compositor: replace role_data with role_resource

This increases type safety, makes it more obvious that role_data
must represent the role object, and will allow for automatic
cleanup when the resource is destroyed.

include/wlr/types/wlr_compositor.h

@@ -167,7 +167,7 @@ struct wlr_surface {
 	 * The role object representing the role. NULL if the role isn't
 	 * represented by any object or the object was destroyed.
 	 */
-	void *role_data;
+	struct wl_resource *role_resource;
 
 	struct {
 		struct wl_signal client_commit;
@@ -247,7 +247,7 @@ bool wlr_surface_set_role(struct wlr_surface *surface, const struct wlr_surface_
  * Set the role object for this surface. The surface must have a role and
  * no already set role object.
  */
-void wlr_surface_set_role_object(struct wlr_surface *surface, void *role_data);
+void wlr_surface_set_role_object(struct wlr_surface *surface, struct wl_resource *role_resource);
 
 /**
  * Destroy the object representing the surface's role. If it doesn't exist,

types/wlr_compositor.c

@@ -37,7 +37,7 @@ static int max(int fst, int snd) {
 static void surface_handle_destroy(struct wl_client *client,
 		struct wl_resource *resource) {
 	struct wlr_surface *surface = wlr_surface_from_resource(resource);
-	if (surface->role_data != NULL) {
+	if (surface->role_resource != NULL) {
 		wl_resource_post_error(resource,
 			WL_SURFACE_ERROR_DEFUNCT_ROLE_OBJECT,
 			"surface was destroyed before its role object");
@@ -492,7 +492,7 @@ static void surface_commit_state(struct wlr_surface *surface,
 	}
 
 	if (surface->role != NULL && surface->role->commit != NULL &&
-			(surface->role_data != NULL || surface->role->no_object)) {
+			(surface->role_resource != NULL || surface->role->no_object)) {
 		surface->role->commit(surface);
 	}
 
@@ -753,7 +753,7 @@ void wlr_surface_unmap(struct wlr_surface *surface) {
 	surface->mapped = false;
 	wl_signal_emit_mutable(&surface->events.unmap, NULL);
 	if (surface->role != NULL && surface->role->unmap != NULL &&
-			(surface->role_data != NULL || surface->role->no_object)) {
+			(surface->role_resource != NULL || surface->role->no_object)) {
 		surface->role->unmap(surface);
 	}
 
@@ -779,7 +779,7 @@ bool wlr_surface_set_role(struct wlr_surface *surface, const struct wlr_surface_
 		}
 		return false;
 	}
-	if (surface->role_data != NULL) {
+	if (surface->role_resource != NULL) {
 		wl_resource_post_error(error_resource, error_code,
 			"Cannot reassign role %s to wl_surface@%" PRIu32 ", role object still exists",
 			role->name, wl_resource_get_id(surface->resource));
@@ -790,23 +790,23 @@ bool wlr_surface_set_role(struct wlr_surface *surface, const struct wlr_surface_
 	return true;
 }
 
-void wlr_surface_set_role_object(struct wlr_surface *surface, void *role_data) {
+void wlr_surface_set_role_object(struct wlr_surface *surface, struct wl_resource *role_resource) {
 	assert(surface->role != NULL);
 	assert(!surface->role->no_object);
-	assert(surface->role_data == NULL);
+	assert(surface->role_resource == NULL);
-	assert(role_data != NULL);
+	assert(role_resource != NULL);
-	surface->role_data = role_data;
+	surface->role_resource = role_resource;
 }
 
 void wlr_surface_destroy_role_object(struct wlr_surface *surface) {
-	if (surface->role_data == NULL) {
+	if (surface->role_resource == NULL) {
 		return;
 	}
 	wlr_surface_unmap(surface);
 	if (surface->role->destroy != NULL) {
 		surface->role->destroy(surface);
 	}
-	surface->role_data = NULL;
+	surface->role_resource = NULL;
 }
 
 uint32_t wlr_surface_lock_pending(struct wlr_surface *surface) {

types/wlr_input_method_v2.c

@@ -138,12 +138,14 @@ static void popup_surface_consider_map(struct wlr_input_popup_surface_v2 *popup_
 }
 
 static void popup_surface_surface_role_commit(struct wlr_surface *surface) {
-	struct wlr_input_popup_surface_v2 *popup_surface = surface->role_data;
+	struct wlr_input_popup_surface_v2 *popup_surface =
+		wlr_input_popup_surface_v2_try_from_wlr_surface(surface);
 	popup_surface_consider_map(popup_surface);
 }
 
 static void popup_surface_surface_role_destroy(struct wlr_surface *surface) {
-	struct wlr_input_popup_surface_v2 *popup_surface = surface->role_data;
+	struct wlr_input_popup_surface_v2 *popup_surface =
+		wlr_input_popup_surface_v2_try_from_wlr_surface(surface);
 
 	wl_signal_emit_mutable(&popup_surface->events.destroy, NULL);
 	wl_list_remove(&popup_surface->link);
@@ -157,14 +159,6 @@ static const struct wlr_surface_role input_popup_surface_v2_role = {
 	.destroy = popup_surface_surface_role_destroy,
 };
 
-struct wlr_input_popup_surface_v2 *wlr_input_popup_surface_v2_try_from_wlr_surface(
-		struct wlr_surface *surface) {
-	if (surface->role != &input_popup_surface_v2_role) {
-		return NULL;
-	}
-	return (struct wlr_input_popup_surface_v2 *)surface->role_data;
-}
-
 static const struct zwp_input_popup_surface_v2_interface input_popup_impl;
 
 static struct wlr_input_popup_surface_v2 *popup_surface_from_resource(struct wl_resource *resource) {
@@ -173,6 +167,14 @@ static struct wlr_input_popup_surface_v2 *popup_surface_from_resource(struct wl_
 	return wl_resource_get_user_data(resource);
 }
 
+struct wlr_input_popup_surface_v2 *wlr_input_popup_surface_v2_try_from_wlr_surface(
+		struct wlr_surface *surface) {
+	if (surface->role != &input_popup_surface_v2_role || surface->role_resource == NULL) {
+		return NULL;
+	}
+	return popup_surface_from_resource(surface->role_resource);
+}
+
 static void popup_resource_destroy(struct wl_resource *resource) {
 	struct wlr_input_popup_surface_v2 *popup_surface =
 		popup_surface_from_resource(resource);
@@ -225,7 +227,7 @@ static void im_get_input_popup_surface(struct wl_client *client,
 	wl_resource_set_implementation(popup_resource, &input_popup_impl,
 		popup_surface, popup_resource_destroy);
 
-	wlr_surface_set_role_object(surface, popup_surface);
+	wlr_surface_set_role_object(surface, popup_resource);
 
 	popup_surface->resource = popup_resource;
 	popup_surface->input_method = input_method;

types/wlr_layer_shell_v1.c

@@ -40,10 +40,10 @@ static const struct wlr_surface_role layer_surface_role;
 
 struct wlr_layer_surface_v1 *wlr_layer_surface_v1_try_from_wlr_surface(
 		struct wlr_surface *surface) {
-	if (surface->role != &layer_surface_role) {
+	if (surface->role != &layer_surface_role || surface->role_resource == NULL) {
 		return NULL;
 	}
-	return (struct wlr_layer_surface_v1 *)surface->role_data;
+	return wlr_layer_surface_v1_from_resource(surface->role_resource);
 }
 
 static void layer_surface_configure_destroy(
@@ -445,7 +445,7 @@ static void layer_shell_handle_get_layer_surface(struct wl_client *wl_client,
 	wl_resource_set_implementation(surface->resource,
 		&layer_surface_implementation, surface, layer_surface_resource_destroy);
 
-	wlr_surface_set_role_object(wlr_surface, surface);
+	wlr_surface_set_role_object(wlr_surface, surface->resource);
 }
 
 static const struct zwlr_layer_shell_v1_interface layer_shell_implementation = {

types/wlr_session_lock_v1.c

@@ -50,10 +50,10 @@ static const struct wlr_surface_role lock_surface_role;
 
 struct wlr_session_lock_surface_v1 *wlr_session_lock_surface_v1_try_from_wlr_surface(
 		struct wlr_surface *surface) {
-	if (surface->role != &lock_surface_role) {
+	if (surface->role != &lock_surface_role || surface->role_resource == NULL) {
 		return NULL;
 	}
-	return (struct wlr_session_lock_surface_v1 *)surface->role_data;
+	return lock_surface_from_resource(surface->role_resource);
 }
 
 uint32_t wlr_session_lock_surface_v1_configure(
@@ -274,7 +274,7 @@ static void lock_handle_get_lock_surface(struct wl_client *client,
 	lock_surface->resource = lock_surface_resource;
 	wl_resource_set_user_data(lock_surface_resource, lock_surface);
 
-	wlr_surface_set_role_object(surface, lock_surface);
+	wlr_surface_set_role_object(surface, lock_surface_resource);
 
 	wl_list_insert(&lock->surfaces, &lock_surface->link);
 

types/wlr_subcompositor.c

@@ -293,10 +293,10 @@ void subsurface_handle_parent_commit(struct wlr_subsurface *subsurface) {
 }
 
 struct wlr_subsurface *wlr_subsurface_try_from_wlr_surface(struct wlr_surface *surface) {
-	if (surface->role != &subsurface_role) {
+	if (surface->role != &subsurface_role || surface->role_resource == NULL) {
 		return NULL;
 	}
-	return (struct wlr_subsurface *)surface->role_data;
+	return subsurface_from_resource(surface->role_resource);
 }
 
 static void subcompositor_handle_destroy(struct wl_client *client,
@@ -344,7 +344,7 @@ static void subcompositor_handle_get_subsurface(struct wl_client *client,
 	wl_resource_set_implementation(subsurface->resource,
 		&subsurface_implementation, subsurface, subsurface_resource_destroy);
 
-	wlr_surface_set_role_object(surface, subsurface);
+	wlr_surface_set_role_object(surface, subsurface->resource);
 
 	wl_signal_init(&subsurface->events.destroy);
 

types/xdg_shell/wlr_xdg_popup.c

@@ -412,7 +412,7 @@ void create_xdg_popup(struct wlr_xdg_surface *surface,
 		&xdg_popup_implementation, surface->popup,
 		xdg_popup_handle_resource_destroy);
 
-	wlr_surface_set_role_object(surface->surface, surface);
+	wlr_surface_set_role_object(surface->surface, surface->resource);
 
 	surface->role = WLR_XDG_SURFACE_ROLE_POPUP;
 

types/xdg_shell/wlr_xdg_surface.c

@@ -11,7 +11,10 @@ struct wlr_xdg_surface *wlr_xdg_surface_try_from_wlr_surface(
 			surface->role != &xdg_popup_surface_role) {
 		return NULL;
 	}
-	return (struct wlr_xdg_surface *)surface->role_data;
+	if (surface->role_resource == NULL) {
+		return NULL;
+	}
+	return wlr_xdg_surface_from_resource(surface->role_resource);
 }
 
 static void xdg_surface_configure_destroy(

types/xdg_shell/wlr_xdg_toplevel.c

@@ -524,7 +524,7 @@ void create_xdg_toplevel(struct wlr_xdg_surface *surface,
 		&xdg_toplevel_implementation, surface->toplevel,
 		xdg_toplevel_handle_resource_destroy);
 
-	wlr_surface_set_role_object(surface->surface, surface);
+	wlr_surface_set_role_object(surface->surface, surface->resource);
 
 	surface->role = WLR_XDG_SURFACE_ROLE_TOPLEVEL;
 }

xwayland/shell.c

@@ -38,7 +38,7 @@ static struct wlr_xwayland_surface_v1 *xwl_surface_from_resource(
 }
 
 static void xwl_surface_role_commit(struct wlr_surface *surface) {
-	struct wlr_xwayland_surface_v1 *xwl_surface = surface->role_data;
+	struct wlr_xwayland_surface_v1 *xwl_surface = xwl_surface_from_resource(surface->role_resource);
 
 	if (xwl_surface->serial != 0 && !xwl_surface->added) {
 		xwl_surface->added = true;
@@ -48,7 +48,7 @@ static void xwl_surface_role_commit(struct wlr_surface *surface) {
 }
 
 static void xwl_surface_role_destroy(struct wlr_surface *surface) {
-	struct wlr_xwayland_surface_v1 *xwl_surface = surface->role_data;
+	struct wlr_xwayland_surface_v1 *xwl_surface = xwl_surface_from_resource(surface->role_resource);
 	wl_list_remove(&xwl_surface->surface_destroy.link);
 	wl_list_remove(&xwl_surface->link);
 	wl_resource_set_user_data(xwl_surface->resource, NULL); // make inert
@@ -131,7 +131,7 @@ static void shell_handle_get_xwayland_surface(struct wl_client *client,
 	wl_resource_set_implementation(xwl_surface->resource, &xwl_surface_impl,
 		xwl_surface, xwl_surface_handle_resource_destroy);
 
-	wlr_surface_set_role_object(surface, xwl_surface);
+	wlr_surface_set_role_object(surface, xwl_surface->resource);
 
 	wl_list_insert(&shell->surfaces, &xwl_surface->link);