[Bug fortran/51639] New: Nested type pointer null initialisation fails

[Bug fortran/51639] New: Nested type pointer null initialisation fails

[jonathan.hogg at stfc dot ac.uk]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=51639

             Bug #: 51639
           Summary: Nested type pointer null initialisation fails
    Classification: Unclassified
           Product: gcc
           Version: 4.6.1
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: fortran
        AssignedTo: unassigned@gcc.gnu.org
        ReportedBy: jonathan.hogg@stfc.ac.uk


The following code appears to produce a regression in 4.6:

program main
   implicit none

   type type1
      integer, dimension(:), allocatable :: member
   end type type1

   type type2
      type(type1), pointer :: t1ptr=>null()
   end type type2

   call test
contains

subroutine test
   type(type2) :: t2

   print *, "associated(t2%t1ptr) = ", associated(t2%t1ptr)

end subroutine test

end program

Produces the output
  associated(t2%t1ptr) =  T

but should produce the output
  associated(t2%t1ptr) =  F

Further valgrind shows that access is to an uninitialised pointer.

The code works as expected under 4.4.6 and 4.5.4.

To provoke the error it seems that the associated() check must occur within a
subroutine, and that type1 must have an allocatable component.

Thanks,

Jonathan.

[Bug fortran/51639] Nested type pointer null initialisation fails

[dominiq at lps dot ens.fr]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=51639

--- Comment #1 from Dominique d'Humieres <dominiq at lps dot ens.fr> 2011-12-20 16:27:46 UTC ---
This seems to have been fixed on trunk between revisions 181881 (valgrind
error) and 182076 (OK).

[Bug fortran/51639] [4.6 Regression] Nested type pointer null initialisation fails

[burnus at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=51639

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |burnus at gcc dot gnu.org
   Target Milestone|---                         |4.6.3
            Summary|Nested type pointer null    |[4.6 Regression] Nested
                   |initialisation fails        |type pointer null
                   |                            |initialisation fails

[Bug fortran/51639] [4.6 Regression] Nested type pointer null initialisation fails

[dominiq at lps dot ens.fr]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=51639

--- Comment #2 from Dominique d'Humieres <dominiq at lps dot ens.fr> 2011-12-20 17:13:31 UTC ---
Tobias,

Do you have a 4.6.3 build after r182062 (p51435)? If yes, could you check its
behavior for this pr? TIA.

[Bug fortran/51639] [4.6 Regression] Nested type pointer null initialisation fails

[burnus at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=51639

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

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

--- Comment #3 from Tobias Burnus <burnus at gcc dot gnu.org> 2011-12-20 17:43:43 UTC ---
(In reply to comment #2)
> Do you have a 4.6.3 build after r182062 (p51435)? If yes, could you check its
> behavior for this pr? TIA.

I have a 4.6 build from Dec 11, which should be after Rev. 182062. There, I do
not see any valgrind error (contrary to the 4.6.2 release version). Seems to be
indeed a duplicate of PR 51435.


Jonathan: Could you try with a newer GCC - either GCC 4.6.3 (newer than
2011-12-06), or GCC 4.7 (experimental) [newer than 2011-12-06]. You could also
try an older version, GCC 4.5 is not affected.
Links to unofficial binaries and to instructions for building from source:
http://gcc.gnu.org/wiki/GFortranBinaries

*** This bug has been marked as a duplicate of bug 51435 ***