Re: Procedure Pointers: a first patch

[Tobias Burnus <burnus at net-b dot de>]

Hi Janus,

Janus Weil wrote:
> the attached update of the patch should handle NULL and ASSOCIATED now
>   
Well, NULL() still does not work. As an example counts more than 
thousand descriptions, here comes one which works with g95 and ifort 
11beta but fails with gfortran. The problem is that the line

 void (*<T5f>) (void) x;

should be

 static void (*<T5f>) (void) x = 0B;

program main
implicit none
call test(.true.)
call test(.false.)

contains
integer function hello()
 print *, 'Hello'
 hello = 42
end function hello
subroutine test(first)
 logical :: first
 integer :: i
 procedure(), pointer :: x => null()

 if(first) then
   if(associated(x)) call abort()
   x => hello
 else
   if(.not. associated(x)) call abort()
   i = hello()
   if(i /= 42) call abort()
 end if
 end subroutine test
end program main


> > subroutine s_out(p)
> >  PROCEDURE(REAL),POINTER,INTENT(OUT) :: p
> >  intrinsic abs
> >  p => abs
> > end subroutine
> >     
> The error message has been cured, but it still produces a segfault at
> runtime (see proc_ptr_5.f90)
>   
Well, the problem is that the procedure pointer is passed as value and 
not as reference.
See  http://gcc.gnu.org/ml/fortran/2008-05/msg00299.html


I think the patch can be committed after:
- NULL() is fixed
- Procedure pointers are passed by reference

Working procedure-pointer-returning functions were nice, but I think 
they can be deferred to a follow up patch. The same is true for the 
other smaller bugs.

Tobias