void newVar(VarSymbol sym) {
        if (nextadr == vars.length) {
            VarSymbol[] newvars = new VarSymbol[nextadr * 2];
            System.arraycopy(vars, 0, newvars, 0, nextadr);
            vars = newvars;
        }
        sym.adr = nextadr;
        vars[nextadr] = sym;
        inits.excl(nextadr);
        uninits.incl(nextadr);
        nextadr++;
    }