[Bug fortran/41583] New: [OOP] TYPE IS rejected because of way vtable index is implemented

[Bug fortran/41583] New: [OOP] TYPE IS rejected because of way vtable index is implemented

[burnus at gcc dot gnu dot org]

The following program is valid but it fails to compile due to the way the
indices in vtable are implemented.

Cf. http://gcc.gnu.org/ml/fortran/2009-09/msg00298.html

========= File: bb.f90 =========
module m
type t
end type t
end module m
========= File: cc.f90 =========
module m2
  use m
  type, extends(t) :: t2
  end type t2
end module m2
========= File: dd.f90 =========
use m
use m2
type,extends(t) :: t3
end type t3

integer :: i
class(t), allocatable :: a
allocate(t3 :: a)
select type(a)
  type is(t)
    i = 1
  type is(t2)
    i = 2
  type is(t3)
    i = 3
end select
print *, i
end
========================

The error message is:

$ gfortran bb.f90 cc.f90 dd.f90
dd.f90:10.10:

  type is(t)
          1
dd.f90:12.10:

  type is(t2)
          2
Error: CASE label at (1) overlaps with CASE label at (2)


-- 
           Summary: [OOP] TYPE IS rejected because of way vtable index is
                    implemented
           Product: gcc
           Version: 4.5.0
            Status: UNCONFIRMED
          Keywords: rejects-valid
          Severity: normal
          Priority: P3
         Component: fortran
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: burnus at gcc dot gnu dot org


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=41583

[Bug fortran/41583] [OOP] TYPE IS rejected because of way vtable index is implemented

[pault at gcc dot gnu dot org]

------- Comment #1 from pault at gcc dot gnu dot org  2009-10-11 12:25 -------
Subject: Bug 41583

Author: pault
Date: Sun Oct 11 12:24:51 2009
New Revision: 152641

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=152641
Log:
2009-10-11  Paul Thomas  <pault@gcc.gnu.org>

        PR fortran/41583
        * decl.c (hash_value): New function.
        (gfc_match_derived_decl): Call it.

2009-10-11  Paul Thomas  <pault@gcc.gnu.org>

        PR fortran/41583
        * gfortran.dg/class_4a.f03: New test with class_4b,c and d.f03.
        * gfortran.dg/class_4b.f03: As above.
        * gfortran.dg/class_4c.f03: As above.
        * gfortran.dg/class_4d.f03: As above.

Modified:
    trunk/gcc/fortran/ChangeLog
    trunk/gcc/testsuite/ChangeLog


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=41583

[Bug fortran/41583] [OOP] TYPE IS rejected because of way vtable index is implemented

[pault at gcc dot gnu dot org]

------- Comment #2 from pault at gcc dot gnu dot org  2009-10-11 12:29 -------
Fixed using a hash function.

TODO a proper job using vtables.

Paul


-- 

pault at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |RESOLVED
         Resolution|                            |FIXED


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=41583