Re: Importing clang/LLVM into FreeBSD HEAD

On Mon, 31 May 2010 09:52:48 +0200 Roman Divacky <rdivacky_at_freebsd.org>  wrote:
> 
> I would like to propose to integrate clang/LLVM into FreeBSD HEAD
> in the near future (days, not weeks).
> 
> clang/LLVM is a C/C++/ObjC compiler (framework) which aims to possibly
> replace gcc. It is BSDL-like licensed. The sources are ~45MB (the
> svn checkout is 97MB). Clang/LLVM is written in C++.
> 
> Clang can compile all of FreeBSD on i386/amd64 including world and booting
> kernel. Other architectures that are close to working are MIPS, PowerPC
> and ARM. We have a branch (clangbsd-import) that just includes clang/LLVM
> sources and the build infrastructure and this is what we aim to integrate
> at first.
>
> The import of clang/LLVM was discussed at the toolchain summit May 10th
> but I would like to hear your opinion. I got approval from core_at_ on
> importing it.
> 
> So please share your support or resistance to the idea of importing clang.
> 
> Roman Divacky

I already use clang for some things but I think the issue
here is not support/resistance but something else:

* IMHO for a change of this nature the core needs to publish
  a set of clear acceptance criteria for importing clang.
  Can this be done?

* Since clang doesn't support all the archs, what is the plan
  for unsupported archs?
  a. Is FreeBSD going to have both compilers in the base?
  b. Is the project drop these FreeBSD ports? or
  c. Do people have to import gcc from ports to build these
     FreeBSD ports?

* What about ports?

* Basically the core needs to lay out a roadmap.

It is clear that not everyone has the same view of what the
acceptance criteria might be so publishing it would help
people understand what to expect.