[Bug fortran/63473] [4.9/5 Regression] Memory leak with ALLOCATABLE, INTENT(OUT) dummy arguments.

[janus at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63473

--- Comment #4 from janus at gcc dot gnu.org ---
(In reply to janus from comment #3)
> The second message (680 bytes) occurs only with 4.9 upwards (and already in
> the first loop execution).

Actually I think this is not a real regression, but rather a change in behavior
which is in line with the Fortran 2008 standard (variables in the main program
automatically get the SAVE attribute, and thus are not auto-deallocated).

One can get rid of that valgrind message, by explicitly deallocating the array
at the end of the main program, so that the test case becomes:


program testprogram
  implicit none
  type :: mytype_type
    integer, allocatable :: i(:)
  end type
  integer :: n
  type(mytype_type), allocatable :: array(:)

  do n = 1, 2
    print *, allocated(array)
    call allocate_mytype(array)
  end do

  deallocate(array)

contains

  subroutine allocate_mytype(array)
    type(mytype_type), allocatable, intent(out) :: array(:)
    integer :: i
    allocate(array(10))
    do i = 1, 10
      allocate(array(i)%i(5))
      array(i)%i = 0
    end do
  end subroutine

end


With this version, one only gets:

==31267== 200 bytes in 10 blocks are definitely lost in loss record 1 of 1
==31267==    at 0x4C2ABA0: malloc (in
/usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so)
==31267==    by 0x400BC6: allocate_mytype.2336 (test.f90:23)
==31267==    by 0x400EF6: MAIN__ (test.f90:11)
==31267==    by 0x401008: main (test.f90:14)