X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=compiler%2Frename%2FRnSource.lhs;h=8f4c1d337e3efef48d0b837d541331a838512820;hb=a835e9faf19400aa6b7999b6f64e60cb1c7737dd;hp=9a92f84b59b5f8c8f364454b3987ad0d30a1ecdd;hpb=82c4d36b187955e3cedbb11cff92688747773456;p=ghc-hetmet.git

diff --git a/compiler/rename/RnSource.lhs b/compiler/rename/RnSource.lhs
index 9a92f84..8f4c1d3 100644
--- a/compiler/rename/RnSource.lhs
+++ b/compiler/rename/RnSource.lhs
@@ -43,7 +43,7 @@ import SrcLoc		( Located(..), unLoc, noLoc )
 import DynFlags	( DynFlag(..) )
 import Maybes		( seqMaybe )
 import Maybe            ( isNothing, isJust )
-import Monad		( liftM )
+import Monad		( liftM, when )
 import BasicTypes       ( Boxity(..) )
 \end{code}
 
@@ -111,10 +111,8 @@ rnSrcDecls (HsGroup { hs_valds  = val_decls,
 	   <- mapFvRn (wrapLocFstM rnDefaultDecl) default_decls ;
 	
 	let {
-           rn_at_decls = concat 
-			   [ats | L _ (InstDecl _ _ _ ats) <- rn_inst_decls] ;
 	   rn_group = HsGroup { hs_valds  = rn_val_decls,
-			    	hs_tyclds = rn_tycl_decls ++ rn_at_decls,
+			    	hs_tyclds = rn_tycl_decls,
 			    	hs_instds = rn_inst_decls,
 			    	hs_fixds  = rn_fix_decls,
 			    	hs_depds  = [],
@@ -282,12 +280,11 @@ rnSrcInstDecl (InstDecl inst_ty mbinds uprags ats)
 	-- The typechecker (not the renamer) checks that all 
 	-- the declarations are for the right class
     let
-	at_doc   = text "In the associated types in an instance declaration"
+	at_doc   = text "In the associated types of an instance declaration"
 	at_names = map (head . tyClDeclNames . unLoc) ats
-	(_, rdrCtxt, _, _) = splitHsInstDeclTy (unLoc inst_ty)
     in
     checkDupNames at_doc at_names		`thenM_`
-    rnATDefs rdrCtxt ats			`thenM` \ (ats', at_fvs) ->
+    rnATInsts ats				`thenM` \ (ats', at_fvs) ->
 
 	-- Rename the bindings
 	-- The typechecker (not the renamer) checks that all 
@@ -333,20 +330,28 @@ rnSrcInstDecl (InstDecl inst_ty mbinds uprags ats)
 	     --     to remove the context).
 \end{code}
 
-Renaming of the associated data definitions requires adding the instance
-context, as the rhs of an AT declaration may use ATs from classes in the
-context.
+Renaming of the associated types in instances.  
+
+* We raise an error if we encounter a kind signature in an instance.
 
 \begin{code}
-rnATDefs :: HsContext RdrName -> [LTyClDecl RdrName] 
-	  -> RnM ([LTyClDecl Name], FreeVars)
-rnATDefs ctxt atDecls = 
-  mapFvRn (wrapLocFstM addCtxtAndRename) atDecls
+rnATInsts :: [LTyClDecl RdrName] -> RnM ([LTyClDecl Name], FreeVars)
+rnATInsts atDecls = 
+  mapFvRn (wrapLocFstM rnATInst) atDecls
   where
-    -- The parser won't accept anything, but a data declaration
-    addCtxtAndRename ty@TyData {tcdCtxt = L l tyCtxt} = 
-      rnTyClDecl (ty {tcdCtxt = L l (ctxt ++ tyCtxt)})
-      -- The source loc is somewhat half hearted... -=chak
+    rnATInst tydecl@TyFunction {} = 
+      do
+        addErr noKindSig
+	rnTyClDecl tydecl
+    rnATInst tydecl@TySynonym  {} = rnTyClDecl tydecl
+    rnATInst tydecl@TyData     {} = 
+      do
+        checkM (not . isKindSigDecl $ tydecl) $ addErr noKindSig
+        rnTyClDecl tydecl
+    rnATInst _                    =
+      panic "RnSource.rnATInsts: not a type declaration"
+
+noKindSig = text "Instances cannot have kind signatures"
 \end{code}
 
 For the method bindings in class and instance decls, we extend the 
@@ -501,7 +506,9 @@ rnTyClDecl (tydecl@TyData {tcdND = new_or_data, tcdCtxt = context,
   = ASSERT( isNothing sig )	-- In normal H98 form, kind signature on the 
 				-- data type is syntactically illegal
     bindTyVarsRn data_doc tyvars		$ \ tyvars' ->
-    do	{ tycon' <- lookupLocatedTopBndrRn tycon
+    do	{ tycon' <- if isIdxTyDecl tydecl
+		    then lookupLocatedOccRn     tycon -- may be imported family
+		    else lookupLocatedTopBndrRn tycon
 	; context' <- rnContext data_doc context
 	; typats' <- rnTyPats data_doc typatsMaybe
 	; (derivs', deriv_fvs) <- rn_derivs derivs
@@ -514,11 +521,17 @@ rnTyClDecl (tydecl@TyData {tcdND = new_or_data, tcdCtxt = context,
 		   delFVs (map hsLTyVarName tyvars')	$
 	     	   extractHsCtxtTyNames context'	`plusFV`
 	     	   plusFVs (map conDeclFVs condecls')   `plusFV`
-	     	   deriv_fvs) }
+	     	   deriv_fvs				`plusFV`
+		   (if isIdxTyDecl tydecl
+		   then unitFV (unLoc tycon')	-- type instance => use
+		   else emptyFVs)) 
+        }
 
   | otherwise	          -- GADT
   = ASSERT( none typatsMaybe )    -- GADTs cannot have type patterns for now
-    do	{ tycon' <- lookupLocatedTopBndrRn tycon
+    do	{ tycon' <- if isIdxTyDecl tydecl
+		    then lookupLocatedOccRn     tycon -- may be imported family
+		    else lookupLocatedTopBndrRn tycon
 	; checkTc (null (unLoc context)) (badGadtStupidTheta tycon)
     	; tyvars' <- bindTyVarsRn data_doc tyvars 
 				  (\ tyvars' -> return tyvars')
@@ -532,8 +545,12 @@ rnTyClDecl (tydecl@TyData {tcdND = new_or_data, tcdCtxt = context,
 			   tcdLName = tycon', tcdTyVars = tyvars', 
 			   tcdTyPats = Nothing, tcdKindSig = sig,
 			   tcdCons = condecls', tcdDerivs = derivs'}, 
-	     	   plusFVs (map conDeclFVs condecls') `plusFV` deriv_fvs) }
-
+	     	   plusFVs (map conDeclFVs condecls') `plusFV` 
+		   deriv_fvs			      `plusFV`
+		   (if isIdxTyDecl tydecl
+		   then unitFV (unLoc tycon')	-- type instance => use
+		   else emptyFVs))
+        }
   where
     is_vanilla = case condecls of	-- Yuk
 		     [] 		   -> True
@@ -556,15 +573,22 @@ rnTyClDecl (tydecl@TyData {tcdND = new_or_data, tcdCtxt = context,
 rnTyClDecl (tydecl@TyFunction {}) =
   rnTySig tydecl bindTyVarsRn
 
-rnTyClDecl (TySynonym {tcdLName = name, tcdTyVars = tyvars,
-		       tcdTyPats = typatsMaybe, tcdSynRhs = ty})
+rnTyClDecl tydecl@(TySynonym {tcdLName = name, tcdTyVars = tyvars,
+			      tcdTyPats = typatsMaybe, tcdSynRhs = ty})
   = bindTyVarsRn syn_doc tyvars		        $ \ tyvars' ->
-    do { name' <- lookupLocatedTopBndrRn name
+    do { name' <- if isIdxTyDecl tydecl
+		  then lookupLocatedOccRn     name -- may be imported family
+		  else lookupLocatedTopBndrRn name
        ; typats' <- rnTyPats syn_doc typatsMaybe
        ; (ty', fvs) <- rnHsTypeFVs syn_doc ty
        ; returnM (TySynonym {tcdLName = name', tcdTyVars = tyvars', 
 			     tcdTyPats = typats', tcdSynRhs = ty'},
-	          delFVs (map hsLTyVarName tyvars') fvs) }
+	          delFVs (map hsLTyVarName tyvars') $
+		  fvs			      `plusFV`
+		   (if isIdxTyDecl tydecl
+		   then unitFV (unLoc name')	-- type instance => use
+		   else emptyFVs))
+       }
   where
     syn_doc = text "In the declaration for type synonym" <+> quotes (ppr name)
 
@@ -751,7 +775,8 @@ rnTySig (tydecl@TyData {tcdCtxt = context, tcdLName = tycon,
 			    tcdTyPats = Nothing, tcdKindSig = sig, 
 			    tcdCons = [], tcdDerivs = Nothing}, 
 		    delFVs (map hsLTyVarName tyvars') $
-	     	    extractHsCtxtTyNames context') } }
+	     	    extractHsCtxtTyNames context') 
+         } }
       where
 
 rnTySig (tydecl@TyFunction {tcdLName = tycon, tcdTyVars = tyvars, 
@@ -762,26 +787,32 @@ rnTySig (tydecl@TyFunction {tcdLName = tycon, tcdTyVars = tyvars,
 	 ; tycon' <- lookupLocatedTopBndrRn tycon
 	 ; returnM (TyFunction {tcdLName = tycon', tcdTyVars = tyvars',
 			        tcdIso = tcdIso tydecl, tcdKind = sig}, 
-		    emptyFVs) } }
+		    emptyFVs) 
+         } }
 
 ksig_doc tycon = text "In the kind signature for" <+> quotes (ppr tycon)
 needOneIdx = text "Kind signature requires at least one type index"
 
 -- Rename associated type declarations (in classes)
 --
--- * This can be data declarations, type function signatures, and (default)
---   type function equations.
+-- * This can be kind signatures and (default) type function equations.
 --
 rnATs :: [LTyClDecl RdrName] -> RnM ([LTyClDecl Name], FreeVars)
 rnATs ats = mapFvRn (wrapLocFstM rn_at) ats
   where
     rn_at (tydecl@TyData     {}) = rnTySig tydecl lookupIdxVars
     rn_at (tydecl@TyFunction {}) = rnTySig tydecl lookupIdxVars
-    rn_at (tydecl@TySynonym  {}) = rnTyClDecl tydecl
+    rn_at (tydecl@TySynonym  {}) = 
+      do
+        checkM (isNothing (tcdTyPats tydecl)) $ addErr noPatterns
+        rnTyClDecl tydecl
     rn_at _                      = panic "RnSource.rnATs: invalid TyClDecl"
 
-    lookupIdxVars _ tyvars cont = mappM lookupIdxVar tyvars >>= cont
-    --
+    lookupIdxVars _ tyvars cont = 
+      do { checkForDups tyvars;
+	 ; tyvars' <- mappM lookupIdxVar tyvars
+	 ; cont tyvars'
+	 }
     -- Type index variables must be class parameters, which are the only
     -- type variables in scope at this point.
     lookupIdxVar (L l tyvar) =
@@ -789,6 +820,27 @@ rnATs ats = mapFvRn (wrapLocFstM rn_at) ats
 	name' <- lookupOccRn (hsTyVarName tyvar)
 	return $ L l (replaceTyVarName tyvar name')
 
+    -- Type variable may only occur once.
+    --
+    checkForDups [] = return ()
+    checkForDups (L loc tv:ltvs) = 
+      do { setSrcSpan loc $
+	     when (hsTyVarName tv `ltvElem` ltvs) $
+	       addErr (repeatedTyVar tv)
+	 ; checkForDups ltvs
+	 }
+
+    rdrName `ltvElem` [] = False
+    rdrName `ltvElem` (L _ tv:ltvs)
+      | rdrName == hsTyVarName tv = True
+      | otherwise		  = rdrName `ltvElem` ltvs
+
+noPatterns = text "Default definition for an associated synonym cannot have"
+	     <+> text "type pattern"
+
+repeatedTyVar tv = ptext SLIT("Illegal repeated type variable") <+>
+		   quotes (ppr tv)
+
 -- This data decl will parse OK
 --	data T = a Int
 -- treating "a" as the constructor.