2 % (c) The University of Glasgow, 2000
4 \section[HscTypes]{Types for the per-module compiler}
8 Finder, ModuleLocation(..),
10 ModDetails(..), ModIface(..), GlobalSymbolTable,
11 HomeSymbolTable, PackageSymbolTable,
12 HomeIfaceTable, PackageIfaceTable,
13 lookupTable, lookupTableByModName,
17 VersionInfo(..), initialVersionInfo,
19 TyThing(..), groupTyThings, isTyClThing,
21 TypeEnv, extendTypeEnv, lookupTypeEnv,
22 typeEnvClasses, typeEnvTyCons,
24 WhetherHasOrphans, ImportVersion, WhatsImported(..),
25 PersistentRenamerState(..), IsBootInterface, Avails, DeclsMap,
26 IfaceInsts, IfaceRules, GatedDecl,
27 OrigNameEnv(..), OrigNameNameEnv, OrigNameIParamEnv,
28 AvailEnv, AvailInfo, GenAvailInfo(..),
29 PersistentCompilerState(..),
31 Deprecations(..), lookupDeprec,
33 InstEnv, ClsInstEnv, DFunId,
34 PackageInstEnv, PackageRuleBase,
36 GlobalRdrEnv, RdrAvailInfo,
39 Provenance(..), ImportReason(..), PrintUnqualified,
40 pprNameProvenance, hasBetterProv
44 #include "HsVersions.h"
46 import RdrName ( RdrNameEnv, emptyRdrEnv )
47 import Name ( Name, NameEnv, NamedThing,
48 emptyNameEnv, unitNameEnv, extendNameEnv, plusNameEnv,
49 lookupNameEnv, emptyNameEnv, getName, nameModule,
50 nameSrcLoc, nameEnvElts )
51 import NameSet ( NameSet )
52 import OccName ( OccName )
53 import Module ( Module, ModuleName, ModuleEnv,
54 extendModuleEnv, lookupModuleEnv, lookupModuleEnvByName
56 import Rules ( RuleBase )
57 import VarSet ( TyVarSet )
59 import Class ( Class )
60 import TyCon ( TyCon )
62 import BasicTypes ( Version, initialVersion, Fixity )
64 import HsSyn ( DeprecTxt )
65 import RdrHsSyn ( RdrNameHsDecl, RdrNameTyClDecl )
66 import RnHsSyn ( RenamedTyClDecl, RenamedRuleDecl, RenamedInstDecl )
68 import CoreSyn ( CoreRule, IdCoreRule )
71 import FiniteMap ( FiniteMap, emptyFM, addToFM, lookupFM, foldFM )
73 import Maybes ( seqMaybe )
74 import UniqFM ( UniqFM )
76 import SrcLoc ( SrcLoc, isGoodSrcLoc )
77 import Util ( thenCmp )
78 import UniqSupply ( UniqSupply )
81 %************************************************************************
83 \subsection{The Finder type}
85 %************************************************************************
88 type Finder = ModuleName -> IO (Maybe (Module, ModuleLocation))
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
125 mi_usages :: [ImportVersion Name], -- Usages; kept sorted so that it's easy
126 -- to decide whether to write a new iface file
127 -- (changing usages doesn't affect the version of
130 mi_exports :: [(ModuleName,Avails)], -- What it exports
131 -- Kept sorted by (mod,occ),
132 -- to make version comparisons easier
134 mi_globals :: GlobalRdrEnv, -- Its top level environment
136 mi_fixities :: NameEnv Fixity, -- Fixities
137 mi_deprecs :: Deprecations, -- Deprecations
139 mi_decls :: IfaceDecls -- The RnDecls form of ModDetails
142 data IfaceDecls = IfaceDecls { dcl_tycl :: [RenamedTyClDecl], -- Sorted
143 dcl_rules :: [RenamedRuleDecl], -- Sorted
144 dcl_insts :: [RenamedInstDecl] } -- Unsorted
146 -- typechecker should only look at this, not ModIface
147 -- Should be able to construct ModDetails from mi_decls in ModIface
150 -- The next three fields are created by the typechecker
152 md_insts :: [DFunId], -- Dfun-ids for the instances in this module
153 md_rules :: [IdCoreRule] -- Domain may include Ids from other modules
158 emptyModDetails :: ModDetails
160 = ModDetails { md_types = emptyTypeEnv,
165 emptyModIface :: Module -> ModIface
167 = ModIface { mi_module = mod,
169 mi_globals = emptyRdrEnv,
170 mi_deprecs = NoDeprecs
174 Symbol tables map modules to ModDetails:
177 type SymbolTable = ModuleEnv ModDetails
178 type IfaceTable = ModuleEnv ModIface
180 type HomeIfaceTable = IfaceTable
181 type PackageIfaceTable = IfaceTable
183 type HomeSymbolTable = SymbolTable -- Domain = modules in the home package
184 type PackageSymbolTable = SymbolTable -- Domain = modules in the some other package
185 type GlobalSymbolTable = SymbolTable -- Domain = all modules
188 Simple lookups in the symbol table.
191 lookupTable :: ModuleEnv a -> ModuleEnv a -> Name -> Maybe a
192 -- We often have two Symbol- or IfaceTables, and want to do a lookup
193 lookupTable ht pt name
194 = lookupModuleEnv ht mod `seqMaybe` lookupModuleEnv pt mod
196 mod = nameModule name
198 lookupTableByModName :: ModuleEnv a -> ModuleEnv a -> ModuleName -> Maybe a
199 -- We often have two Symbol- or IfaceTables, and want to do a lookup
200 lookupTableByModName ht pt mod
201 = lookupModuleEnvByName ht mod `seqMaybe` lookupModuleEnvByName pt mod
205 %************************************************************************
207 \subsection{Type environment stuff}
209 %************************************************************************
212 type TypeEnv = NameEnv TyThing
213 emptyTypeEnv = emptyNameEnv
215 data TyThing = AnId Id
219 isTyClThing :: TyThing -> Bool
220 isTyClThing (ATyCon _) = True
221 isTyClThing (AClass _) = True
222 isTyClThing (AnId _) = False
224 instance NamedThing TyThing where
225 getName (AnId id) = getName id
226 getName (ATyCon tc) = getName tc
227 getName (AClass cl) = getName cl
229 typeEnvClasses env = [cl | AClass cl <- nameEnvElts env]
230 typeEnvTyCons env = [tc | ATyCon tc <- nameEnvElts env]
236 lookupTypeEnv :: SymbolTable -> Name -> Maybe TyThing
237 lookupTypeEnv tbl name
238 = case lookupModuleEnv tbl (nameModule name) of
239 Just details -> lookupNameEnv (md_types details) name
243 groupTyThings :: [TyThing] -> FiniteMap Module TypeEnv
244 -- Finite map because we want the range too
246 = foldl add emptyFM things
248 add :: FiniteMap Module TypeEnv -> TyThing -> FiniteMap Module TypeEnv
249 add tbl thing = addToFM tbl mod new_env
252 mod = nameModule name
253 new_env = case lookupFM tbl mod of
254 Nothing -> unitNameEnv name thing
255 Just env -> extendNameEnv env name thing
257 extendTypeEnv :: SymbolTable -> FiniteMap Module TypeEnv -> SymbolTable
258 extendTypeEnv tbl things
259 = foldFM add tbl things
262 = extendModuleEnv tbl mod new_details
265 = case lookupModuleEnv tbl mod of
266 Nothing -> emptyModDetails {md_types = type_env}
267 Just details -> details {md_types = md_types details
268 `plusNameEnv` type_env}
272 %************************************************************************
274 \subsection{Auxiliary types}
276 %************************************************************************
278 These types are defined here because they are mentioned in ModDetails,
279 but they are mostly elaborated elsewhere
284 vers_module :: Version, -- Changes when anything changes
285 vers_exports :: Version, -- Changes when export list changes
286 vers_rules :: Version, -- Changes when any rule changes
287 vers_decls :: NameEnv Version
288 -- Versions for "big" names only (not data constructors, class ops)
289 -- The version of an Id changes if its fixity changes
290 -- Ditto data constructors, class operations, except that the version of
291 -- the parent class/tycon changes
294 initialVersionInfo :: VersionInfo
295 initialVersionInfo = VersionInfo { vers_module = initialVersion,
296 vers_exports = initialVersion,
297 vers_rules = initialVersion,
298 vers_decls = emptyNameEnv }
300 data Deprecations = NoDeprecs
301 | DeprecAll DeprecTxt -- Whole module deprecated
302 | DeprecSome (NameEnv (Name,DeprecTxt)) -- Some things deprecated
304 -- We keep the Name in the range, so we can print them out
306 lookupDeprec :: ModIface -> Name -> Maybe DeprecTxt
307 lookupDeprec iface name
308 = case mi_deprecs iface of
310 DeprecAll txt -> Just txt
311 DeprecSome env -> case lookupNameEnv env name of
312 Just (_, txt) -> Just txt
315 type InstEnv = UniqFM ClsInstEnv -- Maps Class to instances for that class
317 type ClsInstEnv = [(TyVarSet, [Type], DFunId)] -- The instances for a particular class
323 type Avails = [AvailInfo]
324 type AvailInfo = GenAvailInfo Name
325 type RdrAvailInfo = GenAvailInfo OccName
327 data GenAvailInfo name = Avail name -- An ordinary identifier
328 | AvailTC name -- The name of the type or class
329 [name] -- The available pieces of type/class.
330 -- NB: If the type or class is itself
331 -- to be in scope, it must be in this list.
332 -- Thus, typically: AvailTC Eq [Eq, ==, /=]
334 -- Equality used when deciding if the interface has changed
336 type AvailEnv = NameEnv AvailInfo -- Maps a Name to the AvailInfo that contains it
340 %************************************************************************
342 \subsection{ModIface}
344 %************************************************************************
347 type WhetherHasOrphans = Bool
349 -- * an instance decl in a module other than the defn module for
350 -- one of the tycons or classes in the instance head
351 -- * a transformation rule in a module other than the one defining
352 -- the function in the head of the rule.
354 type IsBootInterface = Bool
356 type ImportVersion name = (ModuleName, WhetherHasOrphans, IsBootInterface, WhatsImported name)
358 data WhatsImported name = NothingAtAll -- The module is below us in the
359 -- hierarchy, but we import nothing
361 | Everything Version -- Used for modules from other packages;
362 -- we record only the module's version number
365 Version -- Module version
366 (Maybe Version) -- Export-list version, if we depend on it
367 [(name,Version)] -- List guaranteed non-empty
368 Version -- Rules version
371 -- 'Specifically' doesn't let you say "I imported f but none of the rules in
372 -- the module". If you use anything in the module you get its rule version
373 -- So if the rules change, you'll recompile, even if you don't use them.
374 -- This is easy to implement, and it's safer: you might not have used the rules last
375 -- time round, but if someone has added a new rule you might need it this time
377 -- The export list field is (Just v) if we depend on the export list:
378 -- we imported the module without saying exactly what we imported
379 -- We need to recompile if the module exports changes, because we might
380 -- now have a name clash in the importing module.
384 %************************************************************************
386 \subsection{The persistent compiler state}
388 %************************************************************************
391 data PersistentCompilerState
393 pcs_PIT :: PackageIfaceTable, -- Domain = non-home-package modules
394 -- the mi_decls component is empty
396 pcs_PST :: PackageSymbolTable, -- Domain = non-home-package modules
397 -- except that the InstEnv components is empty
399 pcs_insts :: PackageInstEnv, -- The total InstEnv accumulated from all
400 -- the non-home-package modules
402 pcs_rules :: PackageRuleBase, -- Ditto RuleEnv
404 pcs_PRS :: PersistentRenamerState
409 The @PersistentRenamerState@ persists across successive calls to the
413 * A name supply, which deals with allocating unique names to
414 (Module,OccName) original names,
416 * An accumulated InstEnv from all the modules in pcs_PST
417 The point is that we don't want to keep recreating it whenever
418 we compile a new module. The InstEnv component of pcPST is empty.
419 (This means we might "see" instances that we shouldn't "really" see;
420 but the Haskell Report is vague on what is meant to be visible,
421 so we just take the easy road here.)
425 * A "holding pen" for declarations that have been read out of
426 interface files but not yet sucked in, renamed, and typechecked
429 type PackageRuleBase = RuleBase
430 type PackageInstEnv = InstEnv
432 data PersistentRenamerState
433 = PRS { prsOrig :: OrigNameEnv,
434 prsDecls :: DeclsMap,
435 prsInsts :: IfaceInsts,
436 prsRules :: IfaceRules,
441 The OrigNameEnv makes sure that there is just one Unique assigned for
442 each original name; i.e. (module-name, occ-name) pair. The Name is
443 always stored as a Global, and has the SrcLoc of its binding location.
444 Actually that's not quite right. When we first encounter the original
445 name, we might not be at its binding site (e.g. we are reading an
446 interface file); so we give it 'noSrcLoc' then. Later, when we find
447 its binding site, we fix it up.
449 Exactly the same is true of the Module stored in the Name. When we first
450 encounter the occurrence, we may not know the details of the module, so
451 we just store junk. Then when we find the binding site, we fix it up.
455 = Orig { origNames :: OrigNameNameEnv,
456 -- Ensures that one original name gets one unique
457 origIParam :: OrigNameIParamEnv
458 -- Ensures that one implicit parameter name gets one unique
461 type OrigNameNameEnv = FiniteMap (ModuleName,OccName) Name
462 type OrigNameIParamEnv = FiniteMap OccName Name
466 A DeclsMap contains a binding for each Name in the declaration
467 including the constructors of a type decl etc. The Bool is True just
471 type DeclsMap = NameEnv (AvailInfo, Bool, (Module, RdrNameTyClDecl))
473 type IfaceInsts = Bag GatedDecl
474 type IfaceRules = Bag GatedDecl
476 type GatedDecl = (NameSet, (Module, RdrNameHsDecl))
480 %************************************************************************
482 \subsection{Provenance and export info}
484 %************************************************************************
486 The GlobalRdrEnv gives maps RdrNames to Names. There is a separate
487 one for each module, corresponding to that module's top-level scope.
490 type GlobalRdrEnv = RdrNameEnv [(Name,Provenance)] -- The list is because there may be name clashes
491 -- These only get reported on lookup,
492 -- not on construction
495 The "provenance" of something says how it came to be in scope.
499 = LocalDef -- Defined locally
501 | NonLocalDef -- Defined non-locally
505 -- Just used for grouping error messages (in RnEnv.warnUnusedBinds)
506 instance Eq Provenance where
507 p1 == p2 = case p1 `compare` p2 of EQ -> True; _ -> False
509 instance Eq ImportReason where
510 p1 == p2 = case p1 `compare` p2 of EQ -> True; _ -> False
512 instance Ord Provenance where
513 compare LocalDef LocalDef = EQ
514 compare LocalDef (NonLocalDef _ _) = LT
515 compare (NonLocalDef _ _) LocalDef = GT
517 compare (NonLocalDef reason1 _) (NonLocalDef reason2 _)
518 = compare reason1 reason2
520 instance Ord ImportReason where
521 compare ImplicitImport ImplicitImport = EQ
522 compare ImplicitImport (UserImport _ _ _) = LT
523 compare (UserImport _ _ _) ImplicitImport = GT
524 compare (UserImport m1 loc1 _) (UserImport m2 loc2 _)
525 = (m1 `compare` m2) `thenCmp` (loc1 `compare` loc2)
529 = UserImport Module SrcLoc Bool -- Imported from module M on line L
530 -- Note the M may well not be the defining module
532 -- The Bool is true iff the thing was named *explicitly* in the import spec,
533 -- rather than being imported as part of a group; e.g.
536 -- Here, everything imported by B, and the constructors of T
537 -- are not named explicitly; only T is named explicitly.
538 -- This info is used when warning of unused names.
540 | ImplicitImport -- Imported implicitly for some other reason
543 type PrintUnqualified = Bool -- True <=> the unqualified name of this thing is
544 -- in scope in this module, so print it
545 -- unqualified in error messages
549 hasBetterProv :: Provenance -> Provenance -> Bool
551 -- a local thing over an imported thing
552 -- a user-imported thing over a non-user-imported thing
553 -- an explicitly-imported thing over an implicitly imported thing
554 hasBetterProv LocalDef _ = True
555 hasBetterProv (NonLocalDef (UserImport _ _ True) _) _ = True
556 hasBetterProv (NonLocalDef (UserImport _ _ _ ) _) (NonLocalDef ImplicitImport _) = True
557 hasBetterProv _ _ = False
559 pprNameProvenance :: Name -> Provenance -> SDoc
560 pprNameProvenance name LocalDef = ptext SLIT("defined at") <+> ppr (nameSrcLoc name)
561 pprNameProvenance name (NonLocalDef why _) = sep [ppr_reason why,
562 nest 2 (parens (ppr_defn (nameSrcLoc name)))]
564 ppr_reason ImplicitImport = ptext SLIT("implicitly imported")
565 ppr_reason (UserImport mod loc _) = ptext SLIT("imported from") <+> ppr mod <+> ptext SLIT("at") <+> ppr loc
567 ppr_defn loc | isGoodSrcLoc loc = ptext SLIT("at") <+> ppr loc