feat(ltl): Make version command output the git commit

src/ltl/app/GitHash.hs

@@ -0,0 +1,19 @@
+module GitHash where
+
+import Control.Exception (throwIO)
+import Language.Haskell.TH.Syntax (Exp, Q, runIO, lift)
+import System.Environment (getEnv)
+import System.IO.Error (catchIOError, isDoesNotExistError)
+
+getVersionFromEnv :: IO String
+getVersionFromEnv = do
+  getEnv "DETSYS_LTL_VERSION"
+    `catchIOError` \e ->
+      if isDoesNotExistError e
+        then return "unknown"
+        else throwIO e
+
+tGetGitInfo :: Q Exp
+tGetGitInfo = do
+  s <- runIO getVersionFromEnv
+  lift s

src/ltl/app/Main.hs

@@ -1,15 +1,18 @@
 {-# LANGUAGE DataKinds #-}
 {-# LANGUAGE DeriveGeneric #-}
+{-# LANGUAGE OverloadedStrings #-}
 {-# LANGUAGE RecordWildCards #-}
+{-# LANGUAGE TemplateHaskell #-}
 {-# LANGUAGE TypeOperators #-}
-{-# LANGUAGE OverloadedStrings #-}
 module Main where
 
 import qualified Data.Aeson as Aeson
 import qualified Data.Aeson.Text as AesonText
 import qualified Data.Text.Lazy.IO as TextIO
 import Options.Generic
 
+import GitHash (tGetGitInfo)
+
 import Ltl
 import Ltl.Json
 import qualified Ltl.Storage as Storage
@@ -26,11 +29,14 @@ data Config
 
 instance ParseRecord Config
 
+gitVersion :: String
+gitVersion = $tGetGitInfo
+
 main :: IO ()
 main = do
   (cfg, help) <- getWithHelp "LTL checker"
   case cfg of
-    Version -> putStrLn "<GIT VERSION NOT IMPLEMENTED>"
+    Version -> putStrLn gitVersion
     Check{..} -> do
       trace <- Storage.sqliteLoad (unHelpful testId) (unHelpful runId)
       testFormula <- case parse (unHelpful formula) of

src/ltl/ltl.cabal

@@ -81,6 +81,9 @@ executable detsys-ltl
     , ltl
     , optparse-generic
     , text
+    , template-haskell
+  other-modules:
+    GitHash
 
   default-language: Haskell2010