diff options
Diffstat (limited to 'compiler/rename')
| -rw-r--r-- | compiler/rename/RnUtils.hs | 40 |
1 files changed, 32 insertions, 8 deletions
diff --git a/compiler/rename/RnUtils.hs b/compiler/rename/RnUtils.hs index 99272c2943..0451e288be 100644 --- a/compiler/rename/RnUtils.hs +++ b/compiler/rename/RnUtils.hs @@ -295,16 +295,40 @@ addNameClashErrRn rdr_name gres -- If there are two or more *local* defns, we'll have reported = return () -- that already, and we don't want an error cascade | otherwise - = addErr (vcat [text "Ambiguous occurrence" <+> quotes (ppr rdr_name), - text "It could refer to" <+> vcat (msg1 : msgs)]) + = addErr (vcat [ text "Ambiguous occurrence" <+> quotes (ppr rdr_name) + , text "It could refer to" + , nest 3 (vcat (msg1 : msgs)) ]) where (np1:nps) = gres - msg1 = ptext (sLit "either") <+> mk_ref np1 - msgs = [text " or" <+> mk_ref np | np <- nps] - mk_ref gre = sep [nom <> comma, pprNameProvenance gre] - where nom = case gre_par gre of - FldParent { par_lbl = Just lbl } -> text "the field" <+> quotes (ppr lbl) - _ -> quotes (ppr (gre_name gre)) + msg1 = text "either" <+> ppr_gre np1 + msgs = [text " or" <+> ppr_gre np | np <- nps] + ppr_gre gre = sep [ pp_gre_name gre <> comma + , pprNameProvenance gre] + + -- When printing the name, take care to qualify it in the same + -- way as the provenance reported by pprNameProvenance, namely + -- the head of 'gre_imp'. Otherwise we get confusing reports like + -- Ambiguous occurrence ‘null’ + -- It could refer to either ‘T15487a.null’, + -- imported from ‘Prelude’ at T15487.hs:1:8-13 + -- or ... + -- See Trac #15487 + pp_gre_name gre@(GRE { gre_name = name, gre_par = parent + , gre_lcl = lcl, gre_imp = iss }) + | FldParent { par_lbl = Just lbl } <- parent + = text "the field" <+> quotes (ppr lbl) + | otherwise + = quotes (pp_qual <> dot <> ppr (nameOccName name)) + where + pp_qual | lcl + = ppr (nameModule name) + | imp : _ <- iss -- This 'imp' is the one that + -- pprNameProvenance chooses + , ImpDeclSpec { is_as = mod } <- is_decl imp + = ppr mod + | otherwise + = pprPanic "addNameClassErrRn" (ppr gre $$ ppr iss) + -- Invariant: either 'lcl' is True or 'iss' is non-empty shadowedNameWarn :: OccName -> [SDoc] -> SDoc shadowedNameWarn occ shadowed_locs |