X-Git-Url: http://git.liburcu.org/?a=blobdiff_plain;f=include%2Flttng%2Ftracepoint.h;h=cf3519cd25739aee8688811e963a48c3d25a7cc1;hb=63661b6634527fca365d4ac9e46cc9c8c94c1e49;hp=1f8b9209de0c1ec4992af786f32ef623230fbc28;hpb=5b675300cd432c3dff378ac5b78eb6b56d4294e6;p=lttng-ust.git

diff --git a/include/lttng/tracepoint.h b/include/lttng/tracepoint.h
index 1f8b9209..cf3519cd 100644
--- a/include/lttng/tracepoint.h
+++ b/include/lttng/tracepoint.h
@@ -11,16 +11,25 @@
 #include <stdlib.h>
 #include <lttng/tracepoint-types.h>
 #include <lttng/tracepoint-rcu.h>
+#include <lttng/ust-utils.h>
+#include <sys/types.h>
+#include <unistd.h>
+
 #include <urcu/compiler.h>
 #include <urcu/system.h>
 #include <dlfcn.h>	/* for dlopen */
 #include <string.h>	/* for memset */
+#include <stdbool.h>
 
 #include <lttng/ust-config.h>	/* for sdt */
 #include <lttng/ust-compiler.h>
 #include <lttng/ust-tracer.h>
 #include <lttng/ust-api-compat.h>
 
+#if (defined(__cplusplus) && (__cplusplus <= 199711L))
+#error "C++11 support is required to build tracepoints and providers as C++"
+#endif
+
 #define LTTNG_UST_TRACEPOINT_NAME_LEN_MAX	256
 
 #ifdef LTTNG_UST_HAVE_SDT_INTEGRATION
@@ -386,9 +395,58 @@ lttng_ust_tracepoint__init_urcu_sym(void)
 }
 #endif
 
+/*
+ * Use getenv() directly and bypass lttng-ust helper functions
+ * because we may not have access to lttng-ust shared libraries.
+ */
+#ifdef LTTNG_UST_DEBUG
+static inline
+bool lttng_ust_tracepoint_logging_debug_enabled(void)
+{
+	return true;
+}
+#else /* #ifdef LTTNG_UST_DEBUG */
+static inline
+bool lttng_ust_tracepoint_logging_debug_enabled(void)
+{
+	return getenv("LTTNG_UST_DEBUG");
+}
+#endif /* #ifdef LTTNG_UST_DEBUG */
+
+#ifdef LTTNG_UST_ABORT_ON_CRITICAL
+static inline
+bool lttng_ust_tracepoint_logging_abort_on_critical_enabled(void)
+{
+	return true;
+}
+#else /* #ifdef LTTNG_UST_ABORT_ON_CRITICAL */
+static inline
+bool lttng_ust_tracepoint_logging_abort_on_critical_enabled(void)
+{
+	return getenv("LTTNG_UST_ABORT_ON_CRITICAL");
+}
+#endif
+
+#define LTTNG_UST_TRACEPOINT_THIS_IP		\
+	({ __label__ here; here: &&here; })
+
+static void
+lttng_ust_tracepoints_print_disabled_message(void)
+{
+	if (lttng_ust_tracepoint_logging_debug_enabled())
+		fprintf(stderr, "lttng-ust-tracepoint [%ld]: Critical: dlopen() failed to find '%s', tracepoints in this binary won't be registered. "
+			"(at addr=%p in %s() at " __FILE__ ":" lttng_ust_stringify(__LINE__) ")\n",
+			(long) getpid(),
+			LTTNG_UST_TRACEPOINT_LIB_SONAME,
+			LTTNG_UST_TRACEPOINT_THIS_IP,
+			__func__);
+	if (lttng_ust_tracepoint_logging_abort_on_critical_enabled())
+		abort();
+}
+
 static void
 lttng_ust__tracepoints__init(void)
-	lttng_ust_notrace __attribute__((constructor));
+	lttng_ust_notrace __attribute__((constructor(LTTNG_UST_CONSTRUCTOR_PRIO)));
 static void
 lttng_ust__tracepoints__init(void)
 {
@@ -404,14 +462,16 @@ lttng_ust__tracepoints__init(void)
 	if (!lttng_ust_tracepoint_dlopen_ptr->liblttngust_handle)
 		lttng_ust_tracepoint_dlopen_ptr->liblttngust_handle =
 			dlopen(LTTNG_UST_TRACEPOINT_LIB_SONAME, RTLD_NOW | RTLD_GLOBAL);
-	if (!lttng_ust_tracepoint_dlopen_ptr->liblttngust_handle)
+	if (!lttng_ust_tracepoint_dlopen_ptr->liblttngust_handle) {
+		lttng_ust_tracepoints_print_disabled_message();
 		return;
+	}
 	lttng_ust_tracepoint__init_urcu_sym();
 }
 
 static void
 lttng_ust__tracepoints__destroy(void)
-	lttng_ust_notrace __attribute__((destructor));
+	lttng_ust_notrace __attribute__((destructor(LTTNG_UST_CONSTRUCTOR_PRIO)));
 static void
 lttng_ust__tracepoints__destroy(void)
 {
@@ -523,7 +583,7 @@ extern struct lttng_ust_tracepoint * const __stop_lttng_ust_tracepoints_ptrs[]
 
 static void
 lttng_ust__tracepoints__ptrs_init(void)
-	lttng_ust_notrace __attribute__((constructor));
+	lttng_ust_notrace __attribute__((constructor(LTTNG_UST_CONSTRUCTOR_PRIO)));
 static void
 lttng_ust__tracepoints__ptrs_init(void)
 {
@@ -534,8 +594,10 @@ lttng_ust__tracepoints__ptrs_init(void)
 	if (!lttng_ust_tracepoint_dlopen_ptr->liblttngust_handle)
 		lttng_ust_tracepoint_dlopen_ptr->liblttngust_handle =
 			dlopen(LTTNG_UST_TRACEPOINT_LIB_SONAME, RTLD_NOW | RTLD_GLOBAL);
-	if (!lttng_ust_tracepoint_dlopen_ptr->liblttngust_handle)
+	if (!lttng_ust_tracepoint_dlopen_ptr->liblttngust_handle) {
+		lttng_ust_tracepoints_print_disabled_message();
 		return;
+	}
 	if (!lttng_ust_tracepoint_destructors_syms_ptr)
 		lttng_ust_tracepoint_destructors_syms_ptr = &lttng_ust_tracepoint_destructors_syms;
 	lttng_ust_tracepoint_dlopen_ptr->lttng_ust_tracepoint_module_register =
@@ -564,7 +626,7 @@ lttng_ust__tracepoints__ptrs_init(void)
 
 static void
 lttng_ust__tracepoints__ptrs_destroy(void)
-	lttng_ust_notrace __attribute__((destructor));
+	lttng_ust_notrace __attribute__((destructor(LTTNG_UST_CONSTRUCTOR_PRIO)));
 static void
 lttng_ust__tracepoints__ptrs_destroy(void)
 {