[keys] support shadowing keys in the KeyAccumulator

src/keys.h

Index: src/keys.h
diff --git a/src/keys.h b/src/keys.h
index 647c5e211121720875ed1a54e973f054a803174b..8bb0dc3f061f36098796c8858bcf0f1b45600406 100644
--- a/src/keys.h
+++ b/src/keys.h
@@ -50,8 +50,8 @@ class KeyAccumulator final BASE_EMBEDDED {
   Maybe<bool> CollectOwnPropertyNames(Handle<JSReceiver> receiver,
                                       Handle<JSObject> object);
 
-  static Handle<FixedArray> GetEnumPropertyKeys(Isolate* isolate,
-                                                Handle<JSObject> object);
+  static Handle<FixedArray> GetOwnEnumPropertyKeys(Isolate* isolate,
+                                                   Handle<JSObject> object);
 
   void AddKey(Object* key, AddKeyConversion convert = DO_NOT_CONVERT);
   void AddKey(Handle<Object> key, AddKeyConversion convert = DO_NOT_CONVERT);
@@ -62,12 +62,15 @@ class KeyAccumulator final BASE_EMBEDDED {
   // |levelLengths_| and adding a new list to |elements_|.
   Isolate* isolate() { return isolate_; }
   PropertyFilter filter() { return filter_; }
+  KeyCollectionMode mode() { return mode_; }
   void set_filter_proxy_keys(bool filter) { filter_proxy_keys_ = filter; }
   void set_is_for_in(bool value) { is_for_in_ = value; }
   void set_skip_indices(bool value) { skip_indices_ = value; }
   void set_last_non_empty_prototype(Handle<JSReceiver> object) {
     last_non_empty_prototype_ = object;
   }
+  void AddShadowKey(Object* key);

[adamk, 2016/06/27 19:19:33]

Please add comments for these methods, outside of this code review and the
attached bug I suspect these names are going to be mysterious to a future
reader.

[Camillo Bruni, 2016/06/29 17:27:56]

added more descriptive comments.

+  void AddShadowKey(Handle<Object> key);
 
  private:
   Maybe<bool> CollectOwnKeys(Handle<JSReceiver> receiver,
@@ -76,10 +79,9 @@ class KeyAccumulator final BASE_EMBEDDED {
                                     Handle<JSProxy> proxy);
   Maybe<bool> CollectOwnJSProxyTargetKeys(Handle<JSProxy> proxy,
                                           Handle<JSReceiver> target);
-
   Maybe<bool> AddKeysFromJSProxy(Handle<JSProxy> proxy,
                                  Handle<FixedArray> keys);
-
+  bool IsShadowed(Handle<Object> key);
   Handle<OrderedHashSet> keys() { return Handle<OrderedHashSet>::cast(keys_); }
 
   Isolate* isolate_;
@@ -87,6 +89,7 @@ class KeyAccumulator final BASE_EMBEDDED {
   // keys a Handle<FixedArray>.
   Handle<FixedArray> keys_;
   Handle<JSReceiver> last_non_empty_prototype_;
+  Handle<ObjectHashSet> shadowed_keys_;
   KeyCollectionMode mode_;
   PropertyFilter filter_;
   bool filter_proxy_keys_ = true;