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 ( RdrName, RdrNameEnv, addListToRdrEnv, emptyRdrEnv,
56 mkRdrUnqual, rdrEnvToList )
57 import Name ( Name, NamedThing, getName, nameOccName, nameModule, nameSrcLoc )
59 import OccName ( OccName )
60 import Module ( Module, ModuleName, ModuleEnv,
61 lookupModuleEnv, lookupModuleEnvByName, emptyModuleEnv
63 import InstEnv ( InstEnv, ClsInstEnv, DFunId )
64 import Rules ( RuleBase )
65 import CoreSyn ( CoreBind )
67 import Class ( Class, classSelIds )
68 import TyCon ( TyCon, isNewTyCon, tyConGenIds, tyConSelIds, tyConDataConsIfAvailable )
69 import DataCon ( dataConId, dataConWrapId )
71 import BasicTypes ( Version, initialVersion, Fixity, IPName )
73 import HsSyn ( DeprecTxt, tyClDeclName, ifaceRuleDeclName )
74 import RdrHsSyn ( RdrNameInstDecl, RdrNameRuleDecl, RdrNameTyClDecl )
75 import RnHsSyn ( RenamedTyClDecl, RenamedRuleDecl, RenamedInstDecl )
77 import CoreSyn ( IdCoreRule )
79 import FiniteMap ( FiniteMap )
81 import Maybes ( seqMaybe, orElse )
83 import SrcLoc ( SrcLoc, isGoodSrcLoc )
84 import Util ( thenCmp, sortLt )
85 import UniqSupply ( UniqSupply )
88 %************************************************************************
90 \subsection{Which mode we're in
92 %************************************************************************
95 data GhciMode = Batch | Interactive | OneShot
100 %************************************************************************
102 \subsection{Module locations}
104 %************************************************************************
109 ml_hs_file :: Maybe FilePath,
110 ml_hspp_file :: Maybe FilePath, -- path of preprocessed source
111 ml_hi_file :: FilePath,
112 ml_obj_file :: Maybe FilePath
116 instance Outputable ModuleLocation where
120 For a module in another package, the hs_file and obj_file
121 components of ModuleLocation are undefined.
123 The locations specified by a ModuleLocation may or may not
124 correspond to actual files yet: for example, even if the object
125 file doesn't exist, the ModuleLocation still contains the path to
126 where the object file will reside if/when it is created.
129 %************************************************************************
131 \subsection{Symbol tables and Module details}
133 %************************************************************************
135 A @ModIface@ plus a @ModDetails@ summarises everything we know
136 about a compiled module. The @ModIface@ is the stuff *before* linking,
137 and can be written out to an interface file. The @ModDetails@ is after
138 linking; it is the "linked" form of the mi_decls field.
143 mi_module :: !Module, -- Complete with package info
144 mi_version :: !VersionInfo, -- Module version number
145 mi_orphan :: WhetherHasOrphans, -- Whether this module has orphans
146 mi_boot :: !IsBootInterface, -- read from an hi-boot file?
148 mi_usages :: ![ImportVersion Name],
149 -- Usages; kept sorted so that it's easy to decide
150 -- whether to write a new iface file (changing usages
151 -- doesn't affect the version of this module)
153 mi_exports :: ![(ModuleName,Avails)],
154 -- What it exports Kept sorted by (mod,occ), to make
155 -- version comparisons easier
157 mi_globals :: !GlobalRdrEnv, -- Its top level environment
159 mi_fixities :: !(NameEnv Fixity), -- Fixities
160 mi_deprecs :: !Deprecations, -- Deprecations
162 mi_decls :: IfaceDecls -- The RnDecls form of ModDetails
165 data IfaceDecls = IfaceDecls { dcl_tycl :: [RenamedTyClDecl], -- Sorted
166 dcl_rules :: [RenamedRuleDecl], -- Sorted
167 dcl_insts :: [RenamedInstDecl] } -- Unsorted
169 mkIfaceDecls :: [RenamedTyClDecl] -> [RenamedRuleDecl] -> [RenamedInstDecl] -> IfaceDecls
170 mkIfaceDecls tycls rules insts
171 = IfaceDecls { dcl_tycl = sortLt lt_tycl tycls,
172 dcl_rules = sortLt lt_rule rules,
175 d1 `lt_tycl` d2 = tyClDeclName d1 < tyClDeclName d2
176 r1 `lt_rule` r2 = ifaceRuleDeclName r1 < ifaceRuleDeclName r2
179 -- typechecker should only look at this, not ModIface
180 -- Should be able to construct ModDetails from mi_decls in ModIface
183 -- The next three fields are created by the typechecker
184 md_types :: !TypeEnv,
185 md_insts :: ![DFunId], -- Dfun-ids for the instances in this module
186 md_rules :: ![IdCoreRule], -- Domain may include Ids from other modules
187 md_binds :: ![CoreBind]
190 -- The ModDetails takes on several slightly different forms:
192 -- After typecheck + desugar
193 -- md_types Contains TyCons, Classes, and implicit Ids
194 -- md_insts All instances from this module (incl derived ones)
195 -- md_rules All rules from this module
196 -- md_binds Desugared bindings
198 -- After simplification
199 -- md_types Same as after typecheck
201 -- md_rules Orphan rules only (local ones now attached to binds)
202 -- md_binds With rules attached
205 -- md_types Now contains Ids as well, replete with final IdInfo
206 -- The Ids are only the ones that are visible from
207 -- importing modules. Without -O that means only
208 -- exported Ids, but with -O importing modules may
209 -- see ids mentioned in unfoldings of exported Ids
211 -- md_insts Same DFunIds as before, but with final IdInfo,
212 -- and the unique might have changed; remember that
213 -- CoreTidy links up the uniques of old and new versions
215 -- md_rules All rules for exported things, substituted with final Ids
219 -- Passed back to compilation manager
220 -- Just as after CoreTidy, but with md_binds nuked
225 emptyModIface :: Module -> ModIface
227 = ModIface { mi_module = mod,
228 mi_version = initialVersionInfo,
233 mi_fixities = emptyNameEnv,
234 mi_globals = emptyRdrEnv,
235 mi_deprecs = NoDeprecs,
236 mi_decls = panic "emptyModIface: decls"
240 Symbol tables map modules to ModDetails:
243 type SymbolTable = ModuleEnv ModDetails
244 type IfaceTable = ModuleEnv ModIface
246 type HomeIfaceTable = IfaceTable
247 type PackageIfaceTable = IfaceTable
249 type HomeSymbolTable = SymbolTable -- Domain = modules in the home package
251 emptySymbolTable :: SymbolTable
252 emptySymbolTable = emptyModuleEnv
254 emptyIfaceTable :: IfaceTable
255 emptyIfaceTable = emptyModuleEnv
258 Simple lookups in the symbol table.
261 lookupIface :: HomeIfaceTable -> PackageIfaceTable -> Name -> Maybe ModIface
262 -- We often have two IfaceTables, and want to do a lookup
263 lookupIface hit pit name
264 = lookupModuleEnv hit mod `seqMaybe` lookupModuleEnv pit mod
266 mod = nameModule name
268 lookupIfaceByModName :: HomeIfaceTable -> PackageIfaceTable -> ModuleName -> Maybe ModIface
269 -- We often have two IfaceTables, and want to do a lookup
270 lookupIfaceByModName hit pit mod
271 = lookupModuleEnvByName hit mod `seqMaybe` lookupModuleEnvByName pit mod
275 %************************************************************************
277 \subsection{The interactive context}
279 %************************************************************************
282 data InteractiveContext
283 = InteractiveContext {
284 ic_module :: Module, -- The current module in which
285 -- the user is sitting
287 ic_rn_env :: LocalRdrEnv, -- Lexical context for variables bound
288 -- during interaction
290 ic_type_env :: TypeEnv -- Ditto for types
295 %************************************************************************
297 \subsection{Type environment stuff}
299 %************************************************************************
302 data TyThing = AnId Id
306 isTyClThing :: TyThing -> Bool
307 isTyClThing (ATyCon _) = True
308 isTyClThing (AClass _) = True
309 isTyClThing (AnId _) = False
311 instance NamedThing TyThing where
312 getName (AnId id) = getName id
313 getName (ATyCon tc) = getName tc
314 getName (AClass cl) = getName cl
316 instance Outputable TyThing where
317 ppr (AnId id) = ptext SLIT("AnId") <+> ppr id
318 ppr (ATyCon tc) = ptext SLIT("ATyCon") <+> ppr tc
319 ppr (AClass cl) = ptext SLIT("AClass") <+> ppr cl
322 typeEnvElts :: TypeEnv -> [TyThing]
323 typeEnvClasses :: TypeEnv -> [Class]
324 typeEnvTyCons :: TypeEnv -> [TyCon]
325 typeEnvIds :: TypeEnv -> [Id]
327 typeEnvElts env = nameEnvElts env
328 typeEnvClasses env = [cl | AClass cl <- typeEnvElts env]
329 typeEnvTyCons env = [tc | ATyCon tc <- typeEnvElts env]
330 typeEnvIds env = [id | AnId id <- typeEnvElts env]
332 implicitTyThingIds :: [TyThing] -> [Id]
333 -- Add the implicit data cons and selectors etc
334 implicitTyThingIds things
335 = concat (map go things)
338 go (AClass cl) = classSelIds cl
339 go (ATyCon tc) = tyConGenIds tc ++
341 [ n | dc <- tyConDataConsIfAvailable tc,
342 n <- implicitConIds tc dc]
343 -- Synonyms return empty list of constructors and selectors
345 implicitConIds tc dc -- Newtypes have a constructor wrapper,
347 | isNewTyCon tc = [dataConWrapId dc]
348 | otherwise = [dataConId dc, dataConWrapId dc]
353 type TypeEnv = NameEnv TyThing
355 emptyTypeEnv = emptyNameEnv
357 mkTypeEnv :: [TyThing] -> TypeEnv
358 mkTypeEnv things = extendTypeEnvList emptyTypeEnv things
360 extendTypeEnvList :: TypeEnv -> [TyThing] -> TypeEnv
361 extendTypeEnvList env things
362 = extendNameEnvList env [(getName thing, thing) | thing <- things]
364 extendTypeEnvWithIds :: TypeEnv -> [Id] -> TypeEnv
365 extendTypeEnvWithIds env ids
366 = extendNameEnvList env [(getName id, AnId id) | id <- ids]
370 lookupType :: HomeSymbolTable -> PackageTypeEnv -> Name -> Maybe TyThing
371 lookupType hst pte name
372 = case lookupModuleEnv hst (nameModule name) of
373 Just details -> lookupNameEnv (md_types details) name
374 Nothing -> lookupNameEnv pte name
377 %************************************************************************
379 \subsection{Auxiliary types}
381 %************************************************************************
383 These types are defined here because they are mentioned in ModDetails,
384 but they are mostly elaborated elsewhere
389 vers_module :: Version, -- Changes when anything changes
390 vers_exports :: Version, -- Changes when export list changes
391 vers_rules :: Version, -- Changes when any rule changes
392 vers_decls :: NameEnv Version
393 -- Versions for "big" names only (not data constructors, class ops)
394 -- The version of an Id changes if its fixity changes
395 -- Ditto data constructors, class operations, except that the version of
396 -- the parent class/tycon changes
398 -- If a name isn't in the map, it means 'initialVersion'
401 initialVersionInfo :: VersionInfo
402 initialVersionInfo = VersionInfo { vers_module = initialVersion,
403 vers_exports = initialVersion,
404 vers_rules = initialVersion,
405 vers_decls = emptyNameEnv
408 lookupVersion :: NameEnv Version -> Name -> Version
409 lookupVersion env name = lookupNameEnv env name `orElse` initialVersion
411 data Deprecations = NoDeprecs
412 | DeprecAll DeprecTxt -- Whole module deprecated
413 | DeprecSome (NameEnv (Name,DeprecTxt)) -- Some things deprecated
415 -- We keep the Name in the range, so we can print them out
417 lookupDeprec :: Deprecations -> Name -> Maybe DeprecTxt
418 lookupDeprec NoDeprecs name = Nothing
419 lookupDeprec (DeprecAll txt) name = Just txt
420 lookupDeprec (DeprecSome env) name = case lookupNameEnv env name of
421 Just (_, txt) -> Just txt
424 instance Eq Deprecations where
425 -- Used when checking whether we need write a new interface
426 NoDeprecs == NoDeprecs = True
427 (DeprecAll t1) == (DeprecAll t2) = t1 == t2
428 (DeprecSome e1) == (DeprecSome e2) = nameEnvElts e1 == nameEnvElts e2
434 type Avails = [AvailInfo]
435 type AvailInfo = GenAvailInfo Name
436 type RdrAvailInfo = GenAvailInfo OccName
438 data GenAvailInfo name = Avail name -- An ordinary identifier
439 | AvailTC name -- The name of the type or class
440 [name] -- The available pieces of type/class.
441 -- NB: If the type or class is itself
442 -- to be in scope, it must be in this list.
443 -- Thus, typically: AvailTC Eq [Eq, ==, /=]
445 -- Equality used when deciding if the interface has changed
447 type AvailEnv = NameEnv AvailInfo -- Maps a Name to the AvailInfo that contains it
449 instance Outputable n => Outputable (GenAvailInfo n) where
452 pprAvail :: Outputable n => GenAvailInfo n -> SDoc
453 pprAvail (AvailTC n ns) = ppr n <> case {- filter (/= n) -} ns of
455 ns' -> braces (hsep (punctuate comma (map ppr ns')))
457 pprAvail (Avail n) = ppr n
461 %************************************************************************
463 \subsection{ModIface}
465 %************************************************************************
468 type WhetherHasOrphans = Bool
470 -- * an instance decl in a module other than the defn module for
471 -- one of the tycons or classes in the instance head
472 -- * a transformation rule in a module other than the one defining
473 -- the function in the head of the rule.
475 type IsBootInterface = Bool
477 type ImportVersion name = (ModuleName, WhetherHasOrphans, IsBootInterface, WhatsImported name)
479 data WhatsImported name = NothingAtAll -- The module is below us in the
480 -- hierarchy, but we import nothing
482 | Everything Version -- Used for modules from other packages;
483 -- we record only the module's version number
486 Version -- Module version
487 (Maybe Version) -- Export-list version, if we depend on it
488 [(name,Version)] -- List guaranteed non-empty
489 Version -- Rules version
492 -- 'Specifically' doesn't let you say "I imported f but none of the rules in
493 -- the module". If you use anything in the module you get its rule version
494 -- So if the rules change, you'll recompile, even if you don't use them.
495 -- This is easy to implement, and it's safer: you might not have used the rules last
496 -- time round, but if someone has added a new rule you might need it this time
498 -- The export list field is (Just v) if we depend on the export list:
499 -- we imported the module without saying exactly what we imported
500 -- We need to recompile if the module exports changes, because we might
501 -- now have a name clash in the importing module.
503 type IsExported = Name -> Bool -- True for names that are exported from this module
507 %************************************************************************
509 \subsection{The persistent compiler state}
511 %************************************************************************
514 data PersistentCompilerState
516 pcs_PIT :: !PackageIfaceTable, -- Domain = non-home-package modules
517 -- the mi_decls component is empty
519 pcs_PTE :: !PackageTypeEnv, -- Domain = non-home-package modules
520 -- except that the InstEnv components is empty
522 pcs_insts :: !PackageInstEnv, -- The total InstEnv accumulated from all
523 -- the non-home-package modules
525 pcs_rules :: !PackageRuleBase, -- Ditto RuleEnv
527 pcs_PRS :: !PersistentRenamerState
531 The @PersistentRenamerState@ persists across successive calls to the
535 * A name supply, which deals with allocating unique names to
536 (Module,OccName) original names,
538 * An accumulated TypeEnv from all the modules in imported packages
540 * An accumulated InstEnv from all the modules in imported packages
541 The point is that we don't want to keep recreating it whenever
542 we compile a new module. The InstEnv component of pcPST is empty.
543 (This means we might "see" instances that we shouldn't "really" see;
544 but the Haskell Report is vague on what is meant to be visible,
545 so we just take the easy road here.)
549 * A "holding pen" for declarations that have been read out of
550 interface files but not yet sucked in, renamed, and typechecked
553 type PackageTypeEnv = TypeEnv
554 type PackageRuleBase = RuleBase
555 type PackageInstEnv = InstEnv
557 data PersistentRenamerState
558 = PRS { prsOrig :: !NameSupply,
559 prsImpMods :: !ImportedModuleInfo,
560 prsDecls :: !DeclsMap,
561 prsInsts :: !IfaceInsts,
562 prsRules :: !IfaceRules
566 The NameSupply makes sure that there is just one Unique assigned for
567 each original name; i.e. (module-name, occ-name) pair. The Name is
568 always stored as a Global, and has the SrcLoc of its binding location.
569 Actually that's not quite right. When we first encounter the original
570 name, we might not be at its binding site (e.g. we are reading an
571 interface file); so we give it 'noSrcLoc' then. Later, when we find
572 its binding site, we fix it up.
574 Exactly the same is true of the Module stored in the Name. When we first
575 encounter the occurrence, we may not know the details of the module, so
576 we just store junk. Then when we find the binding site, we fix it up.
580 = NameSupply { nsUniqs :: UniqSupply,
582 nsNames :: OrigNameCache,
583 -- Ensures that one original name gets one unique
584 nsIPs :: OrigIParamCache
585 -- Ensures that one implicit parameter name gets one unique
588 type OrigNameCache = FiniteMap (ModuleName,OccName) Name
589 type OrigIParamCache = FiniteMap (IPName RdrName) (IPName Name)
592 @ImportedModuleInfo@ contains info ONLY about modules that have not yet
593 been loaded into the iPIT. These modules are mentioned in interfaces we've
594 already read, so we know a tiny bit about them, but we havn't yet looked
595 at the interface file for the module itself. It needs to persist across
596 invocations of the renamer, at least from Rename.checkOldIface to Rename.renameSource.
597 And there's no harm in it persisting across multiple compilations.
600 type ImportedModuleInfo = FiniteMap ModuleName (WhetherHasOrphans, IsBootInterface)
603 A DeclsMap contains a binding for each Name in the declaration
604 including the constructors of a type decl etc. The Bool is True just
608 type DeclsMap = (NameEnv (AvailInfo, Bool, (Module, RdrNameTyClDecl)), Int)
609 -- The Int says how many have been sucked in
611 type IfaceInsts = GatedDecls RdrNameInstDecl
612 type IfaceRules = GatedDecls RdrNameRuleDecl
614 type GatedDecls d = (Bag (GatedDecl d), Int) -- The Int says how many have been sucked in
615 type GatedDecl d = (GateFn, (Module, d))
616 type GateFn = (Name -> Bool) -> Bool -- Returns True <=> gate is open
617 -- The (Name -> Bool) fn returns True for visible Names
618 -- For example, suppose this is in an interface file
619 -- instance C T where ...
620 -- We want to slurp this decl if both C and T are "visible" in
621 -- the importing module. See "The gating story" in RnIfaces for details.
625 %************************************************************************
627 \subsection{Provenance and export info}
629 %************************************************************************
631 A LocalRdrEnv is used for local bindings (let, where, lambda, case)
634 type LocalRdrEnv = RdrNameEnv Name
636 extendLocalRdrEnv :: LocalRdrEnv -> [Name] -> LocalRdrEnv
637 extendLocalRdrEnv env names
638 = addListToRdrEnv env [(mkRdrUnqual (nameOccName n), n) | n <- names]
641 The GlobalRdrEnv gives maps RdrNames to Names. There is a separate
642 one for each module, corresponding to that module's top-level scope.
645 type GlobalRdrEnv = RdrNameEnv [GlobalRdrElt]
646 -- The list is because there may be name clashes
647 -- These only get reported on lookup, not on construction
649 data GlobalRdrElt = GRE Name Provenance (Maybe DeprecTxt)
650 -- The Maybe DeprecTxt tells whether this name is deprecated
653 = vcat (map pp (rdrEnvToList env))
655 pp (rn, nps) = ppr rn <> colon <+>
656 vcat [ppr n <+> pprNameProvenance n p | (GRE n p _) <- nps]
659 The "provenance" of something says how it came to be in scope.
663 = LocalDef -- Defined locally
665 | NonLocalDef -- Defined non-locally
668 -- Just used for grouping error messages (in RnEnv.warnUnusedBinds)
669 instance Eq Provenance where
670 p1 == p2 = case p1 `compare` p2 of EQ -> True; _ -> False
672 instance Eq ImportReason where
673 p1 == p2 = case p1 `compare` p2 of EQ -> True; _ -> False
675 instance Ord Provenance where
676 compare LocalDef LocalDef = EQ
677 compare LocalDef (NonLocalDef _) = LT
678 compare (NonLocalDef _) LocalDef = GT
680 compare (NonLocalDef reason1) (NonLocalDef reason2)
681 = compare reason1 reason2
683 instance Ord ImportReason where
684 compare ImplicitImport ImplicitImport = EQ
685 compare ImplicitImport (UserImport _ _ _) = LT
686 compare (UserImport _ _ _) ImplicitImport = GT
687 compare (UserImport m1 loc1 _) (UserImport m2 loc2 _)
688 = (m1 `compare` m2) `thenCmp` (loc1 `compare` loc2)
692 = UserImport Module SrcLoc Bool -- Imported from module M on line L
693 -- Note the M may well not be the defining module
695 -- The Bool is true iff the thing was named *explicitly* in the import spec,
696 -- rather than being imported as part of a group; e.g.
699 -- Here, everything imported by B, and the constructors of T
700 -- are not named explicitly; only T is named explicitly.
701 -- This info is used when warning of unused names.
703 | ImplicitImport -- Imported implicitly for some other reason
707 hasBetterProv :: Provenance -> Provenance -> Bool
709 -- a local thing over an imported thing
710 -- a user-imported thing over a non-user-imported thing
711 -- an explicitly-imported thing over an implicitly imported thing
712 hasBetterProv LocalDef _ = True
713 hasBetterProv (NonLocalDef (UserImport _ _ _ )) (NonLocalDef ImplicitImport) = True
714 hasBetterProv _ _ = False
716 pprNameProvenance :: Name -> Provenance -> SDoc
717 pprNameProvenance name LocalDef = ptext SLIT("defined at") <+> ppr (nameSrcLoc name)
718 pprNameProvenance name (NonLocalDef why) = sep [ppr_reason why,
719 nest 2 (ppr_defn (nameSrcLoc name))]
721 ppr_reason ImplicitImport = ptext SLIT("implicitly imported")
722 ppr_reason (UserImport mod loc _) = ptext SLIT("imported from") <+> ppr mod <+> ptext SLIT("at") <+> ppr loc
724 ppr_defn loc | isGoodSrcLoc loc = parens (ptext SLIT("at") <+> ppr loc)