[keys] support shadowing keys in the KeyAccumulator

src/keys.h

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef V8_KEYS_H_
 #define V8_KEYS_H_
 
 #include "src/isolate.h"
 #include "src/objects.h"
 
@@ skipping 32 matching lines @@
 
   Handle<FixedArray> GetKeys(
       GetKeysConversion convert = GetKeysConversion::kKeepNumbers);
   Maybe<bool> CollectKeys(Handle<JSReceiver> receiver,
                           Handle<JSReceiver> object);
   Maybe<bool> CollectOwnElementIndices(Handle<JSReceiver> receiver,
                                        Handle<JSObject> object);
   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);
   void AddKeys(Handle<FixedArray> array, AddKeyConversion convert);
   void AddKeys(Handle<JSObject> array_like, AddKeyConversion convert);
 
   // Jump to the next level, pushing the current |levelLength_| to
   // |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,
                              Handle<JSObject> object);
   Maybe<bool> CollectOwnJSProxyKeys(Handle<JSReceiver> receiver,
                                     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_;
   // keys_ is either an Handle<OrderedHashSet> or in the case of own JSProxy
   // 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;
   bool is_for_in_ = false;
   bool skip_indices_ = false;
 
   DISALLOW_COPY_AND_ASSIGN(KeyAccumulator);
 };
 
 // The FastKeyAccumulator handles the cases where there are no elements on the
@@ skipping 30 matching lines @@
   bool is_receiver_simple_enum_ = false;
   bool has_empty_prototype_ = false;
 
   DISALLOW_COPY_AND_ASSIGN(FastKeyAccumulator);
 };
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_KEYS_H_