On ResourceWarning, log traceback where the object was allocated

Issue #26567:

* Add a new function PyErr_ResourceWarning() function to pass the destroyed
  object
* Add a source attribute to warnings.WarningMessage
* Add warnings._showwarnmsg() which uses tracemalloc to get the traceback where
  source object was allocated.

3 files changed, 4 insertions, 6 deletions

diff --git a/Modules/_io/fileio.c b/Modules/_io/fileio.c
index 8bf3922..a02a9c1 100644
--- a/Modules/_io/fileio.c
+++ b/Modules/_io/fileio.c
@@ -92,8 +92,7 @@ fileio_dealloc_warn(fileio *self, PyObject *source)
     if (self->fd >= 0 && self->closefd) {
         PyObject *exc, *val, *tb;
         PyErr_Fetch(&exc, &val, &tb);
-        if (PyErr_WarnFormat(PyExc_ResourceWarning, 1,
-                             "unclosed file %R", source)) {
+        if (PyErr_ResourceWarning(source, 1, "unclosed file %R", source)) {
             /* Spurious errors can appear at shutdown */
             if (PyErr_ExceptionMatches(PyExc_Warning))
                 PyErr_WriteUnraisable((PyObject *) self);
diff --git a/Modules/posixmodule.c b/Modules/posixmodule.c
index 65b20be..3f22d14 100644
--- a/Modules/posixmodule.c
+++ b/Modules/posixmodule.c
@@ -12111,8 +12111,8 @@ ScandirIterator_dealloc(ScandirIterator *iterator)
          */
         ++Py_REFCNT(iterator);
         PyErr_Fetch(&exc, &val, &tb);
-        if (PyErr_WarnFormat(PyExc_ResourceWarning, 1,
-                             "unclosed scandir iterator %R", iterator)) {
+        if (PyErr_ResourceWarning((PyObject *)iterator, 1,
+                                  "unclosed scandir iterator %R", iterator)) {
             /* Spurious errors can appear at shutdown */
             if (PyErr_ExceptionMatches(PyExc_Warning))
                 PyErr_WriteUnraisable((PyObject *) iterator);
diff --git a/Modules/socketmodule.c b/Modules/socketmodule.c
index 77a6b31..657b04b 100644
--- a/Modules/socketmodule.c
+++ b/Modules/socketmodule.c
@@ -4170,8 +4170,7 @@ sock_dealloc(PySocketSockObject *s)
         Py_ssize_t old_refcount = Py_REFCNT(s);
         ++Py_REFCNT(s);
         PyErr_Fetch(&exc, &val, &tb);
-        if (PyErr_WarnFormat(PyExc_ResourceWarning, 1,
-                             "unclosed %R", s))
+        if (PyErr_ResourceWarning(s, 1, "unclosed %R", s))
             /* Spurious errors can appear at shutdown */
             if (PyErr_ExceptionMatches(PyExc_Warning))
                 PyErr_WriteUnraisable((PyObject *) s);