GhcApiError now contains a String, not an SDoc

compiler/main/GHC.hs

@@ -719,9 +719,11 @@ getModSummary :: GhcMonad m => ModuleName -> m ModSummary
 getModSummary mod = do
    mg <- liftM hsc_mod_graph getSession
    case [ ms | ms <- mg, ms_mod_name ms == mod, not (isBootSummary ms) ] of
-     [] -> throw $ mkApiErr (text "Module not part of module graph")
+     [] -> do dflags <- getDynFlags
+              throw $ mkApiErr dflags (text "Module not part of module graph")
      [ms] -> return ms
-     multiple -> throw $ mkApiErr (text "getModSummary is ambiguous: " <+> ppr multiple)
+     multiple -> do dflags <- getDynFlags
+                    throw $ mkApiErr dflags (text "getModSummary is ambiguous: " <+> ppr multiple)
 
 -- | Parse a module.
 --
@@ -1182,7 +1184,8 @@ getModuleSourceAndFlags :: GhcMonad m => Module -> m (String, StringBuffer, DynF
 getModuleSourceAndFlags mod = do
   m <- getModSummary (moduleName mod)
   case ml_hs_file $ ms_location m of
-    Nothing -> throw $ mkApiErr (text "No source available for module " <+> ppr mod)
+    Nothing -> do dflags <- getDynFlags
+                  throw $ mkApiErr dflags (text "No source available for module " <+> ppr mod)
     Just sourceFile -> do
         source <- liftIO $ hGetStringBuffer sourceFile
         return (sourceFile, source, ms_hspp_opts m)

compiler/main/HscTypes.lhs

@@ -181,8 +181,8 @@ mkSrcErr = SourceError
 srcErrorMessages :: SourceError -> ErrorMessages
 srcErrorMessages (SourceError msgs) = msgs
 
-mkApiErr :: SDoc -> GhcApiError
-mkApiErr = GhcApiError
+mkApiErr :: DynFlags -> SDoc -> GhcApiError
+mkApiErr _ msg = GhcApiError (showSDoc msg)
 
 throwOneError :: MonadIO m => ErrMsg -> m ab
 throwOneError err = liftIO $ throwIO $ mkSrcErr $ unitBag err
@@ -221,11 +221,11 @@ handleSourceError handler act =
   gcatch act (\(e :: SourceError) -> handler e)
 
 -- | An error thrown if the GHC API is used in an incorrect fashion.
-newtype GhcApiError = GhcApiError SDoc
+newtype GhcApiError = GhcApiError String
   deriving Typeable
 
 instance Show GhcApiError where
-  show (GhcApiError msg) = showSDoc msg
+  show (GhcApiError msg) = msg
 
 instance Exception GhcApiError