gcc/testsuite/gcc.dg/Wunused-value-1.c

   1 /* Test -Wunused-value.  Bug 23113.  */
   2 /* Origin: Joseph Myers <joseph@codesourcery.com> */
   3 /* { dg-do compile } */
   4 /* { dg-options "-Wunused-value" } */
   5
   6 int f (void);
   7 void g (void);
   8 int *p;
   9
  10 void
  11 h (void)
  12 {
  13   1 + f (); /* { dg-warning "value computed is not used" } */
  14   f () + f (); /* { dg-warning "value computed is not used" } */
  15   f () + f (), f (); /* { dg-warning "value computed is not used" } */
  16   (char) f (); /* { dg-warning "value computed is not used" } */
  17   g ();
  18   f ();
  19   (void) f ();
  20   *p++; /* { dg-warning "value computed is not used" } */
  21   ++*p;
  22   (*p ? f() : 0);
  23   ({ f(); });
  24   /* Statement expressions may be used in macro expansions which like
  25      functions return values which may or may not be of use, so don't
  26      warn for them but do warn inside them.  */
  27   ({ f() + 1; });
  28   ({ f(); 0; });
  29   ({ f() + 1; 0; }); /* { dg-warning "value computed is not used" } */
  30   1 + ({ f(); }); /* { dg-warning "value computed is not used" } */
  31 }