Work towards unifying descriptor array handling.

src/objects.h

 // 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 3434 matching lines @@
   inline void SetSortedKey(int pointer, int descriptor_number);
   inline void InitializeRepresentations(Representation representation);
   inline void SetRepresentation(int descriptor_number,
                                 Representation representation);
 
   // Accessor for complete descriptor.
   inline void Get(int descriptor_number, Descriptor* desc);
   inline void Set(int descriptor_number,
                   Descriptor* desc,
                   const WhitenessWitness&);
-  inline void Set(int descriptor_number, Descriptor* desc);
+  void Replace(int descriptor_number, Descriptor* descriptor);
 
   // Append automatically sets the enumeration index. This should only be used
   // to add descriptors in bulk at the end, followed by sorting the descriptor
   // array.
   inline void Append(Descriptor* desc, const WhitenessWitness&);
   inline void Append(Descriptor* desc);
 
-  // Transfer a complete descriptor from the src descriptor array to this
-  // descriptor array.
-  void CopyFrom(int dst_index,
-                DescriptorArray* src,
-                int src_index,
-                const WhitenessWitness&);
   static Handle<DescriptorArray> Merge(Handle<Map> left_map,
                                        int verbatim,
                                        int valid,
                                        int new_size,
                                        int modify_index,
                                        StoreMode store_mode,
                                        Handle<Map> right_map)
       V8_WARN_UNUSED_RESULT;
 
   bool IsMoreGeneralThan(int verbatim,
                          int valid,
                          int new_size,
                          DescriptorArray* other);
 
   static Handle<DescriptorArray> CopyUpTo(Handle<DescriptorArray> desc,
-                                          int enumeration_index);
+                                          int enumeration_index,
+                                          int slack = 0);
 
   static Handle<DescriptorArray> CopyUpToAddAttributes(
       Handle<DescriptorArray> desc,
       int enumeration_index,
-      PropertyAttributes attributes);
+      PropertyAttributes attributes,
+      int slack = 0);
 
   // Sort the instance descriptors by the hash codes of their keys.
   void Sort();
 
   // Search the instance descriptors for given name.
   INLINE(int Search(Name* name, int number_of_own_descriptors));
 
   // As the above, but uses DescriptorLookupCache and updates it when
   // necessary.
   INLINE(int SearchWithCache(Name* name, Map* map));
@@ skipping 82 matching lines @@
            (descriptor_number * kDescriptorSize) +
            kDescriptorDetails;
   }
 
   static int ToValueIndex(int descriptor_number) {
     return kFirstIndex +
            (descriptor_number * kDescriptorSize) +
            kDescriptorValue;
   }
 
+  // Transfer a complete descriptor from the src descriptor array to this
+  // descriptor array.
+  void CopyFrom(int index,
+                DescriptorArray* src,
+                const WhitenessWitness&);
+
+  inline void Set(int descriptor_number, Descriptor* desc);
+
   // Swap first and second descriptor.
   inline void SwapSortedKeys(int first, int second);
 
   DISALLOW_IMPLICIT_CONSTRUCTORS(DescriptorArray);
 };
 
 
 enum SearchMode { ALL_ENTRIES, VALID_ENTRIES };
 
 template<SearchMode search_mode, typename T>
@@ skipping 7409 matching lines @@
     } else {
       value &= ~(1 << bit_position);
     }
     return value;
   }
 };
 
 } }  // namespace v8::internal
 
 #endif  // V8_OBJECTS_H_