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, NamedThing(..),
30 nameModule, pprModule, pprOccName, nameOccName
32 import TysWiredIn ( unitTyCon, intTyCon, doubleTyCon )
33 import TyCon ( TyCon )
34 import PrelMods ( mAIN, pREL_MAIN )
35 import PrelInfo ( ioTyCon_NAME )
36 import ErrUtils ( pprBagOfErrors, pprBagOfWarnings,
37 doIfSet, dumpIfSet, ghcExit
39 import Bag ( isEmptyBag )
40 import FiniteMap ( fmToList, delListFromFM )
41 import UniqSupply ( UniqSupply )
42 import Util ( equivClasses )
43 import Maybes ( maybeToBool )
44 import List ( partition )
51 renameModule :: UniqSupply
53 -> IO (Maybe (RenamedHsModule, -- Output, after renaming
54 InterfaceDetails, -- Interface; for interface file generatino
55 RnNameSupply, -- Final env; for renaming derivings
56 [Module])) -- Imported modules; for profiling
58 renameModule us this_mod@(HsModule mod_name vers exports imports fixities local_decls loc)
59 = -- Initialise the renamer monad
60 initRn mod_name us (mkSearchPath opt_HiMap) loc
62 \ (maybe_rn_stuff, rn_errs_bag, rn_warns_bag) ->
65 doIfSet (not (isEmptyBag rn_warns_bag))
66 (printErrs (pprBagOfWarnings rn_warns_bag)) >>
68 -- Check for errors; exit if so
69 doIfSet (not (isEmptyBag rn_errs_bag))
70 (printErrs (pprBagOfErrors rn_errs_bag) >>
74 -- Dump output, if any
75 (case maybe_rn_stuff of
77 Just results@(rn_mod, _, _, _)
78 -> dumpIfSet opt_D_dump_rn "Renamer:"
88 rename this_mod@(HsModule mod_name vers exports imports fixities local_decls loc)
89 = -- FIND THE GLOBAL NAME ENVIRONMENT
90 getGlobalNames this_mod `thenRn` \ maybe_stuff ->
92 -- CHECK FOR EARLY EXIT
93 if not (maybeToBool maybe_stuff) then
94 -- Everything is up to date; no need to recompile further
99 Just (export_env, rn_env, explicit_info, print_unqual) = maybe_stuff
103 initRnMS rn_env mod_name SourceMode (
104 addImplicits mod_name `thenRn_`
105 mapRn rnDecl local_decls
106 ) `thenRn` \ rn_local_decls ->
108 -- SLURP IN ALL THE NEEDED DECLARATIONS
109 slurpDecls print_unqual rn_local_decls `thenRn` \ rn_all_decls ->
111 -- EXIT IF ERRORS FOUND
112 checkErrsRn `thenRn` \ no_errs_so_far ->
113 if not no_errs_so_far then
114 -- Found errors already, so exit now
119 -- GENERATE THE VERSION/USAGE INFO
120 getImportVersions mod_name exports `thenRn` \ import_versions ->
121 getNameSupplyRn `thenRn` \ name_supply ->
123 -- REPORT UNUSED NAMES
124 reportUnusedNames export_env explicit_info `thenRn_`
126 -- GENERATE THE SPECIAL-INSTANCE MODULE LIST
127 -- The "special instance" modules are those modules that contain instance
128 -- declarations that contain no type constructor or class that was declared
130 getSpecialInstModules `thenRn` \ imported_special_inst_mods ->
132 special_inst_decls = [d | InstD d@(InstDecl inst_ty _ _ _ _) <- rn_local_decls,
133 all (not.isLocallyDefined) (nameSetToList (extractHsTyNames inst_ty))
135 special_inst_mods | null special_inst_decls = imported_special_inst_mods
136 | otherwise = mod_name : imported_special_inst_mods
140 -- RETURN THE RENAMED MODULE
142 import_mods = [mod | ImportDecl mod _ _ _ _ _ <- imports]
144 renamed_module = HsModule mod_name vers
145 trashed_exports trashed_imports trashed_fixities
149 rnStats rn_all_decls `thenRn_`
150 returnRn (Just (renamed_module,
151 (import_versions, export_env, special_inst_mods),
155 trashed_exports = {-trace "rnSource:trashed_exports"-} Nothing
156 trashed_imports = {-trace "rnSource:trashed_imports"-} []
157 trashed_fixities = []
160 @addImplicits@ forces the renamer to slurp in some things which aren't
161 mentioned explicitly, but which might be needed by the type checker.
164 addImplicits mod_name
165 = addImplicitOccsRn (implicit_main ++ default_tys)
167 -- Add occurrences for Int, Double, and (), because they
168 -- are the types to which ambigious type variables may be defaulted by
169 -- the type checker; so they won't every appear explicitly.
170 -- [The () one is a GHC extension for defaulting CCall results.]
171 default_tys = [getName intTyCon, getName doubleTyCon, getName unitTyCon ]
173 -- Add occurrences for IO or PrimIO
174 implicit_main | mod_name == mAIN
175 || mod_name == pREL_MAIN = [ioTyCon_NAME]
181 slurpDecls print_unqual decls
182 = -- First of all, get all the compulsory decls
183 slurp_compulsories decls `thenRn` \ decls1 ->
185 -- Next get the optional ones
186 closeDecls optional_mode decls1 `thenRn` \ decls2 ->
188 -- Finally get those deferred data type declarations
189 getDeferredDataDecls `thenRn` \ data_decls ->
190 mapRn (rn_data_decl compulsory_mode) data_decls `thenRn` \ rn_data_decls ->
193 returnRn (rn_data_decls ++ decls2)
196 compulsory_mode = InterfaceMode Compulsory print_unqual
197 optional_mode = InterfaceMode Optional print_unqual
199 -- The "slurp_compulsories" function is a loop that alternates
200 -- between slurping compulsory decls and slurping the instance
201 -- decls thus made relavant.
202 -- We *must* loop again here. Why? Two reasons:
203 -- (a) an instance decl will give rise to an unresolved dfun, whose
204 -- decl we must slurp to get its version number; that's the version
205 -- number for the whole instance decl. (And its unfolding might mention new
206 -- unresolved names.)
207 -- (b) an instance decl might give rise to a new unresolved class,
208 -- whose decl we must slurp, which might let in some new instance decls,
209 -- and so on. Example: instance Foo a => Baz [a] where ...
210 slurp_compulsories decls
211 = closeDecls compulsory_mode decls `thenRn` \ decls1 ->
213 -- Instance decls still pending?
214 getImportedInstDecls `thenRn` \ inst_decls ->
215 if null inst_decls then
219 -- Yes, there are some, so rename them and loop
220 traceRn (sep [ptext SLIT("Slurped"), int (length inst_decls), ptext SLIT("instance decls")])
222 mapRn (rn_inst_decl compulsory_mode) inst_decls `thenRn` \ new_inst_decls ->
223 slurp_compulsories (new_inst_decls ++ decls1)
227 closeDecls :: RnSMode
228 -> [RenamedHsDecl] -- Declarations got so far
229 -> RnMG [RenamedHsDecl] -- input + extra decls slurped
230 -- The monad includes a list of possibly-unresolved Names
231 -- This list is empty when closeDecls returns
233 closeDecls mode decls
234 = popOccurrenceName mode `thenRn` \ maybe_unresolved ->
235 case maybe_unresolved of
237 -- No more unresolved names
238 Nothing -> returnRn decls
240 -- An unresolved name
242 -> -- Slurp its declaration, if any
243 -- traceRn (sep [ptext SLIT("Considering"), ppr name_w_loc]) `thenRn_`
244 importDecl name_w_loc mode `thenRn` \ maybe_decl ->
247 -- No declaration... (wired in thing or optional)
248 Nothing -> closeDecls mode decls
250 -- Found a declaration... rename it
251 Just decl -> rn_iface_decl mod_name mode decl `thenRn` \ new_decl ->
252 closeDecls mode (new_decl : decls)
254 mod_name = nameModule (fst name_w_loc)
256 rn_iface_decl mod_name mode decl
257 = initRnMS emptyRnEnv mod_name mode (rnDecl decl)
259 rn_inst_decl mode (mod_name,decl) = rn_iface_decl mod_name mode (InstD decl)
260 rn_data_decl mode (tycon_name,ty_decl) = rn_iface_decl mod_name mode (TyD ty_decl)
262 mod_name = nameModule tycon_name
266 reportUnusedNames (ExportEnv export_avails _) explicit_info
267 | not (opt_WarnUnusedBinds || opt_WarnUnusedImports)
271 = getSlurpedNames `thenRn` \ slurped_names ->
273 unused_info :: FiniteMap Name HowInScope
274 unused_info = foldl delListFromFM
275 (delListFromFM explicit_info (nameSetToList slurped_names))
276 (map availNames export_avails)
277 unused_list = fmToList unused_info
279 groups = filter wanted (equivClasses cmp unused_list)
281 (name1, his1) `cmp` (name2, his2) = his1 `cmph` his2
283 (FromLocalDefn _) `cmph` (FromImportDecl _ _) = LT
284 (FromLocalDefn _) `cmph` (FromLocalDefn _) = EQ
285 (FromImportDecl m1 _) `cmph` (FromImportDecl m2 _) = m1 `compare` m2
288 wanted ((_,FromImportDecl _ _) : _) = opt_WarnUnusedImports
289 wanted ((_,FromLocalDefn _) : _) = opt_WarnUnusedImports
291 pp_imp = sep [text "Warning: the following are unused:",
292 nest 4 (vcat (map pp_group groups))]
294 pp_group group = sep [msg <> char ':',
295 nest 4 (sep (map (pprOccName . nameOccName . fst) group))]
301 FromImportDecl m _ -> text "Imported from" <+> pprModule m
302 FromLocalDefn _ -> text "Locally defined"
307 else addWarnRn pp_imp
309 rnStats :: [RenamedHsDecl] -> RnMG ()
311 | opt_D_show_rn_trace ||
312 opt_D_show_rn_stats ||
314 = getRnStats all_decls `thenRn` \ msg ->
315 ioToRnMG (printErrs msg) `thenRn_`
318 | otherwise = returnRn ()