ES6: Implement Object.setPrototypeOf

src/v8natives.js

Index: src/v8natives.js
diff --git a/src/v8natives.js b/src/v8natives.js
index e987baf6d6b36ff3708c770a76ab8f463b657a46..71b1e4880b7bd75fb7a9e95f25697e7323651861 100644
--- a/src/v8natives.js
+++ b/src/v8natives.js
@@ -1015,6 +1015,24 @@ function ObjectGetPrototypeOf(obj) {
   return %GetPrototype(obj);
 }
 
+// ES6 section 19.1.2.19.
+function ObjectSetPrototypeOf(obj, proto) {
+  if (IS_NULL_OR_UNDEFINED(obj) && !IS_UNDETECTABLE(obj)) {

[arv (Not doing code reviews), 2014/01/17 17:43:23]

The ES6 spec uses CheckObjectCoercible. It comes up in a few places so maybe we
should add new macro for this?

CHECK_OBJECT_COERCIBLE(obj, 'Object.setPrototypeOf')

which would throw the required type error.

[Dmitry Lomov (no reviews), 2014/01/17 20:17:36]

 Agreed, good idea.

+    throw MakeTypeError("called_on_null_or_undefined",
+                        ["Object.setPrototypeOf"]);
+  }
+
+  if (proto !== null && !IS_SPEC_OBJECT(proto)) {
+    throw MakeTypeError("proto_object_or_null", [proto]);
+  }
+
+  if (IS_SPEC_OBJECT(obj)) {
+    %SetPrototype(obj, proto);
+  }
+
+  return obj;
+}
+
 
 // ES5 section 15.2.3.3
 function ObjectGetOwnPropertyDescriptor(obj, p) {
@@ -1443,6 +1461,7 @@ function SetUpObject() {
     "defineProperties", ObjectDefineProperties,
     "freeze", ObjectFreeze,
     "getPrototypeOf", ObjectGetPrototypeOf,
+    "setPrototypeOf", ObjectSetPrototypeOf,
     "getOwnPropertyDescriptor", ObjectGetOwnPropertyDescriptor,
     "getOwnPropertyNames", ObjectGetOwnPropertyNames,
     // getOwnPropertySymbols is added in symbol.js.