2 % (c) The GRASP/AQUA Project, Glasgow University, 1992-1996
4 \section[RnUtils]{Functions used by both renaming passes}
7 #include "HsVersions.h"
10 RnEnv(..), QualNames(..),
11 UnqualNames(..), ScopeStack(..),
12 emptyRnEnv, extendGlobalRnEnv, extendLocalRnEnv,
13 lookupRnEnv, lookupTcRnEnv,
22 -- ToDo: nuke/move? WDP 96/04/05
23 GlobalNameMapper(..), GlobalNameMappers(..)
28 import Bag ( Bag, emptyBag, snocBag, unionBags )
29 import ErrUtils ( addShortErrLocLine, addErrLoc )
30 import FiniteMap ( FiniteMap, emptyFM, isEmptyFM,
31 lookupFM, addListToFM, addToFM )
32 import Maybes ( maybeToBool )
33 import Name ( RdrName(..), isQual )
34 import Outputable ( pprNonOp, getLocalName )
35 import PprStyle ( PprStyle(..) )
37 import RnHsSyn ( RnName )
38 import Util ( assertPanic )
40 type GlobalNameMapper = RnName -> Maybe Name
41 type GlobalNameMappers = (GlobalNameMapper, GlobalNameMapper)
44 *********************************************************
46 \subsection{RnEnv: renaming environment}
48 *********************************************************
50 Seperate FiniteMaps are kept for lookup up Qual names,
51 Unqual names and Local names.
54 type RnEnv = ((QualNames, UnqualNames, QualNames, UnqualNames), ScopeStack)
56 type QualNames = FiniteMap (FAST_STRING,Module) RnName
57 type UnqualNames = FiniteMap FAST_STRING RnName
58 type ScopeStack = FiniteMap FAST_STRING RnName
61 extendGlobalRnEnv :: RnEnv -> [(RdrName,RnName)] -> [(RdrName,RnName)]
62 -> (RnEnv, Bag (RdrName, RnName, RnName))
63 extendLocalRnEnv :: Bool -> RnEnv -> [RnName] -> (RnEnv, [RnName])
64 lookupRnEnv :: RnEnv -> RdrName -> Maybe RnName
65 lookupTcRnEnv :: RnEnv -> RdrName -> Maybe RnName
68 If the @RdrName@ is a @Qual@, @lookupValue@ looks it up in the global
69 value QualNames. If it is @Unqual@, it looks it up first in the
70 ScopeStack, and if it isn't found there, then in the global
73 @lookupTcRnEnv@ looks up tycons/classes in the alternative global
76 @extendGlobalRnEnv@ adds global names to the RnEnv. It takes seperate
77 value and tycon/class name lists. It returns any duplicate names
80 @extendRnEnv@ adds new local names to the ScopeStack in an RnEnv.
81 It optionally reports any shadowed names.
85 = ((emptyFM, emptyFM, emptyFM, emptyFM), emptyFM)
88 extendGlobalRnEnv ((qual, unqual, tc_qual, tc_unqual), stack) val_list tc_list
89 = ASSERT(isEmptyFM stack)
90 (((qual', unqual', tc_qual, tc_unqual), stack), tc_dups `unionBags` dups)
92 (qual', unqual', dups) = extend_global qual unqual val_list
93 (tc_qual', tc_unqual', tc_dups) = extend_global tc_qual tc_unqual tc_list
95 extend_global qual unqual rdr_list = (qual', unqual', dups)
97 (qual_list, unqual_list) = partition (isQual.fst) rdr_list
98 qual_in = map mk_qual qual_list
99 unqual_in = map mk_unqual unqual_list
100 mk_qual (Qual m s, rn) = ((s,m), rn)
101 mk_unqual (Unqual s, rn) = (s, rn)
103 (qual', qual_dups) = do_dups qual_in qual emptyBag (\ (s,m) -> Qual m s)
104 (unqual', unqual_dups) = do_dups unqual_in unqual emptyBag Unqual
106 dups = unqual_dups `unionBags` qual_dups
108 do_dups [] fm dups to_rdr = (fm, dups)
109 do_dups ((k,v):rest) fm dups to_rdr
110 = case lookupFM fm k of
111 Nothing -> do_dups rest (addToFM fm k v) dups to_rdr
112 Just cur -> do_dups rest fm (dups `snocBag` (to_rdr k, cur, v)) to_rdr
115 extendLocalRnEnv report_shadows (global, stack) new_local
116 = ((global, new_stack), dups)
118 (new_stack, dups) = extend new_local stack
121 = if report_shadows then
122 do_shadows names stack []
124 (addListToFM stack [ (getLocalName n, n) | n <- names], [])
126 do_shadows [] stack dups = (stack, dups)
127 do_shadows (name:names) stack dups
128 = do_shadows names (addToFM stack str name) ext_dups
130 str = getLocalName name
131 ext_dups = if maybeToBool (lookupFM stack str)
136 lookupRnEnv ((qual, unqual, _, _), stack) rdr
138 Unqual str -> lookup stack str (lookup unqual str Nothing)
139 Qual mod str -> lookup qual (str,mod) Nothing
141 lookup fm thing do_on_fail
142 = case lookupFM fm thing of
143 found@(Just name) -> found
144 Nothing -> do_on_fail
146 lookupTcRnEnv ((_, _, tc_qual, tc_unqual), _) rdr
148 Unqual str -> lookupFM tc_unqual str
149 Qual mod str -> lookupFM tc_qual (str,mod)
152 *********************************************************
154 \subsection{Errors used in RnMonad}
156 *********************************************************
159 unknownNameErr descriptor name locn
160 = addShortErrLocLine locn ( \ sty ->
161 ppBesides [ppStr "undefined ", ppStr descriptor, ppStr ": ", pprNonOp sty name] )
163 badClassOpErr clas op locn
164 = addErrLoc locn "" ( \ sty ->
165 ppBesides [ppChar '`', pprNonOp sty op, ppStr "' is not an operation of class `",
166 ppr sty clas, ppStr "'"] )
168 qualNameErr descriptor (name,locn)
169 = addShortErrLocLine locn ( \ sty ->
170 ppBesides [ppStr "invalid use of qualified ", ppStr descriptor, ppStr ": ", pprNonOp sty name ] )
172 dupNamesErr descriptor ((name1,locn1) : dup_things) sty
173 = ppAboves (item1 : map dup_item dup_things)
176 = ppBesides [ ppr PprForUser locn1,
177 ppStr ": multiple declarations of a ", ppStr descriptor, ppStr ": ",
180 dup_item (name, locn)
181 = ppBesides [ ppr PprForUser locn,
182 ppStr ": here was another declaration of `", pprNonOp sty name, ppStr "'" ]
184 shadowedNameWarn locn shadow
185 = addShortErrLocLine locn ( \ sty ->
186 ppBesides [ppStr "more than one value with the same name (shadowing): ", ppr sty shadow] )
188 multipleOccWarn (name, occs) sty
189 = ppBesides [ppStr "multiple names used to refer to `", ppr sty name, ppStr "': ",
190 ppInterleave ppComma (map (ppr sty) occs)]