Re: [greybus-dev] [PATCH] Kbuild: remove -std=gnu89 from compiler arguments

[Arnd Bergmann <arnd@kernel.org>]

On Mon, Feb 28, 2022 at 12:04 AM Alex Elder <elder@linaro.org> wrote:
> On 2/27/22 3:52 PM, Arnd Bergmann wrote: From: Arnd Bergmann <arnd@arndb.de>

> > I put the suggestion into patch form, based on what we discussed
> > in the thread.  I only gave it minimal testing, but it would
> > be good to have it in linux-next if we want to do this in the
> > merge window.
>
> Did you determine what needed the new compiler flag based on
> compilation results?
>
> Glancing at the Greybus code, I don't believe there's any
> reason it needs to shift a negative value.  Such warnings
> could be fixed by making certain variables unsigned, for
> example.
>
> I have no objection, I'll just make a note of it.

I've clarified in the changelog that I'm adding the -Wno-shift-negative-value
everywhere that -Wextra is used, not because I saw actual warnings
for greybus and btrfs. The -Wextra is copied from scripts/Makefile.extrawarn,
so this keeps it in sync. Ideally we should have an easier way for a
subdirectory to get the W=1 flags without copying the list, but the
patch I started to do this never got close to getting integrated.

         Arnd