[Bug]: warn_unused_result compilation error in dispenso/priority.cpp for Linux

[AbrilRBS]

Contact Details

N/A

What happened?

While trying to package the library for Conan Center Index, I've come across a compilation issue due to warn_unused_result and the default -Werror.

dispenso/1.2.0: Calling build()
dispenso/1.2.0: Running CMake.configure()
dispenso/1.2.0: RUN: cmake -G "Unix Makefiles" -DCMAKE_TOOLCHAIN_FILE="/root/.conan2/p/b/dispe38c8bf72dbfa0/b/build/Release/generators/conan_toolchain.cmake" -DCMAKE_INSTALL_PREFIX="/root/.conan2/p/b/dispe38c8bf72dbfa0/p" -DCMAKE_POLICY_DEFAULT_CMP0091="NEW" -DCMAKE_BUILD_TYPE="Release" "/root/.conan2/p/b/dispe38c8bf72dbfa0/b/src"
-- Using Conan toolchain: /root/.conan2/p/b/dispe38c8bf72dbfa0/b/build/Release/generators/conan_toolchain.cmake
-- Conan toolchain: Setting CMAKE_POSITION_INDEPENDENT_CODE=ON (options.fPIC)
-- Conan toolchain: C++ Standard 17 with extensions ON
-- Conan toolchain: Setting BUILD_SHARED_LIBS = OFF
-- The CXX compiler identification is GNU 11.4.0
-- Detecting CXX compiler ABI info
-- Detecting CXX compiler ABI info - done
-- Check for working CXX compiler: /usr/bin/c++ - skipped
-- Detecting CXX compile features
-- Detecting CXX compile features - done
SOURCES:  /root/.conan2/p/b/dispe38c8bf72dbfa0/b/src/dispenso/detail/per_thread_info.cpp;/root/.conan2/p/b/dispe38c8bf72dbfa0/b/src/dispenso/detail/quanta.cpp;/root/.conan2/p/b/dispe38c8bf72dbfa0/b/src/dispenso/graph.cpp;/root/.conan2/p/b/dispe38c8bf72dbfa0/b/src/dispenso/graph_executor.cpp;/root/.conan2/p/b/dispe38c8bf72dbfa0/b/src/dispenso/pool_allocator.cpp;/root/.conan2/p/b/dispe38c8bf72dbfa0/b/src/dispenso/priority.cpp;/root/.conan2/p/b/dispe38c8bf72dbfa0/b/src/dispenso/schedulable.cpp;/root/.conan2/p/b/dispe38c8bf72dbfa0/b/src/dispenso/small_buffer_allocator.cpp;/root/.conan2/p/b/dispe38c8bf72dbfa0/b/src/dispenso/task_set.cpp;/root/.conan2/p/b/dispe38c8bf72dbfa0/b/src/dispenso/thread_id.cpp;/root/.conan2/p/b/dispe38c8bf72dbfa0/b/src/dispenso/thread_pool.cpp;/root/.conan2/p/b/dispe38c8bf72dbfa0/b/src/dispenso/timed_task.cpp;/root/.conan2/p/b/dispe38c8bf72dbfa0/b/src/dispenso/timing.cpp;/root/.conan2/p/b/dispe38c8bf72dbfa0/b/src/dispenso/tsan_annotations.cpp
-- Looking for C++ include pthread.h
-- Looking for C++ include pthread.h - found
-- Performing Test CMAKE_HAVE_LIBC_PTHREAD
-- Performing Test CMAKE_HAVE_LIBC_PTHREAD - Success
-- Found Threads: TRUE  
-- Configuring done
-- Generating done
-- Build files have been written to: /root/.conan2/p/b/dispe38c8bf72dbfa0/b/build/Release

dispenso/1.2.0: Running CMake.build()
dispenso/1.2.0: RUN: cmake --build "/root/.conan2/p/b/dispe38c8bf72dbfa0/b/build/Release" -- -j12
[  6%] Building CXX object dispenso/CMakeFiles/dispenso.dir/detail/per_thread_info.cpp.o
[ 13%] Building CXX object dispenso/CMakeFiles/dispenso.dir/graph.cpp.o
[ 26%] Building CXX object dispenso/CMakeFiles/dispenso.dir/detail/quanta.cpp.o
[ 33%] Building CXX object dispenso/CMakeFiles/dispenso.dir/pool_allocator.cpp.o
[ 26%] Building CXX object dispenso/CMakeFiles/dispenso.dir/graph_executor.cpp.o
[ 46%] Building CXX object dispenso/CMakeFiles/dispenso.dir/priority.cpp.o
[ 46%] Building CXX object dispenso/CMakeFiles/dispenso.dir/schedulable.cpp.o
[ 53%] Building CXX object dispenso/CMakeFiles/dispenso.dir/small_buffer_allocator.cpp.o
[ 60%] Building CXX object dispenso/CMakeFiles/dispenso.dir/thread_id.cpp.o
[ 66%] Building CXX object dispenso/CMakeFiles/dispenso.dir/task_set.cpp.o
[ 73%] Building CXX object dispenso/CMakeFiles/dispenso.dir/thread_pool.cpp.o
[ 80%] Building CXX object dispenso/CMakeFiles/dispenso.dir/timed_task.cpp.o
[ 86%] Building CXX object dispenso/CMakeFiles/dispenso.dir/timing.cpp.o
[ 93%] Building CXX object dispenso/CMakeFiles/dispenso.dir/tsan_annotations.cpp.o
/root/.conan2/p/b/dispe38c8bf72dbfa0/b/src/dispenso/priority.cpp: In function ‘bool dispenso::setCurrentThreadPriority(dispenso::ThreadPriority)’:
/root/.conan2/p/b/dispe38c8bf72dbfa0/b/src/dispenso/priority.cpp:136:11: error: ignoring return value of ‘int nice(int)’ declared with attribute ‘warn_unused_result’ [-Werror=unused-result]
  136 |       nice(10);
      |       ~~~~^~~~
/root/.conan2/p/b/dispe38c8bf72dbfa0/b/src/dispenso/priority.cpp:140:11: error: ignoring return value of ‘int nice(int)’ declared with attribute ‘warn_unused_result’ [-Werror=unused-result]
  140 |       nice(0);
      |       ~~~~^~~
/root/.conan2/p/b/dispe38c8bf72dbfa0/b/src/dispenso/priority.cpp:152:11: error: ignoring return value of ‘int nice(int)’ declared with attribute ‘warn_unused_result’ [-Werror=unused-result]
  152 |       nice(static_cast<int>(20 - rlim.rlim_max));
      |       ~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
cc1plus: all warnings being treated as errors

I'm running

# uname -a
Linux 7e741cff55e1 6.6.12-linuxkit #1 SMP Thu Feb  8 06:36:34 UTC 2024 aarch64 aarch64 aarch64 GNU/Linux

and I'm compiling with

arch=armv8
build_type=Release
compiler=gcc
compiler.cppstd=gnu17
compiler.libcxx=libstdc++11
compiler.version=11
os=Linux

This might be something on my end so sorry about the noise if that's the case, I've tried to check for missconfigurations on my end but I can't see where I would be going wrong :)

Version

1.0 (Default)

Code of Conduct

• I agree to follow this project's Code of Conduct

[graphicsMan]

Thanks for the report. I'll try to fix this early next week.

[graphicsMan]

Hi @RubenRBS Have you tried at main branch instead of release 1.2? I believe this has been addressed.

[AbrilRBS]

Hi @graphicsMan thanks for the suggestion, seems like the current head commit does indeed compile, sorry for the noise!

Will there be a tagged release any time soon? I'd much rather merge the Conan recipe once Linux is available so I don't mind waiting :)

[graphicsMan]

I have a few more minor fixes that can go in too. I'll cut a new release once those are all in, which shouldn't be long. Maybe another week or so.

[graphicsMan]

Slowly making progress on this. I was out for more than a week with COVID, so please bear with me :)

[graphicsMan]

Big apologies for this taking so long! Release 1.3 was just cut. Let me know if you run into more issues!

[AbrilRBS]

Hi @graphicsMan thanks a lot for taking the time to address the issue, I appreciate it :)

I've now been able to compile in all my supported configurations without issues with the new 1.3 version, so hopefuly conan-io/conan-center-index#22876 gets merged soon 🤞

Thanks a lot for all your support!