modbus: silence a build warning

Refactor handling the size of modbus_devs, so it doesn't produce a build
warning and still allows the compiler to remove unused code.

This fixes bug #637. It could be reverted once modbus_devs
unconditionally has a member in the struct.

Signed-off-by: Wolfram Sang <redacted>

diff --git a/src/modbus/modbus.c b/src/modbus/modbus.c
index a75685d74d75b83b469c1b79cb103b11619a71ca..bd8c834495b2b0ee0eb3be75318505242341aa44 100644 (file)
--- a/src/modbus/modbus.c
+++ b/src/modbus/modbus.c
@@ -33,6 +33,8 @@ static const struct sr_modbus_dev_inst *modbus_devs[] = {
 #endif
 };
 
+static const unsigned int modbus_devs_size = ARRAY_SIZE(modbus_devs);
+
 static struct sr_dev_inst *sr_modbus_scan_resource(const char *resource,
        const char *serialcomm, int modbusaddr,
        struct sr_dev_inst *(*probe_device)(struct sr_modbus_dev_inst *modbus))
@@ -96,7 +98,7 @@ SR_PRIV GSList *sr_modbus_scan(struct drv_context *drvc, GSList *options,
        }
 
        devices = NULL;
-       for (i = 0; i < ARRAY_SIZE(modbus_devs); i++) {
+       for (i = 0; i < modbus_devs_size; i++) {
                if ((resource && strcmp(resource, modbus_devs[i]->prefix))
                    || !modbus_devs[i]->scan)
                        continue;
@@ -144,7 +146,7 @@ SR_PRIV struct sr_modbus_dev_inst *modbus_dev_inst_new(const char *resource,
        gchar **params;
        unsigned int i;
 
-       for (i = 0; i < ARRAY_SIZE(modbus_devs); i++) {
+       for (i = 0; i < modbus_devs_size; i++) {
                modbus_dev = modbus_devs[i];
                if (!strncmp(resource, modbus_dev->prefix, strlen(modbus_dev->prefix))) {
                        sr_dbg("Opening %s device %s.", modbus_dev->name, resource);