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, 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 isDictId :: Id -> Bool
268 isDictId id = isDictTy (idType id)
270 idDataCon :: Id -> DataCon
271 -- Get from either the worker or the wrapper to the DataCon
272 -- Currently used only in the desugarer
273 -- INVARIANT: idDataCon (dataConWrapId d) = d
274 -- (Remember, dataConWrapId can return either the wrapper or the worker.)
275 idDataCon id = case globalIdDetails id of
276 DataConWorkId con -> con
277 DataConWrapId con -> con
278 other -> pprPanic "idDataCon" (ppr id)
281 -- hasNoBinding returns True of an Id which may not have a
282 -- binding, even though it is defined in this module.
283 -- Data constructor workers used to be things of this kind, but
284 -- they aren't any more. Instead, we inject a binding for
285 -- them at the CorePrep stage.
286 -- EXCEPT: unboxed tuples, which definitely have no binding
287 hasNoBinding id = case globalIdDetails id of
290 DataConWorkId dc -> isUnboxedTupleCon dc
293 isImplicitId :: Id -> Bool
294 -- isImplicitId tells whether an Id's info is implied by other
295 -- declarations, so we don't need to put its signature in an interface
296 -- file, even if it's mentioned in some other interface unfolding.
298 = case globalIdDetails id of
299 RecordSelId {} -> True
303 DataConWorkId _ -> True
304 DataConWrapId _ -> True
305 -- These are are implied by their type or class decl;
306 -- remember that all type and class decls appear in the interface file.
307 -- The dfun id is not an implicit Id; it must *not* be omitted, because
308 -- it carries version info for the instance decl
311 idIsFrom :: Module -> Id -> Bool
312 idIsFrom mod id = nameIsLocalOrFrom mod (idName id)
316 isDeadBinder :: Id -> Bool
317 isDeadBinder bndr | isId bndr = isDeadOcc (idOccInfo bndr)
318 | otherwise = False -- TyVars count as not dead
322 %************************************************************************
324 \subsection{IdInfo stuff}
326 %************************************************************************
329 ---------------------------------
331 idArity :: Id -> Arity
332 idArity id = arityInfo (idInfo id)
334 setIdArity :: Id -> Arity -> Id
335 setIdArity id arity = modifyIdInfo (`setArityInfo` arity) id
337 #ifdef OLD_STRICTNESS
338 ---------------------------------
340 idStrictness :: Id -> StrictnessInfo
341 idStrictness id = strictnessInfo (idInfo id)
343 setIdStrictness :: Id -> StrictnessInfo -> Id
344 setIdStrictness id strict_info = modifyIdInfo (`setStrictnessInfo` strict_info) id
347 -- isBottomingId returns true if an application to n args would diverge
348 isBottomingId :: Id -> Bool
349 isBottomingId id = isBottomingSig (idNewStrictness id)
351 idNewStrictness_maybe :: Id -> Maybe StrictSig
352 idNewStrictness :: Id -> StrictSig
354 idNewStrictness_maybe id = newStrictnessInfo (idInfo id)
355 idNewStrictness id = idNewStrictness_maybe id `orElse` topSig
357 setIdNewStrictness :: Id -> StrictSig -> Id
358 setIdNewStrictness id sig = modifyIdInfo (`setNewStrictnessInfo` Just sig) id
360 zapIdNewStrictness :: Id -> Id
361 zapIdNewStrictness id = modifyIdInfo (`setNewStrictnessInfo` Nothing) id
363 ---------------------------------
365 idWorkerInfo :: Id -> WorkerInfo
366 idWorkerInfo id = workerInfo (idInfo id)
368 setIdWorkerInfo :: Id -> WorkerInfo -> Id
369 setIdWorkerInfo id work_info = modifyIdInfo (`setWorkerInfo` work_info) id
371 ---------------------------------
373 idUnfolding :: Id -> Unfolding
374 idUnfolding id = unfoldingInfo (idInfo id)
376 setIdUnfolding :: Id -> Unfolding -> Id
377 setIdUnfolding id unfolding = modifyIdInfo (`setUnfoldingInfo` unfolding) id
379 #ifdef OLD_STRICTNESS
380 ---------------------------------
382 idDemandInfo :: Id -> Demand.Demand
383 idDemandInfo id = demandInfo (idInfo id)
385 setIdDemandInfo :: Id -> Demand.Demand -> Id
386 setIdDemandInfo id demand_info = modifyIdInfo (`setDemandInfo` demand_info) id
389 idNewDemandInfo_maybe :: Id -> Maybe NewDemand.Demand
390 idNewDemandInfo :: Id -> NewDemand.Demand
392 idNewDemandInfo_maybe id = newDemandInfo (idInfo id)
393 idNewDemandInfo id = newDemandInfo (idInfo id) `orElse` NewDemand.topDmd
395 setIdNewDemandInfo :: Id -> NewDemand.Demand -> Id
396 setIdNewDemandInfo id dmd = modifyIdInfo (`setNewDemandInfo` Just dmd) id
398 ---------------------------------
400 idSpecialisation :: Id -> SpecInfo
401 idSpecialisation id = specInfo (idInfo id)
403 idCoreRules :: Id -> [CoreRule]
404 idCoreRules id = specInfoRules (idSpecialisation id)
406 setIdSpecialisation :: Id -> SpecInfo -> Id
407 setIdSpecialisation id spec_info = modifyIdInfo (`setSpecInfo` spec_info) id
409 ---------------------------------
411 idCafInfo :: Id -> CafInfo
412 #ifdef OLD_STRICTNESS
413 idCafInfo id = case cgInfo (idInfo id) of
414 NoCgInfo -> pprPanic "idCafInfo" (ppr id)
415 info -> cgCafInfo info
417 idCafInfo id = cafInfo (idInfo id)
420 setIdCafInfo :: Id -> CafInfo -> Id
421 setIdCafInfo id caf_info = modifyIdInfo (`setCafInfo` caf_info) id
423 ---------------------------------
425 #ifdef OLD_STRICTNESS
426 idCprInfo :: Id -> CprInfo
427 idCprInfo id = cprInfo (idInfo id)
429 setIdCprInfo :: Id -> CprInfo -> Id
430 setIdCprInfo id cpr_info = modifyIdInfo (`setCprInfo` cpr_info) id
433 ---------------------------------
435 idOccInfo :: Id -> OccInfo
436 idOccInfo id = occInfo (idInfo id)
438 setIdOccInfo :: Id -> OccInfo -> Id
439 setIdOccInfo id occ_info = modifyIdInfo (`setOccInfo` occ_info) id
443 ---------------------------------
445 The inline pragma tells us to be very keen to inline this Id, but it's still
446 OK not to if optimisation is switched off.
449 idInlinePragma :: Id -> InlinePragInfo
450 idInlinePragma id = inlinePragInfo (idInfo id)
452 setInlinePragma :: Id -> InlinePragInfo -> Id
453 setInlinePragma id prag = modifyIdInfo (`setInlinePragInfo` prag) id
455 modifyInlinePragma :: Id -> (InlinePragInfo -> InlinePragInfo) -> Id
456 modifyInlinePragma id fn = modifyIdInfo (\info -> info `setInlinePragInfo` (fn (inlinePragInfo info))) id
460 ---------------------------------
463 idLBVarInfo :: Id -> LBVarInfo
464 idLBVarInfo id = lbvarInfo (idInfo id)
466 isOneShotBndr :: Id -> Bool
467 -- This one is the "business end", called externally.
468 -- Its main purpose is to encapsulate the Horrible State Hack
469 isOneShotBndr id = isOneShotLambda id || (isStateHackType (idType id))
471 isStateHackType :: Type -> Bool
476 = case splitTyConApp_maybe ty of
477 Just (tycon,_) -> tycon == statePrimTyCon
479 -- This is a gross hack. It claims that
480 -- every function over realWorldStatePrimTy is a one-shot
481 -- function. This is pretty true in practice, and makes a big
482 -- difference. For example, consider
483 -- a `thenST` \ r -> ...E...
484 -- The early full laziness pass, if it doesn't know that r is one-shot
485 -- will pull out E (let's say it doesn't mention r) to give
486 -- let lvl = E in a `thenST` \ r -> ...lvl...
487 -- When `thenST` gets inlined, we end up with
488 -- let lvl = E in \s -> case a s of (r, s') -> ...lvl...
489 -- and we don't re-inline E.
491 -- It would be better to spot that r was one-shot to start with, but
492 -- I don't want to rely on that.
494 -- Another good example is in fill_in in PrelPack.lhs. We should be able to
495 -- spot that fill_in has arity 2 (and when Keith is done, we will) but we can't yet.
498 -- The OneShotLambda functions simply fiddle with the IdInfo flag
499 isOneShotLambda :: Id -> Bool
500 isOneShotLambda id = case idLBVarInfo id of
501 IsOneShotLambda -> True
504 setOneShotLambda :: Id -> Id
505 setOneShotLambda id = modifyIdInfo (`setLBVarInfo` IsOneShotLambda) id
507 clearOneShotLambda :: Id -> Id
508 clearOneShotLambda id
509 | isOneShotLambda id = modifyIdInfo (`setLBVarInfo` NoLBVarInfo) id
512 -- But watch out: this may change the type of something else
514 -- If we change the one-shot-ness of x, f's type changes
518 zapLamIdInfo :: Id -> Id
519 zapLamIdInfo id = maybeModifyIdInfo zapLamInfo id
521 zapDemandIdInfo id = maybeModifyIdInfo zapDemandInfo id