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,
24 -- ToDo: nuke/move? WDP 96/04/05
25 GlobalNameMapper(..), GlobalNameMappers(..)
30 import Bag ( Bag, emptyBag, snocBag, unionBags )
31 import ErrUtils ( addShortErrLocLine, addErrLoc )
32 import FiniteMap ( FiniteMap, emptyFM, isEmptyFM,
33 lookupFM, addListToFM, addToFM )
34 import Maybes ( maybeToBool )
35 import Name ( RdrName(..), isQual, pprNonSym, getLocalName, ExportFlag(..) )
36 import PprStyle ( PprStyle(..) )
38 import RnHsSyn ( RnName )
39 import Util ( assertPanic )
41 type GlobalNameMapper = RnName -> Maybe Name
42 type GlobalNameMappers = (GlobalNameMapper, GlobalNameMapper)
45 *********************************************************
47 \subsection{RnEnv: renaming environment}
49 *********************************************************
51 Seperate FiniteMaps are kept for lookup up Qual names,
52 Unqual names and Local names.
55 type RnEnv = ((QualNames, UnqualNames, QualNames, UnqualNames), ScopeStack)
57 type QualNames = FiniteMap (FAST_STRING,Module) RnName
58 type UnqualNames = FiniteMap FAST_STRING RnName
59 type ScopeStack = FiniteMap FAST_STRING RnName
62 extendGlobalRnEnv :: RnEnv -> [(RdrName,RnName)] -> [(RdrName,RnName)]
63 -> (RnEnv, Bag (RdrName, RnName, RnName))
64 extendLocalRnEnv :: Bool -> RnEnv -> [RnName] -> (RnEnv, [RnName])
65 lookupRnEnv :: RnEnv -> RdrName -> Maybe RnName
66 lookupTcRnEnv :: RnEnv -> RdrName -> Maybe RnName
69 If the @RdrName@ is a @Qual@, @lookupValue@ looks it up in the global
70 value QualNames. If it is @Unqual@, it looks it up first in the
71 ScopeStack, and if it isn't found there, then in the global
74 @lookupTcRnEnv@ looks up tycons/classes in the alternative global
77 @extendGlobalRnEnv@ adds global names to the RnEnv. It takes separate
78 value and tycon/class name lists. It returns any duplicate names
81 @extendRnEnv@ adds new local names to the ScopeStack in an RnEnv.
82 It optionally reports any shadowed names.
86 = ((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{Export Flag Functions}
156 *********************************************************
159 lubExportFlag ExportAll ExportAll = ExportAll
160 lubExportFlag ExportAll ExportAbs = ExportAll
161 lubExportFlag ExportAbs ExportAll = ExportAll
162 lubExportFlag ExportAbs ExportAbs = ExportAbs
165 *********************************************************
167 \subsection{Errors used in RnMonad}
169 *********************************************************
172 unknownNameErr descriptor name locn
173 = addShortErrLocLine locn ( \ sty ->
174 ppBesides [ppStr "undefined ", ppStr descriptor, ppStr ": ", pprNonSym sty name] )
176 badClassOpErr clas op locn
177 = addErrLoc locn "" ( \ sty ->
178 ppBesides [ppChar '`', pprNonSym sty op, ppStr "' is not an operation of class `",
179 ppr sty clas, ppStr "'"] )
181 qualNameErr descriptor (name,locn)
182 = addShortErrLocLine locn ( \ sty ->
183 ppBesides [ppStr "invalid use of qualified ", ppStr descriptor, ppStr ": ", pprNonSym sty name ] )
185 dupNamesErr descriptor ((name1,locn1) : dup_things) sty
186 = ppAboves (item1 : map dup_item dup_things)
189 = ppBesides [ ppr PprForUser locn1,
190 ppStr ": multiple declarations of a ", ppStr descriptor, ppStr ": ",
191 pprNonSym sty name1 ]
193 dup_item (name, locn)
194 = ppBesides [ ppr PprForUser locn,
195 ppStr ": here was another declaration of `", pprNonSym sty name, ppStr "'" ]
197 shadowedNameWarn locn shadow
198 = addShortErrLocLine locn ( \ sty ->
199 ppBesides [ppStr "more than one value with the same name (shadowing): ", ppr sty shadow] )
201 multipleOccWarn (name, occs) sty
202 = ppBesides [ppStr "multiple names used to refer to `", ppr sty name, ppStr "': ",
203 ppInterleave ppComma (map (ppr sty) occs)]