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), pprBagOfErrors,
49 doIfSet, dumpIfSet, ghcExit
51 import FiniteMap ( emptyFM, eltsFM, fmToList, addToFM, FiniteMap )
53 import Outputable ( Outputable(..), PprStyle(..),
54 pprErrorsStyle, pprDumpStyle, printErrs
56 import Bag ( isEmptyBag )
57 import Util ( cmpPString, equivClasses, panic, assertPanic, pprTrace )
58 #if __GLASGOW_HASKELL__ >= 202
66 renameModule :: UniqSupply
68 -> IO (Maybe (RenamedHsModule, -- Output, after renaming
69 InterfaceDetails, -- Interface; for interface file generatino
70 RnNameSupply, -- Final env; for renaming derivings
71 [Module])) -- Imported modules; for profiling
73 renameModule us this_mod@(HsModule mod_name vers exports imports fixities local_decls loc)
74 = -- Initialise the renamer monad
75 initRn mod_name us (mkSearchPath opt_HiMap) loc
77 \ (maybe_rn_stuff, rn_errs_bag, rn_warns_bag) ->
80 doIfSet (not (isEmptyBag rn_warns_bag))
81 (print_errs rn_warns_bag) >>
83 -- Check for errors; exit if so
84 doIfSet (not (isEmptyBag rn_errs_bag))
85 (print_errs rn_errs_bag >>
89 -- Dump output, if any
90 (case maybe_rn_stuff of
92 Just results@(rn_mod, _, _, _)
93 -> dumpIfSet opt_D_dump_rn "Renamer:"
94 (ppr pprDumpStyle rn_mod)
101 print_errs errs = printErrs (pprBagOfErrors pprErrorsStyle errs)
106 rename this_mod@(HsModule mod_name vers exports imports fixities local_decls loc)
107 = -- FIND THE GLOBAL NAME ENVIRONMENT
108 getGlobalNames this_mod `thenRn` \ global_name_info ->
110 case global_name_info of {
111 Nothing -> -- Everything is up to date; no need to recompile further
115 -- Otherwise, just carry on
116 Just (export_env, rn_env, explicit_names) ->
119 initRnMS rn_env mod_name SourceMode (
120 addImplicits mod_name `thenRn_`
121 mapRn rnDecl local_decls
122 ) `thenRn` \ rn_local_decls ->
124 -- SLURP IN ALL THE NEEDED DECLARATIONS
125 slurpDecls rn_local_decls `thenRn` \ rn_all_decls ->
128 -- GENERATE THE VERSION/USAGE INFO
129 getImportVersions mod_name exports `thenRn` \ import_versions ->
130 getNameSupplyRn `thenRn` \ name_supply ->
132 -- REPORT UNUSED NAMES
133 reportUnusedNames explicit_names `thenRn_`
135 -- GENERATE THE SPECIAL-INSTANCE MODULE LIST
136 -- The "special instance" modules are those modules that contain instance
137 -- declarations that contain no type constructor or class that was declared
139 getSpecialInstModules `thenRn` \ imported_special_inst_mods ->
141 special_inst_decls = [d | InstD d@(InstDecl inst_ty _ _ _ _) <- rn_local_decls,
142 all (not.isLocallyDefined) (nameSetToList (extractHsTyNames inst_ty))
144 special_inst_mods | null special_inst_decls = imported_special_inst_mods
145 | otherwise = mod_name : imported_special_inst_mods
149 -- RETURN THE RENAMED MODULE
151 import_mods = [mod | ImportDecl mod _ _ _ _ _ <- imports]
153 renamed_module = HsModule mod_name vers
154 trashed_exports trashed_imports trashed_fixities
158 rnStats rn_all_decls `thenRn_`
159 returnRn (Just (renamed_module,
160 (import_versions, export_env, special_inst_mods),
165 trashed_exports = {-trace "rnSource:trashed_exports"-} Nothing
166 trashed_imports = {-trace "rnSource:trashed_imports"-} []
167 trashed_fixities = []
170 @addImplicits@ forces the renamer to slurp in some things which aren't
171 mentioned explicitly, but which might be needed by the type checker.
174 addImplicits mod_name
175 = addImplicitOccsRn (implicit_main ++ default_tys)
177 -- Add occurrences for Int, Double, and (), because they
178 -- are the types to which ambigious type variables may be defaulted by
179 -- the type checker; so they won't every appear explicitly.
180 -- [The () one is a GHC extension for defaulting CCall results.]
181 default_tys = [getName intTyCon, getName doubleTyCon, getName unitTyCon]
183 -- Add occurrences for IO or PrimIO
184 implicit_main | mod_name == mAIN = [ioTyCon_NAME]
185 | mod_name == gHC_MAIN = [primIoTyCon_NAME]
192 = -- First of all, get all the compulsory decls
193 slurp_compulsories decls `thenRn` \ decls1 ->
195 -- Next get the optional ones
196 closeDecls Optional decls1 `thenRn` \ decls2 ->
198 -- Finally get those deferred data type declarations
199 getDeferredDataDecls `thenRn` \ data_decls ->
200 mapRn rn_data_decl data_decls `thenRn` \ rn_data_decls ->
203 returnRn (rn_data_decls ++ decls2)
206 -- The "slurp_compulsories" function is a loop that alternates
207 -- between slurping compulsory decls and slurping the instance
208 -- decls thus made relavant.
209 -- We *must* loop again here. Why? Two reasons:
210 -- (a) an instance decl will give rise to an unresolved dfun, whose
211 -- decl we must slurp to get its version number; that's the version
212 -- number for the whole instance decl. (And its unfolding might mention new
213 -- unresolved names.)
214 -- (b) an instance decl might give rise to a new unresolved class,
215 -- whose decl we must slurp, which might let in some new instance decls,
216 -- and so on. Example: instance Foo a => Baz [a] where ...
217 slurp_compulsories decls
218 = closeDecls Compulsory decls `thenRn` \ decls1 ->
220 -- Instance decls still pending?
221 getImportedInstDecls `thenRn` \ inst_decls ->
222 if null inst_decls then
226 -- Yes, there are some, so rename them and loop
227 traceRn (sep [ptext SLIT("Slurped"), int (length inst_decls), ptext SLIT("instance decls")])
229 mapRn rn_inst_decl inst_decls `thenRn` \ new_inst_decls ->
230 slurp_compulsories (new_inst_decls ++ decls1)
234 closeDecls :: Necessity
235 -> [RenamedHsDecl] -- Declarations got so far
236 -> RnMG [RenamedHsDecl] -- input + extra decls slurped
237 -- The monad includes a list of possibly-unresolved Names
238 -- This list is empty when closeDecls returns
240 closeDecls necessity decls
241 = popOccurrenceName necessity `thenRn` \ maybe_unresolved ->
242 case maybe_unresolved of
244 -- No more unresolved names
245 Nothing -> returnRn decls
247 -- An unresolved name
249 -> -- Slurp its declaration, if any
250 -- traceRn (sep [ptext SLIT("Considering"), ppr PprDebug name]) `thenRn_`
251 importDecl name necessity `thenRn` \ maybe_decl ->
254 -- No declaration... (wired in thing or optional)
255 Nothing -> closeDecls necessity decls
257 -- Found a declaration... rename it
258 Just decl -> rn_iface_decl mod_name necessity decl `thenRn` \ new_decl ->
259 closeDecls necessity (new_decl : decls)
261 mod_name = nameModule name
264 rn_iface_decl mod_name necessity decl -- Notice that the rnEnv starts empty
265 = initRnMS emptyRnEnv mod_name (InterfaceMode necessity) (rnDecl decl)
267 rn_inst_decl (mod_name,decl) = rn_iface_decl mod_name Compulsory (InstD decl)
269 rn_data_decl (tycon_name,ty_decl) = rn_iface_decl mod_name Compulsory (TyD ty_decl)
271 mod_name = nameModule tycon_name
275 reportUnusedNames explicit_avail_names
276 | not opt_D_show_unused_imports
280 = getSlurpedNames `thenRn` \ slurped_names ->
282 unused = explicit_avail_names `minusNameSet` slurped_names
283 (local_unused, imported_unused) = partition isLocallyDefined (nameSetToList unused)
284 imports_by_module = equivClasses cmp imported_unused
285 name1 `cmp` name2 = nameModule name1 `_CMP_STRING_` nameModule name2
287 pp_imp sty = sep [text "For information: the following unqualified imports are unused:",
288 nest 4 (vcat (map (pp_group sty) imports_by_module))]
289 pp_group sty (n:ns) = sep [hcat [text "Module ", pprModule (PprForUser opt_PprUserLength) (nameModule n), char ':'],
290 nest 4 (sep (map (pprOccName sty . nameOccName) (n:ns)))]
292 pp_local sty = sep [text "For information: the following local top-level definitions are unused:",
293 nest 4 (sep (map (pprOccName sty . nameOccName) local_unused))]
295 (if null imported_unused
297 else addWarnRn pp_imp) `thenRn_`
299 (if null local_unused
301 else addWarnRn pp_local)
303 rnStats :: [RenamedHsDecl] -> RnMG ()
305 | opt_D_show_rn_trace ||
306 opt_D_show_rn_stats ||
308 = getRnStats all_decls `thenRn` \ msg ->
309 ioToRnMG (printErrs msg) `thenRn_`
312 | otherwise = returnRn ()