XCode to debug gdb-debuggable executable

Question

I have compiled a cmake-based executable that is (miraculously) debuggable in gdb.

So examining hundreds of variables with the terminal becomes a little bit slow for very large projects and I would prefer to debug using the XCode interface. Since my c++ program is already a debuggable executable, what are the steps i have to take to get it debugged using XCode GUI? It is my understanding that XCode is able to debug using gdb but I am wondering how to set this up, and whether I have to somehow import the source files.

And no, the cmake generator does not work for this particular project.