OverrideInterned.java

import org.checkerframework.checker.interning.qual.Interned;

class OverrideInterned {

    // This code is extracted from FreePastry

    @Interned class NodeHandle {}

    public interface TransportLayer<IDENTIFIER> {
        public void sendMessage(IDENTIFIER i);
    }

    public class CommonAPITransportLayerImpl<IDENTIFIER extends NodeHandle>
            implements TransportLayer<IDENTIFIER> {
        public void sendMessage(IDENTIFIER i) {}
    }

    interface MessageReceipt {
        public NodeHandle getHint();
    }

    void useAnonymousClass() {
        MessageReceipt ret =
                new MessageReceipt() {
                    public NodeHandle getHint() {
                        return null;
                    }
                };
    }

    // This code is from Daikon

    public abstract class TwoSequenceString {
        public abstract Object check_modified1(@Interned String @Interned [] v1);

        public abstract Object check_modified2(String @Interned [] v1);
    }

    /* Changing the array component type in the overriding method is illegal. */
    public class PairwiseStringEqualBad extends TwoSequenceString {
        //TODOINVARR:: error: (override.param.invalid)
        public Object check_modified1(String @Interned [] a1) {
            return new Object();
        }
        //:: error: (override.param.invalid)
        public Object check_modified2(@Interned String @Interned [] a1) {
            return new Object();
        }
    }

    /* Changing the main reference type is allowed, if it is a supertype. */
    public class PairwiseStringEqualGood extends TwoSequenceString {
        public Object check_modified1(@Interned String[] a1) {
            return new Object();
        }

        public Object check_modified2(String[] a1) {
            return new Object();
        }
    }
}