From owner-freebsd-hackers@FreeBSD.ORG  Fri Jun  9 21:35:30 2006
Return-Path: <owner-freebsd-hackers@FreeBSD.ORG>
X-Original-To: freebsd-hackers@FreeBSD.ORG
Delivered-To: freebsd-hackers@FreeBSD.ORG
Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125])
	by hub.freebsd.org (Postfix) with ESMTP id B266516A41F
	for <freebsd-hackers@FreeBSD.ORG>; Fri,  9 Jun 2006 21:35:30 +0000 (UTC)
	(envelope-from imp@bsdimp.com)
Received: from harmony.bsdimp.com (vc4-2-0-87.dsl.netrack.net [199.45.160.85])
	by mx1.FreeBSD.org (Postfix) with ESMTP id 5AB4543D72
	for <freebsd-hackers@FreeBSD.ORG>; Fri,  9 Jun 2006 21:35:30 +0000 (GMT)
	(envelope-from imp@bsdimp.com)
Received: from localhost (localhost.village.org [IPv6:::1] (may be forged))
	by harmony.bsdimp.com (8.13.4/8.13.4) with ESMTP id k59LXXk7058156;
	Fri, 9 Jun 2006 15:33:33 -0600 (MDT) (envelope-from imp@bsdimp.com)
Date: Fri, 09 Jun 2006 15:33:40 -0600 (MDT)
Message-Id: <20060609.153340.-432838362.imp@bsdimp.com>
To: darren.pilgrim@bitfreak.org
From: "M. Warner Losh" <imp@bsdimp.com>
In-Reply-To: <4489E354.5070201@bitfreak.org>
References: <20060609094052.GH1273@obiwan.tataz.chchile.org>
	<20060609.074844.1324583587.imp@bsdimp.com>
	<4489E354.5070201@bitfreak.org>
X-Mailer: Mew version 4.2 on Emacs 21.3 / Mule 5.0 (SAKAKI)
Mime-Version: 1.0
Content-Type: Text/Plain; charset=us-ascii
Content-Transfer-Encoding: 7bit
Cc: freebsd-hackers@FreeBSD.ORG, jeremie@le-hen.org
Subject: Re: How to disable a src.conf on command-line
X-BeenThere: freebsd-hackers@freebsd.org
X-Mailman-Version: 2.1.5
Precedence: list
List-Id: Technical Discussions relating to FreeBSD
	<freebsd-hackers.freebsd.org>
List-Unsubscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-hackers>, 
	<mailto:freebsd-hackers-request@freebsd.org?subject=unsubscribe>
List-Archive: <http://lists.freebsd.org/pipermail/freebsd-hackers>
List-Post: <mailto:freebsd-hackers@freebsd.org>
List-Help: <mailto:freebsd-hackers-request@freebsd.org?subject=help>
List-Subscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-hackers>,
	<mailto:freebsd-hackers-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Fri, 09 Jun 2006 21:35:30 -0000

In message: <4489E354.5070201@bitfreak.org>
            Darren Pilgrim <darren.pilgrim@bitfreak.org> writes:
: M. Warner Losh wrote:
: > So if you make WITH_SSP off by default, then having WITH_SSP in the
: > src.conf can't be overridden.  If you have it on by default, having
: > WITHOUT_SSP in the src.conf file can't be overriden.  this appears to
: > be an unintended flaw with the with/without stuff.  I'm not sure the
: > right way to compensate.
: 
: I can't speak for the "right" way, but if you specify the variable in 
: src.conf/make.conf with ?= instead of =, you can override it on the 
: command-line:
: 
: # grep KERNCONF /etc/make.conf
: KERNCONF?=TTPWEB
: # make -V KERNCONF
: TTPWEB
: # env KERNCONF=SOMETHING_ELSE make -V KERNCONF
: SOMETHING_ELSE

?= doesn't mesh well with WITH/WITHOUT because then it will always be
defined, thus defeating its purpose.

Warner