X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=compiler%2Fmain%2FFinder.lhs;h=29e1fb6c2125f9296823add0b12471833c33d67d;hb=9c84f11b774960077d33d94a23ebc42af79d2ec4;hp=a1558c87c674114c353209b90f075c97a219d63e;hpb=8209ac8cf9f7aeeef1f590cc6d93940afec7fbad;p=ghc-hetmet.git

diff --git a/compiler/main/Finder.lhs b/compiler/main/Finder.lhs
index a1558c8..29e1fb6 100644
--- a/compiler/main/Finder.lhs
+++ b/compiler/main/Finder.lhs
@@ -32,14 +32,15 @@ import Packages
 import FastString
 import Util
 import PrelNames        ( gHC_PRIM )
-import DynFlags		( DynFlags(..), isOneShot, GhcMode(..) )
+import DynFlags
 import Outputable
-import FiniteMap
-import LazyUniqFM
+import UniqFM
 import Maybes		( expectJust )
+import Exception        ( evaluate )
 
+import Distribution.Text
 import Distribution.Package hiding (PackageId)
-import Data.IORef	( IORef, writeIORef, readIORef, modifyIORef )
+import Data.IORef	( IORef, writeIORef, readIORef, atomicModifyIORef )
 import System.Directory
 import System.FilePath
 import Control.Monad
@@ -66,6 +67,7 @@ type BaseName = String	-- Basename of file
 -- assumed to not move around during a session.
 flushFinderCaches :: HscEnv -> IO ()
 flushFinderCaches hsc_env = do
+  -- Ideally the update to both caches be a single atomic operation.
   writeIORef fc_ref emptyUFM
   flushModLocationCache this_pkg mlc_ref
  where
@@ -75,23 +77,27 @@ flushFinderCaches hsc_env = do
 
 flushModLocationCache :: PackageId -> IORef ModLocationCache -> IO ()
 flushModLocationCache this_pkg ref = do
-  fm <- readIORef ref
-  writeIORef ref $! filterFM is_ext fm
+  atomicModifyIORef ref $ \fm -> (filterModuleEnv is_ext fm, ())
+  _ <- evaluate =<< readIORef ref
   return ()
   where is_ext mod _ | modulePackageId mod /= this_pkg = True
 		     | otherwise = False
 
 addToFinderCache :: IORef FinderCache -> ModuleName -> FindResult -> IO ()
-addToFinderCache       ref key val = modifyIORef ref $ \c -> addToUFM c key val
+addToFinderCache ref key val =
+  atomicModifyIORef ref $ \c -> (addToUFM c key val, ())
 
 addToModLocationCache :: IORef ModLocationCache -> Module -> ModLocation -> IO ()
-addToModLocationCache  ref key val = modifyIORef ref $ \c -> addToFM c key val
+addToModLocationCache ref key val =
+  atomicModifyIORef ref $ \c -> (extendModuleEnv c key val, ())
 
 removeFromFinderCache :: IORef FinderCache -> ModuleName -> IO ()
-removeFromFinderCache      ref key = modifyIORef ref $ \c -> delFromUFM c key
+removeFromFinderCache ref key =
+  atomicModifyIORef ref $ \c -> (delFromUFM c key, ())
 
 removeFromModLocationCache :: IORef ModLocationCache -> Module -> IO ()
-removeFromModLocationCache ref key = modifyIORef ref $ \c -> delFromFM c key
+removeFromModLocationCache ref key =
+  atomicModifyIORef ref $ \c -> (delModuleEnv c key, ())
 
 lookupFinderCache :: IORef FinderCache -> ModuleName -> IO (Maybe FindResult)
 lookupFinderCache ref key = do 
@@ -102,7 +108,7 @@ lookupModLocationCache :: IORef ModLocationCache -> Module
                        -> IO (Maybe ModLocation)
 lookupModLocationCache ref key = do
    c <- readIORef ref
-   return $! lookupFM c key
+   return $! lookupModuleEnv c key
 
 -- -----------------------------------------------------------------------------
 -- The two external entry points
@@ -599,7 +605,17 @@ cantFindErr cannot_find _ dflags mod_name find_result
                hang (ptext (sLit "locations searched:")) 2 $ vcat (map text files)
         
     pkg_hidden pkg =
-        ptext (sLit "it is a member of the hidden package") <+> quotes (ppr pkg)
+        ptext (sLit "It is a member of the hidden package") <+> quotes (ppr pkg)
+        <> dot $$ cabal_pkg_hidden_hint pkg
+    cabal_pkg_hidden_hint pkg
+     | dopt Opt_BuildingCabalPackage dflags
+        = case simpleParse (packageIdString pkg) of
+          Just pid ->
+              ptext (sLit "Perhaps you need to add") <+>
+              quotes (text (display (pkgName pid))) <+>
+              ptext (sLit "to the build-depends in your .cabal file.")
+          Nothing -> empty
+     | otherwise = empty
 
     mod_hidden pkg =
         ptext (sLit "it is a hidden module in the package") <+> quotes (ppr pkg)