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From: tif@commlab1..austin.ibm.com (/32767)
Newsgroups: comp.lang.c,comp.unix.wizards,alt.sources,comp.sources.d,misc.misc
Subject: Re: #define DEBUG... (using printf for debugging)
Message-ID: <2294@awdprime.UUCP>
Date: 4 May 90 18:14:26 GMT
References: <11290@hoptoad.uucp> <40628@cornell.UUCP>
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Reply-To: tif@awdprime.austin.ibm.com.UUCP (/32767)
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Organization: IBM AWD, Austin, TX
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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.
>	DEBUG ("debugging information");
>but then how do I turn DEBUG off?

Actually it's easier than you thought:
	#define DEBUG
will turn it off although the string will still be put in your
executable (unless your optimizer is better than mine).  ("xx")
is a parenthesised pointer expression which is a valid C statement.

Most people I know of do
	#define DEBUG(xx)	printf xx
and then
	DEBUG(("the flag is %d\n", flag));
The whole thing is completely removed with
	#define DEBUG(xx)

Paul Chamberlain
tif@doorstop.austin.ibm.com
tif@commlab1.austin.ibm.com
sc30661@ausvm6