src/jdk/nashorn/internal/objects/NativeObject.java

*** 23,32 ****
--- 23,33 ----
   * questions.
   */
  
  package jdk.nashorn.internal.objects;
  
+ import static jdk.nashorn.internal.lookup.Lookup.MH;
  import static jdk.nashorn.internal.runtime.ECMAErrors.typeError;
  import static jdk.nashorn.internal.runtime.ScriptRuntime.UNDEFINED;
  
  import java.lang.invoke.MethodHandle;
  import java.lang.invoke.MethodHandles;
*** 72,81 ****
--- 73,85 ----
   * this class to generate prototype and constructor for "Object".
   *
   */
  @ScriptClass("Object")
  public final class NativeObject {
+     public static final MethodHandle GET__PROTO__ = findOwnMH("get__proto__", ScriptObject.class, Object.class);
+     public static final MethodHandle SET__PROTO__ = findOwnMH("set__proto__", Object.class, Object.class, Object.class);
+ 
      private static final Object TO_STRING = new Object();
  
      private static InvokeByName getTO_STRING() {
          return Global.instance().getInvokeByName(TO_STRING,
                  new Callable<InvokeByName>() {
*** 84,93 ****
--- 88,126 ----
                          return new InvokeByName("toString", ScriptObject.class);
                      }
                  });
      }
  
+     @SuppressWarnings("unused")
+     private static ScriptObject get__proto__(final Object self) {
+         // See ES6 draft spec: B.2.2.1.1 get Object.prototype.__proto__
+         // Step 1 Let O be the result of calling ToObject passing the this.
+         final Object obj = Global.toObject(self);
+         Global.checkObject(obj);
+         final ScriptObject sobj = (ScriptObject)obj;
+         return sobj.getProto();
+     }
+ 
+     @SuppressWarnings("unused")
+     private static Object set__proto__(final Object self, final Object proto) {
+         // See ES6 draft spec: B.2.2.1.2 set Object.prototype.__proto__
+         // Step 1
+         Global.checkObjectCoercible(self);
+         // Step 4
+         if (! (self instanceof ScriptObject)) {
+             return UNDEFINED;
+         }
+ 
+         final ScriptObject sobj = (ScriptObject)self;
+         // __proto__ assignment ignores non-nulls and non-objects
+         // step 3: If Type(proto) is neither Object nor Null, then return undefined.
+         if (proto == null || proto instanceof ScriptObject) {
+             sobj.setPrototypeOf(proto);
+         }
+         return UNDEFINED;
+     }
+ 
      private static final MethodType MIRROR_GETTER_TYPE = MethodType.methodType(Object.class, ScriptObjectMirror.class);
      private static final MethodType MIRROR_SETTER_TYPE = MethodType.methodType(Object.class, ScriptObjectMirror.class, Object.class);
  
      // initialized by nasgen
      @SuppressWarnings("unused")
*** 158,168 ****
       * @return object whose prototype is set
       */
      @Function(attributes = Attribute.NOT_ENUMERABLE, where = Where.CONSTRUCTOR)
      public static Object setPrototypeOf(final Object self, final Object obj, final Object proto) {
          if (obj instanceof ScriptObject) {
!             ((ScriptObject)obj).setProtoCheck(proto);
              return obj;
          } else if (obj instanceof ScriptObjectMirror) {
              ((ScriptObjectMirror)obj).setProto(proto);
              return obj;
          }
--- 191,201 ----
       * @return object whose prototype is set
       */
      @Function(attributes = Attribute.NOT_ENUMERABLE, where = Where.CONSTRUCTOR)
      public static Object setPrototypeOf(final Object self, final Object obj, final Object proto) {
          if (obj instanceof ScriptObject) {
!             ((ScriptObject)obj).setPrototypeOf(proto);
              return obj;
          } else if (obj instanceof ScriptObjectMirror) {
              ((ScriptObjectMirror)obj).setProto(proto);
              return obj;
          }
*** 775,780 ****
--- 808,817 ----
  
      private static LinkRequest createLinkRequest(String operation, MethodType methodType, Object source) {
          return new LinkRequestImpl(CallSiteDescriptorFactory.create(MethodHandles.publicLookup(), operation,
                  methodType), false, source);
      }
+ 
+     private static MethodHandle findOwnMH(final String name, final Class<?> rtype, final Class<?>... types) {
+        return MH.findStatic(MethodHandles.lookup(), NativeObject.class, name, MH.type(rtype, types));
+     }
  }