diff options
Diffstat (limited to 'compiler/GHC/Tc/Deriv.hs')
| -rw-r--r-- | compiler/GHC/Tc/Deriv.hs | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/compiler/GHC/Tc/Deriv.hs b/compiler/GHC/Tc/Deriv.hs index e1a688cd55..afae21e9d7 100644 --- a/compiler/GHC/Tc/Deriv.hs +++ b/compiler/GHC/Tc/Deriv.hs @@ -439,6 +439,7 @@ makeDerivSpecs :: [DerivInfo] -> TcM [EarlyDerivSpec] makeDerivSpecs deriv_infos deriv_decls = do { eqns1 <- sequenceA + -- MP: scoped_tvs here magically converts TyVar into TcTyVar [ deriveClause rep_tc scoped_tvs dcs (deriv_clause_preds dct) err_ctxt | DerivInfo { di_rep_tc = rep_tc , di_scoped_tvs = scoped_tvs @@ -633,6 +634,8 @@ deriveStandalone (L loc (DerivDecl _ deriv_ty mb_lderiv_strat overlap_mode)) ; traceTc "Deriving strategy (standalone deriving)" $ vcat [ppr mb_lderiv_strat, ppr deriv_ty] ; (mb_lderiv_strat, via_tvs) <- tcDerivStrategy mb_lderiv_strat + ; traceTc "Deriving strategy (standalone deriving) 2" $ + vcat [ppr mb_lderiv_strat, ppr via_tvs] ; (cls_tvs, deriv_ctxt, cls, inst_tys) <- tcExtendTyVarEnv via_tvs $ tcStandaloneDerivInstType ctxt deriv_ty |