Re: LLVM

[Graham J Lee]

On 29 Feb 2008, at 15:51, Nicola Pero wrote:

> I mean, IIRC we got our current Objective-C compiler from NeXT  
> *because* of the GNU GPL.
> If GCC had had a license like the LLVM one, we might not even have  
> a free Objective-C compiler
> available! :-)

That's correct - see "Copyleft: Pragmatic Idealism" by RMS: http:// 
www.gnu.org/philosophy/pragmatic.html

> I understand why Apple wants that kind of license - so that they  
> get our improvements to the compiler,
> but we don't get theirs.  They have no requirement to give anything  
> back to us. :-(
>
> GCC's license is much better for us - and much worse for Apple - if  
> you contribute to GCC, Apple
> can take your improvements for free (ie, they use them in the  
> compiler they ship on their computers),
> but then at least they have to give back *their* improvements for  
> free, because of the GNU GPL (well, there
> might be work required to merge back the improvements into mainline  
> GCC trunk, but you definitely
> get to see them, and you get a GPL license to use them).  That  
> seems fair to me ;-)
>
> With the LLVM license, we might never see any of the Apple code/ 
> improvements.

I agree with all of that - remembering of course we have little to no  
influence over what Apple do, so if they decide to go with a  
differently-licenced compiler/runtime we'll never see their  
improvements anyway, and they're the only people really driving new  
features into the language or runtime :-(  Especially their new 64- 
bit runtime.  Consider also:

* the NeXT and Apple64 runtimes aren't really ported to anywhere  
except NeXT and Apple platforms, so practically the advantages they  
offer aren't available except on those proprietary platforms; and
* the GNU runtime isn't really compatible with the above two  
runtimes, so the new Apple features aren't readily available even by  
pasting them into the GNU runtime (and hence aren't available on  
other platforms by this route, either)

I'm not really going anywhere with this :-), just pointing out that  
practically the Free Software advantages of the NeXT/Apple ObjC  
runtime aren't providing any benefits to users on Free Software  
platforms at the moment.

> From a technical standpoint, I'd love to see a free software  
> alternative to GCC to compile Objective-C,
> but this is not a convincing alternative - the license seems  
> designed to abuse contributors.

Given a finite amount of developer time, and the choice between yet  
another ObjC compiler or better ObjC support in GCC, I'd choose the  
latter :-).

Thanks,
Graham.