How to check if a static library is built for 64-bit?
Yes, an arm64 slice is there. To see it, you need to use lipo from the iOS toolchain, not from the host system (which doesn’t know about arm64):
xcrun -sdk iphoneos lipo -info $(FILENAME)
good old file can do the trick, too:
$ file libTestFlight.alibTestFlight.a: Mach-O universal binary with 5 architectureslibTestFlight.a (for architecture armv7): current ar archive random librarylibTestFlight.a (for architecture armv7s): current ar archive random librarylibTestFlight.a (for architecture i386): current ar archive random librarylibTestFlight.a (for architecture x86_64): current ar archive random librarylibTestFlight.a (for architecture cputype (16777228) cpusubtype (0)): current ar archive random libraryIt seems that nobody at Apple cared to add the arm64 cputype to file, yet.
Interestingly, in the iOS 7 Tech Talk Videos ("Architecting Modern Apps, Part 2", PDF page 35) they show a working file tool's output:
