From 35e985edefc98946dee7729ca29c0de292a63597 Mon Sep 17 00:00:00 2001
From: Victor Stinner <vstinner@python.org>
Date: Wed, 15 Nov 2023 20:14:41 +0100
Subject: [PATCH] gh-111798: Use lower Py_C_RECURSION_LIMIT in debug mode

Reenable test_call.test_super_deep() on s390x architecture.
---
 Include/cpython/pystate.h                                   | 6 +++++-
 Lib/test/test_call.py                                       | 3 +--
 .../2023-11-15-20-20-51.gh-issue-111798.cs-3t3.rst          | 4 ++++
 3 files changed, 10 insertions(+), 3 deletions(-)
 create mode 100644 Misc/NEWS.d/next/Core and Builtins/2023-11-15-20-20-51.gh-issue-111798.cs-3t3.rst

diff --git a/Include/cpython/pystate.h b/Include/cpython/pystate.h
index 7f2378ae76fe5c3..61b2fba571c0c0a 100644
--- a/Include/cpython/pystate.h
+++ b/Include/cpython/pystate.h
@@ -214,7 +214,11 @@ struct _ts {
 
 };
 
-#ifdef __wasi__
+#ifdef Py_DEBUG
+   // A debug build is likely built with low optimization level which implies
+   // higher stack memory usage than a release build. Use a lower limit.
+#  define Py_C_RECURSION_LIMIT 500
+#elif defined(__wasi__)
    // WASI has limited call stack. Python's recursion limit depends on code
    // layout, optimization, and WASI runtime. Wasmtime can handle about 700
    // recursions, sometimes less. 500 is a more conservative limit.
diff --git a/Lib/test/test_call.py b/Lib/test/test_call.py
index b1c78d7136fc9ba..fddc6fad24fcd59 100644
--- a/Lib/test/test_call.py
+++ b/Lib/test/test_call.py
@@ -1,5 +1,5 @@
 import unittest
-from test.support import cpython_only, requires_limited_api, skip_on_s390x
+from test.support import cpython_only, requires_limited_api
 try:
     import _testcapi
 except ImportError:
@@ -989,7 +989,6 @@ def case_change_over_substitution(BLuch=None, Luch = None, fluch = None):
 @cpython_only
 class TestRecursion(unittest.TestCase):
 
-    @skip_on_s390x
     def test_super_deep(self):
 
         def recurse(n):
diff --git a/Misc/NEWS.d/next/Core and Builtins/2023-11-15-20-20-51.gh-issue-111798.cs-3t3.rst b/Misc/NEWS.d/next/Core and Builtins/2023-11-15-20-20-51.gh-issue-111798.cs-3t3.rst
new file mode 100644
index 000000000000000..24bb4ec096c2d11
--- /dev/null
+++ b/Misc/NEWS.d/next/Core and Builtins/2023-11-15-20-20-51.gh-issue-111798.cs-3t3.rst	
@@ -0,0 +1,4 @@
+When Python is built in debug mode, set the C recursion limit to 500 instead
+of 1500. A debug build is likely built with low optimization level which
+implies higher stack memory usage than a release build. Patch by Victor
+Stinner.