[Bug fortran/31620] New: Zeroing one component of array of derived types zeros the whole structure.

[Bug fortran/31620] New: Zeroing one component of array of derived types zeros the whole structure.

[David at ham dot dropbear dot id dot au]

If an array of a derived type is declared and one component is set to zero then
all the components are set to zero. The following program illustrates the
problem:

program test_assign

  type my_type
     integer :: a
     integer :: b 
  end type my_type

  type(my_type), dimension(1) :: mine

  mine%b=4

  print *, "Should be 4: ", mine%b

  mine%a=1

  print *, "Should be 4: ", mine%b

  mine%a=0

  print *, "Should be 4: ", mine%b
  print *, "Should be 0: ", mine%a

end program test_assign

The output of this is:

 Should be 4:            4
 Should be 4:            4
 Should be 4:            0
 Should be 0:            0

Note the third line.


-- 
           Summary: Zeroing one component of array of derived types zeros
                    the whole structure.
           Product: gcc
           Version: 4.3.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: fortran
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: David at ham dot dropbear dot id dot au
 GCC build triplet: RHEL4 x86_64
  GCC host triplet: RHEL4 x86_64
GCC target triplet: RHEL4 x86_64


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=31620

[Bug fortran/31620] [regression 4.3] Zeroing one component of array of derived types zeros the whole structure.

[dfranke at gcc dot gnu dot org]

------- Comment #1 from dfranke at gcc dot gnu dot org  2007-04-18 14:09 -------
Strange, indeed. 
Can confirm this behaviour for 4.3 (20070417), neither 4.1.1 nor 4.2 (20070417)
exhibit the problem.


-- 

dfranke at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |dfranke at gcc dot gnu dot
                   |                            |org
             Status|UNCONFIRMED                 |NEW
     Ever Confirmed|0                           |1
      Known to fail|                            |4.3.0
      Known to work|                            |4.1.1 4.2.0
   Last reconfirmed|0000-00-00 00:00:00         |2007-04-18 14:09:12
               date|                            |
            Summary|Zeroing one component of    |[regression 4.3] Zeroing one
                   |array of derived types zeros|component of array of
                   |the whole structure.        |derived types zeros the
                   |                            |whole structure.


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=31620

[Bug fortran/31620] [regression 4.3] Zeroing one component of array of derived types zeros the whole structure.

[dfranke at gcc dot gnu dot org]

------- Comment #2 from dfranke at gcc dot gnu dot org  2007-04-18 14:25 -------
$> cat pr31620.f90
program test_assign
  type my_type
     integer :: a
     integer :: b
  end type my_type
  type(my_type), dimension(1) :: mine        ! note that MINE is an array

  mine%b=4
  mine%a=1
  print *,  mine
  mine%a=0
  print *,  mine
end program test_assign

$> gfortran-svn -g -fdump-tree-original pr31620.f90

The dump shows between the print statements:
[...]
(void) __builtin_memset ((void *) &mine, 0, 8);
[...]
which obviously is the culprit.

Adding Roger Sayle as CC as he worked on this a while ago.


-- 

dfranke at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |roger at eyesopen dot com
           Keywords|                            |wrong-code


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=31620

[Bug fortran/31620] [4.3 regression] Zeroing one component of array of derived types zeros the whole structure.

[pinskia at gcc dot gnu dot org]

-- 

pinskia at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |pinskia at gcc dot gnu dot
                   |                            |org
  GCC build triplet|RHEL4 x86_64                |
   GCC host triplet|RHEL4 x86_64                |
 GCC target triplet|RHEL4 x86_64                |
            Summary|[regression 4.3] Zeroing one|[4.3 regression] Zeroing one
                   |component of array of       |component of array of
                   |derived types zeros the     |derived types zeros the
                   |whole structure.            |whole structure.
   Target Milestone|---                         |4.3.0


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=31620

[Bug fortran/31620] [4.3 regression] Zeroing one component of array of derived types zeros the whole structure.

[kargl at gcc dot gnu dot org]

------- Comment #3 from kargl at gcc dot gnu dot org  2007-04-21 23:51 -------
The OP doesn't understand his own program.
Closing as invalid.


-- 

kargl at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |kargl at gcc dot gnu dot org
             Status|NEW                         |RESOLVED
         Resolution|                            |INVALID


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=31620

[Bug fortran/31620] [4.3 regression] Zeroing one component of array of derived types zeros the whole structure.

[pinskia at gcc dot gnu dot org]

------- Comment #4 from pinskia at gcc dot gnu dot org  2007-04-21 23:56 -------
(In reply to comment #3)
> The OP doesn't understand his own program.
Huh? (or did you close the wrong bug report?)
Here is a simplified testcase that does not call print:
program test_assign
  type my_type
     integer :: a
     integer :: b
  end type my_type
  type(my_type), dimension(1) :: mine        ! note that MINE is an array
  mine%b=4
  mine%a=1
  mine%a=0
  if (any (mine%b .ne. 4)) call abort ()
end program test_assign


-- 

pinskia at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|RESOLVED                    |REOPENED
         Resolution|INVALID                     |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=31620

[Bug fortran/31620] [4.3 regression] Zeroing one component of array of derived types zeros the whole structure.

[kargl at gcc dot gnu dot org]

------- Comment #5 from kargl at gcc dot gnu dot org  2007-04-22 00:10 -------
(In reply to comment #4)
> (In reply to comment #3)
> > The OP doesn't understand his own program.
> Huh? (or did you close the wrong bug report?)
> Here is a simplified testcase that does not call print:
> program test_assign

Sorry, David, I may have read the program too quick.
Two hours of umping behind the plate, followed by 
1.5 hours of soccer, led to a rash decision.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=31620

[Bug fortran/31620] [4.3 regression] Zeroing one component of array of derived types zeros the whole structure.

[patchapp at dberlin dot org]

------- Comment #6 from patchapp at dberlin dot org  2007-04-22 22:05 -------
Subject: Bug number PR31620

A patch for this bug has been added to the patch tracker.
The mailing list url for the patch is
http://gcc.gnu.org/ml/gcc-patches/2007-04/msg01431.html


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=31620

[Bug fortran/31620] [4.3 regression] Zeroing one component of array of derived types zeros the whole structure.

[pault at gcc dot gnu dot org]

------- Comment #7 from pault at gcc dot gnu dot org  2007-04-22 22:05 -------
I just posted a patch.

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|REOPENED                    |ASSIGNED
   Last reconfirmed|2007-04-18 14:09:12         |2007-04-22 22:05:46
               date|                            |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=31620

[Bug fortran/31620] [4.3 regression] Zeroing one component of array of derived types zeros the whole structure.

[pault at gcc dot gnu dot org]

------- Comment #8 from pault at gcc dot gnu dot org  2007-04-23 16:14 -------
Subject: Bug 31620

Author: pault
Date: Mon Apr 23 16:13:48 2007
New Revision: 124069

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=124069
Log:
2007-04-23  Paul Thomas  <pault@gcc.gnu.org>

        PR fortran/31630
        * resolve.c (resolve_symbol): Allow resolution of formal
        namespaces nested within formal namespaces coming from modules.

        PR fortran/31620
        * trans-expr.c (gfc_trans_assignment): Make the call to
        gfc_trans_zero_assign conditional on the lhs array ref being
        the only reference.

2007-04-23  Paul Thomas  <pault@gcc.gnu.org>

        PR fortran/31630
        * gfortran.dg/used_types_17.f90: New test.

        PR fortran/31620
        * gfortran.dg/zero_array_components_1.f90: New test.

Added:
    trunk/gcc/testsuite/gfortran.dg/used_types_17.f90
    trunk/gcc/testsuite/gfortran.dg/zero_array_components_1.f90
Modified:
    trunk/gcc/fortran/ChangeLog
    trunk/gcc/fortran/resolve.c
    trunk/gcc/fortran/trans-expr.c
    trunk/gcc/testsuite/ChangeLog


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=31620

[Bug fortran/31620] [4.3 regression] Zeroing one component of array of derived types zeros the whole structure.

[pault at gcc dot gnu dot org]

------- Comment #9 from pault at gcc dot gnu dot org  2007-04-23 17:52 -------
Fixed on trunk

Paul


-- 

pault at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|ASSIGNED                    |RESOLVED
         Resolution|                            |FIXED


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=31620

[Bug fortran/31620] [4.3 regression] Zeroing one component of array of derived types zeros the whole structure.

[roger at eyesopen dot com]

------- Comment #10 from roger at eyesopen dot com  2007-04-23 20:54 -------
Many thanks to Paul for fixing this, and my apologies for being overloaded at
work and not being available to investigate it fully myself.

I believe that Paul's fix of explicitly checking expr1->ref->next is the
correct way to determine whether a reference is too complex.  My confusion is
that this test should already be being checked/verified in the call to
gfc_full_array_ref_p on the line immediately following his change.
So on line 1124 of dependency.c in gfc_f_a_r_p is the clause

    if (ref->next)
      return false;

which should be doing exactly the same thing.  The reason I mention this
is perhaps GCC is miscompiling itself, and this gfortran failure is the visible
manifestation.  Alternatively, perhaps ref->next isn't getting set properly,
or is getting clobbered somehow.

Paul does your new testcase fail without your fix?

My apologies again if I'm missing something obvious.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=31620

[Bug fortran/31620] [4.3 regression] Zeroing one component of array of derived types zeros the whole structure.

[roger at eyesopen dot com]

------- Comment #11 from roger at eyesopen dot com  2007-04-23 21:05 -------
Duh!  I am missing something obvious!  The ref->u.ar.type == AR_FULL test on
line 1120 returns true.  The test for ref->next needs to be moved earlier.

Sorry again for the inconvenience.  Clearly, my brain isn't working properly at
the moment :-(


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=31620