| // We detect and stop the runaway recursion caused by making onEnterFrame a |
| // wrapper of a debuggee function. |
| |
| // This is all a bit silly. In any reasonable design, both debugger re-entry |
| // (the second onEnterFrame invocation) and debuggee re-entry (the call to g.f |
| // from within the debugger, not via a Debugger invocation function) would raise |
| // errors immediately. We have plans to do so, but in the mean time, we settle |
| // for at least detecting the recursion. |
| |
| load(libdir + 'asserts.js'); |
| |
| var g = newGlobal(); |
| g.eval("function f(frame) { n++; return 42; }"); |
| g.n = 0; |
| |
| var dbg = Debugger(); |
| var gw = dbg.addDebuggee(g); |
| |
| // Register the debuggee function as the onEnterFrame handler. When we first |
| // call or eval in the debuggee: |
| // |
| // - The onEnterFrame call reporting that frame's creation is itself an event |
| // that must be reported, so we call onEnterFrame again. |
| // |
| // - SpiderMonkey detects the out-of-control recursion, and generates a "too |
| // much recursion" InternalError in the youngest onEnterFrame call. |
| // |
| // - We don't catch it, so the onEnterFrame handler call itself throws. |
| // |
| // - Since the Debugger doesn't have an uncaughtExceptionHook (it can't; such a |
| // hook would itself raise a "too much recursion" exception), Spidermonkey |
| // reports the exception immediately and terminates the debuggee --- which is |
| // the next-older onEnterFrame call. |
| // |
| // - This termination propagates all the way out to the initial attempt to |
| // create a frame in the debuggee. |
| dbg.onEnterFrame = g.f; |
| |
| // Get a Debugger.Object instance referring to f. |
| var debuggeeF = gw.makeDebuggeeValue(g.f); |
| |
| // Using f.call allows us to catch the termination. |
| assertEq(debuggeeF.call(), null); |
| |
| // We should never actually begin execution of the function. |
| assertEq(g.n, 0); |
| |
| // When an error is reported, the shell usually exits with a nonzero exit code. |
| // If we get here, the test passed, so override that behavior. |
| quit(0); |