add interceptors which do not mask existing properties

src/api.cc

 // Copyright 2012 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/api.h"
 
 #include <string.h>  // For memcpy, strlen.
 #ifdef V8_USE_ADDRESS_SANITIZER
 #include <sanitizer/asan_interface.h>
 #endif  // V8_USE_ADDRESS_SANITIZER
@@ skipping 1279 matching lines @@
                                  AccessControl settings,
                                  PropertyAttribute attribute,
                                  v8::Handle<AccessorSignature> signature) {
   TemplateSetAccessor(
       this, name, getter, setter, data, settings, attribute, signature);
 }
 
 
 template <typename Getter, typename Setter, typename Query, typename Deleter,
           typename Enumerator>
-static void ObjectTemplateSetNamedPropertyHandler(
-    ObjectTemplate* templ, Getter getter, Setter setter, Query query,
-    Deleter remover, Enumerator enumerator, Handle<Value> data,
-    bool can_intercept_symbols, PropertyHandlerFlags flags) {
+static void ObjectTemplateSetNamedPropertyHandler(ObjectTemplate* templ,
+                                                  Getter getter, Setter setter,
+                                                  Query query, Deleter remover,
+                                                  Enumerator enumerator,
+                                                  Handle<Value> data,
+                                                  PropertyHandlerFlags flags) {
   i::Isolate* isolate = Utils::OpenHandle(templ)->GetIsolate();
   ENTER_V8(isolate);
   i::HandleScope scope(isolate);
   auto cons = EnsureConstructor(isolate, templ);
   EnsureNotInstantiated(cons, "ObjectTemplateSetNamedPropertyHandler");
   auto obj = i::Handle<i::InterceptorInfo>::cast(
       isolate->factory()->NewStruct(i::INTERCEPTOR_INFO_TYPE));
 
   if (getter != 0) SET_FIELD_WRAPPED(obj, set_getter, getter);
   if (setter != 0) SET_FIELD_WRAPPED(obj, set_setter, setter);
   if (query != 0) SET_FIELD_WRAPPED(obj, set_query, query);
   if (remover != 0) SET_FIELD_WRAPPED(obj, set_deleter, remover);
   if (enumerator != 0) SET_FIELD_WRAPPED(obj, set_enumerator, enumerator);
   obj->set_flags(0);
-  obj->set_can_intercept_symbols(can_intercept_symbols);
+  obj->set_can_intercept_symbols(
+      !(static_cast<int>(flags) &
+        static_cast<int>(PropertyHandlerFlags::kOnlyInterceptStrings)));
   obj->set_all_can_read(static_cast<int>(flags) &
                         static_cast<int>(PropertyHandlerFlags::kAllCanRead));
+  obj->set_non_masking(static_cast<int>(flags) &
+                       static_cast<int>(PropertyHandlerFlags::kNonMasking));
 
   if (data.IsEmpty()) {
     data = v8::Undefined(reinterpret_cast<v8::Isolate*>(isolate));
   }
   obj->set_data(*Utils::OpenHandle(*data));
   cons->set_named_property_handler(*obj);
 }
 
 
 void ObjectTemplate::SetNamedPropertyHandler(
     NamedPropertyGetterCallback getter, NamedPropertySetterCallback setter,
     NamedPropertyQueryCallback query, NamedPropertyDeleterCallback remover,
     NamedPropertyEnumeratorCallback enumerator, Handle<Value> data) {
-  ObjectTemplateSetNamedPropertyHandler(this, getter, setter, query, remover,
-                                        enumerator, data, false,
-                                        PropertyHandlerFlags::kNone);
+  ObjectTemplateSetNamedPropertyHandler(
+      this, getter, setter, query, remover, enumerator, data,
+      PropertyHandlerFlags::kOnlyInterceptStrings);
 }
 
 
 void ObjectTemplate::SetHandler(
     const NamedPropertyHandlerConfiguration& config) {
   ObjectTemplateSetNamedPropertyHandler(
       this, config.getter, config.setter, config.query, config.deleter,
-      config.enumerator, config.data, true, config.flags);
+      config.enumerator, config.data, config.flags);
 }
 
 
 void ObjectTemplate::MarkAsUndetectable() {
   i::Isolate* isolate = Utils::OpenHandle(this)->GetIsolate();
   ENTER_V8(isolate);
   i::HandleScope scope(isolate);
   auto cons = EnsureConstructor(isolate, this);
   EnsureNotInstantiated(cons, "v8::ObjectTemplate::MarkAsUndetectable");
   cons->set_undetectable(true);
@@ skipping 6671 matching lines @@
   Isolate* isolate = reinterpret_cast<Isolate*>(info.GetIsolate());
   Address callback_address =
       reinterpret_cast<Address>(reinterpret_cast<intptr_t>(callback));
   VMState<EXTERNAL> state(isolate);
   ExternalCallbackScope call_scope(isolate, callback_address);
   callback(info);
 }
 
 
 } }  // namespace v8::internal