Re: calling an ada procedure from C++

[Ludovic Brenta <ludovic.brenta@insalien.org>]

I think some compilers will also return small structures in processor
registers.  They will neither use the stack not any static memory, if
they can help it.

The basic point remains: how each compiler passes structures between
efunctions is compiler-specific.  It is however possible, both in C
and in Ada, to specify the exact bit pattern for a stucture, and thus
to pass the structure back and forth.  I think the most portable way
would be to pass pointers to the structures (as earlier suggested) but
if the OT uses GNAT (where the compiler handles both C and Ada), there
may be more efficient ways using representation clauses and Pragma
Convention.

BTW, C++ is a different beast altogether.  I would avoid it if
possible, especially if the C++ struct is really a class with methods
and parents or descendants.  Better stick with a strictly C struct.

My 2 cents.

-- 
Ludovic Brenta.