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)
46 import Control.Exception
51 %************************************************************************
55 %************************************************************************
58 ioToTcRn :: IO r -> TcRn r
66 -> Bool -- True <=> retain renamed syntax trees
69 -> IO (Messages, Maybe r)
70 -- Nothing => error thrown by the thing inside
71 -- (error messages should have been printed already)
73 initTc hsc_env hsc_src keep_rn_syntax mod do_this
74 = do { errs_var <- newIORef (emptyBag, emptyBag) ;
75 tvs_var <- newIORef emptyVarSet ;
76 type_env_var <- newIORef emptyNameEnv ;
77 dfuns_var <- newIORef emptyNameSet ;
78 keep_var <- newIORef emptyNameSet ;
79 th_var <- newIORef False ;
80 dfun_n_var <- newIORef 1 ;
82 maybe_rn_syntax empty_val
83 | keep_rn_syntax = Just empty_val
84 | otherwise = Nothing ;
89 tcg_rdr_env = hsc_global_rdr_env hsc_env,
90 tcg_fix_env = emptyNameEnv,
91 tcg_field_env = emptyNameEnv,
92 tcg_default = Nothing,
93 tcg_type_env = hsc_global_type_env hsc_env,
94 tcg_type_env_var = type_env_var,
95 tcg_inst_env = emptyInstEnv,
96 tcg_fam_inst_env = emptyFamInstEnv,
97 tcg_inst_uses = dfuns_var,
100 tcg_imports = emptyImportAvails,
103 tcg_rn_imports = maybe_rn_syntax [],
104 tcg_rn_exports = maybe_rn_syntax [],
105 tcg_rn_decls = maybe_rn_syntax emptyRnGroup,
107 tcg_binds = emptyLHsBinds,
108 tcg_deprecs = NoDeprecs,
113 tcg_dfun_n = dfun_n_var,
116 tcg_hmi = HaddockModInfo Nothing Nothing Nothing Nothing
120 tcl_loc = mkGeneralSrcSpan FSLIT("Top level"),
122 tcl_rdr = emptyLocalRdrEnv,
123 tcl_th_ctxt = topStage,
124 tcl_arrow_ctxt = NoArrowCtxt,
125 tcl_env = emptyNameEnv,
126 tcl_tyvars = tvs_var,
127 tcl_lie = panic "initTc:LIE" -- LIE only valid inside a getLIE
131 -- OK, here's the business end!
132 maybe_res <- initTcRnIf 'a' hsc_env gbl_env lcl_env $
133 addBreakpointBindings $
134 do { r <- tryM do_this
136 Right res -> return (Just res)
137 Left _ -> return Nothing } ;
139 -- Collect any error messages
140 msgs <- readIORef errs_var ;
142 let { dflags = hsc_dflags hsc_env
143 ; final_res | errorsFound dflags msgs = Nothing
144 | otherwise = maybe_res } ;
146 return (msgs, final_res)
149 initTcPrintErrors -- Used from the interactive loop only
154 initTcPrintErrors env mod todo = do
155 (msgs, res) <- initTc env HsSrcFile False mod todo
156 printErrorsAndWarnings (hsc_dflags env) msgs
161 addBreakpointBindings :: TcM a -> TcM a
162 addBreakpointBindings thing_inside
166 %************************************************************************
170 %************************************************************************
174 initTcRnIf :: Char -- Tag for unique supply
179 initTcRnIf uniq_tag hsc_env gbl_env lcl_env thing_inside
180 = do { us <- mkSplitUniqSupply uniq_tag ;
181 ; us_var <- newIORef us ;
183 ; let { env = Env { env_top = hsc_env,
186 env_lcl = lcl_env } }
188 ; runIOEnv env thing_inside
192 %************************************************************************
196 %************************************************************************
199 getTopEnv :: TcRnIf gbl lcl HscEnv
200 getTopEnv = do { env <- getEnv; return (env_top env) }
202 getGblEnv :: TcRnIf gbl lcl gbl
203 getGblEnv = do { env <- getEnv; return (env_gbl env) }
205 updGblEnv :: (gbl -> gbl) -> TcRnIf gbl lcl a -> TcRnIf gbl lcl a
206 updGblEnv upd = updEnv (\ env@(Env { env_gbl = gbl }) ->
207 env { env_gbl = upd gbl })
209 setGblEnv :: gbl -> TcRnIf gbl lcl a -> TcRnIf gbl lcl a
210 setGblEnv gbl_env = updEnv (\ env -> env { env_gbl = gbl_env })
212 getLclEnv :: TcRnIf gbl lcl lcl
213 getLclEnv = do { env <- getEnv; return (env_lcl env) }
215 updLclEnv :: (lcl -> lcl) -> TcRnIf gbl lcl a -> TcRnIf gbl lcl a
216 updLclEnv upd = updEnv (\ env@(Env { env_lcl = lcl }) ->
217 env { env_lcl = upd lcl })
219 setLclEnv :: lcl' -> TcRnIf gbl lcl' a -> TcRnIf gbl lcl a
220 setLclEnv lcl_env = updEnv (\ env -> env { env_lcl = lcl_env })
222 getEnvs :: TcRnIf gbl lcl (gbl, lcl)
223 getEnvs = do { env <- getEnv; return (env_gbl env, env_lcl env) }
225 setEnvs :: (gbl', lcl') -> TcRnIf gbl' lcl' a -> TcRnIf gbl lcl a
226 setEnvs (gbl_env, lcl_env) = updEnv (\ env -> env { env_gbl = gbl_env, env_lcl = lcl_env })
233 getDOpts :: TcRnIf gbl lcl DynFlags
234 getDOpts = do { env <- getTopEnv; return (hsc_dflags env) }
236 doptM :: DynFlag -> TcRnIf gbl lcl Bool
237 doptM flag = do { dflags <- getDOpts; return (dopt flag dflags) }
239 setOptM :: DynFlag -> TcRnIf gbl lcl a -> TcRnIf gbl lcl a
240 setOptM flag = updEnv (\ env@(Env { env_top = top }) ->
241 env { env_top = top { hsc_dflags = dopt_set (hsc_dflags top) flag}} )
243 unsetOptM :: DynFlag -> TcRnIf gbl lcl a -> TcRnIf gbl lcl a
244 unsetOptM flag = updEnv (\ env@(Env { env_top = top }) ->
245 env { env_top = top { hsc_dflags = dopt_unset (hsc_dflags top) flag}} )
247 ifOptM :: DynFlag -> TcRnIf gbl lcl () -> TcRnIf gbl lcl () -- Do it flag is true
248 ifOptM flag thing_inside = do { b <- doptM flag;
249 if b then thing_inside else return () }
251 getGhcMode :: TcRnIf gbl lcl GhcMode
252 getGhcMode = do { env <- getTopEnv; return (ghcMode (hsc_dflags env)) }
256 getEpsVar :: TcRnIf gbl lcl (TcRef ExternalPackageState)
257 getEpsVar = do { env <- getTopEnv; return (hsc_EPS env) }
259 getEps :: TcRnIf gbl lcl ExternalPackageState
260 getEps = do { env <- getTopEnv; readMutVar (hsc_EPS env) }
262 -- Updating the EPS. This should be an atomic operation.
263 -- Note the delicate 'seq' which forces the EPS before putting it in the
264 -- variable. Otherwise what happens is that we get
265 -- write eps_var (....(unsafeRead eps_var)....)
266 -- and if the .... is strict, that's obviously bottom. By forcing it beforehand
267 -- we make the unsafeRead happen before we update the variable.
269 updateEps :: (ExternalPackageState -> (ExternalPackageState, a))
271 updateEps upd_fn = do { traceIf (text "updating EPS")
272 ; eps_var <- getEpsVar
273 ; eps <- readMutVar eps_var
274 ; let { (eps', val) = upd_fn eps }
275 ; seq eps' (writeMutVar eps_var eps')
278 updateEps_ :: (ExternalPackageState -> ExternalPackageState)
280 updateEps_ upd_fn = do { traceIf (text "updating EPS_")
281 ; eps_var <- getEpsVar
282 ; eps <- readMutVar eps_var
283 ; let { eps' = upd_fn eps }
284 ; seq eps' (writeMutVar eps_var eps') }
286 getHpt :: TcRnIf gbl lcl HomePackageTable
287 getHpt = do { env <- getTopEnv; return (hsc_HPT env) }
289 getEpsAndHpt :: TcRnIf gbl lcl (ExternalPackageState, HomePackageTable)
290 getEpsAndHpt = do { env <- getTopEnv; eps <- readMutVar (hsc_EPS env)
291 ; return (eps, hsc_HPT env) }
294 %************************************************************************
298 %************************************************************************
301 newUnique :: TcRnIf gbl lcl Unique
303 = do { env <- getEnv ;
304 let { u_var = env_us env } ;
305 us <- readMutVar u_var ;
306 case splitUniqSupply us of { (us1,_) -> do {
307 writeMutVar u_var us1 ;
308 return $! uniqFromSupply us }}}
309 -- NOTE 1: we strictly split the supply, to avoid the possibility of leaving
310 -- a chain of unevaluated supplies behind.
311 -- NOTE 2: we use the uniq in the supply from the MutVar directly, and
312 -- throw away one half of the new split supply. This is safe because this
313 -- is the only place we use that unique. Using the other half of the split
314 -- supply is safer, but slower.
316 newUniqueSupply :: TcRnIf gbl lcl UniqSupply
318 = do { env <- getEnv ;
319 let { u_var = env_us env } ;
320 us <- readMutVar u_var ;
321 case splitUniqSupply us of { (us1,us2) -> do {
322 writeMutVar u_var us1 ;
325 newLocalName :: Name -> TcRnIf gbl lcl Name
326 newLocalName name -- Make a clone
327 = do { uniq <- newUnique
328 ; return (mkInternalName uniq (nameOccName name) (getSrcSpan name)) }
330 newSysLocalIds :: FastString -> [TcType] -> TcRnIf gbl lcl [TcId]
331 newSysLocalIds fs tys
332 = do { us <- newUniqueSupply
333 ; return (zipWith (mkSysLocal fs) (uniqsFromSupply us) tys) }
337 %************************************************************************
341 %************************************************************************
344 traceTc, traceRn :: SDoc -> TcRn ()
345 traceRn = traceOptTcRn Opt_D_dump_rn_trace
346 traceTc = traceOptTcRn Opt_D_dump_tc_trace
347 traceSplice = traceOptTcRn Opt_D_dump_splices
350 traceIf :: SDoc -> TcRnIf m n ()
351 traceIf = traceOptIf Opt_D_dump_if_trace
352 traceHiDiffs = traceOptIf Opt_D_dump_hi_diffs
355 traceOptIf :: DynFlag -> SDoc -> TcRnIf m n () -- No RdrEnv available, so qualify everything
356 traceOptIf flag doc = ifOptM flag $
357 ioToIOEnv (printForUser stderr alwaysQualify doc)
359 traceOptTcRn :: DynFlag -> SDoc -> TcRn ()
360 traceOptTcRn flag doc = ifOptM flag $ do
363 ; env0 <- tcInitTidyEnv
364 ; ctxt_msgs <- do_ctxt env0 ctxt
365 ; let real_doc = mkLocMessage loc (vcat (doc : ctxt_to_use ctxt_msgs))
366 ; dumpTcRn real_doc }
368 dumpTcRn :: SDoc -> TcRn ()
369 dumpTcRn doc = do { rdr_env <- getGlobalRdrEnv ;
370 ioToTcRn (printForUser stderr (mkPrintUnqualified rdr_env) doc) }
372 dumpOptTcRn :: DynFlag -> SDoc -> TcRn ()
373 dumpOptTcRn flag doc = ifOptM flag (dumpTcRn doc)
377 %************************************************************************
379 Typechecker global environment
381 %************************************************************************
384 getModule :: TcRn Module
385 getModule = do { env <- getGblEnv; return (tcg_mod env) }
387 setModule :: Module -> TcRn a -> TcRn a
388 setModule mod thing_inside = updGblEnv (\env -> env { tcg_mod = mod }) thing_inside
390 tcIsHsBoot :: TcRn Bool
391 tcIsHsBoot = do { env <- getGblEnv; return (isHsBoot (tcg_src env)) }
393 getGlobalRdrEnv :: TcRn GlobalRdrEnv
394 getGlobalRdrEnv = do { env <- getGblEnv; return (tcg_rdr_env env) }
396 getImports :: TcRn ImportAvails
397 getImports = do { env <- getGblEnv; return (tcg_imports env) }
399 getFixityEnv :: TcRn FixityEnv
400 getFixityEnv = do { env <- getGblEnv; return (tcg_fix_env env) }
402 extendFixityEnv :: [(Name,FixItem)] -> RnM a -> RnM a
403 extendFixityEnv new_bit
404 = updGblEnv (\env@(TcGblEnv { tcg_fix_env = old_fix_env }) ->
405 env {tcg_fix_env = extendNameEnvList old_fix_env new_bit})
407 getRecFieldEnv :: TcRn RecFieldEnv
408 getRecFieldEnv = do { env <- getGblEnv; return (tcg_field_env env) }
410 extendRecFieldEnv :: RecFieldEnv -> RnM a -> RnM a
411 extendRecFieldEnv new_bit
412 = updGblEnv (\env@(TcGblEnv { tcg_field_env = old_env }) ->
413 env {tcg_field_env = old_env `plusNameEnv` new_bit})
415 getDeclaredDefaultTys :: TcRn (Maybe [Type])
416 getDeclaredDefaultTys = do { env <- getGblEnv; return (tcg_default env) }
419 %************************************************************************
423 %************************************************************************
426 getSrcSpanM :: TcRn SrcSpan
427 -- Avoid clash with Name.getSrcLoc
428 getSrcSpanM = do { env <- getLclEnv; return (tcl_loc env) }
430 setSrcSpan :: SrcSpan -> TcRn a -> TcRn a
431 setSrcSpan loc thing_inside
432 | isGoodSrcSpan loc = updLclEnv (\env -> env { tcl_loc = loc }) thing_inside
433 | otherwise = thing_inside -- Don't overwrite useful info with useless
435 addLocM :: (a -> TcM b) -> Located a -> TcM b
436 addLocM fn (L loc a) = setSrcSpan loc $ fn a
438 wrapLocM :: (a -> TcM b) -> Located a -> TcM (Located b)
439 wrapLocM fn (L loc a) = setSrcSpan loc $ do b <- fn a; return (L loc b)
441 wrapLocFstM :: (a -> TcM (b,c)) -> Located a -> TcM (Located b, c)
442 wrapLocFstM fn (L loc a) =
447 wrapLocSndM :: (a -> TcM (b,c)) -> Located a -> TcM (b, Located c)
448 wrapLocSndM fn (L loc a) =
456 getErrsVar :: TcRn (TcRef Messages)
457 getErrsVar = do { env <- getLclEnv; return (tcl_errs env) }
459 setErrsVar :: TcRef Messages -> TcRn a -> TcRn a
460 setErrsVar v = updLclEnv (\ env -> env { tcl_errs = v })
462 addErr :: Message -> TcRn ()
463 addErr msg = do { loc <- getSrcSpanM ; addErrAt loc msg }
465 addLocErr :: Located e -> (e -> Message) -> TcRn ()
466 addLocErr (L loc e) fn = addErrAt loc (fn e)
468 addErrAt :: SrcSpan -> Message -> TcRn ()
469 addErrAt loc msg = addLongErrAt loc msg empty
471 addLongErrAt :: SrcSpan -> Message -> Message -> TcRn ()
472 addLongErrAt loc msg extra
473 = do { traceTc (ptext SLIT("Adding error:") <+> (mkLocMessage loc (msg $$ extra))) ;
474 errs_var <- getErrsVar ;
475 rdr_env <- getGlobalRdrEnv ;
476 let { err = mkLongErrMsg loc (mkPrintUnqualified rdr_env) msg extra } ;
477 (warns, errs) <- readMutVar errs_var ;
478 writeMutVar errs_var (warns, errs `snocBag` err) }
480 addErrs :: [(SrcSpan,Message)] -> TcRn ()
481 addErrs msgs = mappM_ add msgs
483 add (loc,msg) = addErrAt loc msg
485 addReport :: Message -> TcRn ()
486 addReport msg = do loc <- getSrcSpanM; addReportAt loc msg
488 addReportAt :: SrcSpan -> Message -> TcRn ()
490 = do { errs_var <- getErrsVar ;
491 rdr_env <- getGlobalRdrEnv ;
492 let { warn = mkWarnMsg loc (mkPrintUnqualified rdr_env) msg } ;
493 (warns, errs) <- readMutVar errs_var ;
494 writeMutVar errs_var (warns `snocBag` warn, errs) }
496 addWarn :: Message -> TcRn ()
497 addWarn msg = addReport (ptext SLIT("Warning:") <+> msg)
499 addWarnAt :: SrcSpan -> Message -> TcRn ()
500 addWarnAt loc msg = addReportAt loc (ptext SLIT("Warning:") <+> msg)
502 addLocWarn :: Located e -> (e -> Message) -> TcRn ()
503 addLocWarn (L loc e) fn = addReportAt loc (fn e)
505 checkErr :: Bool -> Message -> TcRn ()
506 -- Add the error if the bool is False
507 checkErr ok msg = checkM ok (addErr msg)
509 warnIf :: Bool -> Message -> TcRn ()
510 warnIf True msg = addWarn msg
511 warnIf False msg = return ()
513 addMessages :: Messages -> TcRn ()
514 addMessages (m_warns, m_errs)
515 = do { errs_var <- getErrsVar ;
516 (warns, errs) <- readMutVar errs_var ;
517 writeMutVar errs_var (warns `unionBags` m_warns,
518 errs `unionBags` m_errs) }
520 discardWarnings :: TcRn a -> TcRn a
521 -- Ignore warnings inside the thing inside;
522 -- used to ignore-unused-variable warnings inside derived code
523 -- With -dppr-debug, the effects is switched off, so you can still see
524 -- what warnings derived code would give
525 discardWarnings thing_inside
526 | opt_PprStyle_Debug = thing_inside
528 = do { errs_var <- newMutVar emptyMessages
529 ; result <- setErrsVar errs_var thing_inside
530 ; (_warns, errs) <- readMutVar errs_var
531 ; addMessages (emptyBag, errs)
537 try_m :: TcRn r -> TcRn (Either Exception r)
538 -- Does try_m, with a debug-trace on failure
540 = do { mb_r <- tryM thing ;
542 Left exn -> do { traceTc (exn_msg exn); return mb_r }
543 Right r -> return mb_r }
545 exn_msg exn = text "tryTc/recoverM recovering from" <+> text (showException exn)
547 -----------------------
548 recoverM :: TcRn r -- Recovery action; do this if the main one fails
549 -> TcRn r -- Main action: do this first
551 -- Errors in 'thing' are retained
552 recoverM recover thing
553 = do { mb_res <- try_m thing ;
556 Right res -> returnM res }
558 -----------------------
559 tryTc :: TcRn a -> TcRn (Messages, Maybe a)
560 -- (tryTc m) executes m, and returns
561 -- Just r, if m succeeds (returning r)
562 -- Nothing, if m fails
563 -- It also returns all the errors and warnings accumulated by m
564 -- It always succeeds (never raises an exception)
566 = do { errs_var <- newMutVar emptyMessages ;
567 res <- try_m (setErrsVar errs_var m) ;
568 msgs <- readMutVar errs_var ;
569 return (msgs, case res of
571 Right val -> Just val)
572 -- The exception is always the IOEnv built-in
573 -- in exception; see IOEnv.failM
576 -----------------------
577 tryTcErrs :: TcRn a -> TcRn (Messages, Maybe a)
578 -- Run the thing, returning
579 -- Just r, if m succceeds with no error messages
580 -- Nothing, if m fails, or if it succeeds but has error messages
581 -- Either way, the messages are returned; even in the Just case
582 -- there might be warnings
584 = do { (msgs, res) <- tryTc thing
586 ; let errs_found = errorsFound dflags msgs
587 ; return (msgs, case res of
589 Just val | errs_found -> Nothing
590 | otherwise -> Just val)
593 -----------------------
594 tryTcLIE :: TcM a -> TcM (Messages, Maybe a)
595 -- Just like tryTcErrs, except that it ensures that the LIE
596 -- for the thing is propagated only if there are no errors
597 -- Hence it's restricted to the type-check monad
598 tryTcLIE thing_inside
599 = do { ((msgs, mb_res), lie) <- getLIE (tryTcErrs thing_inside) ;
601 Nothing -> return (msgs, Nothing)
602 Just val -> do { extendLIEs lie; return (msgs, Just val) }
605 -----------------------
606 tryTcLIE_ :: TcM r -> TcM r -> TcM r
607 -- (tryTcLIE_ r m) tries m;
608 -- if m succeeds with no error messages, it's the answer
609 -- otherwise tryTcLIE_ drops everything from m and tries r instead.
610 tryTcLIE_ recover main
611 = do { (msgs, mb_res) <- tryTcLIE main
613 Just val -> do { addMessages msgs -- There might be warnings
615 Nothing -> recover -- Discard all msgs
618 -----------------------
619 checkNoErrs :: TcM r -> TcM r
620 -- (checkNoErrs m) succeeds iff m succeeds and generates no errors
621 -- If m fails then (checkNoErrsTc m) fails.
622 -- If m succeeds, it checks whether m generated any errors messages
623 -- (it might have recovered internally)
624 -- If so, it fails too.
625 -- Regardless, any errors generated by m are propagated to the enclosing context.
627 = do { (msgs, mb_res) <- tryTcLIE main
631 Just val -> return val
634 ifErrsM :: TcRn r -> TcRn r -> TcRn r
635 -- ifErrsM bale_out main
636 -- does 'bale_out' if there are errors in errors collection
637 -- otherwise does 'main'
638 ifErrsM bale_out normal
639 = do { errs_var <- getErrsVar ;
640 msgs <- readMutVar errs_var ;
642 if errorsFound dflags msgs then
647 failIfErrsM :: TcRn ()
648 -- Useful to avoid error cascades
649 failIfErrsM = ifErrsM failM (return ())
653 %************************************************************************
655 Context management and error message generation
658 %************************************************************************
661 getErrCtxt :: TcM ErrCtxt
662 getErrCtxt = do { env <- getLclEnv; return (tcl_ctxt env) }
664 setErrCtxt :: ErrCtxt -> TcM a -> TcM a
665 setErrCtxt ctxt = updLclEnv (\ env -> env { tcl_ctxt = ctxt })
667 addErrCtxt :: Message -> TcM a -> TcM a
668 addErrCtxt msg = addErrCtxtM (\env -> returnM (env, msg))
670 addErrCtxtM :: (TidyEnv -> TcM (TidyEnv, Message)) -> TcM a -> TcM a
671 addErrCtxtM msg = updCtxt (\ msgs -> msg : msgs)
673 -- Helper function for the above
674 updCtxt :: (ErrCtxt -> ErrCtxt) -> TcM a -> TcM a
675 updCtxt upd = updLclEnv (\ env@(TcLclEnv { tcl_ctxt = ctxt }) ->
676 env { tcl_ctxt = upd ctxt })
678 -- Conditionally add an error context
679 maybeAddErrCtxt :: Maybe Message -> TcM a -> TcM a
680 maybeAddErrCtxt (Just msg) thing_inside = addErrCtxt msg thing_inside
681 maybeAddErrCtxt Nothing thing_inside = thing_inside
683 popErrCtxt :: TcM a -> TcM a
684 popErrCtxt = updCtxt (\ msgs -> case msgs of { [] -> []; (m:ms) -> ms })
686 getInstLoc :: InstOrigin -> TcM InstLoc
688 = do { loc <- getSrcSpanM ; env <- getLclEnv ;
689 return (InstLoc origin loc (tcl_ctxt env)) }
691 addInstCtxt :: InstLoc -> TcM a -> TcM a
692 -- Add the SrcSpan and context from the first Inst in the list
693 -- (they all have similar locations)
694 addInstCtxt (InstLoc _ src_loc ctxt) thing_inside
695 = setSrcSpan src_loc (updCtxt (\ old_ctxt -> ctxt) thing_inside)
698 The addErrTc functions add an error message, but do not cause failure.
699 The 'M' variants pass a TidyEnv that has already been used to
700 tidy up the message; we then use it to tidy the context messages
703 addErrTc :: Message -> TcM ()
704 addErrTc err_msg = do { env0 <- tcInitTidyEnv
705 ; addErrTcM (env0, err_msg) }
707 addErrsTc :: [Message] -> TcM ()
708 addErrsTc err_msgs = mappM_ addErrTc err_msgs
710 addErrTcM :: (TidyEnv, Message) -> TcM ()
711 addErrTcM (tidy_env, err_msg)
712 = do { ctxt <- getErrCtxt ;
714 add_err_tcm tidy_env err_msg loc ctxt }
717 The failWith functions add an error message and cause failure
720 failWithTc :: Message -> TcM a -- Add an error message and fail
722 = addErrTc err_msg >> failM
724 failWithTcM :: (TidyEnv, Message) -> TcM a -- Add an error message and fail
725 failWithTcM local_and_msg
726 = addErrTcM local_and_msg >> failM
728 checkTc :: Bool -> Message -> TcM () -- Check that the boolean is true
729 checkTc True err = returnM ()
730 checkTc False err = failWithTc err
733 Warnings have no 'M' variant, nor failure
736 addWarnTc :: Message -> TcM ()
737 addWarnTc msg = do { env0 <- tcInitTidyEnv
738 ; addWarnTcM (env0, msg) }
740 addWarnTcM :: (TidyEnv, Message) -> TcM ()
741 addWarnTcM (env0, msg)
742 = do { ctxt <- getErrCtxt ;
743 ctxt_msgs <- do_ctxt env0 ctxt ;
744 addReport (vcat (ptext SLIT("Warning:") <+> msg : ctxt_to_use ctxt_msgs)) }
746 warnTc :: Bool -> Message -> TcM ()
747 warnTc warn_if_true warn_msg
748 | warn_if_true = addWarnTc warn_msg
749 | otherwise = return ()
752 -----------------------------------
755 We initialise the "tidy-env", used for tidying types before printing,
756 by building a reverse map from the in-scope type variables to the
757 OccName that the programmer originally used for them
760 tcInitTidyEnv :: TcM TidyEnv
762 = do { lcl_env <- getLclEnv
763 ; let nm_tv_prs = [ (name, tcGetTyVar "tcInitTidyEnv" ty)
764 | ATyVar name ty <- nameEnvElts (tcl_env lcl_env)
766 ; return (foldl add emptyTidyEnv nm_tv_prs) }
768 add (env,subst) (name, tyvar)
769 = case tidyOccName env (nameOccName name) of
770 (env', occ') -> (env', extendVarEnv subst tyvar tyvar')
772 tyvar' = setTyVarName tyvar name'
773 name' = tidyNameOcc name occ'
776 -----------------------------------
777 Other helper functions
780 add_err_tcm tidy_env err_msg loc ctxt
781 = do { ctxt_msgs <- do_ctxt tidy_env ctxt ;
782 addLongErrAt loc err_msg (vcat (ctxt_to_use ctxt_msgs)) }
786 do_ctxt tidy_env (c:cs)
787 = do { (tidy_env', m) <- c tidy_env ;
788 ms <- do_ctxt tidy_env' cs ;
791 ctxt_to_use ctxt | opt_PprStyle_Debug = ctxt
792 | otherwise = take 3 ctxt
795 debugTc is useful for monadic debugging code
798 debugTc :: TcM () -> TcM ()
800 debugTc thing = thing
802 debugTc thing = return ()
806 %************************************************************************
808 Type constraints (the so-called LIE)
810 %************************************************************************
813 nextDFunIndex :: TcM Int -- Get the next dfun index
814 nextDFunIndex = do { env <- getGblEnv
815 ; let dfun_n_var = tcg_dfun_n env
816 ; n <- readMutVar dfun_n_var
817 ; writeMutVar dfun_n_var (n+1)
820 getLIEVar :: TcM (TcRef LIE)
821 getLIEVar = do { env <- getLclEnv; return (tcl_lie env) }
823 setLIEVar :: TcRef LIE -> TcM a -> TcM a
824 setLIEVar lie_var = updLclEnv (\ env -> env { tcl_lie = lie_var })
826 getLIE :: TcM a -> TcM (a, [Inst])
827 -- (getLIE m) runs m, and returns the type constraints it generates
829 = do { lie_var <- newMutVar emptyLIE ;
830 res <- updLclEnv (\ env -> env { tcl_lie = lie_var })
832 lie <- readMutVar lie_var ;
833 return (res, lieToList lie) }
835 extendLIE :: Inst -> TcM ()
837 = do { lie_var <- getLIEVar ;
838 lie <- readMutVar lie_var ;
839 writeMutVar lie_var (inst `consLIE` lie) }
841 extendLIEs :: [Inst] -> TcM ()
845 = do { lie_var <- getLIEVar ;
846 lie <- readMutVar lie_var ;
847 writeMutVar lie_var (mkLIE insts `plusLIE` lie) }
851 setLclTypeEnv :: TcLclEnv -> TcM a -> TcM a
852 -- Set the local type envt, but do *not* disturb other fields,
853 -- notably the lie_var
854 setLclTypeEnv lcl_env thing_inside
855 = updLclEnv upd thing_inside
857 upd env = env { tcl_env = tcl_env lcl_env,
858 tcl_tyvars = tcl_tyvars lcl_env }
862 %************************************************************************
864 Template Haskell context
866 %************************************************************************
869 recordThUse :: TcM ()
870 recordThUse = do { env <- getGblEnv; writeMutVar (tcg_th_used env) True }
872 keepAliveTc :: Name -> TcM () -- Record the name in the keep-alive set
873 keepAliveTc n = do { env <- getGblEnv;
874 ; updMutVar (tcg_keep env) (`addOneToNameSet` n) }
876 keepAliveSetTc :: NameSet -> TcM () -- Record the name in the keep-alive set
877 keepAliveSetTc ns = do { env <- getGblEnv;
878 ; updMutVar (tcg_keep env) (`unionNameSets` ns) }
880 getStage :: TcM ThStage
881 getStage = do { env <- getLclEnv; return (tcl_th_ctxt env) }
883 setStage :: ThStage -> TcM a -> TcM a
884 setStage s = updLclEnv (\ env -> env { tcl_th_ctxt = s })
888 %************************************************************************
890 Stuff for the renamer's local env
892 %************************************************************************
895 getLocalRdrEnv :: RnM LocalRdrEnv
896 getLocalRdrEnv = do { env <- getLclEnv; return (tcl_rdr env) }
898 setLocalRdrEnv :: LocalRdrEnv -> RnM a -> RnM a
899 setLocalRdrEnv rdr_env thing_inside
900 = updLclEnv (\env -> env {tcl_rdr = rdr_env}) thing_inside
904 %************************************************************************
906 Stuff for interface decls
908 %************************************************************************
911 mkIfLclEnv :: Module -> SDoc -> IfLclEnv
912 mkIfLclEnv mod loc = IfLclEnv { if_mod = mod,
914 if_tv_env = emptyOccEnv,
915 if_id_env = emptyOccEnv }
917 initIfaceTcRn :: IfG a -> TcRn a
918 initIfaceTcRn thing_inside
919 = do { tcg_env <- getGblEnv
920 ; let { if_env = IfGblEnv { if_rec_types = Just (tcg_mod tcg_env, get_type_env) }
921 ; get_type_env = readMutVar (tcg_type_env_var tcg_env) }
922 ; setEnvs (if_env, ()) thing_inside }
924 initIfaceExtCore :: IfL a -> TcRn a
925 initIfaceExtCore thing_inside
926 = do { tcg_env <- getGblEnv
927 ; let { mod = tcg_mod tcg_env
928 ; doc = ptext SLIT("External Core file for") <+> quotes (ppr mod)
929 ; if_env = IfGblEnv {
930 if_rec_types = Just (mod, return (tcg_type_env tcg_env)) }
931 ; if_lenv = mkIfLclEnv mod doc
933 ; setEnvs (if_env, if_lenv) thing_inside }
935 initIfaceCheck :: HscEnv -> IfG a -> IO a
936 -- Used when checking the up-to-date-ness of the old Iface
937 -- Initialise the environment with no useful info at all
938 initIfaceCheck hsc_env do_this
939 = do { let gbl_env = IfGblEnv { if_rec_types = Nothing }
940 ; initTcRnIf 'i' hsc_env gbl_env () do_this
943 initIfaceTc :: ModIface
944 -> (TcRef TypeEnv -> IfL a) -> TcRnIf gbl lcl a
945 -- Used when type-checking checking an up-to-date interface file
946 -- No type envt from the current module, but we do know the module dependencies
947 initIfaceTc iface do_this
948 = do { tc_env_var <- newMutVar emptyTypeEnv
949 ; let { gbl_env = IfGblEnv { if_rec_types = Just (mod, readMutVar tc_env_var) } ;
950 ; if_lenv = mkIfLclEnv mod doc
952 ; setEnvs (gbl_env, if_lenv) (do_this tc_env_var)
955 mod = mi_module iface
956 doc = ptext SLIT("The interface for") <+> quotes (ppr mod)
958 initIfaceRules :: HscEnv -> ModGuts -> IfG a -> IO a
959 -- Used when sucking in new Rules in SimplCore
960 -- We have available the type envt of the module being compiled, and we must use it
961 initIfaceRules hsc_env guts do_this
963 type_info = (mg_module guts, return (mg_types guts))
964 ; gbl_env = IfGblEnv { if_rec_types = Just type_info } ;
967 -- Run the thing; any exceptions just bubble out from here
968 ; initTcRnIf 'i' hsc_env gbl_env () do_this
971 initIfaceLcl :: Module -> SDoc -> IfL a -> IfM lcl a
972 initIfaceLcl mod loc_doc thing_inside
973 = setLclEnv (mkIfLclEnv mod loc_doc) thing_inside
975 getIfModule :: IfL Module
976 getIfModule = do { env <- getLclEnv; return (if_mod env) }
979 failIfM :: Message -> IfL a
980 -- The Iface monad doesn't have a place to accumulate errors, so we
981 -- just fall over fast if one happens; it "shouldnt happen".
982 -- We use IfL here so that we can get context info out of the local env
984 = do { env <- getLclEnv
985 ; let full_msg = (if_loc env <> colon) $$ nest 2 msg
986 ; ioToIOEnv (printErrs (full_msg defaultErrStyle))
990 forkM_maybe :: SDoc -> IfL a -> IfL (Maybe a)
991 -- Run thing_inside in an interleaved thread.
992 -- It shares everything with the parent thread, so this is DANGEROUS.
994 -- It returns Nothing if the computation fails
996 -- It's used for lazily type-checking interface
997 -- signatures, which is pretty benign
999 forkM_maybe doc thing_inside
1000 = do { unsafeInterleaveM $
1001 do { traceIf (text "Starting fork {" <+> doc)
1003 updLclEnv (\env -> env { if_loc = if_loc env $$ doc }) $
1006 Right r -> do { traceIf (text "} ending fork" <+> doc)
1010 -- Bleat about errors in the forked thread, if -ddump-if-trace is on
1011 -- Otherwise we silently discard errors. Errors can legitimately
1012 -- happen when compiling interface signatures (see tcInterfaceSigs)
1013 ifOptM Opt_D_dump_if_trace
1014 (print_errs (hang (text "forkM failed:" <+> doc)
1015 4 (text (show exn))))
1017 ; traceIf (text "} ending fork (badly)" <+> doc)
1021 print_errs sdoc = ioToIOEnv (printErrs (sdoc defaultErrStyle))
1023 forkM :: SDoc -> IfL a -> IfL a
1024 forkM doc thing_inside
1025 = do { mb_res <- forkM_maybe doc thing_inside
1026 ; return (case mb_res of
1027 Nothing -> pgmError "Cannot continue after interface file error"
1028 -- pprPanic "forkM" doc