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(..),
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, PackageName )
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 :: ModuleName,
220 pi_pkg :: PackageName,
221 pi_vers :: Version, -- Module version number
222 pi_orphan :: WhetherHasOrphans, -- Whether this module has orphans
223 pi_usages :: [ImportVersion OccName], -- Usages
224 pi_exports :: (Version, [ExportItem]), -- Exports
225 pi_decls :: [(Version, RdrNameTyClDecl)], -- Local definitions
226 pi_fixity :: [RdrNameFixitySig], -- Local fixity declarations,
227 pi_insts :: [RdrNameInstDecl], -- Local instance declarations
228 pi_rules :: (Version, [RdrNameRuleDecl]), -- Rules, with their version
229 pi_deprecs :: IfaceDeprecs -- Deprecations
233 %************************************************************************
235 \subsection{The renamer state}
237 %************************************************************************
240 data Ifaces = Ifaces {
242 iPIT :: PackageIfaceTable,
243 -- The ModuleIFaces for modules in other packages
244 -- whose interfaces we have opened
245 -- The declarations in these interface files are held in
246 -- iDecls, iInsts, iRules (below), not in the mi_decls fields
247 -- of the iPIT. What _is_ in the iPIT is:
253 -- The iPIT field is initialised from the compiler's persistent
254 -- package symbol table, and the renamer incrementally adds
257 iImpModInfo :: ImportedModuleInfo,
258 -- Modules that we know something about, because they are mentioned
259 -- in interface files, BUT which we have not loaded yet.
260 -- No module is both in here and in the PIT
263 -- A single, global map of Names to unslurped decls
265 iInsts :: IfaceInsts,
266 -- The as-yet un-slurped instance decls; this bag is depleted when we
267 -- slurp an instance decl so that we don't slurp the same one twice.
268 -- Each is 'gated' by the names that must be available before
269 -- this instance decl is needed.
271 iRules :: IfaceRules,
272 -- Similar to instance decls, only for rules
275 -- These fields persist during the compilation of a single module only
277 -- All the names (whether "big" or "small", whether wired-in or not,
278 -- whether locally defined or not) that have been slurped in so far.
280 -- It's used for two things:
281 -- a) To record what we've already slurped, so
282 -- we can no-op if we try to slurp it again
283 -- b) As the 'gates' for importing rules. We import a rule
284 -- if all its LHS free vars have been slurped
286 iVSlurp :: (ModuleSet, NameSet)
287 -- The Names are all the (a) non-wired-in
289 -- (c) non-locally-defined
291 -- names that have been slurped in so far, with their versions.
292 -- This is used to generate the "usage" information for this module.
293 -- Subset of the previous field.
295 -- The module set is the non-home-package modules from which we have
296 -- slurped at least one name.
297 -- It's worth keeping separately, because there's no very easy
298 -- way to distinguish the "big" names from the "non-big" ones.
299 -- But this is a decision we might want to revisit.
304 %************************************************************************
306 \subsection{Main monad code}
308 %************************************************************************
311 runRn dflags hit hst pcs mod do_rn
312 = do { (pcs, msgs, r) <- initRn dflags hit hst pcs mod do_rn ;
313 printErrorsAndWarnings alwaysQualify msgs ;
314 return (pcs, errorsFound msgs, r)
318 -> HomeIfaceTable -> HomeSymbolTable
319 -> PersistentCompilerState
322 -> IO (PersistentCompilerState, Messages, t)
324 initRn dflags hit hst pcs mod do_rn
326 let prs = pcs_PRS pcs
327 let pte = pcs_PTE pcs
328 let ifaces = Ifaces { iPIT = pcs_PIT pcs,
329 iDecls = prsDecls prs,
330 iInsts = prsInsts prs,
331 iRules = prsRules prs,
333 iImpModInfo = prsImpMods prs,
334 iSlurp = unitNameSet (mkUnboundName dummyRdrVarName),
335 -- Pretend that the dummy unbound name has already been
336 -- slurped. This is what's returned for an out-of-scope name,
337 -- and we don't want thereby to try to suck it in!
338 iVSlurp = (emptyModuleSet, emptyNameSet)
340 names_var <- newIORef (prsOrig prs)
341 errs_var <- newIORef (emptyBag,emptyBag)
342 iface_var <- newIORef ifaces
343 let rn_down = RnDown { rn_mod = mod,
348 rn_done = lookupType hst pte,
352 rn_ifaces = iface_var,
356 res <- do_rn rn_down ()
358 -- Grab state and record it
359 (warns, errs) <- readIORef errs_var
360 new_ifaces <- readIORef iface_var
361 new_orig <- readIORef names_var
362 let new_prs = prs { prsOrig = new_orig,
363 prsImpMods = iImpModInfo new_ifaces,
364 prsDecls = iDecls new_ifaces,
365 prsInsts = iInsts new_ifaces,
366 prsRules = iRules new_ifaces }
367 let new_pcs = pcs { pcs_PIT = iPIT new_ifaces,
370 return (new_pcs, (warns, errs), res)
372 initRnMS :: GlobalRdrEnv -> AvailEnv -> LocalRdrEnv -> LocalFixityEnv -> RnMode
375 initRnMS rn_env avails local_env fixity_env mode thing_inside rn_down g_down
376 -- The fixity_env appears in both the rn_fixenv field
377 -- and in the HIT. See comments with RnHiFiles.lookupFixityRn
379 s_down = SDown { rn_genv = rn_env, rn_avails = avails,
380 rn_lenv = local_env, rn_fixenv = fixity_env,
383 thing_inside rn_down s_down
385 initIfaceRnMS :: Module -> RnMS r -> RnM d r
386 initIfaceRnMS mod thing_inside
387 = initRnMS emptyRdrEnv emptyAvailEnv emptyRdrEnv
388 emptyLocalFixityEnv InterfaceMode
389 (setModuleRn mod thing_inside)
392 @renameDerivedCode@ is used to rename stuff ``out-of-line'';
393 that is, not as part of the main renamer.
394 Sole examples: derived definitions,
395 which are only generated in the type checker.
397 The @NameSupply@ includes a @UniqueSupply@, so if you call it more than
398 once you must either split it, or install a fresh unique supply.
401 renameDerivedCode :: DynFlags
403 -> PersistentRenamerState
407 renameDerivedCode dflags mod prs thing_inside
409 -- It's not really unsafe! When renaming source code we
410 -- only do any I/O if we need to read in a fixity declaration;
411 -- and that doesn't happen in pragmas etc
413 do { us <- mkSplitUniqSupply 'r'
414 ; names_var <- newIORef ((prsOrig prs) { nsUniqs = us })
415 ; errs_var <- newIORef (emptyBag,emptyBag)
417 ; let rn_down = RnDown { rn_dflags = dflags,
418 rn_loc = generatedSrcLoc, rn_ns = names_var,
421 rn_done = bogus "rn_done",
422 rn_hit = bogus "rn_hit",
423 rn_ifaces = bogus "rn_ifaces"
425 ; let s_down = SDown { rn_mode = InterfaceMode,
426 -- So that we can refer to PrelBase.True etc
427 rn_avails = emptyAvailEnv,
428 rn_genv = emptyRdrEnv, rn_lenv = emptyRdrEnv,
429 rn_fixenv = emptyLocalFixityEnv }
431 ; result <- thing_inside rn_down s_down
432 ; messages <- readIORef errs_var
434 ; if bad messages then
435 do { hPutStr stderr "Urk! renameDerivedCode found errors or warnings"
436 ; printErrorsAndWarnings alwaysQualify messages
445 bad messages = errorsFound messages || warningsFound messages
447 bad messages = errorsFound messages
450 bogus s = panic ("rnameSourceCode: " ++ s) -- Used for unused record fields
452 {-# INLINE thenRn #-}
453 {-# INLINE thenRn_ #-}
454 {-# INLINE returnRn #-}
457 returnRn :: a -> RnM d a
458 thenRn :: RnM d a -> (a -> RnM d b) -> RnM d b
459 thenRn_ :: RnM d a -> RnM d b -> RnM d b
460 andRn :: (a -> a -> a) -> RnM d a -> RnM d a -> RnM d a
461 mapRn :: (a -> RnM d b) -> [a] -> RnM d [b]
462 mapRn_ :: (a -> RnM d b) -> [a] -> RnM d ()
463 mapMaybeRn :: (a -> RnM d (Maybe b)) -> [a] -> RnM d [b]
464 flatMapRn :: (a -> RnM d [b]) -> [a] -> RnM d [b]
465 sequenceRn :: [RnM d a] -> RnM d [a]
466 sequenceRn_ :: [RnM d a] -> RnM d ()
467 foldlRn :: (b -> a -> RnM d b) -> b -> [a] -> RnM d b
468 mapAndUnzipRn :: (a -> RnM d (b,c)) -> [a] -> RnM d ([b],[c])
469 fixRn :: (a -> RnM d a) -> RnM d a
471 returnRn v gdown ldown = return v
472 thenRn m k gdown ldown = m gdown ldown >>= \ r -> k r gdown ldown
473 thenRn_ m k gdown ldown = m gdown ldown >> k gdown ldown
474 fixRn m gdown ldown = fixIO (\r -> m r gdown ldown)
475 andRn combiner m1 m2 gdown ldown
476 = m1 gdown ldown >>= \ res1 ->
477 m2 gdown ldown >>= \ res2 ->
478 return (combiner res1 res2)
480 sequenceRn [] = returnRn []
481 sequenceRn (m:ms) = m `thenRn` \ r ->
482 sequenceRn ms `thenRn` \ rs ->
485 sequenceRn_ [] = returnRn ()
486 sequenceRn_ (m:ms) = m `thenRn_` sequenceRn_ ms
488 mapRn f [] = returnRn []
490 = f x `thenRn` \ r ->
491 mapRn f xs `thenRn` \ rs ->
494 mapRn_ f [] = returnRn ()
499 foldlRn k z [] = returnRn z
500 foldlRn k z (x:xs) = k z x `thenRn` \ z' ->
503 mapAndUnzipRn f [] = returnRn ([],[])
504 mapAndUnzipRn f (x:xs)
505 = f x `thenRn` \ (r1, r2) ->
506 mapAndUnzipRn f xs `thenRn` \ (rs1, rs2) ->
507 returnRn (r1:rs1, r2:rs2)
509 mapAndUnzip3Rn f [] = returnRn ([],[],[])
510 mapAndUnzip3Rn f (x:xs)
511 = f x `thenRn` \ (r1, r2, r3) ->
512 mapAndUnzip3Rn f xs `thenRn` \ (rs1, rs2, rs3) ->
513 returnRn (r1:rs1, r2:rs2, r3:rs3)
515 mapMaybeRn f [] = returnRn []
516 mapMaybeRn f (x:xs) = f x `thenRn` \ maybe_r ->
517 mapMaybeRn f xs `thenRn` \ rs ->
519 Nothing -> returnRn rs
520 Just r -> returnRn (r:rs)
522 flatMapRn f [] = returnRn []
523 flatMapRn f (x:xs) = f x `thenRn` \ r ->
524 flatMapRn f xs `thenRn` \ rs ->
530 %************************************************************************
532 \subsection{Boring plumbing for common part}
534 %************************************************************************
538 \subsubsection{ Errors and warnings}
539 %=====================
542 failWithRn :: a -> Message -> RnM d a
543 failWithRn res msg (RnDown {rn_errs = errs_var, rn_loc = loc}) l_down
544 = readIORef errs_var >>= \ (warns,errs) ->
545 writeIORef errs_var (warns, errs `snocBag` err) >>
548 err = addShortErrLocLine loc msg
550 warnWithRn :: a -> Message -> RnM d a
551 warnWithRn res msg (RnDown {rn_errs = errs_var, rn_loc = loc}) l_down
552 = readIORef errs_var >>= \ (warns,errs) ->
553 writeIORef errs_var (warns `snocBag` warn, errs) >>
556 warn = addShortWarnLocLine loc msg
558 tryRn :: RnM d a -> RnM d (Either Messages a)
559 tryRn try_this down@(RnDown {rn_errs = errs_var}) l_down
560 = do current_msgs <- readIORef errs_var
561 writeIORef errs_var (emptyBag,emptyBag)
562 a <- try_this down l_down
563 (warns, errs) <- readIORef errs_var
564 writeIORef errs_var current_msgs
566 then return (Right a)
567 else return (Left (warns,errs))
569 setErrsRn :: Messages -> RnM d ()
570 setErrsRn msgs down@(RnDown {rn_errs = errs_var}) l_down
571 = do writeIORef errs_var msgs; return ()
573 addErrRn :: Message -> RnM d ()
574 addErrRn err = failWithRn () err
576 checkRn :: Bool -> Message -> RnM d () -- Check that a condition is true
577 checkRn False err = addErrRn err
578 checkRn True err = returnRn ()
580 warnCheckRn :: Bool -> Message -> RnM d () -- Check that a condition is true
581 warnCheckRn False err = addWarnRn err
582 warnCheckRn True err = returnRn ()
584 addWarnRn :: Message -> RnM d ()
585 addWarnRn warn = warnWithRn () warn
587 checkErrsRn :: RnM d Bool -- True <=> no errors so far
588 checkErrsRn (RnDown {rn_errs = errs_var}) l_down
589 = readIORef errs_var >>= \ (warns,errs) ->
590 return (isEmptyBag errs)
592 doptRn :: DynFlag -> RnM d Bool
593 doptRn dflag (RnDown { rn_dflags = dflags}) l_down
594 = return (dopt dflag dflags)
596 ifOptRn :: DynFlag -> RnM d a -> RnM d ()
597 ifOptRn dflag thing_inside down@(RnDown { rn_dflags = dflags}) l_down
598 | dopt dflag dflags = thing_inside down l_down >> return ()
599 | otherwise = return ()
601 getDOptsRn :: RnM d DynFlags
602 getDOptsRn (RnDown { rn_dflags = dflags}) l_down
608 \subsubsection{Source location}
609 %=====================
612 pushSrcLocRn :: SrcLoc -> RnM d a -> RnM d a
613 pushSrcLocRn loc' m down l_down
614 = m (down {rn_loc = loc'}) l_down
616 getSrcLocRn :: RnM d SrcLoc
617 getSrcLocRn down l_down
618 = return (rn_loc down)
622 \subsubsection{The finder and home symbol table}
623 %=====================
626 getHomeIfaceTableRn :: RnM d HomeIfaceTable
627 getHomeIfaceTableRn down l_down = return (rn_hit down)
629 getTypeEnvRn :: RnM d (Name -> Maybe TyThing)
630 getTypeEnvRn down l_down = return (rn_done down)
632 extendTypeEnvRn :: NameEnv TyThing -> RnM d a -> RnM d a
633 extendTypeEnvRn env inside down l_down
634 = inside down{rn_done=new_rn_done} l_down
635 where new_rn_done = \nm -> lookupNameEnv env nm `seqMaybe` rn_done down nm
639 \subsubsection{Name supply}
640 %=====================
643 getNameSupplyRn :: RnM d NameSupply
644 getNameSupplyRn rn_down l_down
645 = readIORef (rn_ns rn_down)
647 setNameSupplyRn :: NameSupply -> RnM d ()
648 setNameSupplyRn names' (RnDown {rn_ns = names_var}) l_down
649 = writeIORef names_var names'
651 getUniqRn :: RnM d Unique
652 getUniqRn (RnDown {rn_ns = names_var}) l_down
653 = readIORef names_var >>= \ ns ->
655 (us1,us') = splitUniqSupply (nsUniqs ns)
657 writeIORef names_var (ns {nsUniqs = us'}) >>
658 return (uniqFromSupply us1)
662 \subsubsection{ Module}
663 %=====================
666 getModuleRn :: RnM d Module
667 getModuleRn (RnDown {rn_mod = mod}) l_down
670 setModuleRn :: Module -> RnM d a -> RnM d a
671 setModuleRn new_mod enclosed_thing rn_down l_down
672 = enclosed_thing (rn_down {rn_mod = new_mod}) l_down
676 %************************************************************************
678 \subsection{Plumbing for rename-source part}
680 %************************************************************************
683 \subsubsection{ RnEnv}
684 %=====================
687 getLocalNameEnv :: RnMS LocalRdrEnv
688 getLocalNameEnv rn_down (SDown {rn_lenv = local_env})
691 getGlobalNameEnv :: RnMS GlobalRdrEnv
692 getGlobalNameEnv rn_down (SDown {rn_genv = global_env})
695 getGlobalAvails :: RnMS AvailEnv
696 getGlobalAvails rn_down (SDown {rn_avails = avails})
699 setLocalNameEnv :: LocalRdrEnv -> RnMS a -> RnMS a
700 setLocalNameEnv local_env' m rn_down l_down
701 = m rn_down (l_down {rn_lenv = local_env'})
703 getFixityEnv :: RnMS LocalFixityEnv
704 getFixityEnv rn_down (SDown {rn_fixenv = fixity_env})
707 extendFixityEnv :: [(Name, RenamedFixitySig)] -> RnMS a -> RnMS a
708 extendFixityEnv fixes enclosed_scope
709 rn_down l_down@(SDown {rn_fixenv = fixity_env})
711 new_fixity_env = extendNameEnvList fixity_env fixes
713 enclosed_scope rn_down (l_down {rn_fixenv = new_fixity_env})
717 \subsubsection{ Mode}
718 %=====================
721 getModeRn :: RnMS RnMode
722 getModeRn rn_down (SDown {rn_mode = mode})
725 setModeRn :: RnMode -> RnMS a -> RnMS a
726 setModeRn new_mode thing_inside rn_down l_down
727 = thing_inside rn_down (l_down {rn_mode = new_mode})
731 %************************************************************************
733 \subsection{Plumbing for rename-globals part}
735 %************************************************************************
738 getIfacesRn :: RnM d Ifaces
739 getIfacesRn (RnDown {rn_ifaces = iface_var}) _
740 = readIORef iface_var
742 setIfacesRn :: Ifaces -> RnM d ()
743 setIfacesRn ifaces (RnDown {rn_ifaces = iface_var}) _
744 = writeIORef iface_var ifaces