X-Git-Url: http://git.megacz.com/?p=ghc-hetmet.git;a=blobdiff_plain;f=compiler%2Frename%2FRnEnv.lhs;h=e1d90e8df1076807fb1feda25870105e80413242;hp=ae1966c8f36f3470c225bb7d130d531bd75e552f;hb=61bcd16d4f3d4cf84b26bf7bb92f16f0440b7071;hpb=33a10e67b7fd27cc8b41f914c8c37c6972eed673 diff --git a/compiler/rename/RnEnv.lhs b/compiler/rename/RnEnv.lhs index ae1966c..e1d90e8 100644 --- a/compiler/rename/RnEnv.lhs +++ b/compiler/rename/RnEnv.lhs @@ -6,12 +6,12 @@ \begin{code} module RnEnv ( newTopSrcBinder, lookupFamInstDeclBndr, - lookupLocatedBndrRn, lookupBndrRn, lookupBndrRn_maybe, lookupLocatedTopBndrRn, lookupTopBndrRn, lookupLocatedOccRn, lookupOccRn, lookupLocatedGlobalOccRn, lookupGlobalOccRn, lookupLocalDataTcNames, lookupSrcOcc_maybe, - lookupFixityRn, lookupTyFixityRn, lookupLocatedSigOccRn, + lookupSigOccRn, + lookupFixityRn, lookupTyFixityRn, lookupInstDeclBndr, lookupRecordBndr, lookupConstructorFields, lookupSyntaxName, lookupSyntaxTable, lookupImportedName, lookupGreRn, lookupGreLocalRn, lookupGreRn_maybe, @@ -30,7 +30,7 @@ module RnEnv ( mapFvRn, mapFvRnCPS, warnUnusedMatches, warnUnusedModules, warnUnusedImports, warnUnusedTopBinds, warnUnusedLocalBinds, - dataTcOccs, unknownNameErr + dataTcOccs, unknownNameErr, perhapsForallMsg ) where #include "HsVersions.h" @@ -41,8 +41,9 @@ import HsSyn import RdrHsSyn ( extractHsTyRdrTyVars ) import RdrName import HscTypes ( availNames, ModIface(..), FixItem(..), lookupFixity) -import TcEnv ( tcLookupDataCon ) +import TcEnv ( tcLookupDataCon, tcLookupField, isBrackStage ) import TcRnMonad +import Id ( isRecordSelector ) import Name ( Name, nameIsLocalOrFrom, mkInternalName, isWiredInName, nameSrcLoc, nameSrcSpan, nameOccName, nameModule, isExternalName ) import NameSet @@ -55,6 +56,7 @@ import PrelNames ( mkUnboundName, rOOT_MAIN, iNTERACTIVE, consDataConKey, hasKey, forall_tv_RDR ) import UniqSupply import BasicTypes ( IPName, mapIPName, Fixity ) +import ErrUtils ( Message ) import SrcLoc import Outputable import Util @@ -140,7 +142,16 @@ newTopSrcBinder this_mod (L loc rdr_name) (addErrAt loc (badQualBndrErr rdr_name)) -- Binders should not be qualified; if they are, and with a different -- module name, we we get a confusing "M.T is not in scope" error later - ; newGlobalBinder this_mod (rdrNameOcc rdr_name) loc } + + ; stage <- getStage + ; if isBrackStage stage then + -- We are inside a TH bracket, so make an *Internal* name + -- See Note [Top-level Names in Template Haskell decl quotes] in RnNames + do { uniq <- newUnique + ; return (mkInternalName uniq (rdrNameOcc rdr_name) loc) } + else + -- Normal case + newGlobalBinder this_mod (rdrNameOcc rdr_name) loc } \end{code} %********************************************************* @@ -152,16 +163,6 @@ newTopSrcBinder this_mod (L loc rdr_name) Looking up a name in the RnEnv. \begin{code} -lookupLocatedBndrRn :: Located RdrName -> RnM (Located Name) -lookupLocatedBndrRn = wrapLocM lookupBndrRn - -lookupBndrRn :: RdrName -> RnM Name -lookupBndrRn n = do nopt <- lookupBndrRn_maybe n - case nopt of - Just n' -> return n' - Nothing -> do traceRn $ text "lookupTopBndrRn" - unboundName n - lookupTopBndrRn :: RdrName -> RnM Name lookupTopBndrRn n = do nopt <- lookupTopBndrRn_maybe n case nopt of @@ -169,14 +170,6 @@ lookupTopBndrRn n = do nopt <- lookupTopBndrRn_maybe n Nothing -> do traceRn $ text "lookupTopBndrRn" unboundName n -lookupBndrRn_maybe :: RdrName -> RnM (Maybe Name) --- NOTE: assumes that the SrcSpan of the binder has already been setSrcSpan'd -lookupBndrRn_maybe rdr_name - = getLocalRdrEnv `thenM` \ local_env -> - case lookupLocalRdrEnv local_env rdr_name of - Just name -> returnM (Just name) - Nothing -> lookupTopBndrRn_maybe rdr_name - lookupLocatedTopBndrRn :: Located RdrName -> RnM (Located Name) lookupLocatedTopBndrRn = wrapLocM lookupTopBndrRn @@ -215,35 +208,6 @@ lookupTopBndrRn_maybe rdr_name Nothing -> returnM Nothing Just gre -> returnM (Just $ gre_name gre) } --- lookupLocatedSigOccRn is used for type signatures and pragmas --- Is this valid? --- module A --- import M( f ) --- f :: Int -> Int --- f x = x --- It's clear that the 'f' in the signature must refer to A.f --- The Haskell98 report does not stipulate this, but it will! --- So we must treat the 'f' in the signature in the same way --- as the binding occurrence of 'f', using lookupBndrRn --- --- However, consider this case: --- import M( f ) --- f :: Int -> Int --- g x = x --- We don't want to say 'f' is out of scope; instead, we want to --- return the imported 'f', so that later on the reanamer will --- correctly report "misplaced type sig". -lookupLocatedSigOccRn :: Located RdrName -> RnM (Located Name) -lookupLocatedSigOccRn = wrapLocM $ \ rdr_name -> do - { local_env <- getLocalRdrEnv - ; case lookupLocalRdrEnv local_env rdr_name of { - Just n -> return n ; - Nothing -> do - { mb_gre <- lookupGreLocalRn rdr_name - ; case mb_gre of - Just gre -> return (gre_name gre) - Nothing -> lookupGlobalOccRn rdr_name - }}} ----------------------------------------------- lookupInstDeclBndr :: Name -> Located RdrName -> RnM (Located Name) @@ -267,9 +231,16 @@ lookupInstDeclBndr cls rdr = lookup_located_sub_bndr is_op doc rdr ----------------------------------------------- lookupRecordBndr :: Maybe (Located Name) -> Located RdrName -> RnM (Located Name) -- Used for record construction and pattern matching --- When the -fdisambiguate-record-fields flag is on, take account of the +-- When the -XDisambiguateRecordFields flag is on, take account of the -- constructor name to disambiguate which field to use; it's just the -- same as for instance decls +-- +-- NB: Consider this: +-- module Foo where { data R = R { fld :: Int } } +-- module Odd where { import Foo; fld x = x { fld = 3 } } +-- Arguably this should work, because the reference to 'fld' is +-- unambiguous because there is only one field id 'fld' in scope. +-- But currently it's rejected. lookupRecordBndr Nothing rdr_name = lookupLocatedGlobalOccRn rdr_name lookupRecordBndr (Just (L _ data_con)) rdr_name @@ -298,7 +269,7 @@ lookupConstructorFields :: Name -> RnM [Name] lookupConstructorFields con_name = do { this_mod <- getModule ; if nameIsLocalOrFrom this_mod con_name then - do { field_env <- getRecFieldEnv + do { RecFields field_env _ <- getRecFieldEnv ; return (lookupNameEnv field_env con_name `orElse` []) } else do { con <- tcLookupDataCon con_name @@ -351,7 +322,7 @@ lookupFamInstDeclBndr :: Module -> Located RdrName -> RnM Name lookupFamInstDeclBndr mod lrdr_name@(L _ rdr_name) = do { mb_gre <- lookupGreRn_maybe rdr_name ; case mb_gre of - Just gre -> returnM (gre_name gre) ; + Just gre -> returnM (gre_name gre) Nothing -> newTopSrcBinder mod lrdr_name } -------------------------------------------------- @@ -388,23 +359,25 @@ lookupGlobalOccRn rdr_name = lookupImportedName rdr_name | otherwise - = -- First look up the name in the normal environment. - lookupGreRn_maybe rdr_name `thenM` \ mb_gre -> + = do + -- First look up the name in the normal environment. + mb_gre <- lookupGreRn_maybe rdr_name case mb_gre of { Just gre -> returnM (gre_name gre) ; - Nothing -> + Nothing -> do -- We allow qualified names on the command line to refer to -- *any* name exported by any module in scope, just as if -- there was an "import qualified M" declaration for every -- module. - getModule `thenM` \ mod -> - if isQual rdr_name && mod == iNTERACTIVE then - -- This test is not expensive, - lookupQualifiedName rdr_name -- and only happens for failed lookups - else do - traceRn $ text "lookupGlobalOccRn" - unboundName rdr_name } + allow_qual <- doptM Opt_ImplicitImportQualified + mod <- getModule + -- This test is not expensive, + -- and only happens for failed lookups + if isQual rdr_name && allow_qual && mod == iNTERACTIVE + then lookupQualifiedName rdr_name + else unboundName rdr_name + } lookupImportedName :: RdrName -> TcRnIf m n Name -- Lookup the occurrence of an imported name @@ -495,7 +468,7 @@ lookupQualifiedName rdr_name | Just (mod,occ) <- isQual_maybe rdr_name -- Note: we want to behave as we would for a source file import here, -- and respect hiddenness of modules/packages, hence loadSrcInterface. - = loadSrcInterface doc mod False `thenM` \ iface -> + = loadSrcInterface doc mod False Nothing `thenM` \ iface -> case [ (mod,occ) | (mod,avails) <- mi_exports iface, @@ -512,6 +485,120 @@ lookupQualifiedName rdr_name doc = ptext (sLit "Need to find") <+> ppr rdr_name \end{code} +lookupSigOccRn is used for type signatures and pragmas +Is this valid? + module A + import M( f ) + f :: Int -> Int + f x = x +It's clear that the 'f' in the signature must refer to A.f +The Haskell98 report does not stipulate this, but it will! +So we must treat the 'f' in the signature in the same way +as the binding occurrence of 'f', using lookupBndrRn + +However, consider this case: + import M( f ) + f :: Int -> Int + g x = x +We don't want to say 'f' is out of scope; instead, we want to +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 + -- in the same group + -- Nothing => hs-boot file; signatures without + -- binders are expected + -> Sig RdrName + -> Located RdrName -> RnM (Located Name) +lookupSigOccRn mb_bound_names sig + = wrapLocM $ \ rdr_name -> + do { mb_name <- lookupBindGroupOcc mb_bound_names (hsSigDoc sig) rdr_name + ; case mb_name of + 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 + -> 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 +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 + + { 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 + }} + where + check_local_name name -- The name is in scope, and not imported + = case mb_bound_names of + Just bound_names | not (name `elemNameSet` bound_names) + -> bale_out_with local_msg + _other -> return (Right name) + + bale_out_with msg + = return (Left (sep [ ptext (sLit "The") <+> what + <+> ptext (sLit "for") <+> quotes (ppr rdr_name) + , nest 2 $ ptext (sLit "lacks an accompanying binding")] + $$ nest 2 msg)) + + local_msg = parens $ ptext (sLit "The") <+> what <+> ptext (sLit "must be given where") + <+> quotes (ppr rdr_name) <+> ptext (sLit "is declared") + + import_msg = parens $ ptext (sLit "You cannot give a") <+> what + <+> ptext (sLit "for an imported value") + +--------------- +lookupLocalDataTcNames :: NameSet -> SDoc -> RdrName -> RnM [Name] +-- GHC extension: look up both the tycon and data con +-- for con-like things +-- Complain if neither is in scope +lookupLocalDataTcNames bound_names what rdr_name + | Just n <- isExact_maybe rdr_name + -- Special case for (:), which doesn't get into the GlobalRdrEnv + = return [n] -- For this we don't need to try the tycon too + | otherwise + = do { mb_gres <- mapM (lookupBindGroupOcc (Just bound_names) what) + (dataTcOccs rdr_name) + ; let (errs, names) = splitEithers mb_gres + ; when (null names) (addErr (head errs)) -- Bleat about one only + ; return names } + +dataTcOccs :: RdrName -> [RdrName] +-- If the input is a data constructor, return both it and a type +-- constructor. This is useful when we aren't sure which we are +-- looking at. +dataTcOccs rdr_name + | Just n <- isExact_maybe rdr_name -- Ghastly special case + , n `hasKey` consDataConKey = [rdr_name] -- see note below + | isDataOcc occ = [rdr_name, rdr_name_tc] + | otherwise = [rdr_name] + where + occ = rdrNameOcc rdr_name + rdr_name_tc = setRdrNameSpace rdr_name tcName + +-- If the user typed "[]" or "(,,)", we'll generate an Exact RdrName, +-- and setRdrNameSpace generates an Orig, which is fine +-- But it's not fine for (:), because there *is* no corresponding type +-- constructor. If we generate an Orig tycon for GHC.Base.(:), it'll +-- appear to be in scope (because Orig's simply allocate a new name-cache +-- entry) and then we get an error when we use dataTcOccs in +-- TcRnDriver.tcRnGetInfo. Large sigh. +\end{code} + + %********************************************************* %* * Fixities @@ -618,45 +705,6 @@ lookupFixityRn name lookupTyFixityRn :: Located Name -> RnM Fixity lookupTyFixityRn (L _ n) = lookupFixityRn n ---------------- -lookupLocalDataTcNames :: RdrName -> RnM [Name] --- GHC extension: look up both the tycon and data con --- for con-like things --- Complain if neither is in scope -lookupLocalDataTcNames rdr_name - | Just n <- isExact_maybe rdr_name - -- Special case for (:), which doesn't get into the GlobalRdrEnv - = return [n] -- For this we don't need to try the tycon too - | otherwise - = do { mb_gres <- mapM lookupGreLocalRn (dataTcOccs rdr_name) - ; case [gre_name gre | Just gre <- mb_gres] of - [] -> do { - -- run for error reporting - ; unboundName rdr_name - ; return [] } - names -> return names - } - -dataTcOccs :: RdrName -> [RdrName] --- If the input is a data constructor, return both it and a type --- constructor. This is useful when we aren't sure which we are --- looking at. -dataTcOccs rdr_name - | Just n <- isExact_maybe rdr_name -- Ghastly special case - , n `hasKey` consDataConKey = [rdr_name] -- see note below - | isDataOcc occ = [rdr_name_tc, rdr_name] - | otherwise = [rdr_name] - where - occ = rdrNameOcc rdr_name - rdr_name_tc = setRdrNameSpace rdr_name tcName - --- If the user typed "[]" or "(,,)", we'll generate an Exact RdrName, --- and setRdrNameSpace generates an Orig, which is fine --- But it's not fine for (:), because there *is* no corresponding type --- constructor. If we generate an Orig tycon for GHC.Base.(:), it'll --- appear to be in scope (because Orig's simply allocate a new name-cache --- entry) and then we get an error when we use dataTcOccs in --- TcRnDriver.tcRnGetInfo. Large sigh. \end{code} %************************************************************************ @@ -873,14 +921,31 @@ checkShadowedNames doc_str (global_env,local_env) loc_rdr_names where check_shadow (loc, occ) | Just n <- mb_local = complain [ptext (sLit "bound at") <+> ppr (nameSrcLoc n)] - | not (null gres) = complain (map pprNameProvenance gres) - | otherwise = return () + | otherwise = do { gres' <- filterM is_shadowed_gre gres + ; complain (map pprNameProvenance gres') } where + complain [] = return () complain pp_locs = addWarnAt loc (shadowedNameWarn doc_str occ pp_locs) mb_local = lookupLocalRdrOcc local_env occ gres = lookupGRE_RdrName (mkRdrUnqual occ) global_env -- Make an Unqualified RdrName and look that up, so that -- we don't find any GREs that are in scope qualified-only + + is_shadowed_gre :: GlobalRdrElt -> RnM Bool + -- Returns False for record selectors that are shadowed, when + -- 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) + then do { is_fld <- is_rec_fld gre; return (not is_fld) } + else return True } + is_shadowed_gre _other = return True + + is_rec_fld gre -- Return True for record selector ids + | isLocalGRE gre = do { RecFields _ fld_set <- getRecFieldEnv + ; return (gre_name gre `elemNameSet` fld_set) } + | otherwise = do { sel_id <- tcLookupField (gre_name gre) + ; return (isRecordSelector sel_id) } \end{code} @@ -893,11 +958,9 @@ checkShadowedNames doc_str (global_env,local_env) loc_rdr_names \begin{code} -- A useful utility mapFvRn :: (a -> RnM (b, FreeVars)) -> [a] -> RnM ([b], FreeVars) -mapFvRn f xs = mappM f xs `thenM` \ stuff -> - let - (ys, fvs_s) = unzip stuff - in - returnM (ys, plusFVs fvs_s) +mapFvRn f xs = do stuff <- mappM f xs + case unzip stuff of + (ys, fvs_s) -> returnM (ys, plusFVs fvs_s) -- because some of the rename functions are CPSed: -- maps the function across the list from left to right; @@ -1011,9 +1074,13 @@ unknownNameErr rdr_name <+> quotes (ppr rdr_name)) , extra ] where - extra | rdr_name == forall_tv_RDR - = ptext (sLit "Perhaps you intended to use -XRankNTypes or similar flag") - | otherwise = empty + extra | rdr_name == forall_tv_RDR = perhapsForallMsg + | otherwise = empty + +perhapsForallMsg :: SDoc +perhapsForallMsg + = vcat [ ptext (sLit "Perhaps you intended to use -XRankNTypes or similar flag") + , ptext (sLit "to enable explicit-forall syntax: forall . ")] unknownSubordinateErr :: SDoc -> RdrName -> SDoc unknownSubordinateErr doc op -- Doc is "method of class" or