Implement clean target.

Fix #131.

shaking-up-ghc.cabal

@@ -39,6 +39,7 @@ executable ghc-shake
                        , Rules
                        , Rules.Actions
                        , Rules.Cabal
+                       , Rules.Clean
                        , Rules.Compile
                        , Rules.Config
                        , Rules.Data

src/Main.hs

@@ -6,6 +6,7 @@ import qualified Base
 import           CmdLineFlag
 import qualified Rules
 import qualified Rules.Cabal
+import qualified Rules.Clean
 import qualified Rules.Config
 import qualified Rules.Generate
 import qualified Rules.Gmp
@@ -24,6 +25,7 @@ main = shakeArgsWith options flags $ \cmdLineFlags targets -> do
     rules :: Rules ()
     rules = mconcat
         [ Rules.Cabal.cabalRules
+        , Rules.Clean.cleanRules
         , Rules.Config.configRules
         , Rules.Generate.copyRules
         , Rules.Generate.generateRules

src/Rules/Clean.hs

+module Rules.Clean (cleanRules) where
+
+import Base
+import Package
+import Rules.Generate
+import Settings.Packages
+import Settings.Paths
+import Settings.User
+import Stage
+
+cleanRules :: Rules ()
+cleanRules = do
+    "clean" ~> do
+        putBuild $ "| Remove files in " ++ buildRootPath ++ "..."
+        removeFilesAfter buildRootPath ["//*"]
+        putBuild $ "| Remove files in " ++ programInplacePath ++ "..."
+        removeFilesAfter programInplacePath ["//*"]
+        putBuild $ "| Remove files in inplace/lib..."
+        removeFilesAfter "inplace/lib" ["//*"]
+        putBuild $ "| Remove files in " ++ derivedConstantsPath ++ "..."
+        removeFilesAfter derivedConstantsPath ["//*"]
+        forM_ includesDependencies $ \file -> do
+            putBuild $ "| Remove " ++ file
+            removeFileIfExists file
+        putBuild $ "| Remove files generated by ghc-cabal..."
+        forM_ knownPackages $ \pkg ->
+            forM_ [Stage0 ..] $ \stage -> do
+                let dir = pkgPath pkg -/- targetDirectory stage pkg
+                removeDirectoryIfExists dir
+        putSuccess $ "| Done. "

src/Rules/Generate.hs

 module Rules.Generate (
     generatePackageCode, generateRules, installTargets, copyRules,
-    derivedConstantsPath, generatedDependencies
+    includesDependencies, derivedConstantsPath, generatedDependencies
     ) where
 
 import Base