Sorry, I was wrong to characterize the atom being a core part of the MachO object format while it is only a core part of how ld64 works. The compiler is following some convention though that ld64 takes advantages of. Other than ld64 source code (available on opensource.apple.com) I can only point to some design document in the source repo: https://opensource.apple.com/source/ld64/ld64-253.6/doc/desi...