%
-% (c) The GRASP/AQUA Project, Glasgow University, 1992-1996
+% (c) The GRASP/AQUA Project, Glasgow University, 1992-1998
%
\section[RnNames]{Extracting imported and top-level names in scope}
\begin{code}
-#include "HsVersions.h"
-
module RnNames (
- getGlobalNames
+ rnImports, importsFromLocalDecls,
+ rnExports,
+ getLocalDeclBinders, extendRdrEnvRn,
+ reportUnusedNames, reportDeprecations,
+ mkModDeps
) where
-IMP_Ubiq()
-
-import CmdLineOpts ( opt_SourceUnchanged, opt_NoImplicitPrelude )
-import HsSyn ( HsModule(..), HsDecl(..), FixityDecl(..), Fixity, Fake, InPat, IE(..), HsTyVar,
- TyDecl, ClassDecl, InstDecl, DefaultDecl, ImportDecl(..), HsBinds, IfaceSig
- )
-import HsBinds ( collectTopBinders )
-import HsImpExp ( ieName )
-import RdrHsSyn ( RdrNameHsDecl(..), RdrName(..), RdrNameIE(..), SYN_IE(RdrNameImportDecl),
- SYN_IE(RdrNameHsModule), SYN_IE(RdrNameFixityDecl),
- rdrNameOcc
- )
-import RnHsSyn ( RenamedHsModule(..), RenamedFixityDecl(..) )
-import RnIfaces ( getInterfaceExports, getDeclBinders, checkUpToDate )
+#include "HsVersions.h"
+
+import DynFlags ( DynFlag(..), GhcMode(..) )
+import HsSyn ( IE(..), ieName, ImportDecl(..), LImportDecl,
+ ForeignDecl(..), HsGroup(..), HsValBinds(..),
+ Sig(..), collectHsBindLocatedBinders, tyClDeclNames
+ )
import RnEnv
-import RnMonad
+import IfaceEnv ( ifaceExportNames )
+import LoadIface ( loadSrcInterface )
+import TcRnMonad
+
import FiniteMap
-import PrelMods
-import UniqFM ( UniqFM, emptyUFM, addListToUFM_C, lookupUFM )
-import Bag ( Bag, bagToList )
-import Maybes ( maybeToBool, expectJust )
-import Name
-import Pretty
-import PprStyle ( PprStyle(..) )
-import Util ( panic, pprTrace )
+import PrelNames ( pRELUDE, isUnboundName, main_RDR_Unqual )
+import Module ( Module, moduleString, unitModuleEnv,
+ lookupModuleEnv, moduleEnvElts, foldModuleEnv )
+import Name ( Name, nameSrcLoc, nameOccName, nameModule, isWiredInName,
+ nameParent, nameParent_maybe, isExternalName,
+ isBuiltInSyntax )
+import NameSet
+import NameEnv
+import OccName ( srcDataName, isTcOcc, pprNonVarNameSpace,
+ occNameSpace,
+ OccEnv, mkOccEnv, lookupOccEnv, emptyOccEnv,
+ extendOccEnv )
+import HscTypes ( GenAvailInfo(..), AvailInfo,
+ HomePackageTable, PackageIfaceTable,
+ unQualInScope,
+ Deprecs(..), ModIface(..), Dependencies(..),
+ lookupIface, ExternalPackageState(..)
+ )
+import Packages ( PackageIdH(..) )
+import RdrName ( RdrName, rdrNameOcc, setRdrNameSpace,
+ GlobalRdrEnv, mkGlobalRdrEnv, GlobalRdrElt(..),
+ emptyGlobalRdrEnv, plusGlobalRdrEnv, globalRdrEnvElts,
+ extendGlobalRdrEnv, lookupGlobalRdrEnv, unQualOK, lookupGRE_Name,
+ Provenance(..), ImportSpec(..), ImpDeclSpec(..), ImpItemSpec(..),
+ importSpecLoc, importSpecModule, isLocalGRE, pprNameProvenance )
+import Outputable
+import Maybes ( isNothing, catMaybes, mapCatMaybes, seqMaybe, orElse )
+import SrcLoc ( Located(..), mkGeneralSrcSpan,
+ unLoc, noLoc, srcLocSpan, SrcSpan )
+import BasicTypes ( DeprecTxt )
+import DriverPhases ( isHsBoot )
+import Util ( notNull )
+import List ( partition )
+import IO ( openFile, IOMode(..) )
\end{code}
%************************************************************************
%* *
-\subsection{Get global names}
+ rnImports
%* *
%************************************************************************
\begin{code}
-getGlobalNames :: RdrNameHsModule
- -> RnMG (Maybe (ExportEnv, RnEnv, [AvailInfo]))
- -- Nothing <=> no need to recompile
-
-getGlobalNames m@(HsModule this_mod _ exports imports _ _ mod_loc)
- = fixRn (\ ~(rec_exp_fn, _) ->
-
- -- PROCESS LOCAL DECLS
- -- Do these *first* so that the correct provenance gets
- -- into the global name cache.
- importsFromLocalDecls rec_exp_fn m `thenRn` \ (local_rn_env, local_mod_avails) ->
-
- -- PROCESS IMPORT DECLS
- mapAndUnzipRn importsFromImportDecl all_imports
- `thenRn` \ (imp_rn_envs, imp_avails_s) ->
-
- -- CHECK FOR EARLY EXIT
- checkEarlyExit this_mod `thenRn` \ early_exit ->
- if early_exit then
- returnRn (junk_exp_fn, Nothing)
- else
-
- -- COMBINE RESULTS
- -- We put the local env first, so that a local provenance
- -- "wins", even if a module imports itself.
- foldlRn plusRnEnv emptyRnEnv imp_rn_envs `thenRn` \ imp_rn_env ->
- plusRnEnv local_rn_env imp_rn_env `thenRn` \ rn_env ->
- let
- all_avails :: ModuleAvails
- all_avails = foldr plusModuleAvails local_mod_avails imp_avails_s
- local_avails = expectJust "getGlobalNames" (lookupModuleAvails local_mod_avails this_mod)
- in
-
- -- PROCESS EXPORT LISTS
- exportsFromAvail this_mod exports all_avails rn_env
- `thenRn` \ (export_fn, export_env) ->
-
- returnRn (export_fn, Just (export_env, rn_env, local_avails))
- ) `thenRn` \ (_, result) ->
- returnRn result
+rnImports :: [LImportDecl RdrName]
+ -> RnM (GlobalRdrEnv, ImportAvails)
+
+rnImports imports
+ = do { -- PROCESS IMPORT DECLS
+ -- Do the non {- SOURCE -} ones first, so that we get a helpful
+ -- warning for {- SOURCE -} ones that are unnecessary
+ this_mod <- getModule
+ ; implicit_prelude <- doptM Opt_ImplicitPrelude
+ ; let
+ all_imports = mk_prel_imports this_mod implicit_prelude ++ imports
+ (source, ordinary) = partition is_source_import all_imports
+ is_source_import (L _ (ImportDecl _ is_boot _ _ _)) = is_boot
+
+ get_imports = importsFromImportDecl this_mod
+
+ ; stuff1 <- mappM get_imports ordinary
+ ; stuff2 <- mappM get_imports source
+
+ -- COMBINE RESULTS
+ ; let
+ (imp_gbl_envs, imp_avails) = unzip (stuff1 ++ stuff2)
+ gbl_env :: GlobalRdrEnv
+ gbl_env = foldr plusGlobalRdrEnv emptyGlobalRdrEnv imp_gbl_envs
+
+ all_avails :: ImportAvails
+ all_avails = foldr plusImportAvails emptyImportAvails imp_avails
+
+ -- ALL DONE
+ ; return (gbl_env, all_avails) }
where
- junk_exp_fn = error "RnNames:export_fn"
+ -- 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 implicit_prelude
+ | this_mod == pRELUDE
+ || explicit_prelude_import
+ || not implicit_prelude
+ = []
- all_imports = prel_imports ++ imports
+ | otherwise = [preludeImportDecl]
- -- NB: opt_NoImplicitPrelude is slightly different to import Prelude ();
- -- because the former doesn't even look at Prelude.hi for instance declarations,
- -- whereas the latter does.
- prel_imports | this_mod == pRELUDE ||
- explicit_prelude_import ||
- opt_NoImplicitPrelude
- = []
-
- | otherwise = [ImportDecl pRELUDE
- False {- Not qualified -}
- Nothing {- No "as" -}
- Nothing {- No import list -}
- mod_loc]
-
explicit_prelude_import
- = not (null [ () | (ImportDecl mod qual _ _ _) <- imports, mod == pRELUDE ])
+ = notNull [ () | L _ (ImportDecl mod _ _ _ _) <- imports,
+ unLoc mod == pRELUDE ]
+
+preludeImportDecl
+ = L loc $
+ ImportDecl (L loc pRELUDE)
+ False {- Not a boot interface -}
+ False {- Not qualified -}
+ Nothing {- No "as" -}
+ Nothing {- No import list -}
+ where
+ loc = mkGeneralSrcSpan FSLIT("Implicit import declaration")
\end{code}
\begin{code}
-checkEarlyExit mod
- = if not opt_SourceUnchanged then
- -- Source code changed; look no further
- returnRn False
- else
- -- Unchanged source; look further
- -- We check for
- -- (a) errors so far. These can arise if a module imports
- -- something that's no longer exported by the imported module
- -- (b) usage information up to date
- checkErrsRn `thenRn` \ no_errs_so_far ->
- checkUpToDate mod `thenRn` \ up_to_date ->
- returnRn (no_errs_so_far && up_to_date)
-\end{code}
-
+importsFromImportDecl :: Module
+ -> LImportDecl RdrName
+ -> RnM (GlobalRdrEnv, ImportAvails)
-\begin{code}
-importsFromImportDecl :: RdrNameImportDecl
- -> RnMG (RnEnv, ModuleAvails)
+importsFromImportDecl this_mod
+ (L loc (ImportDecl loc_imp_mod_name want_boot qual_only as_mod imp_details))
+ =
+ setSrcSpan loc $
-importsFromImportDecl (ImportDecl mod qual_only as_mod import_spec loc)
- = pushSrcLocRn loc $
- getInterfaceExports mod `thenRn` \ (avails, fixities) ->
- filterImports mod import_spec avails `thenRn` \ filtered_avails ->
+ -- If there's an error in loadInterface, (e.g. interface
+ -- file not found) we get lots of spurious errors from 'filterImports'
let
- filtered_avails' = [ Avail (set_name_prov n) (map set_name_prov ns)
- | Avail n ns <- filtered_avails
- ]
- fixities' = [ (occ,fixity,provenance) | (occ,fixity) <- fixities ]
+ imp_mod_name = unLoc loc_imp_mod_name
+ doc = ppr imp_mod_name <+> ptext SLIT("is directly imported")
in
- qualifyImports mod
- True -- Want qualified names
- (not qual_only) -- Maybe want unqualified names
- as_mod
- (ExportEnv filtered_avails' fixities')
- where
- set_name_prov name = setNameProvenance name provenance
- provenance = Imported mod loc
-\end{code}
+ loadSrcInterface doc imp_mod_name want_boot `thenM` \ iface ->
+ -- Compiler sanity check: if the import didn't say
+ -- {-# SOURCE #-} we should not get a hi-boot file
+ WARN( not want_boot && mi_boot iface, ppr imp_mod_name )
-\begin{code}
-importsFromLocalDecls rec_exp_fn (HsModule mod _ _ _ fix_decls decls _)
- = foldlRn getLocalDeclBinders [] decls `thenRn` \ avails ->
- mapRn fixityFromFixDecl fix_decls `thenRn` \ fixities ->
- qualifyImports mod
- False -- Don't want qualified names
- True -- Want unqualified names
- Nothing -- No "as M" part
- (ExportEnv avails fixities)
- where
- newLocalName rdr_name loc
- = newLocallyDefinedGlobalName mod (rdrNameOcc rdr_name) rec_exp_fn loc
+ -- Issue a user warning for a redundant {- SOURCE -} import
+ -- NB that we arrange to read all the ordinary imports before
+ -- any of the {- SOURCE -} imports
+ warnIf (want_boot && not (mi_boot iface))
+ (warnRedundantSourceImport imp_mod_name) `thenM_`
+
+ let
+ imp_mod = mi_module iface
+ deprecs = mi_deprecs iface
+ is_orph = mi_orphan iface
+ deps = mi_deps iface
+
+ filtered_exports = filter not_this_mod (mi_exports iface)
+ not_this_mod (mod,_) = mod /= this_mod
+ -- If the module exports anything defined in this module, just ignore it.
+ -- Reason: otherwise it looks as if there are two local definition sites
+ -- for the thing, and an error gets reported. Easiest thing is just to
+ -- filter them out up front. This situation only arises if a module
+ -- imports itself, or another module that imported it. (Necessarily,
+ -- this invoves a loop.)
+ --
+ -- Tiresome consequence: if you say
+ -- module A where
+ -- import B( AType )
+ -- type AType = ...
+ --
+ -- module B( AType ) where
+ -- import {-# SOURCE #-} A( AType )
+ --
+ -- then you'll get a 'B does not export AType' message. Oh well.
+
+ qual_mod_name = case as_mod of
+ Nothing -> imp_mod_name
+ Just another_name -> another_name
+ imp_spec = ImpDeclSpec { is_mod = imp_mod_name, is_qual = qual_only,
+ is_dloc = loc, is_as = qual_mod_name }
+ in
+ -- Get the total imports, and filter them according to the import list
+ ifaceExportNames filtered_exports `thenM` \ total_avails ->
+ filterImports iface imp_spec
+ imp_details total_avails `thenM` \ (avail_env, gbl_env) ->
- getLocalDeclBinders avails (ValD binds)
- = mapRn do_one (bagToList (collectTopBinders binds)) `thenRn` \ val_avails ->
- returnRn (val_avails ++ avails)
+ getDOpts `thenM` \ dflags ->
- getLocalDeclBinders avails decl
- = getDeclBinders newLocalName decl `thenRn` \ avail ->
- returnRn (avail : avails)
+ let
+ -- Compute new transitive dependencies
+
+ orphans | is_orph = ASSERT( not (imp_mod_name `elem` dep_orphs deps) )
+ imp_mod_name : dep_orphs deps
+ | otherwise = dep_orphs deps
+
+ (dependent_mods, dependent_pkgs)
+ = case mi_package iface of
+ HomePackage ->
+ -- Imported module is from the home package
+ -- Take its dependent modules and add imp_mod itself
+ -- Take its dependent packages unchanged
+ --
+ -- NB: (dep_mods deps) might include a hi-boot file
+ -- for the module being compiled, CM. Do *not* filter
+ -- this out (as we used to), because when we've
+ -- finished dealing with the direct imports we want to
+ -- know if any of them depended on CM.hi-boot, in
+ -- which case we should do the hi-boot consistency
+ -- check. See LoadIface.loadHiBootInterface
+ ((imp_mod_name, want_boot) : dep_mods deps, dep_pkgs deps)
+
+ ExtPackage pkg ->
+ -- Imported module is from another package
+ -- Dump the dependent modules
+ -- Add the package imp_mod comes from to the dependent packages
+ ASSERT2( not (pkg `elem` dep_pkgs deps), ppr pkg <+> ppr (dep_pkgs deps) )
+ ([], pkg : dep_pkgs deps)
+
+ -- True <=> import M ()
+ import_all = case imp_details of
+ Just (is_hiding, ls) -> not is_hiding && null ls
+ other -> False
+
+ -- unqual_avails is the Avails that are visible in *unqualified* form
+ -- We need to know this so we know what to export when we see
+ -- module M ( module P ) where ...
+ -- Then we must export whatever came from P unqualified.
+ imports = ImportAvails {
+ imp_env = unitModuleEnv qual_mod_name avail_env,
+ imp_mods = unitModuleEnv imp_mod (imp_mod, import_all, loc),
+ imp_orphs = orphans,
+ imp_dep_mods = mkModDeps dependent_mods,
+ imp_dep_pkgs = dependent_pkgs }
- do_one (rdr_name, loc)
- = newLocalName rdr_name loc `thenRn` \ name ->
- returnRn (Avail name [])
+ in
+ -- Complain if we import a deprecated module
+ ifOptM Opt_WarnDeprecations (
+ case deprecs of
+ DeprecAll txt -> addWarn (moduleDeprec imp_mod_name txt)
+ other -> returnM ()
+ ) `thenM_`
+
+ returnM (gbl_env, imports)
+
+warnRedundantSourceImport mod_name
+ = ptext SLIT("Unnecessary {- SOURCE -} in the import of module")
+ <+> quotes (ppr mod_name)
\end{code}
+
%************************************************************************
%* *
-\subsection{Filtering imports}
+ importsFromLocalDecls
%* *
%************************************************************************
-@filterImports@ takes the @ExportEnv@ telling what the imported module makes
-available, and filters it through the import spec (if any).
+From the top-level declarations of this module produce
+ * the lexical environment
+ * the ImportAvails
+created by its bindings.
+
+Complain about duplicate bindings
\begin{code}
-filterImports :: Module
- -> Maybe (Bool, [RdrNameIE]) -- Import spec; True => hidin
- -> [AvailInfo] -- What's available
- -> RnMG [AvailInfo] -- What's actually imported
- -- Complains if import spec mentions things the
- -- module doesn't export
-
-filterImports mod Nothing imports
- = returnRn imports
-
-filterImports mod (Just (want_hiding, import_items)) avails
- = -- Check that each import item mentions things that are actually available
- mapRn check_import_item import_items `thenRn_`
-
- -- Return filtered environment; no need to filter fixities
- returnRn (map new_avail avails)
-
+importsFromLocalDecls :: HsGroup RdrName -> RnM TcGblEnv
+importsFromLocalDecls group
+ = do { gbl_env <- getGblEnv
+
+ ; names <- getLocalDeclBinders gbl_env group
+
+ ; implicit_prelude <- doptM Opt_ImplicitPrelude
+ ; let {
+ -- Optimisation: filter out names for built-in syntax
+ -- They just clutter up the environment (esp tuples), and the parser
+ -- will generate Exact RdrNames for them, so the cluttered
+ -- envt is no use. To avoid doing this filter all the time,
+ -- we use -fno-implicit-prelude as a clue that the filter is
+ -- worth while. Really, it's only useful for GHC.Base and GHC.Tuple.
+ --
+ -- It's worth doing because it makes the environment smaller for
+ -- every module that imports the Prelude
+ --
+ -- Note: don't filter the gbl_env (hence all_names, not filered_all_names
+ -- in defn of gres above). Stupid reason: when parsing
+ -- data type decls, the constructors start as Exact tycon-names,
+ -- and then get turned into data con names by zapping the name space;
+ -- but that stops them being Exact, so they get looked up.
+ -- Ditto in fixity decls; e.g. infix 5 :
+ -- Sigh. It doesn't matter because it only affects the Data.Tuple really.
+ -- The important thing is to trim down the exports.
+ filtered_names
+ | implicit_prelude = names
+ | otherwise = filter (not . isBuiltInSyntax) names ;
+
+ ; this_mod = tcg_mod gbl_env
+ ; imports = emptyImportAvails {
+ imp_env = unitModuleEnv this_mod $
+ mkNameSet filtered_names
+ }
+ }
+
+ ; rdr_env' <- extendRdrEnvRn (tcg_rdr_env gbl_env) names
+
+ ; returnM (gbl_env { tcg_rdr_env = rdr_env',
+ tcg_imports = imports `plusImportAvails` tcg_imports gbl_env })
+ }
+
+extendRdrEnvRn :: GlobalRdrEnv -> [Name] -> RnM GlobalRdrEnv
+-- Add the new locally-bound names one by one, checking for duplicates as
+-- we do so. Remember that in Template Haskell the duplicates
+-- might *already be* in the GlobalRdrEnv from higher up the module
+extendRdrEnvRn rdr_env names
+ = foldlM add_local rdr_env names
where
- import_fm :: FiniteMap OccName RdrNameIE
- import_fm = listToFM [(ieOcc ie, ie) | ie <- import_items]
-
- avail_fm :: FiniteMap OccName AvailInfo
- avail_fm = listToFM [(nameOccName name, avail) | avail@(Avail name ns) <- avails]
-
- new_avail NotAvailable = NotAvailable
- new_avail avail@(Avail name _)
- | not in_import_items && want_hiding = avail
- | not in_import_items && not want_hiding = NotAvailable
- | in_import_items && want_hiding = NotAvailable
- | in_import_items && not want_hiding = filtered_avail
+ add_local rdr_env name
+ | gres <- lookupGlobalRdrEnv rdr_env (nameOccName name)
+ , (dup_gre:_) <- filter isLocalGRE gres -- Check for existing *local* defns
+ = do { addDupDeclErr (gre_name dup_gre) name
+ ; return rdr_env }
+ | otherwise
+ = return (extendGlobalRdrEnv rdr_env new_gre)
where
- maybe_import_item = lookupFM import_fm (nameOccName name)
- in_import_items = maybeToBool maybe_import_item
- Just import_item = maybe_import_item
- filtered_avail = filterAvail import_item avail
-
- check_import_item :: RdrNameIE -> RnMG ()
- check_import_item item
- = checkRn (maybeToBool maybe_matching_avail && sub_names_ok item avail)
- (badImportItemErr mod item)
- where
- item_name = ieOcc item
- maybe_matching_avail = lookupFM avail_fm item_name
- Just avail = maybe_matching_avail
-
- sub_names_ok (IEVar _) _ = True
- sub_names_ok (IEThingAbs _) _ = True
- sub_names_ok (IEThingAll _) _ = True
- sub_names_ok (IEThingWith _ wanted) (Avail _ has) = all ((`elem` has_list) . rdrNameOcc) wanted
- where
- has_list = map nameOccName has
- sub_names_ok other1 other2 = False
+ new_gre = GRE {gre_name = name, gre_prov = LocalDef}
\end{code}
+@getLocalDeclBinders@ returns the names for an @HsDecl@. It's
+used for source 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 qaulified names. It also turns the @Names@ in the @ExportEnv@ into
-fully fledged @Names@.
+ *** See "THE NAMING STORY" in HsDecls ****
\begin{code}
-qualifyImports :: Module -- Imported module
- -> Bool -- True <=> want qualified import
- -> Bool -- True <=> want unqualified import
- -> Maybe Module -- Optional "as M" part
- -> ExportEnv -- What's imported
- -> RnMG (RnEnv, ModuleAvails)
-
-qualifyImports this_mod qual_imp unqual_imp as_mod (ExportEnv avails fixities)
- = -- Make the qualified-name environments, checking of course for clashes
- foldlRn add_name emptyNameEnv avails `thenRn` \ name_env ->
- foldlRn (add_fixity name_env) emptyFixityEnv fixities `thenRn` \ fixity_env ->
- returnRn (RnEnv name_env fixity_env, mod_avail_env)
+getLocalDeclBinders :: TcGblEnv -> HsGroup RdrName -> RnM [Name]
+getLocalDeclBinders gbl_env (HsGroup {hs_valds = ValBindsIn val_decls val_sigs,
+ hs_tyclds = tycl_decls,
+ hs_fords = foreign_decls })
+ = do { tc_names_s <- mappM new_tc tycl_decls
+ ; val_names <- mappM new_simple val_bndrs
+ ; return (foldr (++) val_names tc_names_s) }
where
- qual_mod = case as_mod of
- Nothing -> this_mod
- Just another_name -> another_name
-
- mod_avail_env = unitFM qual_mod avails
-
- add_name name_env NotAvailable = returnRn name_env
- add_name name_env (Avail n ns) = foldlRn add_one name_env (n : ns)
-
- add_one :: NameEnv -> Name -> RnMG NameEnv
- add_one env name = add_to_env addOneToNameEnvRn env occ_name name
- where
- occ_name = nameOccName name
-
- add_to_env add_fn env occ thing | qual_imp && unqual_imp = both
- | qual_imp = qual_only
- | unqual_imp = unqual_only
- where
- unqual_only = add_fn env (Unqual occ) thing
- qual_only = add_fn env (Qual qual_mod occ) thing
- both = unqual_only `thenRn` \ env' ->
- add_fn env' (Qual qual_mod occ) thing
-
- add_fixity name_env fixity_env (occ_name, fixity, provenance)
- | maybeToBool (lookupFM name_env rdr_name) -- It's imported
- = add_to_env addOneToFixityEnvRn fixity_env occ_name (fixity,provenance)
- | otherwise -- It ain't imported
- = returnRn fixity_env
+ mod = tcg_mod gbl_env
+ is_hs_boot = isHsBoot (tcg_src gbl_env) ;
+ val_bndrs | is_hs_boot = sig_hs_bndrs
+ | otherwise = for_hs_bndrs ++ val_hs_bndrs
+ -- In a hs-boot file, the value binders come from the
+ -- *signatures*, and there should be no foreign binders
+
+ new_simple rdr_name = newTopSrcBinder mod Nothing rdr_name
+
+ sig_hs_bndrs = [nm | L _ (TypeSig nm _) <- val_sigs]
+ val_hs_bndrs = collectHsBindLocatedBinders val_decls
+ for_hs_bndrs = [nm | L _ (ForeignImport nm _ _ _) <- foreign_decls]
+
+ new_tc tc_decl
+ = do { main_name <- newTopSrcBinder mod Nothing main_rdr
+ ; sub_names <- mappM (newTopSrcBinder mod (Just main_name)) sub_rdrs
+ ; return (main_name : sub_names) }
where
- -- rdr_name is a name by which the thing is guaranteed to be known,
- -- *if it is imported at all*
- rdr_name | qual_imp = Qual qual_mod occ_name
- | otherwise = Unqual occ_name
+ (main_rdr : sub_rdrs) = tyClDeclNames (unLoc tc_decl)
\end{code}
-unQualify adds an Unqual binding for every existing Qual binding.
-
-\begin{code}
-unQualify :: FiniteMap RdrName elt -> FiniteMap RdrName elt
-unQualify fm = addListToFM fm [(Unqual occ, elt) | (Qual _ occ, elt) <- fmToList fm]
-\end{code}
%************************************************************************
%* *
-\subsection{Local declarations}
+\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}
-fixityFromFixDecl :: RdrNameFixityDecl -> RnMG (OccName, Fixity, Provenance)
+filterImports :: ModIface
+ -> ImpDeclSpec -- The span for the entire import decl
+ -> Maybe (Bool, [Located (IE RdrName)]) -- Import spec; True => hiding
+ -> NameSet -- What's available
+ -> RnM (NameSet, -- What's imported (qualified or unqualified)
+ GlobalRdrEnv) -- Same again, but in GRE form
+
+ -- Complains if import spec mentions things that the module doesn't export
+ -- Warns/informs if import spec contains duplicates.
+
+mkGenericRdrEnv decl_spec names
+ = mkGlobalRdrEnv [ GRE { gre_name = name, gre_prov = Imported [imp_spec] }
+ | name <- nameSetToList names ]
+ where
+ imp_spec = ImpSpec { is_decl = decl_spec, is_item = ImpAll }
+
+filterImports iface decl_spec Nothing all_names
+ = returnM (all_names, mkGenericRdrEnv decl_spec all_names)
-fixityFromFixDecl (FixityDecl rdr_name fixity loc)
- = returnRn (rdrNameOcc rdr_name, fixity, LocalDef (panic "export-flag") loc)
+filterImports iface decl_spec (Just (want_hiding, import_items)) all_names
+ = mappM (addLocM get_item) import_items `thenM` \ gres_s ->
+ let
+ gres = concat gres_s
+ specified_names = mkNameSet (map gre_name gres)
+ in
+ if not want_hiding then
+ return (specified_names, mkGlobalRdrEnv gres)
+ else
+ let
+ keep n = not (n `elemNameSet` specified_names)
+ pruned_avails = filterNameSet keep all_names
+ in
+ return (pruned_avails, mkGenericRdrEnv decl_spec pruned_avails)
+
+ where
+ occ_env :: OccEnv Name -- Maps OccName to corresponding Name
+ occ_env = mkOccEnv [(nameOccName n, n) | n <- nameSetToList all_names]
+ -- This env will have entries for data constructors too,
+ -- they won't make any difference because naked entities like T
+ -- in an import list map to TcOccs, not VarOccs.
+
+ sub_env :: NameEnv [Name]
+ sub_env = mkSubNameEnv all_names
+
+ bale_out item = addErr (badImportItemErr iface decl_spec item) `thenM_`
+ returnM []
+
+ succeed_with :: Bool -> [Name] -> RnM [GlobalRdrElt]
+ succeed_with all_explicit names
+ = do { loc <- getSrcSpanM
+ ; returnM (map (mk_gre loc) names) }
+ where
+ mk_gre loc name = GRE { gre_name = name,
+ gre_prov = Imported [imp_spec] }
+ where
+ imp_spec = ImpSpec { is_decl = decl_spec, is_item = item_spec }
+ item_spec = ImpSome { is_explicit = explicit, is_iloc = loc }
+ explicit = all_explicit || isNothing (nameParent_maybe name)
+
+ get_item :: IE RdrName -> RnM [GlobalRdrElt]
+ -- Empty result for a bad item.
+ -- Singleton result is typical case.
+ -- Can have two when we are hiding, and mention C which might be
+ -- both a class and a data constructor.
+ get_item item@(IEModuleContents _)
+ = bale_out item
+
+ get_item item@(IEThingAll tc)
+ = case check_item item of
+ [] -> bale_out item
+
+ [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_WarnDodgyImports (addWarn (dodgyImportWarn tc)) `thenM_`
+ succeed_with False [n]
+
+ names -> succeed_with False names
+
+ get_item item@(IEThingAbs n)
+ | want_hiding -- hiding( C )
+ -- Here the 'C' can be a data constructor
+ -- *or* a type/class, or even both
+ = case concat [check_item item, check_item (IEVar data_n)] of
+ [] -> bale_out item
+ names -> succeed_with True names
+ where
+ data_n = setRdrNameSpace n srcDataName
+
+ get_item item
+ = case check_item item of
+ [] -> bale_out item
+ names -> succeed_with True names
+
+ check_item :: IE RdrName -> [Name]
+ check_item item
+ = case lookupOccEnv occ_env (rdrNameOcc (ieName item)) of
+ Nothing -> []
+ Just name -> filterAvail item name sub_env
\end{code}
%************************************************************************
%* *
-\subsection{Export list processing
+\subsection{Export list processing}
%* *
%************************************************************************
-The @AvailEnv@ type is just used internally in @exportsFromAvail@.
-When exporting we need to combine the availabilities for a particular
-exported thing, and we also need to check for name clashes -- that
-is: two exported things must have different @OccNames@.
-
-\begin{code}
-type AvailEnv = FiniteMap OccName (RdrNameIE, AvailInfo)
- -- The FM maps each OccName to the RdrNameIE that gave rise to it,
- -- for error reporting, as well as to its AvailInfo
-
-emptyAvailEnv = emptyFM
+Processing the export list.
-unitAvailEnv :: RdrNameIE -> AvailInfo -> AvailEnv
-unitAvailEnv ie NotAvailable
- = emptyFM
-unitAvailEnv ie avail@(Avail n ns)
- = unitFM (nameOccName n) (ie,avail)
+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).
-plusAvailEnv a1 a2
- = mapRn (addErrRn.availClashErr) (conflictsFM bad_avail a1 a2) `thenRn_`
- returnRn (plusFM_C plus_avail a1 a2)
+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...
-listToAvailEnv :: RdrNameIE -> [AvailInfo] -> RnM s d AvailEnv
-listToAvailEnv ie items
- = foldlRn plusAvailEnv emptyAvailEnv (map (unitAvailEnv ie) items)
+\begin{code}
+type ExportAccum -- The type of the accumulating parameter of
+ -- the main worker function in rnExports
+ = ([Module], -- 'module M's seen so far
+ ExportOccMap, -- Tracks exported occurrence names
+ NameSet) -- The accumulated exported stuff
+emptyExportAccum = ([], emptyOccEnv, emptyNameSet)
+
+type ExportOccMap = OccEnv (Name, IE RdrName)
+ -- Tracks what a particular exported OccName
+ -- in an export list refers to, and which item
+ -- it came from. It's illegal to export two distinct things
+ -- that have the same occurrence name
+
+
+rnExports :: Bool -- False => no 'module M(..) where' header at all
+ -> Maybe [Located (IE RdrName)] -- Nothing => no explicit export list
+ -> RnM NameSet
+ -- Complains if two distinct exports have same OccName
+ -- Warns about identical exports.
+ -- Complains about exports items not in scope
-bad_avail (ie1,Avail n1 _) (ie2,Avail n2 _) = n1 /= n2 -- Same OccName, different Name
-plus_avail (ie1,a1) (ie2,a2) = (ie1, a1 `plusAvail` a2)
+rnExports explicit_mod exports
+ = do { TcGblEnv { tcg_rdr_env = rdr_env,
+ tcg_imports = imports } <- getGblEnv ;
+
+ -- If the module header is omitted altogether, then behave
+ -- as if the user had written "module Main(main) where..."
+ -- EXCEPT in interactive mode, when we behave as if he had
+ -- written "module Main where ..."
+ -- Reason: don't want to complain about 'main' not in scope
+ -- in interactive mode
+ ghci_mode <- getGhciMode ;
+ let { real_exports
+ | explicit_mod = exports
+ | ghci_mode == Interactive = Nothing
+ | otherwise = Just [noLoc (IEVar main_RDR_Unqual)] } ;
+ -- ToDo: the 'noLoc' here is unhelpful if 'main' turns out to be out of scope
+ exports_from_avail real_exports rdr_env imports }
+
+
+exports_from_avail Nothing rdr_env imports
+ = -- Export all locally-defined things
+ -- We do this by filtering the global RdrEnv,
+ -- keeping only things that are locally-defined
+ return (mkNameSet [ gre_name gre
+ | gre <- globalRdrEnvElts rdr_env,
+ isLocalGRE gre ])
+
+exports_from_avail (Just items) rdr_env (ImportAvails { imp_env = imp_env })
+ = foldlM do_litem emptyExportAccum items `thenM` \ (_, _, exports) ->
+ returnM exports
+ where
+ sub_env :: NameEnv [Name] -- Classify each name by its parent
+ sub_env = mkSubNameEnv (foldModuleEnv unionNameSets emptyNameSet imp_env)
+
+ do_litem :: ExportAccum -> Located (IE RdrName) -> RnM ExportAccum
+ do_litem acc = addLocM (exports_from_item acc)
+
+ exports_from_item :: ExportAccum -> IE RdrName -> RnM ExportAccum
+ exports_from_item acc@(mods, occs, exports) ie@(IEModuleContents mod)
+ | mod `elem` mods -- Duplicate export of M
+ = do { warn_dup_exports <- doptM Opt_WarnDuplicateExports ;
+ warnIf warn_dup_exports (dupModuleExport mod) ;
+ returnM acc }
+
+ | otherwise
+ = case lookupModuleEnv imp_env mod of
+ Nothing -> addErr (modExportErr mod) `thenM_`
+ returnM acc
+ Just names
+ -> let
+ new_exports = filterNameSet (inScopeUnqual rdr_env) names
+ in
+
+ -- This check_occs not only finds conflicts between this item
+ -- and others, but also internally within this item. That is,
+ -- if 'M.x' is in scope in several ways, we'll have several
+ -- members of mod_avails with the same OccName.
+ check_occs ie occs (nameSetToList new_exports) `thenM` \ occs' ->
+ returnM (mod:mods, occs', exports `unionNameSets` new_exports)
+
+ exports_from_item acc@(mods, occs, exports) ie
+ = lookupGlobalOccRn (ieName ie) `thenM` \ name ->
+ if isUnboundName name then
+ returnM acc -- Avoid error cascade
+ else let
+ new_exports = filterAvail ie name sub_env
+ in
+ checkErr (not (null new_exports)) (exportItemErr ie) `thenM_`
+ checkForDodgyExport ie new_exports `thenM_`
+ check_occs ie occs new_exports `thenM` \ occs' ->
+ returnM (mods, occs', addListToNameSet exports new_exports)
+
+-------------------------------
+filterAvail :: IE RdrName -- Wanted
+ -> Name -- The Name of the ieName of the item
+ -> NameEnv [Name] -- Maps type/class names to their sub-names
+ -> [Name] -- Empty if even one thing reqd is missing
+
+filterAvail (IEVar _) n subs = [n]
+filterAvail (IEThingAbs _) n subs = [n]
+filterAvail (IEThingAll _) n subs = n : subNames subs n
+filterAvail (IEThingWith _ rdrs) n subs
+ | any isNothing mb_names = []
+ | otherwise = n : catMaybes mb_names
+ where
+ env = mkOccEnv [(nameOccName s, s) | s <- subNames subs n]
+ mb_names = map (lookupOccEnv env . rdrNameOcc) rdrs
+filterAvail (IEModuleContents _) _ _ = panic "filterAvail"
+
+subNames :: NameEnv [Name] -> Name -> [Name]
+subNames env n = lookupNameEnv env n `orElse` []
+
+mkSubNameEnv :: NameSet -> NameEnv [Name]
+-- Maps types and classes to their constructors/classops respectively
+-- This mapping just makes it easier to deal with A(..) export items
+mkSubNameEnv names
+ = foldNameSet add_name emptyNameEnv names
+ where
+ add_name name env
+ | Just parent <- nameParent_maybe name
+ = extendNameEnv_C (\ns _ -> name:ns) env parent [name]
+ | otherwise = env
+
+-------------------------------
+inScopeUnqual :: GlobalRdrEnv -> Name -> Bool
+-- Checks whether the Name is in scope unqualified,
+-- regardless of whether it's ambiguous or not
+inScopeUnqual env n = any unQualOK (lookupGRE_Name env n)
+
+-------------------------------
+checkForDodgyExport :: IE RdrName -> [Name] -> RnM ()
+checkForDodgyExport ie@(IEThingAll tc) [n]
+ | isTcOcc (nameOccName n) = addWarn (dodgyExportWarn tc)
+ -- This occurs when you export T(..), but
+ -- only import T abstractly, or T is a synonym.
+ -- The single [n] is the type or class itself
+ | otherwise = addErr (exportItemErr ie)
+ -- This happes if you export x(..), which is bogus
+checkForDodgyExport _ _ = return ()
+
+-------------------------------
+check_occs :: IE RdrName -> ExportOccMap -> [Name] -> RnM ExportOccMap
+check_occs ie occs names
+ = foldlM check occs names
+ where
+ check occs name
+ = case lookupOccEnv occs name_occ of
+ Nothing -> returnM (extendOccEnv occs name_occ (name, ie))
+
+ Just (name', ie')
+ | name == name' -- Duplicate export
+ -> do { warn_dup_exports <- doptM Opt_WarnDuplicateExports ;
+ warnIf warn_dup_exports (dupExportWarn name_occ ie ie') ;
+ returnM occs }
+
+ | otherwise -- Same occ name but different names: an error
+ -> do { global_env <- getGlobalRdrEnv ;
+ addErr (exportClashErr global_env name name' ie ie') ;
+ returnM occs }
+ where
+ name_occ = nameOccName name
\end{code}
+%*********************************************************
+%* *
+ Deprecations
+%* *
+%*********************************************************
\begin{code}
-exportsFromAvail :: Module
- -> Maybe [RdrNameIE] -- Export spec
- -> ModuleAvails
- -> RnEnv
- -> RnMG (Name -> ExportFlag, ExportEnv)
- -- Complains if two distinct exports have same OccName
- -- Complains about exports items not in scope
-exportsFromAvail this_mod Nothing all_avails rn_env
- = exportsFromAvail this_mod (Just [IEModuleContents this_mod]) all_avails rn_env
+reportDeprecations :: TcGblEnv -> RnM ()
+reportDeprecations tcg_env
+ = ifOptM Opt_WarnDeprecations $
+ do { (eps,hpt) <- getEpsAndHpt
+ -- By this time, typechecking is complete,
+ -- so the PIT is fully populated
+ ; mapM_ (check hpt (eps_PIT eps)) all_gres }
+ where
+ used_names = allUses (tcg_dus tcg_env)
+ -- Report on all deprecated uses; hence allUses
+ all_gres = globalRdrEnvElts (tcg_rdr_env tcg_env)
+
+ check hpt pit (GRE {gre_name = name, gre_prov = Imported (imp_spec:_)})
+ | name `elemNameSet` used_names
+ , Just deprec_txt <- lookupDeprec hpt pit name
+ = setSrcSpan (importSpecLoc imp_spec) $
+ addWarn (sep [ptext SLIT("Deprecated use of") <+>
+ pprNonVarNameSpace (occNameSpace (nameOccName name)) <+>
+ quotes (ppr name),
+ (parens imp_msg) <> colon,
+ (ppr deprec_txt) ])
+ where
+ name_mod = nameModule name
+ imp_mod = importSpecModule imp_spec
+ imp_msg = ptext SLIT("imported from") <+> ppr imp_mod <> extra
+ extra | imp_mod == name_mod = empty
+ | otherwise = ptext SLIT(", but defined in") <+> ppr name_mod
+
+ check hpt pit ok_gre = returnM () -- Local, or not used, or not deprectated
+ -- The Imported pattern-match: don't deprecate locally defined names
+ -- For a start, we may be exporting a deprecated thing
+ -- Also we may use a deprecated thing in the defn of another
+ -- deprecated things. We may even use a deprecated thing in
+ -- the defn of a non-deprecated thing, when changing a module's
+ -- interface
+
+lookupDeprec :: HomePackageTable -> PackageIfaceTable
+ -> Name -> Maybe DeprecTxt
+lookupDeprec hpt pit n
+ = case lookupIface hpt pit (nameModule n) of
+ Just iface -> mi_dep_fn iface n `seqMaybe` -- Bleat if the thing, *or
+ mi_dep_fn iface (nameParent n) -- its parent*, is deprec'd
+ Nothing
+ | isWiredInName n -> Nothing
+ -- We have not necessarily loaded the .hi file for a
+ -- wired-in name (yet), although we *could*.
+ -- And we never deprecate them
+
+ | otherwise -> pprPanic "lookupDeprec" (ppr n)
+ -- By now all the interfaces should have been loaded
+
+gre_is_used :: NameSet -> GlobalRdrElt -> Bool
+gre_is_used used_names gre = gre_name gre `elemNameSet` used_names
+\end{code}
-exportsFromAvail this_mod (Just export_items) all_avails (RnEnv name_env fixity_env)
- = mapRn exports_from_item export_items `thenRn` \ avail_envs ->
- foldlRn plusAvailEnv emptyAvailEnv avail_envs `thenRn` \ export_avail_env ->
- let
- export_avails = map snd (eltsFM export_avail_env)
- export_fixities = mk_exported_fixities (availsToNameSet export_avails)
- export_fn = mk_export_fn export_avails
- in
- returnRn (export_fn, ExportEnv export_avails export_fixities)
+%*********************************************************
+%* *
+ Unused names
+%* *
+%*********************************************************
+\begin{code}
+reportUnusedNames :: Maybe [Located (IE RdrName)] -- Export list
+ -> TcGblEnv -> RnM ()
+reportUnusedNames export_decls gbl_env
+ = do { traceRn ((text "RUN") <+> (ppr (tcg_dus gbl_env)))
+ ; warnUnusedTopBinds unused_locals
+ ; warnUnusedModules unused_imp_mods
+ ; warnUnusedImports unused_imports
+ ; warnDuplicateImports defined_and_used
+ ; printMinimalImports minimal_imports }
+ where
+ used_names, all_used_names :: NameSet
+ used_names = findUses (tcg_dus gbl_env) emptyNameSet
+ -- NB: currently, if f x = g, we only treat 'g' as used if 'f' is used
+ -- Hence findUses
+
+ all_used_names = used_names `unionNameSets`
+ mkNameSet (mapCatMaybes nameParent_maybe (nameSetToList used_names))
+ -- A use of C implies a use of T,
+ -- if C was brought into scope by T(..) or T(C)
+
+ -- Collect the defined names from the in-scope environment
+ defined_names :: [GlobalRdrElt]
+ defined_names = globalRdrEnvElts (tcg_rdr_env gbl_env)
+
+ -- Note that defined_and_used, defined_but_not_used
+ -- are both [GRE]; that's why we need defined_and_used
+ -- rather than just all_used_names
+ defined_and_used, defined_but_not_used :: [GlobalRdrElt]
+ (defined_and_used, defined_but_not_used)
+ = partition (gre_is_used all_used_names) defined_names
+
+ -- Filter out the ones that are
+ -- (a) defined in this module, and
+ -- (b) not defined by a 'deriving' clause
+ -- The latter have an Internal Name, so we can filter them out easily
+ unused_locals :: [GlobalRdrElt]
+ unused_locals = filter is_unused_local defined_but_not_used
+ is_unused_local :: GlobalRdrElt -> Bool
+ is_unused_local gre = isLocalGRE gre && isExternalName (gre_name gre)
+
+ unused_imports :: [GlobalRdrElt]
+ unused_imports = filter unused_imp defined_but_not_used
+ unused_imp (GRE {gre_prov = Imported imp_specs})
+ = not (all (module_unused . importSpecModule) imp_specs)
+ && or [exp | ImpSpec { is_item = ImpSome { is_explicit = exp } } <- imp_specs]
+ -- Don't complain about unused imports if we've already said the
+ -- entire import is unused
+ unused_imp other = False
+
+ -- To figure out the minimal set of imports, start with the things
+ -- that are in scope (i.e. in gbl_env). Then just combine them
+ -- into a bunch of avails, so they are properly grouped
+ --
+ -- BUG WARNING: this does not deal properly with qualified imports!
+ minimal_imports :: FiniteMap Module AvailEnv
+ minimal_imports0 = foldr add_expall emptyFM expall_mods
+ minimal_imports1 = foldr add_name minimal_imports0 defined_and_used
+ minimal_imports = foldr add_inst_mod minimal_imports1 direct_import_mods
+ -- The last line makes sure that we retain all direct imports
+ -- even if we import nothing explicitly.
+ -- It's not necessarily redundant to import such modules. Consider
+ -- module This
+ -- import M ()
+ --
+ -- The import M() is not *necessarily* redundant, even if
+ -- we suck in no instance decls from M (e.g. it contains
+ -- no instance decls, or This contains no code). It may be
+ -- that we import M solely to ensure that M's orphan instance
+ -- decls (or those in its imports) are visible to people who
+ -- import This. Sigh.
+ -- There's really no good way to detect this, so the error message
+ -- in RnEnv.warnUnusedModules is weakened instead
+
+ -- We've carefully preserved the provenance so that we can
+ -- construct minimal imports that import the name by (one of)
+ -- the same route(s) as the programmer originally did.
+ add_name (GRE {gre_name = n, gre_prov = Imported imp_specs}) acc
+ = addToFM_C plusAvailEnv acc (importSpecModule (head imp_specs))
+ (unitAvailEnv (mk_avail n (nameParent_maybe n)))
+ add_name other acc
+ = acc
+
+ -- Modules mentioned as 'module M' in the export list
+ expall_mods = case export_decls of
+ Nothing -> []
+ Just es -> [m | L _ (IEModuleContents m) <- es]
+
+ -- This is really bogus. The idea is that if we see 'module M' in
+ -- the export list we must retain the import decls that drive it
+ -- If we aren't careful we might see
+ -- module A( module M ) where
+ -- import M
+ -- import N
+ -- and suppose that N exports everything that M does. Then we
+ -- must not drop the import of M even though N brings it all into
+ -- scope.
+ --
+ -- BUG WARNING: 'module M' exports aside, what if M.x is mentioned?!
+ --
+ -- The reason that add_expall is bogus is that it doesn't take
+ -- qualified imports into account. But it's an improvement.
+ add_expall mod acc = addToFM_C plusAvailEnv acc mod emptyAvailEnv
+
+ -- n is the name of the thing, p is the name of its parent
+ mk_avail n (Just p) = AvailTC p [p,n]
+ mk_avail n Nothing | isTcOcc (nameOccName n) = AvailTC n [n]
+ | otherwise = Avail n
+
+ add_inst_mod (mod,_,_) acc
+ | mod `elemFM` acc = acc -- We import something already
+ | otherwise = addToFM acc mod emptyAvailEnv
+ where
+ -- Add an empty collection of imports for a module
+ -- from which we have sucked only instance decls
+
+ imports = tcg_imports gbl_env
+
+ direct_import_mods :: [(Module, Bool, SrcSpan)]
+ -- See the type of the imp_mods for this triple
+ direct_import_mods = moduleEnvElts (imp_mods imports)
+
+ -- unused_imp_mods are the directly-imported modules
+ -- that are not mentioned in minimal_imports1
+ -- [Note: not 'minimal_imports', because that includes directly-imported
+ -- modules even if we use nothing from them; see notes above]
+ --
+ -- BUG WARNING: does not deal correctly with multiple imports of the same module
+ -- becuase direct_import_mods has only one entry per module
+ unused_imp_mods = [(mod,loc) | (mod,no_imp,loc) <- direct_import_mods,
+ not (mod `elemFM` minimal_imports1),
+ mod /= pRELUDE,
+ not no_imp]
+ -- The not no_imp part is not to complain about
+ -- import M (), which is an idiom for importing
+ -- instance declarations
+
+ module_unused :: Module -> Bool
+ module_unused mod = any (((==) mod) . fst) unused_imp_mods
+
+---------------------
+warnDuplicateImports :: [GlobalRdrElt] -> RnM ()
+-- Given the GREs for names that are used, figure out which imports
+-- could be omitted without changing the top-level environment.
+--
+-- NB: Given import Foo( T )
+-- import qualified Foo
+-- we do not report a duplicate import, even though Foo.T is brought
+-- into scope by both, because there's nothing you can *omit* without
+-- changing the top-level environment. So we complain only if it's
+-- explicitly named in both imports or neither.
+--
+-- Furthermore, we complain about Foo.T only if
+-- there is no complaint about (unqualified) T
+
+warnDuplicateImports gres
+ = ifOptM Opt_WarnUnusedImports $
+ sequenceM_ [ warn name pr
+ -- The 'head' picks the first offending group
+ -- for this particular name
+ | GRE { gre_name = name, gre_prov = Imported imps } <- gres
+ , pr <- redundants imps ]
where
- full_avail_env :: UniqFM AvailInfo
- full_avail_env = addListToUFM_C plusAvail emptyUFM
- [(name,avail) | avail@(Avail name _) <- concat (eltsFM all_avails)]
- -- NB: full_avail_env won't contain bindings for data constructors and class ops,
- -- which is right and proper; attempts to export them on their own will provoke an error
-
- exports_from_item :: RdrNameIE -> RnMG AvailEnv
- exports_from_item ie@(IEModuleContents mod)
- = case lookupFM all_avails mod of
- Nothing -> failWithRn emptyAvailEnv (modExportErr mod)
- Just avails -> addOccurrenceNames Compulsory [n | Avail n _ <- avails] `thenRn_`
- listToAvailEnv ie avails
-
- exports_from_item ie
- | not (maybeToBool maybe_in_scope)
- = failWithRn emptyAvailEnv (unknownNameErr (ieName ie))
-
-#ifdef DEBUG
- -- I can't see why this should ever happen; if the thing is in scope
- -- at all it ought to have some availability
- | not (maybeToBool maybe_avail)
- = pprTrace "exportsFromAvail: curious Nothing:" (ppr PprDebug name)
- returnRn emptyAvailEnv
-#endif
-
- | not enough_avail
- = failWithRn emptyAvailEnv (exportItemErr ie export_avail)
-
- | otherwise -- Phew! It's OK!
- = addOccurrenceName Compulsory name `thenRn_`
- returnRn (unitAvailEnv ie export_avail)
- where
- maybe_in_scope = lookupNameEnv name_env (ieName ie)
- Just name = maybe_in_scope
- maybe_avail = lookupUFM full_avail_env name
- Just avail = maybe_avail
- export_avail = filterAvail ie avail
- enough_avail = case export_avail of {NotAvailable -> False; other -> True}
-
- -- We export a fixity iff we export a thing with the same (qualified) RdrName
- mk_exported_fixities :: NameSet -> [(OccName, Fixity, Provenance)]
- mk_exported_fixities exports
- = [ (rdrNameOcc rdr_name, fixity, prov)
- | (rdr_name, (fixity, prov)) <- fmToList fixity_env,
- export_fixity name_env exports rdr_name
- ]
-
-mk_export_fn :: [AvailInfo] -> (Name -> ExportFlag)
-mk_export_fn avails
- = \name -> if name `elemNameSet` exported_names
- then Exported
- else NotExported
+ warn name (red_imp, cov_imp)
+ = addWarnAt (importSpecLoc red_imp)
+ (vcat [ptext SLIT("Redundant import of:") <+> quotes pp_name,
+ ptext SLIT("It is also") <+> ppr cov_imp])
+ where
+ pp_name | is_qual red_decl = ppr (is_as red_decl) <> dot <> ppr occ
+ | otherwise = ppr occ
+ occ = nameOccName name
+ red_decl = is_decl red_imp
+
+ redundants :: [ImportSpec] -> [(ImportSpec,ImportSpec)]
+ -- The returned pair is (redundant-import, covering-import)
+ redundants imps
+ = [ (red_imp, cov_imp)
+ | red_imp <- imps
+ , cov_imp <- take 1 (filter (covers red_imp) imps) ]
+
+ -- "red_imp" is a putative redundant import
+ -- "cov_imp" potentially covers it
+ -- This test decides whether red_imp could be dropped
+ --
+ -- NOTE: currently the test does not warn about
+ -- import M( x )
+ -- imoprt N( x )
+ -- even if the same underlying 'x' is involved, because dropping
+ -- either import would change the qualified names in scope (M.x, N.x)
+ -- But if the qualified names aren't used, the import is indeed redundant
+ -- Sadly we don't know that. Oh well.
+ covers red_imp@(ImpSpec { is_decl = red_decl, is_item = red_item })
+ cov_imp@(ImpSpec { is_decl = cov_decl, is_item = cov_item })
+ | red_loc == cov_loc
+ = False -- Ignore diagonal elements
+ | not (is_as red_decl == is_as cov_decl)
+ = False -- They bring into scope different qualified names
+ | not (is_qual red_decl) && is_qual cov_decl
+ = False -- Covering one doesn't bring unqualified name into scope
+ | red_selective
+ = not cov_selective -- Redundant one is selective and covering one isn't
+ || red_later -- Both are explicit; tie-break using red_later
+ | otherwise
+ = not cov_selective -- Neither import is selective
+ && (is_mod red_decl == is_mod cov_decl) -- They import the same module
+ && red_later -- Tie-break
+ where
+ red_loc = importSpecLoc red_imp
+ cov_loc = importSpecLoc cov_imp
+ red_later = red_loc > cov_loc
+ cov_selective = selectiveImpItem cov_item
+ red_selective = selectiveImpItem red_item
+
+selectiveImpItem :: ImpItemSpec -> Bool
+selectiveImpItem ImpAll = False
+selectiveImpItem (ImpSome {}) = True
+
+-- ToDo: deal with original imports with 'qualified' and 'as M' clauses
+printMinimalImports :: FiniteMap Module AvailEnv -- Minimal imports
+ -> RnM ()
+printMinimalImports imps
+ = ifOptM Opt_D_dump_minimal_imports $ do {
+
+ mod_ies <- mappM to_ies (fmToList imps) ;
+ this_mod <- getModule ;
+ rdr_env <- getGlobalRdrEnv ;
+ ioToTcRn (do { h <- openFile (mkFilename this_mod) WriteMode ;
+ printForUser h (unQualInScope rdr_env)
+ (vcat (map ppr_mod_ie mod_ies)) })
+ }
where
- exported_names :: NameSet
- exported_names = availsToNameSet avails
-
-export_fixity :: NameEnv -> NameSet -> RdrName -> Bool
-export_fixity name_env exports (Unqual _)
- = False -- The qualified fixity is always there as well
-export_fixity name_env exports rdr_name@(Qual _ occ)
- = case lookupFM name_env rdr_name of
- Just fixity_name -> fixity_name `elemNameSet` exports
- -- Check whether the exported thing is
- -- the one to which the fixity attaches
- other -> False -- Not even in scope
-\end{code}
+ mkFilename this_mod = moduleString this_mod ++ ".imports"
+ ppr_mod_ie (mod_name, ies)
+ | mod_name == pRELUDE
+ = empty
+ | null ies -- Nothing except instances comes from here
+ = ptext SLIT("import") <+> ppr mod_name <> ptext SLIT("() -- Instances only")
+ | otherwise
+ = ptext SLIT("import") <+> ppr mod_name <>
+ parens (fsep (punctuate comma (map ppr ies)))
+
+ to_ies (mod, avail_env) = mappM to_ie (availEnvElts avail_env) `thenM` \ ies ->
+ returnM (mod, ies)
+
+ to_ie :: AvailInfo -> RnM (IE Name)
+ -- The main trick here is that if we're importing all the constructors
+ -- we want to say "T(..)", but if we're importing only a subset we want
+ -- to say "T(A,B,C)". So we have to find out what the module exports.
+ to_ie (Avail n) = returnM (IEVar n)
+ to_ie (AvailTC n [m]) = ASSERT( n==m )
+ returnM (IEThingAbs n)
+ to_ie (AvailTC n ns)
+ = loadSrcInterface doc n_mod False `thenM` \ iface ->
+ case [xs | (m,as) <- mi_exports iface,
+ m == n_mod,
+ AvailTC x xs <- as,
+ x == nameOccName n] of
+ [xs] | all_used xs -> returnM (IEThingAll n)
+ | otherwise -> returnM (IEThingWith n (filter (/= n) ns))
+ other -> pprTrace "to_ie" (ppr n <+> ppr n_mod <+> ppr other) $
+ returnM (IEVar n)
+ where
+ all_used avail_occs = all (`elem` map nameOccName ns) avail_occs
+ doc = text "Compute minimal imports from" <+> ppr n
+ n_mod = nameModule n
+\end{code}
%************************************************************************
%************************************************************************
\begin{code}
-ieOcc ie = rdrNameOcc (ieName ie)
-
-badImportItemErr mod ie sty
- = ppSep [ppStr "Module", pprModule sty mod, ppStr "does not export", ppr sty ie]
-
-modExportErr mod sty
- = ppCat [ ppStr "Unknown module in export list: module", ppPStr mod]
-
-exportItemErr export_item NotAvailable sty
- = ppSep [ ppStr "Export item not in scope:", ppr sty export_item ]
-
-exportItemErr export_item avail sty
- = ppHang (ppStr "Export item not fully in scope:")
- 4 (ppAboves [ppCat [ppStr "Wanted: ", ppr sty export_item],
- ppCat [ppStr "Available: ", ppr sty (ieOcc export_item), pprAvail sty avail]])
-
-availClashErr (occ_name, ((ie1,avail1), (ie2,avail2))) sty
- = ppHang (ppCat [ppStr "Conflicting exports for local name: ", ppr sty occ_name])
- 4 (ppAboves [ppr sty ie1, ppr sty ie2])
+badImportItemErr iface decl_spec ie
+ = sep [ptext SLIT("Module"), quotes (ppr (is_mod decl_spec)), source_import,
+ ptext SLIT("does not export"), quotes (ppr ie)]
+ where
+ source_import | mi_boot iface = ptext SLIT("(hi-boot interface)")
+ | otherwise = empty
+
+dodgyImportWarn item = dodgyMsg (ptext SLIT("import")) item
+dodgyExportWarn item = dodgyMsg (ptext SLIT("export")) item
+
+dodgyMsg kind tc
+ = sep [ ptext SLIT("The") <+> kind <+> ptext SLIT("item") <+> quotes (ppr (IEThingAll tc)),
+ ptext SLIT("suggests that") <+> quotes (ppr tc) <+> ptext SLIT("has constructor or class methods"),
+ ptext SLIT("but it has none; it is a type synonym or abstract type or class") ]
+
+modExportErr mod
+ = hsep [ ptext SLIT("Unknown module in export list: module"), quotes (ppr mod)]
+
+exportItemErr export_item
+ = sep [ ptext SLIT("The export item") <+> quotes (ppr export_item),
+ ptext SLIT("attempts to export constructors or class methods that are not visible here") ]
+
+exportClashErr global_env name1 name2 ie1 ie2
+ = vcat [ ptext SLIT("Conflicting exports for") <+> quotes (ppr occ) <> colon
+ , ppr_export ie1 name1
+ , ppr_export ie2 name2 ]
+ where
+ occ = nameOccName name1
+ ppr_export ie name = nest 2 (quotes (ppr ie) <+> ptext SLIT("exports") <+>
+ quotes (ppr name) <+> pprNameProvenance (get_gre name))
+
+ -- get_gre finds a GRE for the Name, so that we can show its provenance
+ get_gre name
+ = case lookupGRE_Name global_env name of
+ (gre:_) -> gre
+ [] -> pprPanic "exportClashErr" (ppr name)
+
+addDupDeclErr :: Name -> Name -> TcRn ()
+addDupDeclErr name_a name_b
+ = addErrAt (srcLocSpan loc2) $
+ vcat [ptext SLIT("Multiple declarations of") <+> quotes (ppr name1),
+ ptext SLIT("Declared at:") <+> vcat [ppr (nameSrcLoc name1), ppr loc2]]
+ where
+ loc2 = nameSrcLoc name2
+ (name1,name2) | nameSrcLoc name_a > nameSrcLoc name_b = (name_b,name_a)
+ | otherwise = (name_a,name_b)
+ -- Report the error at the later location
+
+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}
-
projects / ghc-hetmet.git / blobdiff