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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) {
HandleScope scope(isolate);
if (args.new_target()->IsUndefined(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. If Type(buffer) is not Object, throw a TypeError exception.
// 3. If buffer does not have an [[ArrayBufferData]] internal slot, throw a
// TypeError exception.
if (!buffer->IsJSArrayBuffer()) {
THROW_NEW_ERROR_RETURN_FAILURE(
isolate, NewTypeError(MessageTemplate::kDataViewNotArrayBuffer));
}
Handle<JSArrayBuffer> array_buffer = Handle<JSArrayBuffer>::cast(buffer);
// 4. 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 = byte_offset->Number();
// 5. If IsDetachedBuffer(buffer) is true, throw a TypeError exception.
// We currently violate the specification at this point. TODO: Fix that.
// 6. Let bufferByteLength be the value of buffer's
// [[ArrayBufferByteLength]] internal slot.
size_t const buffer_byte_length = array_buffer->byte_length();
// 7. 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));
}
size_t view_byte_length;
if (byte_length->IsUndefined(isolate)) {
// 8. If byteLength is either not present or undefined, then
// a. Let viewByteLength be bufferByteLength - offset.
view_byte_length = buffer_byte_length - view_byte_offset;
} else {
// 9. Else,
// a. Let viewByteLength be ? ToIndex(byteLength).
// b. 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 + byte_length->Number() > buffer_byte_length) {
THROW_NEW_ERROR_RETURN_FAILURE(
isolate, NewRangeError(MessageTemplate::kInvalidDataViewLength));
}
view_byte_length = byte_length->Number();
}
// 10. Let O be ? OrdinaryCreateFromConstructor(NewTarget,
// "%DataViewPrototype%", «[[DataView]], [[ViewedArrayBuffer]],
// [[ByteLength]], [[ByteOffset]]»).
Handle<JSObject> result;
ASSIGN_RETURN_FAILURE_ON_EXCEPTION(
isolate, result,
JSObject::New(target, new_target, Handle<AllocationSite>::null()));
for (int i = 0; i < ArrayBufferView::kEmbedderFieldCount; ++i) {
Handle<JSDataView>::cast(result)->SetEmbedderField(i, Smi::kZero);
}
// 11. Set O's [[ViewedArrayBuffer]] internal slot to buffer.
Handle<JSDataView>::cast(result)->set_buffer(*array_buffer);
// 12. Set O's [[ByteLength]] internal slot to viewByteLength.
Handle<JSDataView>::cast(result)->set_byte_length(view_byte_length);
// 13. Set O's [[ByteOffset]] internal slot to offset.
Handle<JSDataView>::cast(result)->set_byte_offset(view_byte_offset);
Handle<JSDataView>::cast(result)->set_data_pointer(
static_cast<uint8_t*>(array_buffer->backing_store()) + view_byte_offset);
// 14. Return O.
return *result;
}
} // namespace internal
} // namespace v8
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