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, typeEnvIds,
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]
251 typeEnvIds env = [id | AnId id <- nameEnvElts env]
253 implicitTyThingIds :: [TyThing] -> [Id]
254 -- Add the implicit data cons and selectors etc
255 implicitTyThingIds things
256 = concat (map go things)
259 go (AClass cl) = classSelIds cl
260 go (ATyCon tc) = tyConGenIds tc ++
262 [ n | dc <- tyConDataConsIfAvailable tc,
263 n <- [dataConId dc, dataConWrapId dc] ]
264 -- Synonyms return empty list of constructors and selectors
269 type TypeEnv = NameEnv TyThing
271 emptyTypeEnv = emptyNameEnv
273 mkTypeEnv :: [TyThing] -> TypeEnv
274 mkTypeEnv things = extendTypeEnvList emptyTypeEnv things
276 extendTypeEnvList :: TypeEnv -> [TyThing] -> TypeEnv
277 extendTypeEnvList env things
278 = foldl add_thing env things
280 add_thing :: TypeEnv -> TyThing -> TypeEnv
281 add_thing env thing = extendNameEnv env (getName thing) thing
285 lookupType :: HomeSymbolTable -> PackageTypeEnv -> Name -> Maybe TyThing
286 lookupType hst pte name
287 = case lookupModuleEnv hst (nameModule name) of
288 Just details -> lookupNameEnv (md_types details) name
289 Nothing -> lookupNameEnv pte name
292 %************************************************************************
294 \subsection{Auxiliary types}
296 %************************************************************************
298 These types are defined here because they are mentioned in ModDetails,
299 but they are mostly elaborated elsewhere
304 vers_module :: Version, -- Changes when anything changes
305 vers_exports :: Version, -- Changes when export list changes
306 vers_rules :: Version, -- Changes when any rule changes
307 vers_decls :: NameEnv Version
308 -- Versions for "big" names only (not data constructors, class ops)
309 -- The version of an Id changes if its fixity changes
310 -- Ditto data constructors, class operations, except that the version of
311 -- the parent class/tycon changes
314 initialVersionInfo :: VersionInfo
315 initialVersionInfo = VersionInfo { vers_module = initialVersion,
316 vers_exports = initialVersion,
317 vers_rules = initialVersion,
318 vers_decls = emptyNameEnv }
320 data Deprecations = NoDeprecs
321 | DeprecAll DeprecTxt -- Whole module deprecated
322 | DeprecSome (NameEnv (Name,DeprecTxt)) -- Some things deprecated
324 -- We keep the Name in the range, so we can print them out
326 lookupDeprec :: Deprecations -> Name -> Maybe DeprecTxt
327 lookupDeprec NoDeprecs name = Nothing
328 lookupDeprec (DeprecAll txt) name = Just txt
329 lookupDeprec (DeprecSome env) name = case lookupNameEnv env name of
330 Just (_, txt) -> Just txt
333 instance Eq Deprecations where
334 -- Used when checking whether we need write a new interface
335 NoDeprecs == NoDeprecs = True
336 (DeprecAll t1) == (DeprecAll t2) = t1 == t2
337 (DeprecSome e1) == (DeprecSome e2) = nameEnvElts e1 == nameEnvElts e2
343 type Avails = [AvailInfo]
344 type AvailInfo = GenAvailInfo Name
345 type RdrAvailInfo = GenAvailInfo OccName
347 data GenAvailInfo name = Avail name -- An ordinary identifier
348 | AvailTC name -- The name of the type or class
349 [name] -- The available pieces of type/class.
350 -- NB: If the type or class is itself
351 -- to be in scope, it must be in this list.
352 -- Thus, typically: AvailTC Eq [Eq, ==, /=]
354 -- Equality used when deciding if the interface has changed
356 type AvailEnv = NameEnv AvailInfo -- Maps a Name to the AvailInfo that contains it
358 instance Outputable n => Outputable (GenAvailInfo n) where
361 pprAvail :: Outputable n => GenAvailInfo n -> SDoc
362 pprAvail (AvailTC n ns) = ppr n <> case {- filter (/= n) -} ns of
364 ns' -> braces (hsep (punctuate comma (map ppr ns')))
366 pprAvail (Avail n) = ppr n
370 %************************************************************************
372 \subsection{ModIface}
374 %************************************************************************
377 type WhetherHasOrphans = Bool
379 -- * an instance decl in a module other than the defn module for
380 -- one of the tycons or classes in the instance head
381 -- * a transformation rule in a module other than the one defining
382 -- the function in the head of the rule.
384 type IsBootInterface = Bool
386 type ImportVersion name = (ModuleName, WhetherHasOrphans, IsBootInterface, WhatsImported name)
388 data WhatsImported name = NothingAtAll -- The module is below us in the
389 -- hierarchy, but we import nothing
391 | Everything Version -- Used for modules from other packages;
392 -- we record only the module's version number
395 Version -- Module version
396 (Maybe Version) -- Export-list version, if we depend on it
397 [(name,Version)] -- List guaranteed non-empty
398 Version -- Rules version
401 -- 'Specifically' doesn't let you say "I imported f but none of the rules in
402 -- the module". If you use anything in the module you get its rule version
403 -- So if the rules change, you'll recompile, even if you don't use them.
404 -- This is easy to implement, and it's safer: you might not have used the rules last
405 -- time round, but if someone has added a new rule you might need it this time
407 -- The export list field is (Just v) if we depend on the export list:
408 -- we imported the module without saying exactly what we imported
409 -- We need to recompile if the module exports changes, because we might
410 -- now have a name clash in the importing module.
412 type IsExported = Name -> Bool -- True for names that are exported from this module
416 %************************************************************************
418 \subsection{The persistent compiler state}
420 %************************************************************************
423 data PersistentCompilerState
425 pcs_PIT :: PackageIfaceTable, -- Domain = non-home-package modules
426 -- the mi_decls component is empty
428 pcs_PTE :: PackageTypeEnv, -- Domain = non-home-package modules
429 -- except that the InstEnv components is empty
431 pcs_insts :: PackageInstEnv, -- The total InstEnv accumulated from all
432 -- the non-home-package modules
434 pcs_rules :: PackageRuleBase, -- Ditto RuleEnv
436 pcs_PRS :: PersistentRenamerState
440 The @PersistentRenamerState@ persists across successive calls to the
444 * A name supply, which deals with allocating unique names to
445 (Module,OccName) original names,
447 * An accumulated TypeEnv from all the modules in imported packages
449 * An accumulated InstEnv from all the modules in imported packages
450 The point is that we don't want to keep recreating it whenever
451 we compile a new module. The InstEnv component of pcPST is empty.
452 (This means we might "see" instances that we shouldn't "really" see;
453 but the Haskell Report is vague on what is meant to be visible,
454 so we just take the easy road here.)
458 * A "holding pen" for declarations that have been read out of
459 interface files but not yet sucked in, renamed, and typechecked
462 type PackageTypeEnv = TypeEnv
463 type PackageRuleBase = RuleBase
464 type PackageInstEnv = InstEnv
466 data PersistentRenamerState
467 = PRS { prsOrig :: NameSupply,
468 prsImpMods :: ImportedModuleInfo,
469 prsDecls :: DeclsMap,
470 prsInsts :: IfaceInsts,
471 prsRules :: IfaceRules
475 The NameSupply makes sure that there is just one Unique assigned for
476 each original name; i.e. (module-name, occ-name) pair. The Name is
477 always stored as a Global, and has the SrcLoc of its binding location.
478 Actually that's not quite right. When we first encounter the original
479 name, we might not be at its binding site (e.g. we are reading an
480 interface file); so we give it 'noSrcLoc' then. Later, when we find
481 its binding site, we fix it up.
483 Exactly the same is true of the Module stored in the Name. When we first
484 encounter the occurrence, we may not know the details of the module, so
485 we just store junk. Then when we find the binding site, we fix it up.
489 = NameSupply { nsUniqs :: UniqSupply,
491 nsNames :: OrigNameCache,
492 -- Ensures that one original name gets one unique
493 nsIPs :: OrigIParamCache
494 -- Ensures that one implicit parameter name gets one unique
497 type OrigNameCache = FiniteMap (ModuleName,OccName) Name
498 type OrigIParamCache = FiniteMap OccName Name
501 @ImportedModuleInfo@ contains info ONLY about modules that have not yet
502 been loaded into the iPIT. These modules are mentioned in interfaces we've
503 already read, so we know a tiny bit about them, but we havn't yet looked
504 at the interface file for the module itself. It needs to persist across
505 invocations of the renamer, at least from Rename.checkOldIface to Rename.renameSource.
506 And there's no harm in it persisting across multiple compilations.
509 type ImportedModuleInfo = FiniteMap ModuleName (WhetherHasOrphans, IsBootInterface)
512 A DeclsMap contains a binding for each Name in the declaration
513 including the constructors of a type decl etc. The Bool is True just
517 type DeclsMap = (NameEnv (AvailInfo, Bool, (Module, RdrNameTyClDecl)), Int)
518 -- The Int says how many have been sucked in
520 type IfaceInsts = GatedDecls RdrNameInstDecl
521 type IfaceRules = GatedDecls RdrNameRuleDecl
523 type GatedDecls d = (Bag (GatedDecl d), Int) -- The Int says how many have been sucked in
524 type GatedDecl d = ([Name], (Module, d))
528 %************************************************************************
530 \subsection{Provenance and export info}
532 %************************************************************************
534 The GlobalRdrEnv gives maps RdrNames to Names. There is a separate
535 one for each module, corresponding to that module's top-level scope.
538 type GlobalRdrEnv = RdrNameEnv [GlobalRdrElt]
539 -- The list is because there may be name clashes
540 -- These only get reported on lookup, not on construction
542 data GlobalRdrElt = GRE Name Provenance (Maybe DeprecTxt)
543 -- The Maybe DeprecTxt tells whether this name is deprecated
546 = vcat (map pp (rdrEnvToList env))
548 pp (rn, nps) = ppr rn <> colon <+>
549 vcat [ppr n <+> pprNameProvenance n p | (GRE n p _) <- nps]
552 The "provenance" of something says how it came to be in scope.
556 = LocalDef -- Defined locally
558 | NonLocalDef -- Defined non-locally
561 -- Just used for grouping error messages (in RnEnv.warnUnusedBinds)
562 instance Eq Provenance where
563 p1 == p2 = case p1 `compare` p2 of EQ -> True; _ -> False
565 instance Eq ImportReason where
566 p1 == p2 = case p1 `compare` p2 of EQ -> True; _ -> False
568 instance Ord Provenance where
569 compare LocalDef LocalDef = EQ
570 compare LocalDef (NonLocalDef _) = LT
571 compare (NonLocalDef _) LocalDef = GT
573 compare (NonLocalDef reason1) (NonLocalDef reason2)
574 = compare reason1 reason2
576 instance Ord ImportReason where
577 compare ImplicitImport ImplicitImport = EQ
578 compare ImplicitImport (UserImport _ _ _) = LT
579 compare (UserImport _ _ _) ImplicitImport = GT
580 compare (UserImport m1 loc1 _) (UserImport m2 loc2 _)
581 = (m1 `compare` m2) `thenCmp` (loc1 `compare` loc2)
585 = UserImport Module SrcLoc Bool -- Imported from module M on line L
586 -- Note the M may well not be the defining module
588 -- The Bool is true iff the thing was named *explicitly* in the import spec,
589 -- rather than being imported as part of a group; e.g.
592 -- Here, everything imported by B, and the constructors of T
593 -- are not named explicitly; only T is named explicitly.
594 -- This info is used when warning of unused names.
596 | ImplicitImport -- Imported implicitly for some other reason
600 hasBetterProv :: Provenance -> Provenance -> Bool
602 -- a local thing over an imported thing
603 -- a user-imported thing over a non-user-imported thing
604 -- an explicitly-imported thing over an implicitly imported thing
605 hasBetterProv LocalDef _ = True
606 hasBetterProv (NonLocalDef (UserImport _ _ _ )) (NonLocalDef ImplicitImport) = True
607 hasBetterProv _ _ = False
609 pprNameProvenance :: Name -> Provenance -> SDoc
610 pprNameProvenance name LocalDef = ptext SLIT("defined at") <+> ppr (nameSrcLoc name)
611 pprNameProvenance name (NonLocalDef why) = sep [ppr_reason why,
612 nest 2 (parens (ppr_defn (nameSrcLoc name)))]
614 ppr_reason ImplicitImport = ptext SLIT("implicitly imported")
615 ppr_reason (UserImport mod loc _) = ptext SLIT("imported from") <+> ppr mod <+> ptext SLIT("at") <+> ppr loc
617 ppr_defn loc | isGoodSrcLoc loc = ptext SLIT("at") <+> ppr loc