On Thu, Sep 24, 2015 at 6:04 PM, Dave Johansen <davejohansen(a)gmail.com> wrote:
On Mon, Sep 21, 2015 at 6:27 AM, Adam Jackson <ajax(a)redhat.com>
wrote:
>
> On Sun, 2015-09-20 at 21:00 +0800, Christopher Meng wrote:
> > On 9/20/15, David Airlie <airlied(a)redhat.com> wrote:
> > > It's llvm, there is never a good time to upgrade it and no llvm
> > > release is
> > > backwards compatible.
> >
> > Yes, so unless someone is pretty familiar with LLVM upstream, keep
> > reading every changeset, no body can guarantee what will happen.
>
> That's not really a fair assessment. By far the most important thing
> in Fedora that needs llvm is Mesa. The llvm build system has a fairly
> comprehensive test suite (which, btw, fails on at least arm with 3.6.1,
> but passes on all arches with 3.7), and Mesa has another test suite in
> the form of piglit that we can use to ensure that changing llvm doesn't
> regress llvmpipe or r600 or radeonsi.
>
> So we can in fact be pretty confident that llvm upgrades won't break
> the things we actually use llvm for in Fedora.
It sounds like there's a lot of momentum behind the update to 3.7 for F23,
but iwyu (
https://github.com/include-what-you-use/include-what-you-use ) is
built on top of clang and there's still not an upstream release that's
compatible with 3.7 so updating in F23 will break iwyu until a release is
made. So, I personally would prefer that the update to 3.7 only happen in
Rawhide where breakage like this is expected, but I realize that I'm only
one voice of many and that iwyu is used a LOT less than other packages like
Mesa.