2 % (c) The University of Glasgow, 2000
4 \section[HscTypes]{Types for the per-module compiler}
10 ModDetails(..), ModIface(..),
11 HomeSymbolTable, emptySymbolTable,
13 HomeIfaceTable, PackageIfaceTable, emptyIfaceTable,
14 lookupIface, lookupIfaceByModName,
17 InteractiveContext(..),
19 IfaceDecls, mkIfaceDecls, dcl_tycl, dcl_rules, dcl_insts,
21 VersionInfo(..), initialVersionInfo,
23 TyThing(..), isTyClThing, implicitTyThingIds,
25 TypeEnv, lookupType, mkTypeEnv, emptyTypeEnv,
26 extendTypeEnvList, extendTypeEnvWithIds,
27 typeEnvClasses, typeEnvTyCons, typeEnvIds,
29 ImportedModuleInfo, WhetherHasOrphans, ImportVersion, WhatsImported(..),
30 PersistentRenamerState(..), IsBootInterface, DeclsMap,
31 IfaceInsts, IfaceRules, GatedDecl, IsExported,
32 NameSupply(..), OrigNameCache, OrigIParamCache,
33 Avails, AvailEnv, GenAvailInfo(..), AvailInfo, RdrAvailInfo,
34 PersistentCompilerState(..),
36 Deprecations(..), lookupDeprec,
38 InstEnv, ClsInstEnv, DFunId,
39 PackageInstEnv, PackageRuleBase,
41 GlobalRdrEnv, GlobalRdrElt(..), pprGlobalRdrEnv,
42 LocalRdrEnv, extendLocalRdrEnv,
46 Provenance(..), ImportReason(..),
47 pprNameProvenance, hasBetterProv
51 #include "HsVersions.h"
53 import RdrName ( RdrNameEnv, addListToRdrEnv, emptyRdrEnv, mkRdrUnqual, rdrEnvToList )
54 import Name ( Name, NamedThing, getName, nameOccName, nameModule, nameSrcLoc )
56 import OccName ( OccName )
57 import Module ( Module, ModuleName, ModuleEnv,
58 lookupModuleEnv, lookupModuleEnvByName, emptyModuleEnv
60 import InstEnv ( InstEnv, ClsInstEnv, DFunId )
61 import Rules ( RuleBase )
63 import Class ( Class, classSelIds )
64 import TyCon ( TyCon, tyConGenIds, tyConSelIds, tyConDataConsIfAvailable )
65 import DataCon ( dataConId, dataConWrapId )
67 import BasicTypes ( Version, initialVersion, Fixity )
69 import HsSyn ( DeprecTxt, tyClDeclName, ifaceRuleDeclName )
70 import RdrHsSyn ( RdrNameInstDecl, RdrNameRuleDecl, RdrNameTyClDecl )
71 import RnHsSyn ( RenamedTyClDecl, RenamedRuleDecl, RenamedInstDecl )
73 import CoreSyn ( IdCoreRule )
75 import FiniteMap ( FiniteMap )
77 import Maybes ( seqMaybe )
79 import SrcLoc ( SrcLoc, isGoodSrcLoc )
80 import Util ( thenCmp, sortLt )
81 import UniqSupply ( UniqSupply )
84 %************************************************************************
86 \subsection{Module locations}
88 %************************************************************************
93 ml_hs_file :: Maybe FilePath,
94 ml_hspp_file :: Maybe FilePath, -- path of preprocessed source
95 ml_hi_file :: Maybe FilePath,
96 ml_obj_file :: Maybe FilePath
100 instance Outputable ModuleLocation where
104 For a module in another package, the hs_file and obj_file
105 components of ModuleLocation are undefined.
107 The locations specified by a ModuleLocation may or may not
108 correspond to actual files yet: for example, even if the object
109 file doesn't exist, the ModuleLocation still contains the path to
110 where the object file will reside if/when it is created.
113 %************************************************************************
115 \subsection{Symbol tables and Module details}
117 %************************************************************************
119 A @ModIface@ plus a @ModDetails@ summarises everything we know
120 about a compiled module. The @ModIface@ is the stuff *before* linking,
121 and can be written out to an interface file. The @ModDetails@ is after
122 linking; it is the "linked" form of the mi_decls field.
127 mi_module :: Module, -- Complete with package info
128 mi_version :: VersionInfo, -- Module version number
129 mi_orphan :: WhetherHasOrphans, -- Whether this module has orphans
130 mi_boot :: IsBootInterface, -- Whether this interface was read from an hi-boot file
132 mi_usages :: [ImportVersion Name], -- Usages; kept sorted so that it's easy
133 -- to decide whether to write a new iface file
134 -- (changing usages doesn't affect the version of
137 mi_exports :: [(ModuleName,Avails)], -- What it exports
138 -- Kept sorted by (mod,occ),
139 -- to make version comparisons easier
141 mi_globals :: GlobalRdrEnv, -- Its top level environment
143 mi_fixities :: NameEnv Fixity, -- Fixities
144 mi_deprecs :: Deprecations, -- Deprecations
146 mi_decls :: IfaceDecls -- The RnDecls form of ModDetails
149 data IfaceDecls = IfaceDecls { dcl_tycl :: [RenamedTyClDecl], -- Sorted
150 dcl_rules :: [RenamedRuleDecl], -- Sorted
151 dcl_insts :: [RenamedInstDecl] } -- Unsorted
153 mkIfaceDecls :: [RenamedTyClDecl] -> [RenamedRuleDecl] -> [RenamedInstDecl] -> IfaceDecls
154 mkIfaceDecls tycls rules insts
155 = IfaceDecls { dcl_tycl = sortLt lt_tycl tycls,
156 dcl_rules = sortLt lt_rule rules,
159 d1 `lt_tycl` d2 = tyClDeclName d1 < tyClDeclName d2
160 r1 `lt_rule` r2 = ifaceRuleDeclName r1 < ifaceRuleDeclName r2
163 -- typechecker should only look at this, not ModIface
164 -- Should be able to construct ModDetails from mi_decls in ModIface
167 -- The next three fields are created by the typechecker
169 md_insts :: [DFunId], -- Dfun-ids for the instances in this module
170 md_rules :: [IdCoreRule] -- Domain may include Ids from other modules
175 emptyModDetails :: ModDetails
177 = ModDetails { md_types = emptyTypeEnv,
182 emptyModIface :: Module -> ModIface
184 = ModIface { mi_module = mod,
185 mi_version = initialVersionInfo,
190 mi_fixities = emptyNameEnv,
191 mi_globals = emptyRdrEnv,
192 mi_deprecs = NoDeprecs,
193 mi_decls = panic "emptyModIface: decls"
197 Symbol tables map modules to ModDetails:
200 type SymbolTable = ModuleEnv ModDetails
201 type IfaceTable = ModuleEnv ModIface
203 type HomeIfaceTable = IfaceTable
204 type PackageIfaceTable = IfaceTable
206 type HomeSymbolTable = SymbolTable -- Domain = modules in the home package
208 emptySymbolTable :: SymbolTable
209 emptySymbolTable = emptyModuleEnv
211 emptyIfaceTable :: IfaceTable
212 emptyIfaceTable = emptyModuleEnv
215 Simple lookups in the symbol table.
218 lookupIface :: HomeIfaceTable -> PackageIfaceTable -> Name -> Maybe ModIface
219 -- We often have two IfaceTables, and want to do a lookup
220 lookupIface hit pit name
221 = lookupModuleEnv hit mod `seqMaybe` lookupModuleEnv pit mod
223 mod = nameModule name
225 lookupIfaceByModName :: HomeIfaceTable -> PackageIfaceTable -> ModuleName -> Maybe ModIface
226 -- We often have two IfaceTables, and want to do a lookup
227 lookupIfaceByModName hit pit mod
228 = lookupModuleEnvByName hit mod `seqMaybe` lookupModuleEnvByName pit mod
232 %************************************************************************
234 \subsection{The interactive context}
236 %************************************************************************
239 data InteractiveContext
240 = InteractiveContext {
241 ic_module :: Module, -- The current module in which
242 -- the user is sitting
244 ic_rn_env :: LocalRdrEnv, -- Lexical context for variables bound
245 -- during interaction
247 ic_type_env :: TypeEnv -- Ditto for types
252 %************************************************************************
254 \subsection{Type environment stuff}
256 %************************************************************************
259 data TyThing = AnId Id
263 isTyClThing :: TyThing -> Bool
264 isTyClThing (ATyCon _) = True
265 isTyClThing (AClass _) = True
266 isTyClThing (AnId _) = False
268 instance NamedThing TyThing where
269 getName (AnId id) = getName id
270 getName (ATyCon tc) = getName tc
271 getName (AClass cl) = getName cl
273 instance Outputable TyThing where
274 ppr (AnId id) = ptext SLIT("AnId") <+> ppr id
275 ppr (ATyCon tc) = ptext SLIT("ATyCon") <+> ppr tc
276 ppr (AClass cl) = ptext SLIT("AClass") <+> ppr cl
278 typeEnvClasses env = [cl | AClass cl <- nameEnvElts env]
279 typeEnvTyCons env = [tc | ATyCon tc <- nameEnvElts env]
280 typeEnvIds env = [id | AnId id <- nameEnvElts env]
282 implicitTyThingIds :: [TyThing] -> [Id]
283 -- Add the implicit data cons and selectors etc
284 implicitTyThingIds things
285 = concat (map go things)
288 go (AClass cl) = classSelIds cl
289 go (ATyCon tc) = tyConGenIds tc ++
291 [ n | dc <- tyConDataConsIfAvailable tc,
292 n <- [dataConId dc, dataConWrapId dc] ]
293 -- Synonyms return empty list of constructors and selectors
298 type TypeEnv = NameEnv TyThing
300 emptyTypeEnv = emptyNameEnv
302 mkTypeEnv :: [TyThing] -> TypeEnv
303 mkTypeEnv things = extendTypeEnvList emptyTypeEnv things
305 extendTypeEnvList :: TypeEnv -> [TyThing] -> TypeEnv
306 extendTypeEnvList env things
307 = extendNameEnvList env [(getName thing, thing) | thing <- things]
309 extendTypeEnvWithIds :: TypeEnv -> [Id] -> TypeEnv
310 extendTypeEnvWithIds env ids
311 = extendNameEnvList env [(getName id, AnId id) | id <- ids]
315 lookupType :: HomeSymbolTable -> PackageTypeEnv -> Name -> Maybe TyThing
316 lookupType hst pte name
317 = case lookupModuleEnv hst (nameModule name) of
318 Just details -> lookupNameEnv (md_types details) name
319 Nothing -> lookupNameEnv pte name
322 %************************************************************************
324 \subsection{Auxiliary types}
326 %************************************************************************
328 These types are defined here because they are mentioned in ModDetails,
329 but they are mostly elaborated elsewhere
334 vers_module :: Version, -- Changes when anything changes
335 vers_exports :: Version, -- Changes when export list changes
336 vers_rules :: Version, -- Changes when any rule changes
337 vers_decls :: NameEnv Version
338 -- Versions for "big" names only (not data constructors, class ops)
339 -- The version of an Id changes if its fixity changes
340 -- Ditto data constructors, class operations, except that the version of
341 -- the parent class/tycon changes
344 initialVersionInfo :: VersionInfo
345 initialVersionInfo = VersionInfo { vers_module = initialVersion,
346 vers_exports = initialVersion,
347 vers_rules = initialVersion,
348 vers_decls = emptyNameEnv }
350 data Deprecations = NoDeprecs
351 | DeprecAll DeprecTxt -- Whole module deprecated
352 | DeprecSome (NameEnv (Name,DeprecTxt)) -- Some things deprecated
354 -- We keep the Name in the range, so we can print them out
356 lookupDeprec :: Deprecations -> Name -> Maybe DeprecTxt
357 lookupDeprec NoDeprecs name = Nothing
358 lookupDeprec (DeprecAll txt) name = Just txt
359 lookupDeprec (DeprecSome env) name = case lookupNameEnv env name of
360 Just (_, txt) -> Just txt
363 instance Eq Deprecations where
364 -- Used when checking whether we need write a new interface
365 NoDeprecs == NoDeprecs = True
366 (DeprecAll t1) == (DeprecAll t2) = t1 == t2
367 (DeprecSome e1) == (DeprecSome e2) = nameEnvElts e1 == nameEnvElts e2
373 type Avails = [AvailInfo]
374 type AvailInfo = GenAvailInfo Name
375 type RdrAvailInfo = GenAvailInfo OccName
377 data GenAvailInfo name = Avail name -- An ordinary identifier
378 | AvailTC name -- The name of the type or class
379 [name] -- The available pieces of type/class.
380 -- NB: If the type or class is itself
381 -- to be in scope, it must be in this list.
382 -- Thus, typically: AvailTC Eq [Eq, ==, /=]
384 -- Equality used when deciding if the interface has changed
386 type AvailEnv = NameEnv AvailInfo -- Maps a Name to the AvailInfo that contains it
388 instance Outputable n => Outputable (GenAvailInfo n) where
391 pprAvail :: Outputable n => GenAvailInfo n -> SDoc
392 pprAvail (AvailTC n ns) = ppr n <> case {- filter (/= n) -} ns of
394 ns' -> braces (hsep (punctuate comma (map ppr ns')))
396 pprAvail (Avail n) = ppr n
400 %************************************************************************
402 \subsection{ModIface}
404 %************************************************************************
407 type WhetherHasOrphans = Bool
409 -- * an instance decl in a module other than the defn module for
410 -- one of the tycons or classes in the instance head
411 -- * a transformation rule in a module other than the one defining
412 -- the function in the head of the rule.
414 type IsBootInterface = Bool
416 type ImportVersion name = (ModuleName, WhetherHasOrphans, IsBootInterface, WhatsImported name)
418 data WhatsImported name = NothingAtAll -- The module is below us in the
419 -- hierarchy, but we import nothing
421 | Everything Version -- Used for modules from other packages;
422 -- we record only the module's version number
425 Version -- Module version
426 (Maybe Version) -- Export-list version, if we depend on it
427 [(name,Version)] -- List guaranteed non-empty
428 Version -- Rules version
431 -- 'Specifically' doesn't let you say "I imported f but none of the rules in
432 -- the module". If you use anything in the module you get its rule version
433 -- So if the rules change, you'll recompile, even if you don't use them.
434 -- This is easy to implement, and it's safer: you might not have used the rules last
435 -- time round, but if someone has added a new rule you might need it this time
437 -- The export list field is (Just v) if we depend on the export list:
438 -- we imported the module without saying exactly what we imported
439 -- We need to recompile if the module exports changes, because we might
440 -- now have a name clash in the importing module.
442 type IsExported = Name -> Bool -- True for names that are exported from this module
446 %************************************************************************
448 \subsection{The persistent compiler state}
450 %************************************************************************
453 data PersistentCompilerState
455 pcs_PIT :: PackageIfaceTable, -- Domain = non-home-package modules
456 -- the mi_decls component is empty
458 pcs_PTE :: PackageTypeEnv, -- Domain = non-home-package modules
459 -- except that the InstEnv components is empty
461 pcs_insts :: PackageInstEnv, -- The total InstEnv accumulated from all
462 -- the non-home-package modules
464 pcs_rules :: PackageRuleBase, -- Ditto RuleEnv
466 pcs_PRS :: PersistentRenamerState
470 The @PersistentRenamerState@ persists across successive calls to the
474 * A name supply, which deals with allocating unique names to
475 (Module,OccName) original names,
477 * An accumulated TypeEnv from all the modules in imported packages
479 * An accumulated InstEnv from all the modules in imported packages
480 The point is that we don't want to keep recreating it whenever
481 we compile a new module. The InstEnv component of pcPST is empty.
482 (This means we might "see" instances that we shouldn't "really" see;
483 but the Haskell Report is vague on what is meant to be visible,
484 so we just take the easy road here.)
488 * A "holding pen" for declarations that have been read out of
489 interface files but not yet sucked in, renamed, and typechecked
492 type PackageTypeEnv = TypeEnv
493 type PackageRuleBase = RuleBase
494 type PackageInstEnv = InstEnv
496 data PersistentRenamerState
497 = PRS { prsOrig :: NameSupply,
498 prsImpMods :: ImportedModuleInfo,
499 prsDecls :: DeclsMap,
500 prsInsts :: IfaceInsts,
501 prsRules :: IfaceRules
505 The NameSupply makes sure that there is just one Unique assigned for
506 each original name; i.e. (module-name, occ-name) pair. The Name is
507 always stored as a Global, and has the SrcLoc of its binding location.
508 Actually that's not quite right. When we first encounter the original
509 name, we might not be at its binding site (e.g. we are reading an
510 interface file); so we give it 'noSrcLoc' then. Later, when we find
511 its binding site, we fix it up.
513 Exactly the same is true of the Module stored in the Name. When we first
514 encounter the occurrence, we may not know the details of the module, so
515 we just store junk. Then when we find the binding site, we fix it up.
519 = NameSupply { nsUniqs :: UniqSupply,
521 nsNames :: OrigNameCache,
522 -- Ensures that one original name gets one unique
523 nsIPs :: OrigIParamCache
524 -- Ensures that one implicit parameter name gets one unique
527 type OrigNameCache = FiniteMap (ModuleName,OccName) Name
528 type OrigIParamCache = FiniteMap OccName Name
531 @ImportedModuleInfo@ contains info ONLY about modules that have not yet
532 been loaded into the iPIT. These modules are mentioned in interfaces we've
533 already read, so we know a tiny bit about them, but we havn't yet looked
534 at the interface file for the module itself. It needs to persist across
535 invocations of the renamer, at least from Rename.checkOldIface to Rename.renameSource.
536 And there's no harm in it persisting across multiple compilations.
539 type ImportedModuleInfo = FiniteMap ModuleName (WhetherHasOrphans, IsBootInterface)
542 A DeclsMap contains a binding for each Name in the declaration
543 including the constructors of a type decl etc. The Bool is True just
547 type DeclsMap = (NameEnv (AvailInfo, Bool, (Module, RdrNameTyClDecl)), Int)
548 -- The Int says how many have been sucked in
550 type IfaceInsts = GatedDecls RdrNameInstDecl
551 type IfaceRules = GatedDecls RdrNameRuleDecl
553 type GatedDecls d = (Bag (GatedDecl d), Int) -- The Int says how many have been sucked in
554 type GatedDecl d = ([Name], (Module, d))
558 %************************************************************************
560 \subsection{Provenance and export info}
562 %************************************************************************
564 A LocalRdrEnv is used for local bindings (let, where, lambda, case)
567 type LocalRdrEnv = RdrNameEnv Name
569 extendLocalRdrEnv :: LocalRdrEnv -> [Name] -> LocalRdrEnv
570 extendLocalRdrEnv env names
571 = addListToRdrEnv env [(mkRdrUnqual (nameOccName n), n) | n <- names]
574 The GlobalRdrEnv gives maps RdrNames to Names. There is a separate
575 one for each module, corresponding to that module's top-level scope.
578 type GlobalRdrEnv = RdrNameEnv [GlobalRdrElt]
579 -- The list is because there may be name clashes
580 -- These only get reported on lookup, not on construction
582 data GlobalRdrElt = GRE Name Provenance (Maybe DeprecTxt)
583 -- The Maybe DeprecTxt tells whether this name is deprecated
586 = vcat (map pp (rdrEnvToList env))
588 pp (rn, nps) = ppr rn <> colon <+>
589 vcat [ppr n <+> pprNameProvenance n p | (GRE n p _) <- nps]
592 The "provenance" of something says how it came to be in scope.
596 = LocalDef -- Defined locally
598 | NonLocalDef -- Defined non-locally
601 -- Just used for grouping error messages (in RnEnv.warnUnusedBinds)
602 instance Eq Provenance where
603 p1 == p2 = case p1 `compare` p2 of EQ -> True; _ -> False
605 instance Eq ImportReason where
606 p1 == p2 = case p1 `compare` p2 of EQ -> True; _ -> False
608 instance Ord Provenance where
609 compare LocalDef LocalDef = EQ
610 compare LocalDef (NonLocalDef _) = LT
611 compare (NonLocalDef _) LocalDef = GT
613 compare (NonLocalDef reason1) (NonLocalDef reason2)
614 = compare reason1 reason2
616 instance Ord ImportReason where
617 compare ImplicitImport ImplicitImport = EQ
618 compare ImplicitImport (UserImport _ _ _) = LT
619 compare (UserImport _ _ _) ImplicitImport = GT
620 compare (UserImport m1 loc1 _) (UserImport m2 loc2 _)
621 = (m1 `compare` m2) `thenCmp` (loc1 `compare` loc2)
625 = UserImport Module SrcLoc Bool -- Imported from module M on line L
626 -- Note the M may well not be the defining module
628 -- The Bool is true iff the thing was named *explicitly* in the import spec,
629 -- rather than being imported as part of a group; e.g.
632 -- Here, everything imported by B, and the constructors of T
633 -- are not named explicitly; only T is named explicitly.
634 -- This info is used when warning of unused names.
636 | ImplicitImport -- Imported implicitly for some other reason
640 hasBetterProv :: Provenance -> Provenance -> Bool
642 -- a local thing over an imported thing
643 -- a user-imported thing over a non-user-imported thing
644 -- an explicitly-imported thing over an implicitly imported thing
645 hasBetterProv LocalDef _ = True
646 hasBetterProv (NonLocalDef (UserImport _ _ _ )) (NonLocalDef ImplicitImport) = True
647 hasBetterProv _ _ = False
649 pprNameProvenance :: Name -> Provenance -> SDoc
650 pprNameProvenance name LocalDef = ptext SLIT("defined at") <+> ppr (nameSrcLoc name)
651 pprNameProvenance name (NonLocalDef why) = sep [ppr_reason why,
652 nest 2 (parens (ppr_defn (nameSrcLoc name)))]
654 ppr_reason ImplicitImport = ptext SLIT("implicitly imported")
655 ppr_reason (UserImport mod loc _) = ptext SLIT("imported from") <+> ppr mod <+> ptext SLIT("at") <+> ppr loc
657 ppr_defn loc | isGoodSrcLoc loc = ptext SLIT("at") <+> ppr loc