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| author | Simon Peyton Jones <simonpj@microsoft.com> | 2013-06-17 22:45:28 +0100 |
|---|---|---|
| committer | Simon Peyton Jones <simonpj@microsoft.com> | 2013-06-17 22:45:28 +0100 |
| commit | b2cde434bbf3060dc5eda39876e4c9180aea1d1a (patch) | |
| tree | 199281b0f47f85e06d967c2593ab9b678eb2c347 /compiler | |
| parent | 4c01e105a75776b31a4507102d00856d9239390e (diff) | |
| download | haskell-b2cde434bbf3060dc5eda39876e4c9180aea1d1a.tar.gz | |
Emit addUsedRdrNames for the datacons in a standalone deriving (Trac #7969)
Diffstat (limited to 'compiler')
| -rw-r--r-- | compiler/typecheck/TcDeriv.lhs | 18 |
1 files changed, 15 insertions, 3 deletions
diff --git a/compiler/typecheck/TcDeriv.lhs b/compiler/typecheck/TcDeriv.lhs index fb3e7ee300..e9f6d28ff3 100644 --- a/compiler/typecheck/TcDeriv.lhs +++ b/compiler/typecheck/TcDeriv.lhs @@ -704,10 +704,22 @@ mkEqnHelp orig tvs cls cls_tys tc_app mtheta -- For standalone deriving (mtheta /= Nothing), -- check that all the data constructors are in scope. ; rdr_env <- getGlobalRdrEnv - ; let hidden_data_cons = not (isWiredInName (tyConName rep_tc)) && + ; let data_con_names = map dataConName (tyConDataCons rep_tc) + hidden_data_cons = not (isWiredInName (tyConName rep_tc)) && (isAbstractTyCon rep_tc || - any not_in_scope (tyConDataCons rep_tc)) - not_in_scope dc = null (lookupGRE_Name rdr_env (dataConName dc)) + any not_in_scope data_con_names) + not_in_scope dc = null (lookupGRE_Name rdr_env dc) + + -- Make a Qual RdrName that will do for each DataCon + -- so we can report it as used (Trac #7969) + data_con_rdrs = [ mkRdrQual (is_as (is_decl imp_spec)) occ + | dc_name <- data_con_names + , let occ = nameOccName dc_name + gres = lookupGRE_Name rdr_env dc_name + , not (null gres) + , Imported (imp_spec:_) <- [gre_prov (head gres)] ] + + ; addUsedRdrNames data_con_rdrs ; unless (isNothing mtheta || not hidden_data_cons) (bale_out (derivingHiddenErr tycon)) |