ament_clang_tidy outputs sysyem header errors despite --system-header is false as default

[pucciland95]

Hi,

I am trying to integrate ament_cmake_clang_tidy in my ROS2 Humble codebase, but I do not understand why it outputs errors about the libraries that I am using (i.e. rclcpp). Therefore, the test is failing but not because of my code. The following is a minimal example to reproduce the problem:

Steps:

1. follow the ros2 tutorial guide about minimal subscriber to create minimal workspace.
2. Build the system with colcon build --cmake-args -DCMAKE_EXPORT_COMPILE_COMMANDS=ON
3. From your ROS2 workspace execute: ament_clang_tidy build/cpp_pubsub/

The output is:

found compilation database for package "cpp_pubsub"...
The invocation of "clang-tidy" failed with error code 1: Command '['/usr/bin/clang-tidy', '-p', 'build/cpp_pubsub', '--header-filter', 'include/cpp_pubsub/.*', '/home/niccolo-hiro/ros/nisa_robot_ws/src/cpp_pubsub/src/publisher_member_function.cpp']' returned non-zero exit status 1.
error: too many errors emitted, stopping now [clang-diagnostic-error]
/opt/ros/humble/include/rclcpp/rclcpp/client.hpp:550:10: error: no member named 'optional' in namespace 'std' [clang-diagnostic-error]
    std::optional<CallbackInfoVariant>
    ~~~~~^
/opt/ros/humble/include/rclcpp/rclcpp/client.hpp:550:19: error: use of undeclared identifier 'CallbackInfoVariant' [clang-diagnostic-error]
    std::optional<CallbackInfoVariant>
                  ^
/opt/ros/humble/include/rclcpp/rclcpp/client.hpp:551:5: error: use of undeclared identifier 'optional_pending_request' [clang-diagnostic-error]
    optional_pending_request = this->get_and_erase_pending_request(request_header->sequence_number);
    ^
/opt/ros/humble/include/rclcpp/rclcpp/client.hpp:552:10: error: use of undeclared identifier 'optional_pending_request' [clang-diagnostic-error]
    if (!optional_pending_request) {
         ^
/opt/ros/humble/include/rclcpp/rclcpp/client.hpp:555:21: error: use of undeclared identifier 'optional_pending_request' [clang-diagnostic-error]
    auto & value = *optional_pending_request;
                    ^
/opt/ros/humble/include/rclcpp/rclcpp/client.hpp:558:14: error: no member named 'holds_alternative' in namespace 'std' [clang-diagnostic-error]
    if (std::holds_alternative<Promise>(value)) {
        ~~~~~^
/opt/ros/humble/include/rclcpp/rclcpp/client.hpp:558:32: error: unexpected type name 'Promise': expected expression [clang-diagnostic-error]
    if (std::holds_alternative<Promise>(value)) {
                               ^
/opt/ros/humble/include/rclcpp/rclcpp/client.hpp:561:21: error: no member named 'holds_alternative' in namespace 'std' [clang-diagnostic-error]
    } else if (std::holds_alternative<CallbackTypeValueVariant>(value)) {
               ~~~~~^
/opt/ros/humble/include/rclcpp/rclcpp/client.hpp:561:39: error: unexpected type name 'CallbackTypeValueVariant': expected expression [clang-diagnostic-error]
    } else if (std::holds_alternative<CallbackTypeValueVariant>(value)) {
                                      ^
/opt/ros/humble/include/rclcpp/rclcpp/client.hpp:568:21: error: no member named 'holds_alternative' in namespace 'std' [clang-diagnostic-error]
    } else if (std::holds_alternative<CallbackWithRequestTypeValueVariant>(value)) {
               ~~~~~^
/opt/ros/humble/include/rclcpp/rclcpp/client.hpp:568:39: error: unexpected type name 'CallbackWithRequestTypeValueVariant': expected expression [clang-diagnostic-error]
    } else if (std::holds_alternative<CallbackWithRequestTypeValueVariant>(value)) {
                                      ^
/opt/ros/humble/include/rclcpp/rclcpp/client.hpp:702:10: error: use of class template 'std::lock_guard' requires template arguments [clang-diagnostic-error]
    std::lock_guard guard(pending_requests_mutex_);
         ^
/usr/bin/../lib/gcc/x86_64-linux-gnu/12/../../../../include/c++/12/bits/std_mutex.h:223:11: note: template is declared here
    class lock_guard
          ^
/opt/ros/humble/include/rclcpp/rclcpp/client.hpp:749:10: error: use of class template 'std::lock_guard' requires template arguments [clang-diagnostic-error]
    std::lock_guard guard(pending_requests_mutex_);
         ^
/usr/bin/../lib/gcc/x86_64-linux-gnu/12/../../../../include/c++/12/bits/std_mutex.h:223:11: note: template is declared here
    class lock_guard
          ^
/opt/ros/humble/include/rclcpp/rclcpp/client.hpp:768:10: error: use of class template 'std::lock_guard' requires template arguments [clang-diagnostic-error]
    std::lock_guard guard(pending_requests_mutex_);
         ^
/usr/bin/../lib/gcc/x86_64-linux-gnu/12/../../../../include/c++/12/bits/std_mutex.h:223:11: note: template is declared here
    class lock_guard
          ^
/opt/ros/humble/include/rclcpp/rclcpp/client.hpp:788:36: error: no template named 'variant' in namespace 'std' [clang-diagnostic-error]
  using CallbackInfoVariant = std::variant<
                              ~~~~~^
/opt/ros/humble/include/rclcpp/rclcpp/client.hpp:794:52: error: unknown type name 'CallbackInfoVariant' [clang-diagnostic-error]
  async_send_request_impl(const Request & request, CallbackInfoVariant value)
                                                   ^
/opt/ros/humble/include/rclcpp/rclcpp/client.hpp:808:8: error: no template named 'optional' in namespace 'std' [clang-diagnostic-error]
  std::optional<CallbackInfoVariant>
  ~~~~~^
/opt/ros/humble/include/rclcpp/rclcpp/client.hpp:808:17: error: use of undeclared identifier 'CallbackInfoVariant' [clang-diagnostic-error]
  std::optional<CallbackInfoVariant>
                ^
/opt/ros/humble/include/rclcpp/rclcpp/client.hpp:830:7: error: use of undeclared identifier 'CallbackInfoVariant' [clang-diagnostic-error]
      CallbackInfoVariant>>

which as you can see is all related to rclcpp.
Furthrmore, setting in package.xml:

<test_depend>ament_lint_auto</test_depend>
<test_depend>ament_cmake_clang_tidy</test_depend>

and in CMakeList.txt:

if(BUILD_TESTING)
  find_package(ament_lint_auto REQUIRED)
  ament_lint_auto_find_test_dependencies()
endif()

issuing: colcon test --packages-select cpp_pubsub --event-handlers console_direct+ provides exactly the same output.
Am I using this tool incorrectly?

Let me know,

cheers,

Niccolo

[pucciland95]

Ok, I think I found the problem. The newer versions of rclcpp use c++17. Indeed, adding --extra-arg=-std=c++17 to the clang-tidy command returns only the problems in the provided files. The full command is:

clang-tidy -p <path_to_compile_commands.json> --extra-arg=-std=c++17 <path_to_cpp_file_to_analyse>

Notice that I used clang-tidy and not ament_clang_tidysince the latter does not provide a way to specify such an argument. A solution has already been proposed in #452, but it has been waiting for more than a year.

I will close the issue since my problem has been fixed.

Niccolo