X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=ghc%2Fcompiler%2Frename%2FRename.lhs;h=377e4baf06f4c77e7f5223488494ee19d836f31a;hb=00eefb90925f224c1e22963df2a00d70fe934d5f;hp=cea1ee7b4dbe9035cb7332596356da51a60f8b91;hpb=7e602b0a11e567fcb035d1afd34015aebcf9a577;p=ghc-hetmet.git diff --git a/ghc/compiler/rename/Rename.lhs b/ghc/compiler/rename/Rename.lhs index cea1ee7..377e4ba 100644 --- a/ghc/compiler/rename/Rename.lhs +++ b/ghc/compiler/rename/Rename.lhs @@ -1,327 +1,578 @@ -% -% (c) The GRASP Project, Glasgow University, 1992-1998 -% -\section[Rename]{Renaming and dependency analysis passes} - -\begin{code} -module Rename ( renameModule ) where - -#include "HsVersions.h" - -import HsSyn -import RdrHsSyn ( RdrName(..), RdrNameHsModule ) -import RnHsSyn ( RenamedHsModule, RenamedHsDecl, extractHsTyNames ) - -import CmdLineOpts ( opt_HiMap, opt_D_show_rn_trace, - opt_D_dump_rn, opt_D_show_rn_stats, - opt_WarnUnusedBinds, opt_WarnUnusedImports - ) -import RnMonad -import RnNames ( getGlobalNames ) -import RnSource ( rnIfaceDecl, rnSourceDecls ) -import RnIfaces ( getImportedInstDecls, importDecl, getImportVersions, getSpecialInstModules, - getDeferredDataDecls, - mkSearchPath, getSlurpedNames, getRnStats - ) -import RnEnv ( addImplicitOccsRn, availName, availNames, availsToNameSet, warnUnusedTopNames ) -import Name ( Name, isLocallyDefined, - NamedThing(..), ImportReason(..), Provenance(..), - nameModule, pprModule, pprOccName, nameOccName, - getNameProvenance - ) -import NameSet -import TyCon ( TyCon ) -import PrelMods ( mAIN, pREL_MAIN ) -import TysWiredIn ( unitTyCon, intTyCon, doubleTyCon ) -import PrelInfo ( ioTyCon_NAME, thinAirIdNames ) -import ErrUtils ( pprBagOfErrors, pprBagOfWarnings, - doIfSet, dumpIfSet, ghcExit - ) -import Bag ( isEmptyBag ) -import FiniteMap ( fmToList, delListFromFM ) -import UniqSupply ( UniqSupply ) -import Util ( equivClasses ) -import Maybes ( maybeToBool ) -import Outputable -\end{code} - - - -\begin{code} -renameModule :: UniqSupply - -> RdrNameHsModule - -> IO (Maybe - ( RenamedHsModule -- Output, after renaming - , InterfaceDetails -- Interface; for interface file generatino - , RnNameSupply -- Final env; for renaming derivings - , [Module] -- Imported modules; for profiling - )) - -renameModule us this_mod@(HsModule mod_name vers exports imports local_decls loc) - = -- Initialise the renamer monad - initRn mod_name us (mkSearchPath opt_HiMap) loc - (rename this_mod) >>= - \ (maybe_rn_stuff, rn_errs_bag, rn_warns_bag) -> - - -- Check for warnings - doIfSet (not (isEmptyBag rn_warns_bag)) - (printErrs (pprBagOfWarnings rn_warns_bag)) >> - - -- Check for errors; exit if so - doIfSet (not (isEmptyBag rn_errs_bag)) - (printErrs (pprBagOfErrors rn_errs_bag) >> - ghcExit 1 - ) >> - - -- Dump output, if any - (case maybe_rn_stuff of - Nothing -> return () - Just results@(rn_mod, _, _, _) - -> dumpIfSet opt_D_dump_rn "Renamer:" - (ppr rn_mod) - ) >> - - -- Return results - return maybe_rn_stuff -\end{code} - - -\begin{code} -rename this_mod@(HsModule mod_name vers exports imports local_decls loc) - = -- FIND THE GLOBAL NAME ENVIRONMENT - getGlobalNames this_mod `thenRn` \ maybe_stuff -> - - -- CHECK FOR EARLY EXIT - if not (maybeToBool maybe_stuff) then - -- Everything is up to date; no need to recompile further - rnStats [] `thenRn_` - returnRn Nothing - else - let - Just (export_env, rn_env, global_avail_env) = maybe_stuff - in - - -- RENAME THE SOURCE - initRnMS rn_env mod_name SourceMode ( - addImplicits mod_name `thenRn_` - rnSourceDecls local_decls - ) `thenRn` \ (rn_local_decls, fvs) -> - - -- SLURP IN ALL THE NEEDED DECLARATIONS - slurpDecls rn_local_decls `thenRn` \ rn_all_decls -> - - -- EXIT IF ERRORS FOUND - checkErrsRn `thenRn` \ no_errs_so_far -> - if not no_errs_so_far then - -- Found errors already, so exit now - rnStats [] `thenRn_` - returnRn Nothing - else - - -- GENERATE THE VERSION/USAGE INFO - getImportVersions mod_name exports `thenRn` \ import_versions -> - getNameSupplyRn `thenRn` \ name_supply -> - - -- REPORT UNUSED NAMES - reportUnusedNames rn_env global_avail_env - export_env - fvs `thenRn_` - - -- GENERATE THE SPECIAL-INSTANCE MODULE LIST - -- The "special instance" modules are those modules that contain instance - -- declarations that contain no type constructor or class that was declared - -- in that module. - getSpecialInstModules `thenRn` \ imported_special_inst_mods -> - let - special_inst_decls = [d | InstD d@(InstDecl inst_ty _ _ _ _) <- rn_local_decls, - all (not.isLocallyDefined) (nameSetToList (extractHsTyNames inst_ty)) - ] - special_inst_mods | null special_inst_decls = imported_special_inst_mods - | otherwise = mod_name : imported_special_inst_mods - in - - - -- RETURN THE RENAMED MODULE - let - import_mods = [mod | ImportDecl mod _ _ _ _ _ <- imports] - - renamed_module = HsModule mod_name vers - trashed_exports trashed_imports - rn_all_decls - loc - in - rnStats rn_all_decls `thenRn_` - returnRn (Just (renamed_module, - (import_versions, export_env, special_inst_mods), - name_supply, - import_mods)) - where - trashed_exports = {-trace "rnSource:trashed_exports"-} Nothing - trashed_imports = {-trace "rnSource:trashed_imports"-} [] -\end{code} - -@addImplicits@ forces the renamer to slurp in some things which aren't -mentioned explicitly, but which might be needed by the type checker. - -\begin{code} -addImplicits mod_name - = addImplicitOccsRn (implicit_main ++ default_tys ++ thinAirIdNames) - where - -- Add occurrences for Int, Double, and (), because they - -- are the types to which ambigious type variables may be defaulted by - -- the type checker; so they won't always appear explicitly. - -- [The () one is a GHC extension for defaulting CCall results.] - default_tys = [getName intTyCon, getName doubleTyCon, getName unitTyCon ] - - -- Add occurrences for IO or PrimIO - implicit_main | mod_name == mAIN - || mod_name == pREL_MAIN = [ioTyCon_NAME] - | otherwise = [] -\end{code} - - -\begin{code} -slurpDecls decls - = -- First of all, get all the compulsory decls - slurp_compulsories decls `thenRn` \ decls1 -> - - -- Next get the optional ones - closeDecls optional_mode decls1 `thenRn` \ decls2 -> - - -- Finally get those deferred data type declarations - getDeferredDataDecls `thenRn` \ data_decls -> - mapRn (rn_data_decl compulsory_mode) data_decls `thenRn` \ rn_data_decls -> - - -- Done - returnRn (rn_data_decls ++ decls2) - - where - compulsory_mode = InterfaceMode Compulsory - optional_mode = InterfaceMode Optional - - -- The "slurp_compulsories" function is a loop that alternates - -- between slurping compulsory decls and slurping the instance - -- decls thus made relavant. - -- We *must* loop again here. Why? Two reasons: - -- (a) an instance decl will give rise to an unresolved dfun, whose - -- decl we must slurp to get its version number; that's the version - -- number for the whole instance decl. (And its unfolding might mention new - -- unresolved names.) - -- (b) an instance decl might give rise to a new unresolved class, - -- whose decl we must slurp, which might let in some new instance decls, - -- and so on. Example: instance Foo a => Baz [a] where ... - slurp_compulsories decls - = closeDecls compulsory_mode decls `thenRn` \ decls1 -> - - -- Instance decls still pending? - getImportedInstDecls `thenRn` \ inst_decls -> - if null inst_decls then - -- No, none - returnRn decls1 - else - -- Yes, there are some, so rename them and loop - traceRn (sep [ptext SLIT("Slurped"), int (length inst_decls), ptext SLIT("instance decls")]) - `thenRn_` - mapRn (rn_inst_decl compulsory_mode) inst_decls `thenRn` \ new_inst_decls -> - slurp_compulsories (new_inst_decls ++ decls1) -\end{code} - -\begin{code} -closeDecls :: RnSMode - -> [RenamedHsDecl] -- Declarations got so far - -> RnMG [RenamedHsDecl] -- input + extra decls slurped - -- The monad includes a list of possibly-unresolved Names - -- This list is empty when closeDecls returns - -closeDecls mode decls - = popOccurrenceName mode `thenRn` \ maybe_unresolved -> - case maybe_unresolved of - - -- No more unresolved names - Nothing -> returnRn decls - - -- An unresolved name - Just name_w_loc - -> -- Slurp its declaration, if any --- traceRn (sep [ptext SLIT("Considering"), ppr name_w_loc]) `thenRn_` - importDecl name_w_loc mode `thenRn` \ maybe_decl -> - case maybe_decl of - - -- No declaration... (wired in thing or optional) - Nothing -> closeDecls mode decls - - -- Found a declaration... rename it - Just decl -> rn_iface_decl mod_name mode decl `thenRn` \ new_decl -> - closeDecls mode (new_decl : decls) - where - mod_name = nameModule (fst name_w_loc) - -rn_iface_decl mod_name mode decl - = initRnMS emptyRnEnv mod_name mode (rnIfaceDecl decl) - -rn_inst_decl mode (mod_name,decl) = rn_iface_decl mod_name mode (InstD decl) -rn_data_decl mode (mod_name,ty_decl) = rn_iface_decl mod_name mode (TyClD ty_decl) -\end{code} - -\begin{code} -reportUnusedNames (RnEnv gbl_env _) avail_env (ExportEnv export_avails _) mentioned_names - | not (opt_WarnUnusedBinds || opt_WarnUnusedImports) - = returnRn () - - | otherwise - = let - used_names = mentioned_names `unionNameSets` availsToNameSet export_avails - - -- Now, a use of C implies a use of T, - -- if C was brought into scope by T(..) or T(C) - really_used_names = used_names `unionNameSets` - mkNameSet [ availName avail - | sub_name <- nameSetToList used_names, - let avail = case lookupNameEnv avail_env sub_name of - Just avail -> avail - Nothing -> pprTrace "r.u.n" (ppr sub_name) $ - Avail sub_name - ] - - defined_names = mkNameSet (concat (rdrEnvElts gbl_env)) - defined_but_not_used = defined_names `minusNameSet` really_used_names - - -- Filter out the ones only defined implicitly - bad_guys = filter is_explicit (nameSetToList defined_but_not_used) - is_explicit n = case getNameProvenance n of - LocalDef _ _ -> True - NonLocalDef (UserImport _ _ explicit) _ _ -> explicit - other -> False - - -- Now group by whether locally defined or imported; - -- one group is the locally-defined ones, one group per import module - groups = equivClasses cmp bad_guys - where - name1 `cmp` name2 = getNameProvenance name1 `cmph` getNameProvenance name2 - - cmph (LocalDef _ _) (NonLocalDef _ _ _) = LT - cmph (LocalDef _ _) (LocalDef _ _) = EQ - cmph (NonLocalDef (UserImport m1 _ _) _ _) - (NonLocalDef (UserImport m2 _ _) _ _) - = m1 `compare` m2 - cmph (NonLocalDef _ _ _) (LocalDef _ _) = GT - -- In-scope NonLocalDefs must have UserImport info on them - - -- ToDo: report somehow on T(..) things where no constructors - -- are imported - in - mapRn warnUnusedTopNames groups `thenRn_` - returnRn () - -rnStats :: [RenamedHsDecl] -> RnMG () -rnStats all_decls - | opt_D_show_rn_trace || - opt_D_show_rn_stats || - opt_D_dump_rn - = getRnStats all_decls `thenRn` \ msg -> - ioToRnMG (printErrs msg) `thenRn_` - returnRn () - - | otherwise = returnRn () -\end{code} - +% +% (c) The GRASP Project, Glasgow University, 1992-1998 +% +\section[Rename]{Renaming and dependency analysis passes} + +\begin{code} +module Rename ( renameModule ) where + +#include "HsVersions.h" + +import HsSyn +import RdrHsSyn ( RdrNameHsModule ) +import RnHsSyn ( RenamedHsModule, RenamedHsDecl, + extractHsTyNames, extractHsCtxtTyNames + ) + +import CmdLineOpts ( opt_HiMap, opt_D_dump_rn_trace, + opt_D_dump_rn, opt_D_dump_rn_stats, + opt_WarnUnusedBinds, opt_WarnUnusedImports + ) +import RnMonad +import RnNames ( getGlobalNames ) +import RnSource ( rnSourceDecls, rnDecl ) +import RnIfaces ( getImportedInstDecls, importDecl, getImportVersions, + getImportedRules, loadHomeInterface, getSlurped + ) +import RnEnv ( availName, availNames, availsToNameSet, + warnUnusedTopNames, mapFvRn, + FreeVars, plusFVs, plusFV, unitFV, emptyFVs, isEmptyFVs + ) +import Module ( Module, ModuleName, pprModule, mkSearchPath, mkThisModule ) +import Name ( Name, isLocallyDefined, + NamedThing(..), ImportReason(..), Provenance(..), + pprOccName, nameOccName, + getNameProvenance, occNameUserString, + maybeWiredInTyConName, maybeWiredInIdName, isWiredInName + ) +import Id ( idType ) +import DataCon ( dataConTyCon, dataConType ) +import TyCon ( TyCon, tyConDataCons, isSynTyCon, getSynTyConDefn ) +import RdrName ( RdrName ) +import NameSet +import PrelMods ( mAIN_Name, pREL_MAIN_Name ) +import TysWiredIn ( unitTyCon, intTyCon, doubleTyCon, boolTyCon ) +import PrelInfo ( ioTyCon_NAME, thinAirIdNames ) +import Type ( namesOfType, funTyCon ) +import ErrUtils ( pprBagOfErrors, pprBagOfWarnings, + doIfSet, dumpIfSet, ghcExit + ) +import BasicTypes ( NewOrData(..) ) +import Bag ( isEmptyBag, bagToList ) +import FiniteMap ( fmToList, delListFromFM, addToFM, sizeFM, eltsFM ) +import UniqSupply ( UniqSupply ) +import Util ( equivClasses ) +import Maybes ( maybeToBool ) +import Outputable +\end{code} + + + +\begin{code} +renameModule :: UniqSupply + -> RdrNameHsModule + -> IO (Maybe + ( Module + , RenamedHsModule -- Output, after renaming + , InterfaceDetails -- Interface; for interface file generation + , RnNameSupply -- Final env; for renaming derivings + , [ModuleName] -- Imported modules; for profiling + )) + +renameModule us this_mod@(HsModule mod_name vers exports imports local_decls loc) + = -- Initialise the renamer monad + initRn mod_name us (mkSearchPath opt_HiMap) loc + (rename this_mod) >>= + \ (maybe_rn_stuff, rn_errs_bag, rn_warns_bag) -> + + -- Check for warnings + doIfSet (not (isEmptyBag rn_warns_bag)) + (printErrs (pprBagOfWarnings rn_warns_bag)) >> + + -- Check for errors; exit if so + doIfSet (not (isEmptyBag rn_errs_bag)) + (printErrs (pprBagOfErrors rn_errs_bag) >> + ghcExit 1 + ) >> + + -- Dump output, if any + (case maybe_rn_stuff of + Nothing -> return () + Just results@(_, rn_mod, _, _, _) + -> dumpIfSet opt_D_dump_rn "Renamer:" + (ppr rn_mod) + ) >> + + -- Return results + return maybe_rn_stuff +\end{code} + + +\begin{code} +rename this_mod@(HsModule mod_name vers exports imports local_decls loc) + = -- FIND THE GLOBAL NAME ENVIRONMENT + getGlobalNames this_mod `thenRn` \ maybe_stuff -> + + -- CHECK FOR EARLY EXIT + if not (maybeToBool maybe_stuff) then + -- Everything is up to date; no need to recompile further + rnStats [] `thenRn_` + returnRn Nothing + else + let + Just (export_env, gbl_env, fixity_env, global_avail_env) = maybe_stuff + in + + -- RENAME THE SOURCE + initRnMS gbl_env fixity_env SourceMode ( + rnSourceDecls local_decls + ) `thenRn` \ (rn_local_decls, source_fvs) -> + + -- SLURP IN ALL THE NEEDED DECLARATIONS + let + real_source_fvs = implicitFVs mod_name `plusFV` source_fvs + -- It's important to do the "plus" this way round, so that + -- when compiling the prelude, locally-defined (), Bool, etc + -- override the implicit ones. + in + slurpImpDecls real_source_fvs `thenRn` \ rn_imp_decls -> + + -- EXIT IF ERRORS FOUND + checkErrsRn `thenRn` \ no_errs_so_far -> + if not no_errs_so_far then + -- Found errors already, so exit now + rnStats [] `thenRn_` + returnRn Nothing + else + + -- GENERATE THE VERSION/USAGE INFO + getImportVersions mod_name exports `thenRn` \ my_usages -> + getNameSupplyRn `thenRn` \ name_supply -> + + -- REPORT UNUSED NAMES + reportUnusedNames gbl_env global_avail_env + export_env + source_fvs `thenRn_` + + -- RETURN THE RENAMED MODULE + let + has_orphans = any isOrphanDecl rn_local_decls + direct_import_mods = [mod | ImportDecl mod _ _ _ _ _ <- imports] + rn_all_decls = rn_imp_decls ++ rn_local_decls + renamed_module = HsModule mod_name vers + trashed_exports trashed_imports + rn_all_decls + loc + in + rnStats rn_imp_decls `thenRn_` + returnRn (Just (mkThisModule mod_name, + renamed_module, + (has_orphans, my_usages, export_env), + name_supply, + direct_import_mods)) + where + trashed_exports = {-trace "rnSource:trashed_exports"-} Nothing + trashed_imports = {-trace "rnSource:trashed_imports"-} [] +\end{code} + +@implicitFVs@ forces the renamer to slurp in some things which aren't +mentioned explicitly, but which might be needed by the type checker. + +\begin{code} +implicitFVs mod_name + = implicit_main `plusFV` + mkNameSet default_tys `plusFV` + mkNameSet thinAirIdNames + where + -- Add occurrences for Int, Double, and (), because they + -- are the types to which ambigious type variables may be defaulted by + -- the type checker; so they won't always appear explicitly. + -- [The () one is a GHC extension for defaulting CCall results.] + -- ALSO: funTyCon, since it occurs implicitly everywhere! + -- (we don't want to be bothered with making funTyCon a + -- free var at every function application!) + default_tys = [getName intTyCon, getName doubleTyCon, + getName unitTyCon, getName funTyCon, getName boolTyCon] + + -- Add occurrences for IO or PrimIO + implicit_main | mod_name == mAIN_Name + || mod_name == pREL_MAIN_Name = unitFV ioTyCon_NAME + | otherwise = emptyFVs +\end{code} + +\begin{code} +isOrphanDecl (InstD (InstDecl inst_ty _ _ _ _)) + = not (foldNameSet ((||) . isLocallyDefined) False (extractHsTyNames inst_ty)) +isOrphanDecl (RuleD (RuleDecl _ _ _ lhs _ _)) + = check lhs + where + check (HsVar v) = not (isLocallyDefined v) + check (HsApp f a) = check f && check a + check other = True +isOrphanDecl other = False +\end{code} + + +%********************************************************* +%* * +\subsection{Slurping declarations} +%* * +%********************************************************* + +\begin{code} +------------------------------------------------------- +slurpImpDecls source_fvs + = traceRn (text "slurpImp" <+> fsep (map ppr (nameSetToList source_fvs))) `thenRn_` + + -- The current slurped-set records all local things + getSlurped `thenRn` \ source_binders -> + slurpSourceRefs source_binders source_fvs `thenRn` \ (decls1, needed1, inst_gates) -> + + -- Now we can get the instance decls + slurpInstDecls decls1 needed1 inst_gates `thenRn` \ (decls2, needed2) -> + + -- And finally get everything else + closeDecls decls2 needed2 + +------------------------------------------------------- +slurpSourceRefs :: NameSet -- Variables defined in source + -> FreeVars -- Variables referenced in source + -> RnMG ([RenamedHsDecl], + FreeVars, -- Un-satisfied needs + FreeVars) -- "Gates" +-- The declaration (and hence home module) of each gate has +-- already been loaded + +slurpSourceRefs source_binders source_fvs + = go [] -- Accumulating decls + emptyFVs -- Unsatisfied needs + source_fvs -- Accumulating gates + (nameSetToList source_fvs) -- Gates whose defn hasn't been loaded yet + where + go decls fvs gates [] + = returnRn (decls, fvs, gates) + + go decls fvs gates (wanted_name:refs) + | isWiredInName wanted_name + = load_home wanted_name `thenRn_` + go decls fvs (gates `plusFV` getWiredInGates wanted_name) refs + + | otherwise + = importDecl wanted_name `thenRn` \ maybe_decl -> + case maybe_decl of + -- No declaration... (already slurped, or local) + Nothing -> go decls fvs gates refs + Just decl -> rnIfaceDecl decl `thenRn` \ (new_decl, fvs1) -> + let + new_gates = getGates source_fvs new_decl + in + go (new_decl : decls) + (fvs1 `plusFV` fvs) + (gates `plusFV` new_gates) + (nameSetToList new_gates ++ refs) + + -- When we find a wired-in name we must load its + -- home module so that we find any instance decls therein + load_home name + | name `elemNameSet` source_binders = returnRn () + -- When compiling the prelude, a wired-in thing may + -- be defined in this module, in which case we don't + -- want to load its home module! + -- Using 'isLocallyDefined' doesn't work because some of + -- the free variables returned are simply 'listTyCon_Name', + -- with a system provenance. We could look them up every time + -- but that seems a waste. + | otherwise = loadHomeInterface doc name `thenRn_` + returnRn () + where + doc = ptext SLIT("need home module for wired in thing") <+> ppr name + +------------------------------------------------------- +-- slurpInstDecls imports appropriate instance decls. +-- It has to incorporate a loop, because consider +-- instance Foo a => Baz (Maybe a) where ... +-- It may be that Baz and Maybe are used in the source module, +-- but not Foo; so we need to chase Foo too. + +slurpInstDecls decls needed gates + | isEmptyFVs gates + = returnRn (decls, needed) + + | otherwise + = getImportedInstDecls gates `thenRn` \ inst_decls -> + rnInstDecls decls needed emptyFVs inst_decls `thenRn` \ (decls1, needed1, gates1) -> + slurpInstDecls decls1 needed1 gates1 + where + rnInstDecls decls fvs gates [] + = returnRn (decls, fvs, gates) + rnInstDecls decls fvs gates (d:ds) + = rnIfaceDecl d `thenRn` \ (new_decl, fvs1) -> + rnInstDecls (new_decl:decls) + (fvs1 `plusFV` fvs) + (gates `plusFV` getInstDeclGates new_decl) + ds + + +------------------------------------------------------- +-- closeDecls keeps going until the free-var set is empty +closeDecls decls needed + | not (isEmptyFVs needed) + = slurpDecls decls needed `thenRn` \ (decls1, needed1) -> + closeDecls decls1 needed1 + + | otherwise + = getImportedRules `thenRn` \ rule_decls -> + case rule_decls of + [] -> returnRn decls -- No new rules, so we are done + other -> rnIfaceDecls decls emptyFVs rule_decls `thenRn` \ (decls1, needed1) -> + closeDecls decls1 needed1 + + +------------------------------------------------------- +rnIfaceDecls :: [RenamedHsDecl] -> FreeVars + -> [(Module, RdrNameHsDecl)] + -> RnM d ([RenamedHsDecl], FreeVars) +rnIfaceDecls decls fvs [] = returnRn (decls, fvs) +rnIfaceDecls decls fvs (d:ds) = rnIfaceDecl d `thenRn` \ (new_decl, fvs1) -> + rnIfaceDecls (new_decl:decls) (fvs1 `plusFV` fvs) ds + +rnIfaceDecl (mod, decl) = initIfaceRnMS mod (rnDecl decl) + + +------------------------------------------------------- +-- Augment decls with any decls needed by needed. +-- Return also free vars of the new decls (only) +slurpDecls decls needed + = go decls emptyFVs (nameSetToList needed) + where + go decls fvs [] = returnRn (decls, fvs) + go decls fvs (ref:refs) = slurpDecl decls fvs ref `thenRn` \ (decls1, fvs1) -> + go decls1 fvs1 refs + +------------------------------------------------------- +slurpDecl decls fvs wanted_name + = importDecl wanted_name `thenRn` \ maybe_decl -> + case maybe_decl of + -- No declaration... (wired in thing) + Nothing -> returnRn (decls, fvs) + + -- Found a declaration... rename it + Just decl -> rnIfaceDecl decl `thenRn` \ (new_decl, fvs1) -> + returnRn (new_decl:decls, fvs1 `plusFV` fvs) +\end{code} + + +%********************************************************* +%* * +\subsection{Extracting the 'gates'} +%* * +%********************************************************* + +When we import a declaration like + + data T = T1 Wibble | T2 Wobble + +we don't want to treat Wibble and Wobble as gates *unless* T1, T2 +respectively are mentioned by the user program. If only T is mentioned +we want only T to be a gate; that way we don't suck in useless instance +decls for (say) Eq Wibble, when they can't possibly be useful. + +@getGates@ takes a newly imported (and renamed) decl, and the free +vars of the source program, and extracts from the decl the gate names. + +\begin{code} +getGates source_fvs (SigD (IfaceSig _ ty _ _)) + = extractHsTyNames ty + +getGates source_fvs (TyClD (ClassDecl ctxt cls tvs sigs _ _ _ _ _ _)) + = delListFromNameSet (foldr (plusFV . get) (extractHsCtxtTyNames ctxt) sigs) + (map getTyVarName tvs) + `addOneToNameSet` cls + where + get (ClassOpSig n _ ty _) + | n `elemNameSet` source_fvs = extractHsTyNames ty + | otherwise = emptyFVs + +getGates source_fvs (TyClD (TySynonym tycon tvs ty _)) + = delListFromNameSet (extractHsTyNames ty) + (map getTyVarName tvs) + -- A type synonym type constructor isn't a "gate" for instance decls + +getGates source_fvs (TyClD (TyData _ ctxt tycon tvs cons _ _ _)) + = delListFromNameSet (foldr (plusFV . get) (extractHsCtxtTyNames ctxt) cons) + (map getTyVarName tvs) + `addOneToNameSet` tycon + where + get (ConDecl n tvs ctxt details _) + | n `elemNameSet` source_fvs + -- If the constructor is method, get fvs from all its fields + = delListFromNameSet (get_details details `plusFV` + extractHsCtxtTyNames ctxt) + (map getTyVarName tvs) + get (ConDecl n tvs ctxt (RecCon fields) _) + -- Even if the constructor isn't mentioned, the fields + -- might be, as selectors. They can't mention existentially + -- bound tyvars (typechecker checks for that) so no need for + -- the deleteListFromNameSet part + = foldr (plusFV . get_field) emptyFVs fields + + get other_con = emptyFVs + + get_details (VanillaCon tys) = plusFVs (map get_bang tys) + get_details (InfixCon t1 t2) = get_bang t1 `plusFV` get_bang t2 + get_details (RecCon fields) = plusFVs [get_bang t | (_, t) <- fields] + get_details (NewCon t _) = extractHsTyNames t + + get_field (fs,t) | any (`elemNameSet` source_fvs) fs = get_bang t + | otherwise = emptyFVs + + get_bang (Banged t) = extractHsTyNames t + get_bang (Unbanged t) = extractHsTyNames t + get_bang (Unpacked t) = extractHsTyNames t + +getGates source_fvs other_decl = emptyFVs +\end{code} + +getWiredInGates is just like getGates, but it sees a wired-in Name +rather than a declaration. + +\begin{code} +getWiredInGates :: Name -> FreeVars +getWiredInGates name -- No classes are wired in + | is_id = getWiredInGates_s (namesOfType (idType the_id)) + | isSynTyCon the_tycon = getWiredInGates_s (delListFromNameSet (namesOfType ty) (map getName tyvars)) + | otherwise = unitFV name + where + maybe_wired_in_id = maybeWiredInIdName name + is_id = maybeToBool maybe_wired_in_id + maybe_wired_in_tycon = maybeWiredInTyConName name + Just the_id = maybe_wired_in_id + Just the_tycon = maybe_wired_in_tycon + (tyvars,ty) = getSynTyConDefn the_tycon + +getWiredInGates_s names = foldr (plusFV . getWiredInGates) emptyFVs (nameSetToList names) +\end{code} + +\begin{code} +getInstDeclGates (InstD (InstDecl inst_ty _ _ _ _)) = extractHsTyNames inst_ty +getInstDeclGates other = emptyFVs +\end{code} + + +%********************************************************* +%* * +\subsection{Unused names} +%* * +%********************************************************* + +\begin{code} +reportUnusedNames gbl_env avail_env (ExportEnv export_avails _) mentioned_names + | not (opt_WarnUnusedBinds || opt_WarnUnusedImports) + = returnRn () + + | otherwise + = let + used_names = mentioned_names `unionNameSets` availsToNameSet export_avails + + -- Now, a use of C implies a use of T, + -- if C was brought into scope by T(..) or T(C) + really_used_names = used_names `unionNameSets` + mkNameSet [ availName avail + | sub_name <- nameSetToList used_names, + let avail = case lookupNameEnv avail_env sub_name of + Just avail -> avail + Nothing -> pprTrace "r.u.n" (ppr sub_name) $ + Avail sub_name + ] + + defined_names = mkNameSet (concat (rdrEnvElts gbl_env)) + defined_but_not_used = nameSetToList (defined_names `minusNameSet` really_used_names) + + -- Filter out the ones only defined implicitly + bad_guys = filter reportableUnusedName defined_but_not_used + in + warnUnusedTopNames bad_guys `thenRn_` + returnRn () + +reportableUnusedName :: Name -> Bool +reportableUnusedName name + = explicitlyImported (getNameProvenance name) && + not (startsWithUnderscore (occNameUserString (nameOccName name))) + where + explicitlyImported (LocalDef _ _) = True -- Report unused defns of local vars + explicitlyImported (NonLocalDef (UserImport _ _ expl) _) = expl -- Report unused explicit imports + explicitlyImported other = False -- Don't report others + + -- Haskell 98 encourages compilers to suppress warnings about + -- unused names in a pattern if they start with "_". + startsWithUnderscore ('_' : _) = True -- Suppress warnings for names starting + startsWithUnderscore other = False -- with an underscore + +rnStats :: [RenamedHsDecl] -> RnMG () +rnStats imp_decls + | opt_D_dump_rn_trace || + opt_D_dump_rn_stats || + opt_D_dump_rn + = getRnStats imp_decls `thenRn` \ msg -> + ioToRnM (printErrs msg) `thenRn_` + returnRn () + + | otherwise = returnRn () +\end{code} + + + +%********************************************************* +%* * +\subsection{Statistics} +%* * +%********************************************************* + +\begin{code} +getRnStats :: [RenamedHsDecl] -> RnMG SDoc +getRnStats imported_decls + = getIfacesRn `thenRn` \ ifaces -> + let + n_mods = length [() | (_, _, Just _) <- eltsFM (iImpModInfo ifaces)] + + decls_read = [decl | (_, avail, True, (_,decl)) <- nameEnvElts (iDecls ifaces), + -- Data, newtype, and class decls are in the decls_fm + -- under multiple names; the tycon/class, and each + -- constructor/class op too. + -- The 'True' selects just the 'main' decl + not (isLocallyDefined (availName avail)) + ] + + (cd_rd, dd_rd, nd_rd, sd_rd, vd_rd, _) = count_decls decls_read + (cd_sp, dd_sp, nd_sp, sd_sp, vd_sp, id_sp) = count_decls imported_decls + + unslurped_insts = iInsts ifaces + inst_decls_unslurped = length (bagToList unslurped_insts) + inst_decls_read = id_sp + inst_decls_unslurped + + stats = vcat + [int n_mods <+> text "interfaces read", + hsep [ int cd_sp, text "class decls imported, out of", + int cd_rd, text "read"], + hsep [ int dd_sp, text "data decls imported, out of", + int dd_rd, text "read"], + hsep [ int nd_sp, text "newtype decls imported, out of", + int nd_rd, text "read"], + hsep [int sd_sp, text "type synonym decls imported, out of", + int sd_rd, text "read"], + hsep [int vd_sp, text "value signatures imported, out of", + int vd_rd, text "read"], + hsep [int id_sp, text "instance decls imported, out of", + int inst_decls_read, text "read"], + text "cls dcls slurp" <+> fsep (map (ppr . tyClDeclName) + [d | TyClD d <- imported_decls, isClassDecl d]), + text "cls dcls read" <+> fsep (map (ppr . tyClDeclName) + [d | TyClD d <- decls_read, isClassDecl d])] + in + returnRn (hcat [text "Renamer stats: ", stats]) + +count_decls decls + = (class_decls, + data_decls, + newtype_decls, + syn_decls, + val_decls, + inst_decls) + where + tycl_decls = [d | TyClD d <- decls] + (class_decls, data_decls, newtype_decls, syn_decls) = countTyClDecls tycl_decls + + val_decls = length [() | SigD _ <- decls] + inst_decls = length [() | InstD _ <- decls] +\end{code} +