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,
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 VarSet ( TyVarSet )
56 import VarEnv ( emptyVarEnv )
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 )
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 :: 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 :: RuleBase -- Domain may include Ids from other modules
157 emptyModDetails :: ModDetails
159 = ModDetails { md_types = emptyTypeEnv,
161 md_rules = emptyRuleBase
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 instance NamedThing TyThing where
219 getName (AnId id) = getName id
220 getName (ATyCon tc) = getName tc
221 getName (AClass cl) = getName cl
226 lookupTypeEnv :: SymbolTable -> Name -> Maybe TyThing
227 lookupTypeEnv tbl name
228 = case lookupModuleEnv tbl (nameModule name) of
229 Just details -> lookupNameEnv (md_types details) name
233 groupTyThings :: [TyThing] -> FiniteMap Module TypeEnv
234 -- Finite map because we want the range too
236 = foldl add emptyFM things
238 add :: FiniteMap Module TypeEnv -> TyThing -> FiniteMap Module TypeEnv
239 add tbl thing = addToFM tbl mod new_env
242 mod = nameModule name
243 new_env = case lookupFM tbl mod of
244 Nothing -> unitNameEnv name thing
245 Just env -> extendNameEnv env name thing
247 extendTypeEnv :: SymbolTable -> FiniteMap Module TypeEnv -> SymbolTable
248 extendTypeEnv tbl things
249 = foldFM add tbl things
252 = panic "extendTypeEnv" --extendModuleEnv mod new_details
255 = case lookupModuleEnv tbl mod of
256 Nothing -> emptyModDetails {md_types = type_env}
257 Just details -> details {md_types = md_types details
258 `plusNameEnv` type_env}
262 %************************************************************************
264 \subsection{Auxiliary types}
266 %************************************************************************
268 These types are defined here because they are mentioned in ModDetails,
269 but they are mostly elaborated elsewhere
274 vers_module :: Version, -- Changes when anything changes
275 vers_exports :: Version, -- Changes when export list changes
276 vers_rules :: Version, -- Changes when any rule changes
277 vers_decls :: NameEnv Version
278 -- Versions for "big" names only (not data constructors, class ops)
279 -- The version of an Id changes if its fixity changes
280 -- Ditto data constructors, class operations, except that the version of
281 -- the parent class/tycon changes
284 initialVersionInfo :: VersionInfo
285 initialVersionInfo = VersionInfo { vers_module = initialVersion,
286 vers_exports = initialVersion,
287 vers_rules = initialVersion,
288 vers_decls = emptyNameEnv }
290 data Deprecations = NoDeprecs
291 | DeprecAll DeprecTxt -- Whole module deprecated
292 | DeprecSome (NameEnv DeprecTxt) -- Some things deprecated
295 lookupDeprec :: ModIface -> Name -> Maybe DeprecTxt
296 lookupDeprec iface name
297 = case mi_deprecs iface of
299 DeprecAll txt -> Just txt
300 DeprecSome env -> lookupNameEnv env name
302 type InstEnv = UniqFM ClsInstEnv -- Maps Class to instances for that class
304 type ClsInstEnv = [(TyVarSet, [Type], DFunId)] -- The instances for a particular class
310 type Avails = [AvailInfo]
311 type AvailInfo = GenAvailInfo Name
312 type RdrAvailInfo = GenAvailInfo OccName
314 data GenAvailInfo name = Avail name -- An ordinary identifier
315 | AvailTC name -- The name of the type or class
316 [name] -- The available pieces of type/class.
317 -- NB: If the type or class is itself
318 -- to be in scope, it must be in this list.
319 -- Thus, typically: AvailTC Eq [Eq, ==, /=]
321 -- Equality used when deciding if the interface has changed
323 type AvailEnv = NameEnv AvailInfo -- Maps a Name to the AvailInfo that contains it
327 %************************************************************************
329 \subsection{ModIface}
331 %************************************************************************
334 type WhetherHasOrphans = Bool
336 -- * an instance decl in a module other than the defn module for
337 -- one of the tycons or classes in the instance head
338 -- * a transformation rule in a module other than the one defining
339 -- the function in the head of the rule.
341 type IsBootInterface = Bool
343 type ImportVersion name = (ModuleName, WhetherHasOrphans, IsBootInterface, WhatsImported name)
345 data WhatsImported name = NothingAtAll -- The module is below us in the
346 -- hierarchy, but we import nothing
348 | Everything Version -- Used for modules from other packages;
349 -- we record only the module's version number
352 Version -- Module version
353 (Maybe Version) -- Export-list version, if we depend on it
354 [(name,Version)] -- List guaranteed non-empty
355 Version -- Rules version
358 -- 'Specifically' doesn't let you say "I imported f but none of the rules in
359 -- the module". If you use anything in the module you get its rule version
360 -- So if the rules change, you'll recompile, even if you don't use them.
361 -- This is easy to implement, and it's safer: you might not have used the rules last
362 -- time round, but if someone has added a new rule you might need it this time
364 -- The export list field is (Just v) if we depend on the export list:
365 -- we imported the module without saying exactly what we imported
366 -- We need to recompile if the module exports changes, because we might
367 -- now have a name clash in the importing module.
371 %************************************************************************
373 \subsection{The persistent compiler state}
375 %************************************************************************
378 data PersistentCompilerState
380 pcs_PIT :: PackageIfaceTable, -- Domain = non-home-package modules
381 -- the mi_decls component is empty
383 pcs_PST :: PackageSymbolTable, -- Domain = non-home-package modules
384 -- except that the InstEnv components is empty
386 pcs_insts :: PackageInstEnv, -- The total InstEnv accumulated from all
387 -- the non-home-package modules
389 pcs_rules :: PackageRuleEnv, -- Ditto RuleEnv
391 pcs_PRS :: PersistentRenamerState
396 The @PersistentRenamerState@ persists across successive calls to the
400 * A name supply, which deals with allocating unique names to
401 (Module,OccName) original names,
403 * An accumulated InstEnv from all the modules in pcs_PST
404 The point is that we don't want to keep recreating it whenever
405 we compile a new module. The InstEnv component of pcPST is empty.
406 (This means we might "see" instances that we shouldn't "really" see;
407 but the Haskell Report is vague on what is meant to be visible,
408 so we just take the easy road here.)
412 * A "holding pen" for declarations that have been read out of
413 interface files but not yet sucked in, renamed, and typechecked
416 type PackageRuleBase = RuleBase
417 type PackageInstEnv = InstEnv
419 data PersistentRenamerState
420 = PRS { prsOrig :: OrigNameEnv,
421 prsDecls :: DeclsMap,
422 prsInsts :: IfaceInsts,
423 prsRules :: IfaceRules,
428 The OrigNameEnv makes sure that there is just one Unique assigned for
429 each original name; i.e. (module-name, occ-name) pair. The Name is
430 always stored as a Global, and has the SrcLoc of its binding location.
431 Actually that's not quite right. When we first encounter the original
432 name, we might not be at its binding site (e.g. we are reading an
433 interface file); so we give it 'noSrcLoc' then. Later, when we find
434 its binding site, we fix it up.
436 Exactly the same is true of the Module stored in the Name. When we first
437 encounter the occurrence, we may not know the details of the module, so
438 we just store junk. Then when we find the binding site, we fix it up.
442 = Orig { origNames :: OrigNameNameEnv,
443 -- Ensures that one original name gets one unique
444 origIParam :: OrigNameIParamEnv
445 -- Ensures that one implicit parameter name gets one unique
448 type OrigNameNameEnv = FiniteMap (ModuleName,OccName) Name
449 type OrigNameIParamEnv = FiniteMap OccName Name
453 A DeclsMap contains a binding for each Name in the declaration
454 including the constructors of a type decl etc. The Bool is True just
458 type DeclsMap = NameEnv (AvailInfo, Bool, (Module, RdrNameTyClDecl))
460 type IfaceInsts = Bag GatedDecl
461 type IfaceRules = Bag GatedDecl
463 type GatedDecl = (NameSet, (Module, RdrNameHsDecl))
467 %************************************************************************
469 \subsection{Provenance and export info}
471 %************************************************************************
473 The GlobalRdrEnv gives maps RdrNames to Names. There is a separate
474 one for each module, corresponding to that module's top-level scope.
477 type GlobalRdrEnv = RdrNameEnv [(Name,Provenance)] -- The list is because there may be name clashes
478 -- These only get reported on lookup,
479 -- not on construction
482 The "provenance" of something says how it came to be in scope.
486 = LocalDef -- Defined locally
488 | NonLocalDef -- Defined non-locally
492 -- Just used for grouping error messages (in RnEnv.warnUnusedBinds)
493 instance Eq Provenance where
494 p1 == p2 = case p1 `compare` p2 of EQ -> True; _ -> False
496 instance Eq ImportReason where
497 p1 == p2 = case p1 `compare` p2 of EQ -> True; _ -> False
499 instance Ord Provenance where
500 compare LocalDef LocalDef = EQ
501 compare LocalDef (NonLocalDef _ _) = LT
502 compare (NonLocalDef _ _) LocalDef = GT
504 compare (NonLocalDef reason1 _) (NonLocalDef reason2 _)
505 = compare reason1 reason2
507 instance Ord ImportReason where
508 compare ImplicitImport ImplicitImport = EQ
509 compare ImplicitImport (UserImport _ _ _) = LT
510 compare (UserImport _ _ _) ImplicitImport = GT
511 compare (UserImport m1 loc1 _) (UserImport m2 loc2 _)
512 = (m1 `compare` m2) `thenCmp` (loc1 `compare` loc2)
516 = UserImport Module SrcLoc Bool -- Imported from module M on line L
517 -- Note the M may well not be the defining module
519 -- The Bool is true iff the thing was named *explicitly* in the import spec,
520 -- rather than being imported as part of a group; e.g.
523 -- Here, everything imported by B, and the constructors of T
524 -- are not named explicitly; only T is named explicitly.
525 -- This info is used when warning of unused names.
527 | ImplicitImport -- Imported implicitly for some other reason
530 type PrintUnqualified = Bool -- True <=> the unqualified name of this thing is
531 -- in scope in this module, so print it
532 -- unqualified in error messages
536 hasBetterProv :: Provenance -> Provenance -> Bool
538 -- a local thing over an imported thing
539 -- a user-imported thing over a non-user-imported thing
540 -- an explicitly-imported thing over an implicitly imported thing
541 hasBetterProv LocalDef _ = True
542 hasBetterProv (NonLocalDef (UserImport _ _ True) _) _ = True
543 hasBetterProv (NonLocalDef (UserImport _ _ _ ) _) (NonLocalDef ImplicitImport _) = True
544 hasBetterProv _ _ = False
546 pprNameProvenance :: Name -> Provenance -> SDoc
547 pprNameProvenance name LocalDef = ptext SLIT("defined at") <+> ppr (nameSrcLoc name)
548 pprNameProvenance name (NonLocalDef why _) = sep [ppr_reason why,
549 nest 2 (parens (ppr_defn (nameSrcLoc name)))]
551 ppr_reason ImplicitImport = ptext SLIT("implicitly imported")
552 ppr_reason (UserImport mod loc _) = ptext SLIT("imported from") <+> ppr mod <+> ptext SLIT("at") <+> ppr loc
554 ppr_defn loc | isGoodSrcLoc loc = ptext SLIT("at") <+> ppr loc