[Bug fortran/98454] Apparent wrong initialization in function result

["anlauf at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98454

anlauf at gcc dot gnu.org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Last reconfirmed|                            |2020-12-27
                 CC|                            |anlauf at gcc dot gnu.org
             Status|UNCONFIRMED                 |NEW
     Ever confirmed|0                           |1

--- Comment #2 from anlauf at gcc dot gnu.org ---
I think there already exists at least one PR with issues with initializers.

A reduced testcase shows that default initialization works for intent(out),
whereas you get random junk for function results.

module m_test
  implicit none
  type t
    integer :: unit = -1
  end type t
  interface test
     module procedure test_fun
  end interface
contains
  function test_fun() result(res)
    type(t) :: res
!    res = t()                     ! <-- workaround
  end function test_fun
  subroutine test_sub (res)
    type(t), intent(out) :: res
  end subroutine test_sub
end module m_test
program p
  use m_test
  implicit none
  type(t) :: x
  write(6,*) 'Before constructor'
  write(6,*) '  unit      = ', x%unit
  x = test()
  write(6,*) 'After constructor (test_fun)'
  write(6,*) '  unit      = ', x%unit
  call test_sub (x)
  write(6,*) 'After test_sub'
  write(6,*) '  unit      = ', x%unit
end program p

If you need a workaround, uncomment the indicated line.