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Subject: [Bug fortran/43895] [OOP] internal compiler error: verify_ssa failed
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------- Comment #12 from pault at gcc dot gnu dot org  2010-06-05 10:40 -------
(In reply to comment #11)
OK, all this has a simple explanation.  A revamped version of the original
testcase segfaults in runtime, at -O0.

! { dg-do compile }
! Test the fix for PR43895, in which the dummy 'a' was not
! dereferenced for the deallocation of component 'a', as required
! for INTENT(OUT).
!
! Contributed by Salvatore Filippone <sfilippone@uniroma2.it>
!
module d_mat_mod
  type  :: base_sparse_mat
  end type base_sparse_mat

  type, extends(base_sparse_mat) :: d_base_sparse_mat
    integer :: i
  end type d_base_sparse_mat

  type :: d_sparse_mat
    class(d_base_sparse_mat), allocatable  :: a 
  end type d_sparse_mat
end module d_mat_mod

  use d_mat_mod
  type(d_sparse_mat) :: b
  allocate (b%a)
  b%a%i = 42
  call bug14 (b)
  if (allocated (b%a)) call abort
contains
  subroutine bug14(a)
    implicit none
    type(d_sparse_mat), intent(out) :: a
  end subroutine bug14
end
! { dg-final { cleanup-modules "d_mat_mod " } }

The reason is quite clear from the code below:

bug14 (struct d_sparse_mat & restrict a)
{
  if (a.a.$data != 0B)
    {
      __builtin_free ((void *) a.a.$data);
    }
  a.a.$data = 0B;
}

The dummy 'a' needs dereferencing, thus...

bug14 (struct d_sparse_mat & restrict a)
{
  if (a->a.$data != 0B)
    {
      __builtin_free ((void *) a->a.$data);
    }
  a->a.$data = 0B;
}

This patch is regtesting right now:

Index: /svn/trunk/gcc/fortran/trans-array.c
===================================================================
*** /svn/trunk/gcc/fortran/trans-array.c        (revision 159851)
--- /svn/trunk/gcc/fortran/trans-array.c        (working copy)
*************** structure_alloc_comps (gfc_symbol * der_
*** 5951,5957 ****

    gfc_init_block (&fnblock);

!   if (POINTER_TYPE_P (TREE_TYPE (decl)) && rank != 0)
      decl = build_fold_indirect_ref_loc (input_location,
                                    decl);

--- 5951,5958 ----

    gfc_init_block (&fnblock);

!   if ((POINTER_TYPE_P (TREE_TYPE (decl)) && rank != 0)
!       || (TREE_CODE (TREE_TYPE (decl)) == REFERENCE_TYPE && rank == 0))
      decl = build_fold_indirect_ref_loc (input_location,
                                    decl);

Cheers

Paul


-- 

pault at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
         AssignedTo|unassigned at gcc dot gnu   |pault at gcc dot gnu dot org
                   |dot org                     |
             Status|NEW                         |ASSIGNED
   Last reconfirmed|2010-04-26 15:04:01         |2010-06-05 10:40:32
               date|                            |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=43895