Start refactoring to support cabal v2-build

5 files changed, 239 insertions, 170 deletions

diff --git a/src/CabalHelper/Compiletime/Compile.hs b/src/CabalHelper/Compiletime/Compile.hs
index 305c11c..3126128 100644
--- a/src/CabalHelper/Compiletime/Compile.hs
+++ b/src/CabalHelper/Compiletime/Compile.hs
@@ -13,8 +13,8 @@
 --
 -- You should have received a copy of the GNU General Public License
 -- along with this program.  If not, see <http://www.gnu.org/licenses/>.
-{-# LANGUAGE RecordWildCards, FlexibleContexts, NamedFieldPuns, DeriveFunctor,
-  GADTs, ImplicitParams, ConstraintKinds #-}
+{-# LANGUAGE FlexibleContexts, DeriveFunctor, GADTs, ConstraintKinds,
+  ImplicitParams, NamedFieldPuns, RecordWildCards #-}
 
 {-|
 Module      : CabalHelper.Compiletime.Compile
@@ -24,7 +24,9 @@ License     : GPL-3
 
 module CabalHelper.Compiletime.Compile where
 
+import qualified Cabal.Plan as CP
 import Cabal.Plan
+  ( PlanJson(..), PkgId(..), PkgName(..), Ver(..), uPId)
 import Control.Applicative
 import Control.Arrow
 import Control.Exception as E
@@ -49,16 +51,24 @@ import System.IO.Error
 import System.IO.Temp
 import Prelude
 
-
 import qualified Data.Text as Text
 import qualified Data.Map.Strict as Map
 
-import Distribution.System (buildPlatform)
-import Distribution.Text (display)
+import Distribution.System
+  ( buildPlatform )
+import Distribution.Text
+  ( display )
+
+import Paths_cabal_helper
+  ( version )
 
-import Paths_cabal_helper (version)
+--import CabalHelper.Compiletime.Cabal
 import CabalHelper.Compiletime.Data
+--import CabalHelper.Compiletime.Log
+--import CabalHelper.Compiletime.Program.GHC
+--import CabalHelper.Compiletime.Program.CabalInstall
 import CabalHelper.Compiletime.Types
+
 import CabalHelper.Shared.Common
 import CabalHelper.Shared.Sandbox (getSandboxPkgDb)
 
@@ -87,18 +97,17 @@ data CompPaths = CompPaths
 data CompilationProductScope = CPSGlobal | CPSProject
 
 compileHelper
-    :: CompileOptions
-    -> Version
+    :: Env
+    => Version
+    -> Maybe PackageDbDir
     -> FilePath
     -> Maybe (PlanJson, FilePath)
     -> FilePath
     -> IO (Either ExitCode FilePath)
-compileHelper opts hdrCabalVersion projdir mnewstyle cachedir = do
-    let ?opts = opts
-
+compileHelper hdrCabalVersion cabalPkgDb projdir mnewstyle cachedir = do
     ghcVer <- ghcVersion
     Just (prepare, comp) <- runMaybeT $ msum $
-      case oCabalPkgDb opts of
+      case cabalPkgDb of
         Nothing ->
           [ compileCabalSource
           , compileNewBuild ghcVer
@@ -107,7 +116,7 @@ compileHelper opts hdrCabalVersion projdir mnewstyle cachedir = do
           , MaybeT $ Just <$> compileWithCabalInPrivatePkgDb
           ]
         Just db ->
-            [ return $ (return (), compileWithPkg (Just db) hdrCabalVersion CPSProject)
+          [ pure $ (pure (), compileWithPkg (Just db) hdrCabalVersion CPSProject)
           ]
 
     appdir <- appCacheDir
@@ -122,7 +131,7 @@ compileHelper opts hdrCabalVersion projdir mnewstyle cachedir = do
         vLog $ "helper exe does not exist, compiling "++compExePath
         prepare >> compile comp cp
 
- where
+  where
    logMsg = "using helper compiled with Cabal from "
 
 -- for relaxed deps: find (sameMajorVersionAs hdrCabalVersion) . reverse . sort
@@ -130,7 +139,7 @@ compileHelper opts hdrCabalVersion projdir mnewstyle cachedir = do
    -- | Check if this version is globally available
    compileGlobal :: Env => MaybeT IO (IO (), Compile)
    compileGlobal = do
-       cabal_versions <- listCabalVersions
+       cabal_versions <- listCabalVersions' Nothing
        ver <- MaybeT $ return $ find (== hdrCabalVersion) cabal_versions
        vLog $ logMsg ++ "user/global package-db"
        return $ (return (), compileWithPkg Nothing ver CPSGlobal)
@@ -150,10 +159,10 @@ compileHelper opts hdrCabalVersion projdir mnewstyle cachedir = do
        (PlanJson {pjUnits}, distdir_newstyle) <- maybe mzero pure mnewstyle
        let cabal_pkgid =
                PkgId (PkgName (Text.pack "Cabal"))
-                     (Ver $ versionBranch hdrCabalVersion)
+                        (Ver $ versionBranch hdrCabalVersion)
            mcabal_unit = listToMaybe $
-             Map.elems $ Map.filter (\Unit {..} -> uPId == cabal_pkgid) pjUnits
-       Unit {} <- maybe mzero pure mcabal_unit
+             Map.elems $ Map.filter (\CP.Unit{..} -> uPId == cabal_pkgid) pjUnits
+       CP.Unit {} <- maybe mzero pure mcabal_unit
        let inplace_db_path = distdir_newstyle
              </> "packagedb" </> ("ghc-" ++ showVersion ghcVer)
            inplace_db = PackageDbDir inplace_db_path
@@ -175,7 +184,7 @@ compileHelper opts hdrCabalVersion projdir mnewstyle cachedir = do
          db_exists <- liftIO $ cabalVersionExistsInPkgDb hdrCabalVersion db
          when (not db_exists) $
            void $ installCabal (Right hdrCabalVersion) `E.catch`
-             \(SomeException _) -> errorInstallCabal hdrCabalVersion cachedir
+             \(SomeException _) -> errorInstallCabal hdrCabalVersion
 
    -- | See if we're in a cabal source tree
    compileCabalSource :: Env => MaybeT IO (IO (), Compile)
@@ -318,7 +327,7 @@ cabalMinVersionMacro _ =
 
 invokeGhc :: Env => GhcInvocation -> IO (Either ExitCode FilePath)
 invokeGhc GhcInvocation {..} = do
-    rv <- callProcessStderr' Nothing oGhcProgram $ concat
+    rv <- callProcessStderr' Nothing (ghcProgram ?progs) $ concat
       [ [ "-outputdir", giOutDir
         , "-o", giOutput
         ]
@@ -335,8 +344,6 @@ invokeGhc GhcInvocation {..} = do
       case rv of
         ExitSuccess -> Right giOutput
         e@(ExitFailure _) -> Left e
-  where
-    CompileOptions {..} = ?opts
 
 
 -- | Cabal library version we're compiling the helper exe against.
@@ -460,7 +467,7 @@ runCabalInstall (PackageDbDir db) (CabalSourceDir srcdir) ever = do
              then ["--no-require-sandbox"]
              else []
         , [ "install", srcdir ]
-        , if oVerbose ?opts
+        , if ?verbose
             then ["-v"]
             else []
         , [ "--only-dependencies" ]
@@ -635,8 +642,8 @@ unpackCabalHEAD tmpdir = do
          (liftIO . setCurrentDirectory)
          (\_ -> liftIO (setCurrentDirectory dir) >> action)
 
-errorInstallCabal :: Version -> FilePath -> IO a
-errorInstallCabal cabalVer _distdir = panicIO $ printf "\
+errorInstallCabal :: Version -> IO a
+errorInstallCabal cabalVer = panicIO $ printf "\
 \Installing Cabal version %s failed.\n\
 \\n\
 \You have the following choices to fix this:\n\
@@ -670,9 +677,6 @@ errorInstallCabal cabalVer _distdir = panicIO $ printf "\
  where
    sver = showVersion cabalVer
 
-listCabalVersions :: Env => MaybeT IO [Version]
-listCabalVersions = listCabalVersions' Nothing
-
 listCabalVersions' :: Env => Maybe PackageDbDir -> MaybeT IO [Version]
 listCabalVersions' mdb = do
   case mdb of
@@ -746,12 +750,12 @@ cabalFileTopField field cabalFile = value
   ls = map (map toLower) $ lines cabalFile
   extract = dropWhile (/=':') >>> drop 1 >>> dropWhile isSpace >>> takeWhile (not . isSpace)
 
-vLog :: (Env, MonadIO m) => String -> m ()
-vLog msg | CompileOptions { oVerbose = True } <- ?opts =
-    liftIO $ hPutStrLn stderr msg
-vLog _ = return ()
+vLog :: (MonadIO m, Verbose) => String -> m ()
+vLog msg
+    | ?verbose  = liftIO $ hPutStrLn stderr msg
+    | otherwise = return ()
 
-logIOError :: Env => String -> IO (Maybe a) -> IO (Maybe a)
+logIOError :: Verbose => String -> IO (Maybe a) -> IO (Maybe a)
 logIOError label a = do
   a `catchIOError` \ex -> do
       vLog $ label ++ ": " ++ show ex
diff --git a/src/CabalHelper/Compiletime/Types.hs b/src/CabalHelper/Compiletime/Types.hs
index 10fe916..843a886 100644
--- a/src/CabalHelper/Compiletime/Types.hs
+++ b/src/CabalHelper/Compiletime/Types.hs
@@ -15,7 +15,8 @@
 -- along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
 {-# LANGUAGE DeriveGeneric, DeriveDataTypeable, DefaultSignatures,
-  KindSignatures, ImplicitParams, ConstraintKinds #-}
+  StandaloneDeriving, GADTs, DataKinds, KindSignatures, ImplicitParams,
+  ConstraintKinds, RankNTypes #-}
 
 {-|
 Module      : CabalHelper.Compiletime.Types
@@ -25,13 +26,25 @@ License     : GPL-3
 
 module CabalHelper.Compiletime.Types where
 
+import Cabal.Plan
+  ( PlanJson )
+import Data.IORef
 import Data.Version
 import Data.Typeable
+import Data.Map.Strict (Map)
 import GHC.Generics
+import System.Posix.Types
+import CabalHelper.Shared.InterfaceTypes
 
-type Env = (?opts :: CompileOptions)
+type Verbose = (?verbose :: Bool)
+type Progs = (?progs :: Programs)
+-- TODO: rname to `CompEnv` or something
+type Env =
+    ( ?verbose :: Bool
+    , ?progs   :: Programs
+    )
 
--- | Paths or names of various programs we need.
+-- | Configurable paths to various programs we use.
 data Programs = Programs {
       -- | The path to the @cabal@ program.
       cabalProgram  :: FilePath,
@@ -44,8 +57,8 @@ data Programs = Programs {
       ghcPkgProgram :: FilePath
     } deriving (Eq, Ord, Show, Read, Generic, Typeable)
 
--- | Default all programs to their unqualified names, i.e. they will be searched
--- for on @PATH@.
+-- | By default all programs use their unqualified names, i.e. they will be
+-- searched for on @PATH@.
 defaultPrograms :: Programs
 defaultPrograms = Programs "cabal" "ghc" "ghc-pkg"
 
@@ -57,13 +70,13 @@ data CompileOptions = CompileOptions
     }
 
 oCabalProgram :: Env => FilePath
-oCabalProgram = cabalProgram $ oPrograms ?opts
+oCabalProgram = cabalProgram ?progs
 
 oGhcProgram :: Env => FilePath
-oGhcProgram = ghcProgram $ oPrograms ?opts
+oGhcProgram = ghcProgram ?progs
 
 oGhcPkgProgram :: Env => FilePath
-oGhcPkgProgram = ghcPkgProgram $ oPrograms ?opts
+oGhcPkgProgram = ghcPkgProgram ?progs
 
 defaultCompileOptions :: CompileOptions
 defaultCompileOptions =
diff --git a/src/CabalHelper/Runtime/Compat.hs b/src/CabalHelper/Runtime/Compat.hs
index cafbfc3..8c32adf 100644
--- a/src/CabalHelper/Runtime/Compat.hs
+++ b/src/CabalHelper/Runtime/Compat.hs
@@ -151,9 +151,9 @@ type UnitId = InstalledPackageId
 
 
 componentNameToCh :: ComponentName -> ChComponentName
-componentNameToCh CLibName = ChLibName
+componentNameToCh CLibName = ChLibName ChMainLibName
 #if CH_MIN_VERSION_Cabal(2,0,0)
-componentNameToCh (CSubLibName n) = ChSubLibName (unUnqualComponentName' n)
+componentNameToCh (CSubLibName n) = ChLibName $ ChSubLibName (unUnqualComponentName' n)
 componentNameToCh (CFLibName n) = ChFLibName (unUnqualComponentName' n)
 #endif
 componentNameToCh (CExeName n) = ChExeName (unUnqualComponentName' n)
diff --git a/src/CabalHelper/Runtime/Main.hs b/src/CabalHelper/Runtime/Main.hs
index ecdbc2a..3a363a3 100644
--- a/src/CabalHelper/Runtime/Main.hs
+++ b/src/CabalHelper/Runtime/Main.hs
@@ -14,7 +14,11 @@
 -- You should have received a copy of the GNU General Public License
 -- along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
-{-# LANGUAGE CPP, BangPatterns, RecordWildCards, RankNTypes, ViewPatterns #-}
+{-# LANGUAGE CPP, BangPatterns, RecordWildCards, RankNTypes, ViewPatterns,
+  TupleSections #-}
+
+{- # OPTIONS_GHC -Wno-missing-signatures #-}
+{- # OPTIONS_GHC -fno-warn-incomplete-patterns #-}
 
 #ifdef MIN_VERSION_Cabal
 #undef CH_MIN_VERSION_Cabal
@@ -34,7 +38,7 @@ import Distribution.PackageDescription
   ( PackageDescription
   , GenericPackageDescription(..)
   , Flag(..)
-  , FlagName(..)
+  , FlagName
   , FlagAssignment
   , Executable(..)
   , Library(..)
@@ -65,7 +69,7 @@ import Distribution.Simple.LocalBuildInfo
   , ComponentLocalBuildInfo(..)
   , componentBuildInfo
   , externalPackageDeps
-  , withComponentsLBI
+  , withAllComponentsInBuildOrder
   , withLibLBI
   , withExeLBI
   )
@@ -141,7 +145,13 @@ import Distribution.Types.ForeignLib
   ( ForeignLib(..)
   )
 import Distribution.Types.UnqualComponentName
-  ( unUnqualComponentName
+  ( UnqualComponentName
+  , unUnqualComponentName
+  )
+#else
+-- <1.25
+import Distribution.PackageDescription
+  ( FlagName(FlagName)
   )
 #endif
 
@@ -198,12 +208,12 @@ import Distribution.Types.GenericPackageDescription
   )
 #endif
 
-import Control.Applicative ((<$>))
+import Control.Applicative ((<$>), (<*>), ZipList(..))
 import Control.Arrow (first, second, (&&&))
 import Control.Monad
 import Control.Exception (catch, PatternMatchFail(..))
 import Data.List
-import qualified Data.Map as Map
+import qualified Data.Map.Strict as Map
 import Data.Maybe
 import Data.Monoid
 import Data.IORef
@@ -227,42 +237,26 @@ usage = do
   hPutStr stderr $ "Usage: " ++ prog ++ " " ++ usageMsg
  where
    usageMsg = ""
-     ++"PROJ_DIR DIST_DIR [--with-* ...] (\n"
-     ++"    version\n"
-     ++"  | print-lbi [--human]\n"
-     ++"  | package-id\n"
+     ++"PROJ_DIR DIST_DIR [--with-* ...]\n"
+     ++"  ( version\n"
      ++"  | flags\n"
      ++"  | config-flags\n"
      ++"  | non-default-config-flags\n"
      ++"  | write-autogen-files\n"
      ++"  | compiler-version\n"
-     ++"  | ghc-options     [--with-inplace]\n"
-     ++"  | ghc-src-options [--with-inplace]\n"
-     ++"  | ghc-pkg-options [--with-inplace]\n"
-     ++"  | ghc-merged-pkg-options [--with-inplace]\n"
-     ++"  | ghc-lang-options [--with-inplace]\n"
-     ++"  | package-db-stack\n"
-     ++"  | entrypoints\n"
-     ++"  | needs-build-output\n"
-     ++"  | source-dirs\n"
+     ++"  | component-info\n"
+     ++"  | print-lbi [--human]\n"
      ++"  ) ...\n"
 
 commands :: [String]
-commands = [ "print-lbi"
-           , "package-id"
-           , "flags"
+commands = [ "flags"
            , "config-flags"
            , "non-default-config-flags"
            , "write-autogen-files"
            , "compiler-version"
-           , "ghc-options"
-           , "ghc-src-options"
-           , "ghc-pkg-options"
-           , "ghc-lang-options"
            , "package-db-stack"
-           , "entrypoints"
-           , "needs-build-output"
-           , "source-dirs"
+           , "component-info"
+           , "print-lbi"
            ]
 
 main :: IO ()
@@ -352,12 +346,41 @@ main = do
       let CompilerId comp ver = compilerId $ compiler lbi
       return $ Just $ ChResponseVersion (show comp) (toDataVersion ver)
 
-    "ghc-options":flags -> do
-      res <- componentOptions lvd True flags id
-      return $ Just $ ChResponseCompList (res ++ [(ChSetupHsName, [])])
+    "package-db-stack":[] -> do
+      let
+          pkgDb GlobalPackageDB = ChPkgGlobal
+          pkgDb UserPackageDB   = ChPkgUser
+          pkgDb (SpecificPackageDB s) = ChPkgSpecific s
+
+      -- TODO: Setup.hs has access to the sandbox as well: ghc-mod#478
+      return $ Just $ ChResponsePkgDbs $ map pkgDb $ withPackageDB lbi
+
+    "component-info":flags -> do
+      res <- componentsInfo flags lvd lbi v distdir
+      return $ Just $ ChResponseComponentsInfo res
+
+    "print-lbi":flags ->
+      case flags of
+        ["--human"] -> print lbi >> return Nothing
+        []          -> return $ Just $ ChResponseLbi $ show lbi
 
-    "ghc-src-options":flags -> do
-      res <- componentOptions lvd False flags $ \opts -> mempty {
+    cmd:_ | not (cmd `elem` commands) ->
+            errMsg ("Unknown command: " ++ cmd) >> usage >> exitFailure
+    _ ->
+            errMsg "Invalid usage!" >> usage >> exitFailure
+
+
+componentsInfo
+    :: [String]
+    -> (LocalBuildInfo, Verbosity, FilePath)
+    -> LocalBuildInfo
+    -> Verbosity
+    -> FilePath
+    -> IO (Map.Map ChComponentName ChComponentInfo)
+componentsInfo flags lvd lbi v distdir = do
+      ciGhcOptions <- componentOptions lvd True flags id
+
+      ciGhcSrcOptions <- componentOptions lvd False flags $ \opts -> mempty {
                -- Not really needed but "unexpected package db stack: []"
                ghcOptPackageDBs      = [GlobalPackageDB, UserPackageDB],
 
@@ -368,90 +391,61 @@ main = do
                ghcOptSourcePathClear = ghcOptSourcePathClear opts,
                ghcOptSourcePath      = ghcOptSourcePath opts
               }
-      return $ Just $ ChResponseCompList (res ++ [(ChSetupHsName, [])])
 
-    "ghc-pkg-options":flags -> do
-      res <- componentOptions lvd True flags $ \opts -> mempty {
+      ciGhcPkgOptions <- componentOptions lvd True flags $ \opts -> mempty {
                        ghcOptPackageDBs = ghcOptPackageDBs opts,
                        ghcOptPackages   = ghcOptPackages opts,
                        ghcOptHideAllPackages = ghcOptHideAllPackages opts
                    }
-      return $ Just $ ChResponseCompList (res ++ [(ChSetupHsName, [])])
-
-    "ghc-merged-pkg-options":flags -> do
-      res <- mconcat . map snd <$> (componentOptions' lvd True flags (\_ _ o -> return o) $ \opts -> mempty {
-                       ghcOptPackageDBs = [],
-                       ghcOptHideAllPackages = NoFlag,
-                       ghcOptPackages   = ghcOptPackages opts
-                   })
-
-      let res' = nubPackageFlags $ res { ghcOptPackageDBs = withPackageDB lbi
-                                       , ghcOptHideAllPackages = Flag True
-                                       }
-
-      Just . ChResponseList <$> renderGhcOptions' lbi v res'
 
-    "ghc-lang-options":flags -> do
-      res <- componentOptions lvd False flags $ \opts -> mempty {
+      ciGhcLangOptions <- componentOptions lvd False flags $ \opts -> mempty {
                        ghcOptPackageDBs      = [GlobalPackageDB, UserPackageDB],
 
                        ghcOptLanguage = ghcOptLanguage opts,
                        ghcOptExtensions = ghcOptExtensions opts,
                        ghcOptExtensionMap = ghcOptExtensionMap opts
                    }
-      return $ Just $ ChResponseCompList (res ++ [(ChSetupHsName, [])])
 
-    "package-db-stack":[] -> do
-      let
-          pkgDb GlobalPackageDB = ChPkgGlobal
-          pkgDb UserPackageDB   = ChPkgUser
-          pkgDb (SpecificPackageDB s) = ChPkgSpecific s
+      ciSourceDirs <- componentsMap lbi v distdir $ \_ _ bi -> return $ hsSourceDirs bi
 
-      -- TODO: Setup.hs has access to the sandbox as well: ghc-mod#478
-      return $ Just $ ChResponsePkgDbs $ map pkgDb $ withPackageDB lbi
-
-    "entrypoints":[] -> do
 #if CH_MIN_VERSION_Cabal(2,0,0)
       includeDirMap <- recursiveDepInfo lbi v distdir
-      eps <- componentsMap lbi v distdir $ \c clbi _bi -> do
+      ciEntrypoints <- componentsMap lbi v distdir $ \c clbi _bi -> do
                case needsBuildOutput includeDirMap (componentUnitId clbi) of
                  ProduceBuildOutput -> return $ componentEntrypoints c
                  NoBuildOutput -> return seps
                    where (_,_,seps) = recursiveIncludeDirs includeDirMap (componentUnitId clbi)
 #else
-      eps <- componentsMap lbi v distdir $ \c _clbi _bi ->
+      ciEntrypoints <- componentsMap lbi v distdir $ \c _clbi _bi ->
                return $ componentEntrypoints c
 #endif
-      -- MUST append Setup component at the end otherwise CabalHelper gets
-      -- confused
-      let eps' = eps ++ [(ChSetupHsName, ChSetupEntrypoint)]
-      return $ Just $ ChResponseEntrypoints eps'
 
-    "needs-build-output":[] -> do
 #if CH_MIN_VERSION_Cabal(2,0,0)
-      includeDirMap <- recursiveDepInfo lbi v distdir
-      nbs <- componentsMap lbi v distdir $ \c clbi _bi ->
+      ciNeedsBuildOutput <- componentsMap lbi v distdir $ \_c clbi _bi ->
                return $ needsBuildOutput includeDirMap (componentUnitId clbi)
 #else
-      nbs <- componentsMap lbi v distdir $ \c _clbi _bi ->
+      ciNeedsBuildOutput <- componentsMap lbi v distdir $ \_c _clbi _bi ->
                return $ NoBuildOutput
 #endif
-      return $ Just $ ChResponseNeedsBuild nbs
 
-    "source-dirs":[] -> do
-      res <- componentsMap lbi v distdir $$ \_ _ bi -> return $ hsSourceDirs bi
-      return $ Just $ ChResponseCompList (res ++ [(ChSetupHsName, [])])
+      let comp_name = map fst ciGhcOptions
+          uiComponents = Map.fromList
+                      $ map (ciComponentName &&& id)
+                      $ getZipList
+                      $ ChComponentInfo
+                     <$> ZipList comp_name
+                     <*> ZipList (map snd ciGhcOptions)
+                     <*> ZipList (map snd ciGhcSrcOptions)
+                     <*> ZipList (map snd ciGhcPkgOptions)
+                     <*> ZipList (map snd ciGhcLangOptions)
+                     <*> ZipList (map snd ciSourceDirs)
+                     <*> ZipList (map snd ciEntrypoints)
+                     <*> ZipList (map snd ciNeedsBuildOutput)
 
-    "print-lbi":flags ->
-      case flags of
-        ["--human"] -> print lbi >> return Nothing
-        []          -> return $ Just $ ChResponseLbi $ show lbi
+      return uiComponents
 
-    cmd:_ | not (cmd `elem` commands) ->
-            errMsg ("Unknown command: " ++ cmd) >> usage >> exitFailure
-    _ ->
-            errMsg "Invalid usage!" >> usage >> exitFailure
 
+flagName' :: Distribution.PackageDescription.Flag -> String
 flagName' = unFlagName . flagName
 
 -- getLibrary :: PackageDescription -> Library
@@ -460,6 +454,10 @@ flagName' = unFlagName . flagName
 --   withLib pd (writeIORef lr)
 --   readIORef lr
 
+getLibraryClbi
+    :: PackageDescription
+    -> LocalBuildInfo
+    -> Maybe (Library, ComponentLocalBuildInfo)
 getLibraryClbi pd lbi = unsafePerformIO $ do
   lr <- newIORef Nothing
 
@@ -469,15 +467,6 @@ getLibraryClbi pd lbi = unsafePerformIO $ do
   readIORef lr
 
 
-getExeClbi pd lbi = unsafePerformIO $ do
-  lr <- newIORef Nothing
-
-  withExeLBI pd lbi $ \ exe clbi ->
-      writeIORef lr $ Just (exe,clbi)
-
-  readIORef lr
-
-
 componentsMap :: LocalBuildInfo
               -> Verbosity
               -> FilePath
@@ -493,20 +482,23 @@ componentsMap lbi _v _distdir f = do
 
     -- withComponentsLBI is deprecated but also exists in very old versions
     -- it's equivalent to withAllComponentsInBuildOrder in newer versions
-    withComponentsLBI pd lbi $ \c clbi -> do
+    withAllComponentsInBuildOrder pd lbi $ \c clbi -> do
         let bi = componentBuildInfo c
-            name = componentNameFromComponent c
+            name = componentNameToCh $ componentNameFromComponent c
 
         l' <- readIORef lr
         r <- f c clbi bi
-#if CH_MIN_VERSION_Cabal(2,0,0)
-        writeIORef lr $ (componentNameToCh name, r):l'
-#else
-        writeIORef lr $ (componentNameToCh name, r):l'
-#endif
+        writeIORef lr $ (name, r) : l'
 
     reverse <$> readIORef lr
 
+componentOptions'
+    :: (LocalBuildInfo, Verbosity, FilePath)
+    -> Bool
+    -> [String]
+    -> (LocalBuildInfo -> Verbosity -> GhcOptions -> IO a)
+    -> (GhcOptions -> GhcOptions)
+    -> IO [(ChComponentName, a)]
 componentOptions' (lbi, v, distdir) inplaceFlag flags rf f = do
   let pd = localPkgDescr lbi
 #if CH_MIN_VERSION_Cabal(2,0,0)
@@ -529,12 +521,18 @@ componentOptions' (lbi, v, distdir) inplaceFlag flags rf f = do
 
          in rf lbi v $ nubPackageFlags $ opts' `mappend` adopts
 
+componentOptions :: (LocalBuildInfo, Verbosity, FilePath)
+                 -> Bool
+                 -> [String]
+                 -> (GhcOptions -> GhcOptions)
+                 -> IO [(ChComponentName, [String])]
 componentOptions (lbi, v, distdir) inplaceFlag flags f =
     componentOptions' (lbi, v, distdir) inplaceFlag flags renderGhcOptions' f
 
 gmModuleName :: C.ModuleName -> ChModuleName
 gmModuleName = ChModuleName . intercalate "." . components
 
+
 #if CH_MIN_VERSION_Cabal(2,0,0)
 removeInplaceDeps :: Verbosity
                   -> LocalBuildInfo
@@ -571,7 +569,7 @@ removeInplaceDeps _v lbi pd clbi includeDirs = let
              , ghcOptPackages   = ghcOptPackages   opts <> toNubListR extraDeps }
 
     libopts =
-      case (getLibraryClbi pd lbi,getExeClbi pd lbi) of
+      case (getLibraryClbi pd lbi, getExeClbi pd lbi) of
         (Just (lib, libclbi),_) | hasIdeps ->
           let
             libbi = libBuildInfo lib
@@ -594,7 +592,21 @@ removeInplaceDeps _v lbi pd clbi includeDirs = let
                  NoBuildOutput -> libopts
                  ProduceBuildOutput -> mempty { ghcOptPackageDBs = [SpecificPackageDB packageDbDir] }
   in (clbi', libopts')
+
+getExeClbi
+    :: PackageDescription
+    -> LocalBuildInfo
+    -> Maybe (Executable, ComponentLocalBuildInfo)
+getExeClbi pd lbi = unsafePerformIO $ do
+  lr <- newIORef Nothing
+
+  withExeLBI pd lbi $ \ exe clbi ->
+      writeIORef lr $ Just (exe,clbi)
+
+  readIORef lr
+
 #else
+
 removeInplaceDeps :: Verbosity
                   -> LocalBuildInfo
                   -> PackageDescription
@@ -616,10 +628,16 @@ removeInplaceDeps _v lbi pd clbi = let
         _ -> mempty
     clbi' = clbi { componentPackageDeps = deps }
   in (clbi', libopts)
+
 #endif
 
 
 #if CH_MIN_VERSION_Cabal(2,0,0)
+recursiveDepInfo
+    :: LocalBuildInfo
+    -> Verbosity
+    -> FilePath
+    -> IO (Map.Map UnitId SubDeps)
 recursiveDepInfo lbi v distdir = do
   includeDirs <- componentsMap lbi v distdir $ \c clbi bi -> do
     return (componentUnitId clbi
@@ -656,7 +674,7 @@ needsBuildOutput includeDirs unit = go [unit]
     go [] = NoBuildOutput
     go (u:us) = case Map.lookup u includeDirs of
       Nothing -> go us
-      Just (SubDeps us' sfp sci sep) ->
+      Just (SubDeps us' _sfp sci _sep) ->
         if any (isIndef . fst) sci
           then ProduceBuildOutput
           else go (us++us')
@@ -666,31 +684,32 @@ needsBuildOutput includeDirs unit = go [unit]
 -- current accumulated value, and the second one is the current sub-dependency
 -- being considered. So the bias should be to preserve the type of entrypoint
 -- from the first parameter.
+combineEp :: Maybe ChEntrypoint -> ChEntrypoint -> ChEntrypoint
 combineEp Nothing e = e
 combineEp (Just ChSetupEntrypoint) e = e
 combineEp (Just (ChLibEntrypoint es1 os1 ss1))   (ChLibEntrypoint es2 os2 ss2) = (ChLibEntrypoint (nub $ es2++es1) (nub $ os2++os1) (nub $ ss2++ss1))
-combineEp _                                    e@(ChExeEntrypoint  mi os2)     = error $ "combineEP: cannot have a sub exe:" ++ show e
+combineEp _                                    e@(ChExeEntrypoint  _mi _os2)     = error $ "combineEP: cannot have a sub exe:" ++ show e
 combineEp (Just (ChExeEntrypoint  mi os1))       (ChLibEntrypoint es2 os2 ss2) = (ChExeEntrypoint mi  (nub $ os1++es2++os2++ss2))
 
 -- no, you unconditionally always wrap the result in Just, so instead of `f x = Just y; f x = Just z` do `f x = y; f x = z` and use f as `Just . f`
 
-
-
-instantiatedGhcPackage :: (ModuleName,OpenModule) -> [(OpenUnitId, ModuleRenaming)]
-instantiatedGhcPackage (_,OpenModule oui@(DefiniteUnitId _) _) = [(oui,DefaultRenaming)]
-instantiatedGhcPackage (_, _) = []
 #endif
 
+
+initialBuildStepsForAllComponents
+    :: FilePath
+    -> PackageDescription
+    -> LocalBuildInfo
+    -> Verbosity
+    -> IO ()
 initialBuildStepsForAllComponents distdir pd lbi v =
   initialBuildSteps distdir pd lbi v
 
 
 
-
-
-
 #if !CH_MIN_VERSION_Cabal(1,25,0)
 -- CPP < 1.25
+unFlagName :: FlagName -> String
 unFlagName (FlagName n) = n
 -- mkFlagName n = FlagName n
 #endif
@@ -742,14 +761,14 @@ componentEntrypoints (CBench Benchmark {})
 #if CH_MIN_VERSION_Cabal(2,0,0)
 isInplaceCompInc :: ComponentLocalBuildInfo -> (OpenUnitId, ModuleRenaming) -> Bool
 isInplaceCompInc clbi (DefiniteUnitId uid, _mr)     = unDefUnitId uid `elem` componentInternalDeps clbi
-isInplaceCompInc clbi (IndefFullUnitId uid _, _mmr) = False
+isInplaceCompInc _clbi (IndefFullUnitId _uid _, _mmr) = False
 #endif
 
 #if CH_MIN_VERSION_Cabal(2,0,0)
-isInplaceDep :: LocalBuildInfo -> ComponentLocalBuildInfo -> (UnitId, MungedPackageId) -> Bool
-isInplaceDep lbi clbi (uid, _mpid) = uid `elem` componentInternalDeps clbi
+-- isInplaceDep :: LocalBuildInfo -> ComponentLocalBuildInfo -> (UnitId, MungedPackageId) -> Bool
+-- isInplaceDep lbi clbi (uid, _mpid) = uid `elem` componentInternalDeps clbi
 #else
-isInplaceDep :: LocalBuildInfo -> (InstalledPackageId, PackageId) -> Bool
+isInplaceDep :: LocalBuildInfo -> (UnitId, PackageId) -> Bool
 #  if CH_MIN_VERSION_Cabal(1,23,0)
 -- CPP >= 1.23
 isInplaceDep lbi (ipid, _pid) = localUnitId lbi == ipid
@@ -759,6 +778,7 @@ isInplaceDep _lbi (ipid, pid) = inplacePackageId pid == ipid
 #  endif
 #endif
 
+nubPackageFlags :: GhcOptions -> GhcOptions
 #if CH_MIN_VERSION_Cabal(1,22,0)
 -- CPP >= 1.22
 -- >= 1.22 uses NubListR
diff --git a/src/CabalHelper/Shared/InterfaceTypes.hs b/src/CabalHelper/Shared/InterfaceTypes.hs
index a108c72..0539b96 100644
--- a/src/CabalHelper/Shared/InterfaceTypes.hs
+++ b/src/CabalHelper/Shared/InterfaceTypes.hs
@@ -34,31 +34,63 @@ module CabalHelper.Shared.InterfaceTypes where
 
 import GHC.Generics
 import Data.Version
+import Data.Map.Strict (Map)
 
 data ChResponse
-    = ChResponseCompList    [(ChComponentName, [String])]
-    | ChResponseEntrypoints [(ChComponentName, ChEntrypoint)]
-    | ChResponseNeedsBuild  [(ChComponentName, NeedsBuildOutput)]
-    | ChResponseList        [String]
-    | ChResponsePkgDbs      [ChPkgDb]
-    | ChResponseLbi         String
-    | ChResponseVersion     String Version
-    | ChResponseLicenses    [(String, [(String, Version)])]
-    | ChResponseFlags       [(String, Bool)]
+    = ChResponseComponentsInfo (Map ChComponentName ChComponentInfo)
+    | ChResponseList           [String]
+    | ChResponsePkgDbs         [ChPkgDb]
+    | ChResponseLbi            String
+    | ChResponseVersion        String Version
+    | ChResponseLicenses       [(String, [(String, Version)])]
+    | ChResponseFlags          [(String, Bool)]
   deriving (Eq, Ord, Read, Show, Generic)
 
 data ChComponentName = ChSetupHsName
-                     | ChLibName
-                     | ChSubLibName String
+                     | ChLibName ChLibraryName
                      | ChFLibName String
                      | ChExeName String
                      | ChTestName String
                      | ChBenchName String
   deriving (Eq, Ord, Read, Show, Generic)
 
+data ChLibraryName = ChMainLibName
+                   | ChSubLibName String
+  deriving (Eq, Ord, Read, Show, Generic)
+
 newtype ChModuleName = ChModuleName String
     deriving (Eq, Ord, Read, Show, Generic)
 
+data ChComponentInfo = ChComponentInfo
+    { ciComponentName         :: ChComponentName
+    -- ^ The component\'s type and name
+
+    , ciGhcOptions            :: [String]
+    -- ^ Full set of GHC options, ready for loading this component into GHCi.
+
+    , ciGhcSrcOptions         :: [String]
+    -- ^ Only search path related GHC options.
+
+    , ciGhcPkgOptions         :: [String]
+    -- ^ Only package related GHC options, sufficient for things don't need to
+    -- access any home modules.
+
+    , ciGhcLangOptions        :: [String]
+    -- ^ Only Haskell language extension related options, i.e. @-XSomeExtension@
+
+    , ciSourceDirs            :: [String]
+    -- ^ A component's @source-dirs@ field, beware since if this is empty
+    -- implicit behaviour in GHC kicks in which you might have to emulate.
+
+    , ciEntrypoints           :: ChEntrypoint
+    -- ^ Modules or files Cabal would have the compiler build directly. Can be
+    -- used to compute the home module closure for a component.
+
+    , ciNeedsBuildOutput      :: NeedsBuildOutput
+    -- ^ If a component has a non-default module renaming (backpack) it cannot
+    -- be built in memory and instead needs proper build output.
+    } deriving (Eq, Ord, Read, Show)
+
 data ChEntrypoint = ChSetupEntrypoint -- ^ Almost like 'ChExeEntrypoint' but
                                       -- @main-is@ could either be @"Setup.hs"@
                                       -- or @"Setup.lhs"@. Since we don't know