1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/js/xpconnect/tests/chrome/test_bug732665.xul Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,76 @@
1.4 +<?xml version="1.0"?>
1.5 +<?xml-stylesheet type="text/css" href="chrome://global/skin"?>
1.6 +<?xml-stylesheet type="text/css" href="chrome://mochikit/content/tests/SimpleTest/test.css"?>
1.7 +<!--
1.8 +https://bugzilla.mozilla.org/show_bug.cgi?id=732665
1.9 +-->
1.10 +<window title="Mozilla Bug 732665"
1.11 + xmlns="http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul">
1.12 + <script type="application/javascript" src="chrome://mochikit/content/tests/SimpleTest/SimpleTest.js"/>
1.13 +
1.14 + <!-- test results are displayed in the html:body -->
1.15 + <body xmlns="http://www.w3.org/1999/xhtml">
1.16 + <a href="https://bugzilla.mozilla.org/show_bug.cgi?id=732665"
1.17 + target="_blank">Mozilla Bug 732665</a>
1.18 + </body>
1.19 +
1.20 + <!-- test code goes here -->
1.21 + <script type="application/javascript">
1.22 + <![CDATA[
1.23 +
1.24 + //
1.25 + // Important! If this test starts failing after a tricky platform-y change,
1.26 + // the stack quota numbers in XPCJSRuntime probably need twiddling. We want
1.27 + // to maintain the invariants in this test (at least to some approximation)
1.28 + // for security reasons.
1.29 + //
1.30 +
1.31 + // Executes f() d steps from the probed native stack limit, and returns
1.32 + // the number of steps to the recursion limit from the caller.
1.33 + function nearNativeStackLimit(d, f) {
1.34 + f = f || function() {};
1.35 + function inner() {
1.36 + try {
1.37 + with ({}) { // keep things predictable -- stay in the interpreter
1.38 + var stepsFromLimit = eval("inner()"); // Use eval to force a number of native stackframes to be created.
1.39 + }
1.40 + if (stepsFromLimit == d) {
1.41 + try { f(); } catch(e) { ok(false, 'nearNativeStackLimit callback threw: ' + e); }
1.42 + }
1.43 + return stepsFromLimit + 1;
1.44 + } catch(e) {
1.45 + // It would be nice to check here that the exception is actually an
1.46 + // over-recursion here. But doing so would require toString()ing the
1.47 + // exception, which we may not have the stack space to do.
1.48 + return 0;
1.49 + }
1.50 + }
1.51 + return inner();
1.52 + }
1.53 +
1.54 + const Cu = Components.utils;
1.55 + var contentSb = new Cu.Sandbox('http://www.example.com');
1.56 + var chromeSb = new Cu.Sandbox(window);
1.57 + chromeSb.ok = contentSb.ok = ok;
1.58 + Cu.evalInSandbox(nearNativeStackLimit.toSource(), chromeSb);
1.59 + Cu.evalInSandbox(nearNativeStackLimit.toSource(), contentSb);
1.60 + var chromeLimit = Cu.evalInSandbox("nearNativeStackLimit(0);", chromeSb);
1.61 + var contentLimit = Cu.evalInSandbox("nearNativeStackLimit(0)", contentSb);
1.62 + ok(chromeLimit >= contentLimit + 10,
1.63 + "Chrome should be able to have at least 10 heavy frames more stack than content: " + chromeLimit + ", " + contentLimit);
1.64 +
1.65 + // Exhaust the stack space in content, and then make sure we can still get 10
1.66 + // heavy frames in chrome.
1.67 + //
1.68 + // Note that sometimes, if we pass |0| to nearNativeStackLimit, we can end up
1.69 + // so close to the border in content that we can't even get ourselves together
1.70 + // enough to make the cross-compartment call. So rather than exhausting the
1.71 + // stack entirely and then checking for 10 chrome frames, we leave ourselves
1.72 + // one frame's worth, and check for 11.
1.73 + contentSb.nnslChrome = chromeSb.nearNativeStackLimit;
1.74 + var nestedLimit = Cu.evalInSandbox("nearNativeStackLimit(1, function() { nestedLimit = nnslChrome(0);}); nestedLimit;", contentSb);
1.75 + ok(nestedLimit >= 11, "Chrome should be invokable from content script with an exhausted stack: " + nestedLimit);
1.76 +
1.77 + ]]>
1.78 + </script>
1.79 +</window>
