2 % (c) The University of Glasgow, 2000
4 \section[HscTypes]{Types for the per-module compiler}
8 ModDetails(..), GlobalSymbolTable,
9 HomeSymbolTable, PackageSymbolTable,
11 TyThing(..), lookupTypeEnv,
13 WhetherHasOrphans, ImportVersion, ExportItem,
14 PersistentRenamerState(..), IsBootInterface, Avails, DeclsMap,
15 IfaceInsts, IfaceRules, DeprecationEnv, OrigNameEnv,
16 AvailEnv, AvailInfo, GenAvailInfo(..),
17 PersistentCompilerState(..),
19 InstEnv, ClsInstEnv, DFunId,
21 GlobalRdrEnv, RdrAvailInfo,
24 Provenance(..), ImportReason(..), PrintUnqualified,
25 pprNameProvenance, hasBetterProv
29 #include "HsVersions.h"
31 import Name ( Name, NameEnv, NamedThing,
32 unitNameEnv, extendNameEnv, plusNameEnv,
33 lookupNameEnv, emptyNameEnv, getName, nameModule,
35 import Module ( Module, ModuleName,
36 extendModuleEnv, lookupModuleEnv )
37 import Class ( Class )
38 import OccName ( OccName )
39 import RdrName ( RdrNameEnv, emptyRdrEnv )
40 import Outputable ( SDoc )
41 import UniqFM ( UniqFM )
42 import FiniteMap ( FiniteMap, emptyFM, addToFM, lookupFM, foldFM )
45 import VarEnv ( IdEnv, emptyVarEnv )
46 import BasicTypes ( Version, Fixity, defaultFixity )
47 import TyCon ( TyCon )
48 import ErrUtils ( ErrMsg, WarnMsg )
49 import CmLink ( Linkable )
50 import RdrHsSyn ( RdrNameInstDecl, RdrNameRuleDecl, RdrNameHsDecl,
51 RdrNameDeprecation, RdrNameFixitySig )
52 import UniqSupply ( UniqSupply )
53 import HsDecls ( DeprecTxt )
54 import CoreSyn ( CoreRule )
55 import NameSet ( NameSet )
57 import VarSet ( TyVarSet )
58 import Panic ( panic )
60 import SrcLoc ( SrcLoc, isGoodSrcLoc )
63 %************************************************************************
65 \subsection{Symbol tables and Module details}
67 %************************************************************************
69 A @ModIface@ plus a @ModDetails@ summarises everything we know
70 about a compiled module. The @ModIface@ is the stuff *before* linking,
71 and can be written out to an interface file. The @ModDetails@ is after
72 linking; it is the "linked" form of the mi_decls field.
77 md_module :: Module, -- Complete with package info
78 md_version :: VersionInfo, -- Module version number
79 md_orphan :: WhetherHasOrphans, -- Whether this module has orphans
80 md_usages :: [ImportVersion Name], -- Usages
82 md_exports :: Avails, -- What it exports
83 md_globals :: GlobalRdrEnv, -- Its top level environment
85 md_fixities :: NameEnv Fixity, -- Fixities
86 md_deprecs :: NameEnv DeprecTxt, -- Deprecations
88 -- The next three fields are created by the typechecker
90 md_insts :: [DFunId], -- Dfun-ids for the instances in this module
91 md_rules :: RuleEnv -- Domain may include Ids from other modules
94 -- ModIFace is nearly the same as RnMonad.ParsedIface.
95 -- Right now it's identical :)
98 mi_mod :: Module, -- Complete with package info
99 mi_vers :: Version, -- Module version number
100 mi_orphan :: WhetherHasOrphans, -- Whether this module has orphans
101 mi_usages :: [ImportVersion OccName], -- Usages
102 mi_exports :: [ExportItem], -- Exports
103 mi_insts :: [RdrNameInstDecl], -- Local instance declarations
104 mi_decls :: [(Version, RdrNameHsDecl)], -- Local definitions
105 mi_fixity :: (Version, [RdrNameFixitySig]), -- Local fixity declarations,
106 -- with their version
107 mi_rules :: (Version, [RdrNameRuleDecl]), -- Rules, with their version
108 mi_deprecs :: [RdrNameDeprecation] -- Deprecations
114 emptyModDetails :: Module -> ModDetails
116 = ModDetails { md_module = mod,
118 md_globals = emptyRdrEnv,
119 md_fixities = emptyNameEnv,
120 md_deprecs = emptyNameEnv,
121 md_types = emptyNameEnv,
123 md_rules = emptyRuleEnv
127 Symbol tables map modules to ModDetails:
130 type SymbolTable = ModuleEnv ModDetails
131 type HomeSymbolTable = SymbolTable -- Domain = modules in the home package
132 type PackageSymbolTable = SymbolTable -- Domain = modules in the some other package
133 type GlobalSymbolTable = SymbolTable -- Domain = all modules
136 Simple lookups in the symbol table.
139 lookupFixityEnv :: SymbolTable -> Name -> Maybe Fixity
140 -- Returns defaultFixity if there isn't an explicit fixity
141 lookupFixityEnv tbl name
142 = case lookupModuleEnv tbl (nameModule name) of
144 Just details -> lookupNameEnv (md_fixities details) name
148 %************************************************************************
150 \subsection{Type environment stuff}
152 %************************************************************************
155 type TypeEnv = NameEnv TyThing
157 data TyThing = AnId Id
161 instance NamedThing TyThing where
162 getName (AnId id) = getName id
163 getName (ATyCon tc) = getName tc
164 getName (AClass cl) = getName cl
169 lookupTypeEnv :: SymbolTable -> Name -> Maybe TyThing
170 lookupTypeEnv tbl name
171 = case lookupModuleEnv tbl (nameModule name) of
172 Just details -> lookupNameEnv (md_types details) name
176 groupTyThings :: [TyThing] -> FiniteMap Module TypeEnv
177 -- Finite map because we want the range too
179 = foldl add emptyFM things
181 add :: FiniteMap Module TypeEnv -> TyThing -> FiniteMap Module TypeEnv
182 add tbl thing = addToFM tbl mod new_env
185 mod = nameModule name
186 new_env = case lookupFM tbl mod of
187 Nothing -> unitNameEnv name thing
188 Just env -> extendNameEnv env name thing
190 extendTypeEnv :: SymbolTable -> FiniteMap Module TypeEnv -> SymbolTable
191 extendTypeEnv tbl things
192 = foldFM add tbl things
195 = panic "extendTypeEnv" --extendModuleEnv mod new_details
198 = case lookupModuleEnv tbl mod of
199 Nothing -> (emptyModDetails mod) {md_types = type_env}
200 Just details -> details {md_types = md_types details
201 `plusNameEnv` type_env}
205 %************************************************************************
207 \subsection{Auxiliary types}
209 %************************************************************************
211 These types are defined here because they are mentioned in ModDetails,
212 but they are mostly elaborated elsewhere
220 declVers :: NameEnv Version
223 type DeprecationEnv = NameEnv DeprecTxt -- Give reason for deprecation
225 type InstEnv = UniqFM ClsInstEnv -- Maps Class to instances for that class
226 type ClsInstEnv = [(TyVarSet, [Type], DFunId)] -- The instances for a particular class
229 type RuleEnv = IdEnv [CoreRule]
231 emptyRuleEnv = emptyVarEnv
236 type Avails = [AvailInfo]
237 type AvailInfo = GenAvailInfo Name
238 type RdrAvailInfo = GenAvailInfo OccName
240 data GenAvailInfo name = Avail name -- An ordinary identifier
241 | AvailTC name -- The name of the type or class
242 [name] -- The available pieces of type/class.
243 -- NB: If the type or class is itself
244 -- to be in scope, it must be in this list.
245 -- Thus, typically: AvailTC Eq [Eq, ==, /=]
247 -- Equality used when deciding if the interface has changed
249 type AvailEnv = NameEnv AvailInfo -- Maps a Name to the AvailInfo that contains it
253 %************************************************************************
255 \subsection{ModIface}
257 %************************************************************************
260 type ExportItem = (ModuleName, [RdrAvailInfo])
262 type ImportVersion name = (ModuleName, WhetherHasOrphans, IsBootInterface, WhatsImported name)
264 type ModVersionInfo = (Version, -- Version of the whole module
265 Version, -- Version number for all fixity decls together
266 Version) -- ...ditto all rules together
268 type WhetherHasOrphans = Bool
270 -- * an instance decl in a module other than the defn module for
271 -- one of the tycons or classes in the instance head
272 -- * a transformation rule in a module other than the one defining
273 -- the function in the head of the rule.
275 type IsBootInterface = Bool
277 data WhatsImported name = NothingAtAll -- The module is below us in the
278 -- hierarchy, but we import nothing
280 | Everything Version -- The module version
282 | Specifically Version -- Module version
283 Version -- Fixity version
284 Version -- Rules version
285 [(name,Version)] -- List guaranteed non-empty
287 -- 'Specifically' doesn't let you say "I imported f but none of the fixities in
288 -- the module". If you use anything in the module you get its fixity and rule version
289 -- So if the fixities or rules change, you'll recompile, even if you don't use either.
290 -- This is easy to implement, and it's safer: you might not have used the rules last
291 -- time round, but if someone has added a new rule you might need it this time
293 -- 'Everything' means there was a "module M" in
294 -- this module's export list, so we just have to go by M's version,
295 -- not the list of (name,version) pairs
299 %************************************************************************
301 \subsection{The persistent compiler state}
303 %************************************************************************
306 data PersistentCompilerState
308 pcs_PST :: PackageSymbolTable, -- Domain = non-home-package modules
309 -- except that the InstEnv components is empty
310 pcs_insts :: InstEnv, -- The total InstEnv accumulated from all
311 -- the non-home-package modules
312 pcs_rules :: RuleEnv, -- Ditto RuleEnv
314 pcs_PRS :: PersistentRenamerState
318 The @PersistentRenamerState@ persists across successive calls to the
322 * A name supply, which deals with allocating unique names to
323 (Module,OccName) original names,
325 * An accumulated InstEnv from all the modules in pcs_PST
326 The point is that we don't want to keep recreating it whenever
327 we compile a new module. The InstEnv component of pcPST is empty.
328 (This means we might "see" instances that we shouldn't "really" see;
329 but the Haskell Report is vague on what is meant to be visible,
330 so we just take the easy road here.)
334 * A "holding pen" for declarations that have been read out of
335 interface files but not yet sucked in, renamed, and typechecked
338 data PersistentRenamerState
339 = PRS { prsOrig :: OrigNameEnv,
340 prsDecls :: DeclsMap,
341 prsInsts :: IfaceInsts,
342 prsRules :: IfaceRules
346 The OrigNameEnv makes sure that there is just one Unique assigned for
347 each original name; i.e. (module-name, occ-name) pair. The Name is
348 always stored as a Global, and has the SrcLoc of its binding location.
349 Actually that's not quite right. When we first encounter the original
350 name, we might not be at its binding site (e.g. we are reading an
351 interface file); so we give it 'noSrcLoc' then. Later, when we find
352 its binding site, we fix it up.
354 Exactly the same is true of the Module stored in the Name. When we first
355 encounter the occurrence, we may not know the details of the module, so
356 we just store junk. Then when we find the binding site, we fix it up.
360 = Orig { origNames :: FiniteMap (ModuleName,OccName) Name, -- Ensures that one original name gets one unique
361 origIParam :: FiniteMap OccName Name -- Ensures that one implicit parameter name gets one unique
366 A DeclsMap contains a binding for each Name in the declaration
367 including the constructors of a type decl etc. The Bool is True just
371 type DeclsMap = NameEnv (AvailInfo, Bool, (Module, RdrNameHsDecl))
373 type IfaceInsts = Bag GatedDecl
374 type IfaceRules = Bag GatedDecl
376 type GatedDecl = (NameSet, (Module, RdrNameHsDecl))
380 %************************************************************************
382 \subsection{The result of compiling one module}
384 %************************************************************************
388 = CompOK ModDetails -- new details (HST additions)
389 (Maybe (ModIFace, Linkable))
390 -- summary and code; Nothing => compilation not reqd
391 -- (old summary and code are still valid)
392 PersistentCompilerState -- updated PCS
393 (Bag WarnMsg) -- warnings
395 | CompErrs PersistentCompilerState -- updated PCS
396 (Bag ErrMsg) -- errors
397 (Bag WarnMsg) -- warnings
400 -- The driver sits between 'compile' and 'hscMain', translating calls
401 -- to the former into calls to the latter, and results from the latter
402 -- into results from the former. It does things like preprocessing
403 -- the .hs file if necessary, and compiling up the .stub_c files to
404 -- generate Linkables.
407 = HscOK ModDetails -- new details (HomeSymbolTable additions)
408 (Maybe ModIFace) -- new iface (if any compilation was done)
409 (Maybe String) -- generated stub_h filename (in /tmp)
410 (Maybe String) -- generated stub_c filename (in /tmp)
411 PersistentCompilerState -- updated PCS
414 | HscErrs PersistentCompilerState -- updated PCS
419 -- These two are only here to avoid recursion between CmCompile and
420 -- CompManager. They really ought to be in the latter.
421 type ModuleEnv a = UniqFM a -- Domain is Module
423 type HomeModMap = FiniteMap ModuleName Module -- domain: home mods only
424 type HomeInterfaceTable = ModuleEnv ModIFace
428 %************************************************************************
430 \subsection{Provenance and export info}
432 %************************************************************************
434 The GlobalRdrEnv gives maps RdrNames to Names. There is a separate
435 one for each module, corresponding to that module's top-level scope.
438 type GlobalRdrEnv = RdrNameEnv [(Name,Provenance)] -- The list is because there may be name clashes
439 -- These only get reported on lookup,
440 -- not on construction
443 The "provenance" of something says how it came to be in scope.
447 = LocalDef -- Defined locally
449 | NonLocalDef -- Defined non-locally
454 Moved here from Name.
455 pp_prov (LocalDef _ Exported) = char 'x'
456 pp_prov (LocalDef _ NotExported) = char 'l'
457 pp_prov (NonLocalDef ImplicitImport _) = char 'j'
458 pp_prov (NonLocalDef (UserImport _ _ True ) _) = char 'I' -- Imported by name
459 pp_prov (NonLocalDef (UserImport _ _ False) _) = char 'i' -- Imported by ..
460 pp_prov SystemProv = char 's'
464 = UserImport Module SrcLoc Bool -- Imported from module M on line L
465 -- Note the M may well not be the defining module
467 -- The Bool is true iff the thing was named *explicitly* in the import spec,
468 -- rather than being imported as part of a group; e.g.
471 -- Here, everything imported by B, and the constructors of T
472 -- are not named explicitly; only T is named explicitly.
473 -- This info is used when warning of unused names.
475 | ImplicitImport -- Imported implicitly for some other reason
478 type PrintUnqualified = Bool -- True <=> the unqualified name of this thing is
479 -- in scope in this module, so print it
480 -- unqualified in error messages
484 hasBetterProv :: Provenance -> Provenance -> Bool
486 -- a local thing over an imported thing
487 -- a user-imported thing over a non-user-imported thing
488 -- an explicitly-imported thing over an implicitly imported thing
489 hasBetterProv LocalDef _ = True
490 hasBetterProv (NonLocalDef (UserImport _ _ True) _) _ = True
491 hasBetterProv (NonLocalDef (UserImport _ _ _ ) _) (NonLocalDef ImplicitImport _) = True
492 hasBetterProv _ _ = False
494 pprNameProvenance :: Name -> Provenance -> SDoc
495 pprNameProvenance name LocalDef = ptext SLIT("defined at") <+> ppr (nameSrcLoc name)
496 pprNameProvenance name (NonLocalDef why _) = sep [ppr_reason why,
497 nest 2 (parens (ppr_defn (nameSrcLoc name)))]
499 ppr_reason ImplicitImport = ptext SLIT("implicitly imported")
500 ppr_reason (UserImport mod loc _) = ptext SLIT("imported from") <+> ppr mod <+> ptext SLIT("at") <+> ppr loc
502 ppr_defn loc | isGoodSrcLoc loc = ptext SLIT("at") <+> ppr loc