bpo-33591: Fix CDLL to accept PathLike objects

Doc/library/ctypes.rst

@@ -1380,6 +1380,10 @@ way is to instantiate one of the following classes:
    DLLs and determine which one is not found using Windows debugging and
    tracing tools.
 
+   .. versionchanged:: 3.12
+
+      The *name* parameter can now be a :term:`path-like object`.
+
 .. seealso::
 
     `Microsoft DUMPBIN tool <https://docs.microsoft.com/cpp/build/reference/dependents>`_
@@ -1398,13 +1402,21 @@ way is to instantiate one of the following classes:
    .. versionchanged:: 3.3
       :exc:`WindowsError` used to be raised.
 
+   .. versionchanged:: 3.12
+
+      The *name* parameter can now be a :term:`path-like object`.
+
 
 .. class:: WinDLL(name, mode=DEFAULT_MODE, handle=None, use_errno=False, use_last_error=False, winmode=None)
 
    Windows only: Instances of this class represent loaded shared libraries,
    functions in these libraries use the ``stdcall`` calling convention, and are
    assumed to return :c:expr:`int` by default.
 
+   .. versionchanged:: 3.12
+
+      The *name* parameter can now be a :term:`path-like object`.
+
 The Python :term:`global interpreter lock` is released before calling any
 function exported by these libraries, and reacquired afterwards.
 
@@ -1418,6 +1430,10 @@ function exported by these libraries, and reacquired afterwards.
 
    Thus, this is only useful to call Python C api functions directly.
 
+   .. versionchanged:: 3.12
+
+      The *name* parameter can now be a :term:`path-like object`.
+
 All these classes can be instantiated by calling them with at least one
 argument, the pathname of the shared library.  If you have an existing handle to
 an already loaded shared library, it can be passed as the ``handle`` named

Lib/ctypes/__init__.py

@@ -344,6 +344,8 @@ def __init__(self, name, mode=DEFAULT_MODE, handle=None,
                  use_errno=False,
                  use_last_error=False,
                  winmode=None):
+        if name:
+            name = _os.fspath(name)
         self._name = name
         flags = self._func_flags_
         if use_errno:

Lib/test/test_ctypes/test_loading.py

@@ -28,10 +28,20 @@ class LoaderTest(unittest.TestCase):
     unknowndll = "xxrandomnamexx"
 
     def test_load(self):
-        if libc_name is None:
-            self.skipTest('could not find libc')
-        CDLL(libc_name)
-        CDLL(os.path.basename(libc_name))
+        if libc_name is not None:
+            test_lib = libc_name
+        else:
+            if os.name == "nt":
+                import _ctypes_test
+                test_lib = _ctypes_test.__file__
+            else:
+                self.skipTest('could not find library to load')
+        CDLL(test_lib)
+        CDLL(os.path.basename(test_lib))
+        class CTypesTestPathLikeCls:
+            def __fspath__(self):
+                return test_lib
+        CDLL(CTypesTestPathLikeCls())
         self.assertRaises(OSError, CDLL, self.unknowndll)
 
     def test_load_version(self):

Misc/ACKS

@@ -754,6 +754,7 @@ Tim Hochberg
 Benjamin Hodgson
 Joerg-Cyril Hoehle
 Douwe Hoekstra
+Robert Hoelzl
 Gregor Hoffleit
 Chris Hoffman
 Tim Hoffmann

Misc/NEWS.d/next/Library/2018-05-21-17-18-00.gh-issue-77772.Fhg84L.rst

@@ -0,0 +1,3 @@
+:class:`ctypes.CDLL`, :class:`ctypes.OleDLL`, :class:`ctypes.WinDLL`,
+and :class:`ctypes.PyDLL` now accept :term:`path-like objects
+<path-like object>` as their ``name`` argument. Patch by Robert Hoelzl.