Re: Can Ada95 interface with C++?

[John Cosby <John.D.Cosby@cpmx.saic.com>]

Robert Dewar wrote:
> 
> Ara says
> 
> "2)  Exceptions cannot propagate across language boundarie"
> 
> In general your comments are confused between implementation and language
> requirements. If your statement referred to some particular compiler
> this might be correct, but as a general statement about Ada 95 and
> C++ interfacing it is wrong.

Perhaps it should be rephrased as "Exceptions usually do not propogate
across language boundaries."  Is there a pair of compilers out there
that
allow exception propogation between Ada95 and C++?  Such has not been my
experience, and I've been looking.

> There is absolutely no reason why exceptions should not propagate across
> language boundiares. GNAT does not currently imlplement this in any
> automatic manner, but certainly it is our plan to do so as part of
> installing the new genral exception scheme.

Well, if even GNAT doesn't do it with gcc/g++, how can one expect
compiler
vendors operating from different code bases to do this?  Even the
definition
of exceptions is being debated in another thread in this group.  How can
we
expect different corporations to come up with an interoperable set of 
exception propogation rules when there's not even a standard way of
making
Ada95 and C++ interface?  Once you decide how to do it for standard
exceptions (Is there a standard set of C++ exceptions?  My reference
doesn't
have any - just base types and the ubiquitous (...)), how will you 
propogate user-defined exceptions?  It's not a small challenge.

Not that I'd mind having the capability, mind you... I'm getting tired
of debugging "glue" code core dumps that happened when my Ada runtime
couldn't
handle the C++ exception in the routines the Ada calls.

John
-- 
John Cosby                    SAIC Orlando               
John.D.Cosby@cpmx.saic.com    (407) 282-6700 x216