From: utzoo!decvax!harpo!seismo!hao!hplabs!sri-unix!chris.umcp-cs@Udel-Relay
Newsgroups: net.unix-wizards
Title: Re:  Multiple statements in C macros: C s - (nf)
Article-I.D.: sri-arpa.890
Posted: Mon Mar 28 12:16:11 1983
Received: Mon Apr 18 07:38:24 1983

From:  Chris Torek <chris.umcp-cs@Udel-Relay>

,
To: Charles F. Von Rospach <CHUQUI@MIT-MC>y>
        hplabs!hao!cires!nbires!crp@UCB-VAX
Cc: Unix-Wizards@SRI-UNIX
Via:  UMCP-CS; 29 Mar 83 0:10-EST

There is only one problem with debug functions, as opposed to macros:
they're slower.  (Though if memory is more important than speed,
they're usually smaller.)  If the stuff can be conditionally compiled
that's even better.  If you have multi line debug functions, or
functions with variable # of args, you can always do this:

/* if DEBUG, call debugfunc for bugout.  Otherwise, discard all bugouts.
   In either case, generate exactly one statement per bugout. */
#ifdef DEBUG
# define bugout(x) debugfunc x
#else not DEBUG
# define bugout(x)
#endif DEBUG

...
	stmt;
	bugout ( (param1,param2,param3) );
	stmt;
	bugout ( ("got here") );
...

While it looks a bit strange, it works.  (I even just tested it!)
				- Chris