Question

I’m developing an application on Windows, but I’d also like to support other platforms (the majority of code I’ve written is platform independent). Anyway, I figured for developments sake I’d like to keep things simple (perhaps I was naive in this approach) so my main.cpp looks a little like the following:

#ifdef _WIN32
int WINAPI WinMain(HINSTANCE hInstance,
                   HINSTANCE hPrevInstance,
                   LPSTR cmdLine,
                   int cmdShow)
#else
int main(int argc, char* argv[])
#endif
{
    /* If the application is launched under Windows */
#ifdef _WIN32
    win_init wi;
    return wi.init(hInstance, hPrevInstance, cmdLine, cmdShow);
#endif

    /* If the application is launched under OS X */
#ifdef __APPLE__
    osx_init oi;
    return oi.init();
#endif
}

So the idea is that if the application is launching under Windows, WinMain is called and then I call wi.init with the WinMain arguments provided to do the rest.

I thought I was being smart, but when I compile I get an error:

MSVCRTD.lib(crtexe.obj) : error LNK2019: unresolved external symbol _main referenced in function ___tmainCRTStartup

I’ve researched this error and it seems to happen when people either forget a main method or try to compile a DLL as an .exe

So for my question; I am curious as to why this is happening, and what do you recommend I do instead of this approach?

Answer 1

You want to use the /SUBSYSTEM:WINDOWS linker option in order for WinMain to be used.