[native_sim] Linking a shared C++ zephyr library with STL.

[JaagupAverin]

I have a zephyr library that is defined as:

zephyr_library_named(gale_ipc)
zephyr_library_sources_ifdef(CONFIG_GALE_IPC gale_ipc.cpp)
zephyr_include_directories(include)

Which is a helper library used by both core firmwares.
When the library does not contain any STL code, it builds and links nicely into both firmwares, and finally into the native_sim zephyr.exe, and is executed properly.

However, when adding any C++ STL code such as std::string, std::string_view, std::function, etc to the shared library, I get linker errors when linking the final zephyr.exe.

e.g when trying to use std::function in this library, the final link fails with:

[248/249] Linking CXX executable zephyr/zephyr.elf
Generating files from /home/jaagup/projects/gale_ws/hmi_app/build/nrf5340bsim_hmi_app_debug/hmi_app/zephyr/zephyr.elf for board: nrf5340bsim
[249/249] Building native simulator runner, and linking final executable
FAILED: zephyr/CMakeFiles/native_runner_executable zephyr/zephyr.exe /home/jaagup/projects/gale_ws/hmi_app/build/nrf5340bsim_hmi_app_debug/hmi_app/zephyr/CMakeFiles/native_runner_executable /home/jaagup/projects/gale_ws/hmi_app/build/nrf5340bsim_hmi_app_debug/hmi_app/zephyr/zephyr.exe
cd /home/jaagup/projects/gale_ws/hmi_app/build/nrf5340bsim_hmi_app_debug/hmi_app/zephyr && /usr/bin/make -f /home/jaagup/projects/gale_ws/zephyr/scripts/native_simulator/Makefile all --warn-undefined-variables -r NSI_CONFIG_FILE=/home/jaagup/projects/gale_ws/hmi_app/build/nrf5340bsim_hmi_app_debug/hmi_app/zephyr/NSI/nsi_config
`_ZNSt8functionIFvRKN10GaleIpcMsg3AnyEEEC1IRS4_vEEOT_' referenced in section `.text._ZL8test_ipcPvS_S_' of /home/jaagup/projects/gale_ws/hmi_app/build/nrf5340bsim_hmi_app_debug/hmi_app/zephyr/NSI/home/jaagup/projects/gale_ws/hmi_app/build/nrf5340bsim_hmi_app_debug/net_app_relay/zephyr/zephyr.elf.loc_cpusw.o: defined in discarded section `.text._ZNSt8functionIFvRKN10GaleIpcMsg3AnyEEEC2IRS4_vEEOT_[_ZNSt8functionIFvRKN10GaleIpcMsg3AnyEEEC5IRS4_vEEOT_]' of /home/jaagup/projects/gale_ws/hmi_app/build/nrf5340bsim_hmi_app_debug/hmi_app/zephyr/NSI/home/jaagup/projects/gale_ws/hmi_app/build/nrf5340bsim_hmi_app_debug/net_app_relay/zephyr/zephyr.elf.loc_cpusw.o
`_ZNSt8functionIFvRKN10GaleIpcMsg3AnyEEED1Ev' referenced in section `.text._ZL8test_ipcPvS_S_' of /home/jaagup/projects/gale_ws/hmi_app/build/nrf5340bsim_hmi_app_debug/hmi_app/zephyr/NSI/home/jaagup/projects/gale_ws/hmi_app/build/nrf5340bsim_hmi_app_debug/net_app_relay/zephyr/zephyr.elf.loc_cpusw.o: defined in discarded section `.text._ZNSt8functionIFvRKN10GaleIpcMsg3AnyEEED2Ev[_ZNSt8functionIFvRKN10GaleIpcMsg3AnyEEED5Ev]' of /home/jaagup/projects/gale_ws/hmi_app/build/nrf5340bsim_hmi_app_debug/hmi_app/zephyr/NSI/home/jaagup/projects/gale_ws/hmi_app/build/nrf5340bsim_hmi_app_debug/net_app_relay/zephyr/zephyr.elf.loc_cpusw.o
`_ZNKSt8functionIFvRKN10GaleIpcMsg3AnyEEEclES3_' referenced in section `.text._ZL20ipc_endpoint_recv_cbPKvjPv' of /home/jaagup/projects/gale_ws/hmi_app/build/nrf5340bsim_hmi_app_debug/hmi_app/zephyr/NSI/home/jaagup/projects/gale_ws/hmi_app/build/nrf5340bsim_hmi_app_debug/net_app_relay/zephyr/zephyr.elf.loc_cpusw.o: defined in discarded section `.text._ZNKSt8functionIFvRKN10GaleIpcMsg3AnyEEEclES3_[_ZNKSt8functionIFvRKN10GaleIpcMsg3AnyEEEclES3_]' of /home/jaagup/projects/gale_ws/hmi_app/build/nrf5340bsim_hmi_app_debug/hmi_app/zephyr/NSI/home/jaagup/projects/gale_ws/hmi_app/build/nrf5340bsim_hmi_app_debug/net_app_relay/zephyr/zephyr.elf.loc_cpusw.o
`_ZNSt8functionIFvRKN10GaleIpcMsg3AnyEEEC1EDn' referenced in section `.text._Z41__static_initialization_and_destruction_0v' of /home/jaagup/projects/gale_ws/hmi_app/build/nrf5340bsim_hmi_app_debug/hmi_app/zephyr/NSI/home/jaagup/projects/gale_ws/hmi_app/build/nrf5340bsim_hmi_app_debug/net_app_relay/zephyr/zephyr.elf.loc_cpusw.o: defined in discarded section `.text._ZNSt8functionIFvRKN10GaleIpcMsg3AnyEEEC2EDn[_ZNSt8functionIFvRKN10GaleIpcMsg3AnyEEEC5EDn]' of /home/jaagup/projects/gale_ws/hmi_app/build/nrf5340bsim_hmi_app_debug/hmi_app/zephyr/NSI/home/jaagup/projects/gale_ws/hmi_app/build/nrf5340bsim_hmi_app_debug/net_app_relay/zephyr/zephyr.elf.loc_cpusw.o
collect2: error: ld returned 1 exit status
make: *** [/home/jaagup/projects/gale_ws/zephyr/scripts/native_simulator/Makefile:142: /home/jaagup/projects/gale_ws/hmi_app/build/nrf5340bsim_hmi_app_debug/hmi_app/zephyr/zephyr.exe] Error 1
ninja: build stopped: subcommand failed.
FAILED: _sysbuild/sysbuild/images/hmi_app-prefix/src/hmi_app-stamp/hmi_app-build /home/jaagup/projects/gale_ws/hmi_app/build/nrf5340bsim_hmi_app_debug/_sysbuild/sysbuild/images/hmi_app-prefix/src/hmi_app-stamp/hmi_app-build
cd /home/jaagup/projects/gale_ws/hmi_app/build/nrf5340bsim_hmi_app_debug/hmi_app && /usr/bin/cmake --build .
ninja: build stopped: subcommand failed.

I understand that C++ support in Zephyr is not as robust as C. Is what I am trying to accomplish possible with some adjustments, or is this a bug/unsupported feature?

Best,
Jaagup

[aescolar]

@JaagupAverin please try to simplify the issue into a simpler reproduction case and be clearer about what happens and what you expected.
In general you should be able to build C++ code in native_sim (or the nrf5340 bsim which you seem to using there) like for other Zephyr targets.
But if you are trying to link to a shared Linux library into your embedded code things may break in a few different ways which may or not have anything to do with some of the parts you mention.

[JaagupAverin]

If this should be possible, then I will make a small reproducible example and raise it as a bug. Thanks!

[JaagupAverin]

#95275