Index: src/BasicTypes-gen.cpp
===================================================================
--- src/BasicTypes-gen.cpp	(revision f660b10d4c1b039ef237b2b44b42d8dd61218061)
+++ src/BasicTypes-gen.cpp	(revision b9b8643e3a9b6960fb9a4f22ad808eb4a280d5b3)
@@ -1,2 +1,6 @@
+// Code generation/updating for basic type information.
+//
+// Should be run by make when it is changed to updated some source files.
+
 #include <algorithm>
 #include <queue>