[Bug fortran/45674] New: [OOP] Undefined references for extended types

[dietmar dot ebner at gmail dot com]

The testcase below leads to the following linker error on current trunk, gcc
4.5.0 and gcc 4.5.1: 
$gfortran fails.f90
/tmp/ccG09ce7.o: In function `__fails_test_MOD_bar':
fails.f90:(.text+0xe): undefined reference to `vtab$b_t.1500'
collect2: ld returned 1 exit status

The patch at the end of the bug report seems to solve the problem for me but
it's mainly a wild guess. The issue seems to be closely related to 44065.

file fails.f90
===
module fails_mod
  implicit none 
  type :: a_t
 integer :: a
  end type
  type, extends(a_t) :: b_t
 integer :: b
  end type
contains
  subroutine foo(a)
class(a_t) :: a
  end subroutine foo
end module fails_mod

module fails_test
  implicit none
contains
  subroutine bar
use fails_mod
type(b_t) :: b
call foo(b)
  end subroutine bar
end module fails_test

end


Index: fortran/interface.c
===
--- fortran/interface.c (revision 164288)
+++ fortran/interface.c (working copy)
@@ -1428,10 +1428,12 @@
   && actual->ts.u.derived && actual->ts.u.derived->ts.is_iso_c)
 return 1;

-  if (formal->ts.type == BT_CLASS)
+  if (formal->ts.type == BT_CLASS) {
 /* Make sure the vtab symbol is present when
the module variables are generated.  */
 gfc_find_derived_vtab (formal->ts.u.derived);
+gfc_find_derived_vtab (actual->ts.u.derived);
+  }

   if (actual->ts.type == BT_PROCEDURE)
 {


-- 
   Summary: [OOP] Undefined references for extended types
   Product: gcc
   Version: 4.6.0
Status: UNCONFIRMED
  Severity: normal
  Priority: P3
 Component: fortran
AssignedTo: unassigned at gcc dot gnu dot org
ReportedBy: dietmar dot ebner at gmail dot com
 GCC build triplet: i686-pc-linux-gnu
  GCC host triplet: i686-pc-linux-gnu
GCC target triplet: i686-pc-linux-gnu


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=45674

[Bug fortran/45674] [OOP] Undefined references for extended types

[dietmar dot ebner at gmail dot com]

--- Comment #3 from dietmar dot ebner at gmail dot com  2010-09-15 15:36 
---
(In reply to comment #2)
> Actually I think this patch is ok. Are you interested in committing it
> yourself? [Note that you'll need an FSF copyright assignment, if you don't
> already have one.] Otherwise I can commit it for you.
I don't have the copyright assignment in place so please go ahead and do it.

Thanks for the quick fix!


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=45674