ISO C++11 requires at least one argument for the "..." in a variadic macro

[jeremyfix]

Hi,

I'm trying to compile kobuki_core for ros2 humble.

I git cloned the package list

https://github.com/stonier/sophus <-  release/1.3.x
https://github.com/stonier/ecl_tools
https://github.com/stonier/ecl_lite
https://github.com/stonier/ecl_core
https://github.com/kobuki-base/cmd_vel_mux
https://github.com/kobuki-base/kobuki_core
https://github.com/kobuki-base/kobuki_ros
https://github.com/kobuki-base/kobuki_ros_interfaces

Then I issued colcon build and got an error when compiling kobuki_core

--- stderr: kobuki_core
In file included from /home/ubuntu/ros2_ws/install/sophus/include/sophus/types.hpp:7,
                 from /home/ubuntu/ros2_ws/install/sophus/include/sophus/rotation_matrix.hpp:9,
                 from /home/ubuntu/ros2_ws/install/sophus/include/sophus/so3.hpp:6,
                 from /home/ubuntu/ros2_ws/install/sophus/include/sophus/se3.hpp:6,
                 from /home/ubuntu/ros2_ws/install/ecl_linear_algebra/include/ecl/linear_algebra/sophus.hpp:15,
                 from /home/ubuntu/ros2_ws/install/ecl_linear_algebra/include/ecl/linear_algebra.hpp:25,
                 from /home/ubuntu/ros2_ws/install/ecl_geometry/include/ecl/geometry/pose2d.hpp:21,
                 from /home/ubuntu/ros2_ws/install/ecl_geometry/include/ecl/geometry.hpp:20,
                 from /home/ubuntu/ros2_ws/src/kobuki_core/src/driver/../../include/kobuki_core/modules/diff_drive.hpp:23,
                 from /home/ubuntu/ros2_ws/src/kobuki_core/src/driver/diff_drive.cpp:14:
/home/ubuntu/ros2_ws/install/sophus/include/sophus/common.hpp:206:45: error: ISO C++11 requires at least one argument for the "..." in a variadic macro [-Werror]
  206 |     SOPHUS_ENSURE(is_valid_, "must be valid");
      |                                             ^
/home/ubuntu/ros2_ws/install/sophus/include/sophus/common.hpp:139:69: error: ISO C++11 requires at least one argument for the "..." in a variadic macro [-Werror]
  139 |       SOPHUS_DEDAULT_ENSURE_FAILURE_IMPL(SOPHUS_FUNCTION, __FILE__, __LINE__, \
      |                                                                     ^~~~~~~~
/home/ubuntu/ros2_ws/install/sophus/include/sophus/common.hpp:139:69: note: in definition of macro ‘SOPHUS_ENSURE’
  139 |       SOPHUS_DEDAULT_ENSURE_FAILURE_IMPL(SOPHUS_FUNCTION, __FILE__, __LINE__, \
      |                                                                     ^~~~~~~~
/home/ubuntu/ros2_ws/install/sophus/include/sophus/common.hpp:211:45: error: ISO C++11 requires at least one argument for the "..." in a variadic macro [-Werror]
  211 |     SOPHUS_ENSURE(is_valid_, "must be valid");
      |                                             ^
/home/ubuntu/ros2_ws/install/sophus/include/sophus/common.hpp:139:69: error: ISO C++11 requires at least one argument for the "..." in a variadic macro [-Werror]
  139 |       SOPHUS_DEDAULT_ENSURE_FAILURE_IMPL(SOPHUS_FUNCTION, __FILE__, __LINE__, \
      |                                                                     ^~~~~~~~
/home/ubuntu/ros2_ws/install/sophus/include/sophus/common.hpp:139:69: note: in definition of macro ‘SOPHUS_ENSURE’
  139 |       SOPHUS_DEDAULT_ENSURE_FAILURE_IMPL(SOPHUS_FUNCTION, __FILE__, __LINE__, \
      |                                                                     ^~~~~~~~
/home/ubuntu/ros2_ws/install/sophus/include/sophus/common.hpp:216:45: error: ISO C++11 requires at least one argument for the "..." in a variadic macro [-Werror]
  216 |     SOPHUS_ENSURE(is_valid_, "must be valid");
      |                                             ^
/home/ubuntu/ros2_ws/install/sophus/include/sophus/common.hpp:139:69: error: ISO C++11 requires at least one argument for the "..." in a variadic macro [-Werror]
  139 |       SOPHUS_DEDAULT_ENSURE_FAILURE_IMPL(SOPHUS_FUNCTION, __FILE__, __LINE__, \
      |                                                                     ^~~~~~~~
/home/ubuntu/ros2_ws/install/sophus/include/sophus/common.hpp:139:69: note: in definition of macro ‘SOPHUS_ENSURE’
  139 |       SOPHUS_DEDAULT_ENSURE_FAILURE_IMPL(SOPHUS_FUNCTION, __FILE__, __LINE__, \
      |                                                                     ^~~~~~~~
/home/ubuntu/ros2_ws/install/sophus/include/sophus/common.hpp:221:45: error: ISO C++11 requires at least one argument for the "..." in a variadic macro [-Werror]
  221 |     SOPHUS_ENSURE(is_valid_, "must be valid");
      |                                             ^
/home/ubuntu/ros2_ws/install/sophus/include/sophus/common.hpp:139:69: error: ISO C++11 requires at least one argument for the "..." in a variadic macro [-Werror]
  139 |       SOPHUS_DEDAULT_ENSURE_FAILURE_IMPL(SOPHUS_FUNCTION, __FILE__, __LINE__, \
      |                                                                     ^~~~~~~~
/home/ubuntu/ros2_ws/install/sophus/include/sophus/common.hpp:139:69: note: in definition of macro ‘SOPHUS_ENSURE’
  139 |       SOPHUS_DEDAULT_ENSURE_FAILURE_IMPL(SOPHUS_FUNCTION, __FILE__, __LINE__, \
.............

If I'm not wrong, due to the ecl_enable_cxx14_compiler() , the CMAKE_CXX_STANDARD is set to C++14.

I do not know if this is the correct fix , but then I added set(CMAKE_CXX_STANDARD 20) just after the ecl_enable_xxxxx in the kobuki_core/CMakeLists.txt and then the compilation succeded.

It has something to do with variadic macros and I blindly applied this standard change by going through this gnu gcc doc page telling C++20 is less restrictive on variadic macros.

[clalancette]

There's a fix in stonier/sophus#23, I'm just waiting for it to be merged.