2 % (c) The GRASP/AQUA Project, Glasgow University, 1992-1998
4 \section{@Vars@: Variables}
10 setVarName, setVarUnique, setVarOcc,
13 TyVar, mkTyVar, mkTcTyVar,
15 setTyVarName, setTyVarUnique,
20 idName, idType, idUnique, idInfo, modifyIdInfo, maybeModifyIdInfo,
21 setIdName, setIdUnique, setIdType, setIdInfo, lazySetIdInfo,
22 setIdLocalExported, zapSpecPragmaId,
24 globalIdDetails, globaliseId,
26 mkLocalId, mkExportedLocalId, mkSpecPragmaId,
29 isTyVar, isTcTyVar, isId, isLocalVar, isLocalId,
30 isGlobalId, isExportedId, isSpecPragmaId,
34 #include "HsVersions.h"
36 import {-# SOURCE #-} TypeRep( Type )
37 import {-# SOURCE #-} TcType( TcTyVarDetails )
38 import {-# SOURCE #-} IdInfo( GlobalIdDetails, notGlobalId, IdInfo, seqIdInfo )
40 import Name ( Name, OccName, NamedThing(..),
41 setNameUnique, setNameOcc, nameUnique
44 import Unique ( Unique, Uniquable(..), mkUniqueGrimily, getKey# )
50 %************************************************************************
52 \subsection{The main data type declarations}
54 %************************************************************************
57 Every @Var@ has a @Unique@, to uniquify it and for fast comparison, a
58 @Type@, and an @IdInfo@ (non-essential info about it, e.g.,
59 strictness). The essential info about different kinds of @Vars@ is
66 realUnique :: FastInt, -- Key for fast comparison
67 -- Identical to the Unique in the name,
68 -- cached here for speed
71 | TcTyVar { -- Used only during type inference
73 realUnique :: FastInt,
75 tcTyVarDetails :: TcTyVarDetails }
77 | GlobalId { -- Used for imported Ids, dict selectors etc
79 realUnique :: FastInt,
82 gblDetails :: GlobalIdDetails }
84 | LocalId { -- Used for locally-defined Ids (see NOTE below)
86 realUnique :: FastInt,
89 lclDetails :: LocalIdDetails }
92 = NotExported -- Not exported
93 | Exported -- Exported
94 | SpecPragma -- Not exported, but not to be discarded either
95 -- It's unclean that this is so deeply built in
101 * always a constant (top-level)
102 * imported, or data constructor, or primop, or record selector
103 * has a Unique that is globally unique across the whole
104 GHC invocation (a single invocation may compile multiple modules)
107 * bound within an expression (lambda, case, local let(rec))
108 * or defined at top level in the module being compiled
110 After CoreTidy, top-level LocalIds are turned into GlobalIds
114 instance Outputable Var where
115 ppr var = ppr (varName var)
117 instance Show Var where
118 showsPrec p var = showsPrecSDoc p (ppr var)
120 instance NamedThing Var where
123 instance Uniquable Var where
124 getUnique = varUnique
126 instance Eq Var where
127 a == b = realUnique a ==# realUnique b
129 instance Ord Var where
130 a <= b = realUnique a <=# realUnique b
131 a < b = realUnique a <# realUnique b
132 a >= b = realUnique a >=# realUnique b
133 a > b = realUnique a ># realUnique b
134 a `compare` b = varUnique a `compare` varUnique b
139 varUnique :: Var -> Unique
140 varUnique var = mkUniqueGrimily (iBox (realUnique var))
142 setVarUnique :: Var -> Unique -> Var
143 setVarUnique var uniq
144 = var { realUnique = getKey# uniq,
145 varName = setNameUnique (varName var) uniq }
147 setVarName :: Var -> Name -> Var
148 setVarName var new_name
149 = var { realUnique = getKey# (getUnique new_name),
152 setVarOcc :: Var -> OccName -> Var
153 setVarOcc var new_occ
154 = var { varName = setNameOcc (varName var) new_occ }
158 %************************************************************************
160 \subsection{Type variables}
162 %************************************************************************
169 setTyVarUnique = setVarUnique
170 setTyVarName = setVarName
174 mkTyVar :: Name -> Kind -> TyVar
175 mkTyVar name kind = TyVar { varName = name
176 , realUnique = getKey# (nameUnique name)
180 mkTcTyVar :: Name -> Kind -> TcTyVarDetails -> TyVar
181 mkTcTyVar name kind details
182 = TcTyVar { varName = name,
183 realUnique = getKey# (nameUnique name),
185 tcTyVarDetails = details
190 %************************************************************************
192 \subsection{Id Construction}
194 %************************************************************************
196 Most Id-related functions are in Id.lhs and MkId.lhs
207 setIdUnique :: Id -> Unique -> Id
208 setIdUnique = setVarUnique
210 setIdName :: Id -> Name -> Id
211 setIdName = setVarName
213 setIdType :: Id -> Type -> Id
214 setIdType id ty = id {idType = ty}
216 setIdLocalExported :: Id -> Id
217 -- It had better be a LocalId already
218 setIdLocalExported id = id { lclDetails = Exported }
220 globaliseId :: GlobalIdDetails -> Id -> Id
221 -- If it's a local, make it global
222 globaliseId details id = GlobalId { varName = varName id,
223 realUnique = realUnique id,
226 gblDetails = details }
228 zapSpecPragmaId :: Id -> Id
230 | isSpecPragmaId id = id {lclDetails = NotExported}
233 lazySetIdInfo :: Id -> IdInfo -> Id
234 lazySetIdInfo id info = id {idInfo = info}
236 setIdInfo :: Id -> IdInfo -> Id
237 setIdInfo id info = seqIdInfo info `seq` id {idInfo = info}
238 -- Try to avoid spack leaks by seq'ing
240 modifyIdInfo :: (IdInfo -> IdInfo) -> Id -> Id
242 = seqIdInfo new_info `seq` id {idInfo = new_info}
244 new_info = fn (idInfo id)
246 -- maybeModifyIdInfo tries to avoid unnecesary thrashing
247 maybeModifyIdInfo :: (IdInfo -> Maybe IdInfo) -> Id -> Id
248 maybeModifyIdInfo fn id
249 = case fn (idInfo id) of
251 Just new_info -> id {idInfo = new_info}
254 %************************************************************************
256 \subsection{Predicates over variables
258 %************************************************************************
261 mkGlobalId :: GlobalIdDetails -> Name -> Type -> IdInfo -> Id
262 mkGlobalId details name ty info
263 = GlobalId { varName = name,
264 realUnique = getKey# (nameUnique name), -- Cache the unique
266 gblDetails = details,
269 mk_local_id :: Name -> Type -> LocalIdDetails -> IdInfo -> Id
270 mk_local_id name ty details info
271 = LocalId { varName = name,
272 realUnique = getKey# (nameUnique name), -- Cache the unique
274 lclDetails = details,
277 mkLocalId :: Name -> Type -> IdInfo -> Id
278 mkLocalId name ty info = mk_local_id name ty NotExported info
280 mkExportedLocalId :: Name -> Type -> IdInfo -> Id
281 mkExportedLocalId name ty info = mk_local_id name ty Exported info
283 mkSpecPragmaId :: Name -> Type -> IdInfo -> Id
284 mkSpecPragmaId name ty info = mk_local_id name ty SpecPragma info
288 isTyVar, isTcTyVar :: Var -> Bool
289 isId, isLocalVar, isLocalId :: Var -> Bool
290 isGlobalId, isExportedId, isSpecPragmaId :: Var -> Bool
291 mustHaveLocalBinding :: Var -> Bool
293 isTyVar (TyVar {}) = True
294 isTyVar (TcTyVar {}) = True
295 isTyVar other = False
297 isTcTyVar (TcTyVar {}) = True
298 isTcTyVar other = False
300 isId (LocalId {}) = True
301 isId (GlobalId {}) = True
304 isLocalId (LocalId {}) = True
305 isLocalId other = False
307 -- isLocalVar returns True for type variables as well as local Ids
308 -- These are the variables that we need to pay attention to when finding free
309 -- variables, or doing dependency analysis.
310 isLocalVar (GlobalId {}) = False
311 isLocalVar other = True
313 -- mustHaveLocalBinding returns True of Ids and TyVars
314 -- that must have a binding in this module. The converse
315 -- is not quite right: there are some GlobalIds that must have
316 -- bindings, such as record selectors. But that doesn't matter,
317 -- because it's only used for assertions
318 mustHaveLocalBinding var = isLocalVar var
320 isGlobalId (GlobalId {}) = True
321 isGlobalId other = False
323 -- isExportedId means "don't throw this away"
324 isExportedId (GlobalId {}) = True
325 isExportedId (LocalId {lclDetails = details})
330 isExportedId other = False
332 isSpecPragmaId (LocalId {lclDetails = SpecPragma}) = True
333 isSpecPragmaId other = False
337 globalIdDetails :: Var -> GlobalIdDetails
338 -- Works OK on local Ids too, returning notGlobalId
339 globalIdDetails (GlobalId {gblDetails = details}) = details
340 globalIdDetails other = notGlobalId