Re: Function move request.

[Luboš Doležel]

On 05/16/2013 08:26 PM, Maxthon Chan wrote:
> Well Apple documented CFRetain and CFRelease as replacements of
> retain/release methods on NSObject which is prohibited with ARC, and
> from an incident I discovered that:
>
> 1) objc_retain and objc_release does exist on Apple's libobjc2, but
> are private API that is not allowed to be used in App Store apps; 2)
> CFRetain and CFRelease calls Apple's objc_retain and objc_release
> internally. 3) By linking to Foundation on OS X, CoreFoundation is
> also included as Foundation is linked to CoreFoundation.

2) Of course. For objects that are not detected to be valid CF objects. 
Such detection would then have to be moved into Base, which doesn't 
sound sane.

> My code have zero intention to use CoreFoundation and it is not
> linked against (at least not by a -framework CoreFoundation), hence I
> will not use CoreBase in the port. This is why I am asking if those
> two functions can be moved.

Linking with Foundation on OS X means linking with CoreFoundation, as 
you noted above in 3). Hence I don't see a problem in making this link 
explicit with GNUstep. After all, you *are* calling CF functions!

> Apple built Foundation on top of CoreFoundation, thanks to Carbon.
> GNUstep started fresh and built Base directly on top of libc (and
> friends), leaving CoreBase out and awkward.

That's not true. Apple's Foundation is not built on top of CF. They are 
intertwined for bridging reasons, but the codebase is separate.

The bridging goes both ways. Meaning:

* CF object:
- C calls are handled by CF
- ObjC calls are handled by CF too

* Foundation object:
- ObjC calls are handhled by Foundation
- C calls are handled by Foundation too

> If you are concerned about CoreBase, try implement it in Objective-C
> and that will make the moved CFRetain and CFRelease useable. Actually
> I think we can safely ditch current CoreBase implementation and start
> fresh implementing it using Objective-C on top of Base, wrapping
> Objective-C methods into C functions.

CoreBase contains features that cannot be nicely implemented on top of 
Base's classes.

The best way forward IMO is for me to complete toll-free bridging and 
contribute that to GNUstep. Hopefully in July/August. There isn't that 
much work left, but I don't have time now.

--
Luboš Doležel