v8/test/mjsunit/regress/regress-crbug-571517.js
jkummerow b4583c0444 [prototype user tracking] Don't skip JSGlobalProxies
For a prototype chain foo -> global_proxy -> global_object, we used to
register a dependency from foo -> global_object. This is incorrect when
the global_proxy/global_object pairing is modified, e.g. when navigating
in iframes. With this patch, we properly register foo -> global_proxy and
global_proxy -> global_object dependencies.
Additionally, when a prototype's prototype changes from null to something
else, this new usage relation must be registered if there are other users
further down on the prototype chain that might expect a complete chain of
registrations to exist (which was the case before, and must be preserved).

BUG=chromium:571517
LOG=n
R=verwaest@chromium.org

Review URL: https://codereview.chromium.org/1559323002

Cr-Commit-Position: refs/heads/master@{#33119}
2016-01-05 16:15:48 +00:00

37 lines
961 B
JavaScript

// Copyright 2015 the V8 project authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
function Receiver() { this.receiver = "receiver"; }
function Proto() { this.proto = "proto"; }
function f(a) {
return a.foo;
}
var rec = new Receiver();
var proto = rec.__proto__.__proto__;
// Initialize prototype chain dependent IC (nonexistent load).
assertEquals(undefined, f(rec));
assertEquals(undefined, f(rec));
// Add a new prototype to the end of the chain.
var p2 = new Proto();
p2.__proto__ = null;
proto.__proto__ = p2;
// Update the IC.
assertEquals(undefined, f(rec));
// Now modify the most recently added prototype by adding a property...
p2.foo = "bar";
assertEquals("bar", f(rec));
// ...and removing it again. Due to missing prototype user registrations,
// this fails to invalidate the IC.
delete p2.foo;
p2.secret = "GAME OVER";
assertEquals(undefined, f(rec));