2 % (c) The University of Glasgow 2006
12 #include "HsVersions.h"
14 import TcRnTypes -- Re-export all
15 import IOEnv -- Re-export all
17 import HsSyn hiding (LIE)
48 import qualified Data.Set as Set
54 %************************************************************************
58 %************************************************************************
64 -> Bool -- True <=> retain renamed syntax trees
67 -> IO (Messages, Maybe r)
68 -- Nothing => error thrown by the thing inside
69 -- (error messages should have been printed already)
71 initTc hsc_env hsc_src keep_rn_syntax mod do_this
72 = do { errs_var <- newIORef (emptyBag, emptyBag) ;
73 tvs_var <- newIORef emptyVarSet ;
74 dfuns_var <- newIORef emptyNameSet ;
75 keep_var <- newIORef emptyNameSet ;
76 used_rdrnames_var <- newIORef Set.empty ;
77 th_var <- newIORef False ;
78 dfun_n_var <- newIORef 1 ;
79 type_env_var <- case hsc_type_env_var hsc_env of {
80 Just (_mod, te_var) -> return te_var ;
81 Nothing -> newIORef emptyNameEnv } ;
83 maybe_rn_syntax empty_val
84 | keep_rn_syntax = Just empty_val
85 | otherwise = Nothing ;
90 tcg_rdr_env = hsc_global_rdr_env hsc_env,
91 tcg_fix_env = emptyNameEnv,
92 tcg_field_env = RecFields emptyNameEnv emptyNameSet,
93 tcg_default = Nothing,
94 tcg_type_env = hsc_global_type_env hsc_env,
95 tcg_type_env_var = type_env_var,
96 tcg_inst_env = emptyInstEnv,
97 tcg_fam_inst_env = emptyFamInstEnv,
98 tcg_inst_uses = dfuns_var,
101 tcg_imports = emptyImportAvails,
102 tcg_used_rdrnames = used_rdrnames_var,
106 tcg_rn_exports = maybe_rn_syntax [],
107 tcg_rn_decls = maybe_rn_syntax emptyRnGroup,
109 tcg_binds = emptyLHsBinds,
110 tcg_warns = NoWarnings,
116 tcg_dfun_n = dfun_n_var,
119 tcg_hmi = HaddockModInfo Nothing Nothing Nothing Nothing,
124 tcl_loc = mkGeneralSrcSpan (fsLit "Top level"),
126 tcl_rdr = emptyLocalRdrEnv,
127 tcl_th_ctxt = topStage,
128 tcl_arrow_ctxt = NoArrowCtxt,
129 tcl_env = emptyNameEnv,
130 tcl_tyvars = tvs_var,
131 tcl_lie = panic "initTc:LIE", -- only valid inside getLIE
132 tcl_tybinds = panic "initTc:tybinds"
133 -- only valid inside a getTyBinds
137 -- OK, here's the business end!
138 maybe_res <- initTcRnIf 'a' hsc_env gbl_env lcl_env $
139 do { r <- tryM do_this
141 Right res -> return (Just res)
142 Left _ -> return Nothing } ;
144 -- Collect any error messages
145 msgs <- readIORef errs_var ;
147 let { dflags = hsc_dflags hsc_env
148 ; final_res | errorsFound dflags msgs = Nothing
149 | otherwise = maybe_res } ;
151 return (msgs, final_res)
154 initTcPrintErrors -- Used from the interactive loop only
158 -> IO (Messages, Maybe r)
159 initTcPrintErrors env mod todo = do
160 (msgs, res) <- initTc env HsSrcFile False mod todo
164 %************************************************************************
168 %************************************************************************
172 initTcRnIf :: Char -- Tag for unique supply
177 initTcRnIf uniq_tag hsc_env gbl_env lcl_env thing_inside
178 = do { us <- mkSplitUniqSupply uniq_tag ;
179 ; us_var <- newIORef us ;
181 ; let { env = Env { env_top = hsc_env,
186 ; runIOEnv env thing_inside
190 %************************************************************************
194 %************************************************************************
197 getTopEnv :: TcRnIf gbl lcl HscEnv
198 getTopEnv = do { env <- getEnv; return (env_top env) }
200 getGblEnv :: TcRnIf gbl lcl gbl
201 getGblEnv = do { env <- getEnv; return (env_gbl env) }
203 updGblEnv :: (gbl -> gbl) -> TcRnIf gbl lcl a -> TcRnIf gbl lcl a
204 updGblEnv upd = updEnv (\ env@(Env { env_gbl = gbl }) ->
205 env { env_gbl = upd gbl })
207 setGblEnv :: gbl -> TcRnIf gbl lcl a -> TcRnIf gbl lcl a
208 setGblEnv gbl_env = updEnv (\ env -> env { env_gbl = gbl_env })
210 getLclEnv :: TcRnIf gbl lcl lcl
211 getLclEnv = do { env <- getEnv; return (env_lcl env) }
213 updLclEnv :: (lcl -> lcl) -> TcRnIf gbl lcl a -> TcRnIf gbl lcl a
214 updLclEnv upd = updEnv (\ env@(Env { env_lcl = lcl }) ->
215 env { env_lcl = upd lcl })
217 setLclEnv :: lcl' -> TcRnIf gbl lcl' a -> TcRnIf gbl lcl a
218 setLclEnv lcl_env = updEnv (\ env -> env { env_lcl = lcl_env })
220 getEnvs :: TcRnIf gbl lcl (gbl, lcl)
221 getEnvs = do { env <- getEnv; return (env_gbl env, env_lcl env) }
223 setEnvs :: (gbl', lcl') -> TcRnIf gbl' lcl' a -> TcRnIf gbl lcl a
224 setEnvs (gbl_env, lcl_env) = updEnv (\ env -> env { env_gbl = gbl_env, env_lcl = lcl_env })
231 getDOpts :: TcRnIf gbl lcl DynFlags
232 getDOpts = do { env <- getTopEnv; return (hsc_dflags env) }
234 doptM :: DynFlag -> TcRnIf gbl lcl Bool
235 doptM flag = do { dflags <- getDOpts; return (dopt flag dflags) }
237 setOptM :: DynFlag -> TcRnIf gbl lcl a -> TcRnIf gbl lcl a
238 setOptM flag = updEnv (\ env@(Env { env_top = top }) ->
239 env { env_top = top { hsc_dflags = dopt_set (hsc_dflags top) flag}} )
241 unsetOptM :: DynFlag -> TcRnIf gbl lcl a -> TcRnIf gbl lcl a
242 unsetOptM flag = updEnv (\ env@(Env { env_top = top }) ->
243 env { env_top = top { hsc_dflags = dopt_unset (hsc_dflags top) flag}} )
245 -- | Do it flag is true
246 ifOptM :: DynFlag -> TcRnIf gbl lcl () -> TcRnIf gbl lcl ()
247 ifOptM flag thing_inside = do { b <- doptM flag;
248 if b then thing_inside else return () }
250 getGhcMode :: TcRnIf gbl lcl GhcMode
251 getGhcMode = do { env <- getTopEnv; return (ghcMode (hsc_dflags env)) }
255 getEpsVar :: TcRnIf gbl lcl (TcRef ExternalPackageState)
256 getEpsVar = do { env <- getTopEnv; return (hsc_EPS env) }
258 getEps :: TcRnIf gbl lcl ExternalPackageState
259 getEps = do { env <- getTopEnv; readMutVar (hsc_EPS env) }
261 -- Updating the EPS. This should be an atomic operation.
262 -- Note the delicate 'seq' which forces the EPS before putting it in the
263 -- variable. Otherwise what happens is that we get
264 -- write eps_var (....(unsafeRead eps_var)....)
265 -- and if the .... is strict, that's obviously bottom. By forcing it beforehand
266 -- we make the unsafeRead happen before we update the variable.
268 updateEps :: (ExternalPackageState -> (ExternalPackageState, a))
270 updateEps upd_fn = do { traceIf (text "updating EPS")
271 ; eps_var <- getEpsVar
272 ; eps <- readMutVar eps_var
273 ; let { (eps', val) = upd_fn eps }
274 ; seq eps' (writeMutVar eps_var eps')
277 updateEps_ :: (ExternalPackageState -> ExternalPackageState)
279 updateEps_ upd_fn = do { traceIf (text "updating EPS_")
280 ; eps_var <- getEpsVar
281 ; eps <- readMutVar eps_var
282 ; let { eps' = upd_fn eps }
283 ; seq eps' (writeMutVar eps_var eps') }
285 getHpt :: TcRnIf gbl lcl HomePackageTable
286 getHpt = do { env <- getTopEnv; return (hsc_HPT env) }
288 getEpsAndHpt :: TcRnIf gbl lcl (ExternalPackageState, HomePackageTable)
289 getEpsAndHpt = do { env <- getTopEnv; eps <- readMutVar (hsc_EPS env)
290 ; return (eps, hsc_HPT env) }
293 %************************************************************************
297 %************************************************************************
300 newUnique :: TcRnIf gbl lcl Unique
302 = do { env <- getEnv ;
303 let { u_var = env_us env } ;
304 us <- readMutVar u_var ;
305 case splitUniqSupply us of { (us1,_) -> do {
306 writeMutVar u_var us1 ;
307 return $! uniqFromSupply us }}}
308 -- NOTE 1: we strictly split the supply, to avoid the possibility of leaving
309 -- a chain of unevaluated supplies behind.
310 -- NOTE 2: we use the uniq in the supply from the MutVar directly, and
311 -- throw away one half of the new split supply. This is safe because this
312 -- is the only place we use that unique. Using the other half of the split
313 -- supply is safer, but slower.
315 newUniqueSupply :: TcRnIf gbl lcl UniqSupply
317 = do { env <- getEnv ;
318 let { u_var = env_us env } ;
319 us <- readMutVar u_var ;
320 case splitUniqSupply us of { (us1,us2) -> do {
321 writeMutVar u_var us1 ;
324 newLocalName :: Name -> TcRnIf gbl lcl Name
325 newLocalName name -- Make a clone
326 = do { uniq <- newUnique
327 ; return (mkInternalName uniq (nameOccName name) (getSrcSpan name)) }
329 newSysLocalIds :: FastString -> [TcType] -> TcRnIf gbl lcl [TcId]
330 newSysLocalIds fs tys
331 = do { us <- newUniqueSupply
332 ; return (zipWith (mkSysLocal fs) (uniqsFromSupply us) tys) }
334 instance MonadUnique (IOEnv (Env gbl lcl)) where
335 getUniqueM = newUnique
336 getUniqueSupplyM = newUniqueSupply
340 %************************************************************************
344 %************************************************************************
347 traceTc, traceRn, traceSplice :: SDoc -> TcRn ()
348 traceRn = traceOptTcRn Opt_D_dump_rn_trace
349 traceTc = traceOptTcRn Opt_D_dump_tc_trace
350 traceSplice = traceOptTcRn Opt_D_dump_splices
353 traceIf, traceHiDiffs :: SDoc -> TcRnIf m n ()
354 traceIf = traceOptIf Opt_D_dump_if_trace
355 traceHiDiffs = traceOptIf Opt_D_dump_hi_diffs
358 traceOptIf :: DynFlag -> SDoc -> TcRnIf m n () -- No RdrEnv available, so qualify everything
359 traceOptIf flag doc = ifOptM flag $
360 liftIO (printForUser stderr alwaysQualify doc)
362 traceOptTcRn :: DynFlag -> SDoc -> TcRn ()
363 traceOptTcRn flag doc = ifOptM flag $ do
366 ; env0 <- tcInitTidyEnv
367 ; ctxt_msgs <- do_ctxt env0 ctxt
368 ; let real_doc = mkLocMessage loc (vcat (doc : ctxt_to_use ctxt_msgs))
369 ; dumpTcRn real_doc }
371 dumpTcRn :: SDoc -> TcRn ()
372 dumpTcRn doc = do { rdr_env <- getGlobalRdrEnv
374 ; liftIO (printForUser stderr (mkPrintUnqualified dflags rdr_env) doc) }
376 debugDumpTcRn :: SDoc -> TcRn ()
377 debugDumpTcRn doc | opt_NoDebugOutput = return ()
378 | otherwise = dumpTcRn doc
380 dumpOptTcRn :: DynFlag -> SDoc -> TcRn ()
381 dumpOptTcRn flag doc = ifOptM flag (dumpTcRn doc)
385 %************************************************************************
387 Typechecker global environment
389 %************************************************************************
392 getModule :: TcRn Module
393 getModule = do { env <- getGblEnv; return (tcg_mod env) }
395 setModule :: Module -> TcRn a -> TcRn a
396 setModule mod thing_inside = updGblEnv (\env -> env { tcg_mod = mod }) thing_inside
398 tcIsHsBoot :: TcRn Bool
399 tcIsHsBoot = do { env <- getGblEnv; return (isHsBoot (tcg_src env)) }
401 getGlobalRdrEnv :: TcRn GlobalRdrEnv
402 getGlobalRdrEnv = do { env <- getGblEnv; return (tcg_rdr_env env) }
404 getRdrEnvs :: TcRn (GlobalRdrEnv, LocalRdrEnv)
405 getRdrEnvs = do { (gbl,lcl) <- getEnvs; return (tcg_rdr_env gbl, tcl_rdr lcl) }
407 getImports :: TcRn ImportAvails
408 getImports = do { env <- getGblEnv; return (tcg_imports env) }
410 getFixityEnv :: TcRn FixityEnv
411 getFixityEnv = do { env <- getGblEnv; return (tcg_fix_env env) }
413 extendFixityEnv :: [(Name,FixItem)] -> RnM a -> RnM a
414 extendFixityEnv new_bit
415 = updGblEnv (\env@(TcGblEnv { tcg_fix_env = old_fix_env }) ->
416 env {tcg_fix_env = extendNameEnvList old_fix_env new_bit})
418 getRecFieldEnv :: TcRn RecFieldEnv
419 getRecFieldEnv = do { env <- getGblEnv; return (tcg_field_env env) }
421 getDeclaredDefaultTys :: TcRn (Maybe [Type])
422 getDeclaredDefaultTys = do { env <- getGblEnv; return (tcg_default env) }
425 %************************************************************************
429 %************************************************************************
432 getSrcSpanM :: TcRn SrcSpan
433 -- Avoid clash with Name.getSrcLoc
434 getSrcSpanM = do { env <- getLclEnv; return (tcl_loc env) }
436 setSrcSpan :: SrcSpan -> TcRn a -> TcRn a
437 setSrcSpan loc thing_inside
438 | isGoodSrcSpan loc = updLclEnv (\env -> env { tcl_loc = loc }) thing_inside
439 | otherwise = thing_inside -- Don't overwrite useful info with useless
441 addLocM :: (a -> TcM b) -> Located a -> TcM b
442 addLocM fn (L loc a) = setSrcSpan loc $ fn a
444 wrapLocM :: (a -> TcM b) -> Located a -> TcM (Located b)
445 wrapLocM fn (L loc a) = setSrcSpan loc $ do b <- fn a; return (L loc b)
447 wrapLocFstM :: (a -> TcM (b,c)) -> Located a -> TcM (Located b, c)
448 wrapLocFstM fn (L loc a) =
453 wrapLocSndM :: (a -> TcM (b,c)) -> Located a -> TcM (b, Located c)
454 wrapLocSndM fn (L loc a) =
462 getErrsVar :: TcRn (TcRef Messages)
463 getErrsVar = do { env <- getLclEnv; return (tcl_errs env) }
465 setErrsVar :: TcRef Messages -> TcRn a -> TcRn a
466 setErrsVar v = updLclEnv (\ env -> env { tcl_errs = v })
468 addErr :: Message -> TcRn () -- Ignores the context stack
469 addErr msg = do { loc <- getSrcSpanM ; addErrAt loc msg }
471 failWith :: Message -> TcRn a
472 failWith msg = addErr msg >> failM
474 addLocErr :: Located e -> (e -> Message) -> TcRn ()
475 addLocErr (L loc e) fn = addErrAt loc (fn e)
477 addErrAt :: SrcSpan -> Message -> TcRn ()
478 addErrAt loc msg = addLongErrAt loc msg empty
480 addLongErrAt :: SrcSpan -> Message -> Message -> TcRn ()
481 addLongErrAt loc msg extra
482 = do { traceTc (ptext (sLit "Adding error:") <+> (mkLocMessage loc (msg $$ extra))) ;
483 errs_var <- getErrsVar ;
484 rdr_env <- getGlobalRdrEnv ;
486 let { err = mkLongErrMsg loc (mkPrintUnqualified dflags rdr_env) msg extra } ;
487 (warns, errs) <- readMutVar errs_var ;
488 writeMutVar errs_var (warns, errs `snocBag` err) }
490 addErrs :: [(SrcSpan,Message)] -> TcRn ()
491 addErrs msgs = mapM_ add msgs
493 add (loc,msg) = addErrAt loc msg
495 addReport :: Message -> TcRn ()
496 addReport msg = do loc <- getSrcSpanM; addReportAt loc msg
498 addReportAt :: SrcSpan -> Message -> TcRn ()
500 = do { errs_var <- getErrsVar ;
501 rdr_env <- getGlobalRdrEnv ;
503 let { warn = mkWarnMsg loc (mkPrintUnqualified dflags rdr_env) msg } ;
504 (warns, errs) <- readMutVar errs_var ;
505 writeMutVar errs_var (warns `snocBag` warn, errs) }
507 addWarn :: Message -> TcRn ()
508 addWarn msg = addReport (ptext (sLit "Warning:") <+> msg)
510 addWarnAt :: SrcSpan -> Message -> TcRn ()
511 addWarnAt loc msg = addReportAt loc (ptext (sLit "Warning:") <+> msg)
513 addLocWarn :: Located e -> (e -> Message) -> TcRn ()
514 addLocWarn (L loc e) fn = addReportAt loc (fn e)
516 checkErr :: Bool -> Message -> TcRn ()
517 -- Add the error if the bool is False
518 checkErr ok msg = unless ok (addErr msg)
520 warnIf :: Bool -> Message -> TcRn ()
521 warnIf True msg = addWarn msg
522 warnIf False _ = return ()
524 addMessages :: Messages -> TcRn ()
525 addMessages (m_warns, m_errs)
526 = do { errs_var <- getErrsVar ;
527 (warns, errs) <- readMutVar errs_var ;
528 writeMutVar errs_var (warns `unionBags` m_warns,
529 errs `unionBags` m_errs) }
531 discardWarnings :: TcRn a -> TcRn a
532 -- Ignore warnings inside the thing inside;
533 -- used to ignore-unused-variable warnings inside derived code
534 -- With -dppr-debug, the effects is switched off, so you can still see
535 -- what warnings derived code would give
536 discardWarnings thing_inside
537 | opt_PprStyle_Debug = thing_inside
539 = do { errs_var <- newMutVar emptyMessages
540 ; result <- setErrsVar errs_var thing_inside
541 ; (_warns, errs) <- readMutVar errs_var
542 ; addMessages (emptyBag, errs)
548 try_m :: TcRn r -> TcRn (Either IOEnvFailure r)
549 -- Does try_m, with a debug-trace on failure
551 = do { mb_r <- tryM thing ;
553 Left exn -> do { traceTc (exn_msg exn); return mb_r }
554 Right _ -> return mb_r }
556 exn_msg exn = text "tryTc/recoverM recovering from" <+> text (showException exn)
558 -----------------------
559 recoverM :: TcRn r -- Recovery action; do this if the main one fails
560 -> TcRn r -- Main action: do this first
562 -- Errors in 'thing' are retained
563 recoverM recover thing
564 = do { mb_res <- try_m thing ;
567 Right res -> return res }
570 -----------------------
571 mapAndRecoverM :: (a -> TcRn b) -> [a] -> TcRn [b]
572 -- Drop elements of the input that fail, so the result
573 -- list can be shorter than the argument list
574 mapAndRecoverM _ [] = return []
575 mapAndRecoverM f (x:xs) = do { mb_r <- try_m (f x)
576 ; rs <- mapAndRecoverM f xs
577 ; return (case mb_r of
582 -----------------------
583 tryTc :: TcRn a -> TcRn (Messages, Maybe a)
584 -- (tryTc m) executes m, and returns
585 -- Just r, if m succeeds (returning r)
586 -- Nothing, if m fails
587 -- It also returns all the errors and warnings accumulated by m
588 -- It always succeeds (never raises an exception)
590 = do { errs_var <- newMutVar emptyMessages ;
591 res <- try_m (setErrsVar errs_var m) ;
592 msgs <- readMutVar errs_var ;
593 return (msgs, case res of
595 Right val -> Just val)
596 -- The exception is always the IOEnv built-in
597 -- in exception; see IOEnv.failM
600 -----------------------
601 tryTcErrs :: TcRn a -> TcRn (Messages, Maybe a)
602 -- Run the thing, returning
603 -- Just r, if m succceeds with no error messages
604 -- Nothing, if m fails, or if it succeeds but has error messages
605 -- Either way, the messages are returned; even in the Just case
606 -- there might be warnings
608 = do { (msgs, res) <- tryTc thing
610 ; let errs_found = errorsFound dflags msgs
611 ; return (msgs, case res of
613 Just val | errs_found -> Nothing
614 | otherwise -> Just val)
617 -----------------------
618 tryTcLIE :: TcM a -> TcM (Messages, Maybe a)
619 -- Just like tryTcErrs, except that it ensures that the LIE
620 -- for the thing is propagated only if there are no errors
621 -- Hence it's restricted to the type-check monad
622 tryTcLIE thing_inside
623 = do { ((msgs, mb_res), lie) <- getLIE (tryTcErrs thing_inside) ;
625 Nothing -> return (msgs, Nothing)
626 Just val -> do { extendLIEs lie; return (msgs, Just val) }
629 -----------------------
630 tryTcLIE_ :: TcM r -> TcM r -> TcM r
631 -- (tryTcLIE_ r m) tries m;
632 -- if m succeeds with no error messages, it's the answer
633 -- otherwise tryTcLIE_ drops everything from m and tries r instead.
634 tryTcLIE_ recover main
635 = do { (msgs, mb_res) <- tryTcLIE main
637 Just val -> do { addMessages msgs -- There might be warnings
639 Nothing -> recover -- Discard all msgs
642 -----------------------
643 checkNoErrs :: TcM r -> TcM r
644 -- (checkNoErrs m) succeeds iff m succeeds and generates no errors
645 -- If m fails then (checkNoErrsTc m) fails.
646 -- If m succeeds, it checks whether m generated any errors messages
647 -- (it might have recovered internally)
648 -- If so, it fails too.
649 -- Regardless, any errors generated by m are propagated to the enclosing context.
651 = do { (msgs, mb_res) <- tryTcLIE main
655 Just val -> return val
658 ifErrsM :: TcRn r -> TcRn r -> TcRn r
659 -- ifErrsM bale_out main
660 -- does 'bale_out' if there are errors in errors collection
661 -- otherwise does 'main'
662 ifErrsM bale_out normal
663 = do { errs_var <- getErrsVar ;
664 msgs <- readMutVar errs_var ;
666 if errorsFound dflags msgs then
671 failIfErrsM :: TcRn ()
672 -- Useful to avoid error cascades
673 failIfErrsM = ifErrsM failM (return ())
677 %************************************************************************
679 Context management and error message generation
682 %************************************************************************
685 getErrCtxt :: TcM ErrCtxt
686 getErrCtxt = do { env <- getLclEnv; return (tcl_ctxt env) }
688 setErrCtxt :: ErrCtxt -> TcM a -> TcM a
689 setErrCtxt ctxt = updLclEnv (\ env -> env { tcl_ctxt = ctxt })
691 addErrCtxt :: Message -> TcM a -> TcM a
692 addErrCtxt msg = addErrCtxtM (\env -> return (env, msg))
694 addErrCtxtM :: (TidyEnv -> TcM (TidyEnv, Message)) -> TcM a -> TcM a
695 addErrCtxtM msg = updCtxt (\ msgs -> msg : msgs)
697 -- Helper function for the above
698 updCtxt :: (ErrCtxt -> ErrCtxt) -> TcM a -> TcM a
699 updCtxt upd = updLclEnv (\ env@(TcLclEnv { tcl_ctxt = ctxt }) ->
700 env { tcl_ctxt = upd ctxt })
702 -- Conditionally add an error context
703 maybeAddErrCtxt :: Maybe Message -> TcM a -> TcM a
704 maybeAddErrCtxt (Just msg) thing_inside = addErrCtxt msg thing_inside
705 maybeAddErrCtxt Nothing thing_inside = thing_inside
707 popErrCtxt :: TcM a -> TcM a
708 popErrCtxt = updCtxt (\ msgs -> case msgs of { [] -> []; (_ : ms) -> ms })
710 getInstLoc :: InstOrigin -> TcM InstLoc
712 = do { loc <- getSrcSpanM ; env <- getLclEnv ;
713 return (InstLoc origin loc (tcl_ctxt env)) }
715 addInstCtxt :: InstLoc -> TcM a -> TcM a
716 -- Add the SrcSpan and context from the first Inst in the list
717 -- (they all have similar locations)
718 addInstCtxt (InstLoc _ src_loc ctxt) thing_inside
719 = setSrcSpan src_loc (updCtxt (\_ -> ctxt) thing_inside)
722 The addErrTc functions add an error message, but do not cause failure.
723 The 'M' variants pass a TidyEnv that has already been used to
724 tidy up the message; we then use it to tidy the context messages
727 addErrTc :: Message -> TcM ()
728 addErrTc err_msg = do { env0 <- tcInitTidyEnv
729 ; addErrTcM (env0, err_msg) }
731 addErrsTc :: [Message] -> TcM ()
732 addErrsTc err_msgs = mapM_ addErrTc err_msgs
734 addErrTcM :: (TidyEnv, Message) -> TcM ()
735 addErrTcM (tidy_env, err_msg)
736 = do { ctxt <- getErrCtxt ;
738 add_err_tcm tidy_env err_msg loc ctxt }
741 The failWith functions add an error message and cause failure
744 failWithTc :: Message -> TcM a -- Add an error message and fail
746 = addErrTc err_msg >> failM
748 failWithTcM :: (TidyEnv, Message) -> TcM a -- Add an error message and fail
749 failWithTcM local_and_msg
750 = addErrTcM local_and_msg >> failM
752 checkTc :: Bool -> Message -> TcM () -- Check that the boolean is true
753 checkTc True _ = return ()
754 checkTc False err = failWithTc err
757 Warnings have no 'M' variant, nor failure
760 addWarnTc :: Message -> TcM ()
761 addWarnTc msg = do { env0 <- tcInitTidyEnv
762 ; addWarnTcM (env0, msg) }
764 addWarnTcM :: (TidyEnv, Message) -> TcM ()
765 addWarnTcM (env0, msg)
766 = do { ctxt <- getErrCtxt ;
767 ctxt_msgs <- do_ctxt env0 ctxt ;
768 addReport (vcat (ptext (sLit "Warning:") <+> msg : ctxt_to_use ctxt_msgs)) }
770 warnTc :: Bool -> Message -> TcM ()
771 warnTc warn_if_true warn_msg
772 | warn_if_true = addWarnTc warn_msg
773 | otherwise = return ()
776 -----------------------------------
779 We initialise the "tidy-env", used for tidying types before printing,
780 by building a reverse map from the in-scope type variables to the
781 OccName that the programmer originally used for them
784 tcInitTidyEnv :: TcM TidyEnv
786 = do { lcl_env <- getLclEnv
787 ; let nm_tv_prs = [ (name, tcGetTyVar "tcInitTidyEnv" ty)
788 | ATyVar name ty <- nameEnvElts (tcl_env lcl_env)
790 ; return (foldl add emptyTidyEnv nm_tv_prs) }
792 add (env,subst) (name, tyvar)
793 = case tidyOccName env (nameOccName name) of
794 (env', occ') -> (env', extendVarEnv subst tyvar tyvar')
796 tyvar' = setTyVarName tyvar name'
797 name' = tidyNameOcc name occ'
800 -----------------------------------
801 Other helper functions
804 add_err_tcm :: TidyEnv -> Message -> SrcSpan
805 -> [TidyEnv -> TcM (TidyEnv, SDoc)]
807 add_err_tcm tidy_env err_msg loc ctxt
808 = do { ctxt_msgs <- do_ctxt tidy_env ctxt ;
809 addLongErrAt loc err_msg (vcat (ctxt_to_use ctxt_msgs)) }
811 do_ctxt :: TidyEnv -> [TidyEnv -> TcM (TidyEnv, SDoc)] -> TcM [SDoc]
814 do_ctxt tidy_env (c:cs)
815 = do { (tidy_env', m) <- c tidy_env ;
816 ms <- do_ctxt tidy_env' cs ;
819 ctxt_to_use :: [SDoc] -> [SDoc]
820 ctxt_to_use ctxt | opt_PprStyle_Debug = ctxt
821 | otherwise = take 3 ctxt
824 debugTc is useful for monadic debugging code
827 debugTc :: TcM () -> TcM ()
830 | otherwise = return ()
833 %************************************************************************
835 Type constraints (the so-called LIE)
837 %************************************************************************
840 nextDFunIndex :: TcM Int -- Get the next dfun index
841 nextDFunIndex = do { env <- getGblEnv
842 ; let dfun_n_var = tcg_dfun_n env
843 ; n <- readMutVar dfun_n_var
844 ; writeMutVar dfun_n_var (n+1)
847 getLIEVar :: TcM (TcRef LIE)
848 getLIEVar = do { env <- getLclEnv; return (tcl_lie env) }
850 setLIEVar :: TcRef LIE -> TcM a -> TcM a
851 setLIEVar lie_var = updLclEnv (\ env -> env { tcl_lie = lie_var })
853 getLIE :: TcM a -> TcM (a, [Inst])
854 -- (getLIE m) runs m, and returns the type constraints it generates
856 = do { lie_var <- newMutVar emptyLIE ;
857 res <- updLclEnv (\ env -> env { tcl_lie = lie_var })
859 lie <- readMutVar lie_var ;
860 return (res, lieToList lie) }
862 extendLIE :: Inst -> TcM ()
864 = do { lie_var <- getLIEVar ;
865 lie <- readMutVar lie_var ;
866 writeMutVar lie_var (inst `consLIE` lie) }
868 extendLIEs :: [Inst] -> TcM ()
872 = do { lie_var <- getLIEVar ;
873 lie <- readMutVar lie_var ;
874 writeMutVar lie_var (mkLIE insts `plusLIE` lie) }
878 setLclTypeEnv :: TcLclEnv -> TcM a -> TcM a
879 -- Set the local type envt, but do *not* disturb other fields,
880 -- notably the lie_var
881 setLclTypeEnv lcl_env thing_inside
882 = updLclEnv upd thing_inside
884 upd env = env { tcl_env = tcl_env lcl_env,
885 tcl_tyvars = tcl_tyvars lcl_env }
889 %************************************************************************
891 Meta type variable bindings
893 %************************************************************************
896 getTcTyVarBindsVar :: TcM (TcRef TcTyVarBinds)
897 getTcTyVarBindsVar = do { env <- getLclEnv; return (tcl_tybinds env) }
899 getTcTyVarBinds :: TcM a -> TcM (a, TcTyVarBinds)
900 getTcTyVarBinds thing_inside
901 = do { tybinds_var <- newMutVar emptyBag
902 ; res <- updLclEnv (\ env -> env { tcl_tybinds = tybinds_var })
904 ; tybinds <- readMutVar tybinds_var
905 ; return (res, tybinds)
908 bindMetaTyVar :: TcTyVar -> TcType -> TcM ()
910 = do { ASSERTM2( do { details <- readMutVar (metaTvRef tv)
911 ; return (isFlexi details) }, ppr tv )
912 ; tybinds_var <- getTcTyVarBindsVar
913 ; tybinds <- readMutVar tybinds_var
914 ; writeMutVar tybinds_var (tybinds `snocBag` TcTyVarBind tv ty)
917 getTcTyVarBindsRelation :: TcM [(TcTyVar, TcTyVarSet)]
918 getTcTyVarBindsRelation
919 = do { tybinds_var <- getTcTyVarBindsVar
920 ; tybinds <- readMutVar tybinds_var
921 ; return $ map freeTvs (bagToList tybinds)
924 freeTvs (TcTyVarBind tv ty) = (tv, tyVarsOfType ty)
927 %************************************************************************
929 Template Haskell context
931 %************************************************************************
934 recordThUse :: TcM ()
935 recordThUse = do { env <- getGblEnv; writeMutVar (tcg_th_used env) True }
937 keepAliveTc :: Id -> TcM () -- Record the name in the keep-alive set
939 | isLocalId id = do { env <- getGblEnv;
940 ; updMutVar (tcg_keep env) (`addOneToNameSet` idName id) }
941 | otherwise = return ()
943 keepAliveSetTc :: NameSet -> TcM () -- Record the name in the keep-alive set
944 keepAliveSetTc ns = do { env <- getGblEnv;
945 ; updMutVar (tcg_keep env) (`unionNameSets` ns) }
947 getStage :: TcM ThStage
948 getStage = do { env <- getLclEnv; return (tcl_th_ctxt env) }
950 setStage :: ThStage -> TcM a -> TcM a
951 setStage s = updLclEnv (\ env -> env { tcl_th_ctxt = s })
955 %************************************************************************
957 Stuff for the renamer's local env
959 %************************************************************************
962 getLocalRdrEnv :: RnM LocalRdrEnv
963 getLocalRdrEnv = do { env <- getLclEnv; return (tcl_rdr env) }
965 setLocalRdrEnv :: LocalRdrEnv -> RnM a -> RnM a
966 setLocalRdrEnv rdr_env thing_inside
967 = updLclEnv (\env -> env {tcl_rdr = rdr_env}) thing_inside
971 %************************************************************************
973 Stuff for interface decls
975 %************************************************************************
978 mkIfLclEnv :: Module -> SDoc -> IfLclEnv
979 mkIfLclEnv mod loc = IfLclEnv { if_mod = mod,
981 if_tv_env = emptyUFM,
982 if_id_env = emptyUFM }
984 initIfaceTcRn :: IfG a -> TcRn a
985 initIfaceTcRn thing_inside
986 = do { tcg_env <- getGblEnv
987 ; let { if_env = IfGblEnv { if_rec_types = Just (tcg_mod tcg_env, get_type_env) }
988 ; get_type_env = readMutVar (tcg_type_env_var tcg_env) }
989 ; setEnvs (if_env, ()) thing_inside }
991 initIfaceExtCore :: IfL a -> TcRn a
992 initIfaceExtCore thing_inside
993 = do { tcg_env <- getGblEnv
994 ; let { mod = tcg_mod tcg_env
995 ; doc = ptext (sLit "External Core file for") <+> quotes (ppr mod)
996 ; if_env = IfGblEnv {
997 if_rec_types = Just (mod, return (tcg_type_env tcg_env)) }
998 ; if_lenv = mkIfLclEnv mod doc
1000 ; setEnvs (if_env, if_lenv) thing_inside }
1002 initIfaceCheck :: HscEnv -> IfG a -> IO a
1003 -- Used when checking the up-to-date-ness of the old Iface
1004 -- Initialise the environment with no useful info at all
1005 initIfaceCheck hsc_env do_this
1006 = do let rec_types = case hsc_type_env_var hsc_env of
1007 Just (mod,var) -> Just (mod, readMutVar var)
1009 gbl_env = IfGblEnv { if_rec_types = rec_types }
1010 initTcRnIf 'i' hsc_env gbl_env () do_this
1012 initIfaceTc :: ModIface
1013 -> (TcRef TypeEnv -> IfL a) -> TcRnIf gbl lcl a
1014 -- Used when type-checking checking an up-to-date interface file
1015 -- No type envt from the current module, but we do know the module dependencies
1016 initIfaceTc iface do_this
1017 = do { tc_env_var <- newMutVar emptyTypeEnv
1018 ; let { gbl_env = IfGblEnv { if_rec_types = Just (mod, readMutVar tc_env_var) } ;
1019 ; if_lenv = mkIfLclEnv mod doc
1021 ; setEnvs (gbl_env, if_lenv) (do_this tc_env_var)
1024 mod = mi_module iface
1025 doc = ptext (sLit "The interface for") <+> quotes (ppr mod)
1027 initIfaceRules :: HscEnv -> ModGuts -> IfG a -> IO a
1028 -- Used when sucking in new Rules in SimplCore
1029 -- We have available the type envt of the module being compiled, and we must use it
1030 initIfaceRules hsc_env guts do_this
1032 type_info = (mg_module guts, return (mg_types guts))
1033 ; gbl_env = IfGblEnv { if_rec_types = Just type_info } ;
1036 -- Run the thing; any exceptions just bubble out from here
1037 ; initTcRnIf 'i' hsc_env gbl_env () do_this
1040 initIfaceLcl :: Module -> SDoc -> IfL a -> IfM lcl a
1041 initIfaceLcl mod loc_doc thing_inside
1042 = setLclEnv (mkIfLclEnv mod loc_doc) thing_inside
1044 getIfModule :: IfL Module
1045 getIfModule = do { env <- getLclEnv; return (if_mod env) }
1047 --------------------
1048 failIfM :: Message -> IfL a
1049 -- The Iface monad doesn't have a place to accumulate errors, so we
1050 -- just fall over fast if one happens; it "shouldnt happen".
1051 -- We use IfL here so that we can get context info out of the local env
1053 = do { env <- getLclEnv
1054 ; let full_msg = (if_loc env <> colon) $$ nest 2 msg
1055 ; liftIO (printErrs (full_msg defaultErrStyle))
1058 --------------------
1059 forkM_maybe :: SDoc -> IfL a -> IfL (Maybe a)
1060 -- Run thing_inside in an interleaved thread.
1061 -- It shares everything with the parent thread, so this is DANGEROUS.
1063 -- It returns Nothing if the computation fails
1065 -- It's used for lazily type-checking interface
1066 -- signatures, which is pretty benign
1068 forkM_maybe doc thing_inside
1069 = do { unsafeInterleaveM $
1070 do { traceIf (text "Starting fork {" <+> doc)
1072 updLclEnv (\env -> env { if_loc = if_loc env $$ doc }) $
1075 Right r -> do { traceIf (text "} ending fork" <+> doc)
1079 -- Bleat about errors in the forked thread, if -ddump-if-trace is on
1080 -- Otherwise we silently discard errors. Errors can legitimately
1081 -- happen when compiling interface signatures (see tcInterfaceSigs)
1082 ifOptM Opt_D_dump_if_trace
1083 (print_errs (hang (text "forkM failed:" <+> doc)
1084 4 (text (show exn))))
1086 ; traceIf (text "} ending fork (badly)" <+> doc)
1090 print_errs sdoc = liftIO (printErrs (sdoc defaultErrStyle))
1092 forkM :: SDoc -> IfL a -> IfL a
1093 forkM doc thing_inside
1094 = do { mb_res <- forkM_maybe doc thing_inside
1095 ; return (case mb_res of
1096 Nothing -> pgmError "Cannot continue after interface file error"
1097 -- pprPanic "forkM" doc