addrof1.c

this is a gcc file, you can download it and learn its usetility, for further detail please look at t

extern "C" void abort ();

typedef struct st {
        unsigned char   a;
        unsigned char   b;
        unsigned char   c;
        unsigned char   d;
} __attribute__((aligned(4))) st;

void testme(int, int, int);

static inline void
stupid_func(st s)
{
        testme(s.a, s.b, s.c);
}

int main()
{
        st s;

        s.a = s.b = s.c = 216;
        stupid_func(s);

        return 0;
}    

void testme(int a, int b, int c)
{
  if (a != 216 || b != 216 || c != 216)
    abort();
}