unifdef(1) on OpenBSD
The text 7508e53124bb, as OpenBSD 5.2, OpenBSD 5.1, OpenBSD 5.0, OpenBSD 4.9 shipped it.
remove preprocessor conditionals from code
Flags it lists
-
-U -
-c -
-e -
-iU -
-k -
-l -
-s -
-t