X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=ghc%2Fcompiler%2Frename%2FRnNames.lhs;h=6b10dd852d956dc4f286d4169c43fec402b53d59;hb=32c62212b35b2b631f3753d432b508de5c79c783;hp=633735bd1c071ada19d30bf2084064cb5792faf6;hpb=00eefb90925f224c1e22963df2a00d70fe934d5f;p=ghc-hetmet.git diff --git a/ghc/compiler/rename/RnNames.lhs b/ghc/compiler/rename/RnNames.lhs index 633735b..6b10dd8 100644 --- a/ghc/compiler/rename/RnNames.lhs +++ b/ghc/compiler/rename/RnNames.lhs @@ -1,694 +1,800 @@ -% -% (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, - 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 -> returnRn [avail] - -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} +% +% (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 + ) where + +#include "HsVersions.h" + +import {-# SOURCE #-} RnHiFiles ( loadInterface ) + +import CmdLineOpts ( DynFlag(..) ) + +import HsSyn ( HsDecl(..), IE(..), ieName, ImportDecl(..), + ForeignDecl(..), + collectLocatedHsBinders, tyClDeclNames + ) +import RdrHsSyn ( RdrNameIE, RdrNameImportDecl, RdrNameHsDecl ) +import RnEnv +import TcRnMonad + +import FiniteMap +import PrelNames ( pRELUDE_Name, mAIN_Name, isBuiltInSyntaxName ) +import Module ( Module, ModuleName, moduleName, + moduleNameUserString, + unitModuleEnvByName, lookupModuleEnvByName, + moduleEnvElts ) +import Name ( Name, nameSrcLoc, nameOccName, nameModule ) +import NameSet +import NameEnv +import OccName ( OccName, dataName, isTcOcc ) +import HscTypes ( Provenance(..), ImportReason(..), GlobalRdrEnv, + GenAvailInfo(..), AvailInfo, Avails, IsBootInterface, + availName, availNames, availsToNameSet, + Deprecations(..), ModIface(..), + GlobalRdrElt(..), unQualInScope, isLocalGRE + ) +import RdrName ( rdrNameOcc, setRdrNameSpace, emptyRdrEnv, foldRdrEnv, isQual ) +import SrcLoc ( noSrcLoc ) +import Outputable +import Maybes ( maybeToBool, catMaybes ) +import ListSetOps ( removeDups ) +import Util ( sortLt, notNull ) +import List ( partition ) +import IO ( openFile, IOMode(..) ) +\end{code} + + + +%************************************************************************ +%* * + rnImports +%* * +%************************************************************************ + +\begin{code} +rnImports :: [RdrNameImportDecl] + -> TcRn m (GlobalRdrEnv, ImportAvails) + +rnImports imports + = -- PROCESS IMPORT DECLS + -- Do the non {- SOURCE -} ones first, so that we get a helpful + -- warning for {- SOURCE -} ones that are unnecessary + getModule `thenM` \ this_mod -> + getSrcLocM `thenM` \ loc -> + doptM Opt_NoImplicitPrelude `thenM` \ opt_no_prelude -> + let + all_imports = mk_prel_imports this_mod loc opt_no_prelude ++ imports + (source, ordinary) = partition is_source_import all_imports + is_source_import (ImportDecl _ is_boot _ _ _ _) = is_boot + + get_imports = importsFromImportDecl (moduleName this_mod) + in + mappM get_imports ordinary `thenM` \ stuff1 -> + mappM get_imports source `thenM` \ stuff2 -> + + -- COMBINE RESULTS + let + (imp_gbl_envs, imp_avails) = unzip (stuff1 ++ stuff2) + gbl_env :: GlobalRdrEnv + gbl_env = foldr plusGlobalRdrEnv emptyRdrEnv imp_gbl_envs + + all_avails :: ImportAvails + all_avails = foldr plusImportAvails emptyImportAvails imp_avails + in + -- ALL DONE + returnM (gbl_env, all_avails) + where + -- NB: opt_NoImplicitPrelude is slightly different to import Prelude (); + -- because the former doesn't even look at Prelude.hi for instance + -- declarations, whereas the latter does. + mk_prel_imports this_mod loc no_prelude + | moduleName this_mod == pRELUDE_Name + || explicit_prelude_import + || no_prelude + = [] + + | otherwise = [preludeImportDecl loc] + + explicit_prelude_import + = notNull [ () | (ImportDecl mod _ _ _ _ _) <- imports, + mod == pRELUDE_Name ] + +preludeImportDecl loc + = ImportDecl pRELUDE_Name + False {- Not a boot interface -} + False {- Not qualified -} + Nothing {- No "as" -} + Nothing {- No import list -} + loc +\end{code} + +\begin{code} +importsFromImportDecl :: ModuleName + -> RdrNameImportDecl + -> TcRn m (GlobalRdrEnv, ImportAvails) + +importsFromImportDecl this_mod_name + (ImportDecl imp_mod_name is_boot qual_only as_mod import_spec iloc) + = addSrcLoc iloc $ + let + doc = ppr imp_mod_name <+> ptext SLIT("is directly imported") + in + + -- If there's an error in loadInterface, (e.g. interface + -- file not found) we get lots of spurious errors from 'filterImports' + recoverM (returnM Nothing) + (loadInterface doc imp_mod_name (ImportByUser is_boot) `thenM` \ iface -> + returnM (Just iface)) `thenM` \ mb_iface -> + + case mb_iface of { + Nothing -> returnM (emptyRdrEnv, emptyImportAvails ) ; + Just iface -> + + let + imp_mod = mi_module iface + avails_by_module = mi_exports iface + deprecs = mi_deprecs iface + dir_imp = unitModuleEnvByName imp_mod_name (imp_mod, import_all import_spec) + + avails :: Avails + avails = [ avail | (mod_name, avails) <- avails_by_module, + mod_name /= this_mod_name, + avail <- avails ] + -- 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. + + 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_` + + -- Filter the imports according to the import list + filterImports imp_mod_name is_boot import_spec avails `thenM` \ (filtered_avails, explicits) -> + + let + unqual_imp = not qual_only -- Maybe want unqualified names + qual_mod = case as_mod of + Nothing -> imp_mod_name + Just another_name -> another_name + + mk_prov name = NonLocalDef (UserImport imp_mod iloc (name `elemNameSet` explicits)) + gbl_env = mkGlobalRdrEnv qual_mod unqual_imp mk_prov filtered_avails deprecs + imports = mkImportAvails qual_mod unqual_imp gbl_env filtered_avails + in + returnM (gbl_env, imports { imp_mods = dir_imp}) + } + +import_all (Just (False, _)) = False -- Imports are spec'd explicitly +import_all other = True -- Everything is imported +\end{code} + + +%************************************************************************ +%* * + importsFromLocalDecls +%* * +%************************************************************************ + +From the top-level declarations of this module produce + * the lexical environment + * the ImportAvails +created by its bindings. + +Complain about duplicate bindings + +\begin{code} +importsFromLocalDecls :: [RdrNameHsDecl] + -> TcRn m (GlobalRdrEnv, ImportAvails) +importsFromLocalDecls decls + = getModule `thenM` \ this_mod -> + mappM (getLocalDeclBinders this_mod) decls `thenM` \ avails_s -> + -- The avails that are returned don't include the "system" names + let + avails = concat avails_s + + all_names :: [Name] -- All the defns; no dups eliminated + all_names = [name | avail <- avails, name <- availNames avail] + + 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 + unqual_imp = True -- Want unqualified names + mk_prov n = LocalDef -- Provenance is local + + gbl_env = mkGlobalRdrEnv mod_name unqual_imp mk_prov avails NoDeprecs + -- NoDeprecs: don't complain about locally defined names + -- For a start, we may be exporting a deprecated thing + -- Also we may use a deprecated thing in the defn of another + -- deprecated things. We may even use a deprecated thing in + -- the defn of a non-deprecated thing, when changing a module's + -- interface + + + -- Optimisation: filter out names for built-in syntax + -- They just clutter up the environment (esp tuples), and the parser + -- will generate Exact RdrNames for them, so the cluttered + -- envt is no use. To avoid doing this filter all the type, + -- we use -fno-implicit-prelude as a clue that the filter is + -- worth while. Really, it's only useful for Base and Tuple. + -- + -- It's worth doing because it makes the environment smaller for + -- every module that imports the Prelude + -- + -- Note: don't filter the gbl_env (hence avails, not avails' in + -- defn of gbl_env above). Stupid reason: when parsing + -- data type decls, the constructors start as Exact tycon-names, + -- and then get turned into data con names by zapping the name space; + -- but that stops them being Exact, so they get looked up. Sigh. + -- It doesn't matter because it only affects the Data.Tuple really. + -- The important thing is to trim down the exports. + imports = mkImportAvails mod_name unqual_imp gbl_env avails' + avails' | implicit_prelude = filter not_built_in_syntax avails + | otherwise = avails + not_built_in_syntax a = not (all isBuiltInSyntaxName (availNames a)) + -- Only filter it if all the names of the avail are built-in + -- In particular, lists have (:) which is not built in syntax + -- so we don't filter it out. + in + returnM (gbl_env, imports) +\end{code} + + +%********************************************************* +%* * +\subsection{Getting binders out of a declaration} +%* * +%********************************************************* + +@getLocalDeclBinders@ returns the names for a @RdrNameHsDecl@. It's +used for both source code (from @importsFromLocalDecls@) and interface +files (@loadDecl@ calls @getTyClDeclBinders@). + + *** See "THE NAMING STORY" in HsDecls **** + +\begin{code} +getLocalDeclBinders :: Module -> RdrNameHsDecl -> TcRn m [AvailInfo] +getLocalDeclBinders mod (TyClD tycl_decl) + = -- 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. + mapM new (tyClDeclNames tycl_decl) `thenM` \ names@(main_name:_) -> + returnM [AvailTC main_name names] + where + new (nm,loc) = newTopBinder mod nm loc + +getLocalDeclBinders mod (ValD binds) + = mappM new (collectLocatedHsBinders binds) `thenM` \ avails -> + returnM avails + where + new (rdr_name, loc) = newTopBinder mod rdr_name loc `thenM` \ name -> + returnM (Avail name) + +getLocalDeclBinders mod (ForD (ForeignImport nm _ _ _ loc)) + = newTopBinder mod nm loc `thenM` \ name -> + returnM [Avail name] +getLocalDeclBinders mod (ForD _) + = returnM [] + +getLocalDeclBinders mod (FixD _) = returnM [] +getLocalDeclBinders mod (DeprecD _) = returnM [] +getLocalDeclBinders mod (DefD _) = returnM [] +getLocalDeclBinders mod (InstD _) = returnM [] +getLocalDeclBinders mod (RuleD _) = returnM [] +\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 + -> IsBootInterface -- Tells whether it's a {-# SOURCE #-} import + -> Maybe (Bool, [RdrNameIE]) -- Import spec; True => hiding + -> [AvailInfo] -- What's available + -> TcRn m ([AvailInfo], -- What's imported + NameSet) -- What was imported explicitly + + -- Complains if import spec mentions things that the module doesn't export + -- Warns/informs if import spec contains duplicates. +filterImports mod from Nothing imports + = returnM (imports, emptyNameSet) + +filterImports mod from (Just (want_hiding, import_items)) total_avails + = mappM get_item import_items `thenM` \ avails_w_explicits_s -> + let + (item_avails, explicits_s) = unzip (concat avails_w_explicits_s) + explicits = foldl addListToNameSet emptyNameSet explicits_s + in + if want_hiding then + let -- All imported; item_avails to be hidden + hidden = availsToNameSet item_avails + keep n = not (n `elemNameSet` hidden) + in + returnM (pruneAvails keep total_avails, emptyNameSet) + else + -- Just item_avails imported; nothing to be hidden + returnM (item_avails, explicits) + where + import_fm :: FiniteMap OccName AvailInfo + import_fm = listToFM [ (nameOccName name, avail) + | avail <- total_avails, + name <- availNames avail] + -- Even though availNames returns data constructors too, + -- they won't make any difference because naked entities like T + -- in an import list map to TcOccs, not VarOccs. + + bale_out item = addErr (badImportItemErr mod from item) `thenM_` + returnM [] + + get_item :: RdrNameIE -> TcRn m [(AvailInfo, [Name])] + -- Empty list for a bad item. + -- Singleton is typical case. + -- Can have two when we are hiding, and mention C which might be + -- both a class and a data constructor. + -- The [Name] is the list of explicitly-mentioned names + get_item item@(IEModuleContents _) = bale_out item + + get_item item@(IEThingAll _) + = case check_item item of + Nothing -> bale_out item + Just avail@(AvailTC _ [n]) -> -- This occurs when you import T(..), but + -- only export T abstractly. The single [n] + -- in the AvailTC is the type or class itself + ifOptM Opt_WarnMisc (addWarn (dodgyImportWarn mod item)) `thenM_` + returnM [(avail, [availName avail])] + Just avail -> returnM [(avail, [availName avail])] + + get_item item@(IEThingAbs n) + | want_hiding -- hiding( C ) + -- Here the 'C' can be a data constructor *or* a type/class + = case catMaybes [check_item item, check_item (IEVar data_n)] of + [] -> bale_out item + avails -> returnM [(a, []) | a <- avails] + -- The 'explicits' list is irrelevant when hiding + where + data_n = setRdrNameSpace n dataName + + get_item item + = case check_item item of + Nothing -> bale_out item + Just avail -> returnM [(avail, availNames avail)] + + check_item item + | not (maybeToBool maybe_in_import_avails) || + not (maybeToBool maybe_filtered_avail) + = Nothing + + | otherwise + = Just filtered_avail + + where + wanted_occ = rdrNameOcc (ieName item) + maybe_in_import_avails = lookupFM import_fm wanted_occ + + Just avail = maybe_in_import_avails + maybe_filtered_avail = filterAvail item avail + Just filtered_avail = maybe_filtered_avail +\end{code} + +\begin{code} +filterAvail :: RdrNameIE -- Wanted + -> AvailInfo -- Available + -> Maybe AvailInfo -- Resulting available; + -- Nothing if (any of the) wanted stuff isn't there + +filterAvail ie@(IEThingWith want wants) avail@(AvailTC n ns) + | sub_names_ok = Just (AvailTC n (filter is_wanted ns)) + | otherwise = Nothing + where + is_wanted name = nameOccName name `elem` wanted_occs + sub_names_ok = all (`elem` avail_occs) wanted_occs + avail_occs = map nameOccName ns + wanted_occs = map rdrNameOcc (want:wants) + +filterAvail (IEThingAbs _) (AvailTC n ns) = ASSERT( n `elem` ns ) + Just (AvailTC n [n]) + +filterAvail (IEThingAbs _) avail@(Avail n) = Just avail -- Type synonyms + +filterAvail (IEVar _) avail@(Avail n) = Just avail +filterAvail (IEVar v) avail@(AvailTC n ns) = Just (AvailTC n (filter wanted ns)) + where + wanted n = nameOccName n == occ + occ = rdrNameOcc v + -- The second equation happens if we import a class op, thus + -- import A( op ) + -- where op is a class operation + +filterAvail (IEThingAll _) avail@(AvailTC _ _) = Just avail + -- We don't complain even if the IE says T(..), but + -- no constrs/class ops of T are available + -- Instead that's caught with a warning by the caller + +filterAvail ie avail = Nothing +\end{code} + + +%************************************************************************ +%* * +\subsection{Export list processing} +%* * +%************************************************************************ + +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 + AvailEnv) -- The accumulated exported stuff, kept in an env + -- so we can common-up related AvailInfos +emptyExportAccum = ([], emptyFM, emptyAvailEnv) + +type ExportOccMap = FiniteMap OccName (Name, RdrNameIE) + -- Tracks what a particular exported OccName + -- in an export list refers to, and which item + -- it came from. It's illegal to export two distinct things + -- that have the same occurrence name + + +exportsFromAvail :: Maybe [RdrNameIE] -> TcRn m Avails + -- Complains if two distinct exports have same OccName + -- Warns about identical exports. + -- Complains about exports items not in scope +exportsFromAvail Nothing + = do { this_mod <- getModule ; + if moduleName this_mod == mAIN_Name then + return [] + -- Export nothing; Main.$main is automatically exported + else + exportsFromAvail (Just [IEModuleContents (moduleName this_mod)]) + -- but for all other modules export everything. + } + +exportsFromAvail (Just exports) + = do { TcGblEnv { tcg_imports = imports } <- getGblEnv ; + warn_dup_exports <- doptM Opt_WarnDuplicateExports ; + exports_from_avail exports warn_dup_exports imports } + +exports_from_avail export_items warn_dup_exports + (ImportAvails { imp_unqual = mod_avail_env, + imp_env = entity_avail_env }) + = foldlM exports_from_item emptyExportAccum + export_items `thenM` \ (_, _, export_avail_map) -> + returnM (nameEnvElts export_avail_map) + + where + exports_from_item :: ExportAccum -> RdrNameIE -> TcRn m ExportAccum + + exports_from_item acc@(mods, occs, avails) ie@(IEModuleContents mod) + | mod `elem` mods -- Duplicate export of M + = warnIf warn_dup_exports (dupModuleExport mod) `thenM_` + returnM acc + + | otherwise + = case lookupModuleEnvByName mod_avail_env mod of + Nothing -> addErr (modExportErr mod) `thenM_` + returnM acc + Just mod_avails + -> foldlM (check_occs warn_dup_exports ie) + occs mod_avails `thenM` \ occs' -> + let + avails' = foldl addAvail avails mod_avails + in + returnM (mod:mods, occs', avails') + + exports_from_item acc@(mods, occs, avails) ie + = lookupGRE (ieName ie) `thenM` \ mb_gre -> + case mb_gre of { + Nothing -> addErr (unknownNameErr (ieName ie)) `thenM_` + returnM acc ; + Just gre -> + + -- Get the AvailInfo for the parent of the specified name + case lookupAvailEnv entity_avail_env (gre_parent gre) of { + Nothing -> pprPanic "exportsFromAvail" + ((ppr (ieName ie)) <+> ppr gre) ; + Just avail -> + + -- Filter out the bits we want + case filterAvail ie avail of { + Nothing -> -- Not enough availability + addErr (exportItemErr ie) `thenM_` + returnM acc ; + + Just export_avail -> + + -- Phew! It's OK! Now to check the occurrence stuff! + warnIf (not (ok_item ie avail)) (dodgyExportWarn ie) `thenM_` + check_occs warn_dup_exports ie occs export_avail `thenM` \ occs' -> + returnM (mods, occs', addAvail avails export_avail) + }}} + + + +ok_item (IEThingAll _) (AvailTC _ [n]) = False + -- This occurs when you import T(..), but + -- only export T abstractly. The single [n] + -- in the AvailTC is the type or class itself +ok_item _ _ = True + +check_occs :: Bool -> RdrNameIE -> ExportOccMap -> AvailInfo -> TcRn m ExportOccMap +check_occs warn_dup_exports ie occs avail + = foldlM check occs (availNames avail) + where + check occs name + = case lookupFM occs name_occ of + Nothing -> returnM (addToFM occs name_occ (name, ie)) + Just (name', ie') + | name == name' -> -- Duplicate export + warnIf warn_dup_exports + (dupExportWarn name_occ ie ie') + `thenM_` returnM occs + + | otherwise -> -- Same occ name but different names: an error + addErr (exportClashErr name_occ ie ie') `thenM_` + returnM occs + where + name_occ = nameOccName name +\end{code} + +%********************************************************* +%* * +\subsection{Unused names} +%* * +%********************************************************* + +\begin{code} +reportUnusedNames :: TcGblEnv + -> NameSet -- Used in this module + -> TcRn m () +reportUnusedNames gbl_env used_names + = warnUnusedModules unused_imp_mods `thenM_` + warnUnusedTopBinds bad_locals `thenM_` + warnUnusedImports bad_imports `thenM_` + printMinimalImports minimal_imports + where + direct_import_mods :: [ModuleName] + direct_import_mods = map (moduleName . fst) + (moduleEnvElts (imp_mods (tcg_imports gbl_env))) + + -- Now, a use of C implies a use of T, + -- if C was brought into scope by T(..) or T(C) + really_used_names :: NameSet + really_used_names = used_names `unionNameSets` + mkNameSet [ gre_parent gre + | gre <- defined_names, + gre_name gre `elemNameSet` used_names] + + -- Collect the defined names from the in-scope environment + -- Look for the qualified ones only, else get duplicates + defined_names :: [GlobalRdrElt] + defined_names = foldRdrEnv add [] (tcg_rdr_env gbl_env) + add rdr_name ns acc | isQual rdr_name = ns ++ acc + | otherwise = acc + + defined_and_used, defined_but_not_used :: [GlobalRdrElt] + (defined_and_used, defined_but_not_used) = partition used defined_names + used gre = gre_name gre `elemNameSet` really_used_names + + -- Filter out the ones only defined implicitly + bad_locals :: [GlobalRdrElt] + bad_locals = filter isLocalGRE defined_but_not_used + + bad_imports :: [GlobalRdrElt] + bad_imports = filter bad_imp defined_but_not_used + bad_imp (GRE {gre_prov = NonLocalDef (UserImport mod _ True)}) = not (module_unused mod) + bad_imp other = False + + -- To figure out the minimal set of imports, start with the things + -- that are in scope (i.e. in gbl_env). Then just combine them + -- into a bunch of avails, so they are properly grouped + minimal_imports :: FiniteMap ModuleName AvailEnv + minimal_imports0 = emptyFM + minimal_imports1 = foldr add_name minimal_imports0 defined_and_used + minimal_imports = foldr add_inst_mod minimal_imports1 direct_import_mods + -- The last line makes sure that we retain all direct imports + -- even if we import nothing explicitly. + -- It's not necessarily redundant to import such modules. Consider + -- module This + -- import M () + -- + -- The import M() is not *necessarily* redundant, even if + -- we suck in no instance decls from M (e.g. it contains + -- no instance decls, or This contains no code). It may be + -- that we import M solely to ensure that M's orphan instance + -- decls (or those in its imports) are visible to people who + -- import This. Sigh. + -- There's really no good way to detect this, so the error message + -- in RnEnv.warnUnusedModules is weakened instead + + + -- We've carefully preserved the provenance so that we can + -- construct minimal imports that import the name by (one of) + -- the same route(s) as the programmer originally did. + add_name (GRE {gre_name = n, gre_parent = p, + gre_prov = NonLocalDef (UserImport m _ _)}) acc + = addToFM_C plusAvailEnv acc (moduleName m) + (unitAvailEnv (mk_avail n p)) + add_name other acc + = acc + + -- n is the name of the thing, p is the name of its parent + mk_avail n p | n/=p = AvailTC p [p,n] + | isTcOcc (nameOccName p) = AvailTC n [n] + | otherwise = Avail n + + add_inst_mod m acc + | m `elemFM` acc = acc -- We import something already + | otherwise = addToFM acc m emptyAvailEnv + -- Add an empty collection of imports for a module + -- from which we have sucked only instance decls + + -- unused_imp_mods are the directly-imported modules + -- that are not mentioned in minimal_imports1 + -- [Note: not 'minimal_imports', because that includes direcly-imported + -- modules even if we use nothing from them; see notes above] + unused_imp_mods = [m | m <- direct_import_mods, + not (maybeToBool (lookupFM minimal_imports1 m)), + m /= pRELUDE_Name] + + module_unused :: Module -> Bool + module_unused mod = moduleName mod `elem` unused_imp_mods + + +-- ToDo: deal with original imports with 'qualified' and 'as M' clauses +printMinimalImports :: FiniteMap ModuleName AvailEnv -- Minimal imports + -> TcRn m () +printMinimalImports imps + = ifOptM Opt_D_dump_minimal_imports $ do { + + mod_ies <- mappM to_ies (fmToList imps) ; + this_mod <- getModule ; + rdr_env <- getGlobalRdrEnv ; + ioToTcRn (do { h <- openFile (mkFilename this_mod) WriteMode ; + printForUser h (unQualInScope rdr_env) + (vcat (map ppr_mod_ie mod_ies)) }) + } + where + mkFilename this_mod = moduleNameUserString (moduleName this_mod) ++ ".imports" + ppr_mod_ie (mod_name, ies) + | mod_name == pRELUDE_Name + = empty + | null ies -- Nothing except instances comes from here + = ptext SLIT("import") <+> ppr mod_name <> ptext SLIT("() -- Instances only") + | otherwise + = ptext SLIT("import") <+> ppr mod_name <> + parens (fsep (punctuate comma (map ppr ies))) + + to_ies (mod, avail_env) = mappM to_ie (availEnvElts avail_env) `thenM` \ ies -> + returnM (mod, ies) + + to_ie :: AvailInfo -> TcRn m (IE Name) + -- The main trick here is that if we're importing all the constructors + -- we want to say "T(..)", but if we're importing only a subset we want + -- to say "T(A,B,C)". So we have to find out what the module exports. + to_ie (Avail n) = returnM (IEVar n) + to_ie (AvailTC n [m]) = ASSERT( n==m ) + returnM (IEThingAbs n) + to_ie (AvailTC n ns) + = loadInterface (text "Compute minimal imports from" <+> ppr n_mod) + n_mod ImportBySystem `thenM` \ iface -> + case [xs | (m,as) <- mi_exports iface, + m == n_mod, + AvailTC x xs <- as, + x == n] of + [xs] | all (`elem` ns) xs -> returnM (IEThingAll n) + | otherwise -> returnM (IEThingWith n (filter (/= n) ns)) + other -> pprTrace "to_ie" (ppr n <+> ppr (nameModule n) <+> ppr other) $ + returnM (IEVar n) + where + n_mod = moduleName (nameModule n) +\end{code} + + +%************************************************************************ +%* * +\subsection{Errors} +%* * +%************************************************************************ + +\begin{code} +badImportItemErr mod from ie + = sep [ptext SLIT("Module"), quotes (ppr mod), source_import, + ptext SLIT("does not export"), quotes (ppr ie)] + where + source_import = case from of + True -> ptext SLIT("(hi-boot interface)") + other -> empty + +dodgyImportWarn mod item = dodgyMsg (ptext SLIT("import")) item +dodgyExportWarn item = dodgyMsg (ptext SLIT("export")) item + +dodgyMsg kind item@(IEThingAll tc) + = sep [ ptext SLIT("The") <+> kind <+> ptext SLIT("item") <+> quotes (ppr item), + ptext SLIT("suggests that") <+> quotes (ppr tc) <+> ptext SLIT("has constructor or class methods"), + ptext SLIT("but it has none; it is a type synonym or abstract type or class") ] + +modExportErr mod + = hsep [ ptext SLIT("Unknown module in export list: module"), quotes (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 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 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}