From owner-freebsd-hackers  Sat Apr 22 12:06:50 1995
Return-Path: hackers-owner
Received: (from majordom@localhost)
          by freefall.cdrom.com (8.6.10/8.6.6) id MAA29831
          for hackers-outgoing; Sat, 22 Apr 1995 12:06:50 -0700
Received: from isl.cf.ac.uk (isl-gate.elsy.cf.ac.uk [131.251.22.1])
          by freefall.cdrom.com (8.6.10/8.6.6) with ESMTP id MAA29814
          ; Sat, 22 Apr 1995 12:06:44 -0700
Received: (from paul@localhost) by isl.cf.ac.uk (8.6.9/8.6.9) id UAA28460; Sat, 22 Apr 1995 20:07:26 +0100
From: Paul Richards <paul@isl.cf.ac.uk>
Message-Id: <199504221907.UAA28460@isl.cf.ac.uk>
Subject: Re: Any objection to adding a .undef(VARNAME) to make?
To: nate@trout.sri.MT.net (Nate Williams)
Date: Sat, 22 Apr 1995 20:07:25 +0100 (BST)
Cc: jkh@freefall.cdrom.com, hackers@freefall.cdrom.com
In-Reply-To: <199504212349.RAA14054@trout.sri.MT.net> from "Nate Williams" at Apr 21, 95 05:49:40 pm
X-Mailer: ELM [version 2.4 PL23]
MIME-Version: 1.0
Content-Type: text/plain; charset=US-ASCII
Content-Transfer-Encoding: 7bit
Content-Length: 821       
Sender: hackers-owner@FreeBSD.org
Precedence: bulk

In reply to Nate Williams who said
> 
> > I've long been bothered by bmake's inability to programmatically unset
> > a variable.  Assuming that nobody feels it to be too evil a hack to
> > live, are there any objections to using the keyword `.undef'?
> 
> I'm kind of partial to '.undefine' myself, but I think the functionality
> is a good addition to the utility.  Too bad we couldn't find a way
> similar to how something is defined to undefine it.
> 
> FOO= 1
> 
> FOO= undefined

Anyone see a problem with FOO=
Seems to make sense to me. How many things would that break?

-- 
  Paul Richards, FreeBSD core team member. 
  Internet: paul@FreeBSD.org,  URL: http://isl.cf.ac.uk/~paul/
  Phone: +44 1222 874000 x6646 (work), +44 1222 457651 (home)
  Dept. Mechanical Engineering, University of Wales, College Cardiff.