This mod of WiiSX adds Wii U Pro Controller support. I wasn't able to test every possible combination of controllers, menu options, etc., but it seems pretty solid.

I've included the entire source tree, as that's how it was passed down before by the previous author who modified the code (matguitarist).

Enjoy, and happy gaming!

P.S.: Big thanks to FIX94 for writing libwupc, which enables WUPCs to work in WiiSX and many other homebrew programs for Wii and vWii.