Make TH capable of quoting GADT declarations (Trac #5217)

[ghc-hetmet.git] / compiler / typecheck / TcMType.lhs

diff --git a/compiler/typecheck/TcMType.lhs b/compiler/typecheck/TcMType.lhs
index 2c01d23..6423a83 100644 (file)
--- a/compiler/typecheck/TcMType.lhs
+++ b/compiler/typecheck/TcMType.lhs
@@ -1162,7 +1162,8 @@ check_pred_ty dflags ctxt pred@(ClassP cls tys)
 check_pred_ty dflags ctxt pred@(EqPred ty1 ty2)
   = do {       -- Equational constraints are valid in all contexts if type
                -- families are permitted
-       ; checkTc (xopt Opt_TypeFamilies dflags) (eqPredTyErr pred)
+       ; checkTc (xopt Opt_TypeFamilies dflags || xopt Opt_GADTs dflags) 
+                 (eqPredTyErr pred)
        ; checkTc (case ctxt of ClassSCCtxt {} -> False; _ -> True)
                  (eqSuperClassErr pred)
 
@@ -1330,7 +1331,7 @@ badPredTyErr, eqPredTyErr, predTyVarErr :: PredType -> SDoc
 badPredTyErr pred = ptext (sLit "Illegal constraint") <+> pprPredTy pred
 eqPredTyErr  pred = ptext (sLit "Illegal equational constraint") <+> pprPredTy pred
                    $$
-                   parens (ptext (sLit "Use -XTypeFamilies to permit this"))
+                   parens (ptext (sLit "Use -XGADTs or -XTypeFamilies to permit this"))
 predTyVarErr pred  = sep [ptext (sLit "Non type-variable argument"),
                          nest 2 (ptext (sLit "in the constraint:") <+> pprPredTy pred)]
 dupPredWarn :: [[PredType]] -> SDoc