bpo-41796: Call _PyAST_Fini() earlier to fix a leak (GH-23131)

Call _PyAST_Fini() on all interpreters, not only on the main
interpreter. Also, call it ealier to fix a reference leak.

Python types contain a reference to themselves in in their
PyTypeObject.tp_mro member. _PyAST_Fini() must called before the last
GC collection to destroy AST types.

_PyInterpreterState_Clear() now calls _PyAST_Fini(). It now also
calls _PyWarnings_Fini() on subinterpeters, not only on the main
interpreter.

Add an assertion in AST init_types() to ensure that the _ast module
is no longer used after _PyAST_Fini() has been called.

1 files changed, 0 insertions, 8 deletions

diff --git a/Python/pylifecycle.c b/Python/pylifecycle.c
index ff58c1b..cad0fa7 100644
--- a/Python/pylifecycle.c
+++ b/Python/pylifecycle.c
@@ -1545,12 +1545,6 @@ flush_std_files(void)
 static void
 finalize_interp_types(PyThreadState *tstate)
 {
-    // The _ast module state is shared by all interpreters.
-    // The state must only be cleared by the main interpreter.
-    if (_Py_IsMainInterpreter(tstate)) {
-        _PyAST_Fini(tstate);
-    }
-
     _PyExc_Fini(tstate);
     _PyFrame_Fini(tstate);
     _PyAsyncGen_Fini(tstate);
@@ -1591,8 +1585,6 @@ finalize_interp_clear(PyThreadState *tstate)
         _Py_ClearFileSystemEncoding();
     }
 
-    _PyWarnings_Fini(tstate->interp);
-
     finalize_interp_types(tstate);
 }