Wrap dynamic len array into stackvar union

[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 1dffd94635364f84a5f7b9bdd9a28036403aa1fa..853b599036865a44b9c5658e00002336a69d3703 100644 (file)
--- a/include/lttng/ust-tracepoint-event.h
+++ b/include/lttng/ust-tracepoint-event.h
@@ -1,14 +1,15 @@
 /*
- * Copyright (c) 2011 - Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
+ * Copyright (c) 2011-2012 - Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
  *
- * THIS MATERIAL IS PROVIDED AS IS, WITH ABSOLUTELY NO WARRANTY EXPRESSED
- * OR IMPLIED.  ANY USE IS AT YOUR OWN RISK.
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
  *
- * Permission is hereby granted to use or copy this program
- * for any purpose,  provided the above notices are retained on all copies.
- * Permission to modify the code and to distribute modified code is granted,
- * provided the above notices are retained, and a notice that the code was
- * modified is included with the above copyright notice.
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
  */
 
 #include <stdio.h>
@@ -203,7 +204,7 @@ static const char                                                   \
        },
 
 #undef TP_FIELDS
-#define TP_FIELDS(args...) args        /* Only one used in this phase */
+#define TP_FIELDS(...) __VA_ARGS__     /* Only one used in this phase */
 
 #undef TRACEPOINT_EVENT_CLASS
 #define TRACEPOINT_EVENT_CLASS(_provider, _name, _args, _fields)                            \
@@ -223,7 +224,7 @@ static const char                                                   \
 #include <lttng/ust-tracepoint-event-reset.h>
 
 #undef TP_ARGS
-#define TP_ARGS(args...) args
+#define TP_ARGS(...) __VA_ARGS__
 
 #undef TRACEPOINT_EVENT_CLASS
 #define TRACEPOINT_EVENT_CLASS(_provider, _name, _args, _fields)               \
@@ -270,10 +271,10 @@ static void __event_probe__##_provider##___##_name(_TP_ARGS_DATA_PROTO(_args));
        __event_len += __dynamic_len[__dynamic_len_idx++] = strlen(_src) + 1;
 
 #undef TP_ARGS
-#define TP_ARGS(args...) args
+#define TP_ARGS(...) __VA_ARGS__
 
 #undef TP_FIELDS
-#define TP_FIELDS(args...) args
+#define TP_FIELDS(...) __VA_ARGS__
 
 #undef TRACEPOINT_EVENT_CLASS
 #define TRACEPOINT_EVENT_CLASS(_provider, _name, _args, _fields)      \
@@ -321,10 +322,10 @@ static inline size_t __event_get_size__##_provider##___##_name(size_t *__dynamic
 #define ctf_string(_item, _src)
 
 #undef TP_ARGS
-#define TP_ARGS(args...) args
+#define TP_ARGS(...) __VA_ARGS__
 
 #undef TP_FIELDS
-#define TP_FIELDS(args...) args
+#define TP_FIELDS(...) __VA_ARGS__
 
 #undef TRACEPOINT_EVENT_CLASS
 #define TRACEPOINT_EVENT_CLASS(_provider, _name, _args, _fields)             \
@@ -374,7 +375,7 @@ size_t __event_get_align__##_provider##___##_name(_TP_ARGS_PROTO(_args))      \
 #define ctf_sequence_encoded(_type, _item, _src, _length_type,         \
                        _src_length, _encoding)                 \
        {                                                               \
-               _length_type __tmpl = __dynamic_len[__dynamic_len_idx]; \
+               _length_type __tmpl = __stackvar.__dynamic_len[__dynamic_len_idx]; \
                lib_ring_buffer_align_ctx(&__ctx, lttng_alignof(_length_type));\
                __chan->ops->event_write(&__ctx, &__tmpl, sizeof(_length_type));\
        }                                                               \
@@ -389,13 +390,13 @@ size_t __event_get_align__##_provider##___##_name(_TP_ARGS_PROTO(_args))      \
 
 /* Beware: this get len actually consumes the len value */
 #undef __get_dynamic_len
-#define __get_dynamic_len(field)       __dynamic_len[__dynamic_len_idx++]
+#define __get_dynamic_len(field)       __stackvar.__dynamic_len[__dynamic_len_idx++]
 
 #undef TP_ARGS
-#define TP_ARGS(args...) args
+#define TP_ARGS(...) __VA_ARGS__
 
 #undef TP_FIELDS
-#define TP_FIELDS(args...) args
+#define TP_FIELDS(...) __VA_ARGS__
 
 #undef TRACEPOINT_EVENT_CLASS
 #define TRACEPOINT_EVENT_CLASS(_provider, _name, _args, _fields)             \
@@ -406,7 +407,9 @@ static void __event_probe__##_provider##___##_name(_TP_ARGS_DATA_PROTO(_args))\
        struct lttng_ust_lib_ring_buffer_ctx __ctx;                           \
        size_t __event_len, __event_align;                                    \
        size_t __dynamic_len_idx = 0;                                         \
-       size_t __dynamic_len[_TP_ARRAY_SIZE(__event_fields___##_provider##___##_name)];       \
+       union {                                                               \
+               size_t __dynamic_len[_TP_ARRAY_SIZE(__event_fields___##_provider##___##_name)];       \
+       } __stackvar;                                                         \
        int __ret;                                                            \
                                                                              \
        if (0)                                                                \
@@ -417,7 +420,7 @@ static void __event_probe__##_provider##___##_name(_TP_ARGS_DATA_PROTO(_args))\
                return;                                                       \
        if (caa_unlikely(!CMM_ACCESS_ONCE(__event->enabled)))                 \
                return;                                                       \
-       __event_len = __event_get_size__##_provider##___##_name(__dynamic_len,\
+       __event_len = __event_get_size__##_provider##___##_name(__stackvar.__dynamic_len,\
                 _TP_ARGS_DATA_VAR(_args));                                   \
        __event_align = __event_get_align__##_provider##___##_name(_TP_ARGS_VAR(_args)); \
        lib_ring_buffer_ctx_init(&__ctx, __chan->chan, __event, __event_len,  \
@@ -443,15 +446,19 @@ static void __event_probe__##_provider##___##_name(_TP_ARGS_DATA_PROTO(_args))\
 #include <lttng/ust-tracepoint-event-reset.h>
 
 #undef TP_ARGS
-#define TP_ARGS(args...) #args
+#define TP_ARGS(...) __VA_ARGS__
+
+#define _TP_EXTRACT_STRING2(...)       #__VA_ARGS__
 
 #undef TRACEPOINT_EVENT_CLASS
 #define TRACEPOINT_EVENT_CLASS(_provider, _name, _args, _fields)       \
 const char __tp_event_signature___##_provider##___##_name[] =          \
-               _args;
+               _TP_EXTRACT_STRING2(_args);
 
 #include TRACEPOINT_INCLUDE
 
+#undef _TP_EXTRACT_STRING2
+
 /*
  * Stage 6 of tracepoint event generation.
  *
@@ -491,7 +498,7 @@ static const int *                                                         \
 const struct lttng_event_desc __event_desc___##_provider##_##_name = {        \
        .fields = __event_fields___##_provider##___##_template,                \
        .name = #_provider ":" #_name,                                         \
-       .probe_callback = (void *) &__event_probe__##_provider##___##_template,\
+       .probe_callback = (void (*)(void)) &__event_probe__##_provider##___##_template,\
        .nr_fields = _TP_ARRAY_SIZE(__event_fields___##_provider##___##_template), \
        .loglevel = &__ref_loglevel___##_provider##___##_name,                 \
        .signature = __tp_event_signature___##_provider##___##_template,       \