2 % (c) The University of Glasgow, 2000
4 \section[HscTypes]{Types for the per-module compiler}
12 ModDetails(..), ModIface(..),
13 HomeSymbolTable, emptySymbolTable,
15 HomeIfaceTable, PackageIfaceTable, emptyIfaceTable,
16 lookupIface, lookupIfaceByModName,
19 InteractiveContext(..),
21 IfaceDecls, mkIfaceDecls, dcl_tycl, dcl_rules, dcl_insts,
23 VersionInfo(..), initialVersionInfo, lookupVersion,
25 TyThing(..), isTyClThing, implicitTyThingIds,
27 TypeEnv, lookupType, mkTypeEnv, emptyTypeEnv,
28 extendTypeEnvList, extendTypeEnvWithIds,
29 typeEnvElts, typeEnvClasses, typeEnvTyCons, typeEnvIds,
31 ImportedModuleInfo, WhetherHasOrphans, ImportVersion, WhatsImported(..),
32 PersistentRenamerState(..), IsBootInterface, DeclsMap,
33 IfaceInsts, IfaceRules, GatedDecl, GatedDecls, GateFn, IsExported,
34 NameSupply(..), OrigNameCache, OrigIParamCache,
35 Avails, AvailEnv, GenAvailInfo(..), AvailInfo, RdrAvailInfo,
36 PersistentCompilerState(..),
38 Deprecations(..), lookupDeprec,
40 InstEnv, ClsInstEnv, DFunId,
41 PackageInstEnv, PackageRuleBase,
43 GlobalRdrEnv, GlobalRdrElt(..), pprGlobalRdrEnv,
44 LocalRdrEnv, extendLocalRdrEnv,
48 Provenance(..), ImportReason(..),
49 pprNameProvenance, hasBetterProv
53 #include "HsVersions.h"
55 import RdrName ( RdrNameEnv, addListToRdrEnv, emptyRdrEnv, mkRdrUnqual, rdrEnvToList )
56 import Name ( Name, NamedThing, getName, nameOccName, nameModule, nameSrcLoc )
58 import OccName ( OccName )
59 import Module ( Module, ModuleName, ModuleEnv,
60 lookupModuleEnv, lookupModuleEnvByName, emptyModuleEnv
62 import InstEnv ( InstEnv, ClsInstEnv, DFunId )
63 import Rules ( RuleBase )
64 import CoreSyn ( CoreBind )
66 import Class ( Class, classSelIds )
67 import TyCon ( TyCon, isNewTyCon, tyConGenIds, tyConSelIds, tyConDataConsIfAvailable )
68 import DataCon ( dataConId, dataConWrapId )
70 import BasicTypes ( Version, initialVersion, Fixity )
72 import HsSyn ( DeprecTxt, tyClDeclName, ifaceRuleDeclName )
73 import RdrHsSyn ( RdrNameInstDecl, RdrNameRuleDecl, RdrNameTyClDecl )
74 import RnHsSyn ( RenamedTyClDecl, RenamedRuleDecl, RenamedInstDecl )
76 import CoreSyn ( IdCoreRule )
78 import FiniteMap ( FiniteMap )
80 import Maybes ( seqMaybe, orElse )
82 import SrcLoc ( SrcLoc, isGoodSrcLoc )
83 import Util ( thenCmp, sortLt )
84 import UniqSupply ( UniqSupply )
87 %************************************************************************
89 \subsection{Which mode we're in
91 %************************************************************************
94 data GhciMode = Batch | Interactive | OneShot
99 %************************************************************************
101 \subsection{Module locations}
103 %************************************************************************
108 ml_hs_file :: Maybe FilePath,
109 ml_hspp_file :: Maybe FilePath, -- path of preprocessed source
110 ml_hi_file :: FilePath,
111 ml_obj_file :: Maybe FilePath
115 instance Outputable ModuleLocation where
119 For a module in another package, the hs_file and obj_file
120 components of ModuleLocation are undefined.
122 The locations specified by a ModuleLocation may or may not
123 correspond to actual files yet: for example, even if the object
124 file doesn't exist, the ModuleLocation still contains the path to
125 where the object file will reside if/when it is created.
128 %************************************************************************
130 \subsection{Symbol tables and Module details}
132 %************************************************************************
134 A @ModIface@ plus a @ModDetails@ summarises everything we know
135 about a compiled module. The @ModIface@ is the stuff *before* linking,
136 and can be written out to an interface file. The @ModDetails@ is after
137 linking; it is the "linked" form of the mi_decls field.
142 mi_module :: Module, -- Complete with package info
143 mi_version :: VersionInfo, -- Module version number
144 mi_orphan :: WhetherHasOrphans, -- Whether this module has orphans
145 mi_boot :: IsBootInterface, -- Whether this interface was read from an hi-boot file
147 mi_usages :: [ImportVersion Name], -- Usages; kept sorted so that it's easy
148 -- to decide whether to write a new iface file
149 -- (changing usages doesn't affect the version of
152 mi_exports :: [(ModuleName,Avails)], -- What it exports
153 -- Kept sorted by (mod,occ),
154 -- to make version comparisons easier
156 mi_globals :: GlobalRdrEnv, -- Its top level environment
158 mi_fixities :: NameEnv Fixity, -- Fixities
159 mi_deprecs :: Deprecations, -- Deprecations
161 mi_decls :: IfaceDecls -- The RnDecls form of ModDetails
164 data IfaceDecls = IfaceDecls { dcl_tycl :: [RenamedTyClDecl], -- Sorted
165 dcl_rules :: [RenamedRuleDecl], -- Sorted
166 dcl_insts :: [RenamedInstDecl] } -- Unsorted
168 mkIfaceDecls :: [RenamedTyClDecl] -> [RenamedRuleDecl] -> [RenamedInstDecl] -> IfaceDecls
169 mkIfaceDecls tycls rules insts
170 = IfaceDecls { dcl_tycl = sortLt lt_tycl tycls,
171 dcl_rules = sortLt lt_rule rules,
174 d1 `lt_tycl` d2 = tyClDeclName d1 < tyClDeclName d2
175 r1 `lt_rule` r2 = ifaceRuleDeclName r1 < ifaceRuleDeclName r2
178 -- typechecker should only look at this, not ModIface
179 -- Should be able to construct ModDetails from mi_decls in ModIface
182 -- The next three fields are created by the typechecker
184 md_insts :: [DFunId], -- Dfun-ids for the instances in this module
185 md_rules :: [IdCoreRule], -- Domain may include Ids from other modules
186 md_binds :: [CoreBind]
189 -- The ModDetails takes on several slightly different forms:
191 -- After typecheck + desugar
192 -- md_types Contains TyCons, Classes, and implicit Ids
193 -- md_insts All instances from this module (incl derived ones)
194 -- md_rules All rules from this module
195 -- md_binds Desugared bindings
197 -- After simplification
198 -- md_types Same as after typecheck
200 -- md_rules Orphan rules only (local ones now attached to binds)
201 -- md_binds With rules attached
204 -- md_types Now contains Ids as well, replete with final IdInfo
205 -- The Ids are only the ones that are visible from
206 -- importing modules. Without -O that means only
207 -- exported Ids, but with -O importing modules may
208 -- see ids mentioned in unfoldings of exported Ids
210 -- md_insts Same DFunIds as before, but with final IdInfo,
211 -- and the unique might have changed; remember that
212 -- CoreTidy links up the uniques of old and new versions
214 -- md_rules All rules for exported things, substituted with final Ids
218 -- Passed back to compilation manager
219 -- Just as after CoreTidy, but with md_binds nuked
224 emptyModIface :: Module -> ModIface
226 = ModIface { mi_module = mod,
227 mi_version = initialVersionInfo,
232 mi_fixities = emptyNameEnv,
233 mi_globals = emptyRdrEnv,
234 mi_deprecs = NoDeprecs,
235 mi_decls = panic "emptyModIface: decls"
239 Symbol tables map modules to ModDetails:
242 type SymbolTable = ModuleEnv ModDetails
243 type IfaceTable = ModuleEnv ModIface
245 type HomeIfaceTable = IfaceTable
246 type PackageIfaceTable = IfaceTable
248 type HomeSymbolTable = SymbolTable -- Domain = modules in the home package
250 emptySymbolTable :: SymbolTable
251 emptySymbolTable = emptyModuleEnv
253 emptyIfaceTable :: IfaceTable
254 emptyIfaceTable = emptyModuleEnv
257 Simple lookups in the symbol table.
260 lookupIface :: HomeIfaceTable -> PackageIfaceTable -> Name -> Maybe ModIface
261 -- We often have two IfaceTables, and want to do a lookup
262 lookupIface hit pit name
263 = lookupModuleEnv hit mod `seqMaybe` lookupModuleEnv pit mod
265 mod = nameModule name
267 lookupIfaceByModName :: HomeIfaceTable -> PackageIfaceTable -> ModuleName -> Maybe ModIface
268 -- We often have two IfaceTables, and want to do a lookup
269 lookupIfaceByModName hit pit mod
270 = lookupModuleEnvByName hit mod `seqMaybe` lookupModuleEnvByName pit mod
274 %************************************************************************
276 \subsection{The interactive context}
278 %************************************************************************
281 data InteractiveContext
282 = InteractiveContext {
283 ic_module :: Module, -- The current module in which
284 -- the user is sitting
286 ic_rn_env :: LocalRdrEnv, -- Lexical context for variables bound
287 -- during interaction
289 ic_type_env :: TypeEnv -- Ditto for types
294 %************************************************************************
296 \subsection{Type environment stuff}
298 %************************************************************************
301 data TyThing = AnId Id
305 isTyClThing :: TyThing -> Bool
306 isTyClThing (ATyCon _) = True
307 isTyClThing (AClass _) = True
308 isTyClThing (AnId _) = False
310 instance NamedThing TyThing where
311 getName (AnId id) = getName id
312 getName (ATyCon tc) = getName tc
313 getName (AClass cl) = getName cl
315 instance Outputable TyThing where
316 ppr (AnId id) = ptext SLIT("AnId") <+> ppr id
317 ppr (ATyCon tc) = ptext SLIT("ATyCon") <+> ppr tc
318 ppr (AClass cl) = ptext SLIT("AClass") <+> ppr cl
321 typeEnvElts :: TypeEnv -> [TyThing]
322 typeEnvClasses :: TypeEnv -> [Class]
323 typeEnvTyCons :: TypeEnv -> [TyCon]
324 typeEnvIds :: TypeEnv -> [Id]
326 typeEnvElts env = nameEnvElts env
327 typeEnvClasses env = [cl | AClass cl <- typeEnvElts env]
328 typeEnvTyCons env = [tc | ATyCon tc <- typeEnvElts env]
329 typeEnvIds env = [id | AnId id <- typeEnvElts env]
331 implicitTyThingIds :: [TyThing] -> [Id]
332 -- Add the implicit data cons and selectors etc
333 implicitTyThingIds things
334 = concat (map go things)
337 go (AClass cl) = classSelIds cl
338 go (ATyCon tc) = tyConGenIds tc ++
340 [ n | dc <- tyConDataConsIfAvailable tc,
341 n <- implicitConIds tc dc]
342 -- Synonyms return empty list of constructors and selectors
344 implicitConIds tc dc -- Newtypes have a constructor wrapper,
346 | isNewTyCon tc = [dataConWrapId dc]
347 | otherwise = [dataConId dc, dataConWrapId dc]
352 type TypeEnv = NameEnv TyThing
354 emptyTypeEnv = emptyNameEnv
356 mkTypeEnv :: [TyThing] -> TypeEnv
357 mkTypeEnv things = extendTypeEnvList emptyTypeEnv things
359 extendTypeEnvList :: TypeEnv -> [TyThing] -> TypeEnv
360 extendTypeEnvList env things
361 = extendNameEnvList env [(getName thing, thing) | thing <- things]
363 extendTypeEnvWithIds :: TypeEnv -> [Id] -> TypeEnv
364 extendTypeEnvWithIds env ids
365 = extendNameEnvList env [(getName id, AnId id) | id <- ids]
369 lookupType :: HomeSymbolTable -> PackageTypeEnv -> Name -> Maybe TyThing
370 lookupType hst pte name
371 = case lookupModuleEnv hst (nameModule name) of
372 Just details -> lookupNameEnv (md_types details) name
373 Nothing -> lookupNameEnv pte name
376 %************************************************************************
378 \subsection{Auxiliary types}
380 %************************************************************************
382 These types are defined here because they are mentioned in ModDetails,
383 but they are mostly elaborated elsewhere
388 vers_module :: Version, -- Changes when anything changes
389 vers_exports :: Version, -- Changes when export list changes
390 vers_rules :: Version, -- Changes when any rule changes
391 vers_decls :: NameEnv Version
392 -- Versions for "big" names only (not data constructors, class ops)
393 -- The version of an Id changes if its fixity changes
394 -- Ditto data constructors, class operations, except that the version of
395 -- the parent class/tycon changes
397 -- If a name isn't in the map, it means 'initialVersion'
400 initialVersionInfo :: VersionInfo
401 initialVersionInfo = VersionInfo { vers_module = initialVersion,
402 vers_exports = initialVersion,
403 vers_rules = initialVersion,
404 vers_decls = emptyNameEnv
407 lookupVersion :: NameEnv Version -> Name -> Version
408 lookupVersion env name = lookupNameEnv env name `orElse` initialVersion
410 data Deprecations = NoDeprecs
411 | DeprecAll DeprecTxt -- Whole module deprecated
412 | DeprecSome (NameEnv (Name,DeprecTxt)) -- Some things deprecated
414 -- We keep the Name in the range, so we can print them out
416 lookupDeprec :: Deprecations -> Name -> Maybe DeprecTxt
417 lookupDeprec NoDeprecs name = Nothing
418 lookupDeprec (DeprecAll txt) name = Just txt
419 lookupDeprec (DeprecSome env) name = case lookupNameEnv env name of
420 Just (_, txt) -> Just txt
423 instance Eq Deprecations where
424 -- Used when checking whether we need write a new interface
425 NoDeprecs == NoDeprecs = True
426 (DeprecAll t1) == (DeprecAll t2) = t1 == t2
427 (DeprecSome e1) == (DeprecSome e2) = nameEnvElts e1 == nameEnvElts e2
433 type Avails = [AvailInfo]
434 type AvailInfo = GenAvailInfo Name
435 type RdrAvailInfo = GenAvailInfo OccName
437 data GenAvailInfo name = Avail name -- An ordinary identifier
438 | AvailTC name -- The name of the type or class
439 [name] -- The available pieces of type/class.
440 -- NB: If the type or class is itself
441 -- to be in scope, it must be in this list.
442 -- Thus, typically: AvailTC Eq [Eq, ==, /=]
444 -- Equality used when deciding if the interface has changed
446 type AvailEnv = NameEnv AvailInfo -- Maps a Name to the AvailInfo that contains it
448 instance Outputable n => Outputable (GenAvailInfo n) where
451 pprAvail :: Outputable n => GenAvailInfo n -> SDoc
452 pprAvail (AvailTC n ns) = ppr n <> case {- filter (/= n) -} ns of
454 ns' -> braces (hsep (punctuate comma (map ppr ns')))
456 pprAvail (Avail n) = ppr n
460 %************************************************************************
462 \subsection{ModIface}
464 %************************************************************************
467 type WhetherHasOrphans = Bool
469 -- * an instance decl in a module other than the defn module for
470 -- one of the tycons or classes in the instance head
471 -- * a transformation rule in a module other than the one defining
472 -- the function in the head of the rule.
474 type IsBootInterface = Bool
476 type ImportVersion name = (ModuleName, WhetherHasOrphans, IsBootInterface, WhatsImported name)
478 data WhatsImported name = NothingAtAll -- The module is below us in the
479 -- hierarchy, but we import nothing
481 | Everything Version -- Used for modules from other packages;
482 -- we record only the module's version number
485 Version -- Module version
486 (Maybe Version) -- Export-list version, if we depend on it
487 [(name,Version)] -- List guaranteed non-empty
488 Version -- Rules version
491 -- 'Specifically' doesn't let you say "I imported f but none of the rules in
492 -- the module". If you use anything in the module you get its rule version
493 -- So if the rules change, you'll recompile, even if you don't use them.
494 -- This is easy to implement, and it's safer: you might not have used the rules last
495 -- time round, but if someone has added a new rule you might need it this time
497 -- The export list field is (Just v) if we depend on the export list:
498 -- we imported the module without saying exactly what we imported
499 -- We need to recompile if the module exports changes, because we might
500 -- now have a name clash in the importing module.
502 type IsExported = Name -> Bool -- True for names that are exported from this module
506 %************************************************************************
508 \subsection{The persistent compiler state}
510 %************************************************************************
513 data PersistentCompilerState
515 pcs_PIT :: PackageIfaceTable, -- Domain = non-home-package modules
516 -- the mi_decls component is empty
518 pcs_PTE :: PackageTypeEnv, -- Domain = non-home-package modules
519 -- except that the InstEnv components is empty
521 pcs_insts :: PackageInstEnv, -- The total InstEnv accumulated from all
522 -- the non-home-package modules
524 pcs_rules :: PackageRuleBase, -- Ditto RuleEnv
526 pcs_PRS :: PersistentRenamerState
530 The @PersistentRenamerState@ persists across successive calls to the
534 * A name supply, which deals with allocating unique names to
535 (Module,OccName) original names,
537 * An accumulated TypeEnv from all the modules in imported packages
539 * An accumulated InstEnv from all the modules in imported packages
540 The point is that we don't want to keep recreating it whenever
541 we compile a new module. The InstEnv component of pcPST is empty.
542 (This means we might "see" instances that we shouldn't "really" see;
543 but the Haskell Report is vague on what is meant to be visible,
544 so we just take the easy road here.)
548 * A "holding pen" for declarations that have been read out of
549 interface files but not yet sucked in, renamed, and typechecked
552 type PackageTypeEnv = TypeEnv
553 type PackageRuleBase = RuleBase
554 type PackageInstEnv = InstEnv
556 data PersistentRenamerState
557 = PRS { prsOrig :: NameSupply,
558 prsImpMods :: ImportedModuleInfo,
559 prsDecls :: DeclsMap,
560 prsInsts :: IfaceInsts,
561 prsRules :: IfaceRules
565 The NameSupply makes sure that there is just one Unique assigned for
566 each original name; i.e. (module-name, occ-name) pair. The Name is
567 always stored as a Global, and has the SrcLoc of its binding location.
568 Actually that's not quite right. When we first encounter the original
569 name, we might not be at its binding site (e.g. we are reading an
570 interface file); so we give it 'noSrcLoc' then. Later, when we find
571 its binding site, we fix it up.
573 Exactly the same is true of the Module stored in the Name. When we first
574 encounter the occurrence, we may not know the details of the module, so
575 we just store junk. Then when we find the binding site, we fix it up.
579 = NameSupply { nsUniqs :: UniqSupply,
581 nsNames :: OrigNameCache,
582 -- Ensures that one original name gets one unique
583 nsIPs :: OrigIParamCache
584 -- Ensures that one implicit parameter name gets one unique
587 type OrigNameCache = FiniteMap (ModuleName,OccName) Name
588 type OrigIParamCache = FiniteMap OccName Name
591 @ImportedModuleInfo@ contains info ONLY about modules that have not yet
592 been loaded into the iPIT. These modules are mentioned in interfaces we've
593 already read, so we know a tiny bit about them, but we havn't yet looked
594 at the interface file for the module itself. It needs to persist across
595 invocations of the renamer, at least from Rename.checkOldIface to Rename.renameSource.
596 And there's no harm in it persisting across multiple compilations.
599 type ImportedModuleInfo = FiniteMap ModuleName (WhetherHasOrphans, IsBootInterface)
602 A DeclsMap contains a binding for each Name in the declaration
603 including the constructors of a type decl etc. The Bool is True just
607 type DeclsMap = (NameEnv (AvailInfo, Bool, (Module, RdrNameTyClDecl)), Int)
608 -- The Int says how many have been sucked in
610 type IfaceInsts = GatedDecls RdrNameInstDecl
611 type IfaceRules = GatedDecls RdrNameRuleDecl
613 type GatedDecls d = (Bag (GatedDecl d), Int) -- The Int says how many have been sucked in
614 type GatedDecl d = (GateFn, (Module, d))
615 type GateFn = (Name -> Bool) -> Bool -- Returns True <=> gate is open
616 -- The (Name -> Bool) fn returns True for visible Names
617 -- For example, suppose this is in an interface file
618 -- instance C T where ...
619 -- We want to slurp this decl if both C and T are "visible" in
620 -- the importing module. See "The gating story" in RnIfaces for details.
624 %************************************************************************
626 \subsection{Provenance and export info}
628 %************************************************************************
630 A LocalRdrEnv is used for local bindings (let, where, lambda, case)
633 type LocalRdrEnv = RdrNameEnv Name
635 extendLocalRdrEnv :: LocalRdrEnv -> [Name] -> LocalRdrEnv
636 extendLocalRdrEnv env names
637 = addListToRdrEnv env [(mkRdrUnqual (nameOccName n), n) | n <- names]
640 The GlobalRdrEnv gives maps RdrNames to Names. There is a separate
641 one for each module, corresponding to that module's top-level scope.
644 type GlobalRdrEnv = RdrNameEnv [GlobalRdrElt]
645 -- The list is because there may be name clashes
646 -- These only get reported on lookup, not on construction
648 data GlobalRdrElt = GRE Name Provenance (Maybe DeprecTxt)
649 -- The Maybe DeprecTxt tells whether this name is deprecated
652 = vcat (map pp (rdrEnvToList env))
654 pp (rn, nps) = ppr rn <> colon <+>
655 vcat [ppr n <+> pprNameProvenance n p | (GRE n p _) <- nps]
658 The "provenance" of something says how it came to be in scope.
662 = LocalDef -- Defined locally
664 | NonLocalDef -- Defined non-locally
667 -- Just used for grouping error messages (in RnEnv.warnUnusedBinds)
668 instance Eq Provenance where
669 p1 == p2 = case p1 `compare` p2 of EQ -> True; _ -> False
671 instance Eq ImportReason where
672 p1 == p2 = case p1 `compare` p2 of EQ -> True; _ -> False
674 instance Ord Provenance where
675 compare LocalDef LocalDef = EQ
676 compare LocalDef (NonLocalDef _) = LT
677 compare (NonLocalDef _) LocalDef = GT
679 compare (NonLocalDef reason1) (NonLocalDef reason2)
680 = compare reason1 reason2
682 instance Ord ImportReason where
683 compare ImplicitImport ImplicitImport = EQ
684 compare ImplicitImport (UserImport _ _ _) = LT
685 compare (UserImport _ _ _) ImplicitImport = GT
686 compare (UserImport m1 loc1 _) (UserImport m2 loc2 _)
687 = (m1 `compare` m2) `thenCmp` (loc1 `compare` loc2)
691 = UserImport Module SrcLoc Bool -- Imported from module M on line L
692 -- Note the M may well not be the defining module
694 -- The Bool is true iff the thing was named *explicitly* in the import spec,
695 -- rather than being imported as part of a group; e.g.
698 -- Here, everything imported by B, and the constructors of T
699 -- are not named explicitly; only T is named explicitly.
700 -- This info is used when warning of unused names.
702 | ImplicitImport -- Imported implicitly for some other reason
706 hasBetterProv :: Provenance -> Provenance -> Bool
708 -- a local thing over an imported thing
709 -- a user-imported thing over a non-user-imported thing
710 -- an explicitly-imported thing over an implicitly imported thing
711 hasBetterProv LocalDef _ = True
712 hasBetterProv (NonLocalDef (UserImport _ _ _ )) (NonLocalDef ImplicitImport) = True
713 hasBetterProv _ _ = False
715 pprNameProvenance :: Name -> Provenance -> SDoc
716 pprNameProvenance name LocalDef = ptext SLIT("defined at") <+> ppr (nameSrcLoc name)
717 pprNameProvenance name (NonLocalDef why) = sep [ppr_reason why,
718 nest 2 (ppr_defn (nameSrcLoc name))]
720 ppr_reason ImplicitImport = ptext SLIT("implicitly imported")
721 ppr_reason (UserImport mod loc _) = ptext SLIT("imported from") <+> ppr mod <+> ptext SLIT("at") <+> ppr loc
723 ppr_defn loc | isGoodSrcLoc loc = parens (ptext SLIT("at") <+> ppr loc)