gh-119049: Fix incorrect usage of GET_WARNINGS_ATTR

Lib/test/test_capi/test_exceptions.py

@@ -3,11 +3,12 @@
 import re
 import sys
 import unittest
+import textwrap
 
 from test import support
 from test.support import import_helper
 from test.support.os_helper import TESTFN, TESTFN_UNDECODABLE
-from test.support.script_helper import assert_python_failure
+from test.support.script_helper import assert_python_failure, assert_python_ok
 from test.support.testcase import ExceptionIsLikeMixin
 
 from .test_misc import decode_stderr
@@ -68,6 +69,45 @@ def test_exc_info(self):
  else:
  self.assertTrue(False)
 
+ def test_warn_with_stacklevel(self):
+ code = textwrap.dedent('''\
+ import _testcapi
+
+ def foo():
+ _testcapi.function_set_warning()
+
+ foo() # line 6
+
+
+ foo() # line 9
+ ''')
+ proc = assert_python_ok("-c", code)
+ warnings = proc.err.splitlines()
+ self.assertEqual(len(warnings), 4)
+ self.assertTrue(
+ warnings[1].startswith(b" foo() # line 6")
+ )
+ self.assertTrue(
+ warnings[3].startswith(b" foo() # line 9")
+ )
+
+ def test_warn_during_finalization(self):
+ code = textwrap.dedent('''\
+ import _testcapi
+
+ class Foo:
+ def __del__(self):
+ _testcapi.function_set_warning()
+
+ ref = Foo()
+ ''')
+ proc = assert_python_ok("-c", code)
+ warnings = proc.err.splitlines()
+ # Due to the finalization of the interpreter, the source will be ommited
+ # because the ``warnings`` module cannot be imported at this time
+ self.assertEqual(len(warnings), 1)
+ self.assertEqual(warnings[0], b'<sys>:0: RuntimeWarning: Testing PyErr_WarnEx')
+
 
 class Test_FatalError(unittest.TestCase):
 

Modules/_testcapimodule.c

@@ -3303,6 +3303,15 @@ test_reftracer(PyObject *ob, PyObject *Py_UNUSED(ignored))
  return NULL;
 }
 
+static PyObject *
+function_set_warning(PyObject *Py_UNUSED(module), PyObject *Py_UNUSED(args))
+{
+ if (PyErr_WarnEx(PyExc_RuntimeWarning, "Testing PyErr_WarnEx", 2)) {
+ return NULL;
+ }
+ Py_RETURN_NONE;
+}
+
 static PyMethodDef TestMethods[] = {
  {"set_errno", set_errno, METH_VARARGS},
  {"test_config", test_config, METH_NOARGS},
@@ -3444,6 +3453,7 @@ static PyMethodDef TestMethods[] = {
  {"function_set_closure", function_set_closure, METH_VARARGS, NULL},
  {"check_pyimport_addmodule", check_pyimport_addmodule, METH_VARARGS},
  {"test_weakref_capi", test_weakref_capi, METH_NOARGS},
+ {"function_set_warning", function_set_warning, METH_NOARGS},
  {NULL, NULL} /* sentinel */
 };
 

Python/_warnings.c

@@ -569,10 +569,9 @@ call_show_warning(PyThreadState *tstate, PyObject *category,
  PyObject *show_fn, *msg, *res, *warnmsg_cls = NULL;
  PyInterpreterState *interp = tstate->interp;
 
- /* If the source parameter is set, try to get the Python implementation.
- The Python implementation is able to log the traceback where the source
+ /* The Python implementation is able to log the traceback where the source
  was allocated, whereas the C implementation doesn't. */
- show_fn = GET_WARNINGS_ATTR(interp, _showwarnmsg, source != NULL);
+ show_fn = GET_WARNINGS_ATTR(interp, _showwarnmsg, 1);
  if (show_fn == NULL) {
  if (PyErr_Occurred())
  return -1;