[Bug fortran/57710] [OOP] _vptr not set for allocatable CLASS components

[Bug fortran/57710] [OOP] _vptr not set for allocatable CLASS components

[dominiq at lps dot ens.fr]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=57710

Dominique d'Humieres <dominiq at lps dot ens.fr> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
   Last reconfirmed|                            |2013-06-25
     Ever confirmed|0                           |1

--- Comment #1 from Dominique d'Humieres <dominiq at lps dot ens.fr> ---
Confirmed.

[Bug fortran/57710] [OOP] _vptr not set for allocatable CLASS components

[janus at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=57710

--- Comment #2 from janus at gcc dot gnu.org ---
(In reply to Tobias Burnus from comment #0)
> The following code (minus the IF condition) shows that _vptr is not set for
> the allocatable component:
>         y.x._data = 0B;
> there should be - but isn't - additionally: y.x._vptr = &__vtab_m_T;

Without the BLOCK, the dump shows:

  static struct t2 y = {.x={._vptr=&__vtab_m_T}};

  y.x._data = 0B;
  y.ii = 123;

while with the BLOCK one gets:

    struct t2 y;

    try
      {
        y.x._data = 0B;
        y.ii = 123;
        L.1:;
      }

Can't we do a 'static' initialization (of _vptr *and* _data) in both cases? As
in

  struct t2 y = {.x={._vptr=&__vtab_m_T,._data = 0B}}

For this gfc_class_null_initializer (from class.c) could be used ...

[Bug fortran/57710] [OOP] [F08] _vptr not set for allocatable CLASS component inside BLOCK

[janus at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=57710

janus at gcc dot gnu.org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
            Summary|[OOP] _vptr not set for     |[OOP] [F08] _vptr not set
                   |allocatable CLASS           |for allocatable CLASS
                   |components                  |component inside BLOCK

--- Comment #3 from janus at gcc dot gnu.org ---
(In reply to Tobias Burnus from comment #0)
> Additionally, the test case as is (with IF condition), currently crashes
> with:
> 
> internal compiler error: in gfc_conv_component_ref, at
> fortran/trans-expr.c:1654

Also the ICE occurs only with the BLOCK construct. Slightly reduced test case:

module m
  type t
  end type
  type t2
    class(t), allocatable :: x
  end type
end module

use m
type(t) :: z
block
  type(t2) :: y
  if (.not. same_type_as(y%x, z)) call abort ()
end block
end

[Bug fortran/57710] [OOP] [F08] _vptr not set for allocatable CLASS component inside BLOCK

[janus at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=57710

--- Comment #4 from janus at gcc dot gnu.org ---
(In reply to janus from comment #2)
> Can't we do a 'static' initialization (of _vptr *and* _data) in both cases?
> As in
> 
>   struct t2 y = {.x={._vptr=&__vtab_m_T,._data = 0B}}
> 
> For this gfc_class_null_initializer (from class.c) could be used ...

... we would just have to enable this for the BLOCK case in gfc_get_symbol
decl. However, I'm not sure if this is really the way to go.

Otherwise, one should do the (non-static) initialization of the _vptr via
gfc_nullify_alloc_comp.

[Bug fortran/57710] [OOP] [F08] _vptr not set for allocatable CLASS component inside BLOCK

[burnus at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=57710

--- Comment #5 from Tobias Burnus <burnus at gcc dot gnu.org> ---
(In reply to janus from comment #2)
> Can't we do a 'static' initialization (of _vptr *and* _data) in both cases?

Well, you need to free and finalize the variable - hence, it cannot be static.