Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261538AbVASB0R (ORCPT ); Tue, 18 Jan 2005 20:26:17 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261540AbVASB0R (ORCPT ); Tue, 18 Jan 2005 20:26:17 -0500 Received: from waste.org ([216.27.176.166]:42715 "EHLO waste.org") by vger.kernel.org with ESMTP id S261538AbVASB0N (ORCPT ); Tue, 18 Jan 2005 20:26:13 -0500 Date: Tue, 18 Jan 2005 17:26:12 -0800 From: Matt Mackall To: "H. Peter Anvin" Cc: linux-kernel@vger.kernel.org Subject: Re: kbuild: Implicit dependence on the C compiler Message-ID: <20050119012612.GD3867@waste.org> References: <20050117220052.GB18293@mars.ravnborg.org> <41EC363D.1090106@zytor.com> <20050118190513.GA16120@mars.ravnborg.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.6+20040907i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1453 Lines: 35 On Tue, Jan 18, 2005 at 07:35:43PM +0000, H. Peter Anvin wrote: > Followup to: <20050118190513.GA16120@mars.ravnborg.org> > By author: Sam Ravnborg > In newsgroup: linux.dev.kernel > > > > To give some background info about why kbuild does what it does. > > A kernel being compiled partly with and partly without say -regparm=3 > > will result in a non-workable kernel. > > > > The same goes for a kernel that is partly built using gcc 2.96, partly > > using 3.3.4 for example. > > > > So kbuild pr. default will force a recompile for any .o file where > > opions to gcc differ, or name of gcc has changed. Today no check has > > been implemented to check the actual gcc executable timestamp - and > > neither is this planned. > > > > I would argue that "name of gcc has changed" is possibly a condition > that does more harm than good. It is just as frequently used to have > wrappers, like distcc, as it is to have different versions. Disagree. I switch compilers all the time and kbuild does the right thing for me. I do occassionally feel your 'make install' pain and some sort of 'make __install' might be called for. -- Mathematics is the supreme nostalgia of our time. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/