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, lookupGlobalRnEnv, lookupTcRnEnv,
23 import Bag ( Bag, emptyBag, snocBag, unionBags )
24 import ErrUtils ( addShortErrLocLine )
25 import FiniteMap ( FiniteMap, emptyFM, isEmptyFM,
26 lookupFM, addListToFM, addToFM )
27 import Maybes ( maybeToBool )
28 import Name ( RdrName(..), isQual, pprNonSym, getLocalName, ExportFlag(..) )
29 import PprStyle ( PprStyle(..) )
31 import RnHsSyn ( RnName )
32 import Util ( assertPanic )
35 *********************************************************
37 \subsection{RnEnv: renaming environment}
39 *********************************************************
41 Seperate FiniteMaps are kept for lookup up Qual names,
42 Unqual names and Local names.
45 type RnEnv = ((QualNames, UnqualNames, QualNames, UnqualNames), ScopeStack)
47 type QualNames = FiniteMap (FAST_STRING,Module) RnName
48 type UnqualNames = FiniteMap FAST_STRING RnName
49 type ScopeStack = FiniteMap FAST_STRING RnName
52 extendGlobalRnEnv :: RnEnv -> [(RdrName,RnName)] -> [(RdrName,RnName)]
53 -> (RnEnv, Bag (RdrName, RnName, RnName))
54 extendLocalRnEnv :: Bool -> RnEnv -> [RnName] -> (RnEnv, [RnName])
55 lookupRnEnv :: RnEnv -> RdrName -> Maybe RnName
56 lookupGlobalRnEnv :: RnEnv -> RdrName -> Maybe RnName
57 lookupTcRnEnv :: RnEnv -> RdrName -> Maybe RnName
60 If the @RdrName@ is a @Qual@, @lookupValue@ looks it up in the global
61 value QualNames. If it is @Unqual@, it looks it up first in the
62 ScopeStack, and if it isn't found there, then in the global
65 @lookupTcRnEnv@ looks up tycons/classes in the alternative global
68 @extendGlobalRnEnv@ adds global names to the RnEnv. It takes separate
69 value and tycon/class name lists. It returns any duplicate names
72 @extendRnEnv@ adds new local names to the ScopeStack in an RnEnv.
73 It optionally reports any shadowed names.
77 = ((emptyFM, emptyFM, emptyFM, emptyFM), emptyFM)
79 extendGlobalRnEnv ((qual, unqual, tc_qual, tc_unqual), stack) val_list tc_list
80 = ASSERT(isEmptyFM stack)
81 (((qual', unqual', tc_qual', tc_unqual'), stack), tc_dups `unionBags` dups)
83 (qual', unqual', dups) = extend_global qual unqual val_list
84 (tc_qual', tc_unqual', tc_dups) = extend_global tc_qual tc_unqual tc_list
86 extend_global qual unqual rdr_list = (qual', unqual', dups)
88 (qual_list, unqual_list) = partition (isQual.fst) rdr_list
89 qual_in = map mk_qual qual_list
90 unqual_in = map mk_unqual unqual_list
91 mk_qual (Qual m s, rn) = ((s,m), rn)
92 mk_unqual (Unqual s, rn) = (s, rn)
94 (qual', qual_dups) = do_dups qual_in qual emptyBag (\ (s,m) -> Qual m s)
95 (unqual', unqual_dups) = do_dups unqual_in unqual emptyBag Unqual
97 dups = unqual_dups `unionBags` qual_dups
99 do_dups [] fm dups to_rdr = (fm, dups)
100 do_dups ((k,v):rest) fm dups to_rdr
101 = case lookupFM fm k of
102 Nothing -> do_dups rest (addToFM fm k v) dups to_rdr
103 Just cur -> do_dups rest fm (dups `snocBag` (to_rdr k, cur, v)) to_rdr
106 extendLocalRnEnv report_shadows (global, stack) new_local
107 = ((global, new_stack), dups)
109 (new_stack, dups) = extend new_local stack
112 = if report_shadows then
113 do_shadows names stack []
115 (addListToFM stack [ (getLocalName n, n) | n <- names], [])
117 do_shadows [] stack dups = (stack, dups)
118 do_shadows (name:names) stack dups
119 = do_shadows names (addToFM stack str name) ext_dups
121 str = getLocalName name
122 ext_dups = if maybeToBool (lookupFM stack str)
127 lookupRnEnv ((qual, unqual, _, _), stack) rdr
129 Unqual str -> lookup stack str (lookup unqual str Nothing)
130 Qual mod str -> lookup qual (str,mod) Nothing
132 lookup fm thing do_on_fail
133 = case lookupFM fm thing of
134 found@(Just name) -> found
135 Nothing -> do_on_fail
137 lookupGlobalRnEnv ((qual, unqual, _, _), _) rdr
139 Unqual str -> lookupFM unqual str
140 Qual mod str -> lookupFM qual (str,mod)
142 lookupTcRnEnv ((_, _, tc_qual, tc_unqual), _) rdr
144 Unqual str -> lookupFM tc_unqual str
145 Qual mod str -> lookupFM tc_qual (str,mod)
148 *********************************************************
150 \subsection{Export Flag Functions}
152 *********************************************************
155 lubExportFlag ExportAll ExportAll = ExportAll
156 lubExportFlag ExportAll ExportAbs = ExportAll
157 lubExportFlag ExportAbs ExportAll = ExportAll
158 lubExportFlag ExportAbs ExportAbs = ExportAbs
161 *********************************************************
163 \subsection{Errors used *more than once* in the renamer}
165 *********************************************************
168 qualNameErr descriptor (name,locn)
169 = addShortErrLocLine locn ( \ sty ->
170 ppBesides [ppStr "invalid use of qualified ", ppStr descriptor, ppStr ": ", pprNonSym sty name ] )
172 dupNamesErr descriptor ((name1,locn1) : dup_things) sty
173 = ppAboves (item1 : map dup_item dup_things)
176 = addShortErrLocLine locn1 (\ sty ->
177 ppBesides [ppStr "multiple declarations of a ", ppStr descriptor, ppStr " `",
178 pprNonSym sty name1, ppStr "'" ]) sty
180 dup_item (name, locn)
181 = addShortErrLocLine locn (\ sty ->
182 ppBesides [ppStr "here was another declaration of `",
183 pprNonSym sty name, ppStr "'" ]) sty