Using Macros

[Matthew Landau]

Seems like this should be on the FAQ list, since it comes up every 
couple of months.  My preferred solution to the problem (which I 
picked up in comp.lang.c about 10 years ago :-) is:

   #define FOO(bar, baz)  do { func1(bar); func2(baz); } while (0)

Since there's no trailing semicolon after the while(0), this construct 
can be used anywhere a simple C statement can be used.  (Indeed, 
syntactically it is one statement.)  Moreover, any compiler worth its
salt should be able to optimize away the do ... while part, since the
code above is guaranteed to execute the stuff inside the braces exactly
once.

Of course lint and Saber will complain bitterly, but you can shut 
Saber up with judicious use of the SUPPRESS directive in the macro
definition.  Still haven't figured out how to get lint to quiet
down, but then again I don't use lint much now that I have Saber.
--
 Matt Landau			Oblivion gallops closer,
 mlandau at bbn.com		    favoring the spur, sparing the rein.