gh-100540: Remove obsolete Modules/_ctypes/darwin/ dlfcn shim

As far as I can tell, this hasn't been actually used since Mac OS X 10.2.

Author: zware

Makefile.pre.in

@@ -2591,7 +2591,7 @@ MODULE_MATH_DEPS=$(srcdir)/Modules/_math.h
 MODULE_PYEXPAT_DEPS=@LIBEXPAT_INTERNAL@
 MODULE_UNICODEDATA_DEPS=$(srcdir)/Modules/unicodedata_db.h $(srcdir)/Modules/unicodename_db.h
 MODULE__BLAKE2_DEPS=$(srcdir)/Modules/_blake2/impl/blake2-config.h $(srcdir)/Modules/_blake2/impl/blake2-impl.h $(srcdir)/Modules/_blake2/impl/blake2.h $(srcdir)/Modules/_blake2/impl/blake2b-load-sse2.h $(srcdir)/Modules/_blake2/impl/blake2b-load-sse41.h $(srcdir)/Modules/_blake2/impl/blake2b-ref.c $(srcdir)/Modules/_blake2/impl/blake2b-round.h $(srcdir)/Modules/_blake2/impl/blake2b.c $(srcdir)/Modules/_blake2/impl/blake2s-load-sse2.h $(srcdir)/Modules/_blake2/impl/blake2s-load-sse41.h $(srcdir)/Modules/_blake2/impl/blake2s-load-xop.h $(srcdir)/Modules/_blake2/impl/blake2s-ref.c $(srcdir)/Modules/_blake2/impl/blake2s-round.h $(srcdir)/Modules/_blake2/impl/blake2s.c $(srcdir)/Modules/_blake2/blake2module.h $(srcdir)/Modules/hashlib.h
-MODULE__CTYPES_DEPS=$(srcdir)/Modules/_ctypes/ctypes.h $(srcdir)/Modules/_ctypes/darwin/dlfcn.h
+MODULE__CTYPES_DEPS=$(srcdir)/Modules/_ctypes/ctypes.h
 MODULE__CTYPES_MALLOC_CLOSURE=@MODULE__CTYPES_MALLOC_CLOSURE@
 MODULE__DECIMAL_DEPS=$(srcdir)/Modules/_decimal/docstrings.h @LIBMPDEC_INTERNAL@
 MODULE__ELEMENTTREE_DEPS=$(srcdir)/Modules/pyexpat.c @LIBEXPAT_INTERNAL@

Misc/NEWS.d/next/macOS/2022-12-26-14-52-37.gh-issue-100540.kYZLtX.rst

@@ -0,0 +1,2 @@
+Removed obsolete ``dlfcn.h`` shim from the ``_ctypes`` extension module,
+which has not been necessary since Mac OS X 10.2.

Modules/_ctypes/_ctypes.c

@@ -120,7 +120,7 @@ bytes(cdata)
 #define IS_INTRESOURCE(x) (((size_t)(x) >> 16) == 0)
 #endif
 #else
-#include "ctypes_dlfcn.h"
+#include <dlfcn.h>
 #endif
 #include "ctypes.h"
 
@@ -768,15 +768,15 @@ CDataType_in_dll(PyObject *type, PyObject *args)
         return NULL;
     }
 #else
-    address = (void *)ctypes_dlsym(handle, name);
+    address = (void *)dlsym(handle, name);
     if (!address) {
 #ifdef __CYGWIN__
 /* dlerror() isn't very helpful on cygwin */
         PyErr_Format(PyExc_ValueError,
                      "symbol '%s' not found",
                      name);
 #else
-        PyErr_SetString(PyExc_ValueError, ctypes_dlerror());
+        PyErr_SetString(PyExc_ValueError, dlerror());
 #endif
         return NULL;
     }
@@ -3560,15 +3560,15 @@ PyCFuncPtr_FromDll(PyTypeObject *type, PyObject *args, PyObject *kwds)
         return NULL;
     }
 #else
-    address = (PPROC)ctypes_dlsym(handle, name);
+    address = (PPROC)dlsym(handle, name);
     if (!address) {
 #ifdef __CYGWIN__
 /* dlerror() isn't very helpful on cygwin */
         PyErr_Format(PyExc_AttributeError,
                      "function '%s' not found",
                      name);
 #else
-        PyErr_SetString(PyExc_AttributeError, ctypes_dlerror());
+        PyErr_SetString(PyExc_AttributeError, dlerror());
 #endif
         Py_DECREF(ftuple);
         return NULL;

Modules/_ctypes/callproc.c

@@ -67,7 +67,7 @@
 #include <windows.h>
 #include <tchar.h>
 #else
-#include "ctypes_dlfcn.h"
+#include <dlfcn.h>
 #endif
 
 #ifdef __APPLE__
@@ -1537,10 +1537,10 @@ static PyObject *py_dl_open(PyObject *self, PyObject *args)
     if (PySys_Audit("ctypes.dlopen", "O", name) < 0) {
         return NULL;
     }
-    handle = ctypes_dlopen(name_str, mode);
+    handle = dlopen(name_str, mode);
     Py_XDECREF(name2);
     if (!handle) {
-        const char *errmsg = ctypes_dlerror();
+        const char *errmsg = dlerror();
         if (!errmsg)
             errmsg = "dlopen() error";
         PyErr_SetString(PyExc_OSError,
@@ -1558,7 +1558,7 @@ static PyObject *py_dl_close(PyObject *self, PyObject *args)
         return NULL;
     if (dlclose(handle)) {
         PyErr_SetString(PyExc_OSError,
-                               ctypes_dlerror());
+                               dlerror());
         return NULL;
     }
     Py_RETURN_NONE;
@@ -1576,10 +1576,10 @@ static PyObject *py_dl_sym(PyObject *self, PyObject *args)
     if (PySys_Audit("ctypes.dlsym/handle", "O", args) < 0) {
         return NULL;
     }
-    ptr = ctypes_dlsym((void*)handle, name);
+    ptr = dlsym((void*)handle, name);
     if (!ptr) {
         PyErr_SetString(PyExc_OSError,
-                               ctypes_dlerror());
+                               dlerror());
         return NULL;
     }
     return PyLong_FromVoidPtr(ptr);