Other method to avoid "unused var" compiler warnings.

The '(void)varname' method is nicer than 'varname = varname' and also
prevents warnings when compiling sigrok with clang instead of gcc.

datastore.c

@@ -69,8 +69,8 @@ void sr_datastore_put(struct sr_datastore *ds, void *data, unsigned int length,
 	gpointer chunk;
 
 	/* Avoid compiler warnings. */
-	in_unitsize = in_unitsize;
+	(void)in_unitsize;
-	probelist = probelist;
+	(void)probelist;
 
 	if (ds->chunklist == NULL)
 		chunk = new_chunk(&ds);

hardware/asix-sigma/asix-sigma.c

@@ -400,7 +400,7 @@ static int hw_init(const char *deviceinfo)
 	struct sigma *sigma;
 
 	/* Avoid compiler warnings. */
-	deviceinfo = deviceinfo;
+	(void)deviceinfo;
 
 	if (!(sigma = g_try_malloc(sizeof(struct sigma)))) {
 		sr_err("sigma: %s: sigma malloc failed", __func__);
@@ -997,8 +997,9 @@ static int receive_data(int fd, int revents, void *session_data)
 	uint64_t running_msec;
 	struct timeval tv;
 
-	fd = fd;
+	/* Avoid compiler warnings. */
-	revents = revents;
+	(void)fd;
+	(void)revents;
 
 	numchunks = (sigma->state.stoppos + 511) / 512;
 
@@ -1245,7 +1246,8 @@ static int hw_start_acquisition(int device_index, gpointer session_data)
 	struct triggerinout triggerinout_conf;
 	struct triggerlut lut;
 
-	session_data = session_data;
+	/* Avoid compiler warnings. */
+	(void)session_data;
 
 	if (!(sdi = sr_get_device_instance(device_instances, device_index)))
 		return SR_ERR;
@@ -1361,7 +1363,8 @@ static void hw_stop_acquisition(int device_index, gpointer session_data)
 
 	sigma = sdi->priv;
 
-	session_data = session_data;
+	/* Avoid compiler warnings. */
+	(void)session_data;
 
 	/* Stop acquisition. */
 	sigma_set_register(WRITE_MODE, 0x11, sigma);

hardware/chronovu-la8/chronovu-la8.c

@@ -470,7 +470,7 @@ static int hw_init(const char *deviceinfo)
 	sr_spew("la8: entering %s", __func__);
 
 	/* Avoid compiler errors. */
-	deviceinfo = deviceinfo;
+	(void)deviceinfo;
 
 	/* Allocate memory for our private driver context. */
 	if (!(la8 = g_try_malloc(sizeof(struct la8)))) {
@@ -981,8 +981,8 @@ static int receive_data(int fd, int revents, void *session_data)
 	struct la8 *la8;
 
 	/* Avoid compiler errors. */
-	fd = fd;
+	(void)fd;
-	revents = revents;
+	(void)revents;
 
 	if (!(sdi = session_data)) {
 		sr_err("la8: %s: user_data was NULL", __func__);

hardware/demo/demo.c

@@ -130,7 +130,7 @@ static int hw_init(const char *deviceinfo)
 	struct sr_device_instance *sdi;
 
 	/* Avoid compiler warnings. */
-	deviceinfo = deviceinfo;
+	(void)deviceinfo;
 
 	sdi = sr_device_instance_new(0, SR_ST_ACTIVE, DEMONAME, NULL, NULL);
 	if (!sdi) {
@@ -146,7 +146,7 @@ static int hw_init(const char *deviceinfo)
 static int hw_opendev(int device_index)
 {
 	/* Avoid compiler warnings. */
-	device_index = device_index;
+	(void)device_index;
 
 	/* Nothing needed so far. */
 
@@ -156,7 +156,7 @@ static int hw_opendev(int device_index)
 static int hw_closedev(int device_index)
 {
 	/* Avoid compiler warnings. */
-	device_index = device_index;
+	(void)device_index;
 
 	/* Nothing needed so far. */
 
@@ -202,7 +202,7 @@ static void *hw_get_device_info(int device_index, int device_info_id)
 static int hw_get_status(int device_index)
 {
 	/* Avoid compiler warnings. */
-	device_index = device_index;
+	(void)device_index;
 
 	return SR_ST_ACTIVE;
 }
@@ -218,7 +218,7 @@ static int hw_set_configuration(int device_index, int capability, void *value)
 	char *stropt;
 
 	/* Avoid compiler warnings. */
-	device_index = device_index;
+	(void)device_index;
 
 	if (capability == SR_HWCAP_PROBECONFIG) {
 		/* Nothing to do, but must be supported */
@@ -359,8 +359,8 @@ static int receive_data(int fd, int revents, void *session_data)
 	gsize z;
 
 	/* Avoid compiler warnings. */
-	fd = fd;
+	(void)fd;
-	revents = revents;
+	(void)revents;
 
 	do {
 		g_io_channel_read_chars(channels[0],
@@ -471,8 +471,8 @@ static int hw_start_acquisition(int device_index, gpointer session_data)
 static void hw_stop_acquisition(int device_index, gpointer session_data)
 {
 	/* Avoid compiler warnings. */
-	device_index = device_index;
+	(void)device_index;
-	session_data = session_data;
+	(void)session_data;
 
 	/* Stop generate thread. */
 	thread_running = 0;

hardware/openbench-logic-sniffer/ols.c

@@ -979,7 +979,7 @@ static void hw_stop_acquisition(int device_index, gpointer session_device_id)
 	struct sr_datafeed_packet packet;
 
 	/* Avoid compiler warnings. */
-	device_index = device_index;
+	(void)device_index;
 
 	packet.type = SR_DF_END;
 	sr_session_bus(session_device_id, &packet);

hardware/saleae-logic/saleae-logic.c

@@ -292,7 +292,7 @@ static int hw_init(const char *deviceinfo)
 	int err, devcnt, i, j;
 
 	/* Avoid compiler warnings. */
-	deviceinfo = deviceinfo;
+	(void)deviceinfo;
 
 	if (libusb_init(&usb_context) != 0) {
 		sr_warn("Failed to initialize USB.");
@@ -554,9 +554,9 @@ static int receive_data(int fd, int revents, void *user_data)
 	struct timeval tv;
 
 	/* Avoid compiler warnings. */
-	fd = fd;
+	(void)fd;
-	revents = revents;
+	(void)revents;
-	user_data = user_data;
+	(void)user_data;
 
 	tv.tv_sec = tv.tv_usec = 0;
 	libusb_handle_events_timeout(usb_context, &tv);
@@ -780,7 +780,7 @@ static void hw_stop_acquisition(int device_index, gpointer session_data)
 	struct sr_datafeed_packet packet;
 
 	/* Avoid compiler warnings. */
-	device_index = device_index;
+	(void)device_index;
 
 	packet.type = SR_DF_END;
 	sr_session_bus(session_data, &packet);

hardware/zeroplus-logic-cube/zeroplus.c

@@ -284,7 +284,7 @@ static int hw_init(const char *deviceinfo)
 	int err, devcnt, i;
 
 	/* Avoid compiler warnings. */
-	deviceinfo = deviceinfo;
+	(void)deviceinfo;
 
 	if (libusb_init(&usb_context) != 0) {
 		sr_warn("Failed to initialize USB.");

hwplugin.c

@@ -218,7 +218,7 @@ struct sr_usb_device_instance *sr_usb_device_instance_new(uint8_t bus,
 void sr_usb_device_instance_free(struct sr_usb_device_instance *usb)
 {
 	/* Avoid compiler warnings. */
-	usb = usb;
+	(void)usb;
 
 	/* Nothing to do for this device instance type. */
 }

output/output_binary.c

@@ -31,7 +31,7 @@ static int data(struct sr_output *o, const char *data_in, uint64_t length_in,
 	char *outbuf;
 
 	/* Prevent compiler warnings. */
-	o = o;
+	(void)o;
 
 	if (!data_in) {
 		sr_warn("binary output: %s: data_in was NULL", __func__);

session_driver.c

@@ -70,9 +70,9 @@ static int feed_chunk(int fd, int revents, void *session_data)
 	void *buf;
 	int ret, got_data;
 
-	/* avoid compiler warning */
+	/* Avoid compiler warnings. */
-	fd = fd;
+	(void)fd;
-	revents = revents;
+	(void)revents;
 
 	sr_dbg("session_driver: feed chunk");
 
@@ -183,9 +183,8 @@ static void *hw_get_device_info(int device_index, int device_info_id)
 
 static int hw_get_status(int device_index)
 {
-
+	/* Avoid compiler warnings. */
-	/* avoid compiler warning */
+	(void)device_index;
-	device_index = device_index;
 
 	if (devices)
 		return SR_OK;
@@ -238,8 +237,8 @@ static int hw_start_acquisition(int device_index, gpointer session_device_id)
 	struct sr_datafeed_packet *packet;
 	int err;
 
-	/* avoid compiler warning */
+	/* Avoid compiler warnings. */
-	session_device_id = session_device_id;
+	(void)session_device_id;
 
 	if (!(vdevice = get_vdevice_by_index(device_index)))
 		return SR_ERR;