sway: change unsupported GPU message to swaynag

This commit shows a swaynag message when an unsupported GPU is detected
which must be acknowledged by users. It also adds an environment
variable (`SWAY_UNSUPPORTED_GPU`) which may be used instead of the
`--unsupported-gpu` argument.

The `static` storage class for flag variables in main has also been
removed, as this should have no effect on the program.

Resolves: #8999

include/sway/server.h

@@ -160,7 +160,7 @@ struct sway_debug {
 
 extern struct sway_debug debug;
 
-extern bool allow_unsupported_gpu;
+extern bool unsupported_gpu_detected;
 
 void sway_terminate(int exit_code);
 

sway/main.c

@@ -224,7 +224,7 @@ static const char usage[] =
 	"\n";
 
 int main(int argc, char **argv) {
-	static bool verbose = false, debug = false, validate = false;
+	bool verbose = false, debug = false, validate = false, allow_unsupported_gpu = false;
 
 	char *config_path = NULL;
 
@@ -286,6 +286,12 @@ int main(int argc, char **argv) {
 		exit(EXIT_FAILURE);
 	}
 
+	char *unsupported_gpu_env = getenv("SWAY_UNSUPPORTED_GPU");
+	// we let the flag override the environment variable
+	if (!allow_unsupported_gpu && unsupported_gpu_env) {
+		allow_unsupported_gpu = parse_boolean(unsupported_gpu_env, false);
+	}
+
 	// As the 'callback' function for wlr_log is equivalent to that for
 	// sway, we do not need to override it.
 	if (debug) {
@@ -373,6 +379,18 @@ int main(int argc, char **argv) {
 		swaynag_show(&config->swaynag_config_errors);
 	}
 
+	struct swaynag_instance nag_gpu = (struct swaynag_instance){
+		.args = "--type error "
+		"--message 'Proprietary GPU drivers are not supported by sway. Do not report issues.' ",
+		.detailed = false,
+	};
+
+	if (unsupported_gpu_detected && !allow_unsupported_gpu) {
+		if (!swaynag_spawn(config->swaynag_command, &nag_gpu)) {
+			sway_log(SWAY_ERROR, "Unable to start swaynag");
+		}
+	}
+
 	server_run(&server);
 
 shutdown:
@@ -385,6 +403,10 @@ shutdown:
 	free(config_path);
 	free_config(config);
 
+	if (nag_gpu.client != NULL) {
+		wl_client_destroy(nag_gpu.client);
+	}
+
 	pango_cairo_font_map_set_default(NULL);
 
 	return exit_value;

sway/server.c

@@ -78,7 +78,7 @@
 #define SWAY_FOREIGN_TOPLEVEL_LIST_VERSION 1
 #define SWAY_PRESENTATION_VERSION 2
 
-bool allow_unsupported_gpu = false;
+bool unsupported_gpu_detected = false;
 
 #if WLR_HAS_DRM_BACKEND
 static void handle_drm_lease_request(struct wl_listener *listener, void *data) {
@@ -161,27 +161,16 @@ static void detect_proprietary(struct wlr_backend *backend, void *data) {
 		return;
 	}
 
-	bool is_unsupported = false;
 	if (strcmp(version->name, "nvidia-drm") == 0) {
-		is_unsupported = true;
+		unsupported_gpu_detected = true;
 		sway_log(SWAY_ERROR, "!!! Proprietary Nvidia drivers are in use !!!");
-		if (!allow_unsupported_gpu) {
-			sway_log(SWAY_ERROR, "Use Nouveau instead");
-		}
 	}
 
 	if (strcmp(version->name, "evdi") == 0) {
-		is_unsupported = true;
+		unsupported_gpu_detected = true;
 		sway_log(SWAY_ERROR, "!!! Proprietary DisplayLink drivers are in use !!!");
 	}
 
-	if (!allow_unsupported_gpu && is_unsupported) {
-		sway_log(SWAY_ERROR,
-			"Proprietary drivers are NOT supported. To launch sway anyway, "
-			"launch with --unsupported-gpu and DO NOT report issues.");
-		exit(EXIT_FAILURE);
-	}
-
 	drmFreeVersion(version);
 }