content: {-# LANGUAGE FlexibleContexts #-}
  {-# LANGUAGE RankNTypes #-}
  
  -----------------------------------------------------------------------------
  -- |
  -- Module      :  Distribution.Simple.Bench
  -- Copyright   :  Johan Tibell 2011
  -- License     :  BSD3
  --
  -- Maintainer  :  cabal-devel@haskell.org
  -- Portability :  portable
  --
  -- This is the entry point into running the benchmarks in a built
  -- package. It performs the \"@.\/setup bench@\" action. It runs
  -- benchmarks designated in the package description.
  
  module Distribution.Simple.Bench
      ( bench
      ) where
  
  import Prelude ()
  import Distribution.Compat.Prelude
  
  import Distribution.Types.UnqualComponentName
  import qualified Distribution.PackageDescription as PD
  import Distribution.Simple.BuildPaths
  import Distribution.Simple.Compiler
  import Distribution.Simple.InstallDirs
  import qualified Distribution.Simple.LocalBuildInfo as LBI
  import Distribution.Simple.Setup
  import Distribution.Simple.UserHooks
  import Distribution.Simple.Utils
  import Distribution.Text
  
  import System.Exit ( ExitCode(..), exitFailure, exitSuccess )
  import System.Directory ( doesFileExist )
  import System.FilePath ( (</>), (<.>) )
  
  -- | Perform the \"@.\/setup bench@\" action.
  bench :: Args                    -- ^positional command-line arguments
        -> PD.PackageDescription   -- ^information from the .cabal file
        -> LBI.LocalBuildInfo      -- ^information from the configure step
        -> BenchmarkFlags          -- ^flags sent to benchmark
        -> IO ()
  bench args pkg_descr lbi flags = do
      let verbosity         = fromFlag $ benchmarkVerbosity flags
          benchmarkNames    = args
          pkgBenchmarks     = PD.benchmarks pkg_descr
          enabledBenchmarks = map fst (LBI.enabledBenchLBIs pkg_descr lbi)
  
          -- Run the benchmark
          doBench :: PD.Benchmark -> IO ExitCode
          doBench bm =
              case PD.benchmarkInterface bm of
                PD.BenchmarkExeV10 _ _ -> do
                    let cmd = LBI.buildDir lbi </> name </> name <.> exeExtension
                        options = map (benchOption pkg_descr lbi bm) $
                                  benchmarkOptions flags
                    -- Check that the benchmark executable exists.
                    exists <- doesFileExist cmd
                    unless exists $ die' verbosity $
                        "Error: Could not find benchmark program \""
                        ++ cmd ++ "\". Did you build the package first?"
  
                    notice verbosity $ startMessage name
                    -- This will redirect the child process
                    -- stdout/stderr to the parent process.
                    exitcode <- rawSystemExitCode verbosity cmd options
                    notice verbosity $ finishMessage name exitcode
                    return exitcode
  
                _ -> do
                    notice verbosity $ "No support for running "
                        ++ "benchmark " ++ name ++ " of type: "
                        ++ display (PD.benchmarkType bm)
                    exitFailure
            where name = unUnqualComponentName $ PD.benchmarkName bm
  
      unless (PD.hasBenchmarks pkg_descr) $ do
          notice verbosity "Package has no benchmarks."
          exitSuccess
  
      when (PD.hasBenchmarks pkg_descr && null enabledBenchmarks) $
          die' verbosity $ "No benchmarks enabled. Did you remember to configure with "
                ++ "\'--enable-benchmarks\'?"
  
      bmsToRun <- case benchmarkNames of
              [] -> return enabledBenchmarks
              names -> for names $ \bmName ->
                  let benchmarkMap = zip enabledNames enabledBenchmarks
                      enabledNames = map PD.benchmarkName enabledBenchmarks
                      allNames = map PD.benchmarkName pkgBenchmarks
                  in case lookup (mkUnqualComponentName bmName) benchmarkMap of
                      Just t -> return t
                      _ | mkUnqualComponentName bmName `elem` allNames ->
                            die' verbosity $ "Package configured with benchmark "
                                  ++ bmName ++ " disabled."
                        | otherwise -> die' verbosity $ "no such benchmark: " ++ bmName
  
      let totalBenchmarks = length bmsToRun
      notice verbosity $ "Running " ++ show totalBenchmarks ++ " benchmarks..."
      exitcodes <- traverse doBench bmsToRun
      let allOk = totalBenchmarks == length (filter (== ExitSuccess) exitcodes)
      unless allOk exitFailure
    where
      startMessage name = "Benchmark " ++ name ++ ": RUNNING...\n"
      finishMessage name exitcode = "Benchmark " ++ name ++ ": "
                                 ++ (case exitcode of
                                          ExitSuccess -> "FINISH"
                                          ExitFailure _ -> "ERROR")
  
  
  -- TODO: This is abusing the notion of a 'PathTemplate'.  The result isn't
  -- necessarily a path.
  benchOption :: PD.PackageDescription
              -> LBI.LocalBuildInfo
              -> PD.Benchmark
              -> PathTemplate
              -> String
  benchOption pkg_descr lbi bm template =
      fromPathTemplate $ substPathTemplate env template
    where
      env = initialPathTemplateEnv
            (PD.package pkg_descr) (LBI.localUnitId lbi)
            (compilerInfo $ LBI.compiler lbi) (LBI.hostPlatform lbi) ++
            [(BenchmarkNameVar, toPathTemplate $ unUnqualComponentName $ PD.benchmarkName bm)]
  