemplate::kInvalidArrayLength), |
| JSArray); |
| } |
| } |
| } |
| return ElementsAccessor::Concat(isolate, args, n_arguments, result_len); |
| } |
| |
| } // namespace |
| |
| // ES6 22.1.3.1 Array.prototype.concat |
| BUILTIN(ArrayConcat) { |
| HandleScope scope(isolate); |
| |
| Handle<Object> receiver = args.receiver(); |
| ASSIGN_RETURN_FAILURE_ON_EXCEPTION( |
| isolate, receiver, |
| Object::ToObject(isolate, args.receiver(), "Array.prototype.concat")); |
| args[0] = *receiver; |
| |
| Handle<JSArray> result_array; |
| |
| // Avoid a real species read to avoid extra lookups to the array constructor |
| if (V8_LIKELY(receiver->IsJSArray() && |
| Handle<JSArray>::cast(receiver)->HasArrayPrototype(isolate) && |
| isolate->IsArraySpeciesLookupChainIntact())) { |
| if (Fast_ArrayConcat(isolate, &args).ToHandle(&result_array)) { |
| return *result_array; |
| } |
| if (isolate->has_pending_exception()) return isolate->heap()->exception(); |
| } |
| // Reading @@species happens before anything else with a side effect, so |
| // we can do it here to determine whether to take the fast path. |
| Handle<Object> species; |
| ASSIGN_RETURN_FAILURE_ON_EXCEPTION( |
| isolate, species, Object::ArraySpeciesConstructor(isolate, receiver)); |
| if (*species == *isolate->array_function()) { |
| if (Fast_ArrayConcat(isolate, &args).ToHandle(&result_array)) { |
| return *result_array; |
| } |
| if (isolate->has_pending_exception()) return isolate->heap()->exception(); |
| } |
| return Slow_ArrayConcat(&args, species, isolate); |
| } |
| |
| } // namespace internal |
| } // namespace v8 |
