\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,
mapFvRn, mapFvRnCPS,
warnUnusedMatches, warnUnusedModules, warnUnusedImports,
warnUnusedTopBinds, warnUnusedLocalBinds,
- dataTcOccs, unknownNameErr
+ dataTcOccs, unknownNameErr, perhapsForallMsg
) where
#include "HsVersions.h"
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
consDataConKey, hasKey, forall_tv_RDR )
import UniqSupply
import BasicTypes ( IPName, mapIPName, Fixity )
+import ErrUtils ( Message )
import SrcLoc
import Outputable
import Util
(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}
%*********************************************************
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
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
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)
-----------------------------------------------
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
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
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 }
--------------------------------------------------
= 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
| 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,
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
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}
%************************************************************************
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}
\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;
<+> 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 <tvs>. <type>")]
unknownSubordinateErr :: SDoc -> RdrName -> SDoc
unknownSubordinateErr doc op -- Doc is "method of class" or
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