From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752482AbbJFJRG (ORCPT ); Tue, 6 Oct 2015 05:17:06 -0400 Received: from lb3-smtp-cloud2.xs4all.net ([194.109.24.29]:46466 "EHLO lb3-smtp-cloud2.xs4all.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751432AbbJFJRD (ORCPT ); Tue, 6 Oct 2015 05:17:03 -0400 Message-ID: <1444123019.2417.39.camel@tiscali.nl> Subject: Re: [PATCH v3] kbuild: document recursive dependency limitation / resolution From: Paul Bolle To: "Luis R. Rodriguez" , Valentin Rothberg Cc: "Luis R. Rodriguez" , mmarek@suse.com, josh@joshtriplett.org, jbottomley@odin.com, geert@linux-m68k.org, herbert@gondor.apana.org.au, tiwai@suse.de, corbet@lwn.net, linux-kbuild@vger.kernel.org, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, roberto@dicosmo.org, zack@upsilon.cc, soos.mate@gmail.com, skl@det.ua.pt, iouliia@det.ua.pt, Armin Biere , Julia Lawall Date: Tue, 06 Oct 2015 11:16:59 +0200 In-Reply-To: <20151005230317.GQ14464@wotan.suse.de> References: <1438200556-13842-1-git-send-email-mcgrof@do-not-panic.com> <1443026498-15081-1-git-send-email-mcgrof@do-not-panic.com> <20151004134247.GA7528@nebuchadnezzar> <20151005230317.GQ14464@wotan.suse.de> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.16.5 (3.16.5-3.fc22) Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On di, 2015-10-06 at 01:03 +0200, Luis R. Rodriguez wrote: > On Sun, Oct 04, 2015 at 03:42:47PM +0200, Valentin Rothberg wrote: > > In contrast to a select, a symbol using a dependency is only > > visible to the user when its dependency are satisfied. I see it as a > > decision between being semantically correct (depends) and being easy to > > configure/user friendly (select). > > Good point, something easy to configure should however still likely only > be visible to the user if and only if it would not break existing user > config. If we are not ensuring that now its perhaps good to annotate that > as a desirable future feature. (This might be going off on a tangent a bit.) Perhaps the issue that people run into, and that Luis is trying to solve, here and in other threads, is that these two approaches currently are used at the same level. In other words, maybe the configuration requirements should only be described using dependency relations while a (new) tool should provide what now is provided, sort of, by selects. Isn't that how package managers work? The packages themselves state things like: "I need Foo", "I conflict with Bar". Package managers use that information to handle what people actually care about, like "Please install Baz", without requiring those people to do the busy work of figuring out the dependencies of all packages. So, would a future SAT solver for Kconfig use a two level approach too: given the set of dependencies of the various features (first level) try to figure out if and how the features a user picks can actually be enabled (second level)? Thanks, Paul Bolle