From owner-freebsd-stable@FreeBSD.ORG Mon Sep 17 22:02:27 2012 Return-Path: Delivered-To: freebsd-stable@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id C9510106566C for ; Mon, 17 Sep 2012 22:02:27 +0000 (UTC) (envelope-from dim@FreeBSD.org) Received: from tensor.andric.com (tensor.andric.com [87.251.56.140]) by mx1.freebsd.org (Postfix) with ESMTP id 805898FC08 for ; Mon, 17 Sep 2012 22:02:26 +0000 (UTC) Received: from [IPv6:2001:7b8:3a7:0:59a6:c010:f3bf:87fa] (unknown [IPv6:2001:7b8:3a7:0:59a6:c010:f3bf:87fa]) (using TLSv1 with cipher DHE-RSA-CAMELLIA256-SHA (256/256 bits)) (No client certificate requested) by tensor.andric.com (Postfix) with ESMTPSA id A05035C59; Tue, 18 Sep 2012 00:02:25 +0200 (CEST) Message-ID: <50579DEC.3060902@FreeBSD.org> Date: Tue, 18 Sep 2012 00:02:20 +0200 From: Dimitry Andric Organization: The FreeBSD Project User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:16.0) Gecko/20120905 Thunderbird/16.0 MIME-Version: 1.0 To: Roland Smith References: <20120912060420.GE31029@lonesome.com> <20120917194317.GB43284@slackbox.erewhon.net> In-Reply-To: <20120917194317.GB43284@slackbox.erewhon.net> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: Mark Linimon , FreeBSD Stable Mailing List , Andreas Nilsson Subject: Re: Clang as default compiler X-BeenThere: freebsd-stable@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Production branch of FreeBSD source code List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 17 Sep 2012 22:02:27 -0000 On 2012-09-17 21:43, Roland Smith wrote: > On Wed, Sep 12, 2012 at 01:04:20AM -0500, Mark Linimon wrote: ... >> For most of the failures, we are already aware of them, as a result of >> our periodic runs. So, just filing a PR to say "broken on clang" doesn't >> really help us all that much. > > Those are build failures. What about crashes? E.g. I've recently had > crashes with x11-wm/i3 and x11/rxvt-unicode. Both problems disappeared after > recompiling them with gcc46. We can't figure them all out without *your* help. :-) Please attempt to run the program in a debugger, gather core dumps, etc. Or at least, try to make it into a reproducible case, so somebody else can attempt to diagnose it. And please specify the exact version of clang you used. Now, most of the time this is because programs contain bugs, or undefined behavior, which happens to go unnoticed with gcc, for example because it optimized by accident in such a way to mask the bug. In a few other cases, real clang bugs are found, and most of the time, those can be fixed quickly. That said, in these cases specifically, how do the applications crash? Right at startup, or after specific inputs or user actions?