Track unpacked and class attribute aliases

tools/generate_popular_node_signatures.py

@@ -36,6 +36,7 @@ _MUTATING_METHODS = {
 _CONTROL_FLOW_TYPES = (ast.If, ast.For, ast.AsyncFor, ast.While, ast.Try, ast.With, ast.AsyncWith, ast.Match)
 if hasattr(ast, "TryStar"):
     _CONTROL_FLOW_TYPES += (ast.TryStar,)
+_CLASS_SIGNATURE_ATTRS = {"INPUT_TYPES", "RETURN_NAMES", "RETURN_TYPES"}
 
 
 def _literal(node, env, allow_mutable_env=True):
@@ -589,6 +590,25 @@ def _input_types_decorators_are_supported(decorators):
     return all(isinstance(decorator, ast.Name) and decorator.id == "classmethod" for decorator in decorators)
 
 
+def _class_attr_alias_sources(value, name, aliases):
+    return isinstance(value, ast.Name) and (value.id == name or value.id in aliases)
+
+
+def _update_class_attr_aliases_from_unpack(target, value, name, aliases):
+    if not isinstance(target, (ast.Tuple, ast.List)) or not isinstance(value, (ast.Tuple, ast.List)):
+        return False
+    if len(target.elts) != len(value.elts):
+        return False
+    found = False
+    for target_item, value_item in zip(target.elts, value.elts):
+        if not isinstance(target_item, ast.Name):
+            continue
+        if _class_attr_alias_sources(value_item, name, aliases):
+            aliases.add(target_item.id)
+            found = True
+    return found
+
+
 def _class_attr(cls, name, env):
     value = _MISSING
     aliases = set()
@@ -604,11 +624,16 @@ def _class_attr(cls, name, env):
                 len(stmt.targets) == 1
                 and isinstance(stmt.targets[0], ast.Name)
                 and stmt.targets[0].id != name
-                and isinstance(stmt.value, ast.Name)
-                and (stmt.value.id == name or stmt.value.id in aliases)
+                and _class_attr_alias_sources(stmt.value, name, aliases)
             ):
                 aliases.add(stmt.targets[0].id)
                 continue
+            if (
+                len(stmt.targets) == 1
+                and name not in target_names
+                and _update_class_attr_aliases_from_unpack(stmt.targets[0], stmt.value, name, aliases)
+            ):
+                continue
             if aliases.intersection(target_names):
                 value = _INVALID
                 aliases.difference_update(target_names)
@@ -830,22 +855,68 @@ def _expanded_class_attribute_names(names, class_aliases):
     return expanded
 
 
+def _class_attribute_alias_sources(value, class_aliases, class_bindings):
+    if not isinstance(value, ast.Attribute) or value.attr not in _CLASS_SIGNATURE_ATTRS:
+        return set()
+    name = _root_name(value.value)
+    if name in class_aliases:
+        return set(class_aliases[name])
+    if name in class_bindings:
+        return {name}
+    return set()
+
+
+def _class_attribute_alias_invalidated_names(stmt, class_attribute_aliases):
+    names = (
+        _mutating_call_target_names(stmt)
+        | _assignment_target_names(stmt)
+        | _delete_target_names(stmt)
+        | _bound_names(stmt)
+    )
+    invalidated = set()
+    for name in names:
+        invalidated.update(class_attribute_aliases.get(name, ()))
+    return invalidated
+
+
+def _update_class_attribute_aliases(stmt, class_attribute_aliases, class_aliases, class_bindings):
+    rebound_names = _assignment_target_names(stmt) | _delete_target_names(stmt) | _bound_names(stmt)
+    for name in rebound_names:
+        class_attribute_aliases.pop(name, None)
+
+    if isinstance(stmt, ast.Assign) and len(stmt.targets) == 1 and isinstance(stmt.targets[0], ast.Name):
+        sources = _class_attribute_alias_sources(stmt.value, class_aliases, class_bindings)
+        if sources:
+            class_attribute_aliases[stmt.targets[0].id] = sources
+    elif isinstance(stmt, ast.AnnAssign) and isinstance(stmt.target, ast.Name) and stmt.value is not None:
+        sources = _class_attribute_alias_sources(stmt.value, class_aliases, class_bindings)
+        if sources:
+            class_attribute_aliases[stmt.target.id] = sources
+
+
 def _final_module_dict(tree, name, value_converter, value_invalidated_by_names=None):
     value_invalidated_by_names = value_invalidated_by_names or (lambda _value, _names: False)
     value = _MISSING
     env = {}
     class_bindings = {}
     class_aliases = {}
+    class_attribute_aliases = {}
 
     def advance_module_state(stmt):
+        _invalidate_class_bindings(
+            class_bindings,
+            _class_attribute_alias_invalidated_names(stmt, class_attribute_aliases),
+        )
         _apply_module_stmt_to_env(stmt, env, class_bindings)
         _update_class_aliases(stmt, class_aliases, class_bindings)
+        _update_class_attribute_aliases(stmt, class_attribute_aliases, class_aliases, class_bindings)
 
     for stmt in tree.body:
         class_attr_names = _expanded_class_attribute_names(
             _class_attribute_mutation_target_names(stmt),
             class_aliases,
         )
+        class_attr_names.update(_class_attribute_alias_invalidated_names(stmt, class_attribute_aliases))
         if (
             value not in (_MISSING, _INVALID)
             and class_attr_names