Error compiling test_toAscii.cpp with higher language level

[jboynes]

Testing on Ubuntu 23 with GCC 12 and glibc-2.37

$ uname -a
Linux foo 6.2.0-27-generic #28-Ubuntu SMP PREEMPT_DYNAMIC Thu Jul 13 00:41:18 UTC 2023 aarch64 aarch64 aarch64 GNU/Linux

I get the following compilation error:

[ 92%] Building CXX object CMakeFiles/test-ArduinoCore-API.dir/src/WCharacter/test_toAscii.cpp.o
In file included from /usr/include/c++/12/bits/atomic_wait.h:49,
                 from /usr/include/c++/12/bits/atomic_base.h:41,
                 from /usr/include/c++/12/bits/shared_ptr_atomic.h:33,
                 from /usr/include/c++/12/memory:77,
                 from /home/ubuntu/ArduinoCore-API/test/external/catch/v2.13.9/include/catch.hpp:2948,
                 from /home/ubuntu/ArduinoCore-API/test/src/WCharacter/test_toAscii.cpp:11:
/usr/include/c++/12/bits/std_mutex.h: In member function ‘void std::__condvar::wait_until(std::mutex&, clockid_t, timespec&)’:
/usr/include/c++/12/bits/std_mutex.h:169:7: error: ‘pthread_cond_clockwait’ was not declared in this scope; did you mean ‘pthread_cond_wait’?
  169 |       pthread_cond_clockwait(&_M_cond, __m.native_handle(), __clock,
      |       ^~~~~~~~~~~~~~~~~~~~~~
      |       pthread_cond_wait
make[2]: *** [CMakeFiles/test-ArduinoCore-API.dir/build.make:1084: CMakeFiles/test-ArduinoCore-API.dir/src/WCharacter/test_toAscii.cpp.o] Error 1
make[1]: *** [CMakeFiles/Makefile2:83: CMakeFiles/test-ArduinoCore-API.dir/all] Error 2
make: *** [Makefile:91: all] Error 2

I'm guessing this is because C++20 added std::atomic<std::shared_ptr>

This test case has an #undef _GNU_SOURCE and if that is removed then it compiles and passes. Can this be removed?

[aentinger]

Thank you @jboynes for this report.

Personally I don't see any reason why this define could not be removed. Why not create a PR and let's see what our CI build makes of this? Alternately, only exclude this macro when an advanced C++ compiler is used.