Add flag for generating build dep for exported dep

Superflore generates a runtime-dependency for elements that depend on a
ROS package that defines packages as build-exports-depends or
buildtool-export-depend. This generates valid buildstream elements.
However, some tooling struggles to consume such dependency graph.

This commit adds a flag to additional generate a runtime-dependency for
elements that depend on a ROS package that defines packages as
build-exports-depends or buildtool-export-depend.

superflore/generators/buildstream/bst_element.py

@@ -40,6 +40,7 @@ def __init__(
         srcrev_cache, skip_keys, repo_dir, external_repos,
         *,
         exclude_source,
+        exported_dependencies_as_build_dependencies,
     ):
         self.repo_dir = repo_dir
         self.external_repos = external_repos
@@ -87,6 +88,7 @@ def __init__(
         self.srcrev = srcrev_cache[self.src_uri]
         self.skip_keys = skip_keys
         self.exclude_source = exclude_source
+        self.exported_dependencies_as_build_dependencies = exported_dependencies_as_build_dependencies
 
     def get_license_line(self):
         self.license_line = ''
@@ -313,9 +315,15 @@ def get_element_text(self, distributor):
         exec_deps, sys_deps = self.get_dependencies(
             self.rdepends, self.rdepends_external)
 
-        element["build-depends"] = buildstack + sorted(deps | buildtool_native_deps)
+        build_deps = deps | buildtool_native_deps
+        runtime_deps = deps | export_deps | buildtool_export_native_deps | exec_deps
 
-        element["runtime-depends"] = [base] + sorted(deps | export_deps | buildtool_export_native_deps | exec_deps)
+        if self.exported_dependencies_as_build_dependencies:
+            build_deps |= runtime_deps
+
+        element["build-depends"] = buildstack + sorted(build_deps)
+
+        element["runtime-depends"] = [base] + sorted(runtime_deps)
 
         variables = {}
         if self.build_type == "ament_cmake":

superflore/generators/buildstream/gen_packages.py

@@ -35,6 +35,7 @@ def regenerate_pkg(
     overlay, pkg, rosdistro, preserve_existing, srcrev_cache,
     skip_keys, external_repos, generated_elements_dir = "elements/generated",
     exclude_source=False,
+    exported_dependencies_as_build_dependencies=False,
 ):
     pkg_names = get_package_names(rosdistro)[0]
     if pkg not in pkg_names:
@@ -99,6 +100,7 @@ def regenerate_pkg(
         current = bst_element(
             rosdistro, pkg, srcrev_cache, skip_keys, repo_dir, external_repos,
             exclude_source=exclude_source,
+            exported_dependencies_as_build_dependencies=exported_dependencies_as_build_dependencies,
         )
     except InvalidPackage as e:
         err('Invalid package: ' + str(e))
@@ -146,6 +148,7 @@ def _gen_element_for_package(
     pkg_rosinstall, srcrev_cache, skip_keys, repo_dir, external_repos,
     *,
     exclude_source,
+    exported_dependencies_as_build_dependencies,
 ):
     pkg_names = get_package_names(rosdistro)
     pkg_dep_walker = DependencyWalker(rosdistro)
@@ -175,6 +178,7 @@ def _gen_element_for_package(
         repo_dir,
         external_repos,
         exclude_source=exclude_source,
+        exported_dependencies_as_build_dependencies=exported_dependencies_as_build_dependencies,
     )
     # add build dependencies
     for bdep in pkg_build_deps:
@@ -204,6 +208,7 @@ def __init__(
         self, rosdistro, pkg_name, srcrev_cache, skip_keys, repo_dir, external_repos,
         *,
         exclude_source,
+        exported_dependencies_as_build_dependencies,
     ):
         pkg = rosdistro.release_packages[pkg_name]
         repo = rosdistro.repositories[pkg.repository_name].release_repository
@@ -217,6 +222,7 @@ def __init__(
             rosdistro, pkg_name, pkg, repo, ros_pkg, pkg_rosinstall,
             srcrev_cache, skip_keys, repo_dir, external_repos,
             exclude_source=exclude_source,
+            exported_dependencies_as_build_dependencies=exported_dependencies_as_build_dependencies,
         )
 
     def element_text(self):

superflore/generators/buildstream/run.py

@@ -75,6 +75,11 @@ def main():
             default="elements/generated",
             help='directory for generated bst elements',
             type=str)
+    parser.add_argument(
+            '--exported-dependencies-as-build-dependencies',
+            default=False,
+            action='store_true',
+            help='Generate a build-dependency for exported dependencies as well as a runtime-dependency')
     parser.add_argument(
             '--exclude-sources-for',
             default=[],
@@ -153,6 +158,7 @@ def main():
                 distro = get_distro(args.ros_distro)
                 packages = args.only
                 exclude_sources_for = args.exclude_sources_for
+                exported_dependencies_as_build_dependencies = args.exported_dependencies_as_build_dependencies
                 include_dependencies = True
                 if include_dependencies:
                     packages = set(packages) | \
@@ -172,7 +178,8 @@ def main():
                             srcrev_cache,
                             skip_keys=skip_keys,
                             external_repos=external_repos,
-                            exclude_source=pkg in exclude_sources_for
+                            exclude_source=pkg in exclude_sources_for,
+                            exported_dependencies_as_build_dependencies=exported_dependencies_as_build_dependencies,
                         )
                     except KeyError:
                         err("No package to satisfy key '%s' available "