maccom4.c

this is a gcc file, you can download it and learn its usetility, for further detail please look at t

/* { dg-do preprocess } */
/* { dg-options "-CC -traditional-cpp" } */

/* This tests to make sure the comment is saved in the macro and copied
   to the output file when the macro is expanded when the -CC option is
   used.

   Jason R. Thorpe, 6 Apr 2002  */

#define def /* passed */

def

/*
   /* The + in the regexp prevents it from matching itself.  */
   { dg-final { if ![file exists maccom4.i] { return }                    } }
   { dg-final { if { [grep maccom4.i "p+assed"] != "" } { return }        } }
   { dg-final { fail "maccom4.c: comment in macro expansion with -CC"     } }
*/