Re: [Patch, fortran] PR66079 - [6 Regression] memory leak with source allocation in internal subprogram

[Andre Vehreschild <vehre at gmx dot de>]

Hi Paul,

does this patch apply to current trunk cleanly? I get an issue with the last
hunk, because all of the prerequisites are gone since r223445. The string copy
is completely handled by the trans_assignment at the bottom of the if
(code->expr3) block. Therefore I doubt the patches last hunk is needed any
longer.

Do you have an example why this hunk is needed?

Index: gcc/fortran/trans-stmt.c
===================================================================
*** gcc/fortran/trans-stmt.c    (revision 223233)
--- gcc/fortran/trans-stmt.c    (working copy)
*************** gfc_trans_allocate (gfc_code * code)
*** 5200,5206 ****
                }
              /* else expr3 = NULL_TREE set above.  */
            }
!         else
            {
              /* In all other cases evaluate the expr3 and create a
                 temporary.  */
--- 5200,5207 ----
                }
              /* else expr3 = NULL_TREE set above.  */
            }
!         else if (!(code->expr3->ts.type == BT_DERIVED
!                    && code->expr3->ts.u.derived->attr.alloc_comp))
            {
              /* In all other cases evaluate the expr3 and create a
                 temporary.  */

When I get the code right, than all derived-typed source= expressions that have
an allocatable component will not be prepared for copy to the allocated object.
This also means, that functions returning an object of such a type are called
multiple times. Once for each object to allocate. Is this really desired?

I am sorry, that I have to say that, but the check2305.diff file does not bring
the testcase with it.

Regards,
	Andre


On Sat, 23 May 2015 14:48:53 +0200
Paul Richard Thomas <paul.richard.thomas@gmail.com> wrote:

> Dear All,
> 
> This patch started out fixing a single source of memory leak and then
> went on to fix various other issues that I found upon investigation.
> 
> The fortran ChangeLog entry is sufficiently descripive that I do not
> think that there is a need to say more.
> 
> Bootstrapped and regtested on x86_64/FC21 - OK for trunk?
> 
> I am rather sure that some of the issues go further back than 6.0. I
> will investigate what should be fixed for 5.2.
> 
> Cheers
> 
> Paul
> 
> 2015-05-23  Paul Thomas  <pault@gcc.gnu.org>
> 
>     PR fortran/66079
>     * trans-expr.c (gfc_conv_procedure_call): Allocatable scalar
>     function results must be freed and nullified after use. Create
>     a temporary to hold the result to prevent duplicate calls.
>     * trans-stmt.c (gfc_trans_allocate): Prevent memory leaks by
>     not evaluating expr3 for scalar derived types with allocatable
>     components. Fixed character length allocatable results and
>     dummies need to be dereferenced. Also, if al_len is NULL use
>     memsz for the string copy.
> 
> 2015-05-23  Paul Thomas  <pault@gcc.gnu.org>
> 
>     PR fortran/66079
>     * gfortran.dg/allocatable_scalar_13.f90: New test


-- 
Andre Vehreschild * Email: vehre ad gmx dot de