ES6: Implement WeakSet

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 42 matching lines @@
 // - MaybeObject    (an object or a failure)
 //   - Failure      (immediate for marking failed operation)
 //   - Object
 //     - Smi          (immediate small integer)
 //     - HeapObject   (superclass for everything allocated in the heap)
 //       - JSReceiver  (suitable for property access)
 //         - JSObject
 //           - JSArray
 //           - JSArrayBuffer
 //           - JSArrayBufferView
-//              - JSTypedArray
-//              - JSDataView
+//             - JSTypedArray
+//             - JSDataView
 //           - JSSet
 //           - JSMap
-//           - JSWeakMap
+//           - WeakCollection

[rossberg, 2013/07/19 09:55:49]

Just one nit: this should be named JSWeakCollection

+//             - JSWeakMap
+//             - JSWeakSet
 //           - JSRegExp
 //           - JSFunction
 //           - JSGeneratorObject
 //           - JSModule
 //           - GlobalObject
 //             - JSGlobalObject
 //             - JSBuiltinsObject
 //           - JSGlobalProxy
 //           - JSValue
 //             - JSDate
@@ skipping 330 matching lines @@
   V(JS_MODULE_TYPE)                                                            \
   V(JS_GLOBAL_OBJECT_TYPE)                                                     \
   V(JS_BUILTINS_OBJECT_TYPE)                                                   \
   V(JS_GLOBAL_PROXY_TYPE)                                                      \
   V(JS_ARRAY_TYPE)                                                             \
   V(JS_ARRAY_BUFFER_TYPE)                                                      \
   V(JS_TYPED_ARRAY_TYPE)                                                       \
   V(JS_DATA_VIEW_TYPE)                                                         \
   V(JS_PROXY_TYPE)                                                             \
   V(JS_WEAK_MAP_TYPE)                                                          \
+  V(JS_WEAK_SET_TYPE)                                                          \
   V(JS_REGEXP_TYPE)                                                            \
                                                                                \
   V(JS_FUNCTION_TYPE)                                                          \
   V(JS_FUNCTION_PROXY_TYPE)                                                    \
 
 #ifdef ENABLE_DEBUGGER_SUPPORT
 #define INSTANCE_TYPE_LIST_DEBUGGER(V)                                         \
   V(DEBUG_INFO_TYPE)                                                           \
   V(BREAK_POINT_INFO_TYPE)
 #else
@@ skipping 319 matching lines @@
   JS_GLOBAL_OBJECT_TYPE,
   JS_BUILTINS_OBJECT_TYPE,
   JS_GLOBAL_PROXY_TYPE,
   JS_ARRAY_TYPE,
   JS_ARRAY_BUFFER_TYPE,
   JS_TYPED_ARRAY_TYPE,
   JS_DATA_VIEW_TYPE,
   JS_SET_TYPE,
   JS_MAP_TYPE,
   JS_WEAK_MAP_TYPE,
+  JS_WEAK_SET_TYPE,
 
   JS_REGEXP_TYPE,
 
   JS_FUNCTION_TYPE,  // LAST_JS_OBJECT_TYPE, LAST_JS_RECEIVER_TYPE
 
   // Pseudo-types
   FIRST_TYPE = 0x0,
   LAST_TYPE = JS_FUNCTION_TYPE,
   INVALID_TYPE = FIRST_TYPE - 1,
   FIRST_NAME_TYPE = FIRST_TYPE,
@@ skipping 229 matching lines @@
   V(Boolean)                                   \
   V(JSArray)                                   \
   V(JSArrayBuffer)                             \
   V(JSArrayBufferView)                         \
   V(JSTypedArray)                              \
   V(JSDataView)                                \
   V(JSProxy)                                   \
   V(JSFunctionProxy)                           \
   V(JSSet)                                     \
   V(JSMap)                                     \
+  V(WeakCollection)                            \
   V(JSWeakMap)                                 \
+  V(JSWeakSet)                                 \
   V(JSRegExp)                                  \
   V(HashTable)                                 \
   V(Dictionary)                                \
   V(StringTable)                               \
   V(JSFunctionResultCache)                     \
   V(NormalizedMapCache)                        \
   V(CompilationCacheTable)                     \
   V(CodeCacheHashTable)                        \
   V(PolymorphicCodeCacheHashTable)             \
   V(MapCache)                                  \
@@ skipping 7849 matching lines @@
   DECLARE_VERIFIER(JSMap)
 
   static const int kTableOffset = JSObject::kHeaderSize;
   static const int kSize = kTableOffset + kPointerSize;
 
  private:
   DISALLOW_IMPLICIT_CONSTRUCTORS(JSMap);
 };
 
 
-// The JSWeakMap describes EcmaScript Harmony weak maps
-class JSWeakMap: public JSObject {
+// Base class for both JSWeakMap and JSWeakSet
+class WeakCollection: public JSObject {
  public:
   // [table]: the backing hash table mapping keys to values.
   DECL_ACCESSORS(table, Object)
 
   // [next]: linked list of encountered weak maps during GC.
   DECL_ACCESSORS(next, Object)
 
+  static const int kTableOffset = JSObject::kHeaderSize;
+  static const int kNextOffset = kTableOffset + kPointerSize;
+  static const int kSize = kNextOffset + kPointerSize;
+
+ private:
+  DISALLOW_IMPLICIT_CONSTRUCTORS(WeakCollection);
+};
+
+
+// The JSWeakMap describes EcmaScript Harmony weak maps
+class JSWeakMap: public WeakCollection {
+ public:
   // Casting.
   static inline JSWeakMap* cast(Object* obj);
 
   // Dispatched behavior.
   DECLARE_PRINTER(JSWeakMap)
   DECLARE_VERIFIER(JSWeakMap)
 
-  static const int kTableOffset = JSObject::kHeaderSize;
-  static const int kNextOffset = kTableOffset + kPointerSize;
-  static const int kSize = kNextOffset + kPointerSize;
-
  private:
   DISALLOW_IMPLICIT_CONSTRUCTORS(JSWeakMap);
 };
 
 
+// The JSWeakSet describes EcmaScript Harmony weak sets
+class JSWeakSet: public WeakCollection {
+ public:
+
+  // Casting.
+  static inline JSWeakSet* cast(Object* obj);
+
+  // Dispatched behavior.
+  DECLARE_PRINTER(JSWeakSet)
+  DECLARE_VERIFIER(JSWeakSet)
+
+ private:
+  DISALLOW_IMPLICIT_CONSTRUCTORS(JSWeakSet);
+};
+
+
 class JSArrayBuffer: public JSObject {
  public:
   // [backing_store]: backing memory for this array
   DECL_ACCESSORS(backing_store, void)
 
   // [byte_length]: length in bytes
   DECL_ACCESSORS(byte_length, Object)
 
   // [flags]
   DECL_ACCESSORS(flag, Smi)
@@ skipping 920 matching lines @@
     } else {
       value &= ~(1 << bit_position);
     }
     return value;
   }
 };
 
 } }  // namespace v8::internal
 
 #endif  // V8_OBJECTS_H_