Hello!

I just noticed that debian/rules adds the powerpc architecture to the UBSAN_ARCH
arch list despite powerpc not supporting `__sync_val_compare_and_swap_8 [1]. This
results in libfixmath trying to build the testsuite and consequently FTBFS [2]:

[ 94%] Linking C executable tests_rn08
/usr/bin/cmake -E cmake_link_script CMakeFiles/tests_rn08.dir/link.txt --verbose=1
/usr/bin/cc -Wall -pedantic -Wextra -Werror=return-type -Wl,-z,relro -fsanitize=undefined CMakeFiles/tests_rn08.dir/tests/tests.c.o CMakeFiles/tests_rn08.dir/tests/tests_basic.c.o CMakeFiles/tests_rn08.dir/tests/tests_lerp.c.o CMakeFiles/tests_rn08.dir/tests/tests_macros.c.o CMakeFiles/tests_rn08.dir/tests/tests_sqrt.c.o CMakeFiles/tests_rn08.dir/tests/tests_str.c.o -o tests_rn08  liblibfixmath_rn08.a -lm -latomic
/usr/bin/ld: /usr/lib/gcc/powerpc-linux-gnu/12/libubsan.so: undefined reference to `__sync_val_compare_and_swap_8'
collect2: error: ld returned 1 exit status

Could you please remove "powerpc" from the UBSAN_ARCH list?

Thanks,
Adrian

Hi,

Am 10.01.23 um 20:30 schrieb John Paul Adrian Glaubitz:

But libubsan.so exists, which was what was intended with this variable...

Removing it there would effectively disabling building and running the
tests...


Regards,


Rene

Hello!

Yes, ubsan.so exists. But in some cases (i.e. some sanitizer checks) it requires
__sync_val_compare_and_swap_8 which is not available on 32-bit PowerPC.

However, __sync_val_compare_and_swap_8 is deprecated anyway and has been replaced
with __atomic_compare_exchange(), so I assume that the ubsan version in gcc-12 is
outdated.

I think in LLVM, we actually replaced __sync_val_compare_and_swap with __atomic_
compare_exchange() at some point for this particular reasons.

Adrian