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 WhetherHasOrphans, ImportVersion, WhatsImported(..),
26 PersistentRenamerState(..), IsBootInterface, Avails, DeclsMap,
27 IfaceInsts, IfaceRules, GatedDecl, IsExported,
28 OrigNameEnv(..), OrigNameNameEnv, OrigNameIParamEnv,
29 AvailEnv, AvailInfo, GenAvailInfo(..),
30 PersistentCompilerState(..),
32 Deprecations(..), lookupDeprec,
34 InstEnv, ClsInstEnv, DFunId,
35 PackageInstEnv, PackageRuleBase,
37 GlobalRdrEnv, 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 = nameOccName (tyClDeclName d1) < nameOccName (tyClDeclName d2)
154 r1 `lt_rule` r2 = nameOccName (ifaceRuleDeclName r1) < nameOccName (ifaceRuleDeclName r2)
156 -- I wanted to sort just by the Name, but there's a problem: we are comparing
157 -- the old version of an interface with the new version. The latter will use
158 -- local names like 'lvl23' that were constructed not by the renamer but by
159 -- the simplifier. So the unqiues aren't going to line up.
161 -- It's ok to compare by OccName because this comparison only drives the
162 -- computation of new version numbers.
164 -- Better solutions: Compare in a way that is insensitive to the name used
165 -- for local things. This would decrease the wobbles due
166 -- to 'lvl23' changing to 'lvl24'.
168 -- NB: there's a related comparision on MkIface.diffDecls!
173 -- typechecker should only look at this, not ModIface
174 -- Should be able to construct ModDetails from mi_decls in ModIface
177 -- The next three fields are created by the typechecker
179 md_insts :: [DFunId], -- Dfun-ids for the instances in this module
180 md_rules :: [IdCoreRule] -- Domain may include Ids from other modules
185 emptyModDetails :: ModDetails
187 = ModDetails { md_types = emptyTypeEnv,
192 emptyModIface :: Module -> ModIface
194 = ModIface { mi_module = mod,
195 mi_version = initialVersionInfo,
200 mi_fixities = emptyNameEnv,
201 mi_globals = emptyRdrEnv,
202 mi_deprecs = NoDeprecs,
203 mi_decls = panic "emptyModIface: decls"
207 Symbol tables map modules to ModDetails:
210 type SymbolTable = ModuleEnv ModDetails
211 type IfaceTable = ModuleEnv ModIface
213 type HomeIfaceTable = IfaceTable
214 type PackageIfaceTable = IfaceTable
216 type HomeSymbolTable = SymbolTable -- Domain = modules in the home package
218 emptyIfaceTable :: IfaceTable
219 emptyIfaceTable = emptyModuleEnv
222 Simple lookups in the symbol table.
225 lookupIface :: HomeIfaceTable -> PackageIfaceTable -> Name -> Maybe ModIface
226 -- We often have two IfaceTables, and want to do a lookup
227 lookupIface hit pit name
228 = lookupModuleEnv hit mod `seqMaybe` lookupModuleEnv pit mod
230 mod = nameModule name
232 lookupIfaceByModName :: HomeIfaceTable -> PackageIfaceTable -> ModuleName -> Maybe ModIface
233 -- We often have two IfaceTables, and want to do a lookup
234 lookupIfaceByModName hit pit mod
235 = lookupModuleEnvByName hit mod `seqMaybe` lookupModuleEnvByName pit mod
239 %************************************************************************
241 \subsection{Type environment stuff}
243 %************************************************************************
246 data TyThing = AnId Id
250 isTyClThing :: TyThing -> Bool
251 isTyClThing (ATyCon _) = True
252 isTyClThing (AClass _) = True
253 isTyClThing (AnId _) = False
255 instance NamedThing TyThing where
256 getName (AnId id) = getName id
257 getName (ATyCon tc) = getName tc
258 getName (AClass cl) = getName cl
260 typeEnvClasses env = [cl | AClass cl <- nameEnvElts env]
261 typeEnvTyCons env = [tc | ATyCon tc <- nameEnvElts env]
263 implicitTyThingIds :: [TyThing] -> [Id]
264 -- Add the implicit data cons and selectors etc
265 implicitTyThingIds things
266 = concat (map go things)
269 go (AClass cl) = classSelIds cl
270 go (ATyCon tc) = tyConGenIds tc ++
272 [ n | dc <- tyConDataConsIfAvailable tc,
273 n <- [dataConId dc, dataConWrapId dc] ]
274 -- Synonyms return empty list of constructors and selectors
279 type TypeEnv = NameEnv TyThing
281 emptyTypeEnv = emptyNameEnv
283 mkTypeEnv :: [TyThing] -> TypeEnv
284 mkTypeEnv things = extendTypeEnvList emptyTypeEnv things
286 extendTypeEnvList :: TypeEnv -> [TyThing] -> TypeEnv
287 extendTypeEnvList env things
288 = foldl add_thing env things
290 add_thing :: TypeEnv -> TyThing -> TypeEnv
291 add_thing env thing = extendNameEnv env (getName thing) thing
295 lookupType :: HomeSymbolTable -> PackageTypeEnv -> Name -> Maybe TyThing
296 lookupType hst pte name
297 = case lookupModuleEnv hst (nameModule name) of
298 Just details -> lookupNameEnv (md_types details) name
299 Nothing -> lookupNameEnv pte name
302 %************************************************************************
304 \subsection{Auxiliary types}
306 %************************************************************************
308 These types are defined here because they are mentioned in ModDetails,
309 but they are mostly elaborated elsewhere
314 vers_module :: Version, -- Changes when anything changes
315 vers_exports :: Version, -- Changes when export list changes
316 vers_rules :: Version, -- Changes when any rule changes
317 vers_decls :: NameEnv Version
318 -- Versions for "big" names only (not data constructors, class ops)
319 -- The version of an Id changes if its fixity changes
320 -- Ditto data constructors, class operations, except that the version of
321 -- the parent class/tycon changes
324 initialVersionInfo :: VersionInfo
325 initialVersionInfo = VersionInfo { vers_module = initialVersion,
326 vers_exports = initialVersion,
327 vers_rules = initialVersion,
328 vers_decls = emptyNameEnv }
330 data Deprecations = NoDeprecs
331 | DeprecAll DeprecTxt -- Whole module deprecated
332 | DeprecSome (NameEnv (Name,DeprecTxt)) -- Some things deprecated
334 -- We keep the Name in the range, so we can print them out
336 lookupDeprec :: Deprecations -> Name -> Maybe DeprecTxt
337 lookupDeprec NoDeprecs name = Nothing
338 lookupDeprec (DeprecAll txt) name = Just txt
339 lookupDeprec (DeprecSome env) name = case lookupNameEnv env name of
340 Just (_, txt) -> Just txt
346 type Avails = [AvailInfo]
347 type AvailInfo = GenAvailInfo Name
348 type RdrAvailInfo = GenAvailInfo OccName
350 data GenAvailInfo name = Avail name -- An ordinary identifier
351 | AvailTC name -- The name of the type or class
352 [name] -- The available pieces of type/class.
353 -- NB: If the type or class is itself
354 -- to be in scope, it must be in this list.
355 -- Thus, typically: AvailTC Eq [Eq, ==, /=]
357 -- Equality used when deciding if the interface has changed
359 type AvailEnv = NameEnv AvailInfo -- Maps a Name to the AvailInfo that contains it
361 instance Outputable n => Outputable (GenAvailInfo n) where
364 pprAvail :: Outputable n => GenAvailInfo n -> SDoc
365 pprAvail (AvailTC n ns) = ppr n <> case {- filter (/= n) -} ns of
367 ns' -> braces (hsep (punctuate comma (map ppr ns')))
369 pprAvail (Avail n) = ppr n
373 %************************************************************************
375 \subsection{ModIface}
377 %************************************************************************
380 type WhetherHasOrphans = Bool
382 -- * an instance decl in a module other than the defn module for
383 -- one of the tycons or classes in the instance head
384 -- * a transformation rule in a module other than the one defining
385 -- the function in the head of the rule.
387 type IsBootInterface = Bool
389 type ImportVersion name = (ModuleName, WhetherHasOrphans, IsBootInterface, WhatsImported name)
391 data WhatsImported name = NothingAtAll -- The module is below us in the
392 -- hierarchy, but we import nothing
394 | Everything Version -- Used for modules from other packages;
395 -- we record only the module's version number
398 Version -- Module version
399 (Maybe Version) -- Export-list version, if we depend on it
400 [(name,Version)] -- List guaranteed non-empty
401 Version -- Rules version
404 -- 'Specifically' doesn't let you say "I imported f but none of the rules in
405 -- the module". If you use anything in the module you get its rule version
406 -- So if the rules change, you'll recompile, even if you don't use them.
407 -- This is easy to implement, and it's safer: you might not have used the rules last
408 -- time round, but if someone has added a new rule you might need it this time
410 -- The export list field is (Just v) if we depend on the export list:
411 -- we imported the module without saying exactly what we imported
412 -- We need to recompile if the module exports changes, because we might
413 -- now have a name clash in the importing module.
415 type IsExported = Name -> Bool -- True for names that are exported from this module
419 %************************************************************************
421 \subsection{The persistent compiler state}
423 %************************************************************************
426 data PersistentCompilerState
428 pcs_PIT :: PackageIfaceTable, -- Domain = non-home-package modules
429 -- the mi_decls component is empty
431 pcs_PTE :: PackageTypeEnv, -- Domain = non-home-package modules
432 -- except that the InstEnv components is empty
434 pcs_insts :: PackageInstEnv, -- The total InstEnv accumulated from all
435 -- the non-home-package modules
437 pcs_rules :: PackageRuleBase, -- Ditto RuleEnv
439 pcs_PRS :: PersistentRenamerState
444 The @PersistentRenamerState@ persists across successive calls to the
448 * A name supply, which deals with allocating unique names to
449 (Module,OccName) original names,
451 * An accumulated TypeEnv from all the modules in imported packages
453 * An accumulated InstEnv from all the modules in imported packages
454 The point is that we don't want to keep recreating it whenever
455 we compile a new module. The InstEnv component of pcPST is empty.
456 (This means we might "see" instances that we shouldn't "really" see;
457 but the Haskell Report is vague on what is meant to be visible,
458 so we just take the easy road here.)
462 * A "holding pen" for declarations that have been read out of
463 interface files but not yet sucked in, renamed, and typechecked
466 type PackageTypeEnv = TypeEnv
467 type PackageRuleBase = RuleBase
468 type PackageInstEnv = InstEnv
470 data PersistentRenamerState
471 = PRS { prsOrig :: OrigNameEnv,
472 prsDecls :: DeclsMap,
473 prsInsts :: IfaceInsts,
474 prsRules :: IfaceRules,
479 The OrigNameEnv makes sure that there is just one Unique assigned for
480 each original name; i.e. (module-name, occ-name) pair. The Name is
481 always stored as a Global, and has the SrcLoc of its binding location.
482 Actually that's not quite right. When we first encounter the original
483 name, we might not be at its binding site (e.g. we are reading an
484 interface file); so we give it 'noSrcLoc' then. Later, when we find
485 its binding site, we fix it up.
487 Exactly the same is true of the Module stored in the Name. When we first
488 encounter the occurrence, we may not know the details of the module, so
489 we just store junk. Then when we find the binding site, we fix it up.
493 = Orig { origNames :: OrigNameNameEnv,
494 -- Ensures that one original name gets one unique
495 origIParam :: OrigNameIParamEnv
496 -- Ensures that one implicit parameter name gets one unique
499 type OrigNameNameEnv = FiniteMap (ModuleName,OccName) Name
500 type OrigNameIParamEnv = FiniteMap OccName Name
504 A DeclsMap contains a binding for each Name in the declaration
505 including the constructors of a type decl etc. The Bool is True just
509 type DeclsMap = (NameEnv (AvailInfo, Bool, (Module, RdrNameTyClDecl)), Int)
510 -- The Int says how many have been sucked in
512 type IfaceInsts = GatedDecls RdrNameInstDecl
513 type IfaceRules = GatedDecls RdrNameRuleDecl
515 type GatedDecls d = (Bag (GatedDecl d), Int) -- The Int says how many have been sucked in
516 type GatedDecl d = ([Name], (Module, d))
520 %************************************************************************
522 \subsection{Provenance and export info}
524 %************************************************************************
526 The GlobalRdrEnv gives maps RdrNames to Names. There is a separate
527 one for each module, corresponding to that module's top-level scope.
530 type GlobalRdrEnv = RdrNameEnv [(Name,Provenance)] -- The list is because there may be name clashes
531 -- These only get reported on lookup,
532 -- not on construction
535 = vcat (map pp (rdrEnvToList env))
537 pp (rn, nps) = ppr rn <> colon <+>
538 vcat [ppr n <+> pprNameProvenance n p | (n,p) <- nps]
541 The "provenance" of something says how it came to be in scope.
545 = LocalDef -- Defined locally
547 | NonLocalDef -- Defined non-locally
550 -- Just used for grouping error messages (in RnEnv.warnUnusedBinds)
551 instance Eq Provenance where
552 p1 == p2 = case p1 `compare` p2 of EQ -> True; _ -> False
554 instance Eq ImportReason where
555 p1 == p2 = case p1 `compare` p2 of EQ -> True; _ -> False
557 instance Ord Provenance where
558 compare LocalDef LocalDef = EQ
559 compare LocalDef (NonLocalDef _) = LT
560 compare (NonLocalDef _) LocalDef = GT
562 compare (NonLocalDef reason1) (NonLocalDef reason2)
563 = compare reason1 reason2
565 instance Ord ImportReason where
566 compare ImplicitImport ImplicitImport = EQ
567 compare ImplicitImport (UserImport _ _ _) = LT
568 compare (UserImport _ _ _) ImplicitImport = GT
569 compare (UserImport m1 loc1 _) (UserImport m2 loc2 _)
570 = (m1 `compare` m2) `thenCmp` (loc1 `compare` loc2)
574 = UserImport Module SrcLoc Bool -- Imported from module M on line L
575 -- Note the M may well not be the defining module
577 -- The Bool is true iff the thing was named *explicitly* in the import spec,
578 -- rather than being imported as part of a group; e.g.
581 -- Here, everything imported by B, and the constructors of T
582 -- are not named explicitly; only T is named explicitly.
583 -- This info is used when warning of unused names.
585 | ImplicitImport -- Imported implicitly for some other reason
589 hasBetterProv :: Provenance -> Provenance -> Bool
591 -- a local thing over an imported thing
592 -- a user-imported thing over a non-user-imported thing
593 -- an explicitly-imported thing over an implicitly imported thing
594 hasBetterProv LocalDef _ = True
595 hasBetterProv (NonLocalDef (UserImport _ _ _ )) (NonLocalDef ImplicitImport) = True
596 hasBetterProv _ _ = False
598 pprNameProvenance :: Name -> Provenance -> SDoc
599 pprNameProvenance name LocalDef = ptext SLIT("defined at") <+> ppr (nameSrcLoc name)
600 pprNameProvenance name (NonLocalDef why) = sep [ppr_reason why,
601 nest 2 (parens (ppr_defn (nameSrcLoc name)))]
603 ppr_reason ImplicitImport = ptext SLIT("implicitly imported")
604 ppr_reason (UserImport mod loc _) = ptext SLIT("imported from") <+> ppr mod <+> ptext SLIT("at") <+> ppr loc
606 ppr_defn loc | isGoodSrcLoc loc = ptext SLIT("at") <+> ppr loc