Since I upgraded to Xcode 9 every time I change even one character in the code, whole file gets its line breaks changed (I checked with xxd) and so it looks like I modified the whole file.
My Preferences->Text Editing is set to CLRF (Original line breaks) and yet it changes everything to LF.
I tried deleting "Caches" and "defaults delete com.apple.dt.Xcode" no luck..
I still have my old Xcode8 in other folder and editor works fine