From: Michael Meissner <meissner AT cygnus DOT com>
Message-ID: <20000720173855.41499@cse.cygnus.com>
Date: Thu, 20 Jul 2000 17:38:55 -0400
To: "Martin v. Loewis" <martin AT loewis DOT home DOT cs DOT tu-berlin DOT de>
Cc: dj AT delorie DOT com, djgpp-workers AT delorie DOT com, gcc AT gcc DOT gnu DOT org
Subject: Re: GCC headers and DJGPP port
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In-Reply-To: <200007202042.WAA00946@loewis.home.cs.tu-berlin.de>; from Martin v. Loewis on Thu, Jul 20, 2000 at 10:42:29PM +0200
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On Thu, Jul 20, 2000 at 10:42:29PM +0200, Martin v. Loewis wrote:
> Please tell me how you implement the above requirement without testing
> whether NULL has been defined?

Speaking as somebody who was there when the original decision was made, it was
the intention of the committee that you either:

   1)	Include a null.h include file that defines NULL, possibly having null.h
	being protected by #ifndef/#endif (IIRC, this was actually discussed,
	but it would be logical to do so);

   2)	Use #ifndef/#endif around the definition;

   3)	Define NULL using exactly the same spelling in each include file, in
	which case it would fall under the rule that identical redefinitions of
	macros using the same spelling are not treated as redefinitions.

-- 
Michael Meissner, Red Hat, Inc.
PMB 198, 174 Littleton Road #3, Westford, Massachusetts 01886, USA
Work:	  meissner AT redhat DOT com		phone: +1 978-486-9304
Non-work: meissner AT spectacle-pond DOT org	fax:   +1 978-692-4482