From: Elijah Newren <newren@gmail.com>
Date: Thu, 16 Apr 2026 23:46:13 GMT
Subject: Re: [PATCH] CodingGuidelines: st_mtimespec vs st_mtim vs st_mtime
Message-ID: <CABPp-BGaN_PtvUVyR8sskpLUev16FjaUbTj21j_Lna73hEYGmw@mail.gmail.com>
In-Reply-To: <xmqqzf3aofdj.fsf_-_@gitster.g>

On Fri, Apr 10, 2026 at 11:10 AM Junio C Hamano <gitster@pobox.com> wrote:
>
> Most unfortunately macOS does not support st_[amc]tim for timestamps
> down to nanosecond resolution as POSIX systems.
>
> Signed-off-by: Junio C Hamano <gitster@pobox.com>
> ---
>  Documentation/CodingGuidelines | 6 ++++++
>  1 file changed, 6 insertions(+)
>
> diff --git c/Documentation/CodingGuidelines w/Documentation/CodingGuidelines
> index 4992e52093..4e54139fd7 100644
> --- c/Documentation/CodingGuidelines
> +++ w/Documentation/CodingGuidelines
> @@ -693,6 +693,12 @@ For C programs:
>           char *dogs[] = ...;
>           walk_all_dogs(dogs);
>
> + - For file timestamps, do not use "st_mtim" (and other timestamp
> +   members in "struct stat") unconditionally; not everybody is POSIX
> +   (grep for USE_ST_TIMESPEC).  If you only need timestamp in whole
> +   second resolution, "st_mtime" should work fine everywhere.
> +
> +
>  For Perl programs:
>
>   - Most of the C guidelines above apply.

Looks good to me.  As a minor nit, "need timestamp" -> "need a timestamp".