[GiNaC-devel] Versioning, SONAME versus file name, and all that.

[Alexei Sheplyakov]

Hi,

On Sun, May 22, 2011 at 03:19:17PM +0200, Jens Vollinga wrote:

> >objdump -p libginac.so | grep SONAME
> 
> and the answer is:
> 
>   SONAME               libginac.so.0
> 
> 
> Looks good? Is it different at your box?

It's the same on my box. But it's not exactly OK.
 
> >>More importantly, why does lexicographic ordering matter?!?
> >
> >Because humans and (package management) software expect SONAMEs
> >(and version numbers) to be increasing.
> 
> Eh? I don't understand, yet. Human expectations aside, why does
> package management rely on lexicographical ordering?

Because it's simple and straightforward. `libginac2 is newer than libginac1.5'
is quite clear, and `libginac0 is newer than libginac1.5' is a bit confusing.
 
> What I plan to do is to go from libginac-1.5.so to libginac.so.

Correct. We want to change the library *file* name from libginac-1.5.so
to libginac.so. Also we want to change the library SONAME from libginac-1.5.so.0
to libginac.so.2 (actually any integer bigger than 1.5 is OK).

> So, is this the actual dissent: you/richy want still a number in
> the name (which better is increasing)?

We don't want to encode the ABI version into the file name. But there *must*
be a version number in the SONAME. Otherwise distro people are going to hit us
with a huge cluestick. And that version should be updated (preferably increased)
whenever we introduce a binary incompatible change. To do so it's enough to
update ginac_lt_current, ginac_lt_age, and ginac_lt_revision in configure.ac
according to the instructions listed in the same file (actually, those
instructions have been shamelessly copied from the libtool manual).

Hope this helps,
	Alexei