public void setUndefined(int adr) {
        state.defined.excl(adr);
        if (adr < lvar.length &&
            lvar[adr] != null &&
            lvar[adr].start_pc != Character.MAX_VALUE) {
            LocalVar v = lvar[adr];
            char length = (char)(curPc() - v.start_pc);
            if (length > 0 && length < Character.MAX_VALUE) {
                lvar[adr] = v.dup();
                v.length = length;
                putVar(v);
            } else {
                v.start_pc = Character.MAX_VALUE;
            }
        }
    }