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

.github/workflows/ci.yml

@@ -303,6 +303,20 @@ jobs:
           echo "::endgroup::"
           echo -e "${{ env.bashPass }} ${{ env.stepName }} ${{ env.bashEnd }}"
 
+      - env:
+          stepName: Build checks (Disable DNS features)
+        name: ${{ env.stepName }}
+        run: |
+          # ${{ env.stepName }}
+          echo -e "::group::${{ env.bashInfo }} ${{ env.stepName }} ${{ env.bashEnd }}"
+
+          cmake -S . -B build -DFREERTOS_PLUS_TCP_ENABLE_BUILD_CHECKS=ON -DFREERTOS_PLUS_TCP_TEST_CONFIGURATION=DISABLE_DNS_FEATURES
+          cmake --build build --target clean
+          cmake --build build --target freertos_plus_tcp_build_test
+
+          echo "::endgroup::"
+          echo -e "${{ env.bashPass }} ${{ env.stepName }} ${{ env.bashEnd }}"
+
       - env:
           stepName: Build checks (Disable all functionalities)
         name: ${{ env.stepName }}

source/FreeRTOS_DNS_Parser.c

@@ -737,10 +737,12 @@
                                          &( pxSet->pucByte[ sizeof( DNSAnswerRecord_t ) ] ),
                                          ipSIZE_OF_IPv6_ADDRESS );
 
+                        #if ( ( ipconfigUSE_DNS_CACHE != 0 ) || ( ipconfigDNS_USE_CALLBACKS != 0 ) || ( ipconfigUSE_MDNS != 0 ) || ( ipconfigUSE_LLMNR != 0 ) )
                         if( ppxAddressInfo != NULL )
                         {
                             pxNewAddress = pxNew_AddrInfo( pxSet->pcName, FREERTOS_AF_INET6, xIP_Address.xIPAddress.xIP_IPv6.ucBytes );
                         }
+                        #endif
 
                         xIP_Address.xIs_IPv6 = pdTRUE;
 
@@ -765,12 +767,14 @@
                         pvCopyDest = &( pxSet->ulIPAddress );
                         ( void ) memcpy( pvCopyDest, pvCopySource, pxSet->uxAddressLength );
 
+                        #if ( ( ipconfigUSE_DNS_CACHE != 0 ) || ( ipconfigDNS_USE_CALLBACKS != 0 ) || ( ipconfigUSE_MDNS != 0 ) || ( ipconfigUSE_LLMNR != 0 ) )
                         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;

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 )