+
+%*********************************************************
+%* *
+\subsection{Fixities}
+%* *
+%*********************************************************
+
+\begin{code}
+fixitiesFromLocalDecls :: GlobalRdrEnv -> [RdrNameHsDecl] -> RnMG LocalFixityEnv
+fixitiesFromLocalDecls gbl_env decls
+ = doptRn Opt_WarnUnusedBinds `thenRn` \ warn_unused ->
+ foldlRn (getFixities warn_unused) emptyNameEnv decls `thenRn` \ env ->
+ traceRn (text "fixity env" <+> vcat (map ppr (nameEnvElts env)))
+ `thenRn_`
+ returnRn env
+ where
+ getFixities :: Bool -> LocalFixityEnv -> RdrNameHsDecl -> RnMG LocalFixityEnv
+ getFixities warn_uu acc (FixD fix)
+ = fix_decl warn_uu acc fix
+
+ getFixities warn_uu acc (TyClD (ClassDecl _ _ _ _ sigs _ _ _ ))
+ = foldlRn (fix_decl warn_uu) acc [sig | FixSig sig <- sigs]
+ -- Get fixities from class decl sigs too.
+ getFixities warn_uu acc other_decl
+ = returnRn acc
+
+ fix_decl warn_uu acc sig@(FixitySig rdr_name fixity loc)
+ = -- Check for fixity decl for something not declared
+ pushSrcLocRn loc $
+ lookupGlobalRn gbl_env rdr_name `thenRn` \ maybe_name ->
+ case maybe_name of {
+ Nothing -> checkRn (not warn_uu) (unusedFixityDecl rdr_name fixity) `thenRn_`
+ returnRn acc ;
+
+ Just name ->
+
+ -- Check for duplicate fixity decl
+ case lookupNameEnv acc name of {
+ Just (FixitySig _ _ loc') -> addErrRn (dupFixityDecl rdr_name loc loc')
+ `thenRn_` returnRn acc ;
+
+ Nothing -> returnRn (extendNameEnv acc name (FixitySig name fixity loc))
+ }}
+\end{code}
+
+
+%*********************************************************
+%* *
+\subsection{Deprecations}
+%* *
+%*********************************************************
+
+For deprecations, all we do is check that the names are in scope.
+It's only imported deprecations, dealt with in RnIfaces, that we
+gather them together.
+
+\begin{code}
+rnDeprecs :: GlobalRdrEnv -> Maybe DeprecTxt
+ -> [RdrNameDeprecation] -> RnMG Deprecations
+rnDeprecs gbl_env Nothing []
+ = returnRn NoDeprecs
+
+rnDeprecs gbl_env (Just txt) decls
+ = mapRn (addErrRn . badDeprec) decls `thenRn_`
+ returnRn (DeprecAll txt)
+
+rnDeprecs gbl_env Nothing decls
+ = mapRn rn_deprec decls `thenRn` \ pairs ->
+ returnRn (DeprecSome (mkNameEnv (catMaybes pairs)))
+ where
+ rn_deprec (Deprecation rdr_name txt loc)
+ = pushSrcLocRn loc $
+ lookupGlobalRn gbl_env rdr_name `thenRn` \ maybe_name ->
+ case maybe_name of
+ Just n -> returnRn (Just (n,txt))
+ Nothing -> returnRn Nothing
+\end{code}
+
+
+%*********************************************************
+%* *
+\subsection{Unused names}
+%* *
+%*********************************************************
+
+\begin{code}
+reportUnusedNames :: ModuleName -> [ModuleName]
+ -> GlobalRdrEnv -> AvailEnv
+ -> Avails -> NameSet -> [RenamedHsDecl]
+ -> RnMG ()
+reportUnusedNames mod_name direct_import_mods
+ gbl_env avail_env
+ export_avails mentioned_names
+ imported_decls
+ = warnUnusedModules unused_imp_mods `thenRn_`
+ warnUnusedLocalBinds bad_locals `thenRn_`
+ warnUnusedImports bad_imp_names `thenRn_`
+ printMinimalImports mod_name minimal_imports `thenRn_`
+ warnDeprecations really_used_names `thenRn_`
+ returnRn ()
+
+ where
+ used_names = mentioned_names `unionNameSets` availsToNameSet export_avails
+
+ -- Now, a use of C implies a use of T,
+ -- if C was brought into scope by T(..) or T(C)
+ really_used_names = used_names `unionNameSets`
+ mkNameSet [ parent_name
+ | sub_name <- nameSetToList used_names
+
+ -- Usually, every used name will appear in avail_env, but there
+ -- is one time when it doesn't: tuples and other built in syntax. When you
+ -- write (a,b) that gives rise to a *use* of "(,)", so that the
+ -- instances will get pulled in, but the tycon "(,)" isn't actually
+ -- in scope. Also, (-x) gives rise to an implicit use of 'negate';
+ -- similarly, 3.5 gives rise to an implcit use of :%
+ -- Hence the silent 'False' in all other cases
+
+ , Just parent_name <- [case lookupNameEnv avail_env sub_name of
+ Just (AvailTC n _) -> Just n
+ other -> Nothing]
+ ]
+
+ defined_names, defined_and_used, defined_but_not_used :: [(Name,Provenance)]
+ defined_names = concat (rdrEnvElts gbl_env)
+ (defined_and_used, defined_but_not_used) = partition used defined_names
+ used (name,_) = not (name `elemNameSet` really_used_names)
+
+ -- Filter out the ones only defined implicitly
+ bad_locals :: [Name]
+ bad_locals = [n | (n,LocalDef) <- defined_but_not_used]
+
+ bad_imp_names :: [(Name,Provenance)]
+ bad_imp_names = [(n,p) | (n,p@(NonLocalDef (UserImport mod _ True) _)) <- defined_but_not_used,
+ not (module_unused mod)]
+
+ -- inst_mods are directly-imported modules that
+ -- contain instance decl(s) that the renamer decided to suck in
+ -- It's not necessarily redundant to import such modules.
+ --
+ -- NOTE: 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
+ inst_mods :: [ModuleName]
+ inst_mods = [m | InstD (InstDecl _ _ _ (Just dfun) _) <- imported_decls,
+ let m = moduleName (nameModule dfun),
+ m `elem` direct_import_mods
+ ]
+
+ -- 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 inst_mods
+
+ add_name (n,NonLocalDef (UserImport m _ _) _) acc = addToFM_C plusAvailEnv acc (moduleName (nameModule n))
+ (unitAvailEnv (mk_avail n))
+ add_name (n,other_prov) acc = acc
+
+ mk_avail n = case lookupNameEnv avail_env n of
+ Just (AvailTC m _) | n==m -> AvailTC n [n]
+ | otherwise -> AvailTC m [n,m]
+ Just avail -> Avail n
+ Nothing -> pprPanic "mk_avail" (ppr n)
+
+ add_inst_mod m acc
+ | m `elemFM` acc = acc -- We import something already
+ | otherwise = addToFM acc m emptyAvailEnv
+ -- Add an empty collection of imports for a module
+ -- from which we have sucked only instance decls
+
+ -- unused_imp_mods are the directly-imported modules
+ -- that are not mentioned in minimal_imports
+ unused_imp_mods = [m | m <- direct_import_mods,
+ not (maybeToBool (lookupFM minimal_imports m)),
+ m /= pRELUDE_Name]
+
+ module_unused :: Module -> Bool
+ module_unused mod = moduleName mod `elem` unused_imp_mods
+
+
+warnDeprecations used_names
+ = doptRn Opt_WarnDeprecations `thenRn` \ warn_drs ->
+ if not warn_drs then returnRn () else
+
+ getIfacesRn `thenRn` \ ifaces ->
+ getHomeIfaceTableRn `thenRn` \ hit ->
+ let
+ pit = iPIT ifaces
+ deprecs = [ (n,txt)
+ | n <- nameSetToList used_names,
+ Just txt <- [lookup_deprec hit pit n] ]
+ in
+ mapRn_ warnDeprec deprecs
+
+ where
+ lookup_deprec hit pit n
+ = case lookupModuleEnv hit mod of
+ Just iface -> lookupDeprec iface n
+ Nothing -> case lookupModuleEnv pit mod of
+ Just iface -> lookupDeprec iface n
+ Nothing -> pprPanic "warnDeprecations:" (ppr n)
+ where
+ mod = nameModule n
+
+-- ToDo: deal with original imports with 'qualified' and 'as M' clauses
+printMinimalImports mod_name imps
+ = doptRn Opt_D_dump_minimal_imports `thenRn` \ dump_minimal ->
+ if not dump_minimal then returnRn () else
+
+ mapRn to_ies (fmToList imps) `thenRn` \ mod_ies ->
+ ioToRnM (do { h <- openFile filename WriteMode ;
+ printForUser h (vcat (map ppr_mod_ie mod_ies))
+ }) `thenRn_`