[llvm-dev] [cfe-dev] [3.9 Release] Release plan and call for testers

[David Chisnall via llvm-dev]

On 13 Jun 2016, at 14:14, Rafael Espíndola via cfe-dev <cfe-dev at lists.llvm.org> wrote:
> 
>> The 4.1 release gives us the opportunity to drop support for 3.x
>> bitcode formats, so  I don't think we should move to 4.x until we have
>> older bitcode features that we really want to drop.  There should
>> probably be a separate discussion thread about this.
> 
> It give the opportunity, not the obligation. Given that I think it is
> an independent issue and would suggest we just keep the revisions
> simple and switch trunk to 4.0.

I don’t think that this makes it simple for anyone.  Existing packaging tools understand dot notation and know that 3.10 > 3.9, even if interpreting the dot as a decimal point would mean that it didn’t.  Without this kind of special handling, they’d be very confused by 3.4.1, which isn’t even a valid number.

LLVM minor revisions break ABI and API compatibility and bugfix revisions don’t.  There is an expectation that major revisions will break the bitcode format, so releasing a 4.0 version but saying ‘this one doesn’t actually break it’ will be confusing.  Particularly if we then release a 5.0 that does, after a 4.5 that doesn’t.

That said, in general I’d prefer if we used semantic versioning and stopped releasing major versions with a bump of the minor version number.

David