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,
34 GlobalRdrEnv, RdrAvailInfo,
37 Provenance(..), ImportReason(..), PrintUnqualified,
38 pprNameProvenance, hasBetterProv
42 #include "HsVersions.h"
44 import RdrName ( RdrNameEnv, emptyRdrEnv )
45 import Name ( Name, NameEnv, NamedThing,
46 emptyNameEnv, unitNameEnv, extendNameEnv, plusNameEnv,
47 lookupNameEnv, emptyNameEnv, getName, nameModule,
49 import NameSet ( NameSet )
50 import OccName ( OccName )
51 import Module ( Module, ModuleName, ModuleEnv,
52 lookupModuleEnv, lookupModuleEnvByName
54 import VarSet ( TyVarSet )
55 import VarEnv ( emptyVarEnv )
57 import Class ( Class )
58 import TyCon ( TyCon )
60 import BasicTypes ( Version, initialVersion, Fixity )
62 import HsSyn ( DeprecTxt )
63 import RdrHsSyn ( RdrNameHsDecl )
64 import RnHsSyn ( RenamedTyClDecl, RenamedIfaceSig, RenamedRuleDecl, RenamedInstDecl )
66 import CoreSyn ( CoreRule )
69 import FiniteMap ( FiniteMap, emptyFM, addToFM, lookupFM, foldFM )
71 import Maybes ( seqMaybe )
72 import UniqFM ( UniqFM )
74 import SrcLoc ( SrcLoc, isGoodSrcLoc )
75 import Util ( thenCmp )
76 import UniqSupply ( UniqSupply )
79 %************************************************************************
81 \subsection{The Finder type}
83 %************************************************************************
86 type Finder = ModuleName -> IO (Maybe (Module, ModuleLocation))
96 For a module in another package, the hs_file and obj_file
97 components of ModuleLocation are undefined.
99 The locations specified by a ModuleLocation may or may not
100 correspond to actual files yet: for example, even if the object
101 file doesn't exist, the ModuleLocation still contains the path to
102 where the object file will reside if/when it is created.
105 %************************************************************************
107 \subsection{Symbol tables and Module details}
109 %************************************************************************
111 A @ModIface@ plus a @ModDetails@ summarises everything we know
112 about a compiled module. The @ModIface@ is the stuff *before* linking,
113 and can be written out to an interface file. The @ModDetails@ is after
114 linking; it is the "linked" form of the mi_decls field.
119 mi_module :: Module, -- Complete with package info
120 mi_version :: VersionInfo, -- Module version number
121 mi_orphan :: WhetherHasOrphans, -- Whether this module has orphans
123 mi_usages :: [ImportVersion Name], -- Usages; kept sorted so that it's easy
124 -- to decide whether to write a new iface file
125 -- (changing usages doesn't affect the version of
128 mi_exports :: Avails, -- What it exports
129 -- Kept sorted by (mod,occ),
130 -- to make version comparisons easier
132 mi_globals :: GlobalRdrEnv, -- Its top level environment
134 mi_fixities :: NameEnv Fixity, -- Fixities
135 mi_deprecs :: Deprecations, -- Deprecations
137 mi_decls :: IfaceDecls -- The RnDecls form of ModDetails
140 data IfaceDecls = IfaceDecls { dcl_tycl :: [RenamedTyClDecl], -- Sorted
141 dcl_sigs :: [RenamedIfaceSig], -- 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 :: RuleEnv -- Domain may include Ids from other modules
157 emptyModDetails :: ModDetails
159 = ModDetails { md_types = emptyTypeEnv,
161 md_rules = emptyRuleEnv
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
303 type ClsInstEnv = [(TyVarSet, [Type], DFunId)] -- The instances for a particular class
306 type RuleEnv = NameEnv [CoreRule]
308 emptyRuleEnv = emptyVarEnv
313 type Avails = [AvailInfo]
314 type AvailInfo = GenAvailInfo Name
315 type RdrAvailInfo = GenAvailInfo OccName
317 data GenAvailInfo name = Avail name -- An ordinary identifier
318 | AvailTC name -- The name of the type or class
319 [name] -- The available pieces of type/class.
320 -- NB: If the type or class is itself
321 -- to be in scope, it must be in this list.
322 -- Thus, typically: AvailTC Eq [Eq, ==, /=]
324 -- Equality used when deciding if the interface has changed
326 type AvailEnv = NameEnv AvailInfo -- Maps a Name to the AvailInfo that contains it
330 %************************************************************************
332 \subsection{ModIface}
334 %************************************************************************
337 type WhetherHasOrphans = Bool
339 -- * an instance decl in a module other than the defn module for
340 -- one of the tycons or classes in the instance head
341 -- * a transformation rule in a module other than the one defining
342 -- the function in the head of the rule.
344 type IsBootInterface = Bool
346 type ImportVersion name = (ModuleName, WhetherHasOrphans, IsBootInterface, WhatsImported name)
348 data WhatsImported name = NothingAtAll -- The module is below us in the
349 -- hierarchy, but we import nothing
351 | Everything Version -- Used for modules from other packages;
352 -- we record only the module's version number
355 Version -- Module version
356 (Maybe Version) -- Export-list version, if we depend on it
357 [(name,Version)] -- List guaranteed non-empty
358 Version -- Rules version
361 -- 'Specifically' doesn't let you say "I imported f but none of the rules in
362 -- the module". If you use anything in the module you get its rule version
363 -- So if the rules change, you'll recompile, even if you don't use them.
364 -- This is easy to implement, and it's safer: you might not have used the rules last
365 -- time round, but if someone has added a new rule you might need it this time
367 -- The export list field is (Just v) if we depend on the export list:
368 -- we imported the module without saying exactly what we imported
369 -- We need to recompile if the module exports changes, because we might
370 -- now have a name clash in the importing module.
374 %************************************************************************
376 \subsection{The persistent compiler state}
378 %************************************************************************
381 data PersistentCompilerState
383 pcs_PIT :: PackageIfaceTable, -- Domain = non-home-package modules
384 -- the mi_decls component is empty
385 pcs_PST :: PackageSymbolTable, -- Domain = non-home-package modules
386 -- except that the InstEnv components is empty
387 pcs_insts :: InstEnv, -- The total InstEnv accumulated from all
388 -- the non-home-package modules
389 pcs_rules :: RuleEnv, -- Ditto RuleEnv
391 pcs_PRS :: PersistentRenamerState
395 The @PersistentRenamerState@ persists across successive calls to the
399 * A name supply, which deals with allocating unique names to
400 (Module,OccName) original names,
402 * An accumulated InstEnv from all the modules in pcs_PST
403 The point is that we don't want to keep recreating it whenever
404 we compile a new module. The InstEnv component of pcPST is empty.
405 (This means we might "see" instances that we shouldn't "really" see;
406 but the Haskell Report is vague on what is meant to be visible,
407 so we just take the easy road here.)
411 * A "holding pen" for declarations that have been read out of
412 interface files but not yet sucked in, renamed, and typechecked
415 data PersistentRenamerState
416 = PRS { prsOrig :: OrigNameEnv,
417 prsDecls :: DeclsMap,
418 prsInsts :: IfaceInsts,
419 prsRules :: IfaceRules,
424 The OrigNameEnv makes sure that there is just one Unique assigned for
425 each original name; i.e. (module-name, occ-name) pair. The Name is
426 always stored as a Global, and has the SrcLoc of its binding location.
427 Actually that's not quite right. When we first encounter the original
428 name, we might not be at its binding site (e.g. we are reading an
429 interface file); so we give it 'noSrcLoc' then. Later, when we find
430 its binding site, we fix it up.
432 Exactly the same is true of the Module stored in the Name. When we first
433 encounter the occurrence, we may not know the details of the module, so
434 we just store junk. Then when we find the binding site, we fix it up.
438 = Orig { origNames :: OrigNameNameEnv,
439 -- Ensures that one original name gets one unique
440 origIParam :: OrigNameIParamEnv
441 -- Ensures that one implicit parameter name gets one unique
444 type OrigNameNameEnv = FiniteMap (ModuleName,OccName) Name
445 type OrigNameIParamEnv = FiniteMap OccName Name
449 A DeclsMap contains a binding for each Name in the declaration
450 including the constructors of a type decl etc. The Bool is True just
454 type DeclsMap = NameEnv (AvailInfo, Bool, (Module, RdrNameHsDecl))
456 type IfaceInsts = Bag GatedDecl
457 type IfaceRules = Bag GatedDecl
459 type GatedDecl = (NameSet, (Module, RdrNameHsDecl))
463 %************************************************************************
465 \subsection{Provenance and export info}
467 %************************************************************************
469 The GlobalRdrEnv gives maps RdrNames to Names. There is a separate
470 one for each module, corresponding to that module's top-level scope.
473 type GlobalRdrEnv = RdrNameEnv [(Name,Provenance)] -- The list is because there may be name clashes
474 -- These only get reported on lookup,
475 -- not on construction
478 The "provenance" of something says how it came to be in scope.
482 = LocalDef -- Defined locally
484 | NonLocalDef -- Defined non-locally
488 -- Just used for grouping error messages (in RnEnv.warnUnusedBinds)
489 instance Eq Provenance where
490 p1 == p2 = case p1 `compare` p2 of EQ -> True; _ -> False
492 instance Eq ImportReason where
493 p1 == p2 = case p1 `compare` p2 of EQ -> True; _ -> False
495 instance Ord Provenance where
496 compare LocalDef LocalDef = EQ
497 compare LocalDef (NonLocalDef _ _) = LT
498 compare (NonLocalDef _ _) LocalDef = GT
500 compare (NonLocalDef reason1 _) (NonLocalDef reason2 _)
501 = compare reason1 reason2
503 instance Ord ImportReason where
504 compare ImplicitImport ImplicitImport = EQ
505 compare ImplicitImport (UserImport _ _ _) = LT
506 compare (UserImport _ _ _) ImplicitImport = GT
507 compare (UserImport m1 loc1 _) (UserImport m2 loc2 _)
508 = (m1 `compare` m2) `thenCmp` (loc1 `compare` loc2)
512 = UserImport Module SrcLoc Bool -- Imported from module M on line L
513 -- Note the M may well not be the defining module
515 -- The Bool is true iff the thing was named *explicitly* in the import spec,
516 -- rather than being imported as part of a group; e.g.
519 -- Here, everything imported by B, and the constructors of T
520 -- are not named explicitly; only T is named explicitly.
521 -- This info is used when warning of unused names.
523 | ImplicitImport -- Imported implicitly for some other reason
526 type PrintUnqualified = Bool -- True <=> the unqualified name of this thing is
527 -- in scope in this module, so print it
528 -- unqualified in error messages
532 hasBetterProv :: Provenance -> Provenance -> Bool
534 -- a local thing over an imported thing
535 -- a user-imported thing over a non-user-imported thing
536 -- an explicitly-imported thing over an implicitly imported thing
537 hasBetterProv LocalDef _ = True
538 hasBetterProv (NonLocalDef (UserImport _ _ True) _) _ = True
539 hasBetterProv (NonLocalDef (UserImport _ _ _ ) _) (NonLocalDef ImplicitImport _) = True
540 hasBetterProv _ _ = False
542 pprNameProvenance :: Name -> Provenance -> SDoc
543 pprNameProvenance name LocalDef = ptext SLIT("defined at") <+> ppr (nameSrcLoc name)
544 pprNameProvenance name (NonLocalDef why _) = sep [ppr_reason why,
545 nest 2 (parens (ppr_defn (nameSrcLoc name)))]
547 ppr_reason ImplicitImport = ptext SLIT("implicitly imported")
548 ppr_reason (UserImport mod loc _) = ptext SLIT("imported from") <+> ppr mod <+> ptext SLIT("at") <+> ppr loc
550 ppr_defn loc | isGoodSrcLoc loc = ptext SLIT("at") <+> ppr loc