[Bug fortran/52531] New: Compilation fails with polymorphic dummy argument and OpenMP

[Bug fortran/52531] New: Compilation fails with polymorphic dummy argument and OpenMP

[kaladhorn at me dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=52531

             Bug #: 52531
           Summary: Compilation fails with polymorphic dummy argument and
                    OpenMP
    Classification: Unclassified
           Product: gcc
           Version: 4.7.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: fortran
        AssignedTo: unassigned@gcc.gnu.org
        ReportedBy: kaladhorn@me.com


The following code does not compile:

--
module test_mod
  type, public :: test_type
  end type
contains
  subroutine foo(bar)
    type(test_type) :: bar
!$omp parallel default(none) shared(bar) ! Compiles if one removes
default(none)
    call question(bar)
!$omp end parallel
  end subroutine
  subroutine question(var)
    class(test_type), intent(in) :: var ! Compiles if one replaces class by
type
  end subroutine
end module
--

The error message is:
‘__vtab_test_mod_Test_type’ not specified in enclosing parallel

This was reproduced with gfortran 4.6 (gcc version 4.6.3 (GCC) ) and 4.7 (gcc
version 4.7.0 20120121 (experimental) (GCC) ) on x86_64-unknown-linux-gnu .

[Bug fortran/52531] [OOP] Compilation fails with polymorphic dummy argument and OpenMP

[jakub at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=52531

Jakub Jelinek <jakub at gcc dot gnu.org> changed:

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

--- Comment #1 from Jakub Jelinek <jakub at gcc dot gnu.org> 2012-03-08 15:11:03 UTC ---
OpenMP 3.1 or earlier releases don't cover Fortran 2003 nor 2008, so what you
are trying to compile is not valid.

[Bug fortran/52531] [OOP] Compilation fails with polymorphic dummy argument and OpenMP

[kaladhorn at me dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=52531

--- Comment #2 from kaladhorn at me dot com 2012-03-08 19:33:24 UTC ---
(In reply to comment #1)
> OpenMP 3.1 or earlier releases don't cover Fortran 2003 nor 2008, so what you
> are trying to compile is not valid.

hmm that's true, I did not think of it that way. My apologies, then.
However, I think a proper error message would be nice.

Out of curiosity, would there be a technical issue in this case?
It sure seemed natural to me.

Thanks!

[Bug fortran/52531] [OOP] Compilation fails with polymorphic dummy argument and OpenMP

[janus at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=52531

janus at gcc dot gnu.org changed:

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

--- Comment #3 from janus at gcc dot gnu.org 2012-06-08 13:00:53 UTC ---
(In reply to comment #2)
> Out of curiosity, would there be a technical issue in this case?
> It sure seemed natural to me.

AFAICS there should not be any huge issues. One might consider to implement
this as an extension.

[Bug fortran/52531] [OOP] Compilation fails with polymorphic dummy argument and OpenMP

[kaladhorn at me dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=52531

--- Comment #4 from kaladhorn at me dot com 2012-06-08 18:46:11 UTC ---
(In reply to comment #3)
> (In reply to comment #2)
> > Out of curiosity, would there be a technical issue in this case?
> > It sure seemed natural to me.
> 
> AFAICS there should not be any huge issues. One might consider to implement
> this as an extension.

If it does not hurt, I think it would be a good thing.

As far as I am concerned, I engineered around it, as it is really an edge case
we do not want to rely on.
It arguably makes some code uglier, though.

[Bug fortran/52531] [OOP] Compilation fails with polymorphic dummy argument and OpenMP

[janus at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=52531

--- Comment #5 from janus at gcc dot gnu.org 2012-06-09 09:34:53 UTC ---
Note: Apart from the two workarounds mentioned in the test case, there is one
other possibility to make it work, namely to make 'bar' also polymorphic (like
the dummy 'var'), e.g.:

class(test_type), allocatable :: bar

[Bug fortran/52531] [OOP] Compilation fails with polymorphic dummy argument and OpenMP

[janus at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=52531

janus at gcc dot gnu.org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |valeryweber at hotmail dot
                   |                            |com

--- Comment #6 from janus at gcc dot gnu.org 2013-03-17 17:06:41 UTC ---
*** Bug 55282 has been marked as a duplicate of this bug. ***

[Bug fortran/52531] [OOP] Compilation fails with polymorphic dummy argument and OpenMP

[janus at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=52531

janus at gcc dot gnu.org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
   Last reconfirmed|                            |2013-03-17
     Ever Confirmed|0                           |1
           Severity|normal                      |enhancement

--- Comment #7 from janus at gcc dot gnu.org 2013-03-17 17:09:12 UTC ---
Note that OpenMP 4.0 RC2 still lists polymorphic entities as unsupported, cf.
http://openmp.org/wp/openmp-specifications/

[Bug fortran/52531] [OOP] Compilation fails with polymorphic dummy argument and OpenMP

[janus at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=52531

--- Comment #8 from janus at gcc dot gnu.org ---
(In reply to janus from comment #7)
> Note that OpenMP 4.0 RC2 still lists polymorphic entities as unsupported,
> cf. http://openmp.org/wp/openmp-specifications/

Update: OpenMP has been officially released by now, but polymorphic variables
continue to be unsupported.