fix compiler warning unused var. add macro unused_var

demo/handler/h_cov.c

@@ -215,7 +215,7 @@ static int cov_encode_subscription(
 
 
     /* FIXME: unused parameter */
-    max_apdu = max_apdu;
+    unused_var(max_apdu);
     if (!cov_subscription) {
         return 0;
     }

demo/handler/h_pt_a.c

@@ -199,8 +199,8 @@ void handler_conf_private_trans_ack(
  * we were expecting. But this is just to silence some compiler
  * warnings from Borland.
  */
-    src = src;
-    service_data = service_data;
+    unused_var(src);
+    unused_var(service_data);
 
     len = 0;
 

demo/handler/h_ucov.c

@@ -69,7 +69,7 @@ void handler_ucov_notification(
     unsigned index = 0;
 
     /* src not needed for this application */
-    src = src;
+    unused_var(src);
     /* create linked list to store data if more
        than one property value is expected */
     pProperty_value = &property_value[0];

demo/object/device-client.c

@@ -184,7 +184,7 @@ unsigned Device_Count(
 uint32_t Device_Index_To_Instance(
     unsigned index)
 {
-    index = index;
+    unused_var(index);
     return Object_Instance_Number;
 }
 

include/bacdef.h

@@ -35,6 +35,9 @@
 #pragma warning( disable : 4996)
 #endif
 
+/* This removes compilation warnings/errors about unreferenced variables. */
+#define unused_var(x) (x)=(x)
+
 /* This stack implements this version of BACnet */
 #define BACNET_PROTOCOL_VERSION 1
 /* Although this stack can implement a later revision,

src/address.c

@@ -748,7 +748,7 @@ int address_list_encode(
     /* FIXME: I really shouild check the length remaining here but it is
        fairly pointless until we have the true length remaining in
        the packet to work with as at the moment it is just MAX_APDU */
-    apdu_len = apdu_len;
+    unused_var(apdu_len);
     /* look for matching address */
     pMatch = Address_Cache;
     while (pMatch <= &Address_Cache[MAX_ADDRESS_CACHE - 1]) {

src/alarm_ack.c

@@ -128,7 +128,7 @@ int alarm_ack_decode_service_request(
     uint32_t enumValue;
 
     /* unused parameter */
-    apdu_len = apdu_len;
+    unused_var(apdu_len);
 
     if (-1 == (section_len =
             decode_context_unsigned(&apdu[len], 0,

src/debug.c

@@ -60,6 +60,6 @@ void debug_printf(
     const char *format,
     ...)
 {
-    format = format;
+    unused_var(format);
 }
 #endif

src/getevent.c

@@ -118,7 +118,7 @@ int getevent_ack_encode_apdu_data(
     unsigned i = 0;     /* counter */
 
     /* unused parameter */
-    max_apdu = max_apdu;
+    unused_var(max_apdu);
     if (apdu) {
         event_data = get_event_data;
         while (event_data) {
@@ -174,7 +174,7 @@ int getevent_ack_encode_apdu_end(
     int apdu_len = 0;   /* total length of the apdu, return value */
 
     /* unused parameter */
-    max_apdu = max_apdu;
+    unused_var(max_apdu);
     if (apdu) {
         apdu_len += encode_closing_tag(&apdu[apdu_len], 0);
         apdu_len += encode_context_boolean(&apdu[apdu_len], 1, moreEvents);

src/lighting.c

@@ -142,7 +142,7 @@ int lighting_command_decode(
     uint32_t unsigned_value = 0;
     float real_value = 0.0;
 
-    apdu_max_len = apdu_max_len;
+    unused_var(apdu_max_len);
     /* check for value pointers */
     if (apdu_max_len && data) {
         /* Tag 0: operation */

src/ptransfer.c

@@ -55,7 +55,7 @@ static int pt_encode_apdu(
     }
 */
     /* unused parameter */
-    max_apdu = max_apdu;
+    unused_var(max_apdu);
     if (apdu) {
         len =
             encode_context_unsigned(&apdu[apdu_len], 0,