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Date:   Wed, 31 Jul 2019 11:02:11 +0200
From:   Peter Zijlstra <peterz@infradead.org>
To:     Joe Perches <joe@perches.com>
Cc:     Linus Torvalds <torvalds@linux-foundation.org>,
        Miguel Ojeda <miguel.ojeda.sandonis@gmail.com>,
        Kees Cook <keescook@chromium.org>,
        Borislav Petkov <bp@alien8.de>,
        "H . Peter Anvin" <hpa@zytor.com>,
        Thomas Gleixner <tglx@linutronix.de>,
        Ingo Molnar <mingo@redhat.com>, Pavel Machek <pavel@ucw.cz>,
        "Gustavo A . R . Silva" <gustavo@embeddedor.com>,
        Arnaldo Carvalho de Melo <acme@kernel.org>,
        Kan Liang <kan.liang@linux.intel.com>,
        Namhyung Kim <namhyung@kernel.org>,
        Jiri Olsa <jolsa@redhat.com>,
        Alexander Shishkin <alexander.shishkin@linux.intel.com>,
        Shawn Landden <shawn@git.icu>, x86@kernel.org,
        linux-kernel@vger.kernel.org
Subject: Re: [RFC PATCH] compiler_attributes.h: Add 'fallthrough' pseudo
 keyword for switch/case use
Message-ID: <20190731090211.GP31381@hirez.programming.kicks-ass.net>
References: <e0dd3af448e38e342c1ac6e7c0c802696eb77fd6.1564549413.git.joe@perches.com>
 <1d2830aadbe9d8151728a7df5b88528fc72a0095.1564549413.git.joe@perches.com>
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On Tue, Jul 30, 2019 at 10:35:18PM -0700, Joe Perches wrote:
> Reserve the pseudo keyword 'fallthrough' for the ability to convert the
> various case block /* fallthrough */ style comments to appear to be an
> actual reserved word with the same gcc case block missing fallthrough
> warning capability.
> 
> All switch/case blocks now must end in one of:
> 
> 	break;
> 	fallthrough;
> 	goto <label>;
> 	return [expression];
> 
> fallthough is gcc's __attribute__((__fallthrough__)) which was introduced
> in gcc version 7..
> 
> fallthrough devolves to an empty "do {} while (0)" if the compiler version
> (any version less than gcc 7) does not support the attribute.
> 
> Signed-off-by: Joe Perches <joe@perches.com>

_MUCH_ better than that silly comment, thanks for doing this!

Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>