Re: [PATCH v2] compat/posix.h: enable UNUSED warning messages for Clang

From: Dominik Loidolt <dominik.loidolt@univie.ac.at>
Date: Jun 5, 2026, 15:53 UTC
Message-ID: <aiLxCWp8Bv-KQoLf@four.local>
In-Reply-To: <aiLNqQgiQPlviB5X@pks.im>

On Fri, Jun 05, 2026 at 03:22:49PM +0200, Patrick Steinhardt wrote:

> I was wondering about that, too. The question that I have is whether
> there's any particular reason why the check was written that way. So in
> the best case we'd do some digging into the history to figure out why
> this looks the way it looks like.

I think the current bit-shift style introduced by 89c855ed3c (git-compat-util.h: implement a different ARRAY_SIZE macro for for safely deriving the size of array, 2015-04-30) was inherited from glibc [0].

I found that NetBSD [1] has long used the more explicit comparison form instead of the bit-shift style, and other BSDs seem to do the same. So there is at least established precedent for writing the version check that way. :-)

I see no obvious reason to prefer the bit-shift style today.

 Dominik

[0] https://sourceware.org/git/?p=glibc.git;a=commitdiff;h=4360eafdd20769fa9d42c075853271debd06f7d1 [1] https://github.com/NetBSD/src/commit/2fffc76da21e012509677f5310464f62797bd1bf