Fix dlopen dependency

Since the addition of the lock manager framework in 6a943419
dlopen is always required, but the checks in configure wasn't changed
to reflect that. This didn't show up directly because the VirtualBox
driver linking dlopen in covered it. But disabling the VirtualBox
driver makes the build fail due to missing dlopen.

Change the dlopen check in configure to pick up dlopen when available.

Reported by Ruben Kerkhof.

configure.ac

@@ -416,6 +416,28 @@ if test x"$with_remote" = x"yes" || test x"$with_libvirtd" = x"yes"; then
 fi
 
 
+dnl
+dnl check for libdl
+dnl
+
+dlfcn_found=yes
+dlopen_found=yes
+
+AC_CHECK_HEADER([dlfcn.h],, [dlfcn_found=no])
+AC_SEARCH_LIBS([dlopen], [dl],, [dlopen_found=no])
+
+case $ac_cv_search_dlopen:$host_os in
+  'none required'* | *:mingw* | *:msvc*) DLOPEN_LIBS= ;;
+  no*) AC_MSG_ERROR([Unable to find dlopen()]) ;;
+  *) if test "x$dlfcn_found" != "xyes"; then
+       AC_MSG_ERROR([Unable to find dlfcn.h])
+     fi
+     DLOPEN_LIBS=$ac_cv_search_dlopen ;;
+esac
+
+AC_SUBST([DLOPEN_LIBS])
+
+
 dnl
 dnl check for VirtualBox XPCOMC location
 dnl
@@ -432,14 +454,6 @@ AC_DEFINE_UNQUOTED([VBOX_XPCOMC_DIR], ["$vbox_xpcomc_dir"],
                    [Location of directory containing VirtualBox XPCOMC library])
 
 if test "x$with_vbox" = "xyes"; then
-    AC_SEARCH_LIBS([dlopen], [dl],,)
-    case $ac_cv_search_dlopen:$host_os in
-      'none required'* | *:mingw* | *:msvc*) DLOPEN_LIBS= ;;
-      no*) AC_MSG_ERROR([Unable to find dlopen()]) ;;
-      *) DLOPEN_LIBS=$ac_cv_search_dlopen ;;
-    esac
-    AC_SUBST([DLOPEN_LIBS])
-
     case "$host" in
       *-*-mingw* | *-*-msvc*) MSCOM_LIBS="-lole32 -loleaut32" ;;
       *) MSCOM_LIBS= ;;
@@ -2138,19 +2152,10 @@ AC_ARG_WITH([driver-modules],
 
 DRIVER_MODULE_CFLAGS=
 DRIVER_MODULE_LIBS=
-if test "x$with_driver_modules" = "xyes" ; then
-  old_cflags="$CFLAGS"
-  old_libs="$LIBS"
-  fail=0
-  AC_CHECK_HEADER([dlfcn.h],[],[fail=1])
-  AC_SEARCH_LIBS([dlopen], [dl], [], [fail=1])
-  test $fail = 1 &&
-      AC_MSG_ERROR([You must have dlfcn.h / dlopen() support to build driver modules])
-
-  CFLAGS="$old_cflags"
-  LIBS="$old_libs"
-fi
 if test "$with_driver_modules" = "yes"; then
+  if test "$dlfcn_found" != "yes" || test "$dlopen_found" != "yes"; then
+    AC_MSG_ERROR([You must have dlfcn.h / dlopen() support to build driver modules])
+  fi
   DRIVER_MODULE_CFLAGS="-export-dynamic"
   case $ac_cv_search_dlopen in
     no*) DRIVER_MODULE_LIBS= ;;
@@ -2468,6 +2473,7 @@ AC_MSG_NOTICE([])
 AC_MSG_NOTICE([Libraries])
 AC_MSG_NOTICE([])
 AC_MSG_NOTICE([  libxml: $LIBXML_CFLAGS $LIBXML_LIBS])
+AC_MSG_NOTICE([  dlopen: $DLOPEN_LIBS])
 if test "$with_esx" = "yes" ; then
 AC_MSG_NOTICE([ libcurl: $LIBCURL_CFLAGS $LIBCURL_LIBS])
 else

src/Makefile.am

@@ -526,7 +526,7 @@ libvirt_driver_la_SOURCES = $(DRIVER_SOURCES)
 
 libvirt_driver_la_CFLAGS = $(NUMACTL_CFLAGS) $(GNUTLS_CFLAGS) \
 		-I@top_srcdir@/src/conf $(AM_CFLAGS)
-libvirt_driver_la_LIBADD = $(NUMACTL_LIBS) $(GNUTLS_LIBS)
+libvirt_driver_la_LIBADD = $(NUMACTL_LIBS) $(GNUTLS_LIBS) $(DLOPEN_LIBS)
 
 USED_SYM_FILES = libvirt_private.syms