Re: [PATCH v2 1/2] commit-slabs: move MAYBE_UNUSED out

[Jeff King <peff@peff.net>]

On Tue, Oct 23, 2018 at 02:50:19PM -0700, Carlo Marcelo Arenas Belón wrote:

> after 36da893114 ("config.mak.dev: enable -Wunused-function", 2018-10-18)
> it is expected to be used to prevent -Wunused-function warnings for code
> that was macro generated

Makes sense.

> diff --git a/commit-slab-impl.h b/commit-slab-impl.h
> index ac1e6d409a..5c0eb91a5d 100644
> --- a/commit-slab-impl.h
> +++ b/commit-slab-impl.h
> @@ -1,10 +1,10 @@
>  #ifndef COMMIT_SLAB_IMPL_H
>  #define COMMIT_SLAB_IMPL_H
>  
> -#define MAYBE_UNUSED __attribute__((__unused__))
> +#include "git-compat-util.h"

We shouldn't need to include git-compat-util.h, as the C files would
already do so, via this rule in CodingGuidelines:

   - The first #include in C files, except in platform specific compat/
   implementations, must be either "git-compat-util.h", "cache.h" or
   "builtin.h".  You do not have to include more than one of these.

(and if there is a case that does not, we should fix that).

>  #define implement_static_commit_slab(slabname, elemtype) \
> -	implement_commit_slab(slabname, elemtype, static MAYBE_UNUSED)
> +	implement_commit_slab(slabname, elemtype, MAYBE_UNUSED static)

Is this hunk necessary?

> diff --git a/git-compat-util.h b/git-compat-util.h
> index 9a64998b24..e4d3967a23 100644
> --- a/git-compat-util.h
> +++ b/git-compat-util.h
> @@ -408,6 +408,8 @@ static inline char *git_find_last_dir_sep(const char *path)
>  #define LAST_ARG_MUST_BE_NULL
>  #endif
>  
> +#define MAYBE_UNUSED __attribute__((__unused__))
> +
>  #include "compat/bswap.h"

Looks good.

-Peff