Object.observe: Make array length and other magic data properties work correctly.

src/objects.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 2925 matching lines @@
     if (strict_mode == kStrictMode) {
       Handle<Object> args[] = { name, self };
       return isolate->Throw(*isolate->factory()->NewTypeError(
           "strict_read_only_property", HandleVector(args, ARRAY_SIZE(args))));
     } else {
       return *value;
     }
   }
 
   Handle<Object> old_value(heap->the_hole_value(), isolate);
-  if (FLAG_harmony_observation && map()->is_observed()) {
-    old_value = handle(lookup->GetLazyValue(), isolate);
+  if (FLAG_harmony_observation &&
+      map()->is_observed() && lookup->IsDataProperty()) {
+    old_value = Object::GetProperty(self, name);
   }
 
   // This is a real property that is not read-only, or it is a
   // transition or null descriptor and there are no setters in the prototypes.
   MaybeObject* result = *value;
   switch (lookup->type()) {
     case NORMAL:
       result = self->SetNormalizedProperty(lookup, *value);
       break;
     case FIELD:
@@ skipping 65 matching lines @@
 
   Handle<Object> hresult;
   if (!result->ToHandle(&hresult, isolate)) return result;
 
   if (FLAG_harmony_observation && map()->is_observed()) {
     if (lookup->IsTransition()) {
       EnqueueChangeRecord(self, "new", name, old_value);
     } else {
       LookupResult new_lookup(isolate);
       self->LocalLookup(*name, &new_lookup, true);
-      ASSERT(!new_lookup.GetLazyValue()->IsTheHole());
-      if (!new_lookup.GetLazyValue()->SameValue(*old_value)) {
+      if (new_lookup.IsDataProperty() &&
+          !Object::GetProperty(self, name)->SameValue(*old_value)) {
         EnqueueChangeRecord(self, "updated", name, old_value);
       }
     }
   }
 
   return *hresult;
 }
 
 
 // Set a real local property, even if it is READ_ONLY.  If the property is not
@@ skipping 58 matching lines @@
   // From this point on everything needs to be handlified.
   HandleScope scope(isolate);
   Handle<JSObject> self(this);
   Handle<String> name(name_raw);
   Handle<Object> value(value_raw, isolate);
 
   Handle<Object> old_value(isolate->heap()->the_hole_value(), isolate);
   PropertyAttributes old_attributes = ABSENT;
   bool is_observed = FLAG_harmony_observation && self->map()->is_observed();
   if (is_observed) {
-    // Function prototypes are stored specially
-    if (self->IsJSFunction() &&
-        JSFunction::cast(*self)->should_have_prototype() &&
-        name->Equals(isolate->heap()->prototype_symbol())) {
-      MaybeObject* maybe = Accessors::FunctionGetPrototype(*self, NULL);
-      if (!maybe->ToHandle(&old_value, isolate)) return maybe;
-    } else {
-      old_value = handle(lookup.GetLazyValue(), isolate);
-    }
+    if (lookup.IsDataProperty()) old_value = Object::GetProperty(self, name);
     old_attributes = lookup.GetAttributes();
   }
 
   // Check of IsReadOnly removed from here in clone.
   MaybeObject* result = *value;
   switch (lookup.type()) {
     case NORMAL: {
       PropertyDetails details = PropertyDetails(attributes, NORMAL);
       result = self->SetNormalizedProperty(*name, *value, details);
       break;
@@ skipping 49 matching lines @@
 
   Handle<Object> hresult;
   if (!result->ToHandle(&hresult, isolate)) return result;
 
   if (is_observed) {
     if (lookup.IsTransition()) {
       EnqueueChangeRecord(self, "new", name, old_value);
     } else {
       LookupResult new_lookup(isolate);
       self->LocalLookup(*name, &new_lookup, true);
-      ASSERT(!new_lookup.GetLazyValue()->IsTheHole());
       if (old_value->IsTheHole() ||
           new_lookup.GetAttributes() != old_attributes) {
         EnqueueChangeRecord(self, "reconfigured", name, old_value);
-      } else if (!new_lookup.GetLazyValue()->SameValue(*old_value)) {
+      } else if (new_lookup.IsDataProperty() &&
+          !Object::GetProperty(self, name)->SameValue(*old_value)) {
         EnqueueChangeRecord(self, "updated", name, old_value);
       }
     }
   }
 
   return *hresult;
 }
 
 
 PropertyAttributes JSObject::GetPropertyAttributePostInterceptor(
@@ skipping 1042 matching lines @@
     return isolate->heap()->false_value();
   }
 
   // From this point on everything needs to be handlified.
   HandleScope scope(isolate);
   Handle<JSObject> self(this);
   Handle<String> hname(name);
 
   Handle<Object> old_value(isolate->heap()->the_hole_value());
   bool is_observed = FLAG_harmony_observation && self->map()->is_observed();
-  if (is_observed) {
-    old_value = handle(lookup.GetLazyValue(), isolate);
+  if (is_observed && lookup.IsDataProperty()) {
+    old_value = Object::GetProperty(self, hname);
   }
   MaybeObject* result;
 
   // Check for interceptor.
   if (lookup.IsInterceptor()) {
     // Skip interceptor if forcing a deletion.
     if (mode == FORCE_DELETION) {
       result = self->DeletePropertyPostInterceptor(*hname, mode);
     } else {
       result = self->DeletePropertyWithInterceptor(*hname);
@@ skipping 670 matching lines @@
   if (is_observed) {
     if (is_element) {
       preexists = HasLocalElement(index);
       if (preexists && self->GetLocalElementAccessorPair(index) == NULL) {
         old_value = Object::GetElement(self, index);
       }
     } else {
       LookupResult lookup(isolate);
       LocalLookup(*name, &lookup, true);
       preexists = lookup.IsProperty();
-      if (preexists) old_value = handle(lookup.GetLazyValue(), isolate);
+      if (preexists && lookup.IsDataProperty()) {
+        old_value = Object::GetProperty(self, name);
+      }
     }
   }
 
   MaybeObject* result = is_element ?
     self->DefineElementAccessor(index, *getter, *setter, attributes) :
     self->DefinePropertyAccessor(*name, *getter, *setter, attributes);
 
   Handle<Object> hresult;
   if (!result->ToHandle(&hresult, isolate)) return result;
 
@@ skipping 9071 matching lines @@
   set_year(Smi::FromInt(year), SKIP_WRITE_BARRIER);
   set_month(Smi::FromInt(month), SKIP_WRITE_BARRIER);
   set_day(Smi::FromInt(day), SKIP_WRITE_BARRIER);
   set_weekday(Smi::FromInt(weekday), SKIP_WRITE_BARRIER);
   set_hour(Smi::FromInt(hour), SKIP_WRITE_BARRIER);
   set_min(Smi::FromInt(min), SKIP_WRITE_BARRIER);
   set_sec(Smi::FromInt(sec), SKIP_WRITE_BARRIER);
 }
 
 } }  // namespace v8::internal