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// Copyright 2016 the V8 project authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include "src/builtins/builtins-utils-inl.h"
#include "src/builtins/builtins.h"
#include "src/execution/isolate.h"
#include "src/heap/factory.h"
#include "src/logging/counters.h"
#include "src/numbers/conversions.h"
#include "src/objects/js-array-buffer-inl.h"
#include "src/objects/objects-inl.h"
namespace v8 {
namespace internal {
// -----------------------------------------------------------------------------
// ES #sec-dataview-objects
// ES #sec-dataview-constructor
BUILTIN(DataViewConstructor) {
const char* const kMethodName = "DataView constructor";
HandleScope scope(isolate);
// 1. If NewTarget is undefined, throw a TypeError exception.
if (IsUndefined(*args.new_target(), isolate)) { // [[Call]]
THROW_NEW_ERROR_RETURN_FAILURE(
isolate, NewTypeError(MessageTemplate::kConstructorNotFunction,
isolate->factory()->NewStringFromAsciiChecked(
"DataView")));
}
// [[Construct]]
Handle<JSFunction> target = args.target();
Handle<JSReceiver> new_target = Handle<JSReceiver>::cast(args.new_target());
Handle<Object> buffer = args.atOrUndefined(isolate, 1);
Handle<Object> byte_offset = args.atOrUndefined(isolate, 2);
Handle<Object> byte_length = args.atOrUndefined(isolate, 3);
// 2. Perform ? RequireInternalSlot(buffer, [[ArrayBufferData]]).
if (!IsJSArrayBuffer(*buffer)) {
THROW_NEW_ERROR_RETURN_FAILURE(
isolate, NewTypeError(MessageTemplate::kDataViewNotArrayBuffer));
}
Handle<JSArrayBuffer> array_buffer = Handle<JSArrayBuffer>::cast(buffer);
// 3. Let offset be ? ToIndex(byteOffset).
ASSIGN_RETURN_FAILURE_ON_EXCEPTION(
isolate, byte_offset,
Object::ToIndex(isolate, byte_offset, MessageTemplate::kInvalidOffset));
size_t view_byte_offset = Object::Number(*byte_offset);
// 4. If IsDetachedBuffer(buffer) is true, throw a TypeError exception.
if (array_buffer->was_detached()) {
THROW_NEW_ERROR_RETURN_FAILURE(
isolate, NewTypeError(MessageTemplate::kDetachedOperation,
isolate->factory()->NewStringFromAsciiChecked(
kMethodName)));
}
// 5. Let bufferByteLength be ArrayBufferByteLength(buffer, SeqCst).
size_t buffer_byte_length = array_buffer->GetByteLength();
// 6. If offset > bufferByteLength, throw a RangeError exception.
if (view_byte_offset > buffer_byte_length) {
THROW_NEW_ERROR_RETURN_FAILURE(
isolate, NewRangeError(MessageTemplate::kInvalidOffset, byte_offset));
}
// 7. Let bufferIsResizable be IsResizableArrayBuffer(buffer).
// 8. Let byteLengthChecked be empty.
// 9. If bufferIsResizable is true and byteLength is undefined, then
// a. Let viewByteLength be auto.
// 10. Else if byteLength is undefined, then
// a. Let viewByteLength be bufferByteLength - offset.
size_t view_byte_length;
bool length_tracking = false;
if (IsUndefined(*byte_length, isolate)) {
view_byte_length = buffer_byte_length - view_byte_offset;
length_tracking = array_buffer->is_resizable_by_js();
} else {
// 11. Else,
// a. Set byteLengthChecked be ? ToIndex(byteLength).
// b. Let viewByteLength be byteLengthChecked.
// c. If offset + viewByteLength > bufferByteLength, throw a
// RangeError exception.
ASSIGN_RETURN_FAILURE_ON_EXCEPTION(
isolate, byte_length,
Object::ToIndex(isolate, byte_length,
MessageTemplate::kInvalidDataViewLength));
if (view_byte_offset + Object::Number(*byte_length) > buffer_byte_length) {
THROW_NEW_ERROR_RETURN_FAILURE(
isolate,
NewRangeError(MessageTemplate::kInvalidDataViewLength, byte_length));
}
view_byte_length = Object::Number(*byte_length);
}
bool is_backed_by_rab =
array_buffer->is_resizable_by_js() && !array_buffer->is_shared();
// 12. Let O be ? OrdinaryCreateFromConstructor(NewTarget,
// "%DataViewPrototype%", «[[DataView]], [[ViewedArrayBuffer]],
// [[ByteLength]], [[ByteOffset]]»).
Handle<JSObject> result;
if (is_backed_by_rab || length_tracking) {
// Create a JSRabGsabDataView.
Handle<Map> initial_map;
ASSIGN_RETURN_FAILURE_ON_EXCEPTION(
isolate, initial_map,
JSFunction::GetDerivedRabGsabDataViewMap(isolate, new_target));
ASSIGN_RETURN_FAILURE_ON_EXCEPTION(
isolate, result,
JSObject::NewWithMap(isolate, initial_map,
Handle<AllocationSite>::null()));
} else {
// Create a JSDataView.
ASSIGN_RETURN_FAILURE_ON_EXCEPTION(
isolate, result,
JSObject::New(target, new_target, Handle<AllocationSite>::null()));
}
Handle<JSDataViewOrRabGsabDataView> data_view =
Handle<JSDataViewOrRabGsabDataView>::cast(result);
{
// Must fully initialize the JSDataViewOrRabGsabDataView here so that it
// passes ObjectVerify, which may for example be triggered when allocating
// error objects below.
DisallowGarbageCollection no_gc;
Tagged<JSDataViewOrRabGsabDataView> raw = *data_view;
for (int i = 0; i < ArrayBufferView::kEmbedderFieldCount; ++i) {
// TODO(v8:10391, saelo): Handle external pointers in EmbedderDataSlot
raw->SetEmbedderField(i, Smi::zero());
}
raw->set_bit_field(0);
raw->set_is_backed_by_rab(is_backed_by_rab);
raw->set_is_length_tracking(length_tracking);
raw->set_byte_length(0);
raw->set_byte_offset(0);
raw->set_data_pointer(isolate, array_buffer->backing_store());
raw->set_buffer(*array_buffer);
}
// 13. If IsDetachedBuffer(buffer) is true, throw a TypeError exception.
if (array_buffer->was_detached()) {
THROW_NEW_ERROR_RETURN_FAILURE(
isolate, NewTypeError(MessageTemplate::kDetachedOperation,
isolate->factory()->NewStringFromAsciiChecked(
kMethodName)));
}
// 14. Let getBufferByteLength be
// MakeIdempotentArrayBufferByteLengthGetter(SeqCst).
// 15. Set bufferByteLength be getBufferByteLength(buffer).
buffer_byte_length = array_buffer->GetByteLength();
// 16. If offset > bufferByteLength, throw a RangeError exception.
if (view_byte_offset > buffer_byte_length) {
THROW_NEW_ERROR_RETURN_FAILURE(
isolate, NewRangeError(MessageTemplate::kInvalidOffset, byte_offset));
}
// 17. If byteLengthChecked is not empty, then
// a. If offset + viewByteLength > bufferByteLength, throw a RangeError
// exception.
if (!length_tracking &&
view_byte_offset + view_byte_length > buffer_byte_length) {
THROW_NEW_ERROR_RETURN_FAILURE(
isolate, NewRangeError(MessageTemplate::kInvalidDataViewLength));
}
// 18. Set O.[[ViewedArrayBuffer]] to buffer.
// Already done during initialization of the JSDataView above.
// 19. Set O.[[ByteLength]] to viewByteLength.
data_view->set_byte_length(length_tracking ? 0 : view_byte_length);
// 20. Set O.[[ByteOffset]] to offset.
data_view->set_byte_offset(view_byte_offset);
data_view->set_data_pointer(
isolate,
static_cast<uint8_t*>(array_buffer->backing_store()) + view_byte_offset);
// 21. Return O.
return *result;
}
} // namespace internal
} // namespace v8
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