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C++ Workspaces

ros2inspector has first-class support for C++ packages using Tree-sitter for accurate AST-level parsing.

What it detects​

For C++ nodes, ros2inspector finds:

  • Classes inheriting from rclcpp::Node
  • Classes inheriting from rclcpp_lifecycle::LifecycleNode
  • All create_publisher<T>(), create_subscription<T>(), create_service<T>(), create_client<T>() calls
  • Template type arguments resolved to message type strings
  • Action servers and clients

Typical C++ node​

#include "rclcpp/rclcpp.hpp"
#include "geometry_msgs/msg/twist.hpp"
#include "nav_msgs/msg/odometry.hpp"

class MyController : public rclcpp::Node
{
public:
  MyController() : Node("my_controller")
  {
    cmd_pub_ = this->create_publisher<geometry_msgs::msg::Twist>("/cmd_vel", 10);
    odom_sub_ = this->create_subscription<nav_msgs::msg::Odometry>(
      "/odom", 10,
      std::bind(&MyController::odomCallback, this, std::placeholders::_1)
    );
  }

private:
  void odomCallback(const nav_msgs::msg::Odometry::SharedPtr msg) {}

  rclcpp::Publisher<geometry_msgs::msg::Twist>::SharedPtr cmd_pub_;
  rclcpp::Subscription<nav_msgs::msg::Odometry>::SharedPtr odom_sub_;
};

ros2inspector extracts:

Node: MyController
  language:      cpp
  publishers:    ["/cmd_vel"]
  publisher_types: ["geometry_msgs/Twist"]
  subscriptions: ["/odom"]
  subscription_types: ["nav_msgs/Odometry"]

Lifecycle nodes​

#include "rclcpp_lifecycle/lifecycle_node.hpp"

class MySensor : public rclcpp_lifecycle::LifecycleNode
{
public:
  MySensor() : LifecycleNode("my_sensor")
  {
    scan_pub_ = this->create_publisher<sensor_msgs::msg::LaserScan>("/scan", 10);
  }
  // ...
};

This is detected the same way as a regular rclcpp::Node.

Mixed Python + C++ workspaces​

ros2inspector handles both in the same workspace scan:

ros2inspector nodes
  ┌──────────────────┬──────────────┬──────────┬───────────────────────┐
  │ Node             │ Package      │ Language │ Publishers            │
  ├──────────────────┼──────────────┼──────────┼───────────────────────┤
  │ MyController     │ my_pkg       │ cpp      │ /cmd_vel              │
  │ MySensor         │ sensor_pkg   │ cpp      │ /scan                 │
  │ DataProcessor    │ proc_pkg     │ python   │ /processed_data       │
  └──────────────────┴──────────────┴──────────┴───────────────────────┘

Filter to C++ only:

ros2inspector packages --filter cpp

Known limitations​

Template metaprogramming​

Topic names computed via template metaprogramming are not resolved:

// Not detected
template<typename T>
class GenericNode : public rclcpp::Node {
  auto pub_ = create_publisher<T>(TopicName<T>::value, 10);
};

Macro-generated nodes​

Nodes registered via PLUGINLIB_EXPORT_CLASS or custom macros may not be detected if the class definition is hidden inside the macro.

Dynamic topic names from parameters​

// Not captured — flagged as has_dynamic_names: true
auto topic = this->get_parameter("topic").as_string();
pub_ = create_publisher<std_msgs::msg::String>(topic, 10);

Header files​

ros2inspector parses .cpp, .hpp, and .h files. If your node class is defined in a header file, it will be detected correctly.

Performance​

C++ parsing with Tree-sitter is fast (~50ms per file), and results are cached. A 20-package C++ workspace typically analyzes in under 2 seconds after the first run.