[Bug fortran/66082] New: [4.9.2/5.1.0/6.0.0] memory leak: automatic array with derived type array constructor actual argument

[Bug fortran/66082] New: [4.9.2/5.1.0/6.0.0] memory leak: automatic array with derived type array constructor actual argument

[damian at sourceryinstitute dot org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66082

            Bug ID: 66082
           Summary: [4.9.2/5.1.0/6.0.0] memory leak: automatic array with
                    derived type array constructor actual argument
           Product: gcc
           Version: 6.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: fortran
          Assignee: unassigned at gcc dot gnu.org
          Reporter: damian at sourceryinstitute dot org
  Target Milestone: ---

The code below demonstrates a memory leak generated by an automatic array dummy
argument with a corresponding actual argument that is a derived type array
constructor with an allocatable component.  Changing the dummy argument
declaration "foo(n)" to an assumed shape array "foo(:)" eliminates the leak.

Damian

$ cat reduced.f90 
  type foo_t
     real, allocatable :: bigarr
  end type 
  block
    type(foo_t) :: foo 
    allocate(foo%bigarr) 
    call foo_1d(1,[foo]) ! definitely lost
  end block
contains
  subroutine foo_1d(n,foo)
    integer n
    type(foo_t) :: foo(n)
  end subroutine 
end 
$ gfortran reduced.f90 
$ valgrind ./a.out
==7891== Memcheck, a memory error detector
==7891== Copyright (C) 2002-2011, and GNU GPL'd, by Julian Seward et al. 
==7891== Using Valgrind-3.7.0 and LibVEX; rerun with -h for copyright info
==7891== Command: ./a.out
==7891== 
==7891== 
==7891== HEAP SUMMARY:
==7891==     in use at exit: 4 bytes in 1 blocks
==7891==   total heap usage: 26 allocs, 25 frees, 12,662 bytes allocated
==7891== 
==7891== LEAK SUMMARY:
==7891==    definitely lost: 4 bytes in 1 blocks
==7891==    indirectly lost: 0 bytes in 0 blocks
==7891==      possibly lost: 0 bytes in 0 blocks
==7891==    still reachable: 0 bytes in 0 blocks
==7891==         suppressed: 0 bytes in 0 blocks
==7891== Rerun with --leak-check=full to see details of leaked memory
==7891== 
==7891== For counts of detected and suppressed errors, rerun with: -v
==7891== ERROR SUMMARY: 0 errors from 0 contexts (suppressed: 2 from 2)
$ gfortran --version
GNU Fortran (GCC) 6.0.0 20150503 (experimental)

[Bug fortran/66082] memory leak with automatic array dummy argument with derived type array constructor actual argument

[pault at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66082

Paul Thomas <pault at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
   Last reconfirmed|                            |2015-05-23
                 CC|                            |pault at gcc dot gnu.org
           Assignee|unassigned at gcc dot gnu.org      |pault at gcc dot gnu.org
     Ever confirmed|0                           |1

--- Comment #1 from Paul Thomas <pault at gcc dot gnu.org> ---
Confirmed.

Oddly, the memory leak goes away at any level of optimization. What makes this
odd is that the assumed shape array case has all the code for deallocation of
the allocatable component after the call to foo_1d:

          foo_1d (&C.3401, &atmp.3);
          if ((struct foo_t[1] * restrict) atmp.3.data != 0B)
            {
              D.3411 = (atmp.3.dim[0].ubound - atmp.3.dim[0].lbound) + 1;
              D.3412 = atmp.3.dim[0].stride * D.3411;
              D.3413 = D.3412 + -1;
              S.6 = 0;
              while (1)
                {
                  if (S.6 > D.3413) goto L.3;
                  if ((*(struct foo_t[1] * restrict) atmp.3.data)[S.6].bigarr
!= 0B)
                    {
                      __builtin_free ((void *) (*(struct foo_t[1] * restrict)
atmp.3.data)[S.6].bigarr);
                    }
                  (*(struct foo_t[1] * restrict) atmp.3.data)[S.6].bigarr = 0B;
                  S.6 = S.6 + 1;
                }
              L.3:;
            }

and this disappears completely for the automatic array dummy. I am pretty sure
that ther problem lies in trans-array.c(gfc_conv_array_parameter), where the
deallocation of allocatable components appears after the return for g77 style
dummies. I cannot check this right now because I am doing a fresh bootstrap
with a clean tree.

Paul

[Bug fortran/66082] memory leak with automatic array dummy argument with derived type array constructor actual argument

[mikael at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66082

Mikael Morin <mikael at gcc dot gnu.org> changed:

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

--- Comment #2 from Mikael Morin <mikael at gcc dot gnu.org> ---
PR61831 is possibly related.
But I don't think the PR61831 patch fixes this.

[Bug fortran/66082] memory leak with automatic array dummy argument with derived type array constructor actual argument

[pault at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66082

--- Comment #3 from Paul Thomas <pault at gcc dot gnu.org> ---
Author: pault
Date: Tue May 26 10:20:41 2015
New Revision: 223677

URL: https://gcc.gnu.org/viewcvs?rev=223677&root=gcc&view=rev
Log:
2015-05-26  Paul Thomas  <pault@gcc.gnu.org>

        PR fortran/66082
        * trans-array.c (gfc_conv_array_parameter): Ensure that all
        non-variable arrays with allocatable components have the
        components deallocated after the procedure call.

2015-05-26  Paul Thomas  <pault@gcc.gnu.org>

        PR fortran/66082
        * gfortran.dg/allocatable_scalar_13.f90: New test

Added:
    trunk/gcc/testsuite/gfortran.dg/alloc_comp_auto_array_3.f90
Modified:
    trunk/gcc/fortran/ChangeLog
    trunk/gcc/fortran/trans-array.c
    trunk/gcc/testsuite/ChangeLog

[Bug fortran/66082] memory leak with automatic array dummy argument with derived type array constructor actual argument

[damian at sourceryinstitute dot org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66082

--- Comment #4 from Damian Rouson <damian at sourceryinstitute dot org> ---
Thanks for fixing this!  I just verified that the leak is gone with a gcc build
dated 20150607.

Damian

[Bug fortran/66082] memory leak with automatic array dummy argument with derived type array constructor actual argument

[mikael at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66082

--- Comment #5 from Mikael Morin <mikael at gcc dot gnu.org> ---
Paul, is there something to be done before closing?

[Bug fortran/66082] memory leak with automatic array dummy argument with derived type array constructor actual argument

[pault at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66082

Paul Thomas <pault at gcc dot gnu.org> changed:

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

--- Comment #6 from Paul Thomas <pault at gcc dot gnu.org> ---
Dear Mikael,

There is no reason at all why it is not closed! Doing so now.

Cheers

Paul