2 % (c) The University of Glasgow 2006
7 TyThing(..), TcTyThing(..), TcId,
9 -- Instance environment, and InstInfo type
10 InstInfo(..), iDFunId, pprInstInfo, pprInstInfoDetails,
11 simpleInstInfoClsTy, simpleInstInfoTy, simpleInstInfoTyCon,
15 tcExtendGlobalEnv, setGlobalTypeEnv,
17 tcLookupLocatedGlobal, tcLookupGlobal,
18 tcLookupField, tcLookupTyCon, tcLookupClass, tcLookupDataCon,
19 tcLookupLocatedGlobalId, tcLookupLocatedTyCon,
20 tcLookupLocatedClass, tcLookupFamInst,
23 tcExtendKindEnv, tcExtendKindEnvTvs,
24 tcExtendTyVarEnv, tcExtendTyVarEnv2,
26 tcExtendIdEnv, tcExtendIdEnv1, tcExtendIdEnv2,
27 tcLookup, tcLookupLocated, tcLookupLocalIds,
28 tcLookupId, tcLookupTyVar, getScopedTyVarBinds,
29 lclEnvElts, getInLocalScope, findGlobals,
30 wrongThingErr, pprBinders,
32 tcExtendRecEnv, -- For knot-tying
37 -- Global type variables
40 -- Template Haskell stuff
41 checkWellStaged, spliceOK, bracketOK, tcMetaTy, thLevel,
42 topIdLvl, thTopLevelId, thRnBrack, isBrackStage,
45 newLocalName, newDFunName, newFamInstTyConName,
46 mkStableIdFromString, mkStableIdFromName
49 #include "HsVersions.h"
57 -- import TcSuspension
83 %************************************************************************
87 %************************************************************************
89 Using the Located versions (eg. tcLookupLocatedGlobal) is preferred,
90 unless you know that the SrcSpan in the monad is already set to the
94 tcLookupLocatedGlobal :: Located Name -> TcM TyThing
95 -- c.f. IfaceEnvEnv.tcIfaceGlobal
96 tcLookupLocatedGlobal name
97 = addLocM tcLookupGlobal name
99 tcLookupGlobal :: Name -> TcM TyThing
100 -- The Name is almost always an ExternalName, but not always
101 -- In GHCi, we may make command-line bindings (ghci> let x = True)
102 -- that bind a GlobalId, but with an InternalName
104 = do { env <- getGblEnv
107 ; case lookupNameEnv (tcg_type_env env) name of {
108 Just thing -> return thing ;
112 { hsc_env <- getTopEnv
113 ; mb_thing <- liftIO (lookupTypeHscEnv hsc_env name)
115 Just thing -> return thing ;
118 -- Should it have been in the local envt?
119 { case nameModule_maybe name of
120 Nothing -> notFound name env -- Internal names can happen in GHCi
122 Just mod | mod == tcg_mod env -- Names from this module
123 -> notFound name env -- should be in tcg_type_env
125 -> tcImportDecl name -- Go find it in an interface
128 tcLookupField :: Name -> TcM Id -- Returns the selector Id
129 tcLookupField name = do
130 thing <- tcLookup name -- Note [Record field lookup]
132 AGlobal (AnId id) -> return id
133 thing -> wrongThingErr "field name" thing name
135 {- Note [Record field lookup]
136 ~~~~~~~~~~~~~~~~~~~~~~~~~~
137 You might think we should have tcLookupGlobal here, since record fields
138 are always top level. But consider
140 Then the renamer (which does not keep track of what is a record selector
141 and what is not) will rename the definition thus
142 f_7 = e { f_7 = True }
143 Now the type checker will find f_7 in the *local* type environment, not
144 the global one. It's wrong, of course, but we want to report a tidy
145 error, not in TcEnv.notFound. -}
147 tcLookupDataCon :: Name -> TcM DataCon
148 tcLookupDataCon name = do
149 thing <- tcLookupGlobal name
151 ADataCon con -> return con
152 _ -> wrongThingErr "data constructor" (AGlobal thing) name
154 tcLookupClass :: Name -> TcM Class
155 tcLookupClass name = do
156 thing <- tcLookupGlobal name
158 AClass cls -> return cls
159 _ -> wrongThingErr "class" (AGlobal thing) name
161 tcLookupTyCon :: Name -> TcM TyCon
162 tcLookupTyCon name = do
163 thing <- tcLookupGlobal name
165 ATyCon tc -> return tc
166 _ -> wrongThingErr "type constructor" (AGlobal thing) name
168 tcLookupLocatedGlobalId :: Located Name -> TcM Id
169 tcLookupLocatedGlobalId = addLocM tcLookupId
171 tcLookupLocatedClass :: Located Name -> TcM Class
172 tcLookupLocatedClass = addLocM tcLookupClass
174 tcLookupLocatedTyCon :: Located Name -> TcM TyCon
175 tcLookupLocatedTyCon = addLocM tcLookupTyCon
177 -- Look up the instance tycon of a family instance.
179 -- The match must be unique - ie, match exactly one instance - but the
180 -- type arguments used for matching may be more specific than those of
181 -- the family instance declaration.
183 -- Return the instance tycon and its type instance. For example, if we have
185 -- tcLookupFamInst 'T' '[Int]' yields (':R42T', 'Int')
187 -- then we have a coercion (ie, type instance of family instance coercion)
189 -- :Co:R42T Int :: T [Int] ~ :R42T Int
191 -- which implies that :R42T was declared as 'data instance T [a]'.
193 tcLookupFamInst :: TyCon -> [Type] -> TcM (Maybe (TyCon, [Type]))
194 tcLookupFamInst tycon tys
195 | not (isOpenTyCon tycon)
198 = do { env <- getGblEnv
200 ; let instEnv = (eps_fam_inst_env eps, tcg_fam_inst_env env)
201 ; case lookupFamInstEnv instEnv tycon tys of
202 [(fam_inst, rep_tys)] -> return $ Just (famInstTyCon fam_inst,
208 %************************************************************************
210 Extending the global environment
212 %************************************************************************
216 setGlobalTypeEnv :: TcGblEnv -> TypeEnv -> TcM TcGblEnv
217 -- Use this to update the global type env
218 -- It updates both * the normal tcg_type_env field
219 -- * the tcg_type_env_var field seen by interface files
220 setGlobalTypeEnv tcg_env new_type_env
221 = do { -- Sync the type-envt variable seen by interface files
222 writeMutVar (tcg_type_env_var tcg_env) new_type_env
223 ; return (tcg_env { tcg_type_env = new_type_env }) }
225 tcExtendGlobalEnv :: [TyThing] -> TcM r -> TcM r
226 -- Given a mixture of Ids, TyCons, Classes, all from the
227 -- module being compiled, extend the global environment
228 tcExtendGlobalEnv things thing_inside
229 = do { tcg_env <- getGblEnv
230 ; let ge' = extendTypeEnvList (tcg_type_env tcg_env) things
231 ; tcg_env' <- setGlobalTypeEnv tcg_env ge'
232 ; setGblEnv tcg_env' thing_inside }
234 tcExtendGlobalValEnv :: [Id] -> TcM a -> TcM a
235 -- Same deal as tcExtendGlobalEnv, but for Ids
236 tcExtendGlobalValEnv ids thing_inside
237 = tcExtendGlobalEnv [AnId id | id <- ids] thing_inside
239 tcExtendRecEnv :: [(Name,TyThing)] -> TcM r -> TcM r
240 -- Extend the global environments for the type/class knot tying game
241 -- Just like tcExtendGlobalEnv, except the argument is a list of pairs
242 tcExtendRecEnv gbl_stuff thing_inside
243 = do { tcg_env <- getGblEnv
244 ; let ge' = extendNameEnvList (tcg_type_env tcg_env) gbl_stuff
245 ; tcg_env' <- setGlobalTypeEnv tcg_env ge'
246 ; setGblEnv tcg_env' thing_inside }
250 %************************************************************************
252 \subsection{The local environment}
254 %************************************************************************
257 tcLookupLocated :: Located Name -> TcM TcTyThing
258 tcLookupLocated = addLocM tcLookup
260 tcLookup :: Name -> TcM TcTyThing
262 local_env <- getLclEnv
263 case lookupNameEnv (tcl_env local_env) name of
264 Just thing -> return thing
265 Nothing -> AGlobal <$> tcLookupGlobal name
267 tcLookupTyVar :: Name -> TcM TcTyVar
268 tcLookupTyVar name = do
269 thing <- tcLookup name
271 ATyVar _ ty -> return (tcGetTyVar "tcLookupTyVar" ty)
272 _ -> pprPanic "tcLookupTyVar" (ppr name)
274 tcLookupId :: Name -> TcM Id
275 -- Used when we aren't interested in the binding level, nor refinement.
276 -- The "no refinement" part means that we return the un-refined Id regardless
278 -- The Id is never a DataCon. (Why does that matter? see TcExpr.tcId)
280 thing <- tcLookup name
282 ATcId { tct_id = id} -> return id
283 AGlobal (AnId id) -> return id
284 _ -> pprPanic "tcLookupId" (ppr name)
286 tcLookupLocalIds :: [Name] -> TcM [TcId]
287 -- We expect the variables to all be bound, and all at
288 -- the same level as the lookup. Only used in one place...
289 tcLookupLocalIds ns = do
291 return (map (lookup (tcl_env env) (thLevel (tcl_th_ctxt env))) ns)
294 = case lookupNameEnv lenv name of
295 Just (ATcId { tct_id = id, tct_level = lvl1 })
296 -> ASSERT( lvl == lvl1 ) id
297 _ -> pprPanic "tcLookupLocalIds" (ppr name)
299 lclEnvElts :: TcLclEnv -> [TcTyThing]
300 lclEnvElts env = nameEnvElts (tcl_env env)
302 getInLocalScope :: TcM (Name -> Bool)
306 let lcl_env = tcl_env env
307 return (`elemNameEnv` lcl_env)
311 tcExtendKindEnv :: [(Name, TcKind)] -> TcM r -> TcM r
312 tcExtendKindEnv things thing_inside
313 = updLclEnv upd thing_inside
315 upd lcl_env = lcl_env { tcl_env = extend (tcl_env lcl_env) }
316 extend env = extendNameEnvList env [(n, AThing k) | (n,k) <- things]
318 tcExtendKindEnvTvs :: [LHsTyVarBndr Name] -> TcM r -> TcM r
319 tcExtendKindEnvTvs bndrs thing_inside
320 = updLclEnv upd thing_inside
322 upd lcl_env = lcl_env { tcl_env = extend (tcl_env lcl_env) }
323 extend env = extendNameEnvList env pairs
324 pairs = [(n, AThing k) | L _ (KindedTyVar n k) <- bndrs]
326 tcExtendTyVarEnv :: [TyVar] -> TcM r -> TcM r
327 tcExtendTyVarEnv tvs thing_inside
328 = tcExtendTyVarEnv2 [(tyVarName tv, mkTyVarTy tv) | tv <- tvs] thing_inside
330 tcExtendTyVarEnv2 :: [(Name,TcType)] -> TcM r -> TcM r
331 tcExtendTyVarEnv2 binds thing_inside = do
332 env@(TcLclEnv {tcl_env = le,
334 tcl_rdr = rdr_env}) <- getLclEnv
336 rdr_env' = extendLocalRdrEnv rdr_env (map fst binds)
337 new_tv_set = tcTyVarsOfTypes (map snd binds)
338 le' = extendNameEnvList le [(name, ATyVar name ty) | (name, ty) <- binds]
340 -- It's important to add the in-scope tyvars to the global tyvar set
342 -- f (_::r) = let g y = y::r in ...
343 -- Here, g mustn't be generalised. This is also important during
344 -- class and instance decls, when we mustn't generalise the class tyvars
345 -- when typechecking the methods.
346 gtvs' <- tc_extend_gtvs gtvs new_tv_set
347 setLclEnv (env {tcl_env = le', tcl_tyvars = gtvs', tcl_rdr = rdr_env'}) thing_inside
349 getScopedTyVarBinds :: TcM [(Name, TcType)]
351 = do { lcl_env <- getLclEnv
352 ; return [(name, ty) | ATyVar name ty <- nameEnvElts (tcl_env lcl_env)] }
357 tcExtendIdEnv :: [TcId] -> TcM a -> TcM a
358 tcExtendIdEnv ids thing_inside = tcExtendIdEnv2 [(idName id, id) | id <- ids] thing_inside
360 tcExtendIdEnv1 :: Name -> TcId -> TcM a -> TcM a
361 tcExtendIdEnv1 name id thing_inside = tcExtendIdEnv2 [(name,id)] thing_inside
363 tcExtendIdEnv2 :: [(Name,TcId)] -> TcM a -> TcM a
364 -- Invariant: the TcIds are fully zonked (see tcExtendIdEnv above)
365 tcExtendIdEnv2 names_w_ids thing_inside
366 = do { env <- getLclEnv
367 ; tc_extend_local_id_env env (thLevel (tcl_th_ctxt env)) names_w_ids thing_inside }
369 tcExtendGhciEnv :: [TcId] -> TcM a -> TcM a
370 -- Used to bind Ids for GHCi identifiers bound earlier in the user interaction
371 -- Note especially that we bind them at TH level 'impLevel'. That's because it's
372 -- OK to use a variable bound earlier in the interaction in a splice, becuase
373 -- GHCi has already compiled it to bytecode
374 tcExtendGhciEnv ids thing_inside
375 = do { env <- getLclEnv
376 ; tc_extend_local_id_env env impLevel [(idName id, id) | id <- ids] thing_inside }
378 tc_extend_local_id_env -- This is the guy who does the work
383 -- Invariant: the TcIds are fully zonked. Reasons:
384 -- (a) The kinds of the forall'd type variables are defaulted
385 -- (see Kind.defaultKind, done in zonkQuantifiedTyVar)
386 -- (b) There are no via-Indirect occurrences of the bound variables
387 -- in the types, because instantiation does not look through such things
388 -- (c) The call to tyVarsOfTypes is ok without looking through refs
390 tc_extend_local_id_env env th_lvl names_w_ids thing_inside
391 = do { traceTc (text "env2")
392 ; traceTc (text "env3" <+> ppr extra_env)
393 ; gtvs' <- tc_extend_gtvs (tcl_tyvars env) extra_global_tyvars
394 ; let env' = env {tcl_env = le', tcl_tyvars = gtvs', tcl_rdr = rdr_env'}
395 ; setLclEnv env' thing_inside }
397 extra_global_tyvars = tcTyVarsOfTypes [idType id | (_,id) <- names_w_ids]
398 extra_env = [ (name, ATcId { tct_id = id,
401 tct_co = case isRefineableTy id_ty of
402 (True,_) -> Unrefineable
403 (_,True) -> Rigid idHsWrapper
405 | (name,id) <- names_w_ids, let id_ty = idType id]
406 le' = extendNameEnvList (tcl_env env) extra_env
407 rdr_env' = extendLocalRdrEnv (tcl_rdr env) [name | (name,_) <- names_w_ids]
412 -----------------------
413 -- findGlobals looks at the value environment and finds values
414 -- whose types mention the offending type variable. It has to be
415 -- careful to zonk the Id's type first, so it has to be in the monad.
416 -- We must be careful to pass it a zonked type variable, too.
418 findGlobals :: TcTyVarSet
420 -> TcM (TidyEnv, [SDoc])
422 findGlobals tvs tidy_env = do
424 go tidy_env [] (lclEnvElts lcl_env)
426 go tidy_env acc [] = return (tidy_env, acc)
427 go tidy_env acc (thing : things) = do
428 (tidy_env1, maybe_doc) <- find_thing ignore_it tidy_env thing
430 Just d -> go tidy_env1 (d:acc) things
431 Nothing -> go tidy_env1 acc things
433 ignore_it ty = tvs `disjointVarSet` tyVarsOfType ty
435 -----------------------
436 find_thing :: (TcType -> Bool) -> TidyEnv -> TcTyThing
437 -> TcM (TidyEnv, Maybe SDoc)
438 find_thing ignore_it tidy_env (ATcId { tct_id = id }) = do
439 id_ty <- zonkTcType (idType id)
440 if ignore_it id_ty then
441 return (tidy_env, Nothing)
443 (tidy_env', tidy_ty) = tidyOpenType tidy_env id_ty
444 msg = sep [ppr id <+> dcolon <+> ppr tidy_ty,
445 nest 2 (parens (ptext (sLit "bound at") <+>
446 ppr (getSrcLoc id)))]
448 return (tidy_env', Just msg)
450 find_thing ignore_it tidy_env (ATyVar tv ty) = do
451 tv_ty <- zonkTcType ty
452 if ignore_it tv_ty then
453 return (tidy_env, Nothing)
455 -- The name tv is scoped, so we don't need to tidy it
456 (tidy_env1, tidy_ty) = tidyOpenType tidy_env tv_ty
457 msg = sep [ptext (sLit "Scoped type variable") <+> quotes (ppr tv) <+> eq_stuff, nest 2 bound_at]
459 eq_stuff | Just tv' <- Type.getTyVar_maybe tv_ty,
460 getOccName tv == getOccName tv' = empty
461 | otherwise = equals <+> ppr tidy_ty
462 -- It's ok to use Type.getTyVar_maybe because ty is zonked by now
463 bound_at = parens $ ptext (sLit "bound at:") <+> ppr (getSrcLoc tv)
465 return (tidy_env1, Just msg)
467 find_thing _ _ thing = pprPanic "find_thing" (ppr thing)
470 %************************************************************************
472 \subsection{The global tyvars}
474 %************************************************************************
477 tc_extend_gtvs :: IORef VarSet -> VarSet -> TcM (IORef VarSet)
478 tc_extend_gtvs gtvs extra_global_tvs = do
479 global_tvs <- readMutVar gtvs
480 newMutVar (global_tvs `unionVarSet` extra_global_tvs)
483 @tcGetGlobalTyVars@ returns a fully-zonked set of tyvars free in the environment.
484 To improve subsequent calls to the same function it writes the zonked set back into
488 tcGetGlobalTyVars :: TcM TcTyVarSet
489 tcGetGlobalTyVars = do
490 (TcLclEnv {tcl_tyvars = gtv_var}) <- getLclEnv
491 gbl_tvs <- readMutVar gtv_var
492 gbl_tvs' <- zonkTcTyVarsAndFV (varSetElems gbl_tvs)
493 writeMutVar gtv_var gbl_tvs'
498 %************************************************************************
502 %************************************************************************
505 tcExtendRules :: [LRuleDecl Id] -> TcM a -> TcM a
506 -- Just pop the new rules into the EPS and envt resp
507 -- All the rules come from an interface file, not soruce
508 -- Nevertheless, some may be for this module, if we read
509 -- its interface instead of its source code
510 tcExtendRules lcl_rules thing_inside
511 = do { env <- getGblEnv
513 env' = env { tcg_rules = lcl_rules ++ tcg_rules env }
514 ; setGblEnv env' thing_inside }
518 %************************************************************************
522 %************************************************************************
525 instance Outputable ThStage where
526 ppr Comp = text "Comp"
527 ppr (Brack l _ _) = text "Brack" <+> int l
528 ppr (Splice l) = text "Splice" <+> int l
531 thLevel :: ThStage -> ThLevel
532 thLevel Comp = topLevel
533 thLevel (Splice l) = l
534 thLevel (Brack l _ _) = l
537 checkWellStaged :: SDoc -- What the stage check is for
538 -> ThLevel -- Binding level (increases inside brackets)
539 -> ThStage -- Use stage
540 -> TcM () -- Fail if badly staged, adding an error
541 checkWellStaged pp_thing bind_lvl use_stage
542 | use_lvl >= bind_lvl -- OK! Used later than bound
543 = return () -- E.g. \x -> [| $(f x) |]
545 | bind_lvl == topLevel -- GHC restriction on top level splices
547 sep [ptext (sLit "GHC stage restriction:") <+> pp_thing,
548 nest 2 (ptext (sLit "is used in a top-level splice, and must be imported, not defined locally"))]
550 | otherwise -- Badly staged
551 = failWithTc $ -- E.g. \x -> $(f x)
552 ptext (sLit "Stage error:") <+> pp_thing <+>
553 hsep [ptext (sLit "is bound at stage") <+> ppr bind_lvl,
554 ptext (sLit "but used at stage") <+> ppr use_lvl]
556 use_lvl = thLevel use_stage
559 topIdLvl :: Id -> ThLevel
560 -- Globals may either be imported, or may be from an earlier "chunk"
561 -- (separated by declaration splices) of this module. The former
562 -- *can* be used inside a top-level splice, but the latter cannot.
563 -- Hence we give the former impLevel, but the latter topLevel
567 -- By the time we are prcessing the $(f x), the binding for "x"
568 -- will be in the global env, not the local one.
569 topIdLvl id | isLocalId id = topLevel
570 | otherwise = impLevel
572 -- Indicates the legal transitions on bracket( [| |] ).
573 bracketOK :: ThStage -> Maybe ThLevel
574 bracketOK (Brack _ _ _) = Nothing -- Bracket illegal inside a bracket
575 bracketOK stage = Just (thLevel stage + 1)
577 -- Indicates the legal transitions on splice($).
578 spliceOK :: ThStage -> Maybe ThLevel
579 spliceOK (Splice _) = Nothing -- Splice illegal inside splice
580 spliceOK stage = Just (thLevel stage - 1)
582 tcMetaTy :: Name -> TcM Type
583 -- Given the name of a Template Haskell data type,
585 -- E.g. given the name "Expr" return the type "Expr"
586 tcMetaTy tc_name = do
587 t <- tcLookupTyCon tc_name
588 return (mkTyConApp t [])
591 -- Used *only* to indicate that we are inside a TH bracket during renaming
592 -- Tested by TcEnv.isBrackStage
593 -- This is a slight hack, used to ensure that
595 thRnBrack = Brack (panic "thRnBrack1") (panic "thRnBrack2") (panic "thRnBrack3")
597 isBrackStage :: ThStage -> Bool
598 isBrackStage (Brack {}) = True
599 isBrackStage _other = False
601 thTopLevelId :: Id -> Bool
602 -- See Note [What is a top-level Id?] in TcSplice
603 thTopLevelId id = isGlobalId id || isExternalName (idName id)
607 %************************************************************************
609 \subsection{The InstInfo type}
611 %************************************************************************
613 The InstInfo type summarises the information in an instance declaration
615 instance c => k (t tvs) where b
617 It is used just for *local* instance decls (not ones from interface files).
618 But local instance decls includes
621 as well as explicit user written ones.
626 iSpec :: Instance, -- Includes the dfun id. Its forall'd type
627 iBinds :: InstBindings a -- variables scope over the stuff in InstBindings!
630 iDFunId :: InstInfo a -> DFunId
631 iDFunId info = instanceDFunId (iSpec info)
634 = VanillaInst -- The normal case
635 (LHsBinds a) -- Bindings for the instance methods
636 [LSig a] -- User pragmas recorded for generating
637 -- specialised instances
639 | NewTypeDerived -- Used for deriving instances of newtypes, where the
640 -- witness dictionary is identical to the argument
641 -- dictionary. Hence no bindings, no pragmas.
643 pprInstInfo :: InstInfo a -> SDoc
644 pprInstInfo info = vcat [ptext (sLit "InstInfo:") <+> ppr (idType (iDFunId info))]
646 pprInstInfoDetails :: OutputableBndr a => InstInfo a -> SDoc
647 pprInstInfoDetails info = pprInstInfo info $$ nest 2 (details (iBinds info))
649 details (VanillaInst b _) = pprLHsBinds b
650 details NewTypeDerived = text "Derived from the representation type"
652 simpleInstInfoClsTy :: InstInfo a -> (Class, Type)
653 simpleInstInfoClsTy info = case instanceHead (iSpec info) of
654 (_, _, cls, [ty]) -> (cls, ty)
655 _ -> panic "simpleInstInfoClsTy"
657 simpleInstInfoTy :: InstInfo a -> Type
658 simpleInstInfoTy info = snd (simpleInstInfoClsTy info)
660 simpleInstInfoTyCon :: InstInfo a -> TyCon
661 -- Gets the type constructor for a simple instance declaration,
662 -- i.e. one of the form instance (...) => C (T a b c) where ...
663 simpleInstInfoTyCon inst = tcTyConAppTyCon (simpleInstInfoTy inst)
666 Make a name for the dict fun for an instance decl. It's an *external*
667 name, like otber top-level names, and hence must be made with newGlobalBinder.
670 newDFunName :: Class -> [Type] -> SrcSpan -> TcM Name
671 newDFunName clas (ty:_) loc
672 = do { index <- nextDFunIndex
673 ; is_boot <- tcIsHsBoot
675 ; let info_string = occNameString (getOccName clas) ++
676 occNameString (getDFunTyKey ty)
677 dfun_occ = mkDFunOcc info_string is_boot index
679 ; newGlobalBinder mod dfun_occ loc }
681 newDFunName clas [] loc = pprPanic "newDFunName" (ppr clas <+> ppr loc)
684 Make a name for the representation tycon of a family instance. It's an
685 *external* name, like otber top-level names, and hence must be made with
689 newFamInstTyConName :: Name -> SrcSpan -> TcM Name
690 newFamInstTyConName tc_name loc
691 = do { index <- nextDFunIndex
693 ; let occ = nameOccName tc_name
694 ; newGlobalBinder mod (mkInstTyTcOcc index occ) loc }
697 Stable names used for foreign exports and annotations.
698 For stable names, the name must be unique (see #1533). If the
699 same thing has several stable Ids based on it, the
700 top-level bindings generated must not have the same name.
701 Hence we create an External name (doesn't change), and we
702 append a Unique to the string right here.
705 mkStableIdFromString :: String -> Type -> SrcSpan -> (OccName -> OccName) -> TcM TcId
706 mkStableIdFromString str sig_ty loc occ_wrapper = do
709 let uniq_str = showSDoc (pprUnique uniq) :: String
710 occ = mkVarOcc (str ++ '_' : uniq_str) :: OccName
711 gnm = mkExternalName uniq mod (occ_wrapper occ) loc :: Name
712 id = mkExportedLocalId gnm sig_ty :: Id
715 mkStableIdFromName :: Name -> Type -> SrcSpan -> (OccName -> OccName) -> TcM TcId
716 mkStableIdFromName nm = mkStableIdFromString (getOccString nm)
719 %************************************************************************
723 %************************************************************************
726 pprBinders :: [Name] -> SDoc
727 -- Used in error messages
728 -- Use quotes for a single one; they look a bit "busy" for several
729 pprBinders [bndr] = quotes (ppr bndr)
730 pprBinders bndrs = pprWithCommas ppr bndrs
732 notFound :: Name -> TcGblEnv -> TcM TyThing
734 = failWithTc (vcat[ptext (sLit "GHC internal error:") <+> quotes (ppr name) <+>
735 ptext (sLit "is not in scope during type checking, but it passed the renamer"),
736 ptext (sLit "tcg_type_env of environment:") <+> ppr (tcg_type_env env)]
739 wrongThingErr :: String -> TcTyThing -> Name -> TcM a
740 wrongThingErr expected thing name
741 = failWithTc (pprTcTyThingCategory thing <+> quotes (ppr name) <+>
742 ptext (sLit "used as a") <+> text expected)