Extensible struct side_event_state

[libside.git] / include / side / trace.h

diff --git a/include/side/trace.h b/include/side/trace.h
index 811a283e8f67f34e1c976ec5758457412390e63e..15d74f2b1ffd146aa2b85005e549c377495763a8 100644 (file)
--- a/include/side/trace.h
+++ b/include/side/trace.h
@@ -88,8 +88,9 @@
  *   receiving the side_call arguments.
  *
  * * Event descriptions can be extended by adding fields at the end of
- *   the structure. The "struct side_event_description" is therefore a
- *   structure with flexible size and must not be used within arrays.
+ *   the structure. The "struct side_event_description" and "struct
+ *   side_event_state" are therefore structures with flexible size and
+ *   must not be used within arrays.
  */
 
 #define SIDE_ABI_VERSION       0
@@ -739,9 +740,12 @@ struct side_event_description {
  * fields.
  */
 struct side_event_state {
-       uintptr_t enabled;
-       const struct side_callback *callbacks;
-       struct side_event_description *desc;
+       uint32_t struct_size;   /* Size of this structure. */
+       uint32_t enabled;
+       side_ptr_t(const struct side_callback) callbacks;
+       side_ptr_t(struct side_event_description) desc;
+
+       char end[];     /* End with a flexible array to account for extensibility. */
 };
 
 /* Event and type attributes */
@@ -1878,9 +1882,10 @@ struct side_event_state {
                        _identifier; \
        _linkage struct side_event_state __attribute__((section("side_event_state"))) \
                        side_event_state__##_identifier = { \
+               .struct_size = offsetof(struct side_event_state, end), \
                .enabled = 0, \
-               .callbacks = &side_empty_callback, \
-               .desc = &(_identifier), \
+               .callbacks = SIDE_PTR_INIT(&side_empty_callback), \
+               .desc = SIDE_PTR_INIT(&(_identifier)), \
        }; \
        _linkage struct side_event_description __attribute__((section("side_event_description"))) \
                        _identifier = { \