ISO/IEC JTC1/SC22/WG5 N1406

                                  EXTERNAL

                               Keith Bierman

During the WG5 meeting in Oulu, it was brought up that any procedure
whose definition is "EXTERNAL" might have to be treated as if it were
coded by means other than Fortran.

In the context of the IEEE TR, for example, as a result, a processor
would have be conservative and do a "get_ieee_flag" prior to the call
of an external procedure, and follow it with an automatic
"set_ieee_flag" (either by generated code, or collusion with  the
system/other language processor). In the alternative, we would have to
change the fundamental model of the IEEE TR with respect to "safety"
and "ease of use".

It seems to the interop subgroup, that we can and should exploit the
BIND attribute to make a distinction that was hitherto impossible.
Procedures defined by any syntax, EXTERNAL or otherwise, will be
defined as following the rules required of a Fortran processor.  Only
procedures with the BIND attribute would be free to ignore the
constraints of Fortran. Thus, in the context of IEEE operations, only
in BIND cases, must the Fortran processor (or the user, depending on
how the issue raised in the first straw vote of O2 is finally resolved
) perform these defensive IEEE operations.

In addition to the IEEE section, subgroup believes that this is likely
to simplify some questions in the area of interoperability (questions
regarding setjmp safety, etc.).

This is a change from previous Fortran standards, but it would seem to
us to be a harmless change (no existing program's semantics change in
the Standard sense, because programs which are currently calling
procedures coded by means other than Fortran do not have precisely
specified semantics now).

This paper passed by unanimous consent.