\begin{code}
module RnNames (
- getGlobalNames
+ rnImports, importsFromLocalDecls, exportsFromAvail,
+ reportUnusedNames, mkModDeps
) where
#include "HsVersions.h"
-import CmdLineOpts ( opt_NoImplicitPrelude, opt_WarnDuplicateExports,
- opt_SourceUnchanged
- )
-
-import HsSyn ( HsModule(..), ImportDecl(..), HsDecl(..),
- IE(..), ieName,
- ForeignDecl(..), ExtName(..), ForKind(..),
- FixityDecl(..),
- collectTopBinders
- )
-import RdrHsSyn ( RdrName(..), RdrNameIE, RdrNameImportDecl,
- RdrNameHsModule, RdrNameFixityDecl,
- rdrNameOcc, ieOcc
- )
-import RnIfaces ( getInterfaceExports, getDeclBinders, recordSlurp, checkUpToDate )
-import BasicTypes ( IfaceFlavour(..) )
+import {-# SOURCE #-} RnHiFiles ( loadInterface )
+
+import CmdLineOpts ( DynFlag(..) )
+
+import HsSyn ( IE(..), ieName, ImportDecl(..),
+ ForeignDecl(..), HsGroup(..),
+ collectLocatedHsBinders, tyClDeclNames
+ )
+import RdrHsSyn ( RdrNameIE, RdrNameImportDecl, main_RDR_Unqual )
import RnEnv
-import RnMonad
+import TcRnMonad
import FiniteMap
-import PrelMods
-import UniqFM ( lookupUFM )
-import Bag ( bagToList )
-import Maybes ( maybeToBool )
-import Name
-import NameSet ( elemNameSet )
+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, GhciMode(..),
+ IsBootInterface,
+ availName, availNames, availsToNameSet,
+ Deprecations(..), ModIface(..), Dependencies(..),
+ GlobalRdrElt(..), unQualInScope, isLocalGRE, pprNameProvenance
+ )
+import RdrName ( RdrName, rdrNameOcc, setRdrNameSpace, lookupRdrEnv, rdrEnvToList,
+ emptyRdrEnv, foldRdrEnv, rdrEnvElts, mkRdrUnqual, isQual )
import Outputable
-import Util ( removeDups )
+import Maybe ( isJust, isNothing, catMaybes )
+import Maybes ( orElse )
+import ListSetOps ( removeDups )
+import Util ( sortLt, notNull )
+import List ( partition, insert )
+import IO ( openFile, IOMode(..) )
\end{code}
%************************************************************************
%* *
-\subsection{Get global names}
+ rnImports
%* *
%************************************************************************
\begin{code}
-getGlobalNames :: RdrNameHsModule
- -> RnMG (Maybe (ExportEnv,
- RnEnv,
- FiniteMap Name HowInScope, -- Locally defined or explicitly imported
- Name -> PrintUnqualified))
- -- Nothing => no need to recompile
-
-getGlobalNames m@(HsModule this_mod _ exports imports _ _ mod_loc)
- = fixRn (\ ~(rec_exp_fn, _) ->
-
- -- PROCESS LOCAL DECLS
- -- Do these *first* so that the correct provenance gets
- -- into the global name cache.
- importsFromLocalDecls rec_exp_fn m `thenRn` \ (local_rn_env, local_mod_avails, local_info) ->
-
- -- PROCESS IMPORT DECLS
- mapAndUnzip3Rn importsFromImportDecl all_imports
- `thenRn` \ (imp_rn_envs, imp_avails_s, explicit_imports_s) ->
-
- -- COMBINE RESULTS
- -- We put the local env second, so that a local provenance
- -- "wins", even if a module imports itself.
- foldlRn plusRnEnv emptyRnEnv imp_rn_envs `thenRn` \ imp_rn_env ->
- plusRnEnv imp_rn_env local_rn_env `thenRn` \ rn_env ->
-
- -- TRY FOR EARLY EXIT
- -- We can't go for an early exit before this because we have to check
- -- for name clashes. Consider:
- --
- -- module A where module B where
- -- import B h = True
- -- f = h
- --
- -- Suppose I've compiled everything up, and then I add a
- -- new definition to module B, that defines "f".
- --
- -- Then I must detect the name clash in A before going for an early
- -- exit. The early-exit code checks what's actually needed from B
- -- to compile A, and of course that doesn't include B.f. That's
- -- why we wait till after the plusRnEnv stuff to do the early-exit.
- checkEarlyExit this_mod `thenRn` \ up_to_date ->
- if up_to_date then
- returnRn (error "early exit", Nothing)
- else
-
-
- -- PROCESS EXPORT LISTS
- let
- export_avails :: ExportAvails
- export_avails = foldr plusExportAvails local_mod_avails imp_avails_s
-
- explicit_info :: FiniteMap Name HowInScope -- Locally defined or explicitly imported
- explicit_info = foldr plusFM local_info explicit_imports_s
- in
- exportsFromAvail this_mod exports export_avails rn_env
- `thenRn` \ (export_fn, export_env) ->
-
- -- BUILD THE "IMPORT FN". It just tells whether a name is in
- -- scope in an unqualified form.
- let
- print_unqual = mkImportFn imp_rn_env
- in
-
- returnRn (export_fn, Just (export_env, rn_env, explicit_info, print_unqual))
- ) `thenRn` \ (_, result) ->
- returnRn result
- where
- junk_exp_fn = error "RnNames:export_fn"
+rnImports :: [RdrNameImportDecl]
+ -> TcRn m (GlobalRdrEnv, ImportAvails)
+
+rnImports imports
+ = -- PROCESS IMPORT DECLS
+ -- Do the non {- SOURCE -} ones first, so that we get a helpful
+ -- warning for {- SOURCE -} ones that are unnecessary
+ getModule `thenM` \ this_mod ->
+ getSrcLocM `thenM` \ loc ->
+ doptM Opt_NoImplicitPrelude `thenM` \ opt_no_prelude ->
+ let
+ all_imports = mk_prel_imports this_mod loc opt_no_prelude ++ imports
+ (source, ordinary) = partition is_source_import all_imports
+ is_source_import (ImportDecl _ is_boot _ _ _ _) = is_boot
- all_imports = prel_imports ++ imports
+ get_imports = importsFromImportDecl this_mod
+ in
+ mappM get_imports ordinary `thenM` \ stuff1 ->
+ mappM get_imports source `thenM` \ stuff2 ->
+ -- COMBINE RESULTS
+ let
+ (imp_gbl_envs, imp_avails) = unzip (stuff1 ++ stuff2)
+ gbl_env :: GlobalRdrEnv
+ gbl_env = foldr plusGlobalRdrEnv emptyRdrEnv imp_gbl_envs
+
+ all_avails :: ImportAvails
+ all_avails = foldr plusImportAvails emptyImportAvails imp_avails
+ in
+ -- ALL DONE
+ returnM (gbl_env, all_avails)
+ where
-- NB: opt_NoImplicitPrelude is slightly different to import Prelude ();
- -- because the former doesn't even look at Prelude.hi for instance declarations,
- -- whereas the latter does.
- prel_imports | this_mod == pRELUDE ||
- explicit_prelude_import ||
- opt_NoImplicitPrelude
- = []
-
- | otherwise = [ImportDecl pRELUDE
- False {- Not qualified -}
- HiFile {- Not source imported -}
- Nothing {- No "as" -}
- Nothing {- No import list -}
- mod_loc]
-
- explicit_prelude_import
- = not (null [ () | (ImportDecl mod qual _ _ _ _) <- imports, mod == pRELUDE ])
-\end{code}
-
-\begin{code}
-checkEarlyExit mod
- = checkErrsRn `thenRn` \ no_errs_so_far ->
- if not no_errs_so_far then
- -- Found errors already, so exit now
- returnRn True
- else
+ -- 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
+ = []
- traceRn (text "Considering whether compilation is required...") `thenRn_`
- if not opt_SourceUnchanged then
- -- Source code changed and no errors yet... carry on
- traceRn (nest 4 (text "source file changed or recompilation check turned off")) `thenRn_`
- returnRn False
- else
+ | otherwise = [preludeImportDecl loc]
- -- Unchanged source, and no errors yet; see if usage info
- -- up to date, and exit if so
- checkUpToDate mod `thenRn` \ up_to_date ->
- putDocRn (text "Compilation" <+>
- text (if up_to_date then "IS NOT" else "IS") <+>
- text "required") `thenRn_`
- returnRn up_to_date
+ explicit_prelude_import
+ = notNull [ () | (ImportDecl mod _ _ _ _ _) <- imports,
+ mod == pRELUDE_Name ]
+
+preludeImportDecl loc
+ = ImportDecl pRELUDE_Name
+ False {- Not a boot interface -}
+ False {- Not qualified -}
+ Nothing {- No "as" -}
+ Nothing {- No import list -}
+ loc
\end{code}
\begin{code}
-importsFromImportDecl :: RdrNameImportDecl
- -> RnMG (RnEnv,
- ExportAvails,
- FiniteMap Name HowInScope) -- Records the explicitly-imported things
-
-importsFromImportDecl (ImportDecl mod qual_only as_source as_mod import_spec loc)
- = pushSrcLocRn loc $
- getInterfaceExports mod as_source `thenRn` \ (avails, fixities) ->
- filterImports mod import_spec avails `thenRn` \ (filtered_avails, hides, explicits) ->
+importsFromImportDecl :: Module
+ -> RdrNameImportDecl
+ -> TcRn m (GlobalRdrEnv, ImportAvails)
+
+importsFromImportDecl this_mod
+ (ImportDecl imp_mod_name is_boot qual_only as_mod imp_spec iloc)
+ = addSrcLoc iloc $
let
- how_in_scope = FromImportDecl mod loc
- explicit_info = listToFM [(name, how_in_scope)
- | avail <- explicits,
- name <- availNames avail
- ]
+ doc = ppr imp_mod_name <+> ptext SLIT("is directly imported")
in
- qualifyImports mod
- True -- Want qualified names
- (not qual_only) -- Maybe want unqualified names
- as_mod
- hides
- filtered_avails (\n -> how_in_scope)
- [ (occ,(fixity,how_in_scope)) | (occ,fixity) <- fixities ]
- `thenRn` \ (rn_env, mod_avails) ->
- returnRn (rn_env, mod_avails, explicit_info)
-\end{code}
+ -- 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 ->
-\begin{code}
-importsFromLocalDecls rec_exp_fn (HsModule mod _ _ _ fix_decls decls _)
- = foldlRn getLocalDeclBinders [] decls `thenRn` \ avails ->
+ case mb_iface of {
+ Left exn -> returnM (emptyRdrEnv, emptyImportAvails ) ;
+ Right iface ->
- -- Record that locally-defined things are available
- mapRn (recordSlurp Nothing Compulsory) avails `thenRn_`
+ let
+ imp_mod = mi_module iface
+ avails_by_module = mi_exports 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
+ -- filter them out up front. This situation only arises if a module
+ -- imports itself, or another module that imported it. (Necessarily,
+ -- this invoves a loop.)
+ --
+ -- Tiresome consequence: if you say
+ -- module A where
+ -- import B( AType )
+ -- type AType = ...
+ --
+ -- module B( AType ) where
+ -- import {-# SOURCE #-} A( AType )
+ --
+ -- then you'll get a 'B does not export AType' message. Oh well.
- -- Fixities
- mapRn fixityFromFixDecl fix_decls `thenRn` \ fixities ->
+ in
+ -- Filter the imports according to the import list
+ filterImports imp_mod is_boot imp_spec avails `thenM` \ (filtered_avails, explicits) ->
- -- Record where the available stuff came from
let
- explicit_info = listToFM [(name, FromLocalDefn (getSrcLoc name))
- | avail <- avails,
- name <- availNames avail
- ]
+ -- 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_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
- qualifyImports mod
- False -- Don't want qualified names
- True -- Want unqualified names
- Nothing -- No "as M" part
- [] -- Hide nothing
- avails (\n -> FromLocalDefn (getSrcLoc n))
- fixities
- `thenRn` \ (rn_env, mod_avails) ->
- returnRn (rn_env, mod_avails, explicit_info)
- where
- newLocalName rdr_name loc
- = newLocallyDefinedGlobalName mod (rdrNameOcc rdr_name) rec_exp_fn loc
-
- getLocalDeclBinders avails (ValD binds)
- = mapRn do_one (bagToList (collectTopBinders binds)) `thenRn` \ val_avails ->
- returnRn (val_avails ++ avails)
-
- -- foreign import declaration
- getLocalDeclBinders avails (ForD (ForeignDecl nm (FoImport _) _ _ _ loc))
- = do_one (nm,loc) `thenRn` \ for_avail ->
- returnRn (for_avail : avails)
-
- -- foreign import declaration
- getLocalDeclBinders avails (ForD (ForeignDecl nm FoLabel _ _ _ loc))
- = do_one (nm,loc) `thenRn` \ for_avail ->
- returnRn (for_avail : avails)
-
- -- foreign export dynamic declaration
- getLocalDeclBinders avails (ForD (ForeignDecl nm FoExport _ Dynamic _ loc))
- = do_one (nm,loc) `thenRn` \ for_avail ->
- returnRn (for_avail : avails)
-
- getLocalDeclBinders avails decl
- = getDeclBinders newLocalName decl `thenRn` \ avail ->
- case avail of
- NotAvailable -> returnRn avails -- Instance decls and suchlike
- other -> returnRn (avail : avails)
-
- do_one (rdr_name, loc)
- = newLocalName rdr_name loc `thenRn` \ name ->
- returnRn (Avail name)
+ -- 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}
+
%************************************************************************
%* *
-\subsection{Filtering imports}
+ importsFromLocalDecls
%* *
%************************************************************************
-@filterImports@ takes the @ExportEnv@ telling what the imported module makes
-available, and filters it through the import spec (if any).
+From the top-level declarations of this module produce
+ * the lexical environment
+ * the ImportAvails
+created by its bindings.
+
+Complain about duplicate bindings
\begin{code}
-filterImports :: Module
- -> Maybe (Bool, [RdrNameIE]) -- Import spec; True => hidin
- -> [AvailInfo] -- What's available
- -> RnMG ([AvailInfo], -- What's actually imported
- [AvailInfo], -- What's to be hidden (the unqualified version, that is)
- [AvailInfo]) -- What was imported explicitly
+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
+ all_names :: [Name] -- All the defns; no dups eliminated
+ all_names = [name | avail <- avails, name <- availNames avail]
- -- Complains if import spec mentions things that the module doesn't export
- -- Warns/informs if import spec contains duplicates.
-filterImports mod Nothing imports
- = returnRn (imports, [], [])
-
-filterImports mod (Just (want_hiding, import_items)) avails
- = mapRn check_item import_items `thenRn` \ item_avails ->
- if want_hiding
- then
- returnRn (avails, item_avails, []) -- All imported; item_avails to be hidden
- else
- returnRn (item_avails, [], item_avails) -- Just item_avails imported; nothing to be hidden
+ dups :: [[Name]]
+ (_, dups) = removeDups compare all_names
+ in
+ -- Check for duplicate definitions
+ -- The complaint will come out as "Multiple declarations of Foo.f" because
+ -- since 'f' is in the env twice, the unQualInScope used by the error-msg
+ -- printer returns False. It seems awkward to fix, unfortunately.
+ mappM_ (addErr . dupDeclErr) dups `thenM_`
- where
- import_fm :: FiniteMap OccName AvailInfo
- import_fm = listToFM [ (nameOccName name, avail)
- | avail <- avails,
- name <- availEntityNames avail]
+ doptM Opt_NoImplicitPrelude `thenM` \ implicit_prelude ->
+ let
+ mod_name = moduleName this_mod
+ mk_prov n = LocalDef -- Provenance is local
+
+ 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
+ -- deprecated things. We may even use a deprecated thing in
+ -- the defn of a non-deprecated thing, when changing a module's
+ -- interface
+
+
+ -- Optimisation: filter out names for built-in syntax
+ -- They just clutter up the environment (esp tuples), and the parser
+ -- will generate Exact RdrNames for them, so the cluttered
+ -- envt is no use. To avoid doing this filter all the 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
+ returnM (gbl_env, imports)
+\end{code}
- check_item item@(IEModuleContents _)
- = addErrRn (badImportItemErr mod item) `thenRn_`
- returnRn NotAvailable
- check_item item
- | not (maybeToBool maybe_in_import_avails) ||
- (case filtered_avail of { NotAvailable -> True; other -> False })
- = addErrRn (badImportItemErr mod item) `thenRn_`
- returnRn NotAvailable
+%*********************************************************
+%* *
+\subsection{Getting binders out of a declaration}
+%* *
+%*********************************************************
- | dodgy_import = addWarnRn (dodgyImportWarn mod item) `thenRn_`
- returnRn filtered_avail
+@getLocalDeclBinders@ returns the names for a @RdrNameHsDecl@. It's
+used for both source code (from @importsFromLocalDecls@) and interface
+files (@loadDecl@ calls @getTyClDeclBinders@).
- | otherwise = returnRn filtered_avail
-
- where
- maybe_in_import_avails = lookupFM import_fm (ieOcc item)
- Just avail = maybe_in_import_avails
- filtered_avail = filterAvail item avail
- dodgy_import = case (item, avail) of
- (IEThingAll _, AvailTC _ [n]) -> True
- -- This occurs when you import T(..), but
- -- only export T abstractly. The single [n]
- -- in the AvailTC is the type or class itself
-
- other -> False
-
-\end{code}
+ *** 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.
+
+ mappM new_tc tycl_decls `thenM` \ tc_avails ->
+ mappM new_bndr (for_hs_bndrs ++ val_hs_bndrs) `thenM` \ simple_bndrs ->
+
+ returnM (tc_avails ++ map Avail simple_bndrs)
+ where
+ new_bndr (rdr_name,loc) = newTopBinder mod rdr_name loc
+
+ val_hs_bndrs = collectLocatedHsBinders val_decls
+ for_hs_bndrs = [(nm,loc) | ForeignImport nm _ _ _ loc <- foreign_decls]
+
+ new_tc tc_decl = mappM new_bndr (tyClDeclNames tc_decl) `thenM` \ names@(main_name:_) ->
+ returnM (AvailTC main_name names)
+\end{code}
%************************************************************************
%* *
-\subsection{Qualifiying imports}
+\subsection{Filtering imports}
%* *
%************************************************************************
-@qualifyImports@ takes the @ExportEnv@ after filtering through the import spec
-of an import decl, and deals with producing an @RnEnv@ with the
-right qualified names. It also turns the @Names@ in the @ExportEnv@ into
-fully fledged @Names@.
+@filterImports@ takes the @ExportEnv@ telling what the imported module makes
+available, and filters it through the import spec (if any).
\begin{code}
-qualifyImports :: Module -- Imported module
- -> Bool -- True <=> want qualified import
- -> Bool -- True <=> want unqualified import
- -> Maybe Module -- Optional "as M" part
- -> [AvailInfo] -- What's to be hidden
- -> Avails -> (Name -> HowInScope) -- Whats imported and how
- -> [(OccName, (Fixity, HowInScope))] -- Ditto for fixities
- -> RnMG (RnEnv, ExportAvails)
-
-qualifyImports this_mod qual_imp unqual_imp as_mod hides
- avails name_to_his fixities
- =
- -- Make the name environment. Even though we're talking about a
- -- single import module there might still be name clashes,
- -- because it might be the module being compiled.
- foldlRn add_avail emptyGlobalNameEnv avails `thenRn` \ name_env1 ->
- let
- -- Delete things that are hidden
- name_env2 = foldl del_avail name_env1 hides
+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
+ -> TcRn m ([AvailInfo], -- What's imported
+ NameSet) -- What was imported explicitly
- -- Create the fixity env
- fixity_env = foldl (add_fixity name_env2) emptyFixityEnv fixities
+ -- Complains if import spec mentions things that the module doesn't export
+ -- Warns/informs if import spec contains duplicates.
+filterImports mod from Nothing imports
+ = returnM (imports, emptyNameSet)
- -- Create the export-availability info
- export_avails = mkExportAvails qual_mod unqual_imp name_env2 avails
+filterImports mod from (Just (want_hiding, import_items)) total_avails
+ = mappM get_item import_items `thenM` \ avails_w_explicits_s ->
+ let
+ (item_avails, explicits_s) = unzip (concat avails_w_explicits_s)
+ explicits = foldl addListToNameSet emptyNameSet explicits_s
in
- returnRn (RnEnv name_env2 fixity_env, export_avails)
+ if want_hiding then
+ let -- All imported; item_avails to be hidden
+ hidden = availsToNameSet item_avails
+ keep n = not (n `elemNameSet` hidden)
+ in
+ returnM (pruneAvails keep total_avails, emptyNameSet)
+ else
+ -- Just item_avails imported; nothing to be hidden
+ returnM (item_avails, explicits)
where
- qual_mod = case as_mod of
- Nothing -> this_mod
- Just another_name -> another_name
-
- add_avail :: GlobalNameEnv -> AvailInfo -> RnMG GlobalNameEnv
- add_avail env avail = foldlRn add_name env (availNames avail)
-
- add_name env name = add qual_imp env (Qual qual_mod occ err_hif) `thenRn` \ env1 ->
- add unqual_imp env1 (Unqual occ)
- where
- add False env rdr_name = returnRn env
- add True env rdr_name = addOneToGlobalNameEnv env rdr_name (name, name_to_his name)
- occ = nameOccName name
-
- del_avail env avail = foldl delOneFromGlobalNameEnv env rdr_names
- where
- rdr_names = map (Unqual . nameOccName) (availNames avail)
-
- add_fixity name_env fix_env (occ_name, fixity)
- = add qual $ add unqual $ fix_env
- where
- qual = Qual qual_mod occ_name err_hif
- unqual = Unqual occ_name
-
- add rdr_name fix_env | maybeToBool (lookupFM name_env rdr_name)
- = addOneToFixityEnv fix_env rdr_name fixity
- | otherwise
- = fix_env
-
-err_hif = error "qualifyImports: hif" -- Not needed in key to mapping
-\end{code}
+ import_fm :: FiniteMap OccName AvailInfo
+ import_fm = listToFM [ (nameOccName name, avail)
+ | avail <- total_avails,
+ name <- availNames avail]
+ -- Even though availNames returns data constructors too,
+ -- they won't make any difference because naked entities like T
+ -- in an import list map to TcOccs, not VarOccs.
+
+ bale_out item = addErr (badImportItemErr mod from item) `thenM_`
+ returnM []
+
+ get_item :: RdrNameIE -> TcRn m [(AvailInfo, [Name])]
+ -- Empty list for a bad item.
+ -- Singleton is typical case.
+ -- Can have two when we are hiding, and mention C which might be
+ -- both a class and a data constructor.
+ -- The [Name] is the list of explicitly-mentioned names
+ get_item item@(IEModuleContents _) = bale_out item
+
+ get_item item@(IEThingAll _)
+ = case check_item item of
+ Nothing -> bale_out item
+ Just avail@(AvailTC _ [n]) -> -- This occurs when you import T(..), but
+ -- only export T abstractly. The single [n]
+ -- in the AvailTC is the type or class itself
+ ifOptM Opt_WarnMisc (addWarn (dodgyImportWarn mod item)) `thenM_`
+ returnM [(avail, [availName avail])]
+ Just avail -> returnM [(avail, [availName avail])]
+
+ get_item item@(IEThingAbs n)
+ | want_hiding -- hiding( C )
+ -- Here the 'C' can be a data constructor *or* a type/class
+ = case catMaybes [check_item item, check_item (IEVar data_n)] of
+ [] -> bale_out item
+ avails -> returnM [(a, []) | a <- avails]
+ -- The 'explicits' list is irrelevant when hiding
+ where
+ data_n = setRdrNameSpace n srcDataName
-unQualify adds an Unqual binding for every existing Qual binding.
+ get_item item
+ = case check_item item of
+ Nothing -> bale_out item
+ Just avail -> returnM [(avail, availNames avail)]
-\begin{code}
-unQualify :: FiniteMap RdrName elt -> FiniteMap RdrName elt
-unQualify fm = addListToFM fm [(Unqual occ, elt) | (Qual _ occ _, elt) <- fmToList fm]
-\end{code}
+ check_item item
+ | isNothing maybe_in_import_avails ||
+ isNothing maybe_filtered_avail
+ = Nothing
-%************************************************************************
-%* *
-\subsection{Local declarations}
-%* *
-%************************************************************************
+ | otherwise
+ = Just filtered_avail
+
+ where
+ wanted_occ = rdrNameOcc (ieName item)
+ maybe_in_import_avails = lookupFM import_fm wanted_occ
+ Just avail = maybe_in_import_avails
+ maybe_filtered_avail = filterAvail item avail
+ Just filtered_avail = maybe_filtered_avail
+\end{code}
\begin{code}
-fixityFromFixDecl :: RdrNameFixityDecl -> RnMG (OccName, (Fixity, HowInScope))
-
-fixityFromFixDecl (FixityDecl rdr_name fixity loc)
- = returnRn (rdrNameOcc rdr_name, (fixity, FromLocalDefn loc))
+filterAvail :: RdrNameIE -- Wanted
+ -> AvailInfo -- Available
+ -> Maybe AvailInfo -- Resulting available;
+ -- Nothing if (any of the) wanted stuff isn't there
+
+filterAvail ie@(IEThingWith want wants) avail@(AvailTC n ns)
+ | sub_names_ok = Just (AvailTC n (filter is_wanted ns))
+ | otherwise = Nothing
+ where
+ is_wanted name = nameOccName name `elem` wanted_occs
+ sub_names_ok = all (`elem` avail_occs) wanted_occs
+ avail_occs = map nameOccName ns
+ wanted_occs = map rdrNameOcc (want:wants)
+
+filterAvail (IEThingAbs _) (AvailTC n ns) = ASSERT( n `elem` ns )
+ Just (AvailTC n [n])
+
+filterAvail (IEThingAbs _) avail@(Avail n) = Just avail -- Type synonyms
+
+filterAvail (IEVar _) avail@(Avail n) = Just avail
+filterAvail (IEVar v) avail@(AvailTC n ns) = Just (AvailTC n (filter wanted ns))
+ where
+ wanted n = nameOccName n == occ
+ occ = rdrNameOcc v
+ -- The second equation happens if we import a class op, thus
+ -- import A( op )
+ -- where op is a class operation
+
+filterAvail (IEThingAll _) avail@(AvailTC _ _) = Just avail
+ -- We don't complain even if the IE says T(..), but
+ -- no constrs/class ops of T are available
+ -- Instead that's caught with a warning by the caller
+
+filterAvail ie avail = Nothing
\end{code}
%************************************************************************
%* *
-\subsection{Export list processing
+\subsection{Export list processing}
%* *
%************************************************************************
-The @AvailEnv@ type is just used internally in @exportsFromAvail@.
-When exporting we need to combine the availabilities for a particular
-exported thing, and we also need to check for name clashes -- that
-is: two exported things must have different @OccNames@.
-
-\begin{code}
-type AvailEnv = FiniteMap OccName (RdrNameIE, AvailInfo, Int{-no. of clashes-})
- -- The FM maps each OccName to the RdrNameIE that gave rise to it,
- -- for error reporting, as well as to its AvailInfo
-
-emptyAvailEnv = emptyFM
-
-{-
- Add new entry to environment. Checks for name clashes, i.e.,
- plain duplicates or exported entity pairs that have different OccNames.
- (c.f. 5.1.1 of Haskell 1.4 report.)
--}
-addAvailEnv :: Bool -> RdrNameIE -> AvailEnv -> AvailInfo -> RnM s d AvailEnv
-addAvailEnv warn_dups ie env NotAvailable = returnRn env
-addAvailEnv warn_dups ie env (AvailTC _ []) = returnRn env
-addAvailEnv warn_dups ie env avail
- | warn_dups = mapMaybeRn (addErrRn . availClashErr) () conflict `thenRn_`
- returnRn (addToFM_C addAvail env key elt)
- | otherwise = returnRn (addToFM_C addAvail env key elt)
- where
- occ_avail = nameOccName (availName avail)
- occ_ie = ieOcc ie
- key
- | not warn_dups || occ_ie == occ_avail = occ_avail
- | otherwise = occ_ie
- -- export item is a class method, use export occ name instead.
- -- (this is only needed to get more precise warnings about
- -- duplicates.)
- elt = (ie,avail,reports_on)
-
- reports_on
- | maybeToBool dup = 1
- | otherwise = 0
-
- conflict = conflictFM bad_avail env key elt
- dup
- | warn_dups = conflictFM dup_avail env key elt
- | otherwise = Nothing
-
-addListToAvailEnv :: AvailEnv -> RdrNameIE -> [AvailInfo] -> RnM s d AvailEnv
-addListToAvailEnv env ie items
- = foldlRn (addAvailEnv False{-don't warn about dups-} ie) env items
-
-bad_avail (ie1,avail1,r1) (ie2,avail2,r2)
- = availName avail1 /= availName avail2 -- Same OccName, different Name
-dup_avail (ie1,avail1,r1) (ie2,avail2,r2)
- = availName avail1 == availName avail2 -- Same OccName & avail.
-
-addAvail (ie1,a1,r1) (ie2,a2,r2) = (ie1, a1 `plusAvail` a2, r1 + r2)
-\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). 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...
+You might think that we should record things that appear in the export
+list as ``occurrences'' (using @addOccurrenceName@), but you'd be
+wrong. We do check (here) that they are in scope, but there is no
+need to slurp in their actual declaration (which is what
+@addOccurrenceName@ forces).
+
+Indeed, doing so would big trouble when compiling @PrelBase@, because
+it re-exports @GHC@, which includes @takeMVar#@, whose type includes
+@ConcBase.StateAndSynchVar#@, and so on...
\begin{code}
-exportsFromAvail :: Module
- -> Maybe [RdrNameIE] -- Export spec
- -> ExportAvails
- -> RnEnv
- -> RnMG (Name -> ExportFlag, ExportEnv)
+type ExportAccum -- The type of the accumulating parameter of
+ -- the main worker function in exportsFromAvail
+ = ([ModuleName], -- 'module M's seen so far
+ ExportOccMap, -- Tracks exported occurrence names
+ AvailEnv) -- The accumulated exported stuff, kept in an env
+ -- so we can common-up related AvailInfos
+emptyExportAccum = ([], emptyFM, emptyAvailEnv)
+
+type ExportOccMap = FiniteMap OccName (Name, RdrNameIE)
+ -- Tracks what a particular exported OccName
+ -- in an export list refers to, and which item
+ -- it came from. It's illegal to export two distinct things
+ -- that have the same occurrence name
+
+
+exportsFromAvail :: Maybe 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 rn_env
- = exportsFromAvail this_mod (Just [IEModuleContents this_mod]) export_avails rn_env
-
-exportsFromAvail this_mod (Just export_items)
- (mod_avail_env, entity_avail_env)
- (RnEnv global_name_env fixity_env)
- = checkForModuleExportDups export_items `thenRn` \ export_items' ->
- foldlRn exports_from_item emptyAvailEnv export_items' `thenRn` \ export_avail_env ->
- let
- dup_entries = fmToList (filterFM (\ _ (_,_,clashes) -> clashes > 0) export_avail_env)
- in
- mapRn (addWarnRn . dupExportWarn) dup_entries `thenRn_`
- let
- export_avails = map (\ (_,a,_) -> a) (eltsFM export_avail_env)
- export_fixities = mk_exported_fixities (availsToNameSet export_avails)
- export_fn = mk_export_fn export_avails
- in
- returnRn (export_fn, ExportEnv export_avails export_fixities)
+
+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 :: AvailEnv -> RdrNameIE -> RnMG AvailEnv
- exports_from_item export_avail_env ie@(IEModuleContents mod)
- = case lookupFM mod_avail_env mod of
- Nothing -> failWithRn export_avail_env (modExportErr mod)
- Just avails -> addListToAvailEnv export_avail_env ie avails
-
- exports_from_item export_avail_env ie
- | not (maybeToBool maybe_in_scope)
- = failWithRn export_avail_env (unknownNameErr (ieName ie))
-
-#ifdef DEBUG
- -- I can't see why this should ever happen; if the thing is in scope
- -- at all it ought to have some availability
- | not (maybeToBool maybe_avail)
- = pprTrace "exportsFromAvail: curious Nothing:" (ppr name)
- returnRn export_avail_env
-#endif
-
- | not enough_avail
- = failWithRn export_avail_env (exportItemErr ie export_avail)
-
- | otherwise -- Phew! It's OK!
- = addAvailEnv opt_WarnDuplicateExports ie export_avail_env export_avail
- where
- maybe_in_scope = lookupFM global_name_env (ieName ie)
- Just (name,_) = maybe_in_scope
- maybe_avail = lookupUFM entity_avail_env name
- Just avail = maybe_avail
- export_avail = filterAvail ie avail
- enough_avail = case export_avail of {NotAvailable -> False; other -> True}
-
- -- We export a fixity iff we export a thing with the same (qualified) RdrName
- mk_exported_fixities :: NameSet -> [(OccName, Fixity)]
- mk_exported_fixities exports
- = fmToList (foldr (perhaps_add_fixity exports)
- emptyFM
- (fmToList fixity_env))
-
- perhaps_add_fixity :: NameSet -> (RdrName, (Fixity, HowInScope))
- -> FiniteMap OccName Fixity
- -> FiniteMap OccName Fixity
- perhaps_add_fixity exports (rdr_name, (fixity, how_in_scope)) fix_env
- = let
- do_nothing = fix_env -- The default is to pass on the env unchanged
- in
- -- Step 1: check whether the rdr_name is in scope; if so find its Name
- case lookupFM global_name_env rdr_name of {
- Nothing -> do_nothing;
- Just (fixity_name,_) ->
-
- -- Step 2: check whether the fixity thing is exported
- if not (fixity_name `elemNameSet` exports) then
- do_nothing
- else
-
- -- Step 3: check whether we already have a fixity for the
- -- Name's OccName in the fix_env we are building up. This can easily
- -- happen. the original fixity_env might contain bindings for
- -- M.a and N.a, if a was imported via M and N.
- -- If this does happen, we expect the fixity to be the same either way.
- let
- occ_name = rdrNameOcc rdr_name
- in
- case lookupFM fix_env occ_name of {
- Just fixity1 -> -- Got it already
- ASSERT( fixity == fixity1 )
- do_nothing;
- Nothing ->
-
- -- Step 3: add it to the outgoing fix_env
- addToFM fix_env occ_name fixity
- }}
-
-{- warn and weed out duplicate module entries from export list. -}
-checkForModuleExportDups :: [RdrNameIE] -> RnMG [RdrNameIE]
-checkForModuleExportDups ls
- | opt_WarnDuplicateExports = check_modules ls
- | otherwise = returnRn ls
+ exports_from_item :: ExportAccum -> RdrNameIE -> TcRn m ExportAccum
+
+ exports_from_item acc@(mods, occs, avails) ie@(IEModuleContents mod)
+ | mod `elem` mods -- Duplicate export of M
+ = do { warn_dup_exports <- doptM Opt_WarnDuplicateExports ;
+ warnIf warn_dup_exports (dupModuleExport mod) ;
+ returnM acc }
+
+ | otherwise
+ = 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
+ addErr (exportItemErr ie) `thenM_`
+ returnM acc ;
+
+ Just export_avail ->
+
+ -- Phew! It's OK! Now to check the occurrence stuff!
+ warnIf (not (ok_item ie avail)) (dodgyExportWarn ie) `thenM_`
+ check_occs 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
- -- NOTE: reorders the export list by moving all module-contents
- -- exports to the end (removing duplicates in the process.)
- check_modules ls =
- (case dups of
- [] -> returnRn ()
- ls -> mapRn (\ ds@(IEModuleContents x:_) ->
- addWarnRn (dupModuleExport x (length ds))) ls `thenRn_`
- returnRn ()) `thenRn_`
- returnRn (ls_no_modules ++ no_module_dups)
- where
- (ls_no_modules,modules) = foldr split_mods ([],[]) ls
-
- split_mods i@(IEModuleContents _) (no_ms,ms) = (no_ms,i:ms)
- split_mods i (no_ms,ms) = (i:no_ms,ms)
-
- (no_module_dups, dups) = removeDups cmp_mods modules
-
- cmp_mods (IEModuleContents m1) (IEModuleContents m2) = m1 `compare` m2
-
-mk_export_fn :: [AvailInfo] -> (Name -> ExportFlag)
-mk_export_fn avails
- = \name -> if name `elemNameSet` exported_names
- then Exported
- else NotExported
+ 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 -> TcRn m ExportOccMap
+check_occs ie occs avail
+ = foldlM check occs (availNames avail)
+ where
+ check occs name
+ = case lookupFM occs name_occ of
+ Nothing -> returnM (addToFM occs name_occ (name, ie))
+
+ Just (name', ie')
+ | name == name' -- Duplicate export
+ -> 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
- exported_names :: NameSet
- exported_names = availsToNameSet avails
+ mkFilename this_mod = moduleNameUserString (moduleName this_mod) ++ ".imports"
+ ppr_mod_ie (mod_name, ies)
+ | mod_name == pRELUDE_Name
+ = empty
+ | null ies -- Nothing except instances comes from here
+ = ptext SLIT("import") <+> ppr mod_name <> ptext SLIT("() -- Instances only")
+ | otherwise
+ = ptext SLIT("import") <+> ppr mod_name <>
+ parens (fsep (punctuate comma (map ppr ies)))
+
+ to_ies (mod, avail_env) = mappM to_ie (availEnvElts avail_env) `thenM` \ ies ->
+ returnM (mod, ies)
+
+ to_ie :: AvailInfo -> TcRn m (IE Name)
+ -- The main trick here is that if we're importing all the constructors
+ -- we want to say "T(..)", but if we're importing only a subset we want
+ -- to say "T(A,B,C)". So we have to find out what the module exports.
+ to_ie (Avail n) = returnM (IEVar n)
+ to_ie (AvailTC n [m]) = ASSERT( n==m )
+ returnM (IEThingAbs n)
+ to_ie (AvailTC n ns)
+ = loadInterface (text "Compute minimal imports from" <+> ppr n_mod)
+ n_mod ImportBySystem `thenM` \ iface ->
+ case [xs | (m,as) <- mi_exports iface,
+ m == n_mod,
+ AvailTC x xs <- as,
+ x == n] of
+ [xs] | all (`elem` ns) xs -> returnM (IEThingAll n)
+ | otherwise -> returnM (IEThingWith n (filter (/= n) ns))
+ other -> pprTrace "to_ie" (ppr n <+> ppr (nameModule n) <+> ppr other) $
+ returnM (IEVar n)
+ where
+ n_mod = moduleName (nameModule n)
\end{code}
+
%************************************************************************
%* *
\subsection{Errors}
%************************************************************************
\begin{code}
-badImportItemErr mod ie
- = sep [ptext SLIT("Module"), quotes (pprModule mod),
+badImportItemErr mod from ie
+ = sep [ptext SLIT("Module"), quotes (ppr mod), source_import,
ptext SLIT("does not export"), quotes (ppr ie)]
-
-dodgyImportWarn mod (IEThingAll tc)
- = sep [ptext SLIT("Module") <+> quotes (pprModule mod) <+> ptext SLIT("exports") <+> quotes (ppr tc),
- ptext SLIT("with no constructors/class operations;"),
- ptext SLIT("yet it is imported with a (..)")]
-
+ where
+ source_import = case from of
+ True -> ptext SLIT("(hi-boot interface)")
+ other -> empty
+
+dodgyImportWarn mod item = dodgyMsg (ptext SLIT("import")) item
+dodgyExportWarn item = dodgyMsg (ptext SLIT("export")) item
+
+dodgyMsg kind item@(IEThingAll tc)
+ = sep [ ptext SLIT("The") <+> kind <+> ptext SLIT("item") <+> quotes (ppr item),
+ ptext SLIT("suggests that") <+> quotes (ppr tc) <+> ptext SLIT("has constructor or class methods"),
+ ptext SLIT("but it has none; it is a type synonym or abstract type or class") ]
+
modExportErr mod
- = hsep [ ptext SLIT("Unknown module in export list: module"), quotes (pprModule mod)]
-
-exportItemErr export_item NotAvailable
- = sep [ ptext SLIT("Export item not in scope:"), quotes (ppr export_item)]
+ = hsep [ ptext SLIT("Unknown module in export list: module"), quotes (ppr mod)]
-exportItemErr export_item avail
- = hang (ptext SLIT("Export item not fully in scope:"))
- 4 (vcat [hsep [ptext SLIT("Wanted: "), ppr export_item],
- hsep [ptext SLIT("Available:"), ppr (ieOcc export_item), pprAvail avail]])
+exportItemErr export_item
+ = sep [ ptext SLIT("The export item") <+> quotes (ppr export_item),
+ ptext SLIT("attempts to export constructors or class methods that are not visible here") ]
-availClashErr (occ_name, ((ie1,avail1,_), (ie2,avail2,_)))
- = 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),
+ nest 4 (vcat (map ppr sorted_locs))]
+ where
+ sorted_locs = sortLt occ'ed_before (map nameSrcLoc (n:ns))
+ occ'ed_before a b = LT == compare a b
-dupExportWarn (occ_name, (_,_,times))
+dupExportWarn occ_name ie1 ie2
= hsep [quotes (ppr occ_name),
- ptext SLIT("mentioned"), speakNTimes (times+1),
- ptext SLIT("in export list")]
+ ptext SLIT("is exported by"), quotes (ppr ie1),
+ ptext SLIT("and"), quotes (ppr ie2)]
-dupModuleExport mod times
- = hsep [ptext SLIT("Module"), quotes (pprModule mod),
- ptext SLIT("mentioned"), speakNTimes times,
+dupModuleExport mod
+ = hsep [ptext SLIT("Duplicate"),
+ quotes (ptext SLIT("Module") <+> ppr mod),
ptext SLIT("in export list")]
-\end{code}
+moduleDeprec mod txt
+ = sep [ ptext SLIT("Module") <+> quotes (ppr mod) <+> ptext SLIT("is deprecated:"),
+ nest 4 (ppr txt) ]
+\end{code}
projects / ghc-hetmet.git / blobdiff