gh-76785: Minor Cleanup of Exception-related Cross-interpreter State (gh-126602)

This change makes it easier to backport the _interpreters, _interpqueues, and _interpchannels modules to Python 3.12.

1 files changed, 49 insertions, 42 deletions

diff --git a/Python/crossinterp_exceptions.h b/Python/crossinterp_exceptions.h
index 278511d..3cb45d2 100644
--- a/Python/crossinterp_exceptions.h
+++ b/Python/crossinterp_exceptions.h
@@ -25,71 +25,78 @@ static PyTypeObject _PyExc_InterpreterNotFoundError = {
 };
 PyObject *PyExc_InterpreterNotFoundError = (PyObject *)&_PyExc_InterpreterNotFoundError;
 
-/* NotShareableError extends ValueError */
-
-static int
-_init_not_shareable_error_type(PyInterpreterState *interp)
-{
-    const char *name = "interpreters.NotShareableError";
-    PyObject *base = PyExc_ValueError;
-    PyObject *ns = NULL;
-    PyObject *exctype = PyErr_NewException(name, base, ns);
-    if (exctype == NULL) {
-        return -1;
-    }
-
-    _PyInterpreterState_GetXIState(interp)->PyExc_NotShareableError = exctype;
-    return 0;
-}
-
-static void
-_fini_not_shareable_error_type(PyInterpreterState *interp)
-{
-    Py_CLEAR(_PyInterpreterState_GetXIState(interp)->PyExc_NotShareableError);
-}
-
-static PyObject *
-_get_not_shareable_error_type(PyInterpreterState *interp)
-{
-    assert(_PyInterpreterState_GetXIState(interp)->PyExc_NotShareableError != NULL);
-    return _PyInterpreterState_GetXIState(interp)->PyExc_NotShareableError;
-}
-
 
 /* lifecycle */
 
 static int
-init_exceptions(PyInterpreterState *interp)
+init_static_exctypes(exceptions_t *state, PyInterpreterState *interp)
 {
+    assert(state == &_PyXI_GET_STATE(interp)->exceptions);
     PyTypeObject *base = (PyTypeObject *)PyExc_Exception;
 
-    // builtin static types
-
+    // PyExc_InterpreterError
     _PyExc_InterpreterError.tp_base = base;
     _PyExc_InterpreterError.tp_traverse = base->tp_traverse;
     _PyExc_InterpreterError.tp_clear = base->tp_clear;
     if (_PyStaticType_InitBuiltin(interp, &_PyExc_InterpreterError) < 0) {
-        return -1;
+        goto error;
     }
+    state->PyExc_InterpreterError = (PyObject *)&_PyExc_InterpreterError;
 
+    // PyExc_InterpreterNotFoundError
     _PyExc_InterpreterNotFoundError.tp_traverse = base->tp_traverse;
     _PyExc_InterpreterNotFoundError.tp_clear = base->tp_clear;
     if (_PyStaticType_InitBuiltin(interp, &_PyExc_InterpreterNotFoundError) < 0) {
-        return -1;
+        goto error;
     }
+    state->PyExc_InterpreterNotFoundError =
+            (PyObject *)&_PyExc_InterpreterNotFoundError;
 
-    // heap types
+    return 0;
 
-    // We would  call _init_not_shareable_error_type() here too,
-    // but that leads to ref leaks
+error:
+    fini_static_exctypes(state, interp);
+    return -1;
+}
+
+static void
+fini_static_exctypes(exceptions_t *state, PyInterpreterState *interp)
+{
+    assert(state == &_PyXI_GET_STATE(interp)->exceptions);
+    if (state->PyExc_InterpreterNotFoundError != NULL) {
+        state->PyExc_InterpreterNotFoundError = NULL;
+        _PyStaticType_FiniBuiltin(interp, &_PyExc_InterpreterNotFoundError);
+    }
+    if (state->PyExc_InterpreterError != NULL) {
+        state->PyExc_InterpreterError = NULL;
+        _PyStaticType_FiniBuiltin(interp, &_PyExc_InterpreterError);
+    }
+}
+
+static int
+init_heap_exctypes(exceptions_t *state)
+{
+    PyObject *exctype;
+
+    /* NotShareableError extends ValueError */
+    const char *name = "interpreters.NotShareableError";
+    PyObject *base = PyExc_ValueError;
+    PyObject *ns = NULL;
+    exctype = PyErr_NewException(name, base, ns);
+    if (exctype == NULL) {
+        goto error;
+    }
+    state->PyExc_NotShareableError = exctype;
 
     return 0;
+
+error:
+    fini_heap_exctypes(state);
+    return -1;
 }
 
 static void
-fini_exceptions(PyInterpreterState *interp)
+fini_heap_exctypes(exceptions_t *state)
 {
-    // Likewise with _fini_not_shareable_error_type().
-    _PyStaticType_FiniBuiltin(interp, &_PyExc_InterpreterNotFoundError);
-    _PyStaticType_FiniBuiltin(interp, &_PyExc_InterpreterError);
+    Py_CLEAR(state->PyExc_NotShareableError);
 }