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

[Hans Wennborg via cfe-dev]

Breaking this out into a separate thread since it's kind of a separate
issue, and to make sure people see it.

If you have opinions on this, please chime in. I'd like to collect as
many arguments here as possible to make a good decision. The main
contestants are 4.0 and 3.10, and I've seen folks being equally
surprised by both.

Brain-dump so far:

- After LLVM 1.9 came 2.0, and after 2.9 came 3.0; naturally, 4.0
comes after 3.9.

- There are special bitcode stability rules [1] concerning major
version bumps. 2.0 and 3.0 had major IR changes, but since there
aren't any this time, we should go to 3.10.

- The bitcode stability rules allow for breakage with major versions,
but it doesn't require it, so 4.0 is fine.

- But maybe we want to save 4.0 for when we do have a significant IR change?

- We've never had an x.10 version before; maybe that would be
confusing? Perhaps it's simply time to move on (like Linux 2.6.39 ->
3.0 and 3.19 -> 4.0).

- Since we do time-based rather than feature-based releases, the major
version number shouldn't mean anything special anyway (e.g. big IR
changes or not), so 4.0?

- Everyone knows that after 9 comes 10, so 3.10 it is. The version is
a tuple after all.

- Let's go for 4.0 now, and 5.0 after that. Then the "dot"-releases in
between would correspond to minor version bumps, which would make
sense (and catch up with GCC!).

- It's just a number, no big deal; flip a coin or something.

What do you think?

 - Hans


 [1]. http://llvm.org/docs/DeveloperPolicy.html#ir-backwards-compatibility