Path: utzoo!mnetor!uunet!mcvax!ukc!stl!stc!idec!alice!fox
From: fox@alice.marlow.reuters.co.uk (Paul Fox)
Newsgroups: comp.lang.c
Subject: Re: macros with parameters in MSC 5.0
Message-ID: <290@alice.marlow.reuters.co.uk>
Date: 2 Mar 88 22:27:39 GMT
References: <11879@brl-adm.ARPA> <2631@haddock.ISC.COM> <898@PT.CS.CMU.EDU>
Reply-To: fox@alice.marlow.reuters.co.uk (Paul Fox)
Organization: Reuters Ltd PLC, Marlow, Bucks, England
Lines: 26

In article <898@PT.CS.CMU.EDU> edw@IUS1.CS.CMU.EDU (Eddie Wyatt) writes:
>> >  #define ctl(c) ('c'&037)
>> >... is not allowed in MSC5.0
>> 
>> Nor in ANSI C.
>
>  Does this imply that a macro parameter will nolonger be expanded in
>strings too?
>
>#define DEBUG_CALL(xxx)	if ((xxx) != OK) {				 \
>  			    (void) printf("xxx\n");			 \
>  			    (void) printf("%s %d\n\n",__FILE__,__LINE__);\
>                            clearline(); }
>-- 
ANSI gets around this via the '#' and '##' operators -- available within
the preprocessor phase only. As I read it 

# define	CTRL(x)		#x & 037
		CTRL(A);

gives:		"A" & 037

# define	CTRL(x)		'##x##' & 037
		CTRL(A);

gives:		'A' & 037