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From: gregory@ritcsh.cs.rit.edu (Greg Conway)
Newsgroups: comp.lang.c
Subject: Re: Re^2: Why nested comments not allowed?
Message-ID: <2385@ritcsh.cs.rit.edu>
Date: 22 Feb 90 17:47:25 GMT
References: <1523@wacsvax.OZ> <13706@cbnewsc.ATT.COM> <4286@jhunix.HCF.JHU.EDU> <4509@jarthur.Claremont.EDU> <4292@jhunix.HCF.JHU.EDU> <5372@ur-cc.UUCP>
Reply-To: gregory@ritcsh.cs.rit.edu.UUCP (Greg Conway)
Organization: Computer Science House @ RIT, Rochester, NY
Lines: 31


In article <5372@ur-cc.UUCP> misu_ss@uhura.cc.rochester.edu (What`s in a name?) writes:
>This leads me to a question on how compilers work...
>Do #defines get worked out before comments are discarded...

The 'traditional' implementation is that #defines's are done by the
preprocessor and comments are handled by the scanner.  Under such a case, 
the #define's are handled first.

>#define OPEN_COMMENT "/*"
>#define CLOSE_COMMENT "*/"

	[ text deleted ]

>	string = OPEN_COMMENT;
>	printf("s% ", string);

	[ further text deleted]

According to K&R II, page 154, the behavior of this program is undefined.
(The correct format conversion is %s).  Assuming that the above is merely
a typo, then the output you got appears to me to be correct.

							- Greg


-- 
		Gregory Conway @ Computer Science House, RIT
"When I was young my father told me just bad guys die -- at that time just a
 little white lie. It was one of the first but it hurt me the most -- and the
 truth stung like tears in my eyes ... and even now it makes me cry." - Fish