Make 'getModSummary' deterministic.

[ghc-hetmet.git] / compiler / main / GHC.hs

diff --git a/compiler/main/GHC.hs b/compiler/main/GHC.hs
index f2f97d8..38208a0 100644 (file)
--- a/compiler/main/GHC.hs
+++ b/compiler/main/GHC.hs
@@ -298,9 +298,6 @@ import Data.IORef
 import System.FilePath
 import System.IO
 import System.IO.Error ( try, isDoesNotExistError )
-#if __GLASGOW_HASKELL__ >= 609
-import Data.Typeable (cast)
-#endif
 import Prelude hiding (init)
 
 
@@ -314,38 +311,22 @@ import Prelude hiding (init)
 defaultErrorHandler :: (ExceptionMonad m, MonadIO m) => DynFlags -> m a -> m a
 defaultErrorHandler dflags inner =
   -- top-level exception handler: any unrecognised exception is a compiler bug.
-#if __GLASGOW_HASKELL__ < 609
   ghandle (\exception -> liftIO $ do
            hFlush stdout
-           case exception of
-                -- an IO exception probably isn't our fault, so don't panic
-                IOException _ ->
-                  fatalErrorMsg dflags (text (show exception))
-                AsyncException StackOverflow ->
-                  fatalErrorMsg dflags (text "stack overflow: use +RTS -K<size> to increase it")
-                ExitException _ -> throw exception
-                _ ->
-                  fatalErrorMsg dflags (text (show (Panic (show exception))))
-           exitWith (ExitFailure 1)
-         ) $
-#else
-  ghandle (\(SomeException exception) -> liftIO $ do
-           hFlush stdout
-           case cast exception of
+           case fromException exception of
                 -- an IO exception probably isn't our fault, so don't panic
                 Just (ioe :: IOException) ->
                   fatalErrorMsg dflags (text (show ioe))
-                _ -> case cast exception of
+                _ -> case fromException exception of
                      Just StackOverflow ->
                          fatalErrorMsg dflags (text "stack overflow: use +RTS -K<size> to increase it")
-                     _ -> case cast exception of
+                     _ -> case fromException exception of
                           Just (ex :: ExitCode) -> throw ex
                           _ ->
                               fatalErrorMsg dflags
                                   (text (show (Panic (show exception))))
            exitWith (ExitFailure 1)
          ) $
-#endif
 
   -- program errors: messages with locations attached.  Sometimes it is
   -- convenient to just throw these as exceptions.
@@ -1017,17 +998,18 @@ type TypecheckedSource = LHsBinds Id
 -- | Return the 'ModSummary' of a module with the given name.
 --
 -- The module must be part of the module graph (see 'hsc_mod_graph' and
--- 'ModuleGraph').  If this is not the case, this function will throw an
+-- 'ModuleGraph').  If this is not the case, this function will throw a
 -- 'GhcApiError'.
 --
--- Note that the module graph may contain several 'ModSummary's matching the
--- same name (for example both a @.hs@ and a @.hs-boot@).
+-- This function ignores boot modules and requires that there is only one
+-- non-boot module with the given name.
 getModSummary :: GhcMonad m => ModuleName -> m ModSummary
 getModSummary mod = do
    mg <- liftM hsc_mod_graph getSession
-   case [ ms | ms <- mg, ms_mod_name ms == mod ] of
+   case [ ms | ms <- mg, ms_mod_name ms == mod, not (isBootSummary ms) ] of
      [] -> throw $ mkApiErr (text "Module not part of module graph")
-     (ms:_) -> return ms
+     [ms] -> return ms
+     multiple -> throw $ mkApiErr (text "getModSummary is ambiguous: " <+> ppr multiple)
 
 -- | Parse a module.
 --