void f_test(void){
  printf("Stack frame size: %d\n", (char *)__builtin_frame_address(1) - (char *)__builtin_frame_address(0) );
}

int main(void){
  int a = 0, b = 1, c = 2, d = 3, e = 4, f = 5, g = 6;
  f_test();
  return 0;
}


=================================================

[alexandernst@stupidbox 0s ~]$ gcc tmp_hex_dump.c && ./a.out
Stack frame size: 48