opt: Warn about expressions we remove while optimizing

1 files changed, 2 insertions, 0 deletions

diff --git a/expr.h b/expr.h
index b825ca1..1f1ece6 100644
--- a/expr.h
+++ b/expr.h
@@ -110,6 +110,8 @@ struct bfs_expr {
 	bool always_true;
 	/** Whether this expression always evaluates to false. */
 	bool always_false;
+	/** Whether this expression doesn't appear on the command line. */
+	bool synthetic;
 
 	/** Estimated cost. */
 	float cost;