Move hash code from hidden string to a private symbol

test/cctest/test-api.cc

 // Copyright 2012 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 2241 matching lines @@
     CompileRun(
         "function cnst() { return 42; };\n"
         "Object.prototype.__defineGetter__('v8::IdentityHash', cnst);\n");
     Local<v8::Object> o1 = v8::Object::New(isolate);
     Local<v8::Object> o2 = v8::Object::New(isolate);
     CHECK_NE(o1->GetIdentityHash(), o2->GetIdentityHash());
   }
 }
 
 
-THREADED_TEST(GlobalProxyIdentityHash) {
+void GlobalProxyIdentityHash(bool set_in_js) {
   LocalContext env;
   v8::Isolate* isolate = env->GetIsolate();
+  i::Isolate* i_isolate = reinterpret_cast<i::Isolate*>(isolate);
   v8::HandleScope scope(isolate);
   Handle<Object> global_proxy = env->Global();
-  int hash1 = global_proxy->GetIdentityHash();
+  i::Handle<i::Object> i_global_proxy = v8::Utils::OpenHandle(*global_proxy);
+  env->Global()->Set(v8_str("global"), global_proxy);
+  i::Handle<i::Object> original_hash;
+  if (set_in_js) {
+    CompileRun("var m = new Set(); m.add(global);");
+    original_hash = i::Handle<i::Object>(i_global_proxy->GetHash(), i_isolate);
+  } else {
+    original_hash = i::Handle<i::Object>(
+        i::Object::GetOrCreateHash(i_isolate, i_global_proxy));
+  }
+  CHECK(original_hash->IsSmi());
+  int32_t hash1 = i::Handle<i::Smi>::cast(original_hash)->value();
   // Hash should be retained after being detached.
   env->DetachGlobal();
   int hash2 = global_proxy->GetIdentityHash();
   CHECK_EQ(hash1, hash2);
   {
     // Re-attach global proxy to a new context, hash should stay the same.
     LocalContext env2(NULL, Handle<ObjectTemplate>(), global_proxy);
     int hash3 = global_proxy->GetIdentityHash();
     CHECK_EQ(hash1, hash3);
   }
 }
 
 
+THREADED_TEST(GlobalProxyIdentityHash) {
+  GlobalProxyIdentityHash(true);
+  GlobalProxyIdentityHash(false);
+}
+
+
 TEST(SymbolIdentityHash) {
   LocalContext env;
   v8::Isolate* isolate = env->GetIsolate();
   v8::HandleScope scope(isolate);
 
   {
     Local<v8::Symbol> symbol = v8::Symbol::New(isolate);
     int hash = symbol->GetIdentityHash();
     int hash1 = symbol->GetIdentityHash();
     CHECK_EQ(hash, hash1);
@@ skipping 18784 matching lines @@
   // add the testExtraShouldReturnFive export
   v8::Local<v8::Object> exports = env->GetExtrasExportsObject();
 
   auto func =
       exports->Get(v8_str("testExtraShouldReturnFive")).As<v8::Function>();
   auto undefined = v8::Undefined(isolate);
   auto result = func->Call(undefined, 0, {}).As<v8::Number>();
 
   CHECK(result->Value() == 5.0);
 }