Re: [cfe-dev] LLVM / Clang 3.0 rc1 Binaries Available

[David Chisnall]

On 21 Oct 2011, at 17:40, Ivan Vučica wrote:

> Just a tiny question: Apple has already shipped "Apple LLVM Compiler 3.0" or 
> something like that in Xcode 4.2. (I have not upgraded yet on my current 
> machine, so I cannot check the exact naming).
> 
> I suppose that Clang shipped by Apple is actually a prerelease as well?

Yup.  Apple periodically branches LLVM releases for Darwin independently of the 
official LLVM release cycle, because LLVM releases don't often coincide with 
XCode / OS X / iOS releases.  You can check this with a Mac:

$ clang -v
Apple clang version 2.1 (tags/Apple/clang-163.7.1) (based on LLVM 3.0svn)
Target: x86_64-apple-darwin11.2.0

'Apple's LLVM Compiler 3.0' is a trunk snapshot (with some bug fixes back 
ported) of Everyone Else's LLVM Compiler sometime between 2.9 and 3.0.  
Basically, they wanted to ship a version with ARC support immediately after the 
WWDC presentation, but there wasn't a release ready, so they shipped a trunk 
version.  They may do a small update for XCode that upgrades LLVM / Clang to 
the real release, or they may not.

Apparently they do periodic snapshots for internal use (every 2 months, I 
think), which then go through some extra testing, and then get used by Apple 
once any regressions have been fixed - I'm not sure how these correspond to 
their public releases either.

David

-- Sent from my brain