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 lookupTable, lookupTableByModName,
18 VersionInfo(..), initialVersionInfo,
20 TyThing(..), isTyClThing,
22 TypeEnv, lookupType, mkTypeEnv, extendTypeEnvList,
23 typeEnvClasses, typeEnvTyCons,
25 WhetherHasOrphans, ImportVersion, WhatsImported(..),
26 PersistentRenamerState(..), IsBootInterface, Avails, DeclsMap,
27 IfaceInsts, IfaceRules, GatedDecl,
28 OrigNameEnv(..), OrigNameNameEnv, OrigNameIParamEnv,
29 AvailEnv, AvailInfo, GenAvailInfo(..),
30 PersistentCompilerState(..),
32 Deprecations(..), lookupDeprec,
34 InstEnv, ClsInstEnv, DFunId,
35 PackageInstEnv, PackageRuleBase,
37 GlobalRdrEnv, RdrAvailInfo,
40 Provenance(..), ImportReason(..), PrintUnqualified,
41 pprNameProvenance, hasBetterProv
45 #include "HsVersions.h"
47 import RdrName ( RdrNameEnv, emptyRdrEnv )
48 import Name ( Name, NameEnv, NamedThing,
49 emptyNameEnv, extendNameEnv,
50 lookupNameEnv, emptyNameEnv, getName, nameModule,
51 nameSrcLoc, nameEnvElts )
52 import NameSet ( NameSet )
53 import OccName ( OccName )
54 import Module ( Module, ModuleName, ModuleEnv,
55 lookupModuleEnv, lookupModuleEnvByName
57 import Rules ( RuleBase )
58 import VarSet ( TyVarSet )
60 import Class ( Class )
61 import TyCon ( TyCon )
63 import BasicTypes ( Version, initialVersion, Fixity )
65 import HsSyn ( DeprecTxt )
66 import RdrHsSyn ( RdrNameHsDecl, RdrNameTyClDecl )
67 import RnHsSyn ( RenamedTyClDecl, RenamedRuleDecl, RenamedInstDecl )
69 import CoreSyn ( IdCoreRule )
72 import FiniteMap ( FiniteMap )
74 import Maybes ( seqMaybe )
75 import UniqFM ( UniqFM, emptyUFM )
77 import SrcLoc ( SrcLoc, isGoodSrcLoc )
78 import Util ( thenCmp )
79 import UniqSupply ( UniqSupply )
82 %************************************************************************
84 \subsection{Module locations}
86 %************************************************************************
91 hs_preprocd_file :: FilePath, -- location after preprocessing
97 instance Outputable ModuleLocation where
101 For a module in another package, the hs_file and obj_file
102 components of ModuleLocation are undefined.
104 The locations specified by a ModuleLocation may or may not
105 correspond to actual files yet: for example, even if the object
106 file doesn't exist, the ModuleLocation still contains the path to
107 where the object file will reside if/when it is created.
110 %************************************************************************
112 \subsection{Symbol tables and Module details}
114 %************************************************************************
116 A @ModIface@ plus a @ModDetails@ summarises everything we know
117 about a compiled module. The @ModIface@ is the stuff *before* linking,
118 and can be written out to an interface file. The @ModDetails@ is after
119 linking; it is the "linked" form of the mi_decls field.
124 mi_module :: Module, -- Complete with package info
125 mi_version :: VersionInfo, -- Module version number
126 mi_orphan :: WhetherHasOrphans, -- Whether this module has orphans
127 mi_boot :: IsBootInterface, -- Whether this interface was read from an hi-boot file
129 mi_usages :: [ImportVersion Name], -- Usages; kept sorted so that it's easy
130 -- to decide whether to write a new iface file
131 -- (changing usages doesn't affect the version of
134 mi_exports :: [(ModuleName,Avails)], -- What it exports
135 -- Kept sorted by (mod,occ),
136 -- to make version comparisons easier
138 mi_globals :: GlobalRdrEnv, -- Its top level environment
140 mi_fixities :: NameEnv Fixity, -- Fixities
141 mi_deprecs :: Deprecations, -- Deprecations
143 mi_decls :: IfaceDecls -- The RnDecls form of ModDetails
146 data IfaceDecls = IfaceDecls { dcl_tycl :: [RenamedTyClDecl], -- Sorted
147 dcl_rules :: [RenamedRuleDecl], -- Sorted
148 dcl_insts :: [RenamedInstDecl] } -- Unsorted
150 -- typechecker should only look at this, not ModIface
151 -- Should be able to construct ModDetails from mi_decls in ModIface
154 -- The next three fields are created by the typechecker
156 md_insts :: [DFunId], -- Dfun-ids for the instances in this module
157 md_rules :: [IdCoreRule] -- Domain may include Ids from other modules
162 emptyModDetails :: ModDetails
164 = ModDetails { md_types = emptyTypeEnv,
169 emptyModIface :: Module -> ModIface
171 = ModIface { mi_module = mod,
172 mi_version = initialVersionInfo,
177 mi_fixities = emptyNameEnv,
178 mi_globals = emptyRdrEnv,
179 mi_deprecs = NoDeprecs,
180 mi_decls = panic "emptyModIface: decls"
184 Symbol tables map modules to ModDetails:
187 type SymbolTable = ModuleEnv ModDetails
188 type IfaceTable = ModuleEnv ModIface
190 type HomeIfaceTable = IfaceTable
191 type PackageIfaceTable = IfaceTable
193 type HomeSymbolTable = SymbolTable -- Domain = modules in the home package
195 emptyIfaceTable :: IfaceTable
196 emptyIfaceTable = emptyUFM
199 Simple lookups in the symbol table.
202 lookupTable :: ModuleEnv a -> ModuleEnv a -> Name -> Maybe a
203 -- We often have two Symbol- or IfaceTables, and want to do a lookup
204 lookupTable ht pt name
205 = lookupModuleEnv ht mod `seqMaybe` lookupModuleEnv pt mod
207 mod = nameModule name
209 lookupTableByModName :: ModuleEnv a -> ModuleEnv a -> ModuleName -> Maybe a
210 -- We often have two Symbol- or IfaceTables, and want to do a lookup
211 lookupTableByModName ht pt mod
212 = lookupModuleEnvByName ht mod `seqMaybe` lookupModuleEnvByName pt mod
216 %************************************************************************
218 \subsection{Type environment stuff}
220 %************************************************************************
223 data TyThing = AnId Id
227 isTyClThing :: TyThing -> Bool
228 isTyClThing (ATyCon _) = True
229 isTyClThing (AClass _) = True
230 isTyClThing (AnId _) = False
232 instance NamedThing TyThing where
233 getName (AnId id) = getName id
234 getName (ATyCon tc) = getName tc
235 getName (AClass cl) = getName cl
237 typeEnvClasses env = [cl | AClass cl <- nameEnvElts env]
238 typeEnvTyCons env = [tc | ATyCon tc <- nameEnvElts env]
244 type TypeEnv = NameEnv TyThing
246 emptyTypeEnv = emptyNameEnv
248 mkTypeEnv :: [TyThing] -> TypeEnv
249 mkTypeEnv things = extendTypeEnvList emptyTypeEnv things
251 extendTypeEnvList :: TypeEnv -> [TyThing] -> TypeEnv
252 extendTypeEnvList env things
253 = foldl add_thing env things
255 add_thing :: TypeEnv -> TyThing -> TypeEnv
256 add_thing env thing = extendNameEnv env (getName thing) thing
260 lookupType :: HomeSymbolTable -> PackageTypeEnv -> Name -> Maybe TyThing
261 lookupType hst pte name
262 = case lookupModuleEnv hst (nameModule name) of
263 Just details -> lookupNameEnv (md_types details) name
264 Nothing -> lookupNameEnv pte name
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 (Name,DeprecTxt)) -- Some things deprecated
299 -- We keep the Name in the range, so we can print them out
301 lookupDeprec :: Deprecations -> Name -> Maybe DeprecTxt
302 lookupDeprec NoDeprecs name = Nothing
303 lookupDeprec (DeprecAll txt) name = Just txt
304 lookupDeprec (DeprecSome env) name = case lookupNameEnv env name of
305 Just (_, txt) -> Just txt
308 type InstEnv = UniqFM ClsInstEnv -- Maps Class to instances for that class
310 type ClsInstEnv = [(TyVarSet, [Type], DFunId)] -- The instances for a particular class
316 type Avails = [AvailInfo]
317 type AvailInfo = GenAvailInfo Name
318 type RdrAvailInfo = GenAvailInfo OccName
320 data GenAvailInfo name = Avail name -- An ordinary identifier
321 | AvailTC name -- The name of the type or class
322 [name] -- The available pieces of type/class.
323 -- NB: If the type or class is itself
324 -- to be in scope, it must be in this list.
325 -- Thus, typically: AvailTC Eq [Eq, ==, /=]
327 -- Equality used when deciding if the interface has changed
329 type AvailEnv = NameEnv AvailInfo -- Maps a Name to the AvailInfo that contains it
333 %************************************************************************
335 \subsection{ModIface}
337 %************************************************************************
340 type WhetherHasOrphans = Bool
342 -- * an instance decl in a module other than the defn module for
343 -- one of the tycons or classes in the instance head
344 -- * a transformation rule in a module other than the one defining
345 -- the function in the head of the rule.
347 type IsBootInterface = Bool
349 type ImportVersion name = (ModuleName, WhetherHasOrphans, IsBootInterface, WhatsImported name)
351 data WhatsImported name = NothingAtAll -- The module is below us in the
352 -- hierarchy, but we import nothing
354 | Everything Version -- Used for modules from other packages;
355 -- we record only the module's version number
358 Version -- Module version
359 (Maybe Version) -- Export-list version, if we depend on it
360 [(name,Version)] -- List guaranteed non-empty
361 Version -- Rules version
364 -- 'Specifically' doesn't let you say "I imported f but none of the rules in
365 -- the module". If you use anything in the module you get its rule version
366 -- So if the rules change, you'll recompile, even if you don't use them.
367 -- This is easy to implement, and it's safer: you might not have used the rules last
368 -- time round, but if someone has added a new rule you might need it this time
370 -- The export list field is (Just v) if we depend on the export list:
371 -- we imported the module without saying exactly what we imported
372 -- We need to recompile if the module exports changes, because we might
373 -- now have a name clash in the importing module.
377 %************************************************************************
379 \subsection{The persistent compiler state}
381 %************************************************************************
384 data PersistentCompilerState
386 pcs_PIT :: PackageIfaceTable, -- Domain = non-home-package modules
387 -- the mi_decls component is empty
389 pcs_PTE :: PackageTypeEnv, -- Domain = non-home-package modules
390 -- except that the InstEnv components is empty
392 pcs_insts :: PackageInstEnv, -- The total InstEnv accumulated from all
393 -- the non-home-package modules
395 pcs_rules :: PackageRuleBase, -- Ditto RuleEnv
397 pcs_PRS :: PersistentRenamerState
402 The @PersistentRenamerState@ persists across successive calls to the
406 * A name supply, which deals with allocating unique names to
407 (Module,OccName) original names,
409 * An accumulated TypeEnv from all the modules in imported packages
411 * An accumulated InstEnv from all the modules in imported packages
412 The point is that we don't want to keep recreating it whenever
413 we compile a new module. The InstEnv component of pcPST is empty.
414 (This means we might "see" instances that we shouldn't "really" see;
415 but the Haskell Report is vague on what is meant to be visible,
416 so we just take the easy road here.)
420 * A "holding pen" for declarations that have been read out of
421 interface files but not yet sucked in, renamed, and typechecked
424 type PackageTypeEnv = TypeEnv
425 type PackageRuleBase = RuleBase
426 type PackageInstEnv = InstEnv
428 data PersistentRenamerState
429 = PRS { prsOrig :: OrigNameEnv,
430 prsDecls :: DeclsMap,
431 prsInsts :: IfaceInsts,
432 prsRules :: IfaceRules,
437 The OrigNameEnv makes sure that there is just one Unique assigned for
438 each original name; i.e. (module-name, occ-name) pair. The Name is
439 always stored as a Global, and has the SrcLoc of its binding location.
440 Actually that's not quite right. When we first encounter the original
441 name, we might not be at its binding site (e.g. we are reading an
442 interface file); so we give it 'noSrcLoc' then. Later, when we find
443 its binding site, we fix it up.
445 Exactly the same is true of the Module stored in the Name. When we first
446 encounter the occurrence, we may not know the details of the module, so
447 we just store junk. Then when we find the binding site, we fix it up.
451 = Orig { origNames :: OrigNameNameEnv,
452 -- Ensures that one original name gets one unique
453 origIParam :: OrigNameIParamEnv
454 -- Ensures that one implicit parameter name gets one unique
457 type OrigNameNameEnv = FiniteMap (ModuleName,OccName) Name
458 type OrigNameIParamEnv = FiniteMap OccName Name
462 A DeclsMap contains a binding for each Name in the declaration
463 including the constructors of a type decl etc. The Bool is True just
467 type DeclsMap = NameEnv (AvailInfo, Bool, (Module, RdrNameTyClDecl))
469 type IfaceInsts = Bag GatedDecl
470 type IfaceRules = Bag GatedDecl
472 type GatedDecl = (NameSet, (Module, RdrNameHsDecl))
476 %************************************************************************
478 \subsection{Provenance and export info}
480 %************************************************************************
482 The GlobalRdrEnv gives maps RdrNames to Names. There is a separate
483 one for each module, corresponding to that module's top-level scope.
486 type GlobalRdrEnv = RdrNameEnv [(Name,Provenance)] -- The list is because there may be name clashes
487 -- These only get reported on lookup,
488 -- not on construction
491 The "provenance" of something says how it came to be in scope.
495 = LocalDef -- Defined locally
497 | NonLocalDef -- Defined non-locally
501 -- Just used for grouping error messages (in RnEnv.warnUnusedBinds)
502 instance Eq Provenance where
503 p1 == p2 = case p1 `compare` p2 of EQ -> True; _ -> False
505 instance Eq ImportReason where
506 p1 == p2 = case p1 `compare` p2 of EQ -> True; _ -> False
508 instance Ord Provenance where
509 compare LocalDef LocalDef = EQ
510 compare LocalDef (NonLocalDef _ _) = LT
511 compare (NonLocalDef _ _) LocalDef = GT
513 compare (NonLocalDef reason1 _) (NonLocalDef reason2 _)
514 = compare reason1 reason2
516 instance Ord ImportReason where
517 compare ImplicitImport ImplicitImport = EQ
518 compare ImplicitImport (UserImport _ _ _) = LT
519 compare (UserImport _ _ _) ImplicitImport = GT
520 compare (UserImport m1 loc1 _) (UserImport m2 loc2 _)
521 = (m1 `compare` m2) `thenCmp` (loc1 `compare` loc2)
525 = UserImport Module SrcLoc Bool -- Imported from module M on line L
526 -- Note the M may well not be the defining module
528 -- The Bool is true iff the thing was named *explicitly* in the import spec,
529 -- rather than being imported as part of a group; e.g.
532 -- Here, everything imported by B, and the constructors of T
533 -- are not named explicitly; only T is named explicitly.
534 -- This info is used when warning of unused names.
536 | ImplicitImport -- Imported implicitly for some other reason
539 type PrintUnqualified = Bool -- True <=> the unqualified name of this thing is
540 -- in scope in this module, so print it
541 -- unqualified in error messages
545 hasBetterProv :: Provenance -> Provenance -> Bool
547 -- a local thing over an imported thing
548 -- a user-imported thing over a non-user-imported thing
549 -- an explicitly-imported thing over an implicitly imported thing
550 hasBetterProv LocalDef _ = True
551 hasBetterProv (NonLocalDef (UserImport _ _ True) _) _ = True
552 hasBetterProv (NonLocalDef (UserImport _ _ _ ) _) (NonLocalDef ImplicitImport _) = True
553 hasBetterProv _ _ = False
555 pprNameProvenance :: Name -> Provenance -> SDoc
556 pprNameProvenance name LocalDef = ptext SLIT("defined at") <+> ppr (nameSrcLoc name)
557 pprNameProvenance name (NonLocalDef why _) = sep [ppr_reason why,
558 nest 2 (parens (ppr_defn (nameSrcLoc name)))]
560 ppr_reason ImplicitImport = ptext SLIT("implicitly imported")
561 ppr_reason (UserImport mod loc _) = ptext SLIT("imported from") <+> ppr mod <+> ptext SLIT("at") <+> ppr loc
563 ppr_defn loc | isGoodSrcLoc loc = ptext SLIT("at") <+> ppr loc