[project @ 2004-02-10 17:55:24 by simonpj]

Always expose newtypes, at least for now (see comments)

diff --git a/ghc/compiler/iface/MkIface.lhs b/ghc/compiler/iface/MkIface.lhs
index 39c3734..019b44f 100644 (file)
--- a/ghc/compiler/iface/MkIface.lhs
+++ b/ghc/compiler/iface/MkIface.lhs
@@ -208,7 +208,7 @@ import OccName              ( OccName, OccEnv, mkOccEnv, lookupOccEnv, emptyOccEnv, extendOc
                          extendOccSet, extendOccSetList,
                          isEmptyOccSet, intersectOccSet, intersectsOccSet,
                          occNameFS, isTcOcc )
-import TyCon           ( visibleDataCons, tyConDataCons )
+import TyCon           ( visibleDataCons, tyConDataCons, isNewTyCon )
 import Class           ( classSelIds )
 import DataCon         ( dataConName )
 import Module          ( Module, ModuleName, moduleNameFS, moduleName, isHomeModule,
@@ -341,8 +341,16 @@ mkIface hsc_env location maybe_old_iface
 
                                              
 isAbstractThing :: NameSet -> TyThing -> Bool
-isAbstractThing exports (ATyCon tc) = not (any exported_data_con (tyConDataCons tc))
-  where                -- Don't expose rep if no datacons are exported
+isAbstractThing exports (ATyCon tc) 
+  =  not (isNewTyCon tc)  
+       -- Always expose the rep for newtypes.  This is for a
+       -- very annoying reason.  'Foreign import' is meant to
+       -- be able to look through newtypes transparently, but it
+       -- can only do that if it can "see" the newtype representation
+       -- So, for now anyway, we always expose the rep of newtypes. Sigh.
+  && not (any exported_data_con (tyConDataCons tc))
+       -- Don't expose rep if no datacons are exported
+  where                
      exported_data_con con = dataConName con `elemNameSet` exports
                
 isAbstractThing exports (AClass cls) = not (any exported_class_op (classSelIds cls))