gcc/testsuite/gcc.dg/tree-ssa/strncat.c

   1 /* PR tree-optimization/83075 - Invalid strncpy optimization */
   2 /* { dg-do run } */
   3 /* { dg-options "-O2 -Wstringop-overflow" } */
   4
   5 typedef __SIZE_TYPE__ size_t;
   6
   7 __attribute__((noipa)) size_t
   8 foo (char *p, char *q, size_t *r)
   9 {
  10   size_t n0 = __builtin_strlen (p);
  11   __builtin_strncat (q, p, n0);         /* { dg-warning "specified bound depends on the length" } */
  12   size_t n1 = __builtin_strlen (p);
  13   *r = n0;
  14   return n1;
  15 }
  16
  17 int
  18 main ()
  19 {
  20   char a[8] = "";
  21   __builtin_strcpy (a, "123");
  22   size_t n0 = __builtin_strlen (a);
  23   __builtin_strncat (a + 3, a, n0);     /* { dg-warning "specified bound depends on the length" } */
  24   size_t n1 = __builtin_strlen (a);
  25   if (n1 == n0)
  26     __builtin_abort ();
  27   a[6] = '7';
  28   __builtin_strcpy (a, "456");
  29   size_t n2;
  30   if (foo (a, a + 3, &n2) != 6 || n2 != 3)
  31     __builtin_abort ();
  32   if (__builtin_memcmp (a, "456456\0", sizeof "456456\0"))
  33     __builtin_abort ();
  34   return 0;
  35 }