Re: How does the GC support work?

[Lloyd Dupont]

So if my understanding of what you said is correct only libobjc must be 
recompiled with Boehm GC to have a Garbage Collected GNUstep app, right?
And retain/release will do nothing, wether or not I recompiled gnustep-base 
with GC?

I suppose I should use the library in dev-libs/libobjc?
And, perhaps, I just have to "make gc=yes" to have it compiled with GC, is 
that right?

Thanks for any tip!

Regards,
Lloyd Dupont

NovaMind development team
NovaMind Software
Mind Mapping Software
<www.nova-mind.com>
----- Original Message ----- 
From: "Richard Frith-Macdonald" <richard@tiptree.demon.co.uk>
To: "Lloyd Dupont" <lloyd@nova-mind.com>
Cc: "GNUstep Discussion" <discuss-gnustep@gnu.org>
Sent: Thursday, June 08, 2006 7:44 PM
Subject: Re: How does the GC support work?


> On 8 Jun 2006, at 10:12, Lloyd Dupont wrote:
>
> > I'm thinking of building GNUstep with GC.
> > Does it works?
>
> Probably not well ... I think it's been years since anyone used  it ... of 
> course someone may know different, but if anyone had been  actively using 
> it I would have hoped they would have provided patches  with bugfixes and 
> nobody has.
>
> > How does that work? I need to know a bit about the internal as I'm  using 
> > GNUstep through a managed C++ wrapper and wonder how this  will work...
>
> That's an easier question ... it uses the boehm garbage collection 
> library.  You want to build gcc (well libobjc anyway) with GC support  and 
> link with that library.
>
> Building the base library with GC enabled will turn off retain/ 
> release/autorelease and also make the RETAIN/RELEASE/AUTORELEASE  macros 
> empty so that all the memory management stuff is removed from  your code.
>
> When an object of a class which implements -gcFinalize is allocated,  that 
> instance is registered with the garbage collection library to  have the 
> method called when the object gets freed by the garbage  collector.  That 
> allows objects to handle the sort of cleanup they  would normally do when 
> dealloc is called (since dealloc is not called  in a garbage collecting 
> system).  Most implementations of -dealloc  just release objects/memory in 
> ivars ... and the garbage collector  will handle that anyway so classes 
> with simple dealloc  implementations like that do not need to have a 
> finalizer.