Build time generation of fixed-size strings

[MiguelCompany]

This is part of a PoC towards achieving the goals of ros2/rclcpp#2201

• On rosidl_runtime_cpp, a new class has been added that behaves as a bounded string but can be considered POD by the underlying middleware.
• On rosidl_generator_cpp, processing of a new cdr_plain annotation has been introduced, so string members with that annotation will be generated using the new class.
• On rosidl_adapter, strings can be annotated with this new annotation depending on the contents of a YAML file specified in the environment variable ROS2_TYPE_FIXED_SIZE_FILE.

[narol1024]

I migrated to the Humble version, but I encountered this error. I’m not sure if it’s an issue with my environment.

In file included from /root/ros_ws/build_arm/build/xbrain_shm_msgs/rosidl_typesupport_fastrtps_cpp/xbrain_shm_msgs/msg/detail/fixed_strings__rosidl_typesupport_fastrtps_cpp.hpp:25,
                 from /root/ros_ws/build_arm/build/xbrain_shm_msgs/rosidl_typesupport_fastrtps_cpp/xbrain_shm_msgs/msg/detail/dds_fastrtps/fixed_strings__type_support.cpp:4:
/cross_compile/arm/opt/ros/humble/include/fastcdr/fastcdr/Cdr.h: In instantiation of ‘eprosima::fastcdr::Cdr& eprosima::fastcdr::Cdr::serializeArray(const _T*, size_t) [with _T = rosidl_runtime_cpp::CDRCompatibleFixedCapacityString<16>; size_t = long unsigned int]’:
/cross_compile/arm/opt/ros/humble/include/fastcdr/fastcdr/Cdr.h:1257:30:   required from ‘eprosima::fastcdr::Cdr& eprosima::fastcdr::Cdr::serialize(const std::array<_Tp, _Nm>&) [with _T = rosidl_runtime_cpp::CDRCompatibleFixedCapacityString<16>; long unsigned int _Size = 10]’
/cross_compile/arm/opt/ros/humble/include/fastcdr/fastcdr/Cdr.h:502:36:   required from ‘eprosima::fastcdr::Cdr& eprosima::fastcdr::Cdr::operator<<(const std::array<_Tp, _Nm>&) [with _T = rosidl_runtime_cpp::CDRCompatibleFixedCapacityString<16>; long unsigned int _Size = 10]’
/root/ros_ws/build_arm/build/xbrain_shm_msgs/rosidl_typesupport_fastrtps_cpp/xbrain_shm_msgs/msg/detail/dds_fastrtps/fixed_strings__type_support.cpp:38:24:   required from here
/cross_compile/arm/opt/ros/humble/include/fastcdr/fastcdr/Cdr.h:1932:27: error: ‘const class rosidl_runtime_cpp::CDRCompatibleFixedCapacityString<16>’ has no member named ‘serialize’
 1932 |             type_t[count].serialize(*this);
      |             ~~~~~~~~~~~~~~^~~~~~~~~
/cross_compile/arm/opt/ros/humble/include/fastcdr/fastcdr/Cdr.h: In instantiation of ‘eprosima::fastcdr::Cdr& eprosima::fastcdr::Cdr::deserializeArray(_T*, size_t) [with _T = rosidl_runtime_cpp::CDRCompatibleFixedCapacityString<16>; size_t = long unsigned int]’:
/cross_compile/arm/opt/ros/humble/include/fastcdr/fastcdr/Cdr.h:2528:32:   required from ‘eprosima::fastcdr::Cdr& eprosima::fastcdr::Cdr::deserialize(std::array<_Tp, _Nm>&) [with _T = rosidl_runtime_cpp::CDRCompatibleFixedCapacityString<16>; long unsigned int _Size = 10]’
/cross_compile/arm/opt/ros/humble/include/fastcdr/fastcdr/Cdr.h:767:38:   required from ‘eprosima::fastcdr::Cdr& eprosima::fastcdr::Cdr::operator>>(std::array<_Tp, _Nm>&) [with _T = rosidl_runtime_cpp::CDRCompatibleFixedCapacityString<16>; long unsigned int _Size = 10]’
/root/ros_ws/build_arm/build/xbrain_shm_msgs/rosidl_typesupport_fastrtps_cpp/xbrain_shm_msgs/msg/detail/dds_fastrtps/fixed_strings__type_support.cpp:51:24:   required from here
/cross_compile/arm/opt/ros/humble/include/fastcdr/fastcdr/Cdr.h:3219:27: error: ‘class rosidl_runtime_cpp::CDRCompatibleFixedCapacityString<16>’ has no member named ‘deserialize’
 3219 |             type_t[count].deserialize(*this);
      |             ~~~~~~~~~~~~~~^~~~~~~~~~~
gmake[2]: *** [CMakeFiles/xbrain_shm_msgs__rosidl_typesupport_fastrtps_cpp.dir/build.make:93: CMakeFiles/xbrain_shm_msgs__rosidl_typesupport_fastrtps_cpp.dir/rosidl_typesupport_fastrtps_cpp/xbrain_shm_msgs/msg/detail/dds_fastrtps/fixed_strings__type_support.cpp.o] Error 1
gmake[1]: *** [CMakeFiles/Makefile2:291: CMakeFiles/xbrain_shm_msgs__rosidl_typesupport_fastrtps_cpp.dir/all] Error 2

[MiguelCompany]

@narol1024 Bear in mind that this is a draft PR over rolling, so it might depend on changes in Fast CDR that are not present in Humble