From: Christoph Hellwig <hch@lst.de>
To: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Christoph Hellwig <hch@lst.de>, Carlos Maiolino <cem@kernel.org>,
Andrew Morton <akpm@linux-foundation.org>,
Luc Van Oostenryck <luc.vanoostenryck@gmail.com>,
Chris Li <sparse@chrisli.org>,
linux-sparse@vger.kernel.org, linux-xfs@vger.kernel.org,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH 1/3] lockref: add a __cond_lock annotation for lockref_put_or_lock
Date: Tue, 18 Nov 2025 06:58:50 +0100 [thread overview]
Message-ID: <20251118055850.GB22733@lst.de> (raw)
In-Reply-To: <CAADWXX_ORdj=PaW5oeMybV6sEV6UxbZnRw4=TDZpa1Ejt0vbJQ@mail.gmail.com>
On Fri, Nov 14, 2025 at 10:18:24AM -0800, Linus Torvalds wrote:
> Macro expansion isn't recursive, and having
>
> #define a(x) something-something a(x)
>
> is actually perfectly fine, and something we do intentionally for
> other reasons (typically because it also allows us to then use "#ifdef
> a" to check whether there is some architecture-specific implementation
> of 'a()')
>
> And yes, you do need that "#undef" to then not get crazy parse errors
> in the actual definition and export of the function, but it would
> allow us to avoid yet another "underscore version of the function".
>
> I dunno. Not a big deal, but it seems annoying to make up a new name
> for this.
I know you can redefine names using macros, and now that you remind
me I remember that you like that. I personally hate it as it means
there are two things with the same name, which makes understanding
the code much harder and confuses tools like cscope. But I can
switch to that approach if you prefer.
next prev parent reply other threads:[~2025-11-18 5:58 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-11-14 5:52 make xfs sparse-warning free Christoph Hellwig
2025-11-14 5:52 ` [PATCH 1/3] lockref: add a __cond_lock annotation for lockref_put_or_lock Christoph Hellwig
2025-11-14 18:18 ` Linus Torvalds
2025-11-18 5:58 ` Christoph Hellwig [this message]
2025-11-14 5:52 ` [PATCH 2/3] xfs: move some code out of xfs_iget_recycle Christoph Hellwig
2025-11-14 17:04 ` Darrick J. Wong
2025-11-14 17:28 ` Linus Torvalds
2025-11-18 5:59 ` Christoph Hellwig
2025-11-14 5:52 ` [PATCH 3/3] xfs: work around sparse context tracking in xfs_qm_dquot_isolate Christoph Hellwig
2025-11-14 17:06 ` Darrick J. Wong
2025-11-18 6:00 ` Christoph Hellwig
2025-11-14 17:56 ` make xfs sparse-warning free Linus Torvalds
2025-11-18 5:57 ` Christoph Hellwig
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