MethodOverrides.java

import testlib.util.*;

public abstract class MethodOverrides {

    public abstract @Odd String method();

    public abstract String methodSub();

    public abstract void param(@Odd String s);

    public abstract void paramSup(@Odd String s);

    public abstract void receiver(@Odd MethodOverrides this);

    public abstract void receiverSub(@Odd MethodOverrides this);

    public static class SubclassA extends MethodOverrides {

        public @Odd String method() {
            //:: error: (assignment.type.incompatible)
            @Odd String s = "";
            return s;
        }

        public @Odd String methodSub() {
            //:: error: (assignment.type.incompatible)
            @Odd String s = "";
            return s;
        }

        public void param(@Odd String s) {}

        public void paramSup(String s) {}

        public void receiver(@Odd SubclassA this) {}

        public void receiverSub() {}
    }

    static class X {
        <T> T @Odd [] method(T @Odd [] t) {
            return null;
        }
    }

    static class Y extends X {
        @Override
        <S> S @Odd [] method(S @Odd [] s) {
            return null;
        }
    }

    static class Z extends X {
        @Override
        // return type is an incorrect override, as it's a supertype
        //:: error: (override.return.invalid)
        <A> A[] method(A[] s) {
            return null;
        }
    }

    static class Z2 extends X {
        @Override
        //:: error: (override.return.invalid) :: error: (override.param.invalid)
        <A> @Odd A[] method(@Odd A[] s) {
            return null;
        }
    }

    static class ClX<T> {
        T @Odd [] method(T @Odd [] t) {
            return null;
        }
    }

    static class ClY<S> extends ClX<S> {
        @Override
        S @Odd [] method(S @Odd [] s) {
            return null;
        }
    }

    static class ClZ<S> extends ClX<S> {
        @Override
        //:: error: (override.return.invalid) :: error: (override.param.invalid)
        @Odd S[] method(@Odd S[] s) {
            return null;
        }
    }

    // TODO others...
}