gh-103092: Isolate `_pickle` module (#102982)

Co-authored-by: Mohamed Koubaa <koubaa.m@gmail.com>
Co-authored-by: Kumar Aditya <59607654+kumaraditya303@users.noreply.github.com>

Lib/test/test_pickle.py

@@ -293,6 +293,34 @@ if has_c_implementation:
             pass
         pickler_class = CustomCPicklerClass
 
+    @support.cpython_only
+    class HeapTypesTests(unittest.TestCase):
+        def setUp(self):
+            pickler = _pickle.Pickler(io.BytesIO())
+            unpickler = _pickle.Unpickler(io.BytesIO())
+
+            self._types = (
+                _pickle.Pickler,
+                _pickle.Unpickler,
+                type(pickler.memo),
+                type(unpickler.memo),
+
+                # We cannot test the _pickle.Pdata;
+                # there's no way to get to it.
+            )
+
+        def test_have_gc(self):
+            import gc
+            for tp in self._types:
+                with self.subTest(tp=tp):
+                    self.assertTrue(gc.is_tracked(tp))
+
+        def test_immutable(self):
+            for tp in self._types:
+                with self.subTest(tp=tp):
+                    with self.assertRaisesRegex(TypeError, "immutable"):
+                        tp.foo = "bar"
+
     @support.cpython_only
     class SizeofTests(unittest.TestCase):
         check_sizeof = support.check_sizeof

Misc/NEWS.d/next/Core and Builtins/2020-07-04-09-04-41.bpo-1635741.ZsP31Y.rst

@@ -0,0 +1 @@
+Adapt :mod:`!_pickle` to :pep:`687`. Patch by Mohamed Koubaa and Erlend Aasland.

Modules/clinic/_pickle.c.h

@@ -38,7 +38,42 @@ PyDoc_STRVAR(_pickle_Pickler_dump__doc__,
 "Write a pickled representation of the given object to the open file.");
 
 #define _PICKLE_PICKLER_DUMP_METHODDEF    \
-    {"dump", (PyCFunction)_pickle_Pickler_dump, METH_O, _pickle_Pickler_dump__doc__},
+    {"dump", _PyCFunction_CAST(_pickle_Pickler_dump), METH_METHOD|METH_FASTCALL|METH_KEYWORDS, _pickle_Pickler_dump__doc__},
+
+static PyObject *
+_pickle_Pickler_dump_impl(PicklerObject *self, PyTypeObject *cls,
+                          PyObject *obj);
+
+static PyObject *
+_pickle_Pickler_dump(PicklerObject *self, PyTypeObject *cls, PyObject *const *args, Py_ssize_t nargs, PyObject *kwnames)
+{
+    PyObject *return_value = NULL;
+    #if defined(Py_BUILD_CORE) && !defined(Py_BUILD_CORE_MODULE)
+    #  define KWTUPLE (PyObject *)&_Py_SINGLETON(tuple_empty)
+    #else
+    #  define KWTUPLE NULL
+    #endif
+
+    static const char * const _keywords[] = {"", NULL};
+    static _PyArg_Parser _parser = {
+        .keywords = _keywords,
+        .fname = "dump",
+        .kwtuple = KWTUPLE,
+    };
+    #undef KWTUPLE
+    PyObject *argsbuf[1];
+    PyObject *obj;
+
+    args = _PyArg_UnpackKeywords(args, nargs, NULL, kwnames, &_parser, 1, 1, 0, argsbuf);
+    if (!args) {
+        goto exit;
+    }
+    obj = args[0];
+    return_value = _pickle_Pickler_dump_impl(self, cls, obj);
+
+exit:
+    return return_value;
+}
 
 PyDoc_STRVAR(_pickle_Pickler___sizeof____doc__,
 "__sizeof__($self, /)\n"
@@ -242,15 +277,19 @@ PyDoc_STRVAR(_pickle_Unpickler_load__doc__,
 "specified therein.");
 
 #define _PICKLE_UNPICKLER_LOAD_METHODDEF    \
-    {"load", (PyCFunction)_pickle_Unpickler_load, METH_NOARGS, _pickle_Unpickler_load__doc__},
+    {"load", _PyCFunction_CAST(_pickle_Unpickler_load), METH_METHOD|METH_FASTCALL|METH_KEYWORDS, _pickle_Unpickler_load__doc__},
 
 static PyObject *
-_pickle_Unpickler_load_impl(UnpicklerObject *self);
+_pickle_Unpickler_load_impl(UnpicklerObject *self, PyTypeObject *cls);
 
 static PyObject *
-_pickle_Unpickler_load(UnpicklerObject *self, PyObject *Py_UNUSED(ignored))
+_pickle_Unpickler_load(UnpicklerObject *self, PyTypeObject *cls, PyObject *const *args, Py_ssize_t nargs, PyObject *kwnames)
 {
-    return _pickle_Unpickler_load_impl(self);
+    if (nargs) {
+        PyErr_SetString(PyExc_TypeError, "load() takes no arguments");
+        return NULL;
+    }
+    return _pickle_Unpickler_load_impl(self, cls);
 }
 
 PyDoc_STRVAR(_pickle_Unpickler_find_class__doc__,
@@ -267,26 +306,41 @@ PyDoc_STRVAR(_pickle_Unpickler_find_class__doc__,
 "needed.  Both arguments passed are str objects.");
 
 #define _PICKLE_UNPICKLER_FIND_CLASS_METHODDEF    \
-    {"find_class", _PyCFunction_CAST(_pickle_Unpickler_find_class), METH_FASTCALL, _pickle_Unpickler_find_class__doc__},
+    {"find_class", _PyCFunction_CAST(_pickle_Unpickler_find_class), METH_METHOD|METH_FASTCALL|METH_KEYWORDS, _pickle_Unpickler_find_class__doc__},
 
 static PyObject *
-_pickle_Unpickler_find_class_impl(UnpicklerObject *self,
+_pickle_Unpickler_find_class_impl(UnpicklerObject *self, PyTypeObject *cls,
                                   PyObject *module_name,
                                   PyObject *global_name);
 
 static PyObject *
-_pickle_Unpickler_find_class(UnpicklerObject *self, PyObject *const *args, Py_ssize_t nargs)
+_pickle_Unpickler_find_class(UnpicklerObject *self, PyTypeObject *cls, PyObject *const *args, Py_ssize_t nargs, PyObject *kwnames)
 {
     PyObject *return_value = NULL;
+    #if defined(Py_BUILD_CORE) && !defined(Py_BUILD_CORE_MODULE)
+    #  define KWTUPLE (PyObject *)&_Py_SINGLETON(tuple_empty)
+    #else
+    #  define KWTUPLE NULL
+    #endif
+
+    static const char * const _keywords[] = {"", "", NULL};
+    static _PyArg_Parser _parser = {
+        .keywords = _keywords,
+        .fname = "find_class",
+        .kwtuple = KWTUPLE,
+    };
+    #undef KWTUPLE
+    PyObject *argsbuf[2];
     PyObject *module_name;
     PyObject *global_name;
 
-    if (!_PyArg_CheckPositional("find_class", nargs, 2, 2)) {
+    args = _PyArg_UnpackKeywords(args, nargs, NULL, kwnames, &_parser, 2, 2, 0, argsbuf);
+    if (!args) {
         goto exit;
     }
     module_name = args[0];
     global_name = args[1];
-    return_value = _pickle_Unpickler_find_class_impl(self, module_name, global_name);
+    return_value = _pickle_Unpickler_find_class_impl(self, cls, module_name, global_name);
 
 exit:
     return return_value;
@@ -980,4 +1034,4 @@ skip_optional_kwonly:
 exit:
     return return_value;
 }
-/*[clinic end generated code: output=730dc26938561313 input=a9049054013a1b77]*/
+/*[clinic end generated code: output=a0e04b85e7bae626 input=a9049054013a1b77]*/

Tools/c-analyzer/cpython/globals-to-fix.tsv

@@ -390,11 +390,6 @@ Modules/_decimal/_decimal.c	-	PyDecContextManager_Type	-
 Modules/_decimal/_decimal.c	-	PyDecContext_Type	-
 Modules/_decimal/_decimal.c	-	PyDecSignalDictMixin_Type	-
 Modules/_decimal/_decimal.c	-	PyDec_Type	-
-Modules/_pickle.c	-	Pdata_Type	-
-Modules/_pickle.c	-	PicklerMemoProxyType	-
-Modules/_pickle.c	-	Pickler_Type	-
-Modules/_pickle.c	-	UnpicklerMemoProxyType	-
-Modules/_pickle.c	-	Unpickler_Type	-
 Modules/ossaudiodev.c	-	OSSAudioType	-
 Modules/ossaudiodev.c	-	OSSMixerType	-
 Modules/socketmodule.c	-	sock_type	-