[lttng-dev] [RFC PATCH lttng-ust] Fix: allow non-LGPL applications to use tracepoints

Mathieu Desnoyers mathieu.desnoyers at efficios.com
Wed Jun 15 20:39:03 UTC 2016


Non-LGPL applications that do not define either TRACEPOINT_DEFINE or
TRACEPOINT_CREATE_PROBES within each compile unit that uses tracepoints
fail to build due to undefined reference to `tracepoint_dlopen_ptr'.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers at efficios.com>
---
 include/lttng/tracepoint.h | 23 ++++++++++++-----------
 1 file changed, 12 insertions(+), 11 deletions(-)

diff --git a/include/lttng/tracepoint.h b/include/lttng/tracepoint.h
index 03bc913..d469765 100644
--- a/include/lttng/tracepoint.h
+++ b/include/lttng/tracepoint.h
@@ -241,17 +241,6 @@ static inline void tracepoint_disable_destructors(void)
 	__tracepoints__disable_destructors = 1;
 }
 
-#if defined(TRACEPOINT_DEFINE) || defined(TRACEPOINT_CREATE_PROBES)
-
-/*
- * These weak symbols, the constructor, and destructor take care of
- * registering only _one_ instance of the tracepoints per shared-ojbect
- * (or for the whole main program).
- */
-int __tracepoint_registered
-	__attribute__((weak, visibility("hidden")));
-int __tracepoint_ptrs_registered
-	__attribute__((weak, visibility("hidden")));
 struct lttng_ust_tracepoint_dlopen tracepoint_dlopen
 	__attribute__((weak, visibility("hidden")));
 /*
@@ -304,6 +293,18 @@ __tracepoint__init_urcu_sym(void)
 }
 #endif
 
+#if defined(TRACEPOINT_DEFINE) || defined(TRACEPOINT_CREATE_PROBES)
+
+/*
+ * These weak symbols, the constructor, and destructor take care of
+ * registering only _one_ instance of the tracepoints per shared-ojbect
+ * (or for the whole main program).
+ */
+int __tracepoint_registered
+	__attribute__((weak, visibility("hidden")));
+int __tracepoint_ptrs_registered
+	__attribute__((weak, visibility("hidden")));
+
 static void lttng_ust_notrace __attribute__((constructor))
 __tracepoints__init(void);
 static void
-- 
2.1.4



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