// Copyright 2012 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/elements.h" #include "src/arguments.h" #include "src/conversions.h" #include "src/frames.h" #include "src/heap/factory.h" #include "src/heap/heap-write-barrier-inl.h" #include "src/isolate-inl.h" #include "src/keys.h" #include "src/messages.h" #include "src/objects-inl.h" #include "src/objects/arguments-inl.h" #include "src/objects/hash-table-inl.h" #include "src/objects/js-array-buffer-inl.h" #include "src/objects/js-array-inl.h" #include "src/utils.h" // Each concrete ElementsAccessor can handle exactly one ElementsKind, // several abstract ElementsAccessor classes are used to allow sharing // common code. // // Inheritance hierarchy: // - ElementsAccessorBase (abstract) // - FastElementsAccessor (abstract) // - FastSmiOrObjectElementsAccessor // - FastPackedSmiElementsAccessor // - FastHoleySmiElementsAccessor // - FastPackedObjectElementsAccessor // - FastHoleyObjectElementsAccessor // - FastDoubleElementsAccessor // - FastPackedDoubleElementsAccessor // - FastHoleyDoubleElementsAccessor // - TypedElementsAccessor: template, with instantiations: // - FixedUint8ElementsAccessor // - FixedInt8ElementsAccessor // - FixedUint16ElementsAccessor // - FixedInt16ElementsAccessor // - FixedUint32ElementsAccessor // - FixedInt32ElementsAccessor // - FixedFloat32ElementsAccessor // - FixedFloat64ElementsAccessor // - FixedUint8ClampedElementsAccessor // - FixedBigUint64ElementsAccessor // - FixedBigInt64ElementsAccessor // - DictionaryElementsAccessor // - SloppyArgumentsElementsAccessor // - FastSloppyArgumentsElementsAccessor // - SlowSloppyArgumentsElementsAccessor // - StringWrapperElementsAccessor // - FastStringWrapperElementsAccessor // - SlowStringWrapperElementsAccessor namespace v8 { namespace internal { namespace { static const int kPackedSizeNotKnown = -1; enum Where { AT_START, AT_END }; // First argument in list is the accessor class, the second argument is the // accessor ElementsKind, and the third is the backing store class. Use the // fast element handler for smi-only arrays. The implementation is currently // identical. Note that the order must match that of the ElementsKind enum for // the |accessor_array[]| below to work. #define ELEMENTS_LIST(V) \ V(FastPackedSmiElementsAccessor, PACKED_SMI_ELEMENTS, FixedArray) \ V(FastHoleySmiElementsAccessor, HOLEY_SMI_ELEMENTS, FixedArray) \ V(FastPackedObjectElementsAccessor, PACKED_ELEMENTS, FixedArray) \ V(FastHoleyObjectElementsAccessor, HOLEY_ELEMENTS, FixedArray) \ V(FastPackedDoubleElementsAccessor, PACKED_DOUBLE_ELEMENTS, \ FixedDoubleArray) \ V(FastHoleyDoubleElementsAccessor, HOLEY_DOUBLE_ELEMENTS, FixedDoubleArray) \ V(DictionaryElementsAccessor, DICTIONARY_ELEMENTS, NumberDictionary) \ V(FastSloppyArgumentsElementsAccessor, FAST_SLOPPY_ARGUMENTS_ELEMENTS, \ FixedArray) \ V(SlowSloppyArgumentsElementsAccessor, SLOW_SLOPPY_ARGUMENTS_ELEMENTS, \ FixedArray) \ V(FastStringWrapperElementsAccessor, FAST_STRING_WRAPPER_ELEMENTS, \ FixedArray) \ V(SlowStringWrapperElementsAccessor, SLOW_STRING_WRAPPER_ELEMENTS, \ FixedArray) \ V(FixedUint8ElementsAccessor, UINT8_ELEMENTS, FixedUint8Array) \ V(FixedInt8ElementsAccessor, INT8_ELEMENTS, FixedInt8Array) \ V(FixedUint16ElementsAccessor, UINT16_ELEMENTS, FixedUint16Array) \ V(FixedInt16ElementsAccessor, INT16_ELEMENTS, FixedInt16Array) \ V(FixedUint32ElementsAccessor, UINT32_ELEMENTS, FixedUint32Array) \ V(FixedInt32ElementsAccessor, INT32_ELEMENTS, FixedInt32Array) \ V(FixedFloat32ElementsAccessor, FLOAT32_ELEMENTS, FixedFloat32Array) \ V(FixedFloat64ElementsAccessor, FLOAT64_ELEMENTS, FixedFloat64Array) \ V(FixedUint8ClampedElementsAccessor, UINT8_CLAMPED_ELEMENTS, \ FixedUint8ClampedArray) \ V(FixedBigUint64ElementsAccessor, BIGUINT64_ELEMENTS, FixedBigUint64Array) \ V(FixedBigInt64ElementsAccessor, BIGINT64_ELEMENTS, FixedBigInt64Array) template class ElementsKindTraits { public: typedef FixedArrayBase BackingStore; }; #define ELEMENTS_TRAITS(Class, KindParam, Store) \ template <> \ class ElementsKindTraits { \ public: /* NOLINT */ \ static constexpr ElementsKind Kind = KindParam; \ typedef Store BackingStore; \ }; \ constexpr ElementsKind ElementsKindTraits::Kind; ELEMENTS_LIST(ELEMENTS_TRAITS) #undef ELEMENTS_TRAITS V8_WARN_UNUSED_RESULT MaybeHandle ThrowArrayLengthRangeError(Isolate* isolate) { THROW_NEW_ERROR(isolate, NewRangeError(MessageTemplate::kInvalidArrayLength), Object); } WriteBarrierMode GetWriteBarrierMode(ElementsKind kind) { if (IsSmiElementsKind(kind)) return SKIP_WRITE_BARRIER; if (IsDoubleElementsKind(kind)) return SKIP_WRITE_BARRIER; return UPDATE_WRITE_BARRIER; } void CopyObjectToObjectElements(Isolate* isolate, FixedArrayBase* from_base, ElementsKind from_kind, uint32_t from_start, FixedArrayBase* to_base, ElementsKind to_kind, uint32_t to_start, int raw_copy_size) { ReadOnlyRoots roots(isolate); DCHECK(to_base->map() != roots.fixed_cow_array_map()); DisallowHeapAllocation no_allocation; int copy_size = raw_copy_size; if (raw_copy_size < 0) { DCHECK(raw_copy_size == ElementsAccessor::kCopyToEnd || raw_copy_size == ElementsAccessor::kCopyToEndAndInitializeToHole); copy_size = Min(from_base->length() - from_start, to_base->length() - to_start); if (raw_copy_size == ElementsAccessor::kCopyToEndAndInitializeToHole) { int start = to_start + copy_size; int length = to_base->length() - start; if (length > 0) { MemsetPointer(FixedArray::cast(to_base)->data_start() + start, roots.the_hole_value(), length); } } } DCHECK((copy_size + static_cast(to_start)) <= to_base->length() && (copy_size + static_cast(from_start)) <= from_base->length()); if (copy_size == 0) return; FixedArray* from = FixedArray::cast(from_base); FixedArray* to = FixedArray::cast(to_base); DCHECK(IsSmiOrObjectElementsKind(from_kind)); DCHECK(IsSmiOrObjectElementsKind(to_kind)); WriteBarrierMode write_barrier_mode = (IsObjectElementsKind(from_kind) && IsObjectElementsKind(to_kind)) ? UPDATE_WRITE_BARRIER : SKIP_WRITE_BARRIER; for (int i = 0; i < copy_size; i++) { Object* value = from->get(from_start + i); to->set(to_start + i, value, write_barrier_mode); } } static void CopyDictionaryToObjectElements( Isolate* isolate, FixedArrayBase* from_base, uint32_t from_start, FixedArrayBase* to_base, ElementsKind to_kind, uint32_t to_start, int raw_copy_size) { DisallowHeapAllocation no_allocation; NumberDictionary* from = NumberDictionary::cast(from_base); int copy_size = raw_copy_size; if (raw_copy_size < 0) { DCHECK(raw_copy_size == ElementsAccessor::kCopyToEnd || raw_copy_size == ElementsAccessor::kCopyToEndAndInitializeToHole); copy_size = from->max_number_key() + 1 - from_start; if (raw_copy_size == ElementsAccessor::kCopyToEndAndInitializeToHole) { int start = to_start + copy_size; int length = to_base->length() - start; if (length > 0) { MemsetPointer(FixedArray::cast(to_base)->data_start() + start, ReadOnlyRoots(isolate).the_hole_value(), length); } } } DCHECK(to_base != from_base); DCHECK(IsSmiOrObjectElementsKind(to_kind)); if (copy_size == 0) return; FixedArray* to = FixedArray::cast(to_base); uint32_t to_length = to->length(); if (to_start + copy_size > to_length) { copy_size = to_length - to_start; } WriteBarrierMode write_barrier_mode = GetWriteBarrierMode(to_kind); for (int i = 0; i < copy_size; i++) { int entry = from->FindEntry(isolate, i + from_start); if (entry != NumberDictionary::kNotFound) { Object* value = from->ValueAt(entry); DCHECK(!value->IsTheHole(isolate)); to->set(i + to_start, value, write_barrier_mode); } else { to->set_the_hole(isolate, i + to_start); } } } // NOTE: this method violates the handlified function signature convention: // raw pointer parameters in the function that allocates. // See ElementsAccessorBase::CopyElements() for details. static void CopyDoubleToObjectElements(Isolate* isolate, FixedArrayBase* from_base, uint32_t from_start, FixedArrayBase* to_base, uint32_t to_start, int raw_copy_size) { int copy_size = raw_copy_size; if (raw_copy_size < 0) { DisallowHeapAllocation no_allocation; DCHECK(raw_copy_size == ElementsAccessor::kCopyToEnd || raw_copy_size == ElementsAccessor::kCopyToEndAndInitializeToHole); copy_size = Min(from_base->length() - from_start, to_base->length() - to_start); if (raw_copy_size == ElementsAccessor::kCopyToEndAndInitializeToHole) { // Also initialize the area that will be copied over since HeapNumber // allocation below can cause an incremental marking step, requiring all // existing heap objects to be propertly initialized. int start = to_start; int length = to_base->length() - start; if (length > 0) { MemsetPointer(FixedArray::cast(to_base)->data_start() + start, ReadOnlyRoots(isolate).the_hole_value(), length); } } } DCHECK((copy_size + static_cast(to_start)) <= to_base->length() && (copy_size + static_cast(from_start)) <= from_base->length()); if (copy_size == 0) return; // From here on, the code below could actually allocate. Therefore the raw // values are wrapped into handles. Handle from(FixedDoubleArray::cast(from_base), isolate); Handle to(FixedArray::cast(to_base), isolate); // Use an outer loop to not waste too much time on creating HandleScopes. // On the other hand we might overflow a single handle scope depending on // the copy_size. int offset = 0; while (offset < copy_size) { HandleScope scope(isolate); offset += 100; for (int i = offset - 100; i < offset && i < copy_size; ++i) { Handle value = FixedDoubleArray::get(*from, i + from_start, isolate); to->set(i + to_start, *value, UPDATE_WRITE_BARRIER); } } } static void CopyDoubleToDoubleElements(FixedArrayBase* from_base, uint32_t from_start, FixedArrayBase* to_base, uint32_t to_start, int raw_copy_size) { DisallowHeapAllocation no_allocation; int copy_size = raw_copy_size; if (raw_copy_size < 0) { DCHECK(raw_copy_size == ElementsAccessor::kCopyToEnd || raw_copy_size == ElementsAccessor::kCopyToEndAndInitializeToHole); copy_size = Min(from_base->length() - from_start, to_base->length() - to_start); if (raw_copy_size == ElementsAccessor::kCopyToEndAndInitializeToHole) { for (int i = to_start + copy_size; i < to_base->length(); ++i) { FixedDoubleArray::cast(to_base)->set_the_hole(i); } } } DCHECK((copy_size + static_cast(to_start)) <= to_base->length() && (copy_size + static_cast(from_start)) <= from_base->length()); if (copy_size == 0) return; FixedDoubleArray* from = FixedDoubleArray::cast(from_base); FixedDoubleArray* to = FixedDoubleArray::cast(to_base); Address to_address = to->address() + FixedDoubleArray::kHeaderSize; Address from_address = from->address() + FixedDoubleArray::kHeaderSize; to_address += kDoubleSize * to_start; from_address += kDoubleSize * from_start; int words_per_double = (kDoubleSize / kPointerSize); CopyWords(reinterpret_cast(to_address), reinterpret_cast(from_address), static_cast(words_per_double * copy_size)); } static void CopySmiToDoubleElements(FixedArrayBase* from_base, uint32_t from_start, FixedArrayBase* to_base, uint32_t to_start, int raw_copy_size) { DisallowHeapAllocation no_allocation; int copy_size = raw_copy_size; if (raw_copy_size < 0) { DCHECK(raw_copy_size == ElementsAccessor::kCopyToEnd || raw_copy_size == ElementsAccessor::kCopyToEndAndInitializeToHole); copy_size = from_base->length() - from_start; if (raw_copy_size == ElementsAccessor::kCopyToEndAndInitializeToHole) { for (int i = to_start + copy_size; i < to_base->length(); ++i) { FixedDoubleArray::cast(to_base)->set_the_hole(i); } } } DCHECK((copy_size + static_cast(to_start)) <= to_base->length() && (copy_size + static_cast(from_start)) <= from_base->length()); if (copy_size == 0) return; FixedArray* from = FixedArray::cast(from_base); FixedDoubleArray* to = FixedDoubleArray::cast(to_base); Object* the_hole = from->GetReadOnlyRoots().the_hole_value(); for (uint32_t from_end = from_start + static_cast(copy_size); from_start < from_end; from_start++, to_start++) { Object* hole_or_smi = from->get(from_start); if (hole_or_smi == the_hole) { to->set_the_hole(to_start); } else { to->set(to_start, Smi::ToInt(hole_or_smi)); } } } static void CopyPackedSmiToDoubleElements(FixedArrayBase* from_base, uint32_t from_start, FixedArrayBase* to_base, uint32_t to_start, int packed_size, int raw_copy_size) { DisallowHeapAllocation no_allocation; int copy_size = raw_copy_size; uint32_t to_end; if (raw_copy_size < 0) { DCHECK(raw_copy_size == ElementsAccessor::kCopyToEnd || raw_copy_size == ElementsAccessor::kCopyToEndAndInitializeToHole); copy_size = packed_size - from_start; if (raw_copy_size == ElementsAccessor::kCopyToEndAndInitializeToHole) { to_end = to_base->length(); for (uint32_t i = to_start + copy_size; i < to_end; ++i) { FixedDoubleArray::cast(to_base)->set_the_hole(i); } } else { to_end = to_start + static_cast(copy_size); } } else { to_end = to_start + static_cast(copy_size); } DCHECK(static_cast(to_end) <= to_base->length()); DCHECK(packed_size >= 0 && packed_size <= copy_size); DCHECK((copy_size + static_cast(to_start)) <= to_base->length() && (copy_size + static_cast(from_start)) <= from_base->length()); if (copy_size == 0) return; FixedArray* from = FixedArray::cast(from_base); FixedDoubleArray* to = FixedDoubleArray::cast(to_base); for (uint32_t from_end = from_start + static_cast(packed_size); from_start < from_end; from_start++, to_start++) { Object* smi = from->get(from_start); DCHECK(!smi->IsTheHole()); to->set(to_start, Smi::ToInt(smi)); } } static void CopyObjectToDoubleElements(FixedArrayBase* from_base, uint32_t from_start, FixedArrayBase* to_base, uint32_t to_start, int raw_copy_size) { DisallowHeapAllocation no_allocation; int copy_size = raw_copy_size; if (raw_copy_size < 0) { DCHECK(raw_copy_size == ElementsAccessor::kCopyToEnd || raw_copy_size == ElementsAccessor::kCopyToEndAndInitializeToHole); copy_size = from_base->length() - from_start; if (raw_copy_size == ElementsAccessor::kCopyToEndAndInitializeToHole) { for (int i = to_start + copy_size; i < to_base->length(); ++i) { FixedDoubleArray::cast(to_base)->set_the_hole(i); } } } DCHECK((copy_size + static_cast(to_start)) <= to_base->length() && (copy_size + static_cast(from_start)) <= from_base->length()); if (copy_size == 0) return; FixedArray* from = FixedArray::cast(from_base); FixedDoubleArray* to = FixedDoubleArray::cast(to_base); Object* the_hole = from->GetReadOnlyRoots().the_hole_value(); for (uint32_t from_end = from_start + copy_size; from_start < from_end; from_start++, to_start++) { Object* hole_or_object = from->get(from_start); if (hole_or_object == the_hole) { to->set_the_hole(to_start); } else { to->set(to_start, hole_or_object->Number()); } } } static void CopyDictionaryToDoubleElements( Isolate* isolate, FixedArrayBase* from_base, uint32_t from_start, FixedArrayBase* to_base, uint32_t to_start, int raw_copy_size) { DisallowHeapAllocation no_allocation; NumberDictionary* from = NumberDictionary::cast(from_base); int copy_size = raw_copy_size; if (copy_size < 0) { DCHECK(copy_size == ElementsAccessor::kCopyToEnd || copy_size == ElementsAccessor::kCopyToEndAndInitializeToHole); copy_size = from->max_number_key() + 1 - from_start; if (raw_copy_size == ElementsAccessor::kCopyToEndAndInitializeToHole) { for (int i = to_start + copy_size; i < to_base->length(); ++i) { FixedDoubleArray::cast(to_base)->set_the_hole(i); } } } if (copy_size == 0) return; FixedDoubleArray* to = FixedDoubleArray::cast(to_base); uint32_t to_length = to->length(); if (to_start + copy_size > to_length) { copy_size = to_length - to_start; } for (int i = 0; i < copy_size; i++) { int entry = from->FindEntry(isolate, i + from_start); if (entry != NumberDictionary::kNotFound) { to->set(i + to_start, from->ValueAt(entry)->Number()); } else { to->set_the_hole(i + to_start); } } } static void TraceTopFrame(Isolate* isolate) { StackFrameIterator it(isolate); if (it.done()) { PrintF("unknown location (no JavaScript frames present)"); return; } StackFrame* raw_frame = it.frame(); if (raw_frame->is_internal()) { Code* current_code_object = isolate->heap()->GcSafeFindCodeForInnerPointer(raw_frame->pc()); if (current_code_object->builtin_index() == Builtins::kFunctionPrototypeApply) { PrintF("apply from "); it.Advance(); raw_frame = it.frame(); } } JavaScriptFrame::PrintTop(isolate, stdout, false, true); } static void SortIndices( Isolate* isolate, Handle indices, uint32_t sort_size, WriteBarrierMode write_barrier_mode = UPDATE_WRITE_BARRIER) { // Use AtomicElement wrapper to ensure that std::sort uses atomic load and // store operations that are safe for concurrent marking. base::AtomicElement* start = reinterpret_cast*>( indices->GetFirstElementAddress()); std::sort(start, start + sort_size, [isolate](const base::AtomicElement& elementA, const base::AtomicElement& elementB) { const Object* a = elementA.value(); const Object* b = elementB.value(); if (a->IsSmi() || !a->IsUndefined(isolate)) { if (!b->IsSmi() && b->IsUndefined(isolate)) { return true; } return a->Number() < b->Number(); } return !b->IsSmi() && b->IsUndefined(isolate); }); if (write_barrier_mode != SKIP_WRITE_BARRIER) { FIXED_ARRAY_ELEMENTS_WRITE_BARRIER(isolate->heap(), *indices, 0, sort_size); } } static Maybe IncludesValueSlowPath(Isolate* isolate, Handle receiver, Handle value, uint32_t start_from, uint32_t length) { bool search_for_hole = value->IsUndefined(isolate); for (uint32_t k = start_from; k < length; ++k) { LookupIterator it(isolate, receiver, k); if (!it.IsFound()) { if (search_for_hole) return Just(true); continue; } Handle element_k; ASSIGN_RETURN_ON_EXCEPTION_VALUE(isolate, element_k, Object::GetProperty(&it), Nothing()); if (value->SameValueZero(*element_k)) return Just(true); } return Just(false); } static Maybe IndexOfValueSlowPath(Isolate* isolate, Handle receiver, Handle value, uint32_t start_from, uint32_t length) { for (uint32_t k = start_from; k < length; ++k) { LookupIterator it(isolate, receiver, k); if (!it.IsFound()) { continue; } Handle element_k; ASSIGN_RETURN_ON_EXCEPTION_VALUE( isolate, element_k, Object::GetProperty(&it), Nothing()); if (value->StrictEquals(*element_k)) return Just(k); } return Just(-1); } // The InternalElementsAccessor is a helper class to expose otherwise protected // methods to its subclasses. Namely, we don't want to publicly expose methods // that take an entry (instead of an index) as an argument. class InternalElementsAccessor : public ElementsAccessor { public: explicit InternalElementsAccessor(const char* name) : ElementsAccessor(name) {} uint32_t GetEntryForIndex(Isolate* isolate, JSObject* holder, FixedArrayBase* backing_store, uint32_t index) override = 0; PropertyDetails GetDetails(JSObject* holder, uint32_t entry) override = 0; }; // Base class for element handler implementations. Contains the // the common logic for objects with different ElementsKinds. // Subclasses must specialize method for which the element // implementation differs from the base class implementation. // // This class is intended to be used in the following way: // // class SomeElementsAccessor : // public ElementsAccessorBase { // ... // } // // This is an example of the Curiously Recurring Template Pattern (see // http://en.wikipedia.org/wiki/Curiously_recurring_template_pattern). We use // CRTP to guarantee aggressive compile time optimizations (i.e. inlining and // specialization of SomeElementsAccessor methods). template class ElementsAccessorBase : public InternalElementsAccessor { public: explicit ElementsAccessorBase(const char* name) : InternalElementsAccessor(name) {} typedef ElementsTraitsParam ElementsTraits; typedef typename ElementsTraitsParam::BackingStore BackingStore; static ElementsKind kind() { return ElementsTraits::Kind; } static void ValidateContents(JSObject* holder, int length) {} static void ValidateImpl(JSObject* holder) { FixedArrayBase* fixed_array_base = holder->elements(); if (!fixed_array_base->IsHeapObject()) return; // Arrays that have been shifted in place can't be verified. if (fixed_array_base->IsFiller()) return; int length = 0; if (holder->IsJSArray()) { Object* length_obj = JSArray::cast(holder)->length(); if (length_obj->IsSmi()) { length = Smi::ToInt(length_obj); } } else { length = fixed_array_base->length(); } Subclass::ValidateContents(holder, length); } void Validate(JSObject* holder) final { DisallowHeapAllocation no_gc; Subclass::ValidateImpl(holder); } static bool IsPackedImpl(JSObject* holder, FixedArrayBase* backing_store, uint32_t start, uint32_t end) { DisallowHeapAllocation no_gc; if (IsFastPackedElementsKind(kind())) return true; Isolate* isolate = holder->GetIsolate(); for (uint32_t i = start; i < end; i++) { if (!Subclass::HasElementImpl(isolate, holder, i, backing_store, ALL_PROPERTIES)) { return false; } } return true; } static void TryTransitionResultArrayToPacked(Handle array) { if (!IsHoleyElementsKind(kind())) return; Handle backing_store(array->elements(), array->GetIsolate()); int length = Smi::ToInt(array->length()); if (!Subclass::IsPackedImpl(*array, *backing_store, 0, length)) return; ElementsKind packed_kind = GetPackedElementsKind(kind()); Handle new_map = JSObject::GetElementsTransitionMap(array, packed_kind); JSObject::MigrateToMap(array, new_map); if (FLAG_trace_elements_transitions) { JSObject::PrintElementsTransition(stdout, array, kind(), backing_store, packed_kind, backing_store); } } bool HasElement(JSObject* holder, uint32_t index, FixedArrayBase* backing_store, PropertyFilter filter) final { return Subclass::HasElementImpl(holder->GetIsolate(), holder, index, backing_store, filter); } static bool HasElementImpl(Isolate* isolate, JSObject* holder, uint32_t index, FixedArrayBase* backing_store, PropertyFilter filter = ALL_PROPERTIES) { return Subclass::GetEntryForIndexImpl(isolate, holder, backing_store, index, filter) != kMaxUInt32; } bool HasEntry(JSObject* holder, uint32_t entry) final { return Subclass::HasEntryImpl(holder->GetIsolate(), holder->elements(), entry); } static bool HasEntryImpl(Isolate* isolate, FixedArrayBase* backing_store, uint32_t entry) { UNIMPLEMENTED(); } bool HasAccessors(JSObject* holder) final { return Subclass::HasAccessorsImpl(holder, holder->elements()); } static bool HasAccessorsImpl(JSObject* holder, FixedArrayBase* backing_store) { return false; } Handle Get(Handle holder, uint32_t entry) final { return Subclass::GetInternalImpl(holder, entry); } static Handle GetInternalImpl(Handle holder, uint32_t entry) { return Subclass::GetImpl(holder->GetIsolate(), holder->elements(), entry); } static Handle GetImpl(Isolate* isolate, FixedArrayBase* backing_store, uint32_t entry) { uint32_t index = GetIndexForEntryImpl(backing_store, entry); return handle(BackingStore::cast(backing_store)->get(index), isolate); } void Set(Handle holder, uint32_t entry, Object* value) final { Subclass::SetImpl(holder, entry, value); } void Reconfigure(Handle object, Handle store, uint32_t entry, Handle value, PropertyAttributes attributes) final { Subclass::ReconfigureImpl(object, store, entry, value, attributes); } static void ReconfigureImpl(Handle object, Handle store, uint32_t entry, Handle value, PropertyAttributes attributes) { UNREACHABLE(); } void Add(Handle object, uint32_t index, Handle value, PropertyAttributes attributes, uint32_t new_capacity) final { Subclass::AddImpl(object, index, value, attributes, new_capacity); } static void AddImpl(Handle object, uint32_t index, Handle value, PropertyAttributes attributes, uint32_t new_capacity) { UNREACHABLE(); } uint32_t Push(Handle receiver, Arguments* args, uint32_t push_size) final { return Subclass::PushImpl(receiver, args, push_size); } static uint32_t PushImpl(Handle receiver, Arguments* args, uint32_t push_sized) { UNREACHABLE(); } uint32_t Unshift(Handle receiver, Arguments* args, uint32_t unshift_size) final { return Subclass::UnshiftImpl(receiver, args, unshift_size); } static uint32_t UnshiftImpl(Handle receiver, Arguments* args, uint32_t unshift_size) { UNREACHABLE(); } Handle Slice(Handle receiver, uint32_t start, uint32_t end) final { return Subclass::SliceImpl(receiver, start, end); } static Handle SliceImpl(Handle receiver, uint32_t start, uint32_t end) { UNREACHABLE(); } Handle Pop(Handle receiver) final { return Subclass::PopImpl(receiver); } static Handle PopImpl(Handle receiver) { UNREACHABLE(); } Handle Shift(Handle receiver) final { return Subclass::ShiftImpl(receiver); } static Handle ShiftImpl(Handle receiver) { UNREACHABLE(); } void SetLength(Handle array, uint32_t length) final { Subclass::SetLengthImpl(array->GetIsolate(), array, length, handle(array->elements(), array->GetIsolate())); } static void SetLengthImpl(Isolate* isolate, Handle array, uint32_t length, Handle backing_store) { DCHECK(!array->SetLengthWouldNormalize(length)); DCHECK(IsFastElementsKind(array->GetElementsKind())); uint32_t old_length = 0; CHECK(array->length()->ToArrayIndex(&old_length)); if (old_length < length) { ElementsKind kind = array->GetElementsKind(); if (!IsHoleyElementsKind(kind)) { kind = GetHoleyElementsKind(kind); JSObject::TransitionElementsKind(array, kind); } } // Check whether the backing store should be shrunk. uint32_t capacity = backing_store->length(); old_length = Min(old_length, capacity); if (length == 0) { array->initialize_elements(); } else if (length <= capacity) { if (IsSmiOrObjectElementsKind(kind())) { JSObject::EnsureWritableFastElements(array); if (array->elements() != *backing_store) { backing_store = handle(array->elements(), isolate); } } if (2 * length + JSObject::kMinAddedElementsCapacity <= capacity) { // If more than half the elements won't be used, trim the array. // Do not trim from short arrays to prevent frequent trimming on // repeated pop operations. // Leave some space to allow for subsequent push operations. int elements_to_trim = length + 1 == old_length ? (capacity - length) / 2 : capacity - length; isolate->heap()->RightTrimFixedArray(*backing_store, elements_to_trim); // Fill the non-trimmed elements with holes. BackingStore::cast(*backing_store) ->FillWithHoles(length, std::min(old_length, capacity - elements_to_trim)); } else { // Otherwise, fill the unused tail with holes. BackingStore::cast(*backing_store)->FillWithHoles(length, old_length); } } else { // Check whether the backing store should be expanded. capacity = Max(length, JSObject::NewElementsCapacity(capacity)); Subclass::GrowCapacityAndConvertImpl(array, capacity); } array->set_length(Smi::FromInt(length)); JSObject::ValidateElements(*array); } uint32_t NumberOfElements(JSObject* receiver) final { return Subclass::NumberOfElementsImpl(receiver, receiver->elements()); } static uint32_t NumberOfElementsImpl(JSObject* receiver, FixedArrayBase* backing_store) { UNREACHABLE(); } static uint32_t GetMaxIndex(JSObject* receiver, FixedArrayBase* elements) { if (receiver->IsJSArray()) { DCHECK(JSArray::cast(receiver)->length()->IsSmi()); return static_cast( Smi::ToInt(JSArray::cast(receiver)->length())); } return Subclass::GetCapacityImpl(receiver, elements); } static uint32_t GetMaxNumberOfEntries(JSObject* receiver, FixedArrayBase* elements) { return Subclass::GetMaxIndex(receiver, elements); } static Handle ConvertElementsWithCapacity( Handle object, Handle old_elements, ElementsKind from_kind, uint32_t capacity) { return ConvertElementsWithCapacity( object, old_elements, from_kind, capacity, 0, 0, ElementsAccessor::kCopyToEndAndInitializeToHole); } static Handle ConvertElementsWithCapacity( Handle object, Handle old_elements, ElementsKind from_kind, uint32_t capacity, int copy_size) { return ConvertElementsWithCapacity(object, old_elements, from_kind, capacity, 0, 0, copy_size); } static Handle ConvertElementsWithCapacity( Handle object, Handle old_elements, ElementsKind from_kind, uint32_t capacity, uint32_t src_index, uint32_t dst_index, int copy_size) { Isolate* isolate = object->GetIsolate(); Handle new_elements; if (IsDoubleElementsKind(kind())) { new_elements = isolate->factory()->NewFixedDoubleArray(capacity); } else { new_elements = isolate->factory()->NewUninitializedFixedArray(capacity); } int packed_size = kPackedSizeNotKnown; if (IsFastPackedElementsKind(from_kind) && object->IsJSArray()) { packed_size = Smi::ToInt(JSArray::cast(*object)->length()); } Subclass::CopyElementsImpl(isolate, *old_elements, src_index, *new_elements, from_kind, dst_index, packed_size, copy_size); return new_elements; } static void TransitionElementsKindImpl(Handle object, Handle to_map) { Handle from_map = handle(object->map(), object->GetIsolate()); ElementsKind from_kind = from_map->elements_kind(); ElementsKind to_kind = to_map->elements_kind(); if (IsHoleyElementsKind(from_kind)) { to_kind = GetHoleyElementsKind(to_kind); } if (from_kind != to_kind) { // This method should never be called for any other case. DCHECK(IsFastElementsKind(from_kind)); DCHECK(IsFastElementsKind(to_kind)); DCHECK_NE(TERMINAL_FAST_ELEMENTS_KIND, from_kind); Handle from_elements(object->elements(), object->GetIsolate()); if (object->elements() == object->GetReadOnlyRoots().empty_fixed_array() || IsDoubleElementsKind(from_kind) == IsDoubleElementsKind(to_kind)) { // No change is needed to the elements() buffer, the transition // only requires a map change. JSObject::MigrateToMap(object, to_map); } else { DCHECK( (IsSmiElementsKind(from_kind) && IsDoubleElementsKind(to_kind)) || (IsDoubleElementsKind(from_kind) && IsObjectElementsKind(to_kind))); uint32_t capacity = static_cast(object->elements()->length()); Handle elements = ConvertElementsWithCapacity( object, from_elements, from_kind, capacity); JSObject::SetMapAndElements(object, to_map, elements); } if (FLAG_trace_elements_transitions) { JSObject::PrintElementsTransition( stdout, object, from_kind, from_elements, to_kind, handle(object->elements(), object->GetIsolate())); } } } static void GrowCapacityAndConvertImpl(Handle object, uint32_t capacity) { ElementsKind from_kind = object->GetElementsKind(); if (IsSmiOrObjectElementsKind(from_kind)) { // Array optimizations rely on the prototype lookups of Array objects // always returning undefined. If there is a store to the initial // prototype object, make sure all of these optimizations are invalidated. object->GetIsolate()->UpdateNoElementsProtectorOnSetLength(object); } Handle old_elements(object->elements(), object->GetIsolate()); // This method should only be called if there's a reason to update the // elements. DCHECK(IsDoubleElementsKind(from_kind) != IsDoubleElementsKind(kind()) || IsDictionaryElementsKind(from_kind) || static_cast(old_elements->length()) < capacity); Subclass::BasicGrowCapacityAndConvertImpl(object, old_elements, from_kind, kind(), capacity); } static void BasicGrowCapacityAndConvertImpl( Handle object, Handle old_elements, ElementsKind from_kind, ElementsKind to_kind, uint32_t capacity) { Handle elements = ConvertElementsWithCapacity(object, old_elements, from_kind, capacity); if (IsHoleyElementsKind(from_kind)) { to_kind = GetHoleyElementsKind(to_kind); } Handle new_map = JSObject::GetElementsTransitionMap(object, to_kind); JSObject::SetMapAndElements(object, new_map, elements); // Transition through the allocation site as well if present. JSObject::UpdateAllocationSite(object, to_kind); if (FLAG_trace_elements_transitions) { JSObject::PrintElementsTransition(stdout, object, from_kind, old_elements, to_kind, elements); } } void TransitionElementsKind(Handle object, Handle map) final { Subclass::TransitionElementsKindImpl(object, map); } void GrowCapacityAndConvert(Handle object, uint32_t capacity) final { Subclass::GrowCapacityAndConvertImpl(object, capacity); } bool GrowCapacity(Handle object, uint32_t index) final { // This function is intended to be called from optimized code. We don't // want to trigger lazy deopts there, so refuse to handle cases that would. if (object->map()->is_prototype_map() || object->WouldConvertToSlowElements(index)) { return false; } Handle old_elements(object->elements(), object->GetIsolate()); uint32_t new_capacity = JSObject::NewElementsCapacity(index + 1); DCHECK(static_cast(old_elements->length()) < new_capacity); Handle elements = ConvertElementsWithCapacity(object, old_elements, kind(), new_capacity); DCHECK_EQ(object->GetElementsKind(), kind()); // Transition through the allocation site as well if present. if (JSObject::UpdateAllocationSite( object, kind())) { return false; } object->set_elements(*elements); return true; } void Delete(Handle obj, uint32_t entry) final { Subclass::DeleteImpl(obj, entry); } static void CopyElementsImpl(Isolate* isolate, FixedArrayBase* from, uint32_t from_start, FixedArrayBase* to, ElementsKind from_kind, uint32_t to_start, int packed_size, int copy_size) { UNREACHABLE(); } void CopyElements(JSObject* from_holder, uint32_t from_start, ElementsKind from_kind, Handle to, uint32_t to_start, int copy_size) final { int packed_size = kPackedSizeNotKnown; bool is_packed = IsFastPackedElementsKind(from_kind) && from_holder->IsJSArray(); if (is_packed) { packed_size = Smi::ToInt(JSArray::cast(from_holder)->length()); if (copy_size >= 0 && packed_size > copy_size) { packed_size = copy_size; } } FixedArrayBase* from = from_holder->elements(); // NOTE: the Subclass::CopyElementsImpl() methods // violate the handlified function signature convention: // raw pointer parameters in the function that allocates. This is done // intentionally to avoid ArrayConcat() builtin performance degradation. // // Details: The idea is that allocations actually happen only in case of // copying from object with fast double elements to object with object // elements. In all the other cases there are no allocations performed and // handle creation causes noticeable performance degradation of the builtin. Subclass::CopyElementsImpl(from_holder->GetIsolate(), from, from_start, *to, from_kind, to_start, packed_size, copy_size); } void CopyElements(Isolate* isolate, Handle source, ElementsKind source_kind, Handle destination, int size) override { Subclass::CopyElementsImpl(isolate, *source, 0, *destination, source_kind, 0, kPackedSizeNotKnown, size); } void CopyTypedArrayElementsSlice(JSTypedArray* source, JSTypedArray* destination, size_t start, size_t end) override { Subclass::CopyTypedArrayElementsSliceImpl(source, destination, start, end); } static void CopyTypedArrayElementsSliceImpl(JSTypedArray* source, JSTypedArray* destination, size_t start, size_t end) { UNREACHABLE(); } Object* CopyElements(Handle source, Handle destination, size_t length, uint32_t offset) final { return Subclass::CopyElementsHandleImpl(source, destination, length, offset); } static Object* CopyElementsHandleImpl(Handle source, Handle destination, size_t length, uint32_t offset) { UNREACHABLE(); } Handle Normalize(Handle object) final { return Subclass::NormalizeImpl( object, handle(object->elements(), object->GetIsolate())); } static Handle NormalizeImpl( Handle object, Handle elements) { UNREACHABLE(); } Maybe CollectValuesOrEntries(Isolate* isolate, Handle object, Handle values_or_entries, bool get_entries, int* nof_items, PropertyFilter filter) override { return Subclass::CollectValuesOrEntriesImpl( isolate, object, values_or_entries, get_entries, nof_items, filter); } static Maybe CollectValuesOrEntriesImpl( Isolate* isolate, Handle object, Handle values_or_entries, bool get_entries, int* nof_items, PropertyFilter filter) { DCHECK_EQ(*nof_items, 0); KeyAccumulator accumulator(isolate, KeyCollectionMode::kOwnOnly, ALL_PROPERTIES); Subclass::CollectElementIndicesImpl( object, handle(object->elements(), isolate), &accumulator); Handle keys = accumulator.GetKeys(); int count = 0; int i = 0; ElementsKind original_elements_kind = object->GetElementsKind(); for (; i < keys->length(); ++i) { Handle key(keys->get(i), isolate); uint32_t index; if (!key->ToUint32(&index)) continue; DCHECK_EQ(object->GetElementsKind(), original_elements_kind); uint32_t entry = Subclass::GetEntryForIndexImpl( isolate, *object, object->elements(), index, filter); if (entry == kMaxUInt32) continue; PropertyDetails details = Subclass::GetDetailsImpl(*object, entry); Handle value; if (details.kind() == kData) { value = Subclass::GetImpl(isolate, object->elements(), entry); } else { // This might modify the elements and/or change the elements kind. LookupIterator it(isolate, object, index, LookupIterator::OWN); ASSIGN_RETURN_ON_EXCEPTION_VALUE( isolate, value, Object::GetProperty(&it), Nothing()); } if (get_entries) value = MakeEntryPair(isolate, index, value); values_or_entries->set(count++, *value); if (object->GetElementsKind() != original_elements_kind) break; } // Slow path caused by changes in elements kind during iteration. for (; i < keys->length(); i++) { Handle key(keys->get(i), isolate); uint32_t index; if (!key->ToUint32(&index)) continue; if (filter & ONLY_ENUMERABLE) { InternalElementsAccessor* accessor = reinterpret_cast( object->GetElementsAccessor()); uint32_t entry = accessor->GetEntryForIndex(isolate, *object, object->elements(), index); if (entry == kMaxUInt32) continue; PropertyDetails details = accessor->GetDetails(*object, entry); if (!details.IsEnumerable()) continue; } Handle value; LookupIterator it(isolate, object, index, LookupIterator::OWN); ASSIGN_RETURN_ON_EXCEPTION_VALUE(isolate, value, Object::GetProperty(&it), Nothing()); if (get_entries) value = MakeEntryPair(isolate, index, value); values_or_entries->set(count++, *value); } *nof_items = count; return Just(true); } void CollectElementIndices(Handle object, Handle backing_store, KeyAccumulator* keys) final { if (keys->filter() & ONLY_ALL_CAN_READ) return; Subclass::CollectElementIndicesImpl(object, backing_store, keys); } static void CollectElementIndicesImpl(Handle object, Handle backing_store, KeyAccumulator* keys) { DCHECK_NE(DICTIONARY_ELEMENTS, kind()); // Non-dictionary elements can't have all-can-read accessors. uint32_t length = Subclass::GetMaxIndex(*object, *backing_store); PropertyFilter filter = keys->filter(); Isolate* isolate = keys->isolate(); Factory* factory = isolate->factory(); for (uint32_t i = 0; i < length; i++) { if (Subclass::HasElementImpl(isolate, *object, i, *backing_store, filter)) { keys->AddKey(factory->NewNumberFromUint(i)); } } } static Handle DirectCollectElementIndicesImpl( Isolate* isolate, Handle object, Handle backing_store, GetKeysConversion convert, PropertyFilter filter, Handle list, uint32_t* nof_indices, uint32_t insertion_index = 0) { uint32_t length = Subclass::GetMaxIndex(*object, *backing_store); uint32_t const kMaxStringTableEntries = isolate->heap()->MaxNumberToStringCacheSize(); for (uint32_t i = 0; i < length; i++) { if (Subclass::HasElementImpl(isolate, *object, i, *backing_store, filter)) { if (convert == GetKeysConversion::kConvertToString) { bool use_cache = i < kMaxStringTableEntries; Handle index_string = isolate->factory()->Uint32ToString(i, use_cache); list->set(insertion_index, *index_string); } else { list->set(insertion_index, Smi::FromInt(i), SKIP_WRITE_BARRIER); } insertion_index++; } } *nof_indices = insertion_index; return list; } MaybeHandle PrependElementIndices( Handle object, Handle backing_store, Handle keys, GetKeysConversion convert, PropertyFilter filter) final { return Subclass::PrependElementIndicesImpl(object, backing_store, keys, convert, filter); } static MaybeHandle PrependElementIndicesImpl( Handle object, Handle backing_store, Handle keys, GetKeysConversion convert, PropertyFilter filter) { Isolate* isolate = object->GetIsolate(); uint32_t nof_property_keys = keys->length(); uint32_t initial_list_length = Subclass::GetMaxNumberOfEntries(*object, *backing_store); initial_list_length += nof_property_keys; if (initial_list_length > FixedArray::kMaxLength || initial_list_length < nof_property_keys) { return isolate->Throw(isolate->factory()->NewRangeError( MessageTemplate::kInvalidArrayLength)); } // Collect the element indices into a new list. MaybeHandle raw_array = isolate->factory()->TryNewFixedArray(initial_list_length); Handle combined_keys; // If we have a holey backing store try to precisely estimate the backing // store size as a last emergency measure if we cannot allocate the big // array. if (!raw_array.ToHandle(&combined_keys)) { if (IsHoleyOrDictionaryElementsKind(kind())) { // If we overestimate the result list size we might end up in the // large-object space which doesn't free memory on shrinking the list. // Hence we try to estimate the final size for holey backing stores more // precisely here. initial_list_length = Subclass::NumberOfElementsImpl(*object, *backing_store); initial_list_length += nof_property_keys; } combined_keys = isolate->factory()->NewFixedArray(initial_list_length); } uint32_t nof_indices = 0; bool needs_sorting = IsDictionaryElementsKind(kind()) || IsSloppyArgumentsElementsKind(kind()); combined_keys = Subclass::DirectCollectElementIndicesImpl( isolate, object, backing_store, needs_sorting ? GetKeysConversion::kKeepNumbers : convert, filter, combined_keys, &nof_indices); if (needs_sorting) { SortIndices(isolate, combined_keys, nof_indices); // Indices from dictionary elements should only be converted after // sorting. if (convert == GetKeysConversion::kConvertToString) { for (uint32_t i = 0; i < nof_indices; i++) { Handle index_string = isolate->factory()->Uint32ToString( combined_keys->get(i)->Number()); combined_keys->set(i, *index_string); } } } // Copy over the passed-in property keys. CopyObjectToObjectElements(isolate, *keys, PACKED_ELEMENTS, 0, *combined_keys, PACKED_ELEMENTS, nof_indices, nof_property_keys); // For holey elements and arguments we might have to shrink the collected // keys since the estimates might be off. if (IsHoleyOrDictionaryElementsKind(kind()) || IsSloppyArgumentsElementsKind(kind())) { // Shrink combined_keys to the final size. int final_size = nof_indices + nof_property_keys; DCHECK_LE(final_size, combined_keys->length()); return FixedArray::ShrinkOrEmpty(isolate, combined_keys, final_size); } return combined_keys; } void AddElementsToKeyAccumulator(Handle receiver, KeyAccumulator* accumulator, AddKeyConversion convert) final { Subclass::AddElementsToKeyAccumulatorImpl(receiver, accumulator, convert); } static uint32_t GetCapacityImpl(JSObject* holder, FixedArrayBase* backing_store) { return backing_store->length(); } uint32_t GetCapacity(JSObject* holder, FixedArrayBase* backing_store) final { return Subclass::GetCapacityImpl(holder, backing_store); } static Object* FillImpl(Handle receiver, Handle obj_value, uint32_t start, uint32_t end) { UNREACHABLE(); } Object* Fill(Handle receiver, Handle obj_value, uint32_t start, uint32_t end) override { return Subclass::FillImpl(receiver, obj_value, start, end); } static Maybe IncludesValueImpl(Isolate* isolate, Handle receiver, Handle value, uint32_t start_from, uint32_t length) { return IncludesValueSlowPath(isolate, receiver, value, start_from, length); } Maybe IncludesValue(Isolate* isolate, Handle receiver, Handle value, uint32_t start_from, uint32_t length) final { return Subclass::IncludesValueImpl(isolate, receiver, value, start_from, length); } static Maybe IndexOfValueImpl(Isolate* isolate, Handle receiver, Handle value, uint32_t start_from, uint32_t length) { return IndexOfValueSlowPath(isolate, receiver, value, start_from, length); } Maybe IndexOfValue(Isolate* isolate, Handle receiver, Handle value, uint32_t start_from, uint32_t length) final { return Subclass::IndexOfValueImpl(isolate, receiver, value, start_from, length); } static Maybe LastIndexOfValueImpl(Handle receiver, Handle value, uint32_t start_from) { UNREACHABLE(); } Maybe LastIndexOfValue(Handle receiver, Handle value, uint32_t start_from) final { return Subclass::LastIndexOfValueImpl(receiver, value, start_from); } static void ReverseImpl(JSObject* receiver) { UNREACHABLE(); } void Reverse(JSObject* receiver) final { Subclass::ReverseImpl(receiver); } static uint32_t GetIndexForEntryImpl(FixedArrayBase* backing_store, uint32_t entry) { return entry; } static uint32_t GetEntryForIndexImpl(Isolate* isolate, JSObject* holder, FixedArrayBase* backing_store, uint32_t index, PropertyFilter filter) { DCHECK(IsFastElementsKind(kind())); uint32_t length = Subclass::GetMaxIndex(holder, backing_store); if (IsHoleyElementsKind(kind())) { return index < length && !BackingStore::cast(backing_store) ->is_the_hole(isolate, index) ? index : kMaxUInt32; } else { return index < length ? index : kMaxUInt32; } } uint32_t GetEntryForIndex(Isolate* isolate, JSObject* holder, FixedArrayBase* backing_store, uint32_t index) final { return Subclass::GetEntryForIndexImpl(isolate, holder, backing_store, index, ALL_PROPERTIES); } static PropertyDetails GetDetailsImpl(FixedArrayBase* backing_store, uint32_t entry) { return PropertyDetails(kData, NONE, PropertyCellType::kNoCell); } static PropertyDetails GetDetailsImpl(JSObject* holder, uint32_t entry) { return PropertyDetails(kData, NONE, PropertyCellType::kNoCell); } PropertyDetails GetDetails(JSObject* holder, uint32_t entry) final { return Subclass::GetDetailsImpl(holder, entry); } Handle CreateListFromArrayLike(Isolate* isolate, Handle object, uint32_t length) final { return Subclass::CreateListFromArrayLikeImpl(isolate, object, length); }; static Handle CreateListFromArrayLikeImpl(Isolate* isolate, Handle object, uint32_t length) { UNREACHABLE(); } private: DISALLOW_COPY_AND_ASSIGN(ElementsAccessorBase); }; class DictionaryElementsAccessor : public ElementsAccessorBase > { public: explicit DictionaryElementsAccessor(const char* name) : ElementsAccessorBase >(name) {} static uint32_t GetMaxIndex(JSObject* receiver, FixedArrayBase* elements) { // We cannot properly estimate this for dictionaries. UNREACHABLE(); } static uint32_t GetMaxNumberOfEntries(JSObject* receiver, FixedArrayBase* backing_store) { return NumberOfElementsImpl(receiver, backing_store); } static uint32_t NumberOfElementsImpl(JSObject* receiver, FixedArrayBase* backing_store) { NumberDictionary* dict = NumberDictionary::cast(backing_store); return dict->NumberOfElements(); } static void SetLengthImpl(Isolate* isolate, Handle array, uint32_t length, Handle backing_store) { Handle dict = Handle::cast(backing_store); int capacity = dict->Capacity(); uint32_t old_length = 0; CHECK(array->length()->ToArrayLength(&old_length)); { DisallowHeapAllocation no_gc; ReadOnlyRoots roots(isolate); if (length < old_length) { if (dict->requires_slow_elements()) { // Find last non-deletable element in range of elements to be // deleted and adjust range accordingly. for (int entry = 0; entry < capacity; entry++) { Object* index = dict->KeyAt(entry); if (dict->IsKey(roots, index)) { uint32_t number = static_cast(index->Number()); if (length <= number && number < old_length) { PropertyDetails details = dict->DetailsAt(entry); if (!details.IsConfigurable()) length = number + 1; } } } } if (length == 0) { // Flush the backing store. array->initialize_elements(); } else { // Remove elements that should be deleted. int removed_entries = 0; for (int entry = 0; entry < capacity; entry++) { Object* index = dict->KeyAt(entry); if (dict->IsKey(roots, index)) { uint32_t number = static_cast(index->Number()); if (length <= number && number < old_length) { dict->ClearEntry(isolate, entry); removed_entries++; } } } if (removed_entries > 0) { // Update the number of elements. dict->ElementsRemoved(removed_entries); } } } } Handle length_obj = isolate->factory()->NewNumberFromUint(length); array->set_length(*length_obj); } static void CopyElementsImpl(Isolate* isolate, FixedArrayBase* from, uint32_t from_start, FixedArrayBase* to, ElementsKind from_kind, uint32_t to_start, int packed_size, int copy_size) { UNREACHABLE(); } static Handle SliceImpl(Handle receiver, uint32_t start, uint32_t end) { Isolate* isolate = receiver->GetIsolate(); uint32_t result_length = end < start ? 0u : end - start; // Result must also be a dictionary. Handle result_array = isolate->factory()->NewJSArray(0, HOLEY_ELEMENTS); JSObject::NormalizeElements(result_array); result_array->set_length(Smi::FromInt(result_length)); Handle source_dict( NumberDictionary::cast(receiver->elements()), isolate); int entry_count = source_dict->Capacity(); ReadOnlyRoots roots(isolate); for (int i = 0; i < entry_count; i++) { Object* key = source_dict->KeyAt(i); if (!source_dict->ToKey(roots, i, &key)) continue; uint64_t key_value = NumberToInt64(key); if (key_value >= start && key_value < end) { Handle dest_dict( NumberDictionary::cast(result_array->elements()), isolate); Handle value(source_dict->ValueAt(i), isolate); PropertyDetails details = source_dict->DetailsAt(i); PropertyAttributes attr = details.attributes(); AddImpl(result_array, static_cast(key_value) - start, value, attr, 0); } } return result_array; } static void DeleteImpl(Handle obj, uint32_t entry) { Handle dict(NumberDictionary::cast(obj->elements()), obj->GetIsolate()); dict = NumberDictionary::DeleteEntry(obj->GetIsolate(), dict, entry); obj->set_elements(*dict); } static bool HasAccessorsImpl(JSObject* holder, FixedArrayBase* backing_store) { DisallowHeapAllocation no_gc; NumberDictionary* dict = NumberDictionary::cast(backing_store); if (!dict->requires_slow_elements()) return false; int capacity = dict->Capacity(); ReadOnlyRoots roots = holder->GetReadOnlyRoots(); for (int i = 0; i < capacity; i++) { Object* key = dict->KeyAt(i); if (!dict->IsKey(roots, key)) continue; PropertyDetails details = dict->DetailsAt(i); if (details.kind() == kAccessor) return true; } return false; } static Object* GetRaw(FixedArrayBase* store, uint32_t entry) { NumberDictionary* backing_store = NumberDictionary::cast(store); return backing_store->ValueAt(entry); } static Handle GetImpl(Isolate* isolate, FixedArrayBase* backing_store, uint32_t entry) { return handle(GetRaw(backing_store, entry), isolate); } static inline void SetImpl(Handle holder, uint32_t entry, Object* value) { SetImpl(holder->elements(), entry, value); } static inline void SetImpl(FixedArrayBase* backing_store, uint32_t entry, Object* value) { NumberDictionary::cast(backing_store)->ValueAtPut(entry, value); } static void ReconfigureImpl(Handle object, Handle store, uint32_t entry, Handle value, PropertyAttributes attributes) { NumberDictionary* dictionary = NumberDictionary::cast(*store); if (attributes != NONE) object->RequireSlowElements(dictionary); dictionary->ValueAtPut(entry, *value); PropertyDetails details = dictionary->DetailsAt(entry); details = PropertyDetails(kData, attributes, PropertyCellType::kNoCell, details.dictionary_index()); dictionary->DetailsAtPut(object->GetIsolate(), entry, details); } static void AddImpl(Handle object, uint32_t index, Handle value, PropertyAttributes attributes, uint32_t new_capacity) { PropertyDetails details(kData, attributes, PropertyCellType::kNoCell); Handle dictionary = object->HasFastElements() || object->HasFastStringWrapperElements() ? JSObject::NormalizeElements(object) : handle(NumberDictionary::cast(object->elements()), object->GetIsolate()); Handle new_dictionary = NumberDictionary::Add( object->GetIsolate(), dictionary, index, value, details); new_dictionary->UpdateMaxNumberKey(index, object); if (attributes != NONE) object->RequireSlowElements(*new_dictionary); if (dictionary.is_identical_to(new_dictionary)) return; object->set_elements(*new_dictionary); } static bool HasEntryImpl(Isolate* isolate, FixedArrayBase* store, uint32_t entry) { DisallowHeapAllocation no_gc; NumberDictionary* dict = NumberDictionary::cast(store); Object* index = dict->KeyAt(entry); return !index->IsTheHole(isolate); } static uint32_t GetIndexForEntryImpl(FixedArrayBase* store, uint32_t entry) { DisallowHeapAllocation no_gc; NumberDictionary* dict = NumberDictionary::cast(store); uint32_t result = 0; CHECK(dict->KeyAt(entry)->ToArrayIndex(&result)); return result; } static uint32_t GetEntryForIndexImpl(Isolate* isolate, JSObject* holder, FixedArrayBase* store, uint32_t index, PropertyFilter filter) { DisallowHeapAllocation no_gc; NumberDictionary* dictionary = NumberDictionary::cast(store); int entry = dictionary->FindEntry(isolate, index); if (entry == NumberDictionary::kNotFound) return kMaxUInt32; if (filter != ALL_PROPERTIES) { PropertyDetails details = dictionary->DetailsAt(entry); PropertyAttributes attr = details.attributes(); if ((attr & filter) != 0) return kMaxUInt32; } return static_cast(entry); } static PropertyDetails GetDetailsImpl(JSObject* holder, uint32_t entry) { return GetDetailsImpl(holder->elements(), entry); } static PropertyDetails GetDetailsImpl(FixedArrayBase* backing_store, uint32_t entry) { return NumberDictionary::cast(backing_store)->DetailsAt(entry); } static uint32_t FilterKey(Handle dictionary, int entry, Object* raw_key, PropertyFilter filter) { DCHECK(raw_key->IsNumber()); DCHECK_LE(raw_key->Number(), kMaxUInt32); PropertyDetails details = dictionary->DetailsAt(entry); PropertyAttributes attr = details.attributes(); if ((attr & filter) != 0) return kMaxUInt32; return static_cast(raw_key->Number()); } static uint32_t GetKeyForEntryImpl(Isolate* isolate, Handle dictionary, int entry, PropertyFilter filter) { DisallowHeapAllocation no_gc; Object* raw_key = dictionary->KeyAt(entry); if (!dictionary->IsKey(ReadOnlyRoots(isolate), raw_key)) return kMaxUInt32; return FilterKey(dictionary, entry, raw_key, filter); } static void CollectElementIndicesImpl(Handle object, Handle backing_store, KeyAccumulator* keys) { if (keys->filter() & SKIP_STRINGS) return; Isolate* isolate = keys->isolate(); Handle dictionary = Handle::cast(backing_store); int capacity = dictionary->Capacity(); Handle elements = isolate->factory()->NewFixedArray( GetMaxNumberOfEntries(*object, *backing_store)); int insertion_index = 0; PropertyFilter filter = keys->filter(); ReadOnlyRoots roots(isolate); for (int i = 0; i < capacity; i++) { Object* raw_key = dictionary->KeyAt(i); if (!dictionary->IsKey(roots, raw_key)) continue; uint32_t key = FilterKey(dictionary, i, raw_key, filter); if (key == kMaxUInt32) { keys->AddShadowingKey(raw_key); continue; } elements->set(insertion_index, raw_key); insertion_index++; } SortIndices(isolate, elements, insertion_index); for (int i = 0; i < insertion_index; i++) { keys->AddKey(elements->get(i)); } } static Handle DirectCollectElementIndicesImpl( Isolate* isolate, Handle object, Handle backing_store, GetKeysConversion convert, PropertyFilter filter, Handle list, uint32_t* nof_indices, uint32_t insertion_index = 0) { if (filter & SKIP_STRINGS) return list; if (filter & ONLY_ALL_CAN_READ) return list; Handle dictionary = Handle::cast(backing_store); uint32_t capacity = dictionary->Capacity(); for (uint32_t i = 0; i < capacity; i++) { uint32_t key = GetKeyForEntryImpl(isolate, dictionary, i, filter); if (key == kMaxUInt32) continue; Handle index = isolate->factory()->NewNumberFromUint(key); list->set(insertion_index, *index); insertion_index++; } *nof_indices = insertion_index; return list; } static void AddElementsToKeyAccumulatorImpl(Handle receiver, KeyAccumulator* accumulator, AddKeyConversion convert) { Isolate* isolate = accumulator->isolate(); Handle dictionary( NumberDictionary::cast(receiver->elements()), isolate); int capacity = dictionary->Capacity(); ReadOnlyRoots roots(isolate); for (int i = 0; i < capacity; i++) { Object* k = dictionary->KeyAt(i); if (!dictionary->IsKey(roots, k)) continue; Object* value = dictionary->ValueAt(i); DCHECK(!value->IsTheHole(isolate)); DCHECK(!value->IsAccessorPair()); DCHECK(!value->IsAccessorInfo()); accumulator->AddKey(value, convert); } } static bool IncludesValueFastPath(Isolate* isolate, Handle receiver, Handle value, uint32_t start_from, uint32_t length, Maybe* result) { DisallowHeapAllocation no_gc; NumberDictionary* dictionary = NumberDictionary::cast(receiver->elements()); int capacity = dictionary->Capacity(); Object* the_hole = ReadOnlyRoots(isolate).the_hole_value(); Object* undefined = ReadOnlyRoots(isolate).undefined_value(); // Scan for accessor properties. If accessors are present, then elements // must be accessed in order via the slow path. bool found = false; for (int i = 0; i < capacity; ++i) { Object* k = dictionary->KeyAt(i); if (k == the_hole) continue; if (k == undefined) continue; uint32_t index; if (!k->ToArrayIndex(&index) || index < start_from || index >= length) { continue; } if (dictionary->DetailsAt(i).kind() == kAccessor) { // Restart from beginning in slow path, otherwise we may observably // access getters out of order return false; } else if (!found) { Object* element_k = dictionary->ValueAt(i); if (value->SameValueZero(element_k)) found = true; } } *result = Just(found); return true; } static Maybe IncludesValueImpl(Isolate* isolate, Handle receiver, Handle value, uint32_t start_from, uint32_t length) { DCHECK(JSObject::PrototypeHasNoElements(isolate, *receiver)); bool search_for_hole = value->IsUndefined(isolate); if (!search_for_hole) { Maybe result = Nothing(); if (DictionaryElementsAccessor::IncludesValueFastPath( isolate, receiver, value, start_from, length, &result)) { return result; } } ElementsKind original_elements_kind = receiver->GetElementsKind(); USE(original_elements_kind); Handle dictionary( NumberDictionary::cast(receiver->elements()), isolate); // Iterate through entire range, as accessing elements out of order is // observable for (uint32_t k = start_from; k < length; ++k) { DCHECK_EQ(receiver->GetElementsKind(), original_elements_kind); int entry = dictionary->FindEntry(isolate, k); if (entry == NumberDictionary::kNotFound) { if (search_for_hole) return Just(true); continue; } PropertyDetails details = GetDetailsImpl(*dictionary, entry); switch (details.kind()) { case kData: { Object* element_k = dictionary->ValueAt(entry); if (value->SameValueZero(element_k)) return Just(true); break; } case kAccessor: { LookupIterator it(isolate, receiver, k, LookupIterator::OWN_SKIP_INTERCEPTOR); DCHECK(it.IsFound()); DCHECK_EQ(it.state(), LookupIterator::ACCESSOR); Handle element_k; ASSIGN_RETURN_ON_EXCEPTION_VALUE( isolate, element_k, JSObject::GetPropertyWithAccessor(&it), Nothing()); if (value->SameValueZero(*element_k)) return Just(true); // Bailout to slow path if elements on prototype changed if (!JSObject::PrototypeHasNoElements(isolate, *receiver)) { return IncludesValueSlowPath(isolate, receiver, value, k + 1, length); } // Continue if elements unchanged if (*dictionary == receiver->elements()) continue; // Otherwise, bailout or update elements // If switched to initial elements, return true if searching for // undefined, and false otherwise. if (receiver->map()->GetInitialElements() == receiver->elements()) { return Just(search_for_hole); } // If switched to fast elements, continue with the correct accessor. if (receiver->GetElementsKind() != DICTIONARY_ELEMENTS) { ElementsAccessor* accessor = receiver->GetElementsAccessor(); return accessor->IncludesValue(isolate, receiver, value, k + 1, length); } dictionary = handle(NumberDictionary::cast(receiver->elements()), isolate); break; } } } return Just(false); } static Maybe IndexOfValueImpl(Isolate* isolate, Handle receiver, Handle value, uint32_t start_from, uint32_t length) { DCHECK(JSObject::PrototypeHasNoElements(isolate, *receiver)); ElementsKind original_elements_kind = receiver->GetElementsKind(); USE(original_elements_kind); Handle dictionary( NumberDictionary::cast(receiver->elements()), isolate); // Iterate through entire range, as accessing elements out of order is // observable. for (uint32_t k = start_from; k < length; ++k) { DCHECK_EQ(receiver->GetElementsKind(), original_elements_kind); int entry = dictionary->FindEntry(isolate, k); if (entry == NumberDictionary::kNotFound) continue; PropertyDetails details = GetDetailsImpl(*dictionary, entry); switch (details.kind()) { case kData: { Object* element_k = dictionary->ValueAt(entry); if (value->StrictEquals(element_k)) { return Just(k); } break; } case kAccessor: { LookupIterator it(isolate, receiver, k, LookupIterator::OWN_SKIP_INTERCEPTOR); DCHECK(it.IsFound()); DCHECK_EQ(it.state(), LookupIterator::ACCESSOR); Handle element_k; ASSIGN_RETURN_ON_EXCEPTION_VALUE( isolate, element_k, JSObject::GetPropertyWithAccessor(&it), Nothing()); if (value->StrictEquals(*element_k)) return Just(k); // Bailout to slow path if elements on prototype changed. if (!JSObject::PrototypeHasNoElements(isolate, *receiver)) { return IndexOfValueSlowPath(isolate, receiver, value, k + 1, length); } // Continue if elements unchanged. if (*dictionary == receiver->elements()) continue; // Otherwise, bailout or update elements. if (receiver->GetElementsKind() != DICTIONARY_ELEMENTS) { // Otherwise, switch to slow path. return IndexOfValueSlowPath(isolate, receiver, value, k + 1, length); } dictionary = handle(NumberDictionary::cast(receiver->elements()), isolate); break; } } } return Just(-1); } static void ValidateContents(JSObject* holder, int length) { DisallowHeapAllocation no_gc; #if DEBUG DCHECK_EQ(holder->map()->elements_kind(), DICTIONARY_ELEMENTS); if (!FLAG_enable_slow_asserts) return; ReadOnlyRoots roots = holder->GetReadOnlyRoots(); NumberDictionary* dictionary = NumberDictionary::cast(holder->elements()); // Validate the requires_slow_elements and max_number_key values. int capacity = dictionary->Capacity(); bool requires_slow_elements = false; int max_key = 0; for (int i = 0; i < capacity; ++i) { Object* k; if (!dictionary->ToKey(roots, i, &k)) continue; DCHECK_LE(0.0, k->Number()); if (k->Number() > NumberDictionary::kRequiresSlowElementsLimit) { requires_slow_elements = true; } else { max_key = Max(max_key, Smi::ToInt(k)); } } if (requires_slow_elements) { DCHECK(dictionary->requires_slow_elements()); } else if (!dictionary->requires_slow_elements()) { DCHECK_LE(max_key, dictionary->max_number_key()); } #endif } }; // Super class for all fast element arrays. template class FastElementsAccessor : public ElementsAccessorBase { public: explicit FastElementsAccessor(const char* name) : ElementsAccessorBase(name) {} typedef typename KindTraits::BackingStore BackingStore; static Handle NormalizeImpl(Handle object, Handle store) { Isolate* isolate = object->GetIsolate(); ElementsKind kind = Subclass::kind(); // Ensure that notifications fire if the array or object prototypes are // normalizing. if (IsSmiOrObjectElementsKind(kind) || kind == FAST_STRING_WRAPPER_ELEMENTS) { isolate->UpdateNoElementsProtectorOnNormalizeElements(object); } int capacity = object->GetFastElementsUsage(); Handle dictionary = NumberDictionary::New(isolate, capacity); PropertyDetails details = PropertyDetails::Empty(); int j = 0; int max_number_key = -1; for (int i = 0; j < capacity; i++) { if (IsHoleyElementsKind(kind)) { if (BackingStore::cast(*store)->is_the_hole(isolate, i)) continue; } max_number_key = i; Handle value = Subclass::GetImpl(isolate, *store, i); dictionary = NumberDictionary::Add(isolate, dictionary, i, value, details); j++; } if (max_number_key > 0) { dictionary->UpdateMaxNumberKey(static_cast(max_number_key), object); } return dictionary; } static void DeleteAtEnd(Handle obj, Handle backing_store, uint32_t entry) { uint32_t length = static_cast(backing_store->length()); Isolate* isolate = obj->GetIsolate(); for (; entry > 0; entry--) { if (!backing_store->is_the_hole(isolate, entry - 1)) break; } if (entry == 0) { FixedArray* empty = ReadOnlyRoots(isolate).empty_fixed_array(); // Dynamically ask for the elements kind here since we manually redirect // the operations for argument backing stores. if (obj->GetElementsKind() == FAST_SLOPPY_ARGUMENTS_ELEMENTS) { SloppyArgumentsElements::cast(obj->elements())->set_arguments(empty); } else { obj->set_elements(empty); } return; } isolate->heap()->RightTrimFixedArray(*backing_store, length - entry); } static void DeleteCommon(Handle obj, uint32_t entry, Handle store) { DCHECK(obj->HasSmiOrObjectElements() || obj->HasDoubleElements() || obj->HasFastArgumentsElements() || obj->HasFastStringWrapperElements()); Handle backing_store = Handle::cast(store); if (!obj->IsJSArray() && entry == static_cast(store->length()) - 1) { DeleteAtEnd(obj, backing_store, entry); return; } Isolate* isolate = obj->GetIsolate(); backing_store->set_the_hole(isolate, entry); // TODO(verwaest): Move this out of elements.cc. // If an old space backing store is larger than a certain size and // has too few used values, normalize it. const int kMinLengthForSparsenessCheck = 64; if (backing_store->length() < kMinLengthForSparsenessCheck) return; if (Heap::InNewSpace(*backing_store)) return; uint32_t length = 0; if (obj->IsJSArray()) { JSArray::cast(*obj)->length()->ToArrayLength(&length); } else { length = static_cast(store->length()); } // To avoid doing the check on every delete, use a counter-based heuristic. const int kLengthFraction = 16; // The above constant must be large enough to ensure that we check for // normalization frequently enough. At a minimum, it should be large // enough to reliably hit the "window" of remaining elements count where // normalization would be beneficial. STATIC_ASSERT(kLengthFraction >= NumberDictionary::kEntrySize * NumberDictionary::kPreferFastElementsSizeFactor); size_t current_counter = isolate->elements_deletion_counter(); if (current_counter < length / kLengthFraction) { isolate->set_elements_deletion_counter(current_counter + 1); return; } // Reset the counter whenever the full check is performed. isolate->set_elements_deletion_counter(0); if (!obj->IsJSArray()) { uint32_t i; for (i = entry + 1; i < length; i++) { if (!backing_store->is_the_hole(isolate, i)) break; } if (i == length) { DeleteAtEnd(obj, backing_store, entry); return; } } int num_used = 0; for (int i = 0; i < backing_store->length(); ++i) { if (!backing_store->is_the_hole(isolate, i)) { ++num_used; // Bail out if a number dictionary wouldn't be able to save much space. if (NumberDictionary::kPreferFastElementsSizeFactor * NumberDictionary::ComputeCapacity(num_used) * NumberDictionary::kEntrySize > static_cast(backing_store->length())) { return; } } } JSObject::NormalizeElements(obj); } static void ReconfigureImpl(Handle object, Handle store, uint32_t entry, Handle value, PropertyAttributes attributes) { Handle dictionary = JSObject::NormalizeElements(object); entry = dictionary->FindEntry(object->GetIsolate(), entry); DictionaryElementsAccessor::ReconfigureImpl(object, dictionary, entry, value, attributes); } static void AddImpl(Handle object, uint32_t index, Handle value, PropertyAttributes attributes, uint32_t new_capacity) { DCHECK_EQ(NONE, attributes); ElementsKind from_kind = object->GetElementsKind(); ElementsKind to_kind = Subclass::kind(); if (IsDictionaryElementsKind(from_kind) || IsDoubleElementsKind(from_kind) != IsDoubleElementsKind(to_kind) || Subclass::GetCapacityImpl(*object, object->elements()) != new_capacity) { Subclass::GrowCapacityAndConvertImpl(object, new_capacity); } else { if (IsFastElementsKind(from_kind) && from_kind != to_kind) { JSObject::TransitionElementsKind(object, to_kind); } if (IsSmiOrObjectElementsKind(from_kind)) { DCHECK(IsSmiOrObjectElementsKind(to_kind)); JSObject::EnsureWritableFastElements(object); } } Subclass::SetImpl(object, index, *value); } static void DeleteImpl(Handle obj, uint32_t entry) { ElementsKind kind = KindTraits::Kind; if (IsFastPackedElementsKind(kind)) { JSObject::TransitionElementsKind(obj, GetHoleyElementsKind(kind)); } if (IsSmiOrObjectElementsKind(KindTraits::Kind)) { JSObject::EnsureWritableFastElements(obj); } DeleteCommon(obj, entry, handle(obj->elements(), obj->GetIsolate())); } static bool HasEntryImpl(Isolate* isolate, FixedArrayBase* backing_store, uint32_t entry) { return !BackingStore::cast(backing_store)->is_the_hole(isolate, entry); } static uint32_t NumberOfElementsImpl(JSObject* receiver, FixedArrayBase* backing_store) { uint32_t max_index = Subclass::GetMaxIndex(receiver, backing_store); if (IsFastPackedElementsKind(Subclass::kind())) return max_index; Isolate* isolate = receiver->GetIsolate(); uint32_t count = 0; for (uint32_t i = 0; i < max_index; i++) { if (Subclass::HasEntryImpl(isolate, backing_store, i)) count++; } return count; } static void AddElementsToKeyAccumulatorImpl(Handle receiver, KeyAccumulator* accumulator, AddKeyConversion convert) { Isolate* isolate = accumulator->isolate(); Handle elements(receiver->elements(), isolate); uint32_t length = Subclass::GetMaxNumberOfEntries(*receiver, *elements); for (uint32_t i = 0; i < length; i++) { if (IsFastPackedElementsKind(KindTraits::Kind) || HasEntryImpl(isolate, *elements, i)) { accumulator->AddKey(Subclass::GetImpl(isolate, *elements, i), convert); } } } static void ValidateContents(JSObject* holder, int length) { #if DEBUG Isolate* isolate = holder->GetIsolate(); Heap* heap = isolate->heap(); FixedArrayBase* elements = holder->elements(); Map* map = elements->map(); if (IsSmiOrObjectElementsKind(KindTraits::Kind)) { DCHECK_NE(map, ReadOnlyRoots(heap).fixed_double_array_map()); } else if (IsDoubleElementsKind(KindTraits::Kind)) { DCHECK_NE(map, ReadOnlyRoots(heap).fixed_cow_array_map()); if (map == ReadOnlyRoots(heap).fixed_array_map()) DCHECK_EQ(0, length); } else { UNREACHABLE(); } if (length == 0) return; // nothing to do! #if ENABLE_SLOW_DCHECKS DisallowHeapAllocation no_gc; BackingStore* backing_store = BackingStore::cast(elements); if (IsSmiElementsKind(KindTraits::Kind)) { HandleScope scope(isolate); for (int i = 0; i < length; i++) { DCHECK(BackingStore::get(backing_store, i, isolate)->IsSmi() || (IsHoleyElementsKind(KindTraits::Kind) && backing_store->is_the_hole(isolate, i))); } } else if (KindTraits::Kind == PACKED_ELEMENTS || KindTraits::Kind == PACKED_DOUBLE_ELEMENTS) { for (int i = 0; i < length; i++) { DCHECK(!backing_store->is_the_hole(isolate, i)); } } else { DCHECK(IsHoleyElementsKind(KindTraits::Kind)); } #endif #endif } static Handle PopImpl(Handle receiver) { return Subclass::RemoveElement(receiver, AT_END); } static Handle ShiftImpl(Handle receiver) { return Subclass::RemoveElement(receiver, AT_START); } static uint32_t PushImpl(Handle receiver, Arguments* args, uint32_t push_size) { Handle backing_store(receiver->elements(), receiver->GetIsolate()); return Subclass::AddArguments(receiver, backing_store, args, push_size, AT_END); } static uint32_t UnshiftImpl(Handle receiver, Arguments* args, uint32_t unshift_size) { Handle backing_store(receiver->elements(), receiver->GetIsolate()); return Subclass::AddArguments(receiver, backing_store, args, unshift_size, AT_START); } static Handle SliceImpl(Handle receiver, uint32_t start, uint32_t end) { Isolate* isolate = receiver->GetIsolate(); Handle backing_store(receiver->elements(), isolate); int result_len = end < start ? 0u : end - start; Handle result_array = isolate->factory()->NewJSArray( KindTraits::Kind, result_len, result_len); DisallowHeapAllocation no_gc; Subclass::CopyElementsImpl(isolate, *backing_store, start, result_array->elements(), KindTraits::Kind, 0, kPackedSizeNotKnown, result_len); Subclass::TryTransitionResultArrayToPacked(result_array); return result_array; } static void MoveElements(Isolate* isolate, Handle receiver, Handle backing_store, int dst_index, int src_index, int len, int hole_start, int hole_end) { Heap* heap = isolate->heap(); Handle dst_elms = Handle::cast(backing_store); if (len > JSArray::kMaxCopyElements && dst_index == 0 && heap->CanMoveObjectStart(*dst_elms)) { // Update all the copies of this backing_store handle. *dst_elms.location() = BackingStore::cast(heap->LeftTrimFixedArray(*dst_elms, src_index)); receiver->set_elements(*dst_elms); // Adjust the hole offset as the array has been shrunk. hole_end -= src_index; DCHECK_LE(hole_start, backing_store->length()); DCHECK_LE(hole_end, backing_store->length()); } else if (len != 0) { if (IsDoubleElementsKind(KindTraits::Kind)) { MemMove(dst_elms->data_start() + dst_index, dst_elms->data_start() + src_index, len * kDoubleSize); } else { DisallowHeapAllocation no_gc; WriteBarrierMode mode = GetWriteBarrierMode(KindTraits::Kind); heap->MoveElements(FixedArray::cast(*dst_elms), dst_index, src_index, len, mode); } } if (hole_start != hole_end) { dst_elms->FillWithHoles(hole_start, hole_end); } } static Object* FillImpl(Handle receiver, Handle obj_value, uint32_t start, uint32_t end) { // Ensure indexes are within array bounds DCHECK_LE(0, start); DCHECK_LE(start, end); // Make sure COW arrays are copied. if (IsSmiOrObjectElementsKind(Subclass::kind())) { JSObject::EnsureWritableFastElements(receiver); } // Make sure we have enough space. uint32_t capacity = Subclass::GetCapacityImpl(*receiver, receiver->elements()); if (end > capacity) { Subclass::GrowCapacityAndConvertImpl(receiver, end); CHECK_EQ(Subclass::kind(), receiver->GetElementsKind()); } DCHECK_LE(end, Subclass::GetCapacityImpl(*receiver, receiver->elements())); for (uint32_t index = start; index < end; ++index) { Subclass::SetImpl(receiver, index, *obj_value); } return *receiver; } static Maybe IncludesValueImpl(Isolate* isolate, Handle receiver, Handle search_value, uint32_t start_from, uint32_t length) { DCHECK(JSObject::PrototypeHasNoElements(isolate, *receiver)); DisallowHeapAllocation no_gc; FixedArrayBase* elements_base = receiver->elements(); Object* the_hole = ReadOnlyRoots(isolate).the_hole_value(); Object* undefined = ReadOnlyRoots(isolate).undefined_value(); Object* value = *search_value; // Elements beyond the capacity of the backing store treated as undefined. if (value == undefined && static_cast(elements_base->length()) < length) { return Just(true); } if (start_from >= length) return Just(false); length = std::min(static_cast(elements_base->length()), length); if (!value->IsNumber()) { if (value == undefined) { // Only PACKED_ELEMENTS, HOLEY_ELEMENTS, HOLEY_SMI_ELEMENTS, and // HOLEY_DOUBLE_ELEMENTS can have `undefined` as a value. if (!IsObjectElementsKind(Subclass::kind()) && !IsHoleyElementsKind(Subclass::kind())) { return Just(false); } // Search for `undefined` or The Hole in PACKED_ELEMENTS, // HOLEY_ELEMENTS or HOLEY_SMI_ELEMENTS if (IsSmiOrObjectElementsKind(Subclass::kind())) { auto elements = FixedArray::cast(receiver->elements()); for (uint32_t k = start_from; k < length; ++k) { Object* element_k = elements->get(k); if (IsHoleyElementsKind(Subclass::kind()) && element_k == the_hole) { return Just(true); } if (IsObjectElementsKind(Subclass::kind()) && element_k == undefined) { return Just(true); } } return Just(false); } else { // Search for The Hole in HOLEY_DOUBLE_ELEMENTS DCHECK_EQ(Subclass::kind(), HOLEY_DOUBLE_ELEMENTS); auto elements = FixedDoubleArray::cast(receiver->elements()); for (uint32_t k = start_from; k < length; ++k) { if (IsHoleyElementsKind(Subclass::kind()) && elements->is_the_hole(k)) { return Just(true); } } return Just(false); } } else if (!IsObjectElementsKind(Subclass::kind())) { // Search for non-number, non-Undefined value, with either // PACKED_SMI_ELEMENTS, PACKED_DOUBLE_ELEMENTS, HOLEY_SMI_ELEMENTS or // HOLEY_DOUBLE_ELEMENTS. Guaranteed to return false, since these // elements kinds can only contain Number values or undefined. return Just(false); } else { // Search for non-number, non-Undefined value with either // PACKED_ELEMENTS or HOLEY_ELEMENTS. DCHECK(IsObjectElementsKind(Subclass::kind())); auto elements = FixedArray::cast(receiver->elements()); for (uint32_t k = start_from; k < length; ++k) { Object* element_k = elements->get(k); if (IsHoleyElementsKind(Subclass::kind()) && element_k == the_hole) { continue; } if (value->SameValueZero(element_k)) return Just(true); } return Just(false); } } else { if (!value->IsNaN()) { double search_value = value->Number(); if (IsDoubleElementsKind(Subclass::kind())) { // Search for non-NaN Number in PACKED_DOUBLE_ELEMENTS or // HOLEY_DOUBLE_ELEMENTS --- Skip TheHole, and trust UCOMISD or // similar operation for result. auto elements = FixedDoubleArray::cast(receiver->elements()); for (uint32_t k = start_from; k < length; ++k) { if (IsHoleyElementsKind(Subclass::kind()) && elements->is_the_hole(k)) { continue; } if (elements->get_scalar(k) == search_value) return Just(true); } return Just(false); } else { // Search for non-NaN Number in PACKED_ELEMENTS, HOLEY_ELEMENTS, // PACKED_SMI_ELEMENTS or HOLEY_SMI_ELEMENTS --- Skip non-Numbers, // and trust UCOMISD or similar operation for result auto elements = FixedArray::cast(receiver->elements()); for (uint32_t k = start_from; k < length; ++k) { Object* element_k = elements->get(k); if (element_k->IsNumber() && element_k->Number() == search_value) { return Just(true); } } return Just(false); } } else { // Search for NaN --- NaN cannot be represented with Smi elements, so // abort if ElementsKind is PACKED_SMI_ELEMENTS or HOLEY_SMI_ELEMENTS if (IsSmiElementsKind(Subclass::kind())) return Just(false); if (IsDoubleElementsKind(Subclass::kind())) { // Search for NaN in PACKED_DOUBLE_ELEMENTS or // HOLEY_DOUBLE_ELEMENTS --- Skip The Hole and trust // std::isnan(elementK) for result auto elements = FixedDoubleArray::cast(receiver->elements()); for (uint32_t k = start_from; k < length; ++k) { if (IsHoleyElementsKind(Subclass::kind()) && elements->is_the_hole(k)) { continue; } if (std::isnan(elements->get_scalar(k))) return Just(true); } return Just(false); } else { // Search for NaN in PACKED_ELEMENTS, HOLEY_ELEMENTS, // PACKED_SMI_ELEMENTS or HOLEY_SMI_ELEMENTS. Return true if // elementK->IsHeapNumber() && std::isnan(elementK->Number()) DCHECK(IsSmiOrObjectElementsKind(Subclass::kind())); auto elements = FixedArray::cast(receiver->elements()); for (uint32_t k = start_from; k < length; ++k) { if (elements->get(k)->IsNaN()) return Just(true); } return Just(false); } } } } static Handle CreateListFromArrayLikeImpl(Isolate* isolate, Handle object, uint32_t length) { Handle result = isolate->factory()->NewFixedArray(length); Handle elements(object->elements(), isolate); for (uint32_t i = 0; i < length; i++) { if (!Subclass::HasElementImpl(isolate, *object, i, *elements)) continue; Handle value; value = Subclass::GetImpl(isolate, *elements, i); if (value->IsName()) { value = isolate->factory()->InternalizeName(Handle::cast(value)); } result->set(i, *value); } return result; } static Handle RemoveElement(Handle receiver, Where remove_position) { Isolate* isolate = receiver->GetIsolate(); ElementsKind kind = KindTraits::Kind; if (IsSmiOrObjectElementsKind(kind)) { HandleScope scope(isolate); JSObject::EnsureWritableFastElements(receiver); } Handle backing_store(receiver->elements(), isolate); uint32_t length = static_cast(Smi::ToInt(receiver->length())); DCHECK_GT(length, 0); int new_length = length - 1; int remove_index = remove_position == AT_START ? 0 : new_length; Handle result = Subclass::GetImpl(isolate, *backing_store, remove_index); if (remove_position == AT_START) { Subclass::MoveElements(isolate, receiver, backing_store, 0, 1, new_length, 0, 0); } Subclass::SetLengthImpl(isolate, receiver, new_length, backing_store); if (IsHoleyElementsKind(kind) && result->IsTheHole(isolate)) { return isolate->factory()->undefined_value(); } return result; } static uint32_t AddArguments(Handle receiver, Handle backing_store, Arguments* args, uint32_t add_size, Where add_position) { uint32_t length = Smi::ToInt(receiver->length()); DCHECK_LT(0, add_size); uint32_t elms_len = backing_store->length(); // Check we do not overflow the new_length. DCHECK(add_size <= static_cast(Smi::kMaxValue - length)); uint32_t new_length = length + add_size; if (new_length > elms_len) { // New backing storage is needed. uint32_t capacity = JSObject::NewElementsCapacity(new_length); // If we add arguments to the start we have to shift the existing objects. int copy_dst_index = add_position == AT_START ? add_size : 0; // Copy over all objects to a new backing_store. backing_store = Subclass::ConvertElementsWithCapacity( receiver, backing_store, KindTraits::Kind, capacity, 0, copy_dst_index, ElementsAccessor::kCopyToEndAndInitializeToHole); receiver->set_elements(*backing_store); } else if (add_position == AT_START) { // If the backing store has enough capacity and we add elements to the // start we have to shift the existing objects. Isolate* isolate = receiver->GetIsolate(); Subclass::MoveElements(isolate, receiver, backing_store, add_size, 0, length, 0, 0); } int insertion_index = add_position == AT_START ? 0 : length; // Copy the arguments to the start. Subclass::CopyArguments(args, backing_store, add_size, 1, insertion_index); // Set the length. receiver->set_length(Smi::FromInt(new_length)); return new_length; } static void CopyArguments(Arguments* args, Handle dst_store, uint32_t copy_size, uint32_t src_index, uint32_t dst_index) { // Add the provided values. DisallowHeapAllocation no_gc; FixedArrayBase* raw_backing_store = *dst_store; WriteBarrierMode mode = raw_backing_store->GetWriteBarrierMode(no_gc); for (uint32_t i = 0; i < copy_size; i++) { Object* argument = (*args)[src_index + i]; DCHECK(!argument->IsTheHole()); Subclass::SetImpl(raw_backing_store, dst_index + i, argument, mode); } } }; template class FastSmiOrObjectElementsAccessor : public FastElementsAccessor { public: explicit FastSmiOrObjectElementsAccessor(const char* name) : FastElementsAccessor(name) {} static inline void SetImpl(Handle holder, uint32_t entry, Object* value) { SetImpl(holder->elements(), entry, value); } static inline void SetImpl(FixedArrayBase* backing_store, uint32_t entry, Object* value) { FixedArray::cast(backing_store)->set(entry, value); } static inline void SetImpl(FixedArrayBase* backing_store, uint32_t entry, Object* value, WriteBarrierMode mode) { FixedArray::cast(backing_store)->set(entry, value, mode); } static Object* GetRaw(FixedArray* backing_store, uint32_t entry) { uint32_t index = Subclass::GetIndexForEntryImpl(backing_store, entry); return backing_store->get(index); } // NOTE: this method violates the handlified function signature convention: // raw pointer parameters in the function that allocates. // See ElementsAccessor::CopyElements() for details. // This method could actually allocate if copying from double elements to // object elements. static void CopyElementsImpl(Isolate* isolate, FixedArrayBase* from, uint32_t from_start, FixedArrayBase* to, ElementsKind from_kind, uint32_t to_start, int packed_size, int copy_size) { DisallowHeapAllocation no_gc; ElementsKind to_kind = KindTraits::Kind; switch (from_kind) { case PACKED_SMI_ELEMENTS: case HOLEY_SMI_ELEMENTS: case PACKED_ELEMENTS: case HOLEY_ELEMENTS: CopyObjectToObjectElements(isolate, from, from_kind, from_start, to, to_kind, to_start, copy_size); break; case PACKED_DOUBLE_ELEMENTS: case HOLEY_DOUBLE_ELEMENTS: { AllowHeapAllocation allow_allocation; DCHECK(IsObjectElementsKind(to_kind)); CopyDoubleToObjectElements(isolate, from, from_start, to, to_start, copy_size); break; } case DICTIONARY_ELEMENTS: CopyDictionaryToObjectElements(isolate, from, from_start, to, to_kind, to_start, copy_size); break; case FAST_SLOPPY_ARGUMENTS_ELEMENTS: case SLOW_SLOPPY_ARGUMENTS_ELEMENTS: case FAST_STRING_WRAPPER_ELEMENTS: case SLOW_STRING_WRAPPER_ELEMENTS: #define TYPED_ARRAY_CASE(Type, type, TYPE, ctype) case TYPE##_ELEMENTS: TYPED_ARRAYS(TYPED_ARRAY_CASE) #undef TYPED_ARRAY_CASE // This function is currently only used for JSArrays with non-zero // length. UNREACHABLE(); break; case NO_ELEMENTS: break; // Nothing to do. } } static Maybe CollectValuesOrEntriesImpl( Isolate* isolate, Handle object, Handle values_or_entries, bool get_entries, int* nof_items, PropertyFilter filter) { int count = 0; if (get_entries) { // Collecting entries needs to allocate, so this code must be handlified. Handle elements(FixedArray::cast(object->elements()), isolate); uint32_t length = elements->length(); for (uint32_t index = 0; index < length; ++index) { if (!Subclass::HasEntryImpl(isolate, *elements, index)) continue; Handle value = Subclass::GetImpl(isolate, *elements, index); value = MakeEntryPair(isolate, index, value); values_or_entries->set(count++, *value); } } else { // No allocations here, so we can avoid handlification overhead. DisallowHeapAllocation no_gc; FixedArray* elements = FixedArray::cast(object->elements()); uint32_t length = elements->length(); for (uint32_t index = 0; index < length; ++index) { if (!Subclass::HasEntryImpl(isolate, elements, index)) continue; Object* value = GetRaw(elements, index); values_or_entries->set(count++, value); } } *nof_items = count; return Just(true); } static Maybe IndexOfValueImpl(Isolate* isolate, Handle receiver, Handle search_value, uint32_t start_from, uint32_t length) { DCHECK(JSObject::PrototypeHasNoElements(isolate, *receiver)); DisallowHeapAllocation no_gc; FixedArrayBase* elements_base = receiver->elements(); Object* value = *search_value; if (start_from >= length) return Just(-1); length = std::min(static_cast(elements_base->length()), length); // Only FAST_{,HOLEY_}ELEMENTS can store non-numbers. if (!value->IsNumber() && !IsObjectElementsKind(Subclass::kind())) { return Just(-1); } // NaN can never be found by strict equality. if (value->IsNaN()) return Just(-1); FixedArray* elements = FixedArray::cast(receiver->elements()); for (uint32_t k = start_from; k < length; ++k) { if (value->StrictEquals(elements->get(k))) return Just(k); } return Just(-1); } }; class FastPackedSmiElementsAccessor : public FastSmiOrObjectElementsAccessor< FastPackedSmiElementsAccessor, ElementsKindTraits> { public: explicit FastPackedSmiElementsAccessor(const char* name) : FastSmiOrObjectElementsAccessor< FastPackedSmiElementsAccessor, ElementsKindTraits>(name) {} }; class FastHoleySmiElementsAccessor : public FastSmiOrObjectElementsAccessor< FastHoleySmiElementsAccessor, ElementsKindTraits> { public: explicit FastHoleySmiElementsAccessor(const char* name) : FastSmiOrObjectElementsAccessor>( name) {} }; class FastPackedObjectElementsAccessor : public FastSmiOrObjectElementsAccessor< FastPackedObjectElementsAccessor, ElementsKindTraits> { public: explicit FastPackedObjectElementsAccessor(const char* name) : FastSmiOrObjectElementsAccessor>( name) {} }; class FastHoleyObjectElementsAccessor : public FastSmiOrObjectElementsAccessor< FastHoleyObjectElementsAccessor, ElementsKindTraits> { public: explicit FastHoleyObjectElementsAccessor(const char* name) : FastSmiOrObjectElementsAccessor>( name) {} }; template class FastDoubleElementsAccessor : public FastElementsAccessor { public: explicit FastDoubleElementsAccessor(const char* name) : FastElementsAccessor(name) {} static Handle GetImpl(Isolate* isolate, FixedArrayBase* backing_store, uint32_t entry) { return FixedDoubleArray::get(FixedDoubleArray::cast(backing_store), entry, isolate); } static inline void SetImpl(Handle holder, uint32_t entry, Object* value) { SetImpl(holder->elements(), entry, value); } static inline void SetImpl(FixedArrayBase* backing_store, uint32_t entry, Object* value) { FixedDoubleArray::cast(backing_store)->set(entry, value->Number()); } static inline void SetImpl(FixedArrayBase* backing_store, uint32_t entry, Object* value, WriteBarrierMode mode) { FixedDoubleArray::cast(backing_store)->set(entry, value->Number()); } static void CopyElementsImpl(Isolate* isolate, FixedArrayBase* from, uint32_t from_start, FixedArrayBase* to, ElementsKind from_kind, uint32_t to_start, int packed_size, int copy_size) { DisallowHeapAllocation no_allocation; switch (from_kind) { case PACKED_SMI_ELEMENTS: CopyPackedSmiToDoubleElements(from, from_start, to, to_start, packed_size, copy_size); break; case HOLEY_SMI_ELEMENTS: CopySmiToDoubleElements(from, from_start, to, to_start, copy_size); break; case PACKED_DOUBLE_ELEMENTS: case HOLEY_DOUBLE_ELEMENTS: CopyDoubleToDoubleElements(from, from_start, to, to_start, copy_size); break; case PACKED_ELEMENTS: case HOLEY_ELEMENTS: CopyObjectToDoubleElements(from, from_start, to, to_start, copy_size); break; case DICTIONARY_ELEMENTS: CopyDictionaryToDoubleElements(isolate, from, from_start, to, to_start, copy_size); break; case FAST_SLOPPY_ARGUMENTS_ELEMENTS: case SLOW_SLOPPY_ARGUMENTS_ELEMENTS: case FAST_STRING_WRAPPER_ELEMENTS: case SLOW_STRING_WRAPPER_ELEMENTS: case NO_ELEMENTS: #define TYPED_ARRAY_CASE(Type, type, TYPE, ctype) case TYPE##_ELEMENTS: TYPED_ARRAYS(TYPED_ARRAY_CASE) #undef TYPED_ARRAY_CASE // This function is currently only used for JSArrays with non-zero // length. UNREACHABLE(); break; } } static Maybe CollectValuesOrEntriesImpl( Isolate* isolate, Handle object, Handle values_or_entries, bool get_entries, int* nof_items, PropertyFilter filter) { Handle elements( FixedDoubleArray::cast(object->elements()), isolate); int count = 0; uint32_t length = elements->length(); for (uint32_t index = 0; index < length; ++index) { if (!Subclass::HasEntryImpl(isolate, *elements, index)) continue; Handle value = Subclass::GetImpl(isolate, *elements, index); if (get_entries) { value = MakeEntryPair(isolate, index, value); } values_or_entries->set(count++, *value); } *nof_items = count; return Just(true); } static Maybe IndexOfValueImpl(Isolate* isolate, Handle receiver, Handle search_value, uint32_t start_from, uint32_t length) { DCHECK(JSObject::PrototypeHasNoElements(isolate, *receiver)); DisallowHeapAllocation no_gc; FixedArrayBase* elements_base = receiver->elements(); Object* value = *search_value; length = std::min(static_cast(elements_base->length()), length); if (start_from >= length) return Just(-1); if (!value->IsNumber()) { return Just(-1); } if (value->IsNaN()) { return Just(-1); } double numeric_search_value = value->Number(); FixedDoubleArray* elements = FixedDoubleArray::cast(receiver->elements()); for (uint32_t k = start_from; k < length; ++k) { if (elements->is_the_hole(k)) { continue; } if (elements->get_scalar(k) == numeric_search_value) { return Just(k); } } return Just(-1); } }; class FastPackedDoubleElementsAccessor : public FastDoubleElementsAccessor< FastPackedDoubleElementsAccessor, ElementsKindTraits> { public: explicit FastPackedDoubleElementsAccessor(const char* name) : FastDoubleElementsAccessor>( name) {} }; class FastHoleyDoubleElementsAccessor : public FastDoubleElementsAccessor< FastHoleyDoubleElementsAccessor, ElementsKindTraits> { public: explicit FastHoleyDoubleElementsAccessor(const char* name) : FastDoubleElementsAccessor>( name) {} }; // Super class for all external element arrays. template class TypedElementsAccessor : public ElementsAccessorBase, ElementsKindTraits> { public: explicit TypedElementsAccessor(const char* name) : ElementsAccessorBase >(name) {} typedef typename ElementsKindTraits::BackingStore BackingStore; typedef TypedElementsAccessor AccessorClass; static inline void SetImpl(Handle holder, uint32_t entry, Object* value) { SetImpl(holder->elements(), entry, value); } static inline void SetImpl(FixedArrayBase* backing_store, uint32_t entry, Object* value) { BackingStore::cast(backing_store)->SetValue(entry, value); } static inline void SetImpl(FixedArrayBase* backing_store, uint32_t entry, Object* value, WriteBarrierMode mode) { BackingStore::cast(backing_store)->SetValue(entry, value); } static Handle GetImpl(Isolate* isolate, FixedArrayBase* backing_store, uint32_t entry) { return BackingStore::get(isolate, BackingStore::cast(backing_store), entry); } static PropertyDetails GetDetailsImpl(JSObject* holder, uint32_t entry) { return PropertyDetails(kData, DONT_DELETE, PropertyCellType::kNoCell); } static PropertyDetails GetDetailsImpl(FixedArrayBase* backing_store, uint32_t entry) { return PropertyDetails(kData, DONT_DELETE, PropertyCellType::kNoCell); } static bool HasElementImpl(Isolate* isolate, JSObject* holder, uint32_t index, FixedArrayBase* backing_store, PropertyFilter filter) { return index < AccessorClass::GetCapacityImpl(holder, backing_store); } static bool HasAccessorsImpl(JSObject* holder, FixedArrayBase* backing_store) { return false; } static void SetLengthImpl(Isolate* isolate, Handle array, uint32_t length, Handle backing_store) { // External arrays do not support changing their length. UNREACHABLE(); } static void DeleteImpl(Handle obj, uint32_t entry) { UNREACHABLE(); } static uint32_t GetIndexForEntryImpl(FixedArrayBase* backing_store, uint32_t entry) { return entry; } static uint32_t GetEntryForIndexImpl(Isolate* isolate, JSObject* holder, FixedArrayBase* backing_store, uint32_t index, PropertyFilter filter) { return index < AccessorClass::GetCapacityImpl(holder, backing_store) ? index : kMaxUInt32; } static bool WasNeutered(JSObject* holder) { JSArrayBufferView* view = JSArrayBufferView::cast(holder); return view->WasNeutered(); } static uint32_t GetCapacityImpl(JSObject* holder, FixedArrayBase* backing_store) { if (WasNeutered(holder)) return 0; return backing_store->length(); } static uint32_t NumberOfElementsImpl(JSObject* receiver, FixedArrayBase* backing_store) { return AccessorClass::GetCapacityImpl(receiver, backing_store); } static void AddElementsToKeyAccumulatorImpl(Handle receiver, KeyAccumulator* accumulator, AddKeyConversion convert) { Isolate* isolate = receiver->GetIsolate(); Handle elements(receiver->elements(), isolate); uint32_t length = AccessorClass::GetCapacityImpl(*receiver, *elements); for (uint32_t i = 0; i < length; i++) { Handle value = AccessorClass::GetImpl(isolate, *elements, i); accumulator->AddKey(value, convert); } } static Maybe CollectValuesOrEntriesImpl( Isolate* isolate, Handle object, Handle values_or_entries, bool get_entries, int* nof_items, PropertyFilter filter) { int count = 0; if ((filter & ONLY_CONFIGURABLE) == 0) { Handle elements(object->elements(), isolate); uint32_t length = AccessorClass::GetCapacityImpl(*object, *elements); for (uint32_t index = 0; index < length; ++index) { Handle value = AccessorClass::GetImpl(isolate, *elements, index); if (get_entries) { value = MakeEntryPair(isolate, index, value); } values_or_entries->set(count++, *value); } } *nof_items = count; return Just(true); } static Object* FillImpl(Handle receiver, Handle obj_value, uint32_t start, uint32_t end) { Handle array = Handle::cast(receiver); DCHECK(!array->WasNeutered()); DCHECK(obj_value->IsNumeric()); ctype value = BackingStore::FromHandle(obj_value); // Ensure indexes are within array bounds CHECK_LE(0, start); CHECK_LE(start, end); CHECK_LE(end, array->length_value()); DisallowHeapAllocation no_gc; BackingStore* elements = BackingStore::cast(receiver->elements()); ctype* data = static_cast(elements->DataPtr()); std::fill(data + start, data + end, value); return *array; } static Maybe IncludesValueImpl(Isolate* isolate, Handle receiver, Handle value, uint32_t start_from, uint32_t length) { DisallowHeapAllocation no_gc; // TODO(caitp): return Just(false) here when implementing strict throwing on // neutered views. if (WasNeutered(*receiver)) { return Just(value->IsUndefined(isolate) && length > start_from); } BackingStore* elements = BackingStore::cast(receiver->elements()); if (value->IsUndefined(isolate) && length > static_cast(elements->length())) { return Just(true); } ctype typed_search_value; // Prototype has no elements, and not searching for the hole --- limit // search to backing store length. if (static_cast(elements->length()) < length) { length = elements->length(); } if (Kind == BIGINT64_ELEMENTS || Kind == BIGUINT64_ELEMENTS) { if (!value->IsBigInt()) return Just(false); bool lossless; typed_search_value = BackingStore::FromHandle(value, &lossless); if (!lossless) return Just(false); } else { if (!value->IsNumber()) return Just(false); double search_value = value->Number(); if (!std::isfinite(search_value)) { // Integral types cannot represent +Inf or NaN. if (Kind < FLOAT32_ELEMENTS || Kind > FLOAT64_ELEMENTS) { return Just(false); } if (std::isnan(search_value)) { for (uint32_t k = start_from; k < length; ++k) { double element_k = elements->get_scalar(k); if (std::isnan(element_k)) return Just(true); } return Just(false); } } else if (search_value < std::numeric_limits::lowest() || search_value > std::numeric_limits::max()) { // Return false if value can't be represented in this space. return Just(false); } typed_search_value = static_cast(search_value); if (static_cast(typed_search_value) != search_value) { return Just(false); // Loss of precision. } } for (uint32_t k = start_from; k < length; ++k) { ctype element_k = elements->get_scalar(k); if (element_k == typed_search_value) return Just(true); } return Just(false); } static Maybe IndexOfValueImpl(Isolate* isolate, Handle receiver, Handle value, uint32_t start_from, uint32_t length) { DisallowHeapAllocation no_gc; if (WasNeutered(*receiver)) return Just(-1); BackingStore* elements = BackingStore::cast(receiver->elements()); ctype typed_search_value; if (Kind == BIGINT64_ELEMENTS || Kind == BIGUINT64_ELEMENTS) { if (!value->IsBigInt()) return Just(-1); bool lossless; typed_search_value = BackingStore::FromHandle(value, &lossless); if (!lossless) return Just(-1); } else { if (!value->IsNumber()) return Just(-1); double search_value = value->Number(); if (!std::isfinite(search_value)) { // Integral types cannot represent +Inf or NaN. if (Kind < FLOAT32_ELEMENTS || Kind > FLOAT64_ELEMENTS) { return Just(-1); } if (std::isnan(search_value)) { return Just(-1); } } else if (search_value < std::numeric_limits::lowest() || search_value > std::numeric_limits::max()) { // Return false if value can't be represented in this ElementsKind. return Just(-1); } typed_search_value = static_cast(search_value); if (static_cast(typed_search_value) != search_value) { return Just(-1); // Loss of precision. } } // Prototype has no elements, and not searching for the hole --- limit // search to backing store length. if (static_cast(elements->length()) < length) { length = elements->length(); } for (uint32_t k = start_from; k < length; ++k) { ctype element_k = elements->get_scalar(k); if (element_k == typed_search_value) return Just(k); } return Just(-1); } static Maybe LastIndexOfValueImpl(Handle receiver, Handle value, uint32_t start_from) { DisallowHeapAllocation no_gc; DCHECK(!WasNeutered(*receiver)); BackingStore* elements = BackingStore::cast(receiver->elements()); ctype typed_search_value; if (Kind == BIGINT64_ELEMENTS || Kind == BIGUINT64_ELEMENTS) { if (!value->IsBigInt()) return Just(-1); bool lossless; typed_search_value = BackingStore::FromHandle(value, &lossless); if (!lossless) return Just(-1); } else { if (!value->IsNumber()) return Just(-1); double search_value = value->Number(); if (!std::isfinite(search_value)) { if (std::is_integral::value) { // Integral types cannot represent +Inf or NaN. return Just(-1); } else if (std::isnan(search_value)) { // Strict Equality Comparison of NaN is always false. return Just(-1); } } else if (search_value < std::numeric_limits::lowest() || search_value > std::numeric_limits::max()) { // Return -1 if value can't be represented in this ElementsKind. return Just(-1); } typed_search_value = static_cast(search_value); if (static_cast(typed_search_value) != search_value) { return Just(-1); // Loss of precision. } } DCHECK_LT(start_from, elements->length()); uint32_t k = start_from; do { ctype element_k = elements->get_scalar(k); if (element_k == typed_search_value) return Just(k); } while (k-- != 0); return Just(-1); } static void ReverseImpl(JSObject* receiver) { DisallowHeapAllocation no_gc; DCHECK(!WasNeutered(receiver)); BackingStore* elements = BackingStore::cast(receiver->elements()); uint32_t len = elements->length(); if (len == 0) return; ctype* data = static_cast(elements->DataPtr()); std::reverse(data, data + len); } static Handle CreateListFromArrayLikeImpl(Isolate* isolate, Handle object, uint32_t length) { DCHECK(!WasNeutered(*object)); DCHECK(object->IsJSTypedArray()); Handle result = isolate->factory()->NewFixedArray(length); Handle elements(BackingStore::cast(object->elements()), isolate); for (uint32_t i = 0; i < length; i++) { Handle value = AccessorClass::GetImpl(isolate, *elements, i); result->set(i, *value); } return result; } static void CopyTypedArrayElementsSliceImpl(JSTypedArray* source, JSTypedArray* destination, size_t start, size_t end) { DisallowHeapAllocation no_gc; DCHECK_EQ(destination->GetElementsKind(), AccessorClass::kind()); CHECK(!source->WasNeutered()); CHECK(!destination->WasNeutered()); DCHECK_LE(start, end); DCHECK_LE(end, source->length_value()); size_t count = end - start; DCHECK_LE(count, destination->length_value()); FixedTypedArrayBase* src_elements = FixedTypedArrayBase::cast(source->elements()); BackingStore* dest_elements = BackingStore::cast(destination->elements()); size_t element_size = source->element_size(); uint8_t* source_data = static_cast(src_elements->DataPtr()) + start * element_size; // Fast path for the same type result array if (source->type() == destination->type()) { uint8_t* dest_data = static_cast(dest_elements->DataPtr()); // The spec defines the copy-step iteratively, which means that we // cannot use memcpy if the buffer is shared. uint8_t* end_ptr = source_data + count * element_size; while (source_data < end_ptr) { *dest_data++ = *source_data++; } return; } switch (source->GetElementsKind()) { #define TYPED_ARRAY_CASE(Type, type, TYPE, ctype) \ case TYPE##_ELEMENTS: \ CopyBetweenBackingStores(source_data, dest_elements, \ count, 0); \ break; TYPED_ARRAYS(TYPED_ARRAY_CASE) #undef TYPED_ARRAY_CASE default: UNREACHABLE(); break; } } static bool HasSimpleRepresentation(InstanceType type) { return !(type == FIXED_FLOAT32_ARRAY_TYPE || type == FIXED_FLOAT64_ARRAY_TYPE || type == FIXED_UINT8_CLAMPED_ARRAY_TYPE); } template static void CopyBetweenBackingStores(void* source_data_ptr, BackingStore* dest, size_t length, uint32_t offset) { DisallowHeapAllocation no_gc; for (uint32_t i = 0; i < length; i++) { // We use scalar accessors to avoid boxing/unboxing, so there are no // allocations. typename SourceTraits::ElementType elem = FixedTypedArray::get_scalar_from_data_ptr( source_data_ptr, i); dest->set(offset + i, dest->from(elem)); } } static void CopyElementsFromTypedArray(JSTypedArray* source, JSTypedArray* destination, size_t length, uint32_t offset) { // The source is a typed array, so we know we don't need to do ToNumber // side-effects, as the source elements will always be a number. DisallowHeapAllocation no_gc; CHECK(!source->WasNeutered()); CHECK(!destination->WasNeutered()); FixedTypedArrayBase* source_elements = FixedTypedArrayBase::cast(source->elements()); BackingStore* destination_elements = BackingStore::cast(destination->elements()); DCHECK_LE(offset, destination->length_value()); DCHECK_LE(length, destination->length_value() - offset); DCHECK(source->length()->IsSmi()); DCHECK_LE(length, source->length_value()); InstanceType source_type = source_elements->map()->instance_type(); InstanceType destination_type = destination_elements->map()->instance_type(); bool same_type = source_type == destination_type; bool same_size = source->element_size() == destination->element_size(); bool both_are_simple = HasSimpleRepresentation(source_type) && HasSimpleRepresentation(destination_type); uint8_t* source_data = static_cast(source_elements->DataPtr()); uint8_t* dest_data = static_cast(destination_elements->DataPtr()); size_t source_byte_length = source->byte_length(); size_t dest_byte_length = destination->byte_length(); // We can simply copy the backing store if the types are the same, or if // we are converting e.g. Uint8 <-> Int8, as the binary representation // will be the same. This is not the case for floats or clamped Uint8, // which have special conversion operations. if (same_type || (same_size && both_are_simple)) { size_t element_size = source->element_size(); std::memmove(dest_data + offset * element_size, source_data, length * element_size); } else { std::unique_ptr cloned_source_elements; // If the typedarrays are overlapped, clone the source. if (dest_data + dest_byte_length > source_data && source_data + source_byte_length > dest_data) { cloned_source_elements.reset(new uint8_t[source_byte_length]); std::memcpy(cloned_source_elements.get(), source_data, source_byte_length); source_data = cloned_source_elements.get(); } switch (source->GetElementsKind()) { #define TYPED_ARRAY_CASE(Type, type, TYPE, ctype) \ case TYPE##_ELEMENTS: \ CopyBetweenBackingStores( \ source_data, destination_elements, length, offset); \ break; TYPED_ARRAYS(TYPED_ARRAY_CASE) default: UNREACHABLE(); break; } #undef TYPED_ARRAY_CASE } } static bool HoleyPrototypeLookupRequired(Isolate* isolate, Context* context, JSArray* source) { DisallowHeapAllocation no_gc; DisallowJavascriptExecution no_js(isolate); #ifdef V8_ENABLE_FORCE_SLOW_PATH if (isolate->force_slow_path()) return true; #endif Object* source_proto = source->map()->prototype(); // Null prototypes are OK - we don't need to do prototype chain lookups on // them. if (source_proto->IsNull(isolate)) return false; if (source_proto->IsJSProxy()) return true; if (!context->native_context()->is_initial_array_prototype( JSObject::cast(source_proto))) { return true; } return !isolate->IsNoElementsProtectorIntact(context); } static bool TryCopyElementsFastNumber(Context* context, JSArray* source, JSTypedArray* destination, size_t length, uint32_t offset) { if (Kind == BIGINT64_ELEMENTS || Kind == BIGUINT64_ELEMENTS) return false; Isolate* isolate = source->GetIsolate(); DisallowHeapAllocation no_gc; DisallowJavascriptExecution no_js(isolate); CHECK(!destination->WasNeutered()); size_t current_length; DCHECK(source->length()->IsNumber() && TryNumberToSize(source->length(), ¤t_length) && length <= current_length); USE(current_length); size_t dest_length = destination->length_value(); DCHECK(length + offset <= dest_length); USE(dest_length); ElementsKind kind = source->GetElementsKind(); BackingStore* dest = BackingStore::cast(destination->elements()); // When we find the hole, we normally have to look up the element on the // prototype chain, which is not handled here and we return false instead. // When the array has the original array prototype, and that prototype has // not been changed in a way that would affect lookups, we can just convert // the hole into undefined. if (HoleyPrototypeLookupRequired(isolate, context, source)) return false; Object* undefined = ReadOnlyRoots(isolate).undefined_value(); // Fastpath for packed Smi kind. if (kind == PACKED_SMI_ELEMENTS) { FixedArray* source_store = FixedArray::cast(source->elements()); for (uint32_t i = 0; i < length; i++) { Object* elem = source_store->get(i); DCHECK(elem->IsSmi()); int int_value = Smi::ToInt(elem); dest->set(offset + i, dest->from(int_value)); } return true; } else if (kind == HOLEY_SMI_ELEMENTS) { FixedArray* source_store = FixedArray::cast(source->elements()); for (uint32_t i = 0; i < length; i++) { if (source_store->is_the_hole(isolate, i)) { dest->SetValue(offset + i, undefined); } else { Object* elem = source_store->get(i); DCHECK(elem->IsSmi()); int int_value = Smi::ToInt(elem); dest->set(offset + i, dest->from(int_value)); } } return true; } else if (kind == PACKED_DOUBLE_ELEMENTS) { // Fastpath for packed double kind. We avoid boxing and then immediately // unboxing the double here by using get_scalar. FixedDoubleArray* source_store = FixedDoubleArray::cast(source->elements()); for (uint32_t i = 0; i < length; i++) { // Use the from_double conversion for this specific TypedArray type, // rather than relying on C++ to convert elem. double elem = source_store->get_scalar(i); dest->set(offset + i, dest->from(elem)); } return true; } else if (kind == HOLEY_DOUBLE_ELEMENTS) { FixedDoubleArray* source_store = FixedDoubleArray::cast(source->elements()); for (uint32_t i = 0; i < length; i++) { if (source_store->is_the_hole(i)) { dest->SetValue(offset + i, undefined); } else { double elem = source_store->get_scalar(i); dest->set(offset + i, dest->from(elem)); } } return true; } return false; } static Object* CopyElementsHandleSlow(Handle source, Handle destination, size_t length, uint32_t offset) { Isolate* isolate = destination->GetIsolate(); Handle destination_elements( BackingStore::cast(destination->elements()), isolate); for (uint32_t i = 0; i < length; i++) { LookupIterator it(isolate, source, i); Handle elem; ASSIGN_RETURN_FAILURE_ON_EXCEPTION(isolate, elem, Object::GetProperty(&it)); if (Kind == BIGINT64_ELEMENTS || Kind == BIGUINT64_ELEMENTS) { ASSIGN_RETURN_FAILURE_ON_EXCEPTION(isolate, elem, BigInt::FromObject(isolate, elem)); } else { ASSIGN_RETURN_FAILURE_ON_EXCEPTION(isolate, elem, Object::ToNumber(isolate, elem)); } if (V8_UNLIKELY(destination->WasNeutered())) { const char* op = "set"; const MessageTemplate::Template message = MessageTemplate::kDetachedOperation; Handle operation = isolate->factory()->NewStringFromAsciiChecked(op); THROW_NEW_ERROR_RETURN_FAILURE(isolate, NewTypeError(message, operation)); } // The spec says we store the length, then get each element, so we don't // need to check changes to length. destination_elements->SetValue(offset + i, *elem); } return *isolate->factory()->undefined_value(); } // This doesn't guarantee that the destination array will be completely // filled. The caller must do this by passing a source with equal length, if // that is required. static Object* CopyElementsHandleImpl(Handle source, Handle destination, size_t length, uint32_t offset) { Isolate* isolate = destination->GetIsolate(); Handle destination_ta = Handle::cast(destination); DCHECK_LE(offset + length, destination_ta->length_value()); CHECK(!destination_ta->WasNeutered()); if (length == 0) return *isolate->factory()->undefined_value(); // All conversions from TypedArrays can be done without allocation. if (source->IsJSTypedArray()) { Handle source_ta = Handle::cast(source); ElementsKind source_kind = source_ta->GetElementsKind(); bool source_is_bigint = source_kind == BIGINT64_ELEMENTS || source_kind == BIGUINT64_ELEMENTS; bool target_is_bigint = Kind == BIGINT64_ELEMENTS || Kind == BIGUINT64_ELEMENTS; if (target_is_bigint) { if (V8_UNLIKELY(!source_is_bigint)) { Handle first = JSReceiver::GetElement(isolate, source_ta, 0).ToHandleChecked(); THROW_NEW_ERROR_RETURN_FAILURE( isolate, NewTypeError(MessageTemplate::kBigIntFromObject, first)); } } else { if (V8_UNLIKELY(source_is_bigint)) { THROW_NEW_ERROR_RETURN_FAILURE( isolate, NewTypeError(MessageTemplate::kBigIntToNumber)); } } // If we have to copy more elements than we have in the source, we need to // do special handling and conversion; that happens in the slow case. if (length + offset <= source_ta->length_value()) { CopyElementsFromTypedArray(*source_ta, *destination_ta, length, offset); return *isolate->factory()->undefined_value(); } } // Fast cases for packed numbers kinds where we don't need to allocate. if (source->IsJSArray()) { Handle source_js_array = Handle::cast(source); size_t current_length; if (source_js_array->length()->IsNumber() && TryNumberToSize(source_js_array->length(), ¤t_length)) { if (length <= current_length) { Handle source_array = Handle::cast(source); if (TryCopyElementsFastNumber(isolate->context(), *source_array, *destination_ta, length, offset)) { return *isolate->factory()->undefined_value(); } } } } // Final generic case that handles prototype chain lookups, getters, proxies // and observable side effects via valueOf, etc. return CopyElementsHandleSlow(source, destination_ta, length, offset); } }; #define FIXED_ELEMENTS_ACCESSOR(Type, type, TYPE, ctype) \ typedef TypedElementsAccessor \ Fixed##Type##ElementsAccessor; TYPED_ARRAYS(FIXED_ELEMENTS_ACCESSOR) #undef FIXED_ELEMENTS_ACCESSOR template class SloppyArgumentsElementsAccessor : public ElementsAccessorBase { public: explicit SloppyArgumentsElementsAccessor(const char* name) : ElementsAccessorBase(name) { USE(KindTraits::Kind); } static void ConvertArgumentsStoreResult( Handle elements, Handle result) { UNREACHABLE(); } static Handle GetImpl(Isolate* isolate, FixedArrayBase* parameters, uint32_t entry) { Handle elements( SloppyArgumentsElements::cast(parameters), isolate); uint32_t length = elements->parameter_map_length(); if (entry < length) { // Read context mapped entry. DisallowHeapAllocation no_gc; Object* probe = elements->get_mapped_entry(entry); DCHECK(!probe->IsTheHole(isolate)); Context* context = elements->context(); int context_entry = Smi::ToInt(probe); DCHECK(!context->get(context_entry)->IsTheHole(isolate)); return handle(context->get(context_entry), isolate); } else { // Entry is not context mapped, defer to the arguments. Handle result = ArgumentsAccessor::GetImpl( isolate, elements->arguments(), entry - length); return Subclass::ConvertArgumentsStoreResult(isolate, elements, result); } } static void TransitionElementsKindImpl(Handle object, Handle map) { UNREACHABLE(); } static void GrowCapacityAndConvertImpl(Handle object, uint32_t capacity) { UNREACHABLE(); } static inline void SetImpl(Handle holder, uint32_t entry, Object* value) { SetImpl(holder->elements(), entry, value); } static inline void SetImpl(FixedArrayBase* store, uint32_t entry, Object* value) { SloppyArgumentsElements* elements = SloppyArgumentsElements::cast(store); uint32_t length = elements->parameter_map_length(); if (entry < length) { // Store context mapped entry. DisallowHeapAllocation no_gc; Object* probe = elements->get_mapped_entry(entry); DCHECK(!probe->IsTheHole()); Context* context = elements->context(); int context_entry = Smi::ToInt(probe); DCHECK(!context->get(context_entry)->IsTheHole()); context->set(context_entry, value); } else { // Entry is not context mapped defer to arguments. FixedArray* arguments = elements->arguments(); Object* current = ArgumentsAccessor::GetRaw(arguments, entry - length); if (current->IsAliasedArgumentsEntry()) { AliasedArgumentsEntry* alias = AliasedArgumentsEntry::cast(current); Context* context = elements->context(); int context_entry = alias->aliased_context_slot(); DCHECK(!context->get(context_entry)->IsTheHole()); context->set(context_entry, value); } else { ArgumentsAccessor::SetImpl(arguments, entry - length, value); } } } static void SetLengthImpl(Isolate* isolate, Handle array, uint32_t length, Handle parameter_map) { // Sloppy arguments objects are not arrays. UNREACHABLE(); } static uint32_t GetCapacityImpl(JSObject* holder, FixedArrayBase* store) { SloppyArgumentsElements* elements = SloppyArgumentsElements::cast(store); FixedArray* arguments = elements->arguments(); return elements->parameter_map_length() + ArgumentsAccessor::GetCapacityImpl(holder, arguments); } static uint32_t GetMaxNumberOfEntries(JSObject* holder, FixedArrayBase* backing_store) { SloppyArgumentsElements* elements = SloppyArgumentsElements::cast(backing_store); FixedArrayBase* arguments = elements->arguments(); return elements->parameter_map_length() + ArgumentsAccessor::GetMaxNumberOfEntries(holder, arguments); } static uint32_t NumberOfElementsImpl(JSObject* receiver, FixedArrayBase* backing_store) { Isolate* isolate = receiver->GetIsolate(); SloppyArgumentsElements* elements = SloppyArgumentsElements::cast(backing_store); FixedArrayBase* arguments = elements->arguments(); uint32_t nof_elements = 0; uint32_t length = elements->parameter_map_length(); for (uint32_t entry = 0; entry < length; entry++) { if (HasParameterMapArg(isolate, elements, entry)) nof_elements++; } return nof_elements + ArgumentsAccessor::NumberOfElementsImpl(receiver, arguments); } static void AddElementsToKeyAccumulatorImpl(Handle receiver, KeyAccumulator* accumulator, AddKeyConversion convert) { Isolate* isolate = accumulator->isolate(); Handle elements(receiver->elements(), isolate); uint32_t length = GetCapacityImpl(*receiver, *elements); for (uint32_t entry = 0; entry < length; entry++) { if (!HasEntryImpl(isolate, *elements, entry)) continue; Handle value = GetImpl(isolate, *elements, entry); accumulator->AddKey(value, convert); } } static bool HasEntryImpl(Isolate* isolate, FixedArrayBase* parameters, uint32_t entry) { SloppyArgumentsElements* elements = SloppyArgumentsElements::cast(parameters); uint32_t length = elements->parameter_map_length(); if (entry < length) { return HasParameterMapArg(isolate, elements, entry); } FixedArrayBase* arguments = elements->arguments(); return ArgumentsAccessor::HasEntryImpl(isolate, arguments, entry - length); } static bool HasAccessorsImpl(JSObject* holder, FixedArrayBase* backing_store) { SloppyArgumentsElements* elements = SloppyArgumentsElements::cast(backing_store); FixedArray* arguments = elements->arguments(); return ArgumentsAccessor::HasAccessorsImpl(holder, arguments); } static uint32_t GetIndexForEntryImpl(FixedArrayBase* parameters, uint32_t entry) { SloppyArgumentsElements* elements = SloppyArgumentsElements::cast(parameters); uint32_t length = elements->parameter_map_length(); if (entry < length) return entry; FixedArray* arguments = elements->arguments(); return ArgumentsAccessor::GetIndexForEntryImpl(arguments, entry - length); } static uint32_t GetEntryForIndexImpl(Isolate* isolate, JSObject* holder, FixedArrayBase* parameters, uint32_t index, PropertyFilter filter) { SloppyArgumentsElements* elements = SloppyArgumentsElements::cast(parameters); if (HasParameterMapArg(isolate, elements, index)) return index; FixedArray* arguments = elements->arguments(); uint32_t entry = ArgumentsAccessor::GetEntryForIndexImpl( isolate, holder, arguments, index, filter); if (entry == kMaxUInt32) return kMaxUInt32; // Arguments entries could overlap with the dictionary entries, hence offset // them by the number of context mapped entries. return elements->parameter_map_length() + entry; } static PropertyDetails GetDetailsImpl(JSObject* holder, uint32_t entry) { SloppyArgumentsElements* elements = SloppyArgumentsElements::cast(holder->elements()); uint32_t length = elements->parameter_map_length(); if (entry < length) { return PropertyDetails(kData, NONE, PropertyCellType::kNoCell); } FixedArray* arguments = elements->arguments(); return ArgumentsAccessor::GetDetailsImpl(arguments, entry - length); } static bool HasParameterMapArg(Isolate* isolate, SloppyArgumentsElements* elements, uint32_t index) { uint32_t length = elements->parameter_map_length(); if (index >= length) return false; return !elements->get_mapped_entry(index)->IsTheHole(isolate); } static void DeleteImpl(Handle obj, uint32_t entry) { Handle elements( SloppyArgumentsElements::cast(obj->elements()), obj->GetIsolate()); uint32_t length = elements->parameter_map_length(); uint32_t delete_or_entry = entry; if (entry < length) { delete_or_entry = kMaxUInt32; } Subclass::SloppyDeleteImpl(obj, elements, delete_or_entry); // SloppyDeleteImpl allocates a new dictionary elements store. For making // heap verification happy we postpone clearing out the mapped entry. if (entry < length) { elements->set_mapped_entry(entry, obj->GetReadOnlyRoots().the_hole_value()); } } static void SloppyDeleteImpl(Handle obj, Handle elements, uint32_t entry) { // Implemented in subclasses. UNREACHABLE(); } static void CollectElementIndicesImpl(Handle object, Handle backing_store, KeyAccumulator* keys) { Isolate* isolate = keys->isolate(); uint32_t nof_indices = 0; Handle indices = isolate->factory()->NewFixedArray( GetCapacityImpl(*object, *backing_store)); DirectCollectElementIndicesImpl(isolate, object, backing_store, GetKeysConversion::kKeepNumbers, ENUMERABLE_STRINGS, indices, &nof_indices); SortIndices(isolate, indices, nof_indices); for (uint32_t i = 0; i < nof_indices; i++) { keys->AddKey(indices->get(i)); } } static Handle DirectCollectElementIndicesImpl( Isolate* isolate, Handle object, Handle backing_store, GetKeysConversion convert, PropertyFilter filter, Handle list, uint32_t* nof_indices, uint32_t insertion_index = 0) { Handle elements = Handle::cast(backing_store); uint32_t length = elements->parameter_map_length(); for (uint32_t i = 0; i < length; ++i) { if (elements->get_mapped_entry(i)->IsTheHole(isolate)) continue; if (convert == GetKeysConversion::kConvertToString) { Handle index_string = isolate->factory()->Uint32ToString(i); list->set(insertion_index, *index_string); } else { list->set(insertion_index, Smi::FromInt(i), SKIP_WRITE_BARRIER); } insertion_index++; } Handle store(elements->arguments(), isolate); return ArgumentsAccessor::DirectCollectElementIndicesImpl( isolate, object, store, convert, filter, list, nof_indices, insertion_index); } static Maybe IncludesValueImpl(Isolate* isolate, Handle object, Handle value, uint32_t start_from, uint32_t length) { DCHECK(JSObject::PrototypeHasNoElements(isolate, *object)); Handle original_map(object->map(), isolate); Handle elements( SloppyArgumentsElements::cast(object->elements()), isolate); bool search_for_hole = value->IsUndefined(isolate); for (uint32_t k = start_from; k < length; ++k) { DCHECK_EQ(object->map(), *original_map); uint32_t entry = GetEntryForIndexImpl(isolate, *object, *elements, k, ALL_PROPERTIES); if (entry == kMaxUInt32) { if (search_for_hole) return Just(true); continue; } Handle element_k = Subclass::GetImpl(isolate, *elements, entry); if (element_k->IsAccessorPair()) { LookupIterator it(isolate, object, k, LookupIterator::OWN); DCHECK(it.IsFound()); DCHECK_EQ(it.state(), LookupIterator::ACCESSOR); ASSIGN_RETURN_ON_EXCEPTION_VALUE(isolate, element_k, Object::GetPropertyWithAccessor(&it), Nothing()); if (value->SameValueZero(*element_k)) return Just(true); if (object->map() != *original_map) { // Some mutation occurred in accessor. Abort "fast" path return IncludesValueSlowPath(isolate, object, value, k + 1, length); } } else if (value->SameValueZero(*element_k)) { return Just(true); } } return Just(false); } static Maybe IndexOfValueImpl(Isolate* isolate, Handle object, Handle value, uint32_t start_from, uint32_t length) { DCHECK(JSObject::PrototypeHasNoElements(isolate, *object)); Handle original_map(object->map(), isolate); Handle elements( SloppyArgumentsElements::cast(object->elements()), isolate); for (uint32_t k = start_from; k < length; ++k) { DCHECK_EQ(object->map(), *original_map); uint32_t entry = GetEntryForIndexImpl(isolate, *object, *elements, k, ALL_PROPERTIES); if (entry == kMaxUInt32) { continue; } Handle element_k = Subclass::GetImpl(isolate, *elements, entry); if (element_k->IsAccessorPair()) { LookupIterator it(isolate, object, k, LookupIterator::OWN); DCHECK(it.IsFound()); DCHECK_EQ(it.state(), LookupIterator::ACCESSOR); ASSIGN_RETURN_ON_EXCEPTION_VALUE(isolate, element_k, Object::GetPropertyWithAccessor(&it), Nothing()); if (value->StrictEquals(*element_k)) { return Just(k); } if (object->map() != *original_map) { // Some mutation occurred in accessor. Abort "fast" path. return IndexOfValueSlowPath(isolate, object, value, k + 1, length); } } else if (value->StrictEquals(*element_k)) { return Just(k); } } return Just(-1); } static Handle SliceImpl(Handle receiver, uint32_t start, uint32_t end) { Isolate* isolate = receiver->GetIsolate(); uint32_t result_len = end < start ? 0u : end - start; Handle result_array = isolate->factory()->NewJSArray(HOLEY_ELEMENTS, result_len, result_len); DisallowHeapAllocation no_gc; FixedArray* elements = FixedArray::cast(result_array->elements()); FixedArray* parameters = FixedArray::cast(receiver->elements()); uint32_t insertion_index = 0; for (uint32_t i = start; i < end; i++) { uint32_t entry = GetEntryForIndexImpl(isolate, *receiver, parameters, i, ALL_PROPERTIES); if (entry != kMaxUInt32 && HasEntryImpl(isolate, parameters, entry)) { elements->set(insertion_index, *GetImpl(isolate, parameters, entry)); } else { elements->set_the_hole(isolate, insertion_index); } insertion_index++; } return result_array; } }; class SlowSloppyArgumentsElementsAccessor : public SloppyArgumentsElementsAccessor< SlowSloppyArgumentsElementsAccessor, DictionaryElementsAccessor, ElementsKindTraits > { public: explicit SlowSloppyArgumentsElementsAccessor(const char* name) : SloppyArgumentsElementsAccessor< SlowSloppyArgumentsElementsAccessor, DictionaryElementsAccessor, ElementsKindTraits >(name) {} static Handle ConvertArgumentsStoreResult( Isolate* isolate, Handle elements, Handle result) { // Elements of the arguments object in slow mode might be slow aliases. if (result->IsAliasedArgumentsEntry()) { DisallowHeapAllocation no_gc; AliasedArgumentsEntry* alias = AliasedArgumentsEntry::cast(*result); Context* context = elements->context(); int context_entry = alias->aliased_context_slot(); DCHECK(!context->get(context_entry)->IsTheHole(isolate)); return handle(context->get(context_entry), isolate); } return result; } static void SloppyDeleteImpl(Handle obj, Handle elements, uint32_t entry) { // No need to delete a context mapped entry from the arguments elements. if (entry == kMaxUInt32) return; Isolate* isolate = obj->GetIsolate(); Handle dict(NumberDictionary::cast(elements->arguments()), isolate); int length = elements->parameter_map_length(); dict = NumberDictionary::DeleteEntry(isolate, dict, entry - length); elements->set_arguments(*dict); } static void AddImpl(Handle object, uint32_t index, Handle value, PropertyAttributes attributes, uint32_t new_capacity) { Isolate* isolate = object->GetIsolate(); Handle elements( SloppyArgumentsElements::cast(object->elements()), isolate); Handle old_arguments( FixedArrayBase::cast(elements->arguments()), isolate); Handle dictionary = old_arguments->IsNumberDictionary() ? Handle::cast(old_arguments) : JSObject::NormalizeElements(object); PropertyDetails details(kData, attributes, PropertyCellType::kNoCell); Handle new_dictionary = NumberDictionary::Add(isolate, dictionary, index, value, details); if (attributes != NONE) object->RequireSlowElements(*new_dictionary); if (*dictionary != *new_dictionary) { elements->set_arguments(*new_dictionary); } } static void ReconfigureImpl(Handle object, Handle store, uint32_t entry, Handle value, PropertyAttributes attributes) { Isolate* isolate = object->GetIsolate(); Handle elements = Handle::cast(store); uint32_t length = elements->parameter_map_length(); if (entry < length) { Object* probe = elements->get_mapped_entry(entry); DCHECK(!probe->IsTheHole(isolate)); Context* context = elements->context(); int context_entry = Smi::ToInt(probe); DCHECK(!context->get(context_entry)->IsTheHole(isolate)); context->set(context_entry, *value); // Redefining attributes of an aliased element destroys fast aliasing. elements->set_mapped_entry(entry, ReadOnlyRoots(isolate).the_hole_value()); // For elements that are still writable we re-establish slow aliasing. if ((attributes & READ_ONLY) == 0) { value = isolate->factory()->NewAliasedArgumentsEntry(context_entry); } PropertyDetails details(kData, attributes, PropertyCellType::kNoCell); Handle arguments( NumberDictionary::cast(elements->arguments()), isolate); arguments = NumberDictionary::Add(isolate, arguments, entry, value, details); // If the attributes were NONE, we would have called set rather than // reconfigure. DCHECK_NE(NONE, attributes); object->RequireSlowElements(*arguments); elements->set_arguments(*arguments); } else { Handle arguments(elements->arguments(), isolate); DictionaryElementsAccessor::ReconfigureImpl( object, arguments, entry - length, value, attributes); } } }; class FastSloppyArgumentsElementsAccessor : public SloppyArgumentsElementsAccessor< FastSloppyArgumentsElementsAccessor, FastHoleyObjectElementsAccessor, ElementsKindTraits > { public: explicit FastSloppyArgumentsElementsAccessor(const char* name) : SloppyArgumentsElementsAccessor< FastSloppyArgumentsElementsAccessor, FastHoleyObjectElementsAccessor, ElementsKindTraits >(name) {} static Handle ConvertArgumentsStoreResult( Isolate* isolate, Handle paramtere_map, Handle result) { DCHECK(!result->IsAliasedArgumentsEntry()); return result; } static Handle GetArguments(Isolate* isolate, FixedArrayBase* store) { SloppyArgumentsElements* elements = SloppyArgumentsElements::cast(store); return Handle(elements->arguments(), isolate); } static Handle NormalizeImpl( Handle object, Handle elements) { Handle arguments = GetArguments(object->GetIsolate(), *elements); return FastHoleyObjectElementsAccessor::NormalizeImpl(object, arguments); } static Handle NormalizeArgumentsElements( Handle object, Handle elements, uint32_t* entry) { Handle dictionary = JSObject::NormalizeElements(object); elements->set_arguments(*dictionary); // kMaxUInt32 indicates that a context mapped element got deleted. In this // case we only normalize the elements (aka. migrate to SLOW_SLOPPY). if (*entry == kMaxUInt32) return dictionary; uint32_t length = elements->parameter_map_length(); if (*entry >= length) { *entry = dictionary->FindEntry(object->GetIsolate(), *entry - length) + length; } return dictionary; } static void SloppyDeleteImpl(Handle obj, Handle elements, uint32_t entry) { // Always normalize element on deleting an entry. NormalizeArgumentsElements(obj, elements, &entry); SlowSloppyArgumentsElementsAccessor::SloppyDeleteImpl(obj, elements, entry); } static void AddImpl(Handle object, uint32_t index, Handle value, PropertyAttributes attributes, uint32_t new_capacity) { DCHECK_EQ(NONE, attributes); Isolate* isolate = object->GetIsolate(); Handle elements( SloppyArgumentsElements::cast(object->elements()), isolate); Handle old_arguments(elements->arguments(), isolate); if (old_arguments->IsNumberDictionary() || static_cast(old_arguments->length()) < new_capacity) { GrowCapacityAndConvertImpl(object, new_capacity); } FixedArray* arguments = elements->arguments(); // For fast holey objects, the entry equals the index. The code above made // sure that there's enough space to store the value. We cannot convert // index to entry explicitly since the slot still contains the hole, so the // current EntryForIndex would indicate that it is "absent" by returning // kMaxUInt32. FastHoleyObjectElementsAccessor::SetImpl(arguments, index, *value); } static void ReconfigureImpl(Handle object, Handle store, uint32_t entry, Handle value, PropertyAttributes attributes) { DCHECK_EQ(object->elements(), *store); Handle elements( SloppyArgumentsElements::cast(*store), object->GetIsolate()); NormalizeArgumentsElements(object, elements, &entry); SlowSloppyArgumentsElementsAccessor::ReconfigureImpl(object, store, entry, value, attributes); } static void CopyElementsImpl(Isolate* isolate, FixedArrayBase* from, uint32_t from_start, FixedArrayBase* to, ElementsKind from_kind, uint32_t to_start, int packed_size, int copy_size) { DCHECK(!to->IsDictionary()); if (from_kind == SLOW_SLOPPY_ARGUMENTS_ELEMENTS) { CopyDictionaryToObjectElements(isolate, from, from_start, to, HOLEY_ELEMENTS, to_start, copy_size); } else { DCHECK_EQ(FAST_SLOPPY_ARGUMENTS_ELEMENTS, from_kind); CopyObjectToObjectElements(isolate, from, HOLEY_ELEMENTS, from_start, to, HOLEY_ELEMENTS, to_start, copy_size); } } static void GrowCapacityAndConvertImpl(Handle object, uint32_t capacity) { Isolate* isolate = object->GetIsolate(); Handle elements( SloppyArgumentsElements::cast(object->elements()), isolate); Handle old_arguments(FixedArray::cast(elements->arguments()), isolate); ElementsKind from_kind = object->GetElementsKind(); // This method should only be called if there's a reason to update the // elements. DCHECK(from_kind == SLOW_SLOPPY_ARGUMENTS_ELEMENTS || static_cast(old_arguments->length()) < capacity); Handle arguments = ConvertElementsWithCapacity(object, old_arguments, from_kind, capacity); Handle new_map = JSObject::GetElementsTransitionMap( object, FAST_SLOPPY_ARGUMENTS_ELEMENTS); JSObject::MigrateToMap(object, new_map); elements->set_arguments(FixedArray::cast(*arguments)); JSObject::ValidateElements(*object); } }; template class StringWrapperElementsAccessor : public ElementsAccessorBase { public: explicit StringWrapperElementsAccessor(const char* name) : ElementsAccessorBase(name) { USE(KindTraits::Kind); } static Handle GetInternalImpl(Handle holder, uint32_t entry) { return GetImpl(holder, entry); } static Handle GetImpl(Handle holder, uint32_t entry) { Isolate* isolate = holder->GetIsolate(); Handle string(GetString(*holder), isolate); uint32_t length = static_cast(string->length()); if (entry < length) { return isolate->factory()->LookupSingleCharacterStringFromCode( String::Flatten(isolate, string)->Get(entry)); } return BackingStoreAccessor::GetImpl(isolate, holder->elements(), entry - length); } static Handle GetImpl(Isolate* isolate, FixedArrayBase* elements, uint32_t entry) { UNREACHABLE(); } static PropertyDetails GetDetailsImpl(JSObject* holder, uint32_t entry) { uint32_t length = static_cast(GetString(holder)->length()); if (entry < length) { PropertyAttributes attributes = static_cast(READ_ONLY | DONT_DELETE); return PropertyDetails(kData, attributes, PropertyCellType::kNoCell); } return BackingStoreAccessor::GetDetailsImpl(holder, entry - length); } static uint32_t GetEntryForIndexImpl(Isolate* isolate, JSObject* holder, FixedArrayBase* backing_store, uint32_t index, PropertyFilter filter) { uint32_t length = static_cast(GetString(holder)->length()); if (index < length) return index; uint32_t backing_store_entry = BackingStoreAccessor::GetEntryForIndexImpl( isolate, holder, backing_store, index, filter); if (backing_store_entry == kMaxUInt32) return kMaxUInt32; DCHECK(backing_store_entry < kMaxUInt32 - length); return backing_store_entry + length; } static void DeleteImpl(Handle holder, uint32_t entry) { uint32_t length = static_cast(GetString(*holder)->length()); if (entry < length) { return; // String contents can't be deleted. } BackingStoreAccessor::DeleteImpl(holder, entry - length); } static void SetImpl(Handle holder, uint32_t entry, Object* value) { uint32_t length = static_cast(GetString(*holder)->length()); if (entry < length) { return; // String contents are read-only. } BackingStoreAccessor::SetImpl(holder->elements(), entry - length, value); } static void AddImpl(Handle object, uint32_t index, Handle value, PropertyAttributes attributes, uint32_t new_capacity) { DCHECK(index >= static_cast(GetString(*object)->length())); // Explicitly grow fast backing stores if needed. Dictionaries know how to // extend their capacity themselves. if (KindTraits::Kind == FAST_STRING_WRAPPER_ELEMENTS && (object->GetElementsKind() == SLOW_STRING_WRAPPER_ELEMENTS || BackingStoreAccessor::GetCapacityImpl(*object, object->elements()) != new_capacity)) { GrowCapacityAndConvertImpl(object, new_capacity); } BackingStoreAccessor::AddImpl(object, index, value, attributes, new_capacity); } static void ReconfigureImpl(Handle object, Handle store, uint32_t entry, Handle value, PropertyAttributes attributes) { uint32_t length = static_cast(GetString(*object)->length()); if (entry < length) { return; // String contents can't be reconfigured. } BackingStoreAccessor::ReconfigureImpl(object, store, entry - length, value, attributes); } static void AddElementsToKeyAccumulatorImpl(Handle receiver, KeyAccumulator* accumulator, AddKeyConversion convert) { Isolate* isolate = receiver->GetIsolate(); Handle string(GetString(*receiver), isolate); string = String::Flatten(isolate, string); uint32_t length = static_cast(string->length()); for (uint32_t i = 0; i < length; i++) { accumulator->AddKey( isolate->factory()->LookupSingleCharacterStringFromCode( string->Get(i)), convert); } BackingStoreAccessor::AddElementsToKeyAccumulatorImpl(receiver, accumulator, convert); } static void CollectElementIndicesImpl(Handle object, Handle backing_store, KeyAccumulator* keys) { uint32_t length = GetString(*object)->length(); Factory* factory = keys->isolate()->factory(); for (uint32_t i = 0; i < length; i++) { keys->AddKey(factory->NewNumberFromUint(i)); } BackingStoreAccessor::CollectElementIndicesImpl(object, backing_store, keys); } static void GrowCapacityAndConvertImpl(Handle object, uint32_t capacity) { Handle old_elements(object->elements(), object->GetIsolate()); ElementsKind from_kind = object->GetElementsKind(); if (from_kind == FAST_STRING_WRAPPER_ELEMENTS) { // The optimizing compiler relies on the prototype lookups of String // objects always returning undefined. If there's a store to the // initial String.prototype object, make sure all the optimizations // are invalidated. object->GetIsolate()->UpdateNoElementsProtectorOnSetLength(object); } // This method should only be called if there's a reason to update the // elements. DCHECK(from_kind == SLOW_STRING_WRAPPER_ELEMENTS || static_cast(old_elements->length()) < capacity); Subclass::BasicGrowCapacityAndConvertImpl(object, old_elements, from_kind, FAST_STRING_WRAPPER_ELEMENTS, capacity); } static void CopyElementsImpl(Isolate* isolate, FixedArrayBase* from, uint32_t from_start, FixedArrayBase* to, ElementsKind from_kind, uint32_t to_start, int packed_size, int copy_size) { DCHECK(!to->IsDictionary()); if (from_kind == SLOW_STRING_WRAPPER_ELEMENTS) { CopyDictionaryToObjectElements(isolate, from, from_start, to, HOLEY_ELEMENTS, to_start, copy_size); } else { DCHECK_EQ(FAST_STRING_WRAPPER_ELEMENTS, from_kind); CopyObjectToObjectElements(isolate, from, HOLEY_ELEMENTS, from_start, to, HOLEY_ELEMENTS, to_start, copy_size); } } static uint32_t NumberOfElementsImpl(JSObject* object, FixedArrayBase* backing_store) { uint32_t length = GetString(object)->length(); return length + BackingStoreAccessor::NumberOfElementsImpl(object, backing_store); } private: static String* GetString(JSObject* holder) { DCHECK(holder->IsJSValue()); JSValue* js_value = JSValue::cast(holder); DCHECK(js_value->value()->IsString()); return String::cast(js_value->value()); } }; class FastStringWrapperElementsAccessor : public StringWrapperElementsAccessor< FastStringWrapperElementsAccessor, FastHoleyObjectElementsAccessor, ElementsKindTraits> { public: explicit FastStringWrapperElementsAccessor(const char* name) : StringWrapperElementsAccessor< FastStringWrapperElementsAccessor, FastHoleyObjectElementsAccessor, ElementsKindTraits>(name) {} static Handle NormalizeImpl( Handle object, Handle elements) { return FastHoleyObjectElementsAccessor::NormalizeImpl(object, elements); } }; class SlowStringWrapperElementsAccessor : public StringWrapperElementsAccessor< SlowStringWrapperElementsAccessor, DictionaryElementsAccessor, ElementsKindTraits> { public: explicit SlowStringWrapperElementsAccessor(const char* name) : StringWrapperElementsAccessor< SlowStringWrapperElementsAccessor, DictionaryElementsAccessor, ElementsKindTraits>(name) {} static bool HasAccessorsImpl(JSObject* holder, FixedArrayBase* backing_store) { return DictionaryElementsAccessor::HasAccessorsImpl(holder, backing_store); } }; } // namespace void CheckArrayAbuse(Handle obj, const char* op, uint32_t index, bool allow_appending) { DisallowHeapAllocation no_allocation; Object* raw_length = nullptr; const char* elements_type = "array"; if (obj->IsJSArray()) { JSArray* array = JSArray::cast(*obj); raw_length = array->length(); } else { raw_length = Smi::FromInt(obj->elements()->length()); elements_type = "object"; } if (raw_length->IsNumber()) { double n = raw_length->Number(); if (FastI2D(FastD2UI(n)) == n) { int32_t int32_length = DoubleToInt32(n); uint32_t compare_length = static_cast(int32_length); if (allow_appending) compare_length++; if (index >= compare_length) { PrintF("[OOB %s %s (%s length = %d, element accessed = %d) in ", elements_type, op, elements_type, static_cast(int32_length), static_cast(index)); TraceTopFrame(obj->GetIsolate()); PrintF("]\n"); } } else { PrintF("[%s elements length not integer value in ", elements_type); TraceTopFrame(obj->GetIsolate()); PrintF("]\n"); } } else { PrintF("[%s elements length not a number in ", elements_type); TraceTopFrame(obj->GetIsolate()); PrintF("]\n"); } } MaybeHandle ArrayConstructInitializeElements(Handle array, Arguments* args) { if (args->length() == 0) { // Optimize the case where there are no parameters passed. JSArray::Initialize(array, JSArray::kPreallocatedArrayElements); return array; } else if (args->length() == 1 && args->at(0)->IsNumber()) { uint32_t length; if (!args->at(0)->ToArrayLength(&length)) { return ThrowArrayLengthRangeError(array->GetIsolate()); } // Optimize the case where there is one argument and the argument is a small // smi. if (length > 0 && length < JSArray::kInitialMaxFastElementArray) { ElementsKind elements_kind = array->GetElementsKind(); JSArray::Initialize(array, length, length); if (!IsHoleyElementsKind(elements_kind)) { elements_kind = GetHoleyElementsKind(elements_kind); JSObject::TransitionElementsKind(array, elements_kind); } } else if (length == 0) { JSArray::Initialize(array, JSArray::kPreallocatedArrayElements); } else { // Take the argument as the length. JSArray::Initialize(array, 0); JSArray::SetLength(array, length); } return array; } Factory* factory = array->GetIsolate()->factory(); // Set length and elements on the array. int number_of_elements = args->length(); JSObject::EnsureCanContainElements( array, args, 0, number_of_elements, ALLOW_CONVERTED_DOUBLE_ELEMENTS); // Allocate an appropriately typed elements array. ElementsKind elements_kind = array->GetElementsKind(); Handle elms; if (IsDoubleElementsKind(elements_kind)) { elms = Handle::cast( factory->NewFixedDoubleArray(number_of_elements)); } else { elms = Handle::cast( factory->NewFixedArrayWithHoles(number_of_elements)); } // Fill in the content switch (elements_kind) { case HOLEY_SMI_ELEMENTS: case PACKED_SMI_ELEMENTS: { Handle smi_elms = Handle::cast(elms); for (int entry = 0; entry < number_of_elements; entry++) { smi_elms->set(entry, (*args)[entry], SKIP_WRITE_BARRIER); } break; } case HOLEY_ELEMENTS: case PACKED_ELEMENTS: { DisallowHeapAllocation no_gc; WriteBarrierMode mode = elms->GetWriteBarrierMode(no_gc); Handle object_elms = Handle::cast(elms); for (int entry = 0; entry < number_of_elements; entry++) { object_elms->set(entry, (*args)[entry], mode); } break; } case HOLEY_DOUBLE_ELEMENTS: case PACKED_DOUBLE_ELEMENTS: { Handle double_elms = Handle::cast(elms); for (int entry = 0; entry < number_of_elements; entry++) { double_elms->set(entry, (*args)[entry]->Number()); } break; } default: UNREACHABLE(); break; } array->set_elements(*elms); array->set_length(Smi::FromInt(number_of_elements)); return array; } void CopyFastNumberJSArrayElementsToTypedArray(Context* context, JSArray* source, JSTypedArray* destination, uintptr_t length, uintptr_t offset) { DCHECK(context->IsContext()); DCHECK(source->IsJSArray()); DCHECK(destination->IsJSTypedArray()); switch (destination->GetElementsKind()) { #define TYPED_ARRAYS_CASE(Type, type, TYPE, ctype) \ case TYPE##_ELEMENTS: \ CHECK(Fixed##Type##ElementsAccessor::TryCopyElementsFastNumber( \ context, source, destination, length, static_cast(offset))); \ break; TYPED_ARRAYS(TYPED_ARRAYS_CASE) #undef TYPED_ARRAYS_CASE default: UNREACHABLE(); } } void CopyTypedArrayElementsToTypedArray(JSTypedArray* source, JSTypedArray* destination, uintptr_t length, uintptr_t offset) { switch (destination->GetElementsKind()) { #define TYPED_ARRAYS_CASE(Type, type, TYPE, ctype) \ case TYPE##_ELEMENTS: \ Fixed##Type##ElementsAccessor::CopyElementsFromTypedArray( \ source, destination, length, static_cast(offset)); \ break; TYPED_ARRAYS(TYPED_ARRAYS_CASE) #undef TYPED_ARRAYS_CASE default: UNREACHABLE(); } } void CopyTypedArrayElementsSlice(JSTypedArray* source, JSTypedArray* destination, uintptr_t start, uintptr_t end) { destination->GetElementsAccessor()->CopyTypedArrayElementsSlice( source, destination, start, end); } void ElementsAccessor::InitializeOncePerProcess() { static ElementsAccessor* accessor_array[] = { #define ACCESSOR_ARRAY(Class, Kind, Store) new Class(#Kind), ELEMENTS_LIST(ACCESSOR_ARRAY) #undef ACCESSOR_ARRAY }; STATIC_ASSERT((sizeof(accessor_array) / sizeof(*accessor_array)) == kElementsKindCount); elements_accessors_ = accessor_array; } void ElementsAccessor::TearDown() { if (elements_accessors_ == nullptr) return; #define ACCESSOR_DELETE(Class, Kind, Store) delete elements_accessors_[Kind]; ELEMENTS_LIST(ACCESSOR_DELETE) #undef ACCESSOR_DELETE elements_accessors_ = nullptr; } Handle ElementsAccessor::Concat(Isolate* isolate, Arguments* args, uint32_t concat_size, uint32_t result_len) { ElementsKind result_elements_kind = GetInitialFastElementsKind(); bool has_raw_doubles = false; { DisallowHeapAllocation no_gc; bool is_holey = false; for (uint32_t i = 0; i < concat_size; i++) { Object* arg = (*args)[i]; ElementsKind arg_kind = JSArray::cast(arg)->GetElementsKind(); has_raw_doubles = has_raw_doubles || IsDoubleElementsKind(arg_kind); is_holey = is_holey || IsHoleyElementsKind(arg_kind); result_elements_kind = GetMoreGeneralElementsKind(result_elements_kind, arg_kind); } if (is_holey) { result_elements_kind = GetHoleyElementsKind(result_elements_kind); } } // If a double array is concatted into a fast elements array, the fast // elements array needs to be initialized to contain proper holes, since // boxing doubles may cause incremental marking. bool requires_double_boxing = has_raw_doubles && !IsDoubleElementsKind(result_elements_kind); ArrayStorageAllocationMode mode = requires_double_boxing ? INITIALIZE_ARRAY_ELEMENTS_WITH_HOLE : DONT_INITIALIZE_ARRAY_ELEMENTS; Handle result_array = isolate->factory()->NewJSArray( result_elements_kind, result_len, result_len, mode); if (result_len == 0) return result_array; uint32_t insertion_index = 0; Handle storage(result_array->elements(), isolate); ElementsAccessor* accessor = ElementsAccessor::ForKind(result_elements_kind); for (uint32_t i = 0; i < concat_size; i++) { // It is crucial to keep |array| in a raw pointer form to avoid // performance degradation. JSArray* array = JSArray::cast((*args)[i]); uint32_t len = 0; array->length()->ToArrayLength(&len); if (len == 0) continue; ElementsKind from_kind = array->GetElementsKind(); accessor->CopyElements(array, 0, from_kind, storage, insertion_index, len); insertion_index += len; } DCHECK_EQ(insertion_index, result_len); return result_array; } ElementsAccessor** ElementsAccessor::elements_accessors_ = nullptr; #undef ELEMENTS_LIST } // namespace internal } // namespace v8