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, lookupVersion,
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, orElse )
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
173 -- NOT YET IMPLEMENTED
174 -- The ModDetails takes on several slightly different forms:
176 -- After typecheck + desugar
177 -- md_types contains TyCons, Classes, and hasNoBinding Ids
178 -- md_insts all instances from this module (incl derived ones)
179 -- md_rules all rules from this module
180 -- md_binds desugared bindings
182 -- After simplification
183 -- md_types same as after typecheck
185 -- md_rules orphan rules only (local ones attached to binds)
186 -- md_binds with rules attached
189 -- md_types now contains Ids as well, replete with correct IdInfo
194 emptyModDetails :: ModDetails
196 = ModDetails { md_types = emptyTypeEnv,
201 emptyModIface :: Module -> ModIface
203 = ModIface { mi_module = mod,
204 mi_version = initialVersionInfo,
209 mi_fixities = emptyNameEnv,
210 mi_globals = emptyRdrEnv,
211 mi_deprecs = NoDeprecs,
212 mi_decls = panic "emptyModIface: decls"
216 Symbol tables map modules to ModDetails:
219 type SymbolTable = ModuleEnv ModDetails
220 type IfaceTable = ModuleEnv ModIface
222 type HomeIfaceTable = IfaceTable
223 type PackageIfaceTable = IfaceTable
225 type HomeSymbolTable = SymbolTable -- Domain = modules in the home package
227 emptySymbolTable :: SymbolTable
228 emptySymbolTable = emptyModuleEnv
230 emptyIfaceTable :: IfaceTable
231 emptyIfaceTable = emptyModuleEnv
234 Simple lookups in the symbol table.
237 lookupIface :: HomeIfaceTable -> PackageIfaceTable -> Name -> Maybe ModIface
238 -- We often have two IfaceTables, and want to do a lookup
239 lookupIface hit pit name
240 = lookupModuleEnv hit mod `seqMaybe` lookupModuleEnv pit mod
242 mod = nameModule name
244 lookupIfaceByModName :: HomeIfaceTable -> PackageIfaceTable -> ModuleName -> Maybe ModIface
245 -- We often have two IfaceTables, and want to do a lookup
246 lookupIfaceByModName hit pit mod
247 = lookupModuleEnvByName hit mod `seqMaybe` lookupModuleEnvByName pit mod
251 %************************************************************************
253 \subsection{The interactive context}
255 %************************************************************************
258 data InteractiveContext
259 = InteractiveContext {
260 ic_module :: Module, -- The current module in which
261 -- the user is sitting
263 ic_rn_env :: LocalRdrEnv, -- Lexical context for variables bound
264 -- during interaction
266 ic_type_env :: TypeEnv -- Ditto for types
271 %************************************************************************
273 \subsection{Type environment stuff}
275 %************************************************************************
278 data TyThing = AnId Id
282 isTyClThing :: TyThing -> Bool
283 isTyClThing (ATyCon _) = True
284 isTyClThing (AClass _) = True
285 isTyClThing (AnId _) = False
287 instance NamedThing TyThing where
288 getName (AnId id) = getName id
289 getName (ATyCon tc) = getName tc
290 getName (AClass cl) = getName cl
292 instance Outputable TyThing where
293 ppr (AnId id) = ptext SLIT("AnId") <+> ppr id
294 ppr (ATyCon tc) = ptext SLIT("ATyCon") <+> ppr tc
295 ppr (AClass cl) = ptext SLIT("AClass") <+> ppr cl
297 typeEnvClasses env = [cl | AClass cl <- nameEnvElts env]
298 typeEnvTyCons env = [tc | ATyCon tc <- nameEnvElts env]
299 typeEnvIds env = [id | AnId id <- nameEnvElts env]
301 implicitTyThingIds :: [TyThing] -> [Id]
302 -- Add the implicit data cons and selectors etc
303 implicitTyThingIds things
304 = concat (map go things)
307 go (AClass cl) = classSelIds cl
308 go (ATyCon tc) = tyConGenIds tc ++
310 [ n | dc <- tyConDataConsIfAvailable tc,
311 n <- [dataConId dc, dataConWrapId dc] ]
312 -- Synonyms return empty list of constructors and selectors
317 type TypeEnv = NameEnv TyThing
319 emptyTypeEnv = emptyNameEnv
321 mkTypeEnv :: [TyThing] -> TypeEnv
322 mkTypeEnv things = extendTypeEnvList emptyTypeEnv things
324 extendTypeEnvList :: TypeEnv -> [TyThing] -> TypeEnv
325 extendTypeEnvList env things
326 = extendNameEnvList env [(getName thing, thing) | thing <- things]
328 extendTypeEnvWithIds :: TypeEnv -> [Id] -> TypeEnv
329 extendTypeEnvWithIds env ids
330 = extendNameEnvList env [(getName id, AnId id) | id <- ids]
334 lookupType :: HomeSymbolTable -> PackageTypeEnv -> Name -> Maybe TyThing
335 lookupType hst pte name
336 = case lookupModuleEnv hst (nameModule name) of
337 Just details -> lookupNameEnv (md_types details) name
338 Nothing -> lookupNameEnv pte name
341 %************************************************************************
343 \subsection{Auxiliary types}
345 %************************************************************************
347 These types are defined here because they are mentioned in ModDetails,
348 but they are mostly elaborated elsewhere
353 vers_module :: Version, -- Changes when anything changes
354 vers_exports :: Version, -- Changes when export list changes
355 vers_rules :: Version, -- Changes when any rule changes
356 vers_decls :: NameEnv Version
357 -- Versions for "big" names only (not data constructors, class ops)
358 -- The version of an Id changes if its fixity changes
359 -- Ditto data constructors, class operations, except that the version of
360 -- the parent class/tycon changes
362 -- If a name isn't in the map, it means 'initialVersion'
365 initialVersionInfo :: VersionInfo
366 initialVersionInfo = VersionInfo { vers_module = initialVersion,
367 vers_exports = initialVersion,
368 vers_rules = initialVersion,
369 vers_decls = emptyNameEnv
372 lookupVersion :: NameEnv Version -> Name -> Version
373 lookupVersion env name = lookupNameEnv env name `orElse` initialVersion
375 data Deprecations = NoDeprecs
376 | DeprecAll DeprecTxt -- Whole module deprecated
377 | DeprecSome (NameEnv (Name,DeprecTxt)) -- Some things deprecated
379 -- We keep the Name in the range, so we can print them out
381 lookupDeprec :: Deprecations -> Name -> Maybe DeprecTxt
382 lookupDeprec NoDeprecs name = Nothing
383 lookupDeprec (DeprecAll txt) name = Just txt
384 lookupDeprec (DeprecSome env) name = case lookupNameEnv env name of
385 Just (_, txt) -> Just txt
388 instance Eq Deprecations where
389 -- Used when checking whether we need write a new interface
390 NoDeprecs == NoDeprecs = True
391 (DeprecAll t1) == (DeprecAll t2) = t1 == t2
392 (DeprecSome e1) == (DeprecSome e2) = nameEnvElts e1 == nameEnvElts e2
398 type Avails = [AvailInfo]
399 type AvailInfo = GenAvailInfo Name
400 type RdrAvailInfo = GenAvailInfo OccName
402 data GenAvailInfo name = Avail name -- An ordinary identifier
403 | AvailTC name -- The name of the type or class
404 [name] -- The available pieces of type/class.
405 -- NB: If the type or class is itself
406 -- to be in scope, it must be in this list.
407 -- Thus, typically: AvailTC Eq [Eq, ==, /=]
409 -- Equality used when deciding if the interface has changed
411 type AvailEnv = NameEnv AvailInfo -- Maps a Name to the AvailInfo that contains it
413 instance Outputable n => Outputable (GenAvailInfo n) where
416 pprAvail :: Outputable n => GenAvailInfo n -> SDoc
417 pprAvail (AvailTC n ns) = ppr n <> case {- filter (/= n) -} ns of
419 ns' -> braces (hsep (punctuate comma (map ppr ns')))
421 pprAvail (Avail n) = ppr n
425 %************************************************************************
427 \subsection{ModIface}
429 %************************************************************************
432 type WhetherHasOrphans = Bool
434 -- * an instance decl in a module other than the defn module for
435 -- one of the tycons or classes in the instance head
436 -- * a transformation rule in a module other than the one defining
437 -- the function in the head of the rule.
439 type IsBootInterface = Bool
441 type ImportVersion name = (ModuleName, WhetherHasOrphans, IsBootInterface, WhatsImported name)
443 data WhatsImported name = NothingAtAll -- The module is below us in the
444 -- hierarchy, but we import nothing
446 | Everything Version -- Used for modules from other packages;
447 -- we record only the module's version number
450 Version -- Module version
451 (Maybe Version) -- Export-list version, if we depend on it
452 [(name,Version)] -- List guaranteed non-empty
453 Version -- Rules version
456 -- 'Specifically' doesn't let you say "I imported f but none of the rules in
457 -- the module". If you use anything in the module you get its rule version
458 -- So if the rules change, you'll recompile, even if you don't use them.
459 -- This is easy to implement, and it's safer: you might not have used the rules last
460 -- time round, but if someone has added a new rule you might need it this time
462 -- The export list field is (Just v) if we depend on the export list:
463 -- we imported the module without saying exactly what we imported
464 -- We need to recompile if the module exports changes, because we might
465 -- now have a name clash in the importing module.
467 type IsExported = Name -> Bool -- True for names that are exported from this module
471 %************************************************************************
473 \subsection{The persistent compiler state}
475 %************************************************************************
478 data PersistentCompilerState
480 pcs_PIT :: PackageIfaceTable, -- Domain = non-home-package modules
481 -- the mi_decls component is empty
483 pcs_PTE :: PackageTypeEnv, -- Domain = non-home-package modules
484 -- except that the InstEnv components is empty
486 pcs_insts :: PackageInstEnv, -- The total InstEnv accumulated from all
487 -- the non-home-package modules
489 pcs_rules :: PackageRuleBase, -- Ditto RuleEnv
491 pcs_PRS :: PersistentRenamerState
495 The @PersistentRenamerState@ persists across successive calls to the
499 * A name supply, which deals with allocating unique names to
500 (Module,OccName) original names,
502 * An accumulated TypeEnv from all the modules in imported packages
504 * An accumulated InstEnv from all the modules in imported packages
505 The point is that we don't want to keep recreating it whenever
506 we compile a new module. The InstEnv component of pcPST is empty.
507 (This means we might "see" instances that we shouldn't "really" see;
508 but the Haskell Report is vague on what is meant to be visible,
509 so we just take the easy road here.)
513 * A "holding pen" for declarations that have been read out of
514 interface files but not yet sucked in, renamed, and typechecked
517 type PackageTypeEnv = TypeEnv
518 type PackageRuleBase = RuleBase
519 type PackageInstEnv = InstEnv
521 data PersistentRenamerState
522 = PRS { prsOrig :: NameSupply,
523 prsImpMods :: ImportedModuleInfo,
524 prsDecls :: DeclsMap,
525 prsInsts :: IfaceInsts,
526 prsRules :: IfaceRules
530 The NameSupply makes sure that there is just one Unique assigned for
531 each original name; i.e. (module-name, occ-name) pair. The Name is
532 always stored as a Global, and has the SrcLoc of its binding location.
533 Actually that's not quite right. When we first encounter the original
534 name, we might not be at its binding site (e.g. we are reading an
535 interface file); so we give it 'noSrcLoc' then. Later, when we find
536 its binding site, we fix it up.
538 Exactly the same is true of the Module stored in the Name. When we first
539 encounter the occurrence, we may not know the details of the module, so
540 we just store junk. Then when we find the binding site, we fix it up.
544 = NameSupply { nsUniqs :: UniqSupply,
546 nsNames :: OrigNameCache,
547 -- Ensures that one original name gets one unique
548 nsIPs :: OrigIParamCache
549 -- Ensures that one implicit parameter name gets one unique
552 type OrigNameCache = FiniteMap (ModuleName,OccName) Name
553 type OrigIParamCache = FiniteMap OccName Name
556 @ImportedModuleInfo@ contains info ONLY about modules that have not yet
557 been loaded into the iPIT. These modules are mentioned in interfaces we've
558 already read, so we know a tiny bit about them, but we havn't yet looked
559 at the interface file for the module itself. It needs to persist across
560 invocations of the renamer, at least from Rename.checkOldIface to Rename.renameSource.
561 And there's no harm in it persisting across multiple compilations.
564 type ImportedModuleInfo = FiniteMap ModuleName (WhetherHasOrphans, IsBootInterface)
567 A DeclsMap contains a binding for each Name in the declaration
568 including the constructors of a type decl etc. The Bool is True just
572 type DeclsMap = (NameEnv (AvailInfo, Bool, (Module, RdrNameTyClDecl)), Int)
573 -- The Int says how many have been sucked in
575 type IfaceInsts = GatedDecls RdrNameInstDecl
576 type IfaceRules = GatedDecls RdrNameRuleDecl
578 type GatedDecls d = (Bag (GatedDecl d), Int) -- The Int says how many have been sucked in
579 type GatedDecl d = ([Name], (Module, d))
583 %************************************************************************
585 \subsection{Provenance and export info}
587 %************************************************************************
589 A LocalRdrEnv is used for local bindings (let, where, lambda, case)
592 type LocalRdrEnv = RdrNameEnv Name
594 extendLocalRdrEnv :: LocalRdrEnv -> [Name] -> LocalRdrEnv
595 extendLocalRdrEnv env names
596 = addListToRdrEnv env [(mkRdrUnqual (nameOccName n), n) | n <- names]
599 The GlobalRdrEnv gives maps RdrNames to Names. There is a separate
600 one for each module, corresponding to that module's top-level scope.
603 type GlobalRdrEnv = RdrNameEnv [GlobalRdrElt]
604 -- The list is because there may be name clashes
605 -- These only get reported on lookup, not on construction
607 data GlobalRdrElt = GRE Name Provenance (Maybe DeprecTxt)
608 -- The Maybe DeprecTxt tells whether this name is deprecated
611 = vcat (map pp (rdrEnvToList env))
613 pp (rn, nps) = ppr rn <> colon <+>
614 vcat [ppr n <+> pprNameProvenance n p | (GRE n p _) <- nps]
617 The "provenance" of something says how it came to be in scope.
621 = LocalDef -- Defined locally
623 | NonLocalDef -- Defined non-locally
626 -- Just used for grouping error messages (in RnEnv.warnUnusedBinds)
627 instance Eq Provenance where
628 p1 == p2 = case p1 `compare` p2 of EQ -> True; _ -> False
630 instance Eq ImportReason where
631 p1 == p2 = case p1 `compare` p2 of EQ -> True; _ -> False
633 instance Ord Provenance where
634 compare LocalDef LocalDef = EQ
635 compare LocalDef (NonLocalDef _) = LT
636 compare (NonLocalDef _) LocalDef = GT
638 compare (NonLocalDef reason1) (NonLocalDef reason2)
639 = compare reason1 reason2
641 instance Ord ImportReason where
642 compare ImplicitImport ImplicitImport = EQ
643 compare ImplicitImport (UserImport _ _ _) = LT
644 compare (UserImport _ _ _) ImplicitImport = GT
645 compare (UserImport m1 loc1 _) (UserImport m2 loc2 _)
646 = (m1 `compare` m2) `thenCmp` (loc1 `compare` loc2)
650 = UserImport Module SrcLoc Bool -- Imported from module M on line L
651 -- Note the M may well not be the defining module
653 -- The Bool is true iff the thing was named *explicitly* in the import spec,
654 -- rather than being imported as part of a group; e.g.
657 -- Here, everything imported by B, and the constructors of T
658 -- are not named explicitly; only T is named explicitly.
659 -- This info is used when warning of unused names.
661 | ImplicitImport -- Imported implicitly for some other reason
665 hasBetterProv :: Provenance -> Provenance -> Bool
667 -- a local thing over an imported thing
668 -- a user-imported thing over a non-user-imported thing
669 -- an explicitly-imported thing over an implicitly imported thing
670 hasBetterProv LocalDef _ = True
671 hasBetterProv (NonLocalDef (UserImport _ _ _ )) (NonLocalDef ImplicitImport) = True
672 hasBetterProv _ _ = False
674 pprNameProvenance :: Name -> Provenance -> SDoc
675 pprNameProvenance name LocalDef = ptext SLIT("defined at") <+> ppr (nameSrcLoc name)
676 pprNameProvenance name (NonLocalDef why) = sep [ppr_reason why,
677 nest 2 (parens (ppr_defn (nameSrcLoc name)))]
679 ppr_reason ImplicitImport = ptext SLIT("implicitly imported")
680 ppr_reason (UserImport mod loc _) = ptext SLIT("imported from") <+> ppr mod <+> ptext SLIT("at") <+> ppr loc
682 ppr_defn loc | isGoodSrcLoc loc = ptext SLIT("at") <+> ppr loc