ES6: Add Object.getOwnPropertySymbols

src/objects.cc

 // Copyright 2013 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 5893 matching lines @@
     ASSERT(!curr->HasNamedInterceptor());
     ASSERT(!curr->HasIndexedInterceptor());
     ASSERT(!curr->IsAccessCheckNeeded());
     if (curr->NumberOfEnumElements() > 0) return false;
     if (curr != this && enum_length != 0) return false;
   }
   return true;
 }
 
 
+static bool FilterKey(Object* key, PropertyAttributes filter) {
+  if (key->IsSymbol()) {

[rossberg, 2013/12/18 16:50:12]

I would prefer to turn this inside out and do the filter checks first and the
(more expensive) instance type checks only if necessary.

[arv (Not doing code reviews), 2013/12/18 18:07:12]

Done.

However, these filters are not mutually exclusive so I can either call IsSymbol
once for each case or I could do it once by adding another bitmask check.

+    if (filter & SYMBOLIC) return true;
+    if ((filter & PRIVATE_SYMBOL) && Symbol::cast(key)->is_private()) {
+      return true;
+    }
+  } else {
+    if (filter & STRING) return true;
+  }
+  return false;
+}
+
+
 int Map::NumberOfDescribedProperties(DescriptorFlag which,
                                      PropertyAttributes filter) {
   int result = 0;
   DescriptorArray* descs = instance_descriptors();
   int limit = which == ALL_DESCRIPTORS
       ? descs->number_of_descriptors()
       : NumberOfOwnDescriptors();
   for (int i = 0; i < limit; i++) {
     if ((descs->GetDetails(i).attributes() & filter) == 0 &&
-        ((filter & SYMBOLIC) == 0 || !descs->GetKey(i)->IsSymbol())) {
+        !FilterKey(descs->GetKey(i), filter)) {
       result++;
     }
   }
   return result;
 }
 
 
 int Map::NextFreePropertyIndex() {
   int max_index = -1;
   int number_of_own_descriptors = NumberOfOwnDescriptors();
@@ skipping 7610 matching lines @@
 // purpose of this function is to provide reflection information for the object
 // mirrors.
 void JSObject::GetLocalPropertyNames(
     FixedArray* storage, int index, PropertyAttributes filter) {
   ASSERT(storage->length() >= (NumberOfLocalProperties(filter) - index));
   if (HasFastProperties()) {
     int real_size = map()->NumberOfOwnDescriptors();
     DescriptorArray* descs = map()->instance_descriptors();
     for (int i = 0; i < real_size; i++) {
       if ((descs->GetDetails(i).attributes() & filter) == 0 &&
-          ((filter & SYMBOLIC) == 0 || !descs->GetKey(i)->IsSymbol())) {
+          !FilterKey(descs->GetKey(i), filter)) {
         storage->set(index++, descs->GetKey(i));
       }
     }
   } else {
     property_dictionary()->CopyKeysTo(storage,
                                       index,
                                       filter,
                                       NameDictionary::UNSORTED);
   }
 }
@@ skipping 2081 matching lines @@
 
 
 template<typename Shape, typename Key>
 int Dictionary<Shape, Key>::NumberOfElementsFilterAttributes(
     PropertyAttributes filter) {
   int capacity = HashTable<Shape, Key>::Capacity();
   int result = 0;
   for (int i = 0; i < capacity; i++) {
     Object* k = HashTable<Shape, Key>::KeyAt(i);
     if (HashTable<Shape, Key>::IsKey(k) &&
-        ((filter & SYMBOLIC) == 0 || !k->IsSymbol())) {
+        !FilterKey(k, filter)) {
       PropertyDetails details = DetailsAt(i);
       if (details.IsDeleted()) continue;
       PropertyAttributes attr = details.attributes();
       if ((attr & filter) == 0) result++;
     }
   }
   return result;
 }
 
 
@@ skipping 984 matching lines @@
 #define ERROR_MESSAGES_TEXTS(C, T) T,
   static const char* error_messages_[] = {
       ERROR_MESSAGES_LIST(ERROR_MESSAGES_TEXTS)
   };
 #undef ERROR_MESSAGES_TEXTS
   return error_messages_[reason];
 }
 
 
 } }  // namespace v8::internal