On Tue, Jun 6, 2017 at 3:18 PM, Jeroen Demeyer <jdeme...@cage.ugent.be> wrote:
> Do you know about sage.misc.citation.get_systems()?
>
> It's supposed to tell which underlying "system" (library, package, ...) is
> used for a particular computation.
>
> One example from a docstring:
>
> sage: from sage.misc.citation import get_systems
> sage: get_systems('((x+1)^2).expand()')
> ['ginac']
>
> This is implemented by using cProfile to look at which modules implement the
> functions called when executing the code.
>
> The problem is that this is totally unreliable when Cython is compiled
> without profiling support (which is the default). The above example only
> works because `Expression.expand()` is called by Python instead of Cython.
> If that call would be inside some other Cython code, then Python's profiler
> would not detect it:
>
> sage: cython('def callexpand(x): return x.expand()')
> sage: from sage.misc.citation import get_systems
> sage: get_systems('callexpand(((x+1)^2))')
> []
>
>
> So what should we do?
>
> (A) Silently ignore this issue (status quo).
>
> (B) Give a warning when get_systems() is called when Cython profiling was
> not enabled.
>
> (C) Deprecate get_systems() completely.
>
>
> I am asking because #22747 (compiling Cython code with binding=True) will
> "break" profiling even further as even the top-level call of
> Expression.expand() would not be detected as something to be entered in the
> profiler.I wonder if there isn't at least some partially technical solution to this, such as providing a way to manually list systems/libraries used by a specific function, and make that easily introspectable. Of course, this is far from foolproof--the developer would have to hand-code it, and it might not remain accurate. Absent something like that, I would give a warning,along with instructions to rebuild with Cython profiling enabled or something. -- You received this message because you are subscribed to the Google Groups "sage-devel" group. To unsubscribe from this group and stop receiving emails from it, send an email to sage-devel+unsubscr...@googlegroups.com. To post to this group, send email to sage-devel@googlegroups.com. Visit this group at https://groups.google.com/group/sage-devel. For more options, visit https://groups.google.com/d/optout.
