X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=ghc%2Fcompiler%2Ftypecheck%2FTcTyClsDecls.lhs;h=95166861ec668c6e0a09546ffc9f5e52a645de73;hb=6a4854eaa266d994ebd0d471614a52b43dd329d9;hp=a99aa2f94a135e4ae8f2aea1aeb1ca4f6924e9cc;hpb=618a704d4c3a1ebcf3b5eba7b16268695f02a369;p=ghc-hetmet.git

diff --git a/ghc/compiler/typecheck/TcTyClsDecls.lhs b/ghc/compiler/typecheck/TcTyClsDecls.lhs
index a99aa2f..9516686 100644
--- a/ghc/compiler/typecheck/TcTyClsDecls.lhs
+++ b/ghc/compiler/typecheck/TcTyClsDecls.lhs
@@ -115,7 +115,8 @@ tcTyAndClassDecls boot_names decls
   = do	{ 	-- First check for cyclic type synonysm or classes
 		-- See notes with checkCycleErrs
 	  checkCycleErrs decls
-
+	; mod <- getModule
+	; traceTc (text "tcTyAndCl" <+> ppr mod <+> ppr boot_names)
 	; (syn_tycons, alg_tyclss) <- fixM (\ ~(rec_syn_tycons, rec_alg_tyclss) ->
 	  do	{ let {	-- Calculate variances and rec-flag
 		      ; (syn_decls, alg_decls) = partition (isSynDecl . unLoc) decls }
@@ -371,6 +372,9 @@ tcTyClDecl1 calc_vrcs calc_isrec
   ; want_generic <- doptM Opt_Generics
   ; tycon <- fixM (\ tycon -> do 
 	{ unbox_strict <- doptM Opt_UnboxStrictFields
+	; gla_exts <- doptM Opt_GlasgowExts
+	; checkTc (gla_exts || h98_syntax) (badGadtDecl tc_name)
+
 	; data_cons <- mappM (addLocM (tcConDecl unbox_strict new_or_data tycon tvs')) cons
 	; let tc_rhs = case new_or_data of
 			DataType -> mkDataTyConRhs stupid_theta data_cons
@@ -384,6 +388,9 @@ tcTyClDecl1 calc_vrcs calc_isrec
   where
     arg_vrcs = calc_vrcs tc_name
     is_rec   = calc_isrec tc_name
+    h98_syntax = case cons of 	-- All constructors have same shape
+			L _ (GadtDecl {}) : _ -> False
+			other -> True
 
 tcTyClDecl1 calc_vrcs calc_isrec 
   (ClassDecl {tcdLName = L _ class_name, tcdTyVars = tvs, 
@@ -643,7 +650,7 @@ checkValidClass cls
 
 		-- Check that for a generic method, the type of 
 		-- the method is sufficiently simple
-	; checkTc (dm /= GenDefMeth || validGenericMethodType op_ty)
+	; checkTc (dm /= GenDefMeth || validGenericMethodType tau)
 		  (badGenericMethodType op_name op_ty)
 	}
 	where
@@ -695,7 +702,7 @@ genericMultiParamErr clas
 badGenericMethodType op op_ty
   = hang (ptext SLIT("Generic method type is too complex"))
        4 (vcat [ppr op <+> dcolon <+> ppr op_ty,
-		ptext SLIT("You can only use type variables, arrows, and tuples")])
+		ptext SLIT("You can only use type variables, arrows, lists, and tuples")])
 
 recSynErr syn_decls
   = setSrcSpan (getLoc (head sorted_decls)) $
@@ -726,4 +733,8 @@ exRecConErr name
 badDataConTyCon data_con
   = hang (ptext SLIT("Data constructor does not return its parent type:"))
        2 (ppr data_con)
+
+badGadtDecl tc_name
+  = vcat [ ptext SLIT("Illegal generalised algebraic data declaration for") <+> quotes (ppr tc_name)
+	 , nest 2 (parens $ ptext SLIT("Use -fglasgow-exts to allow GADTs")) ]
 \end{code}