[project @ 2000-11-30 15:46:01 by simonpj]

[ghc-hetmet.git] / ghc / compiler / rename / RnSource.lhs

diff --git a/ghc/compiler/rename/RnSource.lhs b/ghc/compiler/rename/RnSource.lhs
index fff5f92..11846d6 100644 (file)
--- a/ghc/compiler/rename/RnSource.lhs
+++ b/ghc/compiler/rename/RnSource.lhs
@@ -321,6 +321,7 @@ rnTyClDecl (TySynonym {tcdName = name, tcdTyVars = tyvars, tcdSynRhs = ty, tcdLo
 
        -- For H98 we do *not* universally quantify on the RHS of a synonym
        -- Silently discard context... but the tyvars in the rest won't be in scope
+       -- In interface files all types are quantified, so this is a no-op
     unquantify glaExts (HsForAllTy Nothing ctxt ty) | glaExts = ty
     unquantify glaExys ty                                    = ty
 
@@ -396,12 +397,18 @@ rnClassOp clas clas_tyvars clas_fds sig@(ClassOpSig op dm_stuff ty locn)
     returnRn (ClassOpSig op_name dm_stuff' new_ty locn)
 
 rnClassBinds :: RdrNameTyClDecl -> RenamedTyClDecl -> RnMS (RenamedTyClDecl, FreeVars)
-  -- Rename the mbinds only; the rest is done already
-rnClassBinds (ClassDecl {tcdMeths = Nothing}) rn_cls_decl
-  = returnRn (rn_cls_decl, emptyFVs)   -- No meth binds; decl came from interface file
-
-rnClassBinds (ClassDecl {tcdMeths = Just mbinds})                              -- Get mbinds from here
-            rn_cls_decl@(ClassDecl {tcdTyVars = tyvars, tcdLoc = src_loc})     -- Everything else is here
+rnClassBinds (ClassDecl {tcdMeths = Nothing})
+ rn_cls_decl@(ClassDecl {tcdSigs = sigs})
+  -- No method bindings, so this class decl comes from an interface file, 
+  -- However we want to treat the default-method names as free (they should
+  -- be defined somewhere else).  [In source code this is not so; the class
+  -- decl will bind whatever default-methods are necessary.]
+  = returnRn (rn_cls_decl, mkFVs [v | ClassOpSig _ (DefMeth v) _ _ <- sigs])
+
+rnClassBinds (ClassDecl {tcdMeths = Just mbinds})              -- Get mbinds from here
+ rn_cls_decl@(ClassDecl {tcdTyVars = tyvars, tcdLoc = src_loc})        -- Everything else is here
+  -- There are some default-method bindings (abeit possibly empty) so 
+  -- this is a source-code class declaration
   =    -- The newLocals call is tiresome: given a generic class decl
        --      class C a where
        --        op :: a -> a