[petsc-dev] Unused macros in petscconf.h

[Matthew Knepley]

On Sat, Jun 29, 2019 at 8:39 AM Jed Brown <jed at jedbrown.org> wrote:

> Matthew Knepley <knepley at gmail.com> writes:
>
> > On Fri, Jun 28, 2019 at 4:37 PM Jed Brown <jed at jedbrown.org> wrote:
> >
> >> Matthew Knepley <knepley at gmail.com> writes:
> >>
> >> > On Fri, Jun 28, 2019 at 2:04 PM Smith, Barry F. via petsc-dev <
> >> > petsc-dev at mcs.anl.gov> wrote:
> >> >
> >> >>
> >> >>   You are right, these do not belong in petscconf.h
> >> >>
> >> >
> >> > The problematic thing here is hiding information from users of
> >> > PETSc. If you are a user that counts on PETSc configure to check
> >> > something, but then we hide it because we do not use it, I would not
> >> > be happy.
> >>
> >> You want PETSc to test things that it doesn't use because maybe a user
> >> would want to know?  Where does that end
> >
> >
> > Very clearly it ends with testing the things users SPECIFICALLY ASKED
> > US TO TEST on the configure command line.
>
> They asked us to test the size of short and for the existence of sched.h
> and mkstemp?
>

I have no problem trimming the automatic tests we do (I copied them from
Autoconf),
as long as we provide a way to turn them on again.


> >> and how would we ever know if
> >> the information is correct?
> >>
> >
> > This is just nonsensical. We know its correct because we tested it.
>
> Only by the code that decides whether to define the macro, but if one of
> those tests is/becomes broken (this has happened), we wouldn't know.
>

I am not sure that worrying that code might become broken is a first order
problem.

   Matt

-- 
What most experimenters take for granted before they begin their
experiments is infinitely more interesting than any results to which their
experiments lead.
-- Norbert Wiener

https://www.cse.buffalo.edu/~knepley/ <http://www.cse.buffalo.edu/~knepley/>
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