#include struct in6_addr {int bah;}; extern const struct in6_addr in6addr_any; static const struct in6_addr local_in6addr_any = {1}; #pragma weak in6addr_any = local_in6addr_any __attribute__ ((used)) void foo() { fprintf (stderr, "v1: %p, v2: %p\n", &local_in6addr_any, &in6addr_any); }