gcc/testsuite/gcc.dg/undefined-loop-2.c

   1 /* Check that loops whose final iteration is undefined are detected.  */
   2 /* { dg-do compile } */
   3 /* { dg-options "-O2 -Waggressive-loop-optimizations" } */
   4
   5 void doSomething(char);
   6
   7 char array1[5];
   8 char array2[5];
   9
  10 void
  11 foo (int p)
  12 {
  13   int i;
  14   for (i=0;
  15        (p
  16         ? array1[i]  /* { dg-message "note: possible undefined statement is here" } */
  17         : array2[i]) /* { dg-message "note: possible undefined statement is here" } */
  18        && i < 100;   /* { dg-warning "loop exit may only be reached after undefined behavior" } */
  19        i++)
  20     {
  21       if (i >= 5)    /* { dg-warning "loop exit may only be reached after undefined behavior" } */
  22         break;
  23       doSomething(array1[i]);
  24     }
  25 }