In https://github.com/apple/swift/pull/638, Nadav Rotem mentions supporting ELF as a potential feature for cmpcodesize.
cmpcodesize is a tool used by the Swift performance team to measure the size of built Swift products. It would be useful to see the size of built products on Linux (ELF) as well as on OS X (Mach-O, which cmpcodesize currently supports).
While the script currently uses otool (available on OS X), the readelf executable could be used to analyze files linked with ELF. readelf is available on Linux.
The script could detect the current platform and use the appropriate executable.