Expose C code generation via rosidl generate CLI (#569)

Signed-off-by: Michel Hidalgo <michel@ekumenlabs.com>

rosidl_generator_c/bin/rosidl_generator_c

@@ -31,9 +31,7 @@ def main(argv=sys.argv[1:]):
         help='The location of the file containing the generator arguments')
     args = parser.parse_args(argv)
 
-    return generate_c(
-        args.generator_arguments_file,
-    )
+    generate_c(args.generator_arguments_file)
 
 
 if __name__ == '__main__':

rosidl_generator_c/package.xml

@@ -18,6 +18,8 @@
 
   <build_export_depend>rosidl_typesupport_interface</build_export_depend>
 
+  <exec_depend>ament_index_python</exec_depend>
+  <exec_depend>rosidl_cli</exec_depend>
   <exec_depend>rosidl_parser</exec_depend>
 
   <test_depend>ament_cmake_gtest</test_depend>

rosidl_generator_c/rosidl_generator_c/__init__.py

@@ -34,7 +34,7 @@ def generate_c(generator_arguments_file):
         'idl__struct.h.em': 'detail/%s__struct.h',
         'idl__type_support.h.em': 'detail/%s__type_support.h',
     }
-    generate_files(
+    return generate_files(
         generator_arguments_file, mapping,
         post_process_callback=prefix_with_bom_if_necessary)
 

rosidl_generator_c/rosidl_generator_c/cli.py

@@ -0,0 +1,81 @@
+# Copyright 2021 Open Source Robotics Foundation, Inc.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+import pathlib
+
+from ament_index_python import get_package_share_directory
+from rosidl_cli.command.generate.extensions import GenerateCommandExtension
+from rosidl_cli.command.helpers import generate_visibility_control_file
+from rosidl_cli.command.helpers import legacy_generator_arguments_file
+from rosidl_cli.command.translate.api import translate
+
+from rosidl_generator_c import generate_c
+
+
+class GenerateC(GenerateCommandExtension):
+
+    def generate(
+        self,
+        package_name,
+        interface_files,
+        include_paths,
+        output_path
+    ):
+        generated_files = []
+
+        package_share_path = \
+            pathlib.Path(get_package_share_directory('rosidl_generator_c'))
+        templates_path = package_share_path / 'resource'
+
+        # Normalize interface definition format to .idl
+        idl_interface_files = []
+        non_idl_interface_files = []
+        for path in interface_files:
+            if not path.endswith('.idl'):
+                non_idl_interface_files.append(path)
+            else:
+                idl_interface_files.append(path)
+        if non_idl_interface_files:
+            idl_interface_files.extend(translate(
+                package_name=package_name,
+                interface_files=non_idl_interface_files,
+                include_paths=include_paths,
+                output_format='idl',
+                output_path=output_path / 'tmp',
+            ))
+
+        # Generate visibility control file
+        visibility_control_file_template_path = \
+            templates_path / 'rosidl_generator_c__visibility_control.h.in'
+        visibility_control_file_path = \
+            output_path / 'msg' / 'rosidl_generator_c__visibility_control.h'
+
+        generate_visibility_control_file(
+            package_name=package_name,
+            template_path=visibility_control_file_template_path,
+            output_path=visibility_control_file_path
+        )
+        generated_files.append(visibility_control_file_path)
+
+        # Generate code
+        with legacy_generator_arguments_file(
+            package_name=package_name,
+            interface_files=idl_interface_files,
+            include_paths=include_paths,
+            templates_path=templates_path,
+            output_path=output_path
+        ) as path_to_arguments_file:
+            generated_files.extend(generate_c(path_to_arguments_file))
+
+        return generated_files

rosidl_generator_c/setup.cfg

@@ -0,0 +1,3 @@
+[options.entry_points]
+rosidl_cli.command.generate.type_extensions =
+  c = rosidl_generator_c.cli:GenerateC