From dc416984d92890f31122d32240d8bc0cbf48a48e Mon Sep 17 00:00:00 2001
From: Lukas Slebodnik <lslebodn@redhat.com>
Date: Mon, 7 Nov 2016 11:53:21 +0100
Subject: [PATCH] BUILD: Fix linking with librt

The posix realime extensions defines timer_* functions
but it does not mention library with these functions.
http://www.unix.org/version2/whatsnew/realtime.html

The autoconf macro AC_SEARCH_LIBS firstly check the function
timer_create with no libraries, then for each library listed
in 2nd parameter. Possible libraries librt and libposix4
were used in nspr for similar detection.
---
 Makefile.am  |  1 +
 configure.ac | 13 +++++++++++++
 2 files changed, 14 insertions(+)

diff --git a/Makefile.am b/Makefile.am
index 64328766e09213167dc392ed307c75e318845ed3..e037930ff3a4d462ace5db02dad6c3c0d5fbb0d8 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -980,6 +980,7 @@ libsss_util_la_CFLAGS = \
     $(SYSTEMD_LOGIN_CFLAGS) \
     $(NULL)
 libsss_util_la_LIBADD = \
+    $(LIBADD_TIMER) \
     $(SSSD_LIBS) \
     $(SYSTEMD_LOGIN_LIBS) \
     $(UNICODE_LIBS) \
diff --git a/configure.ac b/configure.ac
index 3dbcf9e1f9e3cd3787dc7c01907d43bc55eda72d..d3ef1e162b2b8f8c1185b64a40584d3078a2c6be 100644
--- a/configure.ac
+++ b/configure.ac
@@ -70,6 +70,19 @@ AC_CHECK_FUNCS([ pthread_mutexattr_setrobust \
                  pthread_mutex_consistent_np ])
 LIBS=$SAVE_LIBS
 
+# Check library for the timer_create function
+SAVE_LIBS=$LIBS
+LIBS=
+LIBADD_TIMER=
+AC_SEARCH_LIBS([timer_create], [rt posix4],
+    [AC_DEFINE([HAVE_LIBRT], [1],
+         [Define if you have the librt library or equivalent.])
+     LIBADD_TIMER="$LIBS"],
+    [AC_MSG_ERROR([unable to find library fot the timer_create() function])])
+
+AC_SUBST([LIBADD_TIMER])
+LIBS=$SAVE_LIBS
+
 # Check for presence of modern functions for setting file timestamps
 AC_CHECK_FUNCS([ utimensat \
                  futimens ])
-- 
2.9.3