Clang: now available from a SVN server near you!
Roman Divacky
rdivacky at FreeBSD.org
Thu Jun 4 12:39:05 UTC 2009
On Thu, Jun 04, 2009 at 02:35:56PM +0200, Erik Cederstrand wrote:
> Den 04/06/2009 kl. 11.38 skrev Ed Schouten:
>
> >You can now build your very own version of FreeBSD with Clang
> >installed
> >as /usr/bin/cc as follows:
>
> Thanks for your hard work, Ed. This is great news!
>
> You might want to mention that a few parts are still GCC-compiled due
> to bugs in Clang ( see http://wiki.freebsd.org/
> BuildingFreeBSDWithClang). Also, it's very encouraging that the ports
> run you did with Erwin
> (http://lists.cs.uiuc.edu/pipermail/cfe-dev/2009-June/005274.html )
> compiles over 7000 ports with Clang.
>
> I've asked in the Clang list, but I'd like an opinion from FreeBSD
> folks, too: Clang supports LTO
> (http://llvm.org/docs/LinkTimeOptimization.html ), which has a potential
> for performance improvements. It doesn't work on FreeBSD because the
> linker we have (in binutils) doesn't know about the libLTO that LLVM
> provides. There's a new linker from GNU called Gold, but as far as I know
> it's GPLv3 licensed and therefore undesirable at least to have in base.
> LLVM provides a linker (http://llvm.org/cmds/llvm-ld.html ) but "it doesn't
> interact correctly with conventional nm/ar/etc"
> (http://lists.cs.uiuc.edu/pipermail/cfe-dev/2009-June/005296.html ).
> There's the ELF toolchain project (elftoolchain.sourceforge.net/) but a
> BSD-licensed ld hasn't been developed yet.
>
> What would be the best way to get LTO to work on FreeBSD?
you could use llvm-ld (see the wiki for instructions how to do it). there's also some
effort to make gnu ld usable with llvm LTO and I guess the patch could be backported
to our ld. I guess
More information about the freebsd-current
mailing list