[mono] Remove unused --arch and --gc switches from driver.c (dotnet#1…

…01934)

We don't support dynamically switching arch/GC anymore with modern dotnet.

src/mono/mono/mini/driver.c

@@ -1597,21 +1597,15 @@ mini_usage (void)
 		"    --help-devel           Shows more options available to developers\n"
 		"\n"
 		"Runtime:\n"
-		"    --config FILE          Loads FILE as the Mono config\n"
 		"    --verbose, -v          Increases the verbosity level\n"
 		"    --help, -h             Show usage information\n"
 		"    --version, -V          Show version information\n"
 		"    --version=number       Show version number\n"
-		"    --runtime=VERSION      Use the VERSION runtime, instead of autodetecting\n"
 		"    --optimize=OPT         Turns on or off a specific optimization\n"
 		"                           Use --list-opt to get a list of optimizations\n"
 		"    --attach=OPTIONS       Pass OPTIONS to the attach agent in the runtime.\n"
 		"                           Currently the only supported option is 'disable'.\n"
 		"    --llvm, --nollvm       Controls whenever the runtime uses LLVM to compile code.\n"
-	        "    --gc=[sgen,boehm]      Select SGen or Boehm GC (runs mono or mono-sgen)\n"
-#ifdef TARGET_OSX
-		"    --arch=[32,64]         Select architecture (runs mono32 or mono64)\n"
-#endif
 		"    --handlers             Install custom handlers, use --help-handlers for details.\n"
 		"    --aot-path=PATH        List of additional directories to search for AOT images.\n"
 		"    --path=DIR             Add DIR to the list of directories to search for assemblies.\n"
@@ -1878,34 +1872,6 @@ mono_set_use_smp (int use_smp)
 #endif
 }
 
-static void
-switch_gc (char* argv[], const char* target_gc)
-{
-	GString *path;
-
-	if (!strcmp (mono_gc_get_gc_name (), target_gc)) {
-		return;
-	}
-
-	path = g_string_new (argv [0]);
-
-	/*Running mono without any argument*/
-	if (strstr (argv [0], "-sgen"))
-		g_string_truncate (path, path->len - 5);
-	else if (strstr (argv [0], "-boehm"))
-		g_string_truncate (path, path->len - 6);
-
-	g_string_append_c (path, '-');
-	g_string_append (path, target_gc);
-
-#ifdef HAVE_EXECVP
-	execvp (path->str, argv);
-	fprintf (stderr, "Error: Failed to switch to %s gc. mono-%s is not installed.\n", target_gc, target_gc);
-#else
-	fprintf (stderr, "Error: --gc=<NAME> option not supported on this platform.\n");
-#endif
-}
-
 static void
 increase_descriptor_limit (void)
 {
@@ -1927,37 +1893,6 @@ increase_descriptor_limit (void)
 #endif
 }
 
-#ifdef TARGET_OSX
-
-static void
-switch_arch (char* argv[], const char* target_arch)
-{
-	GString *path;
-	gsize arch_offset;
-
-	if ((strcmp (target_arch, "32") == 0 && strcmp (MONO_ARCHITECTURE, "x86") == 0) ||
-		(strcmp (target_arch, "64") == 0 && strcmp (MONO_ARCHITECTURE, "amd64") == 0)) {
-		return; /* matching arch loaded */
-	}
-
-	path = g_string_new (argv [0]);
-	arch_offset = path->len -2; /* last two characters */
-
-	/* Remove arch suffix if present */
-	if (strstr (&path->str[arch_offset], "32") || strstr (&path->str[arch_offset], "64")) {
-		g_string_truncate (path, arch_offset);
-	}
-
-	g_string_append (path, target_arch);
-
-	if (execvp (path->str, argv) < 0) {
-		fprintf (stderr, "Error: --arch=%s Failed to switch to '%s'.\n", target_arch, path->str);
-		exit (1);
-	}
-}
-
-#endif
-
 #define MONO_HANDLERS_ARGUMENT "--handlers="
 #define MONO_HANDLERS_ARGUMENT_LEN STRING_LENGTH(MONO_HANDLERS_ARGUMENT)
 
@@ -2174,28 +2109,19 @@ mono_main (int argc, char* argv[])
 			guint32 bisect_opt = parse_optimizations (0, bisect_opt_string, FALSE);
 			g_free (bisect_opt_string);
 			mono_set_bisect_methods (bisect_opt, sep + 1);
-		} else if (strcmp (argv [i], "--gc=sgen") == 0) {
-			switch_gc (argv, "sgen");
-		} else if (strcmp (argv [i], "--gc=boehm") == 0) {
-			switch_gc (argv, "boehm");
+		} else if (strncmp (argv [i], "--gc=", 5) == 0) {
+			// ignore
 		} else if (strncmp (argv[i], "--gc-params=", 12) == 0) {
 			mono_gc_params_set (argv[i] + 12);
 		} else if (strncmp (argv[i], "--gc-debug=", 11) == 0) {
 			mono_gc_debug_set (argv[i] + 11);
 		}
-#ifdef TARGET_OSX
-		else if (strcmp (argv [i], "--arch=32") == 0) {
-			switch_arch (argv, "32");
-		} else if (strcmp (argv [i], "--arch=64") == 0) {
-			switch_arch (argv, "64");
+		else if (strncmp (argv [i], "--arch=", 7) == 0) {
+			// ignore
 		}
-#endif
 		else if (strcmp (argv [i], "--config") == 0) {
-			if (i +1 >= argc){
-				fprintf (stderr, "error: --config requires a filename argument\n");
-				return 1;
-			}
 			++i;
+			// ignore
 #ifndef DISABLE_JIT
 		} else if (strcmp (argv [i], "--ncompile") == 0) {
 			if (i + 1 >= argc){