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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);
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. Perform ? RequireInternalSlot(buffer, [[ArrayBufferData]]).
if (!buffer->IsJSArrayBuffer()) {
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 = byte_offset->Number();
// 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 buffer.[[ArrayBufferByteLength]].
size_t const buffer_byte_length = array_buffer->byte_length();
// 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));
}
size_t view_byte_length;
if (byte_length->IsUndefined(isolate)) {
// 7. If byteLength is undefined, then
// a. Let viewByteLength be bufferByteLength - offset.
view_byte_length = buffer_byte_length - view_byte_offset;
} else {
// 8. 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();
}
// 9. 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()));
Handle<JSDataView> data_view = Handle<JSDataView>::cast(result);
for (int i = 0; i < ArrayBufferView::kEmbedderFieldCount; ++i) {
// TODO(v8:10391, saelo): Handle external pointers in EmbedderDataSlot
data_view->SetEmbedderField(i, Smi::zero());
}
// We have to set the internal slots before the detached check on step 10 or
// the TorqueGeneratedClassVerifier ended up complaining that the slot is
// empty or invalid on heap teardown.
// The result object is not observable from JavaScript when step 10 early
// aborts so it is fine to set internal slots here.
// 11. Set O.[[ViewedArrayBuffer]] to buffer.
data_view->set_buffer(*array_buffer);
// 12. Set O.[[ByteLength]] to viewByteLength.
data_view->set_byte_length(view_byte_length);
// 13. 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);
// 10. 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. Return O.
return *result;
}
} // namespace internal
} // namespace v8
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