X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=ghc%2Fcompiler%2Frename%2FRnNames.lhs;h=9197fd978dcc24ae03094db9faa62bb35bccee41;hb=d28ba8c800901bea01f70c4719278c2a364cf9fc;hp=db749a4451528b6a37b5d70d231f7466f012f401;hpb=438596897ebbe25a07e1c82085cfbc5bdb00f09e;p=ghc-hetmet.git diff --git a/ghc/compiler/rename/RnNames.lhs b/ghc/compiler/rename/RnNames.lhs index db749a4..9197fd9 100644 --- a/ghc/compiler/rename/RnNames.lhs +++ b/ghc/compiler/rename/RnNames.lhs @@ -5,622 +5,851 @@ \begin{code} module RnNames ( - getGlobalNames + rnImports, importsFromLocalDecls, exportsFromAvail, + reportUnusedNames, mkModDeps ) where #include "HsVersions.h" -import CmdLineOpts ( opt_NoImplicitPrelude, opt_WarnDuplicateExports, - opt_SourceUnchanged - ) - -import HsSyn ( HsModule(..), ImportDecl(..), HsDecl(..), - IE(..), ieName, - ForeignDecl(..), ExtName(..), ForKind(..), - FixityDecl(..), - collectTopBinders - ) -import RdrHsSyn ( RdrName(..), RdrNameIE, RdrNameImportDecl, - RdrNameHsModule, RdrNameFixityDecl, - rdrNameOcc, ieOcc - ) -import RnIfaces ( getInterfaceExports, getDeclBinders, recordSlurp, checkUpToDate ) -import BasicTypes ( IfaceFlavour(..) ) +import {-# SOURCE #-} RnHiFiles ( loadInterface ) + +import CmdLineOpts ( DynFlag(..) ) + +import HsSyn ( IE(..), ieName, ImportDecl(..), + ForeignDecl(..), HsGroup(..), + collectLocatedHsBinders, tyClDeclNames + ) +import RdrHsSyn ( RdrNameIE, RdrNameImportDecl, main_RDR_Unqual ) import RnEnv -import RnMonad +import TcRnMonad import FiniteMap -import PrelMods -import UniqFM ( lookupUFM ) -import Bag ( bagToList ) -import Maybes ( maybeToBool ) -import Name -import NameSet ( elemNameSet ) +import PrelNames ( pRELUDE_Name, isBuiltInSyntaxName ) +import Module ( Module, ModuleName, ModuleEnv, moduleName, + moduleNameUserString, isHomeModule, + emptyModuleEnv, unitModuleEnvByName, unitModuleEnv, + lookupModuleEnvByName, extendModuleEnvByName, moduleEnvElts ) +import Name ( Name, nameSrcLoc, nameOccName, nameModule, isExternalName ) +import NameSet +import NameEnv +import OccName ( OccName, srcDataName, isTcOcc ) +import HscTypes ( Provenance(..), ImportReason(..), GlobalRdrEnv, + GenAvailInfo(..), AvailInfo, Avails, GhciMode(..), + IsBootInterface, + availName, availNames, availsToNameSet, + Deprecations(..), ModIface(..), Dependencies(..), + GlobalRdrElt(..), unQualInScope, isLocalGRE, pprNameProvenance + ) +import RdrName ( RdrName, rdrNameOcc, setRdrNameSpace, lookupRdrEnv, rdrEnvToList, + emptyRdrEnv, foldRdrEnv, rdrEnvElts, mkRdrUnqual, isQual ) import Outputable -import Util ( removeDups ) +import Maybe ( isJust, isNothing, catMaybes ) +import Maybes ( orElse ) +import ListSetOps ( removeDups ) +import Util ( sortLt, notNull ) +import List ( partition, insert ) +import IO ( openFile, IOMode(..) ) \end{code} %************************************************************************ %* * -\subsection{Get global names} + rnImports %* * %************************************************************************ \begin{code} -getGlobalNames :: RdrNameHsModule - -> RnMG (Maybe (ExportEnv, - RnEnv, - FiniteMap Name HowInScope, -- Locally defined or explicitly imported - Name -> PrintUnqualified)) - -- Nothing => no need to recompile - -getGlobalNames m@(HsModule this_mod _ exports imports _ _ mod_loc) - = fixRn (\ ~(rec_exp_fn, _) -> - - -- PROCESS LOCAL DECLS - -- Do these *first* so that the correct provenance gets - -- into the global name cache. - importsFromLocalDecls rec_exp_fn m `thenRn` \ (local_rn_env, local_mod_avails, local_info) -> - - -- PROCESS IMPORT DECLS - mapAndUnzip3Rn importsFromImportDecl all_imports - `thenRn` \ (imp_rn_envs, imp_avails_s, explicit_imports_s) -> - - -- COMBINE RESULTS - -- We put the local env second, so that a local provenance - -- "wins", even if a module imports itself. - foldlRn plusRnEnv emptyRnEnv imp_rn_envs `thenRn` \ imp_rn_env -> - plusRnEnv imp_rn_env local_rn_env `thenRn` \ rn_env -> - - -- 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 plusRnEnv stuff to do the early-exit. - checkEarlyExit this_mod `thenRn` \ up_to_date -> - if up_to_date then - returnRn (error "early exit", Nothing) - else - - - -- PROCESS EXPORT LISTS - let - export_avails :: ExportAvails - export_avails = foldr plusExportAvails local_mod_avails imp_avails_s - - explicit_info :: FiniteMap Name HowInScope -- Locally defined or explicitly imported - explicit_info = foldr plusFM local_info explicit_imports_s - in - exportsFromAvail this_mod exports export_avails rn_env - `thenRn` \ (export_fn, export_env) -> - - -- BUILD THE "IMPORT FN". It just tells whether a name is in - -- scope in an unqualified form. - let - print_unqual = mkImportFn imp_rn_env - in - - returnRn (export_fn, Just (export_env, rn_env, explicit_info, print_unqual)) - ) `thenRn` \ (_, result) -> - returnRn result - where - junk_exp_fn = error "RnNames:export_fn" +rnImports :: [RdrNameImportDecl] + -> TcRn m (GlobalRdrEnv, ImportAvails) + +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 -> + getSrcLocM `thenM` \ loc -> + doptM Opt_NoImplicitPrelude `thenM` \ opt_no_prelude -> + let + all_imports = mk_prel_imports this_mod loc opt_no_prelude ++ imports + (source, ordinary) = partition is_source_import all_imports + is_source_import (ImportDecl _ is_boot _ _ _ _) = is_boot - all_imports = prel_imports ++ imports + get_imports = importsFromImportDecl this_mod + in + mappM get_imports ordinary `thenM` \ stuff1 -> + mappM get_imports source `thenM` \ stuff2 -> + -- COMBINE RESULTS + let + (imp_gbl_envs, imp_avails) = unzip (stuff1 ++ stuff2) + gbl_env :: GlobalRdrEnv + gbl_env = foldr plusGlobalRdrEnv emptyRdrEnv imp_gbl_envs + + all_avails :: ImportAvails + all_avails = foldr plusImportAvails emptyImportAvails imp_avails + in + -- ALL DONE + returnM (gbl_env, all_avails) + where -- 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 || - explicit_prelude_import || - opt_NoImplicitPrelude - = [] - - | otherwise = [ImportDecl pRELUDE - False {- Not qualified -} - HiFile {- Not source imported -} - Nothing {- No "as" -} - Nothing {- No import list -} - mod_loc] - - explicit_prelude_import - = not (null [ () | (ImportDecl mod qual _ _ _ _) <- imports, mod == pRELUDE ]) -\end{code} - -\begin{code} -checkEarlyExit mod - = checkErrsRn `thenRn` \ no_errs_so_far -> - if not no_errs_so_far then - -- Found errors already, so exit now - returnRn True - else + -- because the former doesn't even look at Prelude.hi for instance + -- declarations, whereas the latter does. + mk_prel_imports this_mod loc no_prelude + | moduleName this_mod == pRELUDE_Name + || explicit_prelude_import + || no_prelude + = [] - traceRn (text "Considering whether compilation is required...") `thenRn_` - if not opt_SourceUnchanged then - -- Source code changed and no errors yet... carry on - traceRn (nest 4 (text "source file changed or recompilation check turned off")) `thenRn_` - returnRn False - else + | otherwise = [preludeImportDecl loc] - -- Unchanged source, and no errors yet; see if usage info - -- up to date, and exit if so - checkUpToDate mod `thenRn` \ up_to_date -> - putDocRn (text "Compilation" <+> - text (if up_to_date then "IS NOT" else "IS") <+> - text "required") `thenRn_` - returnRn up_to_date + explicit_prelude_import + = notNull [ () | (ImportDecl mod _ _ _ _ _) <- imports, + mod == pRELUDE_Name ] + +preludeImportDecl loc + = ImportDecl pRELUDE_Name + False {- Not a boot interface -} + False {- Not qualified -} + Nothing {- No "as" -} + Nothing {- No import list -} + loc \end{code} \begin{code} -importsFromImportDecl :: RdrNameImportDecl - -> RnMG (RnEnv, - ExportAvails, - FiniteMap Name HowInScope) -- Records the explicitly-imported things - -importsFromImportDecl (ImportDecl mod qual_only as_source as_mod import_spec loc) - = pushSrcLocRn loc $ - getInterfaceExports mod as_source `thenRn` \ (avails, fixities) -> - filterImports mod import_spec avails `thenRn` \ (filtered_avails, hides, explicits) -> +importsFromImportDecl :: Module + -> RdrNameImportDecl + -> TcRn m (GlobalRdrEnv, ImportAvails) + +importsFromImportDecl this_mod + (ImportDecl imp_mod_name is_boot qual_only as_mod imp_spec iloc) + = addSrcLoc iloc $ let - how_in_scope = FromImportDecl mod loc - explicit_info = listToFM [(name, how_in_scope) - | avail <- explicits, - name <- availNames avail - ] + doc = ppr imp_mod_name <+> ptext SLIT("is directly imported") in - qualifyImports mod - True -- Want qualified names - (not qual_only) -- Maybe want unqualified names - as_mod - hides - filtered_avails (\n -> how_in_scope) - [ (occ,(fixity,how_in_scope)) | (occ,fixity) <- fixities ] - `thenRn` \ (rn_env, mod_avails) -> - returnRn (rn_env, mod_avails, explicit_info) -\end{code} + -- If there's an error in loadInterface, (e.g. interface + -- file not found) we get lots of spurious errors from 'filterImports' + tryM (loadInterface doc imp_mod_name (ImportByUser is_boot)) `thenM` \ mb_iface -> -\begin{code} -importsFromLocalDecls rec_exp_fn (HsModule mod _ _ _ fix_decls decls _) - = foldlRn getLocalDeclBinders [] decls `thenRn` \ avails -> + case mb_iface of { + Left exn -> returnM (emptyRdrEnv, emptyImportAvails ) ; + Right iface -> - -- Record that locally-defined things are available - mapRn (recordSlurp Nothing Compulsory) avails `thenRn_` + let + imp_mod = mi_module iface + avails_by_module = mi_exports iface + deprecs = mi_deprecs iface + is_orph = mi_orphan iface + deps = mi_deps iface + + avails :: Avails + avails = [ avail | (mod_name, avails) <- avails_by_module, + mod_name /= this_mod_name, + avail <- avails ] + this_mod_name = moduleName this_mod + -- 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. - -- Fixities - mapRn fixityFromFixDecl fix_decls `thenRn` \ fixities -> + in + -- Filter the imports according to the import list + filterImports imp_mod is_boot imp_spec avails `thenM` \ (filtered_avails, explicits) -> - -- Record where the available stuff came from let - explicit_info = listToFM [(name, FromLocalDefn (getSrcLoc name)) - | avail <- avails, - name <- availNames avail - ] + -- 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, is_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_spec of + (Just (False, _)) -> False -- Imports are spec'd explicitly + other -> True -- Everything is imported, + -- (or almost everything [hiding]) + + qual_mod_name = case as_mod of + Nothing -> imp_mod_name + Just another_name -> another_name + + -- 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. + avail_env = mkAvailEnv filtered_avails + + mk_prov name = NonLocalDef (UserImport imp_mod iloc (name `elemNameSet` explicits)) + gbl_env = mkGlobalRdrEnv qual_mod_name (not qual_only) + mk_prov filtered_avails deprecs + 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 - qualifyImports mod - False -- Don't want qualified names - True -- Want unqualified names - Nothing -- No "as M" part - [] -- Hide nothing - avails (\n -> FromLocalDefn (getSrcLoc n)) - fixities - `thenRn` \ (rn_env, mod_avails) -> - returnRn (rn_env, mod_avails, explicit_info) - where - newLocalName rdr_name loc - = newLocallyDefinedGlobalName mod (rdrNameOcc rdr_name) rec_exp_fn loc - - getLocalDeclBinders avails (ValD binds) - = mapRn do_one (bagToList (collectTopBinders binds)) `thenRn` \ val_avails -> - returnRn (val_avails ++ avails) - - -- foreign import declaration - getLocalDeclBinders avails (ForD (ForeignDecl nm (FoImport _) _ _ _ loc)) - = do_one (nm,loc) `thenRn` \ for_avail -> - returnRn (for_avail : avails) - - -- foreign import declaration - getLocalDeclBinders avails (ForD (ForeignDecl nm FoLabel _ _ _ loc)) - = do_one (nm,loc) `thenRn` \ for_avail -> - returnRn (for_avail : avails) - - -- foreign export dynamic declaration - getLocalDeclBinders avails (ForD (ForeignDecl nm FoExport _ Dynamic _ loc)) - = do_one (nm,loc) `thenRn` \ for_avail -> - returnRn (for_avail : avails) - - getLocalDeclBinders avails decl - = getDeclBinders newLocalName decl `thenRn` \ avail -> - case avail of - NotAvailable -> returnRn avails -- Instance decls and suchlike - other -> returnRn (avail : avails) - - do_one (rdr_name, loc) - = newLocalName rdr_name loc `thenRn` \ name -> - returnRn (Avail name) + -- 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) + } + +mkModDeps :: [(ModuleName, IsBootInterface)] + -> ModuleEnv (ModuleName, IsBootInterface) +mkModDeps deps = foldl add emptyModuleEnv deps + where + add env elt@(m,_) = extendModuleEnvByName env m elt \end{code} + %************************************************************************ %* * -\subsection{Filtering imports} + importsFromLocalDecls %* * %************************************************************************ -@filterImports@ takes the @ExportEnv@ telling what the imported module makes -available, and filters it through the import spec (if any). +From the top-level declarations of this module produce + * the lexical environment + * the ImportAvails +created by its bindings. + +Complain about duplicate bindings \begin{code} -filterImports :: Module - -> Maybe (Bool, [RdrNameIE]) -- Import spec; True => hidin - -> [AvailInfo] -- What's available - -> RnMG ([AvailInfo], -- What's actually imported - [AvailInfo], -- What's to be hidden (the unqualified version, that is) - [AvailInfo]) -- What was imported explicitly +importsFromLocalDecls :: HsGroup RdrName + -> TcRn m (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] - -- 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, [], []) - -filterImports mod (Just (want_hiding, import_items)) avails - = mapRn check_item import_items `thenRn` \ item_avails -> - if want_hiding - then - returnRn (avails, item_avails, []) -- All imported; item_avails to be hidden - else - returnRn (item_avails, [], item_avails) -- Just item_avails imported; nothing to be hidden + dups :: [[Name]] + (_, dups) = removeDups compare all_names + in + -- Check for duplicate definitions + -- 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_` - where - import_fm :: FiniteMap OccName AvailInfo - import_fm = listToFM [ (nameOccName name, avail) - | avail <- avails, - name <- availEntityNames avail] + doptM Opt_NoImplicitPrelude `thenM` \ implicit_prelude -> + let + mod_name = moduleName this_mod + mk_prov n = LocalDef -- Provenance is local + + unqual_imp = True -- Want unqualified names in scope + gbl_env = mkGlobalRdrEnv mod_name unqual_imp mk_prov avails NoDeprecs + -- NoDeprecs: don't complain about 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 + + + -- 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. 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. + + avail_env = mkAvailEnv avails' + imports = emptyImportAvails { + imp_qual = unitModuleEnv this_mod avail_env, + imp_env = avail_env + } + in + returnM (gbl_env, imports) +\end{code} - check_item item@(IEModuleContents _) - = addErrRn (badImportItemErr mod item) `thenRn_` - returnRn NotAvailable - check_item item - | not (maybeToBool maybe_in_import_avails) || - (case filtered_avail of { NotAvailable -> True; other -> False }) - = addErrRn (badImportItemErr mod item) `thenRn_` - returnRn NotAvailable +%********************************************************* +%* * +\subsection{Getting binders out of a declaration} +%* * +%********************************************************* - | dodgy_import = addWarnRn (dodgyImportWarn mod item) `thenRn_` - returnRn filtered_avail +@getLocalDeclBinders@ returns the names for a @RdrNameHsDecl@. It's +used for both source code (from @importsFromLocalDecls@) and interface +files (@loadDecl@ calls @getTyClDeclBinders@). - | otherwise = returnRn filtered_avail - - where - maybe_in_import_avails = lookupFM import_fm (ieOcc item) - Just avail = maybe_in_import_avails - filtered_avail = filterAvail item avail - dodgy_import = case (item, avail) of - (IEThingAll _, AvailTC _ [n]) -> True - -- This occurs when you import T(..), but - -- only export T abstractly. The single [n] - -- in the AvailTC is the type or class itself - - other -> False - -\end{code} + *** See "THE NAMING STORY" in HsDecls **** +\begin{code} +getLocalDeclBinders :: Module -> HsGroup RdrName -> TcRn m [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_bndr (for_hs_bndrs ++ val_hs_bndrs) `thenM` \ simple_bndrs -> + + returnM (tc_avails ++ map Avail simple_bndrs) + where + new_bndr (rdr_name,loc) = newTopBinder mod rdr_name loc + + val_hs_bndrs = collectLocatedHsBinders val_decls + for_hs_bndrs = [(nm,loc) | ForeignImport nm _ _ _ loc <- foreign_decls] + + new_tc tc_decl = mappM new_bndr (tyClDeclNames tc_decl) `thenM` \ names@(main_name:_) -> + returnM (AvailTC main_name names) +\end{code} %************************************************************************ %* * -\subsection{Qualifiying imports} +\subsection{Filtering 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@. +@filterImports@ takes the @ExportEnv@ telling what the imported module makes +available, and filters it through the import spec (if any). \begin{code} -qualifyImports :: Module -- Imported module - -> Bool -- True <=> want qualified import - -> Bool -- True <=> want unqualified import - -> Maybe Module -- Optional "as M" part - -> [AvailInfo] -- What's to be hidden - -> Avails -> (Name -> HowInScope) -- Whats imported and how - -> [(OccName, (Fixity, HowInScope))] -- Ditto for fixities - -> RnMG (RnEnv, ExportAvails) - -qualifyImports this_mod qual_imp unqual_imp as_mod hides - avails name_to_his fixities - = - -- Make the name environment. Even though we're talking about a - -- single import module there might still be name clashes, - -- because it might be the module being compiled. - foldlRn add_avail emptyGlobalNameEnv avails `thenRn` \ name_env1 -> - let - -- Delete things that are hidden - name_env2 = foldl del_avail name_env1 hides +filterImports :: Module -- The module being imported + -> IsBootInterface -- Tells whether it's a {-# SOURCE #-} import + -> Maybe (Bool, [RdrNameIE]) -- Import spec; True => hiding + -> [AvailInfo] -- What's available + -> TcRn m ([AvailInfo], -- What's imported + NameSet) -- What was imported explicitly - -- Create the fixity env - fixity_env = foldl (add_fixity name_env2) emptyFixityEnv fixities + -- Complains if import spec mentions things that the module doesn't export + -- Warns/informs if import spec contains duplicates. +filterImports mod from Nothing imports + = returnM (imports, emptyNameSet) - -- Create the export-availability info - export_avails = mkExportAvails qual_mod unqual_imp name_env2 avails +filterImports mod from (Just (want_hiding, import_items)) total_avails + = mappM get_item import_items `thenM` \ avails_w_explicits_s -> + let + (item_avails, explicits_s) = unzip (concat avails_w_explicits_s) + explicits = foldl addListToNameSet emptyNameSet explicits_s in - returnRn (RnEnv name_env2 fixity_env, export_avails) + if want_hiding then + let -- All imported; item_avails to be hidden + hidden = availsToNameSet item_avails + keep n = not (n `elemNameSet` hidden) + in + returnM (pruneAvails keep total_avails, emptyNameSet) + else + -- Just item_avails imported; nothing to be hidden + returnM (item_avails, explicits) where - qual_mod = case as_mod of - Nothing -> this_mod - Just another_name -> another_name - - add_avail :: GlobalNameEnv -> AvailInfo -> RnMG GlobalNameEnv - add_avail env avail = foldlRn add_name env (availNames avail) - - add_name env name = add qual_imp env (Qual qual_mod occ err_hif) `thenRn` \ env1 -> - add unqual_imp env1 (Unqual occ) - where - add False env rdr_name = returnRn env - add True env rdr_name = addOneToGlobalNameEnv env rdr_name (name, name_to_his name) - occ = nameOccName name - - del_avail env avail = foldl delOneFromGlobalNameEnv env rdr_names - where - rdr_names = map (Unqual . nameOccName) (availNames avail) - - add_fixity name_env fix_env (occ_name, fixity) - = add qual $ add unqual $ fix_env - where - qual = Qual qual_mod occ_name err_hif - unqual = Unqual occ_name - - add rdr_name fix_env | maybeToBool (lookupFM name_env rdr_name) - = addOneToFixityEnv fix_env rdr_name fixity - | otherwise - = fix_env - -err_hif = error "qualifyImports: hif" -- Not needed in key to mapping -\end{code} + import_fm :: FiniteMap OccName AvailInfo + import_fm = listToFM [ (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 = addErr (badImportItemErr mod from item) `thenM_` + returnM [] + + get_item :: RdrNameIE -> TcRn m [(AvailInfo, [Name])] + -- Empty list for a bad item. + -- Singleton is typical case. + -- Can have two when we are hiding, and mention C which might be + -- both a class and a data constructor. + -- The [Name] is the list of explicitly-mentioned names + get_item item@(IEModuleContents _) = bale_out item + + get_item item@(IEThingAll _) + = 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 + ifOptM Opt_WarnMisc (addWarn (dodgyImportWarn mod item)) `thenM_` + returnM [(avail, [availName avail])] + Just avail -> returnM [(avail, [availName 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 (IEVar data_n)] of + [] -> bale_out item + avails -> returnM [(a, []) | a <- avails] + -- The 'explicits' list is irrelevant when hiding + where + data_n = setRdrNameSpace n srcDataName -unQualify adds an Unqual binding for every existing Qual binding. + get_item item + = case check_item item of + Nothing -> bale_out item + Just avail -> returnM [(avail, availNames avail)] -\begin{code} -unQualify :: FiniteMap RdrName elt -> FiniteMap RdrName elt -unQualify fm = addListToFM fm [(Unqual occ, elt) | (Qual _ occ _, elt) <- fmToList fm] -\end{code} + check_item item + | isNothing maybe_in_import_avails || + isNothing maybe_filtered_avail + = Nothing -%************************************************************************ -%* * -\subsection{Local declarations} -%* * -%************************************************************************ + | otherwise + = Just filtered_avail + + where + wanted_occ = rdrNameOcc (ieName item) + maybe_in_import_avails = lookupFM import_fm wanted_occ + Just avail = maybe_in_import_avails + maybe_filtered_avail = filterAvail item avail + Just filtered_avail = maybe_filtered_avail +\end{code} \begin{code} -fixityFromFixDecl :: RdrNameFixityDecl -> RnMG (OccName, (Fixity, HowInScope)) - -fixityFromFixDecl (FixityDecl rdr_name fixity loc) - = returnRn (rdrNameOcc rdr_name, (fixity, FromLocalDefn loc)) +filterAvail :: RdrNameIE -- 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 + 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} %************************************************************************ %* * -\subsection{Export list processing +\subsection{Export list processing} %* * %************************************************************************ -The @AvailEnv@ type is just used internally in @exportsFromAvail@. -When exporting we need to combine the availabilities for a particular -exported thing, and we also need to check for name clashes -- that -is: two exported things must have different @OccNames@. - -\begin{code} -type AvailEnv = FiniteMap OccName (RdrNameIE, AvailInfo, Int{-no. of clashes-}) - -- The FM maps each OccName to the RdrNameIE that gave rise to it, - -- for error reporting, as well as to its AvailInfo - -emptyAvailEnv = emptyFM - -{- - Add new entry to environment. Checks for name clashes, i.e., - plain duplicates or exported entity pairs that have different OccNames. - (c.f. 5.1.1 of Haskell 1.4 report.) --} -addAvailEnv :: Bool -> RdrNameIE -> AvailEnv -> AvailInfo -> RnM s d AvailEnv -addAvailEnv warn_dups ie env NotAvailable = returnRn env -addAvailEnv warn_dups ie env (AvailTC _ []) = returnRn env -addAvailEnv warn_dups ie env avail - | warn_dups = mapMaybeRn (addErrRn . availClashErr) () conflict `thenRn_` - returnRn (addToFM_C addAvail env key elt) - | otherwise = returnRn (addToFM_C addAvail env key elt) - where - occ_avail = nameOccName (availName avail) - occ_ie = ieOcc ie - key - | not warn_dups || occ_ie == occ_avail = occ_avail - | otherwise = occ_ie - -- export item is a class method, use export occ name instead. - -- (this is only needed to get more precise warnings about - -- duplicates.) - elt = (ie,avail,reports_on) - - reports_on - | maybeToBool dup = 1 - | otherwise = 0 - - conflict = conflictFM bad_avail env key elt - dup - | warn_dups = conflictFM dup_avail env key elt - | otherwise = Nothing - -addListToAvailEnv :: AvailEnv -> RdrNameIE -> [AvailInfo] -> RnM s d AvailEnv -addListToAvailEnv env ie items - = foldlRn (addAvailEnv False{-don't warn about dups-} ie) env items - -bad_avail (ie1,avail1,r1) (ie2,avail2,r2) - = availName avail1 /= availName avail2 -- Same OccName, different Name -dup_avail (ie1,avail1,r1) (ie2,avail2,r2) - = availName avail1 == availName avail2 -- Same OccName & avail. - -addAvail (ie1,a1,r1) (ie2,a2,r2) = (ie1, a1 `plusAvail` a2, r1 + r2) -\end{code} - 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). 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... +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... \begin{code} -exportsFromAvail :: Module - -> Maybe [RdrNameIE] -- Export spec - -> ExportAvails - -> RnEnv - -> RnMG (Name -> ExportFlag, ExportEnv) +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 +emptyExportAccum = ([], emptyFM, emptyAvailEnv) + +type ExportOccMap = FiniteMap OccName (Name, RdrNameIE) + -- 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 :: Maybe Module -- Nothing => no 'module M(..) where' header at all + -> Maybe [RdrNameIE] -- Nothing => no explicit export list + -> TcRn m Avails -- 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 rn_env - = exportsFromAvail this_mod (Just [IEModuleContents this_mod]) export_avails rn_env - -exportsFromAvail this_mod (Just export_items) - (mod_avail_env, entity_avail_env) - (RnEnv global_name_env fixity_env) - = checkForModuleExportDups export_items `thenRn` \ export_items' -> - foldlRn exports_from_item emptyAvailEnv export_items' `thenRn` \ export_avail_env -> - let - dup_entries = fmToList (filterFM (\ _ (_,_,clashes) -> clashes > 0) export_avail_env) - in - mapRn (addWarnRn . dupExportWarn) dup_entries `thenRn_` - let - export_avails = map (\ (_,a,_) -> a) (eltsFM export_avail_env) - export_fixities = mk_exported_fixities (availsToNameSet export_avails) - export_fn = mk_export_fn export_avails - in - returnRn (export_fn, ExportEnv export_avails export_fixities) + +exportsFromAvail maybe_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 + = case maybe_mod of + Just mod -> exports + Nothing | ghci_mode == Interactive -> Nothing + | otherwise -> Just [IEVar main_RDR_Unqual] } ; + + exports_from_avail exports rdr_env imports } + +exports_from_avail Nothing rdr_env + imports@(ImportAvails { imp_env = entity_avail_env }) + = -- Export all locally-defined things + -- We do this by filtering the global RdrEnv, + -- keeping only things that are (a) qualified, + -- (b) locally defined, (c) a 'main' name + -- Then we look up in the entity-avail-env + return [ lookupAvailEnv entity_avail_env name + | (rdr_name, gres) <- rdrEnvToList rdr_env, + isQual rdr_name, -- Avoid duplicates + GRE { gre_name = name, + gre_parent = Nothing, -- Main things only + gre_prov = LocalDef } <- gres + ] + +exports_from_avail (Just export_items) rdr_env + (ImportAvails { imp_qual = mod_avail_env, + imp_env = entity_avail_env }) + = foldlM exports_from_item emptyExportAccum + export_items `thenM` \ (_, _, export_avail_map) -> + returnM (nameEnvElts export_avail_map) where - exports_from_item :: AvailEnv -> RdrNameIE -> RnMG AvailEnv - exports_from_item export_avail_env ie@(IEModuleContents mod) - = case lookupFM mod_avail_env mod of - Nothing -> failWithRn export_avail_env (modExportErr mod) - Just avails -> addListToAvailEnv export_avail_env ie avails - - exports_from_item export_avail_env ie - | not (maybeToBool maybe_in_scope) - = failWithRn export_avail_env (unknownNameErr (ieName ie)) - -#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 export_avail_env -#endif - - | not enough_avail - = failWithRn export_avail_env (exportItemErr ie export_avail) - - | otherwise -- Phew! It's OK! - = addAvailEnv opt_WarnDuplicateExports ie export_avail_env export_avail - where - maybe_in_scope = lookupFM global_name_env (ieName ie) - Just (name,_) = maybe_in_scope - maybe_avail = lookupUFM entity_avail_env name - Just avail = maybe_avail - export_avail = filterAvail ie avail - enough_avail = case export_avail of {NotAvailable -> False; other -> True} - - -- We export a fixity iff we export a thing with the same (qualified) RdrName - mk_exported_fixities :: NameSet -> [(OccName, Fixity)] - mk_exported_fixities exports - = fmToList (foldr (perhaps_add_fixity exports) - emptyFM - (fmToList fixity_env)) - - perhaps_add_fixity :: NameSet -> (RdrName, (Fixity, HowInScope)) - -> FiniteMap OccName Fixity - -> FiniteMap OccName Fixity - perhaps_add_fixity exports (rdr_name, (fixity, how_in_scope)) fix_env - = let - do_nothing = fix_env -- The default is to pass on the env unchanged - in - -- Step 1: check whether the rdr_name is in scope; if so find its Name - case lookupFM global_name_env rdr_name of { - Nothing -> do_nothing; - Just (fixity_name,_) -> - - -- Step 2: check whether the fixity thing is exported - if not (fixity_name `elemNameSet` exports) then - do_nothing - else - - -- Step 3: check whether we already have a fixity for the - -- Name's OccName in the fix_env we are building up. This can easily - -- happen. the original fixity_env might contain bindings for - -- M.a and N.a, if a was imported via M and N. - -- If this does happen, we expect the fixity to be the same either way. - let - occ_name = rdrNameOcc rdr_name - in - case lookupFM fix_env occ_name of { - Just fixity1 -> -- Got it already - ASSERT( fixity == fixity1 ) - do_nothing; - Nothing -> - - -- Step 3: add it to the outgoing fix_env - addToFM fix_env occ_name fixity - }} - -{- warn and weed out duplicate module entries from export list. -} -checkForModuleExportDups :: [RdrNameIE] -> RnMG [RdrNameIE] -checkForModuleExportDups ls - | opt_WarnDuplicateExports = check_modules ls - | otherwise = returnRn ls + exports_from_item :: ExportAccum -> RdrNameIE -> TcRn m ExportAccum + + exports_from_item acc@(mods, occs, avails) ie@(IEModuleContents mod) + | mod `elem` mods -- Duplicate export of M + = do { warn_dup_exports <- doptM Opt_WarnDuplicateExports ; + warnIf warn_dup_exports (dupModuleExport mod) ; + returnM acc } + + | otherwise + = case lookupModuleEnvByName mod_avail_env mod of + Nothing -> addErr (modExportErr mod) `thenM_` + returnM acc + + Just avail_env + -> let + mod_avails = [ filtered_avail + | avail <- availEnvElts avail_env, + let mb_avail = filter_unqual rdr_env avail, + isJust mb_avail, + let Just filtered_avail = mb_avail] + + avails' = foldl addAvail avails mod_avails + 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. + + foldlM (check_occs ie) occs mod_avails `thenM` \ occs' -> + returnM (mod:mods, occs', avails') + + exports_from_item acc@(mods, occs, avails) ie + = lookupGRE (ieName ie) `thenM` \ mb_gre -> + case mb_gre of { + Nothing -> addErr (unknownNameErr (ieName ie)) `thenM_` + returnM acc ; + Just gre -> + + -- Get the AvailInfo for the parent of the specified name + let + parent = gre_parent gre `orElse` gre_name gre + 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! + warnIf (not (ok_item ie avail)) (dodgyExportWarn ie) `thenM_` + check_occs ie occs export_avail `thenM` \ occs' -> + returnM (mods, occs', addAvail avails export_avail) + }} + + +------------------------------- +filter_unqual :: GlobalRdrEnv -> AvailInfo -> Maybe AvailInfo +-- Filter the Avail by what's in scope unqualified +filter_unqual env (Avail n) + | in_scope env n = Just (Avail n) + | otherwise = Nothing +filter_unqual env (AvailTC n ns) + | not (null ns') = Just (AvailTC n ns') + | otherwise = Nothing where - -- NOTE: reorders the export list by moving all module-contents - -- exports to the end (removing duplicates in the process.) - check_modules ls = - (case dups of - [] -> returnRn () - ls -> mapRn (\ ds@(IEModuleContents x:_) -> - addWarnRn (dupModuleExport x (length ds))) ls `thenRn_` - returnRn ()) `thenRn_` - returnRn (ls_no_modules ++ no_module_dups) - where - (ls_no_modules,modules) = foldr split_mods ([],[]) ls - - split_mods i@(IEModuleContents _) (no_ms,ms) = (no_ms,i:ms) - split_mods i (no_ms,ms) = (i:no_ms,ms) - - (no_module_dups, dups) = removeDups cmp_mods modules - - cmp_mods (IEModuleContents m1) (IEModuleContents m2) = m1 `compare` m2 - -mk_export_fn :: [AvailInfo] -> (Name -> ExportFlag) -mk_export_fn avails - = \name -> if name `elemNameSet` exported_names - then Exported - else NotExported + ns' = filter (in_scope env) ns + +in_scope :: GlobalRdrEnv -> Name -> Bool +-- Checks whether the Name is in scope unqualified, +-- regardless of whether it's ambiguous or not +in_scope env n + = case lookupRdrEnv env (mkRdrUnqual (nameOccName n)) of + Nothing -> False + Just gres -> or [n == gre_name g | g <- gres] + + +------------------------------- +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 -> TcRn m ExportOccMap +check_occs ie occs avail + = foldlM check occs (availNames avail) + where + check occs name + = case lookupFM occs name_occ of + Nothing -> returnM (addToFM occs name_occ (name, 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 +\end{code} + +%********************************************************* +%* * +\subsection{Unused names} +%* * +%********************************************************* + +\begin{code} +reportUnusedNames :: TcGblEnv -> DefUses -> TcRn m () +reportUnusedNames gbl_env dus + = warnUnusedModules unused_imp_mods `thenM_` + warnUnusedTopBinds bad_locals `thenM_` + warnUnusedImports bad_imports `thenM_` + printMinimalImports minimal_imports + where + used_names :: NameSet + used_names = findUses dus emptyNameSet + + -- Collect the defined names from the in-scope environment + -- Look for the qualified ones only, else get duplicates + defined_names :: [GlobalRdrElt] + defined_names = foldRdrEnv add [] (tcg_rdr_env gbl_env) + add rdr_name ns acc | isQual rdr_name = ns ++ acc + | otherwise = acc + + defined_and_used, defined_but_not_used :: [GlobalRdrElt] + (defined_and_used, defined_but_not_used) = partition is_used defined_names + + is_used gre = n `elemNameSet` used_names || any (`elemNameSet` used_names) kids + -- The 'kids' part is because a use of C implies a use of T, + -- if C was brought into scope by T(..) or T(C) + where + n = gre_name gre + kids = case lookupAvailEnv_maybe avail_env n of + Just (AvailTC n ns) -> ns + other -> [] -- Ids, class ops and datacons + -- (The latter two give Nothing) + + -- 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 + bad_locals :: [GlobalRdrElt] + bad_locals = filter is_bad defined_but_not_used + is_bad :: GlobalRdrElt -> Bool + is_bad gre = isLocalGRE gre && isExternalName (gre_name gre) + + bad_imports :: [GlobalRdrElt] + bad_imports = filter bad_imp defined_but_not_used + bad_imp (GRE {gre_prov = NonLocalDef (UserImport mod _ True)}) = not (module_unused mod) + bad_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_parent = p, + gre_prov = NonLocalDef (UserImport m _ _)}) acc + = addToFM_C plusAvailEnv acc (moduleName m) + (unitAvailEnv (mk_avail n p)) + 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 + avail_env = imp_env imports + + direct_import_mods :: [ModuleName] + direct_import_mods = map (moduleName . fst) + (moduleEnvElts (imp_mods imports)) + + -- unused_imp_mods are the directly-imported modules + -- that are not mentioned in minimal_imports1 + -- [Note: not 'minimal_imports', because that includes direcly-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] + + module_unused :: Module -> Bool + module_unused mod = moduleName mod `elem` unused_imp_mods + + +-- ToDo: deal with original imports with 'qualified' and 'as M' clauses +printMinimalImports :: FiniteMap ModuleName AvailEnv -- Minimal imports + -> TcRn m () +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 - exported_names :: NameSet - exported_names = availsToNameSet avails + 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 -> TcRn m (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) + = loadInterface (text "Compute minimal imports from" <+> ppr n_mod) + n_mod ImportBySystem `thenM` \ iface -> + case [xs | (m,as) <- mi_exports iface, + m == n_mod, + AvailTC x xs <- as, + x == n] of + [xs] | all (`elem` ns) xs -> returnM (IEThingAll n) + | otherwise -> returnM (IEThingWith n (filter (/= n) ns)) + other -> pprTrace "to_ie" (ppr n <+> ppr (nameModule n) <+> ppr other) $ + returnM (IEVar n) + where + n_mod = moduleName (nameModule n) \end{code} + %************************************************************************ %* * \subsection{Errors} @@ -628,38 +857,68 @@ mk_export_fn avails %************************************************************************ \begin{code} -badImportItemErr mod ie - = sep [ptext SLIT("Module"), quotes (pprModule mod), +badImportItemErr mod from ie + = sep [ptext SLIT("Module"), quotes (ppr mod), source_import, ptext SLIT("does not export"), quotes (ppr ie)] - -dodgyImportWarn mod (IEThingAll tc) - = sep [ptext SLIT("Module") <+> quotes (pprModule mod) <+> ptext SLIT("exports") <+> quotes (ppr tc), - ptext SLIT("with no constructors/class operations;"), - ptext SLIT("yet it is imported with a (..)")] - + where + source_import = case from of + True -> ptext SLIT("(hi-boot interface)") + other -> empty + +dodgyImportWarn mod 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), + 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") ] + modExportErr mod - = hsep [ ptext SLIT("Unknown module in export list: module"), quotes (pprModule mod)] - -exportItemErr export_item NotAvailable - = sep [ ptext SLIT("Export item not in scope:"), quotes (ppr export_item)] + = hsep [ ptext SLIT("Unknown module in export list: module"), quotes (ppr mod)] -exportItemErr export_item avail - = hang (ptext SLIT("Export item not fully in scope:")) - 4 (vcat [hsep [ptext SLIT("Wanted: "), ppr export_item], - hsep [ptext SLIT("Available:"), ppr (ieOcc export_item), pprAvail avail]]) +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") ] -availClashErr (occ_name, ((ie1,avail1,_), (ie2,avail2,_))) - = 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, in a very inefficient way + -- There isn't a more efficient way to do it, because we don't necessarily + -- know the RdrName under which this Name is in scope. So we just + -- search linearly. Shouldn't matter because this only happens + -- in an error message. + get_gre name + = case [gre | gres <- rdrEnvElts global_env, + gre <- gres, + gre_name gre == name] of + (gre:_) -> gre + [] -> pprPanic "exportClashErr" (ppr name) + +dupDeclErr (n:ns) + = vcat [ptext SLIT("Multiple declarations of") <+> quotes (ppr n), + nest 4 (vcat (map ppr sorted_locs))] + where + sorted_locs = sortLt occ'ed_before (map nameSrcLoc (n:ns)) + occ'ed_before a b = LT == compare a b -dupExportWarn (occ_name, (_,_,times)) +dupExportWarn occ_name ie1 ie2 = hsep [quotes (ppr occ_name), - ptext SLIT("mentioned"), speakNTimes (times+1), - ptext SLIT("in export list")] + ptext SLIT("is exported by"), quotes (ppr ie1), + ptext SLIT("and"), quotes (ppr ie2)] -dupModuleExport mod times - = hsep [ptext SLIT("Module"), quotes (pprModule mod), - ptext SLIT("mentioned"), speakNTimes times, +dupModuleExport mod + = hsep [ptext SLIT("Duplicate"), + quotes (ptext SLIT("Module") <+> ppr mod), ptext SLIT("in export list")] -\end{code} +moduleDeprec mod txt + = sep [ ptext SLIT("Module") <+> quotes (ppr mod) <+> ptext SLIT("is deprecated:"), + nest 4 (ppr txt) ] +\end{code}