8 #include "HsVersions.h"
10 import TcRnTypes -- Re-export all
11 import IOEnv -- Re-export all
13 import HsSyn ( emptyLHsBinds )
14 import HscTypes ( HscEnv(..), ModGuts(..), ModIface(..),
15 TyThing, TypeEnv, emptyTypeEnv, HscSource(..),
16 isHsBoot, ModSummary(..),
17 ExternalPackageState(..), HomePackageTable,
18 Deprecs(..), FixityEnv, FixItem,
19 lookupType, unQualInScope )
20 import Module ( Module, unitModuleEnv )
21 import RdrName ( GlobalRdrEnv, emptyGlobalRdrEnv,
22 LocalRdrEnv, emptyLocalRdrEnv )
23 import Name ( Name, isInternalName, mkInternalName, tidyNameOcc, nameOccName, getSrcLoc )
25 import TcType ( tcIsTyVarTy, tcGetTyVar )
26 import NameEnv ( extendNameEnvList, nameEnvElts )
27 import InstEnv ( emptyInstEnv )
29 import Var ( setTyVarName )
30 import VarSet ( emptyVarSet )
31 import VarEnv ( TidyEnv, emptyTidyEnv, extendVarEnv )
32 import ErrUtils ( Message, Messages, emptyMessages, errorsFound,
33 mkWarnMsg, printErrorsAndWarnings,
34 mkLocMessage, mkLongErrMsg )
35 import Packages ( mkHomeModules )
36 import SrcLoc ( mkGeneralSrcSpan, isGoodSrcSpan, SrcSpan, Located(..) )
37 import NameEnv ( emptyNameEnv )
38 import NameSet ( NameSet, emptyDUs, emptyNameSet, unionNameSets, addOneToNameSet )
39 import OccName ( emptyOccEnv, tidyOccName )
40 import Bag ( emptyBag )
42 import UniqSupply ( UniqSupply, mkSplitUniqSupply, uniqFromSupply, splitUniqSupply )
43 import Unique ( Unique )
44 import DynFlags ( DynFlags(..), DynFlag(..), dopt, dopt_set, GhcMode )
45 import StaticFlags ( opt_PprStyle_Debug )
46 import Bag ( snocBag, unionBags )
47 import Panic ( showException )
50 import DATA_IOREF ( newIORef, readIORef )
51 import EXCEPTION ( Exception )
56 %************************************************************************
60 %************************************************************************
63 ioToTcRn :: IO r -> TcRn r
72 -> IO (Messages, Maybe r)
73 -- Nothing => error thrown by the thing inside
74 -- (error messages should have been printed already)
76 initTc hsc_env hsc_src mod do_this
77 = do { errs_var <- newIORef (emptyBag, emptyBag) ;
78 tvs_var <- newIORef emptyVarSet ;
79 type_env_var <- newIORef emptyNameEnv ;
80 dfuns_var <- newIORef emptyNameSet ;
81 keep_var <- newIORef emptyNameSet ;
82 th_var <- newIORef False ;
83 dfun_n_var <- newIORef 1 ;
89 tcg_rdr_env = emptyGlobalRdrEnv,
90 tcg_fix_env = emptyNameEnv,
91 tcg_default = Nothing,
92 tcg_type_env = emptyNameEnv,
93 tcg_type_env_var = type_env_var,
94 tcg_inst_env = emptyInstEnv,
95 tcg_inst_uses = dfuns_var,
97 tcg_exports = emptyNameSet,
98 tcg_imports = init_imports,
99 tcg_home_mods = home_mods,
101 tcg_rn_decls = Nothing,
102 tcg_binds = emptyLHsBinds,
103 tcg_deprecs = NoDeprecs,
107 tcg_dfun_n = dfun_n_var,
112 tcl_loc = mkGeneralSrcSpan FSLIT("Top level"),
114 tcl_rdr = emptyLocalRdrEnv,
115 tcl_th_ctxt = topStage,
116 tcl_arrow_ctxt = NoArrowCtxt,
117 tcl_env = emptyNameEnv,
118 tcl_tyvars = tvs_var,
119 tcl_lie = panic "initTc:LIE" -- LIE only valid inside a getLIE
123 -- OK, here's the business end!
124 maybe_res <- initTcRnIf 'a' hsc_env gbl_env lcl_env $
125 do { r <- tryM do_this
127 Right res -> return (Just res)
128 Left _ -> return Nothing } ;
130 -- Collect any error messages
131 msgs <- readIORef errs_var ;
133 let { dflags = hsc_dflags hsc_env
134 ; final_res | errorsFound dflags msgs = Nothing
135 | otherwise = maybe_res } ;
137 return (msgs, final_res)
140 home_mods = mkHomeModules (map ms_mod (hsc_mod_graph hsc_env))
141 -- A guess at the home modules. This will be correct in
142 -- --make and GHCi modes, but in one-shot mode we need to
143 -- fix it up after we know the real dependencies of the current
144 -- module (see tcRnModule).
145 -- Setting it here is necessary for the typechecker entry points
146 -- other than tcRnModule: tcRnGetInfo, for example. These are
147 -- all called via the GHC module, so hsc_mod_graph will contain
148 -- something sensible.
150 init_imports = emptyImportAvails {imp_env = unitModuleEnv mod emptyNameSet}
151 -- Initialise tcg_imports with an empty set of bindings for
152 -- this module, so that if we see 'module M' in the export
153 -- list, and there are no bindings in M, we don't bleat
154 -- "unknown module M".
156 initTcPrintErrors -- Used from the interactive loop only
161 initTcPrintErrors env mod todo = do
162 (msgs, res) <- initTc env HsSrcFile mod todo
163 printErrorsAndWarnings (hsc_dflags env) msgs
166 -- mkImpTypeEnv makes the imported symbol table
167 mkImpTypeEnv :: ExternalPackageState -> HomePackageTable
168 -> Name -> Maybe TyThing
169 mkImpTypeEnv pcs hpt = lookup
172 lookup name | isInternalName name = Nothing
173 | otherwise = lookupType hpt pte name
177 %************************************************************************
181 %************************************************************************
185 initTcRnIf :: Char -- Tag for unique supply
190 initTcRnIf uniq_tag hsc_env gbl_env lcl_env thing_inside
191 = do { us <- mkSplitUniqSupply uniq_tag ;
192 ; us_var <- newIORef us ;
194 ; let { env = Env { env_top = hsc_env,
197 env_lcl = lcl_env } }
199 ; runIOEnv env thing_inside
203 %************************************************************************
207 %************************************************************************
210 getTopEnv :: TcRnIf gbl lcl HscEnv
211 getTopEnv = do { env <- getEnv; return (env_top env) }
213 getGblEnv :: TcRnIf gbl lcl gbl
214 getGblEnv = do { env <- getEnv; return (env_gbl env) }
216 updGblEnv :: (gbl -> gbl) -> TcRnIf gbl lcl a -> TcRnIf gbl lcl a
217 updGblEnv upd = updEnv (\ env@(Env { env_gbl = gbl }) ->
218 env { env_gbl = upd gbl })
220 setGblEnv :: gbl -> TcRnIf gbl lcl a -> TcRnIf gbl lcl a
221 setGblEnv gbl_env = updEnv (\ env -> env { env_gbl = gbl_env })
223 getLclEnv :: TcRnIf gbl lcl lcl
224 getLclEnv = do { env <- getEnv; return (env_lcl env) }
226 updLclEnv :: (lcl -> lcl) -> TcRnIf gbl lcl a -> TcRnIf gbl lcl a
227 updLclEnv upd = updEnv (\ env@(Env { env_lcl = lcl }) ->
228 env { env_lcl = upd lcl })
230 setLclEnv :: lcl' -> TcRnIf gbl lcl' a -> TcRnIf gbl lcl a
231 setLclEnv lcl_env = updEnv (\ env -> env { env_lcl = lcl_env })
233 getEnvs :: TcRnIf gbl lcl (gbl, lcl)
234 getEnvs = do { env <- getEnv; return (env_gbl env, env_lcl env) }
236 setEnvs :: (gbl', lcl') -> TcRnIf gbl' lcl' a -> TcRnIf gbl lcl a
237 setEnvs (gbl_env, lcl_env) = updEnv (\ env -> env { env_gbl = gbl_env, env_lcl = lcl_env })
244 getDOpts :: TcRnIf gbl lcl DynFlags
245 getDOpts = do { env <- getTopEnv; return (hsc_dflags env) }
247 doptM :: DynFlag -> TcRnIf gbl lcl Bool
248 doptM flag = do { dflags <- getDOpts; return (dopt flag dflags) }
250 setOptM :: DynFlag -> TcRnIf gbl lcl a -> TcRnIf gbl lcl a
251 setOptM flag = updEnv (\ env@(Env { env_top = top }) ->
252 env { env_top = top { hsc_dflags = dopt_set (hsc_dflags top) flag}} )
254 ifOptM :: DynFlag -> TcRnIf gbl lcl () -> TcRnIf gbl lcl () -- Do it flag is true
255 ifOptM flag thing_inside = do { b <- doptM flag;
256 if b then thing_inside else return () }
258 getGhciMode :: TcRnIf gbl lcl GhcMode
259 getGhciMode = do { env <- getTopEnv; return (ghcMode (hsc_dflags env)) }
263 getEpsVar :: TcRnIf gbl lcl (TcRef ExternalPackageState)
264 getEpsVar = do { env <- getTopEnv; return (hsc_EPS env) }
266 getEps :: TcRnIf gbl lcl ExternalPackageState
267 getEps = do { env <- getTopEnv; readMutVar (hsc_EPS env) }
269 -- Updating the EPS. This should be an atomic operation.
270 -- Note the delicate 'seq' which forces the EPS before putting it in the
271 -- variable. Otherwise what happens is that we get
272 -- write eps_var (....(unsafeRead eps_var)....)
273 -- and if the .... is strict, that's obviously bottom. By forcing it beforehand
274 -- we make the unsafeRead happen before we update the variable.
276 updateEps :: (ExternalPackageState -> (ExternalPackageState, a))
278 updateEps upd_fn = do { traceIf (text "updating EPS")
279 ; eps_var <- getEpsVar
280 ; eps <- readMutVar eps_var
281 ; let { (eps', val) = upd_fn eps }
282 ; seq eps' (writeMutVar eps_var eps')
285 updateEps_ :: (ExternalPackageState -> ExternalPackageState)
287 updateEps_ upd_fn = do { traceIf (text "updating EPS_")
288 ; eps_var <- getEpsVar
289 ; eps <- readMutVar eps_var
290 ; let { eps' = upd_fn eps }
291 ; seq eps' (writeMutVar eps_var eps') }
293 getHpt :: TcRnIf gbl lcl HomePackageTable
294 getHpt = do { env <- getTopEnv; return (hsc_HPT env) }
296 getEpsAndHpt :: TcRnIf gbl lcl (ExternalPackageState, HomePackageTable)
297 getEpsAndHpt = do { env <- getTopEnv; eps <- readMutVar (hsc_EPS env)
298 ; return (eps, hsc_HPT env) }
301 %************************************************************************
305 %************************************************************************
308 newUnique :: TcRnIf gbl lcl Unique
309 newUnique = do { us <- newUniqueSupply ;
310 return (uniqFromSupply us) }
312 newUniqueSupply :: TcRnIf gbl lcl UniqSupply
314 = do { env <- getEnv ;
315 let { u_var = env_us env } ;
316 us <- readMutVar u_var ;
317 let { (us1, us2) = splitUniqSupply us } ;
318 writeMutVar u_var us1 ;
321 newLocalName :: Name -> TcRnIf gbl lcl Name
322 newLocalName name -- Make a clone
323 = newUnique `thenM` \ uniq ->
324 returnM (mkInternalName uniq (nameOccName name) (getSrcLoc name))
328 %************************************************************************
332 %************************************************************************
335 traceTc, traceRn :: SDoc -> TcRn ()
336 traceRn = traceOptTcRn Opt_D_dump_rn_trace
337 traceTc = traceOptTcRn Opt_D_dump_tc_trace
338 traceSplice = traceOptTcRn Opt_D_dump_splices
341 traceIf :: SDoc -> TcRnIf m n ()
342 traceIf = traceOptIf Opt_D_dump_if_trace
343 traceHiDiffs = traceOptIf Opt_D_dump_hi_diffs
346 traceOptIf :: DynFlag -> SDoc -> TcRnIf m n () -- No RdrEnv available, so qualify everything
347 traceOptIf flag doc = ifOptM flag $
348 ioToIOEnv (printForUser stderr alwaysQualify doc)
350 traceOptTcRn :: DynFlag -> SDoc -> TcRn ()
351 traceOptTcRn flag doc = ifOptM flag $ do
354 ; env0 <- tcInitTidyEnv
355 ; ctxt_msgs <- do_ctxt env0 ctxt
356 ; let real_doc = mkLocMessage loc (vcat (doc : ctxt_to_use ctxt_msgs))
357 ; dumpTcRn real_doc }
359 dumpTcRn :: SDoc -> TcRn ()
360 dumpTcRn doc = do { rdr_env <- getGlobalRdrEnv ;
361 ioToTcRn (printForUser stderr (unQualInScope rdr_env) doc) }
363 dumpOptTcRn :: DynFlag -> SDoc -> TcRn ()
364 dumpOptTcRn flag doc = ifOptM flag (dumpTcRn doc)
368 %************************************************************************
370 Typechecker global environment
372 %************************************************************************
375 getModule :: TcRn Module
376 getModule = do { env <- getGblEnv; return (tcg_mod env) }
378 setModule :: Module -> TcRn a -> TcRn a
379 setModule mod thing_inside = updGblEnv (\env -> env { tcg_mod = mod }) thing_inside
381 tcIsHsBoot :: TcRn Bool
382 tcIsHsBoot = do { env <- getGblEnv; return (isHsBoot (tcg_src env)) }
384 getGlobalRdrEnv :: TcRn GlobalRdrEnv
385 getGlobalRdrEnv = do { env <- getGblEnv; return (tcg_rdr_env env) }
387 getImports :: TcRn ImportAvails
388 getImports = do { env <- getGblEnv; return (tcg_imports env) }
390 getFixityEnv :: TcRn FixityEnv
391 getFixityEnv = do { env <- getGblEnv; return (tcg_fix_env env) }
393 extendFixityEnv :: [(Name,FixItem)] -> RnM a -> RnM a
394 extendFixityEnv new_bit
395 = updGblEnv (\env@(TcGblEnv { tcg_fix_env = old_fix_env }) ->
396 env {tcg_fix_env = extendNameEnvList old_fix_env new_bit})
398 getDefaultTys :: TcRn (Maybe [Type])
399 getDefaultTys = do { env <- getGblEnv; return (tcg_default env) }
402 %************************************************************************
406 %************************************************************************
409 getSrcSpanM :: TcRn SrcSpan
410 -- Avoid clash with Name.getSrcLoc
411 getSrcSpanM = do { env <- getLclEnv; return (tcl_loc env) }
413 setSrcSpan :: SrcSpan -> TcRn a -> TcRn a
414 setSrcSpan loc thing_inside
415 | isGoodSrcSpan loc = updLclEnv (\env -> env { tcl_loc = loc }) thing_inside
416 | otherwise = thing_inside -- Don't overwrite useful info with useless
418 addLocM :: (a -> TcM b) -> Located a -> TcM b
419 addLocM fn (L loc a) = setSrcSpan loc $ fn a
421 wrapLocM :: (a -> TcM b) -> Located a -> TcM (Located b)
422 wrapLocM fn (L loc a) = setSrcSpan loc $ do b <- fn a; return (L loc b)
424 wrapLocFstM :: (a -> TcM (b,c)) -> Located a -> TcM (Located b, c)
425 wrapLocFstM fn (L loc a) =
430 wrapLocSndM :: (a -> TcM (b,c)) -> Located a -> TcM (b, Located c)
431 wrapLocSndM fn (L loc a) =
439 getErrsVar :: TcRn (TcRef Messages)
440 getErrsVar = do { env <- getLclEnv; return (tcl_errs env) }
442 setErrsVar :: TcRef Messages -> TcRn a -> TcRn a
443 setErrsVar v = updLclEnv (\ env -> env { tcl_errs = v })
445 addErr :: Message -> TcRn ()
446 addErr msg = do { loc <- getSrcSpanM ; addErrAt loc msg }
448 addLocErr :: Located e -> (e -> Message) -> TcRn ()
449 addLocErr (L loc e) fn = addErrAt loc (fn e)
451 addErrAt :: SrcSpan -> Message -> TcRn ()
452 addErrAt loc msg = addLongErrAt loc msg empty
454 addLongErrAt :: SrcSpan -> Message -> Message -> TcRn ()
455 addLongErrAt loc msg extra
456 = do { traceTc (ptext SLIT("Adding error:") <+> (mkLocMessage loc (msg $$ extra))) ;
457 errs_var <- getErrsVar ;
458 rdr_env <- getGlobalRdrEnv ;
459 let { err = mkLongErrMsg loc (unQualInScope rdr_env) msg extra } ;
460 (warns, errs) <- readMutVar errs_var ;
461 writeMutVar errs_var (warns, errs `snocBag` err) }
463 addErrs :: [(SrcSpan,Message)] -> TcRn ()
464 addErrs msgs = mappM_ add msgs
466 add (loc,msg) = addErrAt loc msg
468 addReport :: Message -> TcRn ()
469 addReport msg = do loc <- getSrcSpanM; addReportAt loc msg
471 addReportAt :: SrcSpan -> Message -> TcRn ()
473 = do { errs_var <- getErrsVar ;
474 rdr_env <- getGlobalRdrEnv ;
475 let { warn = mkWarnMsg loc (unQualInScope rdr_env) msg } ;
476 (warns, errs) <- readMutVar errs_var ;
477 writeMutVar errs_var (warns `snocBag` warn, errs) }
479 addWarn :: Message -> TcRn ()
480 addWarn msg = addReport (ptext SLIT("Warning:") <+> msg)
482 addWarnAt :: SrcSpan -> Message -> TcRn ()
483 addWarnAt loc msg = addReportAt loc (ptext SLIT("Warning:") <+> msg)
485 addLocWarn :: Located e -> (e -> Message) -> TcRn ()
486 addLocWarn (L loc e) fn = addReportAt loc (fn e)
488 checkErr :: Bool -> Message -> TcRn ()
489 -- Add the error if the bool is False
490 checkErr ok msg = checkM ok (addErr msg)
492 warnIf :: Bool -> Message -> TcRn ()
493 warnIf True msg = addWarn msg
494 warnIf False msg = return ()
496 addMessages :: Messages -> TcRn ()
497 addMessages (m_warns, m_errs)
498 = do { errs_var <- getErrsVar ;
499 (warns, errs) <- readMutVar errs_var ;
500 writeMutVar errs_var (warns `unionBags` m_warns,
501 errs `unionBags` m_errs) }
503 discardWarnings :: TcRn a -> TcRn a
504 -- Ignore warnings inside the thing inside;
505 -- used to ignore-unused-variable warnings inside derived code
506 -- With -dppr-debug, the effects is switched off, so you can still see
507 -- what warnings derived code would give
508 discardWarnings thing_inside
509 | opt_PprStyle_Debug = thing_inside
511 = do { errs_var <- newMutVar emptyMessages
512 ; result <- setErrsVar errs_var thing_inside
513 ; (_warns, errs) <- readMutVar errs_var
514 ; addMessages (emptyBag, errs)
520 try_m :: TcRn r -> TcRn (Either Exception r)
521 -- Does try_m, with a debug-trace on failure
523 = do { mb_r <- tryM thing ;
525 Left exn -> do { traceTc (exn_msg exn); return mb_r }
526 Right r -> return mb_r }
528 exn_msg exn = text "tryTc/recoverM recovering from" <+> text (showException exn)
530 -----------------------
531 recoverM :: TcRn r -- Recovery action; do this if the main one fails
532 -> TcRn r -- Main action: do this first
534 -- Errors in 'thing' are retained
535 recoverM recover thing
536 = do { mb_res <- try_m thing ;
539 Right res -> returnM res }
541 -----------------------
542 tryTc :: TcRn a -> TcRn (Messages, Maybe a)
543 -- (tryTc m) executes m, and returns
544 -- Just r, if m succeeds (returning r)
545 -- Nothing, if m fails
546 -- It also returns all the errors and warnings accumulated by m
547 -- It always succeeds (never raises an exception)
549 = do { errs_var <- newMutVar emptyMessages ;
550 res <- try_m (setErrsVar errs_var m) ;
551 msgs <- readMutVar errs_var ;
552 return (msgs, case res of
554 Right val -> Just val)
555 -- The exception is always the IOEnv built-in
556 -- in exception; see IOEnv.failM
559 -----------------------
560 tryTcErrs :: TcRn a -> TcRn (Messages, Maybe a)
561 -- Run the thing, returning
562 -- Just r, if m succceeds with no error messages
563 -- Nothing, if m fails, or if it succeeds but has error messages
564 -- Either way, the messages are returned; even in the Just case
565 -- there might be warnings
567 = do { (msgs, res) <- tryTc thing
569 ; let errs_found = errorsFound dflags msgs
570 ; return (msgs, case res of
572 Just val | errs_found -> Nothing
573 | otherwise -> Just val)
576 -----------------------
577 tryTcLIE :: TcM a -> TcM (Messages, Maybe a)
578 -- Just like tryTcErrs, except that it ensures that the LIE
579 -- for the thing is propagated only if there are no errors
580 -- Hence it's restricted to the type-check monad
581 tryTcLIE thing_inside
582 = do { ((msgs, mb_res), lie) <- getLIE (tryTcErrs thing_inside) ;
584 Nothing -> return (msgs, Nothing)
585 Just val -> do { extendLIEs lie; return (msgs, Just val) }
588 -----------------------
589 tryTcLIE_ :: TcM r -> TcM r -> TcM r
590 -- (tryTcLIE_ r m) tries m;
591 -- if m succeeds with no error messages, it's the answer
592 -- otherwise tryTcLIE_ drops everything from m and tries r instead.
593 tryTcLIE_ recover main
594 = do { (msgs, mb_res) <- tryTcLIE main
596 Just val -> do { addMessages msgs -- There might be warnings
598 Nothing -> recover -- Discard all msgs
601 -----------------------
602 checkNoErrs :: TcM r -> TcM r
603 -- (checkNoErrs m) succeeds iff m succeeds and generates no errors
604 -- If m fails then (checkNoErrsTc m) fails.
605 -- If m succeeds, it checks whether m generated any errors messages
606 -- (it might have recovered internally)
607 -- If so, it fails too.
608 -- Regardless, any errors generated by m are propagated to the enclosing context.
610 = do { (msgs, mb_res) <- tryTcLIE main
614 Just val -> return val
617 ifErrsM :: TcRn r -> TcRn r -> TcRn r
618 -- ifErrsM bale_out main
619 -- does 'bale_out' if there are errors in errors collection
620 -- otherwise does 'main'
621 ifErrsM bale_out normal
622 = do { errs_var <- getErrsVar ;
623 msgs <- readMutVar errs_var ;
625 if errorsFound dflags msgs then
630 failIfErrsM :: TcRn ()
631 -- Useful to avoid error cascades
632 failIfErrsM = ifErrsM failM (return ())
636 %************************************************************************
638 Context management and error message generation
641 %************************************************************************
644 getErrCtxt :: TcM ErrCtxt
645 getErrCtxt = do { env <- getLclEnv; return (tcl_ctxt env) }
647 setErrCtxt :: ErrCtxt -> TcM a -> TcM a
648 setErrCtxt ctxt = updLclEnv (\ env -> env { tcl_ctxt = ctxt })
650 addErrCtxt :: Message -> TcM a -> TcM a
651 addErrCtxt msg = addErrCtxtM (\env -> returnM (env, msg))
653 addErrCtxtM :: (TidyEnv -> TcM (TidyEnv, Message)) -> TcM a -> TcM a
654 addErrCtxtM msg = updCtxt (\ msgs -> msg : msgs)
656 -- Helper function for the above
657 updCtxt :: (ErrCtxt -> ErrCtxt) -> TcM a -> TcM a
658 updCtxt upd = updLclEnv (\ env@(TcLclEnv { tcl_ctxt = ctxt }) ->
659 env { tcl_ctxt = upd ctxt })
661 -- Conditionally add an error context
662 maybeAddErrCtxt :: Maybe Message -> TcM a -> TcM a
663 maybeAddErrCtxt (Just msg) thing_inside = addErrCtxt msg thing_inside
664 maybeAddErrCtxt Nothing thing_inside = thing_inside
666 popErrCtxt :: TcM a -> TcM a
667 popErrCtxt = updCtxt (\ msgs -> case msgs of { [] -> []; (m:ms) -> ms })
669 getInstLoc :: InstOrigin -> TcM InstLoc
671 = do { loc <- getSrcSpanM ; env <- getLclEnv ;
672 return (InstLoc origin loc (tcl_ctxt env)) }
674 addInstCtxt :: InstLoc -> TcM a -> TcM a
675 -- Add the SrcSpan and context from the first Inst in the list
676 -- (they all have similar locations)
677 addInstCtxt (InstLoc _ src_loc ctxt) thing_inside
678 = setSrcSpan src_loc (updCtxt (\ old_ctxt -> ctxt) thing_inside)
681 The addErrTc functions add an error message, but do not cause failure.
682 The 'M' variants pass a TidyEnv that has already been used to
683 tidy up the message; we then use it to tidy the context messages
686 addErrTc :: Message -> TcM ()
687 addErrTc err_msg = do { env0 <- tcInitTidyEnv
688 ; addErrTcM (env0, err_msg) }
690 addErrsTc :: [Message] -> TcM ()
691 addErrsTc err_msgs = mappM_ addErrTc err_msgs
693 addErrTcM :: (TidyEnv, Message) -> TcM ()
694 addErrTcM (tidy_env, err_msg)
695 = do { ctxt <- getErrCtxt ;
697 add_err_tcm tidy_env err_msg loc ctxt }
700 The failWith functions add an error message and cause failure
703 failWithTc :: Message -> TcM a -- Add an error message and fail
705 = addErrTc err_msg >> failM
707 failWithTcM :: (TidyEnv, Message) -> TcM a -- Add an error message and fail
708 failWithTcM local_and_msg
709 = addErrTcM local_and_msg >> failM
711 checkTc :: Bool -> Message -> TcM () -- Check that the boolean is true
712 checkTc True err = returnM ()
713 checkTc False err = failWithTc err
716 Warnings have no 'M' variant, nor failure
719 addWarnTc :: Message -> TcM ()
721 = do { ctxt <- getErrCtxt ;
722 env0 <- tcInitTidyEnv ;
723 ctxt_msgs <- do_ctxt env0 ctxt ;
724 addWarn (vcat (msg : ctxt_to_use ctxt_msgs)) }
726 warnTc :: Bool -> Message -> TcM ()
727 warnTc warn_if_true warn_msg
728 | warn_if_true = addWarnTc warn_msg
729 | otherwise = return ()
732 -----------------------------------
735 We initialise the "tidy-env", used for tidying types before printing,
736 by building a reverse map from the in-scope type variables to the
737 OccName that the programmer originally used for them
740 tcInitTidyEnv :: TcM TidyEnv
742 = do { lcl_env <- getLclEnv
743 ; let nm_tv_prs = [ (name, tcGetTyVar "tcInitTidyEnv" ty)
744 | ATyVar name ty <- nameEnvElts (tcl_env lcl_env)
746 ; return (foldl add emptyTidyEnv nm_tv_prs) }
748 add (env,subst) (name, tyvar)
749 = case tidyOccName env (nameOccName name) of
750 (env', occ') -> (env', extendVarEnv subst tyvar tyvar')
752 tyvar' = setTyVarName tyvar name'
753 name' = tidyNameOcc name occ'
756 -----------------------------------
757 Other helper functions
760 add_err_tcm tidy_env err_msg loc ctxt
761 = do { ctxt_msgs <- do_ctxt tidy_env ctxt ;
762 addLongErrAt loc err_msg (vcat (ctxt_to_use ctxt_msgs)) }
766 do_ctxt tidy_env (c:cs)
767 = do { (tidy_env', m) <- c tidy_env ;
768 ms <- do_ctxt tidy_env' cs ;
771 ctxt_to_use ctxt | opt_PprStyle_Debug = ctxt
772 | otherwise = take 3 ctxt
775 debugTc is useful for monadic debugging code
778 debugTc :: TcM () -> TcM ()
780 debugTc thing = thing
782 debugTc thing = return ()
786 %************************************************************************
788 Type constraints (the so-called LIE)
790 %************************************************************************
793 nextDFunIndex :: TcM Int -- Get the next dfun index
794 nextDFunIndex = do { env <- getGblEnv
795 ; let dfun_n_var = tcg_dfun_n env
796 ; n <- readMutVar dfun_n_var
797 ; writeMutVar dfun_n_var (n+1)
800 getLIEVar :: TcM (TcRef LIE)
801 getLIEVar = do { env <- getLclEnv; return (tcl_lie env) }
803 setLIEVar :: TcRef LIE -> TcM a -> TcM a
804 setLIEVar lie_var = updLclEnv (\ env -> env { tcl_lie = lie_var })
806 getLIE :: TcM a -> TcM (a, [Inst])
807 -- (getLIE m) runs m, and returns the type constraints it generates
809 = do { lie_var <- newMutVar emptyLIE ;
810 res <- updLclEnv (\ env -> env { tcl_lie = lie_var })
812 lie <- readMutVar lie_var ;
813 return (res, lieToList lie) }
815 extendLIE :: Inst -> TcM ()
817 = do { lie_var <- getLIEVar ;
818 lie <- readMutVar lie_var ;
819 writeMutVar lie_var (inst `consLIE` lie) }
821 extendLIEs :: [Inst] -> TcM ()
825 = do { lie_var <- getLIEVar ;
826 lie <- readMutVar lie_var ;
827 writeMutVar lie_var (mkLIE insts `plusLIE` lie) }
831 setLclTypeEnv :: TcLclEnv -> TcM a -> TcM a
832 -- Set the local type envt, but do *not* disturb other fields,
833 -- notably the lie_var
834 setLclTypeEnv lcl_env thing_inside
835 = updLclEnv upd thing_inside
837 upd env = env { tcl_env = tcl_env lcl_env,
838 tcl_tyvars = tcl_tyvars lcl_env }
842 %************************************************************************
844 Template Haskell context
846 %************************************************************************
849 recordThUse :: TcM ()
850 recordThUse = do { env <- getGblEnv; writeMutVar (tcg_th_used env) True }
852 keepAliveTc :: Name -> TcM () -- Record the name in the keep-alive set
853 keepAliveTc n = do { env <- getGblEnv;
854 ; updMutVar (tcg_keep env) (`addOneToNameSet` n) }
856 keepAliveSetTc :: NameSet -> TcM () -- Record the name in the keep-alive set
857 keepAliveSetTc ns = do { env <- getGblEnv;
858 ; updMutVar (tcg_keep env) (`unionNameSets` ns) }
860 getStage :: TcM ThStage
861 getStage = do { env <- getLclEnv; return (tcl_th_ctxt env) }
863 setStage :: ThStage -> TcM a -> TcM a
864 setStage s = updLclEnv (\ env -> env { tcl_th_ctxt = s })
868 %************************************************************************
870 Stuff for the renamer's local env
872 %************************************************************************
875 getLocalRdrEnv :: RnM LocalRdrEnv
876 getLocalRdrEnv = do { env <- getLclEnv; return (tcl_rdr env) }
878 setLocalRdrEnv :: LocalRdrEnv -> RnM a -> RnM a
879 setLocalRdrEnv rdr_env thing_inside
880 = updLclEnv (\env -> env {tcl_rdr = rdr_env}) thing_inside
884 %************************************************************************
886 Stuff for interface decls
888 %************************************************************************
891 mkIfLclEnv :: Module -> SDoc -> IfLclEnv
892 mkIfLclEnv mod loc = IfLclEnv { if_mod = mod,
894 if_tv_env = emptyOccEnv,
895 if_id_env = emptyOccEnv }
897 initIfaceTcRn :: IfG a -> TcRn a
898 initIfaceTcRn thing_inside
899 = do { tcg_env <- getGblEnv
900 ; let { if_env = IfGblEnv { if_rec_types = Just (tcg_mod tcg_env, get_type_env) }
901 ; get_type_env = readMutVar (tcg_type_env_var tcg_env) }
902 ; setEnvs (if_env, ()) thing_inside }
904 initIfaceExtCore :: IfL a -> TcRn a
905 initIfaceExtCore thing_inside
906 = do { tcg_env <- getGblEnv
907 ; let { mod = tcg_mod tcg_env
908 ; doc = ptext SLIT("External Core file for") <+> quotes (ppr mod)
909 ; if_env = IfGblEnv {
910 if_rec_types = Just (mod, return (tcg_type_env tcg_env)) }
911 ; if_lenv = mkIfLclEnv mod doc
913 ; setEnvs (if_env, if_lenv) thing_inside }
915 initIfaceCheck :: HscEnv -> IfG a -> IO a
916 -- Used when checking the up-to-date-ness of the old Iface
917 -- Initialise the environment with no useful info at all
918 initIfaceCheck hsc_env do_this
919 = do { let gbl_env = IfGblEnv { if_rec_types = Nothing }
920 ; initTcRnIf 'i' hsc_env gbl_env () do_this
923 initIfaceTc :: ModIface
924 -> (TcRef TypeEnv -> IfL a) -> TcRnIf gbl lcl a
925 -- Used when type-checking checking an up-to-date interface file
926 -- No type envt from the current module, but we do know the module dependencies
927 initIfaceTc iface do_this
928 = do { tc_env_var <- newMutVar emptyTypeEnv
929 ; let { gbl_env = IfGblEnv { if_rec_types = Just (mod, readMutVar tc_env_var) } ;
930 ; if_lenv = mkIfLclEnv mod doc
932 ; setEnvs (gbl_env, if_lenv) (do_this tc_env_var)
935 mod = mi_module iface
936 doc = ptext SLIT("The interface for") <+> quotes (ppr mod)
938 initIfaceRules :: HscEnv -> ModGuts -> IfG a -> IO a
939 -- Used when sucking in new Rules in SimplCore
940 -- We have available the type envt of the module being compiled, and we must use it
941 initIfaceRules hsc_env guts do_this
943 type_info = (mg_module guts, return (mg_types guts))
944 ; gbl_env = IfGblEnv { if_rec_types = Just type_info } ;
947 -- Run the thing; any exceptions just bubble out from here
948 ; initTcRnIf 'i' hsc_env gbl_env () do_this
951 initIfaceLcl :: Module -> SDoc -> IfL a -> IfM lcl a
952 initIfaceLcl mod loc_doc thing_inside
953 = setLclEnv (mkIfLclEnv mod loc_doc) thing_inside
955 getIfModule :: IfL Module
956 getIfModule = do { env <- getLclEnv; return (if_mod env) }
959 failIfM :: Message -> IfL a
960 -- The Iface monad doesn't have a place to accumulate errors, so we
961 -- just fall over fast if one happens; it "shouldnt happen".
962 -- We use IfL here so that we can get context info out of the local env
964 = do { env <- getLclEnv
965 ; let full_msg = (if_loc env <> colon) $$ nest 2 msg
966 ; ioToIOEnv (printErrs (full_msg defaultErrStyle))
970 forkM_maybe :: SDoc -> IfL a -> IfL (Maybe a)
971 -- Run thing_inside in an interleaved thread.
972 -- It shares everything with the parent thread, so this is DANGEROUS.
974 -- It returns Nothing if the computation fails
976 -- It's used for lazily type-checking interface
977 -- signatures, which is pretty benign
979 forkM_maybe doc thing_inside
980 = do { unsafeInterleaveM $
981 do { traceIf (text "Starting fork {" <+> doc)
982 ; mb_res <- tryM thing_inside ;
984 Right r -> do { traceIf (text "} ending fork" <+> doc)
988 -- Bleat about errors in the forked thread, if -ddump-if-trace is on
989 -- Otherwise we silently discard errors. Errors can legitimately
990 -- happen when compiling interface signatures (see tcInterfaceSigs)
991 ifOptM Opt_D_dump_if_trace
992 (print_errs (hang (text "forkM failed:" <+> doc)
993 4 (text (show exn))))
995 ; traceIf (text "} ending fork (badly)" <+> doc)
999 print_errs sdoc = ioToIOEnv (printErrs (sdoc defaultErrStyle))
1001 forkM :: SDoc -> IfL a -> IfL a
1002 forkM doc thing_inside
1003 = do { mb_res <- forkM_maybe doc thing_inside
1004 ; return (case mb_res of
1005 Nothing -> pgmError "Cannot continue after interface file error"
1006 -- pprPanic "forkM" doc