configure: improve test for realtime clock

Check first if we need to even link -lrt  - since clock functions
are normally emebeded with recent  glibc (>=2.17)
Use standard  RT_LIBS name.
Avoid duplicate test for realtime clock with lvmlockd
Show better error message when realtime clock support is missing or
disabled.
Link  RT_LIBS explicitely with lvmlockd and lvmetad.

1 files changed, 27 insertions, 11 deletions

diff --git a/configure b/configure
index 8396e3ee3..6c649cf62 100755
--- a/configure
+++ b/configure
@@ -660,7 +660,7 @@ SELINUX_PC
 SELINUX_LIBS
 REPLICATORS
 READLINE_LIBS
-RT_LIB
+RT_LIBS
 RAID
 PYTHON3DIR
 PYTHON2DIR
@@ -14316,8 +14316,24 @@ fi
 fi
 
 ################################################################################
+RT_LIBS=
+HAVE_REALTIME=no
 if test "$REALTIME" = yes; then
-	{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for clock_gettime in -lrt" >&5
+	for ac_func in clock_gettime
+do :
+  ac_fn_c_check_func "$LINENO" "clock_gettime" "ac_cv_func_clock_gettime"
+if test "x$ac_cv_func_clock_gettime" = xyes; then :
+  cat >>confdefs.h <<_ACEOF
+#define HAVE_CLOCK_GETTIME 1
+_ACEOF
+ HAVE_REALTIME=yes
+fi
+done
+
+
+	if test "$HAVE_REALTIME" != yes; then :
+   # try again with -lrt
+	      { $as_echo "$as_me:${as_lineno-$LINENO}: checking for clock_gettime in -lrt" >&5
 $as_echo_n "checking for clock_gettime in -lrt... " >&6; }
 if ${ac_cv_lib_rt_clock_gettime+:} false; then :
   $as_echo_n "(cached) " >&6
@@ -14354,17 +14370,15 @@ fi
 { $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_lib_rt_clock_gettime" >&5
 $as_echo "$ac_cv_lib_rt_clock_gettime" >&6; }
 if test "x$ac_cv_lib_rt_clock_gettime" = xyes; then :
-  HAVE_REALTIME=yes
-else
-  HAVE_REALTIME=no
+  RT_LIBS="-lrt"; HAVE_REALTIME=yes
 fi
 
+fi
 
 	if test "$HAVE_REALTIME" = yes; then
 
 $as_echo "#define HAVE_REALTIME 1" >>confdefs.h
 
-		RT_LIB="-lrt"
 	else
 		{ $as_echo "$as_me:${as_lineno-$LINENO}: WARNING: Disabling realtime clock" >&5
 $as_echo "$as_me: WARNING: Disabling realtime clock" >&2;}
@@ -14876,13 +14890,15 @@ done
 fi
 
 if test "$BUILD_LVMLOCKD" = yes; then
-	for ac_func in clock_gettime strtoull
+	if test "$HAVE_REALTIME" != yes; then :
+  as_fn_error $? "Realtime clock support is mandatory for lvmlockd." "$LINENO" 5
+fi
+	for ac_func in strtoull
 do :
-  as_ac_var=`$as_echo "ac_cv_func_$ac_func" | $as_tr_sh`
-ac_fn_c_check_func "$LINENO" "$ac_func" "$as_ac_var"
-if eval test \"x\$"$as_ac_var"\" = x"yes"; then :
+  ac_fn_c_check_func "$LINENO" "strtoull" "ac_cv_func_strtoull"
+if test "x$ac_cv_func_strtoull" = xyes; then :
   cat >>confdefs.h <<_ACEOF
-#define `$as_echo "HAVE_$ac_func" | $as_tr_cpp` 1
+#define HAVE_STRTOULL 1
 _ACEOF
 
 else