gcc/testsuite/c-c++-common/Wimplicit-fallthrough-1.c

   1 /* PR c/7652 */
   2 /* { dg-do compile } */
   3 /* { dg-options "-Wimplicit-fallthrough" } */
   4 /* Test taken from
   5    <http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2016/p0188r0.pdf>.  */
   6
   7 extern void f (int);
   8
   9 void
  10 foo (int n)
  11 {
  12   switch (n)
  13     {
  14     case 22:
  15     case 33:
  16       f (1);  /* { dg-warning "statement may fall through" } */
  17     case 44:
  18       f (2);
  19       __attribute__((fallthrough));
  20     case 55:
  21       if (n > 10)
  22         {
  23           f (3);
  24           break;
  25         }
  26       else
  27         {
  28           f (4);
  29           __attribute__((fallthrough));
  30         }
  31     case 66:
  32       f (5);
  33      __attribute__((fallthrough)); /* { dg-warning "not preceding" } */
  34       f (6); /* { dg-warning "statement may fall through" } */
  35     case 77:
  36        f (7);
  37     }
  38 }