2 % (c) The GRASP Project, Glasgow University, 1992-1996
4 \section[Rename]{Renaming and dependency analysis passes}
7 module Rename ( renameModule ) where
9 #include "HsVersions.h"
12 import RdrHsSyn ( RdrName(..), RdrNameHsModule, RdrNameImportDecl )
13 import RnHsSyn ( RenamedHsModule, RenamedHsDecl, extractHsTyNames )
15 import CmdLineOpts ( opt_HiMap, opt_WarnNameShadowing, opt_D_show_rn_trace,
16 opt_D_dump_rn, opt_D_show_rn_stats,
20 import RnNames ( getGlobalNames )
21 import RnSource ( rnDecl )
22 import RnIfaces ( getImportedInstDecls, importDecl, getImportVersions, getSpecialInstModules,
24 mkSearchPath, getSlurpedNames, getRnStats
26 import RnEnv ( availsToNameSet, addAvailToNameSet,
27 addImplicitOccsRn, lookupImplicitOccRn )
28 import Name ( Name, PrintUnqualified, Provenance, ExportFlag(..),
30 NameSet(..), elemNameSet, mkNameSet, unionNameSets,
31 nameSetToList, minusNameSet, NamedThing(..),
32 nameModule, pprModule, pprOccName, nameOccName
34 import TysWiredIn ( unitTyCon, intTyCon, doubleTyCon )
35 import TyCon ( TyCon )
36 import PrelMods ( mAIN, gHC_MAIN )
37 import PrelInfo ( ioTyCon_NAME )
38 import ErrUtils ( pprBagOfErrors, pprBagOfWarnings,
39 doIfSet, dumpIfSet, ghcExit
41 import FiniteMap ( emptyFM, eltsFM, fmToList, addToFM, FiniteMap )
42 import Bag ( isEmptyBag )
43 import UniqSupply ( UniqSupply )
44 import Util ( equivClasses )
45 import Maybes ( maybeToBool )
46 import List ( partition )
53 renameModule :: UniqSupply
55 -> IO (Maybe (RenamedHsModule, -- Output, after renaming
56 InterfaceDetails, -- Interface; for interface file generatino
57 RnNameSupply, -- Final env; for renaming derivings
58 [Module])) -- Imported modules; for profiling
60 renameModule us this_mod@(HsModule mod_name vers exports imports fixities local_decls loc)
61 = -- Initialise the renamer monad
62 initRn mod_name us (mkSearchPath opt_HiMap) loc
64 \ (maybe_rn_stuff, rn_errs_bag, rn_warns_bag) ->
67 doIfSet (not (isEmptyBag rn_warns_bag))
68 (printErrs (pprBagOfWarnings rn_warns_bag)) >>
70 -- Check for errors; exit if so
71 doIfSet (not (isEmptyBag rn_errs_bag))
72 (printErrs (pprBagOfErrors rn_errs_bag) >>
76 -- Dump output, if any
77 (case maybe_rn_stuff of
79 Just results@(rn_mod, _, _, _)
80 -> dumpIfSet opt_D_dump_rn "Renamer:"
90 rename this_mod@(HsModule mod_name vers exports imports fixities local_decls loc)
91 = -- FIND THE GLOBAL NAME ENVIRONMENT
92 getGlobalNames this_mod `thenRn` \ maybe_stuff ->
94 -- CHECK FOR EARLY EXIT
95 if not (maybeToBool maybe_stuff) then
96 -- Everything is up to date; no need to recompile further
101 Just (export_env, rn_env, explicit_names, print_unqual) = maybe_stuff
105 initRnMS rn_env mod_name SourceMode (
106 addImplicits mod_name `thenRn_`
107 mapRn rnDecl local_decls
108 ) `thenRn` \ rn_local_decls ->
110 -- SLURP IN ALL THE NEEDED DECLARATIONS
111 slurpDecls print_unqual rn_local_decls `thenRn` \ rn_all_decls ->
113 -- EXIT IF ERRORS FOUND
114 checkErrsRn `thenRn` \ no_errs_so_far ->
115 if not no_errs_so_far then
116 -- Found errors already, so exit now
121 -- GENERATE THE VERSION/USAGE INFO
122 getImportVersions mod_name exports `thenRn` \ import_versions ->
123 getNameSupplyRn `thenRn` \ name_supply ->
125 -- REPORT UNUSED NAMES
126 reportUnusedNames explicit_names `thenRn_`
128 -- GENERATE THE SPECIAL-INSTANCE MODULE LIST
129 -- The "special instance" modules are those modules that contain instance
130 -- declarations that contain no type constructor or class that was declared
132 getSpecialInstModules `thenRn` \ imported_special_inst_mods ->
134 special_inst_decls = [d | InstD d@(InstDecl inst_ty _ _ _ _) <- rn_local_decls,
135 all (not.isLocallyDefined) (nameSetToList (extractHsTyNames inst_ty))
137 special_inst_mods | null special_inst_decls = imported_special_inst_mods
138 | otherwise = mod_name : imported_special_inst_mods
142 -- RETURN THE RENAMED MODULE
144 import_mods = [mod | ImportDecl mod _ _ _ _ _ <- imports]
146 renamed_module = HsModule mod_name vers
147 trashed_exports trashed_imports trashed_fixities
151 rnStats rn_all_decls `thenRn_`
152 returnRn (Just (renamed_module,
153 (import_versions, export_env, special_inst_mods),
157 trashed_exports = {-trace "rnSource:trashed_exports"-} Nothing
158 trashed_imports = {-trace "rnSource:trashed_imports"-} []
159 trashed_fixities = []
162 @addImplicits@ forces the renamer to slurp in some things which aren't
163 mentioned explicitly, but which might be needed by the type checker.
166 addImplicits mod_name
167 = addImplicitOccsRn (implicit_main ++ default_tys)
169 -- Add occurrences for Int, Double, and (), because they
170 -- are the types to which ambigious type variables may be defaulted by
171 -- the type checker; so they won't every appear explicitly.
172 -- [The () one is a GHC extension for defaulting CCall results.]
173 default_tys = [getName intTyCon, getName doubleTyCon, getName unitTyCon ]
175 -- Add occurrences for IO or PrimIO
176 implicit_main | mod_name == mAIN
177 || mod_name == gHC_MAIN = [ioTyCon_NAME]
183 slurpDecls print_unqual decls
184 = -- First of all, get all the compulsory decls
185 slurp_compulsories decls `thenRn` \ decls1 ->
187 -- Next get the optional ones
188 closeDecls optional_mode decls1 `thenRn` \ decls2 ->
190 -- Finally get those deferred data type declarations
191 getDeferredDataDecls `thenRn` \ data_decls ->
192 mapRn (rn_data_decl compulsory_mode) data_decls `thenRn` \ rn_data_decls ->
195 returnRn (rn_data_decls ++ decls2)
198 compulsory_mode = InterfaceMode Compulsory print_unqual
199 optional_mode = InterfaceMode Optional print_unqual
201 -- The "slurp_compulsories" function is a loop that alternates
202 -- between slurping compulsory decls and slurping the instance
203 -- decls thus made relavant.
204 -- We *must* loop again here. Why? Two reasons:
205 -- (a) an instance decl will give rise to an unresolved dfun, whose
206 -- decl we must slurp to get its version number; that's the version
207 -- number for the whole instance decl. (And its unfolding might mention new
208 -- unresolved names.)
209 -- (b) an instance decl might give rise to a new unresolved class,
210 -- whose decl we must slurp, which might let in some new instance decls,
211 -- and so on. Example: instance Foo a => Baz [a] where ...
212 slurp_compulsories decls
213 = closeDecls compulsory_mode decls `thenRn` \ decls1 ->
215 -- Instance decls still pending?
216 getImportedInstDecls `thenRn` \ inst_decls ->
217 if null inst_decls then
221 -- Yes, there are some, so rename them and loop
222 traceRn (sep [ptext SLIT("Slurped"), int (length inst_decls), ptext SLIT("instance decls")])
224 mapRn (rn_inst_decl compulsory_mode) inst_decls `thenRn` \ new_inst_decls ->
225 slurp_compulsories (new_inst_decls ++ decls1)
229 closeDecls :: RnSMode
230 -> [RenamedHsDecl] -- Declarations got so far
231 -> RnMG [RenamedHsDecl] -- input + extra decls slurped
232 -- The monad includes a list of possibly-unresolved Names
233 -- This list is empty when closeDecls returns
235 closeDecls mode decls
236 = popOccurrenceName mode `thenRn` \ maybe_unresolved ->
237 case maybe_unresolved of
239 -- No more unresolved names
240 Nothing -> returnRn decls
242 -- An unresolved name
244 -> -- Slurp its declaration, if any
245 -- traceRn (sep [ptext SLIT("Considering"), ppr name_w_loc]) `thenRn_`
246 importDecl name_w_loc mode `thenRn` \ maybe_decl ->
249 -- No declaration... (wired in thing or optional)
250 Nothing -> closeDecls mode decls
252 -- Found a declaration... rename it
253 Just decl -> rn_iface_decl mod_name mode decl `thenRn` \ new_decl ->
254 closeDecls mode (new_decl : decls)
256 mod_name = nameModule (fst name_w_loc)
258 rn_iface_decl mod_name mode decl
259 = initRnMS emptyRnEnv mod_name mode (rnDecl decl)
261 rn_inst_decl mode (mod_name,decl) = rn_iface_decl mod_name mode (InstD decl)
262 rn_data_decl mode (tycon_name,ty_decl) = rn_iface_decl mod_name mode (TyD ty_decl)
264 mod_name = nameModule tycon_name
268 reportUnusedNames explicit_avail_names
269 | not opt_WarnUnusedNames
273 = getSlurpedNames `thenRn` \ slurped_names ->
275 unused = explicit_avail_names `minusNameSet` slurped_names
276 (local_unused, imported_unused) = partition isLocallyDefined (nameSetToList unused)
277 imports_by_module = equivClasses cmp imported_unused
278 name1 `cmp` name2 = nameModule name1 `compare` nameModule name2
280 pp_imp = sep [text "For information: the following unqualified imports are unused:",
281 nest 4 (vcat (map pp_group imports_by_module))]
282 pp_group (n:ns) = sep [hcat [text "Module ", pprModule (nameModule n), char ':'],
283 nest 4 (sep (map (pprOccName . nameOccName) (n:ns)))]
285 pp_local = sep [text "For information: the following local top-level definitions are unused:",
286 nest 4 (sep (map (pprOccName . nameOccName) local_unused))]
288 (if null imported_unused
290 else addWarnRn pp_imp) `thenRn_`
292 (if null local_unused
294 else addWarnRn pp_local)
296 rnStats :: [RenamedHsDecl] -> RnMG ()
298 | opt_D_show_rn_trace ||
299 opt_D_show_rn_stats ||
301 = getRnStats all_decls `thenRn` \ msg ->
302 ioToRnMG (printErrs msg) `thenRn_`
305 | otherwise = returnRn ()