2 % (c) The University of Glasgow, 2000
4 \section[HscTypes]{Types for the per-module compiler}
10 ModDetails(..), ModIface(..), GlobalSymbolTable,
11 HomeSymbolTable, PackageSymbolTable,
12 HomeIfaceTable, PackageIfaceTable, emptyIfaceTable,
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 ( IdCoreRule )
71 import FiniteMap ( FiniteMap, emptyFM, addToFM, lookupFM, foldFM )
73 import Maybes ( seqMaybe )
74 import UniqFM ( UniqFM, emptyUFM )
76 import SrcLoc ( SrcLoc, isGoodSrcLoc )
77 import Util ( thenCmp )
78 import UniqSupply ( UniqSupply )
81 %************************************************************************
83 \subsection{Module locations}
85 %************************************************************************
96 instance Outputable ModuleLocation where
100 For a module in another package, the hs_file and obj_file
101 components of ModuleLocation are undefined.
103 The locations specified by a ModuleLocation may or may not
104 correspond to actual files yet: for example, even if the object
105 file doesn't exist, the ModuleLocation still contains the path to
106 where the object file will reside if/when it is created.
109 %************************************************************************
111 \subsection{Symbol tables and Module details}
113 %************************************************************************
115 A @ModIface@ plus a @ModDetails@ summarises everything we know
116 about a compiled module. The @ModIface@ is the stuff *before* linking,
117 and can be written out to an interface file. The @ModDetails@ is after
118 linking; it is the "linked" form of the mi_decls field.
123 mi_module :: Module, -- Complete with package info
124 mi_version :: VersionInfo, -- Module version number
125 mi_orphan :: WhetherHasOrphans, -- Whether this module has orphans
127 mi_usages :: [ImportVersion Name], -- Usages; kept sorted so that it's easy
128 -- to decide whether to write a new iface file
129 -- (changing usages doesn't affect the version of
132 mi_exports :: [(ModuleName,Avails)], -- What it exports
133 -- Kept sorted by (mod,occ),
134 -- to make version comparisons easier
136 mi_globals :: GlobalRdrEnv, -- Its top level environment
138 mi_fixities :: NameEnv Fixity, -- Fixities
139 mi_deprecs :: Deprecations, -- Deprecations
141 mi_decls :: IfaceDecls -- The RnDecls form of ModDetails
144 data IfaceDecls = IfaceDecls { dcl_tycl :: [RenamedTyClDecl], -- Sorted
145 dcl_rules :: [RenamedRuleDecl], -- Sorted
146 dcl_insts :: [RenamedInstDecl] } -- Unsorted
148 -- typechecker should only look at this, not ModIface
149 -- Should be able to construct ModDetails from mi_decls in ModIface
152 -- The next three fields are created by the typechecker
154 md_insts :: [DFunId], -- Dfun-ids for the instances in this module
155 md_rules :: [IdCoreRule] -- Domain may include Ids from other modules
160 emptyModDetails :: ModDetails
162 = ModDetails { md_types = emptyTypeEnv,
167 emptyModIface :: Module -> ModIface
169 = ModIface { mi_module = mod,
171 mi_globals = emptyRdrEnv,
172 mi_deprecs = NoDeprecs
176 Symbol tables map modules to ModDetails:
179 type SymbolTable = ModuleEnv ModDetails
180 type IfaceTable = ModuleEnv ModIface
182 type HomeIfaceTable = IfaceTable
183 type PackageIfaceTable = IfaceTable
185 type HomeSymbolTable = SymbolTable -- Domain = modules in the home package
186 type PackageSymbolTable = SymbolTable -- Domain = modules in the some other package
187 type GlobalSymbolTable = SymbolTable -- Domain = all modules
189 emptyIfaceTable :: IfaceTable
190 emptyIfaceTable = emptyUFM
193 Simple lookups in the symbol table.
196 lookupTable :: ModuleEnv a -> ModuleEnv a -> Name -> Maybe a
197 -- We often have two Symbol- or IfaceTables, and want to do a lookup
198 lookupTable ht pt name
199 = lookupModuleEnv ht mod `seqMaybe` lookupModuleEnv pt mod
201 mod = nameModule name
203 lookupTableByModName :: ModuleEnv a -> ModuleEnv a -> ModuleName -> Maybe a
204 -- We often have two Symbol- or IfaceTables, and want to do a lookup
205 lookupTableByModName ht pt mod
206 = lookupModuleEnvByName ht mod `seqMaybe` lookupModuleEnvByName pt mod
210 %************************************************************************
212 \subsection{Type environment stuff}
214 %************************************************************************
217 type TypeEnv = NameEnv TyThing
218 emptyTypeEnv = emptyNameEnv
220 data TyThing = AnId Id
224 isTyClThing :: TyThing -> Bool
225 isTyClThing (ATyCon _) = True
226 isTyClThing (AClass _) = True
227 isTyClThing (AnId _) = False
229 instance NamedThing TyThing where
230 getName (AnId id) = getName id
231 getName (ATyCon tc) = getName tc
232 getName (AClass cl) = getName cl
234 typeEnvClasses env = [cl | AClass cl <- nameEnvElts env]
235 typeEnvTyCons env = [tc | ATyCon tc <- nameEnvElts env]
241 lookupTypeEnv :: SymbolTable -> Name -> Maybe TyThing
242 lookupTypeEnv tbl name
243 = case lookupModuleEnv tbl (nameModule name) of
244 Just details -> lookupNameEnv (md_types details) name
248 groupTyThings :: [TyThing] -> FiniteMap Module TypeEnv
249 -- Finite map because we want the range too
251 = foldl add emptyFM things
253 add :: FiniteMap Module TypeEnv -> TyThing -> FiniteMap Module TypeEnv
254 add tbl thing = addToFM tbl mod new_env
257 mod = nameModule name
258 new_env = case lookupFM tbl mod of
259 Nothing -> unitNameEnv name thing
260 Just env -> extendNameEnv env name thing
262 extendTypeEnv :: SymbolTable -> FiniteMap Module TypeEnv -> SymbolTable
263 extendTypeEnv tbl things
264 = foldFM add tbl things
267 = extendModuleEnv tbl mod new_details
270 = case lookupModuleEnv tbl mod of
271 Nothing -> emptyModDetails {md_types = type_env}
272 Just details -> details {md_types = md_types details
273 `plusNameEnv` type_env}
277 %************************************************************************
279 \subsection{Auxiliary types}
281 %************************************************************************
283 These types are defined here because they are mentioned in ModDetails,
284 but they are mostly elaborated elsewhere
289 vers_module :: Version, -- Changes when anything changes
290 vers_exports :: Version, -- Changes when export list changes
291 vers_rules :: Version, -- Changes when any rule changes
292 vers_decls :: NameEnv Version
293 -- Versions for "big" names only (not data constructors, class ops)
294 -- The version of an Id changes if its fixity changes
295 -- Ditto data constructors, class operations, except that the version of
296 -- the parent class/tycon changes
299 initialVersionInfo :: VersionInfo
300 initialVersionInfo = VersionInfo { vers_module = initialVersion,
301 vers_exports = initialVersion,
302 vers_rules = initialVersion,
303 vers_decls = emptyNameEnv }
305 data Deprecations = NoDeprecs
306 | DeprecAll DeprecTxt -- Whole module deprecated
307 | DeprecSome (NameEnv (Name,DeprecTxt)) -- Some things deprecated
309 -- We keep the Name in the range, so we can print them out
311 lookupDeprec :: ModIface -> Name -> Maybe DeprecTxt
312 lookupDeprec iface name
313 = case mi_deprecs iface of
315 DeprecAll txt -> Just txt
316 DeprecSome env -> case lookupNameEnv env name of
317 Just (_, txt) -> Just txt
320 type InstEnv = UniqFM ClsInstEnv -- Maps Class to instances for that class
322 type ClsInstEnv = [(TyVarSet, [Type], DFunId)] -- The instances for a particular class
328 type Avails = [AvailInfo]
329 type AvailInfo = GenAvailInfo Name
330 type RdrAvailInfo = GenAvailInfo OccName
332 data GenAvailInfo name = Avail name -- An ordinary identifier
333 | AvailTC name -- The name of the type or class
334 [name] -- The available pieces of type/class.
335 -- NB: If the type or class is itself
336 -- to be in scope, it must be in this list.
337 -- Thus, typically: AvailTC Eq [Eq, ==, /=]
339 -- Equality used when deciding if the interface has changed
341 type AvailEnv = NameEnv AvailInfo -- Maps a Name to the AvailInfo that contains it
345 %************************************************************************
347 \subsection{ModIface}
349 %************************************************************************
352 type WhetherHasOrphans = Bool
354 -- * an instance decl in a module other than the defn module for
355 -- one of the tycons or classes in the instance head
356 -- * a transformation rule in a module other than the one defining
357 -- the function in the head of the rule.
359 type IsBootInterface = Bool
361 type ImportVersion name = (ModuleName, WhetherHasOrphans, IsBootInterface, WhatsImported name)
363 data WhatsImported name = NothingAtAll -- The module is below us in the
364 -- hierarchy, but we import nothing
366 | Everything Version -- Used for modules from other packages;
367 -- we record only the module's version number
370 Version -- Module version
371 (Maybe Version) -- Export-list version, if we depend on it
372 [(name,Version)] -- List guaranteed non-empty
373 Version -- Rules version
376 -- 'Specifically' doesn't let you say "I imported f but none of the rules in
377 -- the module". If you use anything in the module you get its rule version
378 -- So if the rules change, you'll recompile, even if you don't use them.
379 -- This is easy to implement, and it's safer: you might not have used the rules last
380 -- time round, but if someone has added a new rule you might need it this time
382 -- The export list field is (Just v) if we depend on the export list:
383 -- we imported the module without saying exactly what we imported
384 -- We need to recompile if the module exports changes, because we might
385 -- now have a name clash in the importing module.
389 %************************************************************************
391 \subsection{The persistent compiler state}
393 %************************************************************************
396 data PersistentCompilerState
398 pcs_PIT :: PackageIfaceTable, -- Domain = non-home-package modules
399 -- the mi_decls component is empty
401 pcs_PST :: PackageSymbolTable, -- Domain = non-home-package modules
402 -- except that the InstEnv components is empty
404 pcs_insts :: PackageInstEnv, -- The total InstEnv accumulated from all
405 -- the non-home-package modules
407 pcs_rules :: PackageRuleBase, -- Ditto RuleEnv
409 pcs_PRS :: PersistentRenamerState
414 The @PersistentRenamerState@ persists across successive calls to the
418 * A name supply, which deals with allocating unique names to
419 (Module,OccName) original names,
421 * An accumulated InstEnv from all the modules in pcs_PST
422 The point is that we don't want to keep recreating it whenever
423 we compile a new module. The InstEnv component of pcPST is empty.
424 (This means we might "see" instances that we shouldn't "really" see;
425 but the Haskell Report is vague on what is meant to be visible,
426 so we just take the easy road here.)
430 * A "holding pen" for declarations that have been read out of
431 interface files but not yet sucked in, renamed, and typechecked
434 type PackageRuleBase = RuleBase
435 type PackageInstEnv = InstEnv
437 data PersistentRenamerState
438 = PRS { prsOrig :: OrigNameEnv,
439 prsDecls :: DeclsMap,
440 prsInsts :: IfaceInsts,
441 prsRules :: IfaceRules,
446 The OrigNameEnv makes sure that there is just one Unique assigned for
447 each original name; i.e. (module-name, occ-name) pair. The Name is
448 always stored as a Global, and has the SrcLoc of its binding location.
449 Actually that's not quite right. When we first encounter the original
450 name, we might not be at its binding site (e.g. we are reading an
451 interface file); so we give it 'noSrcLoc' then. Later, when we find
452 its binding site, we fix it up.
454 Exactly the same is true of the Module stored in the Name. When we first
455 encounter the occurrence, we may not know the details of the module, so
456 we just store junk. Then when we find the binding site, we fix it up.
460 = Orig { origNames :: OrigNameNameEnv,
461 -- Ensures that one original name gets one unique
462 origIParam :: OrigNameIParamEnv
463 -- Ensures that one implicit parameter name gets one unique
466 type OrigNameNameEnv = FiniteMap (ModuleName,OccName) Name
467 type OrigNameIParamEnv = FiniteMap OccName Name
471 A DeclsMap contains a binding for each Name in the declaration
472 including the constructors of a type decl etc. The Bool is True just
476 type DeclsMap = NameEnv (AvailInfo, Bool, (Module, RdrNameTyClDecl))
478 type IfaceInsts = Bag GatedDecl
479 type IfaceRules = Bag GatedDecl
481 type GatedDecl = (NameSet, (Module, RdrNameHsDecl))
485 %************************************************************************
487 \subsection{Provenance and export info}
489 %************************************************************************
491 The GlobalRdrEnv gives maps RdrNames to Names. There is a separate
492 one for each module, corresponding to that module's top-level scope.
495 type GlobalRdrEnv = RdrNameEnv [(Name,Provenance)] -- The list is because there may be name clashes
496 -- These only get reported on lookup,
497 -- not on construction
500 The "provenance" of something says how it came to be in scope.
504 = LocalDef -- Defined locally
506 | NonLocalDef -- Defined non-locally
510 -- Just used for grouping error messages (in RnEnv.warnUnusedBinds)
511 instance Eq Provenance where
512 p1 == p2 = case p1 `compare` p2 of EQ -> True; _ -> False
514 instance Eq ImportReason where
515 p1 == p2 = case p1 `compare` p2 of EQ -> True; _ -> False
517 instance Ord Provenance where
518 compare LocalDef LocalDef = EQ
519 compare LocalDef (NonLocalDef _ _) = LT
520 compare (NonLocalDef _ _) LocalDef = GT
522 compare (NonLocalDef reason1 _) (NonLocalDef reason2 _)
523 = compare reason1 reason2
525 instance Ord ImportReason where
526 compare ImplicitImport ImplicitImport = EQ
527 compare ImplicitImport (UserImport _ _ _) = LT
528 compare (UserImport _ _ _) ImplicitImport = GT
529 compare (UserImport m1 loc1 _) (UserImport m2 loc2 _)
530 = (m1 `compare` m2) `thenCmp` (loc1 `compare` loc2)
534 = UserImport Module SrcLoc Bool -- Imported from module M on line L
535 -- Note the M may well not be the defining module
537 -- The Bool is true iff the thing was named *explicitly* in the import spec,
538 -- rather than being imported as part of a group; e.g.
541 -- Here, everything imported by B, and the constructors of T
542 -- are not named explicitly; only T is named explicitly.
543 -- This info is used when warning of unused names.
545 | ImplicitImport -- Imported implicitly for some other reason
548 type PrintUnqualified = Bool -- True <=> the unqualified name of this thing is
549 -- in scope in this module, so print it
550 -- unqualified in error messages
554 hasBetterProv :: Provenance -> Provenance -> Bool
556 -- a local thing over an imported thing
557 -- a user-imported thing over a non-user-imported thing
558 -- an explicitly-imported thing over an implicitly imported thing
559 hasBetterProv LocalDef _ = True
560 hasBetterProv (NonLocalDef (UserImport _ _ True) _) _ = True
561 hasBetterProv (NonLocalDef (UserImport _ _ _ ) _) (NonLocalDef ImplicitImport _) = True
562 hasBetterProv _ _ = False
564 pprNameProvenance :: Name -> Provenance -> SDoc
565 pprNameProvenance name LocalDef = ptext SLIT("defined at") <+> ppr (nameSrcLoc name)
566 pprNameProvenance name (NonLocalDef why _) = sep [ppr_reason why,
567 nest 2 (parens (ppr_defn (nameSrcLoc name)))]
569 ppr_reason ImplicitImport = ptext SLIT("implicitly imported")
570 ppr_reason (UserImport mod loc _) = ptext SLIT("imported from") <+> ppr mod <+> ptext SLIT("at") <+> ppr loc
572 ppr_defn loc | isGoodSrcLoc loc = ptext SLIT("at") <+> ppr loc