Fix compilation error if DNS features are disabled

The code would fail to compile unless one of ipconfigUSE_DNS_CACHE,
ipconfigUSE_MDNS, ipconfigUSE_LLMNR, and ipconfigDNS_USE_CALLBACKS
were set.

Author: marcusb

source/FreeRTOS_DNS_Parser.c

@@ -637,7 +637,11 @@
         const DNSAnswerRecord_t * pxDNSAnswerRecord;
         IPv46_Address_t xIP_Address;
 
+        #if ( ipconfigUSE_DNS_CALLBACKS == 1 )
         struct freertos_addrinfo * pxNewAddress = NULL;
+        #else
+        (void)ppxAddressInfo;
+        #endif
 
         for( x = 0U; x < pxSet->usAnswers; x++ )
         {
@@ -737,10 +741,12 @@
                                          &( pxSet->pucByte[ sizeof( DNSAnswerRecord_t ) ] ),
                                          ipSIZE_OF_IPv6_ADDRESS );
 
+                        #if ( ipconfigUSE_DNS_CALLBACKS == 1 )
                         if( ppxAddressInfo != NULL )
                         {
                             pxNewAddress = pxNew_AddrInfo( pxSet->pcName, FREERTOS_AF_INET6, xIP_Address.xIPAddress.xIP_IPv6.ucBytes );
                         }
+                        #endif
 
                         xIP_Address.xIs_IPv6 = pdTRUE;
 
@@ -765,17 +771,20 @@
                         pvCopyDest = &( pxSet->ulIPAddress );
                         ( void ) memcpy( pvCopyDest, pvCopySource, pxSet->uxAddressLength );
 
+                        #if ( ipconfigUSE_DNS_CALLBACKS == 1 )
                         if( ppxAddressInfo != NULL )
                         {
                             const uint8_t * ucBytes = ( uint8_t * ) &( pxSet->ulIPAddress );
 
                             pxNewAddress = pxNew_AddrInfo( pxSet->pcName, FREERTOS_AF_INET4, ucBytes );
                         }
+                        #endif
 
                         xIP_Address.xIPAddress.ulIP_IPv4 = pxSet->ulIPAddress;
                         xIP_Address.xIs_IPv6 = pdFALSE;
                     }
 
+                    #if ( ipconfigUSE_DNS_CALLBACKS == 1 )
                     if( pxNewAddress != NULL )
                     {
                         if( *( ppxAddressInfo ) == NULL )
@@ -790,10 +799,7 @@
                         }
 
                         pxSet->ppxLastAddress = &( pxNewAddress->ai_next );
-                    }
 
-                    #if ( ipconfigDNS_USE_CALLBACKS == 1 )
-                    {
                         BaseType_t xCallbackResult;
 
                         xCallbackResult = xDNSDoCallback( pxSet, ( ppxAddressInfo != NULL ) ? *( ppxAddressInfo ) : NULL );

test/build-combination/CMakeLists.txt

@@ -8,6 +8,7 @@ set(FREERTOS_PLUS_TCP_TEST_CONFIGURATION_LIST
     ENABLE_ALL_IPV4_TCP     # Enable all configuration settings IPv4 TCP
     ENABLE_ALL_IPV6_TCP     # Enable all configuration settings IPv6 TCP
     ENABLE_ALL_IPV4_IPV6    # Enable all configuration settings IPv4 IPv6 UDP
+    DISABLE_DNS_FEATURES    # Enable all except DNS caching, callbacks, mDNS
     DISABLE_ALL             # Disable all configuration settings
     HEADER_SELF_CONTAIN     # Enable header self contain test
     DEFAULT_CONF            # Default (typical) configuration
@@ -59,6 +60,11 @@ add_library( freertos_plus_tcp_config_all_enable_ipv6_tcp INTERFACE)
 target_include_directories(freertos_plus_tcp_config_all_enable_ipv6_tcp INTERFACE Enable_IPv6_TCP)
 target_link_libraries(freertos_plus_tcp_config_all_enable_ipv6_tcp INTERFACE freertos_plus_tcp_config_common)
 
+# -------------------------------------------------------------------
+add_library( freertos_plus_tcp_config_disable_dns_features INTERFACE)
+target_include_directories(freertos_plus_tcp_config_disable_dns_features INTERFACE DisableDnsFeatures)
+target_link_libraries(freertos_plus_tcp_config_disable_dns_features INTERFACE freertos_plus_tcp_config_common)
+
 # -------------------------------------------------------------------
 add_library( freertos_plus_tcp_config_header_self_contain INTERFACE)
 target_include_directories(freertos_plus_tcp_config_header_self_contain INTERFACE Header_Self_Contain)
@@ -90,6 +96,8 @@ elseif(FREERTOS_PLUS_TCP_TEST_CONFIGURATION STREQUAL "ENABLE_ALL_IPV6_TCP" )
     add_library( freertos_config ALIAS freertos_plus_tcp_config_all_enable_ipv6_tcp)
 elseif(FREERTOS_PLUS_TCP_TEST_CONFIGURATION STREQUAL "ENABLE_ALL_IPV4_IPV6" )
     add_library( freertos_config ALIAS freertos_plus_tcp_config_all_enable_ipv4_ipv6)
+elseif(FREERTOS_PLUS_TCP_TEST_CONFIGURATION STREQUAL "DISABLE_DNS_FEATURES" )
+    add_library( freertos_config ALIAS freertos_plus_tcp_config_disable_dns_features)
 elseif(FREERTOS_PLUS_TCP_TEST_CONFIGURATION STREQUAL "HEADER_SELF_CONTAIN" )
     add_library( freertos_config ALIAS freertos_plus_tcp_config_header_self_contain)
     include( Header_Self_Contain/headerSelfContain.cmake )