Bluetooth: host: Avoid use of array compound literals in API

Attempt to fix C++ error: taking address of temporary array.

According to GCC documentation:
  In C++, a compound literal designates a temporary object that only
  lives until the end of its full-expression.

Finishing with this recommendation:
  As an optimization, G++ sometimes gives array compound literals
  longer lifetimes: when the array either appears outside a function
  or has a const-qualified type.
  But it is probably safest just to avoid the use of array compound
  literals in C++ code.

Fix the issue by introducing INIT macros as an alternative, and use
these in the inline functions to avoid the use of array compound
literals in Bluetooth headers.

Signed-off-by: Joakim Andersson <joakim.andersson@nordicsemi.no>

include/bluetooth/bluetooth.h

@@ -277,7 +277,7 @@ struct bt_data {
 /** @brief Helper to declare elements of bt_data arrays
  *
  *  This macro is mainly for creating an array of struct bt_data
- *  elements which is then passed to bt_le_adv_start().
+ *  elements which is then passed to e.g. @ref bt_le_adv_start().
  *
  *  @param _type Type of advertising data field
  *  @param _data Pointer to the data field payload
@@ -293,7 +293,7 @@ struct bt_data {
 /** @brief Helper to declare elements of bt_data arrays
  *
  *  This macro is mainly for creating an array of struct bt_data
- *  elements which is then passed to bt_le_adv_start().
+ *  elements which is then passed to e.g. @ref bt_le_adv_start().
  *
  *  @param _type Type of advertising data field
  *  @param _bytes Variable number of single-byte parameters
@@ -495,6 +495,25 @@ struct bt_le_adv_param {
 	const bt_addr_le_t *peer;
 };
 
+/** @brief Initialize advertising parameters
+ *
+ *  @param _options   Advertising Options
+ *  @param _int_min   Minimum advertising interval
+ *  @param _int_max   Maximum advertising interval
+ *  @param _peer      Peer address, set to NULL for undirected advertising or
+ *                    address of peer for directed advertising.
+ */
+#define BT_LE_ADV_PARAM_INIT(_options, _int_min, _int_max, _peer) \
+{ \
+	.id = BT_ID_DEFAULT, \
+	.sid = 0, \
+	.secondary_max_skip = 0, \
+	.options = (_options), \
+	.interval_min = (_int_min), \
+	.interval_max = (_int_max), \
+	.peer = (_peer), \
+}
+
 /** @brief Helper to declare advertising parameters inline
  *
  *  @param _options   Advertising Options
@@ -504,15 +523,9 @@ struct bt_le_adv_param {
  *                    address of peer for directed advertising.
  */
 #define BT_LE_ADV_PARAM(_options, _int_min, _int_max, _peer) \
-		((struct bt_le_adv_param[]) { { \
+	((struct bt_le_adv_param[]) { \
-			.id = BT_ID_DEFAULT, \
+		BT_LE_ADV_PARAM_INIT(_options, _int_min, _int_max, _peer) \
-			.sid = 0, \
+	 })
-			.secondary_max_skip = 0, \
-			.options = (_options), \
-			.interval_min = (_int_min), \
-			.interval_max = (_int_max), \
-			.peer = (_peer), \
-		 } })
 
 #define BT_LE_ADV_CONN_DIR(_peer) BT_LE_ADV_PARAM(BT_LE_ADV_OPT_CONNECTABLE |  \
 						  BT_LE_ADV_OPT_ONE_TIME, 0, 0,\
@@ -878,6 +891,25 @@ struct bt_le_scan_cb {
 	sys_snode_t node;
 };
 
+/** @brief Initialize scan parameters
+ *
+ *  @param _type     Scan Type, BT_LE_SCAN_TYPE_ACTIVE or
+ *                   BT_LE_SCAN_TYPE_PASSIVE.
+ *  @param _options  Scan options
+ *  @param _interval Scan Interval (N * 0.625 ms)
+ *  @param _window   Scan Window (N * 0.625 ms)
+ */
+#define BT_LE_SCAN_PARAM_INIT(_type, _options, _interval, _window) \
+{ \
+	.type = (_type), \
+	.options = (_options), \
+	.interval = (_interval), \
+	.window = (_window), \
+	.timeout = 0, \
+	.interval_coded = 0, \
+	.window_coded = 0, \
+}
+
 /** @brief Helper to declare scan parameters inline
  *
  *  @param _type     Scan Type, BT_LE_SCAN_TYPE_ACTIVE or
@@ -887,15 +919,9 @@ struct bt_le_scan_cb {
  *  @param _window   Scan Window (N * 0.625 ms)
  */
 #define BT_LE_SCAN_PARAM(_type, _options, _interval, _window) \
-		((struct bt_le_scan_param[]) { { \
+	((struct bt_le_scan_param[]) { \
-			.type = (_type), \
+		BT_LE_SCAN_PARAM_INIT(_type, _options, _interval, _window) \
-			.options = (_options), \
+	 })
-			.interval = (_interval), \
-			.window = (_window), \
-			.timeout = 0, \
-			.interval_coded = 0, \
-			.window_coded = 0, \
-		 } })
 
 /** Helper macro to enable active scanning to discover new devices. */
 #define BT_LE_SCAN_ACTIVE BT_LE_SCAN_PARAM(BT_LE_SCAN_TYPE_ACTIVE, \

include/bluetooth/conn.h

@@ -39,6 +39,21 @@ struct bt_le_conn_param {
 	u16_t timeout;
 };
 
+/** @brief Initialize connection parameters
+ *
+ *  @param int_min  Minimum Connection Interval (N * 1.25 ms)
+ *  @param int_max  Maximum Connection Interval (N * 1.25 ms)
+ *  @param lat      Connection Latency
+ *  @param to       Supervision Timeout (N * 10 ms)
+ */
+#define BT_LE_CONN_PARAM_INIT(int_min, int_max, lat, to) \
+{ \
+	.interval_min = (int_min), \
+	.interval_max = (int_max), \
+	.latency = (lat), \
+	.timeout = (to), \
+}
+
 /** Helper to declare connection parameters inline
  *
  *  @param int_min  Minimum Connection Interval (N * 1.25 ms)
@@ -47,12 +62,9 @@ struct bt_le_conn_param {
  *  @param to       Supervision Timeout (N * 10 ms)
  */
 #define BT_LE_CONN_PARAM(int_min, int_max, lat, to) \
-	((struct bt_le_conn_param[]) { { \
+	((struct bt_le_conn_param[]) { \
-		.interval_min = (int_min), \
+		BT_LE_CONN_PARAM_INIT(int_min, int_max, lat, to) \
-		.interval_max = (int_max), \
+	 })
-		.latency = (lat), \
-		.timeout = (to), \
-	 } })
 
 /** Default LE connection parameters:
  *    Connection Interval: 30-50 ms
@@ -334,6 +346,22 @@ struct bt_conn_le_create_param {
 	u16_t timeout;
 };
 
+/** @brief Initialize create connection parameters
+ *
+ *  @param _options  Create connection options.
+ *  @param _interval Create connection scan interval (N * 0.625 ms).
+ *  @param _window   Create connection scan window (N * 0.625 ms).
+ */
+#define BT_CONN_LE_CREATE_PARAM_INIT(_options, _interval, _window) \
+{ \
+	.options = (_options), \
+	.interval = (_interval), \
+	.window = (_window), \
+	.interval_coded = 0, \
+	.window_coded = 0, \
+	.timeout = 0, \
+}
+
 /** Helper to declare create connection parameters inline
  *
  *  @param _options  Create connection options.
@@ -341,14 +369,9 @@ struct bt_conn_le_create_param {
  *  @param _window   Create connection scan window (N * 0.625 ms).
  */
 #define BT_CONN_LE_CREATE_PARAM(_options, _interval, _window) \
-	((struct bt_conn_le_create_param[]) { { \
+	((struct bt_conn_le_create_param[]) { \
-		.options = (_options), \
+		BT_CONN_LE_CREATE_PARAM_INIT(_options, _interval, _window) \
-		.interval = (_interval), \
+	 })
-		.window = (_window), \
-		.interval_coded = 0, \
-		.window_coded = 0, \
-		.timeout = 0, \
-	 } })
 
 /** Default LE create connection parameters.
  *  Scan continuously by setting scan interval equal to scan window.
@@ -393,8 +416,12 @@ struct bt_conn *bt_conn_create_le(const bt_addr_le_t *peer,
 				  const struct bt_le_conn_param *conn_param)
 {
 	struct bt_conn *conn;
+	struct bt_conn_le_create_param param = BT_CONN_LE_CREATE_PARAM_INIT(
+						BT_LE_CONN_OPT_NONE,
+						BT_GAP_SCAN_FAST_INTERVAL,
+						BT_GAP_SCAN_FAST_INTERVAL);
 
-	if (bt_conn_le_create(peer, BT_CONN_LE_CREATE_CONN, conn_param,
+	if (bt_conn_le_create(peer, &param, conn_param,
 			      &conn)) {
 		return NULL;
 	}
@@ -423,7 +450,12 @@ int bt_conn_le_create_auto(const struct bt_conn_le_create_param *create_param,
 __deprecated static inline
 int bt_conn_create_auto_le(const struct bt_le_conn_param *conn_param)
 {
-	return bt_conn_le_create_auto(BT_CONN_LE_CREATE_CONN_AUTO, conn_param);
+	struct bt_conn_le_create_param param = BT_CONN_LE_CREATE_PARAM_INIT(
+						BT_LE_CONN_OPT_NONE,
+						BT_GAP_SCAN_FAST_INTERVAL,
+						BT_GAP_SCAN_FAST_WINDOW);
+
+	return bt_conn_le_create_auto(&param, conn_param);
 }
 
 /** @brief Stop automatic connect creation.
@@ -1151,14 +1183,23 @@ struct bt_br_conn_param {
 	bool allow_role_switch;
 };
 
+/** @brief Initialize BR/EDR connection parameters
+ *
+ *  @param role_switch True if role switch is allowed
+ */
+#define BT_BR_CONN_PARAM_INIT(role_switch) \
+{ \
+	.allow_role_switch = (role_switch), \
+}
+
 /** Helper to declare BR/EDR connection parameters inline
   *
   * @param role_switch True if role switch is allowed
   */
 #define BT_BR_CONN_PARAM(role_switch) \
-	((struct bt_br_conn_param[]) { { \
+	((struct bt_br_conn_param[]) { \
-		.allow_role_switch = (role_switch), \
+		BT_BR_CONN_PARAM_INIT(role_switch) \
-	 } })
+	 })
 
 /** Default BR/EDR connection parameters:
  *    Role switch allowed