Attempt to detect the availability of RSA's MD5 implementation, and the

need to link against libmd to get it.
Attempt to detect the need for linking against librt to get clock_gettime().

git-svn-id: http://www.varnish-cache.org/svn/trunk/varnish-cache@759 d4fa192b-c00b-0410-8231-f00ffab90ce4

bin/varnishd/Makefile.am

@@ -58,5 +58,11 @@ varnishd_LDADD = \
 	$(top_builddir)/lib/libcompat/libcompat.a \
 	$(top_builddir)/lib/libvarnish/libvarnish.la \
 	$(top_builddir)/lib/libvcl/libvcl.la \
-	-lpthread \
-	-lmd
+	-lpthread
+
+if NEED_LIBMD
+varnishd_LDADD += -lmd
+endif
+if NEED_LIBRT
+varnishd_LDADD += -lrt
+endif

bin/varnishd/hash_classic.c

@@ -13,6 +13,11 @@
 
 #include <cache.h>
 
+#if defined(HASH_CLASSIC_MD5) && !defined(HAVE_MD5)
+/* MD5 is not available */
+#undef HASH_CLASSIC_MD5
+#endif
+
 #ifdef HASH_CLASSIC_MD5
 #include <md5.h>
 #endif

configure.ac

@@ -81,6 +81,16 @@ AC_CHECK_DECL([SO_ACCEPTFILER],
 	,
 	[sys/types.h, sys/socket.h])
 
+# On some systems, clock_gettime is in librt rather than libc
+AC_CHECK_LIB(rt, clock_gettime, need_librt=yes)
+AM_CONDITIONAL(NEED_LIBRT, test x$need_librt = xyes)
+
+AC_CHECK_HEADERS([md5.h])
+if test x$ac_cv_header_md5_h = xyes ; then
+	AC_CHECK_LIB(md, MD5Init, need_libmd=yes)
+fi
+AM_CONDITIONAL(NEED_LIBMD, test x$need_libmd = xyes)
+
 AC_CONFIG_FILES([
     Makefile
     bin/Makefile