2 % (c) The GRASP/AQUA Project, Glasgow University, 1992-1998
4 \section[Id]{@Ids@: Value and constructor identifiers}
10 -- Simple construction
11 mkGlobalId, mkLocalId, mkSpecPragmaId, mkLocalIdWithInfo,
12 mkSysLocal, mkSysLocalUnencoded, 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,
28 isSpecPragmaId, isExportedId, isLocalId, isGlobalId,
30 isPrimOpId, isPrimOpId_maybe,
31 isFCallId, isFCallId_maybe,
32 isDataConWorkId, isDataConWorkId_maybe,
33 isBottomingId, idIsFrom,
36 -- Inline pragma stuff
37 idInlinePragma, setInlinePragma, modifyInlinePragma,
40 -- One shot lambda stuff
41 isOneShotBndr, isOneShotLambda, isStateHackType,
42 setOneShotLambda, clearOneShotLambda,
48 setIdNewStrictness, zapIdNewStrictness,
64 idNewDemandInfo, idNewDemandInfo_maybe,
65 idNewStrictness, idNewStrictness_maybe,
68 idSpecialisation, idCoreRules,
74 newStrictnessFromOld -- Temporary
79 #include "HsVersions.h"
82 import CoreSyn ( Unfolding, CoreRules, IdCoreRule(..), rulesRules )
83 import BasicTypes ( Arity )
84 import Var ( Id, DictId,
85 isId, isExportedId, isSpecPragmaId, isLocalId,
86 idName, idType, idUnique, idInfo, isGlobalId,
87 setIdName, setIdType, setIdUnique,
88 setIdExported, setIdNotExported,
89 setIdInfo, lazySetIdInfo, modifyIdInfo,
93 import qualified Var ( mkLocalId, mkGlobalId, mkSpecPragmaId, mkExportedLocalId )
94 import TyCon ( FieldLabel, TyCon )
95 import Type ( Type, typePrimRep, addFreeTyVars, seqType,
96 splitTyConApp_maybe, PrimRep )
97 import TysPrim ( statePrimTyCon )
100 #ifdef OLD_STRICTNESS
101 import qualified Demand ( Demand )
103 import DataCon ( isUnboxedTupleCon )
104 import NewDemand ( Demand, StrictSig, topDmd, topSig, isBottomingSig )
105 import Name ( Name, OccName, nameIsLocalOrFrom,
106 mkSystemName, mkSystemNameEncoded, mkInternalName,
107 getOccName, getSrcLoc
109 import Module ( Module )
110 import OccName ( EncodedFS, mkWorkerOcc )
111 import Maybes ( orElse )
112 import SrcLoc ( SrcLoc )
114 import Unique ( Unique, mkBuiltinUnique )
115 import CmdLineOpts ( opt_NoStateHack )
117 -- infixl so you can say (id `set` a `set` b)
118 infixl 1 `setIdUnfolding`,
120 `setIdNewDemandInfo`,
121 `setIdNewStrictness`,
123 `setIdSpecialisation`,
126 #ifdef OLD_STRICTNESS
135 %************************************************************************
137 \subsection{Simple Id construction}
139 %************************************************************************
141 Absolutely all Ids are made by mkId. It is just like Var.mkId,
142 but in addition it pins free-tyvar-info onto the Id's type,
143 where it can easily be found.
146 mkLocalIdWithInfo :: Name -> Type -> IdInfo -> Id
147 mkLocalIdWithInfo name ty info = Var.mkLocalId name (addFreeTyVars ty) info
149 mkSpecPragmaId :: Name -> Type -> Id
150 mkSpecPragmaId name ty = Var.mkSpecPragmaId name (addFreeTyVars ty) vanillaIdInfo
152 mkExportedLocalId :: Name -> Type -> Id
153 mkExportedLocalId name ty = Var.mkExportedLocalId name (addFreeTyVars ty) vanillaIdInfo
155 mkGlobalId :: GlobalIdDetails -> Name -> Type -> IdInfo -> Id
156 mkGlobalId details name ty info = Var.mkGlobalId details name (addFreeTyVars ty) info
160 mkLocalId :: Name -> Type -> Id
161 mkLocalId name ty = mkLocalIdWithInfo name ty vanillaIdInfo
163 -- SysLocal: for an Id being created by the compiler out of thin air...
164 -- UserLocal: an Id with a name the user might recognize...
165 mkUserLocal :: OccName -> Unique -> Type -> SrcLoc -> Id
166 mkSysLocal :: EncodedFS -> Unique -> Type -> Id
167 mkVanillaGlobal :: Name -> Type -> IdInfo -> Id
169 -- for SysLocal, we assume the base name is already encoded, to avoid
170 -- re-encoding the same string over and over again.
171 mkSysLocal fs uniq ty = mkLocalId (mkSystemNameEncoded uniq fs) ty
173 -- version to use when the faststring needs to be encoded
174 mkSysLocalUnencoded fs uniq ty = mkLocalId (mkSystemName uniq fs) ty
176 mkUserLocal occ uniq ty loc = mkLocalId (mkInternalName uniq occ loc) ty
177 mkVanillaGlobal = mkGlobalId VanillaGlobal
180 Make some local @Ids@ for a template @CoreExpr@. These have bogus
181 @Uniques@, but that's OK because the templates are supposed to be
182 instantiated before use.
185 -- "Wild Id" typically used when you need a binder that you don't expect to use
186 mkWildId :: Type -> Id
187 mkWildId ty = mkSysLocal FSLIT("wild") (mkBuiltinUnique 1) ty
189 mkWorkerId :: Unique -> Id -> Type -> Id
190 -- A worker gets a local name. CoreTidy will externalise it if necessary.
191 mkWorkerId uniq unwrkr ty
192 = mkLocalId wkr_name ty
194 wkr_name = mkInternalName uniq (mkWorkerOcc (getOccName unwrkr)) (getSrcLoc unwrkr)
196 -- "Template locals" typically used in unfoldings
197 mkTemplateLocals :: [Type] -> [Id]
198 mkTemplateLocals tys = zipWith mkTemplateLocal [1..] tys
200 mkTemplateLocalsNum :: Int -> [Type] -> [Id]
201 -- The Int gives the starting point for unique allocation
202 mkTemplateLocalsNum n tys = zipWith mkTemplateLocal [n..] tys
204 mkTemplateLocal :: Int -> Type -> Id
205 mkTemplateLocal i ty = mkSysLocal FSLIT("tpl") (mkBuiltinUnique i) ty
209 %************************************************************************
211 \subsection[Id-general-funs]{General @Id@-related functions}
213 %************************************************************************
216 setIdType :: Id -> Type -> Id
217 -- Add free tyvar info to the type
218 setIdType id ty = seqType ty `seq` Var.setIdType id (addFreeTyVars ty)
220 idPrimRep :: Id -> PrimRep
221 idPrimRep id = typePrimRep (idType id)
225 %************************************************************************
227 \subsection{Special Ids}
229 %************************************************************************
231 The @SpecPragmaId@ exists only to make Ids that are
232 on the *LHS* of bindings created by SPECIALISE pragmas;
234 The SpecPragmaId is never itself mentioned; it
235 exists solely so that the specialiser will find
236 the call to f, and make specialised version of it.
237 The SpecPragmaId binding is discarded by the specialiser
238 when it gathers up overloaded calls.
239 Meanwhile, it is not discarded as dead code.
243 recordSelectorFieldLabel :: Id -> (TyCon, FieldLabel)
244 recordSelectorFieldLabel id = case globalIdDetails id of
245 RecordSelId tycon lbl -> (tycon,lbl)
246 other -> panic "recordSelectorFieldLabel"
248 isRecordSelector id = case globalIdDetails id of
249 RecordSelId _ _ -> True
252 isPrimOpId id = case globalIdDetails id of
256 isPrimOpId_maybe id = case globalIdDetails id of
257 PrimOpId op -> Just op
260 isFCallId id = case globalIdDetails id of
264 isFCallId_maybe id = case globalIdDetails id of
265 FCallId call -> Just call
268 isDataConWorkId id = case globalIdDetails id of
269 DataConWorkId _ -> True
272 isDataConWorkId_maybe id = case globalIdDetails id of
273 DataConWorkId con -> Just con
276 -- hasNoBinding returns True of an Id which may not have a
277 -- binding, even though it is defined in this module.
278 -- Data constructor workers used to be things of this kind, but
279 -- they aren't any more. Instead, we inject a binding for
280 -- them at the CorePrep stage.
281 -- EXCEPT: unboxed tuples, which definitely have no binding
282 hasNoBinding id = case globalIdDetails id of
285 DataConWorkId dc -> isUnboxedTupleCon dc
288 isImplicitId :: Id -> Bool
289 -- isImplicitId tells whether an Id's info is implied by other
290 -- declarations, so we don't need to put its signature in an interface
291 -- file, even if it's mentioned in some other interface unfolding.
293 = case globalIdDetails id of
294 RecordSelId _ _ -> True
298 DataConWorkId _ -> True
299 DataConWrapId _ -> True
300 -- These are are implied by their type or class decl;
301 -- remember that all type and class decls appear in the interface file.
302 -- The dfun id is not an implicit Id; it must *not* be omitted, because
303 -- it carries version info for the instance decl
306 idIsFrom :: Module -> Id -> Bool
307 idIsFrom mod id = nameIsLocalOrFrom mod (idName id)
311 isDeadBinder :: Id -> Bool
312 isDeadBinder bndr | isId bndr = isDeadOcc (idOccInfo bndr)
313 | otherwise = False -- TyVars count as not dead
317 %************************************************************************
319 \subsection{IdInfo stuff}
321 %************************************************************************
324 ---------------------------------
326 idArity :: Id -> Arity
327 idArity id = arityInfo (idInfo id)
329 setIdArity :: Id -> Arity -> Id
330 setIdArity id arity = modifyIdInfo (`setArityInfo` arity) id
332 #ifdef OLD_STRICTNESS
333 ---------------------------------
335 idStrictness :: Id -> StrictnessInfo
336 idStrictness id = strictnessInfo (idInfo id)
338 setIdStrictness :: Id -> StrictnessInfo -> Id
339 setIdStrictness id strict_info = modifyIdInfo (`setStrictnessInfo` strict_info) id
342 -- isBottomingId returns true if an application to n args would diverge
343 isBottomingId :: Id -> Bool
344 isBottomingId id = isBottomingSig (idNewStrictness id)
346 idNewStrictness_maybe :: Id -> Maybe StrictSig
347 idNewStrictness :: Id -> StrictSig
349 idNewStrictness_maybe id = newStrictnessInfo (idInfo id)
350 idNewStrictness id = idNewStrictness_maybe id `orElse` topSig
352 setIdNewStrictness :: Id -> StrictSig -> Id
353 setIdNewStrictness id sig = modifyIdInfo (`setNewStrictnessInfo` Just sig) id
355 zapIdNewStrictness :: Id -> Id
356 zapIdNewStrictness id = modifyIdInfo (`setNewStrictnessInfo` Nothing) id
358 ---------------------------------
360 idWorkerInfo :: Id -> WorkerInfo
361 idWorkerInfo id = workerInfo (idInfo id)
363 setIdWorkerInfo :: Id -> WorkerInfo -> Id
364 setIdWorkerInfo id work_info = modifyIdInfo (`setWorkerInfo` work_info) id
366 ---------------------------------
368 idUnfolding :: Id -> Unfolding
369 idUnfolding id = unfoldingInfo (idInfo id)
371 setIdUnfolding :: Id -> Unfolding -> Id
372 setIdUnfolding id unfolding = modifyIdInfo (`setUnfoldingInfo` unfolding) id
374 #ifdef OLD_STRICTNESS
375 ---------------------------------
377 idDemandInfo :: Id -> Demand.Demand
378 idDemandInfo id = demandInfo (idInfo id)
380 setIdDemandInfo :: Id -> Demand.Demand -> Id
381 setIdDemandInfo id demand_info = modifyIdInfo (`setDemandInfo` demand_info) id
384 idNewDemandInfo_maybe :: Id -> Maybe NewDemand.Demand
385 idNewDemandInfo :: Id -> NewDemand.Demand
387 idNewDemandInfo_maybe id = newDemandInfo (idInfo id)
388 idNewDemandInfo id = newDemandInfo (idInfo id) `orElse` NewDemand.topDmd
390 setIdNewDemandInfo :: Id -> NewDemand.Demand -> Id
391 setIdNewDemandInfo id dmd = modifyIdInfo (`setNewDemandInfo` Just dmd) id
393 ---------------------------------
395 idSpecialisation :: Id -> CoreRules
396 idSpecialisation id = specInfo (idInfo id)
398 idCoreRules :: Id -> [IdCoreRule]
399 idCoreRules id = [IdCoreRule id False rule | rule <- rulesRules (idSpecialisation id)]
401 setIdSpecialisation :: Id -> CoreRules -> Id
402 setIdSpecialisation id spec_info = modifyIdInfo (`setSpecInfo` spec_info) id
404 ---------------------------------
406 idCafInfo :: Id -> CafInfo
407 #ifdef OLD_STRICTNESS
408 idCafInfo id = case cgInfo (idInfo id) of
409 NoCgInfo -> pprPanic "idCafInfo" (ppr id)
410 info -> cgCafInfo info
412 idCafInfo id = cafInfo (idInfo id)
415 setIdCafInfo :: Id -> CafInfo -> Id
416 setIdCafInfo id caf_info = modifyIdInfo (`setCafInfo` caf_info) id
418 ---------------------------------
420 #ifdef OLD_STRICTNESS
421 idCprInfo :: Id -> CprInfo
422 idCprInfo id = cprInfo (idInfo id)
424 setIdCprInfo :: Id -> CprInfo -> Id
425 setIdCprInfo id cpr_info = modifyIdInfo (`setCprInfo` cpr_info) id
428 ---------------------------------
430 idOccInfo :: Id -> OccInfo
431 idOccInfo id = occInfo (idInfo id)
433 setIdOccInfo :: Id -> OccInfo -> Id
434 setIdOccInfo id occ_info = modifyIdInfo (`setOccInfo` occ_info) id
438 ---------------------------------
440 The inline pragma tells us to be very keen to inline this Id, but it's still
441 OK not to if optimisation is switched off.
444 idInlinePragma :: Id -> InlinePragInfo
445 idInlinePragma id = inlinePragInfo (idInfo id)
447 setInlinePragma :: Id -> InlinePragInfo -> Id
448 setInlinePragma id prag = modifyIdInfo (`setInlinePragInfo` prag) id
450 modifyInlinePragma :: Id -> (InlinePragInfo -> InlinePragInfo) -> Id
451 modifyInlinePragma id fn = modifyIdInfo (\info -> info `setInlinePragInfo` (fn (inlinePragInfo info))) id
455 ---------------------------------
458 idLBVarInfo :: Id -> LBVarInfo
459 idLBVarInfo id = lbvarInfo (idInfo id)
461 isOneShotBndr :: Id -> Bool
462 -- This one is the "business end", called externally.
463 -- Its main purpose is to encapsulate the Horrible State Hack
464 isOneShotBndr id = isOneShotLambda id || (isStateHackType (idType id))
466 isStateHackType :: Type -> Bool
471 = case splitTyConApp_maybe ty of
472 Just (tycon,_) -> tycon == statePrimTyCon
474 -- This is a gross hack. It claims that
475 -- every function over realWorldStatePrimTy is a one-shot
476 -- function. This is pretty true in practice, and makes a big
477 -- difference. For example, consider
478 -- a `thenST` \ r -> ...E...
479 -- The early full laziness pass, if it doesn't know that r is one-shot
480 -- will pull out E (let's say it doesn't mention r) to give
481 -- let lvl = E in a `thenST` \ r -> ...lvl...
482 -- When `thenST` gets inlined, we end up with
483 -- let lvl = E in \s -> case a s of (r, s') -> ...lvl...
484 -- and we don't re-inline E.
486 -- It would be better to spot that r was one-shot to start with, but
487 -- I don't want to rely on that.
489 -- Another good example is in fill_in in PrelPack.lhs. We should be able to
490 -- spot that fill_in has arity 2 (and when Keith is done, we will) but we can't yet.
493 -- The OneShotLambda functions simply fiddle with the IdInfo flag
494 isOneShotLambda :: Id -> Bool
495 isOneShotLambda id = case idLBVarInfo id of
496 IsOneShotLambda -> True
499 setOneShotLambda :: Id -> Id
500 setOneShotLambda id = modifyIdInfo (`setLBVarInfo` IsOneShotLambda) id
502 clearOneShotLambda :: Id -> Id
503 clearOneShotLambda id
504 | isOneShotLambda id = modifyIdInfo (`setLBVarInfo` NoLBVarInfo) id
507 -- But watch out: this may change the type of something else
509 -- If we change the one-shot-ness of x, f's type changes
513 zapLamIdInfo :: Id -> Id
514 zapLamIdInfo id = maybeModifyIdInfo zapLamInfo id
516 zapDemandIdInfo id = maybeModifyIdInfo zapDemandInfo id