Use the syntax of a property addition as a hint for controlling the fast-mode vs. dictionary mode h…

src/objects.cc

Index: src/objects.cc
===================================================================
--- src/objects.cc	(revision 11731)
+++ src/objects.cc	(working copy)
@@ -1514,7 +1514,8 @@
 
 MaybeObject* JSObject::AddFastProperty(String* name,
                                        Object* value,
-                                       PropertyAttributes attributes) {
+                                       PropertyAttributes attributes,
+                                       StoreFromKeyed store_mode) {
   ASSERT(!IsJSGlobalProxy());
 
   // Normalize the object if the name is an actual string (not the
@@ -1580,7 +1581,7 @@
   }
 
   if (map()->unused_property_fields() == 0) {
-    if (TooManyFastProperties(properties()->length())) {
+    if (TooManyFastProperties(properties()->length(), store_mode)) {
       Object* obj;
       { MaybeObject* maybe_obj =
             NormalizeProperties(CLEAR_INOBJECT_PROPERTIES, 0);
@@ -1710,7 +1711,8 @@
 MaybeObject* JSObject::AddProperty(String* name,
                                    Object* value,
                                    PropertyAttributes attributes,
-                                   StrictModeFlag strict_mode) {
+                                   StrictModeFlag strict_mode,
+                                   JSReceiver::StoreFromKeyed store_mode) {
   ASSERT(!IsJSGlobalProxy());
   Map* map_of_this = map();
   Heap* heap = GetHeap();
@@ -1733,7 +1735,7 @@
                                            JSFunction::cast(value),
                                            attributes);
       } else {
-        return AddFastProperty(name, value, attributes);
+        return AddFastProperty(name, value, attributes, store_mode);
       }
     } else {
       // Normalize the object to prevent very large instance descriptors.
@@ -1830,7 +1832,7 @@
                                                 Object* new_value,
                                                 PropertyAttributes attributes) {
   if (map()->unused_property_fields() == 0 &&
-      TooManyFastProperties(properties()->length())) {
+      TooManyFastProperties(properties()->length(), MAY_BE_STORE_FROM_KEYED)) {
     Object* obj;
     { MaybeObject* maybe_obj =
           NormalizeProperties(CLEAR_INOBJECT_PROPERTIES, 0);
@@ -1945,10 +1947,11 @@
 MaybeObject* JSReceiver::SetProperty(String* name,
                                      Object* value,
                                      PropertyAttributes attributes,
-                                     StrictModeFlag strict_mode) {
+                                     StrictModeFlag strict_mode,
+                                     JSReceiver::StoreFromKeyed store_mode) {
   LookupResult result(GetIsolate());
   LocalLookup(name, &result);
-  return SetProperty(&result, name, value, attributes, strict_mode);
+  return SetProperty(&result, name, value, attributes, strict_mode, store_mode);
 }
 
 
@@ -2619,13 +2622,14 @@
                                      String* key,
                                      Object* value,
                                      PropertyAttributes attributes,
-                                     StrictModeFlag strict_mode) {
+                                     StrictModeFlag strict_mode,
+                                     JSReceiver::StoreFromKeyed store_mode) {
   if (result->IsFound() && result->type() == HANDLER) {
     return result->proxy()->SetPropertyWithHandler(
         this, key, value, attributes, strict_mode);
   } else {
     return JSObject::cast(this)->SetPropertyForResult(
-        result, key, value, attributes, strict_mode);
+        result, key, value, attributes, strict_mode, store_mode);
   }
 }
 
@@ -2908,7 +2912,8 @@
                                             String* name,
                                             Object* value,
                                             PropertyAttributes attributes,
-                                            StrictModeFlag strict_mode) {
+                                            StrictModeFlag strict_mode,
+                                            StoreFromKeyed store_mode) {
   Heap* heap = GetHeap();
   // Make sure that the top context does not change when doing callbacks or
   // interceptor calls.
@@ -2939,7 +2944,7 @@
     if (proto->IsNull()) return value;
     ASSERT(proto->IsJSGlobalObject());
     return JSObject::cast(proto)->SetPropertyForResult(
-        result, name, value, attributes, strict_mode);
+        result, name, value, attributes, strict_mode, store_mode);
   }
 
   if (!result->IsProperty() && !IsJSContextExtensionObject()) {
@@ -2951,7 +2956,7 @@
 
   if (!result->IsFound()) {
     // Neither properties nor transitions found.
-    return AddProperty(name, value, attributes, strict_mode);
+    return AddProperty(name, value, attributes, strict_mode, store_mode);
   }
   if (result->IsReadOnly() && result->IsProperty()) {
     if (strict_mode == kStrictMode) {