X-Git-Url: http://git.megacz.com/?p=ghc-hetmet.git;a=blobdiff_plain;f=compiler%2Frename%2FRnEnv.lhs;h=b3333731c1a3e04192ee3b1715682678486ad968;hp=ad7709a9367b9e9a2c1a6bcf76e174087f37b7eb;hb=b2bd63f99d643f6b3eb30bb72bb9ae26d4183252;hpb=cec00a4113d5b3079308b11f5e257c25908f9b37 diff --git a/compiler/rename/RnEnv.lhs b/compiler/rename/RnEnv.lhs index ad7709a..b333373 100644 --- a/compiler/rename/RnEnv.lhs +++ b/compiler/rename/RnEnv.lhs @@ -8,12 +8,11 @@ module RnEnv ( newTopSrcBinder, lookupFamInstDeclBndr, lookupLocatedTopBndrRn, lookupTopBndrRn, lookupLocatedOccRn, lookupOccRn, - lookupLocatedGlobalOccRn, - lookupGlobalOccRn, lookupGlobalOccRn_maybe, + lookupGlobalOccRn, lookupGlobalOccRn_maybe, lookupLocalDataTcNames, lookupSigOccRn, lookupFixityRn, lookupTyFixityRn, lookupInstDeclBndr, lookupSubBndr, lookupConstructorFields, - lookupSyntaxName, lookupSyntaxTable, + lookupSyntaxName, lookupSyntaxTable, lookupIfThenElse, lookupGreRn, lookupGreLocalRn, lookupGreRn_maybe, getLookupOccRn, addUsedRdrNames, @@ -28,7 +27,7 @@ module RnEnv ( checkDupRdrNames, checkDupAndShadowedRdrNames, checkDupNames, checkDupAndShadowedNames, addFvRn, mapFvRn, mapMaybeFvRn, mapFvRnCPS, - warnUnusedMatches, warnUnusedModules, warnUnusedImports, + warnUnusedMatches, warnUnusedTopBinds, warnUnusedLocalBinds, dataTcOccs, unknownNameErr, kindSigErr, perhapsForallMsg ) where @@ -44,16 +43,13 @@ import HscTypes ( availNames, ModIface(..), FixItem(..), lookupFixity) import TcEnv ( tcLookupDataCon, tcLookupField, isBrackStage ) import TcRnMonad import Id ( isRecordSelector ) -import Name ( Name, nameIsLocalOrFrom, mkInternalName, isWiredInName, - nameSrcLoc, nameSrcSpan, nameOccName, nameModule, isExternalName ) +import Name import NameSet import NameEnv +import Module ( ModuleName, moduleName ) import UniqFM import DataCon ( dataConFieldLabels ) -import OccName -import Module ( ModuleName ) -import PrelNames ( mkUnboundName, rOOT_MAIN, iNTERACTIVE, - consDataConKey, forall_tv_RDR ) +import PrelNames ( mkUnboundName, rOOT_MAIN, consDataConKey, forall_tv_RDR ) import Unique import BasicTypes import ErrUtils ( Message ) @@ -169,7 +165,7 @@ lookupTopBndrRn n = do nopt <- lookupTopBndrRn_maybe n case nopt of Just n' -> return n' Nothing -> do traceRn $ text "lookupTopBndrRn" - unboundName n + unboundName WL_LocalTop n lookupLocatedTopBndrRn :: Located RdrName -> RnM (Located Name) lookupLocatedTopBndrRn = wrapLocM lookupTopBndrRn @@ -208,7 +204,7 @@ lookupTopBndrRn_maybe rdr_name -- See Note [Type and class operator definitions] let occ = rdrNameOcc rdr_name ; when (isTcOcc occ && isSymOcc occ) - (do { op_ok <- doptM Opt_TypeOperators + (do { op_ok <- xoptM Opt_TypeOperators ; unless op_ok (addErr (opDeclErr rdr_name)) }) ; mb_gre <- lookupGreLocalRn rdr_name @@ -362,22 +358,12 @@ lookupLocatedOccRn = wrapLocM lookupOccRn -- lookupOccRn looks up an occurrence of a RdrName lookupOccRn :: RdrName -> RnM Name lookupOccRn rdr_name - = getLocalRdrEnv `thenM` \ local_env -> - case lookupLocalRdrEnv local_env rdr_name of - Just name -> return name - Nothing -> lookupGlobalOccRn rdr_name - -lookupLocatedGlobalOccRn :: Located RdrName -> RnM (Located Name) -lookupLocatedGlobalOccRn = wrapLocM lookupGlobalOccRn - -lookupGlobalOccRn :: RdrName -> RnM Name --- lookupGlobalOccRn is like lookupOccRn, except that it looks in the global --- environment. Adds an error message if the RdrName is not in scope. --- Also has a special case for GHCi. + = do { local_env <- getLocalRdrEnv + ; case lookupLocalRdrEnv local_env rdr_name of { + Just name -> return name ; + Nothing -> do -lookupGlobalOccRn rdr_name - = do { -- First look up the name in the normal environment. - mb_name <- lookupGlobalOccRn_maybe rdr_name + { mb_name <- lookupGlobalOccRn_maybe rdr_name ; case mb_name of { Just n -> return n ; Nothing -> do @@ -386,12 +372,22 @@ lookupGlobalOccRn rdr_name -- *any* name exported by any module in scope, just as if there -- was an "import qualified M" declaration for every module. allow_qual <- doptM Opt_ImplicitImportQualified - ; mod <- getModule + ; is_ghci <- getIsGHCi -- This test is not expensive, -- and only happens for failed lookups - ; if isQual rdr_name && allow_qual && mod == iNTERACTIVE + ; if isQual rdr_name && allow_qual && is_ghci then lookupQualifiedName rdr_name - else unboundName rdr_name } } } + else unboundName WL_Any rdr_name } } } } } + + +lookupGlobalOccRn :: RdrName -> RnM Name +-- lookupGlobalOccRn is like lookupOccRn, except that it looks in the global +-- environment. Adds an error message if the RdrName is not in scope. +lookupGlobalOccRn rdr_name + = do { mb_name <- lookupGlobalOccRn_maybe rdr_name + ; case mb_name of + Just n -> return n + Nothing -> unboundName WL_Global rdr_name } lookupGlobalOccRn_maybe :: RdrName -> RnM (Maybe Name) -- No filter function; does not report an error on failure @@ -410,15 +406,6 @@ lookupGlobalOccRn_maybe rdr_name Just gre -> return (Just (gre_name gre)) } -unboundName :: RdrName -> RnM Name -unboundName rdr_name - = do { addErr (unknownNameErr rdr_name) - ; env <- getGlobalRdrEnv; - ; traceRn (vcat [unknownNameErr rdr_name, - ptext (sLit "Global envt is:"), - nest 3 (pprGlobalRdrEnv env)]) - ; return (mkUnboundName rdr_name) } - -------------------------------------------------- -- Lookup in the Global RdrEnv of the module -------------------------------------------------- @@ -436,7 +423,7 @@ lookupGreRn rdr_name Just gre -> return gre ; Nothing -> do { traceRn $ text "lookupGreRn" - ; name <- unboundName rdr_name + ; name <- unboundName WL_Global rdr_name ; return (GRE { gre_name = name, gre_par = NoParent, gre_prov = LocalDef }) }}} @@ -498,7 +485,7 @@ lookupQualifiedName rdr_name name == occ ] of ((mod,occ):ns) -> ASSERT (null ns) lookupOrig mod occ - _ -> unboundName rdr_name + _ -> unboundName WL_Any rdr_name | otherwise = pprPanic "RnEnv.lookupQualifiedName" (ppr rdr_name) @@ -506,6 +493,8 @@ lookupQualifiedName rdr_name doc = ptext (sLit "Need to find") <+> ppr rdr_name \end{code} +Note [Looking up signature names] +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ lookupSigOccRn is used for type signatures and pragmas Is this valid? module A @@ -526,10 +515,13 @@ return the imported 'f', so that later on the reanamer will correctly report "misplaced type sig". \begin{code} -lookupSigOccRn :: Maybe NameSet -- Just ns => source file; these are the binders +lookupSigOccRn :: Maybe NameSet -- Just ns => these are the binders -- in the same group - -- Nothing => hs-boot file; signatures without + -- Nothing => signatures without -- binders are expected + -- (a) top-level (SPECIALISE prags) + -- (b) class decls + -- (c) hs-boot files -> Sig RdrName -> Located RdrName -> RnM (Located Name) lookupSigOccRn mb_bound_names sig @@ -539,29 +531,29 @@ lookupSigOccRn mb_bound_names sig Left err -> do { addErr err; return (mkUnboundName rdr_name) } Right name -> return name } -lookupBindGroupOcc :: Maybe NameSet -- Just ns => source file; these are the binders - -- in the same group - -- Nothing => hs-boot file; signatures without - -- binders are expected - -> SDoc +lookupBindGroupOcc :: Maybe NameSet -- See notes on the (Maybe NameSet) + -> SDoc -- in lookupSigOccRn -> RdrName -> RnM (Either Message Name) -- Looks up the RdrName, expecting it to resolve to one of the -- bound names passed in. If not, return an appropriate error message +-- +-- See Note [Looking up signature names] lookupBindGroupOcc mb_bound_names what rdr_name - = do { local_env <- getLocalRdrEnv - ; case lookupLocalRdrEnv local_env rdr_name of - Just n -> check_local_name n - Nothing -> do -- Not defined in a nested scope + = do { local_env <- getLocalRdrEnv + ; case lookupLocalRdrEnv local_env rdr_name of { + Just n -> check_local_name n; + Nothing -> do -- Not defined in a nested scope { env <- getGlobalRdrEnv - ; let gres = lookupGlobalRdrEnv env (rdrNameOcc rdr_name) - ; case (filter isLocalGRE gres) of - (gre:_) -> check_local_name (gre_name gre) - -- If there is more than one local GRE for the - -- same OccName, that will be reported separately - [] | null gres -> bale_out_with empty - | otherwise -> bale_out_with import_msg - }} + ; let gres = lookupGlobalRdrEnv env (rdrNameOcc rdr_name) + ; case (filter isLocalGRE gres) of + (gre:_) -> check_local_name (gre_name gre) + -- If there is more than one local GRE for the + -- same OccName 'f', that will be reported separately + -- as a duplicate top-level binding for 'f' + [] | null gres -> bale_out_with empty + | otherwise -> bale_out_with import_msg + }}} where check_local_name name -- The name is in scope, and not imported = case mb_bound_names of @@ -726,7 +718,7 @@ lookupTyFixityRn (L _ n) = lookupFixityRn n %* * Rebindable names Dealing with rebindable syntax is driven by the - Opt_NoImplicitPrelude dynamic flag. + Opt_RebindableSyntax dynamic flag. In "deriving" code we don't want to use rebindable syntax so we switch off the flag locally @@ -762,11 +754,22 @@ We treat the orignal (standard) names as free-vars too, because the type checker checks the type of the user thing against the type of the standard thing. \begin{code} +lookupIfThenElse :: RnM (Maybe (SyntaxExpr Name), FreeVars) +-- Different to lookupSyntaxName because in the non-rebindable +-- case we desugar directly rather than calling an existing function +-- Hence the (Maybe (SyntaxExpr Name)) return type +lookupIfThenElse + = do { rebind <- xoptM Opt_RebindableSyntax + ; if not rebind + then return (Nothing, emptyFVs) + else do { ite <- lookupOccRn (mkVarUnqual (fsLit "ifThenElse")) + ; return (Just (HsVar ite), unitFV ite) } } + lookupSyntaxName :: Name -- The standard name -> RnM (SyntaxExpr Name, FreeVars) -- Possibly a non-standard name lookupSyntaxName std_name - = doptM Opt_ImplicitPrelude `thenM` \ implicit_prelude -> - if implicit_prelude then normal_case + = xoptM Opt_RebindableSyntax `thenM` \ rebindable_on -> + if not rebindable_on then normal_case else -- Get the similarly named thing from the local environment lookupOccRn (mkRdrUnqual (nameOccName std_name)) `thenM` \ usr_name -> @@ -777,8 +780,8 @@ lookupSyntaxName std_name lookupSyntaxTable :: [Name] -- Standard names -> RnM (SyntaxTable Name, FreeVars) -- See comments with HsExpr.ReboundNames lookupSyntaxTable std_names - = doptM Opt_ImplicitPrelude `thenM` \ implicit_prelude -> - if implicit_prelude then normal_case + = xoptM Opt_RebindableSyntax `thenM` \ rebindable_on -> + if not rebindable_on then normal_case else -- Get the similarly named thing from the local environment mapM (lookupOccRn . mkRdrUnqual . nameOccName) std_names `thenM` \ usr_names -> @@ -867,7 +870,7 @@ bindTyVarsRn :: [LHsTyVarBndr RdrName] -- Haskell-98 binding of type variables; e.g. within a data type decl bindTyVarsRn tyvar_names enclosed_scope = bindLocatedLocalsRn located_tyvars $ \ names -> - do { kind_sigs_ok <- doptM Opt_KindSignatures + do { kind_sigs_ok <- xoptM Opt_KindSignatures ; unless (null kinded_tyvars || kind_sigs_ok) (mapM_ (addErr . kindSigErr) kinded_tyvars) ; enclosed_scope (zipWith replace tyvar_names names) } @@ -880,7 +883,7 @@ bindPatSigTyVars :: [LHsType RdrName] -> ([Name] -> RnM a) -> RnM a -- Find the type variables in the pattern type -- signatures that must be brought into scope bindPatSigTyVars tys thing_inside - = do { scoped_tyvars <- doptM Opt_ScopedTypeVariables + = do { scoped_tyvars <- xoptM Opt_ScopedTypeVariables ; if not scoped_tyvars then thing_inside [] else @@ -907,7 +910,7 @@ bindSigTyVarsFV :: [Name] -> RnM (a, FreeVars) -> RnM (a, FreeVars) bindSigTyVarsFV tvs thing_inside - = do { scoped_tyvars <- doptM Opt_ScopedTypeVariables + = do { scoped_tyvars <- xoptM Opt_ScopedTypeVariables ; if not scoped_tyvars then thing_inside else @@ -951,7 +954,7 @@ checkDupAndShadowedNames envs names ------------------------------------- checkShadowedOccs :: (GlobalRdrEnv, LocalRdrEnv) -> [(SrcSpan,OccName)] -> RnM () checkShadowedOccs (global_env,local_env) loc_occs - = ifOptM Opt_WarnNameShadowing $ + = ifDOptM Opt_WarnNameShadowing $ do { traceRn (text "shadow" <+> ppr loc_occs) ; mapM_ check_shadow loc_occs } where @@ -974,7 +977,7 @@ checkShadowedOccs (global_env,local_env) loc_occs -- punning or wild-cards are on (cf Trac #2723) is_shadowed_gre gre@(GRE { gre_par = ParentIs _ }) = do { dflags <- getDOpts - ; if (dopt Opt_RecordPuns dflags || dopt Opt_RecordWildCards dflags) + ; if (xopt Opt_RecordPuns dflags || xopt Opt_RecordWildCards dflags) then do { is_fld <- is_rec_fld gre; return (not is_fld) } else return True } is_shadowed_gre _other = return True @@ -989,6 +992,161 @@ checkShadowedOccs (global_env,local_env) loc_occs %************************************************************************ %* * + What to do when a lookup fails +%* * +%************************************************************************ + +\begin{code} +data WhereLooking = WL_Any -- Any binding + | WL_Global -- Any top-level binding (local or imported) + | WL_LocalTop -- Any top-level binding in this module + +unboundName :: WhereLooking -> RdrName -> RnM Name +unboundName where_look rdr_name + = do { show_helpful_errors <- doptM Opt_HelpfulErrors + ; let err = unknownNameErr rdr_name + ; if not show_helpful_errors + then addErr err + else do { extra_err <- unknownNameSuggestErr where_look rdr_name + ; addErr (err $$ extra_err) } + + ; env <- getGlobalRdrEnv; + ; traceRn (vcat [unknownNameErr rdr_name, + ptext (sLit "Global envt is:"), + nest 3 (pprGlobalRdrEnv env)]) + + ; return (mkUnboundName rdr_name) } + +unknownNameErr :: RdrName -> SDoc +unknownNameErr rdr_name + = vcat [ hang (ptext (sLit "Not in scope:")) + 2 (pprNonVarNameSpace (occNameSpace (rdrNameOcc rdr_name)) + <+> quotes (ppr rdr_name)) + , extra ] + where + extra | rdr_name == forall_tv_RDR = perhapsForallMsg + | otherwise = empty + +type HowInScope = Either SrcSpan ImpDeclSpec + -- Left loc => locally bound at loc + -- Right ispec => imported as specified by ispec + +unknownNameSuggestErr :: WhereLooking -> RdrName -> RnM SDoc +unknownNameSuggestErr where_look tried_rdr_name + = do { local_env <- getLocalRdrEnv + ; global_env <- getGlobalRdrEnv + + ; let all_possibilities :: [(String, (RdrName, HowInScope))] + all_possibilities + = [ (showSDoc (ppr r), (r, Left loc)) + | (r,loc) <- local_possibilities local_env ] + ++ [ (showSDoc (ppr r), rp) | (r,rp) <- global_possibilities global_env ] + + suggest = fuzzyLookup (showSDoc (ppr tried_rdr_name)) all_possibilities + perhaps = ptext (sLit "Perhaps you meant") + extra_err = case suggest of + [] -> empty + [p] -> perhaps <+> pp_item p + ps -> sep [ perhaps <+> ptext (sLit "one of these:") + , nest 2 (pprWithCommas pp_item ps) ] + ; return extra_err } + where + pp_item :: (RdrName, HowInScope) -> SDoc + pp_item (rdr, Left loc) = quotes (ppr rdr) <+> -- Locally defined + parens (ptext (sLit "line") <+> int (srcSpanStartLine loc')) + where loc' = case loc of + UnhelpfulSpan _ -> + panic "unknownNameSuggestErr UnhelpfulSpan" + RealSrcSpan l -> l + pp_item (rdr, Right is) = quotes (ppr rdr) <+> -- Imported + parens (ptext (sLit "imported from") <+> ppr (is_mod is)) + + tried_occ = rdrNameOcc tried_rdr_name + tried_is_sym = isSymOcc tried_occ + tried_ns = occNameSpace tried_occ + tried_is_qual = isQual tried_rdr_name + + correct_name_space occ = occNameSpace occ == tried_ns + && isSymOcc occ == tried_is_sym + -- Treat operator and non-operators as non-matching + -- This heuristic avoids things like + -- Not in scope 'f'; perhaps you meant '+' (from Prelude) + + local_ok = case where_look of { WL_Any -> True; _ -> False } + local_possibilities :: LocalRdrEnv -> [(RdrName, SrcSpan)] + local_possibilities env + | tried_is_qual = [] + | not local_ok = [] + | otherwise = [ (mkRdrUnqual occ, nameSrcSpan name) + | name <- occEnvElts env + , let occ = nameOccName name + , correct_name_space occ] + + gre_ok :: GlobalRdrElt -> Bool + gre_ok = case where_look of + WL_LocalTop -> isLocalGRE + _ -> \_ -> True + + global_possibilities :: GlobalRdrEnv -> [(RdrName, (RdrName, HowInScope))] + global_possibilities global_env + | tried_is_qual = [ (rdr_qual, (rdr_qual, how)) + | gre <- globalRdrEnvElts global_env + , gre_ok gre + , let name = gre_name gre + occ = nameOccName name + , correct_name_space occ + , (mod, how) <- quals_in_scope name (gre_prov gre) + , let rdr_qual = mkRdrQual mod occ ] + + | otherwise = [ (rdr_unqual, pair) + | gre <- globalRdrEnvElts global_env + , gre_ok gre + , let name = gre_name gre + prov = gre_prov gre + occ = nameOccName name + rdr_unqual = mkRdrUnqual occ + , correct_name_space occ + , pair <- case (unquals_in_scope name prov, quals_only occ prov) of + (how:_, _) -> [ (rdr_unqual, how) ] + ([], pr:_) -> [ pr ] -- See Note [Only-quals] + ([], []) -> [] ] + + -- Note [Only-quals] + -- The second alternative returns those names with the same + -- OccName as the one we tried, but live in *qualified* imports + -- e.g. if you have: + -- + -- > import qualified Data.Map as Map + -- > foo :: Map + -- + -- then we suggest @Map.Map@. + + -------------------- + unquals_in_scope :: Name -> Provenance -> [HowInScope] + unquals_in_scope n LocalDef = [ Left (nameSrcSpan n) ] + unquals_in_scope _ (Imported is) = [ Right ispec + | i <- is, let ispec = is_decl i + , not (is_qual ispec) ] + + -------------------- + quals_in_scope :: Name -> Provenance -> [(ModuleName, HowInScope)] + -- Ones for which the qualified version is in scope + quals_in_scope n LocalDef = case nameModule_maybe n of + Nothing -> [] + Just m -> [(moduleName m, Left (nameSrcSpan n))] + quals_in_scope _ (Imported is) = [ (is_as ispec, Right ispec) + | i <- is, let ispec = is_decl i ] + + -------------------- + quals_only :: OccName -> Provenance -> [(RdrName, HowInScope)] + -- Ones for which *only* the qualified version is in scope + quals_only _ LocalDef = [] + quals_only occ (Imported is) = [ (mkRdrQual (is_as ispec) occ, Right ispec) + | i <- is, let ispec = is_decl i, is_qual ispec ] +\end{code} + +%************************************************************************ +%* * \subsection{Free variable manipulation} %* * %************************************************************************ @@ -1028,23 +1186,9 @@ mapFvRnCPS f (x:xs) cont = f x $ \ x' -> %************************************************************************ \begin{code} -warnUnusedModules :: [(ModuleName,SrcSpan)] -> RnM () -warnUnusedModules mods - = ifOptM Opt_WarnUnusedImports (mapM_ bleat mods) - where - bleat (mod,loc) = addWarnAt loc (mk_warn mod) - mk_warn m = vcat [ptext (sLit "Module") <+> quotes (ppr m) - <+> text "is imported, but nothing from it is used,", - nest 2 (ptext (sLit "except perhaps instances visible in") - <+> quotes (ppr m)), - ptext (sLit "To suppress this warning, use:") - <+> ptext (sLit "import") <+> ppr m <> parens empty ] - - -warnUnusedImports, warnUnusedTopBinds :: [GlobalRdrElt] -> RnM () -warnUnusedImports gres = ifOptM Opt_WarnUnusedImports (warnUnusedGREs gres) +warnUnusedTopBinds :: [GlobalRdrElt] -> RnM () warnUnusedTopBinds gres - = ifOptM Opt_WarnUnusedBinds + = ifDOptM Opt_WarnUnusedBinds $ do isBoot <- tcIsHsBoot let noParent gre = case gre_par gre of NoParent -> True @@ -1062,7 +1206,7 @@ warnUnusedMatches = check_unused Opt_WarnUnusedMatches check_unused :: DynFlag -> [Name] -> FreeVars -> RnM () check_unused flag bound_names used_names - = ifOptM flag (warnUnusedLocals (filterOut (`elemNameSet` used_names) bound_names)) + = ifDOptM flag (warnUnusedLocals (filterOut (`elemNameSet` used_names) bound_names)) ------------------------- -- Helpers @@ -1115,7 +1259,7 @@ addNameClashErrRn rdr_name names (np1:nps) = names msg1 = ptext (sLit "either") <+> mk_ref np1 msgs = [ptext (sLit " or") <+> mk_ref np | np <- nps] - mk_ref gre = quotes (ppr (gre_name gre)) <> comma <+> pprNameProvenance gre + mk_ref gre = sep [quotes (ppr (gre_name gre)) <> comma, pprNameProvenance gre] shadowedNameWarn :: OccName -> [SDoc] -> SDoc shadowedNameWarn occ shadowed_locs @@ -1123,16 +1267,6 @@ shadowedNameWarn occ shadowed_locs <+> ptext (sLit "shadows the existing binding") <> plural shadowed_locs, nest 2 (vcat shadowed_locs)] -unknownNameErr :: RdrName -> SDoc -unknownNameErr rdr_name - = vcat [ hang (ptext (sLit "Not in scope:")) - 2 (pprNonVarNameSpace (occNameSpace (rdrNameOcc rdr_name)) - <+> quotes (ppr rdr_name)) - , extra ] - where - extra | rdr_name == forall_tv_RDR = perhapsForallMsg - | otherwise = empty - perhapsForallMsg :: SDoc perhapsForallMsg = vcat [ ptext (sLit "Perhaps you intended to use -XExplicitForAll or similar flag")