diff --git a/include/lttng/ust-compiler.h b/include/lttng/ust-compiler.h index eb201bdc9..c938361d4 100644 --- a/include/lttng/ust-compiler.h +++ b/include/lttng/ust-compiler.h @@ -86,4 +86,56 @@ typedef char lttng_ust_static_assert_##c_identifier_msg[2*!!(predicate)-1] #endif +/* + * Wrap constructor and destructor functions to invoke them as functions with + * the constructor/destructor GNU C attributes when building as C, or as the + * constructor/destructor of a variable defined within an anonymous namespace + * when building as C++. + */ +#ifdef __cplusplus +#define LTTNG_UST_DECLARE_CONSTRUCTOR_DESTRUCTOR(name, constructor_func, \ + destructor_func, ...) \ +namespace lttng { \ +namespace ust { \ +namespace details { \ +class LTTNG_UST__TP_COMBINE_TOKENS(lttng_ust_constructor_destructor_, \ + name) { \ +public: \ + LTTNG_UST__TP_COMBINE_TOKENS(lttng_ust_constructor_destructor_, \ + name)() __VA_ARGS__ \ + { \ + constructor_func(); \ + } \ + ~LTTNG_UST__TP_COMBINE_TOKENS(lttng_ust_constructor_destructor_, \ + name)() __VA_ARGS__ \ + { \ + destructor_func(); \ + } \ +}; \ +} \ +} \ +} \ + \ +namespace { \ +const lttng::ust::details::LTTNG_UST__TP_COMBINE_TOKENS( \ + lttng_ust_constructor_destructor_, name) \ + LTTNG_UST__TP_COMBINE_TOKENS(name, registration_instance); \ +} +#else /* __cplusplus */ +#define LTTNG_UST_DECLARE_CONSTRUCTOR_DESTRUCTOR(name, constructor_func, \ + destructor_func, ...) \ + static void LTTNG_UST__TP_COMBINE_TOKENS(lttng_ust_constructor_, name)(void) \ + __attribute__((constructor)) __VA_ARGS__; \ + static void LTTNG_UST__TP_COMBINE_TOKENS(lttng_ust_constructor_, name)(void) \ + { \ + constructor_func(); \ + } \ + static void LTTNG_UST__TP_COMBINE_TOKENS(lttng_ust_destructor_, name)(void) \ + __attribute__((destructor)) __VA_ARGS__; \ + static void LTTNG_UST__TP_COMBINE_TOKENS(lttng_ust_destructor_, name)(void) \ + { \ + destructor_func(); \ + } +#endif + #endif /* _LTTNG_UST_COMPILER_H */ diff --git a/include/lttng/ust-tracepoint-event.h b/include/lttng/ust-tracepoint-event.h index c68f7d98c..1edb50c13 100644 --- a/include/lttng/ust-tracepoint-event.h +++ b/include/lttng/ust-tracepoint-event.h @@ -1169,13 +1169,24 @@ static struct lttng_ust_registered_probe *LTTNG_UST__TP_COMBINE_TOKENS(lttng_ust * linking the probe statically. * * Register refcount is protected by libc dynamic loader mutex. + * + * Note that when building this code as C++, the definition of constructors + * and destructors invoking the registration and unregistration functions + * must be performed _after_ the initialization of the probes. + * + * This is because we rely on the order of initialization of static variables + * and anonymous namespaces (their order of declaration) to ensure probes are + * fully initialized, see + * https://en.cppreference.com/w/cpp/language/initialization. This is especially + * important when LTTNG_UST_ALLOCATE_COMPOUND_LITERAL_ON_HEAP is defined as + * compound literals are then dynamically initialized. */ /* Reset all macros within LTTNG_UST_TRACEPOINT_EVENT */ #include + static void -LTTNG_UST__TP_COMBINE_TOKENS(lttng_ust__events_init__, LTTNG_UST_TRACEPOINT_PROVIDER)(void) - lttng_ust_notrace __attribute__((constructor)); +LTTNG_UST__TP_COMBINE_TOKENS(lttng_ust__events_init__, LTTNG_UST_TRACEPOINT_PROVIDER)(void) lttng_ust_notrace; static void LTTNG_UST__TP_COMBINE_TOKENS(lttng_ust__events_init__, LTTNG_UST_TRACEPOINT_PROVIDER)(void) { @@ -1204,8 +1215,7 @@ LTTNG_UST__TP_COMBINE_TOKENS(lttng_ust__events_init__, LTTNG_UST_TRACEPOINT_PROV } static void -LTTNG_UST__TP_COMBINE_TOKENS(lttng_ust__events_exit__, LTTNG_UST_TRACEPOINT_PROVIDER)(void) - lttng_ust_notrace __attribute__((destructor)); +LTTNG_UST__TP_COMBINE_TOKENS(lttng_ust__events_exit__, LTTNG_UST_TRACEPOINT_PROVIDER)(void) lttng_ust_notrace; static void LTTNG_UST__TP_COMBINE_TOKENS(lttng_ust__events_exit__, LTTNG_UST_TRACEPOINT_PROVIDER)(void) { @@ -1217,6 +1227,12 @@ LTTNG_UST__TP_COMBINE_TOKENS(lttng_ust__events_exit__, LTTNG_UST_TRACEPOINT_PROV LTTNG_UST__TP_COMBINE_TOKENS(lttng_ust__probe_register_cookie___, LTTNG_UST_TRACEPOINT_PROVIDER) = NULL; } +LTTNG_UST_DECLARE_CONSTRUCTOR_DESTRUCTOR( + LTTNG_UST_TRACEPOINT_PROVIDER, + LTTNG_UST__TP_COMBINE_TOKENS(lttng_ust__events_init__, LTTNG_UST_TRACEPOINT_PROVIDER), + LTTNG_UST__TP_COMBINE_TOKENS(lttng_ust__events_exit__, LTTNG_UST_TRACEPOINT_PROVIDER), + lttng_ust_notrace) + /* * LTTNG_UST_TRACEPOINT_PROVIDER_HIDDEN_DEFINITION: Define this before * including a tracepoint instrumentation header to hide symbols