JCTree abstractLval(JCTree lval, final TreeBuilder builder) {
        lval = TreeInfo.skipParens(lval);
        switch (lval.getTag()) {
        case JCTree.IDENT:
            return builder.build(lval);
        case JCTree.SELECT: {
            final JCFieldAccess s = (JCFieldAccess)lval;
            JCTree selected = TreeInfo.skipParens(s.selected);
            Symbol lid = TreeInfo.symbol(s.selected);
            if (lid != null && lid.kind == TYP) return builder.build(lval);
            return abstractRval(s.selected, new TreeBuilder() {
                    public JCTree build(final JCTree selected) {
                        return builder.build(make.Select((JCExpression)selected, s.sym));
                    }
                });
        }
        case JCTree.INDEXED: {
            final JCArrayAccess i = (JCArrayAccess)lval;
            return abstractRval(i.indexed, new TreeBuilder() {
                    public JCTree build(final JCTree indexed) {
                        return abstractRval(i.index, syms.intType, new TreeBuilder() {
                                public JCTree build(final JCTree index) {
                                    JCTree newLval = make.Indexed((JCExpression)indexed,
                                                                (JCExpression)index);
                                    newLval.setType(i.type);
                                    return builder.build(newLval);
                                }
                            });
                    }
                });
        }
        }
        throw new AssertionError(lval);
    }