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 Rules ( RuleBase )
56 import VarSet ( TyVarSet )
57 import VarEnv ( emptyVarEnv )
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 ( CoreRule )
71 import FiniteMap ( FiniteMap, emptyFM, addToFM, lookupFM, foldFM )
73 import Maybes ( seqMaybe )
74 import UniqFM ( UniqFM )
76 import SrcLoc ( SrcLoc, isGoodSrcLoc )
77 import Util ( thenCmp )
78 import UniqSupply ( UniqSupply )
81 %************************************************************************
83 \subsection{The Finder type}
85 %************************************************************************
88 type Finder = ModuleName -> IO (Maybe (Module, ModuleLocation))
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
125 mi_usages :: [ImportVersion Name], -- Usages; kept sorted so that it's easy
126 -- to decide whether to write a new iface file
127 -- (changing usages doesn't affect the version of
130 mi_exports :: Avails, -- What it exports
131 -- Kept sorted by (mod,occ),
132 -- to make version comparisons easier
134 mi_globals :: GlobalRdrEnv, -- Its top level environment
136 mi_fixities :: NameEnv Fixity, -- Fixities
137 mi_deprecs :: Deprecations, -- Deprecations
139 mi_decls :: IfaceDecls -- The RnDecls form of ModDetails
142 data IfaceDecls = IfaceDecls { dcl_tycl :: [RenamedTyClDecl], -- Sorted
143 dcl_rules :: [RenamedRuleDecl], -- Sorted
144 dcl_insts :: [RenamedInstDecl] } -- Unsorted
146 -- typechecker should only look at this, not ModIface
147 -- Should be able to construct ModDetails from mi_decls in ModIface
150 -- The next three fields are created by the typechecker
152 md_insts :: [DFunId], -- Dfun-ids for the instances in this module
153 md_rules :: [(Id,CoreRule)] -- Domain may include Ids from other modules
158 emptyModDetails :: ModDetails
160 = ModDetails { md_types = emptyTypeEnv,
165 emptyModIface :: Module -> ModIface
167 = ModIface { mi_module = mod,
169 mi_globals = emptyRdrEnv,
170 mi_deprecs = NoDeprecs
174 Symbol tables map modules to ModDetails:
177 type SymbolTable = ModuleEnv ModDetails
178 type IfaceTable = ModuleEnv ModIface
180 type HomeIfaceTable = IfaceTable
181 type PackageIfaceTable = IfaceTable
183 type HomeSymbolTable = SymbolTable -- Domain = modules in the home package
184 type PackageSymbolTable = SymbolTable -- Domain = modules in the some other package
185 type GlobalSymbolTable = SymbolTable -- Domain = all modules
188 Simple lookups in the symbol table.
191 lookupTable :: ModuleEnv a -> ModuleEnv a -> Name -> Maybe a
192 -- We often have two Symbol- or IfaceTables, and want to do a lookup
193 lookupTable ht pt name
194 = lookupModuleEnv ht mod `seqMaybe` lookupModuleEnv pt mod
196 mod = nameModule name
198 lookupTableByModName :: ModuleEnv a -> ModuleEnv a -> ModuleName -> Maybe a
199 -- We often have two Symbol- or IfaceTables, and want to do a lookup
200 lookupTableByModName ht pt mod
201 = lookupModuleEnvByName ht mod `seqMaybe` lookupModuleEnvByName pt mod
205 %************************************************************************
207 \subsection{Type environment stuff}
209 %************************************************************************
212 type TypeEnv = NameEnv TyThing
213 emptyTypeEnv = emptyNameEnv
215 data TyThing = AnId Id
219 instance NamedThing TyThing where
220 getName (AnId id) = getName id
221 getName (ATyCon tc) = getName tc
222 getName (AClass cl) = getName cl
227 lookupTypeEnv :: SymbolTable -> Name -> Maybe TyThing
228 lookupTypeEnv tbl name
229 = case lookupModuleEnv tbl (nameModule name) of
230 Just details -> lookupNameEnv (md_types details) name
234 groupTyThings :: [TyThing] -> FiniteMap Module TypeEnv
235 -- Finite map because we want the range too
237 = foldl add emptyFM things
239 add :: FiniteMap Module TypeEnv -> TyThing -> FiniteMap Module TypeEnv
240 add tbl thing = addToFM tbl mod new_env
243 mod = nameModule name
244 new_env = case lookupFM tbl mod of
245 Nothing -> unitNameEnv name thing
246 Just env -> extendNameEnv env name thing
248 extendTypeEnv :: SymbolTable -> FiniteMap Module TypeEnv -> SymbolTable
249 extendTypeEnv tbl things
250 = foldFM add tbl things
253 = panic "extendTypeEnv" --extendModuleEnv mod new_details
256 = case lookupModuleEnv tbl mod of
257 Nothing -> emptyModDetails {md_types = type_env}
258 Just details -> details {md_types = md_types details
259 `plusNameEnv` type_env}
263 %************************************************************************
265 \subsection{Auxiliary types}
267 %************************************************************************
269 These types are defined here because they are mentioned in ModDetails,
270 but they are mostly elaborated elsewhere
275 vers_module :: Version, -- Changes when anything changes
276 vers_exports :: Version, -- Changes when export list changes
277 vers_rules :: Version, -- Changes when any rule changes
278 vers_decls :: NameEnv Version
279 -- Versions for "big" names only (not data constructors, class ops)
280 -- The version of an Id changes if its fixity changes
281 -- Ditto data constructors, class operations, except that the version of
282 -- the parent class/tycon changes
285 initialVersionInfo :: VersionInfo
286 initialVersionInfo = VersionInfo { vers_module = initialVersion,
287 vers_exports = initialVersion,
288 vers_rules = initialVersion,
289 vers_decls = emptyNameEnv }
291 data Deprecations = NoDeprecs
292 | DeprecAll DeprecTxt -- Whole module deprecated
293 | DeprecSome (NameEnv DeprecTxt) -- Some things deprecated
296 lookupDeprec :: ModIface -> Name -> Maybe DeprecTxt
297 lookupDeprec iface name
298 = case mi_deprecs iface of
300 DeprecAll txt -> Just txt
301 DeprecSome env -> lookupNameEnv env name
303 type InstEnv = UniqFM ClsInstEnv -- Maps Class to instances for that class
305 type ClsInstEnv = [(TyVarSet, [Type], DFunId)] -- The instances for a particular class
311 type Avails = [AvailInfo]
312 type AvailInfo = GenAvailInfo Name
313 type RdrAvailInfo = GenAvailInfo OccName
315 data GenAvailInfo name = Avail name -- An ordinary identifier
316 | AvailTC name -- The name of the type or class
317 [name] -- The available pieces of type/class.
318 -- NB: If the type or class is itself
319 -- to be in scope, it must be in this list.
320 -- Thus, typically: AvailTC Eq [Eq, ==, /=]
322 -- Equality used when deciding if the interface has changed
324 type AvailEnv = NameEnv AvailInfo -- Maps a Name to the AvailInfo that contains it
328 %************************************************************************
330 \subsection{ModIface}
332 %************************************************************************
335 type WhetherHasOrphans = Bool
337 -- * an instance decl in a module other than the defn module for
338 -- one of the tycons or classes in the instance head
339 -- * a transformation rule in a module other than the one defining
340 -- the function in the head of the rule.
342 type IsBootInterface = Bool
344 type ImportVersion name = (ModuleName, WhetherHasOrphans, IsBootInterface, WhatsImported name)
346 data WhatsImported name = NothingAtAll -- The module is below us in the
347 -- hierarchy, but we import nothing
349 | Everything Version -- Used for modules from other packages;
350 -- we record only the module's version number
353 Version -- Module version
354 (Maybe Version) -- Export-list version, if we depend on it
355 [(name,Version)] -- List guaranteed non-empty
356 Version -- Rules version
359 -- 'Specifically' doesn't let you say "I imported f but none of the rules in
360 -- the module". If you use anything in the module you get its rule version
361 -- So if the rules change, you'll recompile, even if you don't use them.
362 -- This is easy to implement, and it's safer: you might not have used the rules last
363 -- time round, but if someone has added a new rule you might need it this time
365 -- The export list field is (Just v) if we depend on the export list:
366 -- we imported the module without saying exactly what we imported
367 -- We need to recompile if the module exports changes, because we might
368 -- now have a name clash in the importing module.
372 %************************************************************************
374 \subsection{The persistent compiler state}
376 %************************************************************************
379 data PersistentCompilerState
381 pcs_PIT :: PackageIfaceTable, -- Domain = non-home-package modules
382 -- the mi_decls component is empty
384 pcs_PST :: PackageSymbolTable, -- Domain = non-home-package modules
385 -- except that the InstEnv components is empty
387 pcs_insts :: PackageInstEnv, -- The total InstEnv accumulated from all
388 -- the non-home-package modules
390 pcs_rules :: PackageRuleBase, -- Ditto RuleEnv
392 pcs_PRS :: PersistentRenamerState
397 The @PersistentRenamerState@ persists across successive calls to the
401 * A name supply, which deals with allocating unique names to
402 (Module,OccName) original names,
404 * An accumulated InstEnv from all the modules in pcs_PST
405 The point is that we don't want to keep recreating it whenever
406 we compile a new module. The InstEnv component of pcPST is empty.
407 (This means we might "see" instances that we shouldn't "really" see;
408 but the Haskell Report is vague on what is meant to be visible,
409 so we just take the easy road here.)
413 * A "holding pen" for declarations that have been read out of
414 interface files but not yet sucked in, renamed, and typechecked
417 type PackageRuleBase = RuleBase
418 type PackageInstEnv = InstEnv
420 data PersistentRenamerState
421 = PRS { prsOrig :: OrigNameEnv,
422 prsDecls :: DeclsMap,
423 prsInsts :: IfaceInsts,
424 prsRules :: IfaceRules,
429 The OrigNameEnv makes sure that there is just one Unique assigned for
430 each original name; i.e. (module-name, occ-name) pair. The Name is
431 always stored as a Global, and has the SrcLoc of its binding location.
432 Actually that's not quite right. When we first encounter the original
433 name, we might not be at its binding site (e.g. we are reading an
434 interface file); so we give it 'noSrcLoc' then. Later, when we find
435 its binding site, we fix it up.
437 Exactly the same is true of the Module stored in the Name. When we first
438 encounter the occurrence, we may not know the details of the module, so
439 we just store junk. Then when we find the binding site, we fix it up.
443 = Orig { origNames :: OrigNameNameEnv,
444 -- Ensures that one original name gets one unique
445 origIParam :: OrigNameIParamEnv
446 -- Ensures that one implicit parameter name gets one unique
449 type OrigNameNameEnv = FiniteMap (ModuleName,OccName) Name
450 type OrigNameIParamEnv = FiniteMap OccName Name
454 A DeclsMap contains a binding for each Name in the declaration
455 including the constructors of a type decl etc. The Bool is True just
459 type DeclsMap = NameEnv (AvailInfo, Bool, (Module, RdrNameTyClDecl))
461 type IfaceInsts = Bag GatedDecl
462 type IfaceRules = Bag GatedDecl
464 type GatedDecl = (NameSet, (Module, RdrNameHsDecl))
468 %************************************************************************
470 \subsection{Provenance and export info}
472 %************************************************************************
474 The GlobalRdrEnv gives maps RdrNames to Names. There is a separate
475 one for each module, corresponding to that module's top-level scope.
478 type GlobalRdrEnv = RdrNameEnv [(Name,Provenance)] -- The list is because there may be name clashes
479 -- These only get reported on lookup,
480 -- not on construction
483 The "provenance" of something says how it came to be in scope.
487 = LocalDef -- Defined locally
489 | NonLocalDef -- Defined non-locally
493 -- Just used for grouping error messages (in RnEnv.warnUnusedBinds)
494 instance Eq Provenance where
495 p1 == p2 = case p1 `compare` p2 of EQ -> True; _ -> False
497 instance Eq ImportReason where
498 p1 == p2 = case p1 `compare` p2 of EQ -> True; _ -> False
500 instance Ord Provenance where
501 compare LocalDef LocalDef = EQ
502 compare LocalDef (NonLocalDef _ _) = LT
503 compare (NonLocalDef _ _) LocalDef = GT
505 compare (NonLocalDef reason1 _) (NonLocalDef reason2 _)
506 = compare reason1 reason2
508 instance Ord ImportReason where
509 compare ImplicitImport ImplicitImport = EQ
510 compare ImplicitImport (UserImport _ _ _) = LT
511 compare (UserImport _ _ _) ImplicitImport = GT
512 compare (UserImport m1 loc1 _) (UserImport m2 loc2 _)
513 = (m1 `compare` m2) `thenCmp` (loc1 `compare` loc2)
517 = UserImport Module SrcLoc Bool -- Imported from module M on line L
518 -- Note the M may well not be the defining module
520 -- The Bool is true iff the thing was named *explicitly* in the import spec,
521 -- rather than being imported as part of a group; e.g.
524 -- Here, everything imported by B, and the constructors of T
525 -- are not named explicitly; only T is named explicitly.
526 -- This info is used when warning of unused names.
528 | ImplicitImport -- Imported implicitly for some other reason
531 type PrintUnqualified = Bool -- True <=> the unqualified name of this thing is
532 -- in scope in this module, so print it
533 -- unqualified in error messages
537 hasBetterProv :: Provenance -> Provenance -> Bool
539 -- a local thing over an imported thing
540 -- a user-imported thing over a non-user-imported thing
541 -- an explicitly-imported thing over an implicitly imported thing
542 hasBetterProv LocalDef _ = True
543 hasBetterProv (NonLocalDef (UserImport _ _ True) _) _ = True
544 hasBetterProv (NonLocalDef (UserImport _ _ _ ) _) (NonLocalDef ImplicitImport _) = True
545 hasBetterProv _ _ = False
547 pprNameProvenance :: Name -> Provenance -> SDoc
548 pprNameProvenance name LocalDef = ptext SLIT("defined at") <+> ppr (nameSrcLoc name)
549 pprNameProvenance name (NonLocalDef why _) = sep [ppr_reason why,
550 nest 2 (parens (ppr_defn (nameSrcLoc name)))]
552 ppr_reason ImplicitImport = ptext SLIT("implicitly imported")
553 ppr_reason (UserImport mod loc _) = ptext SLIT("imported from") <+> ppr mod <+> ptext SLIT("at") <+> ppr loc
555 ppr_defn loc | isGoodSrcLoc loc = ptext SLIT("at") <+> ppr loc