X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=ghc%2Fcompiler%2Frename%2FRename.lhs;h=8790ef0843d2584e537ac17468df9b3661a72cf4;hb=ebef357f943e8fce48adb73053082204cc892f99;hp=28afe6e2b989ebb9952c2fd0fc0c1829ed5faa96;hpb=1e1de65f050eab2bfb26957415b3aca14eb10ccb;p=ghc-hetmet.git diff --git a/ghc/compiler/rename/Rename.lhs b/ghc/compiler/rename/Rename.lhs index 28afe6e..8790ef0 100644 --- a/ghc/compiler/rename/Rename.lhs +++ b/ghc/compiler/rename/Rename.lhs @@ -1,288 +1,1074 @@ % -% (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 -#if __GLASGOW_HASKELL__ <= 201 -import PreludeGlaST ( thenPrimIO ) -#else -import GlaExts -import IO -#endif - -IMP_Ubiq() -IMPORT_1_3(List(partition)) +#include "HsVersions.h" import HsSyn -import RdrHsSyn ( RdrName(..), SYN_IE(RdrNameHsModule), SYN_IE(RdrNameImportDecl) ) -import RnHsSyn ( SYN_IE(RenamedHsModule), SYN_IE(RenamedHsDecl), extractHsTyNames ) +import HsPragmas ( DataPragmas(..) ) +import RdrHsSyn ( RdrNameHsModule, RdrNameHsDecl, RdrNameDeprecation ) +import RnHsSyn ( RenamedHsModule, RenamedHsDecl, + extractHsTyNames, extractHsCtxtTyNames + ) -import CmdLineOpts ( opt_HiMap, opt_WarnNameShadowing, opt_D_show_rn_trace, - opt_D_dump_rn, opt_D_show_rn_stats, - opt_D_show_unused_imports, opt_PprUserLength - ) +import CmdLineOpts ( DynFlags, DynFlag(..) ) import RnMonad import RnNames ( getGlobalNames ) -import RnSource ( rnDecl ) -import RnIfaces ( getImportedInstDecls, importDecl, getImportVersions, getSpecialInstModules, - getDeferredDataDecls, - mkSearchPath, getSlurpedNames, getRnStats +import RnSource ( rnSourceDecls, rnDecl ) +import RnIfaces ( getImportedInstDecls, importDecl, mkImportInfo, + getInterfaceExports, + getImportedRules, getSlurped, removeContext, + ImportDeclResult(..), findAndReadIface + ) +import RnEnv ( availName, availsToNameSet, + emptyAvailEnv, unitAvailEnv, availEnvElts, plusAvailEnv, sortAvails, + warnUnusedImports, warnUnusedLocalBinds, warnUnusedModules, + lookupOrigNames, unknownNameErr, + FreeVars, plusFVs, plusFV, unitFV, emptyFVs, isEmptyFVs, addOneFV + ) +import Module ( Module, ModuleName, WhereFrom(..), + moduleNameUserString, moduleName, mkModuleInThisPackage, + lookupModuleEnv ) -import RnEnv ( availsToNameSet, addAvailToNameSet, - addImplicitOccsRn, lookupImplicitOccRn ) -import Id ( GenId {- instance NamedThing -} ) -import Name ( Name, Provenance, ExportFlag(..), isLocallyDefined, - NameSet(..), elemNameSet, mkNameSet, unionNameSets, - nameSetToList, minusNameSet, NamedThing(..), - nameModule, pprModule, pprOccName, nameOccName +import Name ( Name, isLocallyDefined, NamedThing(..), getSrcLoc, + nameOccName, nameUnique, nameModule, + isUserExportedName, toRdrName, + mkNameEnv, nameEnvElts, extendNameEnv ) -import TysWiredIn ( unitTyCon, intTyCon, doubleTyCon ) -import PrelInfo ( ioTyCon_NAME, primIoTyCon_NAME ) -import TyCon ( TyCon ) -import PrelMods ( mAIN, gHC_MAIN ) -import ErrUtils ( SYN_IE(Error), SYN_IE(Warning) ) -import FiniteMap ( emptyFM, eltsFM, fmToList, addToFM, FiniteMap ) -import Pretty -import Outputable ( Outputable(..), PprStyle(..) ) -import Util ( cmpPString, equivClasses, panic, assertPanic, pprTrace ) -#if __GLASGOW_HASKELL__ >= 202 -import UniqSupply -#endif +import OccName ( occNameFlavour, isValOcc ) +import Id ( idType ) +import TyCon ( isSynTyCon, getSynTyConDefn ) +import NameSet +import TysWiredIn ( unitTyCon, intTyCon, doubleTyCon, boolTyCon ) +import PrelNames ( mAIN_Name, pREL_MAIN_Name, pRELUDE_Name, + ioTyCon_RDR, + unpackCString_RDR, unpackCStringFoldr_RDR, unpackCStringUtf8_RDR, + eqString_RDR + ) +import PrelInfo ( fractionalClassKeys, derivingOccurrences, wiredInThingEnv ) +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 ( Finder, PersistentCompilerState, HomeIfaceTable, HomeSymbolTable, + ModIface(..), TyThing(..), + GlobalRdrEnv, AvailEnv, Avails, GenAvailInfo(..), AvailInfo, + Provenance(..), pprNameProvenance, ImportReason(..), + lookupDeprec + ) +import List ( partition, nub ) \end{code} \begin{code} -renameModule :: UniqSupply - -> RdrNameHsModule - -> IO (Maybe -- Nothing <=> everything up to date; - -- no ned to recompile any further - (RenamedHsModule, -- Output, after renaming - InterfaceDetails, -- Interface; for interface file generatino - RnNameSupply, -- Final env; for renaming derivings - [Module]), -- Imported modules; for profiling - Bag Error, - Bag Warning - ) -\end{code} +renameModule :: DynFlags -> Finder + -> HomeIfaceTable -> HomeSymbolTable + -> PersistentCompilerState + -> Module -> RdrNameHsModule + -> IO (PersistentCompilerState, Maybe ModIface) + -- The mi_decls in the ModIface include + -- ones imported from packages too +renameModule dflags finder hit hst old_pcs this_module + this_mod@(HsModule _ _ _ _ _ _ loc) + = -- Initialise the renamer monad + do { + ((maybe_rn_stuff, dump_action), (rn_warns_bag, rn_errs_bag), new_pcs) + <- initRn dflags finder hit hst old_pcs this_module loc (rename this_module this_mod) ; -\begin{code} -renameModule us this_mod@(HsModule mod_name vers exports imports fixities local_decls loc) - = -- INITIALISE THE RENAMER MONAD - initRn mod_name us (mkSearchPath opt_HiMap) loc $ + -- Check for warnings + printErrorsAndWarnings (rn_warns_bag, rn_errs_bag) ; + + -- Dump any debugging output + dump_action ; + + -- Return results + if not (isEmptyBag rn_errs_bag) then + return (old_pcs, Nothing) + else + return (new_pcs, maybe_rn_stuff) + } +\end{code} - -- FIND THE GLOBAL NAME ENVIRONMENT - getGlobalNames this_mod `thenRn` \ global_name_info -> +\begin{code} +rename :: Module -> RdrNameHsModule -> RnMG (Maybe ModIface, IO ()) +rename this_module this_mod@(HsModule mod_name vers exports imports local_decls mod_deprec loc) + = -- FIND THE GLOBAL NAME ENVIRONMENT + getGlobalNames this_mod `thenRn` \ maybe_stuff -> - case global_name_info of { + -- CHECK FOR EARLY EXIT + case maybe_stuff of { Nothing -> -- Everything is up to date; no need to recompile further - rnStats [] `thenRn_` - returnRn Nothing ; + rnDump [] [] `thenRn` \ dump_action -> + returnRn (Nothing, dump_action) ; + + Just (gbl_env, local_gbl_env, export_avails, global_avail_env) -> + + -- DEAL WITH DEPRECATIONS + rnDeprecs local_gbl_env mod_deprec local_decls `thenRn` \ my_deprecs -> - -- Otherwise, just carry on - Just (export_env, rn_env, explicit_names) -> + -- DEAL WITH LOCAL FIXITIES + fixitiesFromLocalDecls local_gbl_env local_decls `thenRn` \ local_fixity_env -> -- RENAME THE SOURCE - initRnMS rn_env mod_name SourceMode ( - addImplicits mod_name `thenRn_` - mapRn rnDecl local_decls - ) `thenRn` \ rn_local_decls -> + initRnMS gbl_env local_fixity_env SourceMode ( + rnSourceDecls local_decls + ) `thenRn` \ (rn_local_decls, source_fvs) -> -- SLURP IN ALL THE NEEDED DECLARATIONS - slurpDecls rn_local_decls `thenRn` \ rn_all_decls -> + implicitFVs mod_name rn_local_decls `thenRn` \ implicit_fvs -> + let + -- 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 + 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 + slurpImpDecls slurp_fvs `thenRn` \ rn_imp_decls -> - -- GENERATE THE VERSION/USAGE INFO - getImportVersions mod_name exports `thenRn` \ import_versions -> - getNameSupplyRn `thenRn` \ name_supply -> + -- 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 - -- REPORT UNUSED NAMES - reportUnusedNames explicit_names `thenRn_` + -- GENERATE THE VERSION/USAGE INFO + mkImportInfo mod_name imports `thenRn` \ my_usages -> - -- 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 + getNameSupplyRn `thenRn` \ name_supply -> + getIfacesRn `thenRn` \ ifaces -> let - import_mods = [mod | ImportDecl mod _ _ _ _ _ <- imports] + direct_import_mods :: [ModuleName] + direct_import_mods = nub [m | ImportDecl m _ _ _ _ _ <- imports] + + -- *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 - renamed_module = HsModule mod_name vers - trashed_exports trashed_imports trashed_fixities - rn_all_decls - loc + -- Export only those fixities that are for names that are + -- (a) defined in this module + -- (b) exported + exported_fixities + = mkNameEnv [ (name, fixity) + | FixitySig name fixity loc <- nameEnvElts local_fixity_env, + isUserExportedName name + ] + + + -- Sort the exports to make them easier to compare for versions + my_exports = sortAvails export_avails + + mod_iface = ModIface { mi_module = this_module, + mi_version = panic "mi_version: not filled in yet", + mi_orphan = any isOrphanDecl rn_local_decls, + mi_exports = my_exports, + mi_usages = my_usages, + mi_fixities = exported_fixities, + mi_deprecs = my_deprecs, + mi_decls = rn_local_decls ++ rn_imp_decls + } in - rnStats rn_all_decls `thenRn_` - returnRn (Just (renamed_module, - (import_versions, export_env, special_inst_mods), - name_supply, - import_mods)) - } + + -- 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_` + + returnRn (Just mod_iface, dump_action) } where trashed_exports = {-trace "rnSource:trashed_exports"-} Nothing trashed_imports = {-trace "rnSource:trashed_imports"-} [] - trashed_fixities = [] \end{code} -@addImplicits@ forces the renamer to slurp in some things which aren't +@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} -addImplicits mod_name - = addImplicitOccsRn (implicit_main ++ default_tys) +implicitFVs mod_name decls + = lookupOrigNames implicit_occs `thenRn` \ implicit_names -> + returnRn (mkNameSet (map getName default_tycons) `plusFV` + implicit_names) where - -- Add occurrences for Int, Double, and (), because they + -- 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 every appear explicitly. + -- 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] + -- 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 = [ioTyCon_NAME] - | mod_name == gHC_MAIN = [primIoTyCon_NAME] - | otherwise = [] -\end{code} + 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} -slurpDecls decls - = -- First of all, get all the compulsory decls - slurp_compulsories decls `thenRn` \ decls1 -> +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 - -- Next get the optional ones - closeDecls Optional decls1 `thenRn` \ decls2 -> + check other = True -- Safe fall through - -- Finally get those deferred data type declarations - getDeferredDataDecls `thenRn` \ data_decls -> - mapRn rn_data_decl data_decls `thenRn` \ rn_data_decls -> +isOrphanDecl other = False +\end{code} - -- Done - returnRn (rn_data_decls ++ decls2) +\begin{code} +dupDefaultDeclErrRn (DefaultDecl _ locn1 : dup_things) + = pushSrcLocRn locn1 $ + addErrRn msg where - -- 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 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 inst_decls `thenRn` \ new_inst_decls -> - slurp_compulsories (new_inst_decls ++ decls1) + 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} -closeDecls :: Necessity - -> [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 necessity decls - = popOccurrenceName necessity `thenRn` \ maybe_unresolved -> - case maybe_unresolved of - - -- No more unresolved names - Nothing -> returnRn decls +------------------------------------------------------- +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 - -- An unresolved name - Just name - -> -- Slurp its declaration, if any - traceRn (sep [ptext SLIT("Considering"), ppr PprDebug name]) `thenRn_` - importDecl name necessity `thenRn` \ maybe_decl -> - case maybe_decl of - - -- No declaration... (wired in thing or optional) - Nothing -> closeDecls necessity decls - - -- Found a declaration... rename it - Just decl -> rn_iface_decl mod_name necessity decl `thenRn` \ new_decl -> - closeDecls necessity (new_decl : decls) - where - mod_name = nameModule name - - -rn_iface_decl mod_name necessity decl -- Notice that the rnEnv starts empty - = initRnMS emptyRnEnv mod_name (InterfaceMode necessity) (rnDecl decl) - -rn_inst_decl (mod_name,decl) = rn_iface_decl mod_name Compulsory (InstD decl) - -rn_data_decl (tycon_name,ty_decl) = rn_iface_decl mod_name Compulsory (TyD ty_decl) - where - mod_name = nameModule tycon_name + 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} -reportUnusedNames explicit_avail_names - | not opt_D_show_unused_imports - = returnRn () +------------------------------------------------------- +-- 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 - = getSlurpedNames `thenRn` \ slurped_names -> + = 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 = returnRn decls + +{- OMIT FOR NOW +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. + +@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 + = case lookupNameEnv wiredInThingEnv name of + Just (AnId the_id) -> getWiredInGates_s (namesOfType (idType the_id)) + + Just (ATyCon tc) + | isSynTyCon tc + -> getWiredInGates_s (delListFromNameSet (namesOfType ty) (map getName tyvars)) + where + (tyvars,ty) = getSynTyConDefn tc + + other -> unitFV name + +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 LocalFixityEnv +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 -> LocalFixityEnv -> RdrNameHsDecl -> RnMG LocalFixityEnv + 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 -> [ModuleName] + -> GlobalRdrEnv -> AvailEnv + -> Avails -> NameSet -> [RenamedHsDecl] + -> RnMG () +reportUnusedNames mod_name direct_import_mods + gbl_env avail_env + export_avails mentioned_names + imported_decls + = warnUnusedModules unused_imp_mods `thenRn_` + warnUnusedLocalBinds bad_locals `thenRn_` + warnUnusedImports bad_imp_names `thenRn_` + printMinimalImports mod_name minimal_imports `thenRn_` + warnDeprecations really_used_names `thenRn_` + returnRn () + + where + 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 [ parent_name + | sub_name <- nameSetToList used_names + + -- 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. Also, (-x) gives rise to an implicit use of 'negate'; + -- similarly, 3.5 gives rise to an implcit use of :% + -- Hence the silent 'False' in all other cases + + , Just parent_name <- [case lookupNameEnv avail_env sub_name of + Just (AvailTC n _) -> Just n + other -> Nothing] + ] + + defined_names, defined_and_used, defined_but_not_used :: [(Name,Provenance)] + defined_names = concat (rdrEnvElts gbl_env) + (defined_and_used, defined_but_not_used) = partition used defined_names + 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@(NonLocalDef (UserImport mod _ True) _)) <- defined_but_not_used, + not (module_unused mod)] + + -- 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 :: [ModuleName] + inst_mods = [m | InstD (InstDecl _ _ _ (Just dfun) _) <- imported_decls, + let m = moduleName (nameModule dfun), + m `elem` direct_import_mods + ] + + -- To figure out the minimal set of imports, start with the things + -- that are in scope (i.e. in gbl_env). Then just combine them + -- into a bunch of avails, so they are properly grouped + minimal_imports :: FiniteMap ModuleName AvailEnv + minimal_imports0 = emptyFM + minimal_imports1 = foldr add_name minimal_imports0 defined_and_used + minimal_imports = foldr add_inst_mod minimal_imports1 inst_mods + + add_name (n,NonLocalDef (UserImport m _ _) _) acc = addToFM_C plusAvailEnv acc (moduleName (nameModule n)) + (unitAvailEnv (mk_avail n)) + add_name (n,other_prov) acc = acc + + 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) + + 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 + + -- 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)), + m /= pRELUDE_Name] + + module_unused :: Module -> Bool + module_unused mod = moduleName mod `elem` unused_imp_mods + + +warnDeprecations used_names + = doptRn Opt_WarnDeprecations `thenRn` \ warn_drs -> + if not warn_drs then returnRn () else + + getIfacesRn `thenRn` \ ifaces -> + getHomeIfaceTableRn `thenRn` \ hit -> let - unused = explicit_avail_names `minusNameSet` slurped_names - (local_unused, imported_unused) = partition isLocallyDefined (nameSetToList unused) - imports_by_module = equivClasses cmp imported_unused - name1 `cmp` name2 = nameModule name1 `_CMP_STRING_` nameModule name2 - - pp_imp sty = sep [text "For information: the following unqualified imports are unused:", - nest 4 (vcat (map (pp_group sty) imports_by_module))] - pp_group sty (n:ns) = sep [hcat [text "Module ", pprModule (PprForUser opt_PprUserLength) (nameModule n), char ':'], - nest 4 (sep (map (pprOccName sty . nameOccName) (n:ns)))] - - pp_local sty = sep [text "For information: the following local top-level definitions are unused:", - nest 4 (sep (map (pprOccName sty . nameOccName) local_unused))] + pit = iPIT ifaces + deprecs = [ (n,txt) + | n <- nameSetToList used_names, + Just txt <- [lookup_deprec hit pit n] ] + in + mapRn_ warnDeprec deprecs + + where + lookup_deprec hit pit n + = case lookupModuleEnv hit mod of + Just iface -> lookupDeprec iface n + Nothing -> case lookupModuleEnv pit mod of + Just iface -> lookupDeprec iface n + Nothing -> pprPanic "warnDeprecations:" (ppr n) + where + mod = nameModule n + +-- ToDo: deal with original imports with 'qualified' and 'as M' clauses +printMinimalImports mod_name imps + = doptRn Opt_D_dump_minimal_imports `thenRn` \ dump_minimal -> + if not dump_minimal then returnRn () else + + 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 (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 + n_mods = length [() | (_, _, True) <- 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 - (if null imported_unused - then returnRn () - else addWarnRn pp_imp) `thenRn_` - - (if null local_unused - then returnRn () - else addWarnRn pp_local) - -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 (hPutStr stderr (show msg) >> - hPutStr stderr "\n") `thenRn_` - returnRn () - - | otherwise = returnRn () + 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} + + +%************************************************************************ +%* * +\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)] + +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} + +%******************************************************** +%* * +\subsection{Checking usage information} +%* * +%******************************************************** + +\begin{code} +{- +checkEarlyExit mod_name + = traceRn (text "Considering whether compilation is required...") `thenRn_` + + -- Read the old interface file, if any, for the module being compiled + findAndReadIface doc_str mod_name False {- Not hi-boot -} `thenRn` \ maybe_iface -> + + -- CHECK WHETHER WE HAVE IT ALREADY + case maybe_iface of + Left err -> -- Old interface file not found, so we'd better bail out + traceRn (vcat [ptext SLIT("No old interface file for") <+> ppr mod_name, + err]) `thenRn_` + returnRn (outOfDate, Nothing) + + Right iface + | panic "checkEarlyExit: ???: not opt_SourceUnchanged" + -> -- Source code changed + traceRn (nest 4 (text "source file changed or recompilation check turned off")) `thenRn_` + returnRn (False, Just iface) + + | otherwise + -> -- Source code unchanged and no errors yet... carry on + checkModUsage (pi_usages iface) `thenRn` \ up_to_date -> + returnRn (up_to_date, Just iface) + where + -- Only look in current directory, with suffix .hi + doc_str = sep [ptext SLIT("need usage info from"), ppr mod_name] +\end{code} + +\begin{code} +upToDate = True +outOfDate = False + +checkModUsage :: [ImportVersion OccName] -> RnMG Bool +-- Given the usage information extracted from the old +-- M.hi file for the module being compiled, figure out +-- whether M needs to be recompiled. + +checkModUsage [] = returnRn upToDate -- Yes! Everything is up to date! + +checkModUsage ((mod_name, _, _, NothingAtAll) : rest) + -- If CurrentModule.hi contains + -- import Foo :: ; + -- then that simply records that Foo lies below CurrentModule in the + -- hierarchy, but CurrentModule doesn't depend in any way on Foo. + -- In this case we don't even want to open Foo's interface. + = traceRn (ptext SLIT("Nothing used from:") <+> ppr mod_name) `thenRn_` + checkModUsage rest -- This one's ok, so check the rest + +checkModUsage ((mod_name, _, _, whats_imported) : rest) + = tryLoadInterface doc_str mod_name ImportBySystem `thenRn` \ (ifaces, maybe_err) -> + case maybe_err of { + Just err -> out_of_date (sep [ptext SLIT("Can't find version number for module"), + ppr mod_name]) ; + -- Couldn't find or parse a module mentioned in the + -- old interface file. Don't complain -- it might just be that + -- the current module doesn't need that import and it's been deleted + + Nothing -> + let + (_, new_mod_vers, new_fix_vers, new_rule_vers, _, _) + = case lookupFM (iImpModInfo ifaces) mod_name of + Just (_, _, Just stuff) -> stuff + + old_mod_vers = case whats_imported of + Everything v -> v + Specifically v _ _ _ -> v + -- NothingAtAll case dealt with by previous eqn for checkModUsage + in + -- If the module version hasn't changed, just move on + if new_mod_vers == old_mod_vers then + traceRn (sep [ptext SLIT("Module version unchanged:"), ppr mod_name]) + `thenRn_` checkModUsage rest + else + traceRn (sep [ptext SLIT("Module version has changed:"), ppr mod_name]) + `thenRn_` + -- Module version changed, so check entities inside + + -- If the usage info wants to say "I imported everything from this module" + -- it does so by making whats_imported equal to Everything + -- In that case, we must recompile + case whats_imported of { -- NothingAtAll dealt with earlier + + Everything _ + -> out_of_date (ptext SLIT("...and I needed the whole module")) ; + + Specifically _ old_fix_vers old_rule_vers old_local_vers -> + + if old_fix_vers /= new_fix_vers then + out_of_date (ptext SLIT("Fixities changed")) + else if old_rule_vers /= new_rule_vers then + out_of_date (ptext SLIT("Rules changed")) + else + -- Non-empty usage list, so check item by item + checkEntityUsage mod_name (iDecls ifaces) old_local_vers `thenRn` \ up_to_date -> + if up_to_date then + traceRn (ptext SLIT("...but the bits I use haven't.")) `thenRn_` + checkModUsage rest -- This one's ok, so check the rest + else + returnRn outOfDate -- This one failed, so just bail out now + }} + where + doc_str = sep [ptext SLIT("need version info for"), ppr mod_name] + + +checkEntityUsage mod decls [] + = returnRn upToDate -- Yes! All up to date! + +checkEntityUsage mod decls ((occ_name,old_vers) : rest) + = newGlobalName mod occ_name `thenRn` \ name -> + case lookupNameEnv decls name of + + Nothing -> -- We used it before, but it ain't there now + out_of_date (sep [ptext SLIT("No longer exported:"), ppr name]) + + Just (new_vers,_,_,_) -- It's there, but is it up to date? + | new_vers == old_vers + -- Up to date, so check the rest + -> checkEntityUsage mod decls rest + + | otherwise + -- Out of date, so bale out + -> out_of_date (sep [ptext SLIT("Out of date:"), ppr name]) + +out_of_date msg = traceRn msg `thenRn_` returnRn outOfDate +-} +\end{code} + +