Make 'getModSummary' deterministic.

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

diff --git a/compiler/main/GHC.hs b/compiler/main/GHC.hs
index b023885..38208a0 100644 (file)
--- a/compiler/main/GHC.hs
+++ b/compiler/main/GHC.hs
@@ -53,6 +53,7 @@ module GHC (
         parsedSource, coreModule,
         compileToCoreModule, compileToCoreSimplified,
         compileCoreToObj,
+        getModSummary,
 
        -- * Parsing Haddock comments
        parseHaddockComment,
@@ -297,9 +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)
 
 
@@ -313,38 +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.
@@ -1013,19 +995,27 @@ type TypecheckedSource = LHsBinds Id
 --     - default methods are turned into top-level decls.
 --     - dictionary bindings
 
+-- | 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 a
+-- 'GhcApiError'.
+--
+-- 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.
 --
 -- Throws a 'SourceError' on parse error.
-parseModule :: GhcMonad m => ModuleName -> m ParsedModule
-parseModule mod = do
-   ms <- getModSummary mod
+parseModule :: GhcMonad m => ModSummary -> m ParsedModule
+parseModule ms = do
    hsc_env0 <- getSession
    let hsc_env = hsc_env0 { hsc_dflags = ms_hspp_opts ms }
    rdr_module <- parseFile hsc_env ms
@@ -1195,9 +1185,8 @@ compileCore simplify fn = do
      Just modSummary -> do
        -- Now we have the module name;
        -- parse, typecheck and desugar the module
-       let mod = ms_mod_name modSummary
        mod_guts <- coreModule `fmap`
-                      (desugarModule =<< typecheckModule =<< parseModule mod)
+                      (desugarModule =<< typecheckModule =<< parseModule modSummary)
        liftM gutsToCoreModule $
          if simplify
           then do