[Bug fortran/47601] [OOP] Internal Error: mio_component_ref(): Component not found

["burnus at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47601

Tobias Burnus <burnus at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |burnus at gcc dot gnu.org

--- Comment #16 from Tobias Burnus <burnus at gcc dot gnu.org> 2011-05-28 12:32:11 UTC ---
(In reply to comment #13)
>   type :: matching 
>      integer :: N = -999
>   end type
>   type, extends(matching) :: ellipse
>   end type

>     type(ellipse), intent(in) :: e
>     complex, dimension(e%N) :: a2n

Thus, when loading the expression, one needs to resolve e%N. One thus calls
module.c's mio_component_ref which does (on reading the .mod):

      if (sym->components != NULL && p->u.pointer == NULL)
        {
          /* Symbol already loaded, so search by name.  */
          for (q = sym->components; q; q = q->next)
            if (strcmp (q->name, name) == 0)
              break;

The comparison by name fails for extended types:

(gdb) p sym->components->name
$11 = 0x2aaaacec33b0 "matching"
(gdb) p sym->components->next
$12 = (struct gfc_component *) 0x0

Thus: Not found. However, one has:

(gdb) p sym->attr.extension 
$13 = 1
(gdb) p sym->components->ts.u.derived->name
$14 = 0x2aaaacec33b0 "matching"
(gdb) p sym->components->ts.u.derived->components->name
$15 = 0x2aaaacde3fa8 "n"

Janus, you know type extension better than me. Does one now needs to do:
  if (!p && sym->attr.extension)
    {
      p = search (sym->components->ts.u.derived)
      if (!p && sym->components->ts.u.derived->attr.extension)
        p = search (sym->components->ts.u.derived->...)

or is this the wrong method?