2 % (c) The GRASP Project, Glasgow University, 1992-1996
4 \section[Rename]{Renaming and dependency analysis passes}
7 #include "HsVersions.h"
9 module Rename ( renameModule ) where
11 #if __GLASGOW_HASKELL__ <= 201
12 import PreludeGlaST ( thenPrimIO )
19 IMPORT_1_3(List(partition))
22 import RdrHsSyn ( RdrName(..), SYN_IE(RdrNameHsModule), SYN_IE(RdrNameImportDecl) )
23 import RnHsSyn ( SYN_IE(RenamedHsModule), SYN_IE(RenamedHsDecl), extractHsTyNames )
25 import CmdLineOpts ( opt_HiMap, opt_WarnNameShadowing, opt_D_show_rn_trace,
26 opt_D_dump_rn, opt_D_show_rn_stats,
27 opt_D_show_unused_imports, opt_PprUserLength
30 import RnNames ( getGlobalNames )
31 import RnSource ( rnDecl )
32 import RnIfaces ( getImportedInstDecls, importDecl, getImportVersions, getSpecialInstModules,
34 mkSearchPath, getSlurpedNames, getRnStats
36 import RnEnv ( availsToNameSet, addAvailToNameSet,
37 addImplicitOccsRn, lookupImplicitOccRn )
38 import Id ( GenId {- instance NamedThing -} )
39 import Name ( Name, Provenance, ExportFlag(..), isLocallyDefined,
40 NameSet(..), elemNameSet, mkNameSet, unionNameSets,
41 nameSetToList, minusNameSet, NamedThing(..),
42 nameModule, pprModule, pprOccName, nameOccName
44 import TysWiredIn ( unitTyCon, intTyCon, doubleTyCon )
45 import PrelInfo ( ioTyCon_NAME, primIoTyCon_NAME )
46 import TyCon ( TyCon )
47 import PrelMods ( mAIN, gHC_MAIN )
48 import ErrUtils ( SYN_IE(Error), SYN_IE(Warning) )
49 import FiniteMap ( emptyFM, eltsFM, fmToList, addToFM, FiniteMap )
51 import Outputable ( Outputable(..), PprStyle(..) )
52 import Util ( cmpPString, equivClasses, panic, assertPanic, pprTrace )
53 #if __GLASGOW_HASKELL__ >= 202
61 renameModule :: UniqSupply
63 -> IO (Maybe -- Nothing <=> everything up to date;
64 -- no ned to recompile any further
65 (RenamedHsModule, -- Output, after renaming
66 InterfaceDetails, -- Interface; for interface file generatino
67 RnNameSupply, -- Final env; for renaming derivings
68 [Module]), -- Imported modules; for profiling
76 renameModule us this_mod@(HsModule mod_name vers exports imports fixities local_decls loc)
77 = -- INITIALISE THE RENAMER MONAD
78 initRn mod_name us (mkSearchPath opt_HiMap) loc $
80 -- FIND THE GLOBAL NAME ENVIRONMENT
81 getGlobalNames this_mod `thenRn` \ global_name_info ->
83 case global_name_info of {
84 Nothing -> -- Everything is up to date; no need to recompile further
88 -- Otherwise, just carry on
89 Just (export_env, rn_env, explicit_names) ->
92 initRnMS rn_env mod_name SourceMode (
93 addImplicits mod_name `thenRn_`
94 mapRn rnDecl local_decls
95 ) `thenRn` \ rn_local_decls ->
97 -- SLURP IN ALL THE NEEDED DECLARATIONS
98 slurpDecls rn_local_decls `thenRn` \ rn_all_decls ->
101 -- GENERATE THE VERSION/USAGE INFO
102 getImportVersions mod_name exports `thenRn` \ import_versions ->
103 getNameSupplyRn `thenRn` \ name_supply ->
105 -- REPORT UNUSED NAMES
106 reportUnusedNames explicit_names `thenRn_`
108 -- GENERATE THE SPECIAL-INSTANCE MODULE LIST
109 -- The "special instance" modules are those modules that contain instance
110 -- declarations that contain no type constructor or class that was declared
112 getSpecialInstModules `thenRn` \ imported_special_inst_mods ->
114 special_inst_decls = [d | InstD d@(InstDecl inst_ty _ _ _ _) <- rn_local_decls,
115 all (not.isLocallyDefined) (nameSetToList (extractHsTyNames inst_ty))
117 special_inst_mods | null special_inst_decls = imported_special_inst_mods
118 | otherwise = mod_name : imported_special_inst_mods
122 -- RETURN THE RENAMED MODULE
124 import_mods = [mod | ImportDecl mod _ _ _ _ _ <- imports]
126 renamed_module = HsModule mod_name vers
127 trashed_exports trashed_imports trashed_fixities
131 rnStats rn_all_decls `thenRn_`
132 returnRn (Just (renamed_module,
133 (import_versions, export_env, special_inst_mods),
138 trashed_exports = {-trace "rnSource:trashed_exports"-} Nothing
139 trashed_imports = {-trace "rnSource:trashed_imports"-} []
140 trashed_fixities = []
143 @addImplicits@ forces the renamer to slurp in some things which aren't
144 mentioned explicitly, but which might be needed by the type checker.
147 addImplicits mod_name
148 = addImplicitOccsRn (implicit_main ++ default_tys)
150 -- Add occurrences for Int, Double, and (), because they
151 -- are the types to which ambigious type variables may be defaulted by
152 -- the type checker; so they won't every appear explicitly.
153 -- [The () one is a GHC extension for defaulting CCall results.]
154 default_tys = [getName intTyCon, getName doubleTyCon, getName unitTyCon]
156 -- Add occurrences for IO or PrimIO
157 implicit_main | mod_name == mAIN = [ioTyCon_NAME]
158 | mod_name == gHC_MAIN = [primIoTyCon_NAME]
165 = -- First of all, get all the compulsory decls
166 slurp_compulsories decls `thenRn` \ decls1 ->
168 -- Next get the optional ones
169 closeDecls Optional decls1 `thenRn` \ decls2 ->
171 -- Finally get those deferred data type declarations
172 getDeferredDataDecls `thenRn` \ data_decls ->
173 mapRn rn_data_decl data_decls `thenRn` \ rn_data_decls ->
176 returnRn (rn_data_decls ++ decls2)
179 -- The "slurp_compulsories" function is a loop that alternates
180 -- between slurping compulsory decls and slurping the instance
181 -- decls thus made relavant.
182 -- We *must* loop again here. Why? Two reasons:
183 -- (a) an instance decl will give rise to an unresolved dfun, whose
184 -- decl we must slurp to get its version number; that's the version
185 -- number for the whole instance decl. (And its unfolding might mention new
186 -- unresolved names.)
187 -- (b) an instance decl might give rise to a new unresolved class,
188 -- whose decl we must slurp, which might let in some new instance decls,
189 -- and so on. Example: instance Foo a => Baz [a] where ...
190 slurp_compulsories decls
191 = closeDecls Compulsory decls `thenRn` \ decls1 ->
193 -- Instance decls still pending?
194 getImportedInstDecls `thenRn` \ inst_decls ->
195 if null inst_decls then
199 -- Yes, there are some, so rename them and loop
200 traceRn (sep [ptext SLIT("Slurped"), int (length inst_decls), ptext SLIT("instance decls")])
202 mapRn rn_inst_decl inst_decls `thenRn` \ new_inst_decls ->
203 slurp_compulsories (new_inst_decls ++ decls1)
207 closeDecls :: Necessity
208 -> [RenamedHsDecl] -- Declarations got so far
209 -> RnMG [RenamedHsDecl] -- input + extra decls slurped
210 -- The monad includes a list of possibly-unresolved Names
211 -- This list is empty when closeDecls returns
213 closeDecls necessity decls
214 = popOccurrenceName necessity `thenRn` \ maybe_unresolved ->
215 case maybe_unresolved of
217 -- No more unresolved names
218 Nothing -> returnRn decls
220 -- An unresolved name
222 -> -- Slurp its declaration, if any
223 traceRn (sep [ptext SLIT("Considering"), ppr PprDebug name]) `thenRn_`
224 importDecl name necessity `thenRn` \ maybe_decl ->
227 -- No declaration... (wired in thing or optional)
228 Nothing -> closeDecls necessity decls
230 -- Found a declaration... rename it
231 Just decl -> rn_iface_decl mod_name necessity decl `thenRn` \ new_decl ->
232 closeDecls necessity (new_decl : decls)
234 mod_name = nameModule name
237 rn_iface_decl mod_name necessity decl -- Notice that the rnEnv starts empty
238 = initRnMS emptyRnEnv mod_name (InterfaceMode necessity) (rnDecl decl)
240 rn_inst_decl (mod_name,decl) = rn_iface_decl mod_name Compulsory (InstD decl)
242 rn_data_decl (tycon_name,ty_decl) = rn_iface_decl mod_name Compulsory (TyD ty_decl)
244 mod_name = nameModule tycon_name
248 reportUnusedNames explicit_avail_names
249 | not opt_D_show_unused_imports
253 = getSlurpedNames `thenRn` \ slurped_names ->
255 unused = explicit_avail_names `minusNameSet` slurped_names
256 (local_unused, imported_unused) = partition isLocallyDefined (nameSetToList unused)
257 imports_by_module = equivClasses cmp imported_unused
258 name1 `cmp` name2 = nameModule name1 `_CMP_STRING_` nameModule name2
260 pp_imp sty = sep [text "For information: the following unqualified imports are unused:",
261 nest 4 (vcat (map (pp_group sty) imports_by_module))]
262 pp_group sty (n:ns) = sep [hcat [text "Module ", pprModule (PprForUser opt_PprUserLength) (nameModule n), char ':'],
263 nest 4 (sep (map (pprOccName sty . nameOccName) (n:ns)))]
265 pp_local sty = sep [text "For information: the following local top-level definitions are unused:",
266 nest 4 (sep (map (pprOccName sty . nameOccName) local_unused))]
268 (if null imported_unused
270 else addWarnRn pp_imp) `thenRn_`
272 (if null local_unused
274 else addWarnRn pp_local)
276 rnStats :: [RenamedHsDecl] -> RnMG ()
278 | opt_D_show_rn_trace ||
279 opt_D_show_rn_stats ||
281 = getRnStats all_decls `thenRn` \ msg ->
282 ioToRnMG (hPutStr stderr (show msg) >>
283 hPutStr stderr "\n") `thenRn_`
286 | otherwise = returnRn ()