From: Michael Jeanson <mjeanson@efficios.com>
Date: Fri, 26 Jun 2020 19:44:20 +0000 (-0400)
Subject: Fix: support compile units including 'sys/sdt.h' without defining SDT_USE_VARIADIC
X-Git-Tag: v2.13.0-rc1~495
X-Git-Url: https://git.lttng.org./?a=commitdiff_plain;h=23b75ae5efa941fbd8ab666ae3dcf161789dfde5;p=lttng-ust.git

Fix: support compile units including 'sys/sdt.h' without defining SDT_USE_VARIADIC

Instead of using SDT_USE_VARIADIC from 'sys/sdt.h', use our own namespaced
macros since the instrumented application might already have included
'sys/sdt.h' without variadic support.

Signed-off-by: Michael Jeanson <mjeanson@efficios.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Change-Id: Idfece1a65a5296a90d33370bc8d73ea554c14b0f
---

diff --git a/include/lttng/tracepoint.h b/include/lttng/tracepoint.h
index 7cfae3e4..1cf02188 100644
--- a/include/lttng/tracepoint.h
+++ b/include/lttng/tracepoint.h
@@ -35,9 +35,24 @@
 #include <lttng/ust-compiler.h>
 
 #ifdef LTTNG_UST_HAVE_SDT_INTEGRATION
-#define SDT_USE_VARIADIC
+/*
+ * Instead of using SDT_USE_VARIADIC from 'sys/sdt.h', use our own namespaced
+ * macros since the instrumented application might already have included
+ * 'sys/sdt.h' without variadic support.
+ */
 #include <sys/sdt.h>
-#define LTTNG_STAP_PROBEV STAP_PROBEV
+
+#define _LTTNG_SDT_NARG(...) \
+	__LTTNG_SDT_NARG(__VA_ARGS__, 12,11,10,9,8,7,6,5,4,3,2,1,0)
+
+#define __LTTNG_SDT_NARG(_0,_1,_2,_3,_4,_5,_6,_7,_8,_9,_10,_11,_12, N, ...) N
+
+#define _LTTNG_SDT_PROBE_N(provider, name, N, ...) \
+	_SDT_PROBE(provider, name, N, (__VA_ARGS__))
+
+#define LTTNG_STAP_PROBEV(provider, name, ...) \
+	_LTTNG_SDT_PROBE_N(provider, name, _LTTNG_SDT_NARG(0, ##__VA_ARGS__), ##__VA_ARGS__)
+
 #else
 #define LTTNG_STAP_PROBEV(...)
 #endif