Re: [PATCH, v2] Fortran: ordering of hidden procedure arguments [PR107441]

[Harald Anlauf <anlauf@gmx.de>]

Am 02.11.22 um 18:20 schrieb Mikael Morin:
> Unfortunately no, the coarray case works, but the other problem remains.
> The type problem is not visible in the definition of S, it is in the
> declaration of S's prototype in P.
>
> S is defined as:
>
> void s (character(kind=1)[1:_c] & restrict c, integer(kind=4) o,
> logical(kind=1) _o, integer(kind=8) _c)
> {
> ...
> }
>
> but P has:
>
> void p ()
> {
>    static void s (character(kind=1)[1:] & restrict, integer(kind=4),
> integer(kind=8), logical(kind=1));
>    void (*<T63a>) (character(kind=1)[1:] & restrict, integer(kind=4),
> integer(kind=8), logical(kind=1)) pp;
>
>    pp = s;
> ...
> }

Right, now I see it too.  Simplified case:

program p
   call s ("abcd")
contains
   subroutine s(c, o)
     character(*) :: c
     integer, optional, value :: o
   end subroutine s
end

I do see what needs to be done in gfc_get_function_type, which seems
in fact very simple.  But I get really lost in create_function_arglist
when trying to get the typelist right.

One thing is I really don't understand how the (hidden_)typelist is
managed here.  How does that macro TREE_CHAIN work?  Can we somehow
chain two typelists the same way we chain arguments?

(Failing that, I tried to split the loop over the dummy arguments in
create_function_arglist into two passes, one for the optional+value
variant, and one for the rest.  It turned out to be a bad idea...)

Harald