Abort if proprietary drivers are in use

The idea here is we don't want users to be blissfully unaware that they
are running unsupported drivers. So we abort on startup, and force the
user to add a specific argument to bypass the check.

sway/main.c

@@ -22,6 +22,7 @@
 #include "sway/tree/root.h"
 #include "sway/ipc-server.h"
 #include "ipc-client.h"
+#include "log.h"
 #include "readline.h"
 #include "stringop.h"
 #include "util.h"
@@ -81,7 +82,7 @@ void detect_raspi(void) {
 	}
 }
 
-void detect_proprietary(void) {
+void detect_proprietary(int allow_unsupported_gpu) {
 	FILE *f = fopen("/proc/modules", "r");
 	if (!f) {
 		return;
@@ -92,15 +93,30 @@ void detect_proprietary(void) {
 			break;
 		}
 		if (strstr(line, "nvidia")) {
-			fprintf(stderr, "\x1B[1;31mWarning: Proprietary Nvidia drivers are "
-				"NOT supported. Use Nouveau.\x1B[0m\n");
 			free(line);
+			if (allow_unsupported_gpu) {
+				wlr_log(WLR_ERROR,
+						"!!! Proprietary Nvidia drivers are in use !!!");
+			} else {
+				wlr_log(WLR_ERROR,
+					"Proprietary Nvidia drivers are NOT supported. "
+					"Use Nouveau. To launch sway anyway, launch with "
+					"--my-next-gpu-wont-be-nvidia and DO NOT report issues.");
+				exit(EXIT_FAILURE);
+			}
 			break;
 		}
 		if (strstr(line, "fglrx")) {
-			fprintf(stderr, "\x1B[1;31mWarning: Proprietary AMD drivers do "
-				"NOT support Wayland. Use radeon.\x1B[0m\n");
 			free(line);
+			if (allow_unsupported_gpu) {
+				wlr_log(WLR_ERROR,
+						"!!! Proprietary AMD drivers are in use !!!");
+			} else {
+				wlr_log(WLR_ERROR, "Proprietary AMD drivers do NOT support "
+					"Wayland. Use radeon. To try anyway, launch sway with "
+					"--unsupported-gpu and DO NOT report issues.");
+				exit(EXIT_FAILURE);
+			}
 			break;
 		}
 		free(line);
@@ -214,7 +230,7 @@ void enable_debug_flag(const char *flag) {
 }
 
 int main(int argc, char **argv) {
-	static int verbose = 0, debug = 0, validate = 0;
+	static int verbose = 0, debug = 0, validate = 0, allow_unsupported_gpu = 0;
 
 	static struct option long_options[] = {
 		{"help", no_argument, NULL, 'h'},
@@ -224,6 +240,8 @@ int main(int argc, char **argv) {
 		{"version", no_argument, NULL, 'v'},
 		{"verbose", no_argument, NULL, 'V'},
 		{"get-socketpath", no_argument, NULL, 'p'},
+		{"unsupported-gpu", no_argument, NULL, 'u'},
+		{"my-next-gpu-wont-be-nvidia", no_argument, NULL, 'u'},
 		{0, 0, 0, 0}
 	};
 
@@ -265,6 +283,9 @@ int main(int argc, char **argv) {
 		case 'D': // extended debug options
 			enable_debug_flag(optarg);
 			break;
+		case 'u':
+			allow_unsupported_gpu = 1;
+			break;
 		case 'v': // version
 			fprintf(stdout, "sway version " SWAY_VERSION "\n");
 			exit(EXIT_SUCCESS);
@@ -317,7 +338,7 @@ int main(int argc, char **argv) {
 
 	log_kernel();
 	log_distro();
-	detect_proprietary();
+	detect_proprietary(allow_unsupported_gpu);
 	detect_raspi();
 
 	drop_permissions();