Optional arguments that are also polymorphic seem to have runtime issues. The following inocuous example:
[fortran]MODULE MyChickenIsARooster
IMPLICIT NONE
TYPE :: Parent
INTEGER :: i
END TYPE Parent
CONTAINS
SUBROUTINE Level1(arg)
CLASS(Parent), INTENT(IN), OPTIONAL :: arg
CALL Level2(ARG=arg)
END SUBROUTINE Level1
SUBROUTINE Level2(arg)
CLASS(Parent), INTENT(IN), OPTIONAL :: arg
IF (PRESENT(arg)) THEN
PRINT *, 'Hello play :)'
ELSE
PRINT *, 'Hello work :('
END IF
END SUBROUTINE Level2
END MODULE MyChickenIsARooster
PROGRAM OptionallyPolymorphic
USE MyChickenIsARooster
IMPLICIT NONE
CALL Level1
END PROGRAM OptionallyPolymorphic
[/fortran] compiles ok, but explodes on execution:
[plain]>ifort /check:all /warn:all /standard-semantics /stand:f03 /traceback /debug optionally_polymorphic.f90
Intel Visual Fortran Compiler XE for applications running on IA-32, Version 12.0.4.196 Build 20110427
Copyright (C) 1985-2011 Intel Corporation. All rights reserved.
Microsoft Incremental Linker Version 9.00.21022.08
Copyright (C) Microsoft Corporation. All rights reserved.
-out:optionally_polymorphic.exe
-debug
-pdb:optionally_polymorphic.pdb
-subsystem:console
-incremental:no
optionally_polymorphic.obj
>optionally_polymorphic
forrtl: severe (157): Program Exception - access violation
Image PC Routine Line Source
optionally_polymo 00401006 _MYCHICKENISAROOS 9 optionally_polymorphic.f90
optionally_polymo 0040113B _MAIN__ 25 optionally_polymorphic.f90
optionally_polymo 004786F3 Unknown Unknown Unknown
optionally_polymo 0044DF0B Unknown Unknown Unknown
kernel32.dll 7C817077 Unknown Unknown Unknown[/plain]
