Bugfix/c89 compile fixes (#327)

* Fix code to be able to compile with older C89 ANSI compilers

* Convert C++ comments to C89 comments.

* default to std=gnu89

* Fix to enable CMake 3.1 to build on Centos7

Co-authored-by: Steve Karg <skarg@users.sourceforge.net>

apps/Makefile

@@ -96,9 +96,9 @@ BACNET_SRC_DIR =  $(realpath ../src)
 # Compiler flag to set the C Standard level.
 # c89   - "ANSI" C
 # gnu89 - c89 plus GCC extensions
-# c99   - ISO C99 standard (not yet fully implemented)
+# c99   - ISO C99 standard
 # gnu99 - c99 plus GCC extensions
-CSTANDARD = -std=gnu99
+CSTANDARD = -std=gnu89
 
 #build for release (default) or debug
 OPTIMIZATION ?= -Os

apps/router/ipmodule.c

@@ -189,7 +189,7 @@ bool dl_ip_init(ROUTER_PORT *port, IP_DATA *ip_data)
 
     /* bind the socket to the local port number */
     sin.sin_family = AF_INET;
-    //    sin.sin_addr.s_addr, ip_data->local_addr.s_addr;// = htonl(INADDR_ANY);
+    /*    sin.sin_addr.s_addr, ip_data->local_addr.s_addr;// = htonl(INADDR_ANY); */
     sin.sin_addr.s_addr = htonl(INADDR_ANY);
     sin.sin_port = ip_data->port;
 

apps/router/main.c

@@ -113,7 +113,7 @@ int main(int argc, char *argv[])
             }
         }
 
-        // blocking dequeue here
+        /* blocking dequeue here */
         bacmsg = recv_from_msgbox(head->main_id, &msg_storage, 0);
         if (bacmsg) {
             switch (bacmsg->type) {
@@ -127,7 +127,7 @@ int main(int argc, char *argv[])
                         break;
                     }
 
-                    // print_msg(bacmsg);
+                    /* print_msg(bacmsg); */
 
                     if (is_network_msg(bacmsg)) {
                         buff_len =
@@ -153,7 +153,7 @@ int main(int argc, char *argv[])
                         msg_storage.type = DATA;
                         msg_storage.data = msg_data;
 
-                        // print_msg(bacmsg);
+                        /* print_msg(bacmsg); */
 
                         if (is_network_msg(bacmsg)) {
                             msg_data->ref_count = 1;