Output "(null)" when ctf_string()'s arg is NULL

Signed-off-by: Philippe Proulx <eeppeliteloop@gmail.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>

diff --git a/include/lttng/ust-tracepoint-event.h b/include/lttng/ust-tracepoint-event.h
index 2c037dca204cbd4570b13eb3f4d9cf543afbbf42..26ca1d57c53220196ce3ecf1e74593a139a7a626 100644 (file)
--- a/include/lttng/ust-tracepoint-event.h
+++ b/include/lttng/ust-tracepoint-event.h
@@ -30,6 +30,8 @@
 #include <lttng/tracepoint.h>
 #include <string.h>
 
+#define __LTTNG_UST_NULL_STRING        "(null)"
+
 #undef tp_list_for_each_entry_rcu
 #define tp_list_for_each_entry_rcu(pos, head, member)  \
        for (pos = cds_list_entry(tp_rcu_dereference_bp((head)->next), __typeof__(*pos), member);       \
@@ -328,7 +330,8 @@ static void __event_probe__##_provider##___##_name(_TP_ARGS_DATA_PROTO(_args));
 
 #undef _ctf_string
 #define _ctf_string(_item, _src, _nowrite)                                    \
-       __event_len += __dynamic_len[__dynamic_len_idx++] = strlen(_src) + 1;
+       __event_len += __dynamic_len[__dynamic_len_idx++] =                    \
+               strlen((_src) ? (_src) : __LTTNG_UST_NULL_STRING) + 1;
 
 #undef _ctf_enum
 #define _ctf_enum(_provider, _name, _type, _item, _src, _nowrite)              \
@@ -471,7 +474,8 @@ size_t __event_get_size__##_provider##___##_name(size_t *__dynamic_len, _TP_ARGS
 #undef _ctf_string
 #define _ctf_string(_item, _src, _nowrite)                                    \
        {                                                                      \
-               const void *__ctf_tmp_ptr = (_src);                            \
+               const void *__ctf_tmp_ptr =                                    \
+                       ((_src) ? (_src) : __LTTNG_UST_NULL_STRING);           \
                memcpy(__stack_data, &__ctf_tmp_ptr, sizeof(void *));          \
                __stack_data += sizeof(void *);                                \
        }
@@ -608,13 +612,19 @@ size_t __event_get_align__##_provider##___##_name(_TP_ARGS_PROTO(_args))      \
 
 #undef _ctf_string
 #define _ctf_string(_item, _src, _nowrite)                             \
-       lib_ring_buffer_align_ctx(&__ctx, lttng_alignof(*(_src)));      \
-       if (__chan->ops->u.has_strcpy)                                  \
-               __chan->ops->event_strcpy(&__ctx, _src,                 \
-                       __get_dynamic_len(dest));                       \
-       else                                                            \
-               __chan->ops->event_write(&__ctx, _src,                  \
-                       __get_dynamic_len(dest));
+       {                                                                       \
+               const char *__ctf_tmp_string =                                  \
+                       ((_src) ? (_src) : __LTTNG_UST_NULL_STRING);            \
+               lib_ring_buffer_align_ctx(&__ctx,                               \
+                       lttng_alignof(*__ctf_tmp_string));                      \
+               if (__chan->ops->u.has_strcpy)                                  \
+                       __chan->ops->event_strcpy(&__ctx, __ctf_tmp_string,     \
+                               __get_dynamic_len(dest));                       \
+               else                                                            \
+                       __chan->ops->event_write(&__ctx, __ctf_tmp_string,      \
+                               __get_dynamic_len(dest));                       \
+       }
+
 
 #undef _ctf_enum
 #define _ctf_enum(_provider, _name, _type, _item, _src, _nowrite)      \