Expose C code generation via rosidl generate CLI.

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

rosidl_generator_c/package.xml

@@ -18,6 +18,7 @@
 
   <build_export_depend>rosidl_typesupport_interface</build_export_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/cli.py

@@ -0,0 +1,62 @@
+# 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 os
+
+from ament_index_python import get_package_share_directory
+from rosidl_cli.command.generate.extensions import GenerateCommandExtension
+from rosidl_cli.command.generate.helpers import generate_visibility_control_file
+from rosidl_cli.command.generate.helpers import legacy_generator_arguments_file
+
+from rosidl_generator_c import generate_c
+
+
+class GenerateC(GenerateCommandExtension):
+
+    def generate(
+        self,
+        package_name,
+        interface_files,
+        include_paths,
+        output_path
+    ):
+        package_share_path = \
+            get_package_share_directory(
+                'rosidl_generator_c'
+            )
+        templates_path = os.path.join(
+            package_share_path, 'resource'
+        )
+
+        # Generate visibility control file
+        visibility_control_file_template_path = os.path.join(
+            templates_path, 'rosidl_generator_c__visibility_control.h.in')
+        visibility_control_file_path = os.path.join(
+            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
+        )
+
+        # Generate code
+        with legacy_generator_arguments_file(
+            package_name=package_name,
+            interface_files=interface_files,
+            include_paths=include_paths,
+            templates_path=templates_path,
+            output_path=output_path
+        ) as path_to_arguments_file:
+            generate_c(path_to_arguments_file)

rosidl_generator_c/setup.cfg

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