Fix: add tracepoint signature at tracepoint definition site
[lttng-ust.git] / include / lttng / tracepoint.h
index fa39b272d8ff19527fd065c7e393ac947b46c8b2..b43f8f98458932e3f0c745e73f246a65717df54a 100644 (file)
 #include <lttng/tracepoint-rcu.h>
 #include <urcu/compiler.h>
 #include <dlfcn.h>     /* for dlopen */
+#include <string.h>    /* for memset */
 #include <assert.h>
+#include <lttng/ust-config.h>  /* for sdt */
+
+#ifdef LTTNG_UST_HAVE_SDT_INTEGRATION
+#define SDT_USE_VARIADIC
+#include <sys/sdt.h>
+#else
+#define STAP_PROBEV(...)
+#endif
 
 #ifdef __cplusplus
 extern "C" {
@@ -26,6 +35,7 @@ extern "C" {
 
 #define tracepoint(provider, name, ...)                                            \
        do {                                                                \
+               STAP_PROBEV(provider, name, ## __VA_ARGS__);                \
                if (caa_unlikely(__tracepoint_##provider##___##name.state)) \
                        __tracepoint_cb_##provider##___##name(__VA_ARGS__); \
        } while (0)
@@ -114,16 +124,16 @@ extern "C" {
 #define _TP_ARGS_DATA_VAR(...)         _TP_DATA_VAR_N(_TP_NARGS(0, ##__VA_ARGS__), ##__VA_ARGS__)
 #define _TP_PARAMS(...)                        __VA_ARGS__
 
-#define _DECLARE_TRACEPOINT(provider, name, ...)                                       \
-extern struct tracepoint __tracepoint_##provider##___##name;                           \
-static inline void __tracepoint_cb_##provider##___##name(_TP_ARGS_PROTO(__VA_ARGS__))  \
+#define _DECLARE_TRACEPOINT(_provider, _name, ...)                                     \
+extern struct tracepoint __tracepoint_##_provider##___##_name;                         \
+static inline void __tracepoint_cb_##_provider##___##_name(_TP_ARGS_PROTO(__VA_ARGS__))        \
 {                                                                                      \
        struct tracepoint_probe *__tp_probe;                                            \
                                                                                        \
        if (!TP_RCU_LINK_TEST())                                                        \
                return;                                                                 \
        tp_rcu_read_lock_bp();                                                          \
-       __tp_probe = tp_rcu_dereference_bp(__tracepoint_##provider##___##name.probes);  \
+       __tp_probe = tp_rcu_dereference_bp(__tracepoint_##_provider##___##_name.probes); \
        if (caa_unlikely(!__tp_probe))                                                  \
                goto end;                                                               \
        do {                                                                            \
@@ -136,12 +146,12 @@ static inline void __tracepoint_cb_##provider##___##name(_TP_ARGS_PROTO(__VA_ARG
 end:                                                                                   \
        tp_rcu_read_unlock_bp();                                                        \
 }                                                                                      \
-static inline void __tracepoint_register_##provider##___##name(char *name,             \
+static inline void __tracepoint_register_##_provider##___##_name(char *name,           \
                void *func, void *data)                                                 \
 {                                                                                      \
        __tracepoint_probe_register(name, func, data);                                  \
 }                                                                                      \
-static inline void __tracepoint_unregister_##provider##___##name(char *name,           \
+static inline void __tracepoint_unregister_##_provider##___##_name(char *name,         \
                void *func, void *data)                                                 \
 {                                                                                      \
        __tracepoint_probe_unregister(name, func, data);                                \
@@ -150,28 +160,66 @@ static inline void __tracepoint_unregister_##provider##___##name(char *name,              \
 extern int __tracepoint_probe_register(const char *name, void *func, void *data);
 extern int __tracepoint_probe_unregister(const char *name, void *func, void *data);
 
+/*
+ * tracepoint dynamic linkage handling (callbacks). Hidden visibility:
+ * shared across objects in a module/main executable.
+ */
+struct tracepoint_dlopen {
+       void *liblttngust_handle;
+
+       int (*tracepoint_register_lib)(struct tracepoint * const *tracepoints_start,
+               int tracepoints_count);
+       int (*tracepoint_unregister_lib)(struct tracepoint * const *tracepoints_start);
+#ifndef _LGPL_SOURCE
+       void (*rcu_read_lock_sym_bp)(void);
+       void (*rcu_read_unlock_sym_bp)(void);
+       void *(*rcu_dereference_sym_bp)(void *p);
+#endif
+};
+
+extern struct tracepoint_dlopen tracepoint_dlopen;
+
 #ifdef TRACEPOINT_DEFINE
 
+/*
+ * When TRACEPOINT_PROBE_DYNAMIC_LINKAGE is defined, we do not emit a
+ * unresolved symbol that requires the provider to be linked in. When
+ * TRACEPOINT_PROBE_DYNAMIC_LINKAGE is not defined, we emit an
+ * unresolved symbol that depends on having the provider linked in,
+ * otherwise the linker complains. This deals with use of static
+ * libraries, ensuring that the linker does not remove the provider
+ * object from the executable.
+ */
+#ifdef TRACEPOINT_PROBE_DYNAMIC_LINKAGE
+#define _TRACEPOINT_UNDEFINED_REF(provider)    NULL
+#else  /* TRACEPOINT_PROBE_DYNAMIC_LINKAGE */
+#define _TRACEPOINT_UNDEFINED_REF(provider)    &__tracepoint_provider_##provider
+#endif /* TRACEPOINT_PROBE_DYNAMIC_LINKAGE */
+
 /*
  * Note: to allow PIC code, we need to allow the linker to update the pointers
  * in the __tracepoints_ptrs section.
  * Therefore, this section is _not_ const (read-only).
  */
-#define _DEFINE_TRACEPOINT(provider, name)                                     \
-       static const char __tp_strtab_##provider##___##name[]                   \
+#define _TP_EXTRACT_STRING(...)        #__VA_ARGS__
+
+#define _DEFINE_TRACEPOINT(_provider, _name, _args)                            \
+       extern int __tracepoint_provider_##_provider;                           \
+       static const char __tp_strtab_##_provider##___##_name[]                 \
                __attribute__((section("__tracepoints_strings"))) =             \
-                       #provider ":" #name;                                    \
-       struct tracepoint __tracepoint_##provider##___##name                    \
+                       #_provider ":" #_name;                                  \
+       struct tracepoint __tracepoint_##_provider##___##_name                  \
                __attribute__((section("__tracepoints"))) =                     \
-                       { __tp_strtab_##provider##___##name, 0, NULL };         \
-       static struct tracepoint * __tracepoint_ptr_##provider##___##name       \
+               {                                                               \
+                       __tp_strtab_##_provider##___##_name,                    \
+                       0,                                                      \
+                       NULL,                                                   \
+                       _TRACEPOINT_UNDEFINED_REF(_provider),                   \
+                       _TP_EXTRACT_STRING(_args),                              \
+               };                                                              \
+       static struct tracepoint * __tracepoint_ptr_##_provider##___##_name     \
                __attribute__((used, section("__tracepoints_ptrs"))) =          \
-                       &__tracepoint_##provider##___##name;
-
-static int (*tracepoint_register_lib)(struct tracepoint * const *tracepoints_start,
-               int tracepoints_count);
-static int (*tracepoint_unregister_lib)(struct tracepoint * const *tracepoints_start);
-static void *liblttngust_handle;
+                       &__tracepoint_##_provider##___##_name;
 
 /*
  * These weak symbols, the constructor, and destructor take care of
@@ -184,38 +232,41 @@ extern struct tracepoint * const __stop___tracepoints_ptrs[]
        __attribute__((weak, visibility("hidden")));
 int __tracepoint_registered
        __attribute__((weak, visibility("hidden")));
+struct tracepoint_dlopen tracepoint_dlopen
+       __attribute__((weak, visibility("hidden")));
 
 static void __attribute__((constructor)) __tracepoints__init(void)
 {
        if (__tracepoint_registered++)
                return;
 
-       liblttngust_handle = dlopen("liblttng-ust-tracepoint.so.0", RTLD_NOW | RTLD_GLOBAL);
-       if (!liblttngust_handle)
+       tracepoint_dlopen.liblttngust_handle =
+               dlopen("liblttng-ust-tracepoint.so.0", RTLD_NOW | RTLD_GLOBAL);
+       if (!tracepoint_dlopen.liblttngust_handle)
                return;
-       tracepoint_register_lib =
+       tracepoint_dlopen.tracepoint_register_lib =
                URCU_FORCE_CAST(int (*)(struct tracepoint * const *, int),
-                               dlsym(liblttngust_handle,
+                               dlsym(tracepoint_dlopen.liblttngust_handle,
                                        "tracepoint_register_lib"));
-       tracepoint_unregister_lib =
+       tracepoint_dlopen.tracepoint_unregister_lib =
                URCU_FORCE_CAST(int (*)(struct tracepoint * const *),
-                               dlsym(liblttngust_handle,
+                               dlsym(tracepoint_dlopen.liblttngust_handle,
                                        "tracepoint_unregister_lib"));
 #ifndef _LGPL_SOURCE
-       tp_rcu_read_lock_bp =
+       tracepoint_dlopen.rcu_read_lock_sym_bp =
                URCU_FORCE_CAST(void (*)(void),
-                               dlsym(liblttngust_handle,
+                               dlsym(tracepoint_dlopen.liblttngust_handle,
                                        "tp_rcu_read_lock_bp"));
-       tp_rcu_read_unlock_bp =
+       tracepoint_dlopen.rcu_read_unlock_sym_bp =
                URCU_FORCE_CAST(void (*)(void),
-                               dlsym(liblttngust_handle,
+                               dlsym(tracepoint_dlopen.liblttngust_handle,
                                        "tp_rcu_read_unlock_bp"));
-       tp_rcu_dereference_sym_bp =
+       tracepoint_dlopen.rcu_dereference_sym_bp =
                URCU_FORCE_CAST(void *(*)(void *p),
-                               dlsym(liblttngust_handle,
+                               dlsym(tracepoint_dlopen.liblttngust_handle,
                                        "tp_rcu_dereference_sym_bp"));
 #endif
-       tracepoint_register_lib(__start___tracepoints_ptrs,
+       tracepoint_dlopen.tracepoint_register_lib(__start___tracepoints_ptrs,
                                __stop___tracepoints_ptrs -
                                __start___tracepoints_ptrs);
 }
@@ -223,21 +274,21 @@ static void __attribute__((constructor)) __tracepoints__init(void)
 static void __attribute__((destructor)) __tracepoints__destroy(void)
 {
        int ret;
+
        if (--__tracepoint_registered)
                return;
-       if (tracepoint_unregister_lib)
-               tracepoint_unregister_lib(__start___tracepoints_ptrs);
-       if (liblttngust_handle) {
-               tracepoint_unregister_lib = NULL;
-               tracepoint_register_lib = NULL;
-               ret = dlclose(liblttngust_handle);
+       if (tracepoint_dlopen.tracepoint_unregister_lib)
+               tracepoint_dlopen.tracepoint_unregister_lib(__start___tracepoints_ptrs);
+       if (tracepoint_dlopen.liblttngust_handle) {
+               ret = dlclose(tracepoint_dlopen.liblttngust_handle);
                assert(!ret);
+               memset(&tracepoint_dlopen, 0, sizeof(tracepoint_dlopen));
        }
 }
 
 #else /* TRACEPOINT_DEFINE */
 
-#define _DEFINE_TRACEPOINT(provider, name)
+#define _DEFINE_TRACEPOINT(_provider, _name, _args)
 
 #endif /* #else TRACEPOINT_DEFINE */
 
@@ -332,13 +383,13 @@ static void __attribute__((destructor)) __tracepoints__destroy(void)
 
 #define TRACEPOINT_EVENT(provider, name, args, fields)                 \
        _DECLARE_TRACEPOINT(provider, name, _TP_PARAMS(args))           \
-       _DEFINE_TRACEPOINT(provider, name)
+       _DEFINE_TRACEPOINT(provider, name, _TP_PARAMS(args))
 
 #define TRACEPOINT_EVENT_CLASS(provider, name, args, fields)
 
 #define TRACEPOINT_EVENT_INSTANCE(provider, _template, name, args)     \
        _DECLARE_TRACEPOINT(provider, name, _TP_PARAMS(args))           \
-       _DEFINE_TRACEPOINT(provider, name)
+       _DEFINE_TRACEPOINT(provider, name, _TP_PARAMS(args))
 
 #endif /* #ifndef TRACEPOINT_EVENT */
 
@@ -349,65 +400,63 @@ static void __attribute__((destructor)) __tracepoints__destroy(void)
  *
  * Typical use of these loglevels:
  *
- * The loglevels go from 0 to 15. Higher numbers imply the most
+ * The loglevels go from 0 to 14. Higher numbers imply the most
  * verbosity (higher event throughput expected.
  *
- * Loglevels 0 through 6, and loglevel 15, match syslog(3) loglevels
- * semantic. Loglevels 7 through 14 offer more fine-grained selection of
- * traced information.
+ * Loglevels 0 through 6, and loglevel 14, match syslog(3) loglevels
+ * semantic. Loglevels 7 through 13 offer more fine-grained selection of
+ * debug information.
  *
- * TRACE_EMERG    0
+ * TRACE_EMERG           0
  * system is unusable
  *
- * TRACE_ALERT    1
+ * TRACE_ALERT           1
  * action must be taken immediately
  *
- * TRACE_CRIT     2
+ * TRACE_CRIT            2
  * critical conditions
  *
- * TRACE_ERR      3
+ * TRACE_ERR             3
  * error conditions
  *
- * TRACE_WARNING  4
+ * TRACE_WARNING         4
  * warning conditions
  *
- * TRACE_NOTICE   5
+ * TRACE_NOTICE          5
  * normal, but significant, condition
  *
- * TRACE_INFO     6
+ * TRACE_INFO            6
  * informational message
  *
- * TRACE_SYSTEM   7
- * information has system-level scope (set of programs)
- *
- * TRACE_PROGRAM  8
- * information has program-level scope (set of processes)
+ * TRACE_DEBUG_SYSTEM    7
+ * debug information with system-level scope (set of programs)
  *
- * TRACE_PROCESS  9
- * information has process-level scope (set of modules)
+ * TRACE_DEBUG_PROGRAM   8
+ * debug information with program-level scope (set of processes)
  *
- * TRACE_MODULE   10
- * information has module (executable/library) scope (set of units)
+ * TRACE_DEBUG_PROCESS   9
+ * debug information with process-level scope (set of modules)
  *
- * TRACE_UNIT     11
- * information has compilation unit scope (set of functions)
+ * TRACE_DEBUG_MODULE    10
+ * debug information with module (executable/library) scope (set of units)
  *
- * TRACE_FUNCTION 12
- * information has function-level scope
+ * TRACE_DEBUG_UNIT      11
+ * debug information with compilation unit scope (set of functions)
  *
- * TRACE_DEFAULT  13
- * default trace loglevel (TRACEPOINT_EVENT default)
+ * TRACE_DEBUG_FUNCTION  12
+ * debug information with function-level scope
  *
- * TRACE_VERBOSE  14
- * verbose information
+ * TRACE_DEBUG_LINE      13
+ * debug information with line-level scope (TRACEPOINT_EVENT default)
  *
- * TRACE_DEBUG    15
+ * TRACE_DEBUG           14
  * debug-level message (trace_printf default)
  *
  * Declare tracepoint loglevels for tracepoints. A TRACEPOINT_EVENT
  * should be declared prior to the the TRACEPOINT_LOGLEVEL for a given
- * tracepoint name. The first field is the name of the tracepoint, the
- * second field is the loglevel name.
+ * tracepoint name. The first field is the provider name, the second
+ * field is the name of the tracepoint, the third field is the loglevel
+ * name.
  *
  *      TRACEPOINT_LOGLEVEL(< [com_company_]project[_component] >, < event >,
  *              < loglevel_name >)
@@ -417,22 +466,21 @@ static void __attribute__((destructor)) __tracepoints__destroy(void)
  */
 
 enum {
-       TRACE_EMERG     = 0,
-       TRACE_ALERT     = 1,
-       TRACE_CRIT      = 2,
-       TRACE_ERR       = 3,
-       TRACE_WARNING   = 4,
-       TRACE_NOTICE    = 5,
-       TRACE_INFO      = 6,
-       TRACE_SYSTEM    = 7,
-       TRACE_PROGRAM   = 8,
-       TRACE_PROCESS   = 9,
-       TRACE_MODULE    = 10,
-       TRACE_UNIT      = 11,
-       TRACE_FUNCTION  = 12,
-       TRACE_DEFAULT   = 13,
-       TRACE_VERBOSE   = 14,
-       TRACE_DEBUG     = 15,
+       TRACE_EMERG             = 0,
+       TRACE_ALERT             = 1,
+       TRACE_CRIT              = 2,
+       TRACE_ERR               = 3,
+       TRACE_WARNING           = 4,
+       TRACE_NOTICE            = 5,
+       TRACE_INFO              = 6,
+       TRACE_DEBUG_SYSTEM      = 7,
+       TRACE_DEBUG_PROGRAM     = 8,
+       TRACE_DEBUG_PROCESS     = 9,
+       TRACE_DEBUG_MODULE      = 10,
+       TRACE_DEBUG_UNIT        = 11,
+       TRACE_DEBUG_FUNCTION    = 12,
+       TRACE_DEBUG_LINE        = 13,
+       TRACE_DEBUG             = 14,
 };
 
 #define TRACEPOINT_LOGLEVEL(provider, name, loglevel)
This page took 0.028544 seconds and 4 git commands to generate.