[strong] Implement strong mode restrictions on property access

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 51247b728cf60730d3089b4a5bce6472673172ab..66154ab85c47007693bd9fc00c183e48b6e92a8a 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(),
+                                     Strength::WEAK));
       if (!prototype_parent->IsNull() && !prototype_parent->IsSpecObject()) {
         THROW_NEW_ERROR_RETURN_FAILURE(
             isolate, NewTypeError(MessageTemplate::kPrototypeParentNotAnObject,
@@ -252,7 +253,8 @@ RUNTIME_FUNCTION(Runtime_ClassGetSourceCode) {
 
 
 static Object* LoadFromSuper(Isolate* isolate, Handle<Object> receiver,
-                             Handle<JSObject> home_object, Handle<Name> name) {
+                             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);
@@ -260,18 +262,27 @@ static Object* LoadFromSuper(Isolate* isolate, Handle<Object> receiver,
 
   PrototypeIterator iter(isolate, home_object);
   Handle<Object> proto = PrototypeIterator::GetCurrent(iter);
-  if (!proto->IsJSReceiver()) return isolate->heap()->undefined_value();
+  if (!proto->IsJSReceiver()) {
+    if (is_strong(language_mode)) {
+      THROW_NEW_ERROR_RETURN_FAILURE(
+          isolate,
+          NewTypeError(MessageTemplate::kStrongPropertyAccess, proto, name));
+    }
+    return isolate->heap()->undefined_value();
+  }
 
   LookupIterator it(receiver, name, Handle<JSReceiver>::cast(proto));
   Handle<Object> result;
-  ASSIGN_RETURN_FAILURE_ON_EXCEPTION(isolate, result, Object::GetProperty(&it));
+  ASSIGN_RETURN_FAILURE_ON_EXCEPTION(
+      isolate, result, Object::GetProperty(&it, strength(language_mode)));
   return *result;
 }
 
 
 static Object* LoadElementFromSuper(Isolate* isolate, Handle<Object> receiver,
                                     Handle<JSObject> home_object,
-                                    uint32_t index) {
+                                    uint32_t index,
+                                    LanguageMode language_mode) {
   if (home_object->IsAccessCheckNeeded() && !isolate->MayAccess(home_object)) {
     isolate->ReportFailedAccessCheck(home_object);
     RETURN_FAILURE_IF_SCHEDULED_EXCEPTION(isolate);
@@ -279,45 +290,58 @@ static Object* LoadElementFromSuper(Isolate* isolate, Handle<Object> receiver,
 
   PrototypeIterator iter(isolate, home_object);
   Handle<Object> proto = PrototypeIterator::GetCurrent(iter);
-  if (!proto->IsJSReceiver()) return isolate->heap()->undefined_value();
+  if (!proto->IsJSReceiver()) {
+    if (is_strong(language_mode)) {
+      Handle<Object> name = isolate->factory()->NewNumberFromUint(index);
+      THROW_NEW_ERROR_RETURN_FAILURE(
+          isolate,
+          NewTypeError(MessageTemplate::kStrongPropertyAccess, proto, name));
+    }
+    return isolate->heap()->undefined_value();
+  }
 
   LookupIterator it(isolate, receiver, index, Handle<JSReceiver>::cast(proto));
   Handle<Object> result;
-  ASSIGN_RETURN_FAILURE_ON_EXCEPTION(isolate, result, Object::GetProperty(&it));
+  ASSIGN_RETURN_FAILURE_ON_EXCEPTION(
+      isolate, result, Object::GetProperty(&it, strength(language_mode)));
   return *result;
 }
 
 
 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);
+  return LoadFromSuper(isolate, receiver, home_object, name, language_mode);
 }
 
 
 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;
   if (key->ToArrayIndex(&index)) {
-    return LoadElementFromSuper(isolate, receiver, home_object, index);
+    return LoadElementFromSuper(isolate, receiver, home_object, index,
+                                language_mode);
   }
 
   Handle<Name> name;
   ASSIGN_RETURN_FAILURE_ON_EXCEPTION(isolate, name,
                                      Runtime::ToName(isolate, key));
   if (name->AsArrayIndex(&index)) {
-    return LoadElementFromSuper(isolate, receiver, home_object, index);
+    return LoadElementFromSuper(isolate, receiver, home_object, index,
+                                language_mode);
   }
-  return LoadFromSuper(isolate, receiver, home_object, name);
+  return LoadFromSuper(isolate, receiver, home_object, name, language_mode);
 }