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 ()
97 = doptRn Opt_D_dump_rn_trace `thenRn` \b ->
98 if b then putDocRn msg else returnRn ()
100 traceHiDiffsRn :: SDoc -> RnM d ()
102 = doptRn Opt_D_dump_hi_diffs `thenRn` \b ->
103 if b then putDocRn msg else returnRn ()
105 putDocRn :: SDoc -> RnM d ()
106 putDocRn msg = ioToRnM (printErrs alwaysQualify msg) `thenRn_`
111 %************************************************************************
113 \subsection{Data types}
115 %************************************************************************
117 %===================================================
118 \subsubsection{ MONAD TYPES}
119 %===================================================
122 type RnM d r = RnDown -> d -> IO r
123 type RnMS r = RnM SDown r -- Renaming source
124 type RnMG r = RnM () r -- Getting global names etc
129 rn_mod :: Module, -- This module
130 rn_loc :: SrcLoc, -- Current locn
132 rn_dflags :: DynFlags,
134 rn_hit :: HomeIfaceTable,
135 rn_done :: Name -> Maybe TyThing, -- Tells what things (both in the
136 -- home package and other packages)
137 -- were already available (i.e. in
138 -- the relevant SymbolTable) before
139 -- compiling this module
140 -- The Name passed to rn_done is guaranteed to be a Global,
141 -- so it has a Module, so it can be looked up
143 rn_errs :: IORef Messages,
144 rn_ns :: IORef NameSupply,
145 rn_ifaces :: IORef Ifaces
148 -- For renaming source code
152 rn_genv :: GlobalRdrEnv, -- Top level environment
154 rn_lenv :: LocalRdrEnv, -- Local name envt
155 -- Does *not* include global name envt; may shadow it
156 -- Includes both ordinary variables and type variables;
157 -- they are kept distinct because tyvar have a different
158 -- occurrence contructor (Name.TvOcc)
159 -- We still need the unsullied global name env so that
160 -- we can look up record field names
162 rn_fixenv :: LocalFixityEnv -- Local fixities (for non-top-level
164 -- The global fixities are held in the
165 -- HIT or PIT. Why? See the comments
166 -- with RnIfaces.lookupLocalFixity
169 data RnMode = SourceMode -- Renaming source code
170 | InterfaceMode -- Renaming interface declarations.
171 | CmdLineMode -- Renaming a command-line expression
173 isInterfaceMode InterfaceMode = True
174 isInterfaceMode _ = False
177 %===================================================
178 \subsubsection{ ENVIRONMENTS}
179 %===================================================
182 --------------------------------
183 type LocalFixityEnv = NameEnv RenamedFixitySig
184 -- We keep the whole fixity sig so that we
185 -- can report line-number info when there is a duplicate
186 -- fixity declaration
188 emptyLocalFixityEnv :: LocalFixityEnv
189 emptyLocalFixityEnv = emptyNameEnv
191 lookupLocalFixity :: LocalFixityEnv -> Name -> Fixity
192 lookupLocalFixity env name
193 = case lookupNameEnv env name of
194 Just (FixitySig _ fix _) -> fix
195 Nothing -> defaultFixity
199 type ExportAvails = (FiniteMap ModuleName Avails,
200 -- Used to figure out "module M" export specifiers
201 -- Includes avails only from *unqualified* imports
202 -- (see 1.4 Report Section 5.1.1)
204 AvailEnv) -- Used to figure out all other export specifiers.
207 %===================================================
208 \subsubsection{ INTERFACE FILE STUFF}
209 %===================================================
212 type ExportItem = (ModuleName, [RdrAvailInfo])
213 type IfaceDeprecs = Maybe (Either DeprecTxt [(RdrName,DeprecTxt)])
214 -- Nothing => NoDeprecs
215 -- Just (Left t) => DeprecAll
216 -- Just (Right p) => DeprecSome
220 pi_mod :: Module, -- Complete with package info
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 -> LocalRdrEnv -> LocalFixityEnv -> RnMode
375 initRnMS rn_env 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_lenv = local_env,
380 rn_fixenv = fixity_env, rn_mode = mode }
382 thing_inside rn_down s_down
384 initIfaceRnMS :: Module -> RnMS r -> RnM d r
385 initIfaceRnMS mod thing_inside
386 = initRnMS emptyRdrEnv emptyRdrEnv emptyLocalFixityEnv InterfaceMode $
387 setModuleRn mod thing_inside
390 @renameDerivedCode@ is used to rename stuff ``out-of-line'';
391 that is, not as part of the main renamer.
392 Sole examples: derived definitions,
393 which are only generated in the type checker.
395 The @NameSupply@ includes a @UniqueSupply@, so if you call it more than
396 once you must either split it, or install a fresh unique supply.
399 renameDerivedCode :: DynFlags
401 -> PersistentRenamerState
405 renameDerivedCode dflags mod prs thing_inside
407 -- It's not really unsafe! When renaming source code we
408 -- only do any I/O if we need to read in a fixity declaration;
409 -- and that doesn't happen in pragmas etc
411 do { us <- mkSplitUniqSupply 'r'
412 ; names_var <- newIORef ((prsOrig prs) { nsUniqs = us })
413 ; errs_var <- newIORef (emptyBag,emptyBag)
415 ; let rn_down = RnDown { rn_dflags = dflags,
416 rn_loc = generatedSrcLoc, rn_ns = names_var,
419 rn_done = bogus "rn_done",
420 rn_hit = bogus "rn_hit",
421 rn_ifaces = bogus "rn_ifaces"
423 ; let s_down = SDown { rn_mode = InterfaceMode,
424 -- So that we can refer to PrelBase.True etc
425 rn_genv = emptyRdrEnv, rn_lenv = emptyRdrEnv,
426 rn_fixenv = emptyLocalFixityEnv }
428 ; result <- thing_inside rn_down s_down
429 ; messages <- readIORef errs_var
431 ; if bad messages then
432 do { hPutStr stderr "Urk! renameDerivedCode found errors or warnings"
433 ; printErrorsAndWarnings alwaysQualify messages
442 bad messages = errorsFound messages || warningsFound messages
444 bad messages = errorsFound messages
447 bogus s = panic ("rnameSourceCode: " ++ s) -- Used for unused record fields
449 {-# INLINE thenRn #-}
450 {-# INLINE thenRn_ #-}
451 {-# INLINE returnRn #-}
454 returnRn :: a -> RnM d a
455 thenRn :: RnM d a -> (a -> RnM d b) -> RnM d b
456 thenRn_ :: RnM d a -> RnM d b -> RnM d b
457 andRn :: (a -> a -> a) -> RnM d a -> RnM d a -> RnM d a
458 mapRn :: (a -> RnM d b) -> [a] -> RnM d [b]
459 mapRn_ :: (a -> RnM d b) -> [a] -> RnM d ()
460 mapMaybeRn :: (a -> RnM d (Maybe b)) -> [a] -> RnM d [b]
461 flatMapRn :: (a -> RnM d [b]) -> [a] -> RnM d [b]
462 sequenceRn :: [RnM d a] -> RnM d [a]
463 sequenceRn_ :: [RnM d a] -> RnM d ()
464 foldlRn :: (b -> a -> RnM d b) -> b -> [a] -> RnM d b
465 mapAndUnzipRn :: (a -> RnM d (b,c)) -> [a] -> RnM d ([b],[c])
466 fixRn :: (a -> RnM d a) -> RnM d a
468 returnRn v gdown ldown = return v
469 thenRn m k gdown ldown = m gdown ldown >>= \ r -> k r gdown ldown
470 thenRn_ m k gdown ldown = m gdown ldown >> k gdown ldown
471 fixRn m gdown ldown = fixIO (\r -> m r gdown ldown)
472 andRn combiner m1 m2 gdown ldown
473 = m1 gdown ldown >>= \ res1 ->
474 m2 gdown ldown >>= \ res2 ->
475 return (combiner res1 res2)
477 sequenceRn [] = returnRn []
478 sequenceRn (m:ms) = m `thenRn` \ r ->
479 sequenceRn ms `thenRn` \ rs ->
482 sequenceRn_ [] = returnRn ()
483 sequenceRn_ (m:ms) = m `thenRn_` sequenceRn_ ms
485 mapRn f [] = returnRn []
487 = f x `thenRn` \ r ->
488 mapRn f xs `thenRn` \ rs ->
491 mapRn_ f [] = returnRn ()
496 foldlRn k z [] = returnRn z
497 foldlRn k z (x:xs) = k z x `thenRn` \ z' ->
500 mapAndUnzipRn f [] = returnRn ([],[])
501 mapAndUnzipRn f (x:xs)
502 = f x `thenRn` \ (r1, r2) ->
503 mapAndUnzipRn f xs `thenRn` \ (rs1, rs2) ->
504 returnRn (r1:rs1, r2:rs2)
506 mapAndUnzip3Rn f [] = returnRn ([],[],[])
507 mapAndUnzip3Rn f (x:xs)
508 = f x `thenRn` \ (r1, r2, r3) ->
509 mapAndUnzip3Rn f xs `thenRn` \ (rs1, rs2, rs3) ->
510 returnRn (r1:rs1, r2:rs2, r3:rs3)
512 mapMaybeRn f [] = returnRn []
513 mapMaybeRn f (x:xs) = f x `thenRn` \ maybe_r ->
514 mapMaybeRn f xs `thenRn` \ rs ->
516 Nothing -> returnRn rs
517 Just r -> returnRn (r:rs)
519 flatMapRn f [] = returnRn []
520 flatMapRn f (x:xs) = f x `thenRn` \ r ->
521 flatMapRn f xs `thenRn` \ rs ->
527 %************************************************************************
529 \subsection{Boring plumbing for common part}
531 %************************************************************************
535 \subsubsection{ Errors and warnings}
536 %=====================
539 failWithRn :: a -> Message -> RnM d a
540 failWithRn res msg (RnDown {rn_errs = errs_var, rn_loc = loc}) l_down
541 = readIORef errs_var >>= \ (warns,errs) ->
542 writeIORef errs_var (warns, errs `snocBag` err) >>
545 err = addShortErrLocLine loc msg
547 warnWithRn :: a -> Message -> RnM d a
548 warnWithRn res msg (RnDown {rn_errs = errs_var, rn_loc = loc}) l_down
549 = readIORef errs_var >>= \ (warns,errs) ->
550 writeIORef errs_var (warns `snocBag` warn, errs) >>
553 warn = addShortWarnLocLine loc msg
555 addErrRn :: Message -> RnM d ()
556 addErrRn err = failWithRn () err
558 checkRn :: Bool -> Message -> RnM d () -- Check that a condition is true
559 checkRn False err = addErrRn err
560 checkRn True err = returnRn ()
562 warnCheckRn :: Bool -> Message -> RnM d () -- Check that a condition is true
563 warnCheckRn False err = addWarnRn err
564 warnCheckRn True err = returnRn ()
566 addWarnRn :: Message -> RnM d ()
567 addWarnRn warn = warnWithRn () warn
569 checkErrsRn :: RnM d Bool -- True <=> no errors so far
570 checkErrsRn (RnDown {rn_errs = errs_var}) l_down
571 = readIORef errs_var >>= \ (warns,errs) ->
572 return (isEmptyBag errs)
574 doptRn :: DynFlag -> RnM d Bool
575 doptRn dflag (RnDown { rn_dflags = dflags}) l_down
576 = return (dopt dflag dflags)
578 getDOptsRn :: RnM d DynFlags
579 getDOptsRn (RnDown { rn_dflags = dflags}) l_down
585 \subsubsection{Source location}
586 %=====================
589 pushSrcLocRn :: SrcLoc -> RnM d a -> RnM d a
590 pushSrcLocRn loc' m down l_down
591 = m (down {rn_loc = loc'}) l_down
593 getSrcLocRn :: RnM d SrcLoc
594 getSrcLocRn down l_down
595 = return (rn_loc down)
599 \subsubsection{The finder and home symbol table}
600 %=====================
603 getHomeIfaceTableRn :: RnM d HomeIfaceTable
604 getHomeIfaceTableRn down l_down = return (rn_hit down)
606 getTypeEnvRn :: RnM d (Name -> Maybe TyThing)
607 getTypeEnvRn down l_down = return (rn_done down)
611 \subsubsection{Name supply}
612 %=====================
615 getNameSupplyRn :: RnM d NameSupply
616 getNameSupplyRn rn_down l_down
617 = readIORef (rn_ns rn_down)
619 setNameSupplyRn :: NameSupply -> RnM d ()
620 setNameSupplyRn names' (RnDown {rn_ns = names_var}) l_down
621 = writeIORef names_var names'
623 getUniqRn :: RnM d Unique
624 getUniqRn (RnDown {rn_ns = names_var}) l_down
625 = readIORef names_var >>= \ ns ->
627 (us1,us') = splitUniqSupply (nsUniqs ns)
629 writeIORef names_var (ns {nsUniqs = us'}) >>
630 return (uniqFromSupply us1)
634 \subsubsection{ Module}
635 %=====================
638 getModuleRn :: RnM d Module
639 getModuleRn (RnDown {rn_mod = mod}) l_down
642 setModuleRn :: Module -> RnM d a -> RnM d a
643 setModuleRn new_mod enclosed_thing rn_down l_down
644 = enclosed_thing (rn_down {rn_mod = new_mod}) l_down
648 %************************************************************************
650 \subsection{Plumbing for rename-source part}
652 %************************************************************************
655 \subsubsection{ RnEnv}
656 %=====================
659 getLocalNameEnv :: RnMS LocalRdrEnv
660 getLocalNameEnv rn_down (SDown {rn_lenv = local_env})
663 getGlobalNameEnv :: RnMS GlobalRdrEnv
664 getGlobalNameEnv rn_down (SDown {rn_genv = global_env})
667 setLocalNameEnv :: LocalRdrEnv -> RnMS a -> RnMS a
668 setLocalNameEnv local_env' m rn_down l_down
669 = m rn_down (l_down {rn_lenv = local_env'})
671 getFixityEnv :: RnMS LocalFixityEnv
672 getFixityEnv rn_down (SDown {rn_fixenv = fixity_env})
675 extendFixityEnv :: [(Name, RenamedFixitySig)] -> RnMS a -> RnMS a
676 extendFixityEnv fixes enclosed_scope
677 rn_down l_down@(SDown {rn_fixenv = fixity_env})
679 new_fixity_env = extendNameEnvList fixity_env fixes
681 enclosed_scope rn_down (l_down {rn_fixenv = new_fixity_env})
685 \subsubsection{ Mode}
686 %=====================
689 getModeRn :: RnMS RnMode
690 getModeRn rn_down (SDown {rn_mode = mode})
693 setModeRn :: RnMode -> RnMS a -> RnMS a
694 setModeRn new_mode thing_inside rn_down l_down
695 = thing_inside rn_down (l_down {rn_mode = new_mode})
699 %************************************************************************
701 \subsection{Plumbing for rename-globals part}
703 %************************************************************************
706 getIfacesRn :: RnM d Ifaces
707 getIfacesRn (RnDown {rn_ifaces = iface_var}) _
708 = readIORef iface_var
710 setIfacesRn :: Ifaces -> RnM d ()
711 setIfacesRn ifaces (RnDown {rn_ifaces = iface_var}) _
712 = writeIORef iface_var ifaces