GH-101578: Normalize the current exception (GH-101607)

* Make sure that the current exception is always normalized.

* Remove redundant type and traceback fields for the current exception.

* Add new API functions: PyErr_GetRaisedException, PyErr_SetRaisedException

* Add new API functions: PyException_GetArgs, PyException_SetArgs

1 files changed, 10 insertions, 1 deletions

diff --git a/Include/internal/pycore_pyerrors.h b/Include/internal/pycore_pyerrors.h
index 66f37942ef9..1bb4a9aa103 100644
--- a/Include/internal/pycore_pyerrors.h
+++ b/Include/internal/pycore_pyerrors.h
@@ -20,7 +20,10 @@ extern void _PyErr_FiniTypes(PyInterpreterState *);
 static inline PyObject* _PyErr_Occurred(PyThreadState *tstate)
 {
     assert(tstate != NULL);
-    return tstate->curexc_type;
+    if (tstate->current_exception == NULL) {
+        return NULL;
+    }
+    return (PyObject *)Py_TYPE(tstate->current_exception);
 }
 
 static inline void _PyErr_ClearExcState(_PyErr_StackItem *exc_state)
@@ -37,10 +40,16 @@ PyAPI_FUNC(void) _PyErr_Fetch(
     PyObject **value,
     PyObject **traceback);
 
+extern PyObject *
+_PyErr_GetRaisedException(PyThreadState *tstate);
+
 PyAPI_FUNC(int) _PyErr_ExceptionMatches(
     PyThreadState *tstate,
     PyObject *exc);
 
+void
+_PyErr_SetRaisedException(PyThreadState *tstate, PyObject *exc);
+
 PyAPI_FUNC(void) _PyErr_Restore(
     PyThreadState *tstate,
     PyObject *type,