[C++] Add --warn flag which produces extra warnings
diff --git a/flags.h b/flags.h
index 8c72fa5..d2fe923 100644
--- a/flags.h
+++ b/flags.h
@@ -26,6 +26,7 @@
 struct Flags {
   bool detect_android_echo;
   bool dump_kati_stamp;
+  bool enable_kati_warnings;
   bool enable_stat_logs;
   bool gen_all_targets;
   bool gen_regen_rule;