1 files changed, 31 insertions, 12 deletions
diff --git a/m4/pdns_check_libh2o_evloop.m4 b/m4/pdns_check_libh2o_evloop.m4
index 00781ce..43c1122 100644
--- a/m4/pdns_check_libh2o_evloop.m4
+++ b/m4/pdns_check_libh2o_evloop.m4
@@ -1,21 +1,40 @@
-AC_DEFUN([PDNS_CHECK_LIBH2OEVLOOP], [
+AC_DEFUN([PDNS_WITH_LIBH2OEVLOOP], [
+  AC_MSG_CHECKING([whether we will be linking in libh2o-evloop])
   HAVE_LIBH2OEVLOOP=0
-  PKG_CHECK_MODULES([LIBH2OEVLOOP], [libh2o-evloop], [
-    [HAVE_LIBH2OEVLOOP=1]
-    AC_DEFINE([HAVE_LIBH2OEVLOOP], [1], [Define to 1 if you have libh2o-evloop])
-    save_CFLAGS=$CFLAGS
-    save_LIBS=$LIBS
-    CFLAGS="$LIBH2OEVLOOP_CFLAGS $CFLAGS"
-    LIBS="$LIBH2OEVLOOP_LIBS $LIBS"
-    AC_CHECK_DECLS([h2o_socket_get_ssl_server_name], [
+  AC_ARG_WITH([h2o],
+    AS_HELP_STRING([--with-h2o],[use libh2o-evloop @<:@default=no@:>@]),
+    [with_h2o=$withval],
+    [with_h2o=no],
+  )
+  AC_MSG_RESULT([$with_h2o])
+
+  AS_IF([test "x$with_h2o" = "xyes" -o "x$with_h2o" = "xauto"], [
+    PKG_CHECK_MODULES([LIBH2OEVLOOP], [libh2o-evloop], [
+      [HAVE_LIBH2OEVLOOP=1]
+      AC_DEFINE([HAVE_LIBH2OEVLOOP], [1], [Define to 1 if you have libh2o-evloop])
+      save_CFLAGS=$CFLAGS
+      save_LIBS=$LIBS
+      CFLAGS="$LIBH2OEVLOOP_CFLAGS $CFLAGS"
+      LIBS="$LIBH2OEVLOOP_LIBS $LIBS"
+      AC_CHECK_DECLS([h2o_socket_get_ssl_server_name], [
           AC_DEFINE([HAVE_H2O_SOCKET_GET_SSL_SERVER_NAME], [1], [define to 1 if h2o_socket_get_ssl_server_name is available.])
         ],
         [ : ],
         [AC_INCLUDES_DEFAULT
           #include <h2o/socket.h>
       ])
-    CFLAGS=$save_CFLAGS
-    LIBS=$save_LIBS
-  ], [ : ])
+      CFLAGS=$save_CFLAGS
+      LIBS=$save_LIBS
+    ], [ : ])
+  ])
   AM_CONDITIONAL([HAVE_LIBH2OEVLOOP], [test "x$LIBH2OEVLOOP_LIBS" != "x"])
+  AM_COND_IF([HAVE_LIBH2OEVLOOP], [
+    AC_DEFINE([HAVE_LIBH2OEVLOOP], [1], [Define to 1 if you enable h2o-evloop support])
+  ])
+
+  AS_IF([test "x$with_h2o" = "xyes"], [
+    AS_IF([test x"LIBH2OEVLOOP_LIBS" = "x"], [
+      AC_MSG_ERROR([h2o-evloop requested but libraries were not found])
+    ])
+  ])
 ])