X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=ghc%2Fcompiler%2Frename%2FRnNames.lhs;h=5877872eaa59f1f0c36271ce601f6b6541108afd;hb=e2bcc01c862ab0c4a12040172429075aa5921b49;hp=078863f83cd0f8d6e5b2d6418170e3799e6b6fcc;hpb=c5ba8422faef9ee65d28e706c320cc334f9e97b6;p=ghc-hetmet.git diff --git a/ghc/compiler/rename/RnNames.lhs b/ghc/compiler/rename/RnNames.lhs index 078863f..5877872 100644 --- a/ghc/compiler/rename/RnNames.lhs +++ b/ghc/compiler/rename/RnNames.lhs @@ -5,132 +5,140 @@ \begin{code} module RnNames ( - getGlobalNames, exportsFromAvail + rnImports, importsFromLocalDecls, exportsFromAvail, + reportUnusedNames ) where #include "HsVersions.h" +import {-# SOURCE #-} RnHiFiles ( loadInterface ) + import CmdLineOpts ( DynFlag(..) ) -import HsSyn ( HsModule(..), HsDecl(..), IE(..), ieName, ImportDecl(..), - ForeignDecl(..), - collectLocatedHsBinders - ) -import RdrHsSyn ( RdrNameIE, RdrNameImportDecl, - RdrNameHsModule, RdrNameHsDecl +import HsSyn ( HsDecl(..), IE(..), ieName, ImportDecl(..), + ForeignDecl(..), HsGroup(..), + collectLocatedHsBinders, tyClDeclNames ) -import RnIfaces ( recordLocalSlurps ) -import RnHiFiles ( getTyClDeclBinders, loadInterface ) +import RdrHsSyn ( RdrNameIE, RdrNameImportDecl, RdrNameHsDecl ) import RnEnv -import RnMonad +import TcRnMonad import FiniteMap -import PrelNames ( pRELUDE_Name, mAIN_Name, main_RDR_Unqual, isUnboundName ) -import Module ( ModuleName, moduleName, WhereFrom(..) ) -import Name ( Name, nameSrcLoc, nameOccName ) +import PrelNames ( pRELUDE_Name, mAIN_Name, isBuiltInSyntaxName ) +import Module ( Module, ModuleName, moduleName, + moduleNameUserString, + unitModuleEnvByName, lookupModuleEnvByName, + moduleEnvElts ) +import Name ( Name, nameSrcLoc, nameOccName, nameModule, isExternalName ) import NameSet import NameEnv +import OccName ( OccName, dataName, isTcOcc ) import HscTypes ( Provenance(..), ImportReason(..), GlobalRdrEnv, - GenAvailInfo(..), AvailInfo, Avails, AvailEnv, - Deprecations(..), ModIface(..), emptyAvailEnv + GenAvailInfo(..), AvailInfo, Avails, IsBootInterface, + availName, availNames, availsToNameSet, + Deprecations(..), ModIface(..), + GlobalRdrElt(..), unQualInScope, isLocalGRE ) -import RdrName ( rdrNameOcc, setRdrNameOcc ) -import OccName ( setOccNameSpace, dataName ) -import NameSet ( elemNameSet, emptyNameSet ) +import RdrName ( RdrName, rdrNameOcc, setRdrNameSpace, + emptyRdrEnv, foldRdrEnv, isQual ) import Outputable -import Maybes ( maybeToBool, catMaybes, mapMaybe ) +import Maybes ( maybeToBool, catMaybes ) import ListSetOps ( removeDups ) -import Util ( sortLt ) +import Util ( sortLt, notNull ) import List ( partition ) +import IO ( openFile, IOMode(..) ) \end{code} %************************************************************************ %* * -\subsection{Get global names} + rnImports %* * %************************************************************************ \begin{code} -getGlobalNames :: Module -> RdrNameHsModule - -> RnMG (GlobalRdrEnv, -- Maps all in-scope things - GlobalRdrEnv, -- Maps just *local* things - ExportAvails) -- The exported stuff - -getGlobalNames this_mod (HsModule _ _ _ imports decls _ mod_loc) - = -- PROCESS LOCAL DECLS - -- Do these *first* so that the correct provenance gets - -- into the global name cache. - importsFromLocalDecls this_mod decls `thenRn` \ (local_gbl_env, local_mod_avails) -> - - -- PROCESS IMPORT DECLS +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 - doptRn Opt_NoImplicitPrelude `thenRn` \ opt_no_prelude -> + getModule `thenM` \ this_mod -> + getSrcLocM `thenM` \ loc -> + doptM Opt_NoImplicitPrelude `thenM` \ opt_no_prelude -> let - all_imports = mk_prel_imports opt_no_prelude ++ imports + all_imports = mk_prel_imports this_mod loc 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 (ImportDecl _ is_boot _ _ _ _) = is_boot - get_imports = importsFromImportDecl this_mod_name + get_imports = importsFromImportDecl (moduleName this_mod) in - mapAndUnzipRn get_imports ordinary `thenRn` \ (imp_gbl_envs1, imp_avails_s1) -> - mapAndUnzipRn get_imports 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 emptyRdrEnv imp_gbl_envs - all_avails :: ExportAvails - all_avails = foldr plusExportAvails local_mod_avails (imp_avails_s2 ++ imp_avails_s1) + all_avails :: ImportAvails + all_avails = foldr plusImportAvails emptyImportAvails imp_avails in - -- ALL DONE - returnRn (gbl_env, local_gbl_env, all_avails) + returnM (gbl_env, all_avails) where - this_mod_name = moduleName this_mod - -- 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. - mk_prel_imports no_prelude - | this_mod_name == pRELUDE_Name || - explicit_prelude_import || - no_prelude + -- 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 = [] - | otherwise = [ImportDecl pRELUDE_Name - ImportByUser - False {- Not qualified -} - Nothing {- No "as" -} - Nothing {- No import list -} - mod_loc] - + | otherwise = [preludeImportDecl loc] + explicit_prelude_import - = not (null [ () | (ImportDecl mod _ _ _ _ _) <- imports, mod == pRELUDE_Name ]) + = 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 :: ModuleName -> RdrNameImportDecl - -> RnMG (GlobalRdrEnv, - ExportAvails) + -> TcRn m (GlobalRdrEnv, ImportAvails) + +importsFromImportDecl this_mod_name + (ImportDecl imp_mod_name is_boot qual_only as_mod import_spec iloc) + = addSrcLoc iloc $ + let + doc = ppr imp_mod_name <+> ptext SLIT("is directly imported") + in -importsFromImportDecl this_mod_name (ImportDecl imp_mod_name from qual_only as_mod import_spec iloc) - = pushSrcLocRn iloc $ + -- 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 -> + + case mb_iface of { + Left exn -> returnM (emptyRdrEnv, emptyImportAvails ) ; + Right iface -> - loadInterface (ppr imp_mod_name <+> ptext SLIT("is directly imported")) - imp_mod_name from `thenRn` \ iface -> let imp_mod = mi_module iface avails_by_module = mi_exports iface deprecs = mi_deprecs iface + dir_imp = unitModuleEnvByName imp_mod_name (imp_mod, import_all import_spec) avails :: Avails avails = [ avail | (mod_name, avails) <- avails_by_module, @@ -154,43 +162,55 @@ importsFromImportDecl this_mod_name (ImportDecl imp_mod_name from qual_only as_m -- then you'll get a 'B does not export AType' message. Oh well. in - if null avails_by_module then - -- 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 - -- Complain if we import a deprecated module - ifOptRn Opt_WarnDeprecations ( + ifOptM Opt_WarnDeprecations ( case deprecs of - DeprecAll txt -> addWarnRn (moduleDeprec imp_mod_name txt) - other -> returnRn () - ) `thenRn_` + DeprecAll txt -> addWarn (moduleDeprec imp_mod_name txt) + other -> returnM () + ) `thenM_` -- Filter the imports according to the import list - filterImports imp_mod_name from import_spec avails `thenRn` \ (filtered_avails, hides, explicits) -> + filterImports imp_mod_name is_boot import_spec avails `thenM` \ (filtered_avails, explicits) -> let - unqual_imp = not qual_only -- Maybe want unqualified names + unqual_imp = not qual_only -- Maybe want unqualified names qual_mod = case as_mod of Nothing -> imp_mod_name Just another_name -> another_name mk_prov name = NonLocalDef (UserImport imp_mod iloc (name `elemNameSet` explicits)) - gbl_env = mkGlobalRdrEnv qual_mod unqual_imp mk_prov filtered_avails hides deprecs - exports = mkExportAvails qual_mod unqual_imp gbl_env hides filtered_avails + gbl_env = mkGlobalRdrEnv qual_mod unqual_imp mk_prov filtered_avails deprecs + imports = mkImportAvails qual_mod unqual_imp filtered_avails in - returnRn (gbl_env, exports) + returnM (gbl_env, imports { imp_mods = dir_imp}) + } + +import_all (Just (False, _)) = False -- Imports are spec'd explicitly +import_all other = True -- Everything is imported \end{code} +%************************************************************************ +%* * + importsFromLocalDecls +%* * +%************************************************************************ + +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 this_mod decls - = mapRn (getLocalDeclBinders this_mod) decls `thenRn` \ avails_s -> +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 - avails = concat avails_s - all_names :: [Name] -- All the defns; no dups eliminated all_names = [name | avail <- avails, name <- availNames avail] @@ -201,18 +221,15 @@ importsFromLocalDecls this_mod decls -- 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. - mapRn_ (addErrRn . dupDeclErr) dups `thenRn_` - + mappM_ (addErr . dupDeclErr) dups `thenM_` - -- Record that locally-defined things are available - recordLocalSlurps (availsToNameSet avails) `thenRn_` + doptM Opt_NoImplicitPrelude `thenM` \ implicit_prelude -> let mod_name = moduleName this_mod unqual_imp = True -- Want unqualified names mk_prov n = LocalDef -- Provenance is local - hides = [] -- Hide nothing - gbl_env = mkGlobalRdrEnv mod_name unqual_imp mk_prov avails hides NoDeprecs + 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 @@ -220,41 +237,70 @@ importsFromLocalDecls this_mod decls -- the defn of a non-deprecated thing, when changing a module's -- interface - exports = mkExportAvails mod_name unqual_imp gbl_env hides avails + + -- 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. + imports = mkImportAvails mod_name unqual_imp avails' + 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. in - returnRn (gbl_env, exports) + returnM (gbl_env, imports) +\end{code} + + +%********************************************************* +%* * +\subsection{Getting binders out of a declaration} +%* * +%********************************************************* + +@getLocalDeclBinders@ returns the names for a @RdrNameHsDecl@. It's +used for both source code (from @importsFromLocalDecls@) and interface +files (@loadDecl@ calls @getTyClDeclBinders@). ---------------------------- -getLocalDeclBinders :: Module -> RdrNameHsDecl -> RnMG [AvailInfo] -getLocalDeclBinders mod (TyClD tycl_decl) + *** 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. - getTyClDeclBinders mod tycl_decl `thenRn` \ (avail, sys_names) -> - -- Record that the system names are available - recordLocalSlurps (mkNameSet sys_names) `thenRn_` - returnRn [avail] + mappM new_tc tycl_decls `thenM` \ tc_avails -> + mappM new_bndr (for_hs_bndrs ++ val_hs_bndrs) `thenM` \ simple_bndrs -> -getLocalDeclBinders mod (ValD binds) - = mapRn new (collectLocatedHsBinders binds) `thenRn` \ avails -> - returnRn avails + returnM (tc_avails ++ map Avail simple_bndrs) where - new (rdr_name, loc) = newTopBinder mod rdr_name loc `thenRn` \ name -> - returnRn (Avail name) - -getLocalDeclBinders mod (ForD (ForeignImport nm _ _ loc)) - = newTopBinder mod nm loc `thenRn` \ name -> - returnRn [Avail name] -getLocalDeclBinders mod (ForD _) - = returnRn [] - -getLocalDeclBinders mod (FixD _) = returnRn [] -getLocalDeclBinders mod (DeprecD _) = returnRn [] -getLocalDeclBinders mod (DefD _) = returnRn [] -getLocalDeclBinders mod (InstD _) = returnRn [] -getLocalDeclBinders mod (RuleD _) = returnRn [] + 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} @@ -269,35 +315,32 @@ available, and filters it through the import spec (if any). \begin{code} filterImports :: ModuleName -- The module being imported - -> WhereFrom -- Tells whether it's a {-# SOURCE #-} import + -> IsBootInterface -- Tells whether it's a {-# SOURCE #-} import -> Maybe (Bool, [RdrNameIE]) -- Import spec; True => hiding -> [AvailInfo] -- What's available - -> RnMG ([AvailInfo], -- "chosens" - [AvailInfo], -- "hides" - -- The true imports are "chosens" - "hides" - -- (It's convenient to return both the above sets, because - -- the substraction can be done more efficiently when - -- building the environment.) + -> TcRn m ([AvailInfo], -- What's imported NameSet) -- What was imported explicitly -- Complains if import spec mentions things that the module doesn't export -- Warns/informs if import spec contains duplicates. filterImports mod from Nothing imports - = returnRn (imports, [], emptyNameSet) + = returnM (imports, emptyNameSet) filterImports mod from (Just (want_hiding, import_items)) total_avails - = flatMapRn get_item import_items `thenRn` \ avails_w_explicits -> + = mappM get_item import_items `thenM` \ avails_w_explicits_s -> let - (item_avails, explicits_s) = unzip avails_w_explicits + (item_avails, explicits_s) = unzip (concat avails_w_explicits_s) explicits = foldl addListToNameSet emptyNameSet explicits_s in - if want_hiding - then - -- All imported; item_avails to be hidden - returnRn (total_avails, item_avails, emptyNameSet) + 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 - returnRn (item_avails, [], explicits) + returnM (item_avails, explicits) where import_fm :: FiniteMap OccName AvailInfo import_fm = listToFM [ (nameOccName name, avail) @@ -307,10 +350,15 @@ filterImports mod from (Just (want_hiding, import_items)) total_avails -- 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 from item) `thenRn_` - returnRn [] + bale_out item = addErr (badImportItemErr mod from item) `thenM_` + returnM [] - get_item :: RdrNameIE -> RnMG [(AvailInfo, [Name])] + 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 _) @@ -319,24 +367,24 @@ filterImports mod from (Just (want_hiding, import_items)) total_avails 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 - ifOptRn Opt_WarnMisc (addWarnRn (dodgyImportWarn mod item)) `thenRn_` - returnRn [(avail, [availName avail])] - Just avail -> returnRn [(avail, [availName avail])] + 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 -> returnRn [(a, []) | a <- avails] + avails -> returnM [(a, []) | a <- avails] -- The 'explicits' list is irrelevant when hiding where - data_n = setRdrNameOcc n (setOccNameSpace (rdrNameOcc n) dataName) + data_n = setRdrNameSpace n dataName get_item item = case check_item item of Nothing -> bale_out item - Just avail -> returnRn [(avail, availNames avail)] + Just avail -> returnM [(avail, availNames avail)] check_item item | not (maybeToBool maybe_in_import_avails) || @@ -355,71 +403,41 @@ filterImports mod from (Just (want_hiding, import_items)) total_avails Just filtered_avail = maybe_filtered_avail \end{code} - - -%************************************************************************ -%* * -\subsection{Qualifiying imports} -%* * -%************************************************************************ - \begin{code} -mkEmptyExportAvails :: ModuleName -> ExportAvails -mkEmptyExportAvails mod_name = (unitFM mod_name [], emptyNameEnv) - -mkExportAvails :: ModuleName -> Bool -> GlobalRdrEnv -> [AvailInfo] -> [AvailInfo] -> ExportAvails -mkExportAvails mod_name unqual_imp gbl_env hides avails - = (mod_avail_env, entity_avail_env) +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 - 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) - | 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 gbl_env n - - - entity_avail_env = mkNameEnv ([ (availName avail,avail) | avail <- effective_avails ] ++ - -- sigh - need to have the method/field names in - -- the environment also, so that export lists - -- can be computed precisely (cf. exportsFromAvail) - [ (name,avail) | avail <- effective_avails, - name <- avNames avail ] ) - - avNames (Avail n) = [n] - avNames (AvailTC n ns) = filter (/=n) ns - - -- remove 'hides' names from the avail list. - effective_avails = foldl wipeOut avails hides - where - wipeOut as (Avail n) = mapMaybe (delName n) as - wipeOut as (AvailTC n ns) = foldl wipeOut as (map Avail ns) - - delName x a@(Avail n) - | n == x = Nothing - | otherwise = Just a - delName x (AvailTC n ns) - = case (filter (/=x) ns) of - [] -> Nothing - xs -> Just (AvailTC n xs) - -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} @@ -431,15 +449,15 @@ 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 @@ -448,6 +466,7 @@ type ExportAccum -- The type of the accumulating parameter of 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 @@ -456,79 +475,80 @@ type ExportOccMap = FiniteMap OccName (Name, RdrNameIE) -- that have the same occurrence name -exportsFromAvail :: ModuleName - -> Maybe [RdrNameIE] -- Export spec - -> ExportAvails - -> GlobalRdrEnv - -> RnMG Avails +exportsFromAvail :: Maybe [RdrNameIE] -> 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 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_Unqual] - -- 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 Nothing + = do { this_mod <- getModule ; + if moduleName this_mod == mAIN_Name then + return [] + -- Export nothing; Main.$main is automatically exported + else + exportsFromAvail (Just [IEModuleContents (moduleName this_mod)]) + -- but for all other modules export everything. + } + +exportsFromAvail (Just exports) + = do { TcGblEnv { tcg_imports = imports } <- getGblEnv ; + warn_dup_exports <- doptM Opt_WarnDuplicateExports ; + exports_from_avail exports warn_dup_exports imports } + +exports_from_avail export_items warn_dup_exports + (ImportAvails { imp_unqual = 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 :: Bool -> ExportAccum -> RdrNameIE -> RnMG ExportAccum + exports_from_item :: ExportAccum -> RdrNameIE -> TcRn m ExportAccum - exports_from_item warn_dups acc@(mods, occs, avails) ie@(IEModuleContents mod) + exports_from_item acc@(mods, occs, avails) ie@(IEModuleContents mod) | mod `elem` mods -- Duplicate export of M - = warnCheckRn warn_dups (dupModuleExport mod) `thenRn_` - returnRn acc + = warnIf warn_dup_exports (dupModuleExport mod) `thenM_` + 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 - = lookupSrcName global_name_env (ieName ie) `thenRn` \ name -> - - -- See what's available in the current environment - case lookupNameEnv entity_avail_env name of { - Nothing -> -- Presumably this happens because lookupSrcName didn't find - -- the name and returned an unboundName, which won't be in - -- the entity_avail_env, of course - WARN( not (isUnboundName name), ppr name ) - returnRn acc ; - - Just avail -> + = case lookupModuleEnvByName mod_avail_env mod of + Nothing -> addErr (modExportErr mod) `thenM_` + returnM acc + Just avail_env + -> let + mod_avails = availEnvElts avail_env + avails' = foldl addAvail avails mod_avails + in + foldlM (check_occs warn_dup_exports 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 + case lookupAvailEnv entity_avail_env (gre_parent gre) of { + Nothing -> pprPanic "exportsFromAvail" + ((ppr (ieName ie)) <+> ppr gre) ; + Just avail -> -- Filter out the bits we want case filterAvail ie avail of { Nothing -> -- Not enough availability - failWithRn acc (exportItemErr ie) ; + addErr (exportItemErr ie) `thenM_` + returnM acc ; Just export_avail -> -- 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) - }} + warnIf (not (ok_item ie avail)) (dodgyExportWarn ie) `thenM_` + check_occs warn_dup_exports ie occs export_avail `thenM` \ occs' -> + returnM (mods, occs', addAvail avails export_avail) + }}} @@ -538,26 +558,186 @@ ok_item (IEThingAll _) (AvailTC _ [n]) = False -- 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) +check_occs :: Bool -> RdrNameIE -> ExportOccMap -> AvailInfo -> TcRn m ExportOccMap +check_occs warn_dup_exports ie occs avail + = foldlM check occs (availNames avail) where - check warn_dup occs name + check occs name = case lookupFM occs name_occ of - Nothing -> returnRn (addToFM occs name_occ (name, ie)) + Nothing -> returnM (addToFM occs name_occ (name, ie)) Just (name', ie') | name == name' -> -- Duplicate export - warnCheckRn warn_dup - (dupExportWarn name_occ ie ie') - `thenRn_` returnRn occs + warnIf warn_dup_exports + (dupExportWarn name_occ ie ie') + `thenM_` returnM occs | otherwise -> -- Same occ name but different names: an error - failWithRn occs (exportClashErr name_occ ie ie') + addErr (exportClashErr name_occ ie ie') `thenM_` + returnM occs where name_occ = nameOccName name \end{code} +%********************************************************* +%* * +\subsection{Unused names} +%* * +%********************************************************* + +\begin{code} +reportUnusedNames :: TcGblEnv + -> NameSet -- Used in this module + -> TcRn m () +reportUnusedNames gbl_env used_names + = warnUnusedModules unused_imp_mods `thenM_` + warnUnusedTopBinds bad_locals `thenM_` + warnUnusedImports bad_imports `thenM_` + printMinimalImports minimal_imports + where + direct_import_mods :: [ModuleName] + direct_import_mods = map (moduleName . fst) + (moduleEnvElts (imp_mods (tcg_imports gbl_env))) + + -- Now, a use of C implies a use of T, + -- if C was brought into scope by T(..) or T(C) + really_used_names :: NameSet + really_used_names = used_names `unionNameSets` + mkNameSet [ gre_parent gre + | gre <- defined_names, + gre_name gre `elemNameSet` used_names] + + -- 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 used defined_names + used gre = gre_name gre `elemNameSet` really_used_names + + -- 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 p | n/=p = AvailTC p [p,n] + | isTcOcc (nameOccName p) = 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 + + -- 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, + not (maybeToBool (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 + 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} @@ -570,8 +750,8 @@ badImportItemErr mod from ie ptext SLIT("does not export"), quotes (ppr ie)] where source_import = case from of - ImportByUserSource -> ptext SLIT("(hi-boot interface)") - other -> empty + True -> ptext SLIT("(hi-boot interface)") + other -> empty dodgyImportWarn mod item = dodgyMsg (ptext SLIT("import")) item dodgyExportWarn item = dodgyMsg (ptext SLIT("export")) item