Re: [PATCH v2] CodingGuidelines: also mention MAYBE_UNUSED

From: Jeff King <peff@peff.net>
Date: Aug 29, 2024, 19:40 UTC
Message-ID: <20240829194054.GC423429@coredump.intra.peff.net>
In-Reply-To: <xmqq4j73w5up.fsf_-_@gitster.g>

On Thu, Aug 29, 2024 at 11:18:06AM -0700, Junio C Hamano wrote:

Show 12 quoted lines

> +/*
> + * MAYBE_UNUSED marks a function parameter that may be unused, but
> + * whose use is not an error.  It also can be used to annotate a
> + * function, a variable, or a type that may be unused.
> + *
> + * Depending on a configuration, all uses of such a thing may become
> + * #ifdef'ed away.  Marking it with UNUSED would give a warning in a
> + * compilation where it is indeed used, and not marking it at all
> + * would give a warning in a compilation where it is unused.  In such
> + * a case, MAYBE_UNUSED is the appropriate annotation to use.
> + */
>  #define MAYBE_UNUSED __attribute__((__unused__))

Thanks, I think this is good. There's more nuanced discussion about when the "MAYBE" variant could be used for non-parameters, but I don't know that it's worth trying to enumerate every place we've found it useful.

-Peff