Use a "comm" variant of the LTTNG_OPTIONAL helper in sessiond-comm

[lttng-tools.git] / src / common / optional.h

diff --git a/src/common/optional.h b/src/common/optional.h
index 1da5fda5da21ac0e8d9acd9c4b7f9f3821b950a9..aee5fcc5ec911d9d17e97218632767348f827cb8 100644 (file)
--- a/src/common/optional.h
+++ b/src/common/optional.h
@@ -32,9 +32,6 @@
  * Prefer using this macro where "special" values would be used, e.g.
  * -1ULL for uint64_t types.
  *
- * LTTNG_OPTIONAL should be combined with the LTTNG_PACKED macro when
- * used for IPC / network communication.
- *
  * Declaration example:
  * struct my_struct {
  *     int a;
@@ -57,6 +54,16 @@
                type value;  \
        }
 
+/*
+ * Alias used for communication structures. If the layout of an LTTNG_OPTIONAL
+ * is changed, the original layout should still be used for communication
+ * purposes.
+ *
+ * LTTNG_OPTIONAL_COMM should be combined with the LTTNG_PACKED macro when
+ * used for IPC / network communication.
+ */
+#define LTTNG_OPTIONAL_COMM LTTNG_OPTIONAL
+
 /*
  * This macro is available as a 'convenience' to allow sites that assume
  * an optional value is set to assert() that it is set when accessing it.