gh-111065: Add more tests for the C API with the PySys_ prefix (GH-111067)

* Move existing tests for PySys_GetObject() and PySys_SetObject() into
  specialized files.
* Add test for PySys_GetXOptions() using _testcapi.
* Add tests for PySys_FormatStdout(), PySys_FormatStderr(),
  PySys_WriteStdout() and PySys_WriteStderr() using ctypes.

4 files changed, 61 insertions, 32 deletions

diff --git a/Modules/Setup.stdlib.in b/Modules/Setup.stdlib.in
index 647f442..c73522b 100644
--- a/Modules/Setup.stdlib.in
+++ b/Modules/Setup.stdlib.in
@@ -159,7 +159,7 @@
 @MODULE__XXTESTFUZZ_TRUE@_xxtestfuzz _xxtestfuzz/_xxtestfuzz.c _xxtestfuzz/fuzzer.c
 @MODULE__TESTBUFFER_TRUE@_testbuffer _testbuffer.c
 @MODULE__TESTINTERNALCAPI_TRUE@_testinternalcapi _testinternalcapi.c _testinternalcapi/test_lock.c _testinternalcapi/pytime.c _testinternalcapi/set.c
-@MODULE__TESTCAPI_TRUE@_testcapi _testcapimodule.c _testcapi/vectorcall.c _testcapi/vectorcall_limited.c _testcapi/heaptype.c _testcapi/abstract.c _testcapi/unicode.c _testcapi/dict.c _testcapi/set.c _testcapi/getargs.c _testcapi/datetime.c _testcapi/docstring.c _testcapi/mem.c _testcapi/watchers.c _testcapi/long.c _testcapi/float.c _testcapi/structmember.c _testcapi/exceptions.c _testcapi/code.c _testcapi/buffer.c _testcapi/pyatomic.c _testcapi/pyos.c _testcapi/immortal.c _testcapi/heaptype_relative.c _testcapi/gc.c
+@MODULE__TESTCAPI_TRUE@_testcapi _testcapimodule.c _testcapi/vectorcall.c _testcapi/vectorcall_limited.c _testcapi/heaptype.c _testcapi/abstract.c _testcapi/unicode.c _testcapi/dict.c _testcapi/set.c _testcapi/getargs.c _testcapi/datetime.c _testcapi/docstring.c _testcapi/mem.c _testcapi/watchers.c _testcapi/long.c _testcapi/float.c _testcapi/structmember.c _testcapi/exceptions.c _testcapi/code.c _testcapi/buffer.c _testcapi/pyatomic.c _testcapi/pyos.c _testcapi/immortal.c _testcapi/heaptype_relative.c _testcapi/gc.c _testcapi/sys.c
 @MODULE__TESTCLINIC_TRUE@_testclinic _testclinic.c
 @MODULE__TESTCLINIC_LIMITED_TRUE@_testclinic_limited _testclinic_limited.c
 
diff --git a/Modules/_testcapi/parts.h b/Modules/_testcapi/parts.h
index e5dbb9c..4fa77a8 100644
--- a/Modules/_testcapi/parts.h
+++ b/Modules/_testcapi/parts.h
@@ -49,6 +49,7 @@ int _PyTestCapi_Init_PyAtomic(PyObject *module);
 int _PyTestCapi_Init_PyOS(PyObject *module);
 int _PyTestCapi_Init_Immortal(PyObject *module);
 int _PyTestCapi_Init_GC(PyObject *mod);
+int _PyTestCapi_Init_Sys(PyObject *);
 
 int _PyTestCapi_Init_VectorcallLimited(PyObject *module);
 int _PyTestCapi_Init_HeaptypeRelative(PyObject *module);
diff --git a/Modules/_testcapi/sys.c b/Modules/_testcapi/sys.c
new file mode 100644
index 0000000..aa40e3c
--- /dev/null
+++ b/Modules/_testcapi/sys.c
@@ -0,0 +1,56 @@
+#include "parts.h"
+#include "util.h"
+
+
+static PyObject *
+sys_getobject(PyObject *Py_UNUSED(module), PyObject *arg)
+{
+    const char *name;
+    Py_ssize_t size;
+    if (!PyArg_Parse(arg, "z#", &name, &size)) {
+        return NULL;
+    }
+    PyObject *result = PySys_GetObject(name);
+    if (result == NULL) {
+        result = PyExc_AttributeError;
+    }
+    return Py_NewRef(result);
+}
+
+static PyObject *
+sys_setobject(PyObject *Py_UNUSED(module), PyObject *args)
+{
+    const char *name;
+    Py_ssize_t size;
+    PyObject *value;
+    if (!PyArg_ParseTuple(args, "z#O", &name, &size, &value)) {
+        return NULL;
+    }
+    NULLABLE(value);
+    RETURN_INT(PySys_SetObject(name, value));
+}
+
+static PyObject *
+sys_getxoptions(PyObject *Py_UNUSED(module), PyObject *Py_UNUSED(ignored))
+{
+    PyObject *result = PySys_GetXOptions();
+    return Py_XNewRef(result);
+}
+
+
+static PyMethodDef test_methods[] = {
+    {"sys_getobject", sys_getobject, METH_O},
+    {"sys_setobject", sys_setobject, METH_VARARGS},
+    {"sys_getxoptions", sys_getxoptions, METH_NOARGS},
+    {NULL},
+};
+
+int
+_PyTestCapi_Init_Sys(PyObject *m)
+{
+    if (PyModule_AddFunctions(m, test_methods) < 0) {
+        return -1;
+    }
+
+    return 0;
+}
diff --git a/Modules/_testcapimodule.c b/Modules/_testcapimodule.c
index 577fea3..dc9a25b 100644
--- a/Modules/_testcapimodule.c
+++ b/Modules/_testcapimodule.c
@@ -3231,35 +3231,6 @@ test_weakref_capi(PyObject *Py_UNUSED(module), PyObject *Py_UNUSED(args))
 }
 
 
-static PyObject *
-sys_getobject(PyObject *Py_UNUSED(module), PyObject *arg)
-{
-    const char *name;
-    Py_ssize_t size;
-    if (!PyArg_Parse(arg, "z#", &name, &size)) {
-        return NULL;
-    }
-    PyObject *result = PySys_GetObject(name);
-    if (result == NULL) {
-        result = PyExc_AttributeError;
-    }
-    return Py_NewRef(result);
-}
-
-static PyObject *
-sys_setobject(PyObject *Py_UNUSED(module), PyObject *args)
-{
-    const char *name;
-    Py_ssize_t size;
-    PyObject *value;
-    if (!PyArg_ParseTuple(args, "z#O", &name, &size, &value)) {
-        return NULL;
-    }
-    NULLABLE(value);
-    RETURN_INT(PySys_SetObject(name, value));
-}
-
-
 static PyMethodDef TestMethods[] = {
     {"set_errno",               set_errno,                       METH_VARARGS},
     {"test_config",             test_config,                     METH_NOARGS},
@@ -3392,8 +3363,6 @@ static PyMethodDef TestMethods[] = {
     {"function_set_kw_defaults", function_set_kw_defaults, METH_VARARGS, NULL},
     {"check_pyimport_addmodule", check_pyimport_addmodule, METH_VARARGS},
     {"test_weakref_capi", test_weakref_capi, METH_NOARGS},
-    {"sys_getobject", sys_getobject, METH_O},
-    {"sys_setobject", sys_setobject, METH_VARARGS},
     {NULL, NULL} /* sentinel */
 };
 
@@ -4038,6 +4007,9 @@ PyInit__testcapi(void)
     if (_PyTestCapi_Init_PyOS(m) < 0) {
         return NULL;
     }
+    if (_PyTestCapi_Init_Sys(m) < 0) {
+        return NULL;
+    }
     if (_PyTestCapi_Init_Immortal(m) < 0) {
         return NULL;
     }