[Bug fortran/51995] New: Polymorphic class fails at runtime

[jilfa12 at yahoo dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=51995

             Bug #: 51995
           Summary: Polymorphic class fails at runtime
    Classification: Unclassified
           Product: gcc
           Version: 4.7.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: fortran
        AssignedTo: unassigned@gcc.gnu.org
        ReportedBy: jilfa12@yahoo.com


Created attachment 26458
  --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=26458
A factory pattern design to illustrate class pointers (polymorphic) behavior

The attached factory pattern compiled successfully.

1    PROGRAM main
2
3     USE factory_pattern
4
5     IMPLICIT NONE
6
7     TYPE(CFactory) :: factory
8     CLASS(Connection), POINTER :: db_connect => NULL()
9
10    CALL factory%init("Oracle")
11    db_connect => factory%create_connection()   !! Create Oracle DB
12    CALL db_connect%description()
13
14    !! The same factory can be used to create different connections
15    CALL factory%init("MySQL")                  !! Create MySQL DB
16
17    !! 'connect' is a 'class' pointer. So can be used for either Oracle or 
MySQL
18    db_connect => factory%create_connection()
19    CALL db_connect%description()
20
21    CALL factory%finalize()        ! Destroy the object
22
23   END PROGRAM main


The test driver program above produced this error when compiled with
gfortran-4.7.0:

test_factory.f90:12.29:

  CALL db_connect%description()
                             1
Error: 'description' at (1) is not a member of the 'connection' structure
test_factory.f90:19.29:

  CALL db_connect%description()
                             1
Error: 'description' at (1) is not a member of the 'connection' structure


The program (according to http://fortranwiki.org/fortran/show/Factory+Pattern)
apparently run successfully with gfortran-4.6.0.

Is this a bug?