2 % (c) The University of Glasgow, 2000
4 \section[HscTypes]{Types for the per-module compiler}
10 ModDetails(..), ModIface(..),
11 HomeSymbolTable, PackageTypeEnv,
12 HomeIfaceTable, PackageIfaceTable, emptyIfaceTable,
13 lookupIface, lookupIfaceByModName,
16 IfaceDecls, mkIfaceDecls, dcl_tycl, dcl_rules, dcl_insts,
18 VersionInfo(..), initialVersionInfo,
20 TyThing(..), isTyClThing, implicitTyThingIds,
22 TypeEnv, lookupType, mkTypeEnv, extendTypeEnvList,
23 typeEnvClasses, typeEnvTyCons,
25 ImportedModuleInfo, WhetherHasOrphans, ImportVersion, WhatsImported(..),
26 PersistentRenamerState(..), IsBootInterface, Avails, DeclsMap,
27 IfaceInsts, IfaceRules, GatedDecl, IsExported,
28 NameSupply(..), OrigNameCache, OrigIParamCache,
29 AvailEnv, AvailInfo, GenAvailInfo(..),
30 PersistentCompilerState(..),
32 Deprecations(..), lookupDeprec,
34 InstEnv, ClsInstEnv, DFunId,
35 PackageInstEnv, PackageRuleBase,
37 GlobalRdrEnv, GlobalRdrElt(..), RdrAvailInfo, pprGlobalRdrEnv,
40 Provenance(..), ImportReason(..),
41 pprNameProvenance, hasBetterProv
45 #include "HsVersions.h"
47 import RdrName ( RdrNameEnv, emptyRdrEnv, rdrEnvToList )
48 import Name ( Name, NamedThing, getName, nameModule, nameSrcLoc )
50 import OccName ( OccName )
51 import Module ( Module, ModuleName, ModuleEnv,
52 lookupModuleEnv, lookupModuleEnvByName, emptyModuleEnv
54 import InstEnv ( InstEnv, ClsInstEnv, DFunId )
55 import Rules ( RuleBase )
57 import Class ( Class, classSelIds )
58 import TyCon ( TyCon, tyConGenIds, tyConSelIds, tyConDataConsIfAvailable )
59 import DataCon ( dataConId, dataConWrapId )
61 import BasicTypes ( Version, initialVersion, Fixity )
63 import HsSyn ( DeprecTxt, tyClDeclName, ifaceRuleDeclName )
64 import RdrHsSyn ( RdrNameInstDecl, RdrNameRuleDecl, RdrNameTyClDecl )
65 import RnHsSyn ( RenamedTyClDecl, RenamedRuleDecl, RenamedInstDecl )
67 import CoreSyn ( IdCoreRule )
69 import FiniteMap ( FiniteMap )
71 import Maybes ( seqMaybe )
73 import SrcLoc ( SrcLoc, isGoodSrcLoc )
74 import Util ( thenCmp, sortLt )
75 import UniqSupply ( UniqSupply )
78 %************************************************************************
80 \subsection{Module locations}
82 %************************************************************************
87 ml_hs_file :: Maybe FilePath,
88 ml_hspp_file :: Maybe FilePath, -- path of preprocessed source
89 ml_hi_file :: Maybe FilePath,
90 ml_obj_file :: Maybe FilePath
94 instance Outputable ModuleLocation where
98 For a module in another package, the hs_file and obj_file
99 components of ModuleLocation are undefined.
101 The locations specified by a ModuleLocation may or may not
102 correspond to actual files yet: for example, even if the object
103 file doesn't exist, the ModuleLocation still contains the path to
104 where the object file will reside if/when it is created.
107 %************************************************************************
109 \subsection{Symbol tables and Module details}
111 %************************************************************************
113 A @ModIface@ plus a @ModDetails@ summarises everything we know
114 about a compiled module. The @ModIface@ is the stuff *before* linking,
115 and can be written out to an interface file. The @ModDetails@ is after
116 linking; it is the "linked" form of the mi_decls field.
121 mi_module :: Module, -- Complete with package info
122 mi_version :: VersionInfo, -- Module version number
123 mi_orphan :: WhetherHasOrphans, -- Whether this module has orphans
124 mi_boot :: IsBootInterface, -- Whether this interface was read from an hi-boot file
126 mi_usages :: [ImportVersion Name], -- Usages; kept sorted so that it's easy
127 -- to decide whether to write a new iface file
128 -- (changing usages doesn't affect the version of
131 mi_exports :: [(ModuleName,Avails)], -- What it exports
132 -- Kept sorted by (mod,occ),
133 -- to make version comparisons easier
135 mi_globals :: GlobalRdrEnv, -- Its top level environment
137 mi_fixities :: NameEnv Fixity, -- Fixities
138 mi_deprecs :: Deprecations, -- Deprecations
140 mi_decls :: IfaceDecls -- The RnDecls form of ModDetails
143 data IfaceDecls = IfaceDecls { dcl_tycl :: [RenamedTyClDecl], -- Sorted
144 dcl_rules :: [RenamedRuleDecl], -- Sorted
145 dcl_insts :: [RenamedInstDecl] } -- Unsorted
147 mkIfaceDecls :: [RenamedTyClDecl] -> [RenamedRuleDecl] -> [RenamedInstDecl] -> IfaceDecls
148 mkIfaceDecls tycls rules insts
149 = IfaceDecls { dcl_tycl = sortLt lt_tycl tycls,
150 dcl_rules = sortLt lt_rule rules,
153 d1 `lt_tycl` d2 = tyClDeclName d1 < tyClDeclName d2
154 r1 `lt_rule` r2 = ifaceRuleDeclName r1 < ifaceRuleDeclName r2
157 -- typechecker should only look at this, not ModIface
158 -- Should be able to construct ModDetails from mi_decls in ModIface
161 -- The next three fields are created by the typechecker
163 md_insts :: [DFunId], -- Dfun-ids for the instances in this module
164 md_rules :: [IdCoreRule] -- Domain may include Ids from other modules
169 emptyModDetails :: ModDetails
171 = ModDetails { md_types = emptyTypeEnv,
176 emptyModIface :: Module -> ModIface
178 = ModIface { mi_module = mod,
179 mi_version = initialVersionInfo,
184 mi_fixities = emptyNameEnv,
185 mi_globals = emptyRdrEnv,
186 mi_deprecs = NoDeprecs,
187 mi_decls = panic "emptyModIface: decls"
191 Symbol tables map modules to ModDetails:
194 type SymbolTable = ModuleEnv ModDetails
195 type IfaceTable = ModuleEnv ModIface
197 type HomeIfaceTable = IfaceTable
198 type PackageIfaceTable = IfaceTable
200 type HomeSymbolTable = SymbolTable -- Domain = modules in the home package
202 emptyIfaceTable :: IfaceTable
203 emptyIfaceTable = emptyModuleEnv
206 Simple lookups in the symbol table.
209 lookupIface :: HomeIfaceTable -> PackageIfaceTable -> Name -> Maybe ModIface
210 -- We often have two IfaceTables, and want to do a lookup
211 lookupIface hit pit name
212 = lookupModuleEnv hit mod `seqMaybe` lookupModuleEnv pit mod
214 mod = nameModule name
216 lookupIfaceByModName :: HomeIfaceTable -> PackageIfaceTable -> ModuleName -> Maybe ModIface
217 -- We often have two IfaceTables, and want to do a lookup
218 lookupIfaceByModName hit pit mod
219 = lookupModuleEnvByName hit mod `seqMaybe` lookupModuleEnvByName pit mod
223 %************************************************************************
225 \subsection{Type environment stuff}
227 %************************************************************************
230 data TyThing = AnId Id
234 isTyClThing :: TyThing -> Bool
235 isTyClThing (ATyCon _) = True
236 isTyClThing (AClass _) = True
237 isTyClThing (AnId _) = False
239 instance NamedThing TyThing where
240 getName (AnId id) = getName id
241 getName (ATyCon tc) = getName tc
242 getName (AClass cl) = getName cl
244 instance Outputable TyThing where
245 ppr (AnId id) = ptext SLIT("AnId") <+> ppr id
246 ppr (ATyCon tc) = ptext SLIT("ATyCon") <+> ppr tc
247 ppr (AClass cl) = ptext SLIT("AClass") <+> ppr cl
249 typeEnvClasses env = [cl | AClass cl <- nameEnvElts env]
250 typeEnvTyCons env = [tc | ATyCon tc <- nameEnvElts env]
252 implicitTyThingIds :: [TyThing] -> [Id]
253 -- Add the implicit data cons and selectors etc
254 implicitTyThingIds things
255 = concat (map go things)
258 go (AClass cl) = classSelIds cl
259 go (ATyCon tc) = tyConGenIds tc ++
261 [ n | dc <- tyConDataConsIfAvailable tc,
262 n <- [dataConId dc, dataConWrapId dc] ]
263 -- Synonyms return empty list of constructors and selectors
268 type TypeEnv = NameEnv TyThing
270 emptyTypeEnv = emptyNameEnv
272 mkTypeEnv :: [TyThing] -> TypeEnv
273 mkTypeEnv things = extendTypeEnvList emptyTypeEnv things
275 extendTypeEnvList :: TypeEnv -> [TyThing] -> TypeEnv
276 extendTypeEnvList env things
277 = foldl add_thing env things
279 add_thing :: TypeEnv -> TyThing -> TypeEnv
280 add_thing env thing = extendNameEnv env (getName thing) thing
284 lookupType :: HomeSymbolTable -> PackageTypeEnv -> Name -> Maybe TyThing
285 lookupType hst pte name
286 = case lookupModuleEnv hst (nameModule name) of
287 Just details -> lookupNameEnv (md_types details) name
288 Nothing -> lookupNameEnv pte name
291 %************************************************************************
293 \subsection{Auxiliary types}
295 %************************************************************************
297 These types are defined here because they are mentioned in ModDetails,
298 but they are mostly elaborated elsewhere
303 vers_module :: Version, -- Changes when anything changes
304 vers_exports :: Version, -- Changes when export list changes
305 vers_rules :: Version, -- Changes when any rule changes
306 vers_decls :: NameEnv Version
307 -- Versions for "big" names only (not data constructors, class ops)
308 -- The version of an Id changes if its fixity changes
309 -- Ditto data constructors, class operations, except that the version of
310 -- the parent class/tycon changes
313 initialVersionInfo :: VersionInfo
314 initialVersionInfo = VersionInfo { vers_module = initialVersion,
315 vers_exports = initialVersion,
316 vers_rules = initialVersion,
317 vers_decls = emptyNameEnv }
319 data Deprecations = NoDeprecs
320 | DeprecAll DeprecTxt -- Whole module deprecated
321 | DeprecSome (NameEnv (Name,DeprecTxt)) -- Some things deprecated
323 -- We keep the Name in the range, so we can print them out
325 lookupDeprec :: Deprecations -> Name -> Maybe DeprecTxt
326 lookupDeprec NoDeprecs name = Nothing
327 lookupDeprec (DeprecAll txt) name = Just txt
328 lookupDeprec (DeprecSome env) name = case lookupNameEnv env name of
329 Just (_, txt) -> Just txt
332 instance Eq Deprecations where
333 -- Used when checking whether we need write a new interface
334 NoDeprecs == NoDeprecs = True
335 (DeprecAll t1) == (DeprecAll t2) = t1 == t2
336 (DeprecSome e1) == (DeprecSome e2) = nameEnvElts e1 == nameEnvElts e2
342 type Avails = [AvailInfo]
343 type AvailInfo = GenAvailInfo Name
344 type RdrAvailInfo = GenAvailInfo OccName
346 data GenAvailInfo name = Avail name -- An ordinary identifier
347 | AvailTC name -- The name of the type or class
348 [name] -- The available pieces of type/class.
349 -- NB: If the type or class is itself
350 -- to be in scope, it must be in this list.
351 -- Thus, typically: AvailTC Eq [Eq, ==, /=]
353 -- Equality used when deciding if the interface has changed
355 type AvailEnv = NameEnv AvailInfo -- Maps a Name to the AvailInfo that contains it
357 instance Outputable n => Outputable (GenAvailInfo n) where
360 pprAvail :: Outputable n => GenAvailInfo n -> SDoc
361 pprAvail (AvailTC n ns) = ppr n <> case {- filter (/= n) -} ns of
363 ns' -> braces (hsep (punctuate comma (map ppr ns')))
365 pprAvail (Avail n) = ppr n
369 %************************************************************************
371 \subsection{ModIface}
373 %************************************************************************
376 type WhetherHasOrphans = Bool
378 -- * an instance decl in a module other than the defn module for
379 -- one of the tycons or classes in the instance head
380 -- * a transformation rule in a module other than the one defining
381 -- the function in the head of the rule.
383 type IsBootInterface = Bool
385 type ImportVersion name = (ModuleName, WhetherHasOrphans, IsBootInterface, WhatsImported name)
387 data WhatsImported name = NothingAtAll -- The module is below us in the
388 -- hierarchy, but we import nothing
390 | Everything Version -- Used for modules from other packages;
391 -- we record only the module's version number
394 Version -- Module version
395 (Maybe Version) -- Export-list version, if we depend on it
396 [(name,Version)] -- List guaranteed non-empty
397 Version -- Rules version
400 -- 'Specifically' doesn't let you say "I imported f but none of the rules in
401 -- the module". If you use anything in the module you get its rule version
402 -- So if the rules change, you'll recompile, even if you don't use them.
403 -- This is easy to implement, and it's safer: you might not have used the rules last
404 -- time round, but if someone has added a new rule you might need it this time
406 -- The export list field is (Just v) if we depend on the export list:
407 -- we imported the module without saying exactly what we imported
408 -- We need to recompile if the module exports changes, because we might
409 -- now have a name clash in the importing module.
411 type IsExported = Name -> Bool -- True for names that are exported from this module
415 %************************************************************************
417 \subsection{The persistent compiler state}
419 %************************************************************************
422 data PersistentCompilerState
424 pcs_PIT :: PackageIfaceTable, -- Domain = non-home-package modules
425 -- the mi_decls component is empty
427 pcs_PTE :: PackageTypeEnv, -- Domain = non-home-package modules
428 -- except that the InstEnv components is empty
430 pcs_insts :: PackageInstEnv, -- The total InstEnv accumulated from all
431 -- the non-home-package modules
433 pcs_rules :: PackageRuleBase, -- Ditto RuleEnv
435 pcs_PRS :: PersistentRenamerState
439 The @PersistentRenamerState@ persists across successive calls to the
443 * A name supply, which deals with allocating unique names to
444 (Module,OccName) original names,
446 * An accumulated TypeEnv from all the modules in imported packages
448 * An accumulated InstEnv from all the modules in imported packages
449 The point is that we don't want to keep recreating it whenever
450 we compile a new module. The InstEnv component of pcPST is empty.
451 (This means we might "see" instances that we shouldn't "really" see;
452 but the Haskell Report is vague on what is meant to be visible,
453 so we just take the easy road here.)
457 * A "holding pen" for declarations that have been read out of
458 interface files but not yet sucked in, renamed, and typechecked
461 type PackageTypeEnv = TypeEnv
462 type PackageRuleBase = RuleBase
463 type PackageInstEnv = InstEnv
465 data PersistentRenamerState
466 = PRS { prsOrig :: NameSupply,
467 prsImpMods :: ImportedModuleInfo,
468 prsDecls :: DeclsMap,
469 prsInsts :: IfaceInsts,
470 prsRules :: IfaceRules
474 The NameSupply makes sure that there is just one Unique assigned for
475 each original name; i.e. (module-name, occ-name) pair. The Name is
476 always stored as a Global, and has the SrcLoc of its binding location.
477 Actually that's not quite right. When we first encounter the original
478 name, we might not be at its binding site (e.g. we are reading an
479 interface file); so we give it 'noSrcLoc' then. Later, when we find
480 its binding site, we fix it up.
482 Exactly the same is true of the Module stored in the Name. When we first
483 encounter the occurrence, we may not know the details of the module, so
484 we just store junk. Then when we find the binding site, we fix it up.
488 = NameSupply { nsUniqs :: UniqSupply,
490 nsNames :: OrigNameCache,
491 -- Ensures that one original name gets one unique
492 nsIPs :: OrigIParamCache
493 -- Ensures that one implicit parameter name gets one unique
496 type OrigNameCache = FiniteMap (ModuleName,OccName) Name
497 type OrigIParamCache = FiniteMap OccName Name
500 @ImportedModuleInfo@ contains info ONLY about modules that have not yet
501 been loaded into the iPIT. These modules are mentioned in interfaces we've
502 already read, so we know a tiny bit about them, but we havn't yet looked
503 at the interface file for the module itself. It needs to persist across
504 invocations of the renamer, at least from Rename.checkOldIface to Rename.renameSource.
505 And there's no harm in it persisting across multiple compilations.
508 type ImportedModuleInfo = FiniteMap ModuleName (WhetherHasOrphans, IsBootInterface)
511 A DeclsMap contains a binding for each Name in the declaration
512 including the constructors of a type decl etc. The Bool is True just
516 type DeclsMap = (NameEnv (AvailInfo, Bool, (Module, RdrNameTyClDecl)), Int)
517 -- The Int says how many have been sucked in
519 type IfaceInsts = GatedDecls RdrNameInstDecl
520 type IfaceRules = GatedDecls RdrNameRuleDecl
522 type GatedDecls d = (Bag (GatedDecl d), Int) -- The Int says how many have been sucked in
523 type GatedDecl d = ([Name], (Module, d))
527 %************************************************************************
529 \subsection{Provenance and export info}
531 %************************************************************************
533 The GlobalRdrEnv gives maps RdrNames to Names. There is a separate
534 one for each module, corresponding to that module's top-level scope.
537 type GlobalRdrEnv = RdrNameEnv [GlobalRdrElt]
538 -- The list is because there may be name clashes
539 -- These only get reported on lookup, not on construction
541 data GlobalRdrElt = GRE Name Provenance (Maybe DeprecTxt)
542 -- The Maybe DeprecTxt tells whether this name is deprecated
545 = vcat (map pp (rdrEnvToList env))
547 pp (rn, nps) = ppr rn <> colon <+>
548 vcat [ppr n <+> pprNameProvenance n p | (GRE n p _) <- nps]
551 The "provenance" of something says how it came to be in scope.
555 = LocalDef -- Defined locally
557 | NonLocalDef -- Defined non-locally
560 -- Just used for grouping error messages (in RnEnv.warnUnusedBinds)
561 instance Eq Provenance where
562 p1 == p2 = case p1 `compare` p2 of EQ -> True; _ -> False
564 instance Eq ImportReason where
565 p1 == p2 = case p1 `compare` p2 of EQ -> True; _ -> False
567 instance Ord Provenance where
568 compare LocalDef LocalDef = EQ
569 compare LocalDef (NonLocalDef _) = LT
570 compare (NonLocalDef _) LocalDef = GT
572 compare (NonLocalDef reason1) (NonLocalDef reason2)
573 = compare reason1 reason2
575 instance Ord ImportReason where
576 compare ImplicitImport ImplicitImport = EQ
577 compare ImplicitImport (UserImport _ _ _) = LT
578 compare (UserImport _ _ _) ImplicitImport = GT
579 compare (UserImport m1 loc1 _) (UserImport m2 loc2 _)
580 = (m1 `compare` m2) `thenCmp` (loc1 `compare` loc2)
584 = UserImport Module SrcLoc Bool -- Imported from module M on line L
585 -- Note the M may well not be the defining module
587 -- The Bool is true iff the thing was named *explicitly* in the import spec,
588 -- rather than being imported as part of a group; e.g.
591 -- Here, everything imported by B, and the constructors of T
592 -- are not named explicitly; only T is named explicitly.
593 -- This info is used when warning of unused names.
595 | ImplicitImport -- Imported implicitly for some other reason
599 hasBetterProv :: Provenance -> Provenance -> Bool
601 -- a local thing over an imported thing
602 -- a user-imported thing over a non-user-imported thing
603 -- an explicitly-imported thing over an implicitly imported thing
604 hasBetterProv LocalDef _ = True
605 hasBetterProv (NonLocalDef (UserImport _ _ _ )) (NonLocalDef ImplicitImport) = True
606 hasBetterProv _ _ = False
608 pprNameProvenance :: Name -> Provenance -> SDoc
609 pprNameProvenance name LocalDef = ptext SLIT("defined at") <+> ppr (nameSrcLoc name)
610 pprNameProvenance name (NonLocalDef why) = sep [ppr_reason why,
611 nest 2 (parens (ppr_defn (nameSrcLoc name)))]
613 ppr_reason ImplicitImport = ptext SLIT("implicitly imported")
614 ppr_reason (UserImport mod loc _) = ptext SLIT("imported from") <+> ppr mod <+> ptext SLIT("at") <+> ppr loc
616 ppr_defn loc | isGoodSrcLoc loc = ptext SLIT("at") <+> ppr loc