int printf(const char *, ...);       // pre-declaration of function

void
foo()
{
    int a, b;

    printf("in foo(): a=%d, b=%d\n", a, b);
}

void
dummy()
{
    int a = 42, b = 666;;
    printf("in dummy(): a=%d, b=%d\n", a, b);
}

int
main()
{
    dummy();
    foo();
}