[Python-Dev] Is Lib/test/crashers/recursive_call.py really a crasher? (original) (raw)

Brett Cannon brett at python.org
Tue Jun 27 19:32:08 CEST 2006

On 6/27/06, Michael Hudson <mwh at python.net> wrote:

"Brett Cannon" <brett at python.org> writes: > If you look at that crasher, you will notice that recursion depth is set > to 1 << 30 before any code is run. If you remove that setting high_ _> setting and go with the default then the test doesn't crash and raises the > appropriate RuntimeError. > > Setting the recursion depth to such a high number will crash the > interpreter even when the proper recursion checks are in place. This > doesn't seem like a legit crasher to me if it requires an insane recursion > depth that would crash almost any C program that had recursion in it. > > Anyone have any objections if I call foul on the test and remove it > without any changes to Python? Yes, it's still a way to crash Python :-) (in fact, a problem vaguely like this that made a complete test run segfault on 64-bit platforms was fixed in PyPy recently). More seriously, the recursion limit approach is IMHO something of a hack, as the amount of bytes of C stack in between increments is rather variable (try seeing how high you have to set the recursion limit to when the recursion invovles list.sort() compared to when it doesn't). I don't have a fantastic idea for fixing this, but I quite like having some kind of reminder of it.

OK, with you and Thomas both wanting to keep it I will let it be. I just won't worry about fixing it myself during my interpreter hardening crusade.

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