public Env<AttrContext> attribStatToTree(JCTree stmt, Env<AttrContext> env, JCTree tree) {
        breakTree = tree;
        JavaFileObject prev = log.useSource(env.toplevel.sourcefile);
        try {
            attribStat(stmt, env);
        } catch (BreakAttr b) {
            return b.env;
        } catch (AssertionError ae) {
            if (ae.getCause() instanceof BreakAttr) {
                return ((BreakAttr)(ae.getCause())).env;
            } else {
                throw ae;
            }
        } finally {
            breakTree = null;
            log.useSource(prev);
        }
        return env;
    }