From mboxrd@z Thu Jan 1 00:00:00 1970 Received: with ECARTIS (v1.0.0; list linux-mips); Sat, 22 Nov 2008 09:39:43 +0000 (GMT) Received: from h4.dl5rb.org.uk ([81.2.74.4]:21124 "EHLO ditditdahdahdah-dahdahdahditdit.dl5rb.org.uk") by ftp.linux-mips.org with ESMTP id S23830068AbYKVJjk (ORCPT ); Sat, 22 Nov 2008 09:39:40 +0000 Received: from denk.linux-mips.net (denk.linux-mips.net [127.0.0.1]) by ditditdahdahdah-dahdahdahditdit.dl5rb.org.uk (8.14.2/8.14.1) with ESMTP id mAM9dbl4011381; Sat, 22 Nov 2008 09:39:37 GMT Received: (from ralf@localhost) by denk.linux-mips.net (8.14.2/8.14.2/Submit) id mAM9daHi011379; Sat, 22 Nov 2008 09:39:36 GMT Date: Sat, 22 Nov 2008 09:39:35 +0000 From: Ralf Baechle To: David Daney Cc: linux-mips , linux-kernel@vger.kernel.org Subject: Re: [PATCH] MIPS: Make BUG() __noreturn. Message-ID: <20081122093935.GA31703@linux-mips.org> References: <49260E4C.8080500@caviumnetworks.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <49260E4C.8080500@caviumnetworks.com> User-Agent: Mutt/1.5.18 (2008-05-17) Return-Path: X-Envelope-To: <"|/home/ecartis/ecartis -s linux-mips"> (uid 0) X-Orcpt: rfc822;linux-mips@linux-mips.org Original-Recipient: rfc822;linux-mips@linux-mips.org X-archive-position: 21382 X-ecartis-version: Ecartis v1.0.0 Sender: linux-mips-bounce@linux-mips.org Errors-to: linux-mips-bounce@linux-mips.org X-original-sender: ralf@linux-mips.org Precedence: bulk X-list: linux-mips On Thu, Nov 20, 2008 at 05:26:36PM -0800, David Daney wrote: > From: David Daney > Date: Thu, 20 Nov 2008 17:26:36 -0800 > To: linux-mips > CC: linux-kernel@vger.kernel.org > Subject: [PATCH] MIPS: Make BUG() __noreturn. > Content-Type: text/plain; charset=ISO-8859-1; format=flowed > > MIPS: Make BUG() __noreturn. Please don't repeat the subject in the body of a patch email. Git takes the subject followed by the body upto the --- line as the log message so this is just duplication that will need to be manually deleted again. > Often we do things like put BUG() in the default clause of a case > statement. Since it was not declared __noreturn, this could sometimes > lead to bogus compiler warnings that variables were used > uninitialized. > > There is a small problem in that we have to put a magic while(1); loop to > fool GCC into really thinking it is noreturn. This makes the new > BUG() function 3 instructions long instead of just 1, but I think it > is worth it as it is now unnecessary to do extra work to silence the > 'used uninitialized' warnings. > > I also re-wrote BUG_ON so that if it is given a constant condition, it > just does BUG() instead of loading a constant value in to a register > and testing it. I don't like the endless loop in the BUG() macros but at this time it seems the best solution. Looking forward to __builtin_noreturn(). Patch applied, Ralf