%
-% (c) The GRASP/AQUA Project, Glasgow University, 1992-1996
+% (c) The GRASP/AQUA Project, Glasgow University, 1992-1998
%
\section[RnEnv]{Environment manipulation for the renamer monad}
import CmdLineOpts ( opt_WarnNameShadowing, opt_WarnUnusedMatches,
opt_WarnUnusedBinds, opt_WarnUnusedImports )
import HsSyn
-import RdrHsSyn ( RdrName(..), RdrNameIE,
- rdrNameOcc, isQual, qual, isClassDataConRdrName
+import RdrHsSyn ( RdrNameIE )
+import RnHsSyn ( RenamedHsType )
+import RdrName ( RdrName, rdrNameModule, rdrNameOcc, isQual, isUnqual,
+ mkRdrUnqual, qualifyRdrName
)
-import HsTypes ( getTyVarName, replaceTyVarName )
-import BasicTypes ( Fixity(..), FixityDirection(..), IfaceFlavour(..) )
+import HsTypes ( hsTyVarName, hsTyVarNames, replaceTyVarName )
+
import RnMonad
-import ErrUtils ( ErrMsg )
-import Name ( Name, OccName(..), Provenance(..), ExportFlag(..), NamedThing(..),
- occNameFlavour, getSrcLoc, occNameString,
- NameSet, emptyNameSet, addListToNameSet, nameSetToList,
- mkLocalName, mkGlobalName, modAndOcc,
- nameOccName, setNameProvenance, isVarOcc, getNameProvenance,
- pprOccName, isLocalName
+import Name ( Name, Provenance(..), ExportFlag(..), NamedThing(..),
+ ImportReason(..), getSrcLoc,
+ mkLocalName, mkImportedLocalName, mkGlobalName, mkUnboundName,
+ mkIPName, isWiredInName, hasBetterProv,
+ nameOccName, setNameModule, nameModule,
+ pprOccName, isLocallyDefined, nameUnique,
+ setNameProvenance, getNameProvenance, pprNameProvenance,
+ extendNameEnv_C, plusNameEnv_C, nameEnvElts
+ )
+import NameSet
+import OccName ( OccName,
+ mkDFunOcc, occNameUserString, occNameString,
+ occNameFlavour
)
-import TyCon ( TyCon )
-import TysWiredIn ( tupleTyCon, listTyCon, charTyCon )
+import TysWiredIn ( listTyCon )
+import Type ( funTyCon )
+import Module ( ModuleName, mkThisModule, moduleName, mkVanillaModule, pprModuleName )
import FiniteMap
-import Unique ( Unique, Uniquable(..), unboundKey )
-import UniqFM ( listToUFM, plusUFM_C )
import UniqSupply
import SrcLoc ( SrcLoc, noSrcLoc )
import Outputable
-import Util ( removeDups )
+import Util ( removeDups, equivClasses, thenCmp, sortLt )
import List ( nub )
-import Char ( isAlphanum )
\end{code}
%*********************************************************
\begin{code}
-newImportedGlobalName :: Module -> OccName
- -> IfaceFlavour
- -> RnM s d Name
-newImportedGlobalName mod occ hif
- = -- First check the cache
- getNameSupplyRn `thenRn` \ (us, inst_ns, cache) ->
- let
- key = (mod,occ)
- prov = NonLocalDef noSrcLoc hif False
- in
- case lookupFM cache key of
+implicitImportProvenance = NonLocalDef ImplicitImport False
- -- A hit in the cache!
- -- If it has no provenance at the moment then set its provenance
- -- so that it has the right HiFlag component.
- -- (This is necessary
- -- for known-key things. For example, GHCmain.lhs imports as SOURCE
- -- Main; but Main.main is a known-key thing.)
- -- Don't fiddle with the provenance if it already has one
- Just name -> case getNameProvenance name of
- NoProvenance -> let
- new_name = setNameProvenance name prov
- new_cache = addToFM cache key new_name
- in
- setNameSupplyRn (us, inst_ns, new_cache) `thenRn_`
- returnRn new_name
- other -> returnRn name
-
- Nothing -> -- Miss in the cache!
- -- Build a new original name, and put it in the cache
- let
- (us', us1) = splitUniqSupply us
- uniq = getUnique us1
- name = mkGlobalName uniq mod occ prov
- new_cache = addToFM cache key name
- in
- setNameSupplyRn (us', inst_ns, new_cache) `thenRn_`
- returnRn name
-
-{-
- let
- pprC ((mod,occ),name) = pprModule mod <> text "." <> pprOccName occ <+> text "--->"
- <+> ppr name
- in
- pprTrace "ng" (vcat [text "newGlobalName miss" <+> pprModule mod <+> pprOccName occ,
- brackets (sep (map pprC (fmToList cache))),
- text ""
- ]) $
--}
-
-
-newLocallyDefinedGlobalName :: Module -> OccName
- -> (Name -> ExportFlag) -> SrcLoc
- -> RnM s d Name
-newLocallyDefinedGlobalName mod occ rec_exp_fn loc
+newTopBinder :: Module -> OccName -> RnM d Name
+newTopBinder mod occ
= -- First check the cache
- getNameSupplyRn `thenRn` \ (us, inst_ns, cache) ->
+ traceRn (text "newTopBinder" <+> ppr mod <+> ppr occ) `thenRn_`
+
+ getNameSupplyRn `thenRn` \ (us, cache, ipcache) ->
let
- key = (mod,occ)
+ key = (moduleName mod, occ)
in
case lookupFM cache key of
- -- A hit in the cache!
- -- Overwrite whatever provenance is in the cache already;
- -- this updates WiredIn things and known-key things,
- -- which are there from the start, to LocalDef.
+ -- 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.
+ --
+ -- 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 = setNameProvenance name (LocalDef loc (rec_exp_fn new_name))
+ new_name = setNameModule name mod
new_cache = addToFM cache key new_name
in
- setNameSupplyRn (us, inst_ns, new_cache) `thenRn_`
+ setNameSupplyRn (us, new_cache, ipcache) `thenRn_`
+ traceRn (text "newTopBinder: overwrite" <+> ppr new_name) `thenRn_`
returnRn new_name
-- Miss in the cache!
- -- Build a new original name, and put it 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
- provenance = LocalDef loc (rec_exp_fn new_name)
(us', us1) = splitUniqSupply us
- uniq = getUnique us1
- new_name = mkGlobalName uniq mod occ provenance
+ uniq = uniqFromSupply us1
+ new_name = mkGlobalName uniq mod occ implicitImportProvenance
new_cache = addToFM cache key new_name
in
- setNameSupplyRn (us', inst_ns, new_cache) `thenRn_`
+ setNameSupplyRn (us', new_cache, ipcache) `thenRn_`
+ traceRn (text "newTopBinder: new" <+> ppr new_name) `thenRn_`
returnRn new_name
--- newDfunName is a variant, specially for dfuns.
--- When renaming derived definitions we are in *interface* mode (because we can trip
--- over original names), but we still want to make the Dfun locally-defined.
--- So we can't use whether or not we're in source mode to decide the locally-defined question.
-newDfunName :: OccName -> OccName -> Maybe RdrName -> SrcLoc -> RnMS s Name
-newDfunName _ _ (Just n) src_loc -- Imported ones have "Just n"
- = getModuleRn `thenRn` \ mod_name ->
- newImportedGlobalName mod_name (rdrNameOcc n) HiFile {- Correct? -}
-newDfunName cl_nm tycon_nm Nothing src_loc -- Local instance decls have a "Nothing"
- = getModuleRn `thenRn` \ mod_name ->
- newInstUniq name `thenRn` \ inst_uniq ->
+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.
+ --
+ -- (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
+ -- *binding* declaration. It's the type checker that propagates the
+ -- correct information to all the occurrences.
+ -- Since implicitly-imported names never occur in error messages,
+ -- 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).
+newGlobalName mod_name occ
+ = getNameSupplyRn `thenRn` \ (us, cache, ipcache) ->
let
- dfun_occ = VarOcc (_PK_ ("$d" ++ (_UNPK_ name) ++ show inst_uniq))
+ key = (mod_name, occ)
in
- newLocallyDefinedGlobalName mod_name dfun_occ
- (\_ -> Exported) src_loc
- where
- {-
- Dictionary names have the following form
+ case lookupFM cache key of
+ 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
+ uniq = uniqFromSupply us1
+ mod = mkVanillaModule mod_name
+ name = mkGlobalName uniq mod occ implicitImportProvenance
+ new_cache = addToFM cache key name
+
+
+newIPName rdr_name
+ = getNameSupplyRn `thenRn` \ (us, cache, ipcache) ->
+ case lookupFM ipcache key of
+ Just name -> returnRn name
+ Nothing -> setNameSupplyRn (us', cache, new_ipcache) `thenRn_`
+ returnRn name
+ where
+ (us', us1) = splitUniqSupply us
+ uniq = uniqFromSupply us1
+ 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)
- $d<class><tycon><n>
+ update_prov name_in_cache name_with_prov
+ = setNameProvenance name_in_cache (getNameProvenance name_with_prov)
+\end{code}
- where "n" is a positive number, and "tycon" is the
- name of the type constructor for which a "class"
- instance is derived.
-
- Prefixing dictionary names with their class and instance
- types improves the behaviour of the recompilation checker.
- (fewer recompilations required should an instance or type
- declaration be added to a module.)
- -}
- -- We're dropping the modids on purpose.
- tycon_nm_str = occNameString tycon_nm
- cl_nm_str = occNameString cl_nm
-
- -- give up on any type constructor that starts with a
- -- non-alphanumeric char (e.g., [] (,*)
- name
- | (_NULL_ tycon_nm_str) || not (isAlphanum (_HEAD_ (tycon_nm_str))) = cl_nm_str
- | otherwise = cl_nm_str _APPEND_ tycon_nm_str
-
-
-newLocalNames :: [(RdrName,SrcLoc)] -> RnM s d [Name]
-newLocalNames rdr_names
- = getNameSupplyRn `thenRn` \ (us, inst_ns, cache) ->
- let
- n = length rdr_names
- (us', us1) = splitUniqSupply us
- uniqs = getUniques n us1
- locals = [ mkLocalName uniq (rdrNameOcc rdr_name) loc
- | ((rdr_name,loc), uniq) <- rdr_names `zip` uniqs
- ]
- in
- setNameSupplyRn (us', inst_ns, cache) `thenRn_`
- returnRn locals
+%*********************************************************
+%* *
+\subsection{Looking up names}
+%* *
+%*********************************************************
+
+Looking up a name in the RnEnv.
+
+\begin{code}
+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}
+%
+
+@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}
+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.
--- mkUnboundName makes a place-holder Name; it shouldn't be looked at except possibly
--- during compiler debugging.
-mkUnboundName :: RdrName -> Name
-mkUnboundName rdr_name = mkLocalName unboundKey (rdrNameOcc rdr_name) noSrcLoc
+\begin{code}
+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.
-isUnboundName :: Name -> Bool
-isUnboundName name = uniqueOf name == unboundKey
+\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{Binding}
+%* *
+%*********************************************************
+
\begin{code}
-bindLocatedLocalsRn :: SDoc -- Documentation string for error message
+bindLocatedLocalsRn :: SDoc -- Documentation string for error message
-> [(RdrName,SrcLoc)]
- -> ([Name] -> RnMS s a)
- -> RnMS s a
+ -> ([Name] -> RnMS a)
+ -> 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_`
- newLocalNames rdr_names_w_loc `thenRn` \ names ->
+ getNameSupplyRn `thenRn` \ (us, cache, ipcache) ->
let
- new_name_env = addListToFM name_env (map fst rdr_names_w_loc `zip` names)
+ n = length rdr_names_w_loc
+ (us', us1) = splitUniqSupply us
+ uniqs = uniqsFromSupply n us1
+ names = [ mk_name uniq (rdrNameOcc rdr_name) loc
+ | ((rdr_name,loc), uniq) <- rdr_names_w_loc `zip` uniqs
+ ]
+ mk_name = case mode of
+ SourceMode -> mkLocalName
+ InterfaceMode -> mkImportedLocalName
+ -- Keep track of whether the name originally came from
+ -- an interface file.
+ in
+ setNameSupplyRn (us', cache, ipcache) `thenRn_`
+
+ let
+ new_name_env = addListToRdrEnv name_env (map fst rdr_names_w_loc `zip` names)
in
setLocalNameEnv new_name_env (enclosed_scope names)
+
where
check_shadow name_env (rdr_name,loc)
- = case lookupFM name_env rdr_name of
+ = case lookupRdrEnv name_env rdr_name of
Nothing -> returnRn ()
Just name -> pushSrcLocRn loc $
addWarnRn (shadowedNameWarn rdr_name)
-bindLocalsRn doc_str rdr_names enclosed_scope
+bindCoreLocalFVRn :: RdrName -> (Name -> RnMS (a, FreeVars))
+ -> RnMS (a, FreeVars)
+ -- A specialised variant when renaming stuff from interface
+ -- files (of which there is a lot)
+ -- * one at a time
+ -- * no checks for shadowing
+ -- * always imported
+ -- * deal with free vars
+bindCoreLocalFVRn rdr_name enclosed_scope
+ = getSrcLocRn `thenRn` \ loc ->
+ getLocalNameEnv `thenRn` \ name_env ->
+ getNameSupplyRn `thenRn` \ (us, cache, ipcache) ->
+ let
+ (us', us1) = splitUniqSupply us
+ uniq = uniqFromSupply us1
+ name = mkImportedLocalName uniq (rdrNameOcc rdr_name) loc
+ in
+ setNameSupplyRn (us', cache, ipcache) `thenRn_`
+ let
+ new_name_env = extendRdrEnv name_env rdr_name name
+ in
+ setLocalNameEnv new_name_env (enclosed_scope name) `thenRn` \ (result, fvs) ->
+ returnRn (result, delFromNameSet fvs name)
+
+bindCoreLocalsFVRn [] thing_inside = thing_inside []
+bindCoreLocalsFVRn (b:bs) thing_inside = bindCoreLocalFVRn b $ \ name' ->
+ 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 ->
+ bindLocatedLocalsRn doc [(rdr_name,loc)] $ \ (n:ns) ->
+ ASSERT( null ns )
+ enclosed_scope n
+
+bindLocalsRn doc rdr_names enclosed_scope
= getSrcLocRn `thenRn` \ loc ->
- bindLocatedLocalsRn (text doc_str)
+ bindLocatedLocalsRn doc
(rdr_names `zip` repeat loc)
enclosed_scope
+ -- binLocalsFVRn is the same as bindLocalsRn
+ -- except that it deals with free vars
+bindLocalsFVRn doc rdr_names enclosed_scope
+ = bindLocalsRn doc rdr_names $ \ names ->
+ enclosed_scope names `thenRn` \ (thing, fvs) ->
+ returnRn (thing, delListFromNameSet fvs names)
+
+-------------------------------------
+bindUVarRn :: SDoc -> RdrName -> (Name -> RnMS (a, FreeVars)) -> RnMS (a, FreeVars)
+bindUVarRn = bindLocalRn
+
+-------------------------------------
+extendTyVarEnvFVRn :: [HsTyVarBndr Name] -> RnMS (a, FreeVars) -> RnMS (a, FreeVars)
+ -- This tiresome function is used only in rnDecl on InstDecl
+extendTyVarEnvFVRn tyvars enclosed_scope
+ = bindLocalNames tyvar_names enclosed_scope `thenRn` \ (thing, fvs) ->
+ returnRn (thing, delListFromNameSet fvs tyvar_names)
+ where
+ tyvar_names = hsTyVarNames tyvars
+
+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 -> [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 (zipWith replaceTyVarName tyvar_names names)
-
- -- Works in any variant of the renamer monad
+ enclosed_scope names (zipWith replaceTyVarName tyvar_names names)
+
+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 -> [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 ->
+ enclosed_scope names tyvars `thenRn` \ (thing, fvs) ->
+ returnRn (thing, delListFromNameSet fvs names)
+
+
+-------------------------------------
checkDupOrQualNames, checkDupNames :: SDoc
-> [(RdrName, SrcLoc)]
- -> RnM s d ()
+ -> RnM d ()
+ -- Works in any variant of the renamer monad
checkDupOrQualNames doc_str rdr_names_w_loc
= -- Check for use of qualified names
- mapRn (qualNameErr doc_str) quals `thenRn_`
+ mapRn_ (qualNameErr doc_str) quals `thenRn_`
checkDupNames doc_str rdr_names_w_loc
where
quals = filter (isQual.fst) rdr_names_w_loc
checkDupNames doc_str rdr_names_w_loc
- = -- Check for dupicated names in a binding group
- mapRn (dupNamesErr doc_str) dups `thenRn_`
- returnRn ()
+ = -- Check for duplicated names in a binding group
+ mapRn_ (dupNamesErr doc_str) dups
where
(_, dups) = removeDups (\(n1,l1) (n2,l2) -> n1 `compare` n2) rdr_names_w_loc
-
-
--- Yuk!
-ifaceFlavour name = case getNameProvenance name of
- NonLocalDef _ hif _ -> hif
- other -> HiFile -- Shouldn't happen
-\end{code}
-
-
-%*********************************************************
-%* *
-\subsection{Looking up names}
-%* *
-%*********************************************************
-
-Looking up a name in the RnEnv.
-
-\begin{code}
-checkUnboundRn :: RdrName -> Maybe Name -> RnMS s Name
-checkUnboundRn rdr_name (Just name)
- = -- Found it!
- returnRn name
-
-checkUnboundRn rdr_name Nothing
- = -- Not found by lookup
- 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 _ _ ->
- case rdr_name of
- Qual mod_name occ hif -> newImportedGlobalName mod_name occ hif
-
- -- An Unqual is allowed; interface files contain
- -- unqualified names for locally-defined things, such as
- -- constructors of a data type.
- Unqual occ -> getModuleRn `thenRn ` \ mod_name ->
- newImportedGlobalName mod_name occ HiFile
-
-
-lookupBndrRn rdr_name
- = lookupNameRn rdr_name `thenRn` \ maybe_name ->
- checkUnboundRn rdr_name maybe_name `thenRn` \ name ->
-
- if isLocalName name then
- returnRn name
- else
-
- ----------------------------------------------------
- -- OK, so we're at the binding site of a top-level defn
- -- Check to see whether its an imported decl
- getModeRn `thenRn` \ mode ->
- case mode of {
- SourceMode -> returnRn name ;
-
- InterfaceMode _ print_unqual_fn ->
-
- ----------------------------------------------------
- -- OK, the binding site of an *imported* defn
- -- so we can make the provenance more informative
- getSrcLocRn `thenRn` \ src_loc ->
- let
- name' = case getNameProvenance name of
- NonLocalDef _ hif _ -> setNameProvenance name
- (NonLocalDef src_loc hif (print_unqual_fn name'))
- other -> name
- in
- returnRn 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 s Name
-lookupOccRn rdr_name
- = lookupNameRn rdr_name `thenRn` \ maybe_name ->
- checkUnboundRn rdr_name maybe_name `thenRn` \ name ->
- let
- name' = mungePrintUnqual rdr_name name
- in
- addOccurrenceName 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 s Name
-lookupGlobalOccRn rdr_name
- = lookupGlobalNameRn rdr_name `thenRn` \ maybe_name ->
- checkUnboundRn rdr_name maybe_name `thenRn` \ name ->
- let
- name' = mungePrintUnqual rdr_name name
- in
- addOccurrenceName name'
-
-
--- mungePrintUnqual is used to make *imported* *occurrences* print unqualified
--- if they were mentioned unqualified in the source code.
--- This improves error messages from the type checker.
--- NB: the binding site is treated differently; see lookupBndrRn
--- After the type checker all occurrences are replaced by the one
--- at the binding site.
-mungePrintUnqual (Qual _ _ _) name = name
-mungePrintUnqual (Unqual _) name = case new_prov of
- Nothing -> name
- Just prov' -> setNameProvenance name prov'
- where
- new_prov = case getNameProvenance name of
- NonLocalDef loc hif False -> Just (NonLocalDef loc hif True)
- other -> Nothing
-
--- lookupImplicitOccRn takes an RdrName representing an *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).
--- [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.
-
-lookupImplicitOccRn :: RdrName -> RnMS s Name
-lookupImplicitOccRn (Qual mod occ hif)
- = newImportedGlobalName mod occ hif `thenRn` \ name ->
- addOccurrenceName name
-
-addImplicitOccRn :: Name -> RnMS s Name
-addImplicitOccRn name = addOccurrenceName name
-
-addImplicitOccsRn :: [Name] -> RnMS s ()
-addImplicitOccsRn names = addOccurrenceNames names
-
-listType_RDR = qual (modAndOcc listType_name)
-tupleType_RDR n = qual (modAndOcc (tupleType_name n))
-
-charType_name = getName charTyCon
-listType_name = getName listTyCon
-tupleType_name n = getName (tupleTyCon n)
\end{code}
-\begin{code}
-lookupFixity :: RdrName -> RnMS s Fixity
-lookupFixity rdr_name
- = getFixityEnv `thenRn` \ fixity_env ->
- returnRn (lookupFixityEnv fixity_env rdr_name)
-\end{code}
-
-mkImportFn 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}
-mkImportFn :: RnEnv -> Name -> Bool
-mkImportFn (RnEnv env _)
- = lookup
- where
- lookup name = case lookupFM env (Unqual (nameOccName name)) of
- Just (name', _) -> name == name'
- Nothing -> False
-\end{code}
%************************************************************************
%* *
%* *
%************************************************************************
-=============== RnEnv ================
-\begin{code}
-plusRnEnv (RnEnv n1 f1) (RnEnv n2 f2)
- = plusGlobalNameEnvRn n1 n2 `thenRn` \ n ->
- plusFixityEnvRn f1 f2 `thenRn` \ f ->
- returnRn (RnEnv n f)
-\end{code}
-
+\subsubsection{NameEnv}% ================
-=============== NameEnv ================
\begin{code}
-plusGlobalNameEnvRn :: GlobalNameEnv -> GlobalNameEnv -> RnM s d GlobalNameEnv
-plusGlobalNameEnvRn env1 env2
- = mapRn addNameClashErrRn (conflictsFM conflicting_name env1 env2) `thenRn_`
- returnRn (env1 `plusFM` env2)
-
-addOneToGlobalNameEnv :: GlobalNameEnv -> RdrName -> (Name, HowInScope) -> RnM s d GlobalNameEnv
-addOneToGlobalNameEnv env rdr_name name
- = case lookupFM env rdr_name of
- Just name2 | conflicting_name name name2
- -> addNameClashErrRn (rdr_name, (name, name2)) `thenRn_`
- returnRn env
-
- other -> returnRn (addToFM env rdr_name name)
-
-delOneFromGlobalNameEnv :: GlobalNameEnv -> RdrName -> GlobalNameEnv
-delOneFromGlobalNameEnv env rdr_name = delFromFM env rdr_name
-
-conflicting_name :: (Name, HowInScope) -> (Name, HowInScope) -> Bool
-conflicting_name (n1, FromLocalDefn _) (n2, FromLocalDefn _) = True
-conflicting_name (n1,h1) (n2,h2) = n1 /= n2
- -- We complain of a conflict if one RdrName maps to two different Names,
- -- OR if one RdrName maps to the same *locally-defined* Name. The latter
- -- case is to catch two separate, local definitions of the same thing.
- --
- -- If a module imports itself then there might be a local defn and an imported
- -- defn of the same name; in this case the names will compare as equal, but
- -- will still have different HowInScope fields
-
-lookupNameEnv :: NameEnv -> RdrName -> Maybe Name
-lookupNameEnv = lookupFM
-\end{code}
+plusGlobalRdrEnv :: GlobalRdrEnv -> GlobalRdrEnv -> GlobalRdrEnv
+plusGlobalRdrEnv env1 env2 = plusFM_C combine_globals env1 env2
-=============== FixityEnv ================
-\begin{code}
-plusFixityEnvRn f1 f2
- = mapRn (addErrRn.fixityClashErr) (conflictsFM bad_fix f1 f2) `thenRn_`
- returnRn (f1 `plusFM` f2)
+addOneToGlobalRdrEnv :: GlobalRdrEnv -> RdrName -> Name -> GlobalRdrEnv
+addOneToGlobalRdrEnv env rdr_name name = addToFM_C combine_globals env rdr_name [name]
-addOneToFixityEnv env rdr_name fixity = addToFM env rdr_name fixity
+delOneFromGlobalRdrEnv :: GlobalRdrEnv -> RdrName -> GlobalRdrEnv
+delOneFromGlobalRdrEnv env rdr_name = delFromFM env rdr_name
-lookupFixityEnv env rdr_name
- = case lookupFM env rdr_name of
- Just (fixity,_) -> fixity
- Nothing -> Fixity 9 InfixL -- Default case
+combine_globals :: [Name] -- Old
+ -> [Name] -- New
+ -> [Name]
+combine_globals ns_old ns_new -- ns_new is often short
+ = foldr add ns_old ns_new
+ where
+ add n ns | any (is_duplicate n) ns_old = map choose ns -- Eliminate duplicates
+ | otherwise = n:ns
+ where
+ choose m | n==m && n `hasBetterProv` m = n
+ | otherwise = m
-bad_fix :: (Fixity, HowInScope) -> (Fixity, HowInScope) -> Bool
-bad_fix (f1,_) (f2,_) = f1 /= f2
-pprFixityProvenance :: (Fixity, HowInScope) -> SDoc
-pprFixityProvenance (fixity, how_in_scope) = ppr how_in_scope
+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.
+On the other hand, if you import the same name from two different
+import statements, we {\em d}* want to eliminate the duplicate, not report
+an error.
-=============== ExportAvails ================
-\begin{code}
-mkExportAvails :: Module -> Bool -> GlobalNameEnv -> [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 = [prune avail | avail <- avails]
+If a module imports itself then there might be a local defn and an imported
+defn of the same name; in this case the names will compare as equal, but
+will still have different provenances.
- prune (Avail n) | unqual_in_scope n = Avail n
- prune (Avail n) | otherwise = NotAvailable
- prune (AvailTC n ns) = AvailTC n (filter unqual_in_scope ns)
- unqual_in_scope n = Unqual (nameOccName n) `elemFM` name_env
- entity_avail_env = listToUFM [ (name,avail) | avail <- avails,
- name <- availEntityNames avail]
+\subsubsection{AvailInfo}% ================
-plusExportAvails :: ExportAvails -> ExportAvails -> ExportAvails
-plusExportAvails (m1, e1) (m2, e2)
- = (plusFM_C (++) m1 m2, plusUFM_C plusAvail e1 e2)
-\end{code}
-
-
-=============== AvailInfo ================
\begin{code}
plusAvail (Avail n1) (Avail n2) = Avail n1
-plusAvail (AvailTC n1 ns1) (AvailTC n2 ns2) = AvailTC n1 (nub (ns1 ++ ns2))
-plusAvail a NotAvailable = a
-plusAvail NotAvailable a = a
+plusAvail (AvailTC n1 ns1) (AvailTC n2 ns2) = AvailTC n2 (nub (ns1 ++ ns2))
-- Added SOF 4/97
#ifdef DEBUG
plusAvail a1 a2 = pprPanic "RnEnv.plusAvail" (hsep [pprAvail a1,pprAvail a2])
#endif
+addAvail :: AvailEnv -> AvailInfo -> AvailEnv
+addAvail avails avail = extendNameEnv_C plusAvail avails (availName avail) avail
+
+emptyAvailEnv = emptyNameEnv
+unitAvailEnv :: AvailInfo -> AvailEnv
+unitAvailEnv a = unitNameEnv (availName a) a
+
+plusAvailEnv :: AvailEnv -> AvailEnv -> AvailEnv
+plusAvailEnv = plusNameEnv_C plusAvail
+
+availEnvElts = nameEnvElts
+
addAvailToNameSet :: NameSet -> AvailInfo -> NameSet
addAvailToNameSet names avail = addListToNameSet names (availNames avail)
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 NotAvailable = []
+availNames :: GenAvailInfo name -> [name]
availNames (Avail n) = [n]
availNames (AvailTC n ns) = ns
--- availEntityNames is used to extract the names that can appear on their own in
--- an export or import list. For class decls, class methods can appear on their
--- own, thus import A( op )
--- but constructors cannot; thus
--- import B( T )
--- means import type T from B, not constructor T.
+addSysAvails :: AvailInfo -> [Name] -> AvailInfo
+addSysAvails avail [] = avail
+addSysAvails (AvailTC n ns) sys = AvailTC n (sys ++ ns)
-availEntityNames :: AvailInfo -> [Name]
-availEntityNames NotAvailable = []
-availEntityNames (Avail n) = [n]
-availEntityNames (AvailTC n ns) = n : filter (isVarOcc . nameOccName) 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
- -> AvailInfo -- Resulting available;
- -- NotAvailable if wanted stuff isn't there
+ -> 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 = AvailTC n (filter is_wanted ns)
- | otherwise =
-#ifdef DEBUG
- pprTrace "filterAvail" (hsep [ppr ie, pprAvail avail]) $
-#endif
- NotAvailable
+ | 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
wanted_occs = map rdrNameOcc (want:wants)
filterAvail (IEThingAbs _) (AvailTC n ns) = ASSERT( n `elem` ns )
- AvailTC n [n]
+ Just (AvailTC n [n])
-filterAvail (IEThingAbs _) avail@(Avail n) = avail -- Type synonyms
+filterAvail (IEThingAbs _) avail@(Avail n) = Just avail -- Type synonyms
-filterAvail (IEVar _) avail@(Avail n) = avail
-filterAvail (IEVar v) avail@(AvailTC n ns) = AvailTC n (filter wanted ns)
+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
-- import A( op )
-- where op is a class operation
-filterAvail (IEThingAll _) avail@(AvailTC _ _) = avail
-
-filterAvail ie avail = NotAvailable
+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
--- In interfaces, pprAvail gets given the OccName of the "host" thing
-pprAvail avail = getPprStyle $ \ sty ->
- if ifaceStyle sty then
- ppr_avail (pprOccName . nameOccName) avail
- else
- ppr_avail ppr avail
+pprAvail :: AvailInfo -> SDoc
+pprAvail (AvailTC n ns) = ppr n <> case filter (/= n) ns of
+ [] -> empty
+ ns' -> parens (hsep (punctuate comma (map ppr ns')))
-ppr_avail pp_name NotAvailable = ptext SLIT("NotAvailable")
-ppr_avail pp_name (AvailTC n ns) = hsep [
- pp_name n,
- parens $ hsep $ punctuate comma $
- map pp_name ns
- ]
-ppr_avail pp_name (Avail n) = pp_name n
+pprAvail (Avail n) = ppr n
\end{code}
%************************************************************************
%* *
-\subsection{Finite map utilities}
+\subsection{Free variable manipulation}
%* *
%************************************************************************
-
-Generally useful function on finite maps to check for overlap.
-
\begin{code}
-conflictsFM :: Ord a
- => (b->b->Bool) -- False <=> no conflict; you can pick either
- -> FiniteMap a b -> FiniteMap a b
- -> [(a,(b,b))]
-conflictsFM bad fm1 fm2
- = filter (\(a,(b1,b2)) -> bad b1 b2)
- (fmToList (intersectFM_C (\b1 b2 -> (b1,b2)) fm1 fm2))
-
-conflictFM :: Ord a
- => (b->b->Bool)
- -> FiniteMap a b -> a -> b
- -> Maybe (a,(b,b))
-conflictFM bad fm key elt
- = case lookupFM fm key of
- Just elt' | bad elt elt' -> Just (key,(elt,elt'))
- other -> Nothing
+type FreeVars = NameSet
+
+plusFV :: FreeVars -> FreeVars -> FreeVars
+addOneFV :: FreeVars -> Name -> FreeVars
+unitFV :: Name -> FreeVars
+emptyFVs :: FreeVars
+plusFVs :: [FreeVars] -> FreeVars
+
+isEmptyFVs = isEmptyNameSet
+emptyFVs = emptyNameSet
+plusFVs = unionManyNameSets
+plusFV = unionNameSets
+
+-- No point in adding implicitly imported names to the free-var set
+addOneFV s n = addOneToNameSet s n
+unitFV n = unitNameSet n
+
+-- A useful utility
+mapFvRn f xs = mapRn f xs `thenRn` \ stuff ->
+ let
+ (ys, fvs_s) = unzip stuff
+ in
+ returnRn (ys, plusFVs fvs_s)
\end{code}
%************************************************************************
-\begin{code}
-warnUnusedBinds, warnUnusedMatches, warnUnusedImports :: NameSet -> RnM s d ()
-
-warnUnusedBinds names
- | opt_WarnUnusedBinds = warnUnusedNames names
- | otherwise = returnRn ()
-warnUnusedMatches names
- | opt_WarnUnusedMatches = warnUnusedNames names
- | otherwise = returnRn ()
+\begin{code}
+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
- | opt_WarnUnusedImports = warnUnusedNames names
- | otherwise = returnRn ()
+ | not opt_WarnUnusedImports
+ = returnRn () -- Don't force names unless necessary
+ | otherwise
+ = warnUnusedBinds (const True) names
-warnUnusedNames :: NameSet -> RnM s d ()
-warnUnusedNames names
- = mapRn warn (nameSetToList names) `thenRn_`
- returnRn ()
- where
- warn name = pushSrcLocRn (getSrcLoc name) $
- addWarnRn (unusedNameWarn name)
+warnUnusedLocalBinds ns
+ | not opt_WarnUnusedBinds = returnRn ()
+ | otherwise = warnUnusedBinds (const True) ns
-unusedNameWarn name = quotes (ppr name) <+> ptext SLIT("is bound but not used")
+warnUnusedMatches names
+ | opt_WarnUnusedMatches = warnUnusedGroup (const True) names
+ | otherwise = returnRn ()
-addNameClashErrRn (rdr_name, ((_,how_in_scope1), (_, how_in_scope2)))
- | isClassDataConRdrName rdr_name
- -- Nasty hack to prevent error messages complain about conflicts for ":C",
- -- where "C" is a class. There'll be a message about C, and :C isn't
- -- the programmer's business. There may be a better way to filter this
- -- out, but I couldn't get up the energy to find it.
- = returnRn ()
+-------------------------
+warnUnusedBinds :: (Bool -> Bool) -> [Name] -> RnM d ()
+warnUnusedBinds warn_when_local names
+ = mapRn_ (warnUnusedGroup warn_when_local) groups
+ where
+ -- Group by provenance
+ groups = equivClasses cmp names
+ name1 `cmp` name2 = getNameProvenance name1 `cmp_prov` getNameProvenance name2
+
+ cmp_prov (LocalDef _ _) (NonLocalDef _ _) = LT
+ cmp_prov (LocalDef loc1 _) (LocalDef loc2 _) = loc1 `compare` loc2
+ cmp_prov (NonLocalDef (UserImport m1 loc1 _) _)
+ (NonLocalDef (UserImport m2 loc2 _) _) =
+ (m1 `compare` m2) `thenCmp` (loc1 `compare` loc2)
+ cmp_prov (NonLocalDef _ _) (LocalDef _ _) = GT
+ -- In-scope NonLocalDefs must have UserImport info on them
+
+-------------------------
+
+-- NOTE: the function passed to warnUnusedGroup is
+-- now always (const True) so we should be able to
+-- simplify the code slightly. I'm leaving it there
+-- for now just in case I havn't realised why it was there.
+-- Looks highly bogus to me. SLPJ Dec 99
+
+warnUnusedGroup :: (Bool -> Bool) -> [Name] -> RnM d ()
+warnUnusedGroup emit_warning names
+ | null filtered_names = returnRn ()
+ | not (emit_warning is_local) = returnRn ()
| otherwise
- = addErrRn (hang (hsep [ptext SLIT("Conflicting definitions for"), quotes (ppr rdr_name)])
- 4 (vcat [ppr how_in_scope1,
- ppr how_in_scope2]))
+ = pushSrcLocRn def_loc $
+ addWarnRn $
+ sep [msg <> colon, nest 4 (fsep (punctuate comma (map ppr filtered_names)))]
+ where
+ filtered_names = filter reportable names
+ name1 = head filtered_names
+ (is_local, def_loc, msg)
+ = case getNameProvenance name1 of
+ LocalDef loc _ -> (True, loc, text "Defined but not used")
+ NonLocalDef (UserImport mod loc _) _ ->
+ (True, loc, text "Imported from" <+> quotes (ppr mod) <+>
+ text "but not used")
+ other -> (False, getSrcLoc name1, text "Strangely defined but not used")
+
+ reportable name = case occNameUserString (nameOccName name) of
+ ('_' : _) -> False
+ zz_other -> True
+ -- Haskell 98 encourages compilers to suppress warnings about
+ -- unused names in a pattern if they start with "_".
+\end{code}
+
+\begin{code}
+addNameClashErrRn rdr_name (name1:names)
+ = addErrRn (vcat [ptext SLIT("Ambiguous occurrence") <+> quotes (ppr rdr_name),
+ ptext SLIT("It could refer to") <+> vcat (msg1 : msgs)])
+ where
+ msg1 = ptext SLIT("either") <+> mk_ref name1
+ msgs = [ptext SLIT(" or") <+> mk_ref name | name <- names]
+ mk_ref name = quotes (ppr name) <> comma <+> pprNameProvenance name
fixityClashErr (rdr_name, ((_,how_in_scope1), (_, how_in_scope2)))
= hang (hsep [ptext SLIT("Conflicting fixities for"), quotes (ppr rdr_name)])
dupNamesErr descriptor ((name,loc) : dup_things)
= pushSrcLocRn loc $
- addErrRn (hsep [ptext SLIT("Conflicting definitions for"),
- quotes (ppr name),
- ptext SLIT("in"), descriptor])
+ addErrRn ((ptext SLIT("Conflicting definitions for") <+> quotes (ppr name))
+ $$
+ (ptext SLIT("in") <+> descriptor))
\end{code}
-
projects / ghc-hetmet.git / blobdiff