Re: [PATCH] scripts/unifdef: avoid constexpr keyword

From: Masahiro Yamada <masahiroy@kernel.org>
To: Arnd Bergmann <arnd@kernel.org>
Cc: Tony Finch <dot@dotat.at>, Sam Ravnborg <sam@ravnborg.org>,
	Arnd Bergmann <arnd@arndb.de>,
	 Nathan Chancellor <nathan@kernel.org>,
	Nicolas Schier <nicolas@fjasle.eu>,
	linux-kbuild@vger.kernel.org,  Michal Marek <mmarek@suse.cz>,
	linux-kernel@vger.kernel.org
Subject: Re: [PATCH] scripts/unifdef: avoid constexpr keyword
Date: Fri, 29 Mar 2024 18:59:26 +0900	[thread overview]
Message-ID: <CAK7LNATQJ6HXwsY2ziDPnQ5AdhFHL=M=qPW2idyPQrumsXmkrQ@mail.gmail.com> (raw)
In-Reply-To: <20240320180134.100863-1-arnd@kernel.org>

On Thu, Mar 21, 2024 at 3:01 AM Arnd Bergmann <arnd@kernel.org> wrote:
>
> From: Arnd Bergmann <arnd@arndb.de>
>
> Starting with c23, 'constexpr' is a keyword in C like in C++ and cannot
> be used as an identifier:
>
> scripts/unifdef.c:206:25: error: 'constexpr' can only be used in variable declarations
>   206 | static bool             constexpr;              /* constant #if expression */
>       |                         ^
> scripts/unifdef.c:880:13: error: expected identifier or '('
>   880 |                 constexpr = false;
>       |                           ^
>
> Rename this instance to allow changing to C23 at some point in the future.
>
> Fixes: d8379ab1dde3 ("unifdef: update to upstream revision 1.190")

This can be a problem only for future kernels.
Is it worth adding Fixes?

Even if the kernel bumps to C23 at some point,
such a patch will not be backported.

-- 
Best Regards
Masahiro Yamada