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From:   Arnd Bergmann <arnd@arndb.de>
Date:   Tue, 4 Jun 2019 13:54:21 +0200
Message-ID: <CAK8P3a1oDfNF_T+NCoPsXkJAY2x4_uCWSwrDXHi7dDSaMqfnfA@mail.gmail.com>
Subject: Re: [PATCH] media: do not use C++ style comments in uapi headers
To:     Joe Perches <joe@perches.com>
Cc:     Masahiro Yamada <yamada.masahiro@socionext.com>,
        Linux Media Mailing List <linux-media@vger.kernel.org>,
        Mauro Carvalho Chehab <mchehab@kernel.org>,
        Thomas Gleixner <tglx@linutronix.de>,
        Greg KH <gregkh@linuxfoundation.org>,
        Randy Dunlap <rdunlap@infradead.org>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
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On Tue, Jun 4, 2019 at 1:23 PM Joe Perches <joe@perches.com> wrote:
>
> On Tue, 2019-06-04 at 20:13 +0900, Masahiro Yamada wrote:
> > On the other hand, uapi headers are written in more strict C, where
> > the C++ comment style is forbidden.
>
> Is this a real problem for any toolchain?

There is likely some code that is built with -Wpedandic -Werror --std=c89
or similar. Since glibc allows this combination for its own headers, it seems
best to also allow it in kernel headers that may be included by libc headers
or by applications, at least where it does not hurt.

Realistically though, we probably assume c99 or gnu89 in user space
headers anyway, since there is no 'long long' in earlier standards.

       Arnd