In the ChangeLog, I see this comment:

Sat Apr 12 12:41:49 2008  Nobuyoshi Nakada  <nobu / ruby-lang.org>

  * compile.c, compile.h (ERROR_ARGS), parse.y (node_newnode, fixpos,
    parser_warn, e_option_supplied, warn_unless_e_option, range_op,
    cond0): nd_file is no longer used.

If nd_file is no longer used, is there any reason to keep it in the
RNode struct?

Paul