1: #include <mcheck.h>
    2: #include <stdio.h>
    3: #include <string.h>
    4: 
    5: extern const char *foo (void);
    6: 
    7: int
    8: main (void)
    9: {
   10:   const char *s;
   11: 
   12:   mtrace ();
   13: 
   14:   s = foo ();
   15: 
   16:   printf ("called `foo' from `%s'\n", s);
   17: 
   18:   return strcmp (s, "filtmod2.c");
   19: }