From 7907f8cbc6923240edb0b5b63adafb871c4c8875 Mon Sep 17 00:00:00 2001
From: Victor Stinner <vstinner@python.org>
Date: Mon, 8 Jun 2020 01:22:36 +0200
Subject: [PATCH] bpo-40887: Fix finalize_interp_clear() for free lists
 (GH-20698)

Reorganize code to ensure that free lists are cleared in the right
order. Call _PyWarnings_Fini() before _PyList_Fini().
---
 Python/pylifecycle.c | 56 ++++++++++++++++++--------------------------
 1 file changed, 23 insertions(+), 33 deletions(-)

diff --git a/Python/pylifecycle.c b/Python/pylifecycle.c
index 6d2eb1defc8..d730a98d3e5 100644
--- a/Python/pylifecycle.c
+++ b/Python/pylifecycle.c
@@ -1250,37 +1250,26 @@ static void
 finalize_interp_types(PyThreadState *tstate, int is_main_interp)
 {
     _PyFrame_Fini(tstate);
-    _PyTuple_Fini(tstate);
-    _PyList_Fini(tstate);
-    if (is_main_interp) {
-        _PySet_Fini();
-        _PyBytes_Fini();
-    }
-
-    _PyLong_Fini(tstate);
-    _PyFloat_Fini(tstate);
-
-    if (is_main_interp) {
-        _PyDict_Fini();
-    }
-
-    _PySlice_Fini(tstate);
-    _PyWarnings_Fini(tstate->interp);
-
-    if (is_main_interp) {
-        _Py_HashRandomization_Fini();
-        _PyArg_Fini();
-    }
-
     _PyAsyncGen_Fini(tstate);
     _PyContext_Fini(tstate);
 
-    /* Cleanup Unicode implementation */
-    _PyUnicode_Fini(tstate);
+    if (is_main_interp) {
+        _PySet_Fini();
+    }
+    if (is_main_interp) {
+        _PyDict_Fini();
+    }
+    _PyList_Fini(tstate);
+    _PyTuple_Fini(tstate);
+
+    _PySlice_Fini(tstate);
 
     if (is_main_interp) {
-        _Py_ClearFileSystemEncoding();
+        _PyBytes_Fini();
     }
+    _PyUnicode_Fini(tstate);
+    _PyFloat_Fini(tstate);
+    _PyLong_Fini(tstate);
 }
 
 
@@ -1299,19 +1288,20 @@ finalize_interp_clear(PyThreadState *tstate)
 
     _PyGC_Fini(tstate);
 
-    finalize_interp_types(tstate, is_main_interp);
+    if (is_main_interp) {
+        _Py_HashRandomization_Fini();
+        _PyArg_Fini();
+        _Py_ClearFileSystemEncoding();
+    }
+
+    _PyWarnings_Fini(tstate->interp);
 
     if (is_main_interp) {
-        /* XXX Still allocated:
-           - various static ad-hoc pointers to interned strings
-           - int and float free list blocks
-           - whatever various modules and libraries allocate
-        */
-
         PyGrammar_RemoveAccelerators(&_PyParser_Grammar);
-
         _PyExc_Fini();
     }
+
+    finalize_interp_types(tstate, is_main_interp);
 }