[strong] Implement strong property access semantics

src/runtime/runtime-classes.cc

Index: src/runtime/runtime-classes.cc
diff --git a/src/runtime/runtime-classes.cc b/src/runtime/runtime-classes.cc
index dedff928a79618606824127258f3c9d6930ceffa..121530feab40d641210e11c559cbe6e0607b0c7c 100644
--- a/src/runtime/runtime-classes.cc
+++ b/src/runtime/runtime-classes.cc
@@ -120,7 +120,8 @@ RUNTIME_FUNCTION(Runtime_DefineClass) {
       ASSIGN_RETURN_FAILURE_ON_EXCEPTION(
           isolate, prototype_parent,
           Runtime::GetObjectProperty(isolate, super_class,
-                                     isolate->factory()->prototype_string()));
+                                     isolate->factory()->prototype_string(),
+                                     SLOPPY));
       if (!prototype_parent->IsNull() && !prototype_parent->IsSpecObject()) {
         THROW_NEW_ERROR_RETURN_FAILURE(
             isolate, NewTypeError(MessageTemplate::kPrototypeParentNotAnObject,
@@ -244,64 +245,89 @@ RUNTIME_FUNCTION(Runtime_ClassGetSourceCode) {
 }
 
 
-static Object* LoadFromSuper(Isolate* isolate, Handle<Object> receiver,
-                             Handle<JSObject> home_object, Handle<Name> name) {
+static MaybeHandle<Object> LoadFromSuper(Isolate* isolate,
+                                         Handle<Object> receiver,
+                                         Handle<JSObject> home_object,
+                                         Handle<Name> name,
+                                         LanguageMode language_mode) {
   if (home_object->IsAccessCheckNeeded() && !isolate->MayAccess(home_object)) {
     isolate->ReportFailedAccessCheck(home_object);
-    RETURN_FAILURE_IF_SCHEDULED_EXCEPTION(isolate);
+    RETURN_EXCEPTION_IF_SCHEDULED_EXCEPTION(isolate, Object);
   }
 
   PrototypeIterator iter(isolate, home_object);
   Handle<Object> proto = PrototypeIterator::GetCurrent(iter);
-  if (!proto->IsJSReceiver()) return isolate->heap()->undefined_value();
+  if (!proto->IsJSReceiver()) {
+    return Object::ReadAbsentProperty(isolate, proto, name, language_mode);
+  }
 
   LookupIterator it(receiver, name, Handle<JSReceiver>::cast(proto));
   Handle<Object> result;
-  ASSIGN_RETURN_FAILURE_ON_EXCEPTION(isolate, result, Object::GetProperty(&it));
-  return *result;
+  ASSIGN_RETURN_ON_EXCEPTION(isolate, result,
+                             Object::GetProperty(&it, language_mode), Object);
+  return result;
 }
 
 
-static Object* LoadElementFromSuper(Isolate* isolate, Handle<Object> receiver,
-                                    Handle<JSObject> home_object,
-                                    uint32_t index) {
+static MaybeHandle<Object> LoadElementFromSuper(Isolate* isolate,
+                                                Handle<Object> receiver,
+                                                Handle<JSObject> home_object,
+                                                uint32_t index,
+                                                LanguageMode language_mode) {
   if (home_object->IsAccessCheckNeeded() && !isolate->MayAccess(home_object)) {
     isolate->ReportFailedAccessCheck(home_object);
-    RETURN_FAILURE_IF_SCHEDULED_EXCEPTION(isolate);
+    RETURN_EXCEPTION_IF_SCHEDULED_EXCEPTION(isolate, Object);
   }
 
   PrototypeIterator iter(isolate, home_object);
   Handle<Object> proto = PrototypeIterator::GetCurrent(iter);
-  if (!proto->IsJSReceiver()) return isolate->heap()->undefined_value();
+  if (!proto->IsJSReceiver()) {
+    Handle<Object> name = isolate->factory()->NewNumberFromUint(index);
+    return Object::ReadAbsentProperty(isolate, proto, name, language_mode);
+  }
 
   LookupIterator it(isolate, receiver, index, Handle<JSReceiver>::cast(proto));
   Handle<Object> result;
-  ASSIGN_RETURN_FAILURE_ON_EXCEPTION(isolate, result, Object::GetProperty(&it));
-  return *result;
+  ASSIGN_RETURN_ON_EXCEPTION(isolate, result,
+                             Object::GetProperty(&it, language_mode), Object);
+  return result;
 }
 
 
+// TODO(conradw): It would be more efficient to have a separate runtime function
+// for strong mode.
 RUNTIME_FUNCTION(Runtime_LoadFromSuper) {
   HandleScope scope(isolate);
-  DCHECK(args.length() == 3);
+  DCHECK(args.length() == 4);
   CONVERT_ARG_HANDLE_CHECKED(Object, receiver, 0);
   CONVERT_ARG_HANDLE_CHECKED(JSObject, home_object, 1);
   CONVERT_ARG_HANDLE_CHECKED(Name, name, 2);
+  CONVERT_LANGUAGE_MODE_ARG_CHECKED(language_mode, 3);
 
-  return LoadFromSuper(isolate, receiver, home_object, name);
+  Handle<Object> result;
+  ASSIGN_RETURN_FAILURE_ON_EXCEPTION(
+      isolate, result,
+      LoadFromSuper(isolate, receiver, home_object, name, language_mode));
+  return *result;
 }
 
 
 RUNTIME_FUNCTION(Runtime_LoadKeyedFromSuper) {
   HandleScope scope(isolate);
-  DCHECK(args.length() == 3);
+  DCHECK(args.length() == 4);
   CONVERT_ARG_HANDLE_CHECKED(Object, receiver, 0);
   CONVERT_ARG_HANDLE_CHECKED(JSObject, home_object, 1);
   CONVERT_ARG_HANDLE_CHECKED(Object, key, 2);
+  CONVERT_LANGUAGE_MODE_ARG_CHECKED(language_mode, 3);
 
   uint32_t index = 0;
+  Handle<Object> result;
+
   if (key->ToArrayIndex(&index)) {
-    return LoadElementFromSuper(isolate, receiver, home_object, index);
+    ASSIGN_RETURN_FAILURE_ON_EXCEPTION(
+        isolate, result, LoadElementFromSuper(isolate, receiver, home_object,
+                                              index, language_mode));
+    return *result;
   }
 
   Handle<Name> name;
@@ -309,9 +335,15 @@ RUNTIME_FUNCTION(Runtime_LoadKeyedFromSuper) {
                                      Runtime::ToName(isolate, key));
   // TODO(verwaest): Unify using LookupIterator.
   if (name->AsArrayIndex(&index)) {
-    return LoadElementFromSuper(isolate, receiver, home_object, index);
+    ASSIGN_RETURN_FAILURE_ON_EXCEPTION(
+        isolate, result, LoadElementFromSuper(isolate, receiver, home_object,
+                                              index, language_mode));
+    return *result;
   }
-  return LoadFromSuper(isolate, receiver, home_object, name);
+  ASSIGN_RETURN_FAILURE_ON_EXCEPTION(
+      isolate, result,
+      LoadFromSuper(isolate, receiver, home_object, name, language_mode));
+  return *result;
 }