bfd/config.bfd use of ifdef BFD64 for sh target

[Clarke, Stephen]

I've been puzzling over the following lines in bfd/config.bfd for a
while:

  sh-*-elf* | sh[1234]*-elf* | sh-*-rtemself*)
    targ_defvec=bfd_elf32_sh_vec
    targ_selvecs="bfd_elf32_shl_vec shcoff_vec shlcoff_vec shcoff_small_vec shlcoff_small_vec"
#ifdef BFD64
    targ_selvecs="${targ_selvecs} bfd_elf32_sh64_vec bfd_elf32_sh64l_vec bfd_elf64_sh64_vec bfd_elf64_sh64l_vec"
#endif
    targ_underscore=yes
    ;;

I'm trying to understand the purpose of the #ifdef here.

It appears to be intended to control whether the sh64 variants
get included in targ_selvecs, but how?

I know config.bfd is used for two purposes:

- as a configuration script, in which case the # marks a comment,
  and the ifdef will be ignored,

- as an input to sed when creating targmatch.h, in which case the
  targ_selvecs lines are stripped out anyway, so bracketing just
  that line with an ifdef has no effect.

This seems a pretty dumb question, but I'll ask it anyway ...
is there some usage of config.bfd in which this ifdef does have
some effect?

Steve.
--
Stephen Clarke, Principal Engineer, SuperH Inc.
Phone:1-408-273-3146, Fax:1-408-273-3199, mailto:Stephen.Clarke@superh.com
Mail:  SuperH Inc., 405 River Oaks Pkwy, San Jose, CA 95134, USA.