Upstream .so name versioning?

[robert-scheck]

(Basically the same as at creytiv/re#249, but it seems that this is the new home of re)

As of writing, there doesn't seem to be proper upstream .so name versioning in re. Yes, I'm aware there is something like LIB_SUFFIX=.so.0, but this unfortunately has nothing to do with proper .so name versioning, as the SONAME is still libre.so rather libre.so.0. Yes, even this can be worked around by passing some arguments like SH_LFLAGS="-shared -Wl,-soname,libre.so.0", but this still doesn't let downstreams know whether the old and the new version are ABI compatible or not, thus this should be IMHO really handled by upstream.

Quoting from section "SONAME handling" from https://docs.fedoraproject.org/en-US/packaging-guidelines/#_downstream_so_name_versioning:

The SONAME field is written to the shared object by linker, using (at least in case of ld) the -soname SONAME flags. This can be passed as an option to gcc like this:

$ gcc $CFLAGS -Wl,-soname,libfoo.so.0.n -o libfoo.so.0.n

If you want to check if the SONAME field is set and what value it has, use the objdump command (from binutils):

$ objdump -p /path/to/libfoo.so.0.n | grep 'SONAME'

Please note that this issue is also meant as very kind try to convince you as upstream to start versioning your .so library (as our Fedora Packaging Guidelines request).

[sreimers]

Thanks for pointing this out. I think we need some CI tests to check/ensure ABI compatibility first, i will work on this. We can build baresip and retest with a released shared libre.so and run these prebuilt versions against new libre.so builds. If something breaks, without noticing it, we can decide how to deal with it (bump major/soname version or rewrite code).

[robert-scheck]

Thanks for replying! https://fedoraproject.org/wiki/How_to_check_for_ABI_changes_with_abidiff suggests abidiff, which might also help.