Convert C++ log source snippet to Windows Phone C++/CX

Question

I just started developing for Windows Phone and I'm stuck with one piece of exisiting code I need to maintain. It's a macro from a logging lib that is used in many places of existing code.

This is the macro:

#define LOG_FORMAT_FUNCTION(fmtarg, firstvararg) __attribute__((__format__ (__printf__, fmtarg, firstvararg)))

And this is a method definition that fails to use the above macro with error "{ expected" (In German "Error: Es wurde ein '{' erwartet."):

void LogTrace_s(const char* category, const char* format, ...) LOG_FORMAT_FUNCTION(2, 3);

Can you help me get rid of the error? I'd also like to know what actually the macro does exactly.

Edit: After rading this here I now understand that this macro is good for error checking formatted strings. Now that I know, I need it even more. But I still have no clue how to translate this to MS C++.

Answer 1

Yes you CAN just omit it. Use

#if _MSVC_VER
#define LOG_FORMAT_FUNCTION(fmtarg, firstvararg)
#endif

It is annotating the function with extra information to help gcc give you better warnings. It does not change the behavior of the code in any way.