Re: State of Swarm on Mac OS X

[W . Northcott]

> > Apple say they have done a lot of work on 1..

> This seems to be the compiler flag for the runtime.

I am sorry but I don't understand that comment.

> >> The same is valid for me. So that's perhaps the reason, why I don't
> >> see
> >> yet, why the different message dispatching call is such a huge
> >> problem.
> >> This function should only be called in one object like (Cocoas)
> >> NSInvocation.
> >
> > If this object is compiled with the Next runtime flag (to communicate
> > with
> > Cocoa objects), it would not be possible to invoke its methods from a
> > Swarm library compiled with the GNU runtime flag.

> Of course, but  just compile everything with the same runtime flag.

I will say again - this will NOT work.  The C call to pass a message to an 
object via the Next/Apple library is a different function from that used 
by the GNU library.  If you compile a program with the -fgnu-runtime flag 
it is simply impossible for that code to call a Cocoa object, because it 
would be using the wrong 'language'.  Conversely, if you compile with the 
-fnext-runtime, then the code cannot access a Swarm object.

Scott Christley explained this clearly.

> >
> > That sounds to me like what I would call glue

> Well, you can call it as you wnat of course. But in OpenStep/MOSX, we
> have methods in NSObject (performSelector, superclass, poseAs,...) and
> in separate objects like NSInvocation. Those are all calls to the
> runtime system, but by making it part of an object, you have it just in
> one place.

Every call to an object method is a call to the runtime system. That IS 
the problem.  You cannot quarantine them in one object.

What is needed is a C library.  The object implementation in the Swarm 
code could invoke an NSObject method by making a C call to this library 
that then makes a C call into the Apple runtime.  It has to be done in a 
pure C program so that the compiler generates no Objective-C runtime calls 
when it is compiled.

It would be similar to the avcall/mframe stuff in Swarm.

> Well if this phased creation and destruction of objects could be solved
> in OpenStep, it's automatically also solvable in Gnustep. Because on
> MOSX I don't even have the sources. But I have to have a closer look.

This problem is administrative not technical.  You would need to pursuade 
the GNUstep maintainers to include it in the source tree.

Regards
Bill Northcott

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