[Bug fortran/35824] New: Overloading problems with derived type with allocatable array

[Bug fortran/35824] New: Overloading problems with derived type with allocatable array

[everyo at gmx dot net]

I have a derived type with an allocatable array and have overloaded some
operations. Unfortunately assignments like a=-a don't work.

Code in the Module, where I definde the type:

  type alltype
     double precision :: a
     double precision,allocatable :: b(:)
  end type

      interface assignment(=)
      module procedure at_from_at
      end interface

      interface operator(-)
      module procedure  neg_at
      end interface

  contains

    subroutine at_from_at(b,a)
      type(alltype), intent(in) :: a
      type(alltype), intent(out) :: b

      b%a=a%a
      allocate(b%b(2))
      b%b=a%b

    end subroutine at_from_at

    function neg_at(a) result(b)
      type(alltype), intent(in) :: a
      type(alltype) :: b

      b%a=-a%a
      allocate(b%b(2))
      b%b=-a%b

    end function neg_at

The allocatable array has an dimension of 2 in this example...

Now the code:

 use typemodule

 type(alltype) t1,t2,t3

 allocate(t1%b(2))
 t1%a=0.5d0
 t1%b(1)=1d0
 t1%b(2)=2d0


 t2=-t1
 write(*,*) t2%a, t2%b

 t1=-t1
 write(*,*) t1%a, t1%b

Prints: 
 -0.50000000000000000      -1.00000000000000000       -2.0000000000000000
Segmentation fault

It seems that in the Module, the allocatated array of t1 doesn't get passed
properly in the t1=-t1 part. I have also seg. faults in situations like a=a+b
(where + is overloaded simiarly)

The same code works correctly with ifort.


-- 
           Summary: Overloading problems with derived type with allocatable
                    array
           Product: gcc
           Version: 4.3.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: fortran
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: everyo at gmx dot net
 GCC build triplet: i686-pc-linux-gnu
  GCC host triplet: i686-pc-linux-gnu
GCC target triplet: i686-pc-linux-gnu


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=35824

[Bug fortran/35824] Overloading problems with derived type with allocatable array

[dominiq at lps dot ens dot fr]

------- Comment #1 from dominiq at lps dot ens dot fr  2008-04-04 10:09 -------
Confirmed on powerpc-apple-darwin9 (but not on i686-apple-darwin9). The bus
error comes from the statement 'b%b=-a%b' in function 'neg_at'. If I insert
'print *, allocated(a%b)' in the function, I get .false. on powerpc (but .true.
for i686) for 't1=-t1'.


-- 

dominiq at lps dot ens dot fr changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
            Summary|Overloading problems with   |Overloading problems with
                   |derived type with           |derived type with
                   |allocatable array           |allocatable array


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=35824

[Bug fortran/35824] Overloading problems with derived type with allocatable array

[burnus at gcc dot gnu dot org]

------- Comment #2 from burnus at gcc dot gnu dot org  2008-04-04 14:14 -------
> Confirmed on powerpc-apple-darwin9 (but not on i686-apple-darwin9). The bus
> error comes from the statement 'b%b=-a%b' in function 'neg_at'. If I insert
> 'print *, allocated(a%b)' in the function, I get .false. on powerpc (but .true.
> for i686) for 't1=-t1'.

Also confirmed on x86-64-linux. I always get non allocated before and allocated
after the allocation statement, which looks OK.

I have to admit, I did not quickly see in the dump (-fdump-tree-original) why
it is failing; at a glance, both calling "neg_at" in MAIN__ and the assignment
in "neg_at" itself look ok; and "t2 = -t1" also works.

Side question: Why do we initialize b.b.data with NULL 3 times?

  b.b.data = 0B;
  b.b.data = 0B;
  {
    struct alltype alltype.0;
    alltype.0.b.data = 0B;
    b = alltype.0;
  }


-- 

burnus at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
     Ever Confirmed|0                           |1
           Keywords|                            |wrong-code
   Last reconfirmed|0000-00-00 00:00:00         |2008-04-04 14:14:38
               date|                            |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=35824

[Bug fortran/35824] Overloading problems with derived type with allocatable array

[pault at gcc dot gnu dot org]

------- Comment #3 from pault at gcc dot gnu dot org  2008-05-18 15:37 -------
> I have to admit, I did not quickly see in the dump (-fdump-tree-original) why
> it is failing; at a glance, both calling "neg_at" in MAIN__ and the assignment
> in "neg_at" itself look ok; and "t2 = -t1" also works.

The reason is that the lhs is deallocated and nulled before the assignment:

    if (t1.b.data != 0B)
      {
        __builtin_free (t1.b.data);
      }
    t1.b.data = 0B;
    D.722 = neg_at (&t1);
    at_from_at (&t1, &D.722);
    if (D.722.b.data != 0B)
      {
        __builtin_free (D.722.b.data);
      }
    D.722.b.data = 0B;
  }

Thus a data null is passed to the neg_at.

If the operator assignment is deleted, so that we rely on the intrinsic
assignment for derived types with allocatable components, the correct result is
obtained:

    D.719 = t2;
    t2 = neg_at (&t1);
    if (D.719.b.data != 0B)
      {
        __builtin_free (D.719.b.data);
      }
    D.719.b.data = 0B;

I'll have to see how that can be emulated.

Paul


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=35824

[Bug fortran/35824] Overloading problems with derived type with allocatable array

[pault at gcc dot gnu dot org]

------- Comment #4 from pault at gcc dot gnu dot org  2008-05-18 16:00 -------
(In reply to comment #3)
The patch that I have been working on, which is held up by memory leak
problems, actually cures this fellow too.

I am active again on all the allocatable component bugs.

Watch this space.

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|2008-04-04 14:14:38         |2008-05-18 16:00:55
               date|                            |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=35824

[Bug fortran/35824] Overloading problems with derived type with allocatable array

[pault at gcc dot gnu dot org]

------- Comment #5 from pault at gcc dot gnu dot org  2008-11-30 08:04 -------
This is fixed for trunk and 4.3.

I have prepared a testcase that will be committed tonight.

Thanks for the report.

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=35824

[Bug fortran/35824] Overloading problems with derived type with allocatable array

[pault at gcc dot gnu dot org]

------- Comment #6 from pault at gcc dot gnu dot org  2008-11-30 08:50 -------
Subject: Bug 35824

Author: pault
Date: Sun Nov 30 08:48:51 2008
New Revision: 142292

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=142292
Log:
2008-11-30  Paul Thomas  <pault@gcc.gnu.org>

        PR fortran/35824
        * gfortran.dg/alloc_comp_assign_8.f90 : New test.

Added:
    trunk/gcc/testsuite/gfortran.dg/alloc_comp_assign_8.f90
Modified:
    trunk/gcc/testsuite/ChangeLog


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=35824