+2018-07-09 Tom Tromey <tom@tromey.com>
+
+ * Makefile.in (%.c: %.y): Use ECHO_YACC.
+ (%.c: %.l): Use ECHO_LEX. Just fail if flex not available.
+ * silent-rules.mk (ECHO_YACC, ECHO_LEX): New variables.
+
2018-07-09 Tom Tromey <tom@tromey.com>
* Makefile.in (ALLDEPFILES): Remove exec.c.