Re: [PATCH] git-compat-util.h: GCC deprecated message arg only in GCC 4.5+

["Alejandro R. Sedeño" <asedeno@mit.edu>]

Happy to do so! I build new versions of git on a few systems as they
roll out, and you'll find many of my (not that many) patches involve
breakage on this particularly old system. I'm sure one day a big
change will break git for good there, but in the meantime I'll do what
I can to keep it going. :-)

-Alejandro

On Thu, Oct 6, 2022 at 3:33 AM Ævar Arnfjörð Bjarmason <avarab@gmail.com> wrote:
>
>
> On Wed, Oct 05 2022, Aleajndro R Sedeño wrote:
>
> > From: Alejandro R. Sedeño <asedeno@mit.edu>
> >
> > From: https://gcc.gnu.org/gcc-4.5/changes.html
> >
> >> The deprecated attribute now takes an optional string argument, for
> >> example, __attribute__((deprecated("text string"))), that will be
> >> printed together with the deprecation warning.
> >
> > While GCC 4.5 is already 12 years old, git checks for even older
> > versions in places. Let's not needlessly break older compilers when
> > a small and simple fix is readily available.
> >
> > Signed-off-by: Alejandro R. Sedeño <asedeno@mit.edu>
> > Signed-off-by: Alejandro R Sedeño <asedeno@google.com>
> > ---
> >  git-compat-util.h | 5 ++++-
> >  1 file changed, 4 insertions(+), 1 deletion(-)
> >
> > diff --git a/git-compat-util.h b/git-compat-util.h
> > index b90b64718e..045b47f83a 100644
> > --- a/git-compat-util.h
> > +++ b/git-compat-util.h
> > @@ -189,9 +189,12 @@ struct strbuf;
> >  #define _NETBSD_SOURCE 1
> >  #define _SGI_SOURCE 1
> >
> > -#if defined(__GNUC__)
> > +#if GIT_GNUC_PREREQ(4, 5)
> >  #define UNUSED __attribute__((unused)) \
> >       __attribute__((deprecated ("parameter declared as UNUSED")))
> > +#elif defined(__GNUC__)
> > +#define UNUSED __attribute__((unused)) \
> > +     __attribute__((deprecated))
> >  #else
> >  #define UNUSED
> >  #endif
>
> This LGTM, thanks a lot for that fix & fixing this (minor) breakage of
> mine.
>
> I did test on an older GCC myself, and then (in lieu of logging into an
> ancient system I have access to) scoured the release notes of gcc, and
> discovered that "deprecated" was older than anything we cared about.
>
> But I obviously missed that while the feature had been there for a
> longer time, it didn't take this parameter until GCC 4.5, sorry!