Access the correct dict

python · Dec 16, 2022 · 1aecb3c · 1aecb3c
1 parent e209b9e
commit 1aecb3c
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Showing 3 changed files with 15 additions and 6 deletions.
diff --git a/Python/bytecodes.c b/Python/bytecodes.c
@@ -2738,8 +2738,10 @@ dummy_func(
             assert(self_cls->tp_flags & Py_TPFLAGS_MANAGED_DICT);
             PyDictOrValues dorv = *_PyObject_DictOrValuesPointer(self);
             DEOPT_IF(_PyDictOrValues_IsValues(dorv), LOAD_ATTR);
-            PyDictKeysObject *keys = ((PyHeapTypeObject *)self_cls)->ht_cached_keys;
-            DEOPT_IF(keys->dk_version != read_u32(cache->keys_version), LOAD_ATTR);
+            PyObject *dict = _PyDictOrValues_GetDict(dorv);
+            PyDictKeysObject *keys = (dict == NULL) ? NULL : ((PyDictObject *)dict)->ma_keys;
+            // Note: cache->keys_version can be 0 when dict is NULL.
+            DEOPT_IF(keys != NULL && keys->dk_version != read_u32(cache->keys_version), LOAD_ATTR);
             STAT_INC(LOAD_ATTR, hit);
             PyObject *res = read_obj(cache->descr);
             assert(res != NULL);

diff --git a/Python/generated_cases.c.h b/Python/generated_cases.c.h
diff --git a/Python/specialize.c b/Python/specialize.c
@@ -1014,11 +1014,13 @@ PyObject *descr, DescriptorClassification kind)
     PyDictKeysObject *keys;
     if (owner_cls->tp_flags & Py_TPFLAGS_MANAGED_DICT) {
         PyDictOrValues dorv = *_PyObject_DictOrValuesPointer(owner);
-        keys = ((PyHeapTypeObject *)owner_cls)->ht_cached_keys;
         if (_PyDictOrValues_IsValues(dorv)) {
+            keys = ((PyHeapTypeObject *)owner_cls)->ht_cached_keys;
             dictkind = MANAGED_VALUES;
         }
         else {
+            PyDictObject *dict = (PyDictObject *)_PyDictOrValues_GetDict(dorv);
+            keys = dict != NULL ? dict->ma_keys : NULL;
             // User has directly accessed __dict__.
             dictkind = MANAGED_DICT;
         }
@@ -1046,7 +1048,7 @@ PyObject *descr, DescriptorClassification kind)
             }
         }
     }
-    if (dictkind == MANAGED_VALUES || dictkind == OFFSET_DICT || dictkind == MANAGED_DICT) {
+    if (dictkind == MANAGED_VALUES || dictkind == OFFSET_DICT || (dictkind == MANAGED_DICT && keys != NULL)) {
         Py_ssize_t index = _PyDictKeys_StringLookup(keys, name);
         if (index != DKIX_EMPTY) {
             SPECIALIZATION_FAIL(LOAD_ATTR, SPEC_FAIL_ATTR_SHADOWED);
@@ -1067,6 +1069,9 @@ PyObject *descr, DescriptorClassification kind)
             _py_set_opcode(instr, LOAD_ATTR_METHOD_WITH_VALUES);
             break;
         case MANAGED_DICT:
+            if (keys == NULL) {
+                write_u32(cache->keys_version, 0);
+            }
             _py_set_opcode(instr, LOAD_ATTR_METHOD_MANAGED_DICT);
             break;
         case OFFSET_DICT: