Initial implementation

colcon_override_check/__init__.py

@@ -1,4 +1,4 @@
 # Copyright 2022 Scott K Logan
 # Licensed under the Apache License, Version 2.0
 
-__version__ = '0.0.0'
+__version__ = '0.0.1'

colcon_override_check/package_selection/override_check.py

@@ -0,0 +1,171 @@
+# Copyright 2022 Open Source Robotics Foundation, Inc.
+# Licensed under the Apache License, Version 2.0
+
+import argparse
+from pathlib import Path
+import sys
+
+from colcon_core.location import get_relative_package_index_path
+from colcon_core.package_selection import logger
+from colcon_core.package_selection import PackageSelectionExtensionPoint
+from colcon_core.plugin_system import satisfies_version
+from colcon_installed_package_information.package_augmentation \
+    import augment_packages
+from colcon_installed_package_information.package_discovery \
+    import discover_packages
+from colcon_installed_package_information.package_identification \
+    import get_package_identification_extensions
+
+
+if sys.version_info < (3, 8):
+    # TODO(sloretz) remove when minimum supported Python version is 3.8
+    # https://stackoverflow.com/a/41153081
+    class _ExtendAction(argparse.Action):
+        """Add argparse action to extend a list."""
+
+        def __call__(self, parser, namespace, values, option_string=None):
+            """Extend the list with new arguments."""
+            items = getattr(namespace, self.dest) or []
+            items.extend(values)
+            setattr(namespace, self.dest, items)
+
+
+class OverrideCheckPackageSelection(PackageSelectionExtensionPoint):
+    """Check for potential problems when overriding installed packages."""
+
+    # Because this is effectively observing the selected packages, this
+    # extension should run after other package selection extensions
+    PRIORITY = 10
+
+    TARGET_VERBS = ('build',)
+
+    def __init__(self):  # noqa: D107
+        super().__init__()
+        satisfies_version(
+            PackageSelectionExtensionPoint.EXTENSION_POINT_VERSION, '^1.0')
+
+    def add_arguments(self, *, parser):  # noqa: D102
+        if sys.version_info < (3, 8):
+            # TODO(sloretz) remove when minimum supported Python version is 3.8
+            parser.register('action', 'extend', _ExtendAction)
+
+        parser.add_argument(
+            '--allow-overriding',
+            action='extend',
+            default=[],
+            metavar='PKG_NAME',
+            nargs='+',
+            help='Allow building packages that exist in underlay workspaces')
+
+    def check_parameters(self, args, pkg_names):  # noqa: D102
+        for pkg_name in args.allow_overriding or []:
+            if pkg_name not in pkg_names:
+                logger.warning(
+                    "ignoring unknown package '{pkg_name}' in "
+                    '--allow-overriding'.format_map(locals()))
+
+    def select_packages(self, args, decorators):  # noqa: D102
+        verb_name = getattr(args, 'verb_name', None)
+        if verb_name not in OverrideCheckPackageSelection.TARGET_VERBS:
+            return
+
+        # Enumerate the names of packages selected to be built.
+        selected_names = {d.descriptor.name for d in decorators if d.selected}
+
+        # Enumerate the underlay packages.
+        identification_extensions = get_package_identification_extensions()
+        underlay_descriptors = discover_packages(
+            args, identification_extensions)
+        augment_packages(underlay_descriptors)
+        if not underlay_descriptors:
+            return
+
+        # Enumerate workspace packages already built (if applicable).
+        building_or_built = set(selected_names)
+        if hasattr(args, 'install_base'):
+            install_base = Path(args.install_base).resolve()
+
+            # Drop any enumerated underlay packages in our install base.
+            # This could happen when a workspace install base is activated and
+            # then built again.
+            rebuilding = [
+                d for d in underlay_descriptors if d.path == install_base]
+            underlay_descriptors.difference_update(rebuilding)
+            if not underlay_descriptors:
+                return
+            building_or_built.update(d.name for d in rebuilding)
+
+            # Explicitly enumerate which workspace packages have already been
+            # built/installed in case the install base hasn't already been
+            # activated.
+            index_path = install_base / get_relative_package_index_path()
+            if index_path.is_dir():
+                building_or_built.update(p.name for p in index_path.iterdir())
+
+        # Enumerate dependencies from underlay packages to selected packages.
+        reverse_dependencies = {}
+        for d in underlay_descriptors:
+            # If an underlay package is being built or has already been built,
+            # its dependencies are irrelevant because it is already, or will
+            # be, overridden itself.
+            if d.name in building_or_built:
+                continue
+
+            # Consider only runtime dependencies from underlay packages to
+            # selected packages.
+            deps = {
+                d.name for d in d.get_dependencies(categories=('run',))
+                if d.name in selected_names}
+
+            for dep in deps:
+                reverse_dependencies.setdefault(dep, set())
+                reverse_dependencies[dep].add(d.name)
+
+        # Compute the list of paths where potentially overridden packages are
+        # installed to.
+        underlay_paths = {}
+        for d in underlay_descriptors:
+            underlay_paths.setdefault(d.name, [])
+            underlay_paths[d.name].append(str(d.path))
+
+        # Finally, determine what packages are overriding underlay packages
+        overriding_names = selected_names.intersection(underlay_paths)
+
+        # Of those, ignore specifically allowed overrides
+        overriding_names.difference_update(args.allow_overriding)
+
+        # Of those, Ignore overrides which are (effectively) leaf packages
+        overriding_names.intersection_update(
+            name for name, deps in reverse_dependencies.items()
+            if deps)
+
+        override_messages = {}
+        for overriding_package in overriding_names:
+            override_messages[overriding_package] = (
+                "'{overriding_package}' is in: ".format_map(locals()) +
+                ', '.join(underlay_paths[overriding_package]))
+
+        if override_messages:
+            override_msg = (
+                'Some selected packages are already built in one or more'
+                ' underlay workspaces:'
+                '\n\t' +
+                '\n\t'.join(override_messages.values()) +
+                '\nIf a package in a merged underlay workspace is overridden'
+                ' and it installs headers, then all packages in the overlay'
+                ' must sort their include directories by workspace order.'
+                ' Failure to do so may result in build failures or undefined'
+                ' behavior at run time.'
+                '\nIf the overridden package is used by another package'
+                ' in any underlay, then the overriding package in the'
+                ' overlay must be API and ABI compatible or undefined'
+                ' behavior at run time may occur.'
+                '\n\nIf you understand the risks and want to override a'
+                ' package anyways, add the following to the command'
+                ' line:'
+                '\n\t--allow-overriding ' +
+                ' '.join(sorted(override_messages.keys())))
+
+            logger.warn(
+                override_msg + '\n\nThis may be promoted to an error in a'
+                ' future release of colcon-core.')

setup.cfg

@@ -25,7 +25,8 @@ keywords = colcon
 
 [options]
 install_requires =
-  colcon-core
+  colcon-core>=0.7.1
+  colcon-installed-package-information
 packages = find:
 zip_safe = true
 
@@ -56,6 +57,8 @@ filterwarnings =
 junit_suite_name = colcon-override-check
 
 [options.entry_points]
+colcon_core.package_selection =
+    override_check = colcon_override_check.package_selection.override_check:OverrideCheckPackageSelection
 
 [flake8]
 import-order-style = google

stdeb.cfg

@@ -1,5 +1,5 @@
 [colcon-override-check]
 No-Python2:
-Depends3: python3-colcon-core
+Depends3: python3-colcon-core (>= 0.7.1), python3-colcon-installed-package-information
 Suite: bionic focal jammy stretch buster bullseye
 X-Python3-Version: >= 3.5

test/spell_check.words

@@ -1,9 +1,19 @@
 apache
+argparse
 colcon
+deps
+https
 iterdir
+nargs
+noqa
 pathlib
+plugin
 pytest
 scott
 scspell
 setuptools
+sloretz
+stackoverflow
 thomas
+todo
+workspaces