Re: Basic questions about Gorm

[David Chisnall]

On 8 Apr 2011, at 22:24, Ivan Vučica wrote:

> Problem is in the compiler. I think GCC 4.6 introduced Objective-C 2.0 
> features. You can try using clang compiler, and you'd probably need to switch 
> to libobjc2 runtime; I did not, but your mileage may vary. If you're under 
> Debian (which, although it contains a deceptively named package "libobjc2", 
> does not include the actual "libobjc2") I have a small blog post about this:


Not quite.  GNUstep-base includes a compatibility framework that implements 
most of this stuff on top of the old GCC Objective-C runtime.  All of the 
property-related stuff should work.  The additional things you get from 
libobjc2 are:

- Property introspection (I think - clang emits this data for both ABIs, so we 
can probably add this if it's missing)

- Unique protocols (two protocols returned by @protocol() may give different 
sets of methods - this requires a little bit of help from the compiler, not 
sure if GCC 4.6 does it)

- Cacheable method lookup (requires support from your compiler's optimiser to 
be really useful - currently only implemented as LLVM optimisation passes, so 
only useable with clang and LanguageKit)

- Accelerated proxies (-forwardingTargetForSelector: is very cheap)

- Non-fragile ivars (requires a compiler that supports the new ABI, currently 
only clang)

- Type-checked method lookup (calls a handler when you call a method with the 
wrong signature, by default just logs a message in debug mode or does nothing 
in release mode, can throw an exception or generate a fixup method).

David

-- Sent from my Cray X1