(j3.2006) C1296 in 14-007r1 (concerning pure subprograms), and 16.6.7p1(12)

[Malcolm Cohen]

>Item (6) in C1296 is
>
> (6) as an actual argument corresponding to a dummy argument with
>     INTENT(OUT) or INTENT(INOUT) or with the POINTER attribute.
>
>16.6.7p1(12) is
>
> (12) as an actual argument corresponding to a dummy argument with
>      INTENT(OUT) or INTENT (INOUT),
>
>Should 16.6.7p1(12) include "or with the POINTER attribute"

No.  C1296 is doing something noticably stronger than 16.6.7 (obviously since 
applying 16.6.7 is only one of its effects).

> or maybe "or
>with the POINTER attribute if the actual argument is not a pointer"?

No.  This (ptr dummy nonptr actual) is effectively the same as unspecified 
intent, which deliberately does not appear in 16.6.7.

>Item (4) in C1296 uses "pointer component at any level of component
>selection".  Item (5) uses "has an ultimate pointer component".  Should
>these be the same?

Yes.  Item (4) has the correct formulation.  This only affects pointer 
components within an allocatable component.

>C1296 needs an additional item:
>
>  (7) as the actual argument to the function C_LOC from the intrinsic
>      module ISO_C_BINDING

Already prohibited since C_LOC is not pure.

(Note: What's gone wrong here is the bogus assertion in F2008 that C_PTR does 
not contain a pointer component.  But since C_PTR in fact effectively does have 
a pointer component, that means that to prevent pointer violations of the purity 
rules we have to continue to forbid C_LOC et al.  Or fix the bogus assertion.)

>We maybe need a paragraph (can't be a constraint) that prohibits
>invoking the C_F_POINTER subroutine if the value of the CPTR argument is
>the C address of an object specified in the introductory paragraph of
>C1296.

Already prohibited since C_F_POINTER is not pure.

>Should pointer association context (16.6.8) be in the list in C1296, or
>is it OK to change the pointer association status of a host associated
>pointer in a pure subprogram?

No (16.6.7 is a proper superset of 16.6.8) and No it would not be ok (but is 
already prohibited).

Cheers,
-- 
................................Malcolm Cohen, Nihon NAG, Tokyo.