I got good answser from http://stackoverflow.com/questions/2804893/c-dll-export-decorated-mangled-names for the c++ dll export names.
//---------------------------------------------------------------------------------------------------
// Test cases built using VC2010 - Win32 - Debug / Release << doesn't matter
//---------------------------------------------------------------------------------------------------
// SET: Project > Properties > Linker > Debugging > Generate Debug Info = Yes (/DEBUG)
// || (or, also doesn't matter)
// SET: Project > Properties > Linker > Debugging > Generate Debug Info = No + delete PDB file!
extern "C" __declspec(dllexport) void SetCallback(LPCALLBACK function);
> SetCallback
extern "C" __declspec(dllexport) void __stdcall SetCallback(LPCALLBACK function);
> _SetCallback@4
__declspec(dllexport) void SetCallback(LPCALLBACK function);
> ?SetCallback@@YAXP6AXHPADPAX@Z@Z
__declspec(dllexport) void __stdcall SetCallback(LPCALLBACK function);
> ?SetCallback@@YGXP6GXHPADPAX@Z@Z
//---------------------------------------------------------------------------------------------------
// this also big is nonsense cause as soon you change your calling convention or add / remove
// extern "C" code won't link anymore.
// doesn't work on other cases
#pragma comment(linker, "/EXPORT:SetCallback")
extern "C" __declspec(dllexport) void SetCallback(LPCALLBACK function);
// doesn't work on other cases
#pragma comment(linker, "/EXPORT:SetCallback=SetCallback")
extern "C" __declspec(dllexport) void SetCallback(LPCALLBACK function);
// doesn't work on other cases / creates alias
#pragma comment(linker, "/EXPORT:SetCallback=_SetCallback@4")
extern "C" __declspec(dllexport) void __stdcall SetCallback(LPCALLBACK function);
// doesn't work on other cases / creates alias
#pragma comment(linker, "/EXPORT:SetCallback=?SetCallback@@YAXP6AXHPADPAX@Z@Z")
__declspec(dllexport) void SetCallback(LPCALLBACK function);
// doesn't work on other cases / creates alias
#pragma comment(linker, "/EXPORT:SetCallback=?SetCallback@@YGXP6GXHPADPAX@Z@Z")
__declspec(dllexport) void __stdcall SetCallback(LPCALLBACK function);
//---------------------------------------------------------------------------------------------------
// So far only repetable case is using Module-Definition File (*.def) in all possible cases:
EXPORTS
SetCallback
extern "C" __declspec(dllexport) void SetCallback(LPCALLBACK function);
> SetCallback
extern "C" __declspec(dllexport) void __stdcall SetCallback(LPCALLBACK function);
> SetCallback
__declspec(dllexport) void SetCallback(LPCALLBACK function);
> SetCallback
__declspec(dllexport) void __stdcall SetCallback(LPCALLBACK function);
> SetCallback
// And by far this is most acceptable as it will reproduce exactly same exported function name
// using most common compilers. Header is dictating calling convention so not much trouble for
// other sw/ppl trying to build Interop or similar.
