2 % (c) The GRASP/AQUA Project, Glasgow University, 1992-1998
4 \section[Id]{@Ids@: Value and constructor identifiers}
10 -- Simple construction
11 mkGlobalId, mkLocalId, mkLocalIdWithInfo,
12 mkSysLocal, mkUserLocal, mkVanillaGlobal,
13 mkTemplateLocals, mkTemplateLocalsNum, mkWildId, mkTemplateLocal,
14 mkWorkerId, mkExportedLocalId,
17 idName, idType, idUnique, idInfo,
18 isId, globalIdDetails, idPrimRep,
19 recordSelectorFieldLabel,
22 setIdName, setIdUnique, Id.setIdType, setIdExported, setIdNotExported,
23 setIdInfo, lazySetIdInfo, modifyIdInfo, maybeModifyIdInfo,
24 zapLamIdInfo, zapDemandIdInfo,
27 isImplicitId, isDeadBinder, isDictId,
28 isExportedId, isLocalId, isGlobalId,
29 isRecordSelector, isNaughtyRecordSelector,
31 isPrimOpId, isPrimOpId_maybe,
32 isFCallId, isFCallId_maybe,
33 isDataConWorkId, isDataConWorkId_maybe, isDataConId_maybe, idDataCon,
34 isBottomingId, idIsFrom,
37 -- Inline pragma stuff
38 idInlinePragma, setInlinePragma, modifyInlinePragma,
41 -- One shot lambda stuff
42 isOneShotBndr, isOneShotLambda, isStateHackType,
43 setOneShotLambda, clearOneShotLambda,
49 setIdNewStrictness, zapIdNewStrictness,
65 idNewDemandInfo, idNewDemandInfo_maybe,
66 idNewStrictness, idNewStrictness_maybe,
69 idSpecialisation, idCoreRules,
75 newStrictnessFromOld -- Temporary
80 #include "HsVersions.h"
83 import CoreSyn ( Unfolding, CoreRule )
84 import BasicTypes ( Arity )
85 import Var ( Id, DictId,
86 isId, isExportedId, isLocalId,
87 idName, idType, idUnique, idInfo, isGlobalId,
88 setIdName, setIdType, setIdUnique,
89 setIdExported, setIdNotExported,
90 setIdInfo, lazySetIdInfo, modifyIdInfo,
94 import qualified Var ( mkLocalId, mkGlobalId, mkExportedLocalId )
95 import TyCon ( FieldLabel, TyCon )
96 import Type ( Type, typePrimRep, addFreeTyVars, seqType,
97 splitTyConApp_maybe, PrimRep )
98 import TcType ( isDictTy )
99 import TysPrim ( statePrimTyCon )
102 #ifdef OLD_STRICTNESS
103 import qualified Demand ( Demand )
105 import DataCon ( DataCon, isUnboxedTupleCon )
106 import NewDemand ( Demand, StrictSig, topDmd, topSig, isBottomingSig )
107 import Name ( Name, OccName, nameIsLocalOrFrom,
108 mkSystemVarName, mkInternalName, getOccName,
110 import Module ( Module )
111 import OccName ( mkWorkerOcc )
112 import Maybes ( orElse )
113 import SrcLoc ( SrcLoc )
115 import Unique ( Unique, mkBuiltinUnique )
116 import FastString ( FastString )
117 import StaticFlags ( opt_NoStateHack )
119 -- infixl so you can say (id `set` a `set` b)
120 infixl 1 `setIdUnfolding`,
122 `setIdNewDemandInfo`,
123 `setIdNewStrictness`,
125 `setIdSpecialisation`,
128 #ifdef OLD_STRICTNESS
137 %************************************************************************
139 \subsection{Simple Id construction}
141 %************************************************************************
143 Absolutely all Ids are made by mkId. It is just like Var.mkId,
144 but in addition it pins free-tyvar-info onto the Id's type,
145 where it can easily be found.
148 mkLocalIdWithInfo :: Name -> Type -> IdInfo -> Id
149 mkLocalIdWithInfo name ty info = Var.mkLocalId name (addFreeTyVars ty) info
151 mkExportedLocalId :: Name -> Type -> Id
152 mkExportedLocalId name ty = Var.mkExportedLocalId name (addFreeTyVars ty) vanillaIdInfo
154 mkGlobalId :: GlobalIdDetails -> Name -> Type -> IdInfo -> Id
155 mkGlobalId details name ty info = Var.mkGlobalId details name (addFreeTyVars ty) info
159 mkLocalId :: Name -> Type -> Id
160 mkLocalId name ty = mkLocalIdWithInfo name ty vanillaIdInfo
162 -- SysLocal: for an Id being created by the compiler out of thin air...
163 -- UserLocal: an Id with a name the user might recognize...
164 mkUserLocal :: OccName -> Unique -> Type -> SrcLoc -> Id
165 mkSysLocal :: FastString -> Unique -> Type -> Id
166 mkVanillaGlobal :: Name -> Type -> IdInfo -> Id
168 mkSysLocal fs uniq ty = mkLocalId (mkSystemVarName uniq fs) ty
170 mkUserLocal occ uniq ty loc = mkLocalId (mkInternalName uniq occ loc) ty
171 mkVanillaGlobal = mkGlobalId VanillaGlobal
174 Make some local @Ids@ for a template @CoreExpr@. These have bogus
175 @Uniques@, but that's OK because the templates are supposed to be
176 instantiated before use.
179 -- "Wild Id" typically used when you need a binder that you don't expect to use
180 mkWildId :: Type -> Id
181 mkWildId ty = mkSysLocal FSLIT("wild") (mkBuiltinUnique 1) ty
183 mkWorkerId :: Unique -> Id -> Type -> Id
184 -- A worker gets a local name. CoreTidy will externalise it if necessary.
185 mkWorkerId uniq unwrkr ty
186 = mkLocalId wkr_name ty
188 wkr_name = mkInternalName uniq (mkWorkerOcc (getOccName unwrkr)) (getSrcLoc unwrkr)
190 -- "Template locals" typically used in unfoldings
191 mkTemplateLocals :: [Type] -> [Id]
192 mkTemplateLocals tys = zipWith mkTemplateLocal [1..] tys
194 mkTemplateLocalsNum :: Int -> [Type] -> [Id]
195 -- The Int gives the starting point for unique allocation
196 mkTemplateLocalsNum n tys = zipWith mkTemplateLocal [n..] tys
198 mkTemplateLocal :: Int -> Type -> Id
199 mkTemplateLocal i ty = mkSysLocal FSLIT("tpl") (mkBuiltinUnique i) ty
203 %************************************************************************
205 \subsection[Id-general-funs]{General @Id@-related functions}
207 %************************************************************************
210 setIdType :: Id -> Type -> Id
211 -- Add free tyvar info to the type
212 setIdType id ty = seqType ty `seq` Var.setIdType id (addFreeTyVars ty)
214 idPrimRep :: Id -> PrimRep
215 idPrimRep id = typePrimRep (idType id)
219 %************************************************************************
221 \subsection{Special Ids}
223 %************************************************************************
226 recordSelectorFieldLabel :: Id -> (TyCon, FieldLabel)
227 recordSelectorFieldLabel id = case globalIdDetails id of
228 RecordSelId tycon lbl _ -> (tycon,lbl)
229 other -> panic "recordSelectorFieldLabel"
231 isRecordSelector id = case globalIdDetails id of
232 RecordSelId {} -> True
235 isNaughtyRecordSelector id = case globalIdDetails id of
236 RecordSelId { sel_naughty = n } -> n
239 isClassOpId_maybe id = case globalIdDetails id of
240 ClassOpId cls -> Just cls
243 isPrimOpId id = case globalIdDetails id of
247 isPrimOpId_maybe id = case globalIdDetails id of
248 PrimOpId op -> Just op
251 isFCallId id = case globalIdDetails id of
255 isFCallId_maybe id = case globalIdDetails id of
256 FCallId call -> Just call
259 isDataConWorkId id = case globalIdDetails id of
260 DataConWorkId _ -> True
263 isDataConWorkId_maybe id = case globalIdDetails id of
264 DataConWorkId con -> Just con
267 isDataConId_maybe :: Id -> Maybe DataCon
268 isDataConId_maybe id = case globalIdDetails id of
269 DataConWorkId con -> Just con
270 DataConWrapId con -> Just con
273 idDataCon :: Id -> DataCon
274 -- Get from either the worker or the wrapper to the DataCon
275 -- Currently used only in the desugarer
276 -- INVARIANT: idDataCon (dataConWrapId d) = d
277 -- (Remember, dataConWrapId can return either the wrapper or the worker.)
278 idDataCon id = case globalIdDetails id of
279 DataConWorkId con -> con
280 DataConWrapId con -> con
281 other -> pprPanic "idDataCon" (ppr id)
284 isDictId :: Id -> Bool
285 isDictId id = isDictTy (idType id)
287 -- hasNoBinding returns True of an Id which may not have a
288 -- binding, even though it is defined in this module.
289 -- Data constructor workers used to be things of this kind, but
290 -- they aren't any more. Instead, we inject a binding for
291 -- them at the CorePrep stage.
292 -- EXCEPT: unboxed tuples, which definitely have no binding
293 hasNoBinding id = case globalIdDetails id of
296 DataConWorkId dc -> isUnboxedTupleCon dc
299 isImplicitId :: Id -> Bool
300 -- isImplicitId tells whether an Id's info is implied by other
301 -- declarations, so we don't need to put its signature in an interface
302 -- file, even if it's mentioned in some other interface unfolding.
304 = case globalIdDetails id of
305 RecordSelId {} -> True
309 DataConWorkId _ -> True
310 DataConWrapId _ -> True
311 -- These are are implied by their type or class decl;
312 -- remember that all type and class decls appear in the interface file.
313 -- The dfun id is not an implicit Id; it must *not* be omitted, because
314 -- it carries version info for the instance decl
317 idIsFrom :: Module -> Id -> Bool
318 idIsFrom mod id = nameIsLocalOrFrom mod (idName id)
322 isDeadBinder :: Id -> Bool
323 isDeadBinder bndr | isId bndr = isDeadOcc (idOccInfo bndr)
324 | otherwise = False -- TyVars count as not dead
328 %************************************************************************
330 \subsection{IdInfo stuff}
332 %************************************************************************
335 ---------------------------------
337 idArity :: Id -> Arity
338 idArity id = arityInfo (idInfo id)
340 setIdArity :: Id -> Arity -> Id
341 setIdArity id arity = modifyIdInfo (`setArityInfo` arity) id
343 #ifdef OLD_STRICTNESS
344 ---------------------------------
346 idStrictness :: Id -> StrictnessInfo
347 idStrictness id = strictnessInfo (idInfo id)
349 setIdStrictness :: Id -> StrictnessInfo -> Id
350 setIdStrictness id strict_info = modifyIdInfo (`setStrictnessInfo` strict_info) id
353 -- isBottomingId returns true if an application to n args would diverge
354 isBottomingId :: Id -> Bool
355 isBottomingId id = isBottomingSig (idNewStrictness id)
357 idNewStrictness_maybe :: Id -> Maybe StrictSig
358 idNewStrictness :: Id -> StrictSig
360 idNewStrictness_maybe id = newStrictnessInfo (idInfo id)
361 idNewStrictness id = idNewStrictness_maybe id `orElse` topSig
363 setIdNewStrictness :: Id -> StrictSig -> Id
364 setIdNewStrictness id sig = modifyIdInfo (`setNewStrictnessInfo` Just sig) id
366 zapIdNewStrictness :: Id -> Id
367 zapIdNewStrictness id = modifyIdInfo (`setNewStrictnessInfo` Nothing) id
369 ---------------------------------
371 idWorkerInfo :: Id -> WorkerInfo
372 idWorkerInfo id = workerInfo (idInfo id)
374 setIdWorkerInfo :: Id -> WorkerInfo -> Id
375 setIdWorkerInfo id work_info = modifyIdInfo (`setWorkerInfo` work_info) id
377 ---------------------------------
379 idUnfolding :: Id -> Unfolding
380 idUnfolding id = unfoldingInfo (idInfo id)
382 setIdUnfolding :: Id -> Unfolding -> Id
383 setIdUnfolding id unfolding = modifyIdInfo (`setUnfoldingInfo` unfolding) id
385 #ifdef OLD_STRICTNESS
386 ---------------------------------
388 idDemandInfo :: Id -> Demand.Demand
389 idDemandInfo id = demandInfo (idInfo id)
391 setIdDemandInfo :: Id -> Demand.Demand -> Id
392 setIdDemandInfo id demand_info = modifyIdInfo (`setDemandInfo` demand_info) id
395 idNewDemandInfo_maybe :: Id -> Maybe NewDemand.Demand
396 idNewDemandInfo :: Id -> NewDemand.Demand
398 idNewDemandInfo_maybe id = newDemandInfo (idInfo id)
399 idNewDemandInfo id = newDemandInfo (idInfo id) `orElse` NewDemand.topDmd
401 setIdNewDemandInfo :: Id -> NewDemand.Demand -> Id
402 setIdNewDemandInfo id dmd = modifyIdInfo (`setNewDemandInfo` Just dmd) id
404 ---------------------------------
406 idSpecialisation :: Id -> SpecInfo
407 idSpecialisation id = specInfo (idInfo id)
409 idCoreRules :: Id -> [CoreRule]
410 idCoreRules id = specInfoRules (idSpecialisation id)
412 setIdSpecialisation :: Id -> SpecInfo -> Id
413 setIdSpecialisation id spec_info = modifyIdInfo (`setSpecInfo` spec_info) id
415 ---------------------------------
417 idCafInfo :: Id -> CafInfo
418 #ifdef OLD_STRICTNESS
419 idCafInfo id = case cgInfo (idInfo id) of
420 NoCgInfo -> pprPanic "idCafInfo" (ppr id)
421 info -> cgCafInfo info
423 idCafInfo id = cafInfo (idInfo id)
426 setIdCafInfo :: Id -> CafInfo -> Id
427 setIdCafInfo id caf_info = modifyIdInfo (`setCafInfo` caf_info) id
429 ---------------------------------
431 #ifdef OLD_STRICTNESS
432 idCprInfo :: Id -> CprInfo
433 idCprInfo id = cprInfo (idInfo id)
435 setIdCprInfo :: Id -> CprInfo -> Id
436 setIdCprInfo id cpr_info = modifyIdInfo (`setCprInfo` cpr_info) id
439 ---------------------------------
441 idOccInfo :: Id -> OccInfo
442 idOccInfo id = occInfo (idInfo id)
444 setIdOccInfo :: Id -> OccInfo -> Id
445 setIdOccInfo id occ_info = modifyIdInfo (`setOccInfo` occ_info) id
449 ---------------------------------
451 The inline pragma tells us to be very keen to inline this Id, but it's still
452 OK not to if optimisation is switched off.
455 idInlinePragma :: Id -> InlinePragInfo
456 idInlinePragma id = inlinePragInfo (idInfo id)
458 setInlinePragma :: Id -> InlinePragInfo -> Id
459 setInlinePragma id prag = modifyIdInfo (`setInlinePragInfo` prag) id
461 modifyInlinePragma :: Id -> (InlinePragInfo -> InlinePragInfo) -> Id
462 modifyInlinePragma id fn = modifyIdInfo (\info -> info `setInlinePragInfo` (fn (inlinePragInfo info))) id
466 ---------------------------------
469 idLBVarInfo :: Id -> LBVarInfo
470 idLBVarInfo id = lbvarInfo (idInfo id)
472 isOneShotBndr :: Id -> Bool
473 -- This one is the "business end", called externally.
474 -- Its main purpose is to encapsulate the Horrible State Hack
475 isOneShotBndr id = isOneShotLambda id || (isStateHackType (idType id))
477 isStateHackType :: Type -> Bool
482 = case splitTyConApp_maybe ty of
483 Just (tycon,_) -> tycon == statePrimTyCon
485 -- This is a gross hack. It claims that
486 -- every function over realWorldStatePrimTy is a one-shot
487 -- function. This is pretty true in practice, and makes a big
488 -- difference. For example, consider
489 -- a `thenST` \ r -> ...E...
490 -- The early full laziness pass, if it doesn't know that r is one-shot
491 -- will pull out E (let's say it doesn't mention r) to give
492 -- let lvl = E in a `thenST` \ r -> ...lvl...
493 -- When `thenST` gets inlined, we end up with
494 -- let lvl = E in \s -> case a s of (r, s') -> ...lvl...
495 -- and we don't re-inline E.
497 -- It would be better to spot that r was one-shot to start with, but
498 -- I don't want to rely on that.
500 -- Another good example is in fill_in in PrelPack.lhs. We should be able to
501 -- spot that fill_in has arity 2 (and when Keith is done, we will) but we can't yet.
504 -- The OneShotLambda functions simply fiddle with the IdInfo flag
505 isOneShotLambda :: Id -> Bool
506 isOneShotLambda id = case idLBVarInfo id of
507 IsOneShotLambda -> True
510 setOneShotLambda :: Id -> Id
511 setOneShotLambda id = modifyIdInfo (`setLBVarInfo` IsOneShotLambda) id
513 clearOneShotLambda :: Id -> Id
514 clearOneShotLambda id
515 | isOneShotLambda id = modifyIdInfo (`setLBVarInfo` NoLBVarInfo) id
518 -- But watch out: this may change the type of something else
520 -- If we change the one-shot-ness of x, f's type changes
524 zapLamIdInfo :: Id -> Id
525 zapLamIdInfo id = maybeModifyIdInfo zapLamInfo id
527 zapDemandIdInfo id = maybeModifyIdInfo zapDemandInfo id