gentoo-overlay/app-emulation/xen-tools/files/xen-tools-4.2.2-rt-link.patch

diff --git a/tools/qemu-xen/configure b/tools/qemu-xen/configure
index ea2f8f8..9726440 100755
--- a/tools/qemu-xen/configure
+++ b/tools/qemu-xen/configure
@@ -2459,17 +2459,41 @@ fi
 
 
 ##########################################
+# Do we need libm
+cat > $TMPC << EOF
+#include <math.h>
+int main(void) { return isnan(sin(0.0)); }
+EOF
+if compile_prog "" "" ; then
+  :
+elif compile_prog "" "-lm" ; then
+  LIBS="-lm $LIBS"
+  libs_qga="-lm $libs_qga"
+else
+  error_exit "libm check failed"
+fi
+
+##########################################
 # Do we need librt
+# uClibc provides 2 versions of clock_gettime(), one with realtime
+# support and one without. This means that the clock_gettime() don't
+# need -lrt. We still need it for timer_create() so we check for this
+# function in addition.
 cat > $TMPC <<EOF
 #include <signal.h>
 #include <time.h>
-int main(void) { clockid_t id; return clock_gettime(id, NULL); }
+int main(void) {
+  timer_create(CLOCK_REALTIME, NULL, NULL);
+  return clock_gettime(CLOCK_REALTIME, NULL);
+}
 EOF
 
 if compile_prog "" "" ; then
   :
-elif compile_prog "" "-lrt" ; then
+# we need pthread for static linking. use previous pthread test result
+elif compile_prog "" "-lrt $pthread_lib" ; then
   LIBS="-lrt $LIBS"
+  libs_qga="-lrt $libs_qga"
 fi
 
 if test "$darwin" != "yes" -a "$mingw32" != "yes" -a "$solaris" != yes -a \