Re: Ada/Motif problem...

[kilgallen@eisner.decus.org (Larry Kilgallen)]

 Dale Stanbrough wrote:
> 
> Larry Kilgallen writes:
> 
> "Understanding that you have asked us how to lie to an Ada compiler...
> 
> > Any inspiration on how to pass Ada strings as callback data in Motif?
> 
> Depending on compiler specifics, you may be able to get away with
> an access to a single character (the first in the string).
> 
> Larry Kilgallen"
> 
> But that doesn't really help at the other end, that is the routine that
> gets called and gets passed a pointer to a character. It may know that
> it points to the first character of a string, but how should it know how
> long the string is? We lose the bounds of the string if we do this.

In my experience calling DECwindows from Ada, it wanted a lot of
null-terminated strings.  Thus the called subsystem, being written
in C, cannot tell the difference between a pointer to null-terminated
string and a pointer to the first character thereof.