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From: yval@tasu23.UUCP (Yuval Yarom)
Newsgroups: comp.lang.c
Subject: Re: Nested Macros
Message-ID: <2913@taux01.UUCP>
Date: 21 Nov 89 07:49:31 GMT
References: <gZO1Sce00W0JQ6AKEr@andrew.cmu.edu>
Sender: netnews@taux01.UUCP
Reply-To: yval%taux01@nsc.nsc.com (Yuval Yarom)
Organization: National Semiconductor (IC) Ltd, Israel
Lines: 30

In article <gZO1Sce00W0JQ6AKEr@andrew.cmu.edu> jb3o+@andrew.cmu.edu (Jon Allen Boone) writes:
>A friend is attempting to write a macro along the following lines:
>
>#define DEBUG 1
>
>#define DB(X) #ifdef (DEBUG) printf(X)
>
>however, this results in an error when he attempts to compile it.
>
>does anyone know how he would go about writing a macro that would
>allow him to simply type DB(x) in his code and not have to type #ifdef
>(DEBUG) printf(X) everywhere instead? Any help would be greatly
>appreciated.  Please carbon copy your reply to pg0p@andrew.cmu.edu, as
>well as to jb3o@andrew.cmu.edu and the board.
>
>thank you...

He should use:

#define DEBUG 1

#ifdef DEBUG
#define DB(X) printf(X)
#else
#define DB(X) /* */
#endif

--
Yuval Yarom
yval%taux01@nsc.nsc.com