\begin{code}
module RnNames (
- getGlobalNames, exportsFromAvail
+ rnImports, mkRdrEnvAndImports, importsFromLocalDecls,
+ rnExports, mkExportNameSet,
+ getLocalDeclBinders, extendRdrEnvRn,
+ reportUnusedNames, reportDeprecations
) where
#include "HsVersions.h"
-import CmdLineOpts ( DynFlag(..) )
-
-import HsSyn ( HsModule(..), HsDecl(..), IE(..), ieName, ImportDecl(..),
- ForeignDecl(..),
- collectLocatedHsBinders
- )
-import RdrHsSyn ( RdrNameIE, RdrNameImportDecl,
- RdrNameHsModule, RdrNameHsDecl
- )
-import RnIfaces ( recordLocalSlurps )
-import RnHiFiles ( getTyClDeclBinders, loadInterface )
+import DynFlags ( DynFlag(..), GhcMode(..) )
+import HsSyn ( IE(..), ieName, ImportDecl(..), LImportDecl,
+ ForeignDecl(..), HsGroup(..), HsValBinds(..),
+ Sig(..), collectHsBindLocatedBinders, tyClDeclNames,
+ LIE )
import RnEnv
-import RnMonad
+import IfaceEnv ( ifaceExportNames )
+import LoadIface ( loadSrcInterface )
+import TcRnMonad hiding (LIE)
import FiniteMap
-import PrelNames ( pRELUDE_Name, mAIN_Name, main_RDR_Unqual, isUnboundName )
-import Module ( ModuleName, moduleName, WhereFrom(..) )
-import Name ( Name, nameSrcLoc, nameOccName )
+import PrelNames ( pRELUDE, 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 HscTypes ( Provenance(..), ImportReason(..), GlobalRdrEnv,
- GenAvailInfo(..), AvailInfo, Avails, AvailEnv,
- Deprecations(..), ModIface(..)
+import OccName ( srcDataName, isTcOcc, pprNonVarNameSpace,
+ occNameSpace,
+ OccEnv, mkOccEnv, lookupOccEnv, emptyOccEnv,
+ extendOccEnv )
+import HscTypes ( GenAvailInfo(..), AvailInfo,
+ HomePackageTable, PackageIfaceTable,
+ unQualInScope,
+ Deprecs(..), ModIface(..), Dependencies(..),
+ lookupIface, ExternalPackageState(..)
)
-import RdrName ( rdrNameOcc, setRdrNameOcc )
-import OccName ( setOccNameSpace, dataName )
-import NameSet ( elemNameSet, emptyNameSet )
+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 ( maybeToBool, catMaybes, mapMaybe )
-import ListSetOps ( removeDups )
-import Util ( sortLt )
+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 :: Module -> RdrNameHsModule
- -> RnMG (GlobalRdrEnv, -- Maps all in-scope things
- GlobalRdrEnv, -- Maps just *local* things
- ExportAvails) -- The exported stuff
-
-getGlobalNames this_mod (HsModule _ _ _ imports decls _ mod_loc)
- = -- PROCESS LOCAL DECLS
- -- Do these *first* so that the correct provenance gets
- -- into the global name cache.
- importsFromLocalDecls this_mod decls `thenRn` \ (local_gbl_env, local_mod_avails) ->
-
- -- PROCESS IMPORT DECLS
- -- Do the non {- SOURCE -} ones first, so that we get a helpful
- -- warning for {- SOURCE -} ones that are unnecessary
- doptRn Opt_NoImplicitPrelude `thenRn` \ opt_no_prelude ->
- let
- all_imports = mk_prel_imports opt_no_prelude ++ imports
- (source, ordinary) = partition is_source_import all_imports
- is_source_import (ImportDecl _ ImportByUserSource _ _ _ _) = True
- is_source_import other = False
-
- get_imports = importsFromImportDecl this_mod_name
- in
- mapAndUnzipRn get_imports ordinary `thenRn` \ (imp_gbl_envs1, imp_avails_s1) ->
- mapAndUnzipRn get_imports 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
-
- -- ALL DONE
- returnRn (gbl_env, local_gbl_env, all_avails)
+rnImports :: [LImportDecl RdrName] -> RnM [LImportDecl Name]
+rnImports imports
+ -- PROCESS IMPORT DECLS
+ -- Do the non {- SOURCE -} ones first, so that we get a helpful
+ -- warning for {- SOURCE -} ones that are unnecessary
+ = do 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 = rnImportDecl this_mod
+
+ stuff1 <- mapM get_imports ordinary
+ stuff2 <- mapM get_imports source
+ return (stuff1 ++ stuff2)
+ 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 implicit_prelude
+ | this_mod == pRELUDE
+ || explicit_prelude_import
+ || not implicit_prelude
+ = []
+ | otherwise = [preludeImportDecl]
+ explicit_prelude_import
+ = notNull [ () | L _ (ImportDecl mod _ _ _ _) <- imports,
+ unLoc mod == pRELUDE ]
+
+preludeImportDecl :: LImportDecl RdrName
+preludeImportDecl
+ = L loc $
+ ImportDecl (L loc pRELUDE)
+ False {- Not a boot interface -}
+ False {- Not qualified -}
+ Nothing {- No "as" -}
+ Nothing {- No import list -}
where
- this_mod_name = moduleName this_mod
-
- -- NB: opt_NoImplicitPrelude is slightly different to import Prelude ();
- -- because the former doesn't even look at Prelude.hi for instance declarations,
- -- whereas the latter does.
- mk_prel_imports no_prelude
- | this_mod_name == pRELUDE_Name ||
- explicit_prelude_import ||
- no_prelude
- = []
-
- | 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 ])
+ loc = mkGeneralSrcSpan FSLIT("Implicit import declaration")
+
+mkRdrEnvAndImports :: [LImportDecl Name] -> RnM (GlobalRdrEnv, ImportAvails)
+mkRdrEnvAndImports imports
+ = do this_mod <- getModule
+ let get_imports = importsFromImportDecl this_mod
+ stuff <- mapM get_imports imports
+ let (imp_gbl_envs, imp_avails) = unzip stuff
+ 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)
+
\end{code}
\begin{code}
-importsFromImportDecl :: ModuleName
- -> RdrNameImportDecl
- -> RnMG (GlobalRdrEnv,
- ExportAvails)
+rnImportDecl :: Module
+ -> LImportDecl RdrName
+ -> RnM (LImportDecl Name)
+rnImportDecl this_mod (L loc importDecl@(ImportDecl loc_imp_mod_name want_boot qual_only as_mod imp_details))
+ = setSrcSpan loc $
+ do iface <- loadSrcInterface doc imp_mod_name want_boot
+ let 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 }
+ total_avails <- ifaceExportNames (mi_exports iface)
+ importDecl' <- rnImportDecl' iface imp_spec importDecl total_avails
+ return (L loc importDecl')
+ where imp_mod_name = unLoc loc_imp_mod_name
+ doc = ppr imp_mod_name <+> ptext SLIT("is directly imported")
+
+rnImportDecl' :: ModIface -> ImpDeclSpec -> ImportDecl RdrName -> NameSet -> RnM (ImportDecl Name)
+rnImportDecl' iface decl_spec (ImportDecl mod_name want_boot qual_only as_mod Nothing) all_names
+ = return $ ImportDecl mod_name want_boot qual_only as_mod Nothing
+rnImportDecl' iface decl_spec (ImportDecl mod_name want_boot qual_only as_mod (Just (want_hiding,import_items))) all_names
+ = do import_items_mbs <- mapM (srcSpanWrapper) import_items
+ let rn_import_items = concat . catMaybes $ import_items_mbs
+ return $ ImportDecl mod_name want_boot qual_only as_mod (Just (want_hiding,rn_import_items))
+ where
+ srcSpanWrapper (L span ieRdr)
+ = setSrcSpan span $
+ case get_item ieRdr of
+ Nothing
+ -> do addErr (badImportItemErr iface decl_spec ieRdr)
+ return Nothing
+ Just ieNames
+ -> return (Just [L span ie | ie <- ieNames])
+ 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.
-importsFromImportDecl this_mod_name (ImportDecl imp_mod_name from qual_only as_mod import_spec iloc)
- = pushSrcLocRn iloc $
+ sub_env :: NameEnv [Name]
+ sub_env = mkSubNameEnv all_names
+
+ get_item :: IE RdrName -> Maybe [IE Name]
+ -- 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 _)
+ = Nothing
+ get_item (IEThingAll tc)
+ = do name <- check_name tc
+ return [IEThingAll name]
+ get_item (IEThingAbs tc)
+ | want_hiding -- hiding ( C )
+ -- Here the 'C' can be a data constructor
+ -- *or* a type/class, or even both
+ = case catMaybes [check_name tc, check_name (setRdrNameSpace tc srcDataName)] of
+ [] -> Nothing
+ names -> return [ IEThingAbs n | n <- names ]
+ | otherwise
+ = do name <- check_name tc
+ return [IEThingAbs name]
+ get_item (IEThingWith n ns) -- import (C (A,B))
+ = do name <- check_name n
+ let env = mkOccEnv [(nameOccName s, s) | s <- subNames sub_env name]
+ mb_names = map (lookupOccEnv env . rdrNameOcc) ns
+ names <- sequence mb_names
+ return [IEThingWith name names]
+ get_item (IEVar n)
+ = do name <- check_name n
+ return [IEVar name]
+
+ check_name :: RdrName -> Maybe Name
+ check_name rdrName
+ = lookupOccEnv occ_env (rdrNameOcc rdrName)
+
+
+importsFromImportDecl :: Module
+ -> LImportDecl Name
+ -> RnM (GlobalRdrEnv, ImportAvails)
+
+importsFromImportDecl this_mod
+ (L loc (ImportDecl loc_imp_mod_name want_boot qual_only as_mod imp_details))
+ =
+ setSrcSpan loc $
- loadInterface (ppr imp_mod_name <+> ptext SLIT("is directly imported"))
- imp_mod_name from `thenRn` \ iface ->
+ -- If there's an error in loadInterface, (e.g. interface
+ -- file not found) we get lots of spurious errors from 'filterImports'
let
- imp_mod = mi_module iface
- avails_by_module = mi_exports iface
- deprecs = mi_deprecs iface
-
- avails :: Avails
- avails = [ avail | (mod_name, avails) <- avails_by_module,
- mod_name /= this_mod_name,
- avail <- avails ]
+ imp_mod_name = unLoc loc_imp_mod_name
+ doc = ppr imp_mod_name <+> ptext SLIT("is directly imported")
+ in
+ loadSrcInterface doc imp_mod_name want_boot `thenM` \ iface ->
+
+ -- Compiler sanity check: if the import didn't say
+ -- {-# SOURCE #-} we should not get a hi-boot file
+ WARN( not want_boot && mi_boot iface, ppr imp_mod_name )
+
+ -- Issue a user warning for a redundant {- SOURCE -} import
+ -- NB that we arrange to read all the ordinary imports before
+ -- any of the {- SOURCE -} imports
+ warnIf (want_boot && not (mi_boot iface))
+ (warnRedundantSourceImport imp_mod_name) `thenM_`
+
+ let
+ imp_mod = mi_module iface
+ deprecs = mi_deprecs iface
+ is_orph = mi_orphan iface
+ deps = mi_deps iface
+
+ filtered_exports = filter not_this_mod (mi_exports iface)
+ not_this_mod (mod,_) = mod /= this_mod
-- 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
--
-- 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
- if null avails_by_module then
- -- If there's an error in loadInterface, (e.g. interface
- -- file not found) we get lots of spurious errors from 'filterImports'
- returnRn (emptyRdrEnv, mkEmptyExportAvails imp_mod_name)
- else
-
- -- Complain if we import a deprecated module
- ifOptRn Opt_WarnDeprecations (
- case deprecs of
- DeprecAll txt -> addWarnRn (moduleDeprec imp_mod_name txt)
- other -> returnRn ()
- ) `thenRn_`
-
- -- Filter the imports according to the import list
- filterImports imp_mod_name from import_spec avails `thenRn` \ (filtered_avails, hides, 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 True hides mk_prov filtered_avails deprecs
- exports = mkExportAvails qual_mod unqual_imp gbl_env filtered_avails
- in
- returnRn (gbl_env, exports)
-\end{code}
+ -- 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) ->
+ getDOpts `thenM` \ dflags ->
-\begin{code}
-importsFromLocalDecls this_mod decls
- = mapRn (getLocalDeclBinders this_mod) decls `thenRn` \ avails_s ->
- -- The avails that are returned don't include the "system" names
let
- avails = concat avails_s
+ -- 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 }
- 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.
- mapRn_ (addErrRn . dupDeclErr) dups `thenRn_`
-
-
- -- Record that locally-defined things are available
- recordLocalSlurps (availsToNameSet avails) `thenRn_`
- let
- mod_name = moduleName this_mod
- unqual_imp = True -- Want unqualified names
- mk_prov n = LocalDef -- Provenance is local
- hides = [] -- Hide nothing
+ -- Complain if we import a deprecated module
+ ifOptM Opt_WarnDeprecations (
+ case deprecs of
+ DeprecAll txt -> addWarn (moduleDeprec imp_mod_name txt)
+ other -> returnM ()
+ ) `thenM_`
- gbl_env = mkGlobalRdrEnv mod_name unqual_imp True hides 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
+ returnM (gbl_env, imports)
- exports = mkExportAvails mod_name unqual_imp gbl_env avails
- in
- returnRn (gbl_env, exports)
-
----------------------------
-getLocalDeclBinders :: Module -> RdrNameHsDecl -> RnMG [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.
- getTyClDeclBinders mod tycl_decl `thenRn` \ (avail, sys_names) ->
-
- -- Record that the system names are available
- recordLocalSlurps (mkNameSet sys_names) `thenRn_`
- returnRn [avail]
-
-getLocalDeclBinders mod (ValD binds)
- = mapRn new (collectLocatedHsBinders binds) `thenRn` \ avails ->
- returnRn avails
- where
- new (rdr_name, loc) = newTopBinder mod rdr_name loc `thenRn` \ name ->
- returnRn (Avail name)
-
-getLocalDeclBinders mod (ForD (ForeignImport nm _ _ loc))
- = newTopBinder mod nm loc `thenRn` \ name ->
- returnRn [Avail name]
-getLocalDeclBinders mod (ForD _)
- = returnRn []
-
-getLocalDeclBinders mod (FixD _) = returnRn []
-getLocalDeclBinders mod (DeprecD _) = returnRn []
-getLocalDeclBinders mod (DefD _) = returnRn []
-getLocalDeclBinders mod (InstD _) = returnRn []
-getLocalDeclBinders mod (RuleD _) = returnRn []
+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 :: ModuleName -- The module being imported
- -> WhereFrom -- Tells whether it's a {-# SOURCE #-} import
- -> 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)
- -- (We need to return both the above sets, because
- -- the qualified version is never hidden; so we can't
- -- implement hiding by reducing what's imported.)
- NameSet) -- What was imported explicitly
-
- -- Complains if import spec mentions things that the module doesn't export
- -- Warns/informs if import spec contains duplicates.
-filterImports mod from Nothing imports
- = returnRn (imports, [], emptyNameSet)
-
-filterImports mod from (Just (want_hiding, import_items)) total_avails
- = flatMapRn get_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 (total_avails, item_avails, emptyNameSet)
- else
- -- Just item_avails imported; nothing to be hidden
- returnRn (item_avails, [], explicits)
+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 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 = addErrRn (badImportItemErr mod from item) `thenRn_`
- returnRn []
-
- 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
- ifOptRn Opt_WarnMisc (addWarnRn (dodgyImportWarn mod item)) `thenRn_`
- returnRn [(avail, [availName avail])]
- Just avail -> returnRn [(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 (IEThingAbs data_n)] of
- [] -> bale_out item
- avails -> returnRn [(a, []) | a <- avails]
- -- The 'explicits' list is irrelevant when hiding
- where
- data_n = setRdrNameOcc n (setOccNameSpace (rdrNameOcc n) dataName)
-
- get_item item
- = case check_item item of
- Nothing -> bale_out item
- Just avail -> returnRn [(avail, availNames 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
+ new_gre = GRE {gre_name = name, gre_prov = LocalDef}
+\end{code}
- check_item item
- | not (maybeToBool maybe_in_import_avails) ||
- not (maybeToBool maybe_filtered_avail)
- = Nothing
+@getLocalDeclBinders@ returns the names for an @HsDecl@. It's
+used for source code.
- | otherwise
- = Just filtered_avail
-
- where
- wanted_occ = rdrNameOcc (ieName item)
- maybe_in_import_avails = lookupFM import_fm wanted_occ
+ *** See "THE NAMING STORY" in HsDecls ****
- Just avail = maybe_in_import_avails
- maybe_filtered_avail = filterAvail item avail
- Just filtered_avail = maybe_filtered_avail
+\begin{code}
+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
+ 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
+ (main_rdr : sub_rdrs) = tyClDeclNames (unLoc tc_decl)
\end{code}
-
%************************************************************************
%* *
-\subsection{Qualifiying imports}
+\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}
-mkEmptyExportAvails :: ModuleName -> ExportAvails
-mkEmptyExportAvails mod_name = (unitFM mod_name [], emptyNameEnv)
+filterImports :: ModIface
+ -> ImpDeclSpec -- The span for the entire import decl
+ -> Maybe (Bool, [LIE Name]) -- Import spec; True => hiding
+ -> NameSet -- What's available
+ -> RnM (NameSet, -- What's imported (qualified or unqualified)
+ GlobalRdrEnv) -- Same again, but in GRE form
-mkExportAvails :: ModuleName -> Bool -> GlobalRdrEnv -> [AvailInfo] -> ExportAvails
-mkExportAvails mod_name unqual_imp gbl_env avails
- = (mod_avail_env, entity_avail_env)
+ -- 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
- mod_avail_env = unitFM mod_name unqual_avails
-
- -- unqual_avails is the Avails that are visible in *unqualfied* form
- -- (1.4 Report, Section 5.1.1)
- -- For example, in
- -- import T hiding( f )
- -- we delete f from avails
-
- unqual_avails | not unqual_imp = [] -- Short cut when no unqualified imports
- | otherwise = mapMaybe prune avails
-
- prune (Avail n) | unqual_in_scope n = Just (Avail n)
- prune (Avail n) | otherwise = Nothing
- prune (AvailTC n ns) | null uqs = Nothing
- | otherwise = Just (AvailTC n uqs)
- where
- uqs = filter unqual_in_scope ns
-
- unqual_in_scope n = unQualInScope gbl_env n
+ imp_spec = ImpSpec { is_decl = decl_spec, is_item = ImpAll }
+
+filterImports iface decl_spec Nothing all_names
+ = return (all_names, mkGenericRdrEnv decl_spec all_names)
+
+filterImports iface decl_spec (Just (want_hiding, import_items)) all_names
+ = mapM (addLocM get_item) import_items >>= \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
+ sub_env :: NameEnv [Name] -- Classify each name by its parent
+ sub_env = mkSubNameEnv all_names
- entity_avail_env = mkNameEnv [ (name,avail) | avail <- avails,
- name <- availNames avail]
+ 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 Name -> 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 _)
+ -- This case should be filtered out by 'rnImports'.
+ = panic "filterImports: IEModuleContents?"
+
+ get_item (IEThingAll name)
+ = case subNames sub_env name of
+ [] -> -- This occurs when you import T(..), but
+ -- only export T abstractly.
+ do ifOptM Opt_WarnDodgyImports (addWarn (dodgyImportWarn name))
+ succeed_with False [name]
+ names -> succeed_with False (name:names)
+
+ get_item (IEThingAbs name)
+ = succeed_with True [name]
+
+ get_item (IEThingWith name names)
+ = succeed_with True (name:names)
+ get_item (IEVar name)
+ = succeed_with True [name]
-plusExportAvails :: ExportAvails -> ExportAvails -> ExportAvails
-plusExportAvails (m1, e1) (m2, e2)
- = (plusFM_C (++) m1 m2, plusAvailEnv e1 e2)
- -- ToDo: wasteful: we do this once for each constructor!
\end{code}
Processing the export list.
-You might think that we should record things that appear in the export list
-as ``occurrences'' (using @addOccurrenceName@), but you'd be wrong.
-We do check (here) that they are in scope,
-but there is no need to slurp in their actual declaration
-(which is what @addOccurrenceName@ forces).
+You might think that we should record things that appear in the export
+list as ``occurrences'' (using @addOccurrenceName@), but you'd be
+wrong. We do check (here) that they are in scope, but there is no
+need to slurp in their actual declaration (which is what
+@addOccurrenceName@ forces).
-Indeed, doing so would big trouble when
-compiling @PrelBase@, because it re-exports @GHC@, which includes @takeMVar#@,
-whose type includes @ConcBase.StateAndSynchVar#@, and so on...
+Indeed, doing so would big trouble when compiling @PrelBase@, because
+it re-exports @GHC@, which includes @takeMVar#@, whose type includes
+@ConcBase.StateAndSynchVar#@, and so on...
\begin{code}
type ExportAccum -- The type of the accumulating parameter of
- -- the main worker function in exportsFromAvail
- = ([ModuleName], -- 'module M's seen so far
+ -- the main worker function in rnExports
+ = ([Module], -- '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
+ NameSet) -- The accumulated exported stuff
+emptyExportAccum = ([], emptyOccEnv, emptyNameSet)
-type ExportOccMap = FiniteMap OccName (Name, RdrNameIE)
+type ExportOccMap = OccEnv (Name, IE Name)
-- 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
+rnExports :: Maybe [LIE RdrName]
+ -> RnM (Maybe [LIE Name])
+rnExports Nothing = return Nothing
+rnExports (Just exports)
+ = do TcGblEnv { tcg_imports = ImportAvails { imp_env = imp_env } } <- getGblEnv
+ let sub_env :: NameEnv [Name] -- Classify each name by its parent
+ sub_env = mkSubNameEnv (foldModuleEnv unionNameSets emptyNameSet imp_env)
+ inLoc fn (L span x)
+ = do x' <- fn x
+ return (L span x')
+ rnExport (IEVar rdrName)
+ = do name <- lookupGlobalOccRn rdrName
+ return (IEVar name)
+ rnExport (IEThingAbs rdrName)
+ = do name <- lookupGlobalOccRn rdrName
+ return (IEThingAbs name)
+ rnExport (IEThingAll rdrName)
+ = do name <- lookupGlobalOccRn rdrName
+ return (IEThingAll name)
+ rnExport (IEThingWith rdrName rdrNames)
+ = do name <- lookupGlobalOccRn rdrName
+ let env = mkOccEnv [(nameOccName s, s) | s <- subNames sub_env name]
+ mb_names = map (lookupOccEnv env . rdrNameOcc) rdrNames
+ if any isNothing mb_names
+ then -- The export error will be reporting in 'mkExportNameSet'
+ return (IEThingWith name [])
+ else return (IEThingWith name (catMaybes mb_names))
+ rnExport (IEModuleContents mod)
+ = return (IEModuleContents mod)
+ rn_exports <- mapM (inLoc rnExport) exports
+ return (Just rn_exports)
+
+mkExportNameSet :: Bool -- False => no 'module M(..) where' header at all
+ -> Maybe [LIE Name] -- Nothing => no explicit export list
+ -> RnM NameSet
-- Complains if two distinct exports have same OccName
-- Warns about identical exports.
-- Complains about exports items not in scope
-exportsFromAvail this_mod Nothing export_avails global_name_env
- = exportsFromAvail this_mod true_exports export_avails global_name_env
- where
- true_exports = Just $ if this_mod == mAIN_Name
- then [IEVar main_RDR_Unqual]
- -- export Main.main *only* unless otherwise specified,
- else [IEModuleContents this_mod]
- -- but for all other modules export everything.
-
-exportsFromAvail this_mod (Just export_items)
- (mod_avail_env, entity_avail_env)
- global_name_env
- = doptRn Opt_WarnDuplicateExports `thenRn` \ warn_dup_exports ->
- foldlRn (exports_from_item warn_dup_exports)
- ([], emptyFM, emptyAvailEnv) export_items
- `thenRn` \ (_, _, export_avail_map) ->
- let
- export_avails :: [AvailInfo]
- export_avails = nameEnvElts export_avail_map
- in
- returnRn export_avails
+mkExportNameSet 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
+ ghc_mode <- getGhcMode
+ real_exports <- case () of
+ () | explicit_mod
+ -> return exports
+ | ghc_mode == Interactive
+ -> return Nothing
+ | otherwise
+ -> do mainName <- lookupGlobalOccRn main_RDR_Unqual
+ return (Just [noLoc (IEVar mainName)])
+ -- 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 })
+ = do (_, _, exports) <- foldlM do_litem emptyExportAccum items
+ return exports
where
- exports_from_item :: Bool -> ExportAccum -> RdrNameIE -> RnMG ExportAccum
+ sub_env :: NameEnv [Name] -- Classify each name by its parent
+ sub_env = mkSubNameEnv (foldModuleEnv unionNameSets emptyNameSet imp_env)
- exports_from_item warn_dups acc@(mods, occs, avails) ie@(IEModuleContents mod)
+ do_litem :: ExportAccum -> LIE Name -> RnM ExportAccum
+ do_litem acc = addLocM (exports_from_item acc)
+
+ exports_from_item :: ExportAccum -> IE Name -> RnM ExportAccum
+ exports_from_item acc@(mods, occs, exports) ie@(IEModuleContents mod)
| mod `elem` mods -- Duplicate export of M
- = warnCheckRn warn_dups (dupModuleExport mod) `thenRn_`
- returnRn acc
+ = do { warn_dup_exports <- doptM Opt_WarnDuplicateExports ;
+ warnIf warn_dup_exports (dupModuleExport mod) ;
+ returnM acc }
| otherwise
- = case lookupFM mod_avail_env mod of
- Nothing -> failWithRn acc (modExportErr mod)
- Just mod_avails -> foldlRn (check_occs ie) occs mod_avails
- `thenRn` \ occs' ->
- let
- avails' = foldl addAvail avails mod_avails
- in
- returnRn (mod:mods, occs', avails')
-
- exports_from_item warn_dups acc@(mods, occs, avails) ie
- = lookupSrcName global_name_env (ieName ie) `thenRn` \ name ->
-
- -- See what's available in the current environment
- case lookupNameEnv entity_avail_env name of {
- Nothing -> -- Presumably this happens because lookupSrcName didn't find
- -- the name and returned an unboundName, which won't be in
- -- the entity_avail_env, of course
- WARN( not (isUnboundName name), ppr name )
- returnRn acc ;
-
- Just avail ->
-
- -- Filter out the bits we want
- case filterAvail ie avail of {
- Nothing -> -- Not enough availability
- failWithRn acc (exportItemErr ie) ;
-
- Just export_avail ->
-
- -- Phew! It's OK! Now to check the occurrence stuff!
- warnCheckRn (ok_item ie avail) (dodgyExportWarn ie) `thenRn_`
- check_occs ie occs export_avail `thenRn` \ occs' ->
- returnRn (mods, occs', addAvail avails export_avail)
- }}
-
-
-
-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 :: RdrNameIE -> ExportOccMap -> AvailInfo -> RnMG ExportOccMap
-check_occs ie occs avail
- = doptRn Opt_WarnDuplicateExports `thenRn` \ warn_dup_exports ->
- foldlRn (check warn_dup_exports) occs (availNames avail)
+ = case lookupModuleEnv imp_env mod of
+ Nothing -> do addErr (modExportErr mod)
+ return acc
+ Just names
+ -> do let new_exports = filterNameSet (inScopeUnqual rdr_env) names
+ -- 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.
+ occs' <- check_occs ie occs (nameSetToList new_exports)
+ return (mod:mods, occs', exports `unionNameSets` new_exports)
+
+ exports_from_item acc@(mods, occs, exports) ie
+ = if isUnboundName (ieName ie)
+ then return acc -- Avoid error cascade
+ else let new_exports = filterAvail ie sub_env in
+ do checkErr (not (null new_exports)) (exportItemErr ie)
+ checkForDodgyExport ie new_exports
+ occs' <- check_occs ie occs new_exports
+ return (mods, occs', addListToNameSet exports new_exports)
+
+-------------------------------
+filterAvail :: IE Name -- Wanted
+ -> NameEnv [Name] -- Maps type/class names to their sub-names
+ -> [Name]
+
+filterAvail (IEVar n) subs = [n]
+filterAvail (IEThingAbs n) subs = [n]
+filterAvail (IEThingAll n) subs = n : subNames subs n
+filterAvail (IEThingWith n ns) subs = n : ns
+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
- check warn_dup occs name
- = case lookupFM occs name_occ of
- Nothing -> returnRn (addToFM occs name_occ (name, ie))
- Just (name', ie')
- | name == name' -> -- Duplicate export
- warnCheckRn warn_dup
- (dupExportWarn name_occ ie ie')
- `thenRn_` returnRn occs
+ 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 Name -> [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 Name -> 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))
- | otherwise -> -- Same occ name but different names: an error
- failWithRn occs (exportClashErr name_occ ie ie')
+ Just (name', ie')
+ | name == name' -- Duplicate export
+ -> do { warn_dup_exports <- doptM Opt_WarnDuplicateExports ;
+ warnIf warn_dup_exports (dupExportWarn name_occ ie ie') ;
+ returnM occs }
+
+ | otherwise -- Same occ name but different names: an error
+ -> do { global_env <- getGlobalRdrEnv ;
+ addErr (exportClashErr global_env name name' ie ie') ;
+ returnM occs }
where
name_occ = nameOccName name
\end{code}
+%*********************************************************
+%* *
+ Deprecations
+%* *
+%*********************************************************
+
+\begin{code}
+reportDeprecations :: TcGblEnv -> RnM ()
+reportDeprecations tcg_env
+ = ifOptM Opt_WarnDeprecations $
+ do { (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}
+
+%*********************************************************
+%* *
+ Unused names
+%* *
+%*********************************************************
+
+\begin{code}
+reportUnusedNames :: Maybe [LIE 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
+ 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
+ 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) = do ies <- mapM to_ie (availEnvElts avail_env)
+ 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}
+
+
%************************************************************************
%* *
\subsection{Errors}
%************************************************************************
\begin{code}
-badImportItemErr mod from ie
- = sep [ptext SLIT("Module"), quotes (ppr mod), source_import,
+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 = case from of
- ImportByUserSource -> ptext SLIT("(hi-boot interface)")
- other -> empty
+ source_import | mi_boot iface = ptext SLIT("(hi-boot interface)")
+ | otherwise = empty
-dodgyImportWarn mod item = dodgyMsg (ptext SLIT("import")) item
-dodgyExportWarn item = dodgyMsg (ptext SLIT("export")) item
+dodgyImportWarn 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),
+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") ]
= 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))]
+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
- sorted_locs = sortLt occ'ed_before (map nameSrcLoc (n:ns))
- occ'ed_before a b = LT == compare a b
+ 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),
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