import RdrName ( RdrName, rdrNameModule, rdrNameOcc, isQual, isUnqual,
mkRdrUnqual, qualifyRdrName
)
-import HsTypes ( getTyVarName, replaceTyVarName )
+import HsTypes ( hsTyVarName, hsTyVarNames, replaceTyVarName )
import RnMonad
import Name ( Name, Provenance(..), ExportFlag(..), NamedThing(..),
ImportReason(..), getSrcLoc,
mkLocalName, mkImportedLocalName, mkGlobalName, mkUnboundName,
- mkIPName, isSystemName,
+ mkIPName, isWiredInName, hasBetterProv,
nameOccName, setNameModule, nameModule,
- pprOccName, isLocallyDefined, nameUnique, nameOccName,
- occNameUserString,
- setNameProvenance, getNameProvenance, pprNameProvenance
+ pprOccName, isLocallyDefined, nameUnique,
+ setNameProvenance, getNameProvenance, pprNameProvenance,
+ extendNameEnv_C, plusNameEnv_C, nameEnvElts
)
import NameSet
import OccName ( OccName,
mkDFunOcc, occNameUserString, occNameString,
occNameFlavour
)
-import TysWiredIn ( tupleTyCon, unboxedTupleTyCon, listTyCon )
+import TysWiredIn ( listTyCon )
import Type ( funTyCon )
-import Module ( ModuleName, mkThisModule, moduleName, mkVanillaModule )
-import TyCon ( TyCon )
+import Module ( ModuleName, mkThisModule, moduleName, mkVanillaModule, pprModuleName )
import FiniteMap
-import Unique ( Unique, Uniquable(..) )
-import UniqFM ( emptyUFM, listToUFM, plusUFM_C )
import UniqSupply
import SrcLoc ( SrcLoc, noSrcLoc )
import Outputable
-import Util ( removeDups, equivClasses, thenCmp )
+import Util ( removeDups, equivClasses, thenCmp, sortLt )
import List ( nub )
-import Maybes ( mapMaybe )
\end{code}
%*********************************************************
\begin{code}
-newLocalTopBinder :: Module -> OccName
- -> (Name -> ExportFlag) -> SrcLoc
- -> RnM d Name
-newLocalTopBinder mod occ rec_exp_fn loc
- = newTopBinder mod occ (\name -> LocalDef loc (rec_exp_fn name))
- -- We must set the provenance of the thing in the cache
- -- correctly, particularly whether or not it is locally defined.
- --
- -- Since newLocalTopBinder is used only
- -- at binding occurrences, we may as well get the provenance
- -- dead right first time; hence the rec_exp_fn passed in
-
-newImportedBinder :: Module -> RdrName -> RnM d Name
-newImportedBinder mod rdr_name
- = ASSERT2( isUnqual rdr_name, ppr rdr_name )
- newTopBinder mod (rdrNameOcc rdr_name) (\name -> implicitImportProvenance)
-
implicitImportProvenance = NonLocalDef ImplicitImport False
-newTopBinder :: Module -> OccName -> (Name -> Provenance) -> RnM d Name
-newTopBinder mod occ mk_prov
+newTopBinder :: Module -> OccName -> RnM d Name
+newTopBinder mod occ
= -- First check the cache
- getNameSupplyRn `thenRn` \ (us, inst_ns, cache, ipcache) ->
+ traceRn (text "newTopBinder" <+> ppr mod <+> ppr occ) `thenRn_`
+
+ getNameSupplyRn `thenRn` \ (us, cache, ipcache) ->
let
- key = (moduleName mod, occ)
+ key = (moduleName mod, occ)
in
case lookupFM cache key of
- -- A hit in the cache! Re-use the unique (which may be widely known)
- -- But otherwise build a new name, thereby
- -- overwriting whatever module details and provenance is in the cache already;
- -- This updates WiredIn things and known-key things, which are there from the start.
+ -- A hit in the cache! We are at the binding site of the name, which is
+ -- the time we know all about the Name's host Module (in particular, which
+ -- package it comes from), so update the Module in the name.
+ -- But otherwise *leave the Provenance alone*:
+ --
+ -- * For imported names, the Provenance may already be correct.
+ -- e.g. We imported Prelude.hi, and set the provenance of PrelShow.Show
+ -- to 'UserImport from Prelude'. Note that we havn't yet opened PrelShow.hi
+ -- Later we find we really need PrelShow.Show, so we open PrelShow.hi, and
+ -- that's when we find the binding occurrence of Show.
+ --
+ -- * For locally defined names, we do a setProvenance on the Name
+ -- right after newTopBinder, and then use updateProveances to finally
+ -- set the provenances in the cache correctly.
--
- -- It also means that if there are two defns for the same thing
- -- in a module, then each gets a separate SrcLoc
+ -- NB: for wired-in names it's important not to
+ -- forget that they are wired in even when compiling that module
+ -- (else we spit out redundant defns into the interface file)
Just name -> let
- new_name = mkGlobalName (nameUnique name) mod occ (mk_prov new_name)
+ new_name = setNameModule name mod
new_cache = addToFM cache key new_name
in
- setNameSupplyRn (us, inst_ns, new_cache, ipcache) `thenRn_`
+ setNameSupplyRn (us, new_cache, ipcache) `thenRn_`
+ traceRn (text "newTopBinder: overwrite" <+> ppr new_name) `thenRn_`
returnRn new_name
-- Miss in the cache!
-- Build a completely new Name, and put it in the cache
+ -- Even for locally-defined names we use implicitImportProvenance;
+ -- updateProvenances will set it to rights
Nothing -> let
(us', us1) = splitUniqSupply us
uniq = uniqFromSupply us1
- new_name = mkGlobalName uniq mod occ (mk_prov new_name)
+ new_name = mkGlobalName uniq mod occ implicitImportProvenance
new_cache = addToFM cache key new_name
in
- setNameSupplyRn (us', inst_ns, new_cache, ipcache) `thenRn_`
+ setNameSupplyRn (us', new_cache, ipcache) `thenRn_`
+ traceRn (text "newTopBinder: new" <+> ppr new_name) `thenRn_`
returnRn new_name
-mkImportedGlobalName :: ModuleName -> OccName -> RnM d Name
+newGlobalName :: ModuleName -> OccName -> RnM d Name
-- Used for *occurrences*. We make a place-holder Name, really just
-- to agree on its unique, which gets overwritten when we read in
-- the binding occurence later (newImportedBinder)
-- The place-holder Name doesn't have the right Provenance, and its
- -- Module won't have the right Package either
+ -- Module won't have the right Package either.
+ --
+ -- (We have to pass a ModuleName, not a Module, because we may be
+ -- simply looking at an occurrence M.x in an interface file.)
--
-- This means that a renamed program may have incorrect info
-- on implicitly-imported occurrences, but the correct info on the
-- it doesn't matter that we get the correct info in place till later,
-- (but since it affects DLL-ery it does matter that we get it right
-- in the end).
-mkImportedGlobalName mod_name occ
- = getNameSupplyRn `thenRn` \ (us, inst_ns, cache, ipcache) ->
+newGlobalName mod_name occ
+ = getNameSupplyRn `thenRn` \ (us, cache, ipcache) ->
let
key = (mod_name, occ)
in
case lookupFM cache key of
- Just name -> returnRn name
- Nothing -> setNameSupplyRn (us', inst_ns, new_cache, ipcache) `thenRn_`
+ Just name -> traceRn (text "newGlobalName: hit" <+> ppr name) `thenRn_`
+ returnRn name
+
+ Nothing -> setNameSupplyRn (us', new_cache, ipcache) `thenRn_`
+ traceRn (text "newGlobalName: new" <+> ppr name) `thenRn_`
returnRn name
where
(us', us1) = splitUniqSupply us
name = mkGlobalName uniq mod occ implicitImportProvenance
new_cache = addToFM cache key name
-updateProvenances :: [Name] -> RnM d ()
-updateProvenances names
- = getNameSupplyRn `thenRn` \ (us, inst_ns, cache, ipcache) ->
- setNameSupplyRn (us, inst_ns, update cache names, ipcache)
- where
- update cache [] = cache
- update cache (name:names) = WARN( not (key `elemFM` cache), ppr name )
- update (addToFM cache key name) names
- where
- key = (moduleName (nameModule name), nameOccName name)
-
-
-mkImportedGlobalFromRdrName :: RdrName -> RnM d Name
-mkImportedGlobalFromRdrName rdr_name
- | isQual rdr_name
- = mkImportedGlobalName (rdrNameModule rdr_name) (rdrNameOcc rdr_name)
-
- | otherwise
- = -- An Unqual is allowed; interface files contain
- -- unqualified names for locally-defined things, such as
- -- constructors of a data type.
- getModuleRn `thenRn ` \ mod_name ->
- mkImportedGlobalName mod_name (rdrNameOcc rdr_name)
-
-getIPName rdr_name
- = getNameSupplyRn `thenRn` \ (us, inst_ns, cache, ipcache) ->
+newIPName rdr_name
+ = getNameSupplyRn `thenRn` \ (us, cache, ipcache) ->
case lookupFM ipcache key of
Just name -> returnRn name
- Nothing -> setNameSupplyRn (us', inst_ns, cache, new_ipcache) `thenRn_`
+ Nothing -> setNameSupplyRn (us', cache, new_ipcache) `thenRn_`
returnRn name
where
(us', us1) = splitUniqSupply us
name = mkIPName uniq key
new_ipcache = addToFM ipcache key name
where key = (rdrNameOcc rdr_name)
+
+updateProvenances :: [Name] -> RnM d ()
+-- Update the provenances of everything that is in scope.
+-- We must be careful not to disturb the Module package info
+-- already in the cache. Why not? Consider
+-- module A module M( f )
+-- import M( f ) import N( f)
+-- import N
+-- So f is defined in N, and M re-exports it.
+-- When processing module A:
+-- 1. We read M.hi first, and make a vanilla name N.f
+-- (without reading N.hi). The package info says <THIS>
+-- for lack of anything better.
+-- 2. Now we read N, which update the cache to record
+-- the correct package for N.f.
+-- 3. Finally we update provenances (once we've read all imports).
+-- Step 3 must not destroy package info recorded in Step 2.
+
+updateProvenances names
+ = getNameSupplyRn `thenRn` \ (us, cache, ipcache) ->
+ setNameSupplyRn (us, foldr update cache names, ipcache)
+ where
+ update name cache = addToFM_C update_prov cache key name
+ where
+ key = (moduleName (nameModule name), nameOccName name)
+
+ update_prov name_in_cache name_with_prov
+ = setNameProvenance name_in_cache (getNameProvenance name_with_prov)
\end{code}
%*********************************************************
%* *
-\subsection{Dfuns and default methods}
+\subsection{Looking up names}
%* *
%*********************************************************
-@newImplicitBinder@ is used for (a) dfuns
-(b) default methods, defined in this module.
+Looking up a name in the RnEnv.
\begin{code}
-newImplicitBinder occ src_loc
- = getModuleRn `thenRn` \ mod_name ->
- newLocalTopBinder (mkThisModule mod_name) occ (\_ -> Exported) src_loc
+lookupBndrRn rdr_name
+ = getLocalNameEnv `thenRn` \ local_env ->
+ case lookupRdrEnv local_env rdr_name of
+ Just name -> returnRn name
+ Nothing -> lookupTopBndrRn rdr_name
+
+lookupTopBndrRn rdr_name
+ = getModeRn `thenRn` \ mode ->
+ case mode of
+ InterfaceMode -> -- Look in the global name cache
+ lookupOrigName rdr_name
+
+ SourceMode -> -- Source mode, so look up a *qualified* version
+ -- of the name, so that we get the right one even
+ -- if there are many with the same occ name
+ -- There must *be* a binding
+ getModuleRn `thenRn` \ mod ->
+ getGlobalNameEnv `thenRn` \ global_env ->
+ case lookupRdrEnv global_env (qualifyRdrName (moduleName mod) rdr_name) of
+ Just (name:rest) -> ASSERT( null rest )
+ returnRn name
+ Nothing -> -- Almost always this case is a compiler bug.
+ -- But consider a type signature that doesn't have
+ -- a corresponding binder:
+ -- module M where { f :: Int->Int }
+ -- We use lookupSigOccRn, which uses lookupBndrRn (for good reasons)
+ -- and we don't want to panic. So we report an out-of-scope error
+ failWithRn (mkUnboundName rdr_name)
+ (unknownNameErr rdr_name)
+
+-- lookupSigOccRn is used for type signatures and pragmas
+-- Is this valid?
+-- module A
+-- import M( f )
+-- f :: Int -> Int
+-- f x = x
+-- It's clear that the 'f' in the signature must refer to A.f
+-- The Haskell98 report does not stipulate this, but it will!
+-- So we must treat the 'f' in the signature in the same way
+-- as the binding occurrence of 'f', using lookupBndrRn
+lookupSigOccRn :: RdrName -> RnMS Name
+lookupSigOccRn = lookupBndrRn
+
+-- lookupOccRn looks up an occurrence of a RdrName
+lookupOccRn :: RdrName -> RnMS Name
+lookupOccRn rdr_name
+ = getLocalNameEnv `thenRn` \ local_env ->
+ case lookupRdrEnv local_env rdr_name of
+ Just name -> returnRn name
+ Nothing -> lookupGlobalOccRn rdr_name
+
+-- lookupGlobalOccRn is like lookupOccRn, except that it looks in the global
+-- environment. It's used only for
+-- record field names
+-- class op names in class and instance decls
+lookupGlobalOccRn rdr_name
+ = getModeRn `thenRn` \ mode ->
+ case mode of {
+ -- When processing interface files, the global env
+ -- is always empty, so go straight to the name cache
+ InterfaceMode -> lookupOrigName rdr_name ;
+
+ SourceMode ->
+
+ getGlobalNameEnv `thenRn` \ global_env ->
+ case lookupRdrEnv global_env rdr_name of
+ Just [name] -> returnRn name
+ Just stuff@(name:_) -> addNameClashErrRn rdr_name stuff `thenRn_`
+ returnRn name
+ Nothing -> -- Not found when processing source code; so fail
+ failWithRn (mkUnboundName rdr_name)
+ (unknownNameErr rdr_name)
+ }
\end{code}
+%
-Make a name for the dict fun for an instance decl
+@lookupOrigName@ takes an RdrName representing an {\em original}
+name, and adds it to the occurrence pool so that it'll be loaded
+later. This is used when language constructs (such as monad
+comprehensions, overloaded literals, or deriving clauses) require some
+stuff to be loaded that isn't explicitly mentioned in the code.
+
+This doesn't apply in interface mode, where everything is explicit,
+but we don't check for this case: it does no harm to record an
+``extra'' occurrence and @lookupOrigNames@ isn't used much in
+interface mode (it's only the @Nothing@ clause of @rnDerivs@ that
+calls it at all I think).
+
+ \fbox{{\em Jan 98: this comment is wrong: @rnHsType@ uses it quite a bit.}}
+
+For List and Tuple types it's important to get the correct
+@isLocallyDefined@ flag, which is used in turn when deciding
+whether there are any instance decls in this module are ``special''.
+The name cache should have the correct provenance, though.
\begin{code}
-newDFunName :: (OccName, OccName) -> SrcLoc -> RnMS Name
-newDFunName key@(cl_occ, tycon_occ) loc
- = newInstUniq string `thenRn` \ inst_uniq ->
- newImplicitBinder (mkDFunOcc string inst_uniq) loc
- where
- -- Any string that is somewhat unique will do
- string = occNameString cl_occ ++ occNameString tycon_occ
+lookupOrigName :: RdrName -> RnM d Name
+lookupOrigName rdr_name
+ | isQual rdr_name
+ = newGlobalName (rdrNameModule rdr_name) (rdrNameOcc rdr_name)
+
+ | otherwise
+ = -- An Unqual is allowed; interface files contain
+ -- unqualified names for locally-defined things, such as
+ -- constructors of a data type.
+ getModuleRn `thenRn ` \ mod ->
+ newGlobalName (moduleName mod) (rdrNameOcc rdr_name)
+
+lookupOrigNames :: [RdrName] -> RnM d NameSet
+lookupOrigNames rdr_names
+ = mapRn lookupOrigName rdr_names `thenRn` \ names ->
+ returnRn (mkNameSet names)
\end{code}
+lookupSysBinder is used for the "system binders" of a type, class, or instance decl.
+It ensures that the module is set correctly in the name cache, and sets the provenance
+on the returned name too. The returned name will end up actually in the type, class,
+or instance.
+
\begin{code}
-getDFunKey :: RenamedHsType -> (OccName, OccName) -- Used to manufacture DFun names
-getDFunKey (HsForAllTy _ _ ty) = getDFunKey ty
-getDFunKey (MonoFunTy _ ty) = getDFunKey ty
-getDFunKey (MonoDictTy cls (ty:_)) = (nameOccName cls, get_tycon_key ty)
-
-get_tycon_key (MonoTyVar tv) = nameOccName (getName tv)
-get_tycon_key (MonoTyApp ty _) = get_tycon_key ty
-get_tycon_key (MonoTupleTy tys True) = getOccName (tupleTyCon (length tys))
-get_tycon_key (MonoTupleTy tys False) = getOccName (unboxedTupleTyCon (length tys))
-get_tycon_key (MonoListTy _) = getOccName listTyCon
-get_tycon_key (MonoFunTy _ _) = getOccName funTyCon
+lookupSysBinder rdr_name
+ = ASSERT( isUnqual rdr_name )
+ getModuleRn `thenRn` \ mod ->
+ newTopBinder mod (rdrNameOcc rdr_name) `thenRn` \ name ->
+ getModeRn `thenRn` \ mode ->
+ case mode of
+ SourceMode -> getSrcLocRn `thenRn` \ loc ->
+ returnRn (setNameProvenance name (LocalDef loc Exported))
+ InterfaceMode -> returnRn name
+\end{code}
+
+@unQualInScope@ returns a function that takes a @Name@ and tells whether
+its unqualified name is in scope. This is put as a boolean flag in
+the @Name@'s provenance to guide whether or not to print the name qualified
+in error messages.
+
+\begin{code}
+unQualInScope :: GlobalRdrEnv -> Name -> Bool
+unQualInScope env
+ = lookup
+ where
+ lookup name = case lookupRdrEnv env (mkRdrUnqual (nameOccName name)) of
+ Just [name'] -> name == name'
+ other -> False
\end{code}
%*********************************************************
\begin{code}
--------------------------------------
bindLocatedLocalsRn :: SDoc -- Documentation string for error message
-> [(RdrName,SrcLoc)]
-> ([Name] -> RnMS a)
bindLocatedLocalsRn doc_str rdr_names_w_loc enclosed_scope
= checkDupOrQualNames doc_str rdr_names_w_loc `thenRn_`
+ getModeRn `thenRn` \ mode ->
getLocalNameEnv `thenRn` \ name_env ->
- (if opt_WarnNameShadowing
- then
- mapRn_ (check_shadow name_env) rdr_names_w_loc
- else
- returnRn ()
+
+ -- Warn about shadowing, but only in source modules
+ (case mode of
+ SourceMode | opt_WarnNameShadowing -> mapRn_ (check_shadow name_env) rdr_names_w_loc
+ other -> returnRn ()
) `thenRn_`
- getNameSupplyRn `thenRn` \ (us, inst_ns, cache, ipcache) ->
- getModeRn `thenRn` \ mode ->
+ getNameSupplyRn `thenRn` \ (us, cache, ipcache) ->
let
n = length rdr_names_w_loc
(us', us1) = splitUniqSupply us
-- Keep track of whether the name originally came from
-- an interface file.
in
- setNameSupplyRn (us', inst_ns, cache, ipcache) `thenRn_`
+ setNameSupplyRn (us', cache, ipcache) `thenRn_`
let
new_name_env = addListToRdrEnv name_env (map fst rdr_names_w_loc `zip` names)
bindCoreLocalFVRn rdr_name enclosed_scope
= getSrcLocRn `thenRn` \ loc ->
getLocalNameEnv `thenRn` \ name_env ->
- getNameSupplyRn `thenRn` \ (us, inst_ns, cache, ipcache) ->
+ getNameSupplyRn `thenRn` \ (us, cache, ipcache) ->
let
(us', us1) = splitUniqSupply us
uniq = uniqFromSupply us1
name = mkImportedLocalName uniq (rdrNameOcc rdr_name) loc
in
- setNameSupplyRn (us', inst_ns, cache, ipcache) `thenRn_`
+ setNameSupplyRn (us', cache, ipcache) `thenRn_`
let
new_name_env = extendRdrEnv name_env rdr_name name
in
bindCoreLocalsFVRn bs $ \ names' ->
thing_inside (name':names')
+bindLocalNames names enclosed_scope
+ = getLocalNameEnv `thenRn` \ name_env ->
+ setLocalNameEnv (addListToRdrEnv name_env pairs)
+ enclosed_scope
+ where
+ pairs = [(mkRdrUnqual (nameOccName n), n) | n <- names]
+
-------------------------------------
bindLocalRn doc rdr_name enclosed_scope
= getSrcLocRn `thenRn` \ loc ->
bindUVarRn = bindLocalRn
-------------------------------------
-extendTyVarEnvFVRn :: [HsTyVar Name] -> RnMS (a, FreeVars) -> RnMS (a, FreeVars)
+extendTyVarEnvFVRn :: [HsTyVarBndr Name] -> RnMS (a, FreeVars) -> RnMS (a, FreeVars)
-- This tiresome function is used only in rnDecl on InstDecl
extendTyVarEnvFVRn tyvars enclosed_scope
- = getLocalNameEnv `thenRn` \ env ->
- let
- tyvar_names = map getTyVarName tyvars
- new_env = addListToRdrEnv env [ (mkRdrUnqual (getOccName name), name)
- | name <- tyvar_names
- ]
- in
- setLocalNameEnv new_env enclosed_scope `thenRn` \ (thing, fvs) ->
+ = bindLocalNames tyvar_names enclosed_scope `thenRn` \ (thing, fvs) ->
returnRn (thing, delListFromNameSet fvs tyvar_names)
+ where
+ tyvar_names = hsTyVarNames tyvars
-bindTyVarsRn :: SDoc -> [HsTyVar RdrName]
- -> ([HsTyVar Name] -> RnMS a)
+bindTyVarsRn :: SDoc -> [HsTyVarBndr RdrName]
+ -> ([HsTyVarBndr Name] -> RnMS a)
-> RnMS a
bindTyVarsRn doc_str tyvar_names enclosed_scope
= bindTyVars2Rn doc_str tyvar_names $ \ names tyvars ->
enclosed_scope tyvars
-- Gruesome name: return Names as well as HsTyVars
-bindTyVars2Rn :: SDoc -> [HsTyVar RdrName]
- -> ([Name] -> [HsTyVar Name] -> RnMS a)
+bindTyVars2Rn :: SDoc -> [HsTyVarBndr RdrName]
+ -> ([Name] -> [HsTyVarBndr Name] -> RnMS a)
-> RnMS a
bindTyVars2Rn doc_str tyvar_names enclosed_scope
= getSrcLocRn `thenRn` \ loc ->
let
- located_tyvars = [(getTyVarName tv, loc) | tv <- tyvar_names]
+ located_tyvars = [(hsTyVarName tv, loc) | tv <- tyvar_names]
in
bindLocatedLocalsRn doc_str located_tyvars $ \ names ->
enclosed_scope names (zipWith replaceTyVarName tyvar_names names)
-bindTyVarsFVRn :: SDoc -> [HsTyVar RdrName]
- -> ([HsTyVar Name] -> RnMS (a, FreeVars))
+bindTyVarsFVRn :: SDoc -> [HsTyVarBndr RdrName]
+ -> ([HsTyVarBndr Name] -> RnMS (a, FreeVars))
-> RnMS (a, FreeVars)
bindTyVarsFVRn doc_str rdr_names enclosed_scope
= bindTyVars2Rn doc_str rdr_names $ \ names tyvars ->
enclosed_scope tyvars `thenRn` \ (thing, fvs) ->
returnRn (thing, delListFromNameSet fvs names)
-bindTyVarsFV2Rn :: SDoc -> [HsTyVar RdrName]
- -> ([Name] -> [HsTyVar Name] -> RnMS (a, FreeVars))
+bindTyVarsFV2Rn :: SDoc -> [HsTyVarBndr RdrName]
+ -> ([Name] -> [HsTyVarBndr Name] -> RnMS (a, FreeVars))
-> RnMS (a, FreeVars)
bindTyVarsFV2Rn doc_str rdr_names enclosed_scope
= bindTyVars2Rn doc_str rdr_names $ \ names tyvars ->
\end{code}
-%*********************************************************
-%* *
-\subsection{Looking up names}
-%* *
-%*********************************************************
-
-Looking up a name in the RnEnv.
-
-\begin{code}
-lookupBndrRn rdr_name
- = getNameEnvs `thenRn` \ (global_env, local_env) ->
-
- -- Try local env
- case lookupRdrEnv local_env rdr_name of {
- Just name -> returnRn name ;
- Nothing ->
-
- getModeRn `thenRn` \ mode ->
- case mode of
- InterfaceMode -> -- Look in the global name cache
- mkImportedGlobalFromRdrName rdr_name
-
- SourceMode -> -- Source mode, so look up a *qualified* version
- -- of the name, so that we get the right one even
- -- if there are many with the same occ name
- -- There must *be* a binding
- getModuleRn `thenRn` \ mod ->
- case lookupRdrEnv global_env (qualifyRdrName mod rdr_name) of
- Just (name:rest) -> ASSERT( null rest )
- returnRn name
- Nothing -> pprPanic "lookupBndrRn" (ppr mod <+> ppr rdr_name)
- }
-
--- Just like lookupRn except that we record the occurrence too
--- Perhaps surprisingly, even wired-in names are recorded.
--- Why? So that we know which wired-in names are referred to when
--- deciding which instance declarations to import.
-lookupOccRn :: RdrName -> RnMS Name
-lookupOccRn rdr_name
- = getNameEnvs `thenRn` \ (global_env, local_env) ->
- lookup_occ global_env local_env rdr_name
-
--- lookupGlobalOccRn is like lookupOccRn, except that it looks in the global
--- environment. It's used only for
--- record field names
--- class op names in class and instance decls
-lookupGlobalOccRn :: RdrName -> RnMS Name
-lookupGlobalOccRn rdr_name
- = getNameEnvs `thenRn` \ (global_env, local_env) ->
- lookup_global_occ global_env rdr_name
-
--- Look in both local and global env
-lookup_occ global_env local_env rdr_name
- = case lookupRdrEnv local_env rdr_name of
- Just name -> returnRn name
- Nothing -> lookup_global_occ global_env rdr_name
-
--- Look in global env only
-lookup_global_occ global_env rdr_name
- = case lookupRdrEnv global_env rdr_name of
- Just [name] -> returnRn name
- Just stuff@(name:_) -> addNameClashErrRn rdr_name stuff `thenRn_`
- returnRn name
- Nothing -> getModeRn `thenRn` \ mode ->
- case mode of
- -- Not found when processing source code; so fail
- SourceMode -> failWithRn (mkUnboundName rdr_name)
- (unknownNameErr rdr_name)
-
- -- Not found when processing an imported declaration,
- -- so we create a new name for the purpose
- InterfaceMode -> mkImportedGlobalFromRdrName rdr_name
-\end{code}
-%
-@lookupImplicitOccRn@ takes an RdrName representing an {\em original} name,
-and adds it to the occurrence pool so that it'll be loaded later.
-This is used when language constructs
-(such as monad comprehensions, overloaded literals, or deriving clauses)
-require some stuff to be loaded that isn't explicitly mentioned in the code.
-
-This doesn't apply in interface mode, where everything is explicit,
-but we don't check for this case:
-it does no harm to record an ``extra'' occurrence
-and @lookupImplicitOccRn@ isn't used much in interface mode
-(it's only the @Nothing@ clause of @rnDerivs@ that calls it at all I think).
-
- \fbox{{\em Jan 98: this comment is wrong: @rnHsType@ uses it quite a bit.}}
-
-For List and Tuple types it's important to get the correct
-@isLocallyDefined@ flag, which is used in turn when deciding
-whether there are any instance decls in this module are ``special''.
-The name cache should have the correct provenance, though.
-
-\begin{code}
-lookupImplicitOccRn :: RdrName -> RnM d Name
-lookupImplicitOccRn rdr_name = mkImportedGlobalFromRdrName rdr_name
-\end{code}
-
-@unQualInScope@ returns a function that takes a @Name@ and tells whether
-its unqualified name is in scope. This is put as a boolean flag in
-the @Name@'s provenance to guide whether or not to print the name qualified
-in error messages.
-
-\begin{code}
-unQualInScope :: GlobalRdrEnv -> Name -> Bool
-unQualInScope env
- = lookup
- where
- lookup name = case lookupRdrEnv env (mkRdrUnqual (nameOccName name)) of
- Just [name'] -> name == name'
- other -> False
-\end{code}
-
%************************************************************************
%* *
\subsection{Envt utility functions}
add n ns | any (is_duplicate n) ns_old = map choose ns -- Eliminate duplicates
| otherwise = n:ns
where
- choose n' | n==n' && better_provenance n n' = n
- | otherwise = n'
-
--- Choose
--- a local thing over an imported thing
--- a user-imported thing over a non-user-imported thing
--- an explicitly-imported thing over an implicitly imported thing
-better_provenance n1 n2
- = case (getNameProvenance n1, getNameProvenance n2) of
- (LocalDef _ _, _ ) -> True
- (NonLocalDef (UserImport _ _ True) _, _ ) -> True
- (NonLocalDef (UserImport _ _ _ ) _, NonLocalDef ImplicitImport _) -> True
- other -> False
+ choose m | n==m && n `hasBetterProv` m = n
+ | otherwise = m
+
is_duplicate :: Name -> Name -> Bool
is_duplicate n1 n2 | isLocallyDefined n1 && isLocallyDefined n2 = False
| otherwise = n1 == n2
\end{code}
+
We treat two bindings of a locally-defined name as a duplicate,
because they might be two separate, local defns and we want to report
and error for that, {\em not} eliminate a duplicate.
-\subsubsection{ExportAvails}% ================
-
-\begin{code}
-mkEmptyExportAvails :: ModuleName -> ExportAvails
-mkEmptyExportAvails mod_name = (unitFM mod_name [], emptyUFM)
-
-mkExportAvails :: ModuleName -> Bool -> GlobalRdrEnv -> [AvailInfo] -> ExportAvails
-mkExportAvails mod_name unqual_imp name_env avails
- = (mod_avail_env, entity_avail_env)
- 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 name_env n
-
- entity_avail_env = listToUFM [ (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!
-\end{code}
-
-
\subsubsection{AvailInfo}% ================
\begin{code}
#endif
addAvail :: AvailEnv -> AvailInfo -> AvailEnv
-addAvail avails avail = addToNameEnv_C plusAvail avails (availName avail) avail
+addAvail avails avail = extendNameEnv_C plusAvail avails (availName avail) avail
emptyAvailEnv = emptyNameEnv
unitAvailEnv :: AvailInfo -> AvailEnv
availsToNameSet :: [AvailInfo] -> NameSet
availsToNameSet avails = foldl addAvailToNameSet emptyNameSet avails
-availName :: AvailInfo -> Name
+availName :: GenAvailInfo name -> name
availName (Avail n) = n
availName (AvailTC n _) = n
-availNames :: AvailInfo -> [Name]
+availNames :: GenAvailInfo name -> [name]
availNames (Avail n) = [n]
availNames (AvailTC n ns) = ns
addSysAvails avail [] = avail
addSysAvails (AvailTC n ns) sys = AvailTC n (sys ++ ns)
+rdrAvailInfo :: AvailInfo -> RdrAvailInfo
+-- Used when building the avails we are going to put in an interface file
+-- We sort the components to reduce needless wobbling of interfaces
+rdrAvailInfo (Avail n) = Avail (nameOccName n)
+rdrAvailInfo (AvailTC n ns) = AvailTC (nameOccName n) (sortLt (<) (map nameOccName ns))
+
filterAvail :: RdrNameIE -- Wanted
-> AvailInfo -- Available
-> Maybe AvailInfo -- Resulting available;
\begin{code}
-warnUnusedLocalBinds, warnUnusedImports, warnUnusedMatches :: [Name] -> RnM d ()
+warnUnusedModules :: [Module] -> RnM d ()
+warnUnusedModules mods
+ | not opt_WarnUnusedImports = returnRn ()
+ | otherwise = mapRn_ (addWarnRn . unused_mod . moduleName) mods
+ where
+ unused_mod m = vcat [ptext SLIT("Module") <+> quotes (pprModuleName m) <+>
+ text "is imported, but nothing from it is used",
+ parens (ptext SLIT("except perhaps to re-export instances visible in") <+>
+ quotes (pprModuleName m))]
+warnUnusedLocalBinds, warnUnusedImports, warnUnusedMatches :: [Name] -> RnM d ()
warnUnusedImports names
| not opt_WarnUnusedImports
= returnRn () -- Don't force names unless necessary
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