func machoCodeSigSym(ctxt *Link, codeSize int64) loader.Sym {
	ldr := ctxt.loader
	cs := ldr.CreateSymForUpdate(".machocodesig", 0)
	if !ctxt.NeedCodeSign() || ctxt.IsExternal() {
		return cs.Sym()
	}
	sz := codesign.Size(codeSize, "a.out")
	cs.Grow(sz)
	cs.SetSize(sz)
	return cs.Sym()
}

// machoCodeSign code-signs Mach-O file fname with an ad-hoc signature.

			func(ctxt *Link, exef *os.File, exem *macho.File, outexe string) error {
				return machoRewriteUuid(ctxt, exef, exem, outexe)
			})
	}
	if ctxt.NeedCodeSign() {
		err := machoCodeSign(ctxt, *flagOutfile)
		if err != nil {
			Exitf("%s: code signing failed: %v", os.Args[0], err)
		}
	}
}

// passLongArgsInResponseFile writes the arguments into a file if they
// are very long.