From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <linux-kernel-owner@vger.kernel.org>
Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand
        id S1754159AbdK1Tsr (ORCPT <rfc822;w@1wt.eu>);
        Tue, 28 Nov 2017 14:48:47 -0500
Received: from Galois.linutronix.de ([146.0.238.70]:35379 "EHLO
        Galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org
        with ESMTP id S1754087AbdK1Tsp (ORCPT
        <rfc822;linux-kernel@vger.kernel.org>);
        Tue, 28 Nov 2017 14:48:45 -0500
Date: Tue, 28 Nov 2017 20:48:28 +0100 (CET)
From: Thomas Gleixner <tglx@linutronix.de>
To: "Gustavo A. R. Silva" <garsilva@embeddedor.com>
cc: Ingo Molnar <mingo@redhat.com>, "H. Peter Anvin" <hpa@zytor.com>,
        x86@kernel.org, LKML <linux-kernel@vger.kernel.org>,
        Kees Cook <keescook@chromium.org>,
        Linus Torvalds <torvalds@linux-foundation.org>
Subject: Re: [PATCH] x86/syscalls: Mark expected switch fall-throughs
In-Reply-To: <20171128125331.Horde.XUXRWEiZ7FMJv6yoDylZxN8@gator4166.hostgator.com>
Message-ID: <alpine.DEB.2.20.1711282040500.2222@nanos>
References: <20171127235253.GA20384@embeddedor.com> <alpine.DEB.2.20.1711281448520.1723@nanos> <20171128120512.Horde.1mz61Up1PsNtyHbrjWmK8L7@gator4166.hostgator.com> <alpine.DEB.2.20.1711281908040.2222@nanos> <alpine.DEB.2.20.1711281911280.2222@nanos>
 <20171128122235.Horde.vFP-9ZfAP0f9BFNePB8Z8xi@gator4166.hostgator.com> <alpine.DEB.2.20.1711281924080.2222@nanos> <alpine.DEB.2.20.1711281933170.2222@nanos> <alpine.DEB.2.20.1711281944010.2222@nanos>
 <20171128125331.Horde.XUXRWEiZ7FMJv6yoDylZxN8@gator4166.hostgator.com>
User-Agent: Alpine 2.20 (DEB 67 2015-01-07)
MIME-Version: 1.0
Content-Type: text/plain; charset=US-ASCII
X-Linutronix-Spam-Score: -1.0
X-Linutronix-Spam-Level: -
X-Linutronix-Spam-Status: No , -1.0 points, 5.0 required,  ALL_TRUSTED=-1,SHORTCIRCUIT=-0.0001
Sender: linux-kernel-owner@vger.kernel.org
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org

On Tue, 28 Nov 2017, Gustavo A. R. Silva wrote:
> This is what we want to add:
> 
> # Warn about missing switch break or fall-through comment.
> KBUILD_CFLAGS  += $(call cc-option,-Wimplicit-fallthrough)

Can this be made to ignore comments and only accept the proper annotation?

> > > I have no idea who came up with that brilliant idea of parsing comments in
> > > the code. It's so simple to make this parser completely fail that it's not
> > > even funny anymore.
> > > 
> 
> I don't get why someone would want to do that to himself. :/

Well, it's not intentional.

You add any comment and the parser thinks its correct. Or you typo the
thing and it fails to recognize.

Thanks,

	tglx