On Thu, May 29, 2025 at 09:17:14AM -0700, Junio C Hamano wrote:
> Carlo Marcelo Arenas Belón <carenas@xxxxxxxxx> writes:
>
> > Since f93b2a0424 (reftable/basics: introduce `REFTABLE_UNUSED`
> > annotation, 2025-02-18), the reftable library was migrated to
> > use an internal version of `UNUSED`, which unconditionally sets
> > a GNU __attribute__ to avoid warnings function parameters that
> > are not being used.
> >
> > Make the definition conditional to prevent breaking the build
> > with non GNU compilers.
>
> Quite a reasonable reasoning.
>
> > Reported-by: "Randall S. Becker" <rsbecker@xxxxxxxxxxxxx>
> > Signed-off-by: Carlo Marcelo Arenas Belón <carenas@xxxxxxxxx>
> > ---
> > reftable/basics.h | 4 ++++
> > 1 file changed, 4 insertions(+)
> >
> > diff --git a/reftable/basics.h b/reftable/basics.h
> > index d8888c1262..7d22f96261 100644
> > --- a/reftable/basics.h
> > +++ b/reftable/basics.h
> > @@ -16,7 +16,11 @@
> > #include "system.h"
> > #include "reftable-basics.h"
> >
> > +#ifdef __GNUC__
> > #define REFTABLE_UNUSED __attribute__((__unused__))
> > +#else
> > +#define REFTABLE_UNUSED
> > +#endif
>
> Corresponding definition we use in the main part of the project
> defined in compat/posix.h looks like this:
>
> #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
>
> GCC 4.5 or older may no longer be relevant, in which case yours may
> be good enough.
What I don't understand though: we have a `MAYBE_UNUSED` macro that has
the exact same definition in "git-compat-util.h". Why does the macro
cause issues in the reftable library, but not over there?
Patrick
