-%\r
-% (c) The GRASP/AQUA Project, Glasgow University, 1992-1998\r
-%\r
-\section[RnNames]{Extracting imported and top-level names in scope}\r
-\r
-\begin{code}\r
-module RnNames (\r
- getGlobalNames\r
- ) where\r
-\r
-#include "HsVersions.h"\r
-\r
-import CmdLineOpts ( opt_NoImplicitPrelude, opt_WarnDuplicateExports, \r
- opt_SourceUnchanged, opt_WarnUnusedBinds\r
- )\r
-\r
-import HsSyn ( HsModule(..), HsDecl(..), TyClDecl(..),\r
- IE(..), ieName, \r
- ForeignDecl(..), ForKind(..), isDynamic,\r
- FixitySig(..), Sig(..), ImportDecl(..),\r
- collectTopBinders\r
- )\r
-import RdrHsSyn ( RdrNameIE, RdrNameImportDecl,\r
- RdrNameHsModule, RdrNameHsDecl\r
- )\r
-import RnIfaces ( getInterfaceExports, getDeclBinders,\r
- recordSlurp, checkUpToDate\r
- )\r
-import RnEnv\r
-import RnMonad\r
-\r
-import FiniteMap\r
-import PrelMods\r
-import PrelInfo ( main_RDR )\r
-import UniqFM ( lookupUFM )\r
-import Bag ( bagToList )\r
-import Maybes ( maybeToBool )\r
-import Module ( ModuleName, mkThisModule, pprModuleName, WhereFrom(..) )\r
-import NameSet\r
-import Name ( Name, ExportFlag(..), ImportReason(..), Provenance(..),\r
- isLocallyDefined, setNameProvenance,\r
- nameOccName, getSrcLoc, pprProvenance, getNameProvenance\r
- )\r
-import RdrName ( RdrName, rdrNameOcc, mkRdrQual, mkRdrUnqual, isQual )\r
-import SrcLoc ( SrcLoc )\r
-import NameSet ( elemNameSet, emptyNameSet )\r
-import Outputable\r
-import Unique ( getUnique )\r
-import Util ( removeDups, equivClassesByUniq, sortLt )\r
-import List ( partition )\r
-\end{code}\r
-\r
-\r
-\r
-%************************************************************************\r
-%* *\r
-\subsection{Get global names}\r
-%* *\r
-%************************************************************************\r
-\r
-\begin{code}\r
-getGlobalNames :: RdrNameHsModule\r
- -> RnMG (Maybe (ExportEnv, \r
- GlobalRdrEnv,\r
- FixityEnv, -- Fixities for local decls only\r
- NameEnv AvailInfo -- Maps a name to its parent AvailInfo\r
- -- Just for in-scope things only\r
- ))\r
- -- Nothing => no need to recompile\r
-\r
-getGlobalNames (HsModule this_mod _ exports imports decls mod_loc)\r
- = -- These two fix-loops are to get the right\r
- -- provenance information into a Name\r
- fixRn (\ ~(rec_gbl_env, rec_exported_avails, _) ->\r
-\r
- let\r
- rec_unqual_fn :: Name -> Bool -- Is this chap in scope unqualified?\r
- rec_unqual_fn = unQualInScope rec_gbl_env\r
-\r
- rec_exp_fn :: Name -> ExportFlag\r
- rec_exp_fn = mk_export_fn (availsToNameSet rec_exported_avails)\r
- in\r
- setModuleRn this_mod $\r
-\r
- -- PROCESS LOCAL DECLS\r
- -- Do these *first* so that the correct provenance gets\r
- -- into the global name cache.\r
- importsFromLocalDecls this_mod rec_exp_fn decls `thenRn` \ (local_gbl_env, local_mod_avails) ->\r
-\r
- -- PROCESS IMPORT DECLS\r
- -- Do the non {- SOURCE -} ones first, so that we get a helpful\r
- -- warning for {- SOURCE -} ones that are unnecessary\r
- let\r
- (source, ordinary) = partition is_source_import all_imports\r
- is_source_import (ImportDecl _ ImportByUserSource _ _ _ _) = True\r
- is_source_import other = False\r
- in\r
- mapAndUnzipRn (importsFromImportDecl rec_unqual_fn) ordinary `thenRn` \ (imp_gbl_envs1, imp_avails_s1) ->\r
- mapAndUnzipRn (importsFromImportDecl rec_unqual_fn) source `thenRn` \ (imp_gbl_envs2, imp_avails_s2) ->\r
-\r
- -- COMBINE RESULTS\r
- -- We put the local env second, so that a local provenance\r
- -- "wins", even if a module imports itself.\r
- let\r
- gbl_env :: GlobalRdrEnv\r
- imp_gbl_env = foldr plusGlobalRdrEnv emptyRdrEnv (imp_gbl_envs2 ++ imp_gbl_envs1)\r
- gbl_env = imp_gbl_env `plusGlobalRdrEnv` local_gbl_env\r
-\r
- all_avails :: ExportAvails\r
- all_avails = foldr plusExportAvails local_mod_avails (imp_avails_s2 ++ imp_avails_s1)\r
- in\r
-\r
- -- TRY FOR EARLY EXIT\r
- -- We can't go for an early exit before this because we have to check\r
- -- for name clashes. Consider:\r
- --\r
- -- module A where module B where\r
- -- import B h = True\r
- -- f = h\r
- --\r
- -- Suppose I've compiled everything up, and then I add a\r
- -- new definition to module B, that defines "f".\r
- --\r
- -- Then I must detect the name clash in A before going for an early\r
- -- exit. The early-exit code checks what's actually needed from B\r
- -- to compile A, and of course that doesn't include B.f. That's\r
- -- why we wait till after the plusEnv stuff to do the early-exit.\r
- checkEarlyExit this_mod `thenRn` \ up_to_date ->\r
- if up_to_date then\r
- returnRn (gbl_env, junk_exp_fn, Nothing)\r
- else\r
- \r
- -- RECORD BETTER PROVENANCES IN THE CACHE\r
- -- The names in the envirnoment have better provenances (e.g. imported on line x)\r
- -- than the names in the name cache. We update the latter now, so that we\r
- -- we start renaming declarations we'll get the good names\r
- -- The isQual is because the qualified name is always in scope\r
- updateProvenances (concat [names | (rdr_name, names) <- rdrEnvToList imp_gbl_env, \r
- isQual rdr_name]) `thenRn_`\r
-\r
- -- PROCESS EXPORT LISTS\r
- exportsFromAvail this_mod exports all_avails gbl_env `thenRn` \ exported_avails ->\r
-\r
- -- DONE\r
- returnRn (gbl_env, exported_avails, Just all_avails)\r
- ) `thenRn` \ (gbl_env, exported_avails, maybe_stuff) ->\r
-\r
- case maybe_stuff of {\r
- Nothing -> returnRn Nothing ;\r
- Just all_avails ->\r
-\r
- traceRn (text "updateProv" <+> fsep (map ppr (rdrEnvElts gbl_env))) `thenRn_`\r
- \r
- -- DEAL WITH FIXITIES\r
- fixitiesFromLocalDecls gbl_env decls `thenRn` \ local_fixity_env ->\r
- let\r
- -- Export only those fixities that are for names that are\r
- -- (a) defined in this module\r
- -- (b) exported\r
- exported_fixities :: [(Name,Fixity)]\r
- exported_fixities = [(name,fixity) | FixitySig name fixity _ <- nameEnvElts local_fixity_env,\r
- isLocallyDefined name\r
- ]\r
- in\r
- traceRn (text "fixity env" <+> vcat (map ppr (nameEnvElts local_fixity_env))) `thenRn_`\r
-\r
- --- TIDY UP \r
- let\r
- export_env = ExportEnv exported_avails exported_fixities\r
- (_, global_avail_env) = all_avails\r
- in\r
- returnRn (Just (export_env, gbl_env, local_fixity_env, global_avail_env))\r
- }\r
- where\r
- junk_exp_fn = error "RnNames:export_fn"\r
-\r
- all_imports = prel_imports ++ imports\r
-\r
- -- NB: opt_NoImplicitPrelude is slightly different to import Prelude ();\r
- -- because the former doesn't even look at Prelude.hi for instance declarations,\r
- -- whereas the latter does.\r
- prel_imports | this_mod == pRELUDE_Name ||\r
- explicit_prelude_import ||\r
- opt_NoImplicitPrelude\r
- = []\r
-\r
- | otherwise = [ImportDecl pRELUDE_Name\r
- ImportByUser\r
- False {- Not qualified -}\r
- Nothing {- No "as" -}\r
- Nothing {- No import list -}\r
- mod_loc]\r
- \r
- explicit_prelude_import\r
- = not (null [ () | (ImportDecl mod _ _ _ _ _) <- imports, mod == pRELUDE_Name ])\r
-\end{code}\r
- \r
-\begin{code}\r
-checkEarlyExit mod\r
- = checkErrsRn `thenRn` \ no_errs_so_far ->\r
- if not no_errs_so_far then\r
- -- Found errors already, so exit now\r
- returnRn True\r
- else\r
-\r
- traceRn (text "Considering whether compilation is required...") `thenRn_`\r
- if not opt_SourceUnchanged then\r
- -- Source code changed and no errors yet... carry on \r
- traceRn (nest 4 (text "source file changed or recompilation check turned off")) `thenRn_` \r
- returnRn False\r
- else\r
-\r
- -- Unchanged source, and no errors yet; see if usage info\r
- -- up to date, and exit if so\r
- checkUpToDate mod `thenRn` \ up_to_date ->\r
- putDocRn (text "Compilation" <+> \r
- text (if up_to_date then "IS NOT" else "IS") <+>\r
- text "required") `thenRn_`\r
- returnRn up_to_date\r
-\end{code}\r
- \r
-\begin{code}\r
-importsFromImportDecl :: (Name -> Bool) -- OK to omit qualifier\r
- -> RdrNameImportDecl\r
- -> RnMG (GlobalRdrEnv, \r
- ExportAvails) \r
-\r
-importsFromImportDecl is_unqual (ImportDecl imp_mod_name from qual_only as_mod import_spec iloc)\r
- = pushSrcLocRn iloc $\r
- getInterfaceExports imp_mod_name from `thenRn` \ (imp_mod, avails) ->\r
-\r
- if null avails then\r
- -- If there's an error in getInterfaceExports, (e.g. interface\r
- -- file not found) we get lots of spurious errors from 'filterImports'\r
- returnRn (emptyRdrEnv, mkEmptyExportAvails imp_mod_name)\r
- else\r
-\r
- filterImports imp_mod_name import_spec avails `thenRn` \ (filtered_avails, hides, explicits) ->\r
-\r
- -- We 'improve' the provenance by setting\r
- -- (a) the import-reason field, so that the Name says how it came into scope\r
- -- including whether it's explicitly imported\r
- -- (b) the print-unqualified field\r
- -- But don't fiddle with wired-in things or we get in a twist\r
- let\r
- improve_prov name = setNameProvenance name (NonLocalDef (UserImport imp_mod iloc (is_explicit name)) \r
- (is_unqual name))\r
- is_explicit name = name `elemNameSet` explicits\r
- in\r
- qualifyImports imp_mod_name\r
- (not qual_only) -- Maybe want unqualified names\r
- as_mod hides\r
- filtered_avails improve_prov `thenRn` \ (rdr_name_env, mod_avails) ->\r
-\r
- returnRn (rdr_name_env, mod_avails)\r
-\end{code}\r
-\r
-\r
-\begin{code}\r
-importsFromLocalDecls mod_name rec_exp_fn decls\r
- = mapRn (getLocalDeclBinders newLocalName) decls `thenRn` \ avails_s ->\r
-\r
- let\r
- avails = concat avails_s\r
-\r
- all_names :: [Name] -- All the defns; no dups eliminated\r
- all_names = [name | avail <- avails, name <- availNames avail]\r
-\r
- dups :: [[Name]]\r
- dups = filter non_singleton (equivClassesByUniq getUnique all_names)\r
- where\r
- non_singleton (x1:x2:xs) = True\r
- non_singleton other = False\r
- in\r
- -- Check for duplicate definitions\r
- mapRn_ (addErrRn . dupDeclErr) dups `thenRn_` \r
-\r
- -- Record that locally-defined things are available\r
- mapRn_ (recordSlurp Nothing) avails `thenRn_`\r
-\r
- -- Build the environment\r
- qualifyImports mod_name \r
- True -- Want unqualified names\r
- Nothing -- no 'as M'\r
- [] -- Hide nothing\r
- avails\r
- (\n -> n)\r
-\r
- where\r
- newLocalName rdr_name loc = newLocalTopBinder mod (rdrNameOcc rdr_name)\r
- rec_exp_fn loc\r
- mod = mkThisModule mod_name\r
-\r
-getLocalDeclBinders :: (RdrName -> SrcLoc -> RnMG Name) -- New-name function\r
- -> RdrNameHsDecl\r
- -> RnMG Avails\r
-getLocalDeclBinders new_name (ValD binds)\r
- = mapRn do_one (bagToList (collectTopBinders binds))\r
- where\r
- do_one (rdr_name, loc) = new_name rdr_name loc `thenRn` \ name ->\r
- returnRn (Avail name)\r
-\r
- -- foreign declarations\r
-getLocalDeclBinders new_name (ForD (ForeignDecl nm kind _ dyn _ loc))\r
- | binds_haskell_name kind dyn\r
- = new_name nm loc `thenRn` \ name ->\r
- returnRn [Avail name]\r
-\r
- | otherwise\r
- = returnRn []\r
-\r
-getLocalDeclBinders new_name decl\r
- = getDeclBinders new_name decl `thenRn` \ maybe_avail ->\r
- case maybe_avail of\r
- Nothing -> returnRn [] -- Instance decls and suchlike\r
- Just avail -> returnRn [avail]\r
-\r
-binds_haskell_name (FoImport _) _ = True\r
-binds_haskell_name FoLabel _ = True\r
-binds_haskell_name FoExport ext_nm = isDynamic ext_nm\r
-\r
-fixitiesFromLocalDecls :: GlobalRdrEnv -> [RdrNameHsDecl] -> RnMG FixityEnv\r
-fixitiesFromLocalDecls gbl_env decls\r
- = foldlRn getFixities emptyNameEnv decls\r
- where\r
- getFixities :: FixityEnv -> RdrNameHsDecl -> RnMG FixityEnv\r
- getFixities acc (FixD fix)\r
- = fix_decl acc fix\r
-\r
- getFixities acc (TyClD (ClassDecl _ _ _ sigs _ _ _ _ _ _))\r
- = foldlRn fix_decl acc [sig | FixSig sig <- sigs]\r
- -- Get fixities from class decl sigs too.\r
- getFixities acc other_decl\r
- = returnRn acc\r
-\r
- fix_decl acc sig@(FixitySig rdr_name fixity loc)\r
- = -- Check for fixity decl for something not declared\r
- case lookupRdrEnv gbl_env rdr_name of {\r
- Nothing | opt_WarnUnusedBinds \r
- -> pushSrcLocRn loc (addWarnRn (unusedFixityDecl rdr_name fixity)) `thenRn_`\r
- returnRn acc \r
- | otherwise -> returnRn acc ;\r
- \r
- Just (name:_) ->\r
-\r
- -- Check for duplicate fixity decl\r
- case lookupNameEnv acc name of {\r
- Just (FixitySig _ _ loc') -> addErrRn (dupFixityDecl rdr_name loc loc') `thenRn_`\r
- returnRn acc ;\r
-\r
- Nothing -> returnRn (addToNameEnv acc name (FixitySig name fixity loc))\r
- }}\r
-\end{code}\r
-\r
-%************************************************************************\r
-%* *\r
-\subsection{Filtering imports}\r
-%* *\r
-%************************************************************************\r
-\r
-@filterImports@ takes the @ExportEnv@ telling what the imported module makes\r
-available, and filters it through the import spec (if any).\r
-\r
-\begin{code}\r
-filterImports :: ModuleName -- The module being imported\r
- -> Maybe (Bool, [RdrNameIE]) -- Import spec; True => hiding\r
- -> [AvailInfo] -- What's available\r
- -> RnMG ([AvailInfo], -- What's actually imported\r
- [AvailInfo], -- What's to be hidden (the unqualified version, that is)\r
- NameSet) -- What was imported explicitly\r
-\r
- -- Complains if import spec mentions things that the module doesn't export\r
- -- Warns/informs if import spec contains duplicates.\r
-filterImports mod Nothing imports\r
- = returnRn (imports, [], emptyNameSet)\r
-\r
-filterImports mod (Just (want_hiding, import_items)) avails\r
- = mapMaybeRn check_item import_items `thenRn` \ avails_w_explicits ->\r
- let\r
- (item_avails, explicits_s) = unzip avails_w_explicits\r
- explicits = foldl addListToNameSet emptyNameSet explicits_s\r
- in\r
- if want_hiding \r
- then \r
- -- All imported; item_avails to be hidden\r
- returnRn (avails, item_avails, emptyNameSet)\r
- else\r
- -- Just item_avails imported; nothing to be hidden\r
- returnRn (item_avails, [], explicits)\r
- where\r
- import_fm :: FiniteMap OccName AvailInfo\r
- import_fm = listToFM [ (nameOccName name, avail) \r
- | avail <- avails,\r
- name <- availNames avail]\r
- -- Even though availNames returns data constructors too,\r
- -- they won't make any difference because naked entities like T\r
- -- in an import list map to TcOccs, not VarOccs.\r
-\r
- check_item item@(IEModuleContents _)\r
- = addErrRn (badImportItemErr mod item) `thenRn_`\r
- returnRn Nothing\r
-\r
- check_item item\r
- | not (maybeToBool maybe_in_import_avails) ||\r
- not (maybeToBool maybe_filtered_avail)\r
- = addErrRn (badImportItemErr mod item) `thenRn_`\r
- returnRn Nothing\r
-\r
- | dodgy_import = addWarnRn (dodgyImportWarn mod item) `thenRn_`\r
- returnRn (Just (filtered_avail, explicits))\r
-\r
- | otherwise = returnRn (Just (filtered_avail, explicits))\r
- \r
- where\r
- wanted_occ = rdrNameOcc (ieName item)\r
- maybe_in_import_avails = lookupFM import_fm wanted_occ\r
-\r
- Just avail = maybe_in_import_avails\r
- maybe_filtered_avail = filterAvail item avail\r
- Just filtered_avail = maybe_filtered_avail\r
- explicits | dot_dot = [availName filtered_avail]\r
- | otherwise = availNames filtered_avail\r
-\r
- dot_dot = case item of \r
- IEThingAll _ -> True\r
- other -> False\r
-\r
- dodgy_import = case (item, avail) of\r
- (IEThingAll _, AvailTC _ [n]) -> True\r
- -- This occurs when you import T(..), but\r
- -- only export T abstractly. The single [n]\r
- -- in the AvailTC is the type or class itself\r
- \r
- other -> False\r
-\end{code}\r
-\r
-\r
-\r
-%************************************************************************\r
-%* *\r
-\subsection{Qualifiying imports}\r
-%* *\r
-%************************************************************************\r
-\r
-@qualifyImports@ takes the @ExportEnv@ after filtering through the import spec\r
-of an import decl, and deals with producing an @RnEnv@ with the \r
-right qualified names. It also turns the @Names@ in the @ExportEnv@ into\r
-fully fledged @Names@.\r
-\r
-\begin{code}\r
-qualifyImports :: ModuleName -- Imported module\r
- -> Bool -- True <=> want unqualified import\r
- -> Maybe ModuleName -- Optional "as M" part \r
- -> [AvailInfo] -- What's to be hidden\r
- -> Avails -- Whats imported and how\r
- -> (Name -> Name) -- Improves the provenance on imported things\r
- -> RnMG (GlobalRdrEnv, ExportAvails)\r
- -- NB: the Names in ExportAvails don't have the improve-provenance\r
- -- function applied to them\r
- -- We could fix that, but I don't think it matters\r
-\r
-qualifyImports this_mod unqual_imp as_mod hides\r
- avails improve_prov\r
- = \r
- -- Make the name environment. We're talking about a \r
- -- single module here, so there must be no name clashes.\r
- -- In practice there only ever will be if it's the module\r
- -- being compiled.\r
- let\r
- -- Add the things that are available\r
- name_env1 = foldl add_avail emptyRdrEnv avails\r
-\r
- -- Delete things that are hidden\r
- name_env2 = foldl del_avail name_env1 hides\r
-\r
- -- Create the export-availability info\r
- export_avails = mkExportAvails qual_mod unqual_imp name_env2 avails\r
- in\r
- returnRn (name_env2, export_avails)\r
-\r
- where\r
- qual_mod = case as_mod of\r
- Nothing -> this_mod\r
- Just another_name -> another_name\r
-\r
- add_avail :: GlobalRdrEnv -> AvailInfo -> GlobalRdrEnv\r
- add_avail env avail = foldl add_name env (availNames avail)\r
-\r
- add_name env name\r
- | unqual_imp = env2\r
- | otherwise = env1\r
- where\r
- env1 = addOneToGlobalRdrEnv env (mkRdrQual qual_mod occ) better_name\r
- env2 = addOneToGlobalRdrEnv env1 (mkRdrUnqual occ) better_name\r
- occ = nameOccName name\r
- better_name = improve_prov name\r
-\r
- del_avail env avail = foldl delOneFromGlobalRdrEnv env rdr_names\r
- where\r
- rdr_names = map (mkRdrUnqual . nameOccName) (availNames avail)\r
-\end{code}\r
-\r
-\r
-%************************************************************************\r
-%* *\r
-\subsection{Export list processing\r
-%* *\r
-%************************************************************************\r
-\r
-Processing the export list.\r
-\r
-You might think that we should record things that appear in the export list as\r
-``occurrences'' (using addOccurrenceName), but you'd be wrong. We do check (here)\r
-that they are in scope, but there is no need to slurp in their actual declaration\r
-(which is what addOccurrenceName forces). Indeed, doing so would big trouble when\r
-compiling PrelBase, because it re-exports GHC, which includes takeMVar#, whose type\r
-includes ConcBase.StateAndSynchVar#, and so on...\r
-\r
-\begin{code}\r
-type ExportAccum -- The type of the accumulating parameter of\r
- -- the main worker function in exportsFromAvail\r
- = ([ModuleName], -- 'module M's seen so far\r
- ExportOccMap, -- Tracks exported occurrence names\r
- NameEnv AvailInfo) -- The accumulated exported stuff, kept in an env\r
- -- so we can common-up related AvailInfos\r
-\r
-type ExportOccMap = FiniteMap OccName (Name, RdrNameIE)\r
- -- Tracks what a particular exported OccName\r
- -- in an export list refers to, and which item\r
- -- it came from. It's illegal to export two distinct things\r
- -- that have the same occurrence name\r
-\r
-\r
-exportsFromAvail :: ModuleName\r
- -> Maybe [RdrNameIE] -- Export spec\r
- -> ExportAvails\r
- -> GlobalRdrEnv \r
- -> RnMG Avails\r
- -- Complains if two distinct exports have same OccName\r
- -- Warns about identical exports.\r
- -- Complains about exports items not in scope\r
-exportsFromAvail this_mod Nothing export_avails global_name_env\r
- = exportsFromAvail this_mod true_exports export_avails global_name_env\r
- where\r
- true_exports = Just $ if this_mod == mAIN_Name\r
- then [IEVar main_RDR]\r
- -- export Main.main *only* unless otherwise specified,\r
- else [IEModuleContents this_mod]\r
- -- but for all other modules export everything.\r
-\r
-exportsFromAvail this_mod (Just export_items) \r
- (mod_avail_env, entity_avail_env)\r
- global_name_env\r
- = foldlRn exports_from_item\r
- ([], emptyFM, emptyNameEnv) export_items `thenRn` \ (_, _, export_avail_map) ->\r
- let\r
- export_avails :: [AvailInfo]\r
- export_avails = nameEnvElts export_avail_map\r
- in\r
- returnRn export_avails\r
-\r
- where\r
- exports_from_item :: ExportAccum -> RdrNameIE -> RnMG ExportAccum\r
-\r
- exports_from_item acc@(mods, occs, avails) ie@(IEModuleContents mod)\r
- | mod `elem` mods -- Duplicate export of M\r
- = warnCheckRn opt_WarnDuplicateExports\r
- (dupModuleExport mod) `thenRn_`\r
- returnRn acc\r
-\r
- | otherwise\r
- = case lookupFM mod_avail_env mod of\r
- Nothing -> failWithRn acc (modExportErr mod)\r
- Just mod_avails -> foldlRn (check_occs ie) occs mod_avails `thenRn` \ occs' ->\r
- let\r
- avails' = foldl add_avail avails mod_avails\r
- in\r
- returnRn (mod:mods, occs', avails')\r
-\r
- exports_from_item acc@(mods, occs, avails) ie\r
- | not (maybeToBool maybe_in_scope) \r
- = failWithRn acc (unknownNameErr (ieName ie))\r
-\r
- | not (null dup_names)\r
- = addNameClashErrRn rdr_name (name:dup_names) `thenRn_`\r
- returnRn acc\r
-\r
-#ifdef DEBUG\r
- -- I can't see why this should ever happen; if the thing is in scope\r
- -- at all it ought to have some availability\r
- | not (maybeToBool maybe_avail)\r
- = pprTrace "exportsFromAvail: curious Nothing:" (ppr name)\r
- returnRn acc\r
-#endif\r
-\r
- | not enough_avail\r
- = failWithRn acc (exportItemErr ie)\r
-\r
- | otherwise -- Phew! It's OK! Now to check the occurrence stuff!\r
- = check_occs ie occs export_avail `thenRn` \ occs' ->\r
- returnRn (mods, occs', add_avail avails export_avail)\r
-\r
- where\r
- rdr_name = ieName ie\r
- maybe_in_scope = lookupFM global_name_env rdr_name\r
- Just (name:dup_names) = maybe_in_scope\r
- maybe_avail = lookupUFM entity_avail_env name\r
- Just avail = maybe_avail\r
- maybe_export_avail = filterAvail ie avail\r
- enough_avail = maybeToBool maybe_export_avail\r
- Just export_avail = maybe_export_avail\r
-\r
-add_avail avails avail = addToNameEnv_C plusAvail avails (availName avail) avail\r
-\r
-check_occs :: RdrNameIE -> ExportOccMap -> AvailInfo -> RnMG ExportOccMap\r
-check_occs ie occs avail \r
- = foldlRn check occs (availNames avail)\r
- where\r
- check occs name\r
- = case lookupFM occs name_occ of\r
- Nothing -> returnRn (addToFM occs name_occ (name, ie))\r
- Just (name', ie') \r
- | name == name' -> -- Duplicate export\r
- warnCheckRn opt_WarnDuplicateExports\r
- (dupExportWarn name_occ ie ie') `thenRn_`\r
- returnRn occs\r
-\r
- | otherwise -> -- Same occ name but different names: an error\r
- failWithRn occs (exportClashErr name_occ ie ie')\r
- where\r
- name_occ = nameOccName name\r
- \r
-mk_export_fn :: NameSet -> (Name -> ExportFlag)\r
-mk_export_fn exported_names\r
- = \name -> if name `elemNameSet` exported_names\r
- then Exported\r
- else NotExported\r
-\end{code}\r
-\r
-%************************************************************************\r
-%* *\r
-\subsection{Errors}\r
-%* *\r
-%************************************************************************\r
-\r
-\begin{code}\r
-badImportItemErr mod ie\r
- = sep [ptext SLIT("Module"), quotes (pprModuleName mod), \r
- ptext SLIT("does not export"), quotes (ppr ie)]\r
-\r
-dodgyImportWarn mod (IEThingAll tc)\r
- = sep [ptext SLIT("Module") <+> quotes (pprModuleName mod) <+> ptext SLIT("exports") <+> quotes (ppr tc), \r
- ptext SLIT("with no constructors/class operations;"),\r
- ptext SLIT("yet it is imported with a (..)")]\r
-\r
-modExportErr mod\r
- = hsep [ ptext SLIT("Unknown module in export list: module"), quotes (pprModuleName mod)]\r
-\r
-exportItemErr export_item\r
- = sep [ ptext SLIT("Bad export item"), quotes (ppr export_item)]\r
-\r
-exportClashErr occ_name ie1 ie2\r
- = hsep [ptext SLIT("The export items"), quotes (ppr ie1), ptext SLIT("and"), quotes (ppr ie2),\r
- ptext SLIT("create conflicting exports for"), quotes (ppr occ_name)]\r
-\r
-dupDeclErr (n:ns)\r
- = vcat [ptext SLIT("Multiple declarations of") <+> quotes (ppr n),\r
- nest 4 (vcat (map pp sorted_ns))]\r
- where\r
- sorted_ns = sortLt occ'ed_before (n:ns)\r
-\r
- occ'ed_before a b = LT == compare (getSrcLoc a) (getSrcLoc b)\r
-\r
- pp n = pprProvenance (getNameProvenance n)\r
-\r
-dupExportWarn occ_name ie1 ie2\r
- = hsep [quotes (ppr occ_name), \r
- ptext SLIT("is exported by"), quotes (ppr ie1),\r
- ptext SLIT("and"), quotes (ppr ie2)]\r
-\r
-dupModuleExport mod\r
- = hsep [ptext SLIT("Duplicate"),\r
- quotes (ptext SLIT("Module") <+> pprModuleName mod), \r
- ptext SLIT("in export list")]\r
-\r
-unusedFixityDecl rdr_name fixity\r
- = hsep [ptext SLIT("Unused fixity declaration for"), quotes (ppr rdr_name)]\r
-\r
-dupFixityDecl rdr_name loc1 loc2\r
- = vcat [ptext SLIT("Multiple fixity declarations for") <+> quotes (ppr rdr_name),\r
- ptext SLIT("at ") <+> ppr loc1,\r
- ptext SLIT("and") <+> ppr loc2]\r
-\r
-\end{code}\r
+%
+% (c) The GRASP/AQUA Project, Glasgow University, 1992-1998
+%
+\section[RnNames]{Extracting imported and top-level names in scope}
+
+\begin{code}
+module RnNames (
+ rnImports, importsFromLocalDecls, exportsFromAvail,
+ reportUnusedNames, reportDeprecations,
+ mkModDeps, exportsToAvails
+ ) where
+
+#include "HsVersions.h"
+
+import CmdLineOpts ( DynFlag(..) )
+import HsSyn ( IE(..), ieName, ImportDecl(..), LImportDecl,
+ ForeignDecl(..), HsGroup(..),
+ collectGroupBinders, tyClDeclNames
+ )
+import RnEnv
+import IfaceEnv ( lookupOrig, newGlobalBinder )
+import LoadIface ( loadSrcInterface )
+import TcRnMonad
+
+import FiniteMap
+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 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 ( isJust, isNothing, catMaybes, mapCatMaybes, seqMaybe )
+import SrcLoc ( noSrcLoc, Located(..), mkGeneralSrcSpan,
+ unLoc, noLoc )
+import BasicTypes ( DeprecTxt )
+import ListSetOps ( removeDups )
+import Util ( sortLt, notNull, isSingleton )
+import List ( partition, insert )
+import IO ( openFile, IOMode(..) )
+\end{code}
+
+
+
+%************************************************************************
+%* *
+ rnImports
+%* *
+%************************************************************************
+
+\begin{code}
+rnImports :: [LImportDecl RdrName]
+ -> RnM (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 ->
+ 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 (L _ (ImportDecl _ is_boot _ _ _)) = is_boot
+
+ 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 emptyGlobalRdrEnv 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.
+ mk_prel_imports this_mod no_prelude
+ | moduleName this_mod == pRELUDE_Name
+ || explicit_prelude_import
+ || no_prelude
+ = []
+
+ | otherwise = [preludeImportDecl]
+
+ explicit_prelude_import
+ = 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 :: Module
+ -> LImportDecl RdrName
+ -> RnM (GlobalRdrEnv, ImportAvails)
+
+importsFromImportDecl this_mod
+ (L loc (ImportDecl loc_imp_mod_name want_boot qual_only as_mod imp_details))
+ =
+ addSrcSpan loc $
+
+ -- If there's an error in loadInterface, (e.g. interface
+ -- file not found) we get lots of spurious errors from 'filterImports'
+ 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 ->
+
+ -- 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
+ 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
+
+ -- 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}
+
+
+%************************************************************************
+%* *
+ 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 :: 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]
+
+ 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_`
+
+ 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}
+
+
+%*********************************************************
+%* *
+\subsection{Getting binders out of a declaration}
+%* *
+%*********************************************************
+
+@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
+ 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}
+
+
+%************************************************************************
+%* *
+\subsection{Filtering imports}
+%* *
+%************************************************************************
+
+@filterImports@ takes the @ExportEnv@ telling what the imported module makes
+available, and filters it through the import spec (if any).
+
+\begin{code}
+filterImports :: ModIface
+ -> ImportSpec -- The span for the entire import decl
+ -> Maybe (Bool, [Located (IE RdrName)]) -- Import spec; True => hiding
+ -> [AvailInfo] -- What's available
+ -> 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.
+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
+ all_avails = foldr plusAvailEnv emptyAvailEnv avails
+ rdr_env = foldr plusGlobalRdrEnv emptyGlobalRdrEnv gres
+ in
+ if not want_hiding then
+ returnM (all_avails, rdr_env)
+ else
+ 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 :: 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 = addErr (badImportItemErr iface imp_spec item) `thenM_`
+ returnM (emptyAvailEnv, emptyGlobalRdrEnv)
+
+ 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
+ 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 (IEVar data_n)] of
+ [] -> bale_out item
+ avails -> returnM (mkAvailEnv avails, emptyGlobalRdrEnv)
+ -- The GlobalRdrEnv result is irrelevant when hiding
+ where
+ data_n = setRdrNameSpace n srcDataName
+
+ get_item item
+ = case check_item item of
+ Nothing -> bale_out item
+ Just avail -> succeed_with True avail
+
+ check_item item
+ | isNothing maybe_in_import_avails ||
+ isNothing maybe_filtered_avail
+ = Nothing
+
+ | otherwise
+ = Just filtered_avail
+
+ where
+ wanted_occ = rdrNameOcc (ieName item)
+ 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}
+
+\begin{code}
+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
+ 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}
+%* *
+%************************************************************************
+
+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...
+
+\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
+ NameSet) -- The accumulated exported stuff
+emptyExportAccum = ([], emptyOccEnv, emptyNameSet)
+
+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 :: 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 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_litem :: ExportAccum -> Located (IE RdrName) -> RnM ExportAccum
+ exports_from_litem acc = addLocM (exports_from_item acc)
+
+ 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
+ = 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
+ 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 occs name
+ = case lookupOccEnv occs name_occ of
+ Nothing -> returnM (extendOccEnv 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}
+
+%*********************************************************
+%* *
+ 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}
+%* *
+%************************************************************************
+
+\begin{code}
+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 item = dodgyMsg (ptext SLIT("import")) item
+dodgyExportWarn item = dodgyMsg (ptext SLIT("export")) 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") ]
+
+modExportErr mod
+ = hsep [ ptext SLIT("Unknown module in export list: module"), quotes (ppr mod)]
+
+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 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),
+ 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 ie1 ie2
+ = hsep [quotes (ppr occ_name),
+ ptext SLIT("is exported by"), quotes (ppr ie1),
+ ptext SLIT("and"), quotes (ppr ie2)]
+
+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}
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