qemu-timer: Check for usable fields for SIGEV_THREAD_ID

Older glibc (RHEL 5.x, Debian 5.x) does not have the _sigev_un._tid
member in its structure definition, while the accompanying kernel
headers do define SIGEV_THREAD_ID.  We need configure to check for
both before using it.

Signed-off-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>

1 files changed, 22 insertions, 0 deletions

diff --git a/configure b/configure
index 37f712d475..3685020ffa 100755
--- a/configure
+++ b/configure
@@ -2813,6 +2813,24 @@ if compile_prog "" "" ; then
 fi
 
 ##########################################
+# check if we have usable SIGEV_THREAD_ID
+
+sigev_thread_id=no
+cat > $TMPC << EOF
+#include <signal.h>
+int main(void) {
+  struct sigevent ev;
+  ev.sigev_notify = SIGEV_THREAD_ID;
+  ev._sigev_un._tid = 0;
+  asm volatile("" : : "g"(&ev));
+  return 0;
+}
+EOF
+if compile_prog "" "" ; then
+    sigev_thread_id=yes
+fi
+
+##########################################
 # check if trace backend exists
 
 $python "$source_path/scripts/tracetool.py" "--backend=$trace_backend" --check-backend  > /dev/null 2> /dev/null
@@ -3159,6 +3177,7 @@ echo "preadv support    $preadv"
 echo "fdatasync         $fdatasync"
 echo "madvise           $madvise"
 echo "posix_madvise     $posix_madvise"
+echo "sigev_thread_id   $sigev_thread_id"
 echo "uuid support      $uuid"
 echo "libcap-ng support $cap_ng"
 echo "vhost-net support $vhost_net"
@@ -3443,6 +3462,9 @@ fi
 if test "$posix_madvise" = "yes" ; then
   echo "CONFIG_POSIX_MADVISE=y" >> $config_host_mak
 fi
+if test "$sigev_thread_id" = "yes" ; then
+  echo "CONFIG_SIGEV_THREAD_ID=y" >> $config_host_mak
+fi
 
 if test "$spice" = "yes" ; then
   echo "CONFIG_SPICE=y" >> $config_host_mak