Re: GCC suport for Objective-C [Was: NSSound Reimplementation]

[David Chisnall]

Hi Fred,

On 18 Jul 2009, at 19:23, Fred Kiefer wrote:

> your mail got me thinking, I wont switch to Clang and I don't hope
> GNUstep as a project will. So the only option forward is to start
> working on better Objective-C support in gcc. I surely wont have time
> for this beside my maintainer task on GNUstep, but this seems  
> currently
> the more important task. I will have a look at the code in gcc that
> supports Objective-C and if I am able to make any sense of it, I might
> switch over to work on that.

That would be great.  It's not a task for the faint hearted though.   
You can find all of the GCC Objective-C code in this file:

http://gcc.gnu.org/viewcvs/trunk/gcc/objc/objc-act.c?revision=149722&view=markup

There seem to be two functions in this file related to ivar access /  
assignment, so it ought to be relatively easy for anyone familiar with  
GCC internals to add non-fragile ivar support.  You also need to  
modify the ivar structure initialiser to contain negative values for  
the offsets (this is the hint I give to the runtime to indicate that  
this compilation unit provides support for non-fragile ivars and needs  
the offsets updated accordingly).

David