From owner-freebsd-current@FreeBSD.ORG  Thu Dec 11 05:20:12 2003
Return-Path: <owner-freebsd-current@FreeBSD.ORG>
Delivered-To: freebsd-current@freebsd.org
Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125])
	by hub.freebsd.org (Postfix) with ESMTP id BA34516A4CE
	for <current@freebsd.org>; Thu, 11 Dec 2003 05:20:12 -0800 (PST)
Received: from paladin.fortunaty.net (fortunaty.net [217.160.129.175])
	by mx1.FreeBSD.org (Postfix) with SMTP id 2B88343D09
	for <current@freebsd.org>; Thu, 11 Dec 2003 05:20:11 -0800 (PST)
	(envelope-from ah@paladin.fortunaty.net)
Received: (qmail 2492 invoked by uid 501); 11 Dec 2003 13:20:10 -0000
Date: 11 Dec 2003 13:20:10 -0000
Message-ID: <20031211132010.2491.qmail@paladin.fortunaty.net>
User-Agent: Emai/0.0.2p1
Mime-Version: 1.0
Content-Type: text/plain; charset="iso-8859-1"
Content-Disposition: inline
References: <20031210204642.27989.qmail@paladin.fortunaty.net>,<xzpptevecd4.fsf@dwp.des.no>
In-Reply-To: <xzpptevecd4.fsf@dwp.des.no>
From: andy@splashground.de
To: Dag-Erling =?iso-8859-1?q?Sm=F8rgrav?= <des@des.no>
cc: Damian Gerow <dgerow@afflictions.org>
cc: current@freebsd.org
Subject: Re: buildworld doesn't like -O2
X-BeenThere: freebsd-current@freebsd.org
X-Mailman-Version: 2.1.1
Precedence: list
List-Id: Discussions about the use of FreeBSD-current
	<freebsd-current.freebsd.org>
List-Unsubscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-current>,
	<mailto:freebsd-current-request@freebsd.org?subject=unsubscribe>
List-Archive: <http://lists.freebsd.org/pipermail/freebsd-current>
List-Post: <mailto:freebsd-current@freebsd.org>
List-Help: <mailto:freebsd-current-request@freebsd.org?subject=help>
List-Subscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-current>,
	<mailto:freebsd-current-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Thu, 11 Dec 2003 13:20:12 -0000

des wrote @ Thu, 11 Dec 2003 14:02:31 +0100:
> Andreas Hauser <andy-freebsd@splashground.de> writes:
> > There is a qr about it
> > http://www.freebsd.org/cgi/query-pr.cgi?pr=55774
> > but it was closed by DES saying "Not a problem report".
> > I don't understand why [...]
> 
> Quoting from src/share/examples/etc/make.conf:
> 
> # CFLAGS controls the compiler settings used when compiling C code.
> # Note that optimization settings above -O (-O2, ...) are not recommended
> # or supported for compiling the world or the kernel - please revert any
> # nonstandard optimization settings to "-O" before submitting bug reports
> # to the developers.
> 
> Even if that weren't the case, PRs about a broken build are generally
> not welcome.  We have mailing lists for that.

I know that and i also understand that brocken
optimization levels of GCC have led to a lot of false reports.
But with the newer GCC versions much has improved.

And in this case, as far as i can see,
the code does violate the strict aliasing rules.

const char *rhost;
... (const void **)&rhost ...

You only have (bad) luck that with less
optimizations the compiler doesn't warn about it.
Or is that a wrong representation?


Andy