# F77_FLAG_CHECK [compiler flags]
# check whether compiler supports given Fortran 77 flags or not
AC_DEFUN([F77_FLAG_CHECK],
[
  AC_MSG_CHECKING([if $F77 supports $1])
  AC_LANG_PUSH([Fortran 77])
  ac_saved_fflags="$FFLAGS"
  FFLAGS="-Werror $1"
  AC_COMPILE_IFELSE([AC_LANG_PROGRAM([])],
    [f77_flag_check=yes],
    [f77_flag_check=no]
  )
  AC_MSG_RESULT([$f77_flag_check])
  FFLAGS="$ac_saved_fflags"
  AC_LANG_POP([Fortran 77])
])