Weak symbols presence

[jjerphan]

Currently, warnings are emitted by the linker regarding the presence of weak symbols.

For instance, see this log:

ld: warning: direct access in function 'std::__1::__function::__func<auto google::protobuf::io::Printer::WithVars<absl::lts_20230802::flat_hash_map<std::__1::basic_string_view<char, std::__1::char_traits<char> >, std::__1::basic_string_view<char, std::__1::char_traits<char> >, absl::lts_20230802::container_internal::StringHash, absl::lts_20230802::container_internal::StringEq, std::__1::allocator<std::__1::pair<std::__1::basic_string_view<char, std::__1::char_traits<char> > const, std::__1::basic_string_view<char, std::__1::char_traits<char> > > > > >(absl::lts_20230802::flat_hash_map<std::__1::basic_string_view<char, std::__1::char_traits<char> >, std::__1::basic_string_view<char, std::__1::char_traits<char> >, absl::lts_20230802::container_internal::StringHash, absl::lts_20230802::container_internal::StringEq, std::__1::allocator<std::__1::pair<std::__1::basic_string_view<char, std::__1::char_traits<char> > const, std::__1::basic_string_view<char, std::__1::char_traits<char> > > > > const*)::'lambda'(std::__1::basic_string_view<char, std::__1::char_traits<char> >), std::__1::allocator<auto google::protobuf::io::Printer::WithVars<absl::lts_20230802::flat_hash_map<std::__1::basic_string_view<char, std::__1::char_traits<char> >, std::__1::basic_string_view<char, std::__1::char_traits<char> >, absl::lts_20230802::container_internal::StringHash, absl::lts_20230802::container_internal::StringEq, std::__1::allocator<std::__1::pair<std::__1::basic_string_view<char, std::__1::char_traits<char> > const, std::__1::basic_string_view<char, std::__1::char_traits<char> > > > > >(absl::lts_20230802::flat_hash_map<std::__1::basic_string_view<char, std::__1::char_traits<char> >, std::__1::basic_string_view<char, std::__1::char_traits<char> >, absl::lts_20230802::container_internal::StringHash, absl::lts_20230802::container_internal::StringEq, std::__1::allocator<std::__1::pair<std::__1::basic_string_view<char, std::__1::char_traits<char> > const, std::__1::basic_string_view<char, std::__1::char_traits<char> > > > > const*)::'lambda'(std::__1::basic_string_view<char, std::__1::char_traits<char> >)>, std::__1::optional<google::protobuf::io::Printer::ValueImpl<false> > (std::__1::basic_string_view<char, std::__1::char_traits<char> >)>::target(std::type_info const&) const' from file 'libprotoc.a(command_line_interface.cc.o)' to global weak symbol 'typeinfo name for auto google::protobuf::io::Printer::WithVars<absl::lts_20230802::flat_hash_map<std::__1::basic_string_view<char, std::__1::char_traits<char> >, std::__1::basic_string_view<char, std::__1::char_traits<char> >, absl::lts_20230802::container_internal::StringHash, absl::lts_20230802::container_internal::StringEq, std::__1::allocator<std::__1::pair<std::__1::basic_string_view<char, std::__1::char_traits<char> > const, std::__1::basic_string_view<char, std::__1::char_traits<char> > > > > >(absl::lts_20230802::flat_hash_map<std::__1::basic_string_view<char, std::__1::char_traits<char> >, std::__1::basic_string_view<char, std::__1::char_traits<char> >, absl::lts_20230802::container_internal::StringHash, absl::lts_20230802::container_internal::StringEq, std::__1::allocator<std::__1::pair<std::__1::basic_string_view<char, std::__1::char_traits<char> > const, std::__1::basic_string_view<char, std::__1::char_traits<char> > > > > const*)::'lambda'(std::__1::basic_string_view<char, std::__1::char_traits<char> >)' from file 'CMakeFiles/fake_plugin.dir/src/google/protobuf/compiler/mock_code_generator.cc.o' means the weak symbol cannot be overridden at runtime. This was likely caused by different translation units being compiled with different visibility settings.

Visibility settings might need adaptation.

[h-vetinari]

Visibility settings might need adaptation.

PRs are welcome! Perhaps even better, you might be able to raise the issue upstream and get it fixed at the source.

[jjerphan]

Yes, we need to understand what needs to be adapted first. If we do, we might contribute here and upstream directly.