Migration to dynamic libs for llvm and clang

[Ed Maste]

On 16 December 2014 at 11:15, David Chisnall <theraven at freebsd.org> wrote:
>
> Upstream doesn't call it libclang (that's the name of the library with a stable C ABI, which is why I'd like us not to confuse it with something with a library with an unstable C++ API). They do produce a libLLVM.so from the LLVM builds and work is underway to have shared library builds for clang.

Agreed. Even if there's no potential issue since it will be in
/usr/lib/private it would be confusing. David's suggestion of libcfe
sounds reasonable.

>> That said, I agree with the general idea, but one of the first things
>> we should decide is whether this will be optional or not.  Having to
>> maintain yet another WITH_CLANG_FOO option is burdensome...

Fair enough, I'd definitely like to see fewer build-time knobs over
time, not more.

> I agree.  I'd quite like to see performance numbers for the compiler.  I think I saw about a 10% overhead for buildworld last time I tried, but that was a couple of years ago.

Ok. I will put this together in a branch and we can compare results
and decide which way to go when we have actual numbers.