gcc/testsuite/gcc.dg/20020220-2.c

   1 /* PR c/4697
   2    Test whether operand has no effect warning is given for compound
   3    expression.  */
   4 /* { dg-do compile } */
   5 /* { dg-options "-O2 -Wunused" } */
   6
   7 int b;
   8 int foo (int a)
   9 {
  10   a = a + 1, 5 * b; /* { dg-warning "right-hand operand of comma expression has no effect" } */
  11   return a;
  12 }