// 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/objects/elements.h"
#include "src/common/message-template.h"
#include "src/execution/arguments.h"
#include "src/execution/frames.h"
#include "src/execution/isolate-inl.h"
#include "src/heap/factory.h"
#include "src/heap/heap-inl.h" // For MaxNumberToStringCacheSize.
#include "src/heap/heap-write-barrier-inl.h"
#include "src/numbers/conversions.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/objects/keys.h"
#include "src/objects/objects-inl.h"
#include "src/objects/slots-atomic-inl.h"
#include "src/objects/slots.h"
#include "src/utils/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
// - FastNonextensibleObjectElementsAccessor: template
// - FastPackedNonextensibleObjectElementsAccessor
// - FastHoleyNonextensibleObjectElementsAccessor
// - FastSealedObjectElementsAccessor: template
// - FastPackedSealedObjectElementsAccessor
// - FastHoleySealedObjectElementsAccessor
// - FastFrozenObjectElementsAccessor: template
// - FastPackedFrozenObjectElementsAccessor
// - FastHoleyFrozenObjectElementsAccessor
// - FastHoleyObjectElementsAccessor
// - FastDoubleElementsAccessor
// - FastPackedDoubleElementsAccessor
// - FastHoleyDoubleElementsAccessor
// - TypedElementsAccessor: template, with instantiations:
// - Uint8ElementsAccessor
// - Int8ElementsAccessor
// - Uint16ElementsAccessor
// - Int16ElementsAccessor
// - Uint32ElementsAccessor
// - Int32ElementsAccessor
// - Float32ElementsAccessor
// - Float64ElementsAccessor
// - Uint8ClampedElementsAccessor
// - BigUint64ElementsAccessor
// - BigInt64ElementsAccessor
// - DictionaryElementsAccessor
// - SloppyArgumentsElementsAccessor
// - FastSloppyArgumentsElementsAccessor
// - SlowSloppyArgumentsElementsAccessor
// - StringWrapperElementsAccessor
// - FastStringWrapperElementsAccessor
// - SlowStringWrapperElementsAccessor
namespace v8 {
namespace internal {
namespace {
#define RETURN_NOTHING_IF_NOT_SUCCESSFUL(call) \
do { \
if (!(call)) return Nothing<bool>(); \
} while (false)
#define RETURN_FAILURE_IF_NOT_SUCCESSFUL(call) \
do { \
ExceptionStatus status_enum_result = (call); \
if (!status_enum_result) return status_enum_result; \
} while (false)
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(FastPackedNonextensibleObjectElementsAccessor, \
PACKED_NONEXTENSIBLE_ELEMENTS, FixedArray) \
V(FastHoleyNonextensibleObjectElementsAccessor, \
HOLEY_NONEXTENSIBLE_ELEMENTS, FixedArray) \
V(FastPackedSealedObjectElementsAccessor, PACKED_SEALED_ELEMENTS, \
FixedArray) \
V(FastHoleySealedObjectElementsAccessor, HOLEY_SEALED_ELEMENTS, FixedArray) \
V(FastPackedFrozenObjectElementsAccessor, PACKED_FROZEN_ELEMENTS, \
FixedArray) \
V(FastHoleyFrozenObjectElementsAccessor, HOLEY_FROZEN_ELEMENTS, FixedArray) \
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(Uint8ElementsAccessor, UINT8_ELEMENTS, ByteArray) \
V(Int8ElementsAccessor, INT8_ELEMENTS, ByteArray) \
V(Uint16ElementsAccessor, UINT16_ELEMENTS, ByteArray) \
V(Int16ElementsAccessor, INT16_ELEMENTS, ByteArray) \
V(Uint32ElementsAccessor, UINT32_ELEMENTS, ByteArray) \
V(Int32ElementsAccessor, INT32_ELEMENTS, ByteArray) \
V(Float32ElementsAccessor, FLOAT32_ELEMENTS, ByteArray) \
V(Float64ElementsAccessor, FLOAT64_ELEMENTS, ByteArray) \
V(Uint8ClampedElementsAccessor, UINT8_CLAMPED_ELEMENTS, ByteArray) \
V(BigUint64ElementsAccessor, BIGUINT64_ELEMENTS, ByteArray) \
V(BigInt64ElementsAccessor, BIGINT64_ELEMENTS, ByteArray)
template <ElementsKind Kind>
class ElementsKindTraits {
public:
using BackingStore = FixedArrayBase;
};
#define ELEMENTS_TRAITS(Class, KindParam, Store) \
template <> \
class ElementsKindTraits<KindParam> { \
public: /* NOLINT */ \
static constexpr ElementsKind Kind = KindParam; \
using BackingStore = Store; \
}; \
constexpr ElementsKind ElementsKindTraits<KindParam>::Kind;
ELEMENTS_LIST(ELEMENTS_TRAITS)
#undef ELEMENTS_TRAITS
V8_WARN_UNUSED_RESULT
MaybeHandle<Object> 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;
}
// If kCopyToEndAndInitializeToHole is specified as the copy_size to
// CopyElements, it copies all of elements from source after source_start to
// destination array, padding any remaining uninitialized elements in the
// destination array with the hole.
constexpr int kCopyToEndAndInitializeToHole = -1;
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_EQ(kCopyToEndAndInitializeToHole, raw_copy_size);
copy_size =
Min(from_base.length() - from_start, to_base.length() - to_start);
int start = to_start + copy_size;
int length = to_base.length() - start;
if (length > 0) {
MemsetTagged(FixedArray::cast(to_base).RawFieldOfElementAt(start),
roots.the_hole_value(), length);
}
}
DCHECK((copy_size + static_cast<int>(to_start)) <= to_base.length() &&
(copy_size + static_cast<int>(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;
to.CopyElements(isolate, to_start, from, from_start, copy_size,
write_barrier_mode);
}
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_EQ(kCopyToEndAndInitializeToHole, raw_copy_size);
copy_size = from.max_number_key() + 1 - from_start;
int start = to_start + copy_size;
int length = to_base.length() - start;
if (length > 0) {
MemsetTagged(FixedArray::cast(to_base).RawFieldOfElementAt(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.
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_EQ(kCopyToEndAndInitializeToHole, raw_copy_size);
copy_size =
Min(from_base.length() - from_start, to_base.length() - to_start);
// 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) {
MemsetTagged(FixedArray::cast(to_base).RawFieldOfElementAt(start),
ReadOnlyRoots(isolate).the_hole_value(), length);
}
}
DCHECK((copy_size + static_cast<int>(to_start)) <= to_base.length() &&
(copy_size + static_cast<int>(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<FixedDoubleArray> from(FixedDoubleArray::cast(from_base), isolate);
Handle<FixedArray> 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<Object> value =
FixedDoubleArray::get(*from, i + from_start, isolate);
to->set(i + to_start, *value, UPDATE_WRITE_BARRIER);
}
}
}
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_EQ(kCopyToEndAndInitializeToHole, raw_copy_size);
copy_size =
Min(from_base.length() - from_start, to_base.length() - to_start);
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<int>(to_start)) <= to_base.length() &&
(copy_size + static_cast<int>(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;
#ifdef V8_COMPRESS_POINTERS
// TODO(ishell, v8:8875): we use CopyTagged() in order to avoid unaligned
// access to double values in the arrays. This will no longed be necessary
// once the allocations alignment issue is fixed.
int words_per_double = (kDoubleSize / kTaggedSize);
CopyTagged(to_address, from_address,
static_cast<size_t>(words_per_double * copy_size));
#else
int words_per_double = (kDoubleSize / kSystemPointerSize);
CopyWords(to_address, from_address,
static_cast<size_t>(words_per_double * copy_size));
#endif
}
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_EQ(kCopyToEndAndInitializeToHole, raw_copy_size);
copy_size = from_base.length() - from_start;
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<int>(to_start)) <= to_base.length() &&
(copy_size + static_cast<int>(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<uint32_t>(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));
}
}
}
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_EQ(kCopyToEndAndInitializeToHole, raw_copy_size);
copy_size = packed_size - from_start;
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<uint32_t>(copy_size);
}
DCHECK(static_cast<int>(to_end) <= to_base.length());
DCHECK(packed_size >= 0 && packed_size <= copy_size);
DCHECK((copy_size + static_cast<int>(to_start)) <= to_base.length() &&
(copy_size + static_cast<int>(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<uint32_t>(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));
}
}
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_EQ(kCopyToEndAndInitializeToHole, raw_copy_size);
copy_size = from_base.length() - from_start;
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<int>(to_start)) <= to_base.length() &&
(copy_size + static_cast<int>(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());
}
}
}
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_EQ(kCopyToEndAndInitializeToHole, copy_size);
copy_size = from.max_number_key() + 1 - from_start;
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);
}
}
}
void SortIndices(Isolate* isolate, Handle<FixedArray> indices,
uint32_t sort_size) {
// Use AtomicSlot wrapper to ensure that std::sort uses atomic load and
// store operations that are safe for concurrent marking.
AtomicSlot start(indices->GetFirstElementAddress());
AtomicSlot end(start + sort_size);
std::sort(start, end, [isolate](Tagged_t elementA, Tagged_t elementB) {
#ifdef V8_COMPRESS_POINTERS
Object a(DecompressTaggedAny(isolate, elementA));
Object b(DecompressTaggedAny(isolate, elementB));
#else
Object a(elementA);
Object b(elementB);
#endif
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);
});
isolate->heap()->WriteBarrierForRange(*indices, ObjectSlot(start),
ObjectSlot(end));
}
Maybe<bool> IncludesValueSlowPath(Isolate* isolate, Handle<JSObject> receiver,
Handle<Object> 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<Object> element_k;
ASSIGN_RETURN_ON_EXCEPTION_VALUE(isolate, element_k,
Object::GetProperty(&it), Nothing<bool>());
if (value->SameValueZero(*element_k)) return Just(true);
}
return Just(false);
}
Maybe<int64_t> IndexOfValueSlowPath(Isolate* isolate, Handle<JSObject> receiver,
Handle<Object> 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<Object> element_k;
ASSIGN_RETURN_ON_EXCEPTION_VALUE(
isolate, element_k, Object::GetProperty(&it), Nothing<int64_t>());
if (value->StrictEquals(*element_k)) return Just<int64_t>(k);
}
return Just<int64_t>(-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:
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<SomeElementsAccessor,
// BackingStoreClass> {
// ...
// }
//
// 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 <typename Subclass, typename ElementsTraitsParam>
class ElementsAccessorBase : public InternalElementsAccessor {
public:
ElementsAccessorBase() = default;
using ElementsTraits = ElementsTraitsParam;
using BackingStore = typename ElementsTraitsParam::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 if (holder.IsJSTypedArray()) {
// TODO(bmeurer, v8:4153): Change this to size_t later.
length = static_cast<int>(JSTypedArray::cast(holder).length());
} 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;
}
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<Object> Get(Handle<JSObject> holder, uint32_t entry) final {
return Subclass::GetInternalImpl(holder, entry);
}
static Handle<Object> GetInternalImpl(Handle<JSObject> holder,
uint32_t entry) {
return Subclass::GetImpl(holder->GetIsolate(), holder->elements(), entry);
}
static Handle<Object> 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<JSObject> holder, uint32_t entry, Object value) final {
Subclass::SetImpl(holder, entry, value);
}
void Reconfigure(Handle<JSObject> object, Handle<FixedArrayBase> store,
uint32_t entry, Handle<Object> value,
PropertyAttributes attributes) final {
Subclass::ReconfigureImpl(object, store, entry, value, attributes);
}
static void ReconfigureImpl(Handle<JSObject> object,
Handle<FixedArrayBase> store, uint32_t entry,
Handle<Object> value,
PropertyAttributes attributes) {
UNREACHABLE();
}
void Add(Handle<JSObject> object, uint32_t index, Handle<Object> value,
PropertyAttributes attributes, uint32_t new_capacity) final {
Subclass::AddImpl(object, index, value, attributes, new_capacity);
}
static void AddImpl(Handle<JSObject> object, uint32_t index,
Handle<Object> value, PropertyAttributes attributes,
uint32_t new_capacity) {
UNREACHABLE();
}
uint32_t Push(Handle<JSArray> receiver, Arguments* args,
uint32_t push_size) final {
return Subclass::PushImpl(receiver, args, push_size);
}
static uint32_t PushImpl(Handle<JSArray> receiver, Arguments* args,
uint32_t push_sized) {
UNREACHABLE();
}
uint32_t Unshift(Handle<JSArray> receiver, Arguments* args,
uint32_t unshift_size) final {
return Subclass::UnshiftImpl(receiver, args, unshift_size);
}
static uint32_t UnshiftImpl(Handle<JSArray> receiver, Arguments* args,
uint32_t unshift_size) {
UNREACHABLE();
}
Handle<Object> Pop(Handle<JSArray> receiver) final {
return Subclass::PopImpl(receiver);
}
static Handle<Object> PopImpl(Handle<JSArray> receiver) { UNREACHABLE(); }
Handle<Object> Shift(Handle<JSArray> receiver) final {
return Subclass::ShiftImpl(receiver);
}
static Handle<Object> ShiftImpl(Handle<JSArray> receiver) { UNREACHABLE(); }
void SetLength(Handle<JSArray> array, uint32_t length) final {
Subclass::SetLengthImpl(array->GetIsolate(), array, length,
handle(array->elements(), array->GetIsolate()));
}
static void SetLengthImpl(Isolate* isolate, Handle<JSArray> array,
uint32_t length,
Handle<FixedArrayBase> 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<uint32_t>(
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<FixedArrayBase> ConvertElementsWithCapacity(
Handle<JSObject> object, Handle<FixedArrayBase> old_elements,
ElementsKind from_kind, uint32_t capacity) {
return ConvertElementsWithCapacity(object, old_elements, from_kind,
capacity, 0, 0);
}
static Handle<FixedArrayBase> ConvertElementsWithCapacity(
Handle<JSObject> object, Handle<FixedArrayBase> old_elements,
ElementsKind from_kind, uint32_t capacity, uint32_t src_index,
uint32_t dst_index) {
Isolate* isolate = object->GetIsolate();
Handle<FixedArrayBase> 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,
kCopyToEndAndInitializeToHole);
return new_elements;
}
static void TransitionElementsKindImpl(Handle<JSObject> object,
Handle<Map> to_map) {
Isolate* isolate = object->GetIsolate();
Handle<Map> from_map = handle(object->map(), isolate);
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<FixedArrayBase> from_elements(object->elements(), isolate);
if (object->elements() == ReadOnlyRoots(isolate).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(isolate, object, to_map);
} else {
DCHECK(
(IsSmiElementsKind(from_kind) && IsDoubleElementsKind(to_kind)) ||
(IsDoubleElementsKind(from_kind) && IsObjectElementsKind(to_kind)));
uint32_t capacity = static_cast<uint32_t>(object->elements().length());
Handle<FixedArrayBase> 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(), isolate));
}
}
}
static void GrowCapacityAndConvertImpl(Handle<JSObject> 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<FixedArrayBase> 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<uint32_t>(old_elements->length()) < capacity);
Subclass::BasicGrowCapacityAndConvertImpl(object, old_elements, from_kind,
kind(), capacity);
}
static void BasicGrowCapacityAndConvertImpl(
Handle<JSObject> object, Handle<FixedArrayBase> old_elements,
ElementsKind from_kind, ElementsKind to_kind, uint32_t capacity) {
Handle<FixedArrayBase> elements =
ConvertElementsWithCapacity(object, old_elements, from_kind, capacity);
if (IsHoleyElementsKind(from_kind)) {
to_kind = GetHoleyElementsKind(to_kind);
}
Handle<Map> 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<JSObject> object, Handle<Map> map) final {
Subclass::TransitionElementsKindImpl(object, map);
}
void GrowCapacityAndConvert(Handle<JSObject> object,
uint32_t capacity) final {
Subclass::GrowCapacityAndConvertImpl(object, capacity);
}
bool GrowCapacity(Handle<JSObject> 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<FixedArrayBase> old_elements(object->elements(),
object->GetIsolate());
uint32_t new_capacity = JSObject::NewElementsCapacity(index + 1);
DCHECK(static_cast<uint32_t>(old_elements->length()) < new_capacity);
Handle<FixedArrayBase> 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<AllocationSiteUpdateMode::kCheckOnly>(
object, kind())) {
return false;
}
object->set_elements(*elements);
return true;
}
void Delete(Handle<JSObject> 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<FixedArrayBase> 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<FixedArrayBase> source,
ElementsKind source_kind,
Handle<FixedArrayBase> 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<Object> source, Handle<JSObject> destination,
size_t length, uint32_t offset) final {
return Subclass::CopyElementsHandleImpl(source, destination, length,
offset);
}
static Object CopyElementsHandleImpl(Handle<Object> source,
Handle<JSObject> destination,
size_t length, uint32_t offset) {
UNREACHABLE();
}
Handle<NumberDictionary> Normalize(Handle<JSObject> object) final {
return Subclass::NormalizeImpl(
object, handle(object->elements(), object->GetIsolate()));
}
static Handle<NumberDictionary> NormalizeImpl(
Handle<JSObject> object, Handle<FixedArrayBase> elements) {
UNREACHABLE();
}
Maybe<bool> CollectValuesOrEntries(Isolate* isolate, Handle<JSObject> object,
Handle<FixedArray> 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<bool> CollectValuesOrEntriesImpl(
Isolate* isolate, Handle<JSObject> object,
Handle<FixedArray> values_or_entries, bool get_entries, int* nof_items,
PropertyFilter filter) {
DCHECK_EQ(*nof_items, 0);
KeyAccumulator accumulator(isolate, KeyCollectionMode::kOwnOnly,
ALL_PROPERTIES);
RETURN_NOTHING_IF_NOT_SUCCESSFUL(Subclass::CollectElementIndicesImpl(
object, handle(object->elements(), isolate), &accumulator));
Handle<FixedArray> keys = accumulator.GetKeys();
int count = 0;
int i = 0;
ElementsKind original_elements_kind = object->GetElementsKind();
for (; i < keys->length(); ++i) {
Handle<Object> 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<Object> value;
if (details.kind() == kData) {
value = Subclass::GetInternalImpl(object, 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<bool>());
}
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<Object> key(keys->get(i), isolate);
uint32_t index;
if (!key->ToUint32(&index)) continue;
if (filter & ONLY_ENUMERABLE) {
InternalElementsAccessor* accessor =
reinterpret_cast<InternalElementsAccessor*>(
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<Object> value;
LookupIterator it(isolate, object, index, LookupIterator::OWN);
ASSIGN_RETURN_ON_EXCEPTION_VALUE(isolate, value, Object::GetProperty(&it),
Nothing<bool>());
if (get_entries) value = MakeEntryPair(isolate, index, value);
values_or_entries->set(count++, *value);
}
*nof_items = count;
return Just(true);
}
V8_WARN_UNUSED_RESULT ExceptionStatus CollectElementIndices(
Handle<JSObject> object, Handle<FixedArrayBase> backing_store,
KeyAccumulator* keys) final {
if (keys->filter() & ONLY_ALL_CAN_READ) return ExceptionStatus::kSuccess;
return Subclass::CollectElementIndicesImpl(object, backing_store, keys);
}
V8_WARN_UNUSED_RESULT static ExceptionStatus CollectElementIndicesImpl(
Handle<JSObject> object, Handle<FixedArrayBase> 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)) {
RETURN_FAILURE_IF_NOT_SUCCESSFUL(
keys->AddKey(factory->NewNumberFromUint(i)));
}
}
return ExceptionStatus::kSuccess;
}
static Handle<FixedArray> DirectCollectElementIndicesImpl(
Isolate* isolate, Handle<JSObject> object,
Handle<FixedArrayBase> backing_store, GetKeysConversion convert,
PropertyFilter filter, Handle<FixedArray> 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<String> index_string =
isolate->factory()->Uint32ToString(i, use_cache);
list->set(insertion_index, *index_string);
} else {
list->set(insertion_index, Smi::FromInt(i));
}
insertion_index++;
}
}
*nof_indices = insertion_index;
return list;
}
MaybeHandle<FixedArray> PrependElementIndices(
Handle<JSObject> object, Handle<FixedArrayBase> backing_store,
Handle<FixedArray> keys, GetKeysConversion convert,
PropertyFilter filter) final {
return Subclass::PrependElementIndicesImpl(object, backing_store, keys,
convert, filter);
}
static MaybeHandle<FixedArray> PrependElementIndicesImpl(
Handle<JSObject> object, Handle<FixedArrayBase> backing_store,
Handle<FixedArray> 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<FixedArray>(isolate->factory()->NewRangeError(
MessageTemplate::kInvalidArrayLength));
}
// Collect the element indices into a new list.
MaybeHandle<FixedArray> raw_array =
isolate->factory()->TryNewFixedArray(initial_list_length);
Handle<FixedArray> 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<Object> 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;
}
V8_WARN_UNUSED_RESULT ExceptionStatus AddElementsToKeyAccumulator(
Handle<JSObject> receiver, KeyAccumulator* accumulator,
AddKeyConversion convert) final {
return 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<JSObject> receiver, Handle<Object> obj_value,
uint32_t start, uint32_t end) {
UNREACHABLE();
}
Object Fill(Handle<JSObject> receiver, Handle<Object> obj_value,
uint32_t start, uint32_t end) override {
return Subclass::FillImpl(receiver, obj_value, start, end);
}
static Maybe<bool> IncludesValueImpl(Isolate* isolate,
Handle<JSObject> receiver,
Handle<Object> value,
uint32_t start_from, uint32_t length) {
return IncludesValueSlowPath(isolate, receiver, value, start_from, length);
}
Maybe<bool> IncludesValue(Isolate* isolate, Handle<JSObject> receiver,
Handle<Object> value, uint32_t start_from,
uint32_t length) final {
return Subclass::IncludesValueImpl(isolate, receiver, value, start_from,
length);
}
static Maybe<int64_t> IndexOfValueImpl(Isolate* isolate,
Handle<JSObject> receiver,
Handle<Object> value,
uint32_t start_from, uint32_t length) {
return IndexOfValueSlowPath(isolate, receiver, value, start_from, length);
}
Maybe<int64_t> IndexOfValue(Isolate* isolate, Handle<JSObject> receiver,
Handle<Object> value, uint32_t start_from,
uint32_t length) final {
return Subclass::IndexOfValueImpl(isolate, receiver, value, start_from,
length);
}
static Maybe<int64_t> LastIndexOfValueImpl(Handle<JSObject> receiver,
Handle<Object> value,
uint32_t start_from) {
UNREACHABLE();
}
Maybe<int64_t> LastIndexOfValue(Handle<JSObject> receiver,
Handle<Object> 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()) ||
IsAnyNonextensibleElementsKind(kind()));
uint32_t length = Subclass::GetMaxIndex(holder, backing_store);
if (IsHoleyElementsKindForRead(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<FixedArray> CreateListFromArrayLike(Isolate* isolate,
Handle<JSObject> object,
uint32_t length) final {
return Subclass::CreateListFromArrayLikeImpl(isolate, object, length);
}
static Handle<FixedArray> CreateListFromArrayLikeImpl(Isolate* isolate,
Handle<JSObject> object,
uint32_t length) {
UNREACHABLE();
}
private:
DISALLOW_COPY_AND_ASSIGN(ElementsAccessorBase);
};
class DictionaryElementsAccessor
: public ElementsAccessorBase<DictionaryElementsAccessor,
ElementsKindTraits<DICTIONARY_ELEMENTS>> {
public:
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<JSArray> array,
uint32_t length,
Handle<FixedArrayBase> backing_store) {
Handle<NumberDictionary> dict =
Handle<NumberDictionary>::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<uint32_t>(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<uint32_t>(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<Object> 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 void DeleteImpl(Handle<JSObject> obj, uint32_t entry) {
Handle<NumberDictionary> 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<Object> GetImpl(Isolate* isolate, FixedArrayBase backing_store,
uint32_t entry) {
return handle(GetRaw(backing_store, entry), isolate);
}
static inline void SetImpl(Handle<JSObject> 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<JSObject> object,
Handle<FixedArrayBase> store, uint32_t entry,
Handle<Object> 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<JSObject> object, uint32_t index,
Handle<Object> value, PropertyAttributes attributes,
uint32_t new_capacity) {
PropertyDetails details(kData, attributes, PropertyCellType::kNoCell);
Handle<NumberDictionary> dictionary =
object->HasFastElements() || object->HasFastStringWrapperElements()
? JSObject::NormalizeElements(object)
: handle(NumberDictionary::cast(object->elements()),
object->GetIsolate());
Handle<NumberDictionary> 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<uint32_t>(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<NumberDictionary> 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<uint32_t>(raw_key.Number());
}
static uint32_t GetKeyForEntryImpl(Isolate* isolate,
Handle<NumberDictionary> 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);
}
V8_WARN_UNUSED_RESULT static ExceptionStatus CollectElementIndicesImpl(
Handle<JSObject> object, Handle<FixedArrayBase> backing_store,
KeyAccumulator* keys) {
if (keys->filter() & SKIP_STRINGS) return ExceptionStatus::kSuccess;
Isolate* isolate = keys->isolate();
Handle<NumberDictionary> dictionary =
Handle<NumberDictionary>::cast(backing_store);
int capacity = dictionary->Capacity();
Handle<FixedArray> 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++) {
RETURN_FAILURE_IF_NOT_SUCCESSFUL(keys->AddKey(elements->get(i)));
}
return ExceptionStatus::kSuccess;
}
static Handle<FixedArray> DirectCollectElementIndicesImpl(
Isolate* isolate, Handle<JSObject> object,
Handle<FixedArrayBase> backing_store, GetKeysConversion convert,
PropertyFilter filter, Handle<FixedArray> 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<NumberDictionary> dictionary =
Handle<NumberDictionary>::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<Object> index = isolate->factory()->NewNumberFromUint(key);
list->set(insertion_index, *index);
insertion_index++;
}
*nof_indices = insertion_index;
return list;
}
V8_WARN_UNUSED_RESULT static ExceptionStatus AddElementsToKeyAccumulatorImpl(
Handle<JSObject> receiver, KeyAccumulator* accumulator,
AddKeyConversion convert) {
Isolate* isolate = accumulator->isolate();
Handle<NumberDictionary> 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());
RETURN_FAILURE_IF_NOT_SUCCESSFUL(accumulator->AddKey(value, convert));
}
return ExceptionStatus::kSuccess;
}
static bool IncludesValueFastPath(Isolate* isolate, Handle<JSObject> receiver,
Handle<Object> value, uint32_t start_from,
uint32_t length, Maybe<bool>* 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<bool> IncludesValueImpl(Isolate* isolate,
Handle<JSObject> receiver,
Handle<Object> 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<bool> result = Nothing<bool>();
if (DictionaryElementsAccessor::IncludesValueFastPath(
isolate, receiver, value, start_from, length, &result)) {
return result;
}
}
ElementsKind original_elements_kind = receiver->GetElementsKind();
USE(original_elements_kind);
Handle<NumberDictionary> 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<Object> element_k;
ASSIGN_RETURN_ON_EXCEPTION_VALUE(isolate, element_k,
Object::GetPropertyWithAccessor(&it),
Nothing<bool>());
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<int64_t> IndexOfValueImpl(Isolate* isolate,
Handle<JSObject> receiver,
Handle<Object> value,
uint32_t start_from, uint32_t length) {
DCHECK(JSObject::PrototypeHasNoElements(isolate, *receiver));
ElementsKind original_elements_kind = receiver->GetElementsKind();
USE(original_elements_kind);
Handle<NumberDictionary> 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<int64_t>(k);
}
break;
}
case kAccessor: {
LookupIterator it(isolate, receiver, k,
LookupIterator::OWN_SKIP_INTERCEPTOR);
DCHECK(it.IsFound());
DCHECK_EQ(it.state(), LookupIterator::ACCESSOR);
Handle<Object> element_k;
ASSIGN_RETURN_ON_EXCEPTION_VALUE(isolate, element_k,
Object::GetPropertyWithAccessor(&it),
Nothing<int64_t>());
if (value->StrictEquals(*element_k)) return Just<int64_t>(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<int64_t>(-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 <typename Subclass, typename KindTraits>
class FastElementsAccessor : public ElementsAccessorBase<Subclass, KindTraits> {
public:
using BackingStore = typename KindTraits::BackingStore;
static Handle<NumberDictionary> NormalizeImpl(Handle<JSObject> object,
Handle<FixedArrayBase> 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<NumberDictionary> 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 (IsHoleyElementsKindForRead(kind)) {
if (BackingStore::cast(*store).is_the_hole(isolate, i)) continue;
}
max_number_key = i;
Handle<Object> value = Subclass::GetImpl(isolate, *store, i);
dictionary =
NumberDictionary::Add(isolate, dictionary, i, value, details);
j++;
}
if (max_number_key > 0) {
dictionary->UpdateMaxNumberKey(static_cast<uint32_t>(max_number_key),
object);
}
return dictionary;
}
static void DeleteAtEnd(Handle<JSObject> obj,
Handle<BackingStore> backing_store, uint32_t entry) {
uint32_t length = static_cast<uint32_t>(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<JSObject> obj, uint32_t entry,
Handle<FixedArrayBase> store) {
DCHECK(obj->HasSmiOrObjectElements() || obj->HasDoubleElements() ||
obj->HasNonextensibleElements() || obj->HasFastArgumentsElements() ||
obj->HasFastStringWrapperElements());
Handle<BackingStore> backing_store = Handle<BackingStore>::cast(store);
if (!obj->IsJSArray() &&
entry == static_cast<uint32_t>(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;
// TODO(ulan): Check if it works with young large objects.
if (ObjectInYoungGeneration(*backing_store)) return;
uint32_t length = 0;
if (obj->IsJSArray()) {
JSArray::cast(*obj).length().ToArrayLength(&length);
} else {
length = static_cast<uint32_t>(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<uint32_t>(backing_store->length())) {
return;
}
}
}
JSObject::NormalizeElements(obj);
}
static void ReconfigureImpl(Handle<JSObject> object,
Handle<FixedArrayBase> store, uint32_t entry,
Handle<Object> value,
PropertyAttributes attributes) {
Handle<NumberDictionary> dictionary = JSObject::NormalizeElements(object);
entry = dictionary->FindEntry(object->GetIsolate(), entry);
DictionaryElementsAccessor::ReconfigureImpl(object, dictionary, entry,
value, attributes);
}
static void AddImpl(Handle<JSObject> object, uint32_t index,
Handle<Object> 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<JSObject> obj, uint32_t entry) {
ElementsKind kind = KindTraits::Kind;
if (IsFastPackedElementsKind(kind) ||
kind == PACKED_NONEXTENSIBLE_ELEMENTS) {
JSObject::TransitionElementsKind(obj, GetHoleyElementsKind(kind));
}
if (IsSmiOrObjectElementsKind(KindTraits::Kind) ||
IsNonextensibleElementsKind(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;
}
V8_WARN_UNUSED_RESULT static ExceptionStatus AddElementsToKeyAccumulatorImpl(
Handle<JSObject> receiver, KeyAccumulator* accumulator,
AddKeyConversion convert) {
Isolate* isolate = accumulator->isolate();
Handle<FixedArrayBase> 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)) {
RETURN_FAILURE_IF_NOT_SUCCESSFUL(accumulator->AddKey(
Subclass::GetImpl(isolate, *elements, i), convert));
}
}
return ExceptionStatus::kSuccess;
}
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<Object> PopImpl(Handle<JSArray> receiver) {
return Subclass::RemoveElement(receiver, AT_END);
}
static Handle<Object> ShiftImpl(Handle<JSArray> receiver) {
return Subclass::RemoveElement(receiver, AT_START);
}
static uint32_t PushImpl(Handle<JSArray> receiver, Arguments* args,
uint32_t push_size) {
Handle<FixedArrayBase> backing_store(receiver->elements(),
receiver->GetIsolate());
return Subclass::AddArguments(receiver, backing_store, args, push_size,
AT_END);
}
static uint32_t UnshiftImpl(Handle<JSArray> receiver, Arguments* args,
uint32_t unshift_size) {
Handle<FixedArrayBase> backing_store(receiver->elements(),
receiver->GetIsolate());
return Subclass::AddArguments(receiver, backing_store, args, unshift_size,
AT_START);
}
static void MoveElements(Isolate* isolate, Handle<JSArray> receiver,
Handle<FixedArrayBase> backing_store, int dst_index,
int src_index, int len, int hole_start,
int hole_end) {
Handle<BackingStore> dst_elms = Handle<BackingStore>::cast(backing_store);
if (len > JSArray::kMaxCopyElements && dst_index == 0 &&
isolate->heap()->CanMoveObjectStart(*dst_elms)) {
// Update all the copies of this backing_store handle.
*dst_elms.location() =
BackingStore::cast(
isolate->heap()->LeftTrimFixedArray(*dst_elms, src_index))
.ptr();
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) {
WriteBarrierMode mode = GetWriteBarrierMode(KindTraits::Kind);
dst_elms->MoveElements(isolate, dst_index, src_index, len, mode);
}
if (hole_start != hole_end) {
dst_elms->FillWithHoles(hole_start, hole_end);
}
}
static Object FillImpl(Handle<JSObject> receiver, Handle<Object> 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<bool> IncludesValueImpl(Isolate* isolate,
Handle<JSObject> receiver,
Handle<Object> 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;
if (start_from >= length) return Just(false);
// Elements beyond the capacity of the backing store treated as undefined.
uint32_t elements_length = static_cast<uint32_t>(elements_base.length());
if (value == undefined && elements_length < length) return Just(true);
if (elements_length == 0) {
DCHECK_NE(value, undefined);
return Just(false);
}
length = std::min(elements_length, length);
if (!value.IsNumber()) {
if (value == undefined) {
// Search for `undefined` or The Hole. Even in the case of
// PACKED_DOUBLE_ELEMENTS or PACKED_SMI_ELEMENTS, we might encounter The
// Hole here, since the {length} used here can be larger than
// JSArray::length.
if (IsSmiOrObjectElementsKind(Subclass::kind()) ||
IsAnyNonextensibleElementsKind(Subclass::kind())) {
auto elements = FixedArray::cast(receiver->elements());
for (uint32_t k = start_from; k < length; ++k) {
Object element_k = elements.get(k);
if (element_k == the_hole || element_k == undefined) {
return Just(true);
}
}
return Just(false);
} else {
// Search for The Hole in HOLEY_DOUBLE_ELEMENTS or
// PACKED_DOUBLE_ELEMENTS.
DCHECK(IsDoubleElementsKind(Subclass::kind()));
auto elements = FixedDoubleArray::cast(receiver->elements());
for (uint32_t k = start_from; k < length; ++k) {
if (elements.is_the_hole(k)) {
return Just(true);
}
}
return Just(false);
}
} else if (!IsObjectElementsKind(Subclass::kind()) &&
!IsAnyNonextensibleElementsKind(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()) ||
IsAnyNonextensibleElementsKind(Subclass::kind()));
auto elements = FixedArray::cast(receiver->elements());
for (uint32_t k = start_from; k < length; ++k) {
Object element_k = elements.get(k);
if (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 (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 (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()) ||
IsAnyNonextensibleElementsKind(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<FixedArray> CreateListFromArrayLikeImpl(Isolate* isolate,
Handle<JSObject> object,
uint32_t length) {
Handle<FixedArray> result = isolate->factory()->NewFixedArray(length);
Handle<FixedArrayBase> elements(object->elements(), isolate);
for (uint32_t i = 0; i < length; i++) {
if (!Subclass::HasElementImpl(isolate, *object, i, *elements)) continue;
Handle<Object> value;
value = Subclass::GetImpl(isolate, *elements, i);
if (value->IsName()) {
value = isolate->factory()->InternalizeName(Handle<Name>::cast(value));
}
result->set(i, *value);
}
return result;
}
static Handle<Object> RemoveElement(Handle<JSArray> receiver,
Where remove_position) {
Isolate* isolate = receiver->GetIsolate();
ElementsKind kind = KindTraits::Kind;
if (IsSmiOrObjectElementsKind(kind)) {
HandleScope scope(isolate);
JSObject::EnsureWritableFastElements(receiver);
}
Handle<FixedArrayBase> backing_store(receiver->elements(), isolate);
uint32_t length = static_cast<uint32_t>(Smi::ToInt(receiver->length()));
DCHECK_GT(length, 0);
int new_length = length - 1;
int remove_index = remove_position == AT_START ? 0 : new_length;
Handle<Object> 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<JSArray> receiver,
Handle<FixedArrayBase> 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<uint32_t>(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);
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<FixedArrayBase> 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 <typename Subclass, typename KindTraits>
class FastSmiOrObjectElementsAccessor
: public FastElementsAccessor<Subclass, KindTraits> {
public:
static inline void SetImpl(Handle<JSObject> 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 PACKED_FROZEN_ELEMENTS:
case PACKED_SEALED_ELEMENTS:
case PACKED_NONEXTENSIBLE_ELEMENTS:
case HOLEY_ELEMENTS:
case HOLEY_FROZEN_ELEMENTS:
case HOLEY_SEALED_ELEMENTS:
case HOLEY_NONEXTENSIBLE_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();
case NO_ELEMENTS:
break; // Nothing to do.
}
}
static Maybe<bool> CollectValuesOrEntriesImpl(
Isolate* isolate, Handle<JSObject> object,
Handle<FixedArray> 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<FixedArray> 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<Object> 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<int64_t> IndexOfValueImpl(Isolate* isolate,
Handle<JSObject> receiver,
Handle<Object> 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<int64_t>(-1);
length = std::min(static_cast<uint32_t>(elements_base.length()), length);
// Only FAST_{,HOLEY_}ELEMENTS can store non-numbers.
if (!value.IsNumber() && !IsObjectElementsKind(Subclass::kind()) &&
!IsAnyNonextensibleElementsKind(Subclass::kind())) {
return Just<int64_t>(-1);
}
// NaN can never be found by strict equality.
if (value.IsNaN()) return Just<int64_t>(-1);
// k can be greater than receiver->length() below, but it is bounded by
// elements_base->length() so we never read out of bounds. This means that
// elements->get(k) can return the hole, for which the StrictEquals will
// always fail.
FixedArray elements = FixedArray::cast(receiver->elements());
for (uint32_t k = start_from; k < length; ++k) {
if (value.StrictEquals(elements.get(k))) return Just<int64_t>(k);
}
return Just<int64_t>(-1);
}
};
class FastPackedSmiElementsAccessor
: public FastSmiOrObjectElementsAccessor<
FastPackedSmiElementsAccessor,
ElementsKindTraits<PACKED_SMI_ELEMENTS>> {};
class FastHoleySmiElementsAccessor
: public FastSmiOrObjectElementsAccessor<
FastHoleySmiElementsAccessor,
ElementsKindTraits<HOLEY_SMI_ELEMENTS>> {};
class FastPackedObjectElementsAccessor
: public FastSmiOrObjectElementsAccessor<
FastPackedObjectElementsAccessor,
ElementsKindTraits<PACKED_ELEMENTS>> {};
template <typename Subclass, typename KindTraits>
class FastNonextensibleObjectElementsAccessor
: public FastSmiOrObjectElementsAccessor<Subclass, KindTraits> {
public:
using BackingStore = typename KindTraits::BackingStore;
static uint32_t PushImpl(Handle<JSArray> receiver, Arguments* args,
uint32_t push_size) {
UNREACHABLE();
}
static void AddImpl(Handle<JSObject> object, uint32_t index,
Handle<Object> value, PropertyAttributes attributes,
uint32_t new_capacity) {
UNREACHABLE();
}
// TODO(duongn): refactor this due to code duplication of sealed version.
// Consider using JSObject::NormalizeElements(). Also consider follow the fast
// element logic instead of changing to dictionary mode.
static void SetLengthImpl(Isolate* isolate, Handle<JSArray> array,
uint32_t length,
Handle<FixedArrayBase> backing_store) {
uint32_t old_length = 0;
CHECK(array->length().ToArrayIndex(&old_length));
if (length == old_length) {
// Do nothing.
return;
}
// Transition to DICTIONARY_ELEMENTS.
// Convert to dictionary mode.
Handle<NumberDictionary> new_element_dictionary =
old_length == 0 ? isolate->factory()->empty_slow_element_dictionary()
: array->GetElementsAccessor()->Normalize(array);
// Migrate map.
Handle<Map> new_map = Map::Copy(isolate, handle(array->map(), isolate),
"SlowCopyForSetLengthImpl");
new_map->set_is_extensible(false);
new_map->set_elements_kind(DICTIONARY_ELEMENTS);
JSObject::MigrateToMap(isolate, array, new_map);
if (!new_element_dictionary.is_null()) {
array->set_elements(*new_element_dictionary);
}
if (array->elements() !=
ReadOnlyRoots(isolate).empty_slow_element_dictionary()) {
Handle<NumberDictionary> dictionary(array->element_dictionary(), isolate);
// Make sure we never go back to the fast case
array->RequireSlowElements(*dictionary);
JSObject::ApplyAttributesToDictionary(isolate, ReadOnlyRoots(isolate),
dictionary,
PropertyAttributes::NONE);
}
// Set length.
Handle<FixedArrayBase> new_backing_store(array->elements(), isolate);
DictionaryElementsAccessor::SetLengthImpl(isolate, array, length,
new_backing_store);
}
};
class FastPackedNonextensibleObjectElementsAccessor
: public FastNonextensibleObjectElementsAccessor<
FastPackedNonextensibleObjectElementsAccessor,
ElementsKindTraits<PACKED_NONEXTENSIBLE_ELEMENTS>> {};
class FastHoleyNonextensibleObjectElementsAccessor
: public FastNonextensibleObjectElementsAccessor<
FastHoleyNonextensibleObjectElementsAccessor,
ElementsKindTraits<HOLEY_NONEXTENSIBLE_ELEMENTS>> {};
template <typename Subclass, typename KindTraits>
class FastSealedObjectElementsAccessor
: public FastSmiOrObjectElementsAccessor<Subclass, KindTraits> {
public:
using BackingStore = typename KindTraits::BackingStore;
static Handle<Object> RemoveElement(Handle<JSArray> receiver,
Where remove_position) {
UNREACHABLE();
}
static void DeleteImpl(Handle<JSObject> obj, uint32_t entry) {
UNREACHABLE();
}
static void DeleteAtEnd(Handle<JSObject> obj,
Handle<BackingStore> backing_store, uint32_t entry) {
UNREACHABLE();
}
static void DeleteCommon(Handle<JSObject> obj, uint32_t entry,
Handle<FixedArrayBase> store) {
UNREACHABLE();
}
static Handle<Object> PopImpl(Handle<JSArray> receiver) { UNREACHABLE(); }
static uint32_t PushImpl(Handle<JSArray> receiver, Arguments* args,
uint32_t push_size) {
UNREACHABLE();
}
static void AddImpl(Handle<JSObject> object, uint32_t index,
Handle<Object> value, PropertyAttributes attributes,
uint32_t new_capacity) {
UNREACHABLE();
}
// TODO(duongn): refactor this due to code duplication of nonextensible
// version. Consider using JSObject::NormalizeElements(). Also consider follow
// the fast element logic instead of changing to dictionary mode.
static void SetLengthImpl(Isolate* isolate, Handle<JSArray> array,
uint32_t length,
Handle<FixedArrayBase> backing_store) {
uint32_t old_length = 0;
CHECK(array->length().ToArrayIndex(&old_length));
if (length == old_length) {
// Do nothing.
return;
}
// Transition to DICTIONARY_ELEMENTS.
// Convert to dictionary mode
Handle<NumberDictionary> new_element_dictionary =
old_length == 0 ? isolate->factory()->empty_slow_element_dictionary()
: array->GetElementsAccessor()->Normalize(array);
// Migrate map.
Handle<Map> new_map = Map::Copy(isolate, handle(array->map(), isolate),
"SlowCopyForSetLengthImpl");
new_map->set_is_extensible(false);
new_map->set_elements_kind(DICTIONARY_ELEMENTS);
JSObject::MigrateToMap(isolate, array, new_map);
if (!new_element_dictionary.is_null()) {
array->set_elements(*new_element_dictionary);
}
if (array->elements() !=
ReadOnlyRoots(isolate).empty_slow_element_dictionary()) {
Handle<NumberDictionary> dictionary(array->element_dictionary(), isolate);
// Make sure we never go back to the fast case
array->RequireSlowElements(*dictionary);
JSObject::ApplyAttributesToDictionary(isolate, ReadOnlyRoots(isolate),
dictionary,
PropertyAttributes::SEALED);
}
// Set length
Handle<FixedArrayBase> new_backing_store(array->elements(), isolate);
DictionaryElementsAccessor::SetLengthImpl(isolate, array, length,
new_backing_store);
}
};
class FastPackedSealedObjectElementsAccessor
: public FastSealedObjectElementsAccessor<
FastPackedSealedObjectElementsAccessor,
ElementsKindTraits<PACKED_SEALED_ELEMENTS>> {
};
class FastHoleySealedObjectElementsAccessor
: public FastSealedObjectElementsAccessor<
FastHoleySealedObjectElementsAccessor,
ElementsKindTraits<HOLEY_SEALED_ELEMENTS>> {
};
template <typename Subclass, typename KindTraits>
class FastFrozenObjectElementsAccessor
: public FastSmiOrObjectElementsAccessor<Subclass, KindTraits> {
public:
using BackingStore = typename KindTraits::BackingStore;
static inline void SetImpl(Handle<JSObject> holder, uint32_t entry,
Object value) {
UNREACHABLE();
}
static inline void SetImpl(FixedArrayBase backing_store, uint32_t entry,
Object value) {
UNREACHABLE();
}
static inline void SetImpl(FixedArrayBase backing_store, uint32_t entry,
Object value, WriteBarrierMode mode) {
UNREACHABLE();
}
static Handle<Object> RemoveElement(Handle<JSArray> receiver,
Where remove_position) {
UNREACHABLE();
}
static void DeleteImpl(Handle<JSObject> obj, uint32_t entry) {
UNREACHABLE();
}
static void DeleteAtEnd(Handle<JSObject> obj,
Handle<BackingStore> backing_store, uint32_t entry) {
UNREACHABLE();
}
static void DeleteCommon(Handle<JSObject> obj, uint32_t entry,
Handle<FixedArrayBase> store) {
UNREACHABLE();
}
static Handle<Object> PopImpl(Handle<JSArray> receiver) { UNREACHABLE(); }
static uint32_t PushImpl(Handle<JSArray> receiver, Arguments* args,
uint32_t push_size) {
UNREACHABLE();
}
static void AddImpl(Handle<JSObject> object, uint32_t index,
Handle<Object> value, PropertyAttributes attributes,
uint32_t new_capacity) {
UNREACHABLE();
}
static void SetLengthImpl(Isolate* isolate, Handle<JSArray> array,
uint32_t length,
Handle<FixedArrayBase> backing_store) {
UNREACHABLE();
}
static void ReconfigureImpl(Handle<JSObject> object,
Handle<FixedArrayBase> store, uint32_t entry,
Handle<Object> value,
PropertyAttributes attributes) {
UNREACHABLE();
}
};
class FastPackedFrozenObjectElementsAccessor
: public FastFrozenObjectElementsAccessor<
FastPackedFrozenObjectElementsAccessor,
ElementsKindTraits<PACKED_FROZEN_ELEMENTS>> {
};
class FastHoleyFrozenObjectElementsAccessor
: public FastFrozenObjectElementsAccessor<
FastHoleyFrozenObjectElementsAccessor,
ElementsKindTraits<HOLEY_FROZEN_ELEMENTS>> {
};
class FastHoleyObjectElementsAccessor
: public FastSmiOrObjectElementsAccessor<
FastHoleyObjectElementsAccessor, ElementsKindTraits<HOLEY_ELEMENTS>> {
};
template <typename Subclass, typename KindTraits>
class FastDoubleElementsAccessor
: public FastElementsAccessor<Subclass, KindTraits> {
public:
static Handle<Object> GetImpl(Isolate* isolate, FixedArrayBase backing_store,
uint32_t entry) {
return FixedDoubleArray::get(FixedDoubleArray::cast(backing_store), entry,
isolate);
}
static inline void SetImpl(Handle<JSObject> 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 PACKED_FROZEN_ELEMENTS:
case PACKED_SEALED_ELEMENTS:
case PACKED_NONEXTENSIBLE_ELEMENTS:
case HOLEY_ELEMENTS:
case HOLEY_FROZEN_ELEMENTS:
case HOLEY_SEALED_ELEMENTS:
case HOLEY_NONEXTENSIBLE_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();
}
}
static Maybe<bool> CollectValuesOrEntriesImpl(
Isolate* isolate, Handle<JSObject> object,
Handle<FixedArray> values_or_entries, bool get_entries, int* nof_items,
PropertyFilter filter) {
Handle<FixedDoubleArray> 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<Object> 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<int64_t> IndexOfValueImpl(Isolate* isolate,
Handle<JSObject> receiver,
Handle<Object> 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<uint32_t>(elements_base.length()), length);
if (start_from >= length) return Just<int64_t>(-1);
if (!value.IsNumber()) {
return Just<int64_t>(-1);
}
if (value.IsNaN()) {
return Just<int64_t>(-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<int64_t>(k);
}
}
return Just<int64_t>(-1);
}
};
class FastPackedDoubleElementsAccessor
: public FastDoubleElementsAccessor<
FastPackedDoubleElementsAccessor,
ElementsKindTraits<PACKED_DOUBLE_ELEMENTS>> {};
class FastHoleyDoubleElementsAccessor
: public FastDoubleElementsAccessor<
FastHoleyDoubleElementsAccessor,
ElementsKindTraits<HOLEY_DOUBLE_ELEMENTS>> {};
// Super class for all external element arrays.
template <ElementsKind Kind, typename ElementType>
class TypedElementsAccessor
: public ElementsAccessorBase<TypedElementsAccessor<Kind, ElementType>,
ElementsKindTraits<Kind>> {
public:
using BackingStore = typename ElementsKindTraits<Kind>::BackingStore;
using AccessorClass = TypedElementsAccessor<Kind, ElementType>;
// Conversions from (other) scalar values.
static ElementType FromScalar(int value) {
return static_cast<ElementType>(value);
}
static ElementType FromScalar(uint32_t value) {
return static_cast<ElementType>(value);
}
static ElementType FromScalar(double value) {
return FromScalar(DoubleToInt32(value));
}
static ElementType FromScalar(int64_t value) { UNREACHABLE(); }
static ElementType FromScalar(uint64_t value) { UNREACHABLE(); }
// Conversions from objects / handles.
static ElementType FromObject(Object value, bool* lossless = nullptr) {
if (value.IsSmi()) {
return FromScalar(Smi::ToInt(value));
} else if (value.IsHeapNumber()) {
return FromScalar(HeapNumber::cast(value).value());
} else {
// Clamp undefined here as well. All other types have been
// converted to a number type further up in the call chain.
DCHECK(value.IsUndefined());
return FromScalar(Oddball::cast(value).to_number_raw());
}
}
static ElementType FromHandle(Handle<Object> value,
bool* lossless = nullptr) {
return FromObject(*value, lossless);
}
// Conversion of scalar value to handlified object.
static Handle<Object> ToHandle(Isolate* isolate, ElementType value);
static void SetImpl(Handle<JSObject> holder, uint32_t entry, Object value) {
Handle<JSTypedArray> typed_array = Handle<JSTypedArray>::cast(holder);
DCHECK_LE(entry, typed_array->length());
SetImpl(static_cast<ElementType*>(typed_array->DataPtr()), entry,
FromObject(value));
}
static void SetImpl(ElementType* data_ptr, size_t entry, ElementType value) {
// The JavaScript memory model allows for racy reads and writes to a
// SharedArrayBuffer's backing store. ThreadSanitizer will catch these
// racy accesses and warn about them, so we disable TSAN for these reads
// and writes using annotations.
//
// We don't use relaxed atomics here, as it is not a requirement of the
// JavaScript memory model to have tear-free reads of overlapping accesses,
// and using relaxed atomics may introduce overhead.
TSAN_ANNOTATE_IGNORE_WRITES_BEGIN;
if (COMPRESS_POINTERS_BOOL && alignof(ElementType) > kTaggedSize) {
// TODO(ishell, v8:8875): When pointer compression is enabled 8-byte size
// fields (external pointers, doubles and BigInt data) are only
// kTaggedSize aligned so we have to use unaligned pointer friendly way of
// accessing them in order to avoid undefined behavior in C++ code.
base::WriteUnalignedValue<ElementType>(
reinterpret_cast<Address>(data_ptr + entry), value);
} else {
data_ptr[entry] = value;
}
TSAN_ANNOTATE_IGNORE_WRITES_END;
}
static Handle<Object> GetInternalImpl(Handle<JSObject> holder,
uint32_t entry) {
Handle<JSTypedArray> typed_array = Handle<JSTypedArray>::cast(holder);
Isolate* isolate = typed_array->GetIsolate();
DCHECK_LE(entry, typed_array->length());
DCHECK(!typed_array->WasDetached());
ElementType elem =
GetImpl(static_cast<ElementType*>(typed_array->DataPtr()), entry);
return ToHandle(isolate, elem);
}
static Handle<Object> GetImpl(Isolate* isolate, FixedArrayBase backing_store,
uint32_t entry) {
UNREACHABLE();
}
static ElementType GetImpl(ElementType* data_ptr, size_t entry) {
// The JavaScript memory model allows for racy reads and writes to a
// SharedArrayBuffer's backing store. ThreadSanitizer will catch these
// racy accesses and warn about them, so we disable TSAN for these reads
// and writes using annotations.
//
// We don't use relaxed atomics here, as it is not a requirement of the
// JavaScript memory model to have tear-free reads of overlapping accesses,
// and using relaxed atomics may introduce overhead.
TSAN_ANNOTATE_IGNORE_READS_BEGIN;
ElementType result;
if (COMPRESS_POINTERS_BOOL && alignof(ElementType) > kTaggedSize) {
// TODO(ishell, v8:8875): When pointer compression is enabled 8-byte size
// fields (external pointers, doubles and BigInt data) are only
// kTaggedSize aligned so we have to use unaligned pointer friendly way of
// accessing them in order to avoid undefined behavior in C++ code.
result = base::ReadUnalignedValue<ElementType>(
reinterpret_cast<Address>(data_ptr + entry));
} else {
result = data_ptr[entry];
}
TSAN_ANNOTATE_IGNORE_READS_END;
return result;
}
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<JSArray> array,
uint32_t length,
Handle<FixedArrayBase> backing_store) {
// External arrays do not support changing their length.
UNREACHABLE();
}
static void DeleteImpl(Handle<JSObject> 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 uint32_t GetCapacityImpl(JSObject holder,
FixedArrayBase backing_store) {
JSTypedArray typed_array = JSTypedArray::cast(holder);
if (typed_array.WasDetached()) return 0;
// TODO(bmeurer, v8:4153): We need to support arbitrary size_t here.
return static_cast<uint32_t>(typed_array.length());
}
static uint32_t NumberOfElementsImpl(JSObject receiver,
FixedArrayBase backing_store) {
return AccessorClass::GetCapacityImpl(receiver, backing_store);
}
V8_WARN_UNUSED_RESULT static ExceptionStatus AddElementsToKeyAccumulatorImpl(
Handle<JSObject> receiver, KeyAccumulator* accumulator,
AddKeyConversion convert) {
Isolate* isolate = receiver->GetIsolate();
Handle<FixedArrayBase> elements(receiver->elements(), isolate);
uint32_t length = AccessorClass::GetCapacityImpl(*receiver, *elements);
for (uint32_t i = 0; i < length; i++) {
Handle<Object> value = AccessorClass::GetInternalImpl(receiver, i);
RETURN_FAILURE_IF_NOT_SUCCESSFUL(accumulator->AddKey(value, convert));
}
return ExceptionStatus::kSuccess;
}
static Maybe<bool> CollectValuesOrEntriesImpl(
Isolate* isolate, Handle<JSObject> object,
Handle<FixedArray> values_or_entries, bool get_entries, int* nof_items,
PropertyFilter filter) {
int count = 0;
if ((filter & ONLY_CONFIGURABLE) == 0) {
Handle<FixedArrayBase> elements(object->elements(), isolate);
uint32_t length = AccessorClass::GetCapacityImpl(*object, *elements);
for (uint32_t index = 0; index < length; ++index) {
Handle<Object> value = AccessorClass::GetInternalImpl(object, 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<JSObject> receiver, Handle<Object> value,
uint32_t start, uint32_t end) {
Handle<JSTypedArray> typed_array = Handle<JSTypedArray>::cast(receiver);
DCHECK(!typed_array->WasDetached());
DCHECK_LE(0, start);
DCHECK_LE(start, end);
DCHECK_LE(end, typed_array->length());
DisallowHeapAllocation no_gc;
ElementType scalar = FromHandle(value);
ElementType* data = static_cast<ElementType*>(typed_array->DataPtr());
if (COMPRESS_POINTERS_BOOL && alignof(ElementType) > kTaggedSize) {
// TODO(ishell, v8:8875): See UnalignedSlot<T> for details.
std::fill(UnalignedSlot<ElementType>(data + start),
UnalignedSlot<ElementType>(data + end), scalar);
} else {
std::fill(data + start, data + end, scalar);
}
return *typed_array;
}
static Maybe<bool> IncludesValueImpl(Isolate* isolate,
Handle<JSObject> receiver,
Handle<Object> value,
uint32_t start_from, uint32_t length) {
DisallowHeapAllocation no_gc;
JSTypedArray typed_array = JSTypedArray::cast(*receiver);
// TODO(caitp): return Just(false) here when implementing strict throwing on
// detached views.
if (typed_array.WasDetached()) {
return Just(value->IsUndefined(isolate) && length > start_from);
}
if (value->IsUndefined(isolate) && length > typed_array.length()) {
return Just(true);
}
// Prototype has no elements, and not searching for the hole --- limit
// search to backing store length.
if (typed_array.length() < length) {
// TODO(bmeurer, v8:4153): Don't cast to uint32_t here.
length = static_cast<uint32_t>(typed_array.length());
}
ElementType typed_search_value;
ElementType* data_ptr =
reinterpret_cast<ElementType*>(typed_array.DataPtr());
if (Kind == BIGINT64_ELEMENTS || Kind == BIGUINT64_ELEMENTS) {
if (!value->IsBigInt()) return Just(false);
bool lossless;
typed_search_value = 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 elem_k =
static_cast<double>(AccessorClass::GetImpl(data_ptr, k));
if (std::isnan(elem_k)) return Just(true);
}
return Just(false);
}
} else if (search_value < std::numeric_limits<ElementType>::lowest() ||
search_value > std::numeric_limits<ElementType>::max()) {
// Return false if value can't be represented in this space.
return Just(false);
}
typed_search_value = static_cast<ElementType>(search_value);
if (static_cast<double>(typed_search_value) != search_value) {
return Just(false); // Loss of precision.
}
}
for (uint32_t k = start_from; k < length; ++k) {
ElementType elem_k = AccessorClass::GetImpl(data_ptr, k);
if (elem_k == typed_search_value) return Just(true);
}
return Just(false);
}
static Maybe<int64_t> IndexOfValueImpl(Isolate* isolate,
Handle<JSObject> receiver,
Handle<Object> value,
uint32_t start_from, uint32_t length) {
DisallowHeapAllocation no_gc;
JSTypedArray typed_array = JSTypedArray::cast(*receiver);
if (typed_array.WasDetached()) return Just<int64_t>(-1);
ElementType typed_search_value;
ElementType* data_ptr =
reinterpret_cast<ElementType*>(typed_array.DataPtr());
if (Kind == BIGINT64_ELEMENTS || Kind == BIGUINT64_ELEMENTS) {
if (!value->IsBigInt()) return Just<int64_t>(-1);
bool lossless;
typed_search_value = FromHandle(value, &lossless);
if (!lossless) return Just<int64_t>(-1);
} else {
if (!value->IsNumber()) return Just<int64_t>(-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<int64_t>(-1);
}
if (std::isnan(search_value)) {
return Just<int64_t>(-1);
}
} else if (search_value < std::numeric_limits<ElementType>::lowest() ||
search_value > std::numeric_limits<ElementType>::max()) {
// Return false if value can't be represented in this ElementsKind.
return Just<int64_t>(-1);
}
typed_search_value = static_cast<ElementType>(search_value);
if (static_cast<double>(typed_search_value) != search_value) {
return Just<int64_t>(-1); // Loss of precision.
}
}
// Prototype has no elements, and not searching for the hole --- limit
// search to backing store length.
if (typed_array.length() < length) {
// TODO(bmeurer, v8:4153): Don't cast to uint32_t here.
length = static_cast<uint32_t>(typed_array.length());
}
for (uint32_t k = start_from; k < length; ++k) {
ElementType elem_k = AccessorClass::GetImpl(data_ptr, k);
if (elem_k == typed_search_value) return Just<int64_t>(k);
}
return Just<int64_t>(-1);
}
static Maybe<int64_t> LastIndexOfValueImpl(Handle<JSObject> receiver,
Handle<Object> value,
uint32_t start_from) {
DisallowHeapAllocation no_gc;
JSTypedArray typed_array = JSTypedArray::cast(*receiver);
DCHECK(!typed_array.WasDetached());
ElementType typed_search_value;
ElementType* data_ptr =
reinterpret_cast<ElementType*>(typed_array.DataPtr());
if (Kind == BIGINT64_ELEMENTS || Kind == BIGUINT64_ELEMENTS) {
if (!value->IsBigInt()) return Just<int64_t>(-1);
bool lossless;
typed_search_value = FromHandle(value, &lossless);
if (!lossless) return Just<int64_t>(-1);
} else {
if (!value->IsNumber()) return Just<int64_t>(-1);
double search_value = value->Number();
if (!std::isfinite(search_value)) {
if (std::is_integral<ElementType>::value) {
// Integral types cannot represent +Inf or NaN.
return Just<int64_t>(-1);
} else if (std::isnan(search_value)) {
// Strict Equality Comparison of NaN is always false.
return Just<int64_t>(-1);
}
} else if (search_value < std::numeric_limits<ElementType>::lowest() ||
search_value > std::numeric_limits<ElementType>::max()) {
// Return -1 if value can't be represented in this ElementsKind.
return Just<int64_t>(-1);
}
typed_search_value = static_cast<ElementType>(search_value);
if (static_cast<double>(typed_search_value) != search_value) {
return Just<int64_t>(-1); // Loss of precision.
}
}
DCHECK_LT(start_from, typed_array.length());
uint32_t k = start_from;
do {
ElementType elem_k = AccessorClass::GetImpl(data_ptr, k);
if (elem_k == typed_search_value) return Just<int64_t>(k);
} while (k-- != 0);
return Just<int64_t>(-1);
}
static void ReverseImpl(JSObject receiver) {
DisallowHeapAllocation no_gc;
JSTypedArray typed_array = JSTypedArray::cast(receiver);
DCHECK(!typed_array.WasDetached());
size_t len = typed_array.length();
if (len == 0) return;
ElementType* data = static_cast<ElementType*>(typed_array.DataPtr());
if (COMPRESS_POINTERS_BOOL && alignof(ElementType) > kTaggedSize) {
// TODO(ishell, v8:8875): See UnalignedSlot<T> for details.
std::reverse(UnalignedSlot<ElementType>(data),
UnalignedSlot<ElementType>(data + len));
} else {
std::reverse(data, data + len);
}
}
static Handle<FixedArray> CreateListFromArrayLikeImpl(Isolate* isolate,
Handle<JSObject> object,
uint32_t length) {
Handle<JSTypedArray> typed_array = Handle<JSTypedArray>::cast(object);
Handle<FixedArray> result = isolate->factory()->NewFixedArray(length);
for (uint32_t i = 0; i < length; i++) {
Handle<Object> value = AccessorClass::GetInternalImpl(typed_array, 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.WasDetached());
CHECK(!destination.WasDetached());
DCHECK_LE(start, end);
DCHECK_LE(end, source.length());
size_t count = end - start;
DCHECK_LE(count, destination.length());
ElementType* dest_data = static_cast<ElementType*>(destination.DataPtr());
switch (source.GetElementsKind()) {
#define TYPED_ARRAY_CASE(Type, type, TYPE, ctype) \
case TYPE##_ELEMENTS: { \
ctype* source_data = reinterpret_cast<ctype*>(source.DataPtr()) + start; \
CopyBetweenBackingStores<TYPE##_ELEMENTS, ctype>(source_data, dest_data, \
count); \
break; \
}
TYPED_ARRAYS(TYPED_ARRAY_CASE)
#undef TYPED_ARRAY_CASE
default:
UNREACHABLE();
break;
}
}
static bool HasSimpleRepresentation(ExternalArrayType type) {
return !(type == kExternalFloat32Array || type == kExternalFloat64Array ||
type == kExternalUint8ClampedArray);
}
template <ElementsKind SourceKind, typename SourceElementType>
static void CopyBetweenBackingStores(SourceElementType* source_data_ptr,
ElementType* dest_data_ptr,
size_t length) {
DisallowHeapAllocation no_gc;
for (size_t i = 0; i < length; i++) {
// We use scalar accessors to avoid boxing/unboxing, so there are no
// allocations.
SourceElementType source_elem =
TypedElementsAccessor<SourceKind, SourceElementType>::GetImpl(
source_data_ptr, i);
ElementType dest_elem = FromScalar(source_elem);
SetImpl(dest_data_ptr, i, dest_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.WasDetached());
CHECK(!destination.WasDetached());
DCHECK_LE(offset, destination.length());
DCHECK_LE(length, destination.length() - offset);
DCHECK_LE(length, source.length());
ExternalArrayType source_type = source.type();
ExternalArrayType destination_type = destination.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<uint8_t*>(source.DataPtr());
uint8_t* dest_data = static_cast<uint8_t*>(destination.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<uint8_t[]> 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<TYPE##_ELEMENTS, ctype>( \
reinterpret_cast<ctype*>(source_data), \
reinterpret_cast<ElementType*>(dest_data) + offset, length); \
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.WasDetached());
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();
DCHECK(length + offset <= dest_length);
USE(dest_length);
ElementsKind kind = source.GetElementsKind();
// 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;
Oddball undefined = ReadOnlyRoots(isolate).undefined_value();
ElementType* dest_data =
reinterpret_cast<ElementType*>(destination.DataPtr()) + offset;
// Fast-path 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);
SetImpl(dest_data, i, FromScalar(Smi::ToInt(elem)));
}
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)) {
SetImpl(dest_data, i, FromObject(undefined));
} else {
Object elem = source_store.get(i);
SetImpl(dest_data, i, FromScalar(Smi::ToInt(elem)));
}
}
return true;
} else if (kind == PACKED_DOUBLE_ELEMENTS) {
// Fast-path 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);
SetImpl(dest_data, i, FromScalar(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)) {
SetImpl(dest_data, i, FromObject(undefined));
} else {
double elem = source_store.get_scalar(i);
SetImpl(dest_data, i, FromScalar(elem));
}
}
return true;
}
return false;
}
static Object CopyElementsHandleSlow(Handle<Object> source,
Handle<JSTypedArray> destination,
size_t length, uint32_t offset) {
Isolate* isolate = destination->GetIsolate();
for (size_t i = 0; i < length; i++) {
Handle<Object> elem;
if (i <= kMaxUInt32) {
LookupIterator it(isolate, source, static_cast<uint32_t>(i));
ASSIGN_RETURN_FAILURE_ON_EXCEPTION(isolate, elem,
Object::GetProperty(&it));
} else {
char buffer[kDoubleToCStringMinBufferSize];
Vector<char> string(buffer, arraysize(buffer));
DoubleToCString(static_cast<double>(i), string);
Handle<Name> name = isolate->factory()->InternalizeUtf8String(string);
LookupIterator it(isolate, source, name);
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->WasDetached())) {
const char* op = "set";
const MessageTemplate message = MessageTemplate::kDetachedOperation;
Handle<String> 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.
// TODO(bmeurer, v8:4153): Remove this static_cast.
SetImpl(destination, static_cast<uint32_t>(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<Object> source,
Handle<JSObject> destination,
size_t length, uint32_t offset) {
Isolate* isolate = destination->GetIsolate();
Handle<JSTypedArray> destination_ta =
Handle<JSTypedArray>::cast(destination);
DCHECK_LE(offset + length, destination_ta->length());
CHECK(!destination_ta->WasDetached());
if (length == 0) return *isolate->factory()->undefined_value();
// All conversions from TypedArrays can be done without allocation.
if (source->IsJSTypedArray()) {
Handle<JSTypedArray> source_ta = Handle<JSTypedArray>::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 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 (source_is_bigint == target_is_bigint && !source_ta->WasDetached() &&
length + offset <= source_ta->length()) {
CopyElementsFromTypedArray(*source_ta, *destination_ta, length, offset);
return *isolate->factory()->undefined_value();
}
} else if (source->IsJSArray()) {
// Fast cases for packed numbers kinds where we don't need to allocate.
Handle<JSArray> source_js_array = Handle<JSArray>::cast(source);
size_t current_length;
if (source_js_array->length().IsNumber() &&
TryNumberToSize(source_js_array->length(), ¤t_length)) {
if (length <= current_length) {
Handle<JSArray> source_array = Handle<JSArray>::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);
}
};
// static
template <>
Handle<Object> TypedElementsAccessor<INT8_ELEMENTS, int8_t>::ToHandle(
Isolate* isolate, int8_t value) {
return handle(Smi::FromInt(value), isolate);
}
// static
template <>
Handle<Object> TypedElementsAccessor<UINT8_ELEMENTS, uint8_t>::ToHandle(
Isolate* isolate, uint8_t value) {
return handle(Smi::FromInt(value), isolate);
}
// static
template <>
Handle<Object> TypedElementsAccessor<INT16_ELEMENTS, int16_t>::ToHandle(
Isolate* isolate, int16_t value) {
return handle(Smi::FromInt(value), isolate);
}
// static
template <>
Handle<Object> TypedElementsAccessor<UINT16_ELEMENTS, uint16_t>::ToHandle(
Isolate* isolate, uint16_t value) {
return handle(Smi::FromInt(value), isolate);
}
// static
template <>
Handle<Object> TypedElementsAccessor<INT32_ELEMENTS, int32_t>::ToHandle(
Isolate* isolate, int32_t value) {
return isolate->factory()->NewNumberFromInt(value);
}
// static
template <>
Handle<Object> TypedElementsAccessor<UINT32_ELEMENTS, uint32_t>::ToHandle(
Isolate* isolate, uint32_t value) {
return isolate->factory()->NewNumberFromUint(value);
}
// static
template <>
float TypedElementsAccessor<FLOAT32_ELEMENTS, float>::FromScalar(double value) {
return DoubleToFloat32(value);
}
// static
template <>
Handle<Object> TypedElementsAccessor<FLOAT32_ELEMENTS, float>::ToHandle(
Isolate* isolate, float value) {
return isolate->factory()->NewNumber(value);
}
// static
template <>
double TypedElementsAccessor<FLOAT64_ELEMENTS, double>::FromScalar(
double value) {
return value;
}
// static
template <>
Handle<Object> TypedElementsAccessor<FLOAT64_ELEMENTS, double>::ToHandle(
Isolate* isolate, double value) {
return isolate->factory()->NewNumber(value);
}
// static
template <>
uint8_t TypedElementsAccessor<UINT8_CLAMPED_ELEMENTS, uint8_t>::FromScalar(
int value) {
if (value < 0x00) return 0x00;
if (value > 0xFF) return 0xFF;
return static_cast<uint8_t>(value);
}
// static
template <>
uint8_t TypedElementsAccessor<UINT8_CLAMPED_ELEMENTS, uint8_t>::FromScalar(
uint32_t value) {
// We need this special case for Uint32 -> Uint8Clamped, because the highest
// Uint32 values will be negative as an int, clamping to 0, rather than 255.
if (value > 0xFF) return 0xFF;
return static_cast<uint8_t>(value);
}
// static
template <>
uint8_t TypedElementsAccessor<UINT8_CLAMPED_ELEMENTS, uint8_t>::FromScalar(
double value) {
// Handle NaNs and less than zero values which clamp to zero.
if (!(value > 0)) return 0;
if (value > 0xFF) return 0xFF;
return static_cast<uint8_t>(lrint(value));
}
// static
template <>
Handle<Object> TypedElementsAccessor<UINT8_CLAMPED_ELEMENTS, uint8_t>::ToHandle(
Isolate* isolate, uint8_t value) {
return handle(Smi::FromInt(value), isolate);
}
// static
template <>
int64_t TypedElementsAccessor<BIGINT64_ELEMENTS, int64_t>::FromScalar(
int value) {
UNREACHABLE();
}
// static
template <>
int64_t TypedElementsAccessor<BIGINT64_ELEMENTS, int64_t>::FromScalar(
uint32_t value) {
UNREACHABLE();
}
// static
template <>
int64_t TypedElementsAccessor<BIGINT64_ELEMENTS, int64_t>::FromScalar(
double value) {
UNREACHABLE();
}
// static
template <>
int64_t TypedElementsAccessor<BIGINT64_ELEMENTS, int64_t>::FromScalar(
int64_t value) {
return value;
}
// static
template <>
int64_t TypedElementsAccessor<BIGINT64_ELEMENTS, int64_t>::FromScalar(
uint64_t value) {
return static_cast<int64_t>(value);
}
// static
template <>
int64_t TypedElementsAccessor<BIGINT64_ELEMENTS, int64_t>::FromObject(
Object value, bool* lossless) {
return BigInt::cast(value).AsInt64(lossless);
}
// static
template <>
Handle<Object> TypedElementsAccessor<BIGINT64_ELEMENTS, int64_t>::ToHandle(
Isolate* isolate, int64_t value) {
return BigInt::FromInt64(isolate, value);
}
// static
template <>
uint64_t TypedElementsAccessor<BIGUINT64_ELEMENTS, uint64_t>::FromScalar(
int value) {
UNREACHABLE();
}
// static
template <>
uint64_t TypedElementsAccessor<BIGUINT64_ELEMENTS, uint64_t>::FromScalar(
uint32_t value) {
UNREACHABLE();
}
// static
template <>
uint64_t TypedElementsAccessor<BIGUINT64_ELEMENTS, uint64_t>::FromScalar(
double value) {
UNREACHABLE();
}
// static
template <>
uint64_t TypedElementsAccessor<BIGUINT64_ELEMENTS, uint64_t>::FromScalar(
int64_t value) {
return static_cast<uint64_t>(value);
}
// static
template <>
uint64_t TypedElementsAccessor<BIGUINT64_ELEMENTS, uint64_t>::FromScalar(
uint64_t value) {
return value;
}
// static
template <>
uint64_t TypedElementsAccessor<BIGUINT64_ELEMENTS, uint64_t>::FromObject(
Object value, bool* lossless) {
return BigInt::cast(value).AsUint64(lossless);
}
// static
template <>
Handle<Object> TypedElementsAccessor<BIGUINT64_ELEMENTS, uint64_t>::ToHandle(
Isolate* isolate, uint64_t value) {
return BigInt::FromUint64(isolate, value);
}
#define FIXED_ELEMENTS_ACCESSOR(Type, type, TYPE, ctype) \
using Type##ElementsAccessor = TypedElementsAccessor<TYPE##_ELEMENTS, ctype>;
TYPED_ARRAYS(FIXED_ELEMENTS_ACCESSOR)
#undef FIXED_ELEMENTS_ACCESSOR
template <typename Subclass, typename ArgumentsAccessor, typename KindTraits>
class SloppyArgumentsElementsAccessor
: public ElementsAccessorBase<Subclass, KindTraits> {
public:
static void ConvertArgumentsStoreResult(
Handle<SloppyArgumentsElements> elements, Handle<Object> result) {
UNREACHABLE();
}
static Handle<Object> GetImpl(Isolate* isolate, FixedArrayBase parameters,
uint32_t entry) {
Handle<SloppyArgumentsElements> 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<Object> result = ArgumentsAccessor::GetImpl(
isolate, elements->arguments(), entry - length);
return Subclass::ConvertArgumentsStoreResult(isolate, elements, result);
}
}
static void TransitionElementsKindImpl(Handle<JSObject> object,
Handle<Map> map) {
UNREACHABLE();
}
static void GrowCapacityAndConvertImpl(Handle<JSObject> object,
uint32_t capacity) {
UNREACHABLE();
}
static inline void SetImpl(Handle<JSObject> 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<JSArray> array,
uint32_t length,
Handle<FixedArrayBase> 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);
}
V8_WARN_UNUSED_RESULT static ExceptionStatus AddElementsToKeyAccumulatorImpl(
Handle<JSObject> receiver, KeyAccumulator* accumulator,
AddKeyConversion convert) {
Isolate* isolate = accumulator->isolate();
Handle<FixedArrayBase> 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<Object> value = GetImpl(isolate, *elements, entry);
RETURN_FAILURE_IF_NOT_SUCCESSFUL(accumulator->AddKey(value, convert));
}
return ExceptionStatus::kSuccess;
}
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<JSObject> obj, uint32_t entry) {
Handle<SloppyArgumentsElements> 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<JSObject> obj,
Handle<SloppyArgumentsElements> elements,
uint32_t entry) {
// Implemented in subclasses.
UNREACHABLE();
}
V8_WARN_UNUSED_RESULT static ExceptionStatus CollectElementIndicesImpl(
Handle<JSObject> object, Handle<FixedArrayBase> backing_store,
KeyAccumulator* keys) {
Isolate* isolate = keys->isolate();
uint32_t nof_indices = 0;
Handle<FixedArray> 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++) {
RETURN_FAILURE_IF_NOT_SUCCESSFUL(keys->AddKey(indices->get(i)));
}
return ExceptionStatus::kSuccess;
}
static Handle<FixedArray> DirectCollectElementIndicesImpl(
Isolate* isolate, Handle<JSObject> object,
Handle<FixedArrayBase> backing_store, GetKeysConversion convert,
PropertyFilter filter, Handle<FixedArray> list, uint32_t* nof_indices,
uint32_t insertion_index = 0) {
Handle<SloppyArgumentsElements> elements =
Handle<SloppyArgumentsElements>::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<String> index_string = isolate->factory()->Uint32ToString(i);
list->set(insertion_index, *index_string);
} else {
list->set(insertion_index, Smi::FromInt(i));
}
insertion_index++;
}
Handle<FixedArray> store(elements->arguments(), isolate);
return ArgumentsAccessor::DirectCollectElementIndicesImpl(
isolate, object, store, convert, filter, list, nof_indices,
insertion_index);
}
static Maybe<bool> IncludesValueImpl(Isolate* isolate,
Handle<JSObject> object,
Handle<Object> value,
uint32_t start_from, uint32_t length) {
DCHECK(JSObject::PrototypeHasNoElements(isolate, *object));
Handle<Map> original_map(object->map(), isolate);
Handle<SloppyArgumentsElements> 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<Object> 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<bool>());
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<int64_t> IndexOfValueImpl(Isolate* isolate,
Handle<JSObject> object,
Handle<Object> value,
uint32_t start_from, uint32_t length) {
DCHECK(JSObject::PrototypeHasNoElements(isolate, *object));
Handle<Map> original_map(object->map(), isolate);
Handle<SloppyArgumentsElements> 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<Object> 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<int64_t>());
if (value->StrictEquals(*element_k)) {
return Just<int64_t>(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<int64_t>(k);
}
}
return Just<int64_t>(-1);
}
};
class SlowSloppyArgumentsElementsAccessor
: public SloppyArgumentsElementsAccessor<
SlowSloppyArgumentsElementsAccessor, DictionaryElementsAccessor,
ElementsKindTraits<SLOW_SLOPPY_ARGUMENTS_ELEMENTS>> {
public:
static Handle<Object> ConvertArgumentsStoreResult(
Isolate* isolate, Handle<SloppyArgumentsElements> elements,
Handle<Object> 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<JSObject> obj,
Handle<SloppyArgumentsElements> 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<NumberDictionary> 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<JSObject> object, uint32_t index,
Handle<Object> value, PropertyAttributes attributes,
uint32_t new_capacity) {
Isolate* isolate = object->GetIsolate();
Handle<SloppyArgumentsElements> elements(
SloppyArgumentsElements::cast(object->elements()), isolate);
Handle<FixedArrayBase> old_arguments(
FixedArrayBase::cast(elements->arguments()), isolate);
Handle<NumberDictionary> dictionary =
old_arguments->IsNumberDictionary()
? Handle<NumberDictionary>::cast(old_arguments)
: JSObject::NormalizeElements(object);
PropertyDetails details(kData, attributes, PropertyCellType::kNoCell);
Handle<NumberDictionary> 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<JSObject> object,
Handle<FixedArrayBase> store, uint32_t entry,
Handle<Object> value,
PropertyAttributes attributes) {
Isolate* isolate = object->GetIsolate();
Handle<SloppyArgumentsElements> elements =
Handle<SloppyArgumentsElements>::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<NumberDictionary> 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<FixedArrayBase> arguments(elements->arguments(), isolate);
DictionaryElementsAccessor::ReconfigureImpl(
object, arguments, entry - length, value, attributes);
}
}
};
class FastSloppyArgumentsElementsAccessor
: public SloppyArgumentsElementsAccessor<
FastSloppyArgumentsElementsAccessor, FastHoleyObjectElementsAccessor,
ElementsKindTraits<FAST_SLOPPY_ARGUMENTS_ELEMENTS>> {
public:
static Handle<Object> ConvertArgumentsStoreResult(
Isolate* isolate, Handle<SloppyArgumentsElements> paramtere_map,
Handle<Object> result) {
DCHECK(!result->IsAliasedArgumentsEntry());
return result;
}
static Handle<FixedArray> GetArguments(Isolate* isolate,
FixedArrayBase store) {
SloppyArgumentsElements elements = SloppyArgumentsElements::cast(store);
return Handle<FixedArray>(elements.arguments(), isolate);
}
static Handle<NumberDictionary> NormalizeImpl(
Handle<JSObject> object, Handle<FixedArrayBase> elements) {
Handle<FixedArray> arguments =
GetArguments(object->GetIsolate(), *elements);
return FastHoleyObjectElementsAccessor::NormalizeImpl(object, arguments);
}
static Handle<NumberDictionary> NormalizeArgumentsElements(
Handle<JSObject> object, Handle<SloppyArgumentsElements> elements,
uint32_t* entry) {
Handle<NumberDictionary> 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<JSObject> obj,
Handle<SloppyArgumentsElements> elements,
uint32_t entry) {
// Always normalize element on deleting an entry.
NormalizeArgumentsElements(obj, elements, &entry);
SlowSloppyArgumentsElementsAccessor::SloppyDeleteImpl(obj, elements, entry);
}
static void AddImpl(Handle<JSObject> object, uint32_t index,
Handle<Object> value, PropertyAttributes attributes,
uint32_t new_capacity) {
DCHECK_EQ(NONE, attributes);
Isolate* isolate = object->GetIsolate();
Handle<SloppyArgumentsElements> elements(
SloppyArgumentsElements::cast(object->elements()), isolate);
Handle<FixedArray> old_arguments(elements->arguments(), isolate);
if (old_arguments->IsNumberDictionary() ||
static_cast<uint32_t>(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<JSObject> object,
Handle<FixedArrayBase> store, uint32_t entry,
Handle<Object> value,
PropertyAttributes attributes) {
DCHECK_EQ(object->elements(), *store);
Handle<SloppyArgumentsElements> 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.IsNumberDictionary());
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<JSObject> object,
uint32_t capacity) {
Isolate* isolate = object->GetIsolate();
Handle<SloppyArgumentsElements> elements(
SloppyArgumentsElements::cast(object->elements()), isolate);
Handle<FixedArray> 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<uint32_t>(old_arguments->length()) < capacity);
Handle<FixedArrayBase> arguments =
ConvertElementsWithCapacity(object, old_arguments, from_kind, capacity);
Handle<Map> new_map = JSObject::GetElementsTransitionMap(
object, FAST_SLOPPY_ARGUMENTS_ELEMENTS);
JSObject::MigrateToMap(isolate, object, new_map);
elements->set_arguments(FixedArray::cast(*arguments));
JSObject::ValidateElements(*object);
}
};
template <typename Subclass, typename BackingStoreAccessor, typename KindTraits>
class StringWrapperElementsAccessor
: public ElementsAccessorBase<Subclass, KindTraits> {
public:
static Handle<Object> GetInternalImpl(Handle<JSObject> holder,
uint32_t entry) {
return GetImpl(holder, entry);
}
static Handle<Object> GetImpl(Handle<JSObject> holder, uint32_t entry) {
Isolate* isolate = holder->GetIsolate();
Handle<String> string(GetString(*holder), isolate);
uint32_t length = static_cast<uint32_t>(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<Object> GetImpl(Isolate* isolate, FixedArrayBase elements,
uint32_t entry) {
UNREACHABLE();
}
static PropertyDetails GetDetailsImpl(JSObject holder, uint32_t entry) {
uint32_t length = static_cast<uint32_t>(GetString(holder).length());
if (entry < length) {
PropertyAttributes attributes =
static_cast<PropertyAttributes>(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<uint32_t>(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<JSObject> holder, uint32_t entry) {
uint32_t length = static_cast<uint32_t>(GetString(*holder).length());
if (entry < length) {
return; // String contents can't be deleted.
}
BackingStoreAccessor::DeleteImpl(holder, entry - length);
}
static void SetImpl(Handle<JSObject> holder, uint32_t entry, Object value) {
uint32_t length = static_cast<uint32_t>(GetString(*holder).length());
if (entry < length) {
return; // String contents are read-only.
}
BackingStoreAccessor::SetImpl(holder->elements(), entry - length, value);
}
static void AddImpl(Handle<JSObject> object, uint32_t index,
Handle<Object> value, PropertyAttributes attributes,
uint32_t new_capacity) {
DCHECK(index >= static_cast<uint32_t>(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<JSObject> object,
Handle<FixedArrayBase> store, uint32_t entry,
Handle<Object> value,
PropertyAttributes attributes) {
uint32_t length = static_cast<uint32_t>(GetString(*object).length());
if (entry < length) {
return; // String contents can't be reconfigured.
}
BackingStoreAccessor::ReconfigureImpl(object, store, entry - length, value,
attributes);
}
V8_WARN_UNUSED_RESULT static ExceptionStatus AddElementsToKeyAccumulatorImpl(
Handle<JSObject> receiver, KeyAccumulator* accumulator,
AddKeyConversion convert) {
Isolate* isolate = receiver->GetIsolate();
Handle<String> string(GetString(*receiver), isolate);
string = String::Flatten(isolate, string);
uint32_t length = static_cast<uint32_t>(string->length());
for (uint32_t i = 0; i < length; i++) {
Handle<String> key =
isolate->factory()->LookupSingleCharacterStringFromCode(
string->Get(i));
RETURN_FAILURE_IF_NOT_SUCCESSFUL(accumulator->AddKey(key, convert));
}
return BackingStoreAccessor::AddElementsToKeyAccumulatorImpl(
receiver, accumulator, convert);
}
V8_WARN_UNUSED_RESULT static ExceptionStatus CollectElementIndicesImpl(
Handle<JSObject> object, Handle<FixedArrayBase> backing_store,
KeyAccumulator* keys) {
uint32_t length = GetString(*object).length();
Factory* factory = keys->isolate()->factory();
for (uint32_t i = 0; i < length; i++) {
RETURN_FAILURE_IF_NOT_SUCCESSFUL(
keys->AddKey(factory->NewNumberFromUint(i)));
}
return BackingStoreAccessor::CollectElementIndicesImpl(object,
backing_store, keys);
}
static void GrowCapacityAndConvertImpl(Handle<JSObject> object,
uint32_t capacity) {
Handle<FixedArrayBase> 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<uint32_t>(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.IsNumberDictionary());
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.IsJSPrimitiveWrapper());
JSPrimitiveWrapper js_value = JSPrimitiveWrapper::cast(holder);
DCHECK(js_value.value().IsString());
return String::cast(js_value.value());
}
};
class FastStringWrapperElementsAccessor
: public StringWrapperElementsAccessor<
FastStringWrapperElementsAccessor, FastHoleyObjectElementsAccessor,
ElementsKindTraits<FAST_STRING_WRAPPER_ELEMENTS>> {
public:
static Handle<NumberDictionary> NormalizeImpl(
Handle<JSObject> object, Handle<FixedArrayBase> elements) {
return FastHoleyObjectElementsAccessor::NormalizeImpl(object, elements);
}
};
class SlowStringWrapperElementsAccessor
: public StringWrapperElementsAccessor<
SlowStringWrapperElementsAccessor, DictionaryElementsAccessor,
ElementsKindTraits<SLOW_STRING_WRAPPER_ELEMENTS>> {
public:
static bool HasAccessorsImpl(JSObject holder, FixedArrayBase backing_store) {
return DictionaryElementsAccessor::HasAccessorsImpl(holder, backing_store);
}
};
} // namespace
MaybeHandle<Object> ArrayConstructInitializeElements(Handle<JSArray> 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<FixedArrayBase> elms;
if (IsDoubleElementsKind(elements_kind)) {
elms = Handle<FixedArrayBase>::cast(
factory->NewFixedDoubleArray(number_of_elements));
} else {
elms = Handle<FixedArrayBase>::cast(
factory->NewFixedArrayWithHoles(number_of_elements));
}
// Fill in the content
switch (elements_kind) {
case HOLEY_SMI_ELEMENTS:
case PACKED_SMI_ELEMENTS: {
Handle<FixedArray> smi_elms = Handle<FixedArray>::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<FixedArray> object_elms = Handle<FixedArray>::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<FixedDoubleArray> double_elms =
Handle<FixedDoubleArray>::cast(elms);
for (int entry = 0; entry < number_of_elements; entry++) {
double_elms->set(entry, (*args)[entry].Number());
}
break;
}
default:
UNREACHABLE();
}
array->set_elements(*elms);
array->set_length(Smi::FromInt(number_of_elements));
return array;
}
void CopyFastNumberJSArrayElementsToTypedArray(Address raw_context,
Address raw_source,
Address raw_destination,
uintptr_t length,
uintptr_t offset) {
Context context = Context::cast(Object(raw_context));
JSArray source = JSArray::cast(Object(raw_source));
JSTypedArray destination = JSTypedArray::cast(Object(raw_destination));
switch (destination.GetElementsKind()) {
#define TYPED_ARRAYS_CASE(Type, type, TYPE, ctype) \
case TYPE##_ELEMENTS: \
CHECK(Type##ElementsAccessor::TryCopyElementsFastNumber( \
context, source, destination, length, static_cast<uint32_t>(offset))); \
break;
TYPED_ARRAYS(TYPED_ARRAYS_CASE)
#undef TYPED_ARRAYS_CASE
default:
UNREACHABLE();
}
}
void CopyTypedArrayElementsToTypedArray(Address raw_source,
Address raw_destination,
uintptr_t length, uintptr_t offset) {
JSTypedArray source = JSTypedArray::cast(Object(raw_source));
JSTypedArray destination = JSTypedArray::cast(Object(raw_destination));
switch (destination.GetElementsKind()) {
#define TYPED_ARRAYS_CASE(Type, type, TYPE, ctype) \
case TYPE##_ELEMENTS: \
Type##ElementsAccessor::CopyElementsFromTypedArray( \
source, destination, length, static_cast<uint32_t>(offset)); \
break;
TYPED_ARRAYS(TYPED_ARRAYS_CASE)
#undef TYPED_ARRAYS_CASE
default:
UNREACHABLE();
}
}
void CopyTypedArrayElementsSlice(Address raw_source, Address raw_destination,
uintptr_t start, uintptr_t end) {
JSTypedArray source = JSTypedArray::cast(Object(raw_source));
JSTypedArray destination = JSTypedArray::cast(Object(raw_destination));
destination.GetElementsAccessor()->CopyTypedArrayElementsSlice(
source, destination, start, end);
}
void ElementsAccessor::InitializeOncePerProcess() {
static ElementsAccessor* accessor_array[] = {
#define ACCESSOR_ARRAY(Class, Kind, Store) new Class(),
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<JSArray> 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<JSArray> 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<FixedArrayBase> 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
#undef RETURN_NOTHING_IF_NOT_SUCCESSFUL
#undef RETURN_FAILURE_IF_NOT_SUCCESSFUL
} // namespace internal
} // namespace v8