js/src/jit-test/tests/debug/onEnterFrame-04.js@6474c204b198 (annotated)
js/src/jit-test/tests/debug/onEnterFrame-04.js
Wed, 31 Dec 2014 06:09:35 +0100
- author
- Michael Schloh von Bennewitz <michael@schloh.com>
- date
- Wed, 31 Dec 2014 06:09:35 +0100
- changeset 0
- 6474c204b198
- permissions
- -rw-r--r--
Cloned upstream origin tor-browser at tor-browser-31.3.0esr-4.5-1-build1
revision ID fc1c9ff7c1b2defdbc039f12214767608f46423f for hacking purpose.
| michael@0 | 1 | // We detect and stop the runaway recursion caused by making onEnterFrame a |
| michael@0 | 2 | // wrapper of a debuggee function. |
| michael@0 | 3 | |
| michael@0 | 4 | // This is all a bit silly. In any reasonable design, both debugger re-entry |
| michael@0 | 5 | // (the second onEnterFrame invocation) and debuggee re-entry (the call to g.f |
| michael@0 | 6 | // from within the debugger, not via a Debugger invocation function) would raise |
| michael@0 | 7 | // errors immediately. We have plans to do so, but in the mean time, we settle |
| michael@0 | 8 | // for at least detecting the recursion. |
| michael@0 | 9 | |
| michael@0 | 10 | load(libdir + 'asserts.js'); |
| michael@0 | 11 | |
| michael@0 | 12 | var g = newGlobal(); |
| michael@0 | 13 | g.eval("function f(frame) { n++; return 42; }"); |
| michael@0 | 14 | g.n = 0; |
| michael@0 | 15 | |
| michael@0 | 16 | var dbg = Debugger(); |
| michael@0 | 17 | var gw = dbg.addDebuggee(g); |
| michael@0 | 18 | |
| michael@0 | 19 | // Register the debuggee function as the onEnterFrame handler. When we first |
| michael@0 | 20 | // call or eval in the debuggee: |
| michael@0 | 21 | // |
| michael@0 | 22 | // - The onEnterFrame call reporting that frame's creation is itself an event |
| michael@0 | 23 | // that must be reported, so we call onEnterFrame again. |
| michael@0 | 24 | // |
| michael@0 | 25 | // - SpiderMonkey detects the out-of-control recursion, and generates a "too |
| michael@0 | 26 | // much recursion" InternalError in the youngest onEnterFrame call. |
| michael@0 | 27 | // |
| michael@0 | 28 | // - We don't catch it, so the onEnterFrame handler call itself throws. |
| michael@0 | 29 | // |
| michael@0 | 30 | // - Since the Debugger doesn't have an uncaughtExceptionHook (it can't; such a |
| michael@0 | 31 | // hook would itself raise a "too much recursion" exception), Spidermonkey |
| michael@0 | 32 | // reports the exception immediately and terminates the debuggee --- which is |
| michael@0 | 33 | // the next-older onEnterFrame call. |
| michael@0 | 34 | // |
| michael@0 | 35 | // - This termination propagates all the way out to the initial attempt to |
| michael@0 | 36 | // create a frame in the debuggee. |
| michael@0 | 37 | dbg.onEnterFrame = g.f; |
| michael@0 | 38 | |
| michael@0 | 39 | // Get a Debugger.Object instance referring to f. |
| michael@0 | 40 | var debuggeeF = gw.makeDebuggeeValue(g.f); |
| michael@0 | 41 | |
| michael@0 | 42 | // Using f.call allows us to catch the termination. |
| michael@0 | 43 | assertEq(debuggeeF.call(), null); |
| michael@0 | 44 | |
| michael@0 | 45 | // We should never actually begin execution of the function. |
| michael@0 | 46 | assertEq(g.n, 0); |
| michael@0 | 47 | |
| michael@0 | 48 | // When an error is reported, the shell usually exits with a nonzero exit code. |
| michael@0 | 49 | // If we get here, the test passed, so override that behavior. |
| michael@0 | 50 | quit(0); |
