[igt-dev] [PATCH v2 3/6] lib/igt_aux.h: Fix musl build

[Bernd Kuhls <bernd@kuhls.net>]

Inspired by https://www.openwall.com/lists/musl/2020/10/28/11

Define sigev_notify_thread_id only when needed, quoting
https://sourceware.org/bugzilla/show_bug.cgi?id=27417
Both freebsd and musl actually have this macro defined under <signal.h>

Fixes build error:

../lib/igt_aux.c:191:20: error: ‘struct sigevent’ has no member named ‘_sigev_un’
  191 |                 sev.sigev_notify_thread_id = __igt_sigiter.tid;

../lib/igt_aux.c:1994:12: error: ‘struct sigevent’ has no member named ‘_sigev_un’
 1994 |         sev.sigev_notify_thread_id = gettid();

Link: https://gitlab.freedesktop.org/drm/igt-gpu-tools/-/issues/138
Signed-off-by: Bernd Kuhls <bernd@kuhls.net>
---
 lib/igt_aux.h | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/lib/igt_aux.h b/lib/igt_aux.h
index fb76b0313..55f0aa3b5 100644
--- a/lib/igt_aux.h
+++ b/lib/igt_aux.h
@@ -29,6 +29,7 @@
 #define IGT_AUX_H
 
 #include <inttypes.h>
+#include <signal.h>
 #include <stdbool.h>
 #include <stddef.h>
 #include <sys/time.h>
@@ -48,7 +49,9 @@
 # ifndef HAVE_GETTID
 #  define gettid() (pid_t)(syscall(__NR_gettid))
 # endif
-# define sigev_notify_thread_id _sigev_un._tid
+# ifndef sigev_notify_thread_id
+#  define sigev_notify_thread_id _sigev_un._tid
+# endif
 #endif
 
 /* auxialiary igt helpers from igt_aux.c */
-- 
2.39.2