SoW-2020-0002: Trace Hit Counters: trigger error reporting integration

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

diff --git a/src/common/optional.h b/src/common/optional.h
index 53215b0315e299695e03ec67dc49890176707cd4..ca7d1f043d21bdef1b9ad8dc716452ee49fe7858 100644 (file)
--- a/src/common/optional.h
+++ b/src/common/optional.h
@@ -1,18 +1,8 @@
 /*
- * Copyright (C) 2019 - Jérémie Galarneau <jeremie.galarneau@efficios.com>
+ * Copyright (C) 2019 Jérémie Galarneau <jeremie.galarneau@efficios.com>
  *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License, version 2 only,
- * as published by the Free Software Foundation.
+ * SPDX-License-Identifier: GPL-2.0-only
  *
- * This program is distributed in the hope that it will be useful, but WITHOUT
- * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
- * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
- * more details.
- *
- * You should have received a copy of the GNU General Public License along
- * with this program; if not, write to the Free Software Foundation, Inc.,
- * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  */
 
 #ifndef LTTNG_OPTIONAL_H
@@ -72,18 +62,34 @@
  * wrapped optional types. It is meant to be used with PODs.
  */
 #define LTTNG_OPTIONAL_GET(optional)                   \
-        ({                                             \
+       ({                                              \
                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 assert() that it is set when fecthing the
+ * underlying value's address.
+ */
+#define LTTNG_OPTIONAL_GET_PTR(optional)                       \
+       ({                                              \
+               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 { .is_set = 0 }
+
+/*
+ * Initialize an optional field as 'set' with a given value.
+ */
+#define LTTNG_OPTIONAL_INIT_VALUE(val) { .value = val, .is_set = 1 }
 
 /* Set the value of an optional field. */
 #define LTTNG_OPTIONAL_SET(field_ptr, val)     \