From mboxrd@z Thu Jan  1 00:00:00 1970
From: Johannes Weiner <hannes@saeurebad.de>
Date: Tue, 29 Jul 2008 21:20:24 +0000
Subject: Re: How to fix warning 'control reaches end of non-void function'
Message-Id: <87r69cbd5z.fsf@saeurebad.de>
List-Id: <kernel-janitors.vger.kernel.org>
References: <20080729191738.GA32506@orion>
In-Reply-To: <20080729191738.GA32506@orion>
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To: kernel-janitors@vger.kernel.org

Hi,

Marcin Slusarz <marcin.slusarz@gmail.com> writes:

> On Tue, Jul 29, 2008 at 11:17:38PM +0400, Alexander Beregalov wrote:
>> Hi
>> 
>> What is it a right way to fix these warnings?
>> 
>> smth function()
>> {
>> 	switch (var) {
>> 	case one:
>> 		return 1;
>> 	default:
>> 		BUG();
>> 	}
>> }
>> 
>> warning: control reaches end of non-void function
>
> If BUG() would be normal function it could be marked as __attribute__((noreturn)).
> But it's a macro defined differently depending on architecture and CONFIG_*.
> Sometimes it calls panic() which is annotated properly and sometimes it calls
> other code....
>
> If you are brave, you could fix all implementations.

And sometimes it calls nothing at all (!CONFIG_BUG).  So even if you
mark the thing that _does_ something as noreturn, it will still emit
warnings then on !CONFIG_BUG.

	Hannes