ClassValSubtypingTest.java

import org.checkerframework.common.reflection.qual.ClassBound;
import org.checkerframework.common.reflection.qual.ClassVal;

public class ClassValSubtypingTest {
    @ClassVal("a") Object a = null;

    @ClassVal({"a", "b"}) Object ab = null;

    @ClassVal("c") Object c = null;

    @ClassVal({"c", "d"}) Object cd = null;

    Object unknown = null;

    void assignToUnknown() {
        unknown = a;
        unknown = ab;
        unknown = c;
        unknown = cd;
    }

    void assignUnknown() {
        //:: error: (assignment.type.incompatible)
        a = unknown;
        //:: error: (assignment.type.incompatible)
        ab = unknown;
        //:: error: (assignment.type.incompatible)
        c = unknown;
        //:: error: (assignment.type.incompatible)
        cd = unknown;
    }

    void assignments() {
        //:: error: (assignment.type.incompatible)
        a = ab;
        ab = a;
        //:: error: (assignment.type.incompatible)
        a = c;
        //:: error: (assignment.type.incompatible)
        ab = c;
        //:: error: (assignment.type.incompatible)
        ab = cd;
    }
}

class ClassBoundSubtypingTest {
    @ClassBound("a") Object a = null;

    @ClassBound({"a", "b"}) Object ab = null;

    @ClassBound("c") Object c = null;

    @ClassBound({"c", "d"}) Object cd = null;

    Object unknown = null;

    void assignToUnknown() {
        unknown = a;
        unknown = ab;
        unknown = c;
        unknown = cd;
    }

    void assignUnknown() {
        //:: error: (assignment.type.incompatible)
        a = unknown;
        //:: error: (assignment.type.incompatible)
        ab = unknown;
        //:: error: (assignment.type.incompatible)
        c = unknown;
        //:: error: (assignment.type.incompatible)
        cd = unknown;
    }

    void assignments() {
        //:: error: (assignment.type.incompatible)
        a = ab;
        ab = a;
        //:: error: (assignment.type.incompatible)
        a = c;
        //:: error: (assignment.type.incompatible)
        ab = c;
        //:: error: (assignment.type.incompatible)
        ab = cd;
    }
}

class ClassValClassBoundSubtypingTest {
    @ClassVal("a") Object a = null;

    @ClassVal({"a", "b"}) Object ab = null;

    @ClassBound("a") Object aBound = null;

    @ClassBound({"a", "b"}) Object abBound = null;

    void assignments1() {
        //:: error: (assignment.type.incompatible)
        a = aBound;
        //:: error: (assignment.type.incompatible)
        ab = aBound;
        //:: error: (assignment.type.incompatible)
        a = abBound;
        //:: error: (assignment.type.incompatible)
        ab = abBound;
    }

    void assignments2() {
        aBound = a;
        //:: error: (assignment.type.incompatible)
        aBound = ab;

        abBound = a;
        abBound = ab;
    }
}