Fix literally everything :)

Sorry for the megacommit

- Seperate modules into:
  - Compiletime, modules which are only used while building the package
  - Runtime, modues included in the wrapper binary to be compiled on the
    users machine at runtime
  - Shared, modues used in both contexts
- Refactor runtime compilation
  - Completely revamp output paths
  - Don't chdir when invoking ghc
- Require cabal-version 1.14 in cabal file

3 files changed, 235 insertions, 0 deletions

diff --git a/CabalHelper/Shared/Common.hs b/CabalHelper/Shared/Common.hs
new file mode 100644
index 0000000..3d79f90
--- /dev/null
+++ b/CabalHelper/Shared/Common.hs
@@ -0,0 +1,106 @@
+-- cabal-helper: Simple interface to Cabal's configuration state
+-- Copyright (C) 2015  Daniel Gröber <dxld ÄT darkboxed DOT org>
+--
+-- This program is free software: you can redistribute it and/or modify
+-- it under the terms of the GNU Affero General Public License as published by
+-- the Free Software Foundation, either version 3 of the License, or
+-- (at your option) any later version.
+--
+-- This program is distributed in the hope that it will be useful,
+-- but WITHOUT ANY WARRANTY; without even the implied warranty of
+-- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+-- GNU Affero General Public License for more details.
+--
+-- You should have received a copy of the GNU Affero General Public License
+-- along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+{-# LANGUAGE DeriveDataTypeable, OverloadedStrings #-}
+module CabalHelper.Shared.Common where
+
+import Control.Applicative
+import Control.Exception as E
+import Control.Monad
+import Data.List
+import Data.Maybe
+import Data.Version
+import Data.Typeable
+import Data.ByteString (ByteString)
+import qualified Data.ByteString as BS
+import qualified Data.ByteString.Char8 as BS8
+import System.Environment
+import System.IO
+import System.Exit
+import System.Directory
+import System.FilePath
+import Text.ParserCombinators.ReadP
+import Prelude
+
+data Panic = Panic String deriving (Typeable, Show)
+instance Exception Panic
+
+panic :: String -> a
+panic msg = throw $ Panic msg
+
+handlePanic :: IO a -> IO a
+handlePanic action =
+    action `E.catch` \(Panic msg) -> errMsg msg >> exitFailure
+
+errMsg :: String -> IO ()
+errMsg str = do
+  prog <- getProgName
+  hPutStrLn stderr $ prog ++ ": " ++ str
+
+-- | @getCabalConfigHeader "dist/setup-config"@ returns the cabal version and
+-- compiler version
+getCabalConfigHeader :: FilePath -> IO (Maybe (Version, (ByteString, Version)))
+getCabalConfigHeader file = bracket (openFile file ReadMode) hClose $ \h -> do
+  parseHeader <$> BS.hGetLine h
+
+parseHeader :: ByteString -> Maybe (Version, (ByteString, Version))
+parseHeader header = case BS8.words header of
+  ["Saved", "package", "config", "for", _pkgId ,
+   "written", "by", cabalId,
+   "using", compId]
+    -> liftM2 (,) (snd <$> parsePkgId cabalId) (parsePkgId compId)
+  _ -> Nothing
+
+parsePkgId :: ByteString -> Maybe (ByteString, Version)
+parsePkgId bs =
+    case BS8.split '-' bs of
+      [pkg, vers] -> Just (pkg, parseVer $ BS8.unpack vers)
+      _ -> Nothing
+
+parseVer :: String -> Version
+parseVer vers = runReadP parseVersion vers
+
+majorVer :: Version -> Version
+majorVer (Version b _) = Version (take 2 b) []
+
+sameMajorVersionAs :: Version -> Version -> Bool
+sameMajorVersionAs a b = majorVer a == majorVer b
+
+runReadP :: ReadP t -> String -> t
+runReadP p i = case filter ((=="") . snd) $ readP_to_S p i of
+                 (a,""):[] -> a
+                 _ -> error $ "Error parsing: " ++ show i
+
+appDataDir :: IO FilePath
+appDataDir = (</> "cabal-helper") <$> getAppUserDataDirectory "ghc-mod"
+
+isCabalFile :: FilePath -> Bool
+isCabalFile f = takeExtension' f == ".cabal"
+
+takeExtension' :: FilePath -> String
+takeExtension' p =
+    if takeFileName p == takeExtension p
+      then "" -- just ".cabal" is not a valid cabal file
+      else takeExtension p
+
+replace :: String -> String -> String -> String
+replace n r hs' = go "" hs'
+ where
+   go acc h
+       | take (length n) h == n =
+           reverse acc ++ r ++ drop (length n) h
+   go acc (h:hs) = go (h:acc) hs
+   go acc [] = reverse acc
diff --git a/CabalHelper/Shared/Sandbox.hs b/CabalHelper/Shared/Sandbox.hs
new file mode 100644
index 0000000..3523edc
--- /dev/null
+++ b/CabalHelper/Shared/Sandbox.hs
@@ -0,0 +1,56 @@
+module CabalHelper.Shared.Sandbox where
+
+import Control.Applicative
+import Data.Char
+import Data.Maybe
+import Data.List
+import Data.Version
+import System.FilePath
+import System.Directory
+import Prelude
+
+import qualified Data.Traversable as T
+
+-- | Get the path to the sandbox package-db in a project
+getSandboxPkgDb :: FilePath
+             -- ^ Path to the cabal package root directory (containing the
+             -- @cabal.sandbox.config@ file)
+             -> String
+             -- ^ Cabal build platform, i.e. @buildPlatform@
+             -> Version
+             -- ^ GHC version (@cProjectVersion@ is your friend)
+             -> IO (Maybe FilePath)
+getSandboxPkgDb d platform ghcVer = do
+  mConf <- T.traverse readFile =<< mightExist (d </> "cabal.sandbox.config")
+  return $ fixPkgDbVer <$> (extractSandboxDbDir =<< mConf)
+
+ where
+   fixPkgDbVer dir =
+       case takeFileName dir == ghcSandboxPkgDbDir platform ghcVer of
+         True -> dir
+         False -> takeDirectory dir </> ghcSandboxPkgDbDir platform ghcVer
+
+ghcSandboxPkgDbDir :: String -> Version -> String
+ghcSandboxPkgDbDir platform ghcVer =
+   platform ++ "-ghc-" ++ showVersion ghcVer ++ "-packages.conf.d"
+
+-- | Extract the sandbox package db directory from the cabal.sandbox.config
+-- file. Exception is thrown if the sandbox config file is broken.
+extractSandboxDbDir :: String -> Maybe FilePath
+extractSandboxDbDir conf = extractValue <$> parse conf
+  where
+    key = "package-db:"
+    keyLen = length key
+
+    parse = listToMaybe . filter (key `isPrefixOf`) . lines
+    extractValue = CabalHelper.Shared.Sandbox.dropWhileEnd isSpace . dropWhile isSpace . drop keyLen
+
+
+mightExist :: FilePath -> IO (Maybe FilePath)
+mightExist f = do
+  exists <- doesFileExist f
+  return $ if exists then (Just f) else (Nothing)
+
+-- dropWhileEnd is not provided prior to base 4.5.0.0.
+dropWhileEnd :: (a -> Bool) -> [a] -> [a]
+dropWhileEnd p = foldr (\x xs -> if p x && null xs then [] else x : xs) []
diff --git a/CabalHelper/Shared/Types.hs b/CabalHelper/Shared/Types.hs
new file mode 100644
index 0000000..18d532b
--- /dev/null
+++ b/CabalHelper/Shared/Types.hs
@@ -0,0 +1,73 @@
+-- cabal-helper: Simple interface to Cabal's configuration state
+-- Copyright (C) 2015  Daniel Gröber <dxld ÄT darkboxed DOT org>
+--
+-- This program is free software: you can redistribute it and/or modify
+-- it under the terms of the GNU Affero General Public License as published by
+-- the Free Software Foundation, either version 3 of the License, or
+-- (at your option) any later version.
+--
+-- This program is distributed in the hope that it will be useful,
+-- but WITHOUT ANY WARRANTY; without even the implied warranty of
+-- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+-- GNU Affero General Public License for more details.
+--
+-- You should have received a copy of the GNU Affero General Public License
+-- along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+{-# LANGUAGE DeriveGeneric, DeriveDataTypeable, DefaultSignatures #-}
+module CabalHelper.Shared.Types where
+
+import GHC.Generics
+import Data.Version
+
+newtype ChModuleName = ChModuleName String
+    deriving (Eq, Ord, Read, Show, Generic)
+
+data ChComponentName = ChSetupHsName
+                     | ChLibName
+                     | ChSubLibName String
+                     | ChFLibName String
+                     | ChExeName String
+                     | ChTestName String
+                     | ChBenchName String
+  deriving (Eq, Ord, Read, Show, Generic)
+
+data ChResponse
+    = ChResponseCompList    [(ChComponentName, [String])]
+    | ChResponseEntrypoints [(ChComponentName, ChEntrypoint)]
+    | ChResponseList        [String]
+    | ChResponsePkgDbs      [ChPkgDb]
+    | ChResponseLbi         String
+    | ChResponseVersion     String Version
+    | ChResponseLicenses    [(String, [(String, Version)])]
+    | ChResponseFlags       [(String, Bool)]
+  deriving (Eq, Ord, Read, Show, Generic)
+
+data ChEntrypoint = ChSetupEntrypoint -- ^ Almost like 'ChExeEntrypoint' but
+                                      -- @main-is@ could either be @"Setup.hs"@
+                                      -- or @"Setup.lhs"@. Since we don't know
+                                      -- where the source directory is you have
+                                      -- to find these files.
+                  | ChLibEntrypoint { chExposedModules :: [ChModuleName]
+                                    , chOtherModules   :: [ChModuleName]
+                                    }
+                  | ChExeEntrypoint { chMainIs         :: FilePath
+                                    , chOtherModules   :: [ChModuleName]
+                                    } deriving (Eq, Ord, Read, Show, Generic)
+
+data ChPkgDb = ChPkgGlobal
+             | ChPkgUser
+             | ChPkgSpecific FilePath
+               deriving (Eq, Ord, Read, Show, Generic)
+
+data Options = Options {
+          verbose       :: Bool
+        , ghcProgram    :: FilePath
+        , ghcPkgProgram :: FilePath
+        , cabalProgram  :: FilePath
+        , cabalVersion  :: Maybe Version
+        , cabalPkgDb    :: Maybe FilePath
+}
+
+defaultOptions :: Options
+defaultOptions = Options False "ghc" "ghc-pkg" "cabal" Nothing Nothing