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

[Renato Golin via llvm-dev]

On 13 October 2015 at 13:45, Kuperstein, Michael M via llvm-dev
<llvm-dev at lists.llvm.org> wrote:
> As far as I know, the consensus was that all 3.x versions should retain
> backward compatibility for bitcode.

Emphasis on "should". :)

I don't think we have enough tests to make sure we don't break that
promise, precisely because it's important, but not crucial.


> So, 3.7 should be able to consume bitcode (but not text IR) produced by any
> earlier 3.x. When 4.0 rolls around, all bets are off.

And not the other way around, either.


> Note that “consume” here is a not as strong a guarantee as it may sound,
> since metadata may be stripped off. Debug metadata almost certainly will be.

Yup.

--renato