Add prospective callback register tracepoint

tracetools/include/tracetools/tracetools.h

@@ -152,6 +152,14 @@ void TRACEPOINT(
   rclcpp_timer_callback_end,
   const void * callback);
 
+/**
+ * tp: rclcpp_callback_register
+ */
+void TRACEPOINT(
+  rclcpp_callback_register,
+  const void * handle,
+  const void * callback);
+
 #ifdef __cplusplus
 }
 #endif

tracetools/lttng/tp_call.tp

@@ -219,3 +219,16 @@ TRACEPOINT_EVENT(
         ctf_integer_hex(const void *, callback, callback_arg)
     )
 )
+
+TRACEPOINT_EVENT(
+    ros2,
+    rclcpp_callback_register,
+    TP_ARGS(
+        const void *, handle_arg,
+        const char *, callback_arg
+    ),
+    TP_FIELDS(
+        ctf_integer_hex(const void *, handle, handle_arg)
+        ctf_string(callback, callback_arg)
+    )
+)

tracetools/src/tracetools.c

@@ -1,3 +1,4 @@
+#include <execinfo.h>
 #include "tracetools/tracetools.h"
 
 #if defined(WITH_LTTNG) && !defined(_WIN32)
@@ -9,6 +10,17 @@
 #endif
 
 
+const char * get_symbol(const void * function_ptr) {
+#if defined(WITH_LTTNG) && !defined(_WIN32)
+	char** symbols = backtrace_symbols(&function_ptr, 1);
+	const char * result = symbols[0];
+	free(symbols);
+	return result;
+#else
+	return "";
+#endif
+}
+
 bool ros_trace_compile_status()
 {
 #if defined(WITH_LTTNG) && !defined(_WIN32)
@@ -151,3 +163,11 @@ void TRACEPOINT(
 {
   CONDITIONAL_TP(ros2, rclcpp_timer_callback_end, callback);
 }
+
+void TRACEPOINT(
+  rclcpp_callback_register,
+  const void * handle,
+  const void * callback)
+{
+  CONDITIONAL_TP(ros2, rclcpp_callback_register, handle, get_symbol(callback));
+}