8 #include "HsVersions.h"
10 import TcRnTypes -- Re-export all
11 import IOEnv -- Re-export all
13 import HsSyn ( MonoBinds(..) )
14 import HscTypes ( HscEnv(..), ModGuts(..), ModIface(..),
15 TyThing, Dependencies(..), TypeEnv, emptyTypeEnv,
16 ExternalPackageState(..), HomePackageTable,
17 ModDetails(..), HomeModInfo(..),
18 Deprecs(..), FixityEnv, FixItem,
19 GhciMode, lookupType, unQualInScope )
20 import Module ( Module, ModuleName, unitModuleEnv, foldModuleEnv, emptyModuleEnv )
21 import RdrName ( GlobalRdrEnv, emptyGlobalRdrEnv,
22 LocalRdrEnv, emptyLocalRdrEnv )
23 import Name ( Name, isInternalName )
25 import NameEnv ( extendNameEnvList )
26 import InstEnv ( InstEnv, emptyInstEnv, extendInstEnv )
28 import VarSet ( emptyVarSet )
29 import VarEnv ( TidyEnv, emptyTidyEnv )
30 import ErrUtils ( Message, Messages, emptyMessages, errorsFound,
31 addShortErrLocLine, addShortWarnLocLine, printErrorsAndWarnings )
32 import SrcLoc ( SrcLoc, mkGeneralSrcLoc )
33 import NameEnv ( emptyNameEnv )
34 import NameSet ( emptyDUs, emptyNameSet )
35 import OccName ( emptyOccEnv )
36 import Module ( moduleName )
37 import Bag ( emptyBag )
39 import UniqSupply ( UniqSupply, mkSplitUniqSupply, uniqFromSupply, splitUniqSupply )
40 import Unique ( Unique )
41 import CmdLineOpts ( DynFlags, DynFlag(..), dopt, opt_PprStyle_Debug )
42 import Bag ( snocBag, unionBags )
43 import Panic ( showException )
45 import Maybe ( isJust )
47 import DATA_IOREF ( newIORef, readIORef )
48 import EXCEPTION ( Exception )
53 %************************************************************************
57 %************************************************************************
60 ioToTcRn :: IO r -> TcRn r
69 -- Nothing => error thrown by the thing inside
70 -- (error messages should have been printed already)
72 initTc hsc_env mod do_this
73 = do { errs_var <- newIORef (emptyBag, emptyBag) ;
74 tvs_var <- newIORef emptyVarSet ;
75 type_env_var <- newIORef emptyNameEnv ;
76 dfuns_var <- newIORef emptyNameSet ;
81 tcg_rdr_env = emptyGlobalRdrEnv,
82 tcg_fix_env = emptyNameEnv,
83 tcg_default = Nothing,
84 tcg_type_env = emptyNameEnv,
85 tcg_type_env_var = type_env_var,
86 tcg_inst_env = mkImpInstEnv hsc_env,
87 tcg_inst_uses = dfuns_var,
89 tcg_imports = init_imports,
91 tcg_binds = EmptyMonoBinds,
92 tcg_deprecs = NoDeprecs,
99 tcl_loc = mkGeneralSrcLoc FSLIT("Top level of module"),
101 tcl_rdr = emptyLocalRdrEnv,
102 tcl_th_ctxt = topStage,
103 tcl_arrow_ctxt = topArrowCtxt,
104 tcl_env = emptyNameEnv,
105 tcl_tyvars = tvs_var,
106 tcl_lie = panic "initTc:LIE" -- LIE only valid inside a getLIE
110 -- OK, here's the business end!
111 maybe_res <- initTcRnIf 'a' hsc_env gbl_env lcl_env $
112 do { r <- tryM do_this
114 Right res -> return (Just res)
115 Left _ -> return Nothing } ;
117 -- Print any error messages
118 msgs <- readIORef errs_var ;
119 printErrorsAndWarnings msgs ;
121 let { dflags = hsc_dflags hsc_env
122 ; final_res | errorsFound dflags msgs = Nothing
123 | otherwise = maybe_res } ;
128 init_imports = emptyImportAvails { imp_qual = unitModuleEnv mod emptyAvailEnv }
129 -- Initialise tcg_imports with an empty set of bindings for
130 -- this module, so that if we see 'module M' in the export
131 -- list, and there are no bindings in M, we don't bleat
132 -- "unknown module M".
134 mkImpInstEnv :: HscEnv -> InstEnv
135 -- At the moment we (wrongly) build an instance environment from all the
136 -- home-package modules we have already compiled.
137 -- We should really only get instances from modules below us in the
138 -- module import tree.
139 mkImpInstEnv (HscEnv {hsc_dflags = dflags, hsc_HPT = hpt})
140 = foldModuleEnv (add . md_insts . hm_details) emptyInstEnv hpt
142 add dfuns inst_env = foldl extendInstEnv inst_env dfuns
144 -- mkImpTypeEnv makes the imported symbol table
145 mkImpTypeEnv :: ExternalPackageState -> HomePackageTable
146 -> Name -> Maybe TyThing
147 mkImpTypeEnv pcs hpt = lookup
150 lookup name | isInternalName name = Nothing
151 | otherwise = lookupType hpt pte name
155 %************************************************************************
159 %************************************************************************
163 initTcRnIf :: Char -- Tag for unique supply
168 initTcRnIf uniq_tag hsc_env gbl_env lcl_env thing_inside
169 = do { us <- mkSplitUniqSupply uniq_tag ;
170 ; us_var <- newIORef us ;
172 ; let { env = Env { env_top = hsc_env,
175 env_lcl = lcl_env } }
177 ; runIOEnv env thing_inside
181 %************************************************************************
185 %************************************************************************
188 getTopEnv :: TcRnIf gbl lcl HscEnv
189 getTopEnv = do { env <- getEnv; return (env_top env) }
191 getGblEnv :: TcRnIf gbl lcl gbl
192 getGblEnv = do { env <- getEnv; return (env_gbl env) }
194 updGblEnv :: (gbl -> gbl) -> TcRnIf gbl lcl a -> TcRnIf gbl lcl a
195 updGblEnv upd = updEnv (\ env@(Env { env_gbl = gbl }) ->
196 env { env_gbl = upd gbl })
198 setGblEnv :: gbl -> TcRnIf gbl lcl a -> TcRnIf gbl lcl a
199 setGblEnv gbl_env = updEnv (\ env -> env { env_gbl = gbl_env })
201 getLclEnv :: TcRnIf gbl lcl lcl
202 getLclEnv = do { env <- getEnv; return (env_lcl env) }
204 updLclEnv :: (lcl -> lcl) -> TcRnIf gbl lcl a -> TcRnIf gbl lcl a
205 updLclEnv upd = updEnv (\ env@(Env { env_lcl = lcl }) ->
206 env { env_lcl = upd lcl })
208 setLclEnv :: lcl' -> TcRnIf gbl lcl' a -> TcRnIf gbl lcl a
209 setLclEnv lcl_env = updEnv (\ env -> env { env_lcl = lcl_env })
211 getEnvs :: TcRnIf gbl lcl (gbl, lcl)
212 getEnvs = do { env <- getEnv; return (env_gbl env, env_lcl env) }
214 setEnvs :: (gbl', lcl') -> TcRnIf gbl' lcl' a -> TcRnIf gbl lcl a
215 setEnvs (gbl_env, lcl_env) = updEnv (\ env -> env { env_gbl = gbl_env, env_lcl = lcl_env })
222 getDOpts :: TcRnIf gbl lcl DynFlags
223 getDOpts = do { env <- getTopEnv; return (hsc_dflags env) }
225 doptM :: DynFlag -> TcRnIf gbl lcl Bool
226 doptM flag = do { dflags <- getDOpts; return (dopt flag dflags) }
228 ifOptM :: DynFlag -> TcRnIf gbl lcl () -> TcRnIf gbl lcl () -- Do it flag is true
229 ifOptM flag thing_inside = do { b <- doptM flag;
230 if b then thing_inside else return () }
232 getGhciMode :: TcRnIf gbl lcl GhciMode
233 getGhciMode = do { env <- getTopEnv; return (hsc_mode env) }
237 getEpsVar :: TcRnIf gbl lcl (TcRef ExternalPackageState)
238 getEpsVar = do { env <- getTopEnv; return (hsc_EPS env) }
240 getEps :: TcRnIf gbl lcl ExternalPackageState
241 getEps = do { env <- getTopEnv; readMutVar (hsc_EPS env) }
243 setEps :: ExternalPackageState -> TcRnIf gbl lcl ()
244 setEps eps = do { env <- getTopEnv; writeMutVar (hsc_EPS env) eps }
246 updateEps :: (ExternalPackageState -> (ExternalPackageState, a))
248 updateEps upd_fn = do { eps_var <- getEpsVar
249 ; eps <- readMutVar eps_var
250 ; let { (eps', val) = upd_fn eps }
251 ; writeMutVar eps_var eps'
254 updateEps_ :: (ExternalPackageState -> ExternalPackageState)
256 updateEps_ upd_fn = do { eps_var <- getEpsVar
257 ; updMutVar eps_var upd_fn }
259 getHpt :: TcRnIf gbl lcl HomePackageTable
260 getHpt = do { env <- getTopEnv; return (hsc_HPT env) }
263 %************************************************************************
267 %************************************************************************
270 newUnique :: TcRnIf gbl lcl Unique
271 newUnique = do { us <- newUniqueSupply ;
272 return (uniqFromSupply us) }
274 newUniqueSupply :: TcRnIf gbl lcl UniqSupply
276 = do { env <- getEnv ;
277 let { u_var = env_us env } ;
278 us <- readMutVar u_var ;
279 let { (us1, us2) = splitUniqSupply us } ;
280 writeMutVar u_var us1 ;
285 %************************************************************************
289 %************************************************************************
292 traceTc, traceRn :: SDoc -> TcRn ()
293 traceRn = dumpOptTcRn Opt_D_dump_rn_trace
294 traceTc = dumpOptTcRn Opt_D_dump_tc_trace
295 traceSplice = dumpOptTcRn Opt_D_dump_splices
298 traceIf :: SDoc -> TcRnIf m n ()
299 traceIf = dumpOptIf Opt_D_dump_if_trace
300 traceHiDiffs = dumpOptIf Opt_D_dump_hi_diffs
303 dumpOptIf :: DynFlag -> SDoc -> TcRnIf m n () -- No RdrEnv available, so qualify everything
304 dumpOptIf flag doc = ifOptM flag $
305 ioToIOEnv (printForUser stderr alwaysQualify doc)
307 dumpOptTcRn :: DynFlag -> SDoc -> TcRn ()
308 dumpOptTcRn flag doc = ifOptM flag (dumpTcRn doc)
310 dumpTcRn :: SDoc -> TcRn ()
311 dumpTcRn doc = do { rdr_env <- getGlobalRdrEnv ;
312 ioToTcRn (printForUser stderr (unQualInScope rdr_env) doc) }
316 %************************************************************************
318 Typechecker global environment
320 %************************************************************************
323 getModule :: TcRn Module
324 getModule = do { env <- getGblEnv; return (tcg_mod env) }
326 getGlobalRdrEnv :: TcRn GlobalRdrEnv
327 getGlobalRdrEnv = do { env <- getGblEnv; return (tcg_rdr_env env) }
329 getImports :: TcRn ImportAvails
330 getImports = do { env <- getGblEnv; return (tcg_imports env) }
332 getFixityEnv :: TcRn FixityEnv
333 getFixityEnv = do { env <- getGblEnv; return (tcg_fix_env env) }
335 extendFixityEnv :: [(Name,FixItem)] -> RnM a -> RnM a
336 extendFixityEnv new_bit
337 = updGblEnv (\env@(TcGblEnv { tcg_fix_env = old_fix_env }) ->
338 env {tcg_fix_env = extendNameEnvList old_fix_env new_bit})
340 getDefaultTys :: TcRn (Maybe [Type])
341 getDefaultTys = do { env <- getGblEnv; return (tcg_default env) }
344 %************************************************************************
348 %************************************************************************
351 getSrcLocM :: TcRn SrcLoc
352 -- Avoid clash with Name.getSrcLoc
353 getSrcLocM = do { env <- getLclEnv; return (tcl_loc env) }
355 addSrcLoc :: SrcLoc -> TcRn a -> TcRn a
356 addSrcLoc loc = updLclEnv (\env -> env { tcl_loc = loc })
361 getErrsVar :: TcRn (TcRef Messages)
362 getErrsVar = do { env <- getLclEnv; return (tcl_errs env) }
364 setErrsVar :: TcRef Messages -> TcRn a -> TcRn a
365 setErrsVar v = updLclEnv (\ env -> env { tcl_errs = v })
367 addErr :: Message -> TcRn ()
368 addErr msg = do { loc <- getSrcLocM ; addErrAt loc msg }
370 addErrAt :: SrcLoc -> Message -> TcRn ()
372 = do { errs_var <- getErrsVar ;
373 rdr_env <- getGlobalRdrEnv ;
374 let { err = addShortErrLocLine loc (unQualInScope rdr_env) msg } ;
375 (warns, errs) <- readMutVar errs_var ;
376 writeMutVar errs_var (warns, errs `snocBag` err) }
378 addErrs :: [(SrcLoc,Message)] -> TcRn ()
379 addErrs msgs = mappM_ add msgs
381 add (loc,msg) = addErrAt loc msg
383 addWarn :: Message -> TcRn ()
385 = do { errs_var <- getErrsVar ;
387 rdr_env <- getGlobalRdrEnv ;
388 let { warn = addShortWarnLocLine loc (unQualInScope rdr_env) msg } ;
389 (warns, errs) <- readMutVar errs_var ;
390 writeMutVar errs_var (warns `snocBag` warn, errs) }
392 checkErr :: Bool -> Message -> TcRn ()
393 -- Add the error if the bool is False
394 checkErr ok msg = checkM ok (addErr msg)
396 warnIf :: Bool -> Message -> TcRn ()
397 warnIf True msg = addWarn msg
398 warnIf False msg = return ()
400 addMessages :: Messages -> TcRn ()
401 addMessages (m_warns, m_errs)
402 = do { errs_var <- getErrsVar ;
403 (warns, errs) <- readMutVar errs_var ;
404 writeMutVar errs_var (warns `unionBags` m_warns,
405 errs `unionBags` m_errs) }
407 discardWarnings :: TcRn a -> TcRn a
408 -- Ignore warnings inside the thing inside;
409 -- used to ignore-unused-variable warnings inside derived code
410 -- With -dppr-debug, the effects is switched off, so you can still see
411 -- what warnings derived code would give
412 discardWarnings thing_inside
413 | opt_PprStyle_Debug = thing_inside
415 = do { errs_var <- newMutVar emptyMessages
416 ; result <- setErrsVar errs_var thing_inside
417 ; (_warns, errs) <- readMutVar errs_var
418 ; addMessages (emptyBag, errs)
424 recoverM :: TcRn r -- Recovery action; do this if the main one fails
425 -> TcRn r -- Main action: do this first
427 recoverM recover thing
428 = do { mb_res <- try_m thing ;
431 Right res -> returnM res }
433 tryTc :: TcRn a -> TcRn (Messages, Maybe a)
434 -- (tryTc m) executes m, and returns
435 -- Just r, if m succeeds (returning r) and caused no errors
436 -- Nothing, if m fails, or caused errors
437 -- It also returns all the errors accumulated by m
438 -- (even in the Just case, there might be warnings)
440 -- It always succeeds (never raises an exception)
442 = do { errs_var <- newMutVar emptyMessages ;
444 mb_r <- try_m (setErrsVar errs_var m) ;
446 new_errs <- readMutVar errs_var ;
453 Right r | errorsFound dflags new_errs -> Nothing
454 | otherwise -> Just r)
457 try_m :: TcRn r -> TcRn (Either Exception r)
458 -- Does try_m, with a debug-trace on failure
460 = do { mb_r <- tryM thing ;
462 Left exn -> do { traceTc (exn_msg exn); return mb_r }
463 Right r -> return mb_r }
465 exn_msg exn = text "tryTc/recoverM recovering from" <+> text (showException exn)
467 tryTcLIE :: TcM a -> TcM (Messages, Maybe a)
468 -- Just like tryTc, except that it ensures that the LIE
469 -- for the thing is propagated only if there are no errors
470 -- Hence it's restricted to the type-check monad
471 tryTcLIE thing_inside
472 = do { ((errs, mb_r), lie) <- getLIE (tryTc thing_inside) ;
473 ifM (isJust mb_r) (extendLIEs lie) ;
474 return (errs, mb_r) }
476 tryTcLIE_ :: TcM r -> TcM r -> TcM r
477 -- (tryTcLIE_ r m) tries m; if it succeeds it returns it,
478 -- otherwise it returns r. Any error messages added by m are discarded,
479 -- whether or not m succeeds.
480 tryTcLIE_ recover main
481 = do { (_msgs, mb_res) <- tryTcLIE main ;
483 Just res -> return res
486 checkNoErrs :: TcM r -> TcM r
487 -- (checkNoErrs m) succeeds iff m succeeds and generates no errors
488 -- If m fails then (checkNoErrsTc m) fails.
489 -- If m succeeds, it checks whether m generated any errors messages
490 -- (it might have recovered internally)
491 -- If so, it fails too.
492 -- Regardless, any errors generated by m are propagated to the enclosing context.
494 = do { (msgs, mb_res) <- tryTcLIE main ;
501 ifErrsM :: TcRn r -> TcRn r -> TcRn r
502 -- ifErrsM bale_out main
503 -- does 'bale_out' if there are errors in errors collection
504 -- otherwise does 'main'
505 ifErrsM bale_out normal
506 = do { errs_var <- getErrsVar ;
507 msgs <- readMutVar errs_var ;
509 if errorsFound dflags msgs then
514 failIfErrsM :: TcRn ()
515 -- Useful to avoid error cascades
516 failIfErrsM = ifErrsM failM (return ())
520 %************************************************************************
522 Context management and error message generation
525 %************************************************************************
528 setErrCtxtM, addErrCtxtM :: (TidyEnv -> TcM (TidyEnv, Message)) -> TcM a -> TcM a
529 setErrCtxtM msg = updCtxt (\ msgs -> [msg])
530 addErrCtxtM msg = updCtxt (\ msgs -> msg : msgs)
532 setErrCtxt, addErrCtxt :: Message -> TcM a -> TcM a
533 setErrCtxt msg = setErrCtxtM (\env -> returnM (env, msg))
534 addErrCtxt msg = addErrCtxtM (\env -> returnM (env, msg))
536 popErrCtxt :: TcM a -> TcM a
537 popErrCtxt = updCtxt (\ msgs -> case msgs of { [] -> []; (m:ms) -> ms })
539 getErrCtxt :: TcM ErrCtxt
540 getErrCtxt = do { env <- getLclEnv ; return (tcl_ctxt env) }
542 -- Helper function for the above
543 updCtxt :: (ErrCtxt -> ErrCtxt) -> TcM a -> TcM a
544 updCtxt upd = updLclEnv (\ env@(TcLclEnv { tcl_ctxt = ctxt }) ->
545 env { tcl_ctxt = upd ctxt })
547 getInstLoc :: InstOrigin -> TcM InstLoc
549 = do { loc <- getSrcLocM ; env <- getLclEnv ;
550 return (InstLoc origin loc (tcl_ctxt env)) }
552 addInstCtxt :: InstLoc -> TcM a -> TcM a
553 -- Add the SrcLoc and context from the first Inst in the list
554 -- (they all have similar locations)
555 addInstCtxt (InstLoc _ src_loc ctxt) thing_inside
556 = addSrcLoc src_loc (updCtxt (\ old_ctxt -> ctxt) thing_inside)
559 The addErrTc functions add an error message, but do not cause failure.
560 The 'M' variants pass a TidyEnv that has already been used to
561 tidy up the message; we then use it to tidy the context messages
564 addErrTc :: Message -> TcM ()
565 addErrTc err_msg = addErrTcM (emptyTidyEnv, err_msg)
567 addErrsTc :: [Message] -> TcM ()
568 addErrsTc err_msgs = mappM_ addErrTc err_msgs
570 addErrTcM :: (TidyEnv, Message) -> TcM ()
571 addErrTcM (tidy_env, err_msg)
572 = do { ctxt <- getErrCtxt ;
574 add_err_tcm tidy_env err_msg loc ctxt }
577 The failWith functions add an error message and cause failure
580 failWithTc :: Message -> TcM a -- Add an error message and fail
582 = addErrTc err_msg >> failM
584 failWithTcM :: (TidyEnv, Message) -> TcM a -- Add an error message and fail
585 failWithTcM local_and_msg
586 = addErrTcM local_and_msg >> failM
588 checkTc :: Bool -> Message -> TcM () -- Check that the boolean is true
589 checkTc True err = returnM ()
590 checkTc False err = failWithTc err
593 Warnings have no 'M' variant, nor failure
596 addWarnTc :: Message -> TcM ()
598 = do { ctxt <- getErrCtxt ;
599 ctxt_msgs <- do_ctxt emptyTidyEnv ctxt ;
600 addWarn (vcat (msg : ctxt_to_use ctxt_msgs)) }
602 warnTc :: Bool -> Message -> TcM ()
603 warnTc warn_if_true warn_msg
604 | warn_if_true = addWarnTc warn_msg
605 | otherwise = return ()
611 add_err_tcm tidy_env err_msg loc ctxt
612 = do { ctxt_msgs <- do_ctxt tidy_env ctxt ;
613 addErrAt loc (vcat (err_msg : ctxt_to_use ctxt_msgs)) }
617 do_ctxt tidy_env (c:cs)
618 = do { (tidy_env', m) <- c tidy_env ;
619 ms <- do_ctxt tidy_env' cs ;
622 ctxt_to_use ctxt | opt_PprStyle_Debug = ctxt
623 | otherwise = take 3 ctxt
626 %************************************************************************
628 Type constraints (the so-called LIE)
630 %************************************************************************
633 getLIEVar :: TcM (TcRef LIE)
634 getLIEVar = do { env <- getLclEnv; return (tcl_lie env) }
636 setLIEVar :: TcRef LIE -> TcM a -> TcM a
637 setLIEVar lie_var = updLclEnv (\ env -> env { tcl_lie = lie_var })
639 getLIE :: TcM a -> TcM (a, [Inst])
640 -- (getLIE m) runs m, and returns the type constraints it generates
642 = do { lie_var <- newMutVar emptyLIE ;
643 res <- updLclEnv (\ env -> env { tcl_lie = lie_var })
645 lie <- readMutVar lie_var ;
646 return (res, lieToList lie) }
648 extendLIE :: Inst -> TcM ()
650 = do { lie_var <- getLIEVar ;
651 lie <- readMutVar lie_var ;
652 writeMutVar lie_var (inst `consLIE` lie) }
654 extendLIEs :: [Inst] -> TcM ()
658 = do { lie_var <- getLIEVar ;
659 lie <- readMutVar lie_var ;
660 writeMutVar lie_var (mkLIE insts `plusLIE` lie) }
664 setLclTypeEnv :: TcLclEnv -> TcM a -> TcM a
665 -- Set the local type envt, but do *not* disturb other fields,
666 -- notably the lie_var
667 setLclTypeEnv lcl_env thing_inside
668 = updLclEnv upd thing_inside
670 upd env = env { tcl_env = tcl_env lcl_env,
671 tcl_tyvars = tcl_tyvars lcl_env }
675 %************************************************************************
677 Template Haskell context
679 %************************************************************************
682 getStage :: TcM ThStage
683 getStage = do { env <- getLclEnv; return (tcl_th_ctxt env) }
685 setStage :: ThStage -> TcM a -> TcM a
686 setStage s = updLclEnv (\ env -> env { tcl_th_ctxt = s })
690 %************************************************************************
694 %************************************************************************
697 popArrowBinders :: TcM a -> TcM a -- Move to the left of a (-<); see comments in TcRnTypes
699 = updLclEnv (\ env -> env { tcl_arrow_ctxt = pop (tcl_arrow_ctxt env) })
701 pop (ArrCtxt {proc_level = curr_lvl, proc_banned = banned})
702 = ASSERT( not (curr_lvl `elem` banned) )
703 ArrCtxt {proc_level = curr_lvl, proc_banned = curr_lvl : banned}
705 getBannedProcLevels :: TcM [ProcLevel]
706 = do { env <- getLclEnv; return (proc_banned (tcl_arrow_ctxt env)) }
708 incProcLevel :: TcM a -> TcM a
710 = updLclEnv (\ env -> env { tcl_arrow_ctxt = inc (tcl_arrow_ctxt env) })
712 inc ctxt = ctxt { proc_level = proc_level ctxt + 1 }
716 %************************************************************************
718 Stuff for the renamer's local env
720 %************************************************************************
723 getLocalRdrEnv :: RnM LocalRdrEnv
724 getLocalRdrEnv = do { env <- getLclEnv; return (tcl_rdr env) }
726 setLocalRdrEnv :: LocalRdrEnv -> RnM a -> RnM a
727 setLocalRdrEnv rdr_env thing_inside
728 = updLclEnv (\env -> env {tcl_rdr = rdr_env}) thing_inside
732 %************************************************************************
734 Stuff for interface decls
736 %************************************************************************
739 initIfaceTcRn :: IfG a -> TcRn a
740 initIfaceTcRn thing_inside
741 = do { tcg_env <- getGblEnv
742 ; let { if_env = IfGblEnv {
743 if_rec_types = Just (tcg_mod tcg_env, get_type_env),
744 if_is_boot = imp_dep_mods (tcg_imports tcg_env) }
745 ; get_type_env = readMutVar (tcg_type_env_var tcg_env) }
746 ; setEnvs (if_env, ()) thing_inside }
748 initIfaceExtCore :: IfL a -> TcRn a
749 initIfaceExtCore thing_inside
750 = do { tcg_env <- getGblEnv
751 ; let { mod = tcg_mod tcg_env
752 ; if_env = IfGblEnv {
753 if_rec_types = Just (mod, return (tcg_type_env tcg_env)),
754 if_is_boot = imp_dep_mods (tcg_imports tcg_env) }
755 ; if_lenv = IfLclEnv { if_mod = moduleName mod,
756 if_tv_env = emptyOccEnv,
757 if_id_env = emptyOccEnv }
759 ; setEnvs (if_env, if_lenv) thing_inside }
761 initIfaceCheck :: HscEnv -> IfG a -> IO a
762 -- Used when checking the up-to-date-ness of the old Iface
763 -- Initialise the environment with no useful info at all
764 initIfaceCheck hsc_env do_this
765 = do { let { gbl_env = IfGblEnv { if_is_boot = emptyModuleEnv,
766 if_rec_types = Nothing } ;
768 ; initTcRnIf 'i' hsc_env gbl_env () do_this
771 initIfaceTc :: HscEnv -> ModIface
772 -> (TcRef TypeEnv -> IfL a) -> IO a
773 -- Used when type-checking checking an up-to-date interface file
774 -- No type envt from the current module, but we do know the module dependencies
775 initIfaceTc hsc_env iface do_this
776 = do { tc_env_var <- newIORef emptyTypeEnv
777 ; let { gbl_env = IfGblEnv { if_is_boot = mkModDeps (dep_mods (mi_deps iface)),
778 if_rec_types = Just (mod, readMutVar tc_env_var) } ;
779 ; if_lenv = IfLclEnv { if_mod = moduleName mod,
780 if_tv_env = emptyOccEnv,
781 if_id_env = emptyOccEnv }
783 ; initTcRnIf 'i' hsc_env gbl_env if_lenv (do_this tc_env_var)
786 mod = mi_module iface
788 initIfaceRules :: HscEnv -> ModGuts -> IfG a -> IO a
789 -- Used when sucking in new Rules in SimplCore
790 -- We have available the type envt of the module being compiled, and we must use it
791 initIfaceRules hsc_env guts do_this
793 is_boot = mkModDeps (dep_mods (mg_deps guts))
794 -- Urgh! But we do somehow need to get the info
795 -- on whether (for this particular compilation) we should
796 -- import a hi-boot file or not.
797 ; type_info = (mg_module guts, return (mg_types guts))
798 ; gbl_env = IfGblEnv { if_is_boot = is_boot,
799 if_rec_types = Just type_info } ;
802 -- Run the thing; any exceptions just bubble out from here
803 ; initTcRnIf 'i' hsc_env gbl_env () do_this
806 initIfaceLcl :: ModuleName -> IfL a -> IfM lcl a
807 initIfaceLcl mod thing_inside
808 = setLclEnv (IfLclEnv { if_mod = mod,
809 if_tv_env = emptyOccEnv,
810 if_id_env = emptyOccEnv })
815 forkM_maybe :: SDoc -> IfL a -> IfL (Maybe a)
816 -- Run thing_inside in an interleaved thread.
817 -- It shares everything with the parent thread, so this is DANGEROUS.
819 -- It returns Nothing if the computation fails
821 -- It's used for lazily type-checking interface
822 -- signatures, which is pretty benign
824 forkM_maybe doc thing_inside
825 = do { unsafeInterleaveM $
826 do { traceIf (text "Starting fork {" <+> doc)
827 ; mb_res <- tryM thing_inside ;
829 Right r -> do { traceIf (text "} ending fork" <+> doc)
833 -- Bleat about errors in the forked thread, if -ddump-if-trace is on
834 -- Otherwise we silently discard errors. Errors can legitimately
835 -- happen when compiling interface signatures (see tcInterfaceSigs)
836 ifOptM Opt_D_dump_if_trace
837 (print_errs (hang (text "forkM failed:" <+> doc)
838 4 (text (show exn))))
840 ; traceIf (text "} ending fork (badly)" <+> doc)
844 print_errs sdoc = ioToIOEnv (printErrs (sdoc defaultErrStyle))
846 forkM :: SDoc -> IfL a -> IfL a
847 forkM doc thing_inside
848 = do { mb_res <- forkM_maybe doc thing_inside
849 ; return (case mb_res of
850 Nothing -> pprPanic "forkM" doc