gh-93649: Add Modules/_testcapi/function.c file (#129521)

* Move PyFunction C API tests to a new file.
* Add Lib/test/test_capi/test_function.py.
* Move tests from test_capi.test_misc to test_capi.test_function.

Modules/_testcapi/function.c

@@ -0,0 +1,143 @@
+#include "parts.h"
+#include "util.h"
+
+
+static PyObject *
+function_get_code(PyObject *self, PyObject *func)
+{
+    PyObject *code = PyFunction_GetCode(func);
+    if (code != NULL) {
+        return Py_NewRef(code);
+    } else {
+        return NULL;
+    }
+}
+
+
+static PyObject *
+function_get_globals(PyObject *self, PyObject *func)
+{
+    PyObject *globals = PyFunction_GetGlobals(func);
+    if (globals != NULL) {
+        return Py_NewRef(globals);
+    } else {
+        return NULL;
+    }
+}
+
+
+static PyObject *
+function_get_module(PyObject *self, PyObject *func)
+{
+    PyObject *module = PyFunction_GetModule(func);
+    if (module != NULL) {
+        return Py_NewRef(module);
+    } else {
+        return NULL;
+    }
+}
+
+
+static PyObject *
+function_get_defaults(PyObject *self, PyObject *func)
+{
+    PyObject *defaults = PyFunction_GetDefaults(func);
+    if (defaults != NULL) {
+        return Py_NewRef(defaults);
+    } else if (PyErr_Occurred()) {
+        return NULL;
+    } else {
+        Py_RETURN_NONE;  // This can happen when `defaults` are set to `None`
+    }
+}
+
+
+static PyObject *
+function_set_defaults(PyObject *self, PyObject *args)
+{
+    PyObject *func = NULL, *defaults = NULL;
+    if (!PyArg_ParseTuple(args, "OO", &func, &defaults)) {
+        return NULL;
+    }
+    int result = PyFunction_SetDefaults(func, defaults);
+    if (result == -1)
+        return NULL;
+    Py_RETURN_NONE;
+}
+
+
+static PyObject *
+function_get_kw_defaults(PyObject *self, PyObject *func)
+{
+    PyObject *defaults = PyFunction_GetKwDefaults(func);
+    if (defaults != NULL) {
+        return Py_NewRef(defaults);
+    } else if (PyErr_Occurred()) {
+        return NULL;
+    } else {
+        Py_RETURN_NONE;  // This can happen when `kwdefaults` are set to `None`
+    }
+}
+
+
+static PyObject *
+function_set_kw_defaults(PyObject *self, PyObject *args)
+{
+    PyObject *func = NULL, *defaults = NULL;
+    if (!PyArg_ParseTuple(args, "OO", &func, &defaults)) {
+        return NULL;
+    }
+    int result = PyFunction_SetKwDefaults(func, defaults);
+    if (result == -1)
+        return NULL;
+    Py_RETURN_NONE;
+}
+
+
+static PyObject *
+function_get_closure(PyObject *self, PyObject *func)
+{
+    PyObject *closure = PyFunction_GetClosure(func);
+    if (closure != NULL) {
+        return Py_NewRef(closure);
+    } else if (PyErr_Occurred()) {
+        return NULL;
+    } else {
+        Py_RETURN_NONE;  // This can happen when `closure` is set to `None`
+    }
+}
+
+
+static PyObject *
+function_set_closure(PyObject *self, PyObject *args)
+{
+    PyObject *func = NULL, *closure = NULL;
+    if (!PyArg_ParseTuple(args, "OO", &func, &closure)) {
+        return NULL;
+    }
+    int result = PyFunction_SetClosure(func, closure);
+    if (result == -1) {
+        return NULL;
+    }
+    Py_RETURN_NONE;
+}
+
+
+static PyMethodDef test_methods[] = {
+    {"function_get_code", function_get_code, METH_O, NULL},
+    {"function_get_globals", function_get_globals, METH_O, NULL},
+    {"function_get_module", function_get_module, METH_O, NULL},
+    {"function_get_defaults", function_get_defaults, METH_O, NULL},
+    {"function_set_defaults", function_set_defaults, METH_VARARGS, NULL},
+    {"function_get_kw_defaults", function_get_kw_defaults, METH_O, NULL},
+    {"function_set_kw_defaults", function_set_kw_defaults, METH_VARARGS, NULL},
+    {"function_get_closure", function_get_closure, METH_O, NULL},
+    {"function_set_closure", function_set_closure, METH_VARARGS, NULL},
+    {NULL},
+};
+
+int
+_PyTestCapi_Init_Function(PyObject *m)
+{
+    return PyModule_AddFunctions(m, test_methods);
+}

Modules/_testcapi/parts.h

@@ -64,5 +64,6 @@ int _PyTestCapi_Init_Config(PyObject *mod);
 int _PyTestCapi_Init_Import(PyObject *mod);
 int _PyTestCapi_Init_Frame(PyObject *mod);
 int _PyTestCapi_Init_Type(PyObject *mod);
+int _PyTestCapi_Init_Function(PyObject *mod);
 
 #endif // Py_TESTCAPI_PARTS_H