|  | // 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.h" | 
|  | #include "src/builtins/builtins.h" | 
|  | #include "src/conversions.h" | 
|  | #include "src/counters.h" | 
|  | #include "src/maybe-handles-inl.h" | 
|  | #include "src/objects-inl.h" | 
|  | #include "src/objects/js-array-inl.h" | 
|  |  | 
|  | namespace v8 { | 
|  | namespace internal { | 
|  |  | 
|  | #define CHECK_SHARED(expected, name, method)                                \ | 
|  | if (name->is_shared() != expected) {                                      \ | 
|  | THROW_NEW_ERROR_RETURN_FAILURE(                                         \ | 
|  | isolate,                                                            \ | 
|  | NewTypeError(MessageTemplate::kIncompatibleMethodReceiver,          \ | 
|  | isolate->factory()->NewStringFromAsciiChecked(method), \ | 
|  | name));                                                \ | 
|  | } | 
|  |  | 
|  | // ----------------------------------------------------------------------------- | 
|  | // ES6 section 21.1 ArrayBuffer Objects | 
|  |  | 
|  | namespace { | 
|  |  | 
|  | Object* ConstructBuffer(Isolate* isolate, Handle<JSFunction> target, | 
|  | Handle<JSReceiver> new_target, Handle<Object> length, | 
|  | bool initialize) { | 
|  | Handle<JSObject> result; | 
|  | ASSIGN_RETURN_FAILURE_ON_EXCEPTION(isolate, result, | 
|  | JSObject::New(target, new_target)); | 
|  | size_t byte_length; | 
|  | if (!TryNumberToSize(*length, &byte_length)) { | 
|  | THROW_NEW_ERROR_RETURN_FAILURE( | 
|  | isolate, NewRangeError(MessageTemplate::kInvalidArrayBufferLength)); | 
|  | } | 
|  | SharedFlag shared_flag = | 
|  | (*target == target->native_context()->array_buffer_fun()) | 
|  | ? SharedFlag::kNotShared | 
|  | : SharedFlag::kShared; | 
|  | if (!JSArrayBuffer::SetupAllocatingData(Handle<JSArrayBuffer>::cast(result), | 
|  | isolate, byte_length, initialize, | 
|  | shared_flag)) { | 
|  | THROW_NEW_ERROR_RETURN_FAILURE( | 
|  | isolate, NewRangeError(MessageTemplate::kArrayBufferAllocationFailed)); | 
|  | } | 
|  | return *result; | 
|  | } | 
|  |  | 
|  | }  // namespace | 
|  |  | 
|  | // ES #sec-arraybuffer-constructor | 
|  | BUILTIN(ArrayBufferConstructor) { | 
|  | HandleScope scope(isolate); | 
|  | Handle<JSFunction> target = args.target(); | 
|  | DCHECK(*target == target->native_context()->array_buffer_fun() || | 
|  | *target == target->native_context()->shared_array_buffer_fun()); | 
|  | if (args.new_target()->IsUndefined(isolate)) {  // [[Call]] | 
|  | THROW_NEW_ERROR_RETURN_FAILURE( | 
|  | isolate, NewTypeError(MessageTemplate::kConstructorNotFunction, | 
|  | handle(target->shared()->Name(), isolate))); | 
|  | } else {  // [[Construct]] | 
|  | Handle<JSReceiver> new_target = Handle<JSReceiver>::cast(args.new_target()); | 
|  | Handle<Object> length = args.atOrUndefined(isolate, 1); | 
|  |  | 
|  | Handle<Object> number_length; | 
|  | ASSIGN_RETURN_FAILURE_ON_EXCEPTION(isolate, number_length, | 
|  | Object::ToInteger(isolate, length)); | 
|  | if (number_length->Number() < 0.0) { | 
|  | THROW_NEW_ERROR_RETURN_FAILURE( | 
|  | isolate, NewRangeError(MessageTemplate::kInvalidArrayBufferLength)); | 
|  | } | 
|  |  | 
|  | return ConstructBuffer(isolate, target, new_target, number_length, true); | 
|  | } | 
|  | } | 
|  |  | 
|  | // This is a helper to construct an ArrayBuffer with uinitialized memory. | 
|  | // This means the caller must ensure the buffer is totally initialized in | 
|  | // all cases, or we will expose uinitialized memory to user code. | 
|  | BUILTIN(ArrayBufferConstructor_DoNotInitialize) { | 
|  | HandleScope scope(isolate); | 
|  | Handle<JSFunction> target(isolate->native_context()->array_buffer_fun(), | 
|  | isolate); | 
|  | Handle<Object> length = args.atOrUndefined(isolate, 1); | 
|  | return ConstructBuffer(isolate, target, target, length, false); | 
|  | } | 
|  |  | 
|  | // ES6 section 24.1.4.1 get ArrayBuffer.prototype.byteLength | 
|  | BUILTIN(ArrayBufferPrototypeGetByteLength) { | 
|  | const char* const kMethodName = "get ArrayBuffer.prototype.byteLength"; | 
|  | HandleScope scope(isolate); | 
|  | CHECK_RECEIVER(JSArrayBuffer, array_buffer, kMethodName); | 
|  | CHECK_SHARED(false, array_buffer, kMethodName); | 
|  | // TODO(franzih): According to the ES6 spec, we should throw a TypeError | 
|  | // here if the JSArrayBuffer is detached. | 
|  | return array_buffer->byte_length(); | 
|  | } | 
|  |  | 
|  | // ES7 sharedmem 6.3.4.1 get SharedArrayBuffer.prototype.byteLength | 
|  | BUILTIN(SharedArrayBufferPrototypeGetByteLength) { | 
|  | const char* const kMethodName = "get SharedArrayBuffer.prototype.byteLength"; | 
|  | HandleScope scope(isolate); | 
|  | CHECK_RECEIVER(JSArrayBuffer, array_buffer, | 
|  | "get SharedArrayBuffer.prototype.byteLength"); | 
|  | CHECK_SHARED(true, array_buffer, kMethodName); | 
|  | return array_buffer->byte_length(); | 
|  | } | 
|  |  | 
|  | // ES6 section 24.1.3.1 ArrayBuffer.isView ( arg ) | 
|  | BUILTIN(ArrayBufferIsView) { | 
|  | SealHandleScope shs(isolate); | 
|  | DCHECK_EQ(2, args.length()); | 
|  | Object* arg = args[1]; | 
|  | return isolate->heap()->ToBoolean(arg->IsJSArrayBufferView()); | 
|  | } | 
|  |  | 
|  | static Object* SliceHelper(BuiltinArguments args, Isolate* isolate, | 
|  | const char* kMethodName, bool is_shared) { | 
|  | HandleScope scope(isolate); | 
|  | Handle<Object> start = args.at(1); | 
|  | Handle<Object> end = args.atOrUndefined(isolate, 2); | 
|  |  | 
|  | // * If Type(O) is not Object, throw a TypeError exception. | 
|  | // * If O does not have an [[ArrayBufferData]] internal slot, throw a | 
|  | //   TypeError exception. | 
|  | CHECK_RECEIVER(JSArrayBuffer, array_buffer, kMethodName); | 
|  | // * [AB] If IsSharedArrayBuffer(O) is true, throw a TypeError exception. | 
|  | // * [SAB] If IsSharedArrayBuffer(O) is false, throw a TypeError exception. | 
|  | CHECK_SHARED(is_shared, array_buffer, kMethodName); | 
|  |  | 
|  | // * [AB] If IsDetachedBuffer(buffer) is true, throw a TypeError exception. | 
|  | if (!is_shared && array_buffer->was_neutered()) { | 
|  | THROW_NEW_ERROR_RETURN_FAILURE( | 
|  | isolate, NewTypeError(MessageTemplate::kDetachedOperation, | 
|  | isolate->factory()->NewStringFromAsciiChecked( | 
|  | kMethodName))); | 
|  | } | 
|  |  | 
|  | // * [AB] Let len be O.[[ArrayBufferByteLength]]. | 
|  | // * [SAB] Let len be O.[[ArrayBufferByteLength]]. | 
|  | double const len = array_buffer->byte_length()->Number(); | 
|  |  | 
|  | // * Let relativeStart be ? ToInteger(start). | 
|  | Handle<Object> relative_start; | 
|  | ASSIGN_RETURN_FAILURE_ON_EXCEPTION(isolate, relative_start, | 
|  | Object::ToInteger(isolate, start)); | 
|  |  | 
|  | // * If relativeStart < 0, let first be max((len + relativeStart), 0); else | 
|  | //   let first be min(relativeStart, len). | 
|  | double const first = (relative_start->Number() < 0) | 
|  | ? Max(len + relative_start->Number(), 0.0) | 
|  | : Min(relative_start->Number(), len); | 
|  | Handle<Object> first_obj = isolate->factory()->NewNumber(first); | 
|  |  | 
|  | // * If end is undefined, let relativeEnd be len; else let relativeEnd be ? | 
|  | //   ToInteger(end). | 
|  | double relative_end; | 
|  | if (end->IsUndefined(isolate)) { | 
|  | relative_end = len; | 
|  | } else { | 
|  | Handle<Object> relative_end_obj; | 
|  | ASSIGN_RETURN_FAILURE_ON_EXCEPTION(isolate, relative_end_obj, | 
|  | Object::ToInteger(isolate, end)); | 
|  | relative_end = relative_end_obj->Number(); | 
|  | } | 
|  |  | 
|  | // * If relativeEnd < 0, let final be max((len + relativeEnd), 0); else let | 
|  | //   final be min(relativeEnd, len). | 
|  | double const final_ = (relative_end < 0) ? Max(len + relative_end, 0.0) | 
|  | : Min(relative_end, len); | 
|  |  | 
|  | // * Let newLen be max(final-first, 0). | 
|  | double const new_len = Max(final_ - first, 0.0); | 
|  | Handle<Object> new_len_obj = isolate->factory()->NewNumber(new_len); | 
|  |  | 
|  | // * [AB] Let ctor be ? SpeciesConstructor(O, %ArrayBuffer%). | 
|  | // * [SAB] Let ctor be ? SpeciesConstructor(O, %SharedArrayBuffer%). | 
|  | Handle<JSFunction> constructor_fun = is_shared | 
|  | ? isolate->shared_array_buffer_fun() | 
|  | : isolate->array_buffer_fun(); | 
|  | Handle<Object> ctor; | 
|  | ASSIGN_RETURN_FAILURE_ON_EXCEPTION( | 
|  | isolate, ctor, | 
|  | Object::SpeciesConstructor( | 
|  | isolate, Handle<JSReceiver>::cast(args.receiver()), constructor_fun)); | 
|  |  | 
|  | // * Let new be ? Construct(ctor, newLen). | 
|  | Handle<JSReceiver> new_; | 
|  | { | 
|  | const int argc = 1; | 
|  |  | 
|  | ScopedVector<Handle<Object>> argv(argc); | 
|  | argv[0] = new_len_obj; | 
|  |  | 
|  | Handle<Object> new_obj; | 
|  | ASSIGN_RETURN_FAILURE_ON_EXCEPTION( | 
|  | isolate, new_obj, Execution::New(isolate, ctor, argc, argv.start())); | 
|  |  | 
|  | new_ = Handle<JSReceiver>::cast(new_obj); | 
|  | } | 
|  |  | 
|  | // * If new does not have an [[ArrayBufferData]] internal slot, throw a | 
|  | //   TypeError exception. | 
|  | if (!new_->IsJSArrayBuffer()) { | 
|  | THROW_NEW_ERROR_RETURN_FAILURE( | 
|  | isolate, | 
|  | NewTypeError(MessageTemplate::kIncompatibleMethodReceiver, | 
|  | isolate->factory()->NewStringFromAsciiChecked(kMethodName), | 
|  | new_)); | 
|  | } | 
|  |  | 
|  | // * [AB] If IsSharedArrayBuffer(new) is true, throw a TypeError exception. | 
|  | // * [SAB] If IsSharedArrayBuffer(new) is false, throw a TypeError exception. | 
|  | Handle<JSArrayBuffer> new_array_buffer = Handle<JSArrayBuffer>::cast(new_); | 
|  | CHECK_SHARED(is_shared, new_array_buffer, kMethodName); | 
|  |  | 
|  | // * [AB] If IsDetachedBuffer(new) is true, throw a TypeError exception. | 
|  | if (!is_shared && new_array_buffer->was_neutered()) { | 
|  | THROW_NEW_ERROR_RETURN_FAILURE( | 
|  | isolate, NewTypeError(MessageTemplate::kDetachedOperation, | 
|  | isolate->factory()->NewStringFromAsciiChecked( | 
|  | kMethodName))); | 
|  | } | 
|  |  | 
|  | // * [AB] If SameValue(new, O) is true, throw a TypeError exception. | 
|  | if (!is_shared && new_->SameValue(*args.receiver())) { | 
|  | THROW_NEW_ERROR_RETURN_FAILURE( | 
|  | isolate, NewTypeError(MessageTemplate::kArrayBufferSpeciesThis)); | 
|  | } | 
|  |  | 
|  | // * [SAB] If new.[[ArrayBufferData]] and O.[[ArrayBufferData]] are the same | 
|  | //         Shared Data Block values, throw a TypeError exception. | 
|  | if (is_shared && | 
|  | new_array_buffer->backing_store() == array_buffer->backing_store()) { | 
|  | THROW_NEW_ERROR_RETURN_FAILURE( | 
|  | isolate, NewTypeError(MessageTemplate::kSharedArrayBufferSpeciesThis)); | 
|  | } | 
|  |  | 
|  | // * If new.[[ArrayBufferByteLength]] < newLen, throw a TypeError exception. | 
|  | if (new_array_buffer->byte_length()->Number() < new_len) { | 
|  | THROW_NEW_ERROR_RETURN_FAILURE( | 
|  | isolate, | 
|  | NewTypeError(is_shared ? MessageTemplate::kSharedArrayBufferTooShort | 
|  | : MessageTemplate::kArrayBufferTooShort)); | 
|  | } | 
|  |  | 
|  | // * [AB] NOTE: Side-effects of the above steps may have detached O. | 
|  | // * [AB] If IsDetachedBuffer(O) is true, throw a TypeError exception. | 
|  | if (!is_shared && array_buffer->was_neutered()) { | 
|  | THROW_NEW_ERROR_RETURN_FAILURE( | 
|  | isolate, NewTypeError(MessageTemplate::kDetachedOperation, | 
|  | isolate->factory()->NewStringFromAsciiChecked( | 
|  | kMethodName))); | 
|  | } | 
|  |  | 
|  | // * Let fromBuf be O.[[ArrayBufferData]]. | 
|  | // * Let toBuf be new.[[ArrayBufferData]]. | 
|  | // * Perform CopyDataBlockBytes(toBuf, 0, fromBuf, first, newLen). | 
|  | size_t first_size = 0, new_len_size = 0; | 
|  | CHECK(TryNumberToSize(*first_obj, &first_size)); | 
|  | CHECK(TryNumberToSize(*new_len_obj, &new_len_size)); | 
|  | DCHECK(NumberToSize(new_array_buffer->byte_length()) >= new_len_size); | 
|  |  | 
|  | if (new_len_size != 0) { | 
|  | size_t from_byte_length = NumberToSize(array_buffer->byte_length()); | 
|  | USE(from_byte_length); | 
|  | DCHECK(first_size <= from_byte_length); | 
|  | DCHECK(from_byte_length - first_size >= new_len_size); | 
|  | uint8_t* from_data = | 
|  | reinterpret_cast<uint8_t*>(array_buffer->backing_store()); | 
|  | uint8_t* to_data = | 
|  | reinterpret_cast<uint8_t*>(new_array_buffer->backing_store()); | 
|  | CopyBytes(to_data, from_data + first_size, new_len_size); | 
|  | } | 
|  |  | 
|  | return *new_; | 
|  | } | 
|  |  | 
|  | // ES #sec-sharedarraybuffer.prototype.slice | 
|  | BUILTIN(SharedArrayBufferPrototypeSlice) { | 
|  | const char* const kMethodName = "SharedArrayBuffer.prototype.slice"; | 
|  | return SliceHelper(args, isolate, kMethodName, true); | 
|  | } | 
|  |  | 
|  | // ES #sec-arraybuffer.prototype.slice | 
|  | // ArrayBuffer.prototype.slice ( start, end ) | 
|  | BUILTIN(ArrayBufferPrototypeSlice) { | 
|  | const char* const kMethodName = "ArrayBuffer.prototype.slice"; | 
|  | return SliceHelper(args, isolate, kMethodName, false); | 
|  | } | 
|  |  | 
|  | }  // namespace internal | 
|  | }  // namespace v8 |