Store JSGlobalProxy's identity hash directly on the proxy itself

src/objects.cc

Index: src/objects.cc
diff --git a/src/objects.cc b/src/objects.cc
index 48f962503c320a904c53285395a6a595845ee11d..5b0aac71c03915cd106ce09440853d5ca05422e6 100644
--- a/src/objects.cc
+++ b/src/objects.cc
@@ -4965,9 +4965,7 @@ Handle<SeededNumberDictionary> JSObject::NormalizeElements(
 }
 
 
-Smi* JSReceiver::GenerateIdentityHash() {
-  Isolate* isolate = GetIsolate();
-
+static Smi* GenerateIdentityHash(Isolate* isolate) {
   int hash_value;
   int attempts = 0;
   do {
@@ -4983,33 +4981,48 @@ Smi* JSReceiver::GenerateIdentityHash() {
 
 
 void JSObject::SetIdentityHash(Handle<JSObject> object, Handle<Smi> hash) {
+  ASSERT(!object->IsJSGlobalProxy());
   Isolate* isolate = object->GetIsolate();
   SetHiddenProperty(object, isolate->factory()->identity_hash_string(), hash);
 }
 
 
+template<typename ProxyType>
+static Handle<Object> GetOrCreateIdentityHashHelper(Handle<ProxyType> proxy) {
+  Isolate* isolate = proxy->GetIsolate();
+
+  Handle<Object> hash(proxy->hash(), isolate);
+  if (hash->IsSmi())

[Toon Verwaest, 2014/04/28 14:32:50]

Either put on single line or use { }

[adamk, 2014/04/28 18:44:50]

Done. This was pre-existing code, fwiw.

+    return hash;
+
+  hash = handle(GenerateIdentityHash(isolate), isolate);
+  proxy->set_hash(*hash);
+  return hash;
+}
+
+
 Object* JSObject::GetIdentityHash() {
+  if (IsJSGlobalProxy()) {
+    return JSGlobalProxy::cast(this)->hash();
+  }
   Object* stored_value = GetHiddenProperty(GetHeap()->identity_hash_string());
   return stored_value->IsSmi() ? stored_value : GetHeap()->undefined_value();
 }
 
 
 Handle<Object> JSObject::GetOrCreateIdentityHash(Handle<JSObject> object) {
-  Handle<Object> hash(object->GetIdentityHash(), object->GetIsolate());
-  if (hash->IsSmi())
-    return hash;
+  if (object->IsJSGlobalProxy()) {
+    return GetOrCreateIdentityHashHelper(Handle<JSGlobalProxy>::cast(object));
+  }
 
   Isolate* isolate = object->GetIsolate();
 
-  hash = handle(object->GenerateIdentityHash(), isolate);
-  Handle<Object> result = SetHiddenProperty(object,
-      isolate->factory()->identity_hash_string(), hash);
-
-  if (result->IsUndefined()) {
-    // Trying to get hash of detached proxy.
-    return handle(Smi::FromInt(0), isolate);
-  }
+  Handle<Object> hash(object->GetIdentityHash(), isolate);
+  if (hash->IsSmi())

[Toon Verwaest, 2014/04/28 14:32:50]

Same as above

[adamk, 2014/04/28 18:44:50]

Done.

+    return hash;
 
+  hash = handle(GenerateIdentityHash(isolate), isolate);
+  SetHiddenProperty(object, isolate->factory()->identity_hash_string(), hash);
   return hash;
 }
 
@@ -5020,21 +5033,15 @@ Object* JSProxy::GetIdentityHash() {
 
 
 Handle<Object> JSProxy::GetOrCreateIdentityHash(Handle<JSProxy> proxy) {
-  Isolate* isolate = proxy->GetIsolate();
-
-  Handle<Object> hash(proxy->GetIdentityHash(), isolate);
-  if (hash->IsSmi())
-    return hash;
-
-  hash = handle(proxy->GenerateIdentityHash(), isolate);
-  proxy->set_hash(*hash);
-  return hash;
+  return GetOrCreateIdentityHashHelper(proxy);
 }
 
 
 Object* JSObject::GetHiddenProperty(Name* key) {
   ASSERT(key->IsUniqueName());
   if (IsJSGlobalProxy()) {
+    // JSGlobalProxies store their hash internally.
+    ASSERT(key != GetHeap()->identity_hash_string());
     // For a proxy, use the prototype as target object.
     Object* proxy_parent = GetPrototype();
     // If the proxy is detached, return undefined.
@@ -5069,6 +5076,8 @@ Handle<Object> JSObject::SetHiddenProperty(Handle<JSObject> object,
 
   ASSERT(key->IsUniqueName());
   if (object->IsJSGlobalProxy()) {
+    // JSGlobalProxies store their hash internally.
+    ASSERT(*key != *isolate->factory()->identity_hash_string());
     // For a proxy, use the prototype as target object.
     Handle<Object> proxy_parent(object->GetPrototype(), isolate);
     // If the proxy is detached, return undefined.