[strong] Implement per-object restrictions behaviour of delete operator

src/objects.cc

Index: src/objects.cc
diff --git a/src/objects.cc b/src/objects.cc
index ecb5bf1b5164265ae48d7f4be04d01181a7c8c65..9505800246f849e035de242fb5d874c27d32c833 100644
--- a/src/objects.cc
+++ b/src/objects.cc
@@ -5513,6 +5513,17 @@ MaybeHandle<Object> JSObject::DeleteProperty(Handle<JSObject> object,
 MaybeHandle<Object> JSReceiver::DeleteElement(Handle<JSReceiver> object,
                                               uint32_t index,
                                               LanguageMode language_mode) {
+  if (object->map()->is_strong()) {
+    Isolate* isolate = object->GetIsolate();
+    if (is_strict(language_mode)) {
+      THROW_NEW_ERROR(

[rossberg, 2015/05/22 11:34:50]

Why do we need to throw here? Returning false should already cause an exception
if invoked in strict mode.

[conradw, 2015/05/22 13:37:56]

Discussed offline, throw is needed but is in wrong place.

+          isolate,
+          NewTypeError(MessageTemplate::kStrongDeleteProperty,
+                       isolate->factory()->NewNumberFromUint(index), object),
+          Object);
+    }
+    return isolate->factory()->false_value();
+  }
   if (object->IsJSProxy()) {
     return JSProxy::DeleteElementWithHandler(Handle<JSProxy>::cast(object),
                                              index, language_mode);
@@ -5525,6 +5536,16 @@ MaybeHandle<Object> JSReceiver::DeleteElement(Handle<JSReceiver> object,
 MaybeHandle<Object> JSReceiver::DeleteProperty(Handle<JSReceiver> object,
                                                Handle<Name> name,
                                                LanguageMode language_mode) {
+  if (object->map()->is_strong()) {
+    Isolate* isolate = object->GetIsolate();
+    if (is_strict(language_mode)) {
+      THROW_NEW_ERROR(

[rossberg, 2015/05/22 11:34:50]

Same here.

[conradw, 2015/05/22 13:37:56]

See above.

+          isolate,
+          NewTypeError(MessageTemplate::kStrongDeleteProperty, name, object),
+          Object);
+    }
+    return isolate->factory()->false_value();
+  }
   if (object->IsJSProxy()) {
     return JSProxy::DeletePropertyWithHandler(Handle<JSProxy>::cast(object),
                                               name, language_mode);