Please test libobjc2

[David Chisnall]

Hello everyone,

I'd like to do a release of the GNUstep Objective-C runtime soon, so please can 
everyone test the current trunk.  This adds, among other things, support for 
Apple-compatible garbage collection and the core support for automatic 
reference counting.

The ARC support is compatible with OS X 10.6.  OS X 10.7 and iOS 5 add support 
for zeroing weak references in ARC mode, which I will add soon, but possibly 
after the next release, as they require some support from Foundation to work 
correctly.

You will need Boehm GC 7 (I think, maybe 7.1) or greater to enable GC mode.  If 
you do not have this, then you must build with:

[g]make boehm_gc=no

I've tested GC mode building everything with -fobjc-gc-only.  The GC-optional 
mode for frameworks should work if -base is built with -fobjc-gc or 
-fobjc-gc-only and the frameworks are built with -fobjc-gc.

You can't build GNUstep with -fobjc-arc and some parts of Foundation can not be 
implemented in ARC mode.  For other code, you can try ARC by simply omitting 
-retain, -release, and -autorelease calls.  

Clang includes a migration tool that allows you to switch your code over to 
using automatic reference counting.  You can first add -ccc-arrmt-check to your 
OBJCFLAGS to see if there are any migration issues in your code that need to be 
manually fixed.  Then, after fixing them if you add -ccc-arrmt-modify, clang 
will rewrite your code to use automatic reference counting.  Automatic 
reference counting is now the default development style in XCode.  It's 
important to test this with GNUstep, as code coming from OS X is increasingly 
going to be using this mode.

David

-- Send from my Jacquard Loom