abi.hs

#!/usr/bin/env runghc

import Distribution.Simple.InstallDirs -- Cabal package
  ( platformTemplateEnv
  , fromPathTemplate, toPathTemplate
  , substPathTemplate
  )
import Distribution.System (buildPlatform) -- Cabal package
import System.Process -- process package
  ( shell
  , readCreateProcess
  )

main :: IO ()
main = do
  compiler <- filter (/= '\n') . ("ghc-" ++) <$>
    readCreateProcess (shell "ghc --numeric-version") ""
  let platform = buildPlatform
  let env = platformTemplateEnv platform
  putStrLn $ fromPathTemplate $ substPathTemplate env $ toPathTemplate $ "$arch-$os-" ++ compiler

result

$ ./abi.hs 
x86_64-osx-ghc-7.10.2

System.Info.compilerVersion が patch level をとってくれないのどうなの

cabal-install の Main から Distribution.Client.Install.install -> ... -> Distribution.Simple.Program.Db.lookupProgramVersion まで追っていったけど諦めた