Arguments object has @@iterator

src/accessors.cc

Index: src/accessors.cc
diff --git a/src/accessors.cc b/src/accessors.cc
index c2361b3e9cda753c69ae5e12bb57ded05385cde8..dd09a69c5a0fd2431bdcf6bd9293cebb386b9477 100644
--- a/src/accessors.cc
+++ b/src/accessors.cc
@@ -156,6 +156,53 @@ bool SetPropertyOnInstanceIfInherited(
 
 
 //
+// Accessors::ArgumentsIterator
+//
+
+
+void Accessors::ArgumentsIteratorGetter(
+    v8::Local<v8::Name> name, const v8::PropertyCallbackInfo<v8::Value>& info) {
+  i::Isolate* isolate = reinterpret_cast<i::Isolate*>(info.GetIsolate());
+  DisallowHeapAllocation no_allocation;
+  HandleScope scope(isolate);
+  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);
+  LookupIterator it(object, Utils::OpenHandle(*name));

[Toon Verwaest, 2014/08/22 11:01:02]

What about just

if (SetPropertyOnInstanceIfInherited(isolate, info, name, value)) {
  return;
}

LookupIterator it(object, name);
CHECK(it.HasProperty());
DCHECK(it.HolderisReceiverOrHiddenPrototype());
Object::SetDataProperty(&it, value);

[wingo, 2014/08/25 08:42:30]

Done, works fine; thanks for the tip.  The difference is that setting the
property on a frozen object doesn't throw, because of the strict-mode thing.  I
changed the test case accordingly.  WDYT?

+  if (it.HasProperty() && it.HolderIsReceiverOrHiddenPrototype()) {
+    // The receiver is an arguments object.  Replace this weird accessor with a
+    // normal data property.
+    Object::SetDataProperty(&it, value).Check();
+  } else {
+    // The receiver has an arguments object on the proto chain.  Add a new data
+    // property to the receiver, if it's extensible.
+    if (Object::AddDataProperty(&it, value, DONT_ENUM, STRICT,
+                                Object::CERTAINLY_NOT_STORE_FROM_KEYED)
+            .is_null()) {
+      isolate->OptionalRescheduleException(false);
+    }
+  }
+}
+
+
+Handle<AccessorInfo> Accessors::ArgumentsIteratorInfo(
+    Isolate* isolate, PropertyAttributes attributes) {
+  Handle<Name> name(isolate->native_context()->iterator_symbol(), isolate);
+  return MakeAccessor(isolate, name, &ArgumentsIteratorGetter,
+                      &ArgumentsIteratorSetter, attributes);
+}
+
+
+//
 // Accessors::ArrayLength
 //