bpo-45522: Allow to disable freelists on build time (GH-29056)

Freelists for object structs can now be disabled. A new ``configure``
option ``--without-freelists`` can be used to disable all freelists
except empty tuple singleton. Internal Py*_MAXFREELIST macros can now
be defined as 0 without causing compiler warnings and segfaults.

Signed-off-by: Christian Heimes <christian@python.org>

1 files changed, 12 insertions, 1 deletions

diff --git a/Lib/test/test_sys.py b/Lib/test/test_sys.py
index 2182898..b0688e1 100644
--- a/Lib/test/test_sys.py
+++ b/Lib/test/test_sys.py
@@ -825,7 +825,18 @@ class SysModuleTest(unittest.TestCase):
         from test.support.script_helper import assert_python_ok
         args = ['-c', 'import sys; sys._debugmallocstats()']
         ret, out, err = assert_python_ok(*args)
-        self.assertIn(b"free PyDictObjects", err)
+
+        # Output of sys._debugmallocstats() depends on configure flags.
+        # The sysconfig vars are not available on Windows.
+        if sys.platform != "win32":
+            with_freelists = sysconfig.get_config_var("WITH_FREELISTS")
+            with_pymalloc = sysconfig.get_config_var("WITH_PYMALLOC")
+            if with_freelists:
+                self.assertIn(b"free PyDictObjects", err)
+            if with_pymalloc:
+                self.assertIn(b'Small block threshold', err)
+            if not with_freelists and not with_pymalloc:
+                self.assertFalse(err)
 
         # The function has no parameter
         self.assertRaises(TypeError, sys._debugmallocstats, True)