-\%
+%
% (c) The GRASP/AQUA Project, Glasgow University, 1992-2006
%
\section[RnEnv]{Environment manipulation for the renamer monad}
\begin{code}
module RnEnv (
newTopSrcBinder, lookupFamInstDeclBndr,
- lookupLocatedBndrRn, lookupBndrRn, lookupBndrRn_maybe,
lookupLocatedTopBndrRn, lookupTopBndrRn,
lookupLocatedOccRn, lookupOccRn,
- lookupLocatedGlobalOccRn, lookupGlobalOccRn,
- lookupLocalDataTcNames, lookupSrcOcc_maybe,
+ lookupGlobalOccRn, lookupGlobalOccRn_maybe,
+ lookupLocalDataTcNames, lookupSigOccRn,
lookupFixityRn, lookupTyFixityRn,
- lookupInstDeclBndr, lookupRecordBndr, lookupConstructorFields,
- lookupSyntaxName, lookupSyntaxTable, lookupImportedName,
+ lookupInstDeclBndr, lookupSubBndr, lookupConstructorFields,
+ lookupSyntaxName, lookupSyntaxTable,
lookupGreRn, lookupGreLocalRn, lookupGreRn_maybe,
- getLookupOccRn,
+ getLookupOccRn, addUsedRdrNames,
- newLocalsRn, newIPNameRn,
- bindLocalNames, bindLocalNamesFV,
+ newLocalBndrRn, newLocalBndrsRn, newIPNameRn,
+ bindLocalName, bindLocalNames, bindLocalNamesFV,
MiniFixityEnv, emptyFsEnv, extendFsEnv, lookupFsEnv,
- bindLocalNamesFV_WithFixities,
+ addLocalFixities,
bindLocatedLocalsFV, bindLocatedLocalsRn,
bindSigTyVarsFV, bindPatSigTyVars, bindPatSigTyVarsFV,
- bindTyVarsRn, extendTyVarEnvFVRn,
+ bindTyVarsRn, bindTyVarsFV, extendTyVarEnvFVRn,
- checkDupRdrNames, checkDupNames, checkShadowedNames,
- checkDupAndShadowedRdrNames,
- mapFvRn, mapFvRnCPS,
- warnUnusedMatches, warnUnusedModules, warnUnusedImports,
+ checkDupRdrNames, checkDupAndShadowedRdrNames,
+ checkDupNames, checkDupAndShadowedNames,
+ addFvRn, mapFvRn, mapMaybeFvRn, mapFvRnCPS,
+ warnUnusedMatches,
warnUnusedTopBinds, warnUnusedLocalBinds,
- dataTcOccs, unknownNameErr, perhapsForallMsg
+ dataTcOccs, unknownNameErr, kindSigErr, 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 Name ( Name, nameIsLocalOrFrom, mkInternalName, isWiredInName,
- nameSrcLoc, nameSrcSpan, nameOccName, nameModule, isExternalName )
+import Id ( isRecordSelector )
+import Name
import NameSet
import NameEnv
-import LazyUniqFM
+import Module ( ModuleName, moduleName )
+import UniqFM
import DataCon ( dataConFieldLabels )
-import OccName
-import Module ( Module, ModuleName )
-import PrelNames ( mkUnboundName, rOOT_MAIN, iNTERACTIVE,
- consDataConKey, hasKey, forall_tv_RDR )
-import UniqSupply
-import BasicTypes ( IPName, mapIPName, Fixity )
+import PrelNames ( mkUnboundName, rOOT_MAIN, consDataConKey, forall_tv_RDR )
+import Unique
+import BasicTypes
+import ErrUtils ( Message )
import SrcLoc
import Outputable
import Util
import Maybes
import ListSetOps ( removeDups )
-import List ( nubBy )
import DynFlags
import FastString
import Control.Monad
+import Data.List
+import qualified Data.Set as Set
\end{code}
\begin{code}
-- XXX
thenM :: Monad a => a b -> (b -> a c) -> a c
thenM = (>>=)
-
-thenM_ :: Monad a => a b -> a c -> a c
-thenM_ = (>>)
-
-returnM :: Monad m => a -> m a
-returnM = return
-
-mappM :: (Monad m) => (a -> m b) -> [a] -> m [b]
-mappM = mapM
-
-mappM_ :: (Monad m) => (a -> m b) -> [a] -> m ()
-mappM_ = mapM_
-
-checkM :: Monad m => Bool -> m () -> m ()
-checkM = unless
\end{code}
%*********************************************************
%*********************************************************
\begin{code}
-newTopSrcBinder :: Module -> Located RdrName -> RnM Name
-newTopSrcBinder this_mod (L loc rdr_name)
+newTopSrcBinder :: Located RdrName -> RnM Name
+newTopSrcBinder (L loc rdr_name)
| Just name <- isExact_maybe rdr_name
= -- This is here to catch
-- (a) Exact-name binders created by Template Haskell
-- data T = (,) Int Int
-- unless we are in GHC.Tup
ASSERT2( isExternalName name, ppr name )
- do { checkM (this_mod == nameModule name)
+ do { this_mod <- getModule
+ ; unless (this_mod == nameModule name)
(addErrAt loc (badOrigBinding rdr_name))
; return name }
| Just (rdr_mod, rdr_occ) <- isOrig_maybe rdr_name
- = do { checkM (rdr_mod == this_mod || rdr_mod == rOOT_MAIN)
+ = do { this_mod <- getModule
+ ; unless (rdr_mod == this_mod || rdr_mod == rOOT_MAIN)
(addErrAt loc (badOrigBinding rdr_name))
-- When reading External Core we get Orig names as binders,
-- but they should agree with the module gotten from the monad
--TODO, should pass the whole span
| otherwise
- = do { checkM (not (isQual rdr_name))
+ = do { unless (not (isQual 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
+ do { this_mod <- getModule
+ ; 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
+Note [Type and class operator definitions]
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+We want to reject all of these unless we have -XTypeOperators (Trac #3265)
+ data a :*: b = ...
+ class a :*: b where ...
+ data (:*:) a b = ....
+ class (:*:) a b where ...
+The latter two mean that we are not just looking for a
+*syntactically-infix* declaration, but one that uses an operator
+OccName. We use OccName.isSymOcc to detect that case, which isn't
+terribly efficient, but there seems to be no better way.
+\begin{code}
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_maybe rdr_name
- = getLocalRdrEnv `thenM` \ local_env ->
- case lookupLocalRdrEnv local_env rdr_name of
- Just name -> returnM (Just name)
- Nothing -> lookupTopBndrRn_maybe rdr_name
+ unboundName WL_LocalTop n
lookupLocatedTopBndrRn :: Located RdrName -> RnM (Located Name)
lookupLocatedTopBndrRn = wrapLocM lookupTopBndrRn
lookupTopBndrRn_maybe rdr_name
| Just name <- isExact_maybe rdr_name
- = returnM (Just name)
+ = return (Just name)
| Just (rdr_mod, rdr_occ) <- isOrig_maybe rdr_name
-- This deals with the case of derived bindings, where
; return (Just n)}
| otherwise
- = do { mb_gre <- lookupGreLocalRn rdr_name
+ = do { -- Check for operators in type or class declarations
+ -- See Note [Type and class operator definitions]
+ let occ = rdrNameOcc rdr_name
+ ; when (isTcOcc occ && isSymOcc occ)
+ (do { op_ok <- xoptM Opt_TypeOperators
+ ; unless op_ok (addErr (opDeclErr rdr_name)) })
+
+ ; mb_gre <- lookupGreLocalRn rdr_name
; case mb_gre of
- Nothing -> returnM Nothing
- Just gre -> returnM (Just $ gre_name gre) }
+ Nothing -> return Nothing
+ Just gre -> return (Just $ gre_name gre) }
-----------------------------------------------
-lookupInstDeclBndr :: Name -> Located RdrName -> RnM (Located Name)
+lookupInstDeclBndr :: Name -> RdrName -> RnM Name
-- This is called on the method name on the left-hand side of an
-- instance declaration binding. eg. instance Functor T where
-- fmap = ...
-- 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
+lookupInstDeclBndr cls rdr
+ = do { when (isQual rdr)
+ (addErr (badQualBndrErr rdr))
+ -- In an instance decl you aren't allowed
+ -- to use a qualified name for the method
+ -- (Although it'd make perfect sense.)
+ ; lookupSubBndr (ParentIs cls) doc rdr }
where
doc = ptext (sLit "method of class") <+> quotes (ppr cls)
- is_op (GRE {gre_par = ParentIs n}) = n == cls
- is_op _ = 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,
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
; 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 :: (GlobalRdrElt -> Bool) -> SDoc -> RdrName -> RnM 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
+-- Used for record construction and pattern matching
+-- 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.
+
+lookupSubBndr :: Parent -- NoParent => just look it up as usual
+ -- ParentIs p => use p to disambiguate
+ -> SDoc -> RdrName
+ -> RnM Name
+lookupSubBndr parent doc rdr_name
+ | Just n <- isExact_maybe rdr_name -- This happens in derived code
+ = return n
+
+ | Just (rdr_mod, rdr_occ) <- isOrig_maybe rdr_name
+ = lookupOrig rdr_mod rdr_occ
+
+ | otherwise -- Find all the things the rdr-name maps to
+ = do { -- and pick the one with the right parent name
; env <- getGlobalRdrEnv
- ; case filter is_good (lookupGlobalRdrEnv env (rdrNameOcc rdr_name)) of
+ ; let gres = lookupGlobalRdrEnv env (rdrNameOcc rdr_name)
+ ; case pick parent gres 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)
+ [gre] -> do { addUsedRdrNames (used_rdr_names gre)
+ ; return (gre_name gre) }
[] -> do { addErr (unknownSubordinateErr doc rdr_name)
- ; traceRn (text "RnEnv.lookup_sub_bndr" <+> ppr rdr_name)
+ ; traceRn (text "RnEnv.lookup_sub_bndr" <+> (ppr rdr_name $$ ppr gres))
; 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
- = ASSERT2( not (isQual rdr_name), ppr rdr_name )
- -- NB: qualified names are rejected by the parser
- lookupImportedName rdr_name
+ ; return (gre_name (head gres)) } }
+ where
+ pick NoParent gres -- Normal lookup
+ = pickGREs rdr_name gres
+ pick (ParentIs p) gres -- Disambiguating lookup
+ | isUnqual rdr_name = filter (right_parent p) gres
+ | otherwise = filter (right_parent p) (pickGREs rdr_name gres)
+
+ right_parent p (GRE { gre_par = ParentIs p' }) = p==p'
+ right_parent _ _ = False
+
+ -- Note [Usage for sub-bndrs]
+ used_rdr_names gre
+ | isQual rdr_name = [rdr_name]
+ | otherwise = case gre_prov gre of
+ LocalDef -> [rdr_name]
+ Imported is -> map mk_qual_rdr is
+ mk_qual_rdr imp_spec = mkRdrQual (is_as (is_decl imp_spec)) rdr_occ
+ rdr_occ = rdrNameOcc rdr_name
newIPNameRn :: IPName RdrName -> TcRnIf m n (IPName Name)
newIPNameRn ip_rdr = newIPName (mapIPName rdrNameOcc ip_rdr)
--- Looking up family names in type instances is a subtle affair. The family
--- may be imported, in which case we need to lookup the occurence of a global
--- name. Alternatively, the family may be in the same binding group (and in
--- fact in a declaration processed later), and we need to create a new top
--- source binder.
---
--- So, also this is strictly speaking an occurence, we cannot raise an error
--- message yet for instances without a family declaration. This will happen
--- during renaming the type instance declaration in RnSource.rnTyClDecl.
+-- If the family is declared locally, it will not yet be in the main
+-- environment; hence, we pass in an extra one here, which we check first.
+-- See "Note [Looking up family names in family instances]" in 'RnNames'.
--
-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)
- Nothing -> newTopSrcBinder mod lrdr_name }
+lookupFamInstDeclBndr :: GlobalRdrEnv -> Located RdrName -> RnM Name
+lookupFamInstDeclBndr tyclGroupEnv (L loc rdr_name)
+ = setSrcSpan loc $
+ case lookupGRE_RdrName rdr_name tyclGroupEnv of
+ (gre:_) -> return $ gre_name gre
+ -- if there is more than one, an error will be raised elsewhere
+ [] -> lookupOccRn rdr_name
+\end{code}
+
+Note [Usage for sub-bndrs]
+~~~~~~~~~~~~~~~~~~~~~~~~~~
+If you have this
+ import qualified M( C( f ) )
+ intance M.C T where
+ f x = x
+then is the qualified import M.f used? Obviously yes.
+But the RdrName used in the instance decl is unqualified. In effect,
+we fill in the qualification by looking for f's whose class is M.C
+But when adding to the UsedRdrNames we must make that qualification
+explicit, otherwise we get "Redundant import of M.C".
--------------------------------------------------
-- Occurrences
--------------------------------------------------
+\begin{code}
getLookupOccRn :: RnM (Name -> Maybe Name)
getLookupOccRn
= getLocalRdrEnv `thenM` \ local_env ->
-- 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 -> returnM name
- Nothing -> lookupGlobalOccRn rdr_name
+ = do { local_env <- getLocalRdrEnv
+ ; case lookupLocalRdrEnv local_env rdr_name of {
+ Just name -> return name ;
+ Nothing -> do
+
+ { mb_name <- lookupGlobalOccRn_maybe rdr_name
+ ; case mb_name of {
+ Just n -> return n ;
+ 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.
+ allow_qual <- doptM Opt_ImplicitImportQualified
+ ; is_ghci <- getIsGHCi
+ -- This test is not expensive,
+ -- and only happens for failed lookups
+ ; if isQual rdr_name && allow_qual && is_ghci
+ then lookupQualifiedName rdr_name
+ else unboundName WL_Any 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. It's used only for
--- record field names
--- class op names in class and instance decls
-
+-- environment. Adds an error message if the RdrName is not in scope.
lookupGlobalOccRn rdr_name
- | not (isSrcRdrName rdr_name)
- = lookupImportedName 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
+
+lookupGlobalOccRn_maybe rdr_name
+ | Just n <- isExact_maybe rdr_name -- This happens in derived code
+ = return (Just n)
- | otherwise
- = 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 -> 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.
- 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 do
- traceRn $ text "lookupGlobalOccRn"
- unboundName rdr_name
- }
-
-lookupImportedName :: RdrName -> TcRnIf m n Name
--- Lookup the occurrence of an imported name
--- The RdrName is *always* qualified or Exact
--- Treat it as an original name, and conjure up the Name
--- Usually it's Exact or Orig, but it can be Qual if it
--- comes from an hi-boot file. (This minor infelicity is
--- just to reduce duplication in the parser.)
-lookupImportedName rdr_name
- | Just n <- isExact_maybe rdr_name
- -- This happens in derived code
- = returnM n
-
- -- Always Orig, even when reading a .hi-boot file
| Just (rdr_mod, rdr_occ) <- isOrig_maybe rdr_name
- = lookupOrig rdr_mod rdr_occ
+ = do { n <- lookupOrig rdr_mod rdr_occ; return (Just n) }
| otherwise
- = pprPanic "RnEnv.lookupImportedName" (ppr rdr_name)
+ = do { mb_gre <- lookupGreRn_maybe rdr_name
+ ; case mb_gre of
+ Nothing -> return Nothing
+ 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)])
- ; returnM (mkUnboundName rdr_name) }
--------------------------------------------------
-- Lookup in the Global RdrEnv of the module
--------------------------------------------------
-lookupSrcOcc_maybe :: RdrName -> RnM (Maybe Name)
--- No filter function; does not report an error on failure
-lookupSrcOcc_maybe rdr_name
- = do { mb_gre <- lookupGreRn_maybe rdr_name
- ; case mb_gre of
- Nothing -> returnM Nothing
- Just gre -> returnM (Just (gre_name gre)) }
-
--------------------------
lookupGreRn_maybe :: RdrName -> RnM (Maybe GlobalRdrElt)
-- Just look up the RdrName in the GlobalRdrEnv
lookupGreRn_maybe 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 }) }}}
lookupGreRn_help rdr_name lookup
= do { env <- getGlobalRdrEnv
; case lookup env of
- [] -> returnM Nothing
- [gre] -> returnM (Just gre)
+ [] -> return Nothing
+ [gre] -> do { addUsedRdrName gre rdr_name
+ ; return (Just gre) }
gres -> do { addNameClashErrRn rdr_name gres
- ; returnM (Just (head gres)) } }
+ ; return (Just (head gres)) } }
+
+addUsedRdrName :: GlobalRdrElt -> RdrName -> RnM ()
+-- Record usage of imported RdrNames
+addUsedRdrName gre rdr
+ | isLocalGRE gre = return ()
+ | otherwise = do { env <- getGblEnv
+ ; updMutVar (tcg_used_rdrnames env)
+ (\s -> Set.insert rdr s) }
+
+addUsedRdrNames :: [RdrName] -> RnM ()
+-- Record used sub-binders
+-- We don't check for imported-ness here, because it's inconvenient
+-- and not stritly necessary.
+addUsedRdrNames rdrs
+ = do { env <- getGblEnv
+ ; updMutVar (tcg_used_rdrnames env)
+ (\s -> foldr Set.insert s rdrs) }
------------------------------
-- GHCi support
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)
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
+ 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 => these are the binders
+ -- in the same group
+ -- 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
+ = 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 -- 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
+
+ { 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 '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
+ 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
--------------------------------
-- 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
--- Also check for unused binders
-bindLocalNamesFV_WithFixities :: [Name]
- -> MiniFixityEnv
- -> RnM (a, FreeVars) -> RnM (a, FreeVars)
-bindLocalNamesFV_WithFixities names fixities thing_inside
- = bindLocalNamesFV names $
- extendFixityEnv boundFixities $
- thing_inside
+
+addLocalFixities :: MiniFixityEnv -> [Name] -> RnM a -> RnM a
+addLocalFixities mini_fix_env names thing_inside
+ = extendFixityEnv (mapCatMaybes find_fixity names) thing_inside
where
- -- find the names that have fixity decls
- boundFixities = foldr
- (\ name -> \ acc ->
- -- check whether this name has a fixity decl
- case lookupFsEnv fixities (occNameFS (nameOccName name)) of
- Just (L _ fix) -> (name, FixItem (nameOccName name) fix) : acc
- Nothing -> acc) [] names
- -- bind the names; extend the fixity env; do the thing inside
+ find_fixity name
+ = case lookupFsEnv mini_fix_env (occNameFS occ) of
+ Just (L _ fix) -> Just (name, FixItem occ fix)
+ Nothing -> Nothing
+ where
+ occ = nameOccName name
\end{code}
--------------------------------
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))
+ return (mi_fix_fn iface (nameOccName name))
}
where
doc = ptext (sLit "Checking fixity for") <+> ppr 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}
%************************************************************************
%* *
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
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 ->
- returnM (HsVar usr_name, unitFV usr_name)
+ return (HsVar usr_name, unitFV usr_name)
where
- normal_case = returnM (HsVar std_name, emptyFVs)
+ normal_case = return (HsVar std_name, emptyFVs)
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
- mappM (lookupOccRn . mkRdrUnqual . nameOccName) std_names `thenM` \ usr_names ->
+ mapM (lookupOccRn . mkRdrUnqual . nameOccName) std_names `thenM` \ usr_names ->
- returnM (std_names `zip` map HsVar usr_names, mkFVs usr_names)
+ return (std_names `zip` map HsVar usr_names, mkFVs usr_names)
where
- normal_case = returnM (std_names `zip` map HsVar std_names, emptyFVs)
+ normal_case = return (std_names `zip` map HsVar std_names, emptyFVs)
\end{code}
%*********************************************************
\begin{code}
-newLocalsRn :: [Located RdrName] -> RnM [Name]
-newLocalsRn rdr_names_w_loc
- = newUniqueSupply `thenM` \ us ->
- returnM (zipWith mk rdr_names_w_loc (uniqsFromSupply us))
- where
- mk (L loc rdr_name) uniq
- | Just name <- isExact_maybe rdr_name = name
- -- This happens in code generated by Template Haskell
- | 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) loc
+newLocalBndrRn :: Located RdrName -> RnM Name
+-- Used for non-top-level binders. These should
+-- never be qualified.
+newLocalBndrRn (L loc rdr_name)
+ | Just name <- isExact_maybe rdr_name
+ = return name -- This happens in code generated by Template Haskell
+ -- although I'm not sure why. Perhpas it's the call
+ -- in RnPat.newName LetMk?
+ | otherwise
+ = do { unless (isUnqual rdr_name)
+ (addErrAt loc (badQualBndrErr rdr_name))
+ ; uniq <- newUnique
+ ; return (mkInternalName uniq (rdrNameOcc rdr_name) loc) }
----------------------
-checkDupAndShadowedRdrNames :: SDoc -> [Located RdrName] -> RnM ()
-checkDupAndShadowedRdrNames doc loc_rdr_names
- = do { checkDupRdrNames doc loc_rdr_names
- ; envs <- getRdrEnvs
- ; checkShadowedNames doc envs
- [(loc,rdrNameOcc rdr) | L loc rdr <- loc_rdr_names] }
+newLocalBndrsRn :: [Located RdrName] -> RnM [Name]
+newLocalBndrsRn = mapM newLocalBndrRn
---------------------
-bindLocatedLocalsRn :: SDoc -- Documentation string for error message
- -> [Located RdrName]
+bindLocatedLocalsRn :: [Located RdrName]
-> ([Name] -> RnM a)
-> RnM a
-bindLocatedLocalsRn doc_str rdr_names_w_loc enclosed_scope
- = checkDupAndShadowedRdrNames doc_str rdr_names_w_loc `thenM_`
+bindLocatedLocalsRn rdr_names_w_loc enclosed_scope
+ = do { checkDupAndShadowedRdrNames rdr_names_w_loc
-- Make fresh Names and extend the environment
- newLocalsRn rdr_names_w_loc `thenM` \names ->
- bindLocalNames names (enclosed_scope names)
+ ; names <- newLocalBndrsRn rdr_names_w_loc
+ ; bindLocalNames names (enclosed_scope names) }
bindLocalNames :: [Name] -> RnM a -> RnM a
bindLocalNames names enclosed_scope
- = getLocalRdrEnv `thenM` \ name_env ->
- setLocalRdrEnv (extendLocalRdrEnv name_env names)
- enclosed_scope
+ = do { name_env <- getLocalRdrEnv
+ ; setLocalRdrEnv (extendLocalRdrEnvList name_env names)
+ enclosed_scope }
+
+bindLocalName :: Name -> RnM a -> RnM a
+bindLocalName name enclosed_scope
+ = do { name_env <- getLocalRdrEnv
+ ; setLocalRdrEnv (extendLocalRdrEnv name_env name)
+ enclosed_scope }
bindLocalNamesFV :: [Name] -> RnM (a, FreeVars) -> RnM (a, FreeVars)
bindLocalNamesFV names enclosed_scope
= do { (result, fvs) <- bindLocalNames names enclosed_scope
- ; returnM (result, delListFromNameSet fvs names) }
+ ; return (result, delFVs names fvs) }
-------------------------------------
-- binLocalsFVRn is the same as bindLocalsRn
-- except that it deals with free vars
-bindLocatedLocalsFV :: SDoc -> [Located RdrName]
+bindLocatedLocalsFV :: [Located RdrName]
-> ([Name] -> RnM (a,FreeVars)) -> RnM (a, FreeVars)
-bindLocatedLocalsFV doc rdr_names enclosed_scope
- = bindLocatedLocalsRn doc rdr_names $ \ names ->
+bindLocatedLocalsFV rdr_names enclosed_scope
+ = bindLocatedLocalsRn rdr_names $ \ names ->
enclosed_scope names `thenM` \ (thing, fvs) ->
- returnM (thing, delListFromNameSet fvs names)
+ return (thing, delFVs names fvs)
-------------------------------------
-bindTyVarsRn :: SDoc -> [LHsTyVarBndr RdrName]
+bindTyVarsFV :: [LHsTyVarBndr RdrName]
+ -> ([LHsTyVarBndr Name] -> RnM (a, FreeVars))
+ -> RnM (a, FreeVars)
+bindTyVarsFV tyvars thing_inside
+ = bindTyVarsRn tyvars $ \ tyvars' ->
+ do { (res, fvs) <- thing_inside tyvars'
+ ; return (res, delFVs (map hsLTyVarName tyvars') fvs) }
+
+bindTyVarsRn :: [LHsTyVarBndr RdrName]
-> ([LHsTyVarBndr Name] -> RnM a)
-> RnM a
-- Haskell-98 binding of type variables; e.g. within a data type decl
-bindTyVarsRn doc_str tyvar_names enclosed_scope
- = let
- located_tyvars = hsLTyVarLocNames tyvar_names
- in
- bindLocatedLocalsRn doc_str located_tyvars $ \ names ->
- enclosed_scope (zipWith replace tyvar_names names)
- where
- replace (L loc n1) n2 = L loc (replaceTyVarName n1 n2)
+bindTyVarsRn tyvar_names enclosed_scope
+ = bindLocatedLocalsRn located_tyvars $ \ names ->
+ 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) }
+ where
+ replace (L loc n1) n2 = L loc (replaceTyVarName n1 n2)
+ located_tyvars = hsLTyVarLocNames tyvar_names
+ kinded_tyvars = [n | L _ (KindedTyVar n _) <- tyvar_names]
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
-- f (x :: t) (y :: t) = ....
-- We don't want to complain about binding t twice!
- ; bindLocatedLocalsRn doc_sig nubbed_tvs thing_inside }}
- where
- doc_sig = text "In a pattern type-signature"
+ ; bindLocatedLocalsRn nubbed_tvs thing_inside }}
bindPatSigTyVarsFV :: [LHsType RdrName]
-> RnM (a, FreeVars)
bindPatSigTyVarsFV tys thing_inside
= bindPatSigTyVars tys $ \ tvs ->
thing_inside `thenM` \ (result,fvs) ->
- returnM (result, fvs `delListFromNameSet` tvs)
+ return (result, fvs `delListFromNameSet` tvs)
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
extendTyVarEnvFVRn tyvars thing_inside = bindLocalNamesFV tyvars thing_inside
-------------------------------------
-checkDupRdrNames :: SDoc
- -> [Located RdrName]
- -> RnM ()
-checkDupRdrNames doc_str rdr_names_w_loc
+checkDupRdrNames :: [Located RdrName] -> RnM ()
+checkDupRdrNames rdr_names_w_loc
= -- Check for duplicated names in a binding group
- mappM_ (dupNamesErr getLoc doc_str) dups
+ mapM_ (dupNamesErr getLoc) dups
where
(_, dups) = removeDups (\n1 n2 -> unLoc n1 `compare` unLoc n2) rdr_names_w_loc
-checkDupNames :: SDoc
- -> [Name]
- -> RnM ()
-checkDupNames doc_str names
+checkDupNames :: [Name] -> RnM ()
+checkDupNames names
= -- Check for duplicated names in a binding group
- mappM_ (dupNamesErr nameSrcSpan doc_str) dups
+ mapM_ (dupNamesErr nameSrcSpan) dups
where
(_, dups) = removeDups (\n1 n2 -> nameOccName n1 `compare` nameOccName n2) names
+---------------------
+checkDupAndShadowedRdrNames :: [Located RdrName] -> RnM ()
+checkDupAndShadowedRdrNames loc_rdr_names
+ = do { checkDupRdrNames loc_rdr_names
+ ; envs <- getRdrEnvs
+ ; checkShadowedOccs envs loc_occs }
+ where
+ loc_occs = [(loc,rdrNameOcc rdr) | L loc rdr <- loc_rdr_names]
+
+checkDupAndShadowedNames :: (GlobalRdrEnv, LocalRdrEnv) -> [Name] -> RnM ()
+checkDupAndShadowedNames envs names
+ = do { checkDupNames names
+ ; checkShadowedOccs envs loc_occs }
+ where
+ loc_occs = [(nameSrcSpan name, nameOccName name) | name <- names]
+
-------------------------------------
-checkShadowedNames :: SDoc -> (GlobalRdrEnv, LocalRdrEnv) -> [(SrcSpan,OccName)] -> RnM ()
-checkShadowedNames doc_str (global_env,local_env) loc_rdr_names
- = ifOptM Opt_WarnNameShadowing $
- do { traceRn (text "shadow" <+> ppr loc_rdr_names)
- ; mappM_ check_shadow loc_rdr_names }
+checkShadowedOccs :: (GlobalRdrEnv, LocalRdrEnv) -> [(SrcSpan,OccName)] -> RnM ()
+checkShadowedOccs (global_env,local_env) loc_occs
+ = ifDOptM Opt_WarnNameShadowing $
+ do { traceRn (text "shadow" <+> ppr loc_occs)
+ ; mapM_ check_shadow loc_occs }
where
check_shadow (loc, occ)
+ | startsWithUnderscore occ = return () -- Do not report shadowing for "_x"
+ -- See Trac #3262
| 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 pp_locs = addWarnAt loc (shadowedNameWarn doc_str occ pp_locs)
+ complain [] = return ()
+ complain pp_locs = addWarnAt loc (shadowedNameWarn 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 (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
+
+ 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}
%************************************************************************
%* *
+ 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))
+ 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}
%* *
%************************************************************************
\begin{code}
-- A useful utility
+addFvRn :: FreeVars -> RnM (thing, FreeVars) -> RnM (thing, FreeVars)
+addFvRn fvs1 thing_inside = do { (res, fvs2) <- thing_inside
+ ; return (res, fvs1 `plusFV` fvs2) }
+
mapFvRn :: (a -> RnM (b, FreeVars)) -> [a] -> RnM ([b], FreeVars)
-mapFvRn f xs = do stuff <- mappM f xs
+mapFvRn f xs = do stuff <- mapM f xs
case unzip stuff of
- (ys, fvs_s) -> returnM (ys, plusFVs fvs_s)
+ (ys, fvs_s) -> return (ys, plusFVs fvs_s)
+
+mapMaybeFvRn :: (a -> RnM (b, FreeVars)) -> Maybe a -> RnM (Maybe b, FreeVars)
+mapMaybeFvRn _ Nothing = return (Nothing, emptyFVs)
+mapMaybeFvRn f (Just x) = do { (y, fvs) <- f x; return (Just y, fvs) }
-- because some of the rename functions are CPSed:
-- maps the function across the list from left to right;
%************************************************************************
\begin{code}
-warnUnusedModules :: [(ModuleName,SrcSpan)] -> RnM ()
-warnUnusedModules mods
- = ifOptM Opt_WarnUnusedImports (mappM_ 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 gres = ifOptM Opt_WarnUnusedBinds (warnUnusedGREs gres)
+warnUnusedTopBinds :: [GlobalRdrElt] -> RnM ()
+warnUnusedTopBinds gres
+ = ifDOptM Opt_WarnUnusedBinds
+ $ do isBoot <- tcIsHsBoot
+ let noParent gre = case gre_par gre of
+ NoParent -> True
+ ParentIs _ -> False
+ -- Don't warn about unused bindings with parents in
+ -- .hs-boot files, as you are sometimes required to give
+ -- unused bindings (trac #3449).
+ gres' = if isBoot then filter noParent gres
+ else gres
+ warnUnusedGREs gres'
warnUnusedLocalBinds, warnUnusedMatches :: [Name] -> FreeVars -> RnM ()
warnUnusedLocalBinds = check_unused Opt_WarnUnusedBinds
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
= warnUnusedBinds [(n,LocalDef) | n<-names]
warnUnusedBinds :: [(Name,Provenance)] -> RnM ()
-warnUnusedBinds names = mappM_ warnUnusedName (filter reportable names)
+warnUnusedBinds names = mapM_ warnUnusedName (filter reportable names)
where reportable (name,_)
| isWiredInName name = False -- Don't report unused wired-in names
-- Otherwise we get a zillion warnings
-- from Data.Tuple
- | otherwise = reportIfUnused (nameOccName name)
+ | otherwise = not (startsWithUnderscore (nameOccName name))
-------------------------
warnUnusedName :: (Name, Provenance) -> RnM ()
warnUnusedName (name, LocalDef)
- = addUnusedWarning name (srcLocSpan (nameSrcLoc name))
+ = addUnusedWarning name (nameSrcSpan name)
(ptext (sLit "Defined but not used"))
warnUnusedName (name, Imported is)
(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 :: SDoc -> OccName -> [SDoc] -> SDoc
-shadowedNameWarn doc occ shadowed_locs
+shadowedNameWarn :: OccName -> [SDoc] -> SDoc
+shadowedNameWarn occ shadowed_locs
= sep [ptext (sLit "This binding for") <+> quotes (ppr occ)
<+> ptext (sLit "shadows the existing binding") <> plural shadowed_locs,
nest 2 (vcat shadowed_locs)]
- $$ doc
-
-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 -XRankNTypes or similar flag")
+ = vcat [ ptext (sLit "Perhaps you intended to use -XExplicitForAll or similar flag")
, ptext (sLit "to enable explicit-forall syntax: forall <tvs>. <type>")]
unknownSubordinateErr :: SDoc -> RdrName -> SDoc
= ptext (sLit "Illegal binding of built-in syntax:") <+> ppr (rdrNameOcc name)
-- The rdrNameOcc is because we don't want to print Prelude.(,)
-dupNamesErr :: Outputable n => (n -> SrcSpan) -> SDoc -> [n] -> RnM ()
-dupNamesErr get_loc descriptor names
+dupNamesErr :: Outputable n => (n -> SrcSpan) -> [n] -> RnM ()
+dupNamesErr get_loc names
= addErrAt big_loc $
vcat [ptext (sLit "Conflicting definitions for") <+> quotes (ppr (head names)),
- locations, descriptor]
+ locations]
where
locs = map get_loc names
big_loc = foldr1 combineSrcSpans locs
- one_line = isOneLineSpan big_loc
- locations | one_line = empty
- | otherwise = ptext (sLit "Bound at:") <+>
- vcat (map ppr (sortLe (<=) locs))
+ locations = ptext (sLit "Bound at:") <+> vcat (map ppr (sortLe (<=) locs))
+
+kindSigErr :: Outputable a => a -> SDoc
+kindSigErr thing
+ = hang (ptext (sLit "Illegal kind signature for") <+> quotes (ppr thing))
+ 2 (ptext (sLit "Perhaps you intended to use -XKindSignatures"))
+
badQualBndrErr :: RdrName -> SDoc
badQualBndrErr rdr_name
= ptext (sLit "Qualified name in binding position:") <+> ppr rdr_name
+
+opDeclErr :: RdrName -> SDoc
+opDeclErr n
+ = hang (ptext (sLit "Illegal declaration of a type or class operator") <+> quotes (ppr n))
+ 2 (ptext (sLit "Use -XTypeOperators to declare operators in type and declarations"))
\end{code}