Native simulator build fails with __x86.get_pc_thunk.bx linker errors after adding math library

[surfskidude]

Describe the bug

A previously working Zephyr build started failing after I introduced floating-point arithmetic and linked the math library. The issue occurs when compiling for the native simulator (native_sim).

Environment

• Zephyr version: Latest (VERSION_MAJOR = 4 VERSION_MINOR = 2 PATCHLEVEL = 99)
• Target: native_sim
• Host: WSL2

Description

After adding floating-point operations and linking the math library (-lm), the build fails with multiple linker errors for the symbol __x86.get_pc_thunk.bx.

Regression

• This is a regression.

Steps to reproduce

1. Start from a working native_sim build.
2. Add floating-point arithmetic and link against the math library (-lm).
3. Build the project.

Expected Behavior

The project should compile and link successfully.

Actual Behavior

The build fails with multiple linker errors:

__x86.get_pc_thunk.bx' referenced in section .text' of /home/wini/xedgews/build/zephyr/NSI/home/wini/xedgews/build/zephyr/zephyr.elf.loc_cpusw.o: defined in discarded section .text.__x86.get_pc_thunk.bx[__x86.get_pc_thunk.bx]' of /home/wini/xedgews/build/zephyr/NSI/home/wini/xedgews/build/zephyr/zephyr.elf.loc_cpusw.o

Additional Attempts

• Added -fno-pie and -fno-pic to compile options: no effect.
• Compiled the simulator in 64-bit mode: same link errors.

Relevant log output

Impact

Major – Severely degrades functionality; workaround is difficult or unavailable.

Environment

• WSL2
• zephyr-sdk-0.17.4

Additional Context

No response

[aescolar]

@surfskidude how are you linking the math library?
a) you cannot link it into the zephyr embedded build side.
b) it is already linked into the runner side (so you don't need to link it again)

Issue converted into a discussion as it seems more appropriate

[surfskidude]

Yes I linked with
zephyr_link_libraries(m)
I removed it and it now works. Sorry for the noise :-)