Issue #13959: Re-implement imp.get_suffixes() in Lib/imp.py.

This introduces a new function, imp.extension_suffixes(), which is
currently undocumented. That is forthcoming once issue #14657 is
resolved and how to expose file suffixes is decided.

7 files changed, 14 insertions, 51 deletions

diff --git a/Lib/importlib/_bootstrap.py b/Lib/importlib/_bootstrap.py
index b0c6a84..1b487ef 100644
--- a/Lib/importlib/_bootstrap.py
+++ b/Lib/importlib/_bootstrap.py
@@ -95,16 +95,6 @@ def _path_split(path):
     return front, tail
 
 
-def _path_exists(path):
-    """Replacement for os.path.exists."""
-    try:
-        _os.stat(path)
-    except OSError:
-        return False
-    else:
-        return True
-
-
 def _path_is_mode_type(path, mode):
     """Test whether the path is the specified mode type."""
     try:
@@ -128,28 +118,6 @@ def _path_isdir(path):
     return _path_is_mode_type(path, 0o040000)
 
 
-def _path_without_ext(path, ext_type):
-    """Replacement for os.path.splitext()[0]."""
-    for suffix in _suffix_list(ext_type):
-        if path.endswith(suffix):
-            return path[:-len(suffix)]
-    else:
-        raise ValueError("path is not of the specified type")
-
-
-def _path_absolute(path):
-    """Replacement for os.path.abspath."""
-    if not path:
-        path = _os.getcwd()
-    try:
-        return _os._getfullpathname(path)
-    except AttributeError:
-        if path.startswith('/'):
-            return path
-        else:
-            return _path_join(_os.getcwd(), path)
-
-
 def _write_atomic(path, data):
     """Best-effort function to write data to a path atomically.
     Be prepared to handle a FileExistsError if concurrent writing of the
@@ -338,12 +306,6 @@ def _requires_frozen(fxn):
     return _requires_frozen_wrapper
 
 
-def _suffix_list(suffix_type):
-    """Return a list of file suffixes based on the imp file type."""
-    return [suffix[0] for suffix in _imp.get_suffixes()
-            if suffix[2] == suffix_type]
-
-
 # Loaders #####################################################################
 
 class BuiltinImporter:
@@ -1196,8 +1158,9 @@ def _install(sys_module, _imp_module):
 
     """
     _setup(sys_module, _imp_module)
-    supported_loaders = [(ExtensionFileLoader, _suffix_list(3), False),
-                         (SourceFileLoader, _suffix_list(1), True),
-                         (SourcelessFileLoader, _suffix_list(2), True)]
+    extensions = ExtensionFileLoader, _imp_module.extension_suffixes(), False
+    source = SourceFileLoader, _SOURCE_SUFFIXES, True
+    bytecode = SourcelessFileLoader, [_BYTECODE_SUFFIX], True
+    supported_loaders = [extensions, source, bytecode]
     sys.path_hooks.extend([FileFinder.path_hook(*supported_loaders)])
     sys.meta_path.extend([BuiltinImporter, FrozenImporter, PathFinder])
diff --git a/Lib/importlib/test/extension/test_case_sensitivity.py b/Lib/importlib/test/extension/test_case_sensitivity.py
index 1ba2a33..bdc21e7 100644
--- a/Lib/importlib/test/extension/test_case_sensitivity.py
+++ b/Lib/importlib/test/extension/test_case_sensitivity.py
@@ -16,7 +16,7 @@ class ExtensionModuleCaseSensitivityTest(unittest.TestCase):
         assert good_name != bad_name
         finder = _bootstrap.FileFinder(ext_util.PATH,
                                         (_bootstrap.ExtensionFileLoader,
-                                            _bootstrap._suffix_list(imp.C_EXTENSION),
+                                            imp.extension_suffixes(),
                                             False))
         return finder.find_module(bad_name)
 
diff --git a/Lib/importlib/test/extension/test_finder.py b/Lib/importlib/test/extension/test_finder.py
index a28cd07..804d862 100644
--- a/Lib/importlib/test/extension/test_finder.py
+++ b/Lib/importlib/test/extension/test_finder.py
@@ -12,7 +12,7 @@ class FinderTests(abc.FinderTests):
     def find_module(self, fullname):
         importer = _bootstrap.FileFinder(util.PATH,
                                           (_bootstrap.ExtensionFileLoader,
-                                              _bootstrap._suffix_list(imp.C_EXTENSION),
+                                              imp.extension_suffixes(),
                                               False))
         return importer.find_module(fullname)
 
diff --git a/Lib/importlib/test/extension/test_path_hook.py b/Lib/importlib/test/extension/test_path_hook.py
index 673c300..129e6e2 100644
--- a/Lib/importlib/test/extension/test_path_hook.py
+++ b/Lib/importlib/test/extension/test_path_hook.py
@@ -15,7 +15,7 @@ class PathHookTests(unittest.TestCase):
 
     def hook(self, entry):
         return _bootstrap.FileFinder.path_hook((_bootstrap.ExtensionFileLoader,
-            _bootstrap._suffix_list(imp.C_EXTENSION), False))(entry)
+            imp.extension_suffixes(), False))(entry)
 
     def test_success(self):
         # Path hook should handle a directory where a known extension module
diff --git a/Lib/importlib/test/source/test_case_sensitivity.py b/Lib/importlib/test/source/test_case_sensitivity.py
index f65f285..fade25f 100644
--- a/Lib/importlib/test/source/test_case_sensitivity.py
+++ b/Lib/importlib/test/source/test_case_sensitivity.py
@@ -22,10 +22,10 @@ class CaseSensitivityTest(unittest.TestCase):
     def find(self, path):
         finder = _bootstrap.FileFinder(path,
                                         (_bootstrap.SourceFileLoader,
-                                            _bootstrap._suffix_list(imp.PY_SOURCE),
+                                            _bootstrap._SOURCE_SUFFIXES,
                                             True),
                                         (_bootstrap.SourcelessFileLoader,
-                                            _bootstrap._suffix_list(imp.PY_COMPILED),
+                                            [_bootstrap._BYTECODE_SUFFIX],
                                             True))
         return finder.find_module(self.name)
 
diff --git a/Lib/importlib/test/source/test_finder.py b/Lib/importlib/test/source/test_finder.py
index 32ebd73..45b804f 100644
--- a/Lib/importlib/test/source/test_finder.py
+++ b/Lib/importlib/test/source/test_finder.py
@@ -37,9 +37,9 @@ class FinderTests(abc.FinderTests):
 
     def import_(self, root, module):
         loader_details = [(_bootstrap.SourceFileLoader,
-                            _bootstrap._suffix_list(imp.PY_SOURCE), True),
+                            _bootstrap._SOURCE_SUFFIXES, True),
                           (_bootstrap.SourcelessFileLoader,
-                            _bootstrap._suffix_list(imp.PY_COMPILED), True)]
+                            [_bootstrap._BYTECODE_SUFFIX], True)]
         finder = _bootstrap.FileFinder(root, *loader_details)
         return finder.find_module(module)
 
@@ -139,7 +139,7 @@ class FinderTests(abc.FinderTests):
     def test_empty_string_for_dir(self):
         # The empty string from sys.path means to search in the cwd.
         finder = _bootstrap.FileFinder('', (_bootstrap.SourceFileLoader,
-            _bootstrap._suffix_list(imp.PY_SOURCE), True))
+            _bootstrap._SOURCE_SUFFIXES, True))
         with open('mod.py', 'w') as file:
             file.write("# test file for importlib")
         try:
@@ -151,7 +151,7 @@ class FinderTests(abc.FinderTests):
     def test_invalidate_caches(self):
         # invalidate_caches() should reset the mtime.
         finder = _bootstrap.FileFinder('', (_bootstrap.SourceFileLoader,
-            _bootstrap._suffix_list(imp.PY_SOURCE), True))
+            _bootstrap._SOURCE_SUFFIXES, True))
         finder._path_mtime = 42
         finder.invalidate_caches()
         self.assertEqual(finder._path_mtime, -1)
diff --git a/Lib/importlib/test/source/test_path_hook.py b/Lib/importlib/test/source/test_path_hook.py
index 663a128..df69b4d 100644
--- a/Lib/importlib/test/source/test_path_hook.py
+++ b/Lib/importlib/test/source/test_path_hook.py
@@ -11,7 +11,7 @@ class PathHookTest(unittest.TestCase):
 
     def path_hook(self):
         return _bootstrap.FileFinder.path_hook((_bootstrap.SourceFileLoader,
-            _bootstrap._suffix_list(imp.PY_SOURCE), True))
+            _bootstrap._SOURCE_SUFFIXES, True))
 
     def test_success(self):
         with source_util.create_modules('dummy') as mapping: