[PATCH] Enable C++11

[David Fang]

Hi Chandler,

>> I've actually created a powerpc-darwin8-rel-3.4 branch that tracks
>> 'release_34', and tried to backport some of the fixes that missed the 3.4
>
> Cool, it sounds like these should definitely be back-ported without issue
> and unblock you. That would then allow you to use Clang as a baseline for
> subsequent builds.

>> Depending on how far trunk has diverged from the 3.4 brach, we *may* be 
>> able to backport those fixes as well.  I will certainly make an effort.
>
> Similarly, once you have a working host by backporting these, you should be
> fine to use C++11 features no?

The other remaining major hurdles include fixing the powerpc-darwin ABI 
(Iain and I are testing his data-layout/alignment patches), fixing FDE 
generation for EH-frames (patch approved and commit pending), and getting 
a working libc++ on powerpc-darwin to support C++11.  libc++ built against 
system's libsupc++ at -O0 with a stage-1 clang still exhibits many fatal 
errors, a subject for another thread.  Another wish is to fix issues that 
block compiling with -O1 (e.g. bug 14579).  Compiling stage-3 at -O0 on my 
old h/w takes 3 days, painfully slow for debug/test turn-around.  That 
summarizes our current priorities.

> I'd really like to not hold up this switch too much waiting on this, as it
> has been a really long time coming, and it seems unlikely that there will
> be anything better than backporting some fixes to 3.4 and using that as the
> baseline for a modern host compiler.

I understand, the train can't wait for everyone.  I want to use C++11 as 
much as others.

Was there a consensus about what C++11 features would be 
allowed/encouraged in the llvm/clang code base?  perhaps part of a C++ 
style-guide?

David

-- 
David Fang
http://www.csl.cornell.edu/~fang/