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, 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 Bag ( Bag, emptyBag, isEmptyBag, snocBag )
71 import PrelNames ( mkUnboundName )
73 infixr 9 `thenRn`, `thenRn_`
77 %************************************************************************
79 \subsection{Somewhat magical interface to other monads}
81 %************************************************************************
84 ioToRnM :: IO r -> RnM d (Either IOError r)
85 ioToRnM io rn_down g_down = (io >>= \ ok -> return (Right ok))
87 (\ err -> return (Left err))
89 ioToRnM_no_fail :: IO r -> RnM d r
90 ioToRnM_no_fail io rn_down g_down
91 = (io >>= \ ok -> return ok)
93 (\ err -> panic "ioToRnM_no_fail: the I/O operation failed!")
95 traceRn :: SDoc -> RnM d ()
96 traceRn msg = ifOptRn Opt_D_dump_rn_trace (putDocRn msg)
98 traceHiDiffsRn :: SDoc -> RnM d ()
99 traceHiDiffsRn msg = ifOptRn Opt_D_dump_hi_diffs (putDocRn msg)
101 putDocRn :: SDoc -> RnM d ()
102 putDocRn msg = ioToRnM (printErrs alwaysQualify msg) `thenRn_`
107 %************************************************************************
109 \subsection{Data types}
111 %************************************************************************
113 %===================================================
114 \subsubsection{ MONAD TYPES}
115 %===================================================
118 type RnM d r = RnDown -> d -> IO r
119 type RnMS r = RnM SDown r -- Renaming source
120 type RnMG r = RnM () r -- Getting global names etc
125 rn_mod :: Module, -- This module
126 rn_loc :: SrcLoc, -- Current locn
128 rn_dflags :: DynFlags,
130 rn_hit :: HomeIfaceTable,
131 rn_done :: Name -> Maybe TyThing, -- Tells what things (both in the
132 -- home package and other packages)
133 -- were already available (i.e. in
134 -- the relevant SymbolTable) before
135 -- compiling this module
136 -- The Name passed to rn_done is guaranteed to be a Global,
137 -- so it has a Module, so it can be looked up
139 rn_errs :: IORef Messages,
140 rn_ns :: IORef NameSupply,
141 rn_ifaces :: IORef Ifaces
144 -- For renaming source code
148 rn_genv :: GlobalRdrEnv, -- Top level environment
150 rn_lenv :: LocalRdrEnv, -- Local name envt
151 -- Does *not* include global name envt; may shadow it
152 -- Includes both ordinary variables and type variables;
153 -- they are kept distinct because tyvar have a different
154 -- occurrence contructor (Name.TvOcc)
155 -- We still need the unsullied global name env so that
156 -- we can look up record field names
158 rn_fixenv :: LocalFixityEnv -- Local fixities (for non-top-level
160 -- The global fixities are held in the
161 -- HIT or PIT. Why? See the comments
162 -- with RnIfaces.lookupLocalFixity
165 data RnMode = SourceMode -- Renaming source code
166 | InterfaceMode -- Renaming interface declarations.
167 | CmdLineMode -- Renaming a command-line expression
169 isInterfaceMode InterfaceMode = True
170 isInterfaceMode _ = False
173 %===================================================
174 \subsubsection{ ENVIRONMENTS}
175 %===================================================
178 --------------------------------
179 type LocalFixityEnv = NameEnv RenamedFixitySig
180 -- We keep the whole fixity sig so that we
181 -- can report line-number info when there is a duplicate
182 -- fixity declaration
184 emptyLocalFixityEnv :: LocalFixityEnv
185 emptyLocalFixityEnv = emptyNameEnv
187 lookupLocalFixity :: LocalFixityEnv -> Name -> Fixity
188 lookupLocalFixity env name
189 = case lookupNameEnv env name of
190 Just (FixitySig _ fix _) -> fix
191 Nothing -> defaultFixity
195 type ExportAvails = (FiniteMap ModuleName Avails,
196 -- Used to figure out "module M" export specifiers
197 -- Includes avails only from *unqualified* imports
198 -- (see 1.4 Report Section 5.1.1)
200 AvailEnv) -- Used to figure out all other export specifiers.
203 %===================================================
204 \subsubsection{ INTERFACE FILE STUFF}
205 %===================================================
208 type ExportItem = (ModuleName, [RdrAvailInfo])
209 type IfaceDeprecs = Maybe (Either DeprecTxt [(RdrName,DeprecTxt)])
210 -- Nothing => NoDeprecs
211 -- Just (Left t) => DeprecAll
212 -- Just (Right p) => DeprecSome
216 pi_mod :: Module, -- Complete with package info
217 pi_vers :: Version, -- Module version number
218 pi_orphan :: WhetherHasOrphans, -- Whether this module has orphans
219 pi_usages :: [ImportVersion OccName], -- Usages
220 pi_exports :: (Version, [ExportItem]), -- Exports
221 pi_decls :: [(Version, RdrNameTyClDecl)], -- Local definitions
222 pi_fixity :: [RdrNameFixitySig], -- Local fixity declarations,
223 pi_insts :: [RdrNameInstDecl], -- Local instance declarations
224 pi_rules :: (Version, [RdrNameRuleDecl]), -- Rules, with their version
225 pi_deprecs :: IfaceDeprecs -- Deprecations
229 %************************************************************************
231 \subsection{The renamer state}
233 %************************************************************************
236 data Ifaces = Ifaces {
238 iPIT :: PackageIfaceTable,
239 -- The ModuleIFaces for modules in other packages
240 -- whose interfaces we have opened
241 -- The declarations in these interface files are held in
242 -- iDecls, iInsts, iRules (below), not in the mi_decls fields
243 -- of the iPIT. What _is_ in the iPIT is:
249 -- The iPIT field is initialised from the compiler's persistent
250 -- package symbol table, and the renamer incrementally adds
253 iImpModInfo :: ImportedModuleInfo,
254 -- Modules that we know something about, because they are mentioned
255 -- in interface files, BUT which we have not loaded yet.
256 -- No module is both in here and in the PIT
259 -- A single, global map of Names to unslurped decls
261 iInsts :: IfaceInsts,
262 -- The as-yet un-slurped instance decls; this bag is depleted when we
263 -- slurp an instance decl so that we don't slurp the same one twice.
264 -- Each is 'gated' by the names that must be available before
265 -- this instance decl is needed.
267 iRules :: IfaceRules,
268 -- Similar to instance decls, only for rules
271 -- These fields persist during the compilation of a single module only
273 -- All the names (whether "big" or "small", whether wired-in or not,
274 -- whether locally defined or not) that have been slurped in so far.
276 -- It's used for two things:
277 -- a) To record what we've already slurped, so
278 -- we can no-op if we try to slurp it again
279 -- b) As the 'gates' for importing rules. We import a rule
280 -- if all its LHS free vars have been slurped
282 iVSlurp :: (ModuleSet, NameSet)
283 -- The Names are all the (a) non-wired-in
285 -- (c) non-locally-defined
287 -- names that have been slurped in so far, with their versions.
288 -- This is used to generate the "usage" information for this module.
289 -- Subset of the previous field.
291 -- The module set is the non-home-package modules from which we have
292 -- slurped at least one name.
293 -- It's worth keeping separately, because there's no very easy
294 -- way to distinguish the "big" names from the "non-big" ones.
295 -- But this is a decision we might want to revisit.
300 %************************************************************************
302 \subsection{Main monad code}
304 %************************************************************************
307 runRn dflags hit hst pcs mod do_rn
308 = do { (pcs, msgs, r) <- initRn dflags hit hst pcs mod do_rn ;
309 printErrorsAndWarnings alwaysQualify msgs ;
310 return (pcs, errorsFound msgs, r)
314 -> HomeIfaceTable -> HomeSymbolTable
315 -> PersistentCompilerState
318 -> IO (PersistentCompilerState, Messages, t)
320 initRn dflags hit hst pcs mod do_rn
322 let prs = pcs_PRS pcs
323 let pte = pcs_PTE pcs
324 let ifaces = Ifaces { iPIT = pcs_PIT pcs,
325 iDecls = prsDecls prs,
326 iInsts = prsInsts prs,
327 iRules = prsRules prs,
329 iImpModInfo = prsImpMods prs,
330 iSlurp = unitNameSet (mkUnboundName dummyRdrVarName),
331 -- Pretend that the dummy unbound name has already been
332 -- slurped. This is what's returned for an out-of-scope name,
333 -- and we don't want thereby to try to suck it in!
334 iVSlurp = (emptyModuleSet, emptyNameSet)
336 names_var <- newIORef (prsOrig prs)
337 errs_var <- newIORef (emptyBag,emptyBag)
338 iface_var <- newIORef ifaces
339 let rn_down = RnDown { rn_mod = mod,
344 rn_done = lookupType hst pte,
348 rn_ifaces = iface_var,
352 res <- do_rn rn_down ()
354 -- Grab state and record it
355 (warns, errs) <- readIORef errs_var
356 new_ifaces <- readIORef iface_var
357 new_orig <- readIORef names_var
358 let new_prs = prs { prsOrig = new_orig,
359 prsImpMods = iImpModInfo new_ifaces,
360 prsDecls = iDecls new_ifaces,
361 prsInsts = iInsts new_ifaces,
362 prsRules = iRules new_ifaces }
363 let new_pcs = pcs { pcs_PIT = iPIT new_ifaces,
366 return (new_pcs, (warns, errs), res)
368 initRnMS :: GlobalRdrEnv -> LocalRdrEnv -> LocalFixityEnv -> RnMode
371 initRnMS rn_env local_env fixity_env mode thing_inside rn_down g_down
372 -- The fixity_env appears in both the rn_fixenv field
373 -- and in the HIT. See comments with RnHiFiles.lookupFixityRn
375 s_down = SDown { rn_genv = rn_env, rn_lenv = local_env,
376 rn_fixenv = fixity_env, rn_mode = mode }
378 thing_inside rn_down s_down
380 initIfaceRnMS :: Module -> RnMS r -> RnM d r
381 initIfaceRnMS mod thing_inside
382 = initRnMS emptyRdrEnv emptyRdrEnv emptyLocalFixityEnv InterfaceMode $
383 setModuleRn mod thing_inside
386 @renameDerivedCode@ is used to rename stuff ``out-of-line'';
387 that is, not as part of the main renamer.
388 Sole examples: derived definitions,
389 which are only generated in the type checker.
391 The @NameSupply@ includes a @UniqueSupply@, so if you call it more than
392 once you must either split it, or install a fresh unique supply.
395 renameDerivedCode :: DynFlags
397 -> PersistentRenamerState
401 renameDerivedCode dflags mod prs thing_inside
403 -- It's not really unsafe! When renaming source code we
404 -- only do any I/O if we need to read in a fixity declaration;
405 -- and that doesn't happen in pragmas etc
407 do { us <- mkSplitUniqSupply 'r'
408 ; names_var <- newIORef ((prsOrig prs) { nsUniqs = us })
409 ; errs_var <- newIORef (emptyBag,emptyBag)
411 ; let rn_down = RnDown { rn_dflags = dflags,
412 rn_loc = generatedSrcLoc, rn_ns = names_var,
415 rn_done = bogus "rn_done",
416 rn_hit = bogus "rn_hit",
417 rn_ifaces = bogus "rn_ifaces"
419 ; let s_down = SDown { rn_mode = InterfaceMode,
420 -- So that we can refer to PrelBase.True etc
421 rn_genv = emptyRdrEnv, rn_lenv = emptyRdrEnv,
422 rn_fixenv = emptyLocalFixityEnv }
424 ; result <- thing_inside rn_down s_down
425 ; messages <- readIORef errs_var
427 ; if bad messages then
428 do { hPutStr stderr "Urk! renameDerivedCode found errors or warnings"
429 ; printErrorsAndWarnings alwaysQualify messages
438 bad messages = errorsFound messages || warningsFound messages
440 bad messages = errorsFound messages
443 bogus s = panic ("rnameSourceCode: " ++ s) -- Used for unused record fields
445 {-# INLINE thenRn #-}
446 {-# INLINE thenRn_ #-}
447 {-# INLINE returnRn #-}
450 returnRn :: a -> RnM d a
451 thenRn :: RnM d a -> (a -> RnM d b) -> RnM d b
452 thenRn_ :: RnM d a -> RnM d b -> RnM d b
453 andRn :: (a -> a -> a) -> RnM d a -> RnM d a -> RnM d a
454 mapRn :: (a -> RnM d b) -> [a] -> RnM d [b]
455 mapRn_ :: (a -> RnM d b) -> [a] -> RnM d ()
456 mapMaybeRn :: (a -> RnM d (Maybe b)) -> [a] -> RnM d [b]
457 flatMapRn :: (a -> RnM d [b]) -> [a] -> RnM d [b]
458 sequenceRn :: [RnM d a] -> RnM d [a]
459 sequenceRn_ :: [RnM d a] -> RnM d ()
460 foldlRn :: (b -> a -> RnM d b) -> b -> [a] -> RnM d b
461 mapAndUnzipRn :: (a -> RnM d (b,c)) -> [a] -> RnM d ([b],[c])
462 fixRn :: (a -> RnM d a) -> RnM d a
464 returnRn v gdown ldown = return v
465 thenRn m k gdown ldown = m gdown ldown >>= \ r -> k r gdown ldown
466 thenRn_ m k gdown ldown = m gdown ldown >> k gdown ldown
467 fixRn m gdown ldown = fixIO (\r -> m r gdown ldown)
468 andRn combiner m1 m2 gdown ldown
469 = m1 gdown ldown >>= \ res1 ->
470 m2 gdown ldown >>= \ res2 ->
471 return (combiner res1 res2)
473 sequenceRn [] = returnRn []
474 sequenceRn (m:ms) = m `thenRn` \ r ->
475 sequenceRn ms `thenRn` \ rs ->
478 sequenceRn_ [] = returnRn ()
479 sequenceRn_ (m:ms) = m `thenRn_` sequenceRn_ ms
481 mapRn f [] = returnRn []
483 = f x `thenRn` \ r ->
484 mapRn f xs `thenRn` \ rs ->
487 mapRn_ f [] = returnRn ()
492 foldlRn k z [] = returnRn z
493 foldlRn k z (x:xs) = k z x `thenRn` \ z' ->
496 mapAndUnzipRn f [] = returnRn ([],[])
497 mapAndUnzipRn f (x:xs)
498 = f x `thenRn` \ (r1, r2) ->
499 mapAndUnzipRn f xs `thenRn` \ (rs1, rs2) ->
500 returnRn (r1:rs1, r2:rs2)
502 mapAndUnzip3Rn f [] = returnRn ([],[],[])
503 mapAndUnzip3Rn f (x:xs)
504 = f x `thenRn` \ (r1, r2, r3) ->
505 mapAndUnzip3Rn f xs `thenRn` \ (rs1, rs2, rs3) ->
506 returnRn (r1:rs1, r2:rs2, r3:rs3)
508 mapMaybeRn f [] = returnRn []
509 mapMaybeRn f (x:xs) = f x `thenRn` \ maybe_r ->
510 mapMaybeRn f xs `thenRn` \ rs ->
512 Nothing -> returnRn rs
513 Just r -> returnRn (r:rs)
515 flatMapRn f [] = returnRn []
516 flatMapRn f (x:xs) = f x `thenRn` \ r ->
517 flatMapRn f xs `thenRn` \ rs ->
523 %************************************************************************
525 \subsection{Boring plumbing for common part}
527 %************************************************************************
531 \subsubsection{ Errors and warnings}
532 %=====================
535 failWithRn :: a -> Message -> RnM d a
536 failWithRn res msg (RnDown {rn_errs = errs_var, rn_loc = loc}) l_down
537 = readIORef errs_var >>= \ (warns,errs) ->
538 writeIORef errs_var (warns, errs `snocBag` err) >>
541 err = addShortErrLocLine loc msg
543 warnWithRn :: a -> Message -> RnM d a
544 warnWithRn res msg (RnDown {rn_errs = errs_var, rn_loc = loc}) l_down
545 = readIORef errs_var >>= \ (warns,errs) ->
546 writeIORef errs_var (warns `snocBag` warn, errs) >>
549 warn = addShortWarnLocLine loc msg
551 addErrRn :: Message -> RnM d ()
552 addErrRn err = failWithRn () err
554 checkRn :: Bool -> Message -> RnM d () -- Check that a condition is true
555 checkRn False err = addErrRn err
556 checkRn True err = returnRn ()
558 warnCheckRn :: Bool -> Message -> RnM d () -- Check that a condition is true
559 warnCheckRn False err = addWarnRn err
560 warnCheckRn True err = returnRn ()
562 addWarnRn :: Message -> RnM d ()
563 addWarnRn warn = warnWithRn () warn
565 checkErrsRn :: RnM d Bool -- True <=> no errors so far
566 checkErrsRn (RnDown {rn_errs = errs_var}) l_down
567 = readIORef errs_var >>= \ (warns,errs) ->
568 return (isEmptyBag errs)
570 doptRn :: DynFlag -> RnM d Bool
571 doptRn dflag (RnDown { rn_dflags = dflags}) l_down
572 = return (dopt dflag dflags)
574 ifOptRn :: DynFlag -> RnM d a -> RnM d ()
575 ifOptRn dflag thing_inside down@(RnDown { rn_dflags = dflags}) l_down
576 | dopt dflag dflags = thing_inside down l_down >> return ()
577 | otherwise = return ()
579 getDOptsRn :: RnM d DynFlags
580 getDOptsRn (RnDown { rn_dflags = dflags}) l_down
586 \subsubsection{Source location}
587 %=====================
590 pushSrcLocRn :: SrcLoc -> RnM d a -> RnM d a
591 pushSrcLocRn loc' m down l_down
592 = m (down {rn_loc = loc'}) l_down
594 getSrcLocRn :: RnM d SrcLoc
595 getSrcLocRn down l_down
596 = return (rn_loc down)
600 \subsubsection{The finder and home symbol table}
601 %=====================
604 getHomeIfaceTableRn :: RnM d HomeIfaceTable
605 getHomeIfaceTableRn down l_down = return (rn_hit down)
607 getTypeEnvRn :: RnM d (Name -> Maybe TyThing)
608 getTypeEnvRn down l_down = return (rn_done down)
612 \subsubsection{Name supply}
613 %=====================
616 getNameSupplyRn :: RnM d NameSupply
617 getNameSupplyRn rn_down l_down
618 = readIORef (rn_ns rn_down)
620 setNameSupplyRn :: NameSupply -> RnM d ()
621 setNameSupplyRn names' (RnDown {rn_ns = names_var}) l_down
622 = writeIORef names_var names'
624 getUniqRn :: RnM d Unique
625 getUniqRn (RnDown {rn_ns = names_var}) l_down
626 = readIORef names_var >>= \ ns ->
628 (us1,us') = splitUniqSupply (nsUniqs ns)
630 writeIORef names_var (ns {nsUniqs = us'}) >>
631 return (uniqFromSupply us1)
635 \subsubsection{ Module}
636 %=====================
639 getModuleRn :: RnM d Module
640 getModuleRn (RnDown {rn_mod = mod}) l_down
643 setModuleRn :: Module -> RnM d a -> RnM d a
644 setModuleRn new_mod enclosed_thing rn_down l_down
645 = enclosed_thing (rn_down {rn_mod = new_mod}) l_down
649 %************************************************************************
651 \subsection{Plumbing for rename-source part}
653 %************************************************************************
656 \subsubsection{ RnEnv}
657 %=====================
660 getLocalNameEnv :: RnMS LocalRdrEnv
661 getLocalNameEnv rn_down (SDown {rn_lenv = local_env})
664 getGlobalNameEnv :: RnMS GlobalRdrEnv
665 getGlobalNameEnv rn_down (SDown {rn_genv = global_env})
668 setLocalNameEnv :: LocalRdrEnv -> RnMS a -> RnMS a
669 setLocalNameEnv local_env' m rn_down l_down
670 = m rn_down (l_down {rn_lenv = local_env'})
672 getFixityEnv :: RnMS LocalFixityEnv
673 getFixityEnv rn_down (SDown {rn_fixenv = fixity_env})
676 extendFixityEnv :: [(Name, RenamedFixitySig)] -> RnMS a -> RnMS a
677 extendFixityEnv fixes enclosed_scope
678 rn_down l_down@(SDown {rn_fixenv = fixity_env})
680 new_fixity_env = extendNameEnvList fixity_env fixes
682 enclosed_scope rn_down (l_down {rn_fixenv = new_fixity_env})
686 \subsubsection{ Mode}
687 %=====================
690 getModeRn :: RnMS RnMode
691 getModeRn rn_down (SDown {rn_mode = mode})
694 setModeRn :: RnMode -> RnMS a -> RnMS a
695 setModeRn new_mode thing_inside rn_down l_down
696 = thing_inside rn_down (l_down {rn_mode = new_mode})
700 %************************************************************************
702 \subsection{Plumbing for rename-globals part}
704 %************************************************************************
707 getIfacesRn :: RnM d Ifaces
708 getIfacesRn (RnDown {rn_ifaces = iface_var}) _
709 = readIORef iface_var
711 setIfacesRn :: Ifaces -> RnM d ()
712 setIfacesRn ifaces (RnDown {rn_ifaces = iface_var}) _
713 = writeIORef iface_var ifaces