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,
23 WhetherHasOrphans, ImportVersion, WhatsImported(..),
24 PersistentRenamerState(..), IsBootInterface, Avails, DeclsMap,
25 IfaceInsts, IfaceRules, GatedDecl,
26 OrigNameEnv(..), OrigNameNameEnv, OrigNameIParamEnv,
27 AvailEnv, AvailInfo, GenAvailInfo(..),
28 PersistentCompilerState(..),
30 Deprecations(..), lookupDeprec,
32 InstEnv, ClsInstEnv, DFunId,
33 PackageInstEnv, PackageRuleBase,
35 GlobalRdrEnv, RdrAvailInfo,
38 Provenance(..), ImportReason(..), PrintUnqualified,
39 pprNameProvenance, hasBetterProv
43 #include "HsVersions.h"
45 import RdrName ( RdrNameEnv, emptyRdrEnv )
46 import Name ( Name, NameEnv, NamedThing,
47 emptyNameEnv, unitNameEnv, extendNameEnv, plusNameEnv,
48 lookupNameEnv, emptyNameEnv, getName, nameModule,
50 import NameSet ( NameSet )
51 import OccName ( OccName )
52 import Module ( Module, ModuleName, ModuleEnv,
53 lookupModuleEnv, lookupModuleEnvByName
55 import Rules ( RuleBase )
56 import VarSet ( TyVarSet )
58 import Class ( Class )
59 import TyCon ( TyCon )
61 import BasicTypes ( Version, initialVersion, Fixity )
63 import HsSyn ( DeprecTxt )
64 import RdrHsSyn ( RdrNameHsDecl, RdrNameTyClDecl )
65 import RnHsSyn ( RenamedTyClDecl, RenamedRuleDecl, RenamedInstDecl )
67 import CoreSyn ( CoreRule, IdCoreRule )
70 import FiniteMap ( FiniteMap, emptyFM, addToFM, lookupFM, foldFM )
72 import Maybes ( seqMaybe )
73 import UniqFM ( UniqFM )
75 import SrcLoc ( SrcLoc, isGoodSrcLoc )
76 import Util ( thenCmp )
77 import UniqSupply ( UniqSupply )
80 %************************************************************************
82 \subsection{The Finder type}
84 %************************************************************************
87 type Finder = ModuleName -> IO (Maybe (Module, ModuleLocation))
97 For a module in another package, the hs_file and obj_file
98 components of ModuleLocation are undefined.
100 The locations specified by a ModuleLocation may or may not
101 correspond to actual files yet: for example, even if the object
102 file doesn't exist, the ModuleLocation still contains the path to
103 where the object file will reside if/when it is created.
106 %************************************************************************
108 \subsection{Symbol tables and Module details}
110 %************************************************************************
112 A @ModIface@ plus a @ModDetails@ summarises everything we know
113 about a compiled module. The @ModIface@ is the stuff *before* linking,
114 and can be written out to an interface file. The @ModDetails@ is after
115 linking; it is the "linked" form of the mi_decls field.
120 mi_module :: Module, -- Complete with package info
121 mi_version :: VersionInfo, -- Module version number
122 mi_orphan :: WhetherHasOrphans, -- Whether this module has orphans
124 mi_usages :: [ImportVersion Name], -- Usages; kept sorted so that it's easy
125 -- to decide whether to write a new iface file
126 -- (changing usages doesn't affect the version of
129 mi_exports :: [(ModuleName,Avails)], -- What it exports
130 -- Kept sorted by (mod,occ),
131 -- to make version comparisons easier
133 mi_globals :: GlobalRdrEnv, -- Its top level environment
135 mi_fixities :: NameEnv Fixity, -- Fixities
136 mi_deprecs :: Deprecations, -- Deprecations
138 mi_decls :: IfaceDecls -- The RnDecls form of ModDetails
141 data IfaceDecls = IfaceDecls { dcl_tycl :: [RenamedTyClDecl], -- Sorted
142 dcl_rules :: [RenamedRuleDecl], -- Sorted
143 dcl_insts :: [RenamedInstDecl] } -- Unsorted
145 -- typechecker should only look at this, not ModIface
146 -- Should be able to construct ModDetails from mi_decls in ModIface
149 -- The next three fields are created by the typechecker
151 md_insts :: [DFunId], -- Dfun-ids for the instances in this module
152 md_rules :: [IdCoreRule] -- Domain may include Ids from other modules
157 emptyModDetails :: ModDetails
159 = ModDetails { md_types = emptyTypeEnv,
164 emptyModIface :: Module -> ModIface
166 = ModIface { mi_module = mod,
168 mi_globals = emptyRdrEnv,
169 mi_deprecs = NoDeprecs
173 Symbol tables map modules to ModDetails:
176 type SymbolTable = ModuleEnv ModDetails
177 type IfaceTable = ModuleEnv ModIface
179 type HomeIfaceTable = IfaceTable
180 type PackageIfaceTable = IfaceTable
182 type HomeSymbolTable = SymbolTable -- Domain = modules in the home package
183 type PackageSymbolTable = SymbolTable -- Domain = modules in the some other package
184 type GlobalSymbolTable = SymbolTable -- Domain = all modules
187 Simple lookups in the symbol table.
190 lookupTable :: ModuleEnv a -> ModuleEnv a -> Name -> Maybe a
191 -- We often have two Symbol- or IfaceTables, and want to do a lookup
192 lookupTable ht pt name
193 = lookupModuleEnv ht mod `seqMaybe` lookupModuleEnv pt mod
195 mod = nameModule name
197 lookupTableByModName :: ModuleEnv a -> ModuleEnv a -> ModuleName -> Maybe a
198 -- We often have two Symbol- or IfaceTables, and want to do a lookup
199 lookupTableByModName ht pt mod
200 = lookupModuleEnvByName ht mod `seqMaybe` lookupModuleEnvByName pt mod
204 %************************************************************************
206 \subsection{Type environment stuff}
208 %************************************************************************
211 type TypeEnv = NameEnv TyThing
212 emptyTypeEnv = emptyNameEnv
214 data TyThing = AnId Id
218 isTyClThing :: TyThing -> Bool
219 isTyClThing (ATyCon _) = True
220 isTyClThing (AClass _) = True
221 isTyClThing (AnId _) = False
223 instance NamedThing TyThing where
224 getName (AnId id) = getName id
225 getName (ATyCon tc) = getName tc
226 getName (AClass cl) = getName cl
231 lookupTypeEnv :: SymbolTable -> Name -> Maybe TyThing
232 lookupTypeEnv tbl name
233 = case lookupModuleEnv tbl (nameModule name) of
234 Just details -> lookupNameEnv (md_types details) name
238 groupTyThings :: [TyThing] -> FiniteMap Module TypeEnv
239 -- Finite map because we want the range too
241 = foldl add emptyFM things
243 add :: FiniteMap Module TypeEnv -> TyThing -> FiniteMap Module TypeEnv
244 add tbl thing = addToFM tbl mod new_env
247 mod = nameModule name
248 new_env = case lookupFM tbl mod of
249 Nothing -> unitNameEnv name thing
250 Just env -> extendNameEnv env name thing
252 extendTypeEnv :: SymbolTable -> FiniteMap Module TypeEnv -> SymbolTable
253 extendTypeEnv tbl things
254 = foldFM add tbl things
257 = panic "extendTypeEnv" --extendModuleEnv mod new_details
260 = case lookupModuleEnv tbl mod of
261 Nothing -> emptyModDetails {md_types = type_env}
262 Just details -> details {md_types = md_types details
263 `plusNameEnv` type_env}
267 %************************************************************************
269 \subsection{Auxiliary types}
271 %************************************************************************
273 These types are defined here because they are mentioned in ModDetails,
274 but they are mostly elaborated elsewhere
279 vers_module :: Version, -- Changes when anything changes
280 vers_exports :: Version, -- Changes when export list changes
281 vers_rules :: Version, -- Changes when any rule changes
282 vers_decls :: NameEnv Version
283 -- Versions for "big" names only (not data constructors, class ops)
284 -- The version of an Id changes if its fixity changes
285 -- Ditto data constructors, class operations, except that the version of
286 -- the parent class/tycon changes
289 initialVersionInfo :: VersionInfo
290 initialVersionInfo = VersionInfo { vers_module = initialVersion,
291 vers_exports = initialVersion,
292 vers_rules = initialVersion,
293 vers_decls = emptyNameEnv }
295 data Deprecations = NoDeprecs
296 | DeprecAll DeprecTxt -- Whole module deprecated
297 | DeprecSome (NameEnv DeprecTxt) -- Some things deprecated
300 lookupDeprec :: ModIface -> Name -> Maybe DeprecTxt
301 lookupDeprec iface name
302 = case mi_deprecs iface of
304 DeprecAll txt -> Just txt
305 DeprecSome env -> lookupNameEnv env name
307 type InstEnv = UniqFM ClsInstEnv -- Maps Class to instances for that class
309 type ClsInstEnv = [(TyVarSet, [Type], DFunId)] -- The instances for a particular class
315 type Avails = [AvailInfo]
316 type AvailInfo = GenAvailInfo Name
317 type RdrAvailInfo = GenAvailInfo OccName
319 data GenAvailInfo name = Avail name -- An ordinary identifier
320 | AvailTC name -- The name of the type or class
321 [name] -- The available pieces of type/class.
322 -- NB: If the type or class is itself
323 -- to be in scope, it must be in this list.
324 -- Thus, typically: AvailTC Eq [Eq, ==, /=]
326 -- Equality used when deciding if the interface has changed
328 type AvailEnv = NameEnv AvailInfo -- Maps a Name to the AvailInfo that contains it
332 %************************************************************************
334 \subsection{ModIface}
336 %************************************************************************
339 type WhetherHasOrphans = Bool
341 -- * an instance decl in a module other than the defn module for
342 -- one of the tycons or classes in the instance head
343 -- * a transformation rule in a module other than the one defining
344 -- the function in the head of the rule.
346 type IsBootInterface = Bool
348 type ImportVersion name = (ModuleName, WhetherHasOrphans, IsBootInterface, WhatsImported name)
350 data WhatsImported name = NothingAtAll -- The module is below us in the
351 -- hierarchy, but we import nothing
353 | Everything Version -- Used for modules from other packages;
354 -- we record only the module's version number
357 Version -- Module version
358 (Maybe Version) -- Export-list version, if we depend on it
359 [(name,Version)] -- List guaranteed non-empty
360 Version -- Rules version
363 -- 'Specifically' doesn't let you say "I imported f but none of the rules in
364 -- the module". If you use anything in the module you get its rule version
365 -- So if the rules change, you'll recompile, even if you don't use them.
366 -- This is easy to implement, and it's safer: you might not have used the rules last
367 -- time round, but if someone has added a new rule you might need it this time
369 -- The export list field is (Just v) if we depend on the export list:
370 -- we imported the module without saying exactly what we imported
371 -- We need to recompile if the module exports changes, because we might
372 -- now have a name clash in the importing module.
376 %************************************************************************
378 \subsection{The persistent compiler state}
380 %************************************************************************
383 data PersistentCompilerState
385 pcs_PIT :: PackageIfaceTable, -- Domain = non-home-package modules
386 -- the mi_decls component is empty
388 pcs_PST :: PackageSymbolTable, -- Domain = non-home-package modules
389 -- except that the InstEnv components is empty
391 pcs_insts :: PackageInstEnv, -- The total InstEnv accumulated from all
392 -- the non-home-package modules
394 pcs_rules :: PackageRuleBase, -- Ditto RuleEnv
396 pcs_PRS :: PersistentRenamerState
401 The @PersistentRenamerState@ persists across successive calls to the
405 * A name supply, which deals with allocating unique names to
406 (Module,OccName) original names,
408 * An accumulated InstEnv from all the modules in pcs_PST
409 The point is that we don't want to keep recreating it whenever
410 we compile a new module. The InstEnv component of pcPST is empty.
411 (This means we might "see" instances that we shouldn't "really" see;
412 but the Haskell Report is vague on what is meant to be visible,
413 so we just take the easy road here.)
417 * A "holding pen" for declarations that have been read out of
418 interface files but not yet sucked in, renamed, and typechecked
421 type PackageRuleBase = RuleBase
422 type PackageInstEnv = InstEnv
424 data PersistentRenamerState
425 = PRS { prsOrig :: OrigNameEnv,
426 prsDecls :: DeclsMap,
427 prsInsts :: IfaceInsts,
428 prsRules :: IfaceRules,
433 The OrigNameEnv makes sure that there is just one Unique assigned for
434 each original name; i.e. (module-name, occ-name) pair. The Name is
435 always stored as a Global, and has the SrcLoc of its binding location.
436 Actually that's not quite right. When we first encounter the original
437 name, we might not be at its binding site (e.g. we are reading an
438 interface file); so we give it 'noSrcLoc' then. Later, when we find
439 its binding site, we fix it up.
441 Exactly the same is true of the Module stored in the Name. When we first
442 encounter the occurrence, we may not know the details of the module, so
443 we just store junk. Then when we find the binding site, we fix it up.
447 = Orig { origNames :: OrigNameNameEnv,
448 -- Ensures that one original name gets one unique
449 origIParam :: OrigNameIParamEnv
450 -- Ensures that one implicit parameter name gets one unique
453 type OrigNameNameEnv = FiniteMap (ModuleName,OccName) Name
454 type OrigNameIParamEnv = FiniteMap OccName Name
458 A DeclsMap contains a binding for each Name in the declaration
459 including the constructors of a type decl etc. The Bool is True just
463 type DeclsMap = NameEnv (AvailInfo, Bool, (Module, RdrNameTyClDecl))
465 type IfaceInsts = Bag GatedDecl
466 type IfaceRules = Bag GatedDecl
468 type GatedDecl = (NameSet, (Module, RdrNameHsDecl))
472 %************************************************************************
474 \subsection{Provenance and export info}
476 %************************************************************************
478 The GlobalRdrEnv gives maps RdrNames to Names. There is a separate
479 one for each module, corresponding to that module's top-level scope.
482 type GlobalRdrEnv = RdrNameEnv [(Name,Provenance)] -- The list is because there may be name clashes
483 -- These only get reported on lookup,
484 -- not on construction
487 The "provenance" of something says how it came to be in scope.
491 = LocalDef -- Defined locally
493 | NonLocalDef -- Defined non-locally
497 -- Just used for grouping error messages (in RnEnv.warnUnusedBinds)
498 instance Eq Provenance where
499 p1 == p2 = case p1 `compare` p2 of EQ -> True; _ -> False
501 instance Eq ImportReason where
502 p1 == p2 = case p1 `compare` p2 of EQ -> True; _ -> False
504 instance Ord Provenance where
505 compare LocalDef LocalDef = EQ
506 compare LocalDef (NonLocalDef _ _) = LT
507 compare (NonLocalDef _ _) LocalDef = GT
509 compare (NonLocalDef reason1 _) (NonLocalDef reason2 _)
510 = compare reason1 reason2
512 instance Ord ImportReason where
513 compare ImplicitImport ImplicitImport = EQ
514 compare ImplicitImport (UserImport _ _ _) = LT
515 compare (UserImport _ _ _) ImplicitImport = GT
516 compare (UserImport m1 loc1 _) (UserImport m2 loc2 _)
517 = (m1 `compare` m2) `thenCmp` (loc1 `compare` loc2)
521 = UserImport Module SrcLoc Bool -- Imported from module M on line L
522 -- Note the M may well not be the defining module
524 -- The Bool is true iff the thing was named *explicitly* in the import spec,
525 -- rather than being imported as part of a group; e.g.
528 -- Here, everything imported by B, and the constructors of T
529 -- are not named explicitly; only T is named explicitly.
530 -- This info is used when warning of unused names.
532 | ImplicitImport -- Imported implicitly for some other reason
535 type PrintUnqualified = Bool -- True <=> the unqualified name of this thing is
536 -- in scope in this module, so print it
537 -- unqualified in error messages
541 hasBetterProv :: Provenance -> Provenance -> Bool
543 -- a local thing over an imported thing
544 -- a user-imported thing over a non-user-imported thing
545 -- an explicitly-imported thing over an implicitly imported thing
546 hasBetterProv LocalDef _ = True
547 hasBetterProv (NonLocalDef (UserImport _ _ True) _) _ = True
548 hasBetterProv (NonLocalDef (UserImport _ _ _ ) _) (NonLocalDef ImplicitImport _) = True
549 hasBetterProv _ _ = False
551 pprNameProvenance :: Name -> Provenance -> SDoc
552 pprNameProvenance name LocalDef = ptext SLIT("defined at") <+> ppr (nameSrcLoc name)
553 pprNameProvenance name (NonLocalDef why _) = sep [ppr_reason why,
554 nest 2 (parens (ppr_defn (nameSrcLoc name)))]
556 ppr_reason ImplicitImport = ptext SLIT("implicitly imported")
557 ppr_reason (UserImport mod loc _) = ptext SLIT("imported from") <+> ppr mod <+> ptext SLIT("at") <+> ppr loc
559 ppr_defn loc | isGoodSrcLoc loc = ptext SLIT("at") <+> ppr loc