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