Bug 1072817 - Implement trivial {get,set}PrototypeOf hooks for ScriptedDirectProxyHandler. (r=jorendorff)

js/src/jit-test/tests/proxy/bug1072817.js

@@ -0,0 +1,5 @@
+// |jit-test| error: TypeError
+var r = Proxy.revocable({}, {});
+var p = r.proxy;
+r.revoke();
+p instanceof Object;

js/src/proxy/ScriptedDirectProxyHandler.cpp

@@ -1090,6 +1090,35 @@ ScriptedDirectProxyHandler::isCallable(JSObject *obj) const
     return obj->as<ProxyObject>().extra(IS_CALLABLE_EXTRA).toBoolean();
 }
 
+// ES6 implements both getPrototypeOf and setPrototypeOf traps. We don't have them yet (see bug
+// 888969). For now, use these, to account for proxy revocation.
+bool
+ScriptedDirectProxyHandler::getPrototypeOf(JSContext *cx, HandleObject proxy,
+                                           MutableHandleObject protop) const
+{
+    RootedObject target(cx, proxy->as<ProxyObject>().target());
+    // Though handler is used elsewhere, spec mandates that both get set to null.
+    if (!target) {
+        JS_ReportErrorNumber(cx, js_GetErrorMessage, nullptr, JSMSG_PROXY_REVOKED);
+        return false;
+    }
+
+    return DirectProxyHandler::getPrototypeOf(cx, proxy, protop);
+}
+
+bool
+ScriptedDirectProxyHandler::setPrototypeOf(JSContext *cx, HandleObject proxy,
+                                           HandleObject proto, bool *bp) const
+{
+    RootedObject target(cx, proxy->as<ProxyObject>().target());
+    if (!target) {
+        JS_ReportErrorNumber(cx, js_GetErrorMessage, nullptr, JSMSG_PROXY_REVOKED);
+        return false;
+    }
+
+    return DirectProxyHandler::setPrototypeOf(cx, proxy, proto, bp);
+}
+
 const char ScriptedDirectProxyHandler::family = 0;
 const ScriptedDirectProxyHandler ScriptedDirectProxyHandler::singleton;
 

js/src/proxy/ScriptedDirectProxyHandler.h

@@ -36,6 +36,11 @@ class ScriptedDirectProxyHandler : public DirectProxyHandler {
                      bool strict, MutableHandleValue vp) const MOZ_OVERRIDE;
     virtual bool call(JSContext *cx, HandleObject proxy, const CallArgs &args) const MOZ_OVERRIDE;
     virtual bool construct(JSContext *cx, HandleObject proxy, const CallArgs &args) const MOZ_OVERRIDE;
+    // These are standard internal methods, but are not implemented to spec yet.
+    virtual bool getPrototypeOf(JSContext *cx, HandleObject proxy, MutableHandleObject protop)
+        const MOZ_OVERRIDE;
+    virtual bool setPrototypeOf(JSContext *cx, HandleObject proxy, HandleObject proto, bool *bp)
+        const MOZ_OVERRIDE;
 
     /* SpiderMonkey extensions. */
     virtual bool getPropertyDescriptor(JSContext *cx, HandleObject proxy, HandleId id,