[Bug fortran/88190] compile_options.allow_std does not allow to distinguish between GFC_STD_GNU and GFC_STD_LEGACY

[kargl at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=88190

kargl at gcc dot gnu.org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Priority|P3                          |P5
                 CC|                            |kargl at gcc dot gnu.org
           Severity|normal                      |enhancement

--- Comment #1 from kargl at gcc dot gnu.org ---
(In reply to Dominique d'Humieres from comment #0)
> While playing with pr88052 I have found that the value of
> compile_options.allow_std passed to libgfortran is the same (4095) when
> compiling with -std=gnu or -std=legacy.
> 
> I suspect this is the same at the frontend level.

Good luck.

...
static void
set_default_std_flags (void)
{
  gfc_option.allow_std = GFC_STD_F95_OBS | GFC_STD_F95_DEL
    | GFC_STD_F2003 | GFC_STD_F2008 | GFC_STD_F95 | GFC_STD_F77
    | GFC_STD_F2008_OBS | GFC_STD_GNU | GFC_STD_LEGACY
    | GFC_STD_F2018 | GFC_STD_F2018_DEL | GFC_STD_F2018_OBS;
  gfc_option.warn_std = GFC_STD_F2018_DEL | GFC_STD_F95_DEL | GFC_STD_LEGACY;
}
...

    case OPT_std_gnu:
      set_default_std_flags ();
      break;

    case OPT_std_legacy:
      set_default_std_flags ();
      gfc_option.warn_std = 0;
      break;