\begin{code}
module RnNames (
- getGlobalNames, exportsFromAvail
+ rnImports, importsFromLocalDecls, exportsFromAvail,
+ reportUnusedNames, mkModDeps
) where
#include "HsVersions.h"
+import {-# SOURCE #-} RnHiFiles ( loadInterface )
+
import CmdLineOpts ( DynFlag(..) )
-import HsSyn ( HsModule(..), HsDecl(..), IE(..), ieName, ImportDecl(..),
- ForeignDecl(..), ForKind(..), isDynamicExtName,
- collectLocatedHsBinders
- )
-import RdrHsSyn ( RdrNameIE, RdrNameImportDecl,
- RdrNameHsModule, RdrNameHsDecl
+import HsSyn ( IE(..), ieName, ImportDecl(..),
+ ForeignDecl(..), HsGroup(..),
+ collectLocatedHsBinders, tyClDeclNames
)
-import RnIfaces ( recordLocalSlurps )
-import RnHiFiles ( getTyClDeclBinders, loadInterface )
+import RdrHsSyn ( RdrNameIE, RdrNameImportDecl, main_RDR_Unqual )
import RnEnv
-import RnMonad
+import TcRnMonad
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_Name, isBuiltInSyntaxName )
+import Module ( Module, ModuleName, ModuleEnv, moduleName,
+ moduleNameUserString, isHomeModule,
+ emptyModuleEnv, unitModuleEnvByName, unitModuleEnv,
+ lookupModuleEnvByName, extendModuleEnvByName, moduleEnvElts )
+import Name ( Name, nameSrcLoc, nameOccName, nameModule, isExternalName )
import NameSet
import NameEnv
+import OccName ( OccName, srcDataName, isTcOcc )
import HscTypes ( Provenance(..), ImportReason(..), GlobalRdrEnv,
- GenAvailInfo(..), AvailInfo, Avails, AvailEnv,
- Deprecations(..), ModIface(..)
+ GenAvailInfo(..), AvailInfo, Avails, GhciMode(..),
+ IsBootInterface,
+ availName, availNames, availsToNameSet,
+ Deprecations(..), ModIface(..), Dependencies(..),
+ GlobalRdrElt(..), unQualInScope, isLocalGRE, pprNameProvenance
)
-import RdrName ( rdrNameOcc, setRdrNameOcc )
-import OccName ( setOccNameSpace, dataName )
-import NameSet ( elemNameSet, emptyNameSet )
+import RdrName ( RdrName, rdrNameOcc, setRdrNameSpace, lookupRdrEnv, rdrEnvToList,
+ emptyRdrEnv, foldRdrEnv, rdrEnvElts, mkRdrUnqual, isQual )
import Outputable
-import Maybes ( maybeToBool, catMaybes, mapMaybe )
+import Maybe ( isJust, isNothing, catMaybes )
+import Maybes ( orElse )
import ListSetOps ( removeDups )
-import Util ( sortLt )
-import List ( partition )
+import Util ( sortLt, notNull )
+import List ( partition, insert )
+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
+rnImports :: [RdrNameImportDecl]
+ -> TcRn m (GlobalRdrEnv, ImportAvails)
+
+rnImports imports
+ = -- PROCESS IMPORT DECLS
-- Do the non {- SOURCE -} ones first, so that we get a helpful
-- warning for {- SOURCE -} ones that are unnecessary
- doptRn Opt_NoImplicitPrelude `thenRn` \ opt_no_prelude ->
+ getModule `thenM` \ this_mod ->
+ getSrcLocM `thenM` \ loc ->
+ doptM Opt_NoImplicitPrelude `thenM` \ opt_no_prelude ->
let
- all_imports = mk_prel_imports opt_no_prelude ++ imports
+ all_imports = mk_prel_imports this_mod loc opt_no_prelude ++ imports
(source, ordinary) = partition is_source_import all_imports
- is_source_import (ImportDecl _ ImportByUserSource _ _ _ _) = True
- is_source_import other = False
+ is_source_import (ImportDecl _ is_boot _ _ _ _) = is_boot
- get_imports = importsFromImportDecl this_mod_name
+ get_imports = importsFromImportDecl this_mod
in
- mapAndUnzipRn get_imports ordinary `thenRn` \ (imp_gbl_envs1, imp_avails_s1) ->
- mapAndUnzipRn get_imports source `thenRn` \ (imp_gbl_envs2, imp_avails_s2) ->
+ mappM get_imports ordinary `thenM` \ stuff1 ->
+ mappM get_imports source `thenM` \ stuff2 ->
-- COMBINE RESULTS
- -- We put the local env second, so that a local provenance
- -- "wins", even if a module imports itself.
let
+ (imp_gbl_envs, imp_avails) = unzip (stuff1 ++ stuff2)
gbl_env :: GlobalRdrEnv
- imp_gbl_env = foldr plusGlobalRdrEnv emptyRdrEnv (imp_gbl_envs2 ++ imp_gbl_envs1)
- gbl_env = imp_gbl_env `plusGlobalRdrEnv` local_gbl_env
+ gbl_env = foldr plusGlobalRdrEnv emptyRdrEnv imp_gbl_envs
- all_avails :: ExportAvails
- all_avails = foldr plusExportAvails local_mod_avails (imp_avails_s2 ++ imp_avails_s1)
+ all_avails :: ImportAvails
+ all_avails = foldr plusImportAvails emptyImportAvails imp_avails
in
-
-- ALL DONE
- returnRn (gbl_env, local_gbl_env, all_avails)
+ returnM (gbl_env, all_avails)
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
+ -- because the former doesn't even look at Prelude.hi for instance
+ -- declarations, whereas the latter does.
+ mk_prel_imports this_mod loc no_prelude
+ | moduleName this_mod == pRELUDE_Name
+ || explicit_prelude_import
+ || no_prelude
= []
- | otherwise = [ImportDecl pRELUDE_Name
- ImportByUser
- False {- Not qualified -}
- Nothing {- No "as" -}
- Nothing {- No import list -}
- mod_loc]
-
+ | otherwise = [preludeImportDecl loc]
+
explicit_prelude_import
- = not (null [ () | (ImportDecl mod _ _ _ _ _) <- imports, mod == pRELUDE_Name ])
+ = notNull [ () | (ImportDecl mod _ _ _ _ _) <- imports,
+ mod == pRELUDE_Name ]
+
+preludeImportDecl loc
+ = ImportDecl pRELUDE_Name
+ False {- Not a boot interface -}
+ False {- Not qualified -}
+ Nothing {- No "as" -}
+ Nothing {- No import list -}
+ loc
\end{code}
\begin{code}
-importsFromImportDecl :: ModuleName
+importsFromImportDecl :: Module
-> RdrNameImportDecl
- -> RnMG (GlobalRdrEnv,
- ExportAvails)
+ -> TcRn m (GlobalRdrEnv, ImportAvails)
-importsFromImportDecl this_mod_name (ImportDecl imp_mod_name from qual_only as_mod import_spec iloc)
- = pushSrcLocRn iloc $
+importsFromImportDecl this_mod
+ (ImportDecl imp_mod_name is_boot qual_only as_mod imp_spec iloc)
+ = addSrcLoc iloc $
+ let
+ doc = ppr imp_mod_name <+> ptext SLIT("is directly imported")
+ in
+
+ -- If there's an error in loadInterface, (e.g. interface
+ -- file not found) we get lots of spurious errors from 'filterImports'
+ tryM (loadInterface doc imp_mod_name (ImportByUser is_boot)) `thenM` \ mb_iface ->
+
+ case mb_iface of {
+ Left exn -> returnM (emptyRdrEnv, emptyImportAvails ) ;
+ Right iface ->
- loadInterface (ppr imp_mod_name <+> ptext SLIT("is directly imported"))
- imp_mod_name from `thenRn` \ iface ->
let
- imp_mod = mi_module iface
+ imp_mod = mi_module iface
avails_by_module = mi_exports iface
- deprecs = mi_deprecs iface
+ deprecs = mi_deprecs iface
+ is_orph = mi_orphan iface
+ deps = mi_deps iface
avails :: Avails
avails = [ avail | (mod_name, avails) <- avails_by_module,
mod_name /= this_mod_name,
avail <- avails ]
+ this_mod_name = moduleName 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.
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) ->
+ filterImports imp_mod is_boot imp_spec avails `thenM` \ (filtered_avails, explicits) ->
let
- unqual_imp = not qual_only -- Maybe want unqualified names
- qual_mod = case as_mod of
- Nothing -> imp_mod_name
- Just another_name -> another_name
+ -- Compute new transitive dependencies
+ orphans | is_orph = insert imp_mod_name (dep_orphs deps)
+ | otherwise = dep_orphs deps
+
+ (dependent_mods, dependent_pkgs)
+ | isHomeModule imp_mod
+ = -- Imported module is from the home package
+ -- Take its dependent modules and
+ -- (a) remove this_mod (might be there as a hi-boot)
+ -- (b) add imp_mod itself
+ -- Take its dependent packages unchanged
+ ((imp_mod_name, is_boot) : filter not_self (dep_mods deps), dep_pkgs deps)
+
+ | otherwise
+ = -- Imported module is from another package
+ -- Dump the dependent modules
+ -- Add the package imp_mod comes from to the dependent packages
+ -- from imp_mod
+ ([], insert (mi_package iface) (dep_pkgs deps))
+
+ not_self (m, _) = m /= this_mod_name
+
+ import_all = case imp_spec of
+ (Just (False, _)) -> False -- Imports are spec'd explicitly
+ other -> True -- Everything is imported,
+ -- (or almost everything [hiding])
+
+ qual_mod_name = case as_mod of
+ Nothing -> imp_mod_name
+ Just another_name -> another_name
+
+ -- 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.
+ avail_env = mkAvailEnv filtered_avails
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
+ gbl_env = mkGlobalRdrEnv qual_mod_name (not qual_only)
+ mk_prov filtered_avails deprecs
+ imports = ImportAvails {
+ imp_qual = unitModuleEnvByName qual_mod_name avail_env,
+ imp_env = avail_env,
+ imp_mods = unitModuleEnv imp_mod (imp_mod, import_all),
+ imp_orphs = orphans,
+ imp_dep_mods = mkModDeps dependent_mods,
+ imp_dep_pkgs = dependent_pkgs }
+
in
- returnRn (gbl_env, exports)
+ -- 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)
+ }
+
+mkModDeps :: [(ModuleName, IsBootInterface)]
+ -> ModuleEnv (ModuleName, IsBootInterface)
+mkModDeps deps = foldl add emptyModuleEnv deps
+ where
+ add env elt@(m,_) = extendModuleEnvByName env m elt
\end{code}
+%************************************************************************
+%* *
+ importsFromLocalDecls
+%* *
+%************************************************************************
+
+From the top-level declarations of this module produce
+ * the lexical environment
+ * the ImportAvails
+created by its bindings.
+
+Complain about duplicate bindings
+
\begin{code}
-importsFromLocalDecls this_mod decls
- = mapRn (getLocalDeclBinders this_mod) decls `thenRn` \ avails_s ->
+importsFromLocalDecls :: HsGroup RdrName
+ -> TcRn m (GlobalRdrEnv, ImportAvails)
+importsFromLocalDecls group
+ = getModule `thenM` \ this_mod ->
+ getLocalDeclBinders this_mod group `thenM` \ avails ->
-- The avails that are returned don't include the "system" names
let
- avails = concat avails_s
-
all_names :: [Name] -- All the defns; no dups eliminated
all_names = [name | avail <- avails, name <- availNames avail]
-- 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_`
-
+ mappM_ (addErr . dupDeclErr) dups `thenM_`
- -- Record that locally-defined things are available
- recordLocalSlurps (availsToNameSet avails) `thenRn_`
+ doptM Opt_NoImplicitPrelude `thenM` \ implicit_prelude ->
let
mod_name = moduleName this_mod
- unqual_imp = True -- Want unqualified names
mk_prov n = LocalDef -- Provenance is local
- hides = [] -- Hide nothing
- gbl_env = mkGlobalRdrEnv mod_name unqual_imp True hides mk_prov avails NoDeprecs
+ unqual_imp = True -- Want unqualified names in scope
+ gbl_env = mkGlobalRdrEnv mod_name unqual_imp mk_prov avails NoDeprecs
-- NoDeprecs: don't complain about locally defined names
-- For a start, we may be exporting a deprecated thing
-- Also we may use a deprecated thing in the defn of another
-- the defn of a non-deprecated thing, when changing a module's
-- interface
- exports = mkExportAvails mod_name unqual_imp gbl_env avails
+
+ -- Optimisation: filter out names for built-in syntax
+ -- They just clutter up the environment (esp tuples), and the parser
+ -- will generate Exact RdrNames for them, so the cluttered
+ -- envt is no use. To avoid doing this filter all the time,
+ -- we use -fno-implicit-prelude as a clue that the filter is
+ -- worth while. Really, it's only useful for GHC.Base and GHC.Tuple.
+ --
+ -- It's worth doing because it makes the environment smaller for
+ -- every module that imports the Prelude
+ --
+ -- Note: don't filter the gbl_env (hence avails, not avails' in
+ -- defn of gbl_env above). Stupid reason: when parsing
+ -- data type decls, the constructors start as Exact tycon-names,
+ -- and then get turned into data con names by zapping the name space;
+ -- but that stops them being Exact, so they get looked up. Sigh.
+ -- It doesn't matter because it only affects the Data.Tuple really.
+ -- The important thing is to trim down the exports.
+
+ avails' | implicit_prelude = filter not_built_in_syntax avails
+ | otherwise = avails
+ not_built_in_syntax a = not (all isBuiltInSyntaxName (availNames a))
+ -- Only filter it if all the names of the avail are built-in
+ -- In particular, lists have (:) which is not built in syntax
+ -- so we don't filter it out.
+
+ avail_env = mkAvailEnv avails'
+ imports = emptyImportAvails {
+ imp_qual = unitModuleEnv this_mod avail_env,
+ imp_env = avail_env
+ }
in
- returnRn (gbl_env, exports)
+ returnM (gbl_env, imports)
+\end{code}
+
----------------------------
-getLocalDeclBinders :: Module -> RdrNameHsDecl -> RnMG [AvailInfo]
-getLocalDeclBinders mod (TyClD tycl_decl)
+%*********************************************************
+%* *
+\subsection{Getting binders out of a declaration}
+%* *
+%*********************************************************
+
+@getLocalDeclBinders@ returns the names for a @RdrNameHsDecl@. It's
+used for both source code (from @importsFromLocalDecls@) and interface
+files (@loadDecl@ calls @getTyClDeclBinders@).
+
+ *** See "THE NAMING STORY" in HsDecls ****
+
+\begin{code}
+getLocalDeclBinders :: Module -> HsGroup RdrName -> TcRn m [AvailInfo]
+getLocalDeclBinders mod (HsGroup {hs_valds = val_decls,
+ hs_tyclds = tycl_decls,
+ hs_fords = foreign_decls })
= -- For type and class decls, we generate Global names, with
-- no export indicator. They need to be global because they get
-- permanently bound into the TyCons and Classes. They don't need
-- an export indicator because they are all implicitly exported.
- getTyClDeclBinders mod tycl_decl `thenRn` \ (avail, sys_names) ->
- -- Record that the system names are available
- recordLocalSlurps (mkNameSet sys_names) `thenRn_`
- returnRn [avail]
+ mappM new_tc tycl_decls `thenM` \ tc_avails ->
+ mappM new_bndr (for_hs_bndrs ++ val_hs_bndrs) `thenM` \ simple_bndrs ->
-getLocalDeclBinders mod (ValD binds)
- = mapRn new (collectLocatedHsBinders binds) `thenRn` \ avails ->
- returnRn avails
+ returnM (tc_avails ++ map Avail simple_bndrs)
where
- new (rdr_name, loc) = newTopBinder mod rdr_name loc `thenRn` \ name ->
- returnRn (Avail name)
+ new_bndr (rdr_name,loc) = newTopBinder mod rdr_name loc
-getLocalDeclBinders mod (ForD (ForeignDecl nm kind _ ext_nm _ loc))
- | binds_haskell_name kind
- = newTopBinder mod nm loc `thenRn` \ name ->
- returnRn [Avail name]
+ val_hs_bndrs = collectLocatedHsBinders val_decls
+ for_hs_bndrs = [(nm,loc) | ForeignImport nm _ _ _ loc <- foreign_decls]
- | otherwise -- a foreign export
- = returnRn []
- where
- binds_haskell_name (FoImport _) = True
- binds_haskell_name FoLabel = True
- binds_haskell_name FoExport = isDynamicExtName ext_nm
-
-getLocalDeclBinders mod (FixD _) = returnRn []
-getLocalDeclBinders mod (DeprecD _) = returnRn []
-getLocalDeclBinders mod (DefD _) = returnRn []
-getLocalDeclBinders mod (InstD _) = returnRn []
-getLocalDeclBinders mod (RuleD _) = returnRn []
+ new_tc tc_decl = mappM new_bndr (tyClDeclNames tc_decl) `thenM` \ names@(main_name:_) ->
+ returnM (AvailTC main_name names)
\end{code}
available, and filters it through the import spec (if any).
\begin{code}
-filterImports :: ModuleName -- The module being imported
- -> WhereFrom -- Tells whether it's a {-# SOURCE #-} import
+filterImports :: Module -- The module being imported
+ -> IsBootInterface -- 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.)
+ -> TcRn m ([AvailInfo], -- What's imported
NameSet) -- What was imported explicitly
-- Complains if import spec mentions things that the module doesn't export
-- Warns/informs if import spec contains duplicates.
filterImports mod from Nothing imports
- = returnRn (imports, [], emptyNameSet)
+ = returnM (imports, emptyNameSet)
filterImports mod from (Just (want_hiding, import_items)) total_avails
- = flatMapRn get_item import_items `thenRn` \ avails_w_explicits ->
+ = mappM get_item import_items `thenM` \ avails_w_explicits_s ->
let
- (item_avails, explicits_s) = unzip avails_w_explicits
+ (item_avails, explicits_s) = unzip (concat avails_w_explicits_s)
explicits = foldl addListToNameSet emptyNameSet explicits_s
in
- if want_hiding
- then
- -- All imported; item_avails to be hidden
- returnRn (total_avails, item_avails, emptyNameSet)
+ if want_hiding then
+ let -- All imported; item_avails to be hidden
+ hidden = availsToNameSet item_avails
+ keep n = not (n `elemNameSet` hidden)
+ in
+ returnM (pruneAvails keep total_avails, emptyNameSet)
else
-- Just item_avails imported; nothing to be hidden
- returnRn (item_avails, [], explicits)
+ returnM (item_avails, explicits)
where
import_fm :: FiniteMap OccName AvailInfo
import_fm = listToFM [ (nameOccName name, avail)
-- 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 []
+ bale_out item = addErr (badImportItemErr mod from item) `thenM_`
+ returnM []
+ get_item :: RdrNameIE -> TcRn m [(AvailInfo, [Name])]
+ -- Empty list for a bad item.
+ -- Singleton is typical case.
+ -- Can have two when we are hiding, and mention C which might be
+ -- both a class and a data constructor.
+ -- The [Name] is the list of explicitly-mentioned names
get_item item@(IEModuleContents _) = bale_out item
get_item item@(IEThingAll _)
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])]
+ ifOptM Opt_WarnMisc (addWarn (dodgyImportWarn mod item)) `thenM_`
+ returnM [(avail, [availName avail])]
+ Just avail -> returnM [(avail, [availName avail])]
get_item item@(IEThingAbs n)
| want_hiding -- hiding( C )
-- Here the 'C' can be a data constructor *or* a type/class
- = case catMaybes [check_item item, check_item (IEThingAbs data_n)] of
+ = case catMaybes [check_item item, check_item (IEVar data_n)] of
[] -> bale_out item
- avails -> returnRn [(a, []) | a <- avails]
+ avails -> returnM [(a, []) | a <- avails]
-- The 'explicits' list is irrelevant when hiding
where
- data_n = setRdrNameOcc n (setOccNameSpace (rdrNameOcc n) dataName)
+ data_n = setRdrNameSpace n srcDataName
get_item item
= case check_item item of
Nothing -> bale_out item
- Just avail -> returnRn [(avail, availNames avail)]
+ Just avail -> returnM [(avail, availNames avail)]
check_item item
- | not (maybeToBool maybe_in_import_avails) ||
- not (maybeToBool maybe_filtered_avail)
+ | isNothing maybe_in_import_avails ||
+ isNothing maybe_filtered_avail
= Nothing
| otherwise
Just filtered_avail = maybe_filtered_avail
\end{code}
-
-
-%************************************************************************
-%* *
-\subsection{Qualifiying imports}
-%* *
-%************************************************************************
-
\begin{code}
-mkEmptyExportAvails :: ModuleName -> ExportAvails
-mkEmptyExportAvails mod_name = (unitFM mod_name [], emptyNameEnv)
-
-mkExportAvails :: ModuleName -> Bool -> GlobalRdrEnv -> [AvailInfo] -> ExportAvails
-mkExportAvails mod_name unqual_imp gbl_env avails
- = (mod_avail_env, entity_avail_env)
+filterAvail :: RdrNameIE -- Wanted
+ -> AvailInfo -- Available
+ -> Maybe AvailInfo -- Resulting available;
+ -- Nothing if (any of the) wanted stuff isn't there
+
+filterAvail ie@(IEThingWith want wants) avail@(AvailTC n ns)
+ | sub_names_ok = Just (AvailTC n (filter is_wanted ns))
+ | otherwise = Nothing
where
- 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
-
- entity_avail_env = mkNameEnv [ (name,avail) | avail <- avails,
- name <- availNames avail]
-
-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!
+ is_wanted name = nameOccName name `elem` wanted_occs
+ sub_names_ok = all (`elem` avail_occs) wanted_occs
+ avail_occs = map nameOccName ns
+ wanted_occs = map rdrNameOcc (want:wants)
+
+filterAvail (IEThingAbs _) (AvailTC n ns) = ASSERT( n `elem` ns )
+ Just (AvailTC n [n])
+
+filterAvail (IEThingAbs _) avail@(Avail n) = Just avail -- Type synonyms
+
+filterAvail (IEVar _) avail@(Avail n) = Just avail
+filterAvail (IEVar v) avail@(AvailTC n ns) = Just (AvailTC n (filter wanted ns))
+ where
+ wanted n = nameOccName n == occ
+ occ = rdrNameOcc v
+ -- The second equation happens if we import a class op, thus
+ -- import A( op )
+ -- where op is a class operation
+
+filterAvail (IEThingAll _) avail@(AvailTC _ _) = Just avail
+ -- We don't complain even if the IE says T(..), but
+ -- no constrs/class ops of T are available
+ -- Instead that's caught with a warning by the caller
+
+filterAvail ie avail = Nothing
\end{code}
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
ExportOccMap, -- Tracks exported occurrence names
AvailEnv) -- The accumulated exported stuff, kept in an env
-- so we can common-up related AvailInfos
+emptyExportAccum = ([], emptyFM, emptyAvailEnv)
type ExportOccMap = FiniteMap OccName (Name, RdrNameIE)
-- Tracks what a particular exported OccName
-- that have the same occurrence name
-exportsFromAvail :: ModuleName
- -> Maybe [RdrNameIE] -- Export spec
- -> ExportAvails
- -> GlobalRdrEnv
- -> RnMG Avails
+exportsFromAvail :: Maybe Module -- Nothing => no 'module M(..) where' header at all
+ -> Maybe [RdrNameIE] -- Nothing => no explicit export list
+ -> TcRn m Avails
-- Complains if two distinct exports have same OccName
-- Warns about identical exports.
-- Complains about exports items not in scope
-exportsFromAvail this_mod Nothing export_avails global_name_env
- = exportsFromAvail this_mod true_exports export_avails global_name_env
- where
- true_exports = Just $ if this_mod == mAIN_Name
- then [IEVar main_RDR_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
+
+exportsFromAvail maybe_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
+ = case maybe_mod of
+ Just mod -> exports
+ Nothing | ghci_mode == Interactive -> Nothing
+ | otherwise -> Just [IEVar main_RDR_Unqual] } ;
+
+ exports_from_avail exports rdr_env imports }
+
+exports_from_avail Nothing rdr_env
+ imports@(ImportAvails { imp_env = entity_avail_env })
+ = -- Export all locally-defined things
+ -- We do this by filtering the global RdrEnv,
+ -- keeping only things that are (a) qualified,
+ -- (b) locally defined, (c) a 'main' name
+ -- Then we look up in the entity-avail-env
+ return [ lookupAvailEnv entity_avail_env name
+ | (rdr_name, gres) <- rdrEnvToList rdr_env,
+ isQual rdr_name, -- Avoid duplicates
+ GRE { gre_name = name,
+ gre_parent = Nothing, -- Main things only
+ gre_prov = LocalDef } <- gres
+ ]
+
+exports_from_avail (Just export_items) rdr_env
+ (ImportAvails { imp_qual = mod_avail_env,
+ imp_env = entity_avail_env })
+ = foldlM exports_from_item emptyExportAccum
+ export_items `thenM` \ (_, _, export_avail_map) ->
+ returnM (nameEnvElts export_avail_map)
where
- exports_from_item :: Bool -> ExportAccum -> RdrNameIE -> RnMG ExportAccum
+ exports_from_item :: ExportAccum -> RdrNameIE -> TcRn m ExportAccum
- exports_from_item warn_dups acc@(mods, occs, avails) ie@(IEModuleContents mod)
+ exports_from_item acc@(mods, occs, avails) 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 ->
-
+ = case lookupModuleEnvByName mod_avail_env mod of
+ Nothing -> addErr (modExportErr mod) `thenM_`
+ returnM acc
+
+ Just avail_env
+ -> let
+ mod_avails = [ filtered_avail
+ | avail <- availEnvElts avail_env,
+ let mb_avail = filter_unqual rdr_env avail,
+ isJust mb_avail,
+ let Just filtered_avail = mb_avail]
+
+ avails' = foldl addAvail avails mod_avails
+ 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.
+
+ foldlM (check_occs ie) occs mod_avails `thenM` \ occs' ->
+ returnM (mod:mods, occs', avails')
+
+ exports_from_item acc@(mods, occs, avails) ie
+ = lookupGRE (ieName ie) `thenM` \ mb_gre ->
+ case mb_gre of {
+ Nothing -> addErr (unknownNameErr (ieName ie)) `thenM_`
+ returnM acc ;
+ Just gre ->
+
+ -- Get the AvailInfo for the parent of the specified name
+ let
+ parent = gre_parent gre `orElse` gre_name gre
+ avail = lookupAvailEnv entity_avail_env parent
+ in
-- Filter out the bits we want
case filterAvail ie avail of {
Nothing -> -- Not enough availability
- failWithRn acc (exportItemErr ie) ;
+ addErr (exportItemErr ie) `thenM_`
+ returnM acc ;
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)
+ warnIf (not (ok_item ie avail)) (dodgyExportWarn ie) `thenM_`
+ check_occs ie occs export_avail `thenM` \ occs' ->
+ returnM (mods, occs', addAvail avails export_avail)
}}
+-------------------------------
+filter_unqual :: GlobalRdrEnv -> AvailInfo -> Maybe AvailInfo
+-- Filter the Avail by what's in scope unqualified
+filter_unqual env (Avail n)
+ | in_scope env n = Just (Avail n)
+ | otherwise = Nothing
+filter_unqual env (AvailTC n ns)
+ | not (null ns') = Just (AvailTC n ns')
+ | otherwise = Nothing
+ where
+ ns' = filter (in_scope env) ns
+
+in_scope :: GlobalRdrEnv -> Name -> Bool
+-- Checks whether the Name is in scope unqualified,
+-- regardless of whether it's ambiguous or not
+in_scope env n
+ = case lookupRdrEnv env (mkRdrUnqual (nameOccName n)) of
+ Nothing -> False
+ Just gres -> or [n == gre_name g | g <- gres]
+
+-------------------------------
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 :: RdrNameIE -> ExportOccMap -> AvailInfo -> TcRn m ExportOccMap
check_occs ie occs avail
- = doptRn Opt_WarnDuplicateExports `thenRn` \ warn_dup_exports ->
- foldlRn (check warn_dup_exports) occs (availNames avail)
+ = foldlM check occs (availNames avail)
where
- check warn_dup occs name
+ check occs name
= case lookupFM occs name_occ of
- Nothing -> returnRn (addToFM occs name_occ (name, ie))
- Just (name', ie')
- | name == name' -> -- Duplicate export
- warnCheckRn warn_dup
- (dupExportWarn name_occ ie ie')
- `thenRn_` returnRn occs
+ Nothing -> returnM (addToFM 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}
+%*********************************************************
+%* *
+\subsection{Unused names}
+%* *
+%*********************************************************
+
+\begin{code}
+reportUnusedNames :: TcGblEnv -> DefUses -> TcRn m ()
+reportUnusedNames gbl_env dus
+ = warnUnusedModules unused_imp_mods `thenM_`
+ warnUnusedTopBinds bad_locals `thenM_`
+ warnUnusedImports bad_imports `thenM_`
+ printMinimalImports minimal_imports
+ where
+ used_names :: NameSet
+ used_names = findUses dus emptyNameSet
+
+ -- Collect the defined names from the in-scope environment
+ -- Look for the qualified ones only, else get duplicates
+ defined_names :: [GlobalRdrElt]
+ defined_names = foldRdrEnv add [] (tcg_rdr_env gbl_env)
+ add rdr_name ns acc | isQual rdr_name = ns ++ acc
+ | otherwise = acc
+
+ defined_and_used, defined_but_not_used :: [GlobalRdrElt]
+ (defined_and_used, defined_but_not_used) = partition is_used defined_names
+
+ is_used gre = n `elemNameSet` used_names || any (`elemNameSet` used_names) kids
+ -- The 'kids' part is because a use of C implies a use of T,
+ -- if C was brought into scope by T(..) or T(C)
+ where
+ n = gre_name gre
+ kids = case lookupAvailEnv_maybe avail_env n of
+ Just (AvailTC n ns) -> ns
+ other -> [] -- Ids, class ops and datacons
+ -- (The latter two give Nothing)
+
+ -- 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
+ bad_locals :: [GlobalRdrElt]
+ bad_locals = filter is_bad defined_but_not_used
+ is_bad :: GlobalRdrElt -> Bool
+ is_bad gre = isLocalGRE gre && isExternalName (gre_name gre)
+
+ bad_imports :: [GlobalRdrElt]
+ bad_imports = filter bad_imp defined_but_not_used
+ bad_imp (GRE {gre_prov = NonLocalDef (UserImport mod _ True)}) = not (module_unused mod)
+ bad_imp other = False
+
+ -- To figure out the minimal set of imports, start with the things
+ -- that are in scope (i.e. in gbl_env). Then just combine them
+ -- into a bunch of avails, so they are properly grouped
+ minimal_imports :: FiniteMap ModuleName AvailEnv
+ minimal_imports0 = emptyFM
+ minimal_imports1 = foldr add_name minimal_imports0 defined_and_used
+ minimal_imports = foldr add_inst_mod minimal_imports1 direct_import_mods
+ -- The last line makes sure that we retain all direct imports
+ -- even if we import nothing explicitly.
+ -- It's not necessarily redundant to import such modules. Consider
+ -- module This
+ -- import M ()
+ --
+ -- The import M() is not *necessarily* redundant, even if
+ -- we suck in no instance decls from M (e.g. it contains
+ -- no instance decls, or This contains no code). It may be
+ -- that we import M solely to ensure that M's orphan instance
+ -- decls (or those in its imports) are visible to people who
+ -- import This. Sigh.
+ -- There's really no good way to detect this, so the error message
+ -- in RnEnv.warnUnusedModules is weakened instead
+
+
+ -- We've carefully preserved the provenance so that we can
+ -- construct minimal imports that import the name by (one of)
+ -- the same route(s) as the programmer originally did.
+ add_name (GRE {gre_name = n, gre_parent = p,
+ gre_prov = NonLocalDef (UserImport m _ _)}) acc
+ = addToFM_C plusAvailEnv acc (moduleName m)
+ (unitAvailEnv (mk_avail n p))
+ add_name other acc
+ = acc
+
+ -- n is the name of the thing, p is the name of its parent
+ mk_avail n (Just p) = AvailTC p [p,n]
+ mk_avail n Nothing | isTcOcc (nameOccName n) = AvailTC n [n]
+ | otherwise = Avail n
+
+ add_inst_mod m acc
+ | m `elemFM` acc = acc -- We import something already
+ | otherwise = addToFM acc m emptyAvailEnv
+ -- Add an empty collection of imports for a module
+ -- from which we have sucked only instance decls
+
+ imports = tcg_imports gbl_env
+ avail_env = imp_env imports
+
+ direct_import_mods :: [ModuleName]
+ direct_import_mods = map (moduleName . fst)
+ (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 direcly-imported
+ -- modules even if we use nothing from them; see notes above]
+ unused_imp_mods = [m | m <- direct_import_mods,
+ isNothing (lookupFM minimal_imports1 m),
+ m /= pRELUDE_Name]
+
+ module_unused :: Module -> Bool
+ module_unused mod = moduleName mod `elem` unused_imp_mods
+
+
+-- ToDo: deal with original imports with 'qualified' and 'as M' clauses
+printMinimalImports :: FiniteMap ModuleName AvailEnv -- Minimal imports
+ -> TcRn m ()
+printMinimalImports imps
+ = ifOptM Opt_D_dump_minimal_imports $ do {
+
+ mod_ies <- mappM to_ies (fmToList imps) ;
+ this_mod <- getModule ;
+ rdr_env <- getGlobalRdrEnv ;
+ ioToTcRn (do { h <- openFile (mkFilename this_mod) WriteMode ;
+ printForUser h (unQualInScope rdr_env)
+ (vcat (map ppr_mod_ie mod_ies)) })
+ }
+ where
+ mkFilename this_mod = moduleNameUserString (moduleName this_mod) ++ ".imports"
+ ppr_mod_ie (mod_name, ies)
+ | mod_name == pRELUDE_Name
+ = empty
+ | null ies -- Nothing except instances comes from here
+ = ptext SLIT("import") <+> ppr mod_name <> ptext SLIT("() -- Instances only")
+ | otherwise
+ = ptext SLIT("import") <+> ppr mod_name <>
+ parens (fsep (punctuate comma (map ppr ies)))
+
+ to_ies (mod, avail_env) = mappM to_ie (availEnvElts avail_env) `thenM` \ ies ->
+ returnM (mod, ies)
+
+ to_ie :: AvailInfo -> TcRn m (IE Name)
+ -- The main trick here is that if we're importing all the constructors
+ -- we want to say "T(..)", but if we're importing only a subset we want
+ -- to say "T(A,B,C)". So we have to find out what the module exports.
+ to_ie (Avail n) = returnM (IEVar n)
+ to_ie (AvailTC n [m]) = ASSERT( n==m )
+ returnM (IEThingAbs n)
+ to_ie (AvailTC n ns)
+ = loadInterface (text "Compute minimal imports from" <+> ppr n_mod)
+ n_mod ImportBySystem `thenM` \ iface ->
+ case [xs | (m,as) <- mi_exports iface,
+ m == n_mod,
+ AvailTC x xs <- as,
+ x == n] of
+ [xs] | all (`elem` ns) xs -> returnM (IEThingAll n)
+ | otherwise -> returnM (IEThingWith n (filter (/= n) ns))
+ other -> pprTrace "to_ie" (ppr n <+> ppr (nameModule n) <+> ppr other) $
+ returnM (IEVar n)
+ where
+ n_mod = moduleName (nameModule n)
+\end{code}
+
+
%************************************************************************
%* *
\subsection{Errors}
ptext SLIT("does not export"), quotes (ppr ie)]
where
source_import = case from of
- ImportByUserSource -> ptext SLIT("(hi-boot interface)")
- other -> empty
+ True -> ptext SLIT("(hi-boot interface)")
+ other -> empty
dodgyImportWarn mod item = dodgyMsg (ptext SLIT("import")) item
dodgyExportWarn item = dodgyMsg (ptext SLIT("export")) item
= sep [ ptext SLIT("The export item") <+> quotes (ppr export_item),
ptext SLIT("attempts to export constructors or class methods that are not visible here") ]
-exportClashErr occ_name ie1 ie2
- = hsep [ptext SLIT("The export items"), quotes (ppr ie1)
- ,ptext SLIT("and"), quotes (ppr ie2)
- ,ptext SLIT("create conflicting exports for"), quotes (ppr occ_name)]
+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, in a very inefficient way
+ -- There isn't a more efficient way to do it, because we don't necessarily
+ -- know the RdrName under which this Name is in scope. So we just
+ -- search linearly. Shouldn't matter because this only happens
+ -- in an error message.
+ get_gre name
+ = case [gre | gres <- rdrEnvElts global_env,
+ gre <- gres,
+ gre_name gre == name] of
+ (gre:_) -> gre
+ [] -> pprPanic "exportClashErr" (ppr name)
dupDeclErr (n:ns)
= vcat [ptext SLIT("Multiple declarations of") <+> quotes (ppr n),
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