conversion functions from .msg / .srv to .idl

[dirk-thomas]

This is the third PR integrating #298 step-by-step.

Builds on top of #323.

Since the functionality provided by this patch isn't actively being used yet there isn't a point in running CI.

The command line script msg2idl.py and srv2idl.py can be used to manually convert .msg / .srv files.

[mjcarroll]

I think the only thing that was unexpected is that the scripts had to be run from the package folder.

# Fails
 src/ros2/common_interfaces $ ros2 run rosidl_adapter srv2idl.py ./sensor_msgs/srv/SetCameraInfo.srv
# Succeeds
ros2/common_interfaces/sensor_msgs $ ros2 run rosidl_adapter srv2idl.py ./srv/SetCameraInfo.srv

A short doc or more informative error would be helpful in this case.

[dirk-thomas]

I think the only thing that was unexpected is that the scripts had to be run from the package folder.

That is weird. It worked for me with arbitrary paths independent of the cwd. Can you please share your output when it fails.

[mjcarroll]

ros2_ws)➜  common_interfaces git:(master) ros2 run rosidl_adapter srv2idl.py ./sensor_msgs/srv/SetCameraInfo.srv
Reading input file: sensor_msgs/srv/SetCameraInfo.srv
Traceback (most recent call last):
  File "/home/michael/workspaces/ros2_ws/install/rosidl_adapter/lib/rosidl_adapter/srv2idl.py", line 22, in <module>
    convert_files_to_idl('.srv', convert_srv_to_idl)
  File "/home/michael/workspaces/ros2_ws/install/rosidl_adapter/lib/python3.6/site-packages/rosidl_adapter/cli.py", line 48, in convert_files_to_idl
    package_dir, pkg.name, interface_file, interface_file.parent)
  File "/home/michael/workspaces/ros2_ws/install/rosidl_adapter/lib/python3.6/site-packages/rosidl_adapter/srv/__init__.py", line 26, in convert_srv_to_idl
    content = abs_input_file.read_text(encoding='utf-8')
  File "/usr/lib/python3.6/pathlib.py", line 1194, in read_text
    with self.open(mode='r', encoding=encoding, errors=errors) as f:
  File "/usr/lib/python3.6/pathlib.py", line 1181, in open
    opener=self._opener)
  File "/usr/lib/python3.6/pathlib.py", line 1035, in _opener
    return self._accessor.open(self, flags, mode)
  File "/usr/lib/python3.6/pathlib.py", line 387, in wrapped
    return strfunc(str(pathobj), *args)
FileNotFoundError: [Errno 2] No such file or directory: '/home/michael/workspaces/ros2_ws/src/ros2/common_interfaces/sensor_msgs/sensor_msgs/srv/SetCameraInfo.srv'

[dirk-thomas]

I was able to reproduce the problem. It should be fixed in 9d2cd71.

Please retry with the current state