#define LTTNG_OPTIONAL_H
#include <stdint.h>
-#include <assert.h>
/*
* Define wrapper structure representing an optional value.
* Declaration example:
* struct my_struct {
* int a;
- * LTTNG_OPTIONAL(int, b);
+ * LTTNG_OPTIONAL(int) b;
* };
*
* Usage example:
/*
* 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.
+ * an optional value is set to LTTNG_ASSERT() that it is set when accessing it.
*
* Since this returns the 'optional' by value, it is not suitable for all
* wrapped optional types. It is meant to be used with PODs.
*/
#define LTTNG_OPTIONAL_GET(optional) \
- ({ \
- assert((optional).is_set); \
+ ({ \
+ LTTNG_ASSERT((optional).is_set); \
(optional).value; \
})
/*
- * Initialize an optional field.
+ * This macro is available as a 'convenience' to allow sites that assume
+ * an optional value is set to LTTNG_ASSERT() that it is set when fecthing the
+ * underlying value's address.
+ */
+#define LTTNG_OPTIONAL_GET_PTR(optional) \
+ ({ \
+ LTTNG_ASSERT((optional).is_set); \
+ &(optional).value; \
+ })
+
+/*
+ * Initialize an optional field as unset.
*
* The wrapped field is set to the value it would gave if it had static storage
* duration.
*/
-#define LTTNG_OPTIONAL_INIT { .is_set = 0 }
+#define LTTNG_OPTIONAL_INIT_UNSET {}
+
+/*
+ * Initialize an optional field as 'set' with a given value.
+ */
+#define LTTNG_OPTIONAL_INIT_VALUE(val) { .is_set = 1, .value = val }
/* Set the value of an optional field. */
#define LTTNG_OPTIONAL_SET(field_ptr, val) \
do { \
- (field_ptr)->value = (val); \
(field_ptr)->is_set = 1; \
+ (field_ptr)->value = (val); \
} while (0)
/* Put an optional field in the "unset" (NULL-ed) state. */