Remove noop()

Sending a handler with incompatible pointer types is undefined
behavior, so this removes noop() and implements empty handlers for all
of its previous uses.

This used to work until C23.

wlopm.c

@@ -16,7 +16,6 @@
  * along with this program.  If not, see <https://www.gnu.org/licenses/>.
  */
 
-#include <ctype.h>
 #include <errno.h>
 #include <signal.h>
 #include <stdbool.h>
@@ -93,8 +92,6 @@ struct zwlr_output_power_manager_v1 *wlr_output_power_manager = NULL;
 int ret = EXIT_SUCCESS;
 bool loop = true;
 
-static void noop () {}
-
 static void wlr_output_power_handle_mode (void *data, struct zwlr_output_power_v1 *wlr_output_power,
 		enum zwlr_output_power_v1_mode mode)
 {
@@ -122,13 +119,43 @@ static void wl_output_handle_name (void *data, struct wl_output *wl_output,
 	output->name = strdup(name);
 }
 
+static void wl_output_handle_geometry (void *data, struct wl_output *wl_output,
+		int32_t x, int32_t y, int32_t physical_width, int32_t physical_height,
+		int32_t subpixel, const char* make, const char* model, int32_t transform)
+{
+	/* This function is deliberately left empty. */
+}
+
+static void wl_output_handle_mode (void *data, struct wl_output *wl_output,
+		uint32_t flags, int32_t width, int32_t height, int32_t refresh)
+{
+	/* This function is deliberately left empty. */
+}
+
+static void wl_output_handle_scale (void *data, struct wl_output *wl_output,
+		int32_t scale)
+{
+	/* This function is deliberately left empty. */
+}
+
+static void wl_output_handle_description (void *data, struct wl_output *wl_output,
+		const char *description)
+{
+	/* This function is deliberately left empty. */
+}
+
+static void wl_output_handle_done (void *data, struct wl_output *wl_output)
+{
+	/* This function is deliberately left empty. */
+}
+
 static const struct wl_output_listener wl_output_listener = {
 	.name        = wl_output_handle_name,
-	.geometry    = noop,
-	.mode        = noop,
-	.scale       = noop,
-	.description = noop,
-	.done        = noop,
+	.geometry    = wl_output_handle_geometry,
+	.mode        = wl_output_handle_mode,
+	.scale       = wl_output_handle_scale,
+	.description = wl_output_handle_description,
+	.done        = wl_output_handle_done,
 };
 
 static void registry_handle_global (void *data, struct wl_registry *registry,
@@ -151,7 +178,7 @@ static void registry_handle_global (void *data, struct wl_registry *registry,
 			return;
 		}
 
-		output->wl_output = wl_registry_bind(registry, name, 
+		output->wl_output = wl_registry_bind(registry, name,
 				&wl_output_interface, 4);
 		wl_output_add_listener(output->wl_output, &wl_output_listener, output);
 		output->wlr_output_power = NULL;
@@ -165,9 +192,15 @@ static void registry_handle_global (void *data, struct wl_registry *registry,
 				&zwlr_output_power_manager_v1_interface, version);
 }
 
+static void registry_handle_global_remove (void *data, struct wl_registry *registry,
+    uint32_t name)
+{
+	/* We don't run long enough to care. */
+}
+
 static const struct wl_registry_listener registry_listener = {
 	.global        = registry_handle_global,
-	.global_remove = noop, /* We don't run long enough to care. */
+	.global_remove = registry_handle_global_remove,
 };
 
 static void sync_handle_done (void *data, struct wl_callback *wl_callback, uint32_t other_data);
@@ -570,4 +603,3 @@ int main(int argc, char *argv[])
 
 	return ret;
 }
-