To: J3                                                     10-192r1
From: Bill Long
Subject: Macros in C Interop
Date: 2010 June 17
References: 10-165r1, N1820

Discussion:

The Macros specifying codes for the attribute field of the C
descriptor were never integrated with the addition of assumed-rank
objects. The current Table 5.1 lists macros for "assumed",
"allocatable", and "pointer". For an assumed-rank object that is also
allocatable the caller should use the allocatable code, and one that
is a pointer the caller should use the pointer code. If the
assumed-rank object is neither allocatable nor pointer, the "assumed"
code should be used.  From the C function's point of view, there is no
material difference between an assumed-shape array and an assumed-rank
non-allocatable, non-pointer array. The only new feature for
assumed-rank is that it can be a scalar. Edits are provided to update
Table 5.1 and add an explanation.

Edits to 10-165r1

[10:24+] In Table 5.1, replace "assumed-shape array" with "assumed", and
         remove "object" after "allocatable".

[10:25-] After Table 5.1, add a new paragraph:

"CFI_attribute_pointer specifies an object with the Fortran POINTER
attribute. CFI_attribute_allocatable specifies an object with the
Fortran ALLOCATABLE attribute. CFI_attribute_assumed specifies an
assumed-shape object or an assumed-rank object that is not allocatable
or a pointer."