py/objtype: Implement __set_name__.

AJMansfield · AJMansfield · commit 43ed92898ac7 · 2025-07-20T11:53:22.000-04:00
Signed-off-by: Anson Mansfield &lt;amansfield@mantaro.com&gt;
diff --git a/py/objtype.c b/py/objtype.c
@@ -661,8 +661,8 @@ static void mp_obj_instance_load_attr(mp_obj_t self_in, qstr attr, mp_obj_t *des
     // try __getattr__
     if (attr != MP_QSTR___getattr__) {
         #if MICROPY_PY_DESCRIPTORS
-        // With descriptors enabled, don't delegate lookups of __get__/__set__/__delete__.
-        if (attr == MP_QSTR___get__ || attr == MP_QSTR___set__ || attr == MP_QSTR___delete__) {
+        // With descriptors enabled, don't delegate lookups of __get__/__set__/__delete__/__set_name__.
+        if (attr == MP_QSTR___get__ || attr == MP_QSTR___set__ || attr == MP_QSTR___delete__ || attr == MP_QSTR___set_name__) {
             return;
         }
         #endif
@@ -960,7 +960,7 @@ static bool check_for_special_accessors(mp_obj_t key, mp_obj_t value) {
     #endif
     #if MICROPY_PY_DESCRIPTORS
     static const uint8_t to_check[] = {
-        MP_QSTR___get__, MP_QSTR___set__, MP_QSTR___delete__,
+        MP_QSTR___get__, MP_QSTR___set__, MP_QSTR___delete__, // not needed for MP_QSTR___set_name__ tho
     };
     for (size_t i = 0; i < MP_ARRAY_SIZE(to_check); ++i) {
         mp_obj_t dest_temp[2];
@@ -1241,6 +1241,23 @@ mp_obj_t mp_obj_new_type(qstr name, mp_obj_t bases_tuple, mp_obj_t locals_dict)
         }
     }
 
+    #if MICROPY_PY_DESCRIPTORS
+    // call __set_name__ on all entries (especially descriptors)
+    for (size_t i = 0; i < locals_map->alloc; i++) {
+        if (mp_map_slot_is_filled(locals_map, i)) {
+            elem = &(locals_map->table[i]);
+
+            mp_obj_t set_name_method[4];
+            mp_load_method_maybe(elem->value, MP_QSTR___set_name__, set_name_method);
+            if (set_name_method[1] != MP_OBJ_NULL) {
+                set_name_method[2] = MP_OBJ_FROM_PTR(o);
+                set_name_method[3] = elem->key;
+                mp_call_method_n_kw(2, 0, set_name_method);
+            }
+        }
+    }
+    #endif
+
     return MP_OBJ_FROM_PTR(o);
 }
 
