[Bug fortran/47637] New: Memory leak involving derived types w/ allocatable components

["townsend at astro dot wisc.edu" <gcc-bugzilla at gcc dot gnu dot org>]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47637

           Summary: Memory leak involving derived types w/ allocatable
                    components
           Product: gcc
           Version: 4.6.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: fortran
        AssignedTo: unassigned@gcc.gnu.org
        ReportedBy: townsend@astro.wisc.edu


Created attachment 23271
  --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=23271
Source code plus makefile

The attached test-case code (Makefile included) compiles fine with gfortran 4.6
on Mac OSX 10.6. However, when I run the code I get a significant memory leak.
Valgrind reports:

==84427== LEAK SUMMARY:
==84427==    definitely lost: 38,496,000 bytes in 4,000 blocks
==84427==    indirectly lost: 0 bytes in 0 blocks
==84427==      possibly lost: 0 bytes in 0 blocks
==84427==    still reachable: 88 bytes in 1 blocks
==84427==         suppressed: 0 bytes in 0 blocks
==84427== Rerun with --leak-check=full to see details of leaked memory

The leaks are occurring with the st_l and st_r derived types in the evolve()
subroutine in hydro_evolve.f90; it seems that the allocatable components of
these variables are not being automatically deallocated when the recon()
subroutine is called, even though the corresponding dummy arguments in recon()
are declared as INTENT(out)..

If I uncomment the deallocate statements in evolve(), so that I do the
deallocation 'by hand', then the memory leak is fixed. So, a workaround is
possible, but this seems to be quite a fundamental bug.