Re: [PATCH bpf-next] selftests/bpf: test_progs option for listing test names

[Jesper Dangaard Brouer <brouer@redhat.com>]

On Tue, 30 Jun 2020 08:46:01 -0700
Andrii Nakryiko <andrii.nakryiko@gmail.com> wrote:

> > @@ -688,9 +700,17 @@ int main(int argc, char **argv)
> >                         cleanup_cgroup_environment();
> >         }
> >         stdio_restore();
> > +
> > +       if (env.list_test_names) {
> > +               if (env.succ_cnt == 0)
> > +                       env.fail_cnt = 1;
> > +               goto out;
> > +       }
> > +  
> 
> Why failure if no test matched? Is that to catch bugs in whitelisting?

I would not call it catch bugs, but sort of.  The purpose is to know if
requested test is valid.  This can be used to e.g. run through all the
tests numbers, and stopping when a test number (-n) is no-longer valid,
by using this shell exit value as a test, like:

 n=1;
 while [ $(./test_progs --list -n $n) ] ; do \
   echo "./test_progs -n $n" ; n=$(( n+1 )); \
 done

Notice that this features that be used for looking up a test number,
and returning a testname, which was the original request from CI.  I
choose this implementation as it more generic and generally useful.

 $ ./test_progs --list -n 89
 xdp_adjust_tail


-- 
Best regards,
  Jesper Dangaard Brouer
  MSc.CS, Principal Kernel Engineer at Red Hat
  LinkedIn: http://www.linkedin.com/in/brouer