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(..),
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 @ModDetails@ summarises everything we know about a compiled module.
75 md_exports :: Avails, -- What it exports
76 md_version :: VersionInfo,
77 md_globals :: GlobalRdrEnv, -- Its top level environment
79 md_fixities :: NameEnv Fixity,
80 md_deprecs :: NameEnv DeprecTxt,
83 md_insts :: [DFunId], -- Dfun-ids for the instances in this module
84 md_rules :: RuleEnv -- Domain may include Id from other modules
87 emptyModDetails :: Module -> ModDetails
89 = ModDetails { md_id = mod,
91 md_globals = emptyRdrEnv,
92 md_fixities = emptyNameEnv,
93 md_deprecs = emptyNameEnv,
94 md_types = emptyNameEnv,
96 md_rules = emptyRuleEnv
100 Symbol tables map modules to ModDetails:
103 type SymbolTable = ModuleEnv ModDetails
104 type HomeSymbolTable = SymbolTable -- Domain = modules in the home package
105 type PackageSymbolTable = SymbolTable -- Domain = modules in the some other package
106 type GlobalSymbolTable = SymbolTable -- Domain = all modules
109 Simple lookups in the symbol table.
112 lookupFixityEnv :: SymbolTable -> Name -> Maybe Fixity
113 -- Returns defaultFixity if there isn't an explicit fixity
114 lookupFixityEnv tbl name
115 = case lookupModuleEnv tbl (nameModule name) of
117 Just details -> lookupNameEnv (md_fixities details) name
121 %************************************************************************
123 \subsection{Type environment stuff}
125 %************************************************************************
128 type TypeEnv = NameEnv TyThing
130 data TyThing = AnId Id
134 instance NamedThing TyThing where
135 getName (AnId id) = getName id
136 getName (ATyCon tc) = getName tc
137 getName (AClass cl) = getName cl
142 lookupTypeEnv :: SymbolTable -> Name -> Maybe TyThing
143 lookupTypeEnv tbl name
144 = case lookupModuleEnv tbl (nameModule name) of
145 Just details -> lookupNameEnv (md_types details) name
149 groupTyThings :: [TyThing] -> FiniteMap Module TypeEnv
150 -- Finite map because we want the range too
152 = foldl add emptyFM things
154 add :: FiniteMap Module TypeEnv -> TyThing -> FiniteMap Module TypeEnv
155 add tbl thing = addToFM tbl mod new_env
158 mod = nameModule name
159 new_env = case lookupFM tbl mod of
160 Nothing -> unitNameEnv name thing
161 Just env -> extendNameEnv env name thing
163 extendTypeEnv :: SymbolTable -> FiniteMap Module TypeEnv -> SymbolTable
164 extendTypeEnv tbl things
165 = foldFM add tbl things
168 = panic "extendTypeEnv" --extendModuleEnv mod new_details
171 = case lookupModuleEnv tbl mod of
172 Nothing -> (emptyModDetails mod) {md_types = type_env}
173 Just details -> details {md_types = md_types details
174 `plusNameEnv` type_env}
178 %************************************************************************
180 \subsection{Auxiliary types}
182 %************************************************************************
184 These types are defined here because they are mentioned in ModDetails,
185 but they are mostly elaborated elsewhere
193 declVers :: NameEnv Version
196 type DeprecationEnv = NameEnv DeprecTxt -- Give reason for deprecation
198 type InstEnv = UniqFM ClsInstEnv -- Maps Class to instances for that class
199 type ClsInstEnv = [(TyVarSet, [Type], DFunId)] -- The instances for a particular class
202 type RuleEnv = IdEnv [CoreRule]
204 emptyRuleEnv = emptyVarEnv
209 type Avails = [AvailInfo]
210 type AvailInfo = GenAvailInfo Name
211 type RdrAvailInfo = GenAvailInfo OccName
213 data GenAvailInfo name = Avail name -- An ordinary identifier
214 | AvailTC name -- The name of the type or class
215 [name] -- The available pieces of type/class.
216 -- NB: If the type or class is itself
217 -- to be in scope, it must be in this list.
218 -- Thus, typically: AvailTC Eq [Eq, ==, /=]
220 -- Equality used when deciding if the interface has changed
222 type AvailEnv = NameEnv AvailInfo -- Maps a Name to the AvailInfo that contains it
226 %************************************************************************
228 \subsection{ModIface}
230 %************************************************************************
233 -- ModIFace is nearly the same as RnMonad.ParsedIface.
234 -- Right now it's identical :)
237 mi_mod :: Module, -- Complete with package info
238 mi_vers :: Version, -- Module version number
239 mi_orphan :: WhetherHasOrphans, -- Whether this module has orphans
240 mi_usages :: [ImportVersion OccName], -- Usages
241 mi_exports :: [ExportItem], -- Exports
242 mi_insts :: [RdrNameInstDecl], -- Local instance declarations
243 mi_decls :: [(Version, RdrNameHsDecl)], -- Local definitions
244 mi_fixity :: (Version, [RdrNameFixitySig]), -- Local fixity declarations,
245 -- with their version
246 mi_rules :: (Version, [RdrNameRuleDecl]), -- Rules, with their version
247 mi_deprecs :: [RdrNameDeprecation] -- Deprecations
250 type ExportItem = (ModuleName, [RdrAvailInfo])
252 type ImportVersion name = (ModuleName, WhetherHasOrphans, IsBootInterface, WhatsImported name)
254 type ModVersionInfo = (Version, -- Version of the whole module
255 Version, -- Version number for all fixity decls together
256 Version) -- ...ditto all rules together
258 type WhetherHasOrphans = Bool
260 -- * an instance decl in a module other than the defn module for
261 -- one of the tycons or classes in the instance head
262 -- * a transformation rule in a module other than the one defining
263 -- the function in the head of the rule.
265 type IsBootInterface = Bool
267 data WhatsImported name = NothingAtAll -- The module is below us in the
268 -- hierarchy, but we import nothing
270 | Everything Version -- The module version
272 | Specifically Version -- Module version
273 Version -- Fixity version
274 Version -- Rules version
275 [(name,Version)] -- List guaranteed non-empty
277 -- 'Specifically' doesn't let you say "I imported f but none of the fixities in
278 -- the module". If you use anything in the module you get its fixity and rule version
279 -- So if the fixities or rules change, you'll recompile, even if you don't use either.
280 -- This is easy to implement, and it's safer: you might not have used the rules last
281 -- time round, but if someone has added a new rule you might need it this time
283 -- 'Everything' means there was a "module M" in
284 -- this module's export list, so we just have to go by M's version,
285 -- not the list of (name,version) pairs
289 %************************************************************************
291 \subsection{The persistent compiler state}
293 %************************************************************************
296 data PersistentCompilerState
298 pcs_PST :: PackageSymbolTable, -- Domain = non-home-package modules
299 -- except that the InstEnv components is empty
300 pcs_insts :: InstEnv, -- The total InstEnv accumulated from all
301 -- the non-home-package modules
302 pcs_rules :: RuleEnv, -- Ditto RuleEnv
304 pcs_PRS :: PersistentRenamerState
308 The @PersistentRenamerState@ persists across successive calls to the
312 * A name supply, which deals with allocating unique names to
313 (Module,OccName) original names,
315 * An accumulated InstEnv from all the modules in pcs_PST
316 The point is that we don't want to keep recreating it whenever
317 we compile a new module. The InstEnv component of pcPST is empty.
318 (This means we might "see" instances that we shouldn't "really" see;
319 but the Haskell Report is vague on what is meant to be visible,
320 so we just take the easy road here.)
324 * A "holding pen" for declarations that have been read out of
325 interface files but not yet sucked in, renamed, and typechecked
328 data PersistentRenamerState
329 = PRS { prsOrig :: OrigNameEnv,
330 prsDecls :: DeclsMap,
331 prsInsts :: IfaceInsts,
332 prsRules :: IfaceRules
336 The OrigNameEnv makes sure that there is just one Unique assigned for
337 each original name; i.e. (module-name, occ-name) pair. The Name is
338 always stored as a Global, and has the SrcLoc of its binding location.
339 Actually that's not quite right. When we first encounter the original
340 name, we might not be at its binding site (e.g. we are reading an
341 interface file); so we give it 'noSrcLoc' then. Later, when we find
342 its binding site, we fix it up.
344 Exactly the same is true of the Module stored in the Name. When we first
345 encounter the occurrence, we may not know the details of the module, so
346 we just store junk. Then when we find the binding site, we fix it up.
350 = Orig { origNames :: FiniteMap (ModuleName,OccName) Name, -- Ensures that one original name gets one unique
351 origIParam :: FiniteMap OccName Name -- Ensures that one implicit parameter name gets one unique
356 A DeclsMap contains a binding for each Name in the declaration
357 including the constructors of a type decl etc. The Bool is True just
361 type DeclsMap = NameEnv (AvailInfo, Bool, (Module, RdrNameHsDecl))
363 type IfaceInsts = Bag GatedDecl
364 type IfaceRules = Bag GatedDecl
366 type GatedDecl = (NameSet, (Module, RdrNameHsDecl))
370 %************************************************************************
372 \subsection{The result of compiling one module}
374 %************************************************************************
378 = CompOK ModDetails -- new details (HST additions)
379 (Maybe (ModIFace, Linkable))
380 -- summary and code; Nothing => compilation not reqd
381 -- (old summary and code are still valid)
382 PersistentCompilerState -- updated PCS
383 (Bag WarnMsg) -- warnings
385 | CompErrs PersistentCompilerState -- updated PCS
386 (Bag ErrMsg) -- errors
387 (Bag WarnMsg) -- warnings
390 -- The driver sits between 'compile' and 'hscMain', translating calls
391 -- to the former into calls to the latter, and results from the latter
392 -- into results from the former. It does things like preprocessing
393 -- the .hs file if necessary, and compiling up the .stub_c files to
394 -- generate Linkables.
397 = HscOK ModDetails -- new details (HomeSymbolTable additions)
398 (Maybe ModIFace) -- new iface (if any compilation was done)
399 (Maybe String) -- generated stub_h
400 (Maybe String) -- generated stub_c
401 PersistentCompilerState -- updated PCS
404 | HscErrs PersistentCompilerState -- updated PCS
409 -- These two are only here to avoid recursion between CmCompile and
410 -- CompManager. They really ought to be in the latter.
411 type ModuleEnv a = UniqFM a -- Domain is Module
413 type HomeModMap = FiniteMap ModuleName Module -- domain: home mods only
414 type HomeInterfaceTable = ModuleEnv ModIFace
418 %************************************************************************
420 \subsection{Provenance and export info}
422 %************************************************************************
424 The GlobalRdrEnv gives maps RdrNames to Names. There is a separate
425 one for each module, corresponding to that module's top-level scope.
428 type GlobalRdrEnv = RdrNameEnv [(Name,Provenance)] -- The list is because there may be name clashes
429 -- These only get reported on lookup,
430 -- not on construction
433 The "provenance" of something says how it came to be in scope.
437 = LocalDef -- Defined locally
439 | NonLocalDef -- Defined non-locally
444 Moved here from Name.
445 pp_prov (LocalDef _ Exported) = char 'x'
446 pp_prov (LocalDef _ NotExported) = char 'l'
447 pp_prov (NonLocalDef ImplicitImport _) = char 'j'
448 pp_prov (NonLocalDef (UserImport _ _ True ) _) = char 'I' -- Imported by name
449 pp_prov (NonLocalDef (UserImport _ _ False) _) = char 'i' -- Imported by ..
450 pp_prov SystemProv = char 's'
454 = UserImport Module SrcLoc Bool -- Imported from module M on line L
455 -- Note the M may well not be the defining module
457 -- The Bool is true iff the thing was named *explicitly* in the import spec,
458 -- rather than being imported as part of a group; e.g.
461 -- Here, everything imported by B, and the constructors of T
462 -- are not named explicitly; only T is named explicitly.
463 -- This info is used when warning of unused names.
465 | ImplicitImport -- Imported implicitly for some other reason
468 type PrintUnqualified = Bool -- True <=> the unqualified name of this thing is
469 -- in scope in this module, so print it
470 -- unqualified in error messages
474 hasBetterProv :: Provenance -> Provenance -> Bool
476 -- a local thing over an imported thing
477 -- a user-imported thing over a non-user-imported thing
478 -- an explicitly-imported thing over an implicitly imported thing
479 hasBetterProv LocalDef _ = True
480 hasBetterProv (NonLocalDef (UserImport _ _ True) _) _ = True
481 hasBetterProv (NonLocalDef (UserImport _ _ _ ) _) (NonLocalDef ImplicitImport _) = True
482 hasBetterProv _ _ = False
484 pprNameProvenance :: Name -> Provenance -> SDoc
485 pprNameProvenance name LocalDef = ptext SLIT("defined at") <+> ppr (nameSrcLoc name)
486 pprNameProvenance name (NonLocalDef why _) = sep [ppr_reason why,
487 nest 2 (parens (ppr_defn (nameSrcLoc name)))]
489 ppr_reason ImplicitImport = ptext SLIT("implicitly imported")
490 ppr_reason (UserImport mod loc _) = ptext SLIT("imported from") <+> ppr mod <+> ptext SLIT("at") <+> ppr loc
492 ppr_defn loc | isGoodSrcLoc loc = ptext SLIT("at") <+> ppr loc