Xref: utzoo comp.lang.c:28420 comp.unix.wizards:21784 alt.sources:1831 comp.sources.d:5258 misc.misc:9662
Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!usc!zaphod.mps.ohio-state.edu!rpi!crdgw1!sixhub!davidsen
From: davidsen@sixhub.UUCP (Wm E. Davidsen Jr)
Newsgroups: comp.lang.c,comp.unix.wizards,alt.sources,comp.sources.d,misc.misc
Subject: Re: #define DEBUG... (using printf for debugging)
Message-ID: <908@sixhub.UUCP>
Date: 4 May 90 00:38:46 GMT
References: <11290@hoptoad.uucp> <40628@cornell.UUCP>
Reply-To: davidsen@sixhub.UUCP (bill davidsen)
Followup-To: comp.lang.c
Organization: *IX Public Access UNIX, Schenectady NY
Lines: 22

In article <40628@cornell.UUCP> gordon@cs.cornell.edu (Jeffrey  Adam Gordon) writes:
| I want to have a DEBUG flag which controls whether diagnostic printfs
| are executed or not.

#ifdef	DEBUG
#undef DEBUG /* prevent warning from redef */
#define DEBUG(x) printf x
#else
#define DEBUG(x)
#endif

To use:

	DEBUG(("Any # of args: %d\n", whatever));

  The secret is in having the 2nd level of parens in the invocation of
DEBUG and no parens in the expansion. Works like a charm!
-- 
bill davidsen - davidsen@sixhub.uucp (uunet!crdgw1!sixhub!davidsen)
    sysop *IX BBS and Public Access UNIX
    moderator of comp.binaries.ibm.pc and 80386 mailing list
"Stupidity, like virtue, is its own reward" -me