Trying to create a macro for RPCs leads to unresolved symbols

Development Programming & Scripting C++
1

It’s annoying to have to write 4 functions for server packets, especially when a variable changes. It also clutters up my header file. I was trying to make a preprocessor macro.


// Send a Chat to the Server
UFUNCTION(Reliable, Server, WithValidation)
void ServerSendChat(EPlayerChatChannel ChatChannel, const FString& Message, const FString& Override);
void ServerSendChat_Implementation(EPlayerChatChannel ChatChannel, const FString& Message, const FString& Override);
bool ServerSendChat_Validate(EPlayerChatChannel ChatChannel, const FString& Message, const FString& Override);
void SendChat(EPlayerChatChannel ChatChannel, const FString& Message, const FString& Override);



#define UNREAL_SERVER_FUNCTION(FunctionName, ...)			\
void FunctionName##( __VA_ARGS__);							\
UFUNCTION(Reliable, Server, WithValidation)				\
void Server##FunctionName##(__VA_ARGS__);						\
void Server##FunctionName##_Implementation(__VA_ARGS__);		\
bool Server##FunctionName##_Validate(__VA_ARGS__);



UNREAL_SERVER_FUNCTION(SendChat, EPlayerChatChannel ChatChannel, const FString& Message, const FString& Override)

The problem is Unresolved External Symbols on the Server##FunctionName##(), meaning Unreal isn’t generating that function. I am guessing this macro doesn’t inline everything needed for Unreal’s reflection system. Any suggestions?

2

I’m willing to bet that it’s something to do with UHT and the generated headers. I’m assuming you’ve gone and created the _Implementation and _Validate functions in the CPP as well? If you don’t it will throw that link error.

Oh and, if you’re using GENERATED_UCLASS_BODY instead of GENERATED_BODY for whatever reason, it automatically creates those extra functions in the header.