Javac should issue the potentially ambiguous overload warning only where the problem appears. Classes / interfaces inheriting from or implementing a warned class / interface should not be warned too.

Example having:

    interface F1 {
        void m(String s);
    }

    interface F2 {
        void m(Integer s);
    }

and:

interface Foo { // warning here OK
    void m(F1)
    void m(F2)
}

class Bar implements Foo {} // should not be warned.