storage-daemon: report unexpected arguments on the fly

If the first character of optstring is '-', then each nonoption argv
element is handled as if it were the argument of an option with character
code 1.  This removes the reordering of the argv array, and enables usage
of loc_set_cmdline to provide better error messages.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20210301152844.291799-2-pbonzini@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

storage-daemon/qemu-storage-daemon.c

@@ -174,7 +174,7 @@ static void process_options(int argc, char *argv[])
      * they are given on the command lines. This means that things must be
      * defined first before they can be referenced in another option.
      */
-    while ((c = getopt_long(argc, argv, "hT:V", long_options, NULL)) != -1) {
+    while ((c = getopt_long(argc, argv, "-hT:V", long_options, NULL)) != -1) {
         switch (c) {
         case '?':
             exit(EXIT_FAILURE);
@@ -275,14 +275,13 @@ static void process_options(int argc, char *argv[])
                 qobject_unref(args);
                 break;
             }
+        case 1:
+            error_report("Unexpected argument: %s", optarg);
+            exit(EXIT_FAILURE);
         default:
             g_assert_not_reached();
         }
     }
-    if (optind != argc) {
-        error_report("Unexpected argument: %s", argv[optind]);
-        exit(EXIT_FAILURE);
-    }
 }
 
 int main(int argc, char *argv[])