From ff35dcd95a972d59fa7fbeb8929fed710df366fc Mon Sep 17 00:00:00 2001
From: Jiseok CHOI <jiseok.dev@gmail.com>
Date: Sun, 20 Jul 2025 14:11:36 +0900
Subject: [PATCH] feat(vm/slot): implement `Py_TPFLAGS_MANAGED_DICT` for class
 objects (#5949)

---
 Lib/test/test_array.py                       |  2 --
 Lib/test/test_importlib/test_metadata_api.py |  2 --
 Lib/test/test_property.py                    |  2 --
 Lib/test/test_weakref.py                     |  2 --
 vm/src/builtins/type.rs                      | 10 ++++++----
 vm/src/types/slot.rs                         |  1 +
 6 files changed, 7 insertions(+), 12 deletions(-)

diff --git a/Lib/test/test_array.py b/Lib/test/test_array.py
index be89bec52..0c20e27cf 100644
--- a/Lib/test/test_array.py
+++ b/Lib/test/test_array.py
@@ -1285,8 +1285,6 @@ class NumberTest(BaseTest):
         self.assertRaises(OverflowError, array.array, self.typecode, [upper+1])
         self.assertRaises(OverflowError, a.__setitem__, 0, upper+1)
 
-    # TODO: RUSTPYTHON
-    @unittest.expectedFailure
     def test_subclassing(self):
         typecode = self.typecode
         class ExaggeratingArray(array.array):
diff --git a/Lib/test/test_importlib/test_metadata_api.py b/Lib/test/test_importlib/test_metadata_api.py
index 55c9f8007..33c6e85ee 100644
--- a/Lib/test/test_importlib/test_metadata_api.py
+++ b/Lib/test/test_importlib/test_metadata_api.py
@@ -139,8 +139,6 @@ class APITests(
     def test_entry_points_missing_group(self):
         assert entry_points(group='missing') == ()
 
-    # TODO: RUSTPYTHON
-    @unittest.expectedFailure
     def test_entry_points_allows_no_attributes(self):
         ep = entry_points().select(group='entries', name='main')
         with self.assertRaises(AttributeError):
diff --git a/Lib/test/test_property.py b/Lib/test/test_property.py
index 8411e903b..340f79b84 100644
--- a/Lib/test/test_property.py
+++ b/Lib/test/test_property.py
@@ -242,8 +242,6 @@ class PropertySubSlots(property):
 
 class PropertySubclassTests(unittest.TestCase):
 
-    # TODO: RUSTPYTHON
-    @unittest.expectedFailure
     def test_slots_docstring_copy_exception(self):
         try:
             class Foo(object):
diff --git a/Lib/test/test_weakref.py b/Lib/test/test_weakref.py
index 242c076f9..e7cd5962c 100644
--- a/Lib/test/test_weakref.py
+++ b/Lib/test/test_weakref.py
@@ -1132,8 +1132,6 @@ class SubclassableWeakrefTestCase(TestBase):
         self.assertIn(r1, refs)
         self.assertIn(r2, refs)
 
-    # TODO: RUSTPYTHON
-    @unittest.expectedFailure
     def test_subclass_refs_with_slots(self):
         class MyRef(weakref.ref):
             __slots__ = "slot1", "slot2"
diff --git a/vm/src/builtins/type.rs b/vm/src/builtins/type.rs
index 94334d4a8..498330fa9 100644
--- a/vm/src/builtins/type.rs
+++ b/vm/src/builtins/type.rs
@@ -1038,9 +1038,6 @@ impl Constructor for PyType {
             });
         }
 
-        // TODO: Flags is currently initialized with HAS_DICT. Should be
-        // updated when __slots__ are supported (toggling the flag off if
-        // a class has __slots__ defined).
         let heaptype_slots: Option<PyRef<PyTuple<PyStrRef>>> =
             if let Some(x) = attributes.get(identifier!(vm, __slots__)) {
                 let slots = if x.class().is(vm.ctx.types.str_type) {
@@ -1072,7 +1069,12 @@ impl Constructor for PyType {
         let heaptype_member_count = heaptype_slots.as_ref().map(|x| x.len()).unwrap_or(0);
         let member_count: usize = base_member_count + heaptype_member_count;
 
-        let flags = PyTypeFlags::heap_type_flags() | PyTypeFlags::HAS_DICT;
+        let mut flags = PyTypeFlags::heap_type_flags();
+        // Only add HAS_DICT and MANAGED_DICT if __slots__ is not defined.
+        if heaptype_slots.is_none() {
+            flags |= PyTypeFlags::HAS_DICT | PyTypeFlags::MANAGED_DICT;
+        }
+
         let (slots, heaptype_ext) = {
             let slots = PyTypeSlots {
                 flags,
diff --git a/vm/src/types/slot.rs b/vm/src/types/slot.rs
index 88e0f231c..35a387ed7 100644
--- a/vm/src/types/slot.rs
+++ b/vm/src/types/slot.rs
@@ -122,6 +122,7 @@ bitflags! {
     #[derive(Copy, Clone, Debug, PartialEq)]
     #[non_exhaustive]
     pub struct PyTypeFlags: u64 {
+        const MANAGED_DICT = 1 << 4;
         const IMMUTABLETYPE = 1 << 8;
         const HEAPTYPE = 1 << 9;
         const BASETYPE = 1 << 10;