[llvm-dev] What version comes after 3.9? (Was: [3.9 Release] Release plan and call for testers)

[Renato Golin via llvm-dev]

On 21 June 2016 at 07:38, Chandler Carruth via llvm-dev
<llvm-dev at lists.llvm.org> wrote:
> However, I think it is a really big mistake to *have* a major version and
> just increment it arbitrarily without any associated "major" change. Lacking
> us explaining what we consider to be a major release, people will make
> assumptions that will inevitably lead to missed expectations.

Precisely.


> I personally don't have strong feelings about whether we should or shouldn't
> have a major/minor split. I see arguments on both sides. But I really do not
> want us to have a *meaningless* split.

That is how I feel too. But I think we need to take am informed
decision before July (ie. not continue the status quo).

Continuing (3.9 -> 4.0) is ok for some of us because we've seen 1.9 ->
2.0 and 2.9 -> 3.0, but it's not logical to most people out there,
including many in our community today.

Moving to an OSS-friendly can be very helpful, but not without a good
rule on what's "major". Not having a rule is also *not* a reason to
continue the status quo.

I agree we don't need hard rules, and we can always argue for months
if the next one will be major or not, but I'd rather spend my time
elsewhere.

So, things that *could* influence a major change:

 * IR backwards compatibility: this one is obvious
 * Major internal refactoring: new pass manager, new selection dag,
(ex. when the MC layer was introduced)
 * Major new language support: c++17, openMP complete, etc.
 * DCE: When we delete whole back-ends (which obviously will be
backwards incompatible)

But in the end, it boils down to someone asking to up the number, and
a month long thread to agree or disagree, which is ok.

All in all, we need reasons to either side we pick.

cheers,
--renato