gcc/testsuite/gcc.dg/tree-ssa/20050719-1.c

   1 /* { dg-do run } */
   2 /* { dg-options "-O2" } */
   3
   4 extern void abort (void) __attribute__ ((__nothrow__)) __attribute__
   5 ((__noreturn__));
   6 extern void exit (int __status) __attribute__ ((__nothrow__))
   7 __attribute__ ((__noreturn__));
   8
   9 struct bootLoader {
  10   int x;
  11 };
  12
  13 void
  14 zap(struct bootLoader *bootLoader)
  15 {
  16   /* The expression on the RHS of the assignment is *not* a
  17      dereference of pointer 'bootLoader'.  It is merely used as an
  18      offset calculation.  VRP was erroneously removing the if()
  19      because it thought that 'bootLoader' was always dereferenced.  */
  20   int *boot = &bootLoader->x;
  21
  22   if (bootLoader)
  23     {
  24       useboot (boot);
  25     }
  26 }
  27
  28 int
  29 useboot (void *boot)
  30 {
  31   abort ();
  32 }
  33
  34 main()
  35 {
  36   zap (0);
  37   return 0;
  38 }