m4: virt-xdr: rewrite XDR check

The current code to check XDR support was obsolete and way to
complicated.

On linux we can use pkg-config to check for libtirpc and have
the CFLAGS and LIBS configured by it as well.

On MinGW there is portablexdr library which installs header files
directly into system include directory.

On FreeBSD and macOS XDR functions are part of libc so there is
no library needed, we just need to call AM_CONDITIONAL to silence
configure which otherwise complains about missing WITH_XDR.

Signed-off-by: Pavel Hrdina <phrdina@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>

libvirt.spec.in

@@ -406,11 +406,13 @@ BuildRequires: wireshark-devel >= 2.4.0
 BuildRequires: libssh-devel >= 0.7.0
 %endif
 
+# On RHEL-7 rpcgen is still part of glibc-common package
 %if 0%{?fedora} || 0%{?rhel} > 7
 BuildRequires: rpcgen
-BuildRequires: libtirpc-devel
 %endif
 
+BuildRequires: libtirpc-devel
+
 %if %{with_firewalld_zone}
 BuildRequires: firewalld-filesystem
 %endif

m4/virt-xdr.m4

@@ -18,37 +18,20 @@ dnl <http://www.gnu.org/licenses/>.
 dnl
 
 AC_DEFUN([LIBVIRT_CHECK_XDR], [
-  with_xdr="no"
   if test x"$with_remote" = x"yes" || test x"$with_libvirtd" = x"yes"; then
-    dnl Where are the XDR functions?
-    dnl If portablexdr is installed, prefer that.
-    dnl Otherwise try -lxdr (some MinGW)
-    dnl -ltirpc (glibc 2.13.90 or newer) or none (most Unix)
-    AC_CHECK_LIB([portablexdr],[xdrmem_create],[],[
-      AC_SEARCH_LIBS([xdrmem_create],[xdr tirpc],[],
-        [AC_MSG_ERROR([Cannot find a XDR library])])
-    ])
+    dnl On MinGW portablexdr provides XDR functions, on linux they are
+    dnl provided by libtirpc and on FreeBSD/macOS there is no need to
+    dnl use extra library as it's provided by libc directly.
+
     with_xdr="yes"
 
-    dnl Recent glibc requires -I/usr/include/tirpc for <rpc/rpc.h>
-    old_CFLAGS=$CFLAGS
-    AC_CACHE_CHECK([where to find <rpc/rpc.h>], [lv_cv_xdr_cflags], [
-      for add_CFLAGS in '' '-I/usr/include/tirpc' 'missing'; do
-        if test x"$add_CFLAGS" = xmissing; then
-          lv_cv_xdr_cflags=missing; break
-        fi
-        CFLAGS="$old_CFLAGS $add_CFLAGS"
-        AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[#include <rpc/rpc.h>
-        ]])], [lv_cv_xdr_cflags=${add_CFLAGS:-none}; break])
-      done
-    ])
-    CFLAGS=$old_CFLAGS
-    case $lv_cv_xdr_cflags in
-      none) XDR_CFLAGS= ;;
-      missing) AC_MSG_ERROR([Unable to find <rpc/rpc.h>]) ;;
-      *) XDR_CFLAGS=$lv_cv_xdr_cflags ;;
-    esac
-    AC_SUBST([XDR_CFLAGS])
+    if test "$with_win" = "yes"; then
+      LIBVIRT_CHECK_LIB([XDR], [portablexdr], [xdrmem_create], [rpc/rpc.h])
+    elif test "$with_linux" = "yes"; then
+      LIBVIRT_CHECK_PKG([XDR], [libtirpc], [0.1.10])
+    else
+      AM_CONDITIONAL([WITH_XDR], [test "x$with_xdr" = "xyes"])
+    fi
   fi
 ])
 

src/Makefile.am

@@ -434,7 +434,9 @@ libvirt_la_LDFLAGS = \
 		$(AM_LDFLAGS) \
 		$(NULL)
 libvirt_la_LIBADD += \
-		    $(DLOPEN_LIBS)
+		$(DLOPEN_LIBS) \
+		$(XDR_LIBS) \
+		$(NULL)
 libvirt_la_CFLAGS = -DIN_LIBVIRT $(AM_CFLAGS)
 # Because we specify libvirt_la_DEPENDENCIES for $(LIBVIRT_SYMBOL_FILE), we
 # lose automake's automatic dependencies on an appropriate subset of

src/admin/Makefile.inc.am

@@ -72,6 +72,7 @@ libvirt_admin_la_LDFLAGS = \
 
 libvirt_admin_la_LIBADD = \
 	libvirt.la \
+	$(XDR_LIBS) \
 	$(CAPNG_LIBS) \
 	$(YAJL_LIBS) \
 	$(DEVMAPPER_LIBS) \

src/locking/Makefile.inc.am

@@ -120,6 +120,7 @@ lockd_la_LDFLAGS = $(AM_LDFLAGS_MOD_NOUNDEF)
 lockd_la_LIBADD = \
 	libvirt.la \
 	$(GLIB_LIBS) \
+	$(XDR_LIBS) \
 	$(NULL)
 augeas_DATA += locking/libvirt_lockd.aug
 if WITH_DTRACE_PROBES
@@ -161,6 +162,7 @@ virtlockd_CFLAGS = \
 virtlockd_LDFLAGS = \
 	$(AM_LDFLAGS) \
 	$(PIE_LDFLAGS) \
+	$(XDR_LIBS) \
 	$(NO_UNDEFINED_LDFLAGS) \
 	$(NULL)
 virtlockd_LDADD = \

src/logging/Makefile.inc.am

@@ -98,6 +98,7 @@ virtlogd_CFLAGS = \
 virtlogd_LDFLAGS = \
 		$(AM_LDFLAGS) \
 		$(PIE_LDFLAGS) \
+		$(XDR_LIBS) \
 		$(NO_UNDEFINED_LDFLAGS) \
 		$(NULL)
 virtlogd_LDADD = \

src/remote/Makefile.inc.am

@@ -64,6 +64,7 @@ REMOTE_DAEMON_LD_ADD = \
 	$(LIBXML_LIBS) \
 	$(GNUTLS_LIBS) \
 	$(SASL_LIBS) \
+	$(XDR_LIBS) \
 	$(DBUS_LIBS) \
 	$(LIBNL_LIBS) \
 	$(NULL)