Re: [RFC 0/6] Regressions for "imply" behavior change

From: Saeed Mahameed
Date: Wed Apr 08 2020 - 16:47:57 EST


On Wed, 2020-04-08 at 16:38 -0400, Nicolas Pitre wrote:
> On Wed, 8 Apr 2020, Arnd Bergmann wrote:
>
> > Hi everyone,
> >
> > I've just restarted doing randconfig builds on top of mainline
> > Linux and
> > found a couple of regressions with missing dependency from the
> > recent
> > change in the "imply" keyword in Kconfig, presumably these two
> > patches:
> >
> > 3a9dd3ecb207 kconfig: make 'imply' obey the direct dependency
> > def2fbffe62c kconfig: allow symbols implied by y to become m
> >
> > I have created workarounds for the Kconfig files, which now stop
> > using
> > imply and do something else in each case. I don't know whether
> > there was
> > a bug in the kconfig changes that has led to allowing
> > configurations that
> > were not meant to be legal even with the new semantics, or if the
> > Kconfig
> > files have simply become incorrect now and the tool works as
> > expected.
>
> In most cases it is the code that has to be fixed. It typically does:
>
> if (IS_ENABLED(CONFIG_FOO))
> foo_init();
>
> Where it should rather do:
>
> if (IS_REACHABLE(CONFIG_FOO))
> foo_init();
>
> A couple of such patches have been produced and queued in their
> respective trees already.
>
>

Yes i have a patch in mlx5-net branch converting IS_ENABLED to
IS_REACHABLE in mlx5, i will post it today.

Thanks,
Saeed.