[api] Add PropertyDescriptor and DefineProperty().

src/api.cc

 // Copyright 2012 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/api.h"
 
 #include <string.h>  // For memcpy, strlen.
 #ifdef V8_USE_ADDRESS_SANITIZER
 #include <sanitizer/asan_interface.h>
 #endif  // V8_USE_ADDRESS_SANITIZER
@@ skipping 3673 matching lines @@
   desc.set_enumerable(!(attributes & v8::DontEnum));
   desc.set_configurable(!(attributes & v8::DontDelete));
   desc.set_value(value_obj);
   Maybe<bool> success = i::JSReceiver::DefineOwnProperty(
       isolate, self, key_obj, &desc, i::Object::DONT_THROW);
   // Even though we said DONT_THROW, there might be accessors that do throw.
   RETURN_ON_FAILED_EXECUTION_PRIMITIVE(bool);
   return success;
 }
 
+Maybe<bool> v8::Object::DefineProperty(v8::Local<v8::Context> context,
+                                       v8::Local<Name> key,
+                                       const PropertyDescriptor* descriptor) {
+  PREPARE_FOR_EXECUTION_PRIMITIVE(context, Object, DefineProperty, bool);
+  auto self = Utils::OpenHandle(this);
+  auto key_obj = Utils::OpenHandle(*key);
+
+  if (self->IsAccessCheckNeeded() &&

[Toon Verwaest, 2016/08/18 07:25:39]

I'm pretty sure that access is properly checked in DefineOwnProperty. I don't
think we need it above either.

[Franzi, 2016/08/18 09:56:24]

You're right. Deleted in in v8::Object::DefineOwnProperty() as well. 

+      !isolate->MayAccess(handle(isolate->context()),
+                          i::Handle<i::JSObject>::cast(self))) {
+    isolate->ReportFailedAccessCheck(i::Handle<i::JSObject>::cast(self));
+    return Nothing<bool>();
+  }
+
+  i::PropertyDescriptor desc;
+  if (descriptor->has_value()) {
+    if (descriptor->value().IsEmpty()) {
+      desc.set_value(isolate->factory()->undefined_value());
+    } else {
+      desc.set_value(Utils::OpenHandle(*descriptor->value()));
+    }
+  }
+  if (descriptor->has_get()) {
+    if (descriptor->get().IsEmpty()) {
+      desc.set_get(isolate->factory()->undefined_value());
+    } else {
+      desc.set_get(Utils::OpenHandle(*descriptor->get()));
+    }
+  }
+  if (descriptor->has_set()) {
+    if (descriptor->set().IsEmpty()) {
+      desc.set_set(isolate->factory()->undefined_value());
+    } else {
+      desc.set_set(Utils::OpenHandle(*descriptor->set()));
+    }
+  }
+  if (descriptor->has_enumerable()) {
+    desc.set_enumerable(descriptor->enumerable());
+  }
+  if (descriptor->has_configurable()) {
+    desc.set_configurable(descriptor->configurable());
+  }
+  if (descriptor->has_writable()) {
+    desc.set_writable(descriptor->writable());
+  }
+
+  auto success = i::JSReceiver::DefineOwnProperty(isolate, self, key_obj, &desc,
+                                                  i::Object::DONT_THROW);
+  RETURN_ON_FAILED_EXECUTION_PRIMITIVE(bool);
+  return success;
+}
 
 MUST_USE_RESULT
 static i::MaybeHandle<i::Object> DefineObjectProperty(
     i::Handle<i::JSObject> js_object, i::Handle<i::Object> key,
     i::Handle<i::Object> value, i::PropertyAttributes attrs) {
   i::Isolate* isolate = js_object->GetIsolate();
   bool success = false;
   i::LookupIterator it = i::LookupIterator::PropertyOrElement(
       isolate, js_object, key, &success, i::LookupIterator::OWN);
   if (!success) return i::MaybeHandle<i::Object>();
@@ skipping 5313 matching lines @@
   Address callback_address =
       reinterpret_cast<Address>(reinterpret_cast<intptr_t>(callback));
   VMState<EXTERNAL> state(isolate);
   ExternalCallbackScope call_scope(isolate, callback_address);
   callback(info);
 }
 
 
 }  // namespace internal
 }  // namespace v8