linking for dummies

I have an app where "-lgcc_s.10.5 -lgcc -lSystem" is getting appended at the end of the stuff getting linked, and I can't figure out where this is coming from. It appears to me that gcc is doing it on its own. Instead of the linker item "-lrrd" normally appearing at the end, instead I see it in the middle like this: "-lrrd -lgcc_s.10.5 -lgcc -lSystem" and I'm told that is a problem. But I can't for the life of me see the Makefile doing anything that would cause this. Does anyone know how this extra stuff gets added on, or how to make "-lrrd" go on the end of the linker line? Mark