Re: Re: [Xen-changelog] [xen-unstable] tools: Rationalise library soname versions.

["Daniel P. Berrange" <berrange@redhat.com>]

On Mon, Dec 10, 2007 at 09:59:46AM +0000, Ian Jackson wrote:
> Daniel P. Berrange writes ("Re: [Xen-devel] Re: [Xen-changelog] [xen-unstable] tools: Rationalise library soname versions."):
> > IMHO, the entire rationale of setting all the sonames in one place is just
> > plain wrong. Libraries evolve independantly and thus their sonames change
> > independantly. Tieing sonames to the software release version number does
> > not reflect the reality of their ABI evolution. sonames should only be
> > changed when an existing API changes in a non-backwards compatible manner
> > so its perfectly normal for an soname to stay the same across multiple
> > releases if nothing changes, or merely new APIs are added without changing
> > existing APIs.
> 
> In principle I agree with you.  However, in practice the project has
> not been able to maintain the discipline needed to bump a soname when
> the ABI changes.  Until this change, all of the libraries in
> xen-unstable were claiming ABI-compatibility with 3.0 which was
> definitely not correct.  Bumping the version numbers at release time
> is at least something we can probably manage to do reliably.
> 
> This is perhaps slightly inconvenient but since the dom0 toolstack and
> hypervisor generally don't maintain good binary compatibility across
> releases anyway I don't think there's that much lost.  Do you
> disagree ?

I am fine with libxc.so having its soname change each release, since the
libxc ABI does change all the time. There is no need to force the soname
to match the software release version - they may happen to coincide, but
there's no need to force it if there weren't changes - that said I expect
libxc.so will continue to change every release. libxenstore and libfsimage
have actually been stable & thus don't need to change artificially. 

Regards,
Dan.
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