Simplify the Setup script

See haskellari/cabal-doctest#11

Setup.lhs

@@ -1,182 +1,34 @@
 \begin{code}
 {-# LANGUAGE CPP #-}
-{-# LANGUAGE OverloadedStrings #-}
+{-# OPTIONS_GHC -Wall #-}
 module Main (main) where
 
 #ifndef MIN_VERSION_cabal_doctest
 #define MIN_VERSION_cabal_doctest(x,y,z) 0
 #endif
 
-
 #if MIN_VERSION_cabal_doctest(1,0,0)
-import Distribution.Extra.Doctest ( defaultMainWithDoctests )
-#else
-
--- Otherwise we provide a shim
-
-#ifndef MIN_VERSION_Cabal
-#define MIN_VERSION_Cabal(x,y,z) 0
-#endif
-#ifndef MIN_VERSION_directory
-#define MIN_VERSION_directory(x,y,z) 0
-#endif
-#if MIN_VERSION_Cabal(1,24,0)
-#define InstalledPackageId UnitId
-#endif
-
-import Control.Monad ( when )
-import Data.List ( nub )
-import Data.String ( fromString )
-import Distribution.Package ( InstalledPackageId )
-import Distribution.Package ( PackageId, Package (..), packageVersion )
-import Distribution.PackageDescription ( PackageDescription(), TestSuite(..) , Library (..), BuildInfo (..))
-import Distribution.Simple ( defaultMainWithHooks, UserHooks(..), simpleUserHooks )
-import Distribution.Simple.Utils ( rewriteFile, createDirectoryIfMissingVerbose )
-import Distribution.Simple.BuildPaths ( autogenModulesDir )
-import Distribution.Simple.Setup ( BuildFlags(buildDistPref, buildVerbosity), fromFlag)
-import Distribution.Simple.LocalBuildInfo ( withPackageDB, withLibLBI, withTestLBI, LocalBuildInfo(), ComponentLocalBuildInfo(componentPackageDeps), compiler )
-import Distribution.Simple.Compiler ( showCompilerId , PackageDB (..))
-import Distribution.Text ( display , simpleParse )
-import System.FilePath ( (</>) )
-
-#if MIN_VERSION_Cabal(1,25,0)
-import Distribution.Simple.BuildPaths ( autogenComponentModulesDir )
-#endif
-
-#if MIN_VERSION_directory(1,2,2)
-import System.Directory (makeAbsolute)
-#else
-import System.Directory (getCurrentDirectory)
-import System.FilePath (isAbsolute)
-
-makeAbsolute :: FilePath -> IO FilePath
-makeAbsolute p | isAbsolute p = return p
-               | otherwise    = do
-    cwd <- getCurrentDirectory
-    return $ cwd </> p
-#endif
-
-generateBuildModule :: String -> BuildFlags -> PackageDescription -> LocalBuildInfo -> IO ()
-generateBuildModule testsuiteName flags pkg lbi = do
-  let verbosity = fromFlag (buildVerbosity flags)
-  let distPref = fromFlag (buildDistPref flags)
-
-  -- Package DBs
-  let dbStack = withPackageDB lbi ++ [ SpecificPackageDB $ distPref </> "package.conf.inplace" ]
-  let dbFlags = "-hide-all-packages" : packageDbArgs dbStack
-
-  withLibLBI pkg lbi $ \lib libcfg -> do
-    let libBI = libBuildInfo lib
 
-    -- modules
-    let modules = exposedModules lib ++ otherModules libBI
-    -- it seems that doctest is happy to take in module names, not actual files!
-    let module_sources = modules
+import Distribution.Extra.Doctest ( defaultMainWithDoctests )
+main :: IO ()
+main = defaultMainWithDoctests "doctests"
 
-    -- We need the directory with library's cabal_macros.h!
-#if MIN_VERSION_Cabal(1,25,0)
-    let libAutogenDir = autogenComponentModulesDir lbi libcfg
 #else
-    let libAutogenDir = autogenModulesDir lbi
-#endif
-
-    -- Lib sources and includes
-    iArgs <- mapM (fmap ("-i"++) . makeAbsolute) $ libAutogenDir : hsSourceDirs libBI
-    includeArgs <- mapM (fmap ("-I"++) . makeAbsolute) $ includeDirs libBI
 
-    -- CPP includes, i.e. include cabal_macros.h
-    let cppFlags = map ("-optP"++) $
-            [ "-include", libAutogenDir ++ "/cabal_macros.h" ]
-            ++ cppOptions libBI
-
-    withTestLBI pkg lbi $ \suite suitecfg -> when (testName suite == fromString testsuiteName) $ do
-
-      -- get and create autogen dir
-#if MIN_VERSION_Cabal(1,25,0)
-      let testAutogenDir = autogenComponentModulesDir lbi suitecfg
-#else
-      let testAutogenDir = autogenModulesDir lbi
+#ifdef MIN_VERSION_Cabal
+-- If the macro is defined, we have new cabal-install,
+-- but for some reason we don't have cabal-doctest in package-db
+--
+-- Probably we are running cabal sdist, when otherwise using new-build
+-- workflow
+import Warning ()
 #endif
-      createDirectoryIfMissingVerbose verbosity True testAutogenDir
-
-      -- write autogen'd file
-      rewriteFile (testAutogenDir </> "Build_doctests.hs") $ unlines
-        [ "module Build_doctests where"
-        , ""
-        -- -package-id etc. flags
-        , "pkgs :: [String]"
-        , "pkgs = " ++ (show $ formatDeps $ testDeps libcfg suitecfg)
-        , ""
-        , "flags :: [String]"
-        , "flags = " ++ show (iArgs ++ includeArgs ++ dbFlags ++ cppFlags)
-        , ""
-        , "module_sources :: [String]"
-        , "module_sources = " ++ show (map display module_sources)
-        ]
-  where
-    -- we do this check in Setup, as then doctests don't need to depend on Cabal
-    isOldCompiler = maybe False id $ do
-      a <- simpleParse $ showCompilerId $ compiler lbi
-      b <- simpleParse "7.5"
-      return $ packageVersion (a :: PackageId) < b
 
-    formatDeps = map formatOne
-    formatOne (installedPkgId, pkgId)
-      -- The problem is how different cabal executables handle package databases
-      -- when doctests depend on the library
-      | packageId pkg == pkgId = "-package=" ++ display pkgId
-      | otherwise              = "-package-id=" ++ display installedPkgId
+import Distribution.Simple
 
-    -- From Distribution.Simple.Program.GHC
-    packageDbArgs :: [PackageDB] -> [String]
-    packageDbArgs | isOldCompiler = packageDbArgsConf
-                  | otherwise     = packageDbArgsDb
-
-    -- GHC <7.6 uses '-package-conf' instead of '-package-db'.
-    packageDbArgsConf :: [PackageDB] -> [String]
-    packageDbArgsConf dbstack = case dbstack of
-      (GlobalPackageDB:UserPackageDB:dbs) -> concatMap specific dbs
-      (GlobalPackageDB:dbs)               -> ("-no-user-package-conf")
-                                           : concatMap specific dbs
-      _ -> ierror
-      where
-        specific (SpecificPackageDB db) = [ "-package-conf=" ++ db ]
-        specific _                      = ierror
-        ierror = error $ "internal error: unexpected package db stack: "
-                      ++ show dbstack
-
-    -- GHC >= 7.6 uses the '-package-db' flag. See
-    -- https://ghc.haskell.org/trac/ghc/ticket/5977.
-    packageDbArgsDb :: [PackageDB] -> [String]
-    -- special cases to make arguments prettier in common scenarios
-    packageDbArgsDb dbstack = case dbstack of
-      (GlobalPackageDB:UserPackageDB:dbs)
-        | all isSpecific dbs              -> concatMap single dbs
-      (GlobalPackageDB:dbs)
-        | all isSpecific dbs              -> "-no-user-package-db"
-                                           : concatMap single dbs
-      dbs                                 -> "-clear-package-db"
-                                           : concatMap single dbs
-     where
-       single (SpecificPackageDB db) = [ "-package-db=" ++ db ]
-       single GlobalPackageDB        = [ "-global-package-db" ]
-       single UserPackageDB          = [ "-user-package-db" ]
-       isSpecific (SpecificPackageDB _) = True
-       isSpecific _                     = False
-
-testDeps :: ComponentLocalBuildInfo -> ComponentLocalBuildInfo -> [(InstalledPackageId, PackageId)]
-testDeps xs ys = nub $ componentPackageDeps xs ++ componentPackageDeps ys
-
-defaultMainWithDoctests :: String -> IO ()
-defaultMainWithDoctests testSuiteName = defaultMainWithHooks simpleUserHooks
-  { buildHook = \pkg lbi hooks flags -> do
-     generateBuildModule testSuiteName flags pkg lbi
-     buildHook simpleUserHooks pkg lbi hooks flags
-  }
+main :: IO ()
+main = defaultMain
 
 #endif
 
-main :: IO ()
-main = defaultMainWithDoctests "doctests"
-
 \end{code}

Warning.hs

@@ -0,0 +1,5 @@
+module Warning
+  {-# WARNING ["You are configuring this package without cabal-doctest installed.",
+               "The doctests test-suite will not work as a result.",
+               "To fix this, install cabal-doctest before configuring."] #-}
+  () where

trifecta.cabal

@@ -22,6 +22,7 @@ extra-source-files:
   .travis.yml
   CHANGELOG.markdown
   README.markdown
+  Warning.hs
 
 source-repository head
   type: git