Check for a few more dependencies in configure.ac.

Author: pphaneuf

configure.ac

@@ -30,6 +30,14 @@ AC_HEADER_RESOLV
 AC_CHECK_HEADERS([arpa/inet.h fcntl.h limits.h netinet/in.h stddef.h stdint.h stdlib.h string.h sys/socket.h sys/time.h unistd.h])
 AC_CHECK_HEADER([event2/event.h],,
                 [AC_MSG_ERROR([libevent headers could not be found])])
+AC_CHECK_HEADER([gflags/gflags.h],,
+                [AC_MSG_ERROR([gflags headers could not be found])])
+AC_CHECK_HEADER([glog/logging.h],,
+                [AC_MSG_ERROR([glog headers could not be found])])
+AC_CHECK_HEADER([google/protobuf/message.h],,
+                [AC_MSG_ERROR([protobuf headers could not be found])])
+AC_CHECK_HEADER([ldns/ldns.h],,
+                [AC_MSG_ERROR([ldns headers could not be found])])
 
 # Check for working GTest/GMock.
 saved_CPPFLAGS="$CPPFLAGS"