On Thu, Jul 28, 2022 at 3:17 PM Ilya Maximets <i.maxim...@ovn.org> wrote: > > On 7/27/22 23:02, David Marchand wrote: > > On Mon, Jul 25, 2022 at 2:29 PM Ilya Maximets <i.maxim...@ovn.org> wrote: > >> > >> Current version of debian/rules simply passes the libopenvswitch.a > >> as a command line argument via LDFLAGS, but that doesn't actually > >> lead to this library being statically linked into python extension, > >> which is a shared library. Instead, the build "succeeds", but the > >> resulted extension is not usable, because most of the symbols are > >> missing: > >> > >> from ovs import _json > >> > >> ImportError: > >> > >> /usr/lib/python3/dist-packages/ovs/_json.cpython-310-x86_64-linux-gnu.so: > >> undefined symbol: json_parser_finish > >> > >> '-lopenvswitch' with a path to a static library should be passed > >> instead to make it actually statically linked. But even that is not > >> enough as all the libraries that libopenvswitch.a was built with also > >> has to be passed. Otherwise, we'll have unresolved symbols like ssl, > >> cap-ng, etc. > >> > >> The most convenient way to get all the required libraries and cflags > >> seems to be by using pkg-config. > >> > >> Setting several environment variables for pkg-config, so it can find > >> the libopenvswitch.pc in non-standard directory, not skip default > >> locations and also report them with the right base directory. > >> > >> Extra '-Wl,-Bstatic -lopenvswitch -Wl,-Bdynamic' is added before all > >> the libs to ensure static linking of libopenvswitch even if the > >> dynamic library is available in a system. > > > > Did you consider the simple :filename form to tell ld to link an archive? > > Here that would translate to a simple -l:libopenvswitch.a > > Yes, I looked into that. There shouldn't be any difference for this > particular use case. -l:filename syntax is supported since binutils 2.18 > that was released about 11 years ago, not sure if that's a priblem or > not. It's certainly not a problem for current debian packaging, since it > will likely not work on systems that old anyway. > > > > > This is only a suggestion to avoid adding too many -Wl options as they > > stack up if you are not careful. > > I see. Though, it is probably not a big concern for this particular use-case. > > I can replace '-Wl,-Bstatic -lopenvswitch -Wl,-Bdynamic' with > '-l:libopenvswitch.a' and send a new version, or replace on commit, > if you think that will be better. I don't have a strong preference. > > What do you think? > > Frode, do you have any comments on this?
David, thank you for sharing the `-l:` syntax, I was not aware of that. I have no strong opinions about what to use, if it helps to tip the scale, I have to admit in this specific use-case where we only have two of these, the longer syntax appears more clear on the tin to see what's going on. We could switch to `-l:` if we need to add more of these for example? -- Frode Nordahl > Best regards, Ilya Maximets. _______________________________________________ dev mailing list d...@openvswitch.org https://mail.openvswitch.org/mailman/listinfo/ovs-dev
