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