@@ -181,3 +181,7 @@ Porting to Python 3.10
 
 Removed
 -------
+
+* Remove the :c:func:`_Py_NewReference` and :c:func:`_Py_ForgetReference`
+  functions from the public C API: move them to the internal C API.
+  (Contributed by Victor Stinner in :issue:`40989`.)
diff --git a/Include/cpython/object.h b/Include/cpython/object.h
@@ -2,13 +2,6 @@
 #  error "this header file must not be included directly"
 #endif
 
-PyAPI_FUNC(void) _Py_NewReference(PyObject *op);
-
-#ifdef Py_TRACE_REFS
-/* Py_TRACE_REFS is such major surgery that we call external routines. */
-PyAPI_FUNC(void) _Py_ForgetReference(PyObject *);
-#endif
-
 #ifdef Py_REF_DEBUG
 PyAPI_FUNC(Py_ssize_t) _Py_GetRefTotal(void);
 #endif

diff --git a/Include/internal/pycore_object.h b/Include/internal/pycore_object.h
@@ -15,12 +15,17 @@ extern "C" {
 PyAPI_FUNC(int) _PyType_CheckConsistency(PyTypeObject *type);
 PyAPI_FUNC(int) _PyDict_CheckConsistency(PyObject *mp, int check_content);
 
-/* Update the Python traceback of an object. This function must be called
-   when a memory block is reused from a free list.
+PyAPI_FUNC(void) _Py_NewReference(PyObject *op);
 
-   Internal function called by _Py_NewReference(). */
+/* Update the Python traceback of an object. This function must be called
+   when a memory block is reused from a free list. */
 extern int _PyTraceMalloc_NewReference(PyObject *op);
 
+#ifdef Py_TRACE_REFS
+/* Py_TRACE_REFS is such major surgery that we call external routines. */
+PyAPI_FUNC(void) _Py_ForgetReference(PyObject *);
+#endif
+
 // Fast inlined version of PyType_HasFeature()
 static inline int
 _PyType_HasFeature(PyTypeObject *type, unsigned long feature) {

diff --git a/Lib/test/test_finalization.py b/Lib/test/test_finalization.py
@@ -8,12 +8,12 @@
 import weakref
 
 try:
-    from _testcapi import with_tp_del
+    from _testinternalcapi import with_tp_del
 except ImportError:
     def with_tp_del(cls):
         class C(object):
             def __new__(cls, *args, **kwargs):
-                raise TypeError('requires _testcapi.with_tp_del')
+                raise TypeError('requires _testinternalcapi.with_tp_del')
         return C
 
 from test import support

diff --git a/Lib/test/test_gc.py b/Lib/test/test_gc.py
@@ -15,12 +15,12 @@
 import weakref
 
 try:
-    from _testcapi import with_tp_del
+    from _testinternalcapi import with_tp_del
 except ImportError:
     def with_tp_del(cls):
         class C(object):
             def __new__(cls, *args, **kwargs):
-                raise TypeError('requires _testcapi.with_tp_del')
+                raise TypeError('requires _testinternalcapi.with_tp_del')
         return C
 
 try:
@@ -664,8 +664,8 @@ def test_garbage_at_shutdown(self):
         import subprocess
         code = """if 1:
             import gc
-            import _testcapi
-            @_testcapi.with_tp_del
+            import _testinternalcapi
+            @_testinternalcapi.with_tp_del
             class X:
                 def __init__(self, name):
                     self.name = name

diff --git a/Lib/test/test_regrtest.py b/Lib/test/test_regrtest.py
@@ -1177,11 +1177,11 @@ def test_other_bug(self):
     @support.cpython_only
     def test_findleaks(self):
         code = textwrap.dedent(r"""
-            import _testcapi
+            import _testinternalcapi
             import gc
             import unittest
 
-            @_testcapi.with_tp_del
+            @_testinternalcapi.with_tp_del
             class Garbage:
                 def __tp_del__(self):
                     pass

diff --git a/Misc/NEWS.d/next/C API/2020-06-16-01-53-01.bpo-40989.5d3Eff.rst b/Misc/NEWS.d/next/C API/2020-06-16-01-53-01.bpo-40989.5d3Eff.rst
@@ -0,0 +1,2 @@
+Remove the :c:func:`_Py_NewReference` and :c:func:`_Py_ForgetReference`
+functions from the public C API:(move them to the internal C API.
@@ -1,4 +1,5 @@
 #include "Python.h"
+#include "pycore_object.h"        // _Py_NewReference()
 #include "pycore_pyerrors.h"      // _PyErr_ClearExcState()
 #include <stddef.h>               // offsetof()
 

diff --git a/Modules/_testcapimodule.c b/Modules/_testcapimodule.c
@@ -3544,79 +3544,6 @@ test_pytime_object_to_timespec(PyObject *self, PyObject *args)
     return Py_BuildValue("Nl", _PyLong_FromTime_t(sec), nsec);
 }
 
-static void
-slot_tp_del(PyObject *self)
-{
-    _Py_IDENTIFIER(__tp_del__);
-    PyObject *del, *res;
-    PyObject *error_type, *error_value, *error_traceback;
-
-    /* Temporarily resurrect the object. */
-    assert(Py_REFCNT(self) == 0);
-    Py_SET_REFCNT(self, 1);
-
-    /* Save the current exception, if any. */
-    PyErr_Fetch(&error_type, &error_value, &error_traceback);
-
-    /* Execute __del__ method, if any. */
-    del = _PyObject_LookupSpecial(self, &PyId___tp_del__);
-    if (del != NULL) {
-        res = _PyObject_CallNoArg(del);
-        if (res == NULL)
-            PyErr_WriteUnraisable(del);
-        else
-            Py_DECREF(res);
-        Py_DECREF(del);
-    }
-
-    /* Restore the saved exception. */
-    PyErr_Restore(error_type, error_value, error_traceback);
-
-    /* Undo the temporary resurrection; can't use DECREF here, it would
-     * cause a recursive call.
-     */
-    assert(Py_REFCNT(self) > 0);
-    Py_SET_REFCNT(self, Py_REFCNT(self) - 1);
-    if (Py_REFCNT(self) == 0) {
-        /* this is the normal path out */
-        return;
-    }
-
-    /* __del__ resurrected it!  Make it look like the original Py_DECREF
-     * never happened.
-     */
-    {
-        Py_ssize_t refcnt = Py_REFCNT(self);
-        _Py_NewReference(self);
-        Py_SET_REFCNT(self, refcnt);
-    }
-    assert(!PyType_IS_GC(Py_TYPE(self)) || PyObject_GC_IsTracked(self));
-    /* If Py_REF_DEBUG macro is defined, _Py_NewReference() increased
-       _Py_RefTotal, so we need to undo that. */
-#ifdef Py_REF_DEBUG
-    _Py_RefTotal--;
-#endif
-}
-
-static PyObject *
-with_tp_del(PyObject *self, PyObject *args)
-{
-    PyObject *obj;
-    PyTypeObject *tp;
-
-    if (!PyArg_ParseTuple(args, "O:with_tp_del", &obj))
-        return NULL;
-    tp = (PyTypeObject *) obj;
-    if (!PyType_Check(obj) || !PyType_HasFeature(tp, Py_TPFLAGS_HEAPTYPE)) {
-        PyErr_Format(PyExc_TypeError,
-                     "heap type expected, got %R", obj);
-        return NULL;
-    }
-    tp->tp_del = slot_tp_del;
-    Py_INCREF(obj);
-    return obj;
-}
-
 static PyMethodDef ml;
 
 static PyObject *
@@ -5418,7 +5345,6 @@ static PyMethodDef TestMethods[] = {
     {"pytime_object_to_time_t", test_pytime_object_to_time_t,  METH_VARARGS},
     {"pytime_object_to_timeval", test_pytime_object_to_timeval,  METH_VARARGS},
     {"pytime_object_to_timespec", test_pytime_object_to_timespec,  METH_VARARGS},
-    {"with_tp_del",             with_tp_del,                     METH_VARARGS},
     {"create_cfunction",        create_cfunction,                METH_NOARGS},
     {"test_pymem_alloc0",       test_pymem_alloc0,               METH_NOARGS},
     {"test_pymem_setrawallocators",test_pymem_setrawallocators,  METH_NOARGS},

diff --git a/Modules/_testinternalcapi.c b/Modules/_testinternalcapi.c
@@ -15,6 +15,7 @@
 #include "pycore_bitutils.h"     // _Py_bswap32()
 #include "pycore_initconfig.h"   // _Py_GetConfigsAsDict()
 #include "pycore_hashtable.h"    // _Py_hashtable_new()
+#include "pycore_object.h"       // _Py_NewReference()
 #include "pycore_gc.h"           // PyGC_Head
 
 
@@ -231,13 +232,89 @@ test_hashtable(PyObject *self, PyObject *Py_UNUSED(args))
 }
 
 
+static void
+slot_tp_del(PyObject *self)
+{
+    _Py_IDENTIFIER(__tp_del__);
+    PyObject *del, *res;
+    PyObject *error_type, *error_value, *error_traceback;
+
+    /* Temporarily resurrect the object. */
+    assert(Py_REFCNT(self) == 0);
+    Py_SET_REFCNT(self, 1);
+
+    /* Save the current exception, if any. */
+    PyErr_Fetch(&error_type, &error_value, &error_traceback);
+
+    /* Execute __del__ method, if any. */
+    del = _PyObject_LookupSpecial(self, &PyId___tp_del__);
+    if (del != NULL) {
+        res = _PyObject_CallNoArg(del);
+        if (res == NULL)
+            PyErr_WriteUnraisable(del);
+        else
+            Py_DECREF(res);
+        Py_DECREF(del);
+    }
+
+    /* Restore the saved exception. */
+    PyErr_Restore(error_type, error_value, error_traceback);
+
+    /* Undo the temporary resurrection; can't use DECREF here, it would
+     * cause a recursive call.
+     */
+    assert(Py_REFCNT(self) > 0);
+    Py_SET_REFCNT(self, Py_REFCNT(self) - 1);
+    if (Py_REFCNT(self) == 0) {
+        /* this is the normal path out */
+        return;
+    }
+
+    /* __del__ resurrected it!  Make it look like the original Py_DECREF
+     * never happened.
+     */
+    {
+        Py_ssize_t refcnt = Py_REFCNT(self);
+        _Py_NewReference(self);
+        Py_SET_REFCNT(self, refcnt);
+    }
+    assert(!PyType_IS_GC(Py_TYPE(self)) || PyObject_GC_IsTracked(self));
+    /* If Py_REF_DEBUG macro is defined, _Py_NewReference() increased
+       _Py_RefTotal, so we need to undo that. */
+#ifdef Py_REF_DEBUG
+    _Py_RefTotal--;
+#endif
+}
+
+
+static PyObject *
+with_tp_del(PyObject *self, PyObject *args)
+{
+    PyObject *obj;
+    PyTypeObject *tp;
+
+    if (!PyArg_ParseTuple(args, "O:with_tp_del", &obj))
+        return NULL;
+    tp = (PyTypeObject *) obj;
+    if (!PyType_Check(obj) || !PyType_HasFeature(tp, Py_TPFLAGS_HEAPTYPE)) {
+        PyErr_Format(PyExc_TypeError,
+                     "heap type expected, got %R", obj);
+        return NULL;
+    }
+    tp->tp_del = slot_tp_del;
+    Py_INCREF(obj);
+    return obj;
+}
+
+
 static PyMethodDef TestMethods[] = {
     {"get_configs", get_configs, METH_NOARGS},
     {"get_recursion_depth", get_recursion_depth, METH_NOARGS},
     {"test_bswap", test_bswap, METH_NOARGS},
     {"test_popcount", test_popcount, METH_NOARGS},
     {"test_bit_length", test_bit_length, METH_NOARGS},
     {"test_hashtable", test_hashtable, METH_NOARGS},
+    {"with_tp_del", with_tp_del, METH_VARARGS},
     {NULL, NULL} /* sentinel */
 };
Original file line number	Diff line number	Diff line change
		@@ -0,0 +1,2 @@
		Remove the :c:func:`_Py_NewReference` and :c:func:`_Py_ForgetReference`
		functions from the public C API:(move them to the internal C API.