I have been putting together a thin wrapper around the Direct2D graphics stuff, which I'll post once I've finished writing some documentation. It is working quite nicely, except for a resource leak where the compiler is not invoking the finalizer of a polymorphic allocatable component when objects are deallocated as part of being associated with INTENT(OUT) allocatable dummy arguments.
module direct2d implicit none type manager integer :: comp = 0 contains final :: manager_final end type manager type, extends(manager) :: d2d1resource end type d2d1resource type, extends(d2d1resource) :: d2d1geometry end type d2d1geometry ! THis is ultimately an extension of manager, which has a ! finalizer. type, extends(d2d1geometry) :: d2d1pathgeometry end type d2d1pathgeometry contains subroutine manager_final(obj) type(manager), intent(inout) :: obj print "('manager_final called with comp of ',i0)", obj%comp if (obj%comp > 0) then obj%comp = 0 end if end subroutine manager_final end module direct2d module m2 use direct2d implicit none type parent end type parent type, extends(parent) :: extension class(d2d1geometry), allocatable :: arrow end type extension contains subroutine create_arrow(arrow) class(d2d1geometry), intent(out), allocatable :: arrow type(d2d1pathgeometry), allocatable :: path allocate(path) path%comp = 1 call move_alloc(path, arrow) end subroutine create_arrow end module m2 program p use m2 implicit none print "('Before call to exec')" call exec print "('After call to exec')" contains subroutine exec class(parent), allocatable :: test print "('Before first call to create.')" ! test not allocated, so it is not finalized. call create(test) print "('Before second call to create - where''s the finalizer?')" ! test is allocated here, so we expect finalizer call, ! but we don't get one. call create(test) print "('Before third call to create and explicit deallocate.')" ! test is allocated here, explicit deallocation results in ! finalizer call, as expected. if (allocated(test)) deallocate(test) call create(test) ! Test is allocated here, and gets automatically deallocated ! and finalized as we would expect. print "('Before end of subroutine.')" end subroutine exec subroutine create(test) class(parent), intent(out), allocatable :: test type(extension), allocatable :: ext allocate(ext) call create_arrow(ext%arrow) call move_alloc(ext, test) end subroutine create end program p
>ifort /check:all /warn:all /standard-semantics /traceback "2016-05-01 d2d-finalization.f90" && "2016-05-01 d2d-finaliza tion.exe" Intel(R) Visual Fortran Intel(R) 64 Compiler for applications running on Intel(R) 64, Version 188.8.131.52 Build 20160204 Copyright (C) 1985-2016 Intel Corporation. All rights reserved. Microsoft (R) Incremental Linker Version 14.00.23918.0 Copyright (C) Microsoft Corporation. All rights reserved. "-out:2016-05-01 d2d-finalization.exe" -subsystem:console -incremental:no "2016-05-01 d2d-finalization.obj" Before call to exec Before first call to create. Before second call to create - where's the finalizer? Before third call to create and explicit deallocate. manager_final called with comp of 1 Before end of subroutine. manager_final called with comp of 1 After call to exec