From owner-freebsd-current@FreeBSD.ORG Fri Aug 30 14:41:32 2013 Return-Path: Delivered-To: current@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [8.8.178.115]) (using TLSv1 with cipher ADH-AES256-SHA (256/256 bits)) (No client certificate requested) by hub.freebsd.org (Postfix) with ESMTP id 61824EC5; Fri, 30 Aug 2013 14:41:32 +0000 (UTC) (envelope-from jhb@freebsd.org) Received: from bigwig.baldwin.cx (bigwig.baldwin.cx [IPv6:2001:470:1f11:75::1]) (using TLSv1 with cipher ADH-CAMELLIA256-SHA (256/256 bits)) (No client certificate requested) by mx1.freebsd.org (Postfix) with ESMTPS id 2EB182A1E; Fri, 30 Aug 2013 14:41:32 +0000 (UTC) Received: from jhbbsd.localnet (unknown [38.105.238.108]) by bigwig.baldwin.cx (Postfix) with ESMTPSA id BC2ACB939; Fri, 30 Aug 2013 10:41:30 -0400 (EDT) From: John Baldwin To: David Chisnall , Boris Samorodov Subject: Re: GCC withdraw Date: Fri, 30 Aug 2013 10:41:18 -0400 User-Agent: KMail/1.13.5 (FreeBSD/8.2-CBSD-20110714-p28; KDE/4.5.5; amd64; ; ) References: <20130822200902.GG94127@funkthat.com> <201308291344.25562.jhb@freebsd.org> In-Reply-To: MIME-Version: 1.0 Content-Type: Text/Plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Message-Id: <201308301041.18874.jhb@freebsd.org> X-Greylist: Sender succeeded SMTP AUTH, not delayed by milter-greylist-4.2.7 (bigwig.baldwin.cx); Fri, 30 Aug 2013 10:41:30 -0400 (EDT) Cc: "Sam Fourman Jr." , toolchain@freebsd.org, FreeBSD Current X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: Discussions about the use of FreeBSD-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 30 Aug 2013 14:41:32 -0000 Only a few comments in reply to avoid banging my head against a brick wall and then I'm done: On Friday, August 30, 2013 3:33:21 am David Chisnall wrote: > On 29 Aug 2013, at 18:44, John Baldwin wrote: > > Also, unless you plan on desupporting all non-x86 platforms, you _still_ > > have to do all this work while those platforms require GCC anyway. Just > > turning off GCC on x86 doesn't change this problem one iota. And that point > > is actually relevant to many of the other concerns you raised. It's not at > > all clear what disabling GCC on x86 will buy you unless you are intending on > > short-changing support for GCC on non-x86. > > It gives us a much cleaner deprecation strategy. Ports on tier-2 are best effort. We don't need to be quite as careful to ensure that they build with the base system compiler on tier-2 architectures. We don't make as strong guarantees about compatibility on tier-2 architectures, so removing gcc from their build at some point over the next five years is fine, but this is not the case for tier 1 architectures, where we can be reasonably expected to support anything that is in the base system for the next five years. > [snip] So my take away from this is that you have no plans to support any platform that doesn't support clang as you just expect ia64 and sparc64 to die and not be present in 11.0. That may be the best path, but I've certainly not seen that goal discussed publically. > > Don't get me wrong, I don't love GCC per se, and on my laptop I've hacked > > the relevant ports so that everything is built with clang. I would also > > love to be able to build the base system with GCC 47 instead of 42, it just > > doesn't seem that we are there yet. > > The time to raise objections for this was when the plan was originally raised over a year ago, or at any of the points when it's been discussed in between. It is not after we're ready to flip the switch. So I think the crux of the issue might be this: I have no doubt that this has been discussed extensively on toolchain@ and in toolchain-specific devsummit sessions. The proposal to disable GCC by default does not appear to have been discussed in a wider audience from what I can tell. (I can't find any relevant threads on arch@ or current@ prior to this one.) While this is a toolchain-specific decision, it is a very broad decision. Also, we aren't here because of a new thread started intentionally to say "Hey, we as the toolchain folks think we should disable GCC by default on 10 for x86". Instead, we started off in a thread about adding AES instructions to our binutils and out of left field there is an e-mail of "Oh, don't bother cause I'm disabling GCC next week" (paraphrase). Can you appreciate at all that this is a total surprise to people who aren't subscribed to toolchain@ and haven't been to a toolchain session at a devsummit and that this looks like a drive-by change? -- John Baldwin