fix issues pointed out by no-sign-compare removal

By default comparing signed with unsigned, the compiler converts the
signed value to unsigned, this can cause problems sometimes, as that
would mean -1 > 2U.

In channel.c, context.c, device.c the lengths of strings to a negative
number, so cast to a signed number in all cases.

In dns_sd.c, local.c, tests/iio_stresstest.c we had an iterator, that
was signed, that should have been unsigned (now it is).

In local.c:get_rel_timeout_ms we move the comparision to signed.

Signed-off-by: Robin Getz <[email protected]>

channel.c

@@ -293,14 +293,14 @@ char * iio_channel_get_xml(const struct iio_channel *chn, size_t *length)
 		len = eptr - ptr;
 	}
 
-	if (chn->is_scan_element && len > scan_element_len) {
+	if (chn->is_scan_element && len > (ssize_t) scan_element_len) {
 		memcpy(ptr, scan_element, scan_element_len); /* Flawfinder: ignore */
 		ptr += scan_element_len;
 		len -= scan_element_len;
 	}
 
 	for (i = 0; i < chn->nb_attrs; i++) {
-		if (len > attrs_len[i]) {
+		if (len > (ssize_t) attrs_len[i]) {
 			memcpy(ptr, attrs[i], attrs_len[i]); /* Flawfinder: ignore */
 			ptr += attrs_len[i];
 			len -= attrs_len[i];

context.c

@@ -117,7 +117,7 @@ char * iio_context_create_xml(const struct iio_context *ctx)
 	}
 
 	for (i = 0; i < ctx->nb_devices; i++) {
-		if (len > devices_len[i]) {
+		if (len > (ssize_t) devices_len[i]) {
 			memcpy(ptr, devices[i], devices_len[i]); /* Flawfinder: ignore */
 			ptr += devices_len[i];
 			len -= devices_len[i];

device.c

@@ -173,7 +173,7 @@ char * iio_device_get_xml(const struct iio_device *dev, size_t *length)
 	}
 
 	for (i = 0; i < dev->nb_channels; i++) {
-		if (len > channels_len[i]) {
+		if (len > (ssize_t) channels_len[i]) {
 			memcpy(ptr, channels[i], channels_len[i]); /* Flawfinder: ignore */
 			ptr += channels_len[i];
 			len -= channels_len[i];
@@ -185,7 +185,7 @@ char * iio_device_get_xml(const struct iio_device *dev, size_t *length)
 	free(channels_len);
 
 	for (i = 0; i < dev->nb_attrs; i++) {
-		if (len > attrs_len[i]) {
+		if (len > (ssize_t) attrs_len[i]) {
 			memcpy(ptr, attrs[i], attrs_len[i]); /* Flawfinder: ignore */
 			ptr += attrs_len[i];
 			len -= attrs_len[i];
@@ -197,7 +197,7 @@ char * iio_device_get_xml(const struct iio_device *dev, size_t *length)
 	free(attrs_len);
 
 	for (i = 0; i < dev->nb_buffer_attrs; i++) {
-		if (len > buffer_attrs_len[i]) {
+		if (len > (ssize_t) buffer_attrs_len[i]) {
 			memcpy(ptr, buffer_attrs[i], buffer_attrs_len[i]); /* Flawfinder: ignore */
 			ptr += buffer_attrs_len[i];
 			len -= buffer_attrs_len[i];
@@ -209,7 +209,7 @@ char * iio_device_get_xml(const struct iio_device *dev, size_t *length)
 	free(buffer_attrs_len);
 
 	for (i = 0; i < dev->nb_debug_attrs; i++) {
-		if (len > debug_attrs_len[i]) {
+		if (len > (ssize_t) debug_attrs_len[i]) {
 			memcpy(ptr, debug_attrs[i], debug_attrs_len[i]); /* Flawfinder: ignore */
 			ptr += debug_attrs_len[i];
 			len -= debug_attrs_len[i];

dns_sd.c

@@ -74,7 +74,7 @@ static int dnssd_fill_context_info(struct iio_context_info *info,
 	char uri[sizeof("ip:") + MAXHOSTNAMELEN + sizeof (":65535") + 1];
 	char description[255], *p;
 	const char *hw_model, *serial;
-	int i;
+	unsigned int i;
 
 	ctx = network_create_context(addr_str);
 	if (!ctx) {

local.c

@@ -266,7 +266,7 @@ static int get_rel_timeout_ms(struct timespec *start, unsigned int timeout_rel)
 	diff_ms = (now.tv_sec - start->tv_sec) * 1000;
 	diff_ms += (now.tv_nsec - start->tv_nsec) / 1000000;
 
-	if (diff_ms >= timeout_rel) /* Expired */
+	if (diff_ms >= (int) timeout_rel) /* Expired */
 		return 0;
 	if (diff_ms > 0) /* Should never be false, but lets be safe */
 		timeout_rel -= diff_ms;
@@ -1600,7 +1600,7 @@ static int add_buffer_attr(void *d, const char *path)
 	struct iio_device *dev = (struct iio_device *) d;
 	const char *name = strrchr(path, '/') + 1;
 	char **attrs, *attr;
-	int i;
+	unsigned int i;
 
 	for (i = 0; i < ARRAY_SIZE(buffer_attrs_reserved); i++)
 		if (!strcmp(buffer_attrs_reserved[i], name))

tests/iio_readdev.c

@@ -203,7 +203,7 @@ int main(int argc, char **argv)
 	const char *arg_ip = NULL;
 	int c, option_index = 0;
 	struct iio_device *dev;
-	size_t sample_size;
+	ssize_t sample_size;
 	int timeout = -1;
 	bool scan_for_context = false;
 	ssize_t ret;

tests/iio_stresstest.c

@@ -599,7 +599,7 @@ int main(int argc, char **argv)
 		}
 
 		/* Calculate some stats about the threads */
-		int a =0, b = 0;
+		unsigned int a =0, b = 0;
 		c = 0;
 		for (i = 0; i < info.num_threads; i++) {
 			a+= info.starts[i];