refactor common code into a new _PyErr_FormatNote function

Author: iritkatriel

Include/internal/pycore_pyerrors.h

@@ -109,6 +109,8 @@ extern PyObject* _Py_Offer_Suggestions(PyObject* exception);
 PyAPI_FUNC(Py_ssize_t) _Py_UTF8_Edit_Cost(PyObject *str_a, PyObject *str_b,
                                           Py_ssize_t max_cost);
 
+void _PyErr_FormatNote(const char *format, ...);
+
 #ifdef __cplusplus
 }
 #endif

Objects/typeobject.c

@@ -9137,24 +9137,10 @@ type_new_set_names(PyTypeObject *type)
         Py_DECREF(set_name);
 
         if (res == NULL) {
-            /* Add note to the exception */
-            PyObject *exc = PyErr_GetRaisedException();
-            assert(exc != NULL);
-            PyObject *note = PyUnicode_FromFormat(
+            _PyErr_FormatNote(
                 "Error calling __set_name__ on '%.100s' instance %R "
                 "in '%.100s'",
                 Py_TYPE(value)->tp_name, key, type->tp_name);
-
-            if (note) {
-                int res = _PyException_AddNote(exc, note);
-                Py_DECREF(note);
-                if (res == 0) {
-                    PyErr_SetRaisedException(exc);
-                    goto error;
-                }
-            }
-            _PyErr_ChainExceptions1(exc);
-            goto error;
         }
         else {
             Py_DECREF(res);

Python/codecs.c

@@ -11,6 +11,7 @@ Copyright (c) Corporation for National Research Initiatives.
 #include "Python.h"
 #include "pycore_call.h"          // _PyObject_CallNoArgs()
 #include "pycore_interp.h"        // PyInterpreterState.codec_search_path
+#include "pycore_pyerrors.h"       // _PyErr_FormatNote()
 #include "pycore_pystate.h"       // _PyInterpreterState_GET()
 #include "pycore_ucnhash.h"       // _PyUnicode_Name_CAPI
 #include <ctype.h>
@@ -382,29 +383,6 @@ PyObject *PyCodec_StreamWriter(const char *encoding,
     return codec_getstreamcodec(encoding, stream, errors, 3);
 }
 
-static void
-add_note_to_codec_error(const char *operation,
-                        const char *encoding)
-{
-    PyObject *exc = PyErr_GetRaisedException();
-    if (exc == NULL) {
-        return;
-    }
-    PyObject *note = PyUnicode_FromFormat("%s with '%s' codec failed",
-                                          operation, encoding);
-    if (note == NULL) {
-        _PyErr_ChainExceptions1(exc);
-        return;
-    }
-    int res = _PyException_AddNote(exc, note);
-    Py_DECREF(note);
-    if (res < 0) {
-        _PyErr_ChainExceptions1(exc);
-        return;
-    }
-    PyErr_SetRaisedException(exc);
-}
-
 /* Encode an object (e.g. a Unicode object) using the given encoding
    and return the resulting encoded object (usually a Python string).
 
@@ -425,7 +403,7 @@ _PyCodec_EncodeInternal(PyObject *object,
 
     result = PyObject_Call(encoder, args, NULL);
     if (result == NULL) {
-        add_note_to_codec_error("encoding", encoding);
+        _PyErr_FormatNote("%s with '%s' codec failed", "encoding", encoding);
         goto onError;
     }
 
@@ -470,7 +448,7 @@ _PyCodec_DecodeInternal(PyObject *object,
 
     result = PyObject_Call(decoder, args, NULL);
     if (result == NULL) {
-        add_note_to_codec_error("decoding", encoding);
+        _PyErr_FormatNote("%s with '%s' codec failed", "decoding", encoding);
         goto onError;
     }
     if (!PyTuple_Check(result) ||

Python/errors.c

@@ -1200,6 +1200,33 @@ PyErr_Format(PyObject *exception, const char *format, ...)
 }
 
 
+/* Adds a note to the current exception (if any) */
+void
+_PyErr_FormatNote(const char *format, ...)
+{
+    PyObject *exc = PyErr_GetRaisedException();
+    if (exc == NULL) {
+        return;
+    }
+    va_list vargs;
+    va_start(vargs, format);
+    PyObject *note = PyUnicode_FromFormatV(format, vargs);
+    va_end(vargs);
+    if (note == NULL) {
+        goto error;
+    }
+    int res = _PyException_AddNote(exc, note);
+    Py_DECREF(note);
+    if (res < 0) {
+        goto error;
+    }
+    PyErr_SetRaisedException(exc);
+    return;
+error:
+    _PyErr_ChainExceptions1(exc);
+}
+
+
 PyObject *
 PyErr_NewException(const char *name, PyObject *base, PyObject *dict)
 {