[Bug fortran/78737] [OOP] linking error with deferred, undefined user-defined derived-type I/O

[janus at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=78737

janus at gcc dot gnu.org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Keywords|                            |wrong-code
             Status|UNCONFIRMED                 |NEW
   Last reconfirmed|                            |2016-12-09
                 CC|                            |janus at gcc dot gnu.org
            Summary|linking error with          |[OOP] linking error with
                   |deferred, undefined         |deferred, undefined
                   |user-defined derived-type   |user-defined derived-type
                   |I/O                         |I/O
     Ever confirmed|0                           |1

--- Comment #4 from janus at gcc dot gnu.org ---
Looking at the dump, one probably needs a polymorphic reference to
'a->_vptr->write_formatted' instead of using the interface?

    _gfortran_transfer_derived (&dt_parm.0, (struct
__class_object_interface_Object_t *) a, write_formatted_interface);