2 % (c) The GRASP/AQUA Project, Glasgow University, 1992-2006
4 \section[RnEnv]{Environment manipulation for the renamer monad}
8 newTopSrcBinder, lookupFamInstDeclBndr,
9 lookupLocatedTopBndrRn, lookupTopBndrRn,
10 lookupLocatedOccRn, lookupOccRn,
11 lookupGlobalOccRn, lookupGlobalOccRn_maybe,
12 lookupLocalDataTcNames, lookupSigOccRn,
13 lookupFixityRn, lookupTyFixityRn,
14 lookupInstDeclBndr, lookupSubBndr, lookupConstructorFields,
15 lookupSyntaxName, lookupSyntaxTable, lookupIfThenElse,
16 lookupGreRn, lookupGreLocalRn, lookupGreRn_maybe,
17 getLookupOccRn, addUsedRdrNames,
19 newLocalBndrRn, newLocalBndrsRn, newIPNameRn,
20 bindLocalName, bindLocalNames, bindLocalNamesFV,
21 MiniFixityEnv, emptyFsEnv, extendFsEnv, lookupFsEnv,
23 bindLocatedLocalsFV, bindLocatedLocalsRn,
24 bindSigTyVarsFV, bindPatSigTyVars, bindPatSigTyVarsFV,
25 bindTyVarsRn, bindTyVarsFV, extendTyVarEnvFVRn,
27 checkDupRdrNames, checkDupAndShadowedRdrNames,
28 checkDupNames, checkDupAndShadowedNames,
29 addFvRn, mapFvRn, mapMaybeFvRn, mapFvRnCPS,
31 warnUnusedTopBinds, warnUnusedLocalBinds,
32 dataTcOccs, unknownNameErr, kindSigErr, perhapsForallMsg
35 #include "HsVersions.h"
37 import LoadIface ( loadInterfaceForName, loadSrcInterface )
38 import IfaceEnv ( lookupOrig, newGlobalBinder, newIPName )
39 import TcEnv ( getHetMetLevel )
41 import RdrHsSyn ( extractHsTyRdrTyVars )
43 import HscTypes ( availNames, ModIface(..), FixItem(..), lookupFixity)
44 import TcEnv ( tcLookupDataCon, tcLookupField, isBrackStage )
46 import Id ( isRecordSelector )
50 import Module ( ModuleName, moduleName )
52 import DataCon ( dataConFieldLabels )
53 import PrelNames ( mkUnboundName, rOOT_MAIN, consDataConKey, forall_tv_RDR )
56 import ErrUtils ( Message )
61 import ListSetOps ( removeDups )
66 import qualified Data.Set as Set
71 thenM :: Monad a => a b -> (b -> a c) -> a c
75 %*********************************************************
79 %*********************************************************
82 newTopSrcBinder :: Located RdrName -> RnM Name
83 newTopSrcBinder (L loc rdr_name)
84 | Just name <- isExact_maybe rdr_name
85 = -- This is here to catch
86 -- (a) Exact-name binders created by Template Haskell
87 -- (b) The PrelBase defn of (say) [] and similar, for which
88 -- the parser reads the special syntax and returns an Exact RdrName
89 -- We are at a binding site for the name, so check first that it
90 -- the current module is the correct one; otherwise GHC can get
91 -- very confused indeed. This test rejects code like
92 -- data T = (,) Int Int
93 -- unless we are in GHC.Tup
94 ASSERT2( isExternalName name, ppr name )
95 do { this_mod <- getModule
96 ; unless (this_mod == nameModule name)
97 (addErrAt loc (badOrigBinding rdr_name))
101 | Just (rdr_mod, rdr_occ) <- isOrig_maybe rdr_name
102 = do { this_mod <- getModule
103 ; unless (rdr_mod == this_mod || rdr_mod == rOOT_MAIN)
104 (addErrAt loc (badOrigBinding rdr_name))
105 -- When reading External Core we get Orig names as binders,
106 -- but they should agree with the module gotten from the monad
108 -- We can get built-in syntax showing up here too, sadly. If you type
110 -- the constructor is parsed as a type, and then RdrHsSyn.tyConToDataCon
111 -- uses setRdrNameSpace to make it into a data constructors. At that point
112 -- the nice Exact name for the TyCon gets swizzled to an Orig name.
113 -- Hence the badOrigBinding error message.
115 -- Except for the ":Main.main = ..." definition inserted into
116 -- the Main module; ugh!
118 -- Because of this latter case, we call newGlobalBinder with a module from
119 -- the RdrName, not from the environment. In principle, it'd be fine to
120 -- have an arbitrary mixture of external core definitions in a single module,
121 -- (apart from module-initialisation issues, perhaps).
122 ; newGlobalBinder rdr_mod rdr_occ loc }
123 --TODO, should pass the whole span
126 = do { unless (not (isQual rdr_name))
127 (addErrAt loc (badQualBndrErr rdr_name))
128 -- Binders should not be qualified; if they are, and with a different
129 -- module name, we we get a confusing "M.T is not in scope" error later
132 ; if isBrackStage stage then
133 -- We are inside a TH bracket, so make an *Internal* name
134 -- See Note [Top-level Names in Template Haskell decl quotes] in RnNames
135 do { uniq <- newUnique
136 ; return (mkInternalName uniq (rdrNameOcc rdr_name) loc) }
139 do { this_mod <- getModule
140 ; newGlobalBinder this_mod (rdrNameOcc rdr_name) loc } }
143 %*********************************************************
145 Source code occurrences
147 %*********************************************************
149 Looking up a name in the RnEnv.
151 Note [Type and class operator definitions]
152 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
153 We want to reject all of these unless we have -XTypeOperators (Trac #3265)
155 class a :*: b where ...
156 data (:*:) a b = ....
157 class (:*:) a b where ...
158 The latter two mean that we are not just looking for a
159 *syntactically-infix* declaration, but one that uses an operator
160 OccName. We use OccName.isSymOcc to detect that case, which isn't
161 terribly efficient, but there seems to be no better way.
164 lookupTopBndrRn :: RdrName -> RnM Name
165 lookupTopBndrRn n = do nopt <- lookupTopBndrRn_maybe n
168 Nothing -> do traceRn $ text "lookupTopBndrRn"
169 unboundName WL_LocalTop n
171 lookupLocatedTopBndrRn :: Located RdrName -> RnM (Located Name)
172 lookupLocatedTopBndrRn = wrapLocM lookupTopBndrRn
174 lookupTopBndrRn_maybe :: RdrName -> RnM (Maybe Name)
175 -- Look up a top-level source-code binder. We may be looking up an unqualified 'f',
176 -- and there may be several imported 'f's too, which must not confuse us.
177 -- For example, this is OK:
179 -- infix 9 f -- The 'f' here does not need to be qualified
180 -- f x = x -- Nor here, of course
181 -- So we have to filter out the non-local ones.
183 -- A separate function (importsFromLocalDecls) reports duplicate top level
184 -- decls, so here it's safe just to choose an arbitrary one.
186 -- There should never be a qualified name in a binding position in Haskell,
187 -- but there can be if we have read in an external-Core file.
188 -- The Haskell parser checks for the illegal qualified name in Haskell
189 -- source files, so we don't need to do so here.
191 lookupTopBndrRn_maybe rdr_name
192 | Just name <- isExact_maybe rdr_name
195 | Just (rdr_mod, rdr_occ) <- isOrig_maybe rdr_name
196 -- This deals with the case of derived bindings, where
197 -- we don't bother to call newTopSrcBinder first
198 -- We assume there is no "parent" name
199 = do { loc <- getSrcSpanM
200 ; n <- newGlobalBinder rdr_mod rdr_occ loc
204 = do { -- Check for operators in type or class declarations
205 -- See Note [Type and class operator definitions]
206 let occ = rdrNameOcc rdr_name
207 ; when (isTcOcc occ && isSymOcc occ)
208 (do { op_ok <- xoptM Opt_TypeOperators
209 ; unless op_ok (addErr (opDeclErr rdr_name)) })
211 ; mb_gre <- lookupGreLocalRn rdr_name
213 Nothing -> return Nothing
214 Just gre -> return (Just $ gre_name gre) }
217 -----------------------------------------------
218 lookupInstDeclBndr :: Name -> RdrName -> RnM Name
219 -- This is called on the method name on the left-hand side of an
220 -- instance declaration binding. eg. instance Functor T where
222 -- ^^^^ called on this
223 -- Regardless of how many unqualified fmaps are in scope, we want
224 -- the one that comes from the Functor class.
226 -- Furthermore, note that we take no account of whether the
227 -- name is only in scope qualified. I.e. even if method op is
228 -- in scope as M.op, we still allow plain 'op' on the LHS of
230 lookupInstDeclBndr cls rdr
231 = do { when (isQual rdr)
232 (addErr (badQualBndrErr rdr))
233 -- In an instance decl you aren't allowed
234 -- to use a qualified name for the method
235 -- (Although it'd make perfect sense.)
236 ; lookupSubBndr (ParentIs cls) doc rdr }
238 doc = ptext (sLit "method of class") <+> quotes (ppr cls)
240 -----------------------------------------------
241 lookupConstructorFields :: Name -> RnM [Name]
242 -- Look up the fields of a given constructor
243 -- * For constructors from this module, use the record field env,
244 -- which is itself gathered from the (as yet un-typechecked)
247 -- * For constructors from imported modules, use the *type* environment
248 -- since imported modles are already compiled, the info is conveniently
251 lookupConstructorFields con_name
252 = do { this_mod <- getModule
253 ; if nameIsLocalOrFrom this_mod con_name then
254 do { RecFields field_env _ <- getRecFieldEnv
255 ; return (lookupNameEnv field_env con_name `orElse` []) }
257 do { con <- tcLookupDataCon con_name
258 ; return (dataConFieldLabels con) } }
260 -----------------------------------------------
261 -- Used for record construction and pattern matching
262 -- When the -XDisambiguateRecordFields flag is on, take account of the
263 -- constructor name to disambiguate which field to use; it's just the
264 -- same as for instance decls
266 -- NB: Consider this:
267 -- module Foo where { data R = R { fld :: Int } }
268 -- module Odd where { import Foo; fld x = x { fld = 3 } }
269 -- Arguably this should work, because the reference to 'fld' is
270 -- unambiguous because there is only one field id 'fld' in scope.
271 -- But currently it's rejected.
273 lookupSubBndr :: Parent -- NoParent => just look it up as usual
274 -- ParentIs p => use p to disambiguate
277 lookupSubBndr parent doc rdr_name
278 | Just n <- isExact_maybe rdr_name -- This happens in derived code
281 | Just (rdr_mod, rdr_occ) <- isOrig_maybe rdr_name
282 = lookupOrig rdr_mod rdr_occ
284 | otherwise -- Find all the things the rdr-name maps to
285 = do { -- and pick the one with the right parent name
286 ; env <- getGlobalRdrEnv
287 ; let gres = lookupGlobalRdrEnv env (rdrNameOcc rdr_name)
288 ; case pick parent gres of
289 -- NB: lookupGlobalRdrEnv, not lookupGRE_RdrName!
290 -- The latter does pickGREs, but we want to allow 'x'
291 -- even if only 'M.x' is in scope
292 [gre] -> do { addUsedRdrNames (used_rdr_names gre)
293 ; return (gre_name gre) }
294 [] -> do { addErr (unknownSubordinateErr doc rdr_name)
295 ; traceRn (text "RnEnv.lookup_sub_bndr" <+> (ppr rdr_name $$ ppr gres))
296 ; return (mkUnboundName rdr_name) }
297 gres -> do { addNameClashErrRn rdr_name gres
298 ; return (gre_name (head gres)) } }
300 pick NoParent gres -- Normal lookup
301 = pickGREs rdr_name gres
302 pick (ParentIs p) gres -- Disambiguating lookup
303 | isUnqual rdr_name = filter (right_parent p) gres
304 | otherwise = filter (right_parent p) (pickGREs rdr_name gres)
306 right_parent p (GRE { gre_par = ParentIs p' }) = p==p'
307 right_parent _ _ = False
309 -- Note [Usage for sub-bndrs]
311 | isQual rdr_name = [rdr_name]
312 | otherwise = case gre_prov gre of
313 LocalDef -> [rdr_name]
314 Imported is -> map mk_qual_rdr is
315 mk_qual_rdr imp_spec = mkRdrQual (is_as (is_decl imp_spec)) rdr_occ
316 rdr_occ = rdrNameOcc rdr_name
318 newIPNameRn :: IPName RdrName -> TcRnIf m n (IPName Name)
319 newIPNameRn ip_rdr = newIPName (mapIPName rdrNameOcc ip_rdr)
321 -- If the family is declared locally, it will not yet be in the main
322 -- environment; hence, we pass in an extra one here, which we check first.
323 -- See "Note [Looking up family names in family instances]" in 'RnNames'.
325 lookupFamInstDeclBndr :: GlobalRdrEnv -> Located RdrName -> RnM Name
326 lookupFamInstDeclBndr tyclGroupEnv (L loc rdr_name)
328 case lookupGRE_RdrName rdr_name tyclGroupEnv of
329 (gre:_) -> return $ gre_name gre
330 -- if there is more than one, an error will be raised elsewhere
331 [] -> lookupOccRn rdr_name
334 Note [Usage for sub-bndrs]
335 ~~~~~~~~~~~~~~~~~~~~~~~~~~
337 import qualified M( C( f ) )
340 then is the qualified import M.f used? Obviously yes.
341 But the RdrName used in the instance decl is unqualified. In effect,
342 we fill in the qualification by looking for f's whose class is M.C
343 But when adding to the UsedRdrNames we must make that qualification
344 explicit, otherwise we get "Redundant import of M.C".
346 --------------------------------------------------
348 --------------------------------------------------
351 getLookupOccRn :: RnM (Name -> Maybe Name)
353 = getLocalRdrEnv `thenM` \ local_env ->
354 return (lookupLocalRdrOcc local_env . nameOccName)
356 lookupLocatedOccRn :: Located RdrName -> RnM (Located Name)
357 lookupLocatedOccRn = wrapLocM lookupOccRn
359 -- lookupOccRn looks up an occurrence of a RdrName
360 lookupOccRn :: RdrName -> RnM Name
362 = do { local_env <- getLocalRdrEnv
363 ; case lookupLocalRdrEnv local_env rdr_name of {
364 Just name -> return name ;
367 { mb_name <- lookupGlobalOccRn_maybe rdr_name
372 { -- We allow qualified names on the command line to refer to
373 -- *any* name exported by any module in scope, just as if there
374 -- was an "import qualified M" declaration for every module.
375 allow_qual <- doptM Opt_ImplicitImportQualified
376 ; is_ghci <- getIsGHCi
377 -- This test is not expensive,
378 -- and only happens for failed lookups
379 ; if isQual rdr_name && allow_qual && is_ghci
380 then lookupQualifiedName rdr_name
381 else unboundName WL_Any rdr_name } } } } }
384 lookupGlobalOccRn :: RdrName -> RnM Name
385 -- lookupGlobalOccRn is like lookupOccRn, except that it looks in the global
386 -- environment. Adds an error message if the RdrName is not in scope.
387 lookupGlobalOccRn rdr_name
388 = do { mb_name <- lookupGlobalOccRn_maybe rdr_name
391 Nothing -> unboundName WL_Global rdr_name }
393 lookupGlobalOccRn_maybe :: RdrName -> RnM (Maybe Name)
394 -- No filter function; does not report an error on failure
396 lookupGlobalOccRn_maybe rdr_name
397 | Just n <- isExact_maybe rdr_name -- This happens in derived code
400 | Just (rdr_mod, rdr_occ) <- isOrig_maybe rdr_name
401 = do { n <- lookupOrig rdr_mod rdr_occ; return (Just n) }
404 = do { mb_gre <- lookupGreRn_maybe rdr_name
406 Nothing -> return Nothing
407 Just gre -> return (Just (gre_name gre)) }
410 --------------------------------------------------
411 -- Lookup in the Global RdrEnv of the module
412 --------------------------------------------------
414 lookupGreRn_maybe :: RdrName -> RnM (Maybe GlobalRdrElt)
415 -- Just look up the RdrName in the GlobalRdrEnv
416 lookupGreRn_maybe rdr_name
417 = lookupGreRn_help rdr_name (lookupGRE_RdrName rdr_name)
419 lookupGreRn :: RdrName -> RnM GlobalRdrElt
420 -- If not found, add error message, and return a fake GRE
422 = do { mb_gre <- lookupGreRn_maybe rdr_name
424 Just gre -> return gre ;
426 { traceRn $ text "lookupGreRn"
427 ; name <- unboundName WL_Global rdr_name
428 ; return (GRE { gre_name = name, gre_par = NoParent,
429 gre_prov = LocalDef }) }}}
431 lookupGreLocalRn :: RdrName -> RnM (Maybe GlobalRdrElt)
432 -- Similar, but restricted to locally-defined things
433 lookupGreLocalRn rdr_name
434 = lookupGreRn_help rdr_name lookup_fn
436 lookup_fn env = filter isLocalGRE (lookupGRE_RdrName rdr_name env)
438 lookupGreRn_help :: RdrName -- Only used in error message
439 -> (GlobalRdrEnv -> [GlobalRdrElt]) -- Lookup function
440 -> RnM (Maybe GlobalRdrElt)
441 -- Checks for exactly one match; reports deprecations
442 -- Returns Nothing, without error, if too few
443 lookupGreRn_help rdr_name lookup
444 = do { env <- getGlobalRdrEnv
447 [gre] -> do { addUsedRdrName gre rdr_name
448 ; return (Just gre) }
449 gres -> do { addNameClashErrRn rdr_name gres
450 ; return (Just (head gres)) } }
452 addUsedRdrName :: GlobalRdrElt -> RdrName -> RnM ()
453 -- Record usage of imported RdrNames
454 addUsedRdrName gre rdr
455 | isLocalGRE gre = return ()
456 | otherwise = do { env <- getGblEnv
457 ; updMutVar (tcg_used_rdrnames env)
458 (\s -> Set.insert rdr s) }
460 addUsedRdrNames :: [RdrName] -> RnM ()
461 -- Record used sub-binders
462 -- We don't check for imported-ness here, because it's inconvenient
463 -- and not stritly necessary.
465 = do { env <- getGblEnv
466 ; updMutVar (tcg_used_rdrnames env)
467 (\s -> foldr Set.insert s rdrs) }
469 ------------------------------
471 ------------------------------
473 -- A qualified name on the command line can refer to any module at all: we
474 -- try to load the interface if we don't already have it.
475 lookupQualifiedName :: RdrName -> RnM Name
476 lookupQualifiedName rdr_name
477 | Just (mod,occ) <- isQual_maybe rdr_name
478 -- Note: we want to behave as we would for a source file import here,
479 -- and respect hiddenness of modules/packages, hence loadSrcInterface.
480 = loadSrcInterface doc mod False Nothing `thenM` \ iface ->
483 (mod,avails) <- mi_exports iface,
485 name <- availNames avail,
487 ((mod,occ):ns) -> ASSERT (null ns)
489 _ -> unboundName WL_Any rdr_name
492 = pprPanic "RnEnv.lookupQualifiedName" (ppr rdr_name)
494 doc = ptext (sLit "Need to find") <+> ppr rdr_name
497 Note [Looking up signature names]
498 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
499 lookupSigOccRn is used for type signatures and pragmas
505 It's clear that the 'f' in the signature must refer to A.f
506 The Haskell98 report does not stipulate this, but it will!
507 So we must treat the 'f' in the signature in the same way
508 as the binding occurrence of 'f', using lookupBndrRn
510 However, consider this case:
514 We don't want to say 'f' is out of scope; instead, we want to
515 return the imported 'f', so that later on the reanamer will
516 correctly report "misplaced type sig".
519 lookupSigOccRn :: Maybe NameSet -- Just ns => these are the binders
521 -- Nothing => signatures without
522 -- binders are expected
523 -- (a) top-level (SPECIALISE prags)
527 -> Located RdrName -> RnM (Located Name)
528 lookupSigOccRn mb_bound_names sig
529 = wrapLocM $ \ rdr_name ->
530 do { mb_name <- lookupBindGroupOcc mb_bound_names (hsSigDoc sig) rdr_name
532 Left err -> do { addErr err; return (mkUnboundName rdr_name) }
533 Right name -> return name }
535 lookupBindGroupOcc :: Maybe NameSet -- See notes on the (Maybe NameSet)
536 -> SDoc -- in lookupSigOccRn
537 -> RdrName -> RnM (Either Message Name)
538 -- Looks up the RdrName, expecting it to resolve to one of the
539 -- bound names passed in. If not, return an appropriate error message
541 -- See Note [Looking up signature names]
542 lookupBindGroupOcc mb_bound_names what rdr_name
543 = do { local_env <- getLocalRdrEnv
544 ; case lookupLocalRdrEnv local_env rdr_name of {
545 Just n -> check_local_name n;
546 Nothing -> do -- Not defined in a nested scope
548 { env <- getGlobalRdrEnv
549 ; let gres = lookupGlobalRdrEnv env (rdrNameOcc rdr_name)
550 ; case (filter isLocalGRE gres) of
551 (gre:_) -> check_local_name (gre_name gre)
552 -- If there is more than one local GRE for the
553 -- same OccName 'f', that will be reported separately
554 -- as a duplicate top-level binding for 'f'
555 [] | null gres -> bale_out_with empty
556 | otherwise -> bale_out_with import_msg
559 check_local_name name -- The name is in scope, and not imported
560 = case mb_bound_names of
561 Just bound_names | not (name `elemNameSet` bound_names)
562 -> bale_out_with local_msg
563 _other -> return (Right name)
566 = return (Left (sep [ ptext (sLit "The") <+> what
567 <+> ptext (sLit "for") <+> quotes (ppr rdr_name)
568 , nest 2 $ ptext (sLit "lacks an accompanying binding")]
571 local_msg = parens $ ptext (sLit "The") <+> what <+> ptext (sLit "must be given where")
572 <+> quotes (ppr rdr_name) <+> ptext (sLit "is declared")
574 import_msg = parens $ ptext (sLit "You cannot give a") <+> what
575 <+> ptext (sLit "for an imported value")
578 lookupLocalDataTcNames :: NameSet -> SDoc -> RdrName -> RnM [Name]
579 -- GHC extension: look up both the tycon and data con
580 -- for con-like things
581 -- Complain if neither is in scope
582 lookupLocalDataTcNames bound_names what rdr_name
583 | Just n <- isExact_maybe rdr_name
584 -- Special case for (:), which doesn't get into the GlobalRdrEnv
585 = return [n] -- For this we don't need to try the tycon too
587 = do { mb_gres <- mapM (lookupBindGroupOcc (Just bound_names) what)
588 (dataTcOccs rdr_name)
589 ; let (errs, names) = splitEithers mb_gres
590 ; when (null names) (addErr (head errs)) -- Bleat about one only
593 dataTcOccs :: RdrName -> [RdrName]
594 -- If the input is a data constructor, return both it and a type
595 -- constructor. This is useful when we aren't sure which we are
598 | Just n <- isExact_maybe rdr_name -- Ghastly special case
599 , n `hasKey` consDataConKey = [rdr_name] -- see note below
600 | isDataOcc occ = [rdr_name, rdr_name_tc]
601 | otherwise = [rdr_name]
603 occ = rdrNameOcc rdr_name
604 rdr_name_tc = setRdrNameSpace rdr_name tcName
606 -- If the user typed "[]" or "(,,)", we'll generate an Exact RdrName,
607 -- and setRdrNameSpace generates an Orig, which is fine
608 -- But it's not fine for (:), because there *is* no corresponding type
609 -- constructor. If we generate an Orig tycon for GHC.Base.(:), it'll
610 -- appear to be in scope (because Orig's simply allocate a new name-cache
611 -- entry) and then we get an error when we use dataTcOccs in
612 -- TcRnDriver.tcRnGetInfo. Large sigh.
616 %*********************************************************
620 %*********************************************************
623 --------------------------------
624 type FastStringEnv a = UniqFM a -- Keyed by FastString
627 emptyFsEnv :: FastStringEnv a
628 lookupFsEnv :: FastStringEnv a -> FastString -> Maybe a
629 extendFsEnv :: FastStringEnv a -> FastString -> a -> FastStringEnv a
631 emptyFsEnv = emptyUFM
632 lookupFsEnv = lookupUFM
633 extendFsEnv = addToUFM
635 --------------------------------
636 type MiniFixityEnv = FastStringEnv (Located Fixity)
637 -- Mini fixity env for the names we're about
638 -- to bind, in a single binding group
640 -- It is keyed by the *FastString*, not the *OccName*, because
641 -- the single fixity decl infix 3 T
642 -- affects both the data constructor T and the type constrctor T
644 -- We keep the location so that if we find
645 -- a duplicate, we can report it sensibly
647 --------------------------------
648 -- Used for nested fixity decls to bind names along with their fixities.
649 -- the fixities are given as a UFM from an OccName's FastString to a fixity decl
651 addLocalFixities :: MiniFixityEnv -> [Name] -> RnM a -> RnM a
652 addLocalFixities mini_fix_env names thing_inside
653 = extendFixityEnv (mapCatMaybes find_fixity names) thing_inside
656 = case lookupFsEnv mini_fix_env (occNameFS occ) of
657 Just (L _ fix) -> Just (name, FixItem occ fix)
660 occ = nameOccName name
663 --------------------------------
664 lookupFixity is a bit strange.
666 * Nested local fixity decls are put in the local fixity env, which we
667 find with getFixtyEnv
669 * Imported fixities are found in the HIT or PIT
671 * Top-level fixity decls in this module may be for Names that are
672 either Global (constructors, class operations)
673 or Local/Exported (everything else)
674 (See notes with RnNames.getLocalDeclBinders for why we have this split.)
675 We put them all in the local fixity environment
678 lookupFixityRn :: Name -> RnM Fixity
680 = getModule `thenM` \ this_mod ->
681 if nameIsLocalOrFrom this_mod name
682 then do -- It's defined in this module
683 local_fix_env <- getFixityEnv
684 traceRn (text "lookupFixityRn: looking up name in local environment:" <+>
685 vcat [ppr name, ppr local_fix_env])
686 return $ lookupFixity local_fix_env name
687 else -- It's imported
688 -- For imported names, we have to get their fixities by doing a
689 -- loadInterfaceForName, and consulting the Ifaces that comes back
690 -- from that, because the interface file for the Name might not
691 -- have been loaded yet. Why not? Suppose you import module A,
692 -- which exports a function 'f', thus;
693 -- module CurrentModule where
695 -- module A( f ) where
697 -- Then B isn't loaded right away (after all, it's possible that
698 -- nothing from B will be used). When we come across a use of
699 -- 'f', we need to know its fixity, and it's then, and only
700 -- then, that we load B.hi. That is what's happening here.
702 -- loadInterfaceForName will find B.hi even if B is a hidden module,
703 -- and that's what we want.
704 loadInterfaceForName doc name `thenM` \ iface -> do {
705 traceRn (text "lookupFixityRn: looking up name in iface cache and found:" <+>
706 vcat [ppr name, ppr $ mi_fix_fn iface (nameOccName name)]);
707 return (mi_fix_fn iface (nameOccName name))
710 doc = ptext (sLit "Checking fixity for") <+> ppr name
713 lookupTyFixityRn :: Located Name -> RnM Fixity
714 lookupTyFixityRn (L _ n) = lookupFixityRn n
718 %************************************************************************
721 Dealing with rebindable syntax is driven by the
722 Opt_RebindableSyntax dynamic flag.
724 In "deriving" code we don't want to use rebindable syntax
725 so we switch off the flag locally
728 %************************************************************************
730 Haskell 98 says that when you say "3" you get the "fromInteger" from the
731 Standard Prelude, regardless of what is in scope. However, to experiment
732 with having a language that is less coupled to the standard prelude, we're
733 trying a non-standard extension that instead gives you whatever "Prelude.fromInteger"
734 happens to be in scope. Then you can
736 import MyPrelude as Prelude
737 to get the desired effect.
739 At the moment this just happens for
740 * fromInteger, fromRational on literals (in expressions and patterns)
741 * negate (in expressions)
742 * minus (arising from n+k patterns)
745 We store the relevant Name in the HsSyn tree, in
746 * HsIntegral/HsFractional/HsIsString
750 respectively. Initially, we just store the "standard" name (PrelNames.fromIntegralName,
751 fromRationalName etc), but the renamer changes this to the appropriate user
752 name if Opt_NoImplicitPrelude is on. That is what lookupSyntaxName does.
754 We treat the orignal (standard) names as free-vars too, because the type checker
755 checks the type of the user thing against the type of the standard thing.
758 lookupIfThenElse :: RnM (Maybe (SyntaxExpr Name), FreeVars)
759 -- Different to lookupSyntaxName because in the non-rebindable
760 -- case we desugar directly rather than calling an existing function
761 -- Hence the (Maybe (SyntaxExpr Name)) return type
763 = do { rebind <- xoptM Opt_RebindableSyntax
765 then return (Nothing, emptyFVs)
766 else do { ite <- lookupOccRn (mkVarUnqual (fsLit "ifThenElse"))
767 ; return (Just (HsVar ite), unitFV ite) } }
769 lookupSyntaxName :: Name -- The standard name
770 -> RnM (SyntaxExpr Name, FreeVars) -- Possibly a non-standard name
771 lookupSyntaxName std_name
772 = do ec <- getHetMetLevel
773 std_name' <- return $ setNameDepth (length ec) std_name
774 rebindable_on <- xoptM Opt_RebindableSyntax
776 then return (HsVar std_name', emptyFVs)
777 else do usr_name <- lookupOccRn (mkRdrUnqual (nameOccName std_name'))
778 return (HsVar usr_name, unitFV usr_name)
779 -- Get the similarly named thing from the local environment
781 lookupSyntaxTable :: [Name] -- Standard names
782 -> RnM (SyntaxTable Name, FreeVars) -- See comments with HsExpr.ReboundNames
783 lookupSyntaxTable std_names
784 = xoptM Opt_RebindableSyntax `thenM` \ rebindable_on ->
785 if not rebindable_on then normal_case
787 -- Get the similarly named thing from the local environment
788 mapM (lookupOccRn . mkRdrUnqual . nameOccName) std_names `thenM` \ usr_names ->
790 return (std_names `zip` map HsVar usr_names, mkFVs usr_names)
792 normal_case = return (std_names `zip` map HsVar std_names, emptyFVs)
796 %*********************************************************
800 %*********************************************************
803 newLocalBndrRn :: Located RdrName -> RnM Name
804 -- Used for non-top-level binders. These should
805 -- never be qualified.
806 newLocalBndrRn (L loc rdr_name)
807 | Just name <- isExact_maybe rdr_name
808 = return name -- This happens in code generated by Template Haskell
809 -- although I'm not sure why. Perhpas it's the call
810 -- in RnPat.newName LetMk?
812 = do { unless (isUnqual rdr_name)
813 (addErrAt loc (badQualBndrErr rdr_name))
815 ; return (mkInternalName uniq (rdrNameOcc rdr_name) loc) }
817 newLocalBndrsRn :: [Located RdrName] -> RnM [Name]
818 newLocalBndrsRn = mapM newLocalBndrRn
820 ---------------------
821 bindLocatedLocalsRn :: [Located RdrName]
824 bindLocatedLocalsRn rdr_names_w_loc enclosed_scope
825 = do { checkDupAndShadowedRdrNames rdr_names_w_loc
827 -- Make fresh Names and extend the environment
828 ; names <- newLocalBndrsRn rdr_names_w_loc
829 ; bindLocalNames names (enclosed_scope names) }
831 bindLocalNames :: [Name] -> RnM a -> RnM a
832 bindLocalNames names enclosed_scope
833 = do { name_env <- getLocalRdrEnv
834 ; setLocalRdrEnv (extendLocalRdrEnvList name_env names)
837 bindLocalName :: Name -> RnM a -> RnM a
838 bindLocalName name enclosed_scope
839 = do { name_env <- getLocalRdrEnv
840 ; setLocalRdrEnv (extendLocalRdrEnv name_env name)
843 bindLocalNamesFV :: [Name] -> RnM (a, FreeVars) -> RnM (a, FreeVars)
844 bindLocalNamesFV names enclosed_scope
845 = do { (result, fvs) <- bindLocalNames names enclosed_scope
846 ; return (result, delFVs names fvs) }
849 -------------------------------------
850 -- binLocalsFVRn is the same as bindLocalsRn
851 -- except that it deals with free vars
852 bindLocatedLocalsFV :: [Located RdrName]
853 -> ([Name] -> RnM (a,FreeVars)) -> RnM (a, FreeVars)
854 bindLocatedLocalsFV rdr_names enclosed_scope
855 = bindLocatedLocalsRn rdr_names $ \ names ->
856 enclosed_scope names `thenM` \ (thing, fvs) ->
857 return (thing, delFVs names fvs)
859 -------------------------------------
860 bindTyVarsFV :: [LHsTyVarBndr RdrName]
861 -> ([LHsTyVarBndr Name] -> RnM (a, FreeVars))
863 bindTyVarsFV tyvars thing_inside
864 = bindTyVarsRn tyvars $ \ tyvars' ->
865 do { (res, fvs) <- thing_inside tyvars'
866 ; return (res, delFVs (map hsLTyVarName tyvars') fvs) }
868 bindTyVarsRn :: [LHsTyVarBndr RdrName]
869 -> ([LHsTyVarBndr Name] -> RnM a)
871 -- Haskell-98 binding of type variables; e.g. within a data type decl
872 bindTyVarsRn tyvar_names enclosed_scope
873 = bindLocatedLocalsRn located_tyvars $ \ names ->
874 do { kind_sigs_ok <- xoptM Opt_KindSignatures
875 ; unless (null kinded_tyvars || kind_sigs_ok)
876 (mapM_ (addErr . kindSigErr) kinded_tyvars)
877 ; enclosed_scope (zipWith replace tyvar_names names) }
879 replace (L loc n1) n2 = L loc (replaceTyVarName n1 n2)
880 located_tyvars = hsLTyVarLocNames tyvar_names
881 kinded_tyvars = [n | L _ (KindedTyVar n _) <- tyvar_names]
883 bindPatSigTyVars :: [LHsType RdrName] -> ([Name] -> RnM a) -> RnM a
884 -- Find the type variables in the pattern type
885 -- signatures that must be brought into scope
886 bindPatSigTyVars tys thing_inside
887 = do { scoped_tyvars <- xoptM Opt_ScopedTypeVariables
888 ; if not scoped_tyvars then
891 do { name_env <- getLocalRdrEnv
892 ; let locd_tvs = [ tv | ty <- tys
893 , tv <- extractHsTyRdrTyVars ty
894 , not (unLoc tv `elemLocalRdrEnv` name_env) ]
895 nubbed_tvs = nubBy eqLocated locd_tvs
896 -- The 'nub' is important. For example:
897 -- f (x :: t) (y :: t) = ....
898 -- We don't want to complain about binding t twice!
900 ; bindLocatedLocalsRn nubbed_tvs thing_inside }}
902 bindPatSigTyVarsFV :: [LHsType RdrName]
905 bindPatSigTyVarsFV tys thing_inside
906 = bindPatSigTyVars tys $ \ tvs ->
907 thing_inside `thenM` \ (result,fvs) ->
908 return (result, fvs `delListFromNameSet` tvs)
910 bindSigTyVarsFV :: [Name]
913 bindSigTyVarsFV tvs thing_inside
914 = do { scoped_tyvars <- xoptM Opt_ScopedTypeVariables
915 ; if not scoped_tyvars then
918 bindLocalNamesFV tvs thing_inside }
920 extendTyVarEnvFVRn :: [Name] -> RnM (a, FreeVars) -> RnM (a, FreeVars)
921 -- This function is used only in rnSourceDecl on InstDecl
922 extendTyVarEnvFVRn tyvars thing_inside = bindLocalNamesFV tyvars thing_inside
924 -------------------------------------
925 checkDupRdrNames :: [Located RdrName] -> RnM ()
926 checkDupRdrNames rdr_names_w_loc
927 = -- Check for duplicated names in a binding group
928 mapM_ (dupNamesErr getLoc) dups
930 (_, dups) = removeDups (\n1 n2 -> unLoc n1 `compare` unLoc n2) rdr_names_w_loc
932 checkDupNames :: [Name] -> RnM ()
934 = -- Check for duplicated names in a binding group
935 mapM_ (dupNamesErr nameSrcSpan) dups
937 (_, dups) = removeDups (\n1 n2 -> nameOccName n1 `compare` nameOccName n2) names
939 ---------------------
940 checkDupAndShadowedRdrNames :: [Located RdrName] -> RnM ()
941 checkDupAndShadowedRdrNames loc_rdr_names
942 = do { checkDupRdrNames loc_rdr_names
944 ; checkShadowedOccs envs loc_occs }
946 loc_occs = [(loc,rdrNameOcc rdr) | L loc rdr <- loc_rdr_names]
948 checkDupAndShadowedNames :: (GlobalRdrEnv, LocalRdrEnv) -> [Name] -> RnM ()
949 checkDupAndShadowedNames envs names
950 = do { checkDupNames names
951 ; checkShadowedOccs envs loc_occs }
953 loc_occs = [(nameSrcSpan name, nameOccName name) | name <- names]
955 -------------------------------------
956 checkShadowedOccs :: (GlobalRdrEnv, LocalRdrEnv) -> [(SrcSpan,OccName)] -> RnM ()
957 checkShadowedOccs (global_env,local_env) loc_occs
958 = ifDOptM Opt_WarnNameShadowing $
959 do { traceRn (text "shadow" <+> ppr loc_occs)
960 ; mapM_ check_shadow loc_occs }
962 check_shadow (loc, occ)
963 | startsWithUnderscore occ = return () -- Do not report shadowing for "_x"
965 | Just n <- mb_local = complain [ptext (sLit "bound at") <+> ppr (nameSrcLoc n)]
966 | otherwise = do { gres' <- filterM is_shadowed_gre gres
967 ; complain (map pprNameProvenance gres') }
969 complain [] = return ()
970 complain pp_locs = addWarnAt loc (shadowedNameWarn occ pp_locs)
971 mb_local = lookupLocalRdrOcc local_env occ
972 gres = lookupGRE_RdrName (mkRdrUnqual occ) global_env
973 -- Make an Unqualified RdrName and look that up, so that
974 -- we don't find any GREs that are in scope qualified-only
976 is_shadowed_gre :: GlobalRdrElt -> RnM Bool
977 -- Returns False for record selectors that are shadowed, when
978 -- punning or wild-cards are on (cf Trac #2723)
979 is_shadowed_gre gre@(GRE { gre_par = ParentIs _ })
980 = do { dflags <- getDOpts
981 ; if (xopt Opt_RecordPuns dflags || xopt Opt_RecordWildCards dflags)
982 then do { is_fld <- is_rec_fld gre; return (not is_fld) }
984 is_shadowed_gre _other = return True
986 is_rec_fld gre -- Return True for record selector ids
987 | isLocalGRE gre = do { RecFields _ fld_set <- getRecFieldEnv
988 ; return (gre_name gre `elemNameSet` fld_set) }
989 | otherwise = do { sel_id <- tcLookupField (gre_name gre)
990 ; return (isRecordSelector sel_id) }
994 %************************************************************************
996 What to do when a lookup fails
998 %************************************************************************
1001 data WhereLooking = WL_Any -- Any binding
1002 | WL_Global -- Any top-level binding (local or imported)
1003 | WL_LocalTop -- Any top-level binding in this module
1005 unboundName :: WhereLooking -> RdrName -> RnM Name
1006 unboundName where_look rdr_name
1007 = do { show_helpful_errors <- doptM Opt_HelpfulErrors
1008 ; let err = unknownNameErr rdr_name
1009 ; if not show_helpful_errors
1011 else do { extra_err <- unknownNameSuggestErr where_look rdr_name
1012 ; addErr (err $$ extra_err) }
1014 ; env <- getGlobalRdrEnv;
1015 ; traceRn (vcat [unknownNameErr rdr_name,
1016 ptext (sLit "Global envt is:"),
1017 nest 3 (pprGlobalRdrEnv env)])
1019 ; return (mkUnboundName rdr_name) }
1021 unknownNameErr :: RdrName -> SDoc
1022 unknownNameErr rdr_name
1023 = vcat [ hang (ptext (sLit "Not in scope:"))
1024 2 (pprNonVarNameSpace (occNameSpace (rdrNameOcc rdr_name))
1025 <+> quotes (ppr rdr_name))
1028 extra | rdr_name == forall_tv_RDR = perhapsForallMsg
1031 type HowInScope = Either SrcSpan ImpDeclSpec
1032 -- Left loc => locally bound at loc
1033 -- Right ispec => imported as specified by ispec
1035 unknownNameSuggestErr :: WhereLooking -> RdrName -> RnM SDoc
1036 unknownNameSuggestErr where_look tried_rdr_name
1037 = do { local_env <- getLocalRdrEnv
1038 ; global_env <- getGlobalRdrEnv
1040 ; let all_possibilities :: [(String, (RdrName, HowInScope))]
1042 = [ (showSDoc (ppr r), (r, Left loc))
1043 | (r,loc) <- local_possibilities local_env ]
1044 ++ [ (showSDoc (ppr r), rp) | (r,rp) <- global_possibilities global_env ]
1046 suggest = fuzzyLookup (showSDoc (ppr tried_rdr_name)) all_possibilities
1047 perhaps = ptext (sLit "Perhaps you meant")
1048 extra_err = case suggest of
1050 [p] -> perhaps <+> pp_item p
1051 ps -> sep [ perhaps <+> ptext (sLit "one of these:")
1052 , nest 2 (pprWithCommas pp_item ps) ]
1053 ; return extra_err }
1055 pp_item :: (RdrName, HowInScope) -> SDoc
1056 pp_item (rdr, Left loc) = quotes (ppr rdr) <+> -- Locally defined
1057 parens (ptext (sLit "line") <+> int (srcSpanStartLine loc))
1058 pp_item (rdr, Right is) = quotes (ppr rdr) <+> -- Imported
1059 parens (ptext (sLit "imported from") <+> ppr (is_mod is))
1061 tried_occ = rdrNameOcc tried_rdr_name
1062 tried_is_sym = isSymOcc tried_occ
1063 tried_ns = occNameSpace tried_occ
1064 tried_is_qual = isQual tried_rdr_name
1066 correct_name_space occ = occNameSpace occ == tried_ns
1067 && isSymOcc occ == tried_is_sym
1068 -- Treat operator and non-operators as non-matching
1069 -- This heuristic avoids things like
1070 -- Not in scope 'f'; perhaps you meant '+' (from Prelude)
1072 local_ok = case where_look of { WL_Any -> True; _ -> False }
1073 local_possibilities :: LocalRdrEnv -> [(RdrName, SrcSpan)]
1074 local_possibilities env
1075 | tried_is_qual = []
1077 | otherwise = [ (mkRdrUnqual occ, nameSrcSpan name)
1078 | name <- occEnvElts env
1079 , let occ = nameOccName name
1080 , correct_name_space occ]
1082 gre_ok :: GlobalRdrElt -> Bool
1083 gre_ok = case where_look of
1084 WL_LocalTop -> isLocalGRE
1087 global_possibilities :: GlobalRdrEnv -> [(RdrName, (RdrName, HowInScope))]
1088 global_possibilities global_env
1089 | tried_is_qual = [ (rdr_qual, (rdr_qual, how))
1090 | gre <- globalRdrEnvElts global_env
1092 , let name = gre_name gre
1093 occ = nameOccName name
1094 , correct_name_space occ
1095 , (mod, how) <- quals_in_scope name (gre_prov gre)
1096 , let rdr_qual = mkRdrQual mod occ ]
1098 | otherwise = [ (rdr_unqual, pair)
1099 | gre <- globalRdrEnvElts global_env
1101 , let name = gre_name gre
1103 occ = nameOccName name
1104 rdr_unqual = mkRdrUnqual occ
1105 , correct_name_space occ
1106 , pair <- case (unquals_in_scope name prov, quals_only occ prov) of
1107 (how:_, _) -> [ (rdr_unqual, how) ]
1108 ([], pr:_) -> [ pr ] -- See Note [Only-quals]
1111 -- Note [Only-quals]
1112 -- The second alternative returns those names with the same
1113 -- OccName as the one we tried, but live in *qualified* imports
1114 -- e.g. if you have:
1116 -- > import qualified Data.Map as Map
1119 -- then we suggest @Map.Map@.
1121 --------------------
1122 unquals_in_scope :: Name -> Provenance -> [HowInScope]
1123 unquals_in_scope n LocalDef = [ Left (nameSrcSpan n) ]
1124 unquals_in_scope _ (Imported is) = [ Right ispec
1125 | i <- is, let ispec = is_decl i
1126 , not (is_qual ispec) ]
1128 --------------------
1129 quals_in_scope :: Name -> Provenance -> [(ModuleName, HowInScope)]
1130 -- Ones for which the qualified version is in scope
1131 quals_in_scope n LocalDef = case nameModule_maybe n of
1133 Just m -> [(moduleName m, Left (nameSrcSpan n))]
1134 quals_in_scope _ (Imported is) = [ (is_as ispec, Right ispec)
1135 | i <- is, let ispec = is_decl i ]
1137 --------------------
1138 quals_only :: OccName -> Provenance -> [(RdrName, HowInScope)]
1139 -- Ones for which *only* the qualified version is in scope
1140 quals_only _ LocalDef = []
1141 quals_only occ (Imported is) = [ (mkRdrQual (is_as ispec) occ, Right ispec)
1142 | i <- is, let ispec = is_decl i, is_qual ispec ]
1145 %************************************************************************
1147 \subsection{Free variable manipulation}
1149 %************************************************************************
1153 addFvRn :: FreeVars -> RnM (thing, FreeVars) -> RnM (thing, FreeVars)
1154 addFvRn fvs1 thing_inside = do { (res, fvs2) <- thing_inside
1155 ; return (res, fvs1 `plusFV` fvs2) }
1157 mapFvRn :: (a -> RnM (b, FreeVars)) -> [a] -> RnM ([b], FreeVars)
1158 mapFvRn f xs = do stuff <- mapM f xs
1160 (ys, fvs_s) -> return (ys, plusFVs fvs_s)
1162 mapMaybeFvRn :: (a -> RnM (b, FreeVars)) -> Maybe a -> RnM (Maybe b, FreeVars)
1163 mapMaybeFvRn _ Nothing = return (Nothing, emptyFVs)
1164 mapMaybeFvRn f (Just x) = do { (y, fvs) <- f x; return (Just y, fvs) }
1166 -- because some of the rename functions are CPSed:
1167 -- maps the function across the list from left to right;
1168 -- collects all the free vars into one set
1169 mapFvRnCPS :: (a -> (b -> RnM c) -> RnM c)
1170 -> [a] -> ([b] -> RnM c) -> RnM c
1172 mapFvRnCPS _ [] cont = cont []
1173 mapFvRnCPS f (x:xs) cont = f x $ \ x' ->
1174 mapFvRnCPS f xs $ \ xs' ->
1179 %************************************************************************
1181 \subsection{Envt utility functions}
1183 %************************************************************************
1186 warnUnusedTopBinds :: [GlobalRdrElt] -> RnM ()
1187 warnUnusedTopBinds gres
1188 = ifDOptM Opt_WarnUnusedBinds
1189 $ do isBoot <- tcIsHsBoot
1190 let noParent gre = case gre_par gre of
1193 -- Don't warn about unused bindings with parents in
1194 -- .hs-boot files, as you are sometimes required to give
1195 -- unused bindings (trac #3449).
1196 gres' = if isBoot then filter noParent gres
1198 warnUnusedGREs gres'
1200 warnUnusedLocalBinds, warnUnusedMatches :: [Name] -> FreeVars -> RnM ()
1201 warnUnusedLocalBinds = check_unused Opt_WarnUnusedBinds
1202 warnUnusedMatches = check_unused Opt_WarnUnusedMatches
1204 check_unused :: DynFlag -> [Name] -> FreeVars -> RnM ()
1205 check_unused flag bound_names used_names
1206 = ifDOptM flag (warnUnusedLocals (filterOut (`elemNameSet` used_names) bound_names))
1208 -------------------------
1210 warnUnusedGREs :: [GlobalRdrElt] -> RnM ()
1212 = warnUnusedBinds [(n,p) | GRE {gre_name = n, gre_prov = p} <- gres]
1214 warnUnusedLocals :: [Name] -> RnM ()
1215 warnUnusedLocals names
1216 = warnUnusedBinds [(n,LocalDef) | n<-names]
1218 warnUnusedBinds :: [(Name,Provenance)] -> RnM ()
1219 warnUnusedBinds names = mapM_ warnUnusedName (filter reportable names)
1220 where reportable (name,_)
1221 | isWiredInName name = False -- Don't report unused wired-in names
1222 -- Otherwise we get a zillion warnings
1224 | otherwise = not (startsWithUnderscore (nameOccName name))
1226 -------------------------
1228 warnUnusedName :: (Name, Provenance) -> RnM ()
1229 warnUnusedName (name, LocalDef)
1230 = addUnusedWarning name (nameSrcSpan name)
1231 (ptext (sLit "Defined but not used"))
1233 warnUnusedName (name, Imported is)
1236 warn spec = addUnusedWarning name span msg
1238 span = importSpecLoc spec
1239 pp_mod = quotes (ppr (importSpecModule spec))
1240 msg = ptext (sLit "Imported from") <+> pp_mod <+> ptext (sLit "but not used")
1242 addUnusedWarning :: Name -> SrcSpan -> SDoc -> RnM ()
1243 addUnusedWarning name span msg
1246 nest 2 $ pprNonVarNameSpace (occNameSpace (nameOccName name))
1247 <+> quotes (ppr name)]
1251 addNameClashErrRn :: RdrName -> [GlobalRdrElt] -> RnM ()
1252 addNameClashErrRn rdr_name names
1253 = addErr (vcat [ptext (sLit "Ambiguous occurrence") <+> quotes (ppr rdr_name),
1254 ptext (sLit "It could refer to") <+> vcat (msg1 : msgs)])
1257 msg1 = ptext (sLit "either") <+> mk_ref np1
1258 msgs = [ptext (sLit " or") <+> mk_ref np | np <- nps]
1259 mk_ref gre = sep [quotes (ppr (gre_name gre)) <> comma, pprNameProvenance gre]
1261 shadowedNameWarn :: OccName -> [SDoc] -> SDoc
1262 shadowedNameWarn occ shadowed_locs
1263 = sep [ptext (sLit "This binding for") <+> quotes (ppr occ)
1264 <+> ptext (sLit "shadows the existing binding") <> plural shadowed_locs,
1265 nest 2 (vcat shadowed_locs)]
1267 perhapsForallMsg :: SDoc
1269 = vcat [ ptext (sLit "Perhaps you intended to use -XExplicitForAll or similar flag")
1270 , ptext (sLit "to enable explicit-forall syntax: forall <tvs>. <type>")]
1272 unknownSubordinateErr :: SDoc -> RdrName -> SDoc
1273 unknownSubordinateErr doc op -- Doc is "method of class" or
1274 -- "field of constructor"
1275 = quotes (ppr op) <+> ptext (sLit "is not a (visible)") <+> doc
1277 badOrigBinding :: RdrName -> SDoc
1279 = ptext (sLit "Illegal binding of built-in syntax:") <+> ppr (rdrNameOcc name)
1280 -- The rdrNameOcc is because we don't want to print Prelude.(,)
1282 dupNamesErr :: Outputable n => (n -> SrcSpan) -> [n] -> RnM ()
1283 dupNamesErr get_loc names
1284 = addErrAt big_loc $
1285 vcat [ptext (sLit "Conflicting definitions for") <+> quotes (ppr (head names)),
1288 locs = map get_loc names
1289 big_loc = foldr1 combineSrcSpans locs
1290 locations = ptext (sLit "Bound at:") <+> vcat (map ppr (sortLe (<=) locs))
1292 kindSigErr :: Outputable a => a -> SDoc
1294 = hang (ptext (sLit "Illegal kind signature for") <+> quotes (ppr thing))
1295 2 (ptext (sLit "Perhaps you intended to use -XKindSignatures"))
1298 badQualBndrErr :: RdrName -> SDoc
1299 badQualBndrErr rdr_name
1300 = ptext (sLit "Qualified name in binding position:") <+> ppr rdr_name
1302 opDeclErr :: RdrName -> SDoc
1304 = hang (ptext (sLit "Illegal declaration of a type or class operator") <+> quotes (ppr n))
1305 2 (ptext (sLit "Use -XTypeOperators to declare operators in type and declarations"))