[llvm-dev] Should I worry about test failures in a release?

[Renato Golin via llvm-dev]

On 13 October 2015 at 12:56, mats petersson via llvm-dev
<llvm-dev at lists.llvm.org> wrote:
> I've worked on/with
> projects that have very strict rules of compatibility, where changes to ABI
> and API are very difficult to make and everything has to be motivated,
> debated, change-controlled and finally agreed with "customers"

This is more pertinent to low-level *stable* libraries, where
innovation happens elsewhere. :)

In LLVM we worry more about some parts (like the C-API) than others
(like the pass manager), depending on how much *external* code is
likely to change.

But IR compatibility is one of the most public APIs we have and that
changes considerably between releases. AFAIK, there isn't any concern
in keeping it backwards compatible between all 3.x releases. That
surprises a lot of people. :)

Maybe, by 4.x we'll have more stability and new IR features could be a
reason to move to 5.x. But we've been there before, and have chosen
not to do it that way.

cheers,
--renato