Fixing Sloppy Symbol.iterator setter

src/accessors.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/accessors.h"
 
 #include "src/api.h"
 #include "src/contexts.h"
 #include "src/deoptimizer.h"
 #include "src/execution.h"
@@ skipping 128 matching lines @@
   Object* result = isolate->native_context()->array_values_iterator();
   info.GetReturnValue().Set(Utils::ToLocal(Handle<Object>(result, isolate)));
 }
 
 
 void Accessors::ArgumentsIteratorSetter(
     v8::Local<v8::Name> name, v8::Local<v8::Value> val,
     const v8::PropertyCallbackInfo<void>& info) {
   i::Isolate* isolate = reinterpret_cast<i::Isolate*>(info.GetIsolate());
   HandleScope scope(isolate);
-  Handle<JSObject> object = Utils::OpenHandle(*info.This());
-  Handle<Object> value = Utils::OpenHandle(*val);
+  Handle<JSObject> object_handle = Utils::OpenHandle(*info.This());
+  Handle<Object> value_handle = Utils::OpenHandle(*val);
+  Handle<Name> name_handle = Utils::OpenHandle(*name);
 
-  LookupIterator it(object, Utils::OpenHandle(*name));
-  CHECK_EQ(LookupIterator::ACCESSOR, it.state());
-  DCHECK(it.HolderIsReceiverOrHiddenPrototype());
-
-  if (Object::SetDataProperty(&it, value).is_null()) {
-    isolate->OptionalRescheduleException(false);
-  }
+  JSObject::DefinePropertyOrElementIgnoreAttributes(object_handle, name_handle,
+                                                    value_handle, NONE)
+      .Check();

[Camillo Bruni, 2015/09/10 13:59:48]

I am not fully sure if and how I should check for exceptions here...

[Jakob Kummerow, 2015/09/10 14:29:20]

if: yes, I think you should. (Rule of thumb: if a CHECK or .Check() ever fails
in production, it's a bug. It's conceivable that this one might fail.)
how: like the old code did. If the MaybeHandle is_null(), call
isolate->OptionalRescheduleException.

 }
 
 
 Handle<AccessorInfo> Accessors::ArgumentsIteratorInfo(
     Isolate* isolate, PropertyAttributes attributes) {
   Handle<Name> name = isolate->factory()->iterator_symbol();
   return MakeAccessor(isolate, name, &ArgumentsIteratorGetter,
                       &ArgumentsIteratorSetter, attributes);
 }
 
@@ skipping 1320 matching lines @@
   Handle<Object> getter = v8::FromCData(isolate, &ModuleGetExport);
   Handle<Object> setter = v8::FromCData(isolate, &ModuleSetExport);
   info->set_getter(*getter);
   if (!(attributes & ReadOnly)) info->set_setter(*setter);
   return info;
 }
 
 
 }  // namespace internal
 }  // namespace v8