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, emptyAvailEnv,
36 GenAvailInfo(..), AvailInfo, RdrAvailInfo,
37 PersistentCompilerState(..),
39 Deprecations(..), lookupDeprec,
41 InstEnv, ClsInstEnv, DFunId,
42 PackageInstEnv, PackageRuleBase,
44 GlobalRdrEnv, GlobalRdrElt(..), pprGlobalRdrEnv,
45 LocalRdrEnv, extendLocalRdrEnv,
49 Provenance(..), ImportReason(..),
50 pprNameProvenance, hasBetterProv
54 #include "HsVersions.h"
56 import RdrName ( RdrName, RdrNameEnv, addListToRdrEnv, emptyRdrEnv,
57 mkRdrUnqual, rdrEnvToList )
58 import Name ( Name, NamedThing, getName, nameOccName, nameModule, nameSrcLoc )
60 import OccName ( OccName )
61 import Module ( Module, ModuleName, ModuleEnv,
62 lookupModuleEnv, lookupModuleEnvByName, emptyModuleEnv
64 import InstEnv ( InstEnv, ClsInstEnv, DFunId )
65 import Rules ( RuleBase )
66 import CoreSyn ( CoreBind )
68 import Class ( Class, classSelIds )
69 import TyCon ( TyCon, isNewTyCon, tyConGenIds, tyConSelIds, tyConDataConsIfAvailable )
70 import DataCon ( dataConId, dataConWrapId )
72 import BasicTypes ( Version, initialVersion, Fixity, IPName )
74 import HsSyn ( DeprecTxt, tyClDeclName, ifaceRuleDeclName )
75 import RdrHsSyn ( RdrNameInstDecl, RdrNameRuleDecl, RdrNameTyClDecl )
76 import RnHsSyn ( RenamedTyClDecl, RenamedRuleDecl, RenamedInstDecl )
78 import CoreSyn ( IdCoreRule )
80 import FiniteMap ( FiniteMap )
82 import Maybes ( seqMaybe, orElse )
84 import SrcLoc ( SrcLoc, isGoodSrcLoc )
85 import Util ( thenCmp, sortLt )
86 import UniqSupply ( UniqSupply )
89 %************************************************************************
91 \subsection{Which mode we're in
93 %************************************************************************
96 data GhciMode = Batch | Interactive | OneShot
101 %************************************************************************
103 \subsection{Module locations}
105 %************************************************************************
110 ml_hs_file :: Maybe FilePath,
111 ml_hspp_file :: Maybe FilePath, -- path of preprocessed source
112 ml_hi_file :: FilePath,
113 ml_obj_file :: Maybe FilePath
117 instance Outputable ModuleLocation where
121 For a module in another package, the hs_file and obj_file
122 components of ModuleLocation are undefined.
124 The locations specified by a ModuleLocation may or may not
125 correspond to actual files yet: for example, even if the object
126 file doesn't exist, the ModuleLocation still contains the path to
127 where the object file will reside if/when it is created.
130 %************************************************************************
132 \subsection{Symbol tables and Module details}
134 %************************************************************************
136 A @ModIface@ plus a @ModDetails@ summarises everything we know
137 about a compiled module. The @ModIface@ is the stuff *before* linking,
138 and can be written out to an interface file. The @ModDetails@ is after
139 linking; it is the "linked" form of the mi_decls field.
144 mi_module :: !Module, -- Complete with package info
145 mi_version :: !VersionInfo, -- Module version number
146 mi_orphan :: WhetherHasOrphans, -- Whether this module has orphans
147 mi_boot :: !IsBootInterface, -- read from an hi-boot file?
149 mi_usages :: ![ImportVersion Name],
150 -- Usages; kept sorted so that it's easy to decide
151 -- whether to write a new iface file (changing usages
152 -- doesn't affect the version of this module)
154 mi_exports :: ![(ModuleName,Avails)],
155 -- What it exports Kept sorted by (mod,occ), to make
156 -- version comparisons easier
158 mi_globals :: !GlobalRdrEnv, -- Its top level environment
160 mi_fixities :: !(NameEnv Fixity), -- Fixities
161 mi_deprecs :: !Deprecations, -- Deprecations
163 mi_decls :: IfaceDecls -- The RnDecls form of ModDetails
166 data IfaceDecls = IfaceDecls { dcl_tycl :: [RenamedTyClDecl], -- Sorted
167 dcl_rules :: [RenamedRuleDecl], -- Sorted
168 dcl_insts :: [RenamedInstDecl] } -- Unsorted
170 mkIfaceDecls :: [RenamedTyClDecl] -> [RenamedRuleDecl] -> [RenamedInstDecl] -> IfaceDecls
171 mkIfaceDecls tycls rules insts
172 = IfaceDecls { dcl_tycl = sortLt lt_tycl tycls,
173 dcl_rules = sortLt lt_rule rules,
176 d1 `lt_tycl` d2 = tyClDeclName d1 < tyClDeclName d2
177 r1 `lt_rule` r2 = ifaceRuleDeclName r1 < ifaceRuleDeclName r2
180 -- typechecker should only look at this, not ModIface
181 -- Should be able to construct ModDetails from mi_decls in ModIface
184 -- The next three fields are created by the typechecker
185 md_types :: !TypeEnv,
186 md_insts :: ![DFunId], -- Dfun-ids for the instances in this module
187 md_rules :: ![IdCoreRule], -- Domain may include Ids from other modules
188 md_binds :: ![CoreBind]
191 -- The ModDetails takes on several slightly different forms:
193 -- After typecheck + desugar
194 -- md_types Contains TyCons, Classes, and implicit Ids
195 -- md_insts All instances from this module (incl derived ones)
196 -- md_rules All rules from this module
197 -- md_binds Desugared bindings
199 -- After simplification
200 -- md_types Same as after typecheck
202 -- md_rules Orphan rules only (local ones now attached to binds)
203 -- md_binds With rules attached
206 -- md_types Now contains Ids as well, replete with final IdInfo
207 -- The Ids are only the ones that are visible from
208 -- importing modules. Without -O that means only
209 -- exported Ids, but with -O importing modules may
210 -- see ids mentioned in unfoldings of exported Ids
212 -- md_insts Same DFunIds as before, but with final IdInfo,
213 -- and the unique might have changed; remember that
214 -- CoreTidy links up the uniques of old and new versions
216 -- md_rules All rules for exported things, substituted with final Ids
220 -- Passed back to compilation manager
221 -- Just as after CoreTidy, but with md_binds nuked
226 emptyModIface :: Module -> ModIface
228 = ModIface { mi_module = mod,
229 mi_version = initialVersionInfo,
234 mi_fixities = emptyNameEnv,
235 mi_globals = emptyRdrEnv,
236 mi_deprecs = NoDeprecs,
237 mi_decls = panic "emptyModIface: decls"
241 Symbol tables map modules to ModDetails:
244 type SymbolTable = ModuleEnv ModDetails
245 type IfaceTable = ModuleEnv ModIface
247 type HomeIfaceTable = IfaceTable
248 type PackageIfaceTable = IfaceTable
250 type HomeSymbolTable = SymbolTable -- Domain = modules in the home package
252 emptySymbolTable :: SymbolTable
253 emptySymbolTable = emptyModuleEnv
255 emptyIfaceTable :: IfaceTable
256 emptyIfaceTable = emptyModuleEnv
259 Simple lookups in the symbol table.
262 lookupIface :: HomeIfaceTable -> PackageIfaceTable -> Name -> Maybe ModIface
263 -- We often have two IfaceTables, and want to do a lookup
264 lookupIface hit pit name
265 = lookupModuleEnv hit mod `seqMaybe` lookupModuleEnv pit mod
267 mod = nameModule name
269 lookupIfaceByModName :: HomeIfaceTable -> PackageIfaceTable -> ModuleName -> Maybe ModIface
270 -- We often have two IfaceTables, and want to do a lookup
271 lookupIfaceByModName hit pit mod
272 = lookupModuleEnvByName hit mod `seqMaybe` lookupModuleEnvByName pit mod
276 %************************************************************************
278 \subsection{The interactive context}
280 %************************************************************************
283 data InteractiveContext
284 = InteractiveContext {
285 ic_module :: Module, -- The current module in which
286 -- the user is sitting
288 ic_rn_env :: LocalRdrEnv, -- Lexical context for variables bound
289 -- during interaction
291 ic_type_env :: TypeEnv -- Ditto for types
296 %************************************************************************
298 \subsection{Type environment stuff}
300 %************************************************************************
303 data TyThing = AnId Id
307 isTyClThing :: TyThing -> Bool
308 isTyClThing (ATyCon _) = True
309 isTyClThing (AClass _) = True
310 isTyClThing (AnId _) = False
312 instance NamedThing TyThing where
313 getName (AnId id) = getName id
314 getName (ATyCon tc) = getName tc
315 getName (AClass cl) = getName cl
317 instance Outputable TyThing where
318 ppr (AnId id) = ptext SLIT("AnId") <+> ppr id
319 ppr (ATyCon tc) = ptext SLIT("ATyCon") <+> ppr tc
320 ppr (AClass cl) = ptext SLIT("AClass") <+> ppr cl
323 typeEnvElts :: TypeEnv -> [TyThing]
324 typeEnvClasses :: TypeEnv -> [Class]
325 typeEnvTyCons :: TypeEnv -> [TyCon]
326 typeEnvIds :: TypeEnv -> [Id]
328 typeEnvElts env = nameEnvElts env
329 typeEnvClasses env = [cl | AClass cl <- typeEnvElts env]
330 typeEnvTyCons env = [tc | ATyCon tc <- typeEnvElts env]
331 typeEnvIds env = [id | AnId id <- typeEnvElts env]
333 implicitTyThingIds :: [TyThing] -> [Id]
334 -- Add the implicit data cons and selectors etc
335 implicitTyThingIds things
336 = concat (map go things)
339 go (AClass cl) = classSelIds cl
340 go (ATyCon tc) = tyConGenIds tc ++
342 [ n | dc <- tyConDataConsIfAvailable tc,
343 n <- implicitConIds tc dc]
344 -- Synonyms return empty list of constructors and selectors
346 implicitConIds tc dc -- Newtypes have a constructor wrapper,
348 | isNewTyCon tc = [dataConWrapId dc]
349 | otherwise = [dataConId dc, dataConWrapId dc]
354 type TypeEnv = NameEnv TyThing
356 emptyTypeEnv = emptyNameEnv
358 mkTypeEnv :: [TyThing] -> TypeEnv
359 mkTypeEnv things = extendTypeEnvList emptyTypeEnv things
361 extendTypeEnvList :: TypeEnv -> [TyThing] -> TypeEnv
362 extendTypeEnvList env things
363 = extendNameEnvList env [(getName thing, thing) | thing <- things]
365 extendTypeEnvWithIds :: TypeEnv -> [Id] -> TypeEnv
366 extendTypeEnvWithIds env ids
367 = extendNameEnvList env [(getName id, AnId id) | id <- ids]
371 lookupType :: HomeSymbolTable -> PackageTypeEnv -> Name -> Maybe TyThing
372 lookupType hst pte name
373 = case lookupModuleEnv hst (nameModule name) of
374 Just details -> lookupNameEnv (md_types details) name
375 Nothing -> lookupNameEnv pte name
378 %************************************************************************
380 \subsection{Auxiliary types}
382 %************************************************************************
384 These types are defined here because they are mentioned in ModDetails,
385 but they are mostly elaborated elsewhere
390 vers_module :: Version, -- Changes when anything changes
391 vers_exports :: Version, -- Changes when export list changes
392 vers_rules :: Version, -- Changes when any rule changes
393 vers_decls :: NameEnv Version
394 -- Versions for "big" names only (not data constructors, class ops)
395 -- The version of an Id changes if its fixity changes
396 -- Ditto data constructors, class operations, except that the version of
397 -- the parent class/tycon changes
399 -- If a name isn't in the map, it means 'initialVersion'
402 initialVersionInfo :: VersionInfo
403 initialVersionInfo = VersionInfo { vers_module = initialVersion,
404 vers_exports = initialVersion,
405 vers_rules = initialVersion,
406 vers_decls = emptyNameEnv
409 lookupVersion :: NameEnv Version -> Name -> Version
410 lookupVersion env name = lookupNameEnv env name `orElse` initialVersion
412 data Deprecations = NoDeprecs
413 | DeprecAll DeprecTxt -- Whole module deprecated
414 | DeprecSome (NameEnv (Name,DeprecTxt)) -- Some things deprecated
416 -- We keep the Name in the range, so we can print them out
418 lookupDeprec :: Deprecations -> Name -> Maybe DeprecTxt
419 lookupDeprec NoDeprecs name = Nothing
420 lookupDeprec (DeprecAll txt) name = Just txt
421 lookupDeprec (DeprecSome env) name = case lookupNameEnv env name of
422 Just (_, txt) -> Just txt
425 instance Eq Deprecations where
426 -- Used when checking whether we need write a new interface
427 NoDeprecs == NoDeprecs = True
428 (DeprecAll t1) == (DeprecAll t2) = t1 == t2
429 (DeprecSome e1) == (DeprecSome e2) = nameEnvElts e1 == nameEnvElts e2
435 type Avails = [AvailInfo]
436 type AvailInfo = GenAvailInfo Name
437 type RdrAvailInfo = GenAvailInfo OccName
439 data GenAvailInfo name = Avail name -- An ordinary identifier
440 | AvailTC name -- The name of the type or class
441 [name] -- The available pieces of type/class.
442 -- NB: If the type or class is itself
443 -- to be in scope, it must be in this list.
444 -- Thus, typically: AvailTC Eq [Eq, ==, /=]
446 -- Equality used when deciding if the interface has changed
448 type AvailEnv = NameEnv AvailInfo -- Maps a Name to the AvailInfo that contains it
450 emptyAvailEnv :: AvailEnv
451 emptyAvailEnv = emptyNameEnv
453 instance Outputable n => Outputable (GenAvailInfo n) where
456 pprAvail :: Outputable n => GenAvailInfo n -> SDoc
457 pprAvail (AvailTC n ns) = ppr n <> case {- filter (/= n) -} ns of
459 ns' -> braces (hsep (punctuate comma (map ppr ns')))
461 pprAvail (Avail n) = ppr n
465 %************************************************************************
467 \subsection{ModIface}
469 %************************************************************************
472 type WhetherHasOrphans = Bool
474 -- * an instance decl in a module other than the defn module for
475 -- one of the tycons or classes in the instance head
476 -- * a transformation rule in a module other than the one defining
477 -- the function in the head of the rule.
479 type IsBootInterface = Bool
481 type ImportVersion name = (ModuleName, WhetherHasOrphans, IsBootInterface, WhatsImported name)
483 data WhatsImported name = NothingAtAll -- The module is below us in the
484 -- hierarchy, but we import nothing
486 | Everything Version -- Used for modules from other packages;
487 -- we record only the module's version number
490 Version -- Module version
491 (Maybe Version) -- Export-list version, if we depend on it
492 [(name,Version)] -- List guaranteed non-empty
493 Version -- Rules version
496 -- 'Specifically' doesn't let you say "I imported f but none of the rules in
497 -- the module". If you use anything in the module you get its rule version
498 -- So if the rules change, you'll recompile, even if you don't use them.
499 -- This is easy to implement, and it's safer: you might not have used the rules last
500 -- time round, but if someone has added a new rule you might need it this time
502 -- The export list field is (Just v) if we depend on the export list:
503 -- we imported the module without saying exactly what we imported
504 -- We need to recompile if the module exports changes, because we might
505 -- now have a name clash in the importing module.
507 type IsExported = Name -> Bool -- True for names that are exported from this module
511 %************************************************************************
513 \subsection{The persistent compiler state}
515 %************************************************************************
518 data PersistentCompilerState
520 pcs_PIT :: !PackageIfaceTable, -- Domain = non-home-package modules
521 -- the mi_decls component is empty
523 pcs_PTE :: !PackageTypeEnv, -- Domain = non-home-package modules
524 -- except that the InstEnv components is empty
526 pcs_insts :: !PackageInstEnv, -- The total InstEnv accumulated from all
527 -- the non-home-package modules
529 pcs_rules :: !PackageRuleBase, -- Ditto RuleEnv
531 pcs_PRS :: !PersistentRenamerState
535 The @PersistentRenamerState@ persists across successive calls to the
539 * A name supply, which deals with allocating unique names to
540 (Module,OccName) original names,
542 * An accumulated TypeEnv from all the modules in imported packages
544 * An accumulated InstEnv from all the modules in imported packages
545 The point is that we don't want to keep recreating it whenever
546 we compile a new module. The InstEnv component of pcPST is empty.
547 (This means we might "see" instances that we shouldn't "really" see;
548 but the Haskell Report is vague on what is meant to be visible,
549 so we just take the easy road here.)
553 * A "holding pen" for declarations that have been read out of
554 interface files but not yet sucked in, renamed, and typechecked
557 type PackageTypeEnv = TypeEnv
558 type PackageRuleBase = RuleBase
559 type PackageInstEnv = InstEnv
561 data PersistentRenamerState
562 = PRS { prsOrig :: !NameSupply,
563 prsImpMods :: !ImportedModuleInfo,
564 prsDecls :: !DeclsMap,
565 prsInsts :: !IfaceInsts,
566 prsRules :: !IfaceRules
570 The NameSupply makes sure that there is just one Unique assigned for
571 each original name; i.e. (module-name, occ-name) pair. The Name is
572 always stored as a Global, and has the SrcLoc of its binding location.
573 Actually that's not quite right. When we first encounter the original
574 name, we might not be at its binding site (e.g. we are reading an
575 interface file); so we give it 'noSrcLoc' then. Later, when we find
576 its binding site, we fix it up.
578 Exactly the same is true of the Module stored in the Name. When we first
579 encounter the occurrence, we may not know the details of the module, so
580 we just store junk. Then when we find the binding site, we fix it up.
584 = NameSupply { nsUniqs :: UniqSupply,
586 nsNames :: OrigNameCache,
587 -- Ensures that one original name gets one unique
588 nsIPs :: OrigIParamCache
589 -- Ensures that one implicit parameter name gets one unique
592 type OrigNameCache = FiniteMap (ModuleName,OccName) Name
593 type OrigIParamCache = FiniteMap (IPName RdrName) (IPName Name)
596 @ImportedModuleInfo@ contains info ONLY about modules that have not yet
597 been loaded into the iPIT. These modules are mentioned in interfaces we've
598 already read, so we know a tiny bit about them, but we havn't yet looked
599 at the interface file for the module itself. It needs to persist across
600 invocations of the renamer, at least from Rename.checkOldIface to Rename.renameSource.
601 And there's no harm in it persisting across multiple compilations.
604 type ImportedModuleInfo = FiniteMap ModuleName (WhetherHasOrphans, IsBootInterface)
607 A DeclsMap contains a binding for each Name in the declaration
608 including the constructors of a type decl etc. The Bool is True just
612 type DeclsMap = (NameEnv (AvailInfo, Bool, (Module, RdrNameTyClDecl)), Int)
613 -- The Int says how many have been sucked in
615 type IfaceInsts = GatedDecls RdrNameInstDecl
616 type IfaceRules = GatedDecls RdrNameRuleDecl
618 type GatedDecls d = (Bag (GatedDecl d), Int) -- The Int says how many have been sucked in
619 type GatedDecl d = (GateFn, (Module, d))
620 type GateFn = (Name -> Bool) -> Bool -- Returns True <=> gate is open
621 -- The (Name -> Bool) fn returns True for visible Names
622 -- For example, suppose this is in an interface file
623 -- instance C T where ...
624 -- We want to slurp this decl if both C and T are "visible" in
625 -- the importing module. See "The gating story" in RnIfaces for details.
629 %************************************************************************
631 \subsection{Provenance and export info}
633 %************************************************************************
635 A LocalRdrEnv is used for local bindings (let, where, lambda, case)
638 type LocalRdrEnv = RdrNameEnv Name
640 extendLocalRdrEnv :: LocalRdrEnv -> [Name] -> LocalRdrEnv
641 extendLocalRdrEnv env names
642 = addListToRdrEnv env [(mkRdrUnqual (nameOccName n), n) | n <- names]
645 The GlobalRdrEnv gives maps RdrNames to Names. There is a separate
646 one for each module, corresponding to that module's top-level scope.
649 type GlobalRdrEnv = RdrNameEnv [GlobalRdrElt]
650 -- The list is because there may be name clashes
651 -- These only get reported on lookup, not on construction
653 data GlobalRdrElt = GRE Name Provenance (Maybe DeprecTxt)
654 -- The Maybe DeprecTxt tells whether this name is deprecated
657 = vcat (map pp (rdrEnvToList env))
659 pp (rn, nps) = ppr rn <> colon <+>
660 vcat [ppr n <+> pprNameProvenance n p | (GRE n p _) <- nps]
663 The "provenance" of something says how it came to be in scope.
667 = LocalDef -- Defined locally
669 | NonLocalDef -- Defined non-locally
672 -- Just used for grouping error messages (in RnEnv.warnUnusedBinds)
673 instance Eq Provenance where
674 p1 == p2 = case p1 `compare` p2 of EQ -> True; _ -> False
676 instance Eq ImportReason where
677 p1 == p2 = case p1 `compare` p2 of EQ -> True; _ -> False
679 instance Ord Provenance where
680 compare LocalDef LocalDef = EQ
681 compare LocalDef (NonLocalDef _) = LT
682 compare (NonLocalDef _) LocalDef = GT
684 compare (NonLocalDef reason1) (NonLocalDef reason2)
685 = compare reason1 reason2
687 instance Ord ImportReason where
688 compare ImplicitImport ImplicitImport = EQ
689 compare ImplicitImport (UserImport _ _ _) = LT
690 compare (UserImport _ _ _) ImplicitImport = GT
691 compare (UserImport m1 loc1 _) (UserImport m2 loc2 _)
692 = (m1 `compare` m2) `thenCmp` (loc1 `compare` loc2)
696 = UserImport Module SrcLoc Bool -- Imported from module M on line L
697 -- Note the M may well not be the defining module
699 -- The Bool is true iff the thing was named *explicitly* in the import spec,
700 -- rather than being imported as part of a group; e.g.
703 -- Here, everything imported by B, and the constructors of T
704 -- are not named explicitly; only T is named explicitly.
705 -- This info is used when warning of unused names.
707 | ImplicitImport -- Imported implicitly for some other reason
711 hasBetterProv :: Provenance -> Provenance -> Bool
713 -- a local thing over an imported thing
714 -- a user-imported thing over a non-user-imported thing
715 -- an explicitly-imported thing over an implicitly imported thing
716 hasBetterProv LocalDef _ = True
717 hasBetterProv (NonLocalDef (UserImport _ _ _ )) (NonLocalDef ImplicitImport) = True
718 hasBetterProv _ _ = False
720 pprNameProvenance :: Name -> Provenance -> SDoc
721 pprNameProvenance name LocalDef = ptext SLIT("defined at") <+> ppr (nameSrcLoc name)
722 pprNameProvenance name (NonLocalDef why) = sep [ppr_reason why,
723 nest 2 (ppr_defn (nameSrcLoc name))]
725 ppr_reason ImplicitImport = ptext SLIT("implicitly imported")
726 ppr_reason (UserImport mod loc _) = ptext SLIT("imported from") <+> ppr mod <+> ptext SLIT("at") <+> ppr loc
728 ppr_defn loc | isGoodSrcLoc loc = parens (ptext SLIT("at") <+> ppr loc)