-%
+\%
% (c) The GRASP/AQUA Project, Glasgow University, 1992-2006
%
\section[RnEnv]{Environment manipulation for the renamer monad}
\begin{code}
+{-# OPTIONS -w #-}
+-- The above warning supression flag is a temporary kludge.
+-- While working on this module you are encouraged to remove it and fix
+-- any warnings in the module. See
+-- http://hackage.haskell.org/trac/ghc/wiki/Commentary/CodingStyle#Warnings
+-- for details
+
module RnEnv (
newTopSrcBinder, lookupFamInstDeclBndr,
- lookupLocatedBndrRn, lookupBndrRn,
- lookupLocatedTopBndrRn, lookupTopBndrRn,
+ lookupLocatedBndrRn, lookupBndrRn, lookupBndrRn_maybe,
+ lookupLocatedTopBndrRn, lookupTopBndrRn, lookupBndrRn_maybe,
lookupLocatedOccRn, lookupOccRn,
lookupLocatedGlobalOccRn, lookupGlobalOccRn,
lookupLocalDataTcNames, lookupSrcOcc_maybe,
lookupFixityRn, lookupTyFixityRn, lookupLocatedSigOccRn,
- lookupLocatedInstDeclBndr,
+ lookupInstDeclBndr, lookupRecordBndr, lookupConstructorFields,
lookupSyntaxName, lookupSyntaxTable, lookupImportedName,
- lookupGreRn, lookupGreRn_maybe,
+ lookupGreRn, lookupGreLocalRn, lookupGreRn_maybe,
getLookupOccRn,
newLocalsRn, newIPNameRn,
- bindLocalNames, bindLocalNamesFV,
+ bindLocalNames, bindLocalNamesFV, bindLocalNamesFV_WithFixities,
bindLocatedLocalsFV, bindLocatedLocalsRn,
bindSigTyVarsFV, bindPatSigTyVars, bindPatSigTyVarsFV,
bindTyVarsRn, extendTyVarEnvFVRn,
bindLocalFixities,
- checkDupNames, mapFvRn,
+ checkDupNames, checkShadowing, mapFvRn, mapFvRnCPS,
warnUnusedMatches, warnUnusedModules, warnUnusedImports,
warnUnusedTopBinds, warnUnusedLocalBinds,
dataTcOccs, unknownNameErr,
Provenance(..), pprNameProvenance,
importSpecLoc, importSpecModule
)
-import HscTypes ( availNames, ModIface(..), FixItem(..), lookupFixity )
+import HscTypes ( availNames, ModIface(..), FixItem(..), lookupFixity)
+import TcEnv ( tcLookupDataCon )
import TcRnMonad
import Name ( Name, nameIsLocalOrFrom, mkInternalName, isWiredInName,
nameSrcLoc, nameOccName, nameModule, isExternalName )
import NameSet
+import NameEnv
+import UniqFM
+import DataCon ( dataConFieldLabels )
import OccName ( tcName, isDataOcc, pprNonVarNameSpace, occNameSpace,
- reportIfUnused )
+ reportIfUnused, occNameFS )
import Module ( Module, ModuleName )
import PrelNames ( mkUnboundName, rOOT_MAIN, iNTERACTIVE, consDataConKey, hasKey )
import UniqSupply
-import BasicTypes ( IPName, mapIPName )
+import BasicTypes ( IPName, mapIPName, Fixity )
import SrcLoc ( SrcSpan, srcSpanStart, Located(..), eqLocated, unLoc,
srcLocSpan, getLoc, combineSrcSpans, isOneLineSpan )
import Outputable
import Util ( sortLe )
+import Maybes
import ListSetOps ( removeDups )
import List ( nubBy )
import Monad ( when )
import DynFlags
+import FastString
\end{code}
%*********************************************************
-- the RdrName, not from the environment. In principle, it'd be fine to
-- have an arbitrary mixture of external core definitions in a single module,
-- (apart from module-initialisation issues, perhaps).
- ; newGlobalBinder rdr_mod rdr_occ (srcSpanStart loc) }
+ ; newGlobalBinder rdr_mod rdr_occ loc }
--TODO, should pass the whole span
| otherwise
(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) (srcSpanStart loc) }
+ ; newGlobalBinder this_mod (rdrNameOcc rdr_name) loc }
\end{code}
%*********************************************************
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
+ Just n' -> return 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 rdr_name
+lookupBndrRn_maybe rdr_name
= getLocalRdrEnv `thenM` \ local_env ->
case lookupLocalRdrEnv local_env rdr_name of
- Just name -> returnM name
- Nothing -> lookupTopBndrRn rdr_name
+ Just name -> returnM (Just name)
+ Nothing -> lookupTopBndrRn_maybe rdr_name
lookupLocatedTopBndrRn :: Located RdrName -> RnM (Located Name)
lookupLocatedTopBndrRn = wrapLocM lookupTopBndrRn
-lookupTopBndrRn :: RdrName -> RnM Name
+lookupTopBndrRn_maybe :: RdrName -> RnM (Maybe Name)
-- Look up a top-level source-code binder. We may be looking up an unqualified 'f',
-- and there may be several imported 'f's too, which must not confuse us.
-- For example, this is OK:
-- The Haskell parser checks for the illegal qualified name in Haskell
-- source files, so we don't need to do so here.
-lookupTopBndrRn rdr_name
+lookupTopBndrRn_maybe rdr_name
| Just name <- isExact_maybe rdr_name
- = returnM name
+ = returnM (Just name)
| Just (rdr_mod, rdr_occ) <- isOrig_maybe rdr_name
-- This deals with the case of derived bindings, where
-- we don't bother to call newTopSrcBinder first
-- We assume there is no "parent" name
= do { loc <- getSrcSpanM
- ; newGlobalBinder rdr_mod rdr_occ (srcSpanStart loc) }
+ ; n <- newGlobalBinder rdr_mod rdr_occ loc
+ ; return (Just n)}
| otherwise
= do { mb_gre <- lookupGreLocalRn rdr_name
; case mb_gre of
- Nothing -> do
- traceRn $ text "lookupTopBndrRn"
- unboundName rdr_name
- Just gre -> returnM (gre_name gre) }
+ Nothing -> returnM Nothing
+ Just gre -> returnM (Just $ gre_name gre) }
-- lookupLocatedSigOccRn is used for type signatures and pragmas
-- Is this valid?
-- 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 = lookupLocatedBndrRn
-
--- lookupInstDeclBndr is used for the binders in an
--- instance declaration. Here we use the class name to
--- disambiguate.
-
-lookupLocatedInstDeclBndr :: Name -> Located RdrName -> RnM (Located Name)
-lookupLocatedInstDeclBndr cls rdr = wrapLocM (lookupInstDeclBndr cls) rdr
-
-lookupInstDeclBndr :: Name -> RdrName -> RnM 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)
-- This is called on the method name on the left-hand side of an
-- instance declaration binding. eg. instance Functor T where
-- fmap = ...
-- ^^^^ called on this
-- Regardless of how many unqualified fmaps are in scope, we want
-- the one that comes from the Functor class.
-lookupInstDeclBndr cls_name rdr_name
+--
+-- Furthermore, note that we take no account of whether the
+-- name is only in scope qualified. I.e. even if method op is
+-- in scope as M.op, we still allow plain 'op' on the LHS of
+-- an instance decl
+lookupInstDeclBndr cls rdr = lookup_located_sub_bndr is_op doc rdr
+ where
+ doc = ptext SLIT("method of class") <+> quotes (ppr cls)
+ is_op gre@(GRE {gre_par = ParentIs n}) = n == cls
+ is_op other = False
+
+-----------------------------------------------
+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
+-- constructor name to disambiguate which field to use; it's just the
+-- same as for instance decls
+lookupRecordBndr Nothing rdr_name
+ = lookupLocatedGlobalOccRn rdr_name
+lookupRecordBndr (Just (L _ data_con)) rdr_name
+ = do { flag_on <- doptM Opt_DisambiguateRecordFields
+ ; if not flag_on
+ then lookupLocatedGlobalOccRn rdr_name
+ else do {
+ fields <- lookupConstructorFields data_con
+ ; let is_field gre = gre_name gre `elem` fields
+ ; lookup_located_sub_bndr is_field doc rdr_name
+ }}
+ where
+ doc = ptext SLIT("field of constructor") <+> quotes (ppr data_con)
+
+
+lookupConstructorFields :: Name -> RnM [Name]
+-- Look up the fields of a given constructor
+-- * For constructors from this module, use the record field env,
+-- which is itself gathered from the (as yet un-typechecked)
+-- data type decls
+--
+-- * For constructors from imported modules, use the *type* environment
+-- since imported modles are already compiled, the info is conveniently
+-- right there
+
+lookupConstructorFields con_name
+ = do { this_mod <- getModule
+ ; if nameIsLocalOrFrom this_mod con_name then
+ do { field_env <- getRecFieldEnv
+ ; return (lookupNameEnv field_env con_name `orElse` []) }
+ else
+ do { con <- tcLookupDataCon con_name
+ ; return (dataConFieldLabels con) } }
+
+-----------------------------------------------
+lookup_located_sub_bndr :: (GlobalRdrElt -> Bool)
+ -> SDoc -> Located RdrName
+ -> RnM (Located Name)
+lookup_located_sub_bndr is_good doc rdr_name
+ = wrapLocM (lookup_sub_bndr is_good doc) rdr_name
+
+lookup_sub_bndr is_good doc rdr_name
| isUnqual rdr_name -- Find all the things the rdr-name maps to
= do { -- and pick the one with the right parent name
- let { is_op gre@(GRE {gre_par = ParentIs n}) = cls_name == n
- ; is_op other = False
- ; occ = rdrNameOcc rdr_name
- ; lookup_fn env = filter is_op (lookupGlobalRdrEnv env occ) }
- ; mb_gre <- lookupGreRn_help rdr_name lookup_fn
- ; case mb_gre of
- Just gre -> return (gre_name gre)
- Nothing -> do { addErr (unknownInstBndrErr cls_name rdr_name)
- ; traceRn (text "lookupInstDeclBndr" <+> ppr rdr_name)
- ; return (mkUnboundName rdr_name) } }
+ ; env <- getGlobalRdrEnv
+ ; case filter is_good (lookupGlobalRdrEnv env (rdrNameOcc rdr_name)) of
+ -- NB: lookupGlobalRdrEnv, not lookupGRE_RdrName!
+ -- The latter does pickGREs, but we want to allow 'x'
+ -- even if only 'M.x' is in scope
+ [gre] -> return (gre_name gre)
+ [] -> do { addErr (unknownSubordinateErr doc rdr_name)
+ ; traceRn (text "RnEnv.lookup_sub_bndr" <+> ppr rdr_name)
+ ; return (mkUnboundName rdr_name) }
+ gres -> do { addNameClashErrRn rdr_name gres
+ ; return (gre_name (head gres)) }
+ }
| otherwise -- Occurs in derived instances, where we just
-- refer directly to the right method
| otherwise
= do { mb_gres <- mapM lookupGreLocalRn (dataTcOccs rdr_name)
; case [gre_name gre | Just gre <- mb_gres] of
- [] -> do { addErr (unknownNameErr rdr_name)
- ; return [] }
+ [] -> do {
+ -- run for error reporting
+ ; unboundName rdr_name
+ ; return [] }
names -> return names
}
--------------------------------
-bindLocalFixities :: [FixitySig RdrName] -> RnM a -> RnM a
--- Used for nested fixity decls
+bindLocalFixities :: [FixitySig RdrName] -> (UniqFM (Located Fixity) -> RnM a) -> RnM a
+-- Used for nested fixity decls:
+-- bind the names that are in scope already;
+-- pass the rest to the continuation for later
+-- as a FastString->(Located Fixity) map
+--
-- No need to worry about type constructors here,
--- Should check for duplicates but we don't
+-- Should check for duplicates?
bindLocalFixities fixes thing_inside
- | null fixes = thing_inside
- | otherwise = mappM rn_sig fixes `thenM` \ new_bit ->
- extendFixityEnv new_bit thing_inside
+ | null fixes = thing_inside emptyUFM
+ | otherwise = do ls <- mappM rn_sig fixes
+ let (now, later) = nowAndLater ls
+ extendFixityEnv now $ thing_inside later
where
- rn_sig (FixitySig lv@(L loc v) fix)
- = addLocM lookupBndrRn lv `thenM` \ new_v ->
- returnM (new_v, (FixItem (rdrNameOcc v) fix loc))
+ rn_sig (FixitySig lv@(L loc v) fix) = do
+ vopt <- lookupBndrRn_maybe v
+ case vopt of
+ Just new_v -> returnM (Left (new_v, (FixItem (rdrNameOcc v) fix)))
+ Nothing -> returnM (Right (occNameFS $ rdrNameOcc v, (L loc fix)))
+
+ nowAndLater (ls :: [Either (Name, FixItem) (FastString, Located Fixity)]) =
+ foldr (\ cur -> \ (now, later) ->
+ case cur of
+ Left (n, f) -> ((n, f) : now, later)
+ Right (fs, f) -> (now, addToUFM later fs f))
+ ([], emptyUFM) ls
+
+-- Used for nested fixity decls to bind names along with their fixities.
+-- the fixities are given as a UFM from an OccName's FastString to a fixity decl
+bindLocalNamesFV_WithFixities :: [Name] -> UniqFM (Located Fixity) -> RnM (a, FreeVars) -> RnM (a, FreeVars)
+bindLocalNamesFV_WithFixities names fixities cont =
+ -- find the names that have fixity decls
+ let boundFixities = foldr
+ (\ name -> \ acc ->
+ -- check whether this name has a fixity decl
+ case lookupUFM fixities (occNameFS (nameOccName name)) of
+ Just (L _ fix) -> (name, FixItem (nameOccName name) fix) : acc
+ Nothing -> acc) [] names in
+ -- bind the names; extend the fixity env; do the thing inside
+ bindLocalNamesFV names (extendFixityEnv boundFixities cont)
\end{code}
--------------------------------
\begin{code}
lookupFixityRn :: Name -> RnM Fixity
lookupFixityRn name
- = getModule `thenM` \ this_mod ->
+ = getModule `thenM` \ this_mod ->
if nameIsLocalOrFrom this_mod name
- then -- It's defined in this module
- getFixityEnv `thenM` \ local_fix_env ->
- traceRn (text "lookupFixityRn" <+> (ppr name $$ ppr local_fix_env)) `thenM_`
- returnM (lookupFixity local_fix_env name)
-
+ then do -- It's defined in this module
+ local_fix_env <- getFixityEnv
+ traceRn (text "lookupFixityRn: looking up name in local environment:" <+>
+ vcat [ppr name, ppr local_fix_env])
+ return $ lookupFixity local_fix_env name
else -- It's imported
-- For imported names, we have to get their fixities by doing a
-- loadInterfaceForName, and consulting the Ifaces that comes back
--
-- loadInterfaceForName will find B.hi even if B is a hidden module,
-- and that's what we want.
- loadInterfaceForName doc name `thenM` \ iface ->
- returnM (mi_fix_fn iface (nameOccName name))
+ loadInterfaceForName doc name `thenM` \ iface -> do {
+ traceRn (text "lookupFixityRn: looking up name in iface cache and found:" <+>
+ vcat [ppr name, ppr $ mi_fix_fn iface (nameOccName name)]);
+ returnM (mi_fix_fn iface (nameOccName name))
+ }
where
doc = ptext SLIT("Checking fixity for") <+> ppr name
---------------
lookupTyFixityRn :: Located Name -> RnM Fixity
-lookupTyFixityRn (L loc n)
- = do { glaExts <- doptM Opt_GlasgowExts
- ; when (not glaExts) (addWarnAt loc (infixTyConWarn n))
- ; lookupFixityRn n }
+lookupTyFixityRn (L loc n) = lookupFixityRn n
---------------
dataTcOccs :: RdrName -> [RdrName]
| otherwise = ASSERT2( isUnqual rdr_name, ppr rdr_name )
-- We only bind unqualified names here
-- lookupRdrEnv doesn't even attempt to look up a qualified RdrName
- mkInternalName uniq (rdrNameOcc rdr_name) (srcSpanStart loc)
+ mkInternalName uniq (rdrNameOcc rdr_name) loc
bindLocatedLocalsRn :: SDoc -- Documentation string for error message
-> [Located RdrName]
setLocalRdrEnv (extendLocalRdrEnv local_env names)
(enclosed_scope names)
-
bindLocalNames :: [Name] -> RnM a -> RnM a
bindLocalNames names enclosed_scope
= getLocalRdrEnv `thenM` \ name_env ->
-------------------------------------
-- binLocalsFVRn is the same as bindLocalsRn
-- except that it deals with free vars
-bindLocatedLocalsFV :: SDoc -> [Located RdrName] -> ([Name] -> RnM (a,FreeVars))
- -> RnM (a, FreeVars)
+bindLocatedLocalsFV :: SDoc -> [Located RdrName]
+ -> ([Name] -> RnM (a,FreeVars)) -> RnM (a, FreeVars)
bindLocatedLocalsFV doc rdr_names enclosed_scope
= bindLocatedLocalsRn doc rdr_names $ \ names ->
enclosed_scope names `thenM` \ (thing, fvs) ->
(ys, fvs_s) = unzip stuff
in
returnM (ys, plusFVs fvs_s)
+
+-- because some of the rename functions are CPSed:
+-- maps the function across the list from left to right;
+-- collects all the free vars into one set
+mapFvRnCPS :: (a -> ((b,FreeVars) -> RnM (c, FreeVars)) -> RnM(c, FreeVars))
+ -> [a]
+ -> (([b],FreeVars) -> RnM (c, FreeVars))
+ -> RnM (c, FreeVars)
+
+mapFvRnCPS _ [] cont = cont ([], emptyFVs)
+
+mapFvRnCPS f (h:t) cont = f h $ \ (h',hfv) ->
+ mapFvRnCPS f t $ \ (t',tfv) ->
+ cont (h':t', hfv `plusFV` tfv)
\end{code}
nest 2 $ pprNonVarNameSpace (occNameSpace (rdrNameOcc rdr_name))
<+> quotes (ppr rdr_name)]
-unknownInstBndrErr cls op
- = quotes (ppr op) <+> ptext SLIT("is not a (visible) method of class") <+> quotes (ppr cls)
+unknownSubordinateErr doc op -- Doc is "method of class" or
+ -- "field of constructor"
+ = quotes (ppr op) <+> ptext SLIT("is not a (visible)") <+> doc
badOrigBinding name
= ptext SLIT("Illegal binding of built-in syntax:") <+> ppr (rdrNameOcc name)
badQualBndrErr rdr_name
= ptext SLIT("Qualified name in binding position:") <+> ppr rdr_name
-
-infixTyConWarn op
- = vcat [ftext FSLIT("Accepting non-standard infix type constructor") <+> quotes (ppr op),
- ftext FSLIT("Use -fglasgow-exts to avoid this warning")]
\end{code}