Fixes to allow object-less callables throughout Godot

This fixes #81887

core/core_bind.cpp

@@ -1211,8 +1211,7 @@ void Thread::_start_func(void *ud) {
  Ref<Thread> t = *tud;
  memdelete(tud);
 
- Object *target_instance = t->target_callable.get_object();
- if (!target_instance) {
+ if (!t->target_callable.is_valid()) {
  t->running.clear();
  ERR_FAIL_MSG(vformat("Could not call function '%s' on previously freed instance to start thread %s.", t->target_callable.get_method(), t->get_id()));
  }

core/object/object.cpp

@@ -1109,8 +1109,7 @@ Error Object::emit_signalp(const StringName &p_name, const Variant **p_args, int
  Error err = OK;
 
  for (const Connection &c : slot_conns) {
- Object *target = c.callable.get_object();
- if (!target) {
+ if (!c.callable.is_valid()) {
  // Target might have been deleted during signal callback, this is expected and OK.
  continue;
  }
@@ -1133,7 +1132,8 @@ Error Object::emit_signalp(const StringName &p_name, const Variant **p_args, int
  continue;
  }
 #endif
- if (ce.error == Callable::CallError::CALL_ERROR_INVALID_METHOD && !ClassDB::class_exists(target->get_class_name())) {
+ Object *target = c.callable.get_object();
+ if (ce.error == Callable::CallError::CALL_ERROR_INVALID_METHOD && target && !ClassDB::class_exists(target->get_class_name())) {
  //most likely object is not initialized yet, do not throw error.
  } else {
  ERR_PRINT("Error calling from signal '" + String(p_name) + "' to callable: " + Variant::get_callable_error_text(c.callable, args, argc, ce) + ".");
@@ -1313,8 +1313,14 @@ void Object::get_signals_connected_to_this(List<Connection> *p_connections) cons
 Error Object::connect(const StringName &p_signal, const Callable &p_callable, uint32_t p_flags) {
  ERR_FAIL_COND_V_MSG(p_callable.is_null(), ERR_INVALID_PARAMETER, "Cannot connect to '" + p_signal + "': the provided callable is null.");
 
- Object *target_object = p_callable.get_object();
- ERR_FAIL_NULL_V_MSG(target_object, ERR_INVALID_PARAMETER, "Cannot connect to '" + p_signal + "' to callable '" + p_callable + "': the callable object is null.");
+ if (p_callable.is_standard()) {
+ // FIXME: This branch should probably removed in favor of the `is_valid()` branch, but there exist some classes
+ // that call `connect()` before they are fully registered with ClassDB. Until all such classes can be found
+ // and registered soon enough this branch is needed to allow `connect()` to succeed.
+ ERR_FAIL_NULL_V_MSG(p_callable.get_object(), ERR_INVALID_PARAMETER, "Cannot connect to '" + p_signal + "' to callable '" + p_callable + "': the callable object is null.");
+ } else {
+ ERR_FAIL_COND_V_MSG(!p_callable.is_valid(), ERR_INVALID_PARAMETER, "Cannot connect to '" + p_signal + "': the provided callable is not valid: " + p_callable);
+ }
 
  SignalData *s = signal_map.getptr(p_signal);
  if (!s) {
@@ -1352,14 +1358,18 @@ Error Object::connect(const StringName &p_signal, const Callable &p_callable, ui
  }
  }
 
+ Object *target_object = p_callable.get_object();
+
  SignalData::Slot slot;
 
  Connection conn;
  conn.callable = target;
  conn.signal = ::Signal(this, p_signal);
  conn.flags = p_flags;
  slot.conn = conn;
- slot.cE = target_object->connections.push_back(conn);
+ if (target_object) {
+ slot.cE = target_object->connections.push_back(conn);
+ }
  if (p_flags & CONNECT_REFERENCE_COUNTED) {
  slot.reference_count = 1;
  }
@@ -1398,9 +1408,6 @@ void Object::disconnect(const StringName &p_signal, const Callable &p_callable)
 bool Object::_disconnect(const StringName &p_signal, const Callable &p_callable, bool p_force) {
  ERR_FAIL_COND_V_MSG(p_callable.is_null(), false, "Cannot disconnect from '" + p_signal + "': the provided callable is null.");
 
- Object *target_object = p_callable.get_object();
- ERR_FAIL_NULL_V_MSG(target_object, false, "Cannot disconnect '" + p_signal + "' from callable '" + p_callable + "': the callable object is null.");
-
  SignalData *s = signal_map.getptr(p_signal);
  if (!s) {
  bool signal_is_valid = ClassDB::has_signal(get_class_name(), p_signal) ||
@@ -1420,7 +1427,13 @@ bool Object::_disconnect(const StringName &p_signal, const Callable &p_callable,
  }
  }
 
- target_object->connections.erase(slot->cE);
+ if (slot->cE) {
+ Object *target_object = p_callable.get_object();
+ if (target_object) {
+ target_object->connections.erase(slot->cE);
+ }
+ }
+
  s->slot_map.erase(*p_callable.get_base_comparator());
 
  if (s->slot_map.is_empty() && ClassDB::has_signal(get_class_name(), p_signal)) {

core/object/undo_redo.cpp

@@ -136,17 +136,22 @@ void UndoRedo::add_do_method(const Callable &p_callable) {
  ERR_FAIL_COND(action_level <= 0);
  ERR_FAIL_COND((current_action + 1) >= actions.size());
 
- Object *object = p_callable.get_object();
- ERR_FAIL_NULL(object);
+ ObjectID object_id = p_callable.get_object_id();
+ Object *object = ObjectDB::get_instance(object_id);
+ ERR_FAIL_COND(object_id.is_valid() && object == nullptr);
 
  Operation do_op;
  do_op.callable = p_callable;
- do_op.object = p_callable.get_object_id();
+ do_op.object = object_id;
  if (Object::cast_to<RefCounted>(object)) {
  do_op.ref = Ref<RefCounted>(Object::cast_to<RefCounted>(object));
  }
  do_op.type = Operation::TYPE_METHOD;
  do_op.name = p_callable.get_method();
+ if (do_op.name == StringName()) {
+ // There's no `get_method()` for custom callables, so use `operator String()` instead.
+ do_op.name = static_cast<String>(p_callable);
+ }
 
  actions.write[current_action + 1].do_ops.push_back(do_op);
 }
@@ -161,18 +166,23 @@ void UndoRedo::add_undo_method(const Callable &p_callable) {
  return;
  }
 
- Object *object = p_callable.get_object();
- ERR_FAIL_NULL(object);
+ ObjectID object_id = p_callable.get_object_id();
+ Object *object = ObjectDB::get_instance(object_id);
+ ERR_FAIL_COND(object_id.is_valid() && object == nullptr);
 
  Operation undo_op;
  undo_op.callable = p_callable;
- undo_op.object = p_callable.get_object_id();
+ undo_op.object = object_id;
  if (Object::cast_to<RefCounted>(object)) {
  undo_op.ref = Ref<RefCounted>(Object::cast_to<RefCounted>(object));
  }
  undo_op.type = Operation::TYPE_METHOD;
  undo_op.force_keep_in_merge_ends = force_keep_in_merge_ends;
  undo_op.name = p_callable.get_method();
+ if (undo_op.name == StringName()) {
+ // There's no `get_method()` for custom callables, so use `operator String()` instead.
+ undo_op.name = static_cast<String>(p_callable);
+ }
 
  actions.write[current_action + 1].undo_ops.push_back(undo_op);
 }

core/variant/callable.cpp

@@ -47,6 +47,13 @@ void Callable::callp(const Variant **p_arguments, int p_argcount, Variant &r_ret
  r_call_error.expected = 0;
  r_return_value = Variant();
  } else if (is_custom()) {
+ if (!is_valid()) {
+ r_call_error.error = CallError::CALL_ERROR_INSTANCE_IS_NULL;
+ r_call_error.argument = 0;
+ r_call_error.expected = 0;
+ r_return_value = Variant();
+ return;
+ }
  custom->call(p_arguments, p_argcount, r_return_value, r_call_error);
  } else {
  Object *obj = ObjectDB::get_instance(ObjectID(object));

scene/animation/tween.cpp

@@ -675,7 +675,7 @@ bool CallbackTweener::step(double &r_delta) {
  return false;
  }
 
- if (!callback.get_object()) {
+ if (!callback.is_valid()) {
  return false;
  }
 
@@ -740,7 +740,7 @@ bool MethodTweener::step(double &r_delta) {
  return false;
  }
 
- if (!callback.get_object()) {
+ if (!callback.is_valid()) {
  return false;
  }
 

servers/physics_2d/godot_area_2d.cpp

@@ -78,13 +78,6 @@ void GodotArea2D::set_space(GodotSpace2D *p_space) {
 }
 
 void GodotArea2D::set_monitor_callback(const Callable &p_callback) {
- ObjectID id = p_callback.get_object_id();
-
- if (id == monitor_callback.get_object_id()) {
- monitor_callback = p_callback;
- return;
- }
-
  _unregister_shapes();
 
  monitor_callback = p_callback;
@@ -100,13 +93,6 @@ void GodotArea2D::set_monitor_callback(const Callable &p_callback) {
 }
 
 void GodotArea2D::set_area_monitor_callback(const Callable &p_callback) {
- ObjectID id = p_callback.get_object_id();
-
- if (id == area_monitor_callback.get_object_id()) {
- area_monitor_callback = p_callback;
- return;
- }
-
  _unregister_shapes();
 
  area_monitor_callback = p_callback;

servers/physics_2d/godot_body_2d.cpp

@@ -615,7 +615,7 @@ void GodotBody2D::integrate_velocities(real_t p_step) {
  return;
  }
 
- if (fi_callback_data || body_state_callback.get_object()) {
+ if (fi_callback_data || body_state_callback.is_valid()) {
  get_space()->body_add_to_state_query_list(&direct_state_query_list);
  }
 
@@ -676,7 +676,7 @@ void GodotBody2D::call_queries() {
  Variant direct_state_variant = get_direct_state();
 
  if (fi_callback_data) {
- if (!fi_callback_data->callable.get_object()) {
+ if (!fi_callback_data->callable.is_valid()) {
  set_force_integration_callback(Callable());
  } else {
  const Variant *vp[2] = { &direct_state_variant, &fi_callback_data->udata };
@@ -692,7 +692,7 @@ void GodotBody2D::call_queries() {
  }
  }
 
- if (body_state_callback.get_object()) {
+ if (body_state_callback.is_valid()) {
  body_state_callback.call(direct_state_variant);
  }
 }
@@ -719,7 +719,7 @@ void GodotBody2D::set_state_sync_callback(const Callable &p_callable) {
 }
 
 void GodotBody2D::set_force_integration_callback(const Callable &p_callable, const Variant &p_udata) {
- if (p_callable.get_object()) {
+ if (p_callable.is_valid()) {
  if (!fi_callback_data) {
  fi_callback_data = memnew(ForceIntegrationCallbackData);
  }

servers/physics_3d/godot_area_3d.cpp

@@ -87,12 +87,6 @@ void GodotArea3D::set_space(GodotSpace3D *p_space) {
 }
 
 void GodotArea3D::set_monitor_callback(const Callable &p_callback) {
- ObjectID id = p_callback.get_object_id();
- if (id == monitor_callback.get_object_id()) {
- monitor_callback = p_callback;
- return;
- }
-
  _unregister_shapes();
 
  monitor_callback = p_callback;
@@ -108,12 +102,6 @@ void GodotArea3D::set_monitor_callback(const Callable &p_callback) {
 }
 
 void GodotArea3D::set_area_monitor_callback(const Callable &p_callback) {
- ObjectID id = p_callback.get_object_id();
- if (id == area_monitor_callback.get_object_id()) {
- area_monitor_callback = p_callback;
- return;
- }
-
  _unregister_shapes();
 
  area_monitor_callback = p_callback;

servers/physics_3d/godot_body_3d.cpp

@@ -674,7 +674,7 @@ void GodotBody3D::integrate_velocities(real_t p_step) {
  return;
  }
 
- if (fi_callback_data || body_state_callback.get_object()) {
+ if (fi_callback_data || body_state_callback.is_valid()) {
  get_space()->body_add_to_state_query_list(&direct_state_query_list);
  }
 
@@ -759,7 +759,7 @@ void GodotBody3D::call_queries() {
  Variant direct_state_variant = get_direct_state();
 
  if (fi_callback_data) {
- if (!fi_callback_data->callable.get_object()) {
+ if (!fi_callback_data->callable.is_valid()) {
  set_force_integration_callback(Callable());
  } else {
  const Variant *vp[2] = { &direct_state_variant, &fi_callback_data->udata };
@@ -771,7 +771,7 @@ void GodotBody3D::call_queries() {
  }
  }
 
- if (body_state_callback.get_object()) {
+ if (body_state_callback.is_valid()) {
  body_state_callback.call(direct_state_variant);
  }
 }
@@ -798,7 +798,7 @@ void GodotBody3D::set_state_sync_callback(const Callable &p_callable) {
 }
 
 void GodotBody3D::set_force_integration_callback(const Callable &p_callable, const Variant &p_udata) {
- if (p_callable.get_object()) {
+ if (p_callable.is_valid()) {
  if (!fi_callback_data) {
  fi_callback_data = memnew(ForceIntegrationCallbackData);
  }