X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=ghc%2Fcompiler%2Frename%2FRnNames.lhs;h=62cb2dbb837bf3263f184cf3cae82f6eb178935a;hb=3721dd37a707d2aacb5cac814410a78096e28a2c;hp=a33df882cb40023c58ecaf972562c3c6398601c1;hpb=33d4a6bdb9a9b267464459aa049a25f4542305f1;p=ghc-hetmet.git diff --git a/ghc/compiler/rename/RnNames.lhs b/ghc/compiler/rename/RnNames.lhs index a33df88..62cb2db 100644 --- a/ghc/compiler/rename/RnNames.lhs +++ b/ghc/compiler/rename/RnNames.lhs @@ -5,200 +5,294 @@ \begin{code} module RnNames ( - getGlobalNames + rnImports, importsFromLocalDecls, exportsFromAvail, + reportUnusedNames, reportDeprecations, + mkModDeps, exportsToAvails ) where #include "HsVersions.h" -import CmdLineOpts ( DynFlag(..), opt_NoImplicitPrelude ) - -import HsSyn ( HsModule(..), HsDecl(..), IE(..), ieName, ImportDecl(..), - ForeignDecl(..), ForKind(..), isDynamicExtName, - collectTopBinders - ) -import RdrHsSyn ( RdrNameIE, RdrNameImportDecl, - RdrNameHsModule, RdrNameHsDecl +import CmdLineOpts ( DynFlag(..) ) +import HsSyn ( IE(..), ieName, ImportDecl(..), LImportDecl, + ForeignDecl(..), HsGroup(..), + collectGroupBinders, tyClDeclNames ) -import RnIfaces ( getInterfaceExports, recordLocalSlurps ) -import RnHiFiles ( getTyClDeclBinders ) import RnEnv -import RnMonad +import IfaceEnv ( lookupOrig, newGlobalBinder ) +import LoadIface ( loadSrcInterface ) +import TcRnMonad import FiniteMap -import PrelNames ( pRELUDE_Name, mAIN_Name, main_RDR ) -import UniqFM ( lookupUFM ) -import Bag ( bagToList ) -import Module ( ModuleName, mkModuleInThisPackage, WhereFrom(..) ) +import PrelNames ( pRELUDE_Name, isBuiltInSyntaxName, isUnboundName, + main_RDR_Unqual ) +import Module ( Module, ModuleName, moduleName, mkPackageModule, + moduleNameUserString, isHomeModule, + unitModuleEnvByName, unitModuleEnv, + lookupModuleEnvByName, moduleEnvElts ) +import Name ( Name, nameSrcLoc, nameOccName, nameModuleName, + nameParent, nameParent_maybe, isExternalName, nameModule ) import NameSet -import Name ( Name, nameSrcLoc, - setLocalNameSort, nameOccName, nameEnvElts ) -import HscTypes ( Provenance(..), ImportReason(..), GlobalRdrEnv, - GenAvailInfo(..), AvailInfo, Avails, AvailEnv ) -import RdrName ( RdrName, rdrNameOcc, setRdrNameOcc, mkRdrQual, mkRdrUnqual, isUnqual ) -import OccName ( setOccNameSpace, dataName ) -import NameSet ( elemNameSet, emptyNameSet ) -import SrcLoc ( SrcLoc ) +import NameEnv +import OccName ( srcDataName, isTcOcc, occNameFlavour, OccEnv, + mkOccEnv, lookupOccEnv, emptyOccEnv, extendOccEnv ) +import HscTypes ( GenAvailInfo(..), AvailInfo, Avails, GhciMode(..), + IfaceExport, HomePackageTable, PackageIfaceTable, + availName, availNames, availsToNameSet, unQualInScope, + Deprecs(..), ModIface(..), Dependencies(..), lookupIface, + ExternalPackageState(..) + ) +import RdrName ( RdrName, rdrNameOcc, setRdrNameSpace, + GlobalRdrEnv, mkGlobalRdrEnv, GlobalRdrElt(..), + emptyGlobalRdrEnv, plusGlobalRdrEnv, globalRdrEnvElts, + unQualOK, lookupGRE_Name, + Provenance(..), ImportSpec(..), + isLocalGRE, pprNameProvenance ) import Outputable -import Maybes ( maybeToBool, catMaybes, mapMaybe ) -import UniqFM ( emptyUFM, listToUFM ) +import Maybes ( isJust, isNothing, catMaybes, mapCatMaybes, seqMaybe ) +import SrcLoc ( noSrcLoc, Located(..), mkGeneralSrcSpan, + unLoc, noLoc ) +import BasicTypes ( DeprecTxt ) import ListSetOps ( removeDups ) -import Util ( sortLt ) -import List ( partition ) +import Util ( sortLt, notNull, isSingleton ) +import List ( partition, insert ) +import IO ( openFile, IOMode(..) ) \end{code} %************************************************************************ %* * -\subsection{Get global names} + rnImports %* * %************************************************************************ \begin{code} -getGlobalNames :: RdrNameHsModule - -> RnMG (Maybe (GlobalRdrEnv, -- Maps all in-scope things - GlobalRdrEnv, -- Maps just *local* things - Avails, -- The exported stuff - AvailEnv -- Maps a name to its parent AvailInfo - -- Just for in-scope things only - )) - -- Nothing => no need to recompile - -getGlobalNames (HsModule this_mod _ exports imports decls _ mod_loc) - = -- These two fix-loops are to get the right - -- provenance information into a Name - fixRn ( \ ~(Just (rec_gbl_env, _, rec_export_avails, _)) -> - - let - rec_unqual_fn :: Name -> Bool -- Is this chap in scope unqualified? - rec_unqual_fn = unQualInScope rec_gbl_env - - rec_exp_fn :: Name -> Bool - rec_exp_fn = mk_export_fn (availsToNameSet rec_export_avails) - in - - -- PROCESS LOCAL DECLS - -- Do these *first* so that the correct provenance gets - -- into the global name cache. - importsFromLocalDecls this_mod rec_exp_fn decls - `thenRn` \ (local_gbl_env, local_mod_avails) -> +rnImports :: [LImportDecl RdrName] + -> RnM (GlobalRdrEnv, ImportAvails) - -- PROCESS IMPORT DECLS +rnImports imports + = -- PROCESS IMPORT DECLS -- Do the non {- SOURCE -} ones first, so that we get a helpful -- warning for {- SOURCE -} ones that are unnecessary + getModule `thenM` \ this_mod -> + doptM Opt_NoImplicitPrelude `thenM` \ opt_no_prelude -> let + all_imports = mk_prel_imports this_mod opt_no_prelude ++ imports (source, ordinary) = partition is_source_import all_imports - is_source_import (ImportDecl _ ImportByUserSource _ _ _ _) = True - is_source_import other = False + is_source_import (L _ (ImportDecl _ is_boot _ _ _)) = is_boot + + get_imports = importsFromImportDecl this_mod in - mapAndUnzipRn (importsFromImportDecl rec_unqual_fn) ordinary - `thenRn` \ (imp_gbl_envs1, imp_avails_s1) -> - mapAndUnzipRn (importsFromImportDecl rec_unqual_fn) source - `thenRn` \ (imp_gbl_envs2, imp_avails_s2) -> + mappM get_imports ordinary `thenM` \ stuff1 -> + mappM get_imports source `thenM` \ stuff2 -> -- COMBINE RESULTS - -- We put the local env second, so that a local provenance - -- "wins", even if a module imports itself. let + (imp_gbl_envs, imp_avails) = unzip (stuff1 ++ stuff2) gbl_env :: GlobalRdrEnv - imp_gbl_env = foldr plusGlobalRdrEnv emptyRdrEnv (imp_gbl_envs2 ++ imp_gbl_envs1) - gbl_env = imp_gbl_env `plusGlobalRdrEnv` local_gbl_env + gbl_env = foldr plusGlobalRdrEnv emptyGlobalRdrEnv imp_gbl_envs - all_avails :: ExportAvails - all_avails = foldr plusExportAvails local_mod_avails (imp_avails_s2 ++ imp_avails_s1) - (_, global_avail_env) = all_avails + all_avails :: ImportAvails + all_avails = foldr plusImportAvails emptyImportAvails imp_avails in - - -- TRY FOR EARLY EXIT - -- We can't go for an early exit before this because we have to check - -- for name clashes. Consider: - -- - -- module A where module B where - -- import B h = True - -- f = h - -- - -- Suppose I've compiled everything up, and then I add a - -- new definition to module B, that defines "f". - -- - -- Then I must detect the name clash in A before going for an early - -- exit. The early-exit code checks what's actually needed from B - -- to compile A, and of course that doesn't include B.f. That's - -- why we wait till after the plusEnv stuff to do the early-exit. - - -- Check For early exit - checkErrsRn `thenRn` \ no_errs_so_far -> - if not no_errs_so_far then - -- Found errors already, so exit now - returnRn Nothing - else - - -- PROCESS EXPORT LISTS - exportsFromAvail this_mod exports all_avails gbl_env `thenRn` \ export_avails -> - - -- ALL DONE - returnRn (Just (gbl_env, local_gbl_env, export_avails, global_avail_env)) - ) + returnM (gbl_env, all_avails) where - all_imports = prel_imports ++ imports - -- NB: opt_NoImplicitPrelude is slightly different to import Prelude (); - -- because the former doesn't even look at Prelude.hi for instance declarations, - -- whereas the latter does. - prel_imports | this_mod == pRELUDE_Name || - explicit_prelude_import || - opt_NoImplicitPrelude - = [] - - | otherwise = [ImportDecl pRELUDE_Name - ImportByUser - False {- Not qualified -} - Nothing {- No "as" -} - Nothing {- No import list -} - mod_loc] - + -- because the former doesn't even look at Prelude.hi for instance + -- declarations, whereas the latter does. + mk_prel_imports this_mod no_prelude + | moduleName this_mod == pRELUDE_Name + || explicit_prelude_import + || no_prelude + = [] + + | otherwise = [preludeImportDecl] + explicit_prelude_import - = not (null [ () | (ImportDecl mod _ _ _ _ _) <- imports, mod == pRELUDE_Name ]) + = notNull [ () | L _ (ImportDecl mod _ _ _ _) <- imports, + unLoc mod == pRELUDE_Name ] + +preludeImportDecl + = L loc $ + ImportDecl (L loc pRELUDE_Name) + False {- Not a boot interface -} + False {- Not qualified -} + Nothing {- No "as" -} + Nothing {- No import list -} + where + loc = mkGeneralSrcSpan FSLIT("Implicit import declaration") \end{code} \begin{code} -importsFromImportDecl :: (Name -> Bool) -- OK to omit qualifier - -> RdrNameImportDecl - -> RnMG (GlobalRdrEnv, - ExportAvails) +importsFromImportDecl :: Module + -> LImportDecl RdrName + -> RnM (GlobalRdrEnv, ImportAvails) -importsFromImportDecl is_unqual (ImportDecl imp_mod_name from qual_only as_mod import_spec iloc) - = pushSrcLocRn iloc $ - getInterfaceExports imp_mod_name from `thenRn` \ (imp_mod, avails) -> +importsFromImportDecl this_mod + (L loc (ImportDecl loc_imp_mod_name want_boot qual_only as_mod imp_details)) + = + addSrcSpan loc $ - if null avails then - -- If there's an error in getInterfaceExports, (e.g. interface + -- If there's an error in loadInterface, (e.g. interface -- file not found) we get lots of spurious errors from 'filterImports' - returnRn (emptyRdrEnv, mkEmptyExportAvails imp_mod_name) - else + let + imp_mod_name = unLoc loc_imp_mod_name + this_mod_name = moduleName this_mod + doc = ppr imp_mod_name <+> ptext SLIT("is directly imported") + in + loadSrcInterface doc imp_mod_name want_boot `thenM` \ iface -> - filterImports imp_mod_name import_spec avails `thenRn` \ (filtered_avails, hides, explicits) -> + -- Compiler sanity check: if the import didn't say + -- {-# SOURCE #-} we should not get a hi-boot file + WARN( not want_boot && mi_boot iface, ppr imp_mod_name ) + + -- Issue a user warning for a redundant {- SOURCE -} import + -- NB that we arrange to read all the ordinary imports before + -- any of the {- SOURCE -} imports + warnIf (want_boot && not (mi_boot iface)) + (warnRedundantSourceImport imp_mod_name) `thenM_` let - mk_provenance name = NonLocalDef (UserImport imp_mod iloc (name `elemNameSet` explicits)) - (is_unqual name) + imp_mod = mi_module iface + deprecs = mi_deprecs iface + is_orph = mi_orphan iface + deps = mi_deps iface + + filtered_exports = filter not_this_mod (mi_exports iface) + not_this_mod (mod,_) = mod /= this_mod_name + -- If the module exports anything defined in this module, just ignore it. + -- Reason: otherwise it looks as if there are two local definition sites + -- for the thing, and an error gets reported. Easiest thing is just to + -- filter them out up front. This situation only arises if a module + -- imports itself, or another module that imported it. (Necessarily, + -- this invoves a loop.) + -- + -- Tiresome consequence: if you say + -- module A where + -- import B( AType ) + -- type AType = ... + -- + -- module B( AType ) where + -- import {-# SOURCE #-} A( AType ) + -- + -- then you'll get a 'B does not export AType' message. Oh well. + + qual_mod_name = case as_mod of + Nothing -> imp_mod_name + Just another_name -> another_name + imp_spec = ImportSpec { is_mod = imp_mod_name, is_qual = qual_only, + is_loc = loc, is_as = qual_mod_name } in - qualifyImports imp_mod_name - (not qual_only) -- Maybe want unqualified names - as_mod hides - mk_provenance - filtered_avails + -- Get the total imports, and filter them according to the import list + exportsToAvails filtered_exports `thenM` \ total_avails -> + filterImports iface imp_spec + imp_details total_avails `thenM` \ (avail_env, gbl_env) -> + + let + -- Compute new transitive dependencies + orphans | is_orph = insert imp_mod_name (dep_orphs deps) + | otherwise = dep_orphs deps + + (dependent_mods, dependent_pkgs) + | isHomeModule imp_mod + = -- Imported module is from the home package + -- Take its dependent modules and + -- (a) remove this_mod (might be there as a hi-boot) + -- (b) add imp_mod itself + -- Take its dependent packages unchanged + ((imp_mod_name, want_boot) : filter not_self (dep_mods deps), dep_pkgs deps) + + | otherwise + = -- Imported module is from another package + -- Dump the dependent modules + -- Add the package imp_mod comes from to the dependent packages + -- from imp_mod + ([], insert (mi_package iface) (dep_pkgs deps)) + + not_self (m, _) = m /= this_mod_name + + import_all = case imp_details of + Just (is_hiding, ls) -- Imports are spec'd explicitly + | not is_hiding -> Just (not (null ls)) + _ -> Nothing -- Everything is imported, + -- (or almost everything [hiding]) + + -- unqual_avails is the Avails that are visible in *unqualified* form + -- We need to know this so we know what to export when we see + -- module M ( module P ) where ... + -- Then we must export whatever came from P unqualified. + imports = ImportAvails { + imp_qual = unitModuleEnvByName qual_mod_name avail_env, + imp_env = avail_env, + imp_mods = unitModuleEnv imp_mod (imp_mod, import_all), + imp_orphs = orphans, + imp_dep_mods = mkModDeps dependent_mods, + imp_dep_pkgs = dependent_pkgs } + + in + -- Complain if we import a deprecated module + ifOptM Opt_WarnDeprecations ( + case deprecs of + DeprecAll txt -> addWarn (moduleDeprec imp_mod_name txt) + other -> returnM () + ) `thenM_` + + returnM (gbl_env, imports) + +exportsToAvails :: [IfaceExport] -> TcRnIf gbl lcl Avails +exportsToAvails exports + = do { avails_by_module <- mappM do_one exports + ; return (concat avails_by_module) } + where + do_one (mod_name, exports) = mapM (do_avail mod_name) exports + do_avail mod_nm (Avail n) = do { n' <- lookupOrig mod_nm n; + ; return (Avail n') } + do_avail mod_nm (AvailTC n ns) = do { n' <- lookupOrig mod_nm n + ; ns' <- mappM (lookup_sub n') ns + ; return (AvailTC n' ns') } + where + mod = mkPackageModule mod_nm -- Not necessarily right yet + lookup_sub parent occ = newGlobalBinder mod occ (Just parent) noSrcLoc + -- Hack alert! Notice the newGlobalBinder. It ensures that the subordinate + -- names record their parent; and that in turn ensures that the GlobalRdrEnv + -- has the correct parent for all the names in its range. + -- For imported things, we only suck in the binding site later, if ever. + -- Reason for all this: + -- Suppose module M exports type A.T, and constructor A.MkT + -- Then, we know that A.MkT is a subordinate name of A.T, + -- even though we aren't at the binding site of A.T + -- And it's important, because we may simply re-export A.T + -- without ever sucking in the declaration itself. + +warnRedundantSourceImport mod_name + = ptext SLIT("Unnecessary {- SOURCE -} in the import of module") + <+> quotes (ppr mod_name) \end{code} -\begin{code} -importsFromLocalDecls mod_name rec_exp_fn decls - = mapRn (getLocalDeclBinders (newLocalName mod rec_exp_fn)) decls `thenRn` \ avails_s -> +%************************************************************************ +%* * + importsFromLocalDecls +%* * +%************************************************************************ - let - avails = concat avails_s +From the top-level declarations of this module produce + * the lexical environment + * the ImportAvails +created by its bindings. + +Complain about duplicate bindings +\begin{code} +importsFromLocalDecls :: HsGroup RdrName + -> RnM (GlobalRdrEnv, ImportAvails) +importsFromLocalDecls group + = getModule `thenM` \ this_mod -> + getLocalDeclBinders this_mod group `thenM` \ avails -> + -- The avails that are returned don't include the "system" names + let all_names :: [Name] -- All the defns; no dups eliminated all_names = [name | avail <- avails, name <- availNames avail] @@ -206,66 +300,92 @@ importsFromLocalDecls mod_name rec_exp_fn decls (_, dups) = removeDups compare all_names in -- Check for duplicate definitions - mapRn_ (addErrRn . dupDeclErr) dups `thenRn_` - - -- Record that locally-defined things are available - recordLocalSlurps avails `thenRn_` - - -- Build the environment - qualifyImports mod_name - True -- Want unqualified names - Nothing -- no 'as M' - [] -- Hide nothing - (\n -> LocalDef) -- Provenance is local - avails - where - mod = mkModuleInThisPackage mod_name + -- The complaint will come out as "Multiple declarations of Foo.f" because + -- since 'f' is in the env twice, the unQualInScope used by the error-msg + -- printer returns False. It seems awkward to fix, unfortunately. + mappM_ (addErr . dupDeclErr) dups `thenM_` ---------------------------- -getLocalDeclBinders :: (RdrName -> SrcLoc -> RnMG Name) - -> RdrNameHsDecl -> RnMG Avails -getLocalDeclBinders new_name (ValD binds) - = mapRn do_one (bagToList (collectTopBinders binds)) - where - do_one (rdr_name, loc) = new_name rdr_name loc `thenRn` \ name -> - returnRn (Avail name) + doptM Opt_NoImplicitPrelude `thenM` \ implicit_prelude -> + let + mod_name = moduleName this_mod + prov = LocalDef mod_name + gbl_env = mkGlobalRdrEnv gres + gres = [ GRE { gre_name = name, gre_prov = prov} + | name <- all_names] + + -- Optimisation: filter out names for built-in syntax + -- They just clutter up the environment (esp tuples), and the parser + -- will generate Exact RdrNames for them, so the cluttered + -- envt is no use. To avoid doing this filter all the time, + -- we use -fno-implicit-prelude as a clue that the filter is + -- worth while. Really, it's only useful for GHC.Base and GHC.Tuple. + -- + -- It's worth doing because it makes the environment smaller for + -- every module that imports the Prelude + -- + -- Note: don't filter the gbl_env (hence avails, not avails' in + -- defn of gbl_env above). Stupid reason: when parsing + -- data type decls, the constructors start as Exact tycon-names, + -- and then get turned into data con names by zapping the name space; + -- but that stops them being Exact, so they get looked up. + -- Ditto in fixity decls; e.g. infix 5 : + -- Sigh. It doesn't matter because it only affects the Data.Tuple really. + -- The important thing is to trim down the exports. + + avails' | implicit_prelude = filter not_built_in_syntax avails + | otherwise = avails + not_built_in_syntax a = not (all isBuiltInSyntaxName (availNames a)) + -- Only filter it if all the names of the avail are built-in + -- In particular, lists have (:) which is not built in syntax + -- so we don't filter it out. [Sept 03: wrong: see isBuiltInSyntaxName] + + avail_env = mkAvailEnv avails' + imports = emptyImportAvails { + imp_qual = unitModuleEnv this_mod avail_env, + imp_env = avail_env + } + in + returnM (gbl_env, imports) +\end{code} -getLocalDeclBinders new_name (TyClD tycl_decl) - = getTyClDeclBinders new_name tycl_decl `thenRn` \ avail -> - returnRn [avail] -getLocalDeclBinders new_name (ForD (ForeignDecl nm kind _ ext_nm _ loc)) - | binds_haskell_name kind - = new_name nm loc `thenRn` \ name -> - returnRn [Avail name] +%********************************************************* +%* * +\subsection{Getting binders out of a declaration} +%* * +%********************************************************* - | otherwise -- a foreign export - = lookupOrigName nm `thenRn_` - returnRn [] - where - binds_haskell_name (FoImport _) = True - binds_haskell_name FoLabel = True - binds_haskell_name FoExport = isDynamicExtName ext_nm - -getLocalDeclBinders new_name (FixD _) = returnRn [] -getLocalDeclBinders new_name (DeprecD _) = returnRn [] -getLocalDeclBinders new_name (DefD _) = returnRn [] -getLocalDeclBinders new_name (InstD _) = returnRn [] -getLocalDeclBinders new_name (RuleD _) = returnRn [] - - ---------------------------- -newLocalName mod rec_exp_fn rdr_name loc - = check_unqual rdr_name loc `thenRn_` - newTopBinder mod rdr_name loc `thenRn` \ name -> - returnRn (setLocalNameSort name (rec_exp_fn name)) +@getLocalDeclBinders@ returns the names for an @HsDecl@. It's +used for source code. + + *** See "THE NAMING STORY" in HsDecls **** + +\begin{code} +getLocalDeclBinders :: Module -> HsGroup RdrName -> RnM [AvailInfo] +getLocalDeclBinders mod (HsGroup {hs_valds = val_decls, + hs_tyclds = tycl_decls, + hs_fords = foreign_decls }) + = -- For type and class decls, we generate Global names, with + -- no export indicator. They need to be global because they get + -- permanently bound into the TyCons and Classes. They don't need + -- an export indicator because they are all implicitly exported. + + mappM new_tc tycl_decls `thenM` \ tc_avails -> + mappM new_simple (for_hs_bndrs ++ val_hs_bndrs) `thenM` \ simple_avails -> + returnM (tc_avails ++ simple_avails) where - -- There should never be a qualified name in a binding position (except in instance decls) - -- The parser doesn't check this because the same parser parses instance decls - check_unqual rdr_name loc - | isUnqual rdr_name = returnRn () - | otherwise = qualNameErr (text "the binding for" <+> quotes (ppr rdr_name)) - (rdr_name,loc) + new_simple rdr_name = newTopSrcBinder mod Nothing rdr_name `thenM` \ name -> + returnM (Avail name) + + val_hs_bndrs = collectGroupBinders val_decls + for_hs_bndrs = [nm | L _ (ForeignImport nm _ _ _) <- foreign_decls] + + new_tc tc_decl + = newTopSrcBinder mod Nothing main_rdr `thenM` \ main_name -> + mappM (newTopSrcBinder mod (Just main_name)) sub_rdrs `thenM` \ sub_names -> + returnM (AvailTC main_name (main_name : sub_names)) + where + (main_rdr : sub_rdrs) = tyClDeclNames (unLoc tc_decl) \end{code} @@ -279,77 +399,97 @@ newLocalName mod rec_exp_fn rdr_name loc available, and filters it through the import spec (if any). \begin{code} -filterImports :: ModuleName -- The module being imported - -> Maybe (Bool, [RdrNameIE]) -- Import spec; True => hiding +filterImports :: ModIface + -> ImportSpec -- The span for the entire import decl + -> Maybe (Bool, [Located (IE RdrName)]) -- Import spec; True => hiding -> [AvailInfo] -- What's available - -> RnMG ([AvailInfo], -- What's actually imported - [AvailInfo], -- What's to be hidden - -- (the unqualified version, that is) - -- (We need to return both the above sets, because - -- the qualified version is never hidden; so we can't - -- implement hiding by reducing what's imported.) - NameSet) -- What was imported explicitly + -> RnM (AvailEnv, -- What's imported + GlobalRdrEnv) -- ...in two forms -- Complains if import spec mentions things that the module doesn't export -- Warns/informs if import spec contains duplicates. -filterImports mod Nothing imports - = returnRn (imports, [], emptyNameSet) - -filterImports mod (Just (want_hiding, import_items)) avails - = flatMapRn get_item import_items `thenRn` \ avails_w_explicits -> +mkGenericRdrEnv imp_spec avails + = mkGlobalRdrEnv [ GRE { gre_name = name, gre_prov = Imported [imp_spec] False } + | avail <- avails, name <- availNames avail ] + +filterImports iface imp_spec Nothing total_avails + = returnM (mkAvailEnv total_avails, mkGenericRdrEnv imp_spec total_avails) + +filterImports iface imp_spec (Just (want_hiding, import_items)) total_avails + = mapAndUnzipM (addLocM get_item) import_items `thenM` \ (avails, gres) -> let - (item_avails, explicits_s) = unzip avails_w_explicits - explicits = foldl addListToNameSet emptyNameSet explicits_s + all_avails = foldr plusAvailEnv emptyAvailEnv avails + rdr_env = foldr plusGlobalRdrEnv emptyGlobalRdrEnv gres in - if want_hiding - then - -- All imported; item_avails to be hidden - returnRn (avails, item_avails, emptyNameSet) + if not want_hiding then + returnM (all_avails, rdr_env) else - -- Just item_avails imported; nothing to be hidden - returnRn (item_avails, [], explicits) + let -- Hide stuff in all_avails + hidden = availsToNameSet (availEnvElts all_avails) + keep n = not (n `elemNameSet` hidden) + pruned_avails = pruneAvails keep total_avails + in + returnM (mkAvailEnv pruned_avails, mkGenericRdrEnv imp_spec pruned_avails) where - import_fm :: FiniteMap OccName AvailInfo - import_fm = listToFM [ (nameOccName name, avail) - | avail <- avails, + import_fm :: OccEnv AvailInfo + import_fm = mkOccEnv [ (nameOccName name, avail) + | avail <- total_avails, name <- availNames avail] -- Even though availNames returns data constructors too, -- they won't make any difference because naked entities like T -- in an import list map to TcOccs, not VarOccs. - bale_out item = addErrRn (badImportItemErr mod item) `thenRn_` - returnRn [] - - get_item item@(IEModuleContents _) = bale_out item + bale_out item = addErr (badImportItemErr iface imp_spec item) `thenM_` + returnM (emptyAvailEnv, emptyGlobalRdrEnv) - get_item item@(IEThingAll _) + succeed_with :: Bool -> AvailInfo -> RnM (AvailEnv, GlobalRdrEnv) + succeed_with all_explicit avail + = do { loc <- getSrcSpanM + ; returnM (unitAvailEnv avail, + mkGlobalRdrEnv (map (mk_gre loc) (availNames avail))) } + where + mk_gre loc name = GRE { gre_name = name, + gre_prov = Imported [this_imp_spec loc] (explicit name) } + this_imp_spec loc = imp_spec { is_loc = loc } + explicit name = all_explicit || name == main_name + main_name = availName avail + + get_item :: IE RdrName -> RnM (AvailEnv, GlobalRdrEnv) + -- Empty result for a bad item. + -- Singleton result is typical case. + -- Can have two when we are hiding, and mention C which might be + -- both a class and a data constructor. + get_item item@(IEModuleContents _) + = bale_out item + + get_item item@(IEThingAll tc) = case check_item item of Nothing -> bale_out item Just avail@(AvailTC _ [n]) -> -- This occurs when you import T(..), but -- only export T abstractly. The single [n] -- in the AvailTC is the type or class itself - addWarnRn (dodgyImportWarn mod item) `thenRn_` - returnRn [(avail, [availName avail])] - Just avail -> returnRn [(avail, [availName avail])] + ifOptM Opt_WarnMisc (addWarn (dodgyImportWarn tc)) `thenM_` + succeed_with False avail + Just avail -> succeed_with False avail get_item item@(IEThingAbs n) | want_hiding -- hiding( C ) -- Here the 'C' can be a data constructor *or* a type/class - = case catMaybes [check_item item, check_item (IEThingAbs data_n)] of - [] -> bale_out item - avails -> returnRn [(a, []) | a <- avails] - -- The 'explicits' list is irrelevant when hiding + = case catMaybes [check_item item, check_item (IEVar data_n)] of + [] -> bale_out item + avails -> returnM (mkAvailEnv avails, emptyGlobalRdrEnv) + -- The GlobalRdrEnv result is irrelevant when hiding where - data_n = setRdrNameOcc n (setOccNameSpace (rdrNameOcc n) dataName) + data_n = setRdrNameSpace n srcDataName get_item item = case check_item item of Nothing -> bale_out item - Just avail -> returnRn [(avail, availNames avail)] + Just avail -> succeed_with True avail check_item item - | not (maybeToBool maybe_in_import_avails) || - not (maybeToBool maybe_filtered_avail) + | isNothing maybe_in_import_avails || + isNothing maybe_filtered_avail = Nothing | otherwise @@ -357,109 +497,48 @@ filterImports mod (Just (want_hiding, import_items)) avails where wanted_occ = rdrNameOcc (ieName item) - maybe_in_import_avails = lookupFM import_fm wanted_occ + maybe_in_import_avails = lookupOccEnv import_fm wanted_occ Just avail = maybe_in_import_avails maybe_filtered_avail = filterAvail item avail Just filtered_avail = maybe_filtered_avail \end{code} - - -%************************************************************************ -%* * -\subsection{Qualifiying imports} -%* * -%************************************************************************ - -@qualifyImports@ takes the @ExportEnv@ after filtering through the import spec -of an import decl, and deals with producing an @RnEnv@ with the -right qualified names. It also turns the @Names@ in the @ExportEnv@ into -fully fledged @Names@. - \begin{code} -qualifyImports :: ModuleName -- Imported module - -> Bool -- True <=> want unqualified import - -> Maybe ModuleName -- Optional "as M" part - -> [AvailInfo] -- What's to be hidden - -> (Name -> Provenance) - -> Avails -- Whats imported and how - -> RnMG (GlobalRdrEnv, ExportAvails) - -qualifyImports this_mod unqual_imp as_mod hides mk_provenance avails - = - -- Make the name environment. We're talking about a - -- single module here, so there must be no name clashes. - -- In practice there only ever will be if it's the module - -- being compiled. - let - -- Add the things that are available - name_env1 = foldl add_avail emptyRdrEnv avails - - -- Delete things that are hidden - name_env2 = foldl del_avail name_env1 hides - - -- Create the export-availability info - export_avails = mkExportAvails qual_mod unqual_imp name_env2 avails - in - returnRn (name_env2, export_avails) - - where - qual_mod = case as_mod of - Nothing -> this_mod - Just another_name -> another_name - - add_avail :: GlobalRdrEnv -> AvailInfo -> GlobalRdrEnv - add_avail env avail = foldl add_name env (availNames avail) - - add_name env name - | unqual_imp = env2 - | otherwise = env1 - where - env1 = addOneToGlobalRdrEnv env (mkRdrQual qual_mod occ) (name,prov) - env2 = addOneToGlobalRdrEnv env1 (mkRdrUnqual occ) (name,prov) - occ = nameOccName name - prov = mk_provenance name - - del_avail env avail = foldl delOneFromGlobalRdrEnv env rdr_names - where - rdr_names = map (mkRdrUnqual . nameOccName) (availNames avail) - - -mkEmptyExportAvails :: ModuleName -> ExportAvails -mkEmptyExportAvails mod_name = (unitFM mod_name [], emptyUFM) - -mkExportAvails :: ModuleName -> Bool -> GlobalRdrEnv -> [AvailInfo] -> ExportAvails -mkExportAvails mod_name unqual_imp name_env avails - = (mod_avail_env, entity_avail_env) +filterAvail :: IE RdrName -- Wanted + -> AvailInfo -- Available + -> Maybe AvailInfo -- Resulting available; + -- Nothing if (any of the) wanted stuff isn't there + +filterAvail ie@(IEThingWith want wants) avail@(AvailTC n ns) + | sub_names_ok = Just (AvailTC n (filter is_wanted ns)) + | otherwise = Nothing where - mod_avail_env = unitFM mod_name unqual_avails - - -- unqual_avails is the Avails that are visible in *unqualfied* form - -- (1.4 Report, Section 5.1.1) - -- For example, in - -- import T hiding( f ) - -- we delete f from avails - - unqual_avails | not unqual_imp = [] -- Short cut when no unqualified imports - | otherwise = mapMaybe prune avails - - prune (Avail n) | unqual_in_scope n = Just (Avail n) - prune (Avail n) | otherwise = Nothing - prune (AvailTC n ns) | null uqs = Nothing - | otherwise = Just (AvailTC n uqs) - where - uqs = filter unqual_in_scope ns - - unqual_in_scope n = unQualInScope name_env n - - entity_avail_env = listToUFM [ (name,avail) | avail <- avails, - name <- availNames avail] - -plusExportAvails :: ExportAvails -> ExportAvails -> ExportAvails -plusExportAvails (m1, e1) (m2, e2) - = (plusFM_C (++) m1 m2, plusAvailEnv e1 e2) - -- ToDo: wasteful: we do this once for each constructor! + is_wanted name = nameOccName name `elem` wanted_occs + sub_names_ok = all (`elem` avail_occs) wanted_occs + avail_occs = map nameOccName ns + wanted_occs = map rdrNameOcc (want:wants) + +filterAvail (IEThingAbs _) (AvailTC n ns) = ASSERT( n `elem` ns ) + Just (AvailTC n [n]) + +filterAvail (IEThingAbs _) avail@(Avail n) = Just avail -- Type synonyms + +filterAvail (IEVar _) avail@(Avail n) = Just avail +filterAvail (IEVar v) avail@(AvailTC n ns) = Just (AvailTC n (filter wanted ns)) + where + wanted n = nameOccName n == occ + occ = rdrNameOcc v + -- The second equation happens if we import a class op, thus + -- import A( op ) + -- where op is a class operation + +filterAvail (IEThingAll _) avail@(AvailTC _ _) = Just avail + -- We don't complain even if the IE says T(..), but + -- no constrs/class ops of T are available + -- Instead that's caught with a warning by the caller + +filterAvail ie avail = Nothing \end{code} @@ -471,144 +550,407 @@ plusExportAvails (m1, e1) (m2, e2) Processing the export list. -You might think that we should record things that appear in the export list -as ``occurrences'' (using @addOccurrenceName@), but you'd be wrong. -We do check (here) that they are in scope, -but there is no need to slurp in their actual declaration -(which is what @addOccurrenceName@ forces). +You might think that we should record things that appear in the export +list as ``occurrences'' (using @addOccurrenceName@), but you'd be +wrong. We do check (here) that they are in scope, but there is no +need to slurp in their actual declaration (which is what +@addOccurrenceName@ forces). -Indeed, doing so would big trouble when -compiling @PrelBase@, because it re-exports @GHC@, which includes @takeMVar#@, -whose type includes @ConcBase.StateAndSynchVar#@, and so on... +Indeed, doing so would big trouble when compiling @PrelBase@, because +it re-exports @GHC@, which includes @takeMVar#@, whose type includes +@ConcBase.StateAndSynchVar#@, and so on... \begin{code} type ExportAccum -- The type of the accumulating parameter of -- the main worker function in exportsFromAvail = ([ModuleName], -- 'module M's seen so far ExportOccMap, -- Tracks exported occurrence names - AvailEnv) -- The accumulated exported stuff, kept in an env - -- so we can common-up related AvailInfos + NameSet) -- The accumulated exported stuff +emptyExportAccum = ([], emptyOccEnv, emptyNameSet) -type ExportOccMap = FiniteMap OccName (Name, RdrNameIE) +type ExportOccMap = OccEnv (Name, IE RdrName) -- Tracks what a particular exported OccName -- in an export list refers to, and which item -- it came from. It's illegal to export two distinct things -- that have the same occurrence name -exportsFromAvail :: ModuleName - -> Maybe [RdrNameIE] -- Export spec - -> ExportAvails - -> GlobalRdrEnv - -> RnMG Avails +exportsFromAvail :: Bool -- False => no 'module M(..) where' header at all + -> Maybe [Located (IE RdrName)] -- Nothing => no explicit export list + -> RnM NameSet -- Complains if two distinct exports have same OccName -- Warns about identical exports. -- Complains about exports items not in scope -exportsFromAvail this_mod Nothing export_avails global_name_env - = exportsFromAvail this_mod true_exports export_avails global_name_env - where - true_exports = Just $ if this_mod == mAIN_Name - then [IEVar main_RDR] - -- export Main.main *only* unless otherwise specified, - else [IEModuleContents this_mod] - -- but for all other modules export everything. - -exportsFromAvail this_mod (Just export_items) - (mod_avail_env, entity_avail_env) - global_name_env - = doptRn Opt_WarnDuplicateExports `thenRn` \ warn_dup_exports -> - foldlRn (exports_from_item warn_dup_exports) - ([], emptyFM, emptyAvailEnv) export_items - `thenRn` \ (_, _, export_avail_map) -> - let - export_avails :: [AvailInfo] - export_avails = nameEnvElts export_avail_map - in - returnRn export_avails + +exportsFromAvail explicit_mod exports + = do { TcGblEnv { tcg_rdr_env = rdr_env, + tcg_imports = imports } <- getGblEnv ; + + -- If the module header is omitted altogether, then behave + -- as if the user had written "module Main(main) where..." + -- EXCEPT in interactive mode, when we behave as if he had + -- written "module Main where ..." + -- Reason: don't want to complain about 'main' not in scope + -- in interactive mode + ghci_mode <- getGhciMode ; + let { real_exports + | explicit_mod = exports + | ghci_mode == Interactive = Nothing + | otherwise = Just [noLoc (IEVar main_RDR_Unqual)] } ; + exports_from_avail real_exports rdr_env imports } + + +exports_from_avail Nothing rdr_env imports + = -- Export all locally-defined things + -- We do this by filtering the global RdrEnv, + -- keeping only things that are locally-defined + return (mkNameSet [ gre_name gre + | gre <- globalRdrEnvElts rdr_env, + isLocalGRE gre ]) + +exports_from_avail (Just export_items) rdr_env + (ImportAvails { imp_qual = mod_avail_env, + imp_env = entity_avail_env }) + = foldlM (exports_from_litem) emptyExportAccum + export_items `thenM` \ (_, _, exports) -> + returnM exports where - exports_from_item :: Bool -> ExportAccum -> RdrNameIE -> RnMG ExportAccum + exports_from_litem :: ExportAccum -> Located (IE RdrName) -> RnM ExportAccum + exports_from_litem acc = addLocM (exports_from_item acc) - exports_from_item warn_dups acc@(mods, occs, avails) ie@(IEModuleContents mod) + exports_from_item :: ExportAccum -> IE RdrName -> RnM ExportAccum + exports_from_item acc@(mods, occs, exports) ie@(IEModuleContents mod) | mod `elem` mods -- Duplicate export of M - = warnCheckRn warn_dups (dupModuleExport mod) `thenRn_` - returnRn acc + = do { warn_dup_exports <- doptM Opt_WarnDuplicateExports ; + warnIf warn_dup_exports (dupModuleExport mod) ; + returnM acc } | otherwise - = case lookupFM mod_avail_env mod of - Nothing -> failWithRn acc (modExportErr mod) - Just mod_avails -> foldlRn (check_occs ie) occs mod_avails - `thenRn` \ occs' -> - let - avails' = foldl addAvail avails mod_avails - in - returnRn (mod:mods, occs', avails') - - exports_from_item warn_dups acc@(mods, occs, avails) ie - | not (maybeToBool maybe_in_scope) - = failWithRn acc (unknownNameErr (ieName ie)) - - | not (null dup_names) - = addNameClashErrRn rdr_name ((name,prov):dup_names) `thenRn_` - returnRn acc - -#ifdef DEBUG - -- I can't see why this should ever happen; if the thing is in scope - -- at all it ought to have some availability - | not (maybeToBool maybe_avail) - = pprTrace "exportsFromAvail: curious Nothing:" (ppr name) - returnRn acc -#endif - - | not enough_avail - = failWithRn acc (exportItemErr ie) - - | otherwise -- Phew! It's OK! Now to check the occurrence stuff! - - - = warnCheckRn (ok_item ie avail) (dodgyExportWarn ie) `thenRn_` - check_occs ie occs export_avail `thenRn` \ occs' -> - returnRn (mods, occs', addAvail avails export_avail) - - where - rdr_name = ieName ie - maybe_in_scope = lookupFM global_name_env rdr_name - Just ((name,prov):dup_names) = maybe_in_scope - maybe_avail = lookupUFM entity_avail_env name - Just avail = maybe_avail - maybe_export_avail = filterAvail ie avail - enough_avail = maybeToBool maybe_export_avail - Just export_avail = maybe_export_avail - - ok_item (IEThingAll _) (AvailTC _ [n]) = False - -- This occurs when you import T(..), but - -- only export T abstractly. The single [n] - -- in the AvailTC is the type or class itself - ok_item _ _ = True - -check_occs :: RdrNameIE -> ExportOccMap -> AvailInfo -> RnMG ExportOccMap -check_occs ie occs avail - = doptRn Opt_WarnDuplicateExports `thenRn` \ warn_dup_exports -> - foldlRn (check warn_dup_exports) occs (availNames avail) + = case lookupModuleEnvByName mod_avail_env mod of + Nothing -> addErr (modExportErr mod) `thenM_` + returnM acc + + Just avail_env + -> let + new_exports = [ name | avail <- availEnvElts avail_env, + name <- availNames avail, + inScopeUnqual rdr_env name ] + in + + -- This check_occs not only finds conflicts between this item + -- and others, but also internally within this item. That is, + -- if 'M.x' is in scope in several ways, we'll have several + -- members of mod_avails with the same OccName. + check_occs ie occs new_exports `thenM` \ occs' -> + returnM (mod:mods, occs', addListToNameSet exports new_exports) + + exports_from_item acc@(mods, occs, exports) ie + = lookupGlobalOccRn (ieName ie) `thenM` \ name -> + if isUnboundName name then + returnM acc -- Avoid error cascade + else + -- Get the AvailInfo for the parent of the specified name + let + parent = nameParent name + avail = lookupAvailEnv entity_avail_env parent + in + -- Filter out the bits we want + case filterAvail ie avail of { + Nothing -> -- Not enough availability + addErr (exportItemErr ie) `thenM_` + returnM acc ; + + Just export_avail -> + + -- Phew! It's OK! Now to check the occurrence stuff! + + let + new_exports = availNames export_avail + in + checkForDodgyExport ie new_exports `thenM_` + check_occs ie occs new_exports `thenM` \ occs' -> + returnM (mods, occs', addListToNameSet exports new_exports) + } + + +------------------------------- +inScopeUnqual :: GlobalRdrEnv -> Name -> Bool +-- Checks whether the Name is in scope unqualified, +-- regardless of whether it's ambiguous or not +inScopeUnqual env n = any unQualOK (lookupGRE_Name env n) + +------------------------------- +checkForDodgyExport :: IE RdrName -> [Name] -> RnM () +checkForDodgyExport (IEThingAll tc) [n] = addWarn (dodgyExportWarn tc) + -- This occurs when you import T(..), but + -- only export T abstractly. The single [n] + -- in the AvailTC is the type or class itself +checkForDodgyExport _ _ = return () + +------------------------------- +check_occs :: IE RdrName -> ExportOccMap -> [Name] -> RnM ExportOccMap +check_occs ie occs names + = foldlM check occs names where - check warn_dup occs name - = case lookupFM occs name_occ of - Nothing -> returnRn (addToFM occs name_occ (name, ie)) - Just (name', ie') - | name == name' -> -- Duplicate export - warnCheckRn warn_dup - (dupExportWarn name_occ ie ie') - `thenRn_` returnRn occs + check occs name + = case lookupOccEnv occs name_occ of + Nothing -> returnM (extendOccEnv occs name_occ (name, ie)) - | otherwise -> -- Same occ name but different names: an error - failWithRn occs (exportClashErr name_occ ie ie') + Just (name', ie') + | name == name' -- Duplicate export + -> do { warn_dup_exports <- doptM Opt_WarnDuplicateExports ; + warnIf warn_dup_exports (dupExportWarn name_occ ie ie') ; + returnM occs } + + | otherwise -- Same occ name but different names: an error + -> do { global_env <- getGlobalRdrEnv ; + addErr (exportClashErr global_env name name' ie ie') ; + returnM occs } where name_occ = nameOccName name - -mk_export_fn :: NameSet -> (Name -> Bool) -- True => exported -mk_export_fn exported_names = \name -> name `elemNameSet` exported_names \end{code} +%********************************************************* +%* * + Deprecations +%* * +%********************************************************* + +\begin{code} +reportDeprecations :: TcGblEnv -> RnM () +reportDeprecations tcg_env + = ifOptM Opt_WarnDeprecations $ + do { hpt <- getHpt + ; eps <- getEps + ; mapM_ (check hpt (eps_PIT eps)) all_gres } + where + used_names = findUses (tcg_dus tcg_env) emptyNameSet + all_gres = globalRdrEnvElts (tcg_rdr_env tcg_env) + + check hpt pit (GRE {gre_name = name, gre_prov = Imported (imp_spec:_) _}) + | name `elemNameSet` used_names + , Just deprec_txt <- lookupDeprec hpt pit name + = addSrcSpan (is_loc imp_spec) $ + addWarn (sep [ptext SLIT("Deprecated use of") <+> + text (occNameFlavour (nameOccName name)) <+> + quotes (ppr name), + (parens imp_msg), + (ppr deprec_txt) ]) + where + name_mod = nameModuleName name + imp_mod = is_mod imp_spec + imp_msg = ptext SLIT("imported from") <+> ppr imp_mod <> extra + extra | imp_mod == name_mod = empty + | otherwise = ptext SLIT(", but defined in") <+> ppr name_mod + + check hpt pit ok_gre = returnM () -- Local, or not used, or not deprectated + -- The Imported pattern-match: don't deprecate locally defined names + -- For a start, we may be exporting a deprecated thing + -- Also we may use a deprecated thing in the defn of another + -- deprecated things. We may even use a deprecated thing in + -- the defn of a non-deprecated thing, when changing a module's + -- interface + +lookupDeprec :: HomePackageTable -> PackageIfaceTable + -> Name -> Maybe DeprecTxt +lookupDeprec hpt pit n + = case lookupIface hpt pit (nameModule n) of + Just iface -> mi_dep_fn iface n `seqMaybe` -- Bleat if the thing, *or + mi_dep_fn iface (nameParent n) -- its parent*, is deprec'd + Nothing -> pprPanic "lookupDeprec" (ppr n) + -- By now all the interfaces should have been loaded + +gre_is_used :: NameSet -> GlobalRdrElt -> Bool +gre_is_used used_names gre = gre_name gre `elemNameSet` used_names +\end{code} + +%********************************************************* +%* * + Unused names +%* * +%********************************************************* + +\begin{code} +reportUnusedNames :: TcGblEnv -> RnM () +reportUnusedNames gbl_env + = do { warnUnusedTopBinds unused_locals + ; warnUnusedModules unused_imp_mods + ; warnUnusedImports unused_imports + ; warnDuplicateImports dup_imps + ; printMinimalImports minimal_imports } + where + used_names, all_used_names :: NameSet + used_names = findUses (tcg_dus gbl_env) emptyNameSet + all_used_names = used_names `unionNameSets` + mkNameSet (mapCatMaybes nameParent_maybe (nameSetToList used_names)) + -- A use of C implies a use of T, + -- if C was brought into scope by T(..) or T(C) + + -- Collect the defined names from the in-scope environment + defined_names :: [GlobalRdrElt] + defined_names = globalRdrEnvElts (tcg_rdr_env gbl_env) + + -- Note that defined_and_used, defined_but_not_used + -- are both [GRE]; that's why we need defined_and_used + -- rather than just all_used_names + defined_and_used, defined_but_not_used :: [GlobalRdrElt] + (defined_and_used, defined_but_not_used) + = partition (gre_is_used all_used_names) defined_names + + -- Find the duplicate imports + dup_imps = filter is_dup defined_and_used + is_dup (GRE {gre_prov = Imported imp_spec True}) = not (isSingleton imp_spec) + is_dup other = False + + -- Filter out the ones that are + -- (a) defined in this module, and + -- (b) not defined by a 'deriving' clause + -- The latter have an Internal Name, so we can filter them out easily + unused_locals :: [GlobalRdrElt] + unused_locals = filter is_unused_local defined_but_not_used + is_unused_local :: GlobalRdrElt -> Bool + is_unused_local gre = isLocalGRE gre && isExternalName (gre_name gre) + + unused_imports :: [GlobalRdrElt] + unused_imports = filter unused_imp defined_but_not_used + unused_imp (GRE {gre_prov = Imported imp_specs True}) + = not (all (module_unused . is_mod) imp_specs) + -- Don't complain about unused imports if we've already said the + -- entire import is unused + unused_imp other = False + + -- 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 direct_import_mods + -- The last line makes sure that we retain all direct imports + -- even if we import nothing explicitly. + -- It's not necessarily redundant to import such modules. 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 + + -- We've carefully preserved the provenance so that we can + -- construct minimal imports that import the name by (one of) + -- the same route(s) as the programmer originally did. + add_name (GRE {gre_name = n, + gre_prov = Imported imp_specs _}) acc + = addToFM_C plusAvailEnv acc (is_mod (head imp_specs)) + (unitAvailEnv (mk_avail n (nameParent_maybe n))) + add_name other acc + = acc + + -- n is the name of the thing, p is the name of its parent + mk_avail n (Just p) = AvailTC p [p,n] + mk_avail n Nothing | isTcOcc (nameOccName n) = AvailTC n [n] + | otherwise = 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 + + imports = tcg_imports gbl_env + + direct_import_mods :: [ModuleName] + direct_import_mods = map (moduleName . fst) + (moduleEnvElts (imp_mods imports)) + + hasEmptyImpList :: ModuleName -> Bool + hasEmptyImpList m = + case lookupModuleEnvByName (imp_mods imports) m of + Just (_,Just x) -> not x + _ -> False + + -- unused_imp_mods are the directly-imported modules + -- that are not mentioned in minimal_imports1 + -- [Note: not 'minimal_imports', because that includes directly-imported + -- modules even if we use nothing from them; see notes above] + unused_imp_mods = [m | m <- direct_import_mods, + isNothing (lookupFM minimal_imports1 m), + m /= pRELUDE_Name, + not (hasEmptyImpList m)] + -- hasEmptyImpList arranges not to complain about + -- import M (), which is an idiom for importing + -- instance declarations + + module_unused :: ModuleName -> Bool + module_unused mod = mod `elem` unused_imp_mods + +--------------------- +warnDuplicateImports :: [GlobalRdrElt] -> RnM () +warnDuplicateImports gres + = ifOptM Opt_WarnUnusedImports (mapM_ warn gres) + where + warn (GRE { gre_name = name, gre_prov = Imported imps _ }) + = addWarn ((quotes (ppr name) <+> ptext SLIT("is imported more than once:")) + $$ nest 2 (vcat (map ppr imps))) + + +-- ToDo: deal with original imports with 'qualified' and 'as M' clauses +printMinimalImports :: FiniteMap ModuleName AvailEnv -- Minimal imports + -> RnM () +printMinimalImports imps + = ifOptM Opt_D_dump_minimal_imports $ do { + + mod_ies <- mappM to_ies (fmToList imps) ; + this_mod <- getModule ; + rdr_env <- getGlobalRdrEnv ; + ioToTcRn (do { h <- openFile (mkFilename this_mod) WriteMode ; + printForUser h (unQualInScope rdr_env) + (vcat (map ppr_mod_ie mod_ies)) }) + } + where + mkFilename this_mod = moduleNameUserString (moduleName this_mod) ++ ".imports" + ppr_mod_ie (mod_name, ies) + | mod_name == pRELUDE_Name + = empty + | null ies -- Nothing except instances comes from here + = ptext SLIT("import") <+> ppr mod_name <> ptext SLIT("() -- Instances only") + | otherwise + = ptext SLIT("import") <+> ppr mod_name <> + parens (fsep (punctuate comma (map ppr ies))) + + to_ies (mod, avail_env) = mappM to_ie (availEnvElts avail_env) `thenM` \ ies -> + returnM (mod, ies) + + to_ie :: AvailInfo -> RnM (IE Name) + -- The main trick here is that if we're importing all the constructors + -- we want to say "T(..)", but if we're importing only a subset we want + -- to say "T(A,B,C)". So we have to find out what the module exports. + to_ie (Avail n) = returnM (IEVar n) + to_ie (AvailTC n [m]) = ASSERT( n==m ) + returnM (IEThingAbs n) + to_ie (AvailTC n ns) + = loadSrcInterface doc n_mod False `thenM` \ iface -> + case [xs | (m,as) <- mi_exports iface, + m == n_mod, + AvailTC x xs <- as, + x == nameOccName n] of + [xs] | all_used xs -> returnM (IEThingAll n) + | otherwise -> returnM (IEThingWith n (filter (/= n) ns)) + other -> pprTrace "to_ie" (ppr n <+> ppr n_mod <+> ppr other) $ + returnM (IEVar n) + where + all_used avail_occs = all (`elem` map nameOccName ns) avail_occs + doc = text "Compute minimal imports from" <+> ppr n + n_mod = nameModuleName n +\end{code} + + %************************************************************************ %* * \subsection{Errors} @@ -616,15 +958,18 @@ mk_export_fn exported_names = \name -> name `elemNameSet` exported_names %************************************************************************ \begin{code} -badImportItemErr mod ie - = sep [ptext SLIT("Module"), quotes (ppr mod), +badImportItemErr iface imp_spec ie + = sep [ptext SLIT("Module"), quotes (ppr (is_mod imp_spec)), source_import, ptext SLIT("does not export"), quotes (ppr ie)] + where + source_import | mi_boot iface = ptext SLIT("(hi-boot interface)") + | otherwise = empty -dodgyImportWarn mod item = dodgyMsg (ptext SLIT("import")) item -dodgyExportWarn item = dodgyMsg (ptext SLIT("export")) item +dodgyImportWarn item = dodgyMsg (ptext SLIT("import")) item +dodgyExportWarn item = dodgyMsg (ptext SLIT("export")) item -dodgyMsg kind item@(IEThingAll tc) - = sep [ ptext SLIT("The") <+> kind <+> ptext SLIT("item") <+> quotes (ppr item), +dodgyMsg kind tc + = sep [ ptext SLIT("The") <+> kind <+> ptext SLIT("item") <+> quotes (ppr (IEThingAll tc)), ptext SLIT("suggests that") <+> quotes (ppr tc) <+> ptext SLIT("has constructor or class methods"), ptext SLIT("but it has none; it is a type synonym or abstract type or class") ] @@ -635,10 +980,20 @@ exportItemErr export_item = sep [ ptext SLIT("The export item") <+> quotes (ppr export_item), ptext SLIT("attempts to export constructors or class methods that are not visible here") ] -exportClashErr occ_name ie1 ie2 - = hsep [ptext SLIT("The export items"), quotes (ppr ie1) - ,ptext SLIT("and"), quotes (ppr ie2) - ,ptext SLIT("create conflicting exports for"), quotes (ppr occ_name)] +exportClashErr global_env name1 name2 ie1 ie2 + = vcat [ ptext SLIT("Conflicting exports for") <+> quotes (ppr occ) <> colon + , ppr_export ie1 name1 + , ppr_export ie2 name2 ] + where + occ = nameOccName name1 + ppr_export ie name = nest 2 (quotes (ppr ie) <+> ptext SLIT("exports") <+> + quotes (ppr name) <+> pprNameProvenance (get_gre name)) + + -- get_gre finds a GRE for the Name, so that we can show its provenance + get_gre name + = case lookupGRE_Name global_env name of + (gre:_) -> gre + [] -> pprPanic "exportClashErr" (ppr name) dupDeclErr (n:ns) = vcat [ptext SLIT("Multiple declarations of") <+> quotes (ppr n), @@ -656,4 +1011,8 @@ dupModuleExport mod = hsep [ptext SLIT("Duplicate"), quotes (ptext SLIT("Module") <+> ppr mod), ptext SLIT("in export list")] + +moduleDeprec mod txt + = sep [ ptext SLIT("Module") <+> quotes (ppr mod) <+> ptext SLIT("is deprecated:"), + nest 4 (ppr txt) ] \end{code}