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 )
78 %************************************************************************
80 \subsection{The Finder type}
82 %************************************************************************
85 type Finder = ModuleName -> IO (Maybe (Module, ModuleLocation))
95 For a module in another package, the hs_file and obj_file
96 components of ModuleLocation are undefined.
98 The locations specified by a ModuleLocation may or may not
99 correspond to actual files yet: for example, even if the object
100 file doesn't exist, the ModuleLocation still contains the path to
101 where the object file will reside if/when it is created.
104 %************************************************************************
106 \subsection{Symbol tables and Module details}
108 %************************************************************************
110 A @ModIface@ plus a @ModDetails@ summarises everything we know
111 about a compiled module. The @ModIface@ is the stuff *before* linking,
112 and can be written out to an interface file. The @ModDetails@ is after
113 linking; it is the "linked" form of the mi_decls field.
118 mi_module :: Module, -- Complete with package info
119 mi_version :: VersionInfo, -- Module version number
120 mi_orphan :: WhetherHasOrphans, -- Whether this module has orphans
122 mi_usages :: [ImportVersion Name], -- Usages; kept sorted so that it's easy
123 -- to decide whether to write a new iface file
124 -- (changing usages doesn't affect the version of
127 mi_exports :: Avails, -- What it exports
128 -- Kept sorted by (mod,occ),
129 -- to make version comparisons easier
131 mi_globals :: GlobalRdrEnv, -- Its top level environment
133 mi_fixities :: NameEnv Fixity, -- Fixities
134 mi_deprecs :: Deprecations, -- Deprecations
136 mi_decls :: IfaceDecls -- The RnDecls form of ModDetails
139 data IfaceDecls = IfaceDecls { dcl_tycl :: [RenamedTyClDecl], -- Sorted
140 dcl_sigs :: [RenamedIfaceSig], -- Sorted
141 dcl_rules :: [RenamedRuleDecl], -- Sorted
142 dcl_insts :: [RenamedInstDecl] } -- Unsorted
144 -- typechecker should only look at this, not ModIface
145 -- Should be able to construct ModDetails from mi_decls in ModIface
148 -- The next three fields are created by the typechecker
150 md_insts :: [DFunId], -- Dfun-ids for the instances in this module
151 md_rules :: RuleEnv -- Domain may include Ids from other modules
156 emptyModDetails :: ModDetails
158 = ModDetails { md_types = emptyTypeEnv,
160 md_rules = emptyRuleEnv
163 emptyModIface :: Module -> ModIface
165 = ModIface { mi_module = mod,
167 mi_globals = emptyRdrEnv,
168 mi_deprecs = NoDeprecs
172 Symbol tables map modules to ModDetails:
175 type SymbolTable = ModuleEnv ModDetails
176 type IfaceTable = ModuleEnv ModIface
178 type HomeIfaceTable = IfaceTable
179 type PackageIfaceTable = IfaceTable
181 type HomeSymbolTable = SymbolTable -- Domain = modules in the home package
182 type PackageSymbolTable = SymbolTable -- Domain = modules in the some other package
183 type GlobalSymbolTable = SymbolTable -- Domain = all modules
186 Simple lookups in the symbol table.
189 lookupTable :: ModuleEnv a -> ModuleEnv a -> Name -> Maybe a
190 -- We often have two Symbol- or IfaceTables, and want to do a lookup
191 lookupTable ht pt name
192 = lookupModuleEnv ht mod `seqMaybe` lookupModuleEnv pt mod
194 mod = nameModule name
196 lookupTableByModName :: ModuleEnv a -> ModuleEnv a -> ModuleName -> Maybe a
197 -- We often have two Symbol- or IfaceTables, and want to do a lookup
198 lookupTableByModName ht pt mod
199 = lookupModuleEnvByName ht mod `seqMaybe` lookupModuleEnvByName pt mod
203 %************************************************************************
205 \subsection{Type environment stuff}
207 %************************************************************************
210 type TypeEnv = NameEnv TyThing
211 emptyTypeEnv = emptyNameEnv
213 data TyThing = AnId Id
217 instance NamedThing TyThing where
218 getName (AnId id) = getName id
219 getName (ATyCon tc) = getName tc
220 getName (AClass cl) = getName cl
225 lookupTypeEnv :: SymbolTable -> Name -> Maybe TyThing
226 lookupTypeEnv tbl name
227 = case lookupModuleEnv tbl (nameModule name) of
228 Just details -> lookupNameEnv (md_types details) name
232 groupTyThings :: [TyThing] -> FiniteMap Module TypeEnv
233 -- Finite map because we want the range too
235 = foldl add emptyFM things
237 add :: FiniteMap Module TypeEnv -> TyThing -> FiniteMap Module TypeEnv
238 add tbl thing = addToFM tbl mod new_env
241 mod = nameModule name
242 new_env = case lookupFM tbl mod of
243 Nothing -> unitNameEnv name thing
244 Just env -> extendNameEnv env name thing
246 extendTypeEnv :: SymbolTable -> FiniteMap Module TypeEnv -> SymbolTable
247 extendTypeEnv tbl things
248 = foldFM add tbl things
251 = panic "extendTypeEnv" --extendModuleEnv mod new_details
254 = case lookupModuleEnv tbl mod of
255 Nothing -> emptyModDetails {md_types = type_env}
256 Just details -> details {md_types = md_types details
257 `plusNameEnv` type_env}
261 %************************************************************************
263 \subsection{Auxiliary types}
265 %************************************************************************
267 These types are defined here because they are mentioned in ModDetails,
268 but they are mostly elaborated elsewhere
273 vers_module :: Version, -- Changes when anything changes
274 vers_exports :: Version, -- Changes when export list changes
275 vers_rules :: Version, -- Changes when any rule changes
276 vers_decls :: NameEnv Version
277 -- Versions for "big" names only (not data constructors, class ops)
278 -- The version of an Id changes if its fixity changes
279 -- Ditto data constructors, class operations, except that the version of
280 -- the parent class/tycon changes
283 initialVersionInfo :: VersionInfo
284 initialVersionInfo = VersionInfo { vers_module = initialVersion,
285 vers_exports = initialVersion,
286 vers_rules = initialVersion,
287 vers_decls = emptyNameEnv }
289 data Deprecations = NoDeprecs
290 | DeprecAll DeprecTxt -- Whole module deprecated
291 | DeprecSome (NameEnv DeprecTxt) -- Some things deprecated
294 lookupDeprec :: ModIface -> Name -> Maybe DeprecTxt
295 lookupDeprec iface name
296 = case mi_deprecs iface of
298 DeprecAll txt -> Just txt
299 DeprecSome env -> lookupNameEnv env name
301 type InstEnv = UniqFM ClsInstEnv -- Maps Class to instances for that class
302 type ClsInstEnv = [(TyVarSet, [Type], DFunId)] -- The instances for a particular class
305 type RuleEnv = NameEnv [CoreRule]
307 emptyRuleEnv = emptyVarEnv
312 type Avails = [AvailInfo]
313 type AvailInfo = GenAvailInfo Name
314 type RdrAvailInfo = GenAvailInfo OccName
316 data GenAvailInfo name = Avail name -- An ordinary identifier
317 | AvailTC name -- The name of the type or class
318 [name] -- The available pieces of type/class.
319 -- NB: If the type or class is itself
320 -- to be in scope, it must be in this list.
321 -- Thus, typically: AvailTC Eq [Eq, ==, /=]
323 -- Equality used when deciding if the interface has changed
325 type AvailEnv = NameEnv AvailInfo -- Maps a Name to the AvailInfo that contains it
329 %************************************************************************
331 \subsection{ModIface}
333 %************************************************************************
336 type WhetherHasOrphans = Bool
338 -- * an instance decl in a module other than the defn module for
339 -- one of the tycons or classes in the instance head
340 -- * a transformation rule in a module other than the one defining
341 -- the function in the head of the rule.
343 type IsBootInterface = Bool
345 type ImportVersion name = (ModuleName, WhetherHasOrphans, IsBootInterface, WhatsImported name)
347 data WhatsImported name = NothingAtAll -- The module is below us in the
348 -- hierarchy, but we import nothing
350 | Everything Version -- Used for modules from other packages;
351 -- we record only the module's version number
354 Version -- Module version
355 (Maybe Version) -- Export-list version, if we depend on it
356 [(name,Version)] -- List guaranteed non-empty
357 Version -- Rules version
360 -- 'Specifically' doesn't let you say "I imported f but none of the rules in
361 -- the module". If you use anything in the module you get its rule version
362 -- So if the rules change, you'll recompile, even if you don't use them.
363 -- This is easy to implement, and it's safer: you might not have used the rules last
364 -- time round, but if someone has added a new rule you might need it this time
366 -- The export list field is (Just v) if we depend on the export list:
367 -- we imported the module without saying exactly what we imported
368 -- We need to recompile if the module exports changes, because we might
369 -- now have a name clash in the importing module.
373 %************************************************************************
375 \subsection{The persistent compiler state}
377 %************************************************************************
380 data PersistentCompilerState
382 pcs_PIT :: PackageIfaceTable, -- Domain = non-home-package modules
383 -- the mi_decls component is empty
384 pcs_PST :: PackageSymbolTable, -- Domain = non-home-package modules
385 -- except that the InstEnv components is empty
386 pcs_insts :: InstEnv, -- The total InstEnv accumulated from all
387 -- the non-home-package modules
388 pcs_rules :: RuleEnv, -- Ditto RuleEnv
390 pcs_PRS :: PersistentRenamerState
394 The @PersistentRenamerState@ persists across successive calls to the
398 * A name supply, which deals with allocating unique names to
399 (Module,OccName) original names,
401 * An accumulated InstEnv from all the modules in pcs_PST
402 The point is that we don't want to keep recreating it whenever
403 we compile a new module. The InstEnv component of pcPST is empty.
404 (This means we might "see" instances that we shouldn't "really" see;
405 but the Haskell Report is vague on what is meant to be visible,
406 so we just take the easy road here.)
410 * A "holding pen" for declarations that have been read out of
411 interface files but not yet sucked in, renamed, and typechecked
414 data PersistentRenamerState
415 = PRS { prsOrig :: OrigNameEnv,
416 prsDecls :: DeclsMap,
417 prsInsts :: IfaceInsts,
418 prsRules :: IfaceRules
422 The OrigNameEnv makes sure that there is just one Unique assigned for
423 each original name; i.e. (module-name, occ-name) pair. The Name is
424 always stored as a Global, and has the SrcLoc of its binding location.
425 Actually that's not quite right. When we first encounter the original
426 name, we might not be at its binding site (e.g. we are reading an
427 interface file); so we give it 'noSrcLoc' then. Later, when we find
428 its binding site, we fix it up.
430 Exactly the same is true of the Module stored in the Name. When we first
431 encounter the occurrence, we may not know the details of the module, so
432 we just store junk. Then when we find the binding site, we fix it up.
436 = Orig { origNames :: OrigNameNameEnv,
437 -- Ensures that one original name gets one unique
438 origIParam :: OrigNameIParamEnv
439 -- Ensures that one implicit parameter name gets one unique
442 type OrigNameNameEnv = FiniteMap (ModuleName,OccName) Name
443 type OrigNameIParamEnv = FiniteMap OccName Name
447 A DeclsMap contains a binding for each Name in the declaration
448 including the constructors of a type decl etc. The Bool is True just
452 type DeclsMap = NameEnv (AvailInfo, Bool, (Module, RdrNameHsDecl))
454 type IfaceInsts = Bag GatedDecl
455 type IfaceRules = Bag GatedDecl
457 type GatedDecl = (NameSet, (Module, RdrNameHsDecl))
461 %************************************************************************
463 \subsection{Provenance and export info}
465 %************************************************************************
467 The GlobalRdrEnv gives maps RdrNames to Names. There is a separate
468 one for each module, corresponding to that module's top-level scope.
471 type GlobalRdrEnv = RdrNameEnv [(Name,Provenance)] -- The list is because there may be name clashes
472 -- These only get reported on lookup,
473 -- not on construction
476 The "provenance" of something says how it came to be in scope.
480 = LocalDef -- Defined locally
482 | NonLocalDef -- Defined non-locally
486 -- Just used for grouping error messages (in RnEnv.warnUnusedBinds)
487 instance Eq Provenance where
488 p1 == p2 = case p1 `compare` p2 of EQ -> True; _ -> False
490 instance Eq ImportReason where
491 p1 == p2 = case p1 `compare` p2 of EQ -> True; _ -> False
493 instance Ord Provenance where
494 compare LocalDef LocalDef = EQ
495 compare LocalDef (NonLocalDef _ _) = LT
496 compare (NonLocalDef _ _) LocalDef = GT
498 compare (NonLocalDef reason1 _) (NonLocalDef reason2 _)
499 = compare reason1 reason2
501 instance Ord ImportReason where
502 compare ImplicitImport ImplicitImport = EQ
503 compare ImplicitImport (UserImport _ _ _) = LT
504 compare (UserImport _ _ _) ImplicitImport = GT
505 compare (UserImport m1 loc1 _) (UserImport m2 loc2 _)
506 = (m1 `compare` m2) `thenCmp` (loc1 `compare` loc2)
510 = UserImport Module SrcLoc Bool -- Imported from module M on line L
511 -- Note the M may well not be the defining module
513 -- The Bool is true iff the thing was named *explicitly* in the import spec,
514 -- rather than being imported as part of a group; e.g.
517 -- Here, everything imported by B, and the constructors of T
518 -- are not named explicitly; only T is named explicitly.
519 -- This info is used when warning of unused names.
521 | ImplicitImport -- Imported implicitly for some other reason
524 type PrintUnqualified = Bool -- True <=> the unqualified name of this thing is
525 -- in scope in this module, so print it
526 -- unqualified in error messages
530 hasBetterProv :: Provenance -> Provenance -> Bool
532 -- a local thing over an imported thing
533 -- a user-imported thing over a non-user-imported thing
534 -- an explicitly-imported thing over an implicitly imported thing
535 hasBetterProv LocalDef _ = True
536 hasBetterProv (NonLocalDef (UserImport _ _ True) _) _ = True
537 hasBetterProv (NonLocalDef (UserImport _ _ _ ) _) (NonLocalDef ImplicitImport _) = True
538 hasBetterProv _ _ = False
540 pprNameProvenance :: Name -> Provenance -> SDoc
541 pprNameProvenance name LocalDef = ptext SLIT("defined at") <+> ppr (nameSrcLoc name)
542 pprNameProvenance name (NonLocalDef why _) = sep [ppr_reason why,
543 nest 2 (parens (ppr_defn (nameSrcLoc name)))]
545 ppr_reason ImplicitImport = ptext SLIT("implicitly imported")
546 ppr_reason (UserImport mod loc _) = ptext SLIT("imported from") <+> ppr mod <+> ptext SLIT("at") <+> ppr loc
548 ppr_defn loc | isGoodSrcLoc loc = ptext SLIT("at") <+> ppr loc