Warnings are not errors. If it compiles and links you are most likely all good to go.
This code has obviously been used and tested by others.
As far as warnings go, all that matters is that the assembly code generated works the way it is intended to work.
If this was a commercial radio, you would have bought it without open source firmware, and never even considered if the source code was warning free on compile.
You just care that it works as intended.
If you are getting 50 "Errors", something else is going wrong for you.
If you post the Errors, maybe someone could help you.