fsanitize=undefined in parent project causes to link due to missing rtti infos in soci.so

[MTRNord]

Hi :)

I am using soci in my project via meson (essentially via cmake). In my project, I wanted to use -fsanitize=address,undefined. So far so good. However, while using this with clang++16 I got the following linker errors with soci:

FAILED: persephone 
clang++  -o persephone persephone.p/src_database_database.cpp.o persephone.p/src_utils_config.cpp.o persephone.p/src_utils_json_utils.cpp.o persephone.p/src_utils_utils.cpp.o persephone.p/src_webserver_client_server_api_auth.cpp.o persephone.p/src_webserver_json.cpp.o persephone.p/src_webserver_webserver.cpp.o persephone.p/src_main.cpp.o -flto -fsanitize=address,undefined -Wl,--as-needed -Wl,--allow-shlib-undefined '-Wl,-rpath,$ORIGIN/subprojects/soci-4.0.3' -Wl,-rpath-link,/run/media/marcel/1ac60e61-e5e2-4157-9a7a-830801a3fb0b/projects/persephone/builddir/subprojects/soci-4.0.3 -Wl,--start-group subprojects/soci-4.0.3/libsoci_core.so subprojects/soci-4.0.3/libsoci_postgresql.so subprojects/yaml-cpp-0.8.0/libyaml_cpp.a -pthread /usr/lib64/libssl.so /usr/lib64/libcrypto.so /usr/lib64/libz.so /usr/lib64/libbrotlicommon.so /usr/lib64/libbrotlidec.so /usr/lib64/libbrotlienc.so -Wl,-Bstatic -ldl -Wl,-Bdynamic /usr/lib64/libboost_date_time.so.1.78.0 /usr/lib64/libdl.a -Wl,-Bstatic -Wl,-Bdynamic /usr/lib64/libpq.so -lpq /usr/lib64/libsodium.so -Wl,--end-group
/usr/bin/ld: /tmp/lto-llvm-c51c3f.o:(.data..Lanon.e2fefa1b5e301ebe1275295b6754704c.20+0x18): undefined reference to `typeinfo for soci::postgresql_session_backend'
/usr/bin/ld: /tmp/lto-llvm-c51c3f.o:(.data..Lanon.e2fefa1b5e301ebe1275295b6754704c.23+0x18): undefined reference to `typeinfo for soci::postgresql_session_backend'
/usr/bin/ld: /tmp/lto-llvm-c51c3f.o:(.data..Lanon.e2fefa1b5e301ebe1275295b6754704c.157+0x18): undefined reference to `typeinfo for soci::details::ref_counted_statement'
/usr/bin/ld: /tmp/lto-llvm-c51c3f.o:(.data..Lanon.e2fefa1b5e301ebe1275295b6754704c.158+0x18): undefined reference to `typeinfo for soci::details::ref_counted_statement'
/usr/bin/ld: /tmp/lto-llvm-c51c3f.o:(.data..Lanon.e2fefa1b5e301ebe1275295b6754704c.193+0x18): undefined reference to `typeinfo for soci::details::ref_counted_statement'
/usr/bin/ld: /tmp/lto-llvm-c51c3f.o:(.data..Lanon.e2fefa1b5e301ebe1275295b6754704c.194+0x18): undefined reference to `typeinfo for soci::details::ref_counted_statement'
/usr/bin/ld: /tmp/lto-llvm-c51c3f.o:(.data..Lanon.e2fefa1b5e301ebe1275295b6754704c.222+0x18): undefined reference to `typeinfo for soci::details::ref_counted_statement'
/usr/bin/ld: /tmp/lto-llvm-c51c3f.o:(.data..Lanon.e2fefa1b5e301ebe1275295b6754704c.223+0x18): more undefined references to `typeinfo for soci::details::ref_counted_statement' follow
clang-16: error: linker command failed with exit code 1 (use -v to see invocation)

The sourcecode for this can be found at https://github.com/MTRNord/persephone/tree/291b037e5f57e2eabb0b214509de9c231061e8ea

Relevant in the meson.build is probably only that I disable the boost part and use lto. However, neither seem to make any difference in outcome.

I am targeting c++20 if this matters.

(also sorry if I miss some obvious thing here. I am still fairly new to C++)

The whole project compiled fine if I remove the undefined sanitizer. (Likely because then no RTTI is required)

[MTRNord]

Hm it gets even weirder after I disable the vptr sanitizer. After successful build it fails with further lookup errors:

./persephone: symbol lookup error: /run/media/marcel/1ac60e61-e5e2-4157-9a7a-830801a3fb0b/projects/persephone/builddir/subprojects/soci-4.0.3/libsoci_postgresql.so: undefined symbol: _ZTIN4soci7details21ref_counted_statementE

[vadz]

Sorry, no idea what's going on here but it would definitely be best to compile both SOCI and your project with the same options.

[Krzmbrzl]

@MTRNord could you maybe retry with #1118 ? I have no idea what the exact cause for the behavior you're seeing could be but given that the current cmake setup does have qutie a few quirks and oddities, I wouldn't be surprised if this issue is fixed as a side-effect of my PR.

[vadz]

This was actually due to UBSAN vtbl sanitizer which really needs typeinfo to be accessible, so I've fixed it in the commit linked above now and the problem will be fixed once #1172 is merged.