gh-141510: Add PyAnyDict_AsNewDict() function

Doc/c-api/dict.rst

@@ -542,6 +542,10 @@ Frozen dictionary objects
 
    Create an empty dictionary if *iterable* is ``NULL``.
 
+.. c:function:: PyObject* PyAnyDict_AsNewDict(PyObject *p)
+
+   Create a new dictionary from a :class:`dict` or a :class:`frozendict`.
+
 
 Ordered dictionaries
 ^^^^^^^^^^^^^^^^^^^^

Include/cpython/dictobject.h

@@ -106,3 +106,6 @@ PyAPI_FUNC(int) PyDict_Unwatch(int watcher_id, PyObject* dict);
 
 // Create a frozendict. Create an empty dictionary if iterable is NULL.
 PyAPI_FUNC(PyObject*) PyFrozenDict_New(PyObject *iterable);
+
+// Create a new dictionary from a dict or a frozendict.
+PyAPI_FUNC(PyObject*) PyAnyDict_AsNewDict(PyObject *o);

Include/internal/pycore_dict.h

@@ -160,9 +160,6 @@ extern void _PyDict_Clear_LockHeld(PyObject *op);
 PyAPI_FUNC(void) _PyDict_EnsureSharedOnRead(PyDictObject *mp);
 #endif
 
-// Export for '_elementtree' shared extension
-PyAPI_FUNC(PyObject*) _PyDict_CopyAsDict(PyObject *op);
-
 #define DKIX_EMPTY (-1)
 #define DKIX_DUMMY (-2)  /* Used internally */
 #define DKIX_ERROR (-3)

Lib/test/test_capi/test_dict.py

@@ -624,6 +624,19 @@ def test_frozendict_new(self):
         self.assertEqual(dct, frozendict())
         self.assertIs(type(dct), frozendict)
 
+    def test_anydict_asnewdict(self):
+        # Test PyAnyDict_AsNewDict()
+        anydict_asnewdict = _testcapi.anydict_asnewdict
+        for dict_type in ANYDICT_TYPES:
+            dct = dict_type({1: 2})
+            dct_copy = anydict_asnewdict(dct)
+            self.assertIs(type(dct_copy), dict)
+            self.assertEqual(dct_copy, dct)
+
+        for test_type in NOT_ANYDICT_TYPES + OTHER_TYPES:
+            self.assertRaises(SystemError, anydict_asnewdict, test_type())
+        self.assertRaises(SystemError, anydict_asnewdict, NULL)
+
 
 if __name__ == "__main__":
     unittest.main()

Modules/_elementtree.c

@@ -16,7 +16,6 @@
 #endif
 
 #include "Python.h"
-#include "pycore_dict.h"          // _PyDict_CopyAsDict()
 #include "pycore_pyhash.h"        // _Py_HashSecret
 #include "pycore_weakref.h"       // FT_CLEAR_WEAKREFS()
 
@@ -390,7 +389,7 @@ get_attrib_from_keywords(PyObject *kwds)
             Py_DECREF(attrib);
             return NULL;
         }
-        Py_SETREF(attrib, _PyDict_CopyAsDict(attrib));
+        Py_SETREF(attrib, PyAnyDict_AsNewDict(attrib));
     }
     else {
         attrib = PyDict_New();
@@ -429,7 +428,7 @@ element_init(PyObject *self, PyObject *args, PyObject *kwds)
 
     if (attrib) {
         /* attrib passed as positional arg */
-        attrib = _PyDict_CopyAsDict(attrib);
+        attrib = PyAnyDict_AsNewDict(attrib);
         if (!attrib)
             return -1;
         if (kwds) {

Modules/_testcapi/dict.c

@@ -295,6 +295,14 @@ frozendict_new(PyObject *self, PyObject *obj)
 }
 
 
+static PyObject*
+anydict_asnewdict(PyObject *self, PyObject *obj)
+{
+    NULLABLE(obj);
+    return PyAnyDict_AsNewDict(obj);
+}
+
+
 static PyMethodDef test_methods[] = {
     {"dict_containsstring", dict_containsstring, METH_VARARGS},
     {"dict_getitemref", dict_getitemref, METH_VARARGS},
@@ -311,6 +319,7 @@ static PyMethodDef test_methods[] = {
     {"anydict_check", anydict_check, METH_O},
     {"anydict_checkexact", anydict_checkexact, METH_O},
     {"frozendict_new", frozendict_new, METH_O},
+    {"anydict_asnewdict", anydict_asnewdict, METH_O},
     {NULL},
 };
 

Objects/dictobject.c

@@ -4414,12 +4414,13 @@ anydict_copy(PyObject *o)
     return res;
 }
 
-// Similar to PyDict_Copy(), but accept also frozendict:
-// convert frozendict to a new dict.
 PyObject*
-_PyDict_CopyAsDict(PyObject *o)
+PyAnyDict_AsNewDict(PyObject *o)
 {
-    assert(PyAnyDict_Check(o));
+    if (o == NULL || !PyAnyDict_Check(o)) {
+        PyErr_BadInternalCall();
+        return NULL;
+    }
 
     PyObject *res;
     Py_BEGIN_CRITICAL_SECTION(o);

Objects/typeobject.c

@@ -4850,7 +4850,7 @@ type_new_get_slots(type_new_ctx *ctx, PyObject *dict)
 static PyTypeObject*
 type_new_init(type_new_ctx *ctx)
 {
-    PyObject *dict = _PyDict_CopyAsDict(ctx->orig_dict);
+    PyObject *dict = PyAnyDict_AsNewDict(ctx->orig_dict);
     if (dict == NULL) {
         goto error;
     }