find_library linkable check is too strict for RTEMS

[rohel01]

Describe the bug
In an existing repo where build was working, upgrading to meson 1.10 breaks meson setup

-----------
Command line: `/home/michael/sdk/rtems-noel-1.0.4/2022.06/bin/riscv-rtems5-gcc -I/home/michael/sdk/rtems-noel-1.0.4/2022.06/bin/../lib/gcc/riscv-rtems5/9.3.0/include -I/home/michael/sdk/rtems-noel-1.0.4/2022.06/bin/../lib/gcc/riscv-rtems5/9.3.0/include-fixed -I/home/michael/sdk/rtems-noel-1.0.4/2022.06/bin/../lib/gcc/riscv-rtems5/9.3.0/../../../../riscv-rtems5/include -I/home/michael/sdk/rtems-noel-1.0.4/2022.06/riscv-rtems5/noel32imafd/lib/include/ -I/home/michael/sdk/rtems-noel-1.0.4/2022.06/kernel/riscv-rtems5/noel32imafd/lib/include/ /home/michael/proj/pfgen/endurance-flight-software/cmake/build/meson-private/tmpxn87jx67/testfile.c -o /home/michael/proj/pfgen/endurance-flight-software/cmake/build/meson-private/tmpxn87jx67/output.exe -B/home/michael/sdk/rtems-noel-1.0.4/2022.06/riscv-rtems5/noel32imafd/lib -B/home/michael/sdk/rtems-noel-1.0.4/2022.06/kernel/riscv-rtems5/noel32imafd/lib -Wall -Wextra -fno-common -ffunction-sections -fdata-sections -D_RTEMS_5_ -U_FILE_OFFSET_BITS -qrtems -Wfatal-errors -Werror=int-conversion -Werror=format -Werror=format-nonliteral -Werror=format-signedness -Werror=nonnull -Werror=implicit -Werror=implicit-fallthrough -Werror=missing-braces -Werror=incompatible-pointer-types -Werror=overflow -D_FILE_OFFSET_BITS=64 -O0 -Wl,--start-group /home/michael/proj/pfgen/endurance-flight-software/cmake/karvel/modules/karvel_endurance/lib/libkarvel_endurance.a -Wl,--allow-shlib-undefined /home/michael/sdk/rtems-noel-1.0.4/2022.06/bin/../lib/gcc/riscv-rtems5/9.3.0/crti.o /home/michael/sdk/rtems-noel-1.0.4/2022.06/bin/../lib/gcc/riscv-rtems5/9.3.0/crtbegin.o -nostdlib -nodefaultlibs -lrtemscpu -lrtemsbsp -lgcc -lc -Wl,--end-group -Wl,--gc-sections /home/michael/sdk/rtems-noel-1.0.4/2022.06/bin/../lib/gcc/riscv-rtems5/9.3.0/crtend.o /home/michael/sdk/rtems-noel-1.0.4/2022.06/bin/../lib/gcc/riscv-rtems5/9.3.0/crtn.o -T/home/michael/sdk/rtems-noel-1.0.4/2022.06/kernel/riscv-rtems5/noel32imafd/lib/linkcmds` -> 1
stderr:
/home/michael/sdk/rtems-noel-1.0.4/2022.06/bin/../lib/gcc/riscv-rtems5/9.3.0/../../../../riscv-rtems5/bin/ld: /home/michael/sdk/rtems-noel-1.0.4/2022.06/kernel/riscv-rtems5/noel32imafd/lib/start.o: in function `.L0 ':
/home/jernej/repositories/rsb/build-toolchain/src/bsp/riscv-rtems5/c/noel32imafd/lib/libbsp/riscv/riscv/../../../../../../../../rtems-noel-1.0.4/c/src/lib/libbsp/riscv/riscv/../../../../../../bsps/riscv/shared/start/start.S:77: undefined reference to `_ISR_Stack_area_end'
/home/michael/sdk/rtems-noel-1.0.4/2022.06/bin/../lib/gcc/riscv-rtems5/9.3.0/../../../../riscv-rtems5/bin/ld: /home/michael/sdk/rtems-noel-1.0.4/2022.06/kernel/riscv-rtems5/noel32imafd/lib/librtemscpu.a(userextiterate.o): in function `_User_extensions_Iterate':
/home/jernej/repositories/rsb/build-toolchain/src/bsp/riscv-rtems5/c/noel32imafd/cpukit/../../../../../rtems-noel-1.0.4/c/src/../../cpukit/score/src/userextiterate.c:167: undefined reference to `_User_extensions_Initial_count'

[...]

/home/michael/sdk/rtems-noel-1.0.4/2022.06/bin/../lib/gcc/riscv-rtems5/9.3.0/../../../../riscv-rtems5/bin/ld: /home/michael/sdk/rtems-noel-1.0.4/2022.06/kernel/riscv-rtems5/noel32imafd/lib/librtemscpu.a(ftruncate.o): in function `rtems_libio_iop':
/home/jernej/repositories/rsb/build-toolchain/src/rtems-noel-1.0.4/cpukit/include/rtems/libio_.h:130: undefined reference to `rtems_libio_iops'
/home/michael/sdk/rtems-noel-1.0.4/2022.06/bin/../lib/gcc/riscv-rtems5/9.3.0/../../../../riscv-rtems5/bin/ld: /home/jernej/repositories/rsb/build-toolchain/src/rtems-noel-1.0.4/cpukit/include/rtems/libio_.h:130: undefined reference to `rtems_libio_iops'
collect2: error: ld returned 1 exit status
-----------

karvel/meson.build:190:11: ERROR: C static library 'karvel_endurance' not found

To Reproduce

1. uv tool install meson@1.9.2
2. meson setup build/ --cross cross_riscv-rtems5-noel32imafd.ini
3. Setup works
4. uv tool install meson@1.10.1
5. rm -Rf build/
6. meson setup build/ --cross cross_riscv-rtems5-noel32imafd.ini
7. Setup fails

I have attached the meson-logs.txt for each case and the cross file I am using

The relevant part of the meson.build file are:

# Binary libraries
karvel_bin_lib = [
  'modules/karvel_endurance',
]

cc = meson.get_compiler('c')
root = meson.current_source_dir()

# We deal with binary modules first, since source modules are likely to depend on them
foreach l : karvel_bin_lib

  # Fetch variables from subdir
  subdir(l)

  lib = cc.find_library(lib_name, dirs: [f'@root@/@l@/lib'], required: true, static: true)

meson-log.1.9.2.txt
meson-log.1.10.1.txt
cross_riscv-rtems5-noel32imafd.ini.txt

Expected behavior
Setup should work as before

system parameters

• Cross-build
• OS: Ubuntu 24.04 LTS
• Python 3.13.3
• Meson 1.10.1
• Ninja 1.13.0

[eli-schwartz]

In general it is advisable to include an excerpt of the error such that reading the initial bug report does not require downloading a text file attachment with the real bug report. Let me post your build error for you. :)

-----------
Command line: `/home/michael/sdk/rtems-noel-1.0.4/2022.06/bin/riscv-rtems5-gcc -I/home/michael/sdk/rtems-noel-1.0.4/2022.06/bin/../lib/gcc/riscv-rtems5/9.3.0/include -I/home/michael/sdk/rtems-noel-1.0.4/2022.06/bin/../lib/gcc/riscv-rtems5/9.3.0/include-fixed -I/home/michael/sdk/rtems-noel-1.0.4/2022.06/bin/../lib/gcc/riscv-rtems5/9.3.0/../../../../riscv-rtems5/include -I/home/michael/sdk/rtems-noel-1.0.4/2022.06/riscv-rtems5/noel32imafd/lib/include/ -I/home/michael/sdk/rtems-noel-1.0.4/2022.06/kernel/riscv-rtems5/noel32imafd/lib/include/ /home/michael/proj/pfgen/endurance-flight-software/cmake/build/meson-private/tmpxn87jx67/testfile.c -o /home/michael/proj/pfgen/endurance-flight-software/cmake/build/meson-private/tmpxn87jx67/output.exe -B/home/michael/sdk/rtems-noel-1.0.4/2022.06/riscv-rtems5/noel32imafd/lib -B/home/michael/sdk/rtems-noel-1.0.4/2022.06/kernel/riscv-rtems5/noel32imafd/lib -Wall -Wextra -fno-common -ffunction-sections -fdata-sections -D_RTEMS_5_ -U_FILE_OFFSET_BITS -qrtems -Wfatal-errors -Werror=int-conversion -Werror=format -Werror=format-nonliteral -Werror=format-signedness -Werror=nonnull -Werror=implicit -Werror=implicit-fallthrough -Werror=missing-braces -Werror=incompatible-pointer-types -Werror=overflow -D_FILE_OFFSET_BITS=64 -O0 -Wl,--start-group /home/michael/proj/pfgen/endurance-flight-software/cmake/karvel/modules/karvel_endurance/lib/libkarvel_endurance.a -Wl,--allow-shlib-undefined /home/michael/sdk/rtems-noel-1.0.4/2022.06/bin/../lib/gcc/riscv-rtems5/9.3.0/crti.o /home/michael/sdk/rtems-noel-1.0.4/2022.06/bin/../lib/gcc/riscv-rtems5/9.3.0/crtbegin.o -nostdlib -nodefaultlibs -lrtemscpu -lrtemsbsp -lgcc -lc -Wl,--end-group -Wl,--gc-sections /home/michael/sdk/rtems-noel-1.0.4/2022.06/bin/../lib/gcc/riscv-rtems5/9.3.0/crtend.o /home/michael/sdk/rtems-noel-1.0.4/2022.06/bin/../lib/gcc/riscv-rtems5/9.3.0/crtn.o -T/home/michael/sdk/rtems-noel-1.0.4/2022.06/kernel/riscv-rtems5/noel32imafd/lib/linkcmds` -> 1
stderr:
/home/michael/sdk/rtems-noel-1.0.4/2022.06/bin/../lib/gcc/riscv-rtems5/9.3.0/../../../../riscv-rtems5/bin/ld: /home/michael/sdk/rtems-noel-1.0.4/2022.06/kernel/riscv-rtems5/noel32imafd/lib/start.o: in function `.L0 ':
/home/jernej/repositories/rsb/build-toolchain/src/bsp/riscv-rtems5/c/noel32imafd/lib/libbsp/riscv/riscv/../../../../../../../../rtems-noel-1.0.4/c/src/lib/libbsp/riscv/riscv/../../../../../../bsps/riscv/shared/start/start.S:77: undefined reference to `_ISR_Stack_area_end'
/home/michael/sdk/rtems-noel-1.0.4/2022.06/bin/../lib/gcc/riscv-rtems5/9.3.0/../../../../riscv-rtems5/bin/ld: /home/michael/sdk/rtems-noel-1.0.4/2022.06/kernel/riscv-rtems5/noel32imafd/lib/librtemscpu.a(userextiterate.o): in function `_User_extensions_Iterate':
/home/jernej/repositories/rsb/build-toolchain/src/bsp/riscv-rtems5/c/noel32imafd/cpukit/../../../../../rtems-noel-1.0.4/c/src/../../cpukit/score/src/userextiterate.c:167: undefined reference to `_User_extensions_Initial_count'

[...]

/home/michael/sdk/rtems-noel-1.0.4/2022.06/bin/../lib/gcc/riscv-rtems5/9.3.0/../../../../riscv-rtems5/bin/ld: /home/michael/sdk/rtems-noel-1.0.4/2022.06/kernel/riscv-rtems5/noel32imafd/lib/librtemscpu.a(ftruncate.o): in function `rtems_libio_iop':
/home/jernej/repositories/rsb/build-toolchain/src/rtems-noel-1.0.4/cpukit/include/rtems/libio_.h:130: undefined reference to `rtems_libio_iops'
/home/michael/sdk/rtems-noel-1.0.4/2022.06/bin/../lib/gcc/riscv-rtems5/9.3.0/../../../../riscv-rtems5/bin/ld: /home/jernej/repositories/rsb/build-toolchain/src/rtems-noel-1.0.4/cpukit/include/rtems/libio_.h:130: undefined reference to `rtems_libio_iops'
collect2: error: ld returned 1 exit status
-----------

karvel/meson.build:190:11: ERROR: C static library 'karvel_endurance' not found

[rohel01]

Thanks for the suggestion. I have updated the report to include the error message.

[eli-schwartz]

@thesamesam it is #15134. :P

Not sure what the answer is here. We are finding static libs in sourcedir so maybe just assume those always work?

[bonzini]

Isn't the problem here that --allow-shlib-undefined simply isn't enough because this is a static library?

The original description said "We can workaround that by building a shared library as a test rather than an executable", but in the end that wasn't done. Maybe it was necessary after all.

[rohel01]

Would it be possible to not rely on building test artifacts for the target under the hood?

This can be difficult on bare metal targets:

• Some runtime environment must be provided
• That runtime can be difficult to build on its own because of static configuration constraints
• ...

RTEMS requires a configuration header to be injected in the build. I believe other RTOS (Zephyr?) solve these issues by provided their own build/package managers.

Also, you now need to use user-provided flags to compiler for the target, but some of them might need to be filtered out. For example, some -Werror flags might reject your test code.

[eli-schwartz]

Werror should never be included in e.g. $CC, only $CFLAGS. But also it's a goal to write test code that is very robust against even weird and unusual -Werror=*

Building test artifacts is valuable for detecting cases where e.g. the library is a binutils ld linker script that doesn't resolve cleanly, or where the library is for a different CPU architecture, or the library is a clang bitcode archive that ld.bfd isn't configured to recognize, etc.

I'd much rather provide a toolchain toggle for this, because it is kind of a more specific version of "can we compile and run a sanitycheckc.c source code file", which is also something that bare metal targets would normally opt out of.

[rohel01]

Werror should never be included in e.g. $CC, only $CFLAGS.

I agree but this already how it is done in my case right? Your comment made me check my cross file again, and those flags are added in c_args

But also it's a goal to write test code that is very robust against even weird and unusual -Werror=*

Building test artifacts is valuable for detecting cases where e.g. the library is a binutils ld linker script that doesn't resolve cleanly, or where the library is for a different CPU architecture, or the library is a clang bitcode archive that ld.bfd isn't configured to recognize, etc.

I'd much rather provide a toolchain toggle for this, because it is kind of a more specific version of "can we compile and run a sanitycheckc.c source code file", which is also something that bare metal targets would normally opt out of.

Yes, and I belive this is what CMake ended up doing with CMAKE_<LANG>_COMPILER_WORKS