Trying to use clang/head and XCC

[Garrett Cooper]

> On May 19, 2015, at 09:53, Brooks Davis <brooks at freebsd.org> wrote:
> 
>> On Tue, May 19, 2015 at 09:23:42AM -0700, Sean Bruno wrote:
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>> 
>> Following the External Tool Chain instructions on the wiki seem to not
>> work:
>> https://wiki.freebsd.org/ExternalToolchain
>> 
>> I've gotten about this far:
>> https://people.freebsd.org/~sbruno/clang_head_build_log.txt
> 
> You need to delete
> /home/sbruno/bsd/clang/build/bin/../lib/clang/3.7.0/include/std* and
> possibly also limits.h (it's broken for libstand on mips).  If you use
> the ports/pkgs they do this.
> 
>> Two items of note.
>> -- The bootstrap bits *completely* ignore XCC and build with the host
>> cc/c++
> 
> That's expected.  In principle clang could be used as the cross compiler
> since it's multi-target, but gcc could never work unless the host and
> target are the same.
> 
>> -- No documentation of what CFLAGS are required to build and ignore
>> warnings.
> 
> It will change with every clang/gcc release.  In practice you will need
> to either fix the warnings wack-a-mole style or set NO_WERROR in the
> environment.
> 
> -- Brooks
> 
>> 
>> Anyone out there have success doing this?

It'd be really nice if FreeBSD had HOST_CC, etc or something like that. It's unfortunate that I can't build 10.x on hosts with clang 3.6 installed because it fails to make bootstrap-tools (which needs to be built with the host compiler) because of -Werror ;(...

Thanks,
-NGie