From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Sun, 20 May 2001 11:45:53 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Sun, 20 May 2001 11:45:43 -0400 Received: from snark.tuxedo.org ([207.106.50.26]:47118 "EHLO snark.thyrsus.com") by vger.kernel.org with ESMTP id ; Sun, 20 May 2001 11:45:34 -0400 Date: Sun, 20 May 2001 11:44:11 -0400 From: "Eric S. Raymond" To: David Woodhouse Cc: Arjan van de Ven , linux-kernel@vger.kernel.org Subject: Re: CML2 design philosophy heads-up Message-ID: <20010520114411.A3600@thyrsus.com> Reply-To: esr@thyrsus.com Mail-Followup-To: "Eric S. Raymond" , David Woodhouse , Arjan van de Ven , linux-kernel@vger.kernel.org In-Reply-To: <20010518034307.A10784@thyrsus.com> <20010518105353.A13684@thyrsus.com> <3B053B9B.23286E6C@redhat.com> <20010518112625.A14309@thyrsus.com> <20010518113726.A29617@devserv.devel.redhat.com> <20010518114922.C14309@thyrsus.com> <8485.990357599@redhat.com> <20010520111856.C3431@thyrsus.com> <15823.990372866@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.2.5i In-Reply-To: <15823.990372866@redhat.com>; from dwmw2@infradead.org on Sun, May 20, 2001 at 04:34:26PM +0100 Organization: Eric Conspiracy Secret Labs X-Eric-Conspiracy: There is no conspiracy Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org David Woodhouse : > On one hand you have dependencies which are present to make life easier for > Aunt Tillie, by refraining from confusing her with strange questions to > which the answer is _probably_ 'no'. Like the question of whether she has > an IDE controller on her MVME board. > > One the other hand, you have the dependencies present in the existing CML1 > configuration, which are _absolute_ dependencies - which specify for example > that you cannot enable support for PCI peripherals if !CONFIG_PCI, etc. > These dependencies are there to prevent you from enabling combinations of > options which are utterly meaningless, and usually won't even compile. There are no `advisory' dependencies in CML2. They're all absolute. What you call an `advisory' dependency would be simulated by having a policy symbol for Aunt Tillie mode and writing constraints like this: require AUNT_TILLIE implies FOO >= BAR This is exactly why the CML2 ruleset has EXPERT, WIZARD, and TUNING policy symbols, as hooks for doing things like this. -- Eric S. Raymond No one who's seen it in action can say the phrase "government help" without either laughing or crying.