2 % (c) The GRASP/AQUA Project, Glasgow University, 1992-1998
4 \section[RnMonad]{The monad used by the renamer}
10 module RdrName, -- Re-exports
11 module Name, -- from these two
24 #include "HsVersions.h"
26 #if defined(__GLASGOW_HASKELL__) && __GLASGOW_HASKELL__ >= 405
27 import IOExts ( fixIO )
28 #elif defined(__GLASGOW_HASKELL__) && __GLASGOW_HASKELL__ >= 302
29 import PrelIOBase ( fixIO ) -- Should be in GlaExts
31 import IOBase ( fixIO )
33 import IOExts ( IORef, newIORef, readIORef, writeIORef, unsafePerformIO )
34 import IO ( hPutStr, stderr )
38 import RnHsSyn ( RenamedFixitySig )
39 import HscTypes ( AvailEnv, emptyAvailEnv, lookupType,
41 ImportedModuleInfo, WhetherHasOrphans, ImportVersion,
42 PersistentRenamerState(..), Avails,
43 DeclsMap, IfaceInsts, IfaceRules,
44 HomeSymbolTable, TyThing,
45 PersistentCompilerState(..), GlobalRdrEnv, LocalRdrEnv,
46 HomeIfaceTable, PackageIfaceTable,
48 import BasicTypes ( Version, defaultFixity )
49 import ErrUtils ( addShortErrLocLine, addShortWarnLocLine,
50 Message, Messages, errorsFound, warningsFound,
51 printErrorsAndWarnings
53 import RdrName ( RdrName, dummyRdrVarName, rdrNameModule, rdrNameOcc,
54 RdrNameEnv, emptyRdrEnv, extendRdrEnv,
55 addListToRdrEnv, rdrEnvToList, rdrEnvElts
57 import Name ( Name, OccName, NamedThing(..),
59 decode, mkLocalName, mkKnownKeyGlobal
61 import NameEnv ( NameEnv, lookupNameEnv, emptyNameEnv, extendNameEnvList )
62 import Module ( Module, ModuleName, ModuleSet, emptyModuleSet )
64 import CmdLineOpts ( DynFlags, DynFlag(..), dopt )
65 import SrcLoc ( SrcLoc, generatedSrcLoc, noSrcLoc )
66 import Unique ( Unique )
67 import FiniteMap ( FiniteMap )
68 import Maybes ( seqMaybe )
69 import Bag ( Bag, emptyBag, isEmptyBag, snocBag )
72 import PrelNames ( mkUnboundName )
74 infixr 9 `thenRn`, `thenRn_`
78 %************************************************************************
80 \subsection{Somewhat magical interface to other monads}
82 %************************************************************************
85 ioToRnM :: IO r -> RnM d (Either IOError r)
86 ioToRnM io rn_down g_down = (io >>= \ ok -> return (Right ok))
88 (\ err -> return (Left err))
90 ioToRnM_no_fail :: IO r -> RnM d r
91 ioToRnM_no_fail io rn_down g_down
92 = (io >>= \ ok -> return ok)
94 (\ err -> panic "ioToRnM_no_fail: the I/O operation failed!")
96 traceRn :: SDoc -> RnM d ()
97 traceRn msg = ifOptRn Opt_D_dump_rn_trace (putDocRn msg)
99 traceHiDiffsRn :: SDoc -> RnM d ()
100 traceHiDiffsRn msg = ifOptRn Opt_D_dump_hi_diffs (putDocRn msg)
102 putDocRn :: SDoc -> RnM d ()
103 putDocRn msg = ioToRnM (printErrs alwaysQualify msg) `thenRn_`
108 %************************************************************************
110 \subsection{Data types}
112 %************************************************************************
114 %===================================================
115 \subsubsection{ MONAD TYPES}
116 %===================================================
119 type RnM d r = RnDown -> d -> IO r
120 type RnMS r = RnM SDown r -- Renaming source
121 type RnMG r = RnM () r -- Getting global names etc
126 rn_mod :: Module, -- This module
127 rn_loc :: SrcLoc, -- Current locn
129 rn_dflags :: DynFlags,
131 rn_hit :: HomeIfaceTable,
132 rn_done :: Name -> Maybe TyThing, -- Tells what things (both in the
133 -- home package and other packages)
134 -- were already available (i.e. in
135 -- the relevant SymbolTable) before
136 -- compiling this module
137 -- The Name passed to rn_done is guaranteed to be a Global,
138 -- so it has a Module, so it can be looked up
140 rn_errs :: IORef Messages,
141 rn_ns :: IORef NameSupply,
142 rn_ifaces :: IORef Ifaces
145 -- For renaming source code
149 rn_genv :: GlobalRdrEnv, -- Top level environment
151 rn_avails :: AvailEnv,
152 -- Top level AvailEnv; contains all the things that
153 -- are nameable in the top-level scope, regardless of
154 -- *how* they can be named (qualified, unqualified...)
155 -- It is used only to map a Class to its class ops, and
156 -- hence to resolve the binders in an instance decl
158 rn_lenv :: LocalRdrEnv, -- Local name envt
159 -- Does *not* include global name envt; may shadow it
160 -- Includes both ordinary variables and type variables;
161 -- they are kept distinct because tyvar have a different
162 -- occurrence contructor (Name.TvOcc)
163 -- We still need the unsullied global name env so that
164 -- we can look up record field names
166 rn_fixenv :: LocalFixityEnv -- Local fixities (for non-top-level
168 -- The global fixities are held in the
169 -- HIT or PIT. Why? See the comments
170 -- with RnIfaces.lookupLocalFixity
173 data RnMode = SourceMode -- Renaming source code
174 | InterfaceMode -- Renaming interface declarations.
175 | CmdLineMode -- Renaming a command-line expression
177 isInterfaceMode InterfaceMode = True
178 isInterfaceMode _ = False
180 isCmdLineMode CmdLineMode = True
181 isCmdLineMode _ = False
184 %===================================================
185 \subsubsection{ ENVIRONMENTS}
186 %===================================================
189 --------------------------------
190 type LocalFixityEnv = NameEnv RenamedFixitySig
191 -- We keep the whole fixity sig so that we
192 -- can report line-number info when there is a duplicate
193 -- fixity declaration
195 emptyLocalFixityEnv :: LocalFixityEnv
196 emptyLocalFixityEnv = emptyNameEnv
198 lookupLocalFixity :: LocalFixityEnv -> Name -> Fixity
199 lookupLocalFixity env name
200 = case lookupNameEnv env name of
201 Just (FixitySig _ fix _) -> fix
202 Nothing -> defaultFixity
206 %===================================================
207 \subsubsection{ INTERFACE FILE STUFF}
208 %===================================================
211 type ExportItem = (ModuleName, [RdrAvailInfo])
212 type IfaceDeprecs = Maybe (Either DeprecTxt [(RdrName,DeprecTxt)])
213 -- Nothing => NoDeprecs
214 -- Just (Left t) => DeprecAll
215 -- Just (Right p) => DeprecSome
219 pi_mod :: Module, -- Complete with package info
220 pi_vers :: Version, -- Module version number
221 pi_orphan :: WhetherHasOrphans, -- Whether this module has orphans
222 pi_usages :: [ImportVersion OccName], -- Usages
223 pi_exports :: (Version, [ExportItem]), -- Exports
224 pi_decls :: [(Version, RdrNameTyClDecl)], -- Local definitions
225 pi_fixity :: [RdrNameFixitySig], -- Local fixity declarations,
226 pi_insts :: [RdrNameInstDecl], -- Local instance declarations
227 pi_rules :: (Version, [RdrNameRuleDecl]), -- Rules, with their version
228 pi_deprecs :: IfaceDeprecs -- Deprecations
232 %************************************************************************
234 \subsection{The renamer state}
236 %************************************************************************
239 data Ifaces = Ifaces {
241 iPIT :: PackageIfaceTable,
242 -- The ModuleIFaces for modules in other packages
243 -- whose interfaces we have opened
244 -- The declarations in these interface files are held in
245 -- iDecls, iInsts, iRules (below), not in the mi_decls fields
246 -- of the iPIT. What _is_ in the iPIT is:
252 -- The iPIT field is initialised from the compiler's persistent
253 -- package symbol table, and the renamer incrementally adds
256 iImpModInfo :: ImportedModuleInfo,
257 -- Modules that we know something about, because they are mentioned
258 -- in interface files, BUT which we have not loaded yet.
259 -- No module is both in here and in the PIT
262 -- A single, global map of Names to unslurped decls
264 iInsts :: IfaceInsts,
265 -- The as-yet un-slurped instance decls; this bag is depleted when we
266 -- slurp an instance decl so that we don't slurp the same one twice.
267 -- Each is 'gated' by the names that must be available before
268 -- this instance decl is needed.
270 iRules :: IfaceRules,
271 -- Similar to instance decls, only for rules
274 -- These fields persist during the compilation of a single module only
276 -- All the names (whether "big" or "small", whether wired-in or not,
277 -- whether locally defined or not) that have been slurped in so far.
279 -- It's used for two things:
280 -- a) To record what we've already slurped, so
281 -- we can no-op if we try to slurp it again
282 -- b) As the 'gates' for importing rules. We import a rule
283 -- if all its LHS free vars have been slurped
285 iVSlurp :: (ModuleSet, NameSet)
286 -- The Names are all the (a) non-wired-in
288 -- (c) non-locally-defined
290 -- names that have been slurped in so far, with their versions.
291 -- This is used to generate the "usage" information for this module.
292 -- Subset of the previous field.
294 -- The module set is the non-home-package modules from which we have
295 -- slurped at least one name.
296 -- It's worth keeping separately, because there's no very easy
297 -- way to distinguish the "big" names from the "non-big" ones.
298 -- But this is a decision we might want to revisit.
303 %************************************************************************
305 \subsection{Main monad code}
307 %************************************************************************
310 runRn dflags hit hst pcs mod do_rn
311 = do { (pcs, msgs, r) <- initRn dflags hit hst pcs mod do_rn ;
312 printErrorsAndWarnings alwaysQualify msgs ;
313 return (pcs, errorsFound msgs, r)
317 -> HomeIfaceTable -> HomeSymbolTable
318 -> PersistentCompilerState
321 -> IO (PersistentCompilerState, Messages, t)
323 initRn dflags hit hst pcs mod do_rn
325 let prs = pcs_PRS pcs
326 let pte = pcs_PTE pcs
327 let ifaces = Ifaces { iPIT = pcs_PIT pcs,
328 iDecls = prsDecls prs,
329 iInsts = prsInsts prs,
330 iRules = prsRules prs,
332 iImpModInfo = prsImpMods prs,
333 iSlurp = unitNameSet (mkUnboundName dummyRdrVarName),
334 -- Pretend that the dummy unbound name has already been
335 -- slurped. This is what's returned for an out-of-scope name,
336 -- and we don't want thereby to try to suck it in!
337 iVSlurp = (emptyModuleSet, emptyNameSet)
339 names_var <- newIORef (prsOrig prs)
340 errs_var <- newIORef (emptyBag,emptyBag)
341 iface_var <- newIORef ifaces
342 let rn_down = RnDown { rn_mod = mod,
347 rn_done = lookupType hst pte,
351 rn_ifaces = iface_var,
355 res <- do_rn rn_down ()
357 -- Grab state and record it
358 (warns, errs) <- readIORef errs_var
359 new_ifaces <- readIORef iface_var
360 new_orig <- readIORef names_var
361 let new_prs = prs { prsOrig = new_orig,
362 prsImpMods = iImpModInfo new_ifaces,
363 prsDecls = iDecls new_ifaces,
364 prsInsts = iInsts new_ifaces,
365 prsRules = iRules new_ifaces }
366 let new_pcs = pcs { pcs_PIT = iPIT new_ifaces,
369 return (new_pcs, (warns, errs), res)
371 initRnMS :: GlobalRdrEnv -> AvailEnv -> LocalRdrEnv -> LocalFixityEnv -> RnMode
374 initRnMS rn_env avails local_env fixity_env mode thing_inside rn_down g_down
375 -- The fixity_env appears in both the rn_fixenv field
376 -- and in the HIT. See comments with RnHiFiles.lookupFixityRn
378 s_down = SDown { rn_genv = rn_env, rn_avails = avails,
379 rn_lenv = local_env, rn_fixenv = fixity_env,
382 thing_inside rn_down s_down
384 initIfaceRnMS :: Module -> RnMS r -> RnM d r
385 initIfaceRnMS mod thing_inside
386 = initRnMS emptyRdrEnv emptyAvailEnv emptyRdrEnv
387 emptyLocalFixityEnv InterfaceMode
388 (setModuleRn mod thing_inside)
391 @renameDerivedCode@ is used to rename stuff ``out-of-line'';
392 that is, not as part of the main renamer.
393 Sole examples: derived definitions,
394 which are only generated in the type checker.
396 The @NameSupply@ includes a @UniqueSupply@, so if you call it more than
397 once you must either split it, or install a fresh unique supply.
400 renameDerivedCode :: DynFlags
402 -> PersistentRenamerState
406 renameDerivedCode dflags mod prs thing_inside
408 -- It's not really unsafe! When renaming source code we
409 -- only do any I/O if we need to read in a fixity declaration;
410 -- and that doesn't happen in pragmas etc
412 do { us <- mkSplitUniqSupply 'r'
413 ; names_var <- newIORef ((prsOrig prs) { nsUniqs = us })
414 ; errs_var <- newIORef (emptyBag,emptyBag)
416 ; let rn_down = RnDown { rn_dflags = dflags,
417 rn_loc = generatedSrcLoc, rn_ns = names_var,
420 rn_done = bogus "rn_done",
421 rn_hit = bogus "rn_hit",
422 rn_ifaces = bogus "rn_ifaces"
424 ; let s_down = SDown { rn_mode = InterfaceMode,
425 -- So that we can refer to PrelBase.True etc
426 rn_avails = emptyAvailEnv,
427 rn_genv = emptyRdrEnv, rn_lenv = emptyRdrEnv,
428 rn_fixenv = emptyLocalFixityEnv }
430 ; result <- thing_inside rn_down s_down
431 ; messages <- readIORef errs_var
433 ; if bad messages then
434 do { hPutStr stderr "Urk! renameDerivedCode found errors or warnings"
435 ; printErrorsAndWarnings alwaysQualify messages
444 bad messages = errorsFound messages || warningsFound messages
446 bad messages = errorsFound messages
449 bogus s = panic ("rnameSourceCode: " ++ s) -- Used for unused record fields
451 {-# INLINE thenRn #-}
452 {-# INLINE thenRn_ #-}
453 {-# INLINE returnRn #-}
456 returnRn :: a -> RnM d a
457 thenRn :: RnM d a -> (a -> RnM d b) -> RnM d b
458 thenRn_ :: RnM d a -> RnM d b -> RnM d b
459 andRn :: (a -> a -> a) -> RnM d a -> RnM d a -> RnM d a
460 mapRn :: (a -> RnM d b) -> [a] -> RnM d [b]
461 mapRn_ :: (a -> RnM d b) -> [a] -> RnM d ()
462 mapMaybeRn :: (a -> RnM d (Maybe b)) -> [a] -> RnM d [b]
463 flatMapRn :: (a -> RnM d [b]) -> [a] -> RnM d [b]
464 sequenceRn :: [RnM d a] -> RnM d [a]
465 sequenceRn_ :: [RnM d a] -> RnM d ()
466 foldlRn :: (b -> a -> RnM d b) -> b -> [a] -> RnM d b
467 mapAndUnzipRn :: (a -> RnM d (b,c)) -> [a] -> RnM d ([b],[c])
468 fixRn :: (a -> RnM d a) -> RnM d a
470 returnRn v gdown ldown = return v
471 thenRn m k gdown ldown = m gdown ldown >>= \ r -> k r gdown ldown
472 thenRn_ m k gdown ldown = m gdown ldown >> k gdown ldown
473 fixRn m gdown ldown = fixIO (\r -> m r gdown ldown)
474 andRn combiner m1 m2 gdown ldown
475 = m1 gdown ldown >>= \ res1 ->
476 m2 gdown ldown >>= \ res2 ->
477 return (combiner res1 res2)
479 sequenceRn [] = returnRn []
480 sequenceRn (m:ms) = m `thenRn` \ r ->
481 sequenceRn ms `thenRn` \ rs ->
484 sequenceRn_ [] = returnRn ()
485 sequenceRn_ (m:ms) = m `thenRn_` sequenceRn_ ms
487 mapRn f [] = returnRn []
489 = f x `thenRn` \ r ->
490 mapRn f xs `thenRn` \ rs ->
493 mapRn_ f [] = returnRn ()
498 foldlRn k z [] = returnRn z
499 foldlRn k z (x:xs) = k z x `thenRn` \ z' ->
502 mapAndUnzipRn f [] = returnRn ([],[])
503 mapAndUnzipRn f (x:xs)
504 = f x `thenRn` \ (r1, r2) ->
505 mapAndUnzipRn f xs `thenRn` \ (rs1, rs2) ->
506 returnRn (r1:rs1, r2:rs2)
508 mapAndUnzip3Rn f [] = returnRn ([],[],[])
509 mapAndUnzip3Rn f (x:xs)
510 = f x `thenRn` \ (r1, r2, r3) ->
511 mapAndUnzip3Rn f xs `thenRn` \ (rs1, rs2, rs3) ->
512 returnRn (r1:rs1, r2:rs2, r3:rs3)
514 mapMaybeRn f [] = returnRn []
515 mapMaybeRn f (x:xs) = f x `thenRn` \ maybe_r ->
516 mapMaybeRn f xs `thenRn` \ rs ->
518 Nothing -> returnRn rs
519 Just r -> returnRn (r:rs)
521 flatMapRn f [] = returnRn []
522 flatMapRn f (x:xs) = f x `thenRn` \ r ->
523 flatMapRn f xs `thenRn` \ rs ->
529 %************************************************************************
531 \subsection{Boring plumbing for common part}
533 %************************************************************************
537 \subsubsection{ Errors and warnings}
538 %=====================
541 failWithRn :: a -> Message -> RnM d a
542 failWithRn res msg (RnDown {rn_errs = errs_var, rn_loc = loc}) l_down
543 = readIORef errs_var >>= \ (warns,errs) ->
544 writeIORef errs_var (warns, errs `snocBag` err) >>
547 err = addShortErrLocLine loc msg
549 warnWithRn :: a -> Message -> RnM d a
550 warnWithRn res msg (RnDown {rn_errs = errs_var, rn_loc = loc}) l_down
551 = readIORef errs_var >>= \ (warns,errs) ->
552 writeIORef errs_var (warns `snocBag` warn, errs) >>
555 warn = addShortWarnLocLine loc msg
557 tryRn :: RnM d a -> RnM d (Either Messages a)
558 tryRn try_this down@(RnDown {rn_errs = errs_var}) l_down
559 = do current_msgs <- readIORef errs_var
560 writeIORef errs_var (emptyBag,emptyBag)
561 a <- try_this down l_down
562 (warns, errs) <- readIORef errs_var
563 writeIORef errs_var current_msgs
565 then return (Right a)
566 else return (Left (warns,errs))
568 setErrsRn :: Messages -> RnM d ()
569 setErrsRn msgs down@(RnDown {rn_errs = errs_var}) l_down
570 = do writeIORef errs_var msgs; return ()
572 addErrRn :: Message -> RnM d ()
573 addErrRn err = failWithRn () err
575 checkRn :: Bool -> Message -> RnM d () -- Check that a condition is true
576 checkRn False err = addErrRn err
577 checkRn True err = returnRn ()
579 warnCheckRn :: Bool -> Message -> RnM d () -- Check that a condition is true
580 warnCheckRn False err = addWarnRn err
581 warnCheckRn True err = returnRn ()
583 addWarnRn :: Message -> RnM d ()
584 addWarnRn warn = warnWithRn () warn
586 checkErrsRn :: RnM d Bool -- True <=> no errors so far
587 checkErrsRn (RnDown {rn_errs = errs_var}) l_down
588 = readIORef errs_var >>= \ (warns,errs) ->
589 return (isEmptyBag errs)
591 doptRn :: DynFlag -> RnM d Bool
592 doptRn dflag (RnDown { rn_dflags = dflags}) l_down
593 = return (dopt dflag dflags)
595 ifOptRn :: DynFlag -> RnM d a -> RnM d ()
596 ifOptRn dflag thing_inside down@(RnDown { rn_dflags = dflags}) l_down
597 | dopt dflag dflags = thing_inside down l_down >> return ()
598 | otherwise = return ()
600 getDOptsRn :: RnM d DynFlags
601 getDOptsRn (RnDown { rn_dflags = dflags}) l_down
607 \subsubsection{Source location}
608 %=====================
611 pushSrcLocRn :: SrcLoc -> RnM d a -> RnM d a
612 pushSrcLocRn loc' m down l_down
613 = m (down {rn_loc = loc'}) l_down
615 getSrcLocRn :: RnM d SrcLoc
616 getSrcLocRn down l_down
617 = return (rn_loc down)
621 \subsubsection{The finder and home symbol table}
622 %=====================
625 getHomeIfaceTableRn :: RnM d HomeIfaceTable
626 getHomeIfaceTableRn down l_down = return (rn_hit down)
628 getTypeEnvRn :: RnM d (Name -> Maybe TyThing)
629 getTypeEnvRn down l_down = return (rn_done down)
631 extendTypeEnvRn :: NameEnv TyThing -> RnM d a -> RnM d a
632 extendTypeEnvRn env inside down l_down
633 = inside down{rn_done=new_rn_done} l_down
634 where new_rn_done = \nm -> lookupNameEnv env nm `seqMaybe` rn_done down nm
638 \subsubsection{Name supply}
639 %=====================
642 getNameSupplyRn :: RnM d NameSupply
643 getNameSupplyRn rn_down l_down
644 = readIORef (rn_ns rn_down)
646 setNameSupplyRn :: NameSupply -> RnM d ()
647 setNameSupplyRn names' (RnDown {rn_ns = names_var}) l_down
648 = writeIORef names_var names'
650 getUniqRn :: RnM d Unique
651 getUniqRn (RnDown {rn_ns = names_var}) l_down
652 = readIORef names_var >>= \ ns ->
654 (us1,us') = splitUniqSupply (nsUniqs ns)
656 writeIORef names_var (ns {nsUniqs = us'}) >>
657 return (uniqFromSupply us1)
661 \subsubsection{ Module}
662 %=====================
665 getModuleRn :: RnM d Module
666 getModuleRn (RnDown {rn_mod = mod}) l_down
669 setModuleRn :: Module -> RnM d a -> RnM d a
670 setModuleRn new_mod enclosed_thing rn_down l_down
671 = enclosed_thing (rn_down {rn_mod = new_mod}) l_down
675 %************************************************************************
677 \subsection{Plumbing for rename-source part}
679 %************************************************************************
682 \subsubsection{ RnEnv}
683 %=====================
686 getLocalNameEnv :: RnMS LocalRdrEnv
687 getLocalNameEnv rn_down (SDown {rn_lenv = local_env})
690 getGlobalNameEnv :: RnMS GlobalRdrEnv
691 getGlobalNameEnv rn_down (SDown {rn_genv = global_env})
694 getGlobalAvails :: RnMS AvailEnv
695 getGlobalAvails rn_down (SDown {rn_avails = avails})
698 setLocalNameEnv :: LocalRdrEnv -> RnMS a -> RnMS a
699 setLocalNameEnv local_env' m rn_down l_down
700 = m rn_down (l_down {rn_lenv = local_env'})
702 getFixityEnv :: RnMS LocalFixityEnv
703 getFixityEnv rn_down (SDown {rn_fixenv = fixity_env})
706 extendFixityEnv :: [(Name, RenamedFixitySig)] -> RnMS a -> RnMS a
707 extendFixityEnv fixes enclosed_scope
708 rn_down l_down@(SDown {rn_fixenv = fixity_env})
710 new_fixity_env = extendNameEnvList fixity_env fixes
712 enclosed_scope rn_down (l_down {rn_fixenv = new_fixity_env})
716 \subsubsection{ Mode}
717 %=====================
720 getModeRn :: RnMS RnMode
721 getModeRn rn_down (SDown {rn_mode = mode})
724 setModeRn :: RnMode -> RnMS a -> RnMS a
725 setModeRn new_mode thing_inside rn_down l_down
726 = thing_inside rn_down (l_down {rn_mode = new_mode})
730 %************************************************************************
732 \subsection{Plumbing for rename-globals part}
734 %************************************************************************
737 getIfacesRn :: RnM d Ifaces
738 getIfacesRn (RnDown {rn_ifaces = iface_var}) _
739 = readIORef iface_var
741 setIfacesRn :: Ifaces -> RnM d ()
742 setIfacesRn ifaces (RnDown {rn_ifaces = iface_var}) _
743 = writeIORef iface_var ifaces