[LLVMdev] RFC: Bug fix releases for 3.3 and beyond

[Tom Stellard]

On Wed, Apr 03, 2013 at 05:12:42PM -0400, Sean Silva wrote:
> On Wed, Apr 3, 2013 at 4:09 PM, Tom Stellard <tom at stellard.net> wrote:
> >
> >
> > > How many customers out there are shipping their LLVM-based products
> > > without actually including the LLVM sources?  If they do include the
> > > sources, they may fix the bug locally, especially if they are
> > > capable of investigating what the problem is.
> > >
> >
> > Projects that wants to be distributed as part of a Linux or *BSD
> > distribution really can't ship their own custom version of LLVM
> > with their project.  They need to use the LLVM version that is provided
> > by distributions, so this rules out this kind of solution.
> >
> >
> Your initial proposal seems to be trying to cast a very wide net (affecting
> possible every LLVM developer) in the hope of getting patches needed by
> downstream rolled into stable dot-releases. It may be more appropriate to
> let the needs of the external projects drive the stable branch than for the
> LLVM developers to try to guess what might be good to have on a stable
> branch. i.e. it may be better for the needs of external projects to "pull"
> just the patches they need into a stable branch than for LLVM developers to
> globally try to "push" patches into a stable branch in the hopes that one
> of those patches will be needed by downstream.
> 

I agree with you here.  I think the changes that end up in the stable
branch should be ones that somebody cares about and is willing to put at
least some effort into getting it backported.  This may be developers or
it may be external projects that need a bug-fix, but if a developer
doesn't think backporting a fix is important than they shouldn't be
forced to do it.

> 
> On another level, it seems like what you are asking for is just an easier
> way for downstream projects that run into bugs to get those bugfixes rolled
> into a packaged release in a timely fashion. Is this correct? If so, I'm
> sure it would be possible to set up a fairly simple protocol for getting
> just the code they need into an "official" release.
> 

I'm not quite sure if I follow you here.  How would this help with
bugs that are found after an "official" release.


> You also appear to have suggested pushing new C API changes and possibly
> new target features (!), and in light of this the above statement could be
> extended to "get new C API and target features into a packaged release in a
> timely fashion", which seems awfully close to simply being a way for code
> owners to push new code into "official dot-releases" in circumvention of
> our release schedule. While having such a side-channel may be pragmatically
> useful I can't help but feel that it is a bit hackish and would be better
> addressed by improving the automation of our release process (and the
> infrastructure supporting it) to enable a faster release schedule.
> 

A faster release cycle would help for new features, and I think it
would be great to have a more automated release process, but I think
there would still be value in dot releases.  Mainly for giving users the chance
to stabilize their projects with a stable version of LLVM and know that
if they found an LLVM bug, they would have the opportunity to fix it.

-Tom