Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1762411AbXETJky (ORCPT ); Sun, 20 May 2007 05:40:54 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754864AbXETJkr (ORCPT ); Sun, 20 May 2007 05:40:47 -0400 Received: from caramon.arm.linux.org.uk ([217.147.92.249]:2103 "EHLO caramon.arm.linux.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754488AbXETJkq (ORCPT ); Sun, 20 May 2007 05:40:46 -0400 Date: Sun, 20 May 2007 10:40:33 +0100 From: Russell King To: Andrew Morton Cc: Adrian Bunk , Sam Ravnborg , LKML , Roman Zippel Subject: Re: RFC: kconfig select warnings bogus? Message-ID: <20070520094033.GA9645@flint.arm.linux.org.uk> Mail-Followup-To: Andrew Morton , Adrian Bunk , Sam Ravnborg , LKML , Roman Zippel References: <20070519151523.GA26724@uranus.ravnborg.org> <20070519110944.2a52061e.akpm@linux-foundation.org> <20070519230537.GI6291@stusta.de> <20070519162239.1bcb03d6.akpm@linux-foundation.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20070519162239.1bcb03d6.akpm@linux-foundation.org> User-Agent: Mutt/1.4.2.1i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2130 Lines: 60 On Sat, May 19, 2007 at 04:22:39PM -0700, Andrew Morton wrote: > On Sun, 20 May 2007 01:05:37 +0200 Adrian Bunk wrote: > > > Look for example at the last one in drivers/input/mouse/Kconfig: > > > > config MOUSE_ATARI > > tristate "Atari mouse" > > depends on ATARI > > select ATARI_KBD_CORE > > > > This is perfectly correct (the select'ed symbol is only unavailable when > > the dependency can't be fulfilled), and all things to "fix" the warning > > will make it worse. > > If ATARI is unset then we shouldn't be generating the "'select' used by > config symbol 'KEYBOARD_ATARI' refers to undefined symbol 'ATARI_KBD_CORE'" > warnings, should we? Playing devils advocate here. What if "ATARI_KBD_CORE" never exists? Let's say you run 'make kconfig' and you select the ATARI option. When does the lack of ATARI_KBD_CORE get noticed and what is the expected result? Let's put it another way. Given the complexities of the configuration system as it is today, if we do not generate a warning at parse time, how do we find things like: config SHARPSL_PM bool select APM_EMULATION config PXA_SHARP_C7xx bool select PXA_SSP select SHARPSL_PM config MACH_CORGI bool "Enable Sharp SL-C700 (Corgi) Support" depends on PXA_SHARPSL_25x select PXA_SHARP_C7xx and (lets say for the sake of argument) APM_EMULATION were to go away. Do we really need an exhaustive set of configuration combinations to run through Kconfig to find possible missing symbols? Or do we need a Kconfig lint to find them? If we're going to make Kconfig warn on missing symbols only when they're attempted to be selected, you'll have to choose one of those two options. Choosing none is not an option. -- Russell King Linux kernel 2.6 ARM Linux - http://www.arm.linux.org.uk/ maintainer of: - 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/