| // 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/handles/maybe-handles-inl.h" | 
 | #include "src/heap/heap-inl.h"  // For ToBoolean. TODO(jkummerow): Drop. | 
 | #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 { | 
 |  | 
 | #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));                                                \ | 
 |   } | 
 |  | 
 | // ----------------------------------------------------------------------------- | 
 | // ES#sec-arraybuffer-objects | 
 |  | 
 | namespace { | 
 |  | 
 | Object ConstructBuffer(Isolate* isolate, Handle<JSFunction> target, | 
 |                        Handle<JSReceiver> new_target, Handle<Object> length, | 
 |                        InitializedFlag initialized) { | 
 |   SharedFlag shared = (*target != target->native_context().array_buffer_fun()) | 
 |                           ? SharedFlag::kShared | 
 |                           : SharedFlag::kNotShared; | 
 |   Handle<JSObject> result; | 
 |   ASSIGN_RETURN_FAILURE_ON_EXCEPTION( | 
 |       isolate, result, | 
 |       JSObject::New(target, new_target, Handle<AllocationSite>::null())); | 
 |   auto array_buffer = Handle<JSArrayBuffer>::cast(result); | 
 |   // Ensure that all fields are initialized because BackingStore::Allocate is | 
 |   // allowed to GC. Note that we cannot move the allocation of the ArrayBuffer | 
 |   // after BackingStore::Allocate because of the spec. | 
 |   array_buffer->Setup(shared, nullptr); | 
 |  | 
 |   size_t byte_length; | 
 |   if (!TryNumberToSize(*length, &byte_length) || | 
 |       byte_length > JSArrayBuffer::kMaxByteLength) { | 
 |     // ToNumber failed. | 
 |     THROW_NEW_ERROR_RETURN_FAILURE( | 
 |         isolate, NewRangeError(MessageTemplate::kInvalidArrayBufferLength)); | 
 |   } | 
 |  | 
 |   auto backing_store = | 
 |       BackingStore::Allocate(isolate, byte_length, shared, initialized); | 
 |   if (!backing_store) { | 
 |     // Allocation of backing store failed. | 
 |     THROW_NEW_ERROR_RETURN_FAILURE( | 
 |         isolate, NewRangeError(MessageTemplate::kArrayBufferAllocationFailed)); | 
 |   } | 
 |  | 
 |   array_buffer->Attach(std::move(backing_store)); | 
 |   return *array_buffer; | 
 | } | 
 |  | 
 | }  // 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))); | 
 |   } | 
 |   // [[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, | 
 |                            InitializedFlag::kZeroInitialized); | 
 | } | 
 |  | 
 | // 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, | 
 |                          InitializedFlag::kUninitialized); | 
 | } | 
 |  | 
 | 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_detached()) { | 
 |     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(); | 
 |  | 
 |   // * 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) | 
 |                            ? std::max(len + relative_start->Number(), 0.0) | 
 |                            : std::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) ? std::max(len + relative_end, 0.0) | 
 |                                            : std::min(relative_end, len); | 
 |  | 
 |   // * Let newLen be max(final-first, 0). | 
 |   double const new_len = std::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.begin())); | 
 |  | 
 |     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_detached()) { | 
 |     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() < 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_detached()) { | 
 |     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(new_array_buffer->byte_length() >= new_len_size); | 
 |  | 
 |   if (new_len_size != 0) { | 
 |     size_t from_byte_length = 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 |