X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;ds=sidebyside;f=ghc%2Fcompiler%2Frename%2FRename.lhs;h=1f7ba6125974518a65453f35ab9aef3b15989700;hb=9bedea20f62a1da832c69833c39dd1d15e6ee9a3;hp=c040d6d4a3cb5b206c33a3bca983526bdb0e0279;hpb=c49d51f812da9b1c2ceca7e0dad8f2a3626041a9;p=ghc-hetmet.git diff --git a/ghc/compiler/rename/Rename.lhs b/ghc/compiler/rename/Rename.lhs index c040d6d..1f7ba61 100644 --- a/ghc/compiler/rename/Rename.lhs +++ b/ghc/compiler/rename/Rename.lhs @@ -1,151 +1,948 @@ % -% (c) The GRASP Project, Glasgow University, 1992-1996 +% (c) The GRASP Project, Glasgow University, 1992-1998 % \section[Rename]{Renaming and dependency analysis passes} \begin{code} -#include "HsVersions.h" - module Rename ( renameModule ) where -import PreludeGlaST ( thenPrimIO, returnPrimIO, fixPrimIO, newVar, MutableVar(..) ) - -import Ubiq +#include "HsVersions.h" import HsSyn -import RdrHsSyn ( RdrNameHsModule(..), RdrNameImportDecl(..) ) -import RnHsSyn ( RnName, RenamedHsModule(..), isRnTyCon, isRnClass ) +import HsPragmas ( DataPragmas(..) ) +import RdrHsSyn ( RdrNameHsModule, RdrNameHsDecl, RdrNameDeprecation ) +import RnHsSyn ( RenamedHsModule, RenamedHsDecl, + extractHsTyNames, extractHsCtxtTyNames + ) -import ParseIface ( ParsedIface ) +import CmdLineOpts ( DynFlags, DynFlag(..) ) import RnMonad -import RnNames ( getGlobalNames, GlobalNameInfo(..) ) -import RnSource ( rnSource ) -import RnIfaces ( findHiFiles, rnIfaces, finalIfaceInfo, VersionInfo(..) ) -import RnUtils ( extendGlobalRnEnv, emptyRnEnv, multipleOccWarn ) -import MainMonad +import Finder ( Finder ) +import RnNames ( getGlobalNames ) +import RnSource ( rnSourceDecls, rnDecl ) +import RnIfaces ( getImportedInstDecls, importDecl, mkImportExportInfo, + getInterfaceExports, + getImportedRules, getSlurped, removeContext, + loadBuiltinRules, getDeferredDecls, ImportDeclResult(..) + ) +import RnEnv ( availName, availsToNameSet, + emptyAvailEnv, unitAvailEnv, availEnvElts, plusAvailEnv, + warnUnusedImports, warnUnusedLocalBinds, warnUnusedModules, + lookupOrigNames, unknownNameErr, + FreeVars, plusFVs, plusFV, unitFV, emptyFVs, isEmptyFVs, addOneFV + ) +import Module ( Module, ModuleName, WhereFrom(..), + moduleNameUserString, moduleName, mkModuleInThisPackage + ) +import Name ( Name, isLocallyDefined, NamedThing(..), getSrcLoc, + nameOccName, nameUnique, nameModule, +-- maybeUserImportedFrom, +-- isUserImportedExplicitlyName, isUserImportedName, +-- maybeWiredInTyConName, maybeWiredInIdName, + isUserExportedName, toRdrName, + nameEnvElts, extendNameEnv + ) +import OccName ( occNameFlavour, isValOcc ) +import Id ( idType ) +import TyCon ( isSynTyCon, getSynTyConDefn ) +import NameSet +import TysWiredIn ( unitTyCon, intTyCon, doubleTyCon, boolTyCon ) +import PrelRules ( builtinRules ) +import PrelNames ( mAIN_Name, pREL_MAIN_Name, pRELUDE_Name, + ioTyCon_RDR, + unpackCString_RDR, unpackCStringFoldr_RDR, unpackCStringUtf8_RDR, + eqString_RDR + ) +import PrelInfo ( fractionalClassKeys, derivingOccurrences, + maybeWiredInTyConName, maybeWiredInIdName ) +import Type ( namesOfType, funTyCon ) +import ErrUtils ( printErrorsAndWarnings, dumpIfSet, ghcExit ) +import BasicTypes ( Version, initialVersion ) +import Bag ( isEmptyBag, bagToList ) +import FiniteMap ( FiniteMap, eltsFM, fmToList, emptyFM, lookupFM, + addToFM_C, elemFM, addToFM + ) +import UniqSupply ( UniqSupply ) +import UniqFM ( lookupUFM ) +import SrcLoc ( noSrcLoc ) +import Maybes ( maybeToBool, expectJust ) +import Outputable +import IO ( openFile, IOMode(..) ) +import HscTypes ( PersistentCompilerState, HomeSymbolTable, GlobalRdrEnv, + AvailEnv, Avails, GenAvailInfo(..), AvailInfo, + Provenance(..), ImportReason(..) ) -import Bag ( isEmptyBag, unionBags, bagToList, listToBag ) -import CmdLineOpts ( opt_HiDirList, opt_SysHiDirList ) -import ErrUtils ( Error(..), Warning(..) ) -import FiniteMap ( emptyFM, eltsFM ) -import Name ( getOrigNameRdr, isLocallyDefined, Name, RdrName(..) ) -import PrelInfo ( BuiltinNames(..), BuiltinKeys(..) ) -import UniqFM ( emptyUFM, lookupUFM, addListToUFM_C, eltsUFM ) -import UniqSupply ( splitUniqSupply ) -import Util ( panic, assertPanic ) +-- HACKS: +maybeUserImportedFrom = panic "maybeUserImportedFrom" +isUserImportedExplicitlyName = panic "isUserImportedExplicitlyName" +isUserImportedName = panic "isUserImportedName" +iDeprecs = panic "iDeprecs" +type FixityEnv = LocalFixityEnv \end{code} + + \begin{code} -renameModule :: BuiltinNames - -> BuiltinKeys - -> UniqSupply - -> RdrNameHsModule +type RenameResult = ( PersistentCompilerState + , Module -- This module + , RenamedHsModule -- Renamed module + , Maybe ParsedIface -- The existing interface file, if any + , ParsedIface -- The new interface + , [Module]) -- Imported modules + +renameModule :: DynFlags -> Finder + -> PersistentCompilerState -> HomeSymbolTable + -> RdrNameHsModule -> IO (Maybe RenameResult) +renameModule dflags finder old_pcs hst + this_mod@(HsModule mod_name vers exports imports local_decls _ loc) + = -- Initialise the renamer monad + do { + ((maybe_rn_stuff, dump_action), (rn_warns_bag, rn_errs_bag), new_pcs) + <- initRn dflags finder old_pcs hst loc (rename this_mod) ; - -> MainIO - ( - RenamedHsModule, -- output, after renaming - [Module], -- imported modules; for profiling + -- Check for warnings + printErrorsAndWarnings (rn_warns_bag, rn_errs_bag) ; - VersionInfo, -- version info; for usage - [Module], -- instance modules; for iface + -- Dump any debugging output + dump_action ; - Bag Error, - Bag Warning - ) + -- Return results + if not (isEmptyBag rn_errs_bag) then + return (old_pcs, Nothing) + else + return (new_pcs, maybe_rn_stuff) + } \end{code} -ToDo: May want to arrange to return old interface for this module! -ToDo: Return OrigName RnEnv to rename derivings etc with. -ToDo: Builtin names which must be read. -ToDo: Deal with instances (instance version, this module on instance list ???) - \begin{code} -renameModule b_names b_keys us - input@(HsModule mod _ _ imports _ _ _ _ _ _ _ _ _ _) +rename :: RdrNameHsModule -> RnMG (Maybe RenameResult, IO ()) +rename this_mod@(HsModule mod_name vers exports imports local_decls mod_deprec loc) + = -- FIND THE GLOBAL NAME ENVIRONMENT + getGlobalNames this_mod `thenRn` \ maybe_stuff -> + + -- CHECK FOR EARLY EXIT + case maybe_stuff of { + Nothing -> -- Everything is up to date; no need to recompile further + rnDump [] [] `thenRn` \ dump_action -> + returnRn (Nothing, dump_action) ; + + Just (gbl_env, local_gbl_env, export_avails, global_avail_env, old_iface) -> + + -- DEAL WITH DEPRECATIONS + rnDeprecs local_gbl_env mod_deprec local_decls `thenRn` \ my_deprecs -> - = findHiFiles opt_HiDirList opt_SysHiDirList `thenMn` \ hi_files -> - newVar (emptyFM, hi_files) `thenPrimIO` \ iface_var -> + -- DEAL WITH LOCAL FIXITIES + fixitiesFromLocalDecls local_gbl_env local_decls `thenRn` \ local_fixity_env -> - fixPrimIO ( \ ~(_, _, _, _, rec_occ_fm, rec_export_fn) -> + -- RENAME THE SOURCE + initRnMS gbl_env local_fixity_env SourceMode ( + rnSourceDecls local_decls + ) `thenRn` \ (rn_local_decls, source_fvs) -> + + -- SLURP IN ALL THE NEEDED DECLARATIONS + implicitFVs mod_name rn_local_decls `thenRn` \ implicit_fvs -> let - rec_occ_fn :: Name -> [RdrName] - rec_occ_fn n = case lookupUFM rec_occ_fm n of - Nothing -> [] - Just (rn,occs) -> occs + -- The export_fvs make the exported names look just as if they + -- occurred in the source program. For the reasoning, see the + -- comments with RnIfaces.getImportVersions. + -- We only need the 'parent name' of the avail; + -- that's enough to suck in the declaration. + export_fvs = mkNameSet (map availName export_avails) + real_source_fvs = source_fvs `plusFV` export_fvs - global_name_info = (b_names, b_keys, rec_export_fn, rec_occ_fn) + slurp_fvs = implicit_fvs `plusFV` real_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 - getGlobalNames iface_var global_name_info us1 input - `thenPrimIO` \ (occ_env, imp_mods, unqual_imps, imp_fixes, top_errs, top_warns) -> + loadBuiltinRules builtinRules `thenRn_` + slurpImpDecls slurp_fvs `thenRn` \ rn_imp_decls -> - if not (isEmptyBag top_errs) then - returnPrimIO (rn_panic, rn_panic, top_errs, top_warns, emptyUFM, rn_panic) + -- EXIT IF ERRORS FOUND + rnDump rn_imp_decls rn_local_decls `thenRn` \ dump_action -> + checkErrsRn `thenRn` \ no_errs_so_far -> + if not no_errs_so_far then + -- Found errors already, so exit now + returnRn (Nothing, dump_action) else - -- No top-level name errors so rename source ... - case initRn True mod occ_env us2 - (rnSource imp_mods unqual_imps imp_fixes input) of { - ((rn_module, export_fn, src_occs), src_errs, src_warns) -> + -- GENERATE THE VERSION/USAGE INFO + mkImportExportInfo mod_name export_avails exports `thenRn` \ (my_exports, my_usages) -> + -- RETURN THE RENAMED MODULE + getNameSupplyRn `thenRn` \ name_supply -> + getIfacesRn `thenRn` \ ifaces -> let - occ_fm :: UniqFM (RnName, [RdrName]) + direct_import_mods :: [Module] + direct_import_mods = [m | (_, _, Just (m, _, _, _, imp, _)) + <- eltsFM (iImpModInfo ifaces), user_import imp] + + -- *don't* just pick the forward edges. It's entirely possible + -- that a module is only reachable via back edges. + user_import ImportByUser = True + user_import ImportByUserSource = True + user_import _ = False - occ_list = [ (rn,(rn,[occ])) | (rn,occ) <- bagToList src_occs] - occ_fm = addListToUFM_C insert_occ emptyUFM occ_list + this_module = mkModuleInThisPackage mod_name - insert_occ (rn,olds) (rn',[new]) = (rn, insert new olds) + -- Export only those fixities that are for names that are + -- (a) defined in this module + -- (b) exported + exported_fixities + = [ FixitySig (toRdrName name) fixity loc + | FixitySig name fixity loc <- nameEnvElts local_fixity_env, + isUserExportedName name + ] - insert new [] = [new] - insert new xxs@(x:xs) = case cmp new x of LT_ -> new : xxs - EQ_ -> xxs - GT__ -> x : insert new xs + new_iface = ParsedIface { pi_mod = this_module + , pi_vers = initialVersion + , pi_orphan = any isOrphanDecl rn_local_decls + , pi_exports = my_exports + , pi_usages = my_usages + , pi_fixity = (initialVersion, exported_fixities) + , pi_deprecs = my_deprecs + -- These ones get filled in later + , pi_insts = [], pi_decls = [] + , pi_rules = (initialVersion, []) + } + + renamed_module = HsModule mod_name vers + trashed_exports trashed_imports + (rn_local_decls ++ rn_imp_decls) + mod_deprec + loc - occ_warns = map multipleOccWarn (filter multiple_occs (eltsUFM occ_fm)) - multiple_occs (rn, (o1:o2:_)) = True - multiple_occs _ = False + result = (this_module, renamed_module, + old_iface, new_iface, + name_supply, local_fixity_env, + direct_import_mods) in - returnPrimIO (rn_module, imp_mods, - top_errs `unionBags` src_errs, - top_warns `unionBags` src_warns `unionBags` listToBag occ_warns, - occ_fm, export_fn) - }) `thenPrimIO` \ (rn_module, imp_mods, errs_so_far, warns_so_far, occ_fm, _) -> + -- REPORT UNUSED NAMES, AND DEBUG DUMP + reportUnusedNames mod_name direct_import_mods + gbl_env global_avail_env + export_avails source_fvs + rn_imp_decls `thenRn_` - if not (isEmptyBag errs_so_far) then - returnMn (rn_panic, rn_panic, rn_panic, rn_panic, - errs_so_far, warns_so_far) - else + returnRn (Just result, dump_action) } + where + trashed_exports = {-trace "rnSource:trashed_exports"-} Nothing + trashed_imports = {-trace "rnSource:trashed_imports"-} [] +\end{code} - -- No errors renaming source so rename the interfaces ... - let - imports_used = [ rn | (rn,_) <- eltsUFM occ_fm, not (isLocallyDefined rn) ] - (import_tcs, import_vals) = partition (\ rn -> isRnTyCon rn || isRnClass rn) imports_used +@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 decls + = lookupOrigNames implicit_occs `thenRn` \ implicit_names -> + returnRn (mkNameSet (map getName default_tycons) `plusFV` + implicit_names) + where + -- Add occurrences for Int, 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!) + -- Double is dealt with separately in getGates + default_tycons = [unitTyCon, funTyCon, boolTyCon, intTyCon] + + -- Add occurrences for IO or PrimIO + implicit_main | mod_name == mAIN_Name + || mod_name == pREL_MAIN_Name = [ioTyCon_RDR] + | otherwise = [] + + -- Now add extra "occurrences" for things that + -- the deriving mechanism, or defaulting, will later need in order to + -- generate code + implicit_occs = string_occs ++ foldr ((++) . get) implicit_main decls + + -- Virtually every program has error messages in it somewhere + string_occs = [unpackCString_RDR, unpackCStringFoldr_RDR, unpackCStringUtf8_RDR, + eqString_RDR] + + get (TyClD (TyData _ _ _ _ _ _ (Just deriv_classes) _ _ _ _)) + = concat (map get_deriv deriv_classes) + get other = [] + + get_deriv cls = case lookupUFM derivingOccurrences cls of + Nothing -> [] + Just occs -> occs +\end{code} + +\begin{code} +isOrphanDecl (InstD (InstDecl inst_ty _ _ _ _)) + = not (foldNameSet ((||) . isLocallyDefined) False (extractHsTyNames (removeContext inst_ty))) + -- The 'removeContext' is because of + -- instance Foo a => Baz T where ... + -- The decl is an orphan if Baz and T are both not locally defined, + -- even if Foo *is* locally defined + +isOrphanDecl (RuleD (HsRule _ _ _ lhs _ _)) + = check lhs + where + -- At the moment we just check for common LHS forms + -- Expand as necessary. Getting it wrong just means + -- more orphans than necessary + check (HsVar v) = not (isLocallyDefined v) + check (HsApp f a) = check f && check a + check (HsLit _) = False + check (HsOverLit _) = False + check (OpApp l o _ r) = check l && check o && check r + check (NegApp e _) = check e + check (HsPar e) = check e + check (SectionL e o) = check e && check o + check (SectionR o e) = check e && check o + + check other = True -- Safe fall through + +isOrphanDecl other = False +\end{code} + + +\begin{code} +dupDefaultDeclErrRn (DefaultDecl _ locn1 : dup_things) + = pushSrcLocRn locn1 $ + addErrRn msg + where + msg = hang (ptext SLIT("Multiple default declarations")) + 4 (vcat (map pp dup_things)) + pp (DefaultDecl _ locn) = ptext SLIT("here was another default declaration") <+> ppr locn +\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` \ (decls, needed) -> + + -- Then get everything else + closeDecls decls needed `thenRn` \ decls1 -> + + -- Finally, get any deferred data type decls + slurpDeferredDecls decls1 `thenRn` \ final_decls -> + + returnRn final_decls + +------------------------------------------------------- +slurpSourceRefs :: NameSet -- Variables defined in source + -> FreeVars -- Variables referenced in source + -> RnMG ([RenamedHsDecl], + FreeVars) -- Un-satisfied needs +-- The declaration (and hence home module) of each gate has +-- already been loaded + +slurpSourceRefs source_binders source_fvs + = go_outer [] -- Accumulating decls + emptyFVs -- Unsatisfied needs + emptyFVs -- Accumulating gates + (nameSetToList source_fvs) -- Things whose defn hasn't been loaded yet + where + -- The outer loop repeatedly slurps the decls for the current gates + -- and the instance decls + + -- The outer loop is needed 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. + -- + -- We also need to follow superclass refs. In particular, 'chasing @Foo@' must + -- include actually getting in Foo's class decl + -- class Wib a => Foo a where .. + -- so that its superclasses are discovered. The point is that Wib is a gate too. + -- We do this for tycons too, so that we look through type synonyms. + + go_outer decls fvs all_gates [] + = returnRn (decls, fvs) + + go_outer decls fvs all_gates refs -- refs are not necessarily slurped yet + = traceRn (text "go_outer" <+> ppr refs) `thenRn_` + foldlRn go_inner (decls, fvs, emptyFVs) refs `thenRn` \ (decls1, fvs1, gates1) -> + getImportedInstDecls (all_gates `plusFV` gates1) `thenRn` \ inst_decls -> + rnInstDecls decls1 fvs1 gates1 inst_decls `thenRn` \ (decls2, fvs2, gates2) -> + go_outer decls2 fvs2 (all_gates `plusFV` gates2) + (nameSetToList (gates2 `minusNameSet` all_gates)) + -- Knock out the all_gates because even if we don't slurp any new + -- decls we can get some apparently-new gates from wired-in names + + go_inner (decls, fvs, gates) wanted_name + = importDecl wanted_name `thenRn` \ import_result -> + case import_result of + AlreadySlurped -> returnRn (decls, fvs, gates) + WiredIn -> returnRn (decls, fvs, gates `plusFV` getWiredInGates wanted_name) + Deferred -> returnRn (decls, fvs, gates `addOneFV` wanted_name) -- It's a type constructor + + HereItIs decl -> rnIfaceDecl decl `thenRn` \ (new_decl, fvs1) -> + returnRn (new_decl : decls, + fvs1 `plusFV` fvs, + gates `plusFV` getGates source_fvs new_decl) + +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 +\end{code} + + +\begin{code} +------------------------------------------------------- +-- 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 + + +------------------------------------------------------- +-- 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` \ import_result -> + case import_result of + -- Found a declaration... rename it + HereItIs decl -> rnIfaceDecl decl `thenRn` \ (new_decl, fvs1) -> + returnRn (new_decl:decls, fvs1 `plusFV` fvs) + + -- No declaration... (wired in thing, or deferred, or already slurped) + other -> returnRn (decls, fvs) + + +------------------------------------------------------- +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) +\end{code} + + +%********************************************************* +%* * +\subsection{Deferred declarations} +%* * +%********************************************************* + +The idea of deferred declarations is this. Suppose we have a function + f :: T -> Int + data T = T1 A | T2 B + data A = A1 X | A2 Y + data B = B1 P | B2 Q +Then we don't want to load T and all its constructors, and all +the types those constructors refer to, and all the types *those* +constructors refer to, and so on. That might mean loading many more +interface files than is really necessary. So we 'defer' loading T. + +But f might be strict, and the calling convention for evaluating +values of type T depends on how many constructors T has, so +we do need to load T, but not the full details of the type T. +So we load the full decl for T, but only skeleton decls for A and B: + f :: T -> Int + data T = {- 2 constructors -} + +Whether all this is worth it is moot. + +\begin{code} +slurpDeferredDecls :: [RenamedHsDecl] -> RnMG [RenamedHsDecl] +slurpDeferredDecls decls + = getDeferredDecls `thenRn` \ def_decls -> + rnIfaceDecls decls emptyFVs (map stripDecl def_decls) `thenRn` \ (decls1, fvs) -> + ASSERT( isEmptyFVs fvs ) + returnRn decls1 + +stripDecl (mod, TyClD (TyData dt _ tc tvs _ nconstrs _ _ loc name1 name2)) + = (mod, TyClD (TyData dt [] tc tvs [] nconstrs Nothing NoDataPragmas loc + name1 name2)) + -- Nuke the context and constructors + -- But retain the *number* of constructors! + -- Also the tvs will have kinds on them. +\end{code} + + +%********************************************************* +%* * +\subsection{Extracting the `gates'} +%* * +%********************************************************* + +When we import a declaration like +\begin{verbatim} + data T = T1 Wibble | T2 Wobble +\end{verbatim} +we don't want to treat @Wibble@ and @Wobble@ as gates +{\em 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. - (orig_env, orig_dups) = extendGlobalRnEnv emptyRnEnv (map pair_orig import_vals) - (map pair_orig import_tcs) - pair_orig rn = (getOrigNameRdr rn, rn) +@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) + (hsTyVarNames tvs) + `addOneToNameSet` cls) + `plusFV` maybe_double + where + get (ClassOpSig n _ ty _) + | n `elemNameSet` source_fvs = extractHsTyNames ty + | otherwise = emptyFVs + + -- If we load any numeric class that doesn't have + -- Int as an instance, add Double to the gates. + -- This takes account of the fact that Double might be needed for + -- defaulting, but we don't want to load Double (and all its baggage) + -- if the more exotic classes aren't used at all. + maybe_double | nameUnique cls `elem` fractionalClassKeys + = unitFV (getName doubleTyCon) + | otherwise + = emptyFVs + +getGates source_fvs (TyClD (TySynonym tycon tvs ty _)) + = delListFromNameSet (extractHsTyNames ty) + (hsTyVarNames 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) + (hsTyVarNames 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) + (hsTyVarNames 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_field (fs,t) | any (`elemNameSet` source_fvs) fs = get_bang t + | otherwise = emptyFVs + + get_bang bty = extractHsTyNames (getBangType bty) + +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{Fixities} +%* * +%********************************************************* + +\begin{code} +fixitiesFromLocalDecls :: GlobalRdrEnv -> [RdrNameHsDecl] -> RnMG FixityEnv +fixitiesFromLocalDecls gbl_env decls + = doptRn Opt_WarnUnusedBinds `thenRn` \ warn_unused -> + foldlRn (getFixities warn_unused) emptyNameEnv decls `thenRn` \ env -> + traceRn (text "fixity env" <+> vcat (map ppr (nameEnvElts env))) + `thenRn_` + returnRn env + where + getFixities :: Bool -> FixityEnv -> RdrNameHsDecl -> RnMG FixityEnv + getFixities warn_uu acc (FixD fix) + = fix_decl warn_uu acc fix + + getFixities warn_uu acc (TyClD (ClassDecl _ _ _ _ sigs _ _ _ _ )) + = foldlRn (fix_decl warn_uu) acc [sig | FixSig sig <- sigs] + -- Get fixities from class decl sigs too. + getFixities warn_uu acc other_decl + = returnRn acc + + fix_decl warn_uu acc sig@(FixitySig rdr_name fixity loc) + = -- Check for fixity decl for something not declared + case lookupRdrEnv gbl_env rdr_name of { + Nothing | warn_uu + -> pushSrcLocRn loc (addWarnRn (unusedFixityDecl rdr_name fixity)) + `thenRn_` returnRn acc + | otherwise -> returnRn acc ; + + Just ((name,_):_) -> + + -- Check for duplicate fixity decl + case lookupNameEnv acc name of { + Just (FixitySig _ _ loc') -> addErrRn (dupFixityDecl rdr_name loc loc') + `thenRn_` returnRn acc ; + + Nothing -> returnRn (extendNameEnv acc name (FixitySig name fixity loc)) + }} +\end{code} + + +%********************************************************* +%* * +\subsection{Deprecations} +%* * +%********************************************************* + +For deprecations, all we do is check that the names are in scope. +It's only imported deprecations, dealt with in RnIfaces, that we +gather them together. + +\begin{code} +rnDeprecs :: GlobalRdrEnv -> Maybe DeprecTxt + -> [RdrNameHsDecl] -> RnMG [RdrNameDeprecation] +rnDeprecs gbl_env mod_deprec decls + = mapRn rn_deprec deprecs `thenRn_` + returnRn (extra_deprec ++ deprecs) + where + deprecs = [d | DeprecD d <- decls] + extra_deprec = case mod_deprec of + Nothing -> [] + Just txt -> [Deprecation (IEModuleContents undefined) txt noSrcLoc] + + rn_deprec (Deprecation ie txt loc) + = pushSrcLocRn loc $ + mapRn check (ieNames ie) + + check n = case lookupRdrEnv gbl_env n of + Nothing -> addErrRn (unknownNameErr n) + Just _ -> returnRn () +\end{code} + + +%********************************************************* +%* * +\subsection{Unused names} +%* * +%********************************************************* + +\begin{code} +reportUnusedNames :: ModuleName -> [Module] + -> GlobalRdrEnv -> AvailEnv + -> Avails -> NameSet -> [RenamedHsDecl] + -> RnMG () +reportUnusedNames mod_name direct_import_mods + gbl_env avail_env + export_avails mentioned_names + imported_decls + = 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 parent_avail + | sub_name <- nameSetToList used_names + , isValOcc (getOccName sub_name) + + -- Usually, every used name will appear in avail_env, but there + -- is one time when it doesn't: tuples and other built in syntax. When you + -- write (a,b) that gives rise to a *use* of "(,)", so that the + -- instances will get pulled in, but the tycon "(,)" isn't actually + -- in scope. Hence the isValOcc filter. + -- + -- Also, (-x) gives rise to an implicit use of 'negate'; similarly, + -- 3.5 gives rise to an implcit use of :% + -- hence the isUserImportedName filter on the warning + + , let parent_avail + = case lookupNameEnv avail_env sub_name of + Just avail -> avail + Nothing -> WARN( isUserImportedName sub_name, + text "reportUnusedName: not in avail_env" <+> + ppr sub_name ) + Avail sub_name + + , case parent_avail of { AvailTC _ _ -> True; other -> False } + ] + + defined_names, defined_but_not_used :: [(Name,Provenance)] + defined_names = concat (rdrEnvElts gbl_env) + defined_but_not_used = filter not_used defined_names + not_used name = not (name `elemNameSet` really_used_names) + + -- Filter out the ones only defined implicitly + bad_locals :: [Name] + bad_locals = [n | (n,LocalDef) <- defined_but_not_used] + + bad_imp_names :: [(Name,Provenance)] + bad_imp_names = [(n,p) | (n,p@(UserImport mod _ True)) <- defined_but_not_used, + not (module_unused mod)] + + deprec_used deprec_env = [ (n,txt) + | n <- nameSetToList mentioned_names, + not (isLocallyDefined n), + Just txt <- [lookupNameEnv deprec_env n] ] + + -- inst_mods are directly-imported modules that + -- contain instance decl(s) that the renamer decided to suck in + -- It's not necessarily redundant to import such modules. + -- + -- NOTE: Consider + -- module This + -- import M () + -- + -- The import M() is not *necessarily* redundant, even if + -- we suck in no instance decls from M (e.g. it contains + -- no instance decls, or This contains no code). It may be + -- that we import M solely to ensure that M's orphan instance + -- decls (or those in its imports) are visible to people who + -- import This. Sigh. + -- There's really no good way to detect this, so the error message + -- in RnEnv.warnUnusedModules is weakened instead + inst_mods = [m | InstD (InstDecl _ _ _ (Just dfun) _) <- imported_decls, + let m = nameModule dfun, + m `elem` direct_import_mods + ] + + minimal_imports :: FiniteMap Module AvailEnv + minimal_imports0 = emptyFM + minimal_imports1 = foldNameSet add_name minimal_imports0 really_used_names + minimal_imports = foldr add_inst_mod minimal_imports1 inst_mods + + add_name n acc = case maybeUserImportedFrom n of + Nothing -> acc + Just m -> addToFM_C plusAvailEnv acc m + (unitAvailEnv (mk_avail n)) + add_inst_mod m acc + | m `elemFM` acc = acc -- We import something already + | otherwise = addToFM acc m emptyAvailEnv + -- Add an empty collection of imports for a module + -- from which we have sucked only instance decls + + mk_avail n = case lookupNameEnv avail_env n of + Just (AvailTC m _) | n==m -> AvailTC n [n] + | otherwise -> AvailTC m [n,m] + Just avail -> Avail n + Nothing -> pprPanic "mk_avail" (ppr n) + + -- unused_imp_mods are the directly-imported modules + -- that are not mentioned in minimal_imports + unused_imp_mods = [m | m <- direct_import_mods, + not (maybeToBool (lookupFM minimal_imports m)), + moduleName m /= pRELUDE_Name] + + module_unused :: Module -> Bool + module_unused mod = mod `elem` unused_imp_mods - -- ToDo: Do we need top-level names from this module in orig_env ??? in - ASSERT (isEmptyBag orig_dups) - rnIfaces iface_var orig_env us3 rn_module imports_used - `thenPrimIO` \ (rn_module_with_imports, - (implicit_val_fm, implicit_tc_fm), - iface_errs, iface_warns) -> + warnUnusedModules unused_imp_mods `thenRn_` + warnUnusedLocalBinds bad_locals `thenRn_` + warnUnusedImports bad_imp_names `thenRn_` + printMinimalImports mod_name minimal_imports `thenRn_` + getIfacesRn `thenRn` \ ifaces -> + doptRn Opt_WarnDeprecations `thenRn` \ warn_drs -> + (if warn_drs + then mapRn_ warnDeprec (deprec_used (iDeprecs ifaces)) + else returnRn ()) + +-- ToDo: deal with original imports with 'qualified' and 'as M' clauses +printMinimalImports mod_name imps + = doptRn Opt_D_dump_minimal_imports `thenRn` \ dump_minimal -> + printMinimalImports_wrk dump_minimal mod_name imps + +printMinimalImports_wrk dump_minimal mod_name imps + | not dump_minimal + = returnRn () + | otherwise + = mapRn to_ies (fmToList imps) `thenRn` \ mod_ies -> + ioToRnM (do { h <- openFile filename WriteMode ; + printForUser h (vcat (map ppr_mod_ie mod_ies)) + }) `thenRn_` + returnRn () + where + filename = moduleNameUserString mod_name ++ ".imports" + ppr_mod_ie (mod_name, ies) + | mod_name == pRELUDE_Name + = empty + | otherwise + = ptext SLIT("import") <+> ppr mod_name <> + parens (fsep (punctuate comma (map ppr ies))) + + to_ies (mod, avail_env) = mapRn to_ie (availEnvElts avail_env) `thenRn` \ ies -> + returnRn (moduleName mod, ies) + + to_ie :: AvailInfo -> RnMG (IE Name) + to_ie (Avail n) = returnRn (IEVar n) + to_ie (AvailTC n [m]) = ASSERT( n==m ) + returnRn (IEThingAbs n) + to_ie (AvailTC n ns) = getInterfaceExports (moduleName (nameModule n)) + ImportBySystem `thenRn` \ (_, avails) -> + case [ms | AvailTC m ms <- avails, m == n] of + [ms] | all (`elem` ns) ms -> returnRn (IEThingAll n) + | otherwise -> returnRn (IEThingWith n (filter (/= n) ns)) + other -> pprTrace "to_ie" (ppr n <+> ppr (nameModule n) <+> ppr other) $ + returnRn (IEVar n) + +rnDump :: [RenamedHsDecl] -- Renamed imported decls + -> [RenamedHsDecl] -- Renamed local decls + -> RnMG (IO ()) +rnDump imp_decls local_decls + = doptRn Opt_D_dump_rn_trace `thenRn` \ dump_rn_trace -> + doptRn Opt_D_dump_rn_stats `thenRn` \ dump_rn_stats -> + doptRn Opt_D_dump_rn `thenRn` \ dump_rn -> + if dump_rn_trace || dump_rn_stats || dump_rn then + getRnStats imp_decls `thenRn` \ stats_msg -> + returnRn (printErrs stats_msg >> + dumpIfSet dump_rn "Renamer:" + (vcat (map ppr (local_decls ++ imp_decls)))) + else + returnRn (return ()) +\end{code} + + +%********************************************************* +%* * +\subsection{Statistics} +%* * +%********************************************************* + +\begin{code} +getRnStats :: [RenamedHsDecl] -> RnMG SDoc +getRnStats imported_decls + = getIfacesRn `thenRn` \ ifaces -> let - all_imports_used = imports_used ++ eltsFM implicit_tc_fm ++ eltsFM implicit_val_fm - in - finalIfaceInfo iface_var all_imports_used imp_mods - `thenPrimIO` \ (version_info, instance_mods) -> + 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 - returnMn (rn_module_with_imports, imp_mods, - version_info, instance_mods, - errs_so_far `unionBags` iface_errs, - warns_so_far `unionBags` iface_warns) + 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 - rn_panic = panic "renameModule: aborted with errors" + 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} + + +%************************************************************************ +%* * +\subsection{Errors and warnings} +%* * +%************************************************************************ + +\begin{code} +warnDeprec :: (Name, DeprecTxt) -> RnM d () +warnDeprec (name, txt) + = pushSrcLocRn (getSrcLoc name) $ + addWarnRn $ + sep [ text (occNameFlavour (nameOccName name)) <+> ppr name <+> + text "is deprecated:", nest 4 (ppr txt) ] + + +unusedFixityDecl rdr_name fixity + = hsep [ptext SLIT("Unused fixity declaration for"), quotes (ppr rdr_name)] - (us1, us') = splitUniqSupply us - (us2, us3) = splitUniqSupply us' +dupFixityDecl rdr_name loc1 loc2 + = vcat [ptext SLIT("Multiple fixity declarations for") <+> quotes (ppr rdr_name), + ptext SLIT("at ") <+> ppr loc1, + ptext SLIT("and") <+> ppr loc2] \end{code}