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 )
13 import RnHsSyn ( RenamedHsModule, RenamedHsDecl, extractHsTyNames )
15 import CmdLineOpts ( opt_HiMap, opt_D_show_rn_trace,
16 opt_D_dump_rn, opt_D_show_rn_stats,
17 opt_WarnUnusedBinds, opt_WarnUnusedImports
20 import RnNames ( getGlobalNames )
21 import RnSource ( rnDecl )
22 import RnIfaces ( getImportedInstDecls, importDecl, getImportVersions, getSpecialInstModules,
24 mkSearchPath, getSlurpedNames, getRnStats
26 import RnEnv ( addImplicitOccsRn, availNames )
27 import Name ( Name, PrintUnqualified, Provenance, isLocallyDefined,
29 nameSetToList, minusNameSet,
31 nameModule, pprModule, pprOccName, nameOccName
33 import TysWiredIn ( unitTyCon, intTyCon, doubleTyCon )
34 import TyCon ( TyCon )
35 import PrelMods ( mAIN, pREL_MAIN )
36 import PrelInfo ( ioTyCon_NAME )
37 import ErrUtils ( pprBagOfErrors, pprBagOfWarnings,
38 doIfSet, dumpIfSet, ghcExit
40 import Bag ( isEmptyBag )
41 import FiniteMap ( fmToList, delListFromFM )
42 import UniqSupply ( UniqSupply )
43 import Util ( equivClasses )
44 import Maybes ( maybeToBool )
45 import List ( partition )
52 renameModule :: UniqSupply
55 ( RenamedHsModule -- Output, after renaming
56 , InterfaceDetails -- Interface; for interface file generatino
57 , RnNameSupply -- Final env; for renaming derivings
58 , [Module] -- Imported modules; for profiling
61 renameModule us this_mod@(HsModule mod_name vers exports imports fixities local_decls loc)
62 = -- Initialise the renamer monad
63 initRn mod_name us (mkSearchPath opt_HiMap) loc
65 \ (maybe_rn_stuff, rn_errs_bag, rn_warns_bag) ->
68 doIfSet (not (isEmptyBag rn_warns_bag))
69 (printErrs (pprBagOfWarnings rn_warns_bag)) >>
71 -- Check for errors; exit if so
72 doIfSet (not (isEmptyBag rn_errs_bag))
73 (printErrs (pprBagOfErrors rn_errs_bag) >>
77 -- Dump output, if any
78 (case maybe_rn_stuff of
80 Just results@(rn_mod, _, _, _)
81 -> dumpIfSet opt_D_dump_rn "Renamer:"
91 rename this_mod@(HsModule mod_name vers exports imports fixities local_decls loc)
92 = -- FIND THE GLOBAL NAME ENVIRONMENT
93 getGlobalNames this_mod `thenRn` \ maybe_stuff ->
95 -- CHECK FOR EARLY EXIT
96 if not (maybeToBool maybe_stuff) then
97 -- Everything is up to date; no need to recompile further
102 Just (export_env, rn_env, explicit_info, print_unqual) = maybe_stuff
106 initRnMS rn_env mod_name SourceMode (
107 addImplicits mod_name `thenRn_`
108 mapRn rnDecl local_decls
109 ) `thenRn` \ rn_local_decls ->
111 -- SLURP IN ALL THE NEEDED DECLARATIONS
112 slurpDecls print_unqual rn_local_decls `thenRn` \ rn_all_decls ->
114 -- EXIT IF ERRORS FOUND
115 checkErrsRn `thenRn` \ no_errs_so_far ->
116 if not no_errs_so_far then
117 -- Found errors already, so exit now
122 -- GENERATE THE VERSION/USAGE INFO
123 getImportVersions mod_name exports `thenRn` \ import_versions ->
124 getNameSupplyRn `thenRn` \ name_supply ->
126 -- REPORT UNUSED NAMES
127 reportUnusedNames export_env explicit_info `thenRn_`
129 -- GENERATE THE SPECIAL-INSTANCE MODULE LIST
130 -- The "special instance" modules are those modules that contain instance
131 -- declarations that contain no type constructor or class that was declared
133 getSpecialInstModules `thenRn` \ imported_special_inst_mods ->
135 special_inst_decls = [d | InstD d@(InstDecl inst_ty _ _ _ _) <- rn_local_decls,
136 all (not.isLocallyDefined) (nameSetToList (extractHsTyNames inst_ty))
138 special_inst_mods | null special_inst_decls = imported_special_inst_mods
139 | otherwise = mod_name : imported_special_inst_mods
143 -- RETURN THE RENAMED MODULE
145 import_mods = [mod | ImportDecl mod _ _ _ _ _ <- imports]
147 renamed_module = HsModule mod_name vers
148 trashed_exports trashed_imports trashed_fixities
152 rnStats rn_all_decls `thenRn_`
153 returnRn (Just (renamed_module,
154 (import_versions, export_env, special_inst_mods),
158 trashed_exports = {-trace "rnSource:trashed_exports"-} Nothing
159 trashed_imports = {-trace "rnSource:trashed_imports"-} []
160 trashed_fixities = []
163 @addImplicits@ forces the renamer to slurp in some things which aren't
164 mentioned explicitly, but which might be needed by the type checker.
167 addImplicits mod_name
168 = addImplicitOccsRn (implicit_main ++ default_tys)
170 -- Add occurrences for Int, Double, and (), because they
171 -- are the types to which ambigious type variables may be defaulted by
172 -- the type checker; so they won't every appear explicitly.
173 -- [The () one is a GHC extension for defaulting CCall results.]
174 default_tys = [getName intTyCon, getName doubleTyCon, getName unitTyCon ]
176 -- Add occurrences for IO or PrimIO
177 implicit_main | mod_name == mAIN
178 || mod_name == pREL_MAIN = [ioTyCon_NAME]
184 slurpDecls print_unqual decls
185 = -- First of all, get all the compulsory decls
186 slurp_compulsories decls `thenRn` \ decls1 ->
188 -- Next get the optional ones
189 closeDecls optional_mode decls1 `thenRn` \ decls2 ->
191 -- Finally get those deferred data type declarations
192 getDeferredDataDecls `thenRn` \ data_decls ->
193 mapRn (rn_data_decl compulsory_mode) data_decls `thenRn` \ rn_data_decls ->
196 returnRn (rn_data_decls ++ decls2)
199 compulsory_mode = InterfaceMode Compulsory print_unqual
200 optional_mode = InterfaceMode Optional print_unqual
202 -- The "slurp_compulsories" function is a loop that alternates
203 -- between slurping compulsory decls and slurping the instance
204 -- decls thus made relavant.
205 -- We *must* loop again here. Why? Two reasons:
206 -- (a) an instance decl will give rise to an unresolved dfun, whose
207 -- decl we must slurp to get its version number; that's the version
208 -- number for the whole instance decl. (And its unfolding might mention new
209 -- unresolved names.)
210 -- (b) an instance decl might give rise to a new unresolved class,
211 -- whose decl we must slurp, which might let in some new instance decls,
212 -- and so on. Example: instance Foo a => Baz [a] where ...
213 slurp_compulsories decls
214 = closeDecls compulsory_mode decls `thenRn` \ decls1 ->
216 -- Instance decls still pending?
217 getImportedInstDecls `thenRn` \ inst_decls ->
218 if null inst_decls then
222 -- Yes, there are some, so rename them and loop
223 traceRn (sep [ptext SLIT("Slurped"), int (length inst_decls), ptext SLIT("instance decls")])
225 mapRn (rn_inst_decl compulsory_mode) inst_decls `thenRn` \ new_inst_decls ->
226 slurp_compulsories (new_inst_decls ++ decls1)
230 closeDecls :: RnSMode
231 -> [RenamedHsDecl] -- Declarations got so far
232 -> RnMG [RenamedHsDecl] -- input + extra decls slurped
233 -- The monad includes a list of possibly-unresolved Names
234 -- This list is empty when closeDecls returns
236 closeDecls mode decls
237 = popOccurrenceName mode `thenRn` \ maybe_unresolved ->
238 case maybe_unresolved of
240 -- No more unresolved names
241 Nothing -> returnRn decls
243 -- An unresolved name
245 -> -- Slurp its declaration, if any
246 -- traceRn (sep [ptext SLIT("Considering"), ppr name_w_loc]) `thenRn_`
247 importDecl name_w_loc mode `thenRn` \ maybe_decl ->
250 -- No declaration... (wired in thing or optional)
251 Nothing -> closeDecls mode decls
253 -- Found a declaration... rename it
254 Just decl -> rn_iface_decl mod_name mode decl `thenRn` \ new_decl ->
255 closeDecls mode (new_decl : decls)
257 mod_name = nameModule (fst name_w_loc)
259 rn_iface_decl mod_name mode decl
260 = initRnMS emptyRnEnv mod_name mode (rnDecl decl)
262 rn_inst_decl mode (mod_name,decl) = rn_iface_decl mod_name mode (InstD decl)
263 rn_data_decl mode (tycon_name,ty_decl) = rn_iface_decl mod_name mode (TyD ty_decl)
265 mod_name = nameModule tycon_name
269 reportUnusedNames (ExportEnv export_avails _) explicit_info
270 | not (opt_WarnUnusedBinds || opt_WarnUnusedImports)
274 = getSlurpedNames `thenRn` \ slurped_names ->
276 unused_info :: FiniteMap Name HowInScope
277 unused_info = foldl delListFromFM
278 (delListFromFM explicit_info (nameSetToList slurped_names))
279 (map availNames export_avails)
280 unused_list = fmToList unused_info
282 groups = filter wanted (equivClasses cmp unused_list)
284 (name1, his1) `cmp` (name2, his2) = his1 `cmph` his2
286 (FromLocalDefn _) `cmph` (FromImportDecl _ _) = LT
287 (FromLocalDefn _) `cmph` (FromLocalDefn _) = EQ
288 (FromImportDecl m1 _) `cmph` (FromImportDecl m2 _) = m1 `compare` m2
291 wanted ((_,FromImportDecl _ _) : _) = opt_WarnUnusedImports
292 wanted ((_,FromLocalDefn _) : _) = opt_WarnUnusedImports
294 pp_imp = sep [text "Warning: the following are unused:",
295 nest 4 (vcat (map pp_group groups))]
297 pp_group group = sep [msg <> char ':',
298 nest 4 (sep (map (pprOccName . nameOccName . fst) group))]
304 FromImportDecl m _ -> text "Imported from" <+> pprModule m
305 FromLocalDefn _ -> text "Locally defined"
310 else addWarnRn pp_imp
312 rnStats :: [RenamedHsDecl] -> RnMG ()
314 | opt_D_show_rn_trace ||
315 opt_D_show_rn_stats ||
317 = getRnStats all_decls `thenRn` \ msg ->
318 ioToRnMG (printErrs msg) `thenRn_`
321 | otherwise = returnRn ()