[feature] Add AmentDeps generator for ROS2 support in colcon builds

conan/internal/api/install/generators.py

@@ -32,7 +32,8 @@
                "SConsDeps": "conan.tools.scons",
                "QbsDeps": "conan.tools.qbs",
                "QbsProfile": "conan.tools.qbs",
-               "CPSDeps": "conan.tools.cps"
+               "CPSDeps": "conan.tools.cps",
+               "AmentDeps": "conan.tools.ros"
                }
 
 

conan/tools/ros/__init__.py

@@ -0,0 +1 @@
+from conan.tools.ros.amentdeps import AmentDeps

conan/tools/ros/amentdeps.py

@@ -0,0 +1,53 @@
+from conan.tools.files import save
+from conan.tools.cmake import CMakeDeps
+
+import os
+
+class AmentDeps(object):
+    """
+    Generator to serve as integration for Robot Operating System 2 development workspaces.
+    It is able to generate CMake files and place them correctly so they can be found by Colcon.
+    """
+
+    def __init__(self, conanfile):
+        self.cmakedeps_files = None
+        self.cmakedeps = CMakeDeps(conanfile)
+        self._conanfile = conanfile
+
+    def generate(self):
+        # This is called here so the CMakeDeps output is only showed once
+        self.cmakedeps_files = self.cmakedeps.content
+
+        output_folder = self._conanfile.generators_folder
+        if not output_folder.endswith("install"):
+            self._conanfile.output.warning("The output folder for the Ament generator should be"
+                                           " always 'install'. Make sure you are using "
+                                           "'--output-folder install' in your 'conan install'"
+                                           "command")
+        # Get the name of the ROS package that requires the Conan packages
+        ros_package_name = os.path.basename(self._conanfile.source_folder)
+        self._conanfile.output.info(f"ROS2 workspace install folder: {output_folder}")
+
+        for require, _ in self._conanfile.dependencies.items():
+            self.generate_cmake_files(output_folder, ros_package_name, require.ref.name)
+
+    def generate_cmake_files(self, install_folder, ros_package_name, require_name):
+        """
+        Generate CMakeDeps files in <install_folder>/<ros_package_name>/share/<require_name>/cmake
+        Fox example : install/consumer/share/bzip2/cmake
+
+        @param install_folder: folder to generate the
+        @param ros_package_name: name of ROS package that has de Conan dependencies
+        @param require_name: name of the dependency
+        """
+        self._conanfile.output.info(f"Generating CMake files for {require_name} dependency")
+        for generator_file, content in self.cmakedeps_files.items():
+            # Create CMake files in install/<ros_package_name>/share/<require_name>/cmake directory
+            if require_name in generator_file.lower() or \
+                    "cmakedeps_macros.cmake" in generator_file.lower():
+                self._conanfile.output.info(f"Generating CMake file {generator_file}")
+                # FIXME: This is a way to save only the require_name related cmake files
+                #  (and helper cmake files), however, names might not match!!
+                file_path = os.path.join(install_folder, ros_package_name, "share", require_name,
+                                         "cmake", generator_file)
+                save(self._conanfile, file_path, content)

test/integration/tools/ros/test_amentdeps.py

@@ -0,0 +1,65 @@
+import os
+import textwrap
+
+from conan.test.assets.genconanfile import GenConanfile
+from conan.test.utils.tools import TestClient
+
+
+def test_amentdeps():
+    """
+    Test that the amentdeps generator generates conan_<name> folders and place CMake files
+    in the correct path
+    """
+    client = TestClient()
+    conanfile1 = textwrap.dedent('''
+        import os
+        from conan import ConanFile
+        from conan.tools.files import save
+        class Recipe(ConanFile):
+            name = "lib1"
+            version = "1.0"
+            settings = "os", "compiler", "build_type", "arch"
+
+            def package(self):
+                save(self, os.path.join(self.package_folder, "lib", "lib1"), "")
+        ''')
+    conanfile2 = textwrap.dedent('''
+        import os
+        from conan import ConanFile
+        from conan.tools.files import save
+
+        class Recipe(ConanFile):
+            name = "lib2"
+            version = "1.0"
+            settings = "os", "compiler", "build_type", "arch"
+
+            def requirements(self):
+                self.requires('lib1/1.0')
+
+            def package(self):
+                save(self, os.path.join(self.package_folder, "lib", "lib2"), "")
+        ''')
+    conanfile3 = textwrap.dedent('''
+        [requires]
+        lib2/1.0
+        [generators]
+        AmentDeps
+        ''')
+    client.save({
+        "conanfile1.py": conanfile1,
+        "conanfile2.py": conanfile2,
+        os.path.join("ros_package", "conanfile3.txt"): conanfile3
+    })
+
+    client.run("create conanfile1.py")
+    client.run("create conanfile2.py")
+    client.run("install ros_package/conanfile3.txt --output-folder install")
+    assert "Generating CMake files for lib2 dependency" in client.out
+    # Check CMake files generated
+    lib2_cmake_config = os.path.join(client.current_folder, "install", "ros_package", "share",
+                                     "lib2", "cmake", "lib2-config.cmake")
+    assert os.path.exists(lib2_cmake_config)
+    # Check lib2's transitive dependency
+    lib1_cmake_config = os.path.join(client.current_folder, "install", "ros_package", "share",
+                                     "lib1", "cmake", "lib1-config.cmake")
+    assert os.path.exists(lib1_cmake_config)