Make private symbols non-enumerable

src/lookup.cc

 // Copyright 2014 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/lookup.h"
 
 #include "src/bootstrapper.h"
 #include "src/deoptimizer.h"
 #include "src/elements.h"
 #include "src/field-type.h"
@@ skipping 290 matching lines @@
 #endif
 }
 
 // Can only be called when the receiver is a JSObject. JSProxy has to be handled
 // via a trap. Adding properties to primitive values is not observable.
 void LookupIterator::PrepareTransitionToDataProperty(
     Handle<JSObject> receiver, Handle<Object> value,
     PropertyAttributes attributes, Object::StoreFromKeyed store_mode) {
   DCHECK(receiver.is_identical_to(GetStoreTarget()));
   if (state_ == TRANSITION) return;
+
+  if (!IsElement() && name()->IsPrivate()) {
+    attributes = static_cast<PropertyAttributes>(attributes | DONT_ENUM);
+  }
+
   DCHECK(state_ != LookupIterator::ACCESSOR ||
          (GetAccessors()->IsAccessorInfo() &&
           AccessorInfo::cast(*GetAccessors())->is_special_data_property()));
   DCHECK_NE(INTEGER_INDEXED_EXOTIC, state_);
   DCHECK(state_ == NOT_FOUND || !HolderIsReceiverOrHiddenPrototype());
 
   Handle<Map> map(receiver->map(), isolate_);
 
   // Dictionary maps can always have additional data properties.
   if (map->is_dictionary_map()) {
@@ skipping 114 matching lines @@
 }
 
 void LookupIterator::TransitionToAccessorProperty(
     Handle<Object> getter, Handle<Object> setter,
     PropertyAttributes attributes) {
   DCHECK(!getter->IsNull(isolate_) || !setter->IsNull(isolate_));
   // Can only be called when the receiver is a JSObject. JSProxy has to be
   // handled via a trap. Adding properties to primitive values is not
   // observable.
   Handle<JSObject> receiver = GetStoreTarget();
+  if (!IsElement() && name()->IsPrivate()) {
+    attributes = static_cast<PropertyAttributes>(attributes | DONT_ENUM);
+  }
 
   if (!IsElement() && !receiver->map()->is_dictionary_map()) {
     Handle<Map> old_map(receiver->map(), isolate_);
 
     if (!holder_.is_identical_to(receiver)) {
       holder_ = receiver;
       state_ = NOT_FOUND;
     } else if (state_ == INTERCEPTOR) {
       LookupInRegularHolder<false>(*old_map, *holder_);
     }
@@ skipping 404 matching lines @@
 
   // We have found a cached property! Modify the iterator accordingly.
   name_ = maybe_name.ToHandleChecked();
   Restart();
   CHECK_EQ(state(), LookupIterator::DATA);
   return true;
 }
 
 }  // namespace internal
 }  // namespace v8