Java object cloning for Jikes RVM

CopyMachine.java

import java.lang.reflect.Array;
import org.vmmagic.unboxed.Address;
import org.vmmagic.unboxed.ObjectReference;
import org.vmmagic.unboxed.Offset;
import org.mmtk.vm.VM;
import org.vmmagic.pragma.Uninterruptible;
import org.jikesrvm.classloader.RVMType;
import org.jikesrvm.runtime.RuntimeEntrypoints;
import org.jikesrvm.runtime.Memory;

public class CopyMachine {
    // Copy the contents of one object into another. Both objects should have
    // the same type (and certainly must have the same size), although this is
    // not checked.
    @Uninterruptible
    public static void copy(Object src, Object dest) {
        ObjectReference srcRef = ObjectReference.fromObject(src);
        int size = VM.objectModel.getCurrentSize(srcRef);
        Address srcAddr = VM.objectModel.objectStartRef(srcRef);
        Address destAddr = VM.objectModel.objectStartRef(
            ObjectReference.fromObject(dest)
        );
        Memory.memcopy(destAddr, srcAddr, size);
    }

    // Create a new object that is a (shallow) copy of a different object.
    @SuppressWarnings("unchecked")
    public static <T> T clone(T obj) {
        RVMType rtype = java.lang.JikesRVMSupport.getTypeForClass(
            obj.getClass()
        );
        if (rtype.isClassType()) {
            Object out = RuntimeEntrypoints.resolvedNewScalar(rtype.asClass());
            copy(obj, out);
            return (T)out;
        } else if (rtype.isArrayType()) {
            Object out = RuntimeEntrypoints.resolvedNewArray(
                Array.getLength(obj),
                rtype.asArray()
            );
            copy(obj, out);
            return (T)out;
        } else {
            assert false;
            return null;
        }
    }

    public static void main(String[] args) {
        String foo = "foo";
        String bar = clone(foo);
        System.out.println(bar);
    }
}