Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP
Path: utzoo!mnetor!uunet!pilchuck!amc!jon
From: jon@amc.UUCP (Jon Mandrell)
Newsgroups: comp.sys.ibm.pc
Subject: Re: ** Re: MSC 4.0 Large Model ** Original Posters problem solved!!!
Message-ID: <513@amc.UUCP>
Date: Fri, 21-Aug-87 14:56:37 EDT
Article-I.D.: amc.513
Posted: Fri Aug 21 14:56:37 1987
Date-Received: Sun, 23-Aug-87 08:18:59 EDT
References: <10400006@altger.UUCP> <72@cunixc.columbia.edu> <698@ucdavis.UUCP>
Reply-To: jon@amc.UUCP (Jon Mandrell)
Distribution: na
Organization: Applied Microsystems Corp., Redmond, WA.
Lines: 31

In article <698@ucdavis.UUCP> ccs016@ucdavis.UUCP (Patrick Tully) writes:
>> 	1) Use NULL not 0 as often as applicable.
>     Why??  Null is defined in stdio as 0.
> 
NO!!!!  If you use large model on a PC, you end up with the wonderful situation
of having integers and pointers as a differnet size.  On most compilers, it
should be the following:
	#define	NULL	(char *)0
or
	#define	NULL	0L	/* I hate this one! */

If you have a routine that wants to see some arguments, one of which is a
pointer:
	int junk(a,b,c)
	int a;
	char *b;
	int c;

And want to pass a 0 for b, DON'T call the function with 0!!!!!!  This will
screw up your stack offsets.  You want to call it with NULL, which is the
width of a pointer (large and small model).  That is:
	junk(1, NULL, 2);
instead of:
	junk(1, 0, 2);
--------------------

-- 
Jon Mandrell, Applied Microsystems Corp., (ihnp4!uw-beaver!tikal!amc!jon)

Jung vs Ze G. jrer tnl?  Jbhyqa'g "Gur N Grnz" gnxr ba n jubyr
qvssrerag zrnavat?