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

Thomas Wouters thomas at python.org
Tue Jun 27 18:46:15 CEST 2006


On 6/27/06, Brett Cannon <brett at python.org> wrote:
>
> 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?
>

Well, it's a valid crasher. It crashes Python to recurse too much. The
recursion limit was added to CPython to prevent the crash from happening too
easily, but that limit is just an implementation detail (and furthermore,
the actual limit is just guessed.) It's not like a real solution is
impossible, it's just very complex. Much like, say, restricted execution :-)

-- 
Thomas Wouters <thomas at python.org>

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