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,
18 VersionInfo(..), initialVersionInfo,
20 TyThing(..), isTyClThing,
22 TypeEnv, lookupType, mkTypeEnv, extendTypeEnvList,
23 typeEnvClasses, typeEnvTyCons,
25 WhetherHasOrphans, ImportVersion, WhatsImported(..),
26 PersistentRenamerState(..), IsBootInterface, Avails, DeclsMap,
27 IfaceInsts, IfaceRules, GatedDecl,
28 OrigNameEnv(..), OrigNameNameEnv, OrigNameIParamEnv,
29 AvailEnv, AvailInfo, GenAvailInfo(..),
30 PersistentCompilerState(..),
32 Deprecations(..), lookupDeprec,
34 InstEnv, ClsInstEnv, DFunId,
35 PackageInstEnv, PackageRuleBase,
37 GlobalRdrEnv, RdrAvailInfo,
40 Provenance(..), ImportReason(..), PrintUnqualified,
41 pprNameProvenance, hasBetterProv
45 #include "HsVersions.h"
47 import RdrName ( RdrNameEnv, emptyRdrEnv )
48 import Name ( Name, NamedThing, isLocallyDefined,
49 getName, nameModule, nameSrcLoc )
51 import NameSet ( NameSet )
52 import OccName ( OccName )
53 import Module ( Module, ModuleName, ModuleEnv,
54 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 )
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 %************************************************************************
90 ml_hs_file :: Maybe FilePath,
91 ml_hspp_file :: Maybe FilePath, -- path of preprocessed source
92 ml_hi_file :: Maybe FilePath,
93 ml_obj_file :: Maybe FilePath
97 instance Outputable ModuleLocation where
101 For a module in another package, the hs_file and obj_file
102 components of ModuleLocation are undefined.
104 The locations specified by a ModuleLocation may or may not
105 correspond to actual files yet: for example, even if the object
106 file doesn't exist, the ModuleLocation still contains the path to
107 where the object file will reside if/when it is created.
110 %************************************************************************
112 \subsection{Symbol tables and Module details}
114 %************************************************************************
116 A @ModIface@ plus a @ModDetails@ summarises everything we know
117 about a compiled module. The @ModIface@ is the stuff *before* linking,
118 and can be written out to an interface file. The @ModDetails@ is after
119 linking; it is the "linked" form of the mi_decls field.
124 mi_module :: Module, -- Complete with package info
125 mi_version :: VersionInfo, -- Module version number
126 mi_orphan :: WhetherHasOrphans, -- Whether this module has orphans
127 mi_boot :: IsBootInterface, -- Whether this interface was read from an hi-boot file
129 mi_usages :: [ImportVersion Name], -- Usages; kept sorted so that it's easy
130 -- to decide whether to write a new iface file
131 -- (changing usages doesn't affect the version of
134 mi_exports :: [(ModuleName,Avails)], -- What it exports
135 -- Kept sorted by (mod,occ),
136 -- to make version comparisons easier
138 mi_globals :: GlobalRdrEnv, -- Its top level environment
140 mi_fixities :: NameEnv Fixity, -- Fixities
141 mi_deprecs :: Deprecations, -- Deprecations
143 mi_decls :: IfaceDecls -- The RnDecls form of ModDetails
146 data IfaceDecls = IfaceDecls { dcl_tycl :: [RenamedTyClDecl], -- Sorted
147 dcl_rules :: [RenamedRuleDecl], -- Sorted
148 dcl_insts :: [RenamedInstDecl] } -- Unsorted
150 -- typechecker should only look at this, not ModIface
151 -- Should be able to construct ModDetails from mi_decls in ModIface
154 -- The next three fields are created by the typechecker
156 md_insts :: [DFunId], -- Dfun-ids for the instances in this module
157 md_rules :: [IdCoreRule] -- Domain may include Ids from other modules
162 emptyModDetails :: ModDetails
164 = ModDetails { md_types = emptyTypeEnv,
169 emptyModIface :: Module -> ModIface
171 = ModIface { mi_module = mod,
172 mi_version = initialVersionInfo,
177 mi_fixities = emptyNameEnv,
178 mi_globals = emptyRdrEnv,
179 mi_deprecs = NoDeprecs,
180 mi_decls = panic "emptyModIface: decls"
184 Symbol tables map modules to ModDetails:
187 type SymbolTable = ModuleEnv ModDetails
188 type IfaceTable = ModuleEnv ModIface
190 type HomeIfaceTable = IfaceTable
191 type PackageIfaceTable = IfaceTable
193 type HomeSymbolTable = SymbolTable -- Domain = modules in the home package
195 emptyIfaceTable :: IfaceTable
196 emptyIfaceTable = emptyUFM
199 Simple lookups in the symbol table.
202 lookupIface :: HomeIfaceTable -> PackageIfaceTable
203 -> Module -> Name -- The module is to use for locally-defined names
205 -- We often have two IfaceTables, and want to do a lookup
206 lookupIface hit pit this_mod name
207 | isLocallyDefined name = lookupModuleEnv hit this_mod
208 | otherwise = lookupModuleEnv hit mod `seqMaybe` lookupModuleEnv pit mod
210 mod = nameModule name
212 lookupIfaceByModName :: ModuleEnv a -> ModuleEnv a -> ModuleName -> Maybe a
213 -- We often have two Symbol- or IfaceTables, and want to do a lookup
214 lookupIfaceByModName ht pt mod
215 = lookupModuleEnvByName ht mod `seqMaybe` lookupModuleEnvByName pt mod
219 %************************************************************************
221 \subsection{Type environment stuff}
223 %************************************************************************
226 data TyThing = AnId Id
230 isTyClThing :: TyThing -> Bool
231 isTyClThing (ATyCon _) = True
232 isTyClThing (AClass _) = True
233 isTyClThing (AnId _) = False
235 instance NamedThing TyThing where
236 getName (AnId id) = getName id
237 getName (ATyCon tc) = getName tc
238 getName (AClass cl) = getName cl
240 typeEnvClasses env = [cl | AClass cl <- nameEnvElts env]
241 typeEnvTyCons env = [tc | ATyCon tc <- nameEnvElts env]
247 type TypeEnv = NameEnv TyThing
249 emptyTypeEnv = emptyNameEnv
251 mkTypeEnv :: [TyThing] -> TypeEnv
252 mkTypeEnv things = extendTypeEnvList emptyTypeEnv things
254 extendTypeEnvList :: TypeEnv -> [TyThing] -> TypeEnv
255 extendTypeEnvList env things
256 = foldl add_thing env things
258 add_thing :: TypeEnv -> TyThing -> TypeEnv
259 add_thing env thing = extendNameEnv env (getName thing) thing
263 lookupType :: HomeSymbolTable -> PackageTypeEnv -> Name -> Maybe TyThing
264 lookupType hst pte name
265 = ASSERT2( not (isLocallyDefined name), ppr name )
266 case lookupModuleEnv hst (nameModule name) of
267 Just details -> lookupNameEnv (md_types details) name
268 Nothing -> lookupNameEnv pte name
271 %************************************************************************
273 \subsection{Auxiliary types}
275 %************************************************************************
277 These types are defined here because they are mentioned in ModDetails,
278 but they are mostly elaborated elsewhere
283 vers_module :: Version, -- Changes when anything changes
284 vers_exports :: Version, -- Changes when export list changes
285 vers_rules :: Version, -- Changes when any rule changes
286 vers_decls :: NameEnv Version
287 -- Versions for "big" names only (not data constructors, class ops)
288 -- The version of an Id changes if its fixity changes
289 -- Ditto data constructors, class operations, except that the version of
290 -- the parent class/tycon changes
293 initialVersionInfo :: VersionInfo
294 initialVersionInfo = VersionInfo { vers_module = initialVersion,
295 vers_exports = initialVersion,
296 vers_rules = initialVersion,
297 vers_decls = emptyNameEnv }
299 data Deprecations = NoDeprecs
300 | DeprecAll DeprecTxt -- Whole module deprecated
301 | DeprecSome (NameEnv (Name,DeprecTxt)) -- Some things deprecated
303 -- We keep the Name in the range, so we can print them out
305 lookupDeprec :: Deprecations -> Name -> Maybe DeprecTxt
306 lookupDeprec NoDeprecs name = Nothing
307 lookupDeprec (DeprecAll txt) name = Just txt
308 lookupDeprec (DeprecSome env) name = case lookupNameEnv env name of
309 Just (_, txt) -> Just txt
312 type InstEnv = UniqFM ClsInstEnv -- Maps Class to instances for that class
314 type ClsInstEnv = [(TyVarSet, [Type], DFunId)] -- The instances for a particular class
320 type Avails = [AvailInfo]
321 type AvailInfo = GenAvailInfo Name
322 type RdrAvailInfo = GenAvailInfo OccName
324 data GenAvailInfo name = Avail name -- An ordinary identifier
325 | AvailTC name -- The name of the type or class
326 [name] -- The available pieces of type/class.
327 -- NB: If the type or class is itself
328 -- to be in scope, it must be in this list.
329 -- Thus, typically: AvailTC Eq [Eq, ==, /=]
331 -- Equality used when deciding if the interface has changed
333 type AvailEnv = NameEnv AvailInfo -- Maps a Name to the AvailInfo that contains it
335 instance Outputable n => Outputable (GenAvailInfo n) where
338 pprAvail :: Outputable n => GenAvailInfo n -> SDoc
339 pprAvail (AvailTC n ns) = ppr n <> case {- filter (/= n) -} ns of
341 ns' -> braces (hsep (punctuate comma (map ppr ns')))
343 pprAvail (Avail n) = ppr n
347 %************************************************************************
349 \subsection{ModIface}
351 %************************************************************************
354 type WhetherHasOrphans = Bool
356 -- * an instance decl in a module other than the defn module for
357 -- one of the tycons or classes in the instance head
358 -- * a transformation rule in a module other than the one defining
359 -- the function in the head of the rule.
361 type IsBootInterface = Bool
363 type ImportVersion name = (ModuleName, WhetherHasOrphans, IsBootInterface, WhatsImported name)
365 data WhatsImported name = NothingAtAll -- The module is below us in the
366 -- hierarchy, but we import nothing
368 | Everything Version -- Used for modules from other packages;
369 -- we record only the module's version number
372 Version -- Module version
373 (Maybe Version) -- Export-list version, if we depend on it
374 [(name,Version)] -- List guaranteed non-empty
375 Version -- Rules version
378 -- 'Specifically' doesn't let you say "I imported f but none of the rules in
379 -- the module". If you use anything in the module you get its rule version
380 -- So if the rules change, you'll recompile, even if you don't use them.
381 -- This is easy to implement, and it's safer: you might not have used the rules last
382 -- time round, but if someone has added a new rule you might need it this time
384 -- The export list field is (Just v) if we depend on the export list:
385 -- we imported the module without saying exactly what we imported
386 -- We need to recompile if the module exports changes, because we might
387 -- now have a name clash in the importing module.
391 %************************************************************************
393 \subsection{The persistent compiler state}
395 %************************************************************************
398 data PersistentCompilerState
400 pcs_PIT :: PackageIfaceTable, -- Domain = non-home-package modules
401 -- the mi_decls component is empty
403 pcs_PTE :: PackageTypeEnv, -- Domain = non-home-package modules
404 -- except that the InstEnv components is empty
406 pcs_insts :: PackageInstEnv, -- The total InstEnv accumulated from all
407 -- the non-home-package modules
409 pcs_rules :: PackageRuleBase, -- Ditto RuleEnv
411 pcs_PRS :: PersistentRenamerState
416 The @PersistentRenamerState@ persists across successive calls to the
420 * A name supply, which deals with allocating unique names to
421 (Module,OccName) original names,
423 * An accumulated TypeEnv from all the modules in imported packages
425 * An accumulated InstEnv from all the modules in imported packages
426 The point is that we don't want to keep recreating it whenever
427 we compile a new module. The InstEnv component of pcPST is empty.
428 (This means we might "see" instances that we shouldn't "really" see;
429 but the Haskell Report is vague on what is meant to be visible,
430 so we just take the easy road here.)
434 * A "holding pen" for declarations that have been read out of
435 interface files but not yet sucked in, renamed, and typechecked
438 type PackageTypeEnv = TypeEnv
439 type PackageRuleBase = RuleBase
440 type PackageInstEnv = InstEnv
442 data PersistentRenamerState
443 = PRS { prsOrig :: OrigNameEnv,
444 prsDecls :: DeclsMap,
445 prsInsts :: IfaceInsts,
446 prsRules :: IfaceRules,
451 The OrigNameEnv makes sure that there is just one Unique assigned for
452 each original name; i.e. (module-name, occ-name) pair. The Name is
453 always stored as a Global, and has the SrcLoc of its binding location.
454 Actually that's not quite right. When we first encounter the original
455 name, we might not be at its binding site (e.g. we are reading an
456 interface file); so we give it 'noSrcLoc' then. Later, when we find
457 its binding site, we fix it up.
459 Exactly the same is true of the Module stored in the Name. When we first
460 encounter the occurrence, we may not know the details of the module, so
461 we just store junk. Then when we find the binding site, we fix it up.
465 = Orig { origNames :: OrigNameNameEnv,
466 -- Ensures that one original name gets one unique
467 origIParam :: OrigNameIParamEnv
468 -- Ensures that one implicit parameter name gets one unique
471 type OrigNameNameEnv = FiniteMap (ModuleName,OccName) Name
472 type OrigNameIParamEnv = FiniteMap OccName Name
476 A DeclsMap contains a binding for each Name in the declaration
477 including the constructors of a type decl etc. The Bool is True just
481 type DeclsMap = NameEnv (AvailInfo, Bool, (Module, RdrNameTyClDecl))
483 type IfaceInsts = Bag GatedDecl
484 type IfaceRules = Bag GatedDecl
486 type GatedDecl = (NameSet, (Module, RdrNameHsDecl))
490 %************************************************************************
492 \subsection{Provenance and export info}
494 %************************************************************************
496 The GlobalRdrEnv gives maps RdrNames to Names. There is a separate
497 one for each module, corresponding to that module's top-level scope.
500 type GlobalRdrEnv = RdrNameEnv [(Name,Provenance)] -- The list is because there may be name clashes
501 -- These only get reported on lookup,
502 -- not on construction
505 The "provenance" of something says how it came to be in scope.
509 = LocalDef -- Defined locally
511 | NonLocalDef -- Defined non-locally
515 -- Just used for grouping error messages (in RnEnv.warnUnusedBinds)
516 instance Eq Provenance where
517 p1 == p2 = case p1 `compare` p2 of EQ -> True; _ -> False
519 instance Eq ImportReason where
520 p1 == p2 = case p1 `compare` p2 of EQ -> True; _ -> False
522 instance Ord Provenance where
523 compare LocalDef LocalDef = EQ
524 compare LocalDef (NonLocalDef _ _) = LT
525 compare (NonLocalDef _ _) LocalDef = GT
527 compare (NonLocalDef reason1 _) (NonLocalDef reason2 _)
528 = compare reason1 reason2
530 instance Ord ImportReason where
531 compare ImplicitImport ImplicitImport = EQ
532 compare ImplicitImport (UserImport _ _ _) = LT
533 compare (UserImport _ _ _) ImplicitImport = GT
534 compare (UserImport m1 loc1 _) (UserImport m2 loc2 _)
535 = (m1 `compare` m2) `thenCmp` (loc1 `compare` loc2)
539 = UserImport Module SrcLoc Bool -- Imported from module M on line L
540 -- Note the M may well not be the defining module
542 -- The Bool is true iff the thing was named *explicitly* in the import spec,
543 -- rather than being imported as part of a group; e.g.
546 -- Here, everything imported by B, and the constructors of T
547 -- are not named explicitly; only T is named explicitly.
548 -- This info is used when warning of unused names.
550 | ImplicitImport -- Imported implicitly for some other reason
553 type PrintUnqualified = Bool -- True <=> the unqualified name of this thing is
554 -- in scope in this module, so print it
555 -- unqualified in error messages
559 hasBetterProv :: Provenance -> Provenance -> Bool
561 -- a local thing over an imported thing
562 -- a user-imported thing over a non-user-imported thing
563 -- an explicitly-imported thing over an implicitly imported thing
564 hasBetterProv LocalDef _ = True
565 hasBetterProv (NonLocalDef (UserImport _ _ True) _) _ = True
566 hasBetterProv (NonLocalDef (UserImport _ _ _ ) _) (NonLocalDef ImplicitImport _) = True
567 hasBetterProv _ _ = False
569 pprNameProvenance :: Name -> Provenance -> SDoc
570 pprNameProvenance name LocalDef = ptext SLIT("defined at") <+> ppr (nameSrcLoc name)
571 pprNameProvenance name (NonLocalDef why _) = sep [ppr_reason why,
572 nest 2 (parens (ppr_defn (nameSrcLoc name)))]
574 ppr_reason ImplicitImport = ptext SLIT("implicitly imported")
575 ppr_reason (UserImport mod loc _) = ptext SLIT("imported from") <+> ppr mod <+> ptext SLIT("at") <+> ppr loc
577 ppr_defn loc | isGoodSrcLoc loc = ptext SLIT("at") <+> ppr loc