[Bug fortran/46838] [OOP] Wrong allocation status for polymorphic component INTENT(OUT) dummy

[burnus at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=46838

Tobias Burnus <burnus at gcc dot gnu.org> changed:

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

--- Comment #1 from Tobias Burnus <burnus at gcc dot gnu.org> 2010-12-07 17:00:19 UTC ---
Work here as expected - but I get:

==32139== Conditional jump or move depends on uninitialised value(s)
==32139==    at 0x400A36: cdall.1593 (oop.f90:139)
==32139==    by 0x400CCE: create_matrix.1606 (oop.f90:117)

Line 139 is:
    if (allocated(desc%indxmap)) then

>From the dump:

cdall (struct desc_type & restrict desc)
    struct desc_type D.1561;
    struct desc_type desc_type.0;
    desc_type.0.matrix_data = 0B;
    D.1561 = *desc;
    *desc = desc_type.0;
    D.1561.matrix_data = 0B;
    D.1561.indxmap._data = 0B;

  if (desc->indxmap._data != 0B)

The way one has to read it is as follows:

  D.1561 = *desc;       // Save pointers
  *dest = desc_type.0;  // Default initialize
  // free allocatables via D.1561

The freeing works OK (except for a missing deep freeing, which is a different
PR). However, the initializing does not work. There is a line missing which
reads:
    desc_type.0.indxmap._data = 0B;

The initialization happens via gfc_init_default_dt, which uses sym->value.
Hence, the problem might be in resolve.c.

* * *

Modified version: If one changes indxmap into an array, one gets:

oop.f90:21:0: internal compiler error: in gfc_conv_descriptor_data_get, at
fortran/trans-array.c:144

* * *


Reduced test case:
module descriptor_type
  implicit none
  type      :: indx_map
  end type indx_map
  type desc_type
    integer, allocatable  :: matrix_data
    class(indx_map), allocatable :: indxmap
  end type desc_type
end module descriptor_type

program bug28
  use descriptor_type
  implicit none
  type(desc_type)   :: desc_a
  call cdall(desc_a)
contains
  subroutine cdall(desc)
    type(desc_type), intent(out)  :: desc
    if (allocated(desc%indxmap)) stop 'ERROR'
    STOP 'OK'
  end subroutine cdall
end program bug28