Merge pull request #255 from bgamari/ghc7.8

GHC 7.8: Fix sandbox support  and some debugging conveniences

ghc-parser/build-parser.sh

-#!/bin/sh -e
+#!/bin/bash -e
 # Called from Setup.hs.
 
 function make_parser {

src/IHaskell/Eval/Evaluate.hs

@@ -77,9 +77,14 @@ import Data.Version (versionBranch)
 
 data ErrorOccurred = Success | Failure deriving (Show, Eq)
 
+-- | Enable debugging output
 debug :: Bool
 debug = False
 
+-- | Set GHC's verbosity for debugging
+ghcVerbosity :: Maybe Int
+ghcVerbosity = Nothing -- Just 5
+
 ignoreTypePrefixes :: [String]
 ignoreTypePrefixes = ["GHC.Types", "GHC.Base", "GHC.Show", "System.IO",
                       "GHC.Float", ":Interactive", "GHC.Num", "GHC.IO",
@@ -119,18 +124,13 @@ globalImports =
 -- is handled specially, which cannot be done in a testing environment.
 interpret :: Bool -> Interpreter a -> IO a
 interpret allowedStdin action = runGhc (Just libdir) $ do
-  initGhci
-
   -- If we're in a sandbox, add the relevant package database
-  dflags <- getSessionDynFlags
   sandboxPackages <- liftIO getSandboxPackageConf
-  let pkgConfs = case sandboxPackages of
-        Nothing -> extraPkgConfs dflags
-        Just path ->
-          let pkg  = PkgConfFile path in
-            (pkg:) . extraPkgConfs dflags
-
-  void $ setSessionDynFlags $ dflags { extraPkgConfs = pkgConfs }
+  initGhci sandboxPackages
+  case ghcVerbosity of
+    Just verb -> do dflags <- getSessionDynFlags
+                    void $ setSessionDynFlags $ dflags { verbosity = verb }
+    Nothing   -> return ()
 
   initializeImports
 

src/IHaskell/Eval/Util.hs

@@ -131,18 +131,28 @@ doc sdoc = do
 -- @NoMonomorphismRestriction@), sets the target to interpreted, link in
 -- memory, sets a reasonable output width, and potentially a few other
 -- things. It should be invoked before other functions from this module.
-initGhci :: GhcMonad m => m ()
-initGhci = do
+--
+-- We also require that the sandbox PackageConf (if any) is passed here
+-- as setSessionDynFlags will read the package database the first time
+-- (and only the first time) it is called.
+initGhci :: GhcMonad m => Maybe String -> m ()
+initGhci sandboxPackages = do
   -- Initialize dyn flags.
   -- Start with -XExtendedDefaultRules and -XNoMonomorphismRestriction.
   originalFlags <- getSessionDynFlags
   let flag = flip xopt_set
       unflag = flip xopt_unset
       dflags = flag Opt_ExtendedDefaultRules . unflag Opt_MonomorphismRestriction $ originalFlags
+      pkgConfs = case sandboxPackages of
+        Nothing -> extraPkgConfs originalFlags
+        Just path ->
+          let pkg  = PkgConfFile path in
+            (pkg:) . extraPkgConfs originalFlags
 
   void $ setSessionDynFlags $ dflags { hscTarget = HscInterpreted,
                                        ghcLink = LinkInMemory,
-                                       pprCols = 300 }
+                                       pprCols = 300,
+                                       extraPkgConfs = pkgConfs }
 
 -- | Evaluate a single import statement.
 -- If this import statement is importing a module which was previously