How does support for custom messages work.

[tdejager]

Hi,

This is more of a question than an issue. I wanted to test the rosrust library with our own message types. But I'm unable to get it working with our workspace setup. The catkin workspace is set-up, and everything is sourced. It seems that the include_message macro looks at the following locations:

        /home/tdejager/ros/melodic/smart_robotics/devel/share
          /opt/ros/melodic/share
          /home/tdejager/ros/melodic/smart_robotics/devel/../src
          /opt/ros/melodic/../src

So that is the share folder for the catkin workspace and the source folder. However, I think that the messages for packages in the user workspace are not copied to the share folder. At least, I can't seem to find them there. As opposed to std_msgs, which are included in the installation.

Also as for the source folder, the required package is not located directly in the root, but in a subdirectory.

Am I missing something? Could you maybe share some info on how the include macro is supposed to work or how your workspace is setup?

Thanks!

[adnanademovic]

Where are your messages located? The actual .msg files I mean. Are they in /home/tdejager/ros/melodic/smart_robotics/src/my_package/msg/SomeMessage.msg?

[tdejager]

They are actually in a subfolder for our (mono)-repo, so /home/tdejager/melodic/smart_robotics/sr-common/sr_msgs/msg/Foo.msg

[adnanademovic]

Oh I never considered if catkin_make can find packages that aren't directly located in the src folder. I guess the codegen should search through the subfolders as well. I'll try to get to that soon.

[andresv]

I have following structure:

|-common/msg/SomeMsg.msg
|-rustnode

All custom messages are under common/msg. I use ROSRUST_MSG_PATH to specify where those messages are.
So following lines are in rustnode/CMakeLists.txt

COMMAND ROSRUST_MSG_PATH=${CMAKE_CURRENT_SOURCE_DIR}/.. cargo build --release --target-dir ${CMAKE_BINARY_DIR}/cargo/
COMMAND ${CMAKE_COMMAND} -E copy ${CMAKE_BINARY_DIR}/cargo/release/rustnode ${CMAKE_RUNTIME_OUTPUT_DIRECTORY}/rustnode

In rustnode I can include them as:

use rosrust;

rosrust::rosmsg_include!(
                common/SomeMsg,
);

[tdejager]

Wow, thank you both for the answers. And thank you for making this project btw @adnanademovic, you have done a lot of great work :)

@andresv Thanks for that solution, I'll try it out. Is that also how you are building the rust project in the catkin workspace?

@adnanademovic If you give me some pointers where to start, I've checked the proc-macro code a bit. I could try to make a PR for that?

[andresv]

@tdejager, yes, this how my rust nodes are integrated with catkin. So basically others almost even do not know that there are rust nodes. They just run catkin_make as always.

[OTL]

+1 for searching subdirectories as @adnanademovic says.
I need a lot of ROSRUST_MSG_PATH to handle my/others meta packages.