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From:   Arnd Bergmann <arnd@kernel.org>
Date:   Tue, 1 Mar 2022 15:45:51 +0100
Message-ID: <CAK8P3a2ZBOdEWTB1K9wA0v657VTZc-BC4LkDoQ0uw8Hw8FfSyg@mail.gmail.com>
Subject: Re: [PATCH] [v2] Kbuild: move to -std=gnu11
To:     Fangrui Song <maskray@google.com>
Cc:     Nick Desaulniers <ndesaulniers@google.com>,
        Linux Kbuild mailing list <linux-kbuild@vger.kernel.org>,
        Arnd Bergmann <arnd@arndb.de>,
        Linus Torvalds <torvalds@linux-foundation.org>,
        Masahiro Yamada <masahiroy@kernel.org>, llvm@lists.linux.dev,
        Jonathan Corbet <corbet@lwn.net>,
        Federico Vaga <federico.vaga@vaga.pv.it>,
        Alex Shi <alexs@kernel.org>, Hu Haowen <src.res@email.cn>,
        Michal Marek <michal.lkml@markovi.net>,
        "open list:DOCUMENTATION" <linux-doc@vger.kernel.org>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
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        Intel Graphics <intel-gfx@lists.freedesktop.org>,
        dri-devel <dri-devel@lists.freedesktop.org>,
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On Mon, Feb 28, 2022 at 10:41 PM Fangrui Song <maskray@google.com> wrote:
> >
> >More precisely, the semantics of "extern inline" functions changed
> >between ISO C90 and ISO C99.
>
> Perhaps a clearer explanation to readers is: "extern inline" and "inline" swap
> semantics with gnu_inline (-fgnu89-inline or __attribute__((__gnu_inline__))).
>
> >That's the only concern I have, which I doubt is an issue. The kernel
> >is already covered by the function attribute as you note.
> >
> >Just to have some measure:
> >$ git grep -rn "extern inline" | wc -l
> >116
>
> "^inline" behaves like C99+ "extern inline"
>
> Agree this is handled by
>
>      #define inline inline __gnu_inline __inline_maybe_unused notrace
>

Ok, I've reworded it again, but kept it a bit shorter, I don't think we
need the full explanation in this patch description in the end.

Thanks,

      Arnd