[Bug fortran/40453] [F95] Enhanced (recursive) argument checking

[janus at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=40453

janus at gcc dot gnu.org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
            Summary|Enhanced argument checking: |[F95] Enhanced (recursive)
                   |                            |argument checking

--- Comment #1 from janus at gcc dot gnu.org 2012-10-06 14:39:48 UTC ---
(In reply to comment #0)
> I think some other checks should still be added, e.g.
> 
> a) PUREness check (see example below); passing/assigning
>    a pure to a non-pure dummy/proc-pointer is OK; doing vice versa
>    is not.
> 
> [...]
> 
> b) Similarly for ELEMENTAL. For proc-pointer assignments, use the
>    first example with PURE changed to ELEMENTAL. That non-intrinsic
>    elementals are not allowed as actual argument, is already checked
>    for (cf. C1228). Except of the remark in parentheses I could not
>    find in F2003/F2008 anything which prohibits ELEMENTAL for the
>    dummy argument; however, the parentheses is normative. Maybe one
>    should re-check the standard before adding an error check (see
>    example below).

Both checks for PURE and ELEMENTAL have been implemented in r179080 for
PR41733.


> c) One needs to go recursively over the arguments as the second
>    example below shows.
> 
> [...] 
>
> program RecursiveInterface
>   interface
>     subroutine a(x)
>       real :: x
>     end subroutine a
>     subroutine b(a)
>       integer :: a
>     end subroutine b
>     subroutine c(f)
>       procedure(a) :: f
>     end subroutine c
>     subroutine d(f)
>       procedure(b) :: f
>     end subroutine d
>     subroutine e(f)
>      procedure(c) :: f
>     end subroutine e
>   end interface
>   call e(d) ! Argument (dummy subroutine) d has an integer argument
>             ! but e's f expects a real argument
> end program RecursiveInterface

In fact this is still accepted without error.