gh-121604: Make sure all deprecated items in importlib raise DeprecationWarning

Lib/importlib/_bootstrap_external.py

@@ -692,6 +692,14 @@ class WindowsRegistryFinder:
         '\\Modules\\{fullname}\\Debug')
     DEBUG_BUILD = (_MS_WINDOWS and '_d.pyd' in EXTENSION_SUFFIXES)
 
+    def __init__(self):
+        import warnings
+        warnings.warn('importlib.machinery.WindowsRegistryFinder is '
+                      'deprecated. Use site configuration instead. '
+                      'Future versions of Python may not enable this '
+                      'finder by default.',
+                      DeprecationWarning, stacklevel=2)
+
     @staticmethod
     def _open_registry(key):
         try:

Lib/importlib/abc.py

@@ -70,6 +70,15 @@ class ResourceLoader(Loader):
 
     """
 
+    def __init__(self):
+        import warnings
+        warnings.warn('importlib.abc.ResourceLoader is deprecated in '
+                      'favour of supporting resource loading through '
+                      'importlib.resources.abc.ResourceReader.',
+                      DeprecationWarning, stacklevel=2)
+        super().__init__()
+
+
     @abc.abstractmethod
     def get_data(self, path):
         """Abstract method which when implemented should return the bytes for
@@ -199,6 +208,11 @@ class SourceLoader(_bootstrap_external.SourceLoader, ResourceLoader, ExecutionLo
 
     def path_mtime(self, path):
         """Return the (int) modification time for the path (str)."""
+        import warnings
+        warnings.warn('SourceLoader.path_mtime is deprecated in favour of '
+                      'SourceLoader.path_stats().',
+                      DeprecationWarning,
+                      stacklevel=2)
         if self.path_stats.__func__ is SourceLoader.path_stats:
             raise OSError
         return int(self.path_stats(path)['mtime'])

Lib/importlib/machinery.py

@@ -3,9 +3,11 @@
 from ._bootstrap import ModuleSpec
 from ._bootstrap import BuiltinImporter
 from ._bootstrap import FrozenImporter
-from ._bootstrap_external import (SOURCE_SUFFIXES, DEBUG_BYTECODE_SUFFIXES,
-                     OPTIMIZED_BYTECODE_SUFFIXES, BYTECODE_SUFFIXES,
-                     EXTENSION_SUFFIXES)
+from ._bootstrap_external import (
+    SOURCE_SUFFIXES, BYTECODE_SUFFIXES, EXTENSION_SUFFIXES,
+    DEBUG_BYTECODE_SUFFIXES as _DEBUG_BYTECODE_SUFFIXES,
+    OPTIMIZED_BYTECODE_SUFFIXES as _OPTIMIZED_BYTECODE_SUFFIXES
+)
 from ._bootstrap_external import WindowsRegistryFinder
 from ._bootstrap_external import PathFinder
 from ._bootstrap_external import FileFinder
@@ -27,3 +29,22 @@ def all_suffixes():
            'NamespaceLoader', 'OPTIMIZED_BYTECODE_SUFFIXES', 'PathFinder',
            'SOURCE_SUFFIXES', 'SourceFileLoader', 'SourcelessFileLoader',
            'WindowsRegistryFinder', 'all_suffixes']
+
+
+def __getattr__(name):
+    import warnings
+
+    if name == 'DEBUG_BYTECODE_SUFFIXES':
+        warnings.warn('importlib.machinery.DEBUG_BYTECODE_SUFFIXES is '
+                      'deprecated. Use importlib.machinery.BYTECODE_SUFFIXES '
+                      'instead.',
+                      DeprecationWarning, stacklevel=2)
+        return _DEBUG_BYTECODE_SUFFIXES
+    elif name == 'OPTIMIZED_BYTECODE_SUFFIXES':
+        warnings.warn('importlib.machinery.OPTIMIZED_BYTECODE_SUFFIXES is '
+                      'deprecated. Use importlib.machinery.BYTECODE_SUFFIXES '
+                      'instead.',
+                      DeprecationWarning, stacklevel=2)
+        return _OPTIMIZED_BYTECODE_SUFFIXES
+
+    raise AttributeError(f'module {__name__!r} has no attribute {name!r}')

Lib/test/test_importlib/test_abc.py

@@ -913,5 +913,37 @@ def test_universal_newlines(self):
                          SourceOnlyLoaderMock=SPLIT_SOL)
 
 
+class SourceLoaderDeprecationWarningsTests(unittest.TestCase):
+    """Tests SourceLoader deprecation warnings."""
+
+    def test_deprecated_path_mtime(self):
+        from importlib.abc import SourceLoader
+        class DummySourceLoader(SourceLoader):
+            def get_data(self, path):
+                return b''
+
+            def get_filename(self, fullname):
+                return 'foo.py'
+
+            def path_stats(self, path):
+                return {'mtime': 1}
+
+        loader = DummySourceLoader()
+        with self.assertWarns(DeprecationWarning):
+            loader.path_mtime('foo.py')
+
+
+class ResourceLoaderDeprecationWarningsTests(unittest.TestCase):
+    """Tests ResourceLoader deprecation warnings."""
+
+    def test_deprecated_resource_loader(self):
+        from importlib.abc import ResourceLoader
+        class DummyLoader(ResourceLoader):
+            def get_data(self, path):
+                return b''
+
+        with self.assertWarns(DeprecationWarning):
+            DummyLoader()
+
 if __name__ == '__main__':
     unittest.main()

Lib/test/test_importlib/test_api.py

@@ -492,5 +492,23 @@ def test_util(self):
         support.check__all__(self, util['Source'], extra=extra)
 
 
+class TestDeprecations(unittest.TestCase):
+    def test_machinery_deprecated_attributes(self):
+        from importlib import machinery
+        attributes = (
+            'DEBUG_BYTECODE_SUFFIXES',
+            'OPTIMIZED_BYTECODE_SUFFIXES',
+        )
+        for attr in attributes:
+            with self.subTest(attr=attr):
+                with self.assertWarns(DeprecationWarning):
+                    getattr(machinery, attr)
+
+    def test_deprecated_windows_registry_finder(self):
+        from importlib.machinery import WindowsRegistryFinder
+        with self.assertWarns(DeprecationWarning):
+            WindowsRegistryFinder()
+
+
 if __name__ == '__main__':
     unittest.main()

Misc/NEWS.d/next/Library/2024-12-16-22-20-38.gh-issue-121604.m3Xn4G.rst

@@ -0,0 +1 @@
+Add missing Deprecation warnings for several :mod:`importlib` members.