content: -----------------------------------------------------------------------------
  -- |
  -- Module      :  Distribution.Simple.Hpc
  -- Copyright   :  Thomas Tuegel 2011
  --
  -- Maintainer  :  cabal-devel@haskell.org
  -- Portability :  portable
  --
  -- This module provides functions for locating various HPC-related paths and
  -- a function for adding the necessary options to a PackageDescription to
  -- build test suites with HPC enabled.
  
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      * Neither the name of Isaac Jones nor the names of other
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  module Distribution.Simple.Hpc
      ( enableCoverage
      , htmlDir
      , tixDir
      , tixFilePath
      , markupPackage
      , markupTest
      ) where
  
  import Control.Monad ( when )
  import Distribution.Compiler ( CompilerFlavor(..) )
  import Distribution.ModuleName ( main )
  import Distribution.PackageDescription
      ( BuildInfo(..)
      , Library(..)
      , PackageDescription(..)
      , TestSuite(..)
      , testModules
      )
  import Distribution.Simple.LocalBuildInfo ( LocalBuildInfo(..) )
  import Distribution.Simple.Program ( hpcProgram, requireProgram )
  import Distribution.Simple.Program.Hpc ( markup, union )
  import Distribution.Simple.Utils ( notice )
  import Distribution.Text
  import Distribution.Verbosity ( Verbosity() )
  import System.Directory ( createDirectoryIfMissing, doesFileExist )
  import System.FilePath
  
  -- -------------------------------------------------------------------------
  -- Haskell Program Coverage
  
  -- | Conditionally enable Haskell Program Coverage by adding the necessary
  -- GHC options to a PackageDescription.
  --
  -- TODO: do this differently in the build stage by constructing local build
  -- info, not by modifying the original PackageDescription.
  --
  enableCoverage :: Bool                  -- ^ Enable coverage?
                 -> String                -- ^ \"dist/\" prefix
                 -> PackageDescription
                 -> PackageDescription
  enableCoverage False _ x = x
  enableCoverage True distPref p =
      p { library = fmap enableLibCoverage (library p)
        , testSuites = map enableTestCoverage (testSuites p)
        }
    where
      enableBICoverage name oldBI =
          let oldOptions = options oldBI
              oldGHCOpts = lookup GHC oldOptions
              newGHCOpts = case oldGHCOpts of
                               Just xs -> (GHC, hpcOpts ++ xs)
                               _ -> (GHC, hpcOpts)
              newOptions = (:) newGHCOpts $ filter ((== GHC) . fst) oldOptions
              hpcOpts = ["-fhpc", "-hpcdir", mixDir distPref name]
          in oldBI { options = newOptions }
      enableLibCoverage l =
          l { libBuildInfo = enableBICoverage (display $ package p)
                                              (libBuildInfo l)
            }
      enableTestCoverage t =
          t { testBuildInfo = enableBICoverage (testName t) (testBuildInfo t) }
  
  hpcDir :: FilePath  -- ^ \"dist/\" prefix
         -> FilePath  -- ^ Directory containing component's HPC .mix files
  hpcDir distPref = distPref </> "hpc"
  
  mixDir :: FilePath  -- ^ \"dist/\" prefix
         -> FilePath  -- ^ Component name
         -> FilePath  -- ^ Directory containing test suite's .mix files
  mixDir distPref name = hpcDir distPref </> "mix" </> name
  
  tixDir :: FilePath  -- ^ \"dist/\" prefix
         -> FilePath  -- ^ Component name
         -> FilePath  -- ^ Directory containing test suite's .tix files
  tixDir distPref name = hpcDir distPref </> "tix" </> name
  
  -- | Path to the .tix file containing a test suite's sum statistics.
  tixFilePath :: FilePath     -- ^ \"dist/\" prefix
              -> FilePath     -- ^ Component name
              -> FilePath     -- ^ Path to test suite's .tix file
  tixFilePath distPref name = tixDir distPref name </> name <.> "tix"
  
  htmlDir :: FilePath     -- ^ \"dist/\" prefix
          -> FilePath     -- ^ Component name
          -> FilePath     -- ^ Path to test suite's HTML markup directory
  htmlDir distPref name = hpcDir distPref </> "html" </> name
  
  -- | Generate the HTML markup for a test suite.
  markupTest :: Verbosity
             -> LocalBuildInfo
             -> FilePath     -- ^ \"dist/\" prefix
             -> String       -- ^ Library name
             -> TestSuite
             -> IO ()
  markupTest verbosity lbi distPref libName suite = do
      tixFileExists <- doesFileExist $ tixFilePath distPref $ testName suite
      when tixFileExists $ do
          (hpc, _) <- requireProgram verbosity hpcProgram $ withPrograms lbi
          markup hpc verbosity (tixFilePath distPref $ testName suite)
                               (mixDir distPref libName)
                               (htmlDir distPref $ testName suite)
                               (testModules suite ++ [ main ])
          notice verbosity $ "Test coverage report written to "
                              ++ htmlDir distPref (testName suite)
                              </> "hpc_index" <.> "html"
  
  -- | Generate the HTML markup for all of a package's test suites.
  markupPackage :: Verbosity
                -> LocalBuildInfo
                -> FilePath       -- ^ \"dist/\" prefix
                -> String         -- ^ Library name
                -> [TestSuite]
                -> IO ()
  markupPackage verbosity lbi distPref libName suites = do
      let tixFiles = map (tixFilePath distPref . testName) suites
      tixFilesExist <- mapM doesFileExist tixFiles
      when (and tixFilesExist) $ do
          (hpc, _) <- requireProgram verbosity hpcProgram $ withPrograms lbi
          let outFile = tixFilePath distPref libName
              mixDir' = mixDir distPref libName
              htmlDir' = htmlDir distPref libName
              excluded = concatMap testModules suites ++ [ main ]
          createDirectoryIfMissing True $ takeDirectory outFile
          union hpc verbosity tixFiles outFile excluded
          markup hpc verbosity outFile mixDir' htmlDir' excluded
          notice verbosity $ "Package coverage report written to "
                             ++ htmlDir' </> "hpc_index.html"
  