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
172 isCmdLineMode CmdLineMode = True
173 isCmdLineMode _ = False
176 %===================================================
177 \subsubsection{ ENVIRONMENTS}
178 %===================================================
181 --------------------------------
182 type LocalFixityEnv = NameEnv RenamedFixitySig
183 -- We keep the whole fixity sig so that we
184 -- can report line-number info when there is a duplicate
185 -- fixity declaration
187 emptyLocalFixityEnv :: LocalFixityEnv
188 emptyLocalFixityEnv = emptyNameEnv
190 lookupLocalFixity :: LocalFixityEnv -> Name -> Fixity
191 lookupLocalFixity env name
192 = case lookupNameEnv env name of
193 Just (FixitySig _ fix _) -> fix
194 Nothing -> defaultFixity
198 type ExportAvails = (FiniteMap ModuleName Avails,
199 -- Used to figure out "module M" export specifiers
200 -- Includes avails only from *unqualified* imports
201 -- (see 1.4 Report Section 5.1.1)
203 AvailEnv) -- Used to figure out all other export specifiers.
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 -> LocalRdrEnv -> LocalFixityEnv -> RnMode
374 initRnMS rn_env 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_lenv = local_env,
379 rn_fixenv = fixity_env, rn_mode = mode }
381 thing_inside rn_down s_down
383 initIfaceRnMS :: Module -> RnMS r -> RnM d r
384 initIfaceRnMS mod thing_inside
385 = initRnMS emptyRdrEnv emptyRdrEnv emptyLocalFixityEnv InterfaceMode $
386 setModuleRn mod thing_inside
389 @renameDerivedCode@ is used to rename stuff ``out-of-line'';
390 that is, not as part of the main renamer.
391 Sole examples: derived definitions,
392 which are only generated in the type checker.
394 The @NameSupply@ includes a @UniqueSupply@, so if you call it more than
395 once you must either split it, or install a fresh unique supply.
398 renameDerivedCode :: DynFlags
400 -> PersistentRenamerState
404 renameDerivedCode dflags mod prs thing_inside
406 -- It's not really unsafe! When renaming source code we
407 -- only do any I/O if we need to read in a fixity declaration;
408 -- and that doesn't happen in pragmas etc
410 do { us <- mkSplitUniqSupply 'r'
411 ; names_var <- newIORef ((prsOrig prs) { nsUniqs = us })
412 ; errs_var <- newIORef (emptyBag,emptyBag)
414 ; let rn_down = RnDown { rn_dflags = dflags,
415 rn_loc = generatedSrcLoc, rn_ns = names_var,
418 rn_done = bogus "rn_done",
419 rn_hit = bogus "rn_hit",
420 rn_ifaces = bogus "rn_ifaces"
422 ; let s_down = SDown { rn_mode = InterfaceMode,
423 -- So that we can refer to PrelBase.True etc
424 rn_genv = emptyRdrEnv, rn_lenv = emptyRdrEnv,
425 rn_fixenv = emptyLocalFixityEnv }
427 ; result <- thing_inside rn_down s_down
428 ; messages <- readIORef errs_var
430 ; if bad messages then
431 do { hPutStr stderr "Urk! renameDerivedCode found errors or warnings"
432 ; printErrorsAndWarnings alwaysQualify messages
441 bad messages = errorsFound messages || warningsFound messages
443 bad messages = errorsFound messages
446 bogus s = panic ("rnameSourceCode: " ++ s) -- Used for unused record fields
448 {-# INLINE thenRn #-}
449 {-# INLINE thenRn_ #-}
450 {-# INLINE returnRn #-}
453 returnRn :: a -> RnM d a
454 thenRn :: RnM d a -> (a -> RnM d b) -> RnM d b
455 thenRn_ :: RnM d a -> RnM d b -> RnM d b
456 andRn :: (a -> a -> a) -> RnM d a -> RnM d a -> RnM d a
457 mapRn :: (a -> RnM d b) -> [a] -> RnM d [b]
458 mapRn_ :: (a -> RnM d b) -> [a] -> RnM d ()
459 mapMaybeRn :: (a -> RnM d (Maybe b)) -> [a] -> RnM d [b]
460 flatMapRn :: (a -> RnM d [b]) -> [a] -> RnM d [b]
461 sequenceRn :: [RnM d a] -> RnM d [a]
462 sequenceRn_ :: [RnM d a] -> RnM d ()
463 foldlRn :: (b -> a -> RnM d b) -> b -> [a] -> RnM d b
464 mapAndUnzipRn :: (a -> RnM d (b,c)) -> [a] -> RnM d ([b],[c])
465 fixRn :: (a -> RnM d a) -> RnM d a
467 returnRn v gdown ldown = return v
468 thenRn m k gdown ldown = m gdown ldown >>= \ r -> k r gdown ldown
469 thenRn_ m k gdown ldown = m gdown ldown >> k gdown ldown
470 fixRn m gdown ldown = fixIO (\r -> m r gdown ldown)
471 andRn combiner m1 m2 gdown ldown
472 = m1 gdown ldown >>= \ res1 ->
473 m2 gdown ldown >>= \ res2 ->
474 return (combiner res1 res2)
476 sequenceRn [] = returnRn []
477 sequenceRn (m:ms) = m `thenRn` \ r ->
478 sequenceRn ms `thenRn` \ rs ->
481 sequenceRn_ [] = returnRn ()
482 sequenceRn_ (m:ms) = m `thenRn_` sequenceRn_ ms
484 mapRn f [] = returnRn []
486 = f x `thenRn` \ r ->
487 mapRn f xs `thenRn` \ rs ->
490 mapRn_ f [] = returnRn ()
495 foldlRn k z [] = returnRn z
496 foldlRn k z (x:xs) = k z x `thenRn` \ z' ->
499 mapAndUnzipRn f [] = returnRn ([],[])
500 mapAndUnzipRn f (x:xs)
501 = f x `thenRn` \ (r1, r2) ->
502 mapAndUnzipRn f xs `thenRn` \ (rs1, rs2) ->
503 returnRn (r1:rs1, r2:rs2)
505 mapAndUnzip3Rn f [] = returnRn ([],[],[])
506 mapAndUnzip3Rn f (x:xs)
507 = f x `thenRn` \ (r1, r2, r3) ->
508 mapAndUnzip3Rn f xs `thenRn` \ (rs1, rs2, rs3) ->
509 returnRn (r1:rs1, r2:rs2, r3:rs3)
511 mapMaybeRn f [] = returnRn []
512 mapMaybeRn f (x:xs) = f x `thenRn` \ maybe_r ->
513 mapMaybeRn f xs `thenRn` \ rs ->
515 Nothing -> returnRn rs
516 Just r -> returnRn (r:rs)
518 flatMapRn f [] = returnRn []
519 flatMapRn f (x:xs) = f x `thenRn` \ r ->
520 flatMapRn f xs `thenRn` \ rs ->
526 %************************************************************************
528 \subsection{Boring plumbing for common part}
530 %************************************************************************
534 \subsubsection{ Errors and warnings}
535 %=====================
538 failWithRn :: a -> Message -> RnM d a
539 failWithRn res msg (RnDown {rn_errs = errs_var, rn_loc = loc}) l_down
540 = readIORef errs_var >>= \ (warns,errs) ->
541 writeIORef errs_var (warns, errs `snocBag` err) >>
544 err = addShortErrLocLine loc msg
546 warnWithRn :: a -> Message -> RnM d a
547 warnWithRn res msg (RnDown {rn_errs = errs_var, rn_loc = loc}) l_down
548 = readIORef errs_var >>= \ (warns,errs) ->
549 writeIORef errs_var (warns `snocBag` warn, errs) >>
552 warn = addShortWarnLocLine loc msg
554 addErrRn :: Message -> RnM d ()
555 addErrRn err = failWithRn () err
557 checkRn :: Bool -> Message -> RnM d () -- Check that a condition is true
558 checkRn False err = addErrRn err
559 checkRn True err = returnRn ()
561 warnCheckRn :: Bool -> Message -> RnM d () -- Check that a condition is true
562 warnCheckRn False err = addWarnRn err
563 warnCheckRn True err = returnRn ()
565 addWarnRn :: Message -> RnM d ()
566 addWarnRn warn = warnWithRn () warn
568 checkErrsRn :: RnM d Bool -- True <=> no errors so far
569 checkErrsRn (RnDown {rn_errs = errs_var}) l_down
570 = readIORef errs_var >>= \ (warns,errs) ->
571 return (isEmptyBag errs)
573 doptRn :: DynFlag -> RnM d Bool
574 doptRn dflag (RnDown { rn_dflags = dflags}) l_down
575 = return (dopt dflag dflags)
577 ifOptRn :: DynFlag -> RnM d a -> RnM d ()
578 ifOptRn dflag thing_inside down@(RnDown { rn_dflags = dflags}) l_down
579 | dopt dflag dflags = thing_inside down l_down >> return ()
580 | otherwise = return ()
582 getDOptsRn :: RnM d DynFlags
583 getDOptsRn (RnDown { rn_dflags = dflags}) l_down
589 \subsubsection{Source location}
590 %=====================
593 pushSrcLocRn :: SrcLoc -> RnM d a -> RnM d a
594 pushSrcLocRn loc' m down l_down
595 = m (down {rn_loc = loc'}) l_down
597 getSrcLocRn :: RnM d SrcLoc
598 getSrcLocRn down l_down
599 = return (rn_loc down)
603 \subsubsection{The finder and home symbol table}
604 %=====================
607 getHomeIfaceTableRn :: RnM d HomeIfaceTable
608 getHomeIfaceTableRn down l_down = return (rn_hit down)
610 getTypeEnvRn :: RnM d (Name -> Maybe TyThing)
611 getTypeEnvRn down l_down = return (rn_done down)
615 \subsubsection{Name supply}
616 %=====================
619 getNameSupplyRn :: RnM d NameSupply
620 getNameSupplyRn rn_down l_down
621 = readIORef (rn_ns rn_down)
623 setNameSupplyRn :: NameSupply -> RnM d ()
624 setNameSupplyRn names' (RnDown {rn_ns = names_var}) l_down
625 = writeIORef names_var names'
627 getUniqRn :: RnM d Unique
628 getUniqRn (RnDown {rn_ns = names_var}) l_down
629 = readIORef names_var >>= \ ns ->
631 (us1,us') = splitUniqSupply (nsUniqs ns)
633 writeIORef names_var (ns {nsUniqs = us'}) >>
634 return (uniqFromSupply us1)
638 \subsubsection{ Module}
639 %=====================
642 getModuleRn :: RnM d Module
643 getModuleRn (RnDown {rn_mod = mod}) l_down
646 setModuleRn :: Module -> RnM d a -> RnM d a
647 setModuleRn new_mod enclosed_thing rn_down l_down
648 = enclosed_thing (rn_down {rn_mod = new_mod}) l_down
652 %************************************************************************
654 \subsection{Plumbing for rename-source part}
656 %************************************************************************
659 \subsubsection{ RnEnv}
660 %=====================
663 getLocalNameEnv :: RnMS LocalRdrEnv
664 getLocalNameEnv rn_down (SDown {rn_lenv = local_env})
667 getGlobalNameEnv :: RnMS GlobalRdrEnv
668 getGlobalNameEnv rn_down (SDown {rn_genv = global_env})
671 setLocalNameEnv :: LocalRdrEnv -> RnMS a -> RnMS a
672 setLocalNameEnv local_env' m rn_down l_down
673 = m rn_down (l_down {rn_lenv = local_env'})
675 getFixityEnv :: RnMS LocalFixityEnv
676 getFixityEnv rn_down (SDown {rn_fixenv = fixity_env})
679 extendFixityEnv :: [(Name, RenamedFixitySig)] -> RnMS a -> RnMS a
680 extendFixityEnv fixes enclosed_scope
681 rn_down l_down@(SDown {rn_fixenv = fixity_env})
683 new_fixity_env = extendNameEnvList fixity_env fixes
685 enclosed_scope rn_down (l_down {rn_fixenv = new_fixity_env})
689 \subsubsection{ Mode}
690 %=====================
693 getModeRn :: RnMS RnMode
694 getModeRn rn_down (SDown {rn_mode = mode})
697 setModeRn :: RnMode -> RnMS a -> RnMS a
698 setModeRn new_mode thing_inside rn_down l_down
699 = thing_inside rn_down (l_down {rn_mode = new_mode})
703 %************************************************************************
705 \subsection{Plumbing for rename-globals part}
707 %************************************************************************
710 getIfacesRn :: RnM d Ifaces
711 getIfacesRn (RnDown {rn_ifaces = iface_var}) _
712 = readIORef iface_var
714 setIfacesRn :: Ifaces -> RnM d ()
715 setIfacesRn ifaces (RnDown {rn_ifaces = iface_var}) _
716 = writeIORef iface_var ifaces