ust-events.h API const-ness

[lttng-ust.git] / include / lttng / ust-tracepoint-event.h

diff --git a/include/lttng/ust-tracepoint-event.h b/include/lttng/ust-tracepoint-event.h
index c50047d0baf4c6fc5a262b70b9f2ed72328e1e23..e663e839bc0e5426b643dfce5f4f93e17ca57b8b 100644 (file)
--- a/include/lttng/ust-tracepoint-event.h
+++ b/include/lttng/ust-tracepoint-event.h
@@ -203,7 +203,7 @@ void __event_template_proto___##_provider##___##_name(_TP_ARGS_DATA_PROTO(_args)
 
 #undef TRACEPOINT_ENUM
 #define TRACEPOINT_ENUM(_provider, _name, _values)                     \
-       const struct lttng_ust_enum_entry *__enum_values__##_provider##_##_name[] = { \
+       const struct lttng_ust_enum_entry * const __enum_values__##_provider##_##_name[] = { \
                _values                                                 \
                ctf_enum_value("", 0)   /* Dummy, 0-len array forbidden by C99. */ \
        };
@@ -362,7 +362,7 @@ void __event_template_proto___##_provider##___##_name(_TP_ARGS_DATA_PROTO(_args)
 
 #undef _TRACEPOINT_EVENT_CLASS
 #define _TRACEPOINT_EVENT_CLASS(_provider, _name, _args, _fields)                           \
-       static const struct lttng_ust_event_field *__event_fields___##_provider##___##_name[] = { \
+       static const struct lttng_ust_event_field * const __event_fields___##_provider##___##_name[] = { \
                _fields                                                                      \
                ctf_integer(int, dummy, 0)      /* Dummy, C99 forbids 0-len array. */        \
        };
@@ -972,10 +972,10 @@ static const char __tp_event_signature___##_provider##___##_name[] =      \
 #endif
 
 #undef TRACEPOINT_LOGLEVEL
-#define TRACEPOINT_LOGLEVEL(__provider, __name, __loglevel)               \
-static const int _loglevel_value___##__provider##___##__name = __loglevel; \
-LTTNG_UST_TP_EXTERN_C const int *_loglevel___##__provider##___##__name    \
-               __attribute__((visibility("hidden"))) =                    \
+#define TRACEPOINT_LOGLEVEL(__provider, __name, __loglevel)                    \
+static const int _loglevel_value___##__provider##___##__name = __loglevel;     \
+LTTNG_UST_TP_EXTERN_C const int * const _loglevel___##__provider##___##__name  \
+               __attribute__((visibility("hidden"))) =                         \
                &_loglevel_value___##__provider##___##__name;
 
 #include TRACEPOINT_INCLUDE
@@ -1005,7 +1005,7 @@ LTTNG_UST_TP_EXTERN_C const int *_loglevel___##__provider##___##__name       \
 
 #undef TRACEPOINT_MODEL_EMF_URI
 #define TRACEPOINT_MODEL_EMF_URI(__provider, __name, __uri)               \
-LTTNG_UST_TP_EXTERN_C const char *_model_emf_uri___##__provider##___##__name   \
+LTTNG_UST_TP_EXTERN_C const char * const _model_emf_uri___##__provider##___##__name   \
                __attribute__((visibility("hidden"))) = __uri;             \
 
 #include TRACEPOINT_INCLUDE
@@ -1029,8 +1029,14 @@ extern const struct lttng_ust_probe_desc _TP_COMBINE_TOKENS(__probe_desc___, TRA
  * Stage 7.1 of tracepoint event generation.
  *
  * Create events description structures. We use a weakref because
- * loglevels are optional. If not declared, the event will point to the
+ * loglevels are optional. If not declared, the event will point to
  * a loglevel that contains NULL.
+ *
+ * C++ requires that const objects have a user-declared default
+ * constructor. However, in both C++ and C, weakref cannot be
+ * initialized because it causes the weakref attribute to be ignored.
+ * Therefore, the loglevel and model_emf_uri pointers are not const
+ * to ensure C++ compilers default-initialize them.
  */
 
 /* Reset all macros within TRACEPOINT_EVENT */
@@ -1071,7 +1077,7 @@ static const struct lttng_ust_event_desc __event_desc___##_provider##_##_name =
 #define _TRACEPOINT_EVENT_INSTANCE(_provider, _template, _name, _args)        \
        &__event_desc___##_provider##_##_name,
 
-static const struct lttng_ust_event_desc *_TP_COMBINE_TOKENS(__event_desc___, TRACEPOINT_PROVIDER)[] = {
+static const struct lttng_ust_event_desc * const _TP_COMBINE_TOKENS(__event_desc___, TRACEPOINT_PROVIDER)[] = {
 #include TRACEPOINT_INCLUDE
        NULL,   /* Dummy, C99 forbids 0-len array. */
 };