Use a private own symbol instead of a hidden property for hash codes

src/isolate.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 <stdlib.h>
 
 #include <fstream>  // NOLINT(readability/streams)
 #include <sstream>
 
 #include "src/v8.h"
@@ skipping 761 matching lines @@
   }
 
   // Leaving JavaScript.
   VMState<EXTERNAL> state(this);
   thread_local_top()->failed_access_check_callback_(
       v8::Utils::ToLocal(receiver), v8::ACCESS_HAS, v8::Utils::ToLocal(data));
 }
 
 
 bool Isolate::IsInternallyUsedPropertyName(Handle<Object> name) {
+  if (name->IsSymbol()) {
+    return (Handle<Symbol>::cast(name)->is_private()) &&
+           Handle<Symbol>::cast(name)->is_own();
+  }
   return name.is_identical_to(factory()->hidden_string());
 }
 
 
 bool Isolate::IsInternallyUsedPropertyName(Object* name) {
   return name == heap()->hidden_string();

[arv (Not doing code reviews), 2015/05/14 19:58:54]

Does this one need to be updated too?

 }
 
 
 bool Isolate::MayAccess(Handle<JSObject> receiver) {
   DCHECK(receiver->IsJSGlobalProxy() || receiver->IsAccessCheckNeeded());
 
   // Check for compatibility between the security tokens in the
   // current lexical context and the accessed object.
   DCHECK(context());
 
@@ skipping 1723 matching lines @@
     Handle<JSObject> registry = factory()->NewJSObjectFromMap(map);
     heap()->set_symbol_registry(*registry);
 
     static const char* nested[] = {"for", "for_api", "keyFor", "private_api",
                                    "private_intern"};
     for (unsigned i = 0; i < arraysize(nested); ++i) {
       Handle<String> name = factory()->InternalizeUtf8String(nested[i]);
       Handle<JSObject> obj = factory()->NewJSObjectFromMap(map);
       JSObject::NormalizeProperties(obj, KEEP_INOBJECT_PROPERTIES, 8,
                                     "SetupSymbolRegistry");
+      if (strcmp(nested[i], "private_intern") == 0) {
+        heap()->AddPrivateGlobalSymbols(obj);
+      }
       JSObject::SetProperty(registry, name, obj, STRICT).Assert();
     }
   }
   return Handle<JSObject>::cast(factory()->symbol_registry());
 }
 
 
 void Isolate::AddCallCompletedCallback(CallCompletedCallback callback) {
   for (int i = 0; i < call_completed_callbacks_.length(); i++) {
     if (callback == call_completed_callbacks_.at(i)) return;
@@ skipping 237 matching lines @@
   if (prev_ && prev_->Intercept(flag)) return true;
   // Then check whether this scope intercepts.
   if ((flag & intercept_mask_)) {
     intercepted_flags_ |= flag;
     return true;
   }
   return false;
 }
 
 } }  // namespace v8::internal