go/src/cmd/link/internal/ld/macho_update_uuid.go

// uuidFromGoBuildId hashes the Go build ID and returns a slice of 16
// bytes suitable for use as the payload in a Macho LC_UUID load
// command.
func uuidFromGoBuildId(buildID string) []byte { … }

// machoRewriteUuid copies over the contents of the Macho executable
// exef into the output file outexe, and in the process updates the
// LC_UUID command to a new value recomputed from the Go build id.
func machoRewriteUuid(ctxt *Link, exef *os.File, exem *macho.File, outexe string) error { … }