gh-116417: Move limited C API list.c tests to _testlimitedcapi (#116602)

Split list.c and set.c tests of _testcapi into two parts: limited C
API tests in _testlimitedcapi and non-limited C API tests in
_testcapi.

7 files changed, 368 insertions, 322 deletions

diff --git a/Modules/Setup.stdlib.in b/Modules/Setup.stdlib.in
index deada66..d4743d3 100644
--- a/Modules/Setup.stdlib.in
+++ b/Modules/Setup.stdlib.in
@@ -163,7 +163,7 @@
 @MODULE__TESTBUFFER_TRUE@_testbuffer _testbuffer.c
 @MODULE__TESTINTERNALCAPI_TRUE@_testinternalcapi _testinternalcapi.c _testinternalcapi/test_lock.c _testinternalcapi/pytime.c _testinternalcapi/set.c _testinternalcapi/test_critical_sections.c
 @MODULE__TESTCAPI_TRUE@_testcapi _testcapimodule.c _testcapi/vectorcall.c _testcapi/heaptype.c _testcapi/abstract.c _testcapi/unicode.c _testcapi/dict.c _testcapi/set.c _testcapi/list.c _testcapi/tuple.c _testcapi/getargs.c _testcapi/datetime.c _testcapi/docstring.c _testcapi/mem.c _testcapi/watchers.c _testcapi/long.c _testcapi/float.c _testcapi/complex.c _testcapi/numbers.c _testcapi/structmember.c _testcapi/exceptions.c _testcapi/code.c _testcapi/buffer.c _testcapi/pyatomic.c _testcapi/file.c _testcapi/codec.c _testcapi/immortal.c _testcapi/gc.c _testcapi/hash.c _testcapi/time.c
-@MODULE__TESTLIMITEDCAPI_TRUE@_testlimitedcapi _testlimitedcapi.c _testlimitedcapi/bytearray.c _testlimitedcapi/bytes.c _testlimitedcapi/heaptype_relative.c _testlimitedcapi/pyos.c _testlimitedcapi/sys.c _testlimitedcapi/vectorcall_limited.c
+@MODULE__TESTLIMITEDCAPI_TRUE@_testlimitedcapi _testlimitedcapi.c _testlimitedcapi/bytearray.c _testlimitedcapi/bytes.c _testlimitedcapi/heaptype_relative.c _testlimitedcapi/list.c _testlimitedcapi/pyos.c _testlimitedcapi/set.c _testlimitedcapi/sys.c _testlimitedcapi/vectorcall_limited.c
 @MODULE__TESTCLINIC_TRUE@_testclinic _testclinic.c
 @MODULE__TESTCLINIC_LIMITED_TRUE@_testclinic_limited _testclinic_limited.c
 
diff --git a/Modules/_testcapi/list.c b/Modules/_testcapi/list.c
index 2cb6499..09cec4c 100644
--- a/Modules/_testcapi/list.c
+++ b/Modules/_testcapi/list.c
@@ -1,32 +1,6 @@
 #include "parts.h"
 #include "util.h"
 
-static PyObject *
-list_check(PyObject* Py_UNUSED(module), PyObject *obj)
-{
-    NULLABLE(obj);
-    return PyLong_FromLong(PyList_Check(obj));
-}
-
-static PyObject *
-list_check_exact(PyObject* Py_UNUSED(module), PyObject *obj)
-{
-    NULLABLE(obj);
-    return PyLong_FromLong(PyList_CheckExact(obj));
-}
-
-static PyObject *
-list_new(PyObject* Py_UNUSED(module), PyObject *obj)
-{
-    return PyList_New(PyLong_AsSsize_t(obj));
-}
-
-static PyObject *
-list_size(PyObject *Py_UNUSED(module), PyObject *obj)
-{
-    NULLABLE(obj);
-    RETURN_SIZE(PyList_Size(obj));
-}
 
 static PyObject *
 list_get_size(PyObject *Py_UNUSED(module), PyObject *obj)
@@ -35,17 +9,6 @@ list_get_size(PyObject *Py_UNUSED(module), PyObject *obj)
     RETURN_SIZE(PyList_GET_SIZE(obj));
 }
 
-static PyObject *
-list_getitem(PyObject *Py_UNUSED(module), PyObject *args)
-{
-    PyObject *obj;
-    Py_ssize_t i;
-    if (!PyArg_ParseTuple(args, "On", &obj, &i)) {
-        return NULL;
-    }
-    NULLABLE(obj);
-    return Py_XNewRef(PyList_GetItem(obj, i));
-}
 
 static PyObject *
 list_get_item(PyObject *Py_UNUSED(module), PyObject *args)
@@ -59,31 +22,6 @@ list_get_item(PyObject *Py_UNUSED(module), PyObject *args)
     return Py_XNewRef(PyList_GET_ITEM(obj, i));
 }
 
-static PyObject *
-list_get_item_ref(PyObject *Py_UNUSED(module), PyObject *args)
-{
-    PyObject *obj;
-    Py_ssize_t i;
-    if (!PyArg_ParseTuple(args, "On", &obj, &i)) {
-        return NULL;
-    }
-    NULLABLE(obj);
-    return PyList_GetItemRef(obj, i);
-}
-
-static PyObject *
-list_setitem(PyObject *Py_UNUSED(module), PyObject *args)
-{
-    PyObject *obj, *value;
-    Py_ssize_t i;
-    if (!PyArg_ParseTuple(args, "OnO", &obj, &i, &value)) {
-        return NULL;
-    }
-    NULLABLE(obj);
-    NULLABLE(value);
-    RETURN_INT(PyList_SetItem(obj, i, Py_XNewRef(value)));
-
-}
 
 static PyObject *
 list_set_item(PyObject *Py_UNUSED(module), PyObject *args)
@@ -100,79 +38,6 @@ list_set_item(PyObject *Py_UNUSED(module), PyObject *args)
 
 }
 
-static PyObject *
-list_insert(PyObject *Py_UNUSED(module), PyObject *args)
-{
-    PyObject *obj, *value;
-    Py_ssize_t where;
-    if (!PyArg_ParseTuple(args, "OnO", &obj, &where, &value)) {
-        return NULL;
-    }
-    NULLABLE(obj);
-    NULLABLE(value);
-    RETURN_INT(PyList_Insert(obj, where, Py_XNewRef(value)));
-
-}
-
-static PyObject *
-list_append(PyObject *Py_UNUSED(module), PyObject *args)
-{
-    PyObject *obj, *value;
-    if (!PyArg_ParseTuple(args, "OO", &obj, &value)) {
-        return NULL;
-    }
-    NULLABLE(obj);
-    NULLABLE(value);
-    RETURN_INT(PyList_Append(obj, value));
-}
-
-static PyObject *
-list_getslice(PyObject *Py_UNUSED(module), PyObject *args)
-{
-    PyObject *obj;
-    Py_ssize_t ilow, ihigh;
-    if (!PyArg_ParseTuple(args, "Onn", &obj, &ilow, &ihigh)) {
-        return NULL;
-    }
-    NULLABLE(obj);
-    return PyList_GetSlice(obj, ilow, ihigh);
-
-}
-
-static PyObject *
-list_setslice(PyObject *Py_UNUSED(module), PyObject *args)
-{
-    PyObject *obj, *value;
-    Py_ssize_t ilow, ihigh;
-    if (!PyArg_ParseTuple(args, "OnnO", &obj, &ilow, &ihigh, &value)) {
-        return NULL;
-    }
-    NULLABLE(obj);
-    NULLABLE(value);
-    RETURN_INT(PyList_SetSlice(obj, ilow, ihigh, value));
-}
-
-static PyObject *
-list_sort(PyObject* Py_UNUSED(module), PyObject *obj)
-{
-    NULLABLE(obj);
-    RETURN_INT(PyList_Sort(obj));
-}
-
-static PyObject *
-list_reverse(PyObject* Py_UNUSED(module), PyObject *obj)
-{
-    NULLABLE(obj);
-    RETURN_INT(PyList_Reverse(obj));
-}
-
-static PyObject *
-list_astuple(PyObject* Py_UNUSED(module), PyObject *obj)
-{
-    NULLABLE(obj);
-    return PyList_AsTuple(obj);
-}
-
 
 static PyObject *
 list_clear(PyObject* Py_UNUSED(module), PyObject *obj)
@@ -196,25 +61,12 @@ list_extend(PyObject* Py_UNUSED(module), PyObject *args)
 
 
 static PyMethodDef test_methods[] = {
-    {"list_check", list_check, METH_O},
-    {"list_check_exact", list_check_exact, METH_O},
-    {"list_new", list_new, METH_O},
-    {"list_size", list_size, METH_O},
     {"list_get_size", list_get_size, METH_O},
-    {"list_getitem", list_getitem, METH_VARARGS},
     {"list_get_item", list_get_item, METH_VARARGS},
-    {"list_get_item_ref", list_get_item_ref, METH_VARARGS},
-    {"list_setitem", list_setitem, METH_VARARGS},
     {"list_set_item", list_set_item, METH_VARARGS},
-    {"list_insert", list_insert, METH_VARARGS},
-    {"list_append", list_append, METH_VARARGS},
-    {"list_getslice", list_getslice, METH_VARARGS},
-    {"list_setslice", list_setslice, METH_VARARGS},
-    {"list_sort", list_sort, METH_O},
-    {"list_reverse", list_reverse, METH_O},
-    {"list_astuple", list_astuple, METH_O},
     {"list_clear", list_clear, METH_O},
     {"list_extend", list_extend, METH_VARARGS},
+
     {NULL},
 };
 
diff --git a/Modules/_testcapi/set.c b/Modules/_testcapi/set.c
index 2fbd0ae..31b52ce 100644
--- a/Modules/_testcapi/set.c
+++ b/Modules/_testcapi/set.c
@@ -2,186 +2,14 @@
 #include "util.h"
 
 static PyObject *
-set_check(PyObject *self, PyObject *obj)
-{
-    NULLABLE(obj);
-    RETURN_INT(PySet_Check(obj));
-}
-
-static PyObject *
-set_checkexact(PyObject *self, PyObject *obj)
-{
-    NULLABLE(obj);
-    RETURN_INT(PySet_CheckExact(obj));
-}
-
-static PyObject *
-frozenset_check(PyObject *self, PyObject *obj)
-{
-    NULLABLE(obj);
-    RETURN_INT(PyFrozenSet_Check(obj));
-}
-
-static PyObject *
-frozenset_checkexact(PyObject *self, PyObject *obj)
-{
-    NULLABLE(obj);
-    RETURN_INT(PyFrozenSet_CheckExact(obj));
-}
-
-static PyObject *
-anyset_check(PyObject *self, PyObject *obj)
-{
-    NULLABLE(obj);
-    RETURN_INT(PyAnySet_Check(obj));
-}
-
-static PyObject *
-anyset_checkexact(PyObject *self, PyObject *obj)
-{
-    NULLABLE(obj);
-    RETURN_INT(PyAnySet_CheckExact(obj));
-}
-
-static PyObject *
-set_new(PyObject *self, PyObject *args)
-{
-    PyObject *iterable = NULL;
-    if (!PyArg_ParseTuple(args, "|O", &iterable)) {
-        return NULL;
-    }
-    return PySet_New(iterable);
-}
-
-static PyObject *
-frozenset_new(PyObject *self, PyObject *args)
-{
-    PyObject *iterable = NULL;
-    if (!PyArg_ParseTuple(args, "|O", &iterable)) {
-        return NULL;
-    }
-    return PyFrozenSet_New(iterable);
-}
-
-static PyObject *
-set_size(PyObject *self, PyObject *obj)
-{
-    NULLABLE(obj);
-    RETURN_SIZE(PySet_Size(obj));
-}
-
-static PyObject *
 set_get_size(PyObject *self, PyObject *obj)
 {
     NULLABLE(obj);
     RETURN_SIZE(PySet_GET_SIZE(obj));
 }
 
-static PyObject *
-set_contains(PyObject *self, PyObject *args)
-{
-    PyObject *obj, *item;
-    if (!PyArg_ParseTuple(args, "OO", &obj, &item)) {
-        return NULL;
-    }
-    NULLABLE(obj);
-    NULLABLE(item);
-    RETURN_INT(PySet_Contains(obj, item));
-}
-
-static PyObject *
-set_add(PyObject *self, PyObject *args)
-{
-    PyObject *obj, *item;
-    if (!PyArg_ParseTuple(args, "OO", &obj, &item)) {
-        return NULL;
-    }
-    NULLABLE(obj);
-    NULLABLE(item);
-    RETURN_INT(PySet_Add(obj, item));
-}
-
-static PyObject *
-set_discard(PyObject *self, PyObject *args)
-{
-    PyObject *obj, *item;
-    if (!PyArg_ParseTuple(args, "OO", &obj, &item)) {
-        return NULL;
-    }
-    NULLABLE(obj);
-    NULLABLE(item);
-    RETURN_INT(PySet_Discard(obj, item));
-}
-
-static PyObject *
-set_pop(PyObject *self, PyObject *obj)
-{
-    NULLABLE(obj);
-    return PySet_Pop(obj);
-}
-
-static PyObject *
-set_clear(PyObject *self, PyObject *obj)
-{
-    NULLABLE(obj);
-    RETURN_INT(PySet_Clear(obj));
-}
-
-static PyObject *
-test_frozenset_add_in_capi(PyObject *self, PyObject *Py_UNUSED(obj))
-{
-    // Test that `frozenset` can be used with `PySet_Add`,
-    // when frozenset is just created in CAPI.
-    PyObject *fs = PyFrozenSet_New(NULL);
-    if (fs == NULL) {
-        return NULL;
-    }
-    PyObject *num = PyLong_FromLong(1);
-    if (num == NULL) {
-        goto error;
-    }
-    if (PySet_Add(fs, num) < 0) {
-        goto error;
-    }
-    int contains = PySet_Contains(fs, num);
-    if (contains < 0) {
-        goto error;
-    }
-    else if (contains == 0) {
-        goto unexpected;
-    }
-    Py_DECREF(fs);
-    Py_DECREF(num);
-    Py_RETURN_NONE;
-
-unexpected:
-    PyErr_SetString(PyExc_ValueError, "set does not contain expected value");
-error:
-    Py_DECREF(fs);
-    Py_XDECREF(num);
-    return NULL;
-}
-
 static PyMethodDef test_methods[] = {
-    {"set_check", set_check, METH_O},
-    {"set_checkexact", set_checkexact, METH_O},
-    {"frozenset_check", frozenset_check, METH_O},
-    {"frozenset_checkexact", frozenset_checkexact, METH_O},
-    {"anyset_check", anyset_check, METH_O},
-    {"anyset_checkexact", anyset_checkexact, METH_O},
-
-    {"set_new", set_new, METH_VARARGS},
-    {"frozenset_new", frozenset_new, METH_VARARGS},
-
-    {"set_size", set_size, METH_O},
     {"set_get_size", set_get_size, METH_O},
-    {"set_contains", set_contains, METH_VARARGS},
-    {"set_add", set_add, METH_VARARGS},
-    {"set_discard", set_discard, METH_VARARGS},
-    {"set_pop", set_pop, METH_O},
-    {"set_clear", set_clear, METH_O},
-
-    {"test_frozenset_add_in_capi", test_frozenset_add_in_capi, METH_NOARGS},
 
     {NULL},
 };
diff --git a/Modules/_testlimitedcapi.c b/Modules/_testlimitedcapi.c
index 49bf6a3..a25b0aa 100644
--- a/Modules/_testlimitedcapi.c
+++ b/Modules/_testlimitedcapi.c
@@ -35,9 +35,15 @@ PyInit__testlimitedcapi(void)
     if (_PyTestCapi_Init_HeaptypeRelative(mod) < 0) {
         return NULL;
     }
+    if (_PyTestCapi_Init_List(mod) < 0) {
+        return NULL;
+    }
     if (_PyTestCapi_Init_PyOS(mod) < 0) {
         return NULL;
     }
+    if (_PyTestCapi_Init_Set(mod) < 0) {
+        return NULL;
+    }
     if (_PyTestCapi_Init_Sys(mod) < 0) {
         return NULL;
     }
diff --git a/Modules/_testlimitedcapi/list.c b/Modules/_testlimitedcapi/list.c
new file mode 100644
index 0000000..0917900
--- /dev/null
+++ b/Modules/_testlimitedcapi/list.c
@@ -0,0 +1,169 @@
+#include "parts.h"
+#include "util.h"
+
+static PyObject *
+list_check(PyObject* Py_UNUSED(module), PyObject *obj)
+{
+    NULLABLE(obj);
+    return PyLong_FromLong(PyList_Check(obj));
+}
+
+static PyObject *
+list_check_exact(PyObject* Py_UNUSED(module), PyObject *obj)
+{
+    NULLABLE(obj);
+    return PyLong_FromLong(PyList_CheckExact(obj));
+}
+
+static PyObject *
+list_new(PyObject* Py_UNUSED(module), PyObject *obj)
+{
+    return PyList_New(PyLong_AsSsize_t(obj));
+}
+
+static PyObject *
+list_size(PyObject *Py_UNUSED(module), PyObject *obj)
+{
+    NULLABLE(obj);
+    RETURN_SIZE(PyList_Size(obj));
+}
+
+static PyObject *
+list_getitem(PyObject *Py_UNUSED(module), PyObject *args)
+{
+    PyObject *obj;
+    Py_ssize_t i;
+    if (!PyArg_ParseTuple(args, "On", &obj, &i)) {
+        return NULL;
+    }
+    NULLABLE(obj);
+    return Py_XNewRef(PyList_GetItem(obj, i));
+}
+
+static PyObject *
+list_get_item_ref(PyObject *Py_UNUSED(module), PyObject *args)
+{
+    PyObject *obj;
+    Py_ssize_t i;
+    if (!PyArg_ParseTuple(args, "On", &obj, &i)) {
+        return NULL;
+    }
+    NULLABLE(obj);
+    return PyList_GetItemRef(obj, i);
+}
+
+static PyObject *
+list_setitem(PyObject *Py_UNUSED(module), PyObject *args)
+{
+    PyObject *obj, *value;
+    Py_ssize_t i;
+    if (!PyArg_ParseTuple(args, "OnO", &obj, &i, &value)) {
+        return NULL;
+    }
+    NULLABLE(obj);
+    NULLABLE(value);
+    RETURN_INT(PyList_SetItem(obj, i, Py_XNewRef(value)));
+
+}
+
+static PyObject *
+list_insert(PyObject *Py_UNUSED(module), PyObject *args)
+{
+    PyObject *obj, *value;
+    Py_ssize_t where;
+    if (!PyArg_ParseTuple(args, "OnO", &obj, &where, &value)) {
+        return NULL;
+    }
+    NULLABLE(obj);
+    NULLABLE(value);
+    RETURN_INT(PyList_Insert(obj, where, Py_XNewRef(value)));
+
+}
+
+static PyObject *
+list_append(PyObject *Py_UNUSED(module), PyObject *args)
+{
+    PyObject *obj, *value;
+    if (!PyArg_ParseTuple(args, "OO", &obj, &value)) {
+        return NULL;
+    }
+    NULLABLE(obj);
+    NULLABLE(value);
+    RETURN_INT(PyList_Append(obj, value));
+}
+
+static PyObject *
+list_getslice(PyObject *Py_UNUSED(module), PyObject *args)
+{
+    PyObject *obj;
+    Py_ssize_t ilow, ihigh;
+    if (!PyArg_ParseTuple(args, "Onn", &obj, &ilow, &ihigh)) {
+        return NULL;
+    }
+    NULLABLE(obj);
+    return PyList_GetSlice(obj, ilow, ihigh);
+
+}
+
+static PyObject *
+list_setslice(PyObject *Py_UNUSED(module), PyObject *args)
+{
+    PyObject *obj, *value;
+    Py_ssize_t ilow, ihigh;
+    if (!PyArg_ParseTuple(args, "OnnO", &obj, &ilow, &ihigh, &value)) {
+        return NULL;
+    }
+    NULLABLE(obj);
+    NULLABLE(value);
+    RETURN_INT(PyList_SetSlice(obj, ilow, ihigh, value));
+}
+
+static PyObject *
+list_sort(PyObject* Py_UNUSED(module), PyObject *obj)
+{
+    NULLABLE(obj);
+    RETURN_INT(PyList_Sort(obj));
+}
+
+static PyObject *
+list_reverse(PyObject* Py_UNUSED(module), PyObject *obj)
+{
+    NULLABLE(obj);
+    RETURN_INT(PyList_Reverse(obj));
+}
+
+static PyObject *
+list_astuple(PyObject* Py_UNUSED(module), PyObject *obj)
+{
+    NULLABLE(obj);
+    return PyList_AsTuple(obj);
+}
+
+
+static PyMethodDef test_methods[] = {
+    {"list_check", list_check, METH_O},
+    {"list_check_exact", list_check_exact, METH_O},
+    {"list_new", list_new, METH_O},
+    {"list_size", list_size, METH_O},
+    {"list_getitem", list_getitem, METH_VARARGS},
+    {"list_get_item_ref", list_get_item_ref, METH_VARARGS},
+    {"list_setitem", list_setitem, METH_VARARGS},
+    {"list_insert", list_insert, METH_VARARGS},
+    {"list_append", list_append, METH_VARARGS},
+    {"list_getslice", list_getslice, METH_VARARGS},
+    {"list_setslice", list_setslice, METH_VARARGS},
+    {"list_sort", list_sort, METH_O},
+    {"list_reverse", list_reverse, METH_O},
+    {"list_astuple", list_astuple, METH_O},
+    {NULL},
+};
+
+int
+_PyTestCapi_Init_List(PyObject *m)
+{
+    if (PyModule_AddFunctions(m, test_methods) < 0) {
+        return -1;
+    }
+
+    return 0;
+}
diff --git a/Modules/_testlimitedcapi/parts.h b/Modules/_testlimitedcapi/parts.h
index 9bc5241..bb867ec 100644
--- a/Modules/_testlimitedcapi/parts.h
+++ b/Modules/_testlimitedcapi/parts.h
@@ -25,7 +25,9 @@
 int _PyTestCapi_Init_ByteArray(PyObject *module);
 int _PyTestCapi_Init_Bytes(PyObject *module);
 int _PyTestCapi_Init_HeaptypeRelative(PyObject *module);
+int _PyTestCapi_Init_List(PyObject *module);
 int _PyTestCapi_Init_PyOS(PyObject *module);
+int _PyTestCapi_Init_Set(PyObject *module);
 int _PyTestCapi_Init_Sys(PyObject *module);
 int _PyTestCapi_Init_VectorcallLimited(PyObject *module);
 
diff --git a/Modules/_testlimitedcapi/set.c b/Modules/_testlimitedcapi/set.c
new file mode 100644
index 0000000..471b515
--- /dev/null
+++ b/Modules/_testlimitedcapi/set.c
@@ -0,0 +1,189 @@
+#include "parts.h"
+#include "util.h"
+
+static PyObject *
+set_check(PyObject *self, PyObject *obj)
+{
+    NULLABLE(obj);
+    RETURN_INT(PySet_Check(obj));
+}
+
+static PyObject *
+set_checkexact(PyObject *self, PyObject *obj)
+{
+    NULLABLE(obj);
+    RETURN_INT(PySet_CheckExact(obj));
+}
+
+static PyObject *
+frozenset_check(PyObject *self, PyObject *obj)
+{
+    NULLABLE(obj);
+    RETURN_INT(PyFrozenSet_Check(obj));
+}
+
+static PyObject *
+frozenset_checkexact(PyObject *self, PyObject *obj)
+{
+    NULLABLE(obj);
+    RETURN_INT(PyFrozenSet_CheckExact(obj));
+}
+
+static PyObject *
+anyset_check(PyObject *self, PyObject *obj)
+{
+    NULLABLE(obj);
+    RETURN_INT(PyAnySet_Check(obj));
+}
+
+static PyObject *
+anyset_checkexact(PyObject *self, PyObject *obj)
+{
+    NULLABLE(obj);
+    RETURN_INT(PyAnySet_CheckExact(obj));
+}
+
+static PyObject *
+set_new(PyObject *self, PyObject *args)
+{
+    PyObject *iterable = NULL;
+    if (!PyArg_ParseTuple(args, "|O", &iterable)) {
+        return NULL;
+    }
+    return PySet_New(iterable);
+}
+
+static PyObject *
+frozenset_new(PyObject *self, PyObject *args)
+{
+    PyObject *iterable = NULL;
+    if (!PyArg_ParseTuple(args, "|O", &iterable)) {
+        return NULL;
+    }
+    return PyFrozenSet_New(iterable);
+}
+
+static PyObject *
+set_size(PyObject *self, PyObject *obj)
+{
+    NULLABLE(obj);
+    RETURN_SIZE(PySet_Size(obj));
+}
+
+static PyObject *
+set_contains(PyObject *self, PyObject *args)
+{
+    PyObject *obj, *item;
+    if (!PyArg_ParseTuple(args, "OO", &obj, &item)) {
+        return NULL;
+    }
+    NULLABLE(obj);
+    NULLABLE(item);
+    RETURN_INT(PySet_Contains(obj, item));
+}
+
+static PyObject *
+set_add(PyObject *self, PyObject *args)
+{
+    PyObject *obj, *item;
+    if (!PyArg_ParseTuple(args, "OO", &obj, &item)) {
+        return NULL;
+    }
+    NULLABLE(obj);
+    NULLABLE(item);
+    RETURN_INT(PySet_Add(obj, item));
+}
+
+static PyObject *
+set_discard(PyObject *self, PyObject *args)
+{
+    PyObject *obj, *item;
+    if (!PyArg_ParseTuple(args, "OO", &obj, &item)) {
+        return NULL;
+    }
+    NULLABLE(obj);
+    NULLABLE(item);
+    RETURN_INT(PySet_Discard(obj, item));
+}
+
+static PyObject *
+set_pop(PyObject *self, PyObject *obj)
+{
+    NULLABLE(obj);
+    return PySet_Pop(obj);
+}
+
+static PyObject *
+set_clear(PyObject *self, PyObject *obj)
+{
+    NULLABLE(obj);
+    RETURN_INT(PySet_Clear(obj));
+}
+
+static PyObject *
+test_frozenset_add_in_capi(PyObject *self, PyObject *Py_UNUSED(obj))
+{
+    // Test that `frozenset` can be used with `PySet_Add`,
+    // when frozenset is just created in CAPI.
+    PyObject *fs = PyFrozenSet_New(NULL);
+    if (fs == NULL) {
+        return NULL;
+    }
+    PyObject *num = PyLong_FromLong(1);
+    if (num == NULL) {
+        goto error;
+    }
+    if (PySet_Add(fs, num) < 0) {
+        goto error;
+    }
+    int contains = PySet_Contains(fs, num);
+    if (contains < 0) {
+        goto error;
+    }
+    else if (contains == 0) {
+        goto unexpected;
+    }
+    Py_DECREF(fs);
+    Py_DECREF(num);
+    Py_RETURN_NONE;
+
+unexpected:
+    PyErr_SetString(PyExc_ValueError, "set does not contain expected value");
+error:
+    Py_DECREF(fs);
+    Py_XDECREF(num);
+    return NULL;
+}
+
+static PyMethodDef test_methods[] = {
+    {"set_check", set_check, METH_O},
+    {"set_checkexact", set_checkexact, METH_O},
+    {"frozenset_check", frozenset_check, METH_O},
+    {"frozenset_checkexact", frozenset_checkexact, METH_O},
+    {"anyset_check", anyset_check, METH_O},
+    {"anyset_checkexact", anyset_checkexact, METH_O},
+
+    {"set_new", set_new, METH_VARARGS},
+    {"frozenset_new", frozenset_new, METH_VARARGS},
+
+    {"set_size", set_size, METH_O},
+    {"set_contains", set_contains, METH_VARARGS},
+    {"set_add", set_add, METH_VARARGS},
+    {"set_discard", set_discard, METH_VARARGS},
+    {"set_pop", set_pop, METH_O},
+    {"set_clear", set_clear, METH_O},
+
+    {"test_frozenset_add_in_capi", test_frozenset_add_in_capi, METH_NOARGS},
+
+    {NULL},
+};
+
+int
+_PyTestCapi_Init_Set(PyObject *m)
+{
+    if (PyModule_AddFunctions(m, test_methods) < 0) {
+        return -1;
+    }
+
+    return 0;
+}