gcc/testsuite/gcc.dg/gnu23-tag-alias-1.c

   1 /* { dg-do run }
   2  * { dg-options "-std=gnu23 -O2" }
   3  */
   4
   5 /* Check that structs with flexible array member can alias.  */
   6
   7 struct bar { int x; int f[]; };
   8
   9 [[gnu::noinline,gnu::noipa]]
  10 int test_bar2(struct bar* a, void* b)
  11 {
  12         a->x = 1;
  13
  14         struct bar { int x; int f[0]; }* p = b;
  15         struct bar* q = a;
  16         p->x = 2;
  17
  18         return a->x;
  19 }
  20
  21
  22
  23 int main()
  24 {
  25         struct bar z;
  26
  27         if (2 != test_bar2(&z, &z))
  28                 __builtin_abort();
  29
  30         return 0;
  31 }
  32
  33