genmsg-extras: Added a BASE_DIR argument to add_service_files to be able...

[dreuter]

... to compile autogenerated messages.

[dirk-thomas]

Please describe your use case for this patch. It also looks like that the argument is very similar to the existing argument DIRECTORY.

[dreuter]

Okay, I'm sorry that I didn't provide them before.

It is quite similar to DIRECTORY but it does not take a relative path, but an absolute. For add_message_files both arguments exist.

A typical usecase would be autogenerated service files. I am currently writing a database API, which uses ROS services. Since I don't want to generate a service for each message used in our system, I wanted to create an autogenerator.

This could be used like this:

autogenerate_srvs(autogen_srvs a b c d)

add_service_files(
  FILES ${autogen_srvs}
  BASE_DIR ${CMAKE_CURRENT_BINARY_DIR}
)

where autogenerate_srvs would write some services (for each argument) in ${CMAKE_CURRENT_BINARY_DIR}

There are some (hacky) ways around this, but I think it is a good idea to integrate it, especially because add_message_files has such an argument.

[dirk-thomas]

The BASE_DIR argument for add_message_files solely exists for backward compatibility with actions.

I don't think we should mimic the same (actually pretty weird) arguments to add_service_files. Instead the DIRECTORY argument could be modified that it accepts an absolute path. Can you please update your pull request that way?

[dreuter]

I actually tried DIRECTORY first and I thought it would handle the path as absolute, if I prepend a slash. So I will give it a try :)

Is BASE_DIR used somewhere? I'm just asking because I am wondering, if I should remove it then.

[dreuter]

I pushed the new changes. DIRECTORY now handles absolute and relative paths.

I also added a commit, which removes the BASE_DIR argument, so you can omit it, if necessary.

[dreuter]

I forgot to mention, that deleting BASE_DIR will break action files at the moment. I will try to fix this.

I also created a repository, which tests the different calling methods: https://github.com/dreuter/test_genmsg

[dreuter]

My pull request in common_msgs should fix the problem mentioned above.

See: ros/common_msgs#43

[dirk-thomas]

Removing public API from an already release distro is not feasible.

[dreuter]

I fixed this. The public API now remains unchanged... Could you please merge it?

[dirk-thomas]

Thank you for the patch - I committed a modified version which is a bit more concise: 80c0d2a