pythongh-108082: Use PyErr_FormatUnraisable() (pythonGH-111580)

Replace most of calls of _PyErr_WriteUnraisableMsg() and some
calls of PyErr_WriteUnraisable(NULL) with PyErr_FormatUnraisable().

Co-authored-by: Victor Stinner <[email protected]>

Lib/test/test_capi/test_watchers.py

@@ -110,9 +110,11 @@ def test_error(self):
             with catch_unraisable_exception() as cm:
                 d["foo"] = "bar"
                 self.assertIn(
-                    "PyDict_EVENT_ADDED watcher callback for <dict at",
-                    cm.unraisable.object
+                    "Exception ignored in "
+                    "PyDict_EVENT_ADDED watcher callback for <dict at ",
+                    cm.unraisable.err_msg
                 )
+                self.assertIsNone(cm.unraisable.object)
                 self.assertEqual(str(cm.unraisable.exc_value), "boom!")
             self.assert_events([])
 
@@ -278,7 +280,9 @@ class C: pass
             self.watch(wid, C)
             with catch_unraisable_exception() as cm:
                 C.foo = "bar"
-                self.assertIs(cm.unraisable.object, C)
+                self.assertEqual(cm.unraisable.err_msg,
+                    f"Exception ignored in type watcher callback #0 for {C!r}")
+                self.assertIs(cm.unraisable.object, None)
                 self.assertEqual(str(cm.unraisable.exc_value), "boom!")
             self.assert_events([])
 
@@ -416,9 +420,11 @@ def test_error(self):
                 co = _testcapi.code_newempty("test_watchers", "dummy0", 0)
 
                 self.assertEqual(
-                    cm.unraisable.object,
+                    cm.unraisable.err_msg,
+                    f"Exception ignored in "
                     f"PY_CODE_EVENT_CREATE watcher callback for {co!r}"
                 )
+                self.assertIsNone(cm.unraisable.object)
                 self.assertEqual(str(cm.unraisable.exc_value), "boom!")
 
     def test_dealloc_error(self):
@@ -520,9 +526,11 @@ def myfunc():
                     pass
 
                 self.assertEqual(
-                    cm.unraisable.object,
-                    f"PyFunction_EVENT_CREATE watcher callback for {myfunc!r}"
+                    cm.unraisable.err_msg,
+                    f"Exception ignored in "
+                    f"PyFunction_EVENT_CREATE watcher callback for {repr(myfunc)[1:-1]}"
                 )
+                self.assertIsNone(cm.unraisable.object)
 
     def test_dealloc_watcher_raises_error(self):
         class MyError(Exception):

Lib/test/test_cmd_line.py

@@ -479,8 +479,9 @@ def test_stdout_flush_at_shutdown(self):
         rc, out, err = assert_python_failure('-c', code)
         self.assertEqual(b'', out)
         self.assertEqual(120, rc)
-        self.assertRegex(err.decode('ascii', 'ignore'),
-                         'Exception ignored in.*\nOSError: .*')
+        self.assertIn(b'Exception ignored on flushing sys.stdout:\n'
+                      b'OSError: '.replace(b'\n', os.linesep.encode()),
+                      err)
 
     def test_closed_stdout(self):
         # Issue #13444: if stdout has been explicitly closed, we should

Modules/_ctypes/_ctypes.c

@@ -113,7 +113,6 @@ bytes(cdata)
 #ifdef MS_WIN32
 #  include "pycore_modsupport.h"  // _PyArg_NoKeywords()
 #endif
-#include "pycore_pyerrors.h"      // _PyErr_WriteUnraisableMsg()
 
 
 #include <ffi.h>
@@ -185,7 +184,7 @@ _DictRemover_call(PyObject *myself, PyObject *args, PyObject *kw)
     DictRemoverObject *self = (DictRemoverObject *)myself;
     if (self->key && self->dict) {
         if (-1 == PyDict_DelItem(self->dict, self->key)) {
-            _PyErr_WriteUnraisableMsg("on calling _ctypes.DictRemover", NULL);
+            PyErr_FormatUnraisable("Exception ignored on calling _ctypes.DictRemover");
         }
         Py_CLEAR(self->key);
         Py_CLEAR(self->dict);

Modules/_lsprof.c

@@ -5,7 +5,6 @@
 #include "Python.h"
 #include "pycore_call.h"          // _PyObject_CallNoArgs()
 #include "pycore_ceval.h"         // _PyEval_SetProfile()
-#include "pycore_pyerrors.h"      // _PyErr_WriteUnraisableMsg()
 #include "pycore_pystate.h"       // _PyThreadState_GET()
 
 #include "rotatingtree.h"
@@ -847,7 +846,7 @@ profiler_dealloc(ProfilerObject *op)
     if (op->flags & POF_ENABLED) {
         PyThreadState *tstate = _PyThreadState_GET();
         if (_PyEval_SetProfile(tstate, NULL, NULL) < 0) {
-            _PyErr_WriteUnraisableMsg("When destroying _lsprof profiler", NULL);
+            PyErr_FormatUnraisable("Exception ignored when destroying _lsprof profiler");
         }
     }
 

Modules/gcmodule.c

@@ -1032,8 +1032,8 @@ delete_garbage(PyThreadState *tstate, GCState *gcstate,
                 Py_INCREF(op);
                 (void) clear(op);
                 if (_PyErr_Occurred(tstate)) {
-                    _PyErr_WriteUnraisableMsg("in tp_clear of",
-                                              (PyObject*)Py_TYPE(op));
+                    PyErr_FormatUnraisable("Exception ignored in tp_clear of %s",
+                                           Py_TYPE(op)->tp_name);
                 }
                 Py_DECREF(op);
             }
@@ -1344,7 +1344,7 @@ gc_collect_main(PyThreadState *tstate, int generation,
             _PyErr_Clear(tstate);
         }
         else {
-            _PyErr_WriteUnraisableMsg("in garbage collection", NULL);
+            PyErr_FormatUnraisable("Exception ignored in garbage collection");
         }
     }
 
@@ -1403,15 +1403,15 @@ invoke_gc_callback(PyThreadState *tstate, const char *phase,
             "collected", collected,
             "uncollectable", uncollectable);
         if (info == NULL) {
-            PyErr_WriteUnraisable(NULL);
+            PyErr_FormatUnraisable("Exception ignored on invoking gc callbacks");
             return;
         }
     }
 
     PyObject *phase_obj = PyUnicode_FromString(phase);
     if (phase_obj == NULL) {
         Py_XDECREF(info);
-        PyErr_WriteUnraisable(NULL);
+        PyErr_FormatUnraisable("Exception ignored on invoking gc callbacks");
         return;
     }
 

Modules/getpath.c

@@ -4,7 +4,6 @@
 #include "pycore_fileutils.h"     // _Py_abspath()
 #include "pycore_initconfig.h"    // _PyStatus_EXCEPTION()
 #include "pycore_pathconfig.h"    // _PyPathConfig_ReadGlobal()
-#include "pycore_pyerrors.h"      // _PyErr_WriteUnraisableMsg()
 #include "pycore_pymem.h"         // _PyMem_RawWcsdup()
 #include "pycore_pystate.h"       // _PyThreadState_GET()
 
@@ -911,7 +910,7 @@ _PyConfig_InitPathConfig(PyConfig *config, int compute_path_config)
     ) {
         Py_DECREF(co);
         Py_DECREF(dict);
-        _PyErr_WriteUnraisableMsg("error evaluating initial values", NULL);
+        PyErr_FormatUnraisable("Exception ignored in preparing getpath");
         return PyStatus_Error("error evaluating initial values");
     }
 
@@ -920,13 +919,13 @@ _PyConfig_InitPathConfig(PyConfig *config, int compute_path_config)
 
     if (!r) {
         Py_DECREF(dict);
-        _PyErr_WriteUnraisableMsg("error evaluating path", NULL);
+        PyErr_FormatUnraisable("Exception ignored in running getpath");
         return PyStatus_Error("error evaluating path");
     }
     Py_DECREF(r);
 
     if (_PyConfig_FromDict(config, configDict) < 0) {
-        _PyErr_WriteUnraisableMsg("reading getpath results", NULL);
+        PyErr_FormatUnraisable("Exception ignored in reading getpath results");
         Py_DECREF(dict);
         return PyStatus_Error("error getting getpath results");
     }

Modules/signalmodule.c

@@ -244,8 +244,7 @@ report_wakeup_write_error(void *data)
     errno = (int) (intptr_t) data;
     PyObject *exc = PyErr_GetRaisedException();
     PyErr_SetFromErrno(PyExc_OSError);
-    _PyErr_WriteUnraisableMsg("when trying to write to the signal wakeup fd",
-                              NULL);
+    PyErr_FormatUnraisable("Exception ignored when trying to write to the signal wakeup fd");
     PyErr_SetRaisedException(exc);
     errno = save_errno;
     return 0;
@@ -262,7 +261,7 @@ report_wakeup_send_error(void* data)
        recognizes the error codes used by both GetLastError() and
        WSAGetLastError */
     PyErr_SetExcFromWindowsErr(PyExc_OSError, send_errno);
-    _PyErr_WriteUnraisableMsg("when trying to send to the signal wakeup fd", NULL);
+    PyErr_FormatUnraisable("Exception ignored when trying to send to the signal wakeup fd");
     PyErr_SetRaisedException(exc);
     return 0;
 }

Objects/codeobject.c

@@ -12,8 +12,6 @@
 #include "pycore_tuple.h"         // _PyTuple_ITEMS()
 #include "clinic/codeobject.c.h"
 
-static PyObject* code_repr(PyCodeObject *co);
-
 static const char *
 code_event_name(PyCodeEvent event) {
     switch (event) {
@@ -41,21 +39,9 @@ notify_code_watchers(PyCodeEvent event, PyCodeObject *co)
             // callback must be non-null if the watcher bit is set
             assert(cb != NULL);
             if (cb(event, co) < 0) {
-                // Don't risk resurrecting the object if an unraisablehook keeps
-                // a reference; pass a string as context.
-                PyObject *context = NULL;
-                PyObject *repr = code_repr(co);
-                if (repr) {
-                    context = PyUnicode_FromFormat(
-                        "%s watcher callback for %U",
-                        code_event_name(event), repr);
-                    Py_DECREF(repr);
-                }
-                if (context == NULL) {
-                    context = Py_NewRef(Py_None);
-                }
-                PyErr_WriteUnraisable(context);
-                Py_DECREF(context);
+                PyErr_FormatUnraisable(
+                    "Exception ignored in %s watcher callback for %R",
+                    code_event_name(event), co);
             }
         }
         i++;

Objects/dictobject.c

@@ -5912,14 +5912,9 @@ _PyDict_SendEvent(int watcher_bits,
                 // unraisablehook keep a reference to it, so we don't pass the
                 // dict as context, just an informative string message.  Dict
                 // repr can call arbitrary code, so we invent a simpler version.
-                PyObject *context = PyUnicode_FromFormat(
-                    "%s watcher callback for <dict at %p>",
+                PyErr_FormatUnraisable(
+                    "Exception ignored in %s watcher callback for <dict at %p>",
                     dict_event_name(event), mp);
-                if (context == NULL) {
-                    context = Py_NewRef(Py_None);
-                }
-                PyErr_WriteUnraisable(context);
-                Py_DECREF(context);
             }
         }
         watcher_bits >>= 1;

Objects/funcobject.c

@@ -8,8 +8,6 @@
 #include "pycore_pyerrors.h"      // _PyErr_Occurred()
 
 
-static PyObject* func_repr(PyFunctionObject *op);
-
 static const char *
 func_event_name(PyFunction_WatchEvent event) {
     switch (event) {
@@ -35,21 +33,9 @@ notify_func_watchers(PyInterpreterState *interp, PyFunction_WatchEvent event,
             // callback must be non-null if the watcher bit is set
             assert(cb != NULL);
             if (cb(event, func, new_value) < 0) {
-                // Don't risk resurrecting the func if an unraisablehook keeps a
-                // reference; pass a string as context.
-                PyObject *context = NULL;
-                PyObject *repr = func_repr(func);
-                if (repr != NULL) {
-                    context = PyUnicode_FromFormat(
-                        "%s watcher callback for %U",
-                        func_event_name(event), repr);
-                    Py_DECREF(repr);
-                }
-                if (context == NULL) {
-                    context = Py_NewRef(Py_None);
-                }
-                PyErr_WriteUnraisable(context);
-                Py_DECREF(context);
+                PyErr_FormatUnraisable(
+                    "Exception ignored in %s watcher callback for function %U at %p",
+                    func_event_name(event), func->func_qualname, func);
             }
         }
         i++;

Objects/moduleobject.c

@@ -647,7 +647,7 @@ _PyModule_ClearDict(PyObject *d)
                         PyErr_Clear();
                 }
                 if (PyDict_SetItem(d, key, Py_None) != 0) {
-                    PyErr_WriteUnraisable(NULL);
+                    PyErr_FormatUnraisable("Exception ignored on clearing module dict");
                 }
             }
         }
@@ -668,7 +668,7 @@ _PyModule_ClearDict(PyObject *d)
                         PyErr_Clear();
                 }
                 if (PyDict_SetItem(d, key, Py_None) != 0) {
-                    PyErr_WriteUnraisable(NULL);
+                    PyErr_FormatUnraisable("Exception ignored on clearing module dict");
                 }
             }
         }
@@ -902,10 +902,9 @@ module_clear(PyModuleObject *m)
     {
         int res = m->md_def->m_clear((PyObject*)m);
         if (PyErr_Occurred()) {
-            PySys_FormatStderr("Exception ignored in m_clear of module%s%V\n",
-                               m->md_name ? " " : "",
-                               m->md_name, "");
-            PyErr_WriteUnraisable(NULL);
+            PyErr_FormatUnraisable("Exception ignored in m_clear of module%s%V",
+                                   m->md_name ? " " : "",
+                                   m->md_name, "");
         }
         if (res)
             return res;

Objects/typeobject.c

@@ -828,7 +828,9 @@ PyType_Modified(PyTypeObject *type)
             if (bits & 1) {
                 PyType_WatchCallback cb = interp->type_watchers[i];
                 if (cb && (cb(type) < 0)) {
-                    PyErr_WriteUnraisable((PyObject *)type);
+                    PyErr_FormatUnraisable(
+                        "Exception ignored in type watcher callback #%d for %R",
+                        i, type);
                 }
             }
             i++;
@@ -9291,7 +9293,7 @@ releasebuffer_call_python(PyObject *self, Py_buffer *buffer)
         // from a Python __buffer__ function.
         mv = PyMemoryView_FromBuffer(buffer);
         if (mv == NULL) {
-            PyErr_WriteUnraisable(self);
+            PyErr_FormatUnraisable("Exception ignored in bf_releasebuffer of %s", Py_TYPE(self)->tp_name);
             goto end;
         }
         // Set the memoryview to restricted mode, which forbids
@@ -9304,15 +9306,15 @@ releasebuffer_call_python(PyObject *self, Py_buffer *buffer)
     PyObject *stack[2] = {self, mv};
     PyObject *ret = vectorcall_method(&_Py_ID(__release_buffer__), stack, 2);
     if (ret == NULL) {
-        PyErr_WriteUnraisable(self);
+        PyErr_FormatUnraisable("Exception ignored in __release_buffer__ of %s", Py_TYPE(self)->tp_name);
     }
     else {
         Py_DECREF(ret);
     }
     if (!is_buffer_wrapper) {
         PyObject *res = PyObject_CallMethodNoArgs(mv, &_Py_ID(release));
         if (res == NULL) {
-            PyErr_WriteUnraisable(self);
+            PyErr_FormatUnraisable("Exception ignored in bf_releasebuffer of %s", Py_TYPE(self)->tp_name);
         }
         else {
             Py_DECREF(res);

Python/ceval.c

@@ -2235,7 +2235,7 @@ PyEval_SetProfile(Py_tracefunc func, PyObject *arg)
     PyThreadState *tstate = _PyThreadState_GET();
     if (_PyEval_SetProfile(tstate, func, arg) < 0) {
         /* Log _PySys_Audit() error */
-        _PyErr_WriteUnraisableMsg("in PyEval_SetProfile", NULL);
+        PyErr_FormatUnraisable("Exception ignored in PyEval_SetProfile");
     }
 }
 
@@ -2252,7 +2252,7 @@ PyEval_SetProfileAllThreads(Py_tracefunc func, PyObject *arg)
 
     while (ts) {
         if (_PyEval_SetProfile(ts, func, arg) < 0) {
-            _PyErr_WriteUnraisableMsg("in PyEval_SetProfileAllThreads", NULL);
+            PyErr_FormatUnraisable("Exception ignored in PyEval_SetProfileAllThreads");
         }
         HEAD_LOCK(runtime);
         ts = PyThreadState_Next(ts);
@@ -2266,7 +2266,7 @@ PyEval_SetTrace(Py_tracefunc func, PyObject *arg)
     PyThreadState *tstate = _PyThreadState_GET();
     if (_PyEval_SetTrace(tstate, func, arg) < 0) {
         /* Log _PySys_Audit() error */
-        _PyErr_WriteUnraisableMsg("in PyEval_SetTrace", NULL);
+        PyErr_FormatUnraisable("Exception ignored in PyEval_SetTrace");
     }
 }
 
@@ -2283,7 +2283,7 @@ PyEval_SetTraceAllThreads(Py_tracefunc func, PyObject *arg)
 
     while (ts) {
         if (_PyEval_SetTrace(ts, func, arg) < 0) {
-            _PyErr_WriteUnraisableMsg("in PyEval_SetTraceAllThreads", NULL);
+            PyErr_FormatUnraisable("Exception ignored in PyEval_SetTraceAllThreads");
         }
         HEAD_LOCK(runtime);
         ts = PyThreadState_Next(ts);

Python/compile.c

@@ -34,7 +34,6 @@
 #include "pycore_flowgraph.h"
 #include "pycore_intrinsics.h"
 #include "pycore_long.h"          // _PyLong_GetZero()
-#include "pycore_pyerrors.h"      // _PyErr_WriteUnraisableMsg()
 #include "pycore_pystate.h"       // _Py_GetConfig()
 #include "pycore_setobject.h"     // _PySet_NextEntry()
 #include "pycore_symtable.h"      // PySTEntryObject, _PyFuture_FromAST()
@@ -1407,8 +1406,8 @@ compiler_exit_scope(struct compiler *c)
         assert(c->u);
         /* we are deleting from a list so this really shouldn't fail */
         if (PySequence_DelItem(c->c_stack, n) < 0) {
-            _PyErr_WriteUnraisableMsg("on removing the last compiler "
-                                      "stack item", NULL);
+            PyErr_FormatUnraisable("Exception ignored on removing "
+                                   "the last compiler stack item");
         }
     }
     else {