From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 20562 invoked by alias); 10 Jun 2003 01:40:31 -0000 Mailing-List: contact gdb-help@sources.redhat.com; run by ezmlm Precedence: bulk List-Subscribe: List-Archive: List-Post: List-Help: , Sender: gdb-owner@sources.redhat.com Received: (qmail 20390 invoked from network); 10 Jun 2003 01:40:30 -0000 Received: from unknown (HELO ms-smtp-02.nyroc.rr.com) (24.92.226.49) by sources.redhat.com with SMTP; 10 Jun 2003 01:40:30 -0000 Received: from doctormoo (syr-24-24-16-157.twcny.rr.com [24.24.16.157]) by ms-smtp-02.nyroc.rr.com (8.12.5/8.12.2) with ESMTP id h5A1eTpn012691; Mon, 9 Jun 2003 21:40:29 -0400 (EDT) Received: from neroden by doctormoo with local (Exim 3.36 #1 (Debian)) id 19PY7X-0008VK-00; Mon, 09 Jun 2003 21:40:19 -0400 Date: Tue, 10 Jun 2003 01:40:00 -0000 To: aoliva@redhat.com Cc: gcc@gcc.gnu.org, gdb@sources.redhat.com, binutils@sources.redhat.com Subject: Re: Partial autoconf transition thoughts Message-ID: <20030610014019.GA14933@doctormoo> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.5.4i From: Nathanael Nerode X-SW-Source: 2003-06/txt/msg00140.txt.bz2 Alexandre said: >I.e., assume you're always cross compiling? That would be a Actually, assume you're always Canadian cross compiling. :-) Except when you aren't. >reasonable approach too, but there are some tests that you can't >possibly do in the cross case, autoconf lets you actually do them in >the native case as long as you set a safe default or alternate test >for the cross case. And when I write my own tests for these circumstances, I would guard them by one of build=host or build=target, depending on which is correct under the circumstances. This generally tests in the correct situations, and is if anything too conservative (assuming untestability when build=i686-pc-linux-gnu and host=i386-pc-linux-gnu). I suppose the idea behind the proposal is that you can always force nativeness by not specifying 'host' (since it defaults to build); but there's no clear way to force 'crossness' when host=build. But why would you *want* to? Perhaps you have two machines with the same canonical name, but differing in the particular feature. This is most likely due to a bug in config.guess or config.sub, which is Not Autoconf's Problem. Otherwise, the feature is probably one where I don't *want* autoconf to decide based on my particular build machine; it will presumably make the produced program quite unportable, and will likely break if I make some small change to my machine's configuration. Such a feature probably deserves its own --with option and notes in the documentation, and should certainly be defaulted to the 'baseline' option, not to whatever's on my machine today. So the only use case I can think of for 'forcing crossness' when build=host depends on either bugs in config.* or poor 'configure' design. Hmm. Now who should I say this to? Akim, I guess, but he still hasn't done anything with the autoconf patch I sent him a long while ago. --Nathanael