What are you wanting to compile? Is it for something that runs on the WiiU or runs on your machine.

What environment are you in? The thing is - knowing how to compile source is not necessarily within the scope of this forum as it is heavily covered/documented elsewhere.
Like, "compile c in windows" / "compile c in osx" / "compile c in linux" are some search terms google understands and will point you where you need to go.
Also, you will more than likely need http://devkitpro.org/wiki/Getting_Started/devkitPPC in your build environment.
Depending on what you are trying to build you may also need the ARM stuff ( http://devkitpro.org/wiki/Getting_Started/devkitARM ).

In OSX I just do everything in the terminal with gcc and a properly setup build environment.
There are a ton of resources and tutorials already on the internet specifically for this...

 

You will need to setup gcc, devkitPro (both PPC and ARM), armips and python at the very minimum.
(http://webcache.googleusercontent.com/search?q=cache:aB5E7OEs4joJ:www.wiiubru.com/forum/forum/viewtopic.php?t=10+&cd=2&hl=en&ct=clnk&gl=us)
Also, still not knowing your OS is a problem - I really cannot give you anything step by step not knowing that. Though, I can tell you how to do this in a unix like environment - but windows... not so much.

I heard windows 10 got a bash shell - but know nothing more about it than what I glanced at here.
http://www.howtogeek.com/265900/everything-you-can-do-with-windows-10s-new-bash-shell/

Also, take a look at the readme on github under "how to use":
https://github.com/FIX94/iosuhax

Once you have everything you need setup - the build process is really EASY. Pastebin is also your friend for things that cannot be provided here.

 

I can't believe I wasnt aware of this! I'm really glad you brought this to my attention. Neat stuff. Says you can even run bash commands in a batch script. Nice.

 

Surely it would be better to just follow this guide:

https://gbatemp.net/threads/building-iosuhax-on-windows.447023/

Written by FIX himself.