1extern void abort (void); 2 3/* Since GCC 5 folds symbol address comparison, assuming each symbol has 4 different address, &foo == &bar is always false for GCC 5. Use 5 check_ptr_eq to check if two functions are the same. */ 6 7void 8check_ptr_eq (void (*f1) (void), void (*f2) (void)) 9{ 10 if (f1 != f2) 11 abort (); 12} 13