%
-% (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}
\begin{code}
-#include "HsVersions.h"
-
module RnEnv where -- Export everything
-IMP_Ubiq()
+#include "HsVersions.h"
-import CmdLineOpts ( opt_WarnNameShadowing )
+import CmdLineOpts ( opt_WarnNameShadowing, opt_WarnUnusedMatches,
+ opt_WarnUnusedBinds, opt_WarnUnusedImports )
import HsSyn
-import RdrHsSyn ( RdrName(..), SYN_IE(RdrNameIE),
- rdrNameOcc, ieOcc, isQual, qual
+import RdrHsSyn ( RdrNameIE )
+import RnHsSyn ( RenamedHsType )
+import RdrName ( RdrName, rdrNameModule, rdrNameOcc, isQual, isUnqual,
+ mkRdrUnqual, qualifyRdrName
)
-import HsTypes ( getTyVarName, replaceTyVarName )
+import HsTypes ( hsTyVarName, hsTyVarNames, replaceTyVarName )
+
import RnMonad
-import Name ( Name, OccName(..), Provenance(..), DefnInfo(..), ExportFlag(..),
- occNameString, occNameFlavour,
- SYN_IE(NameSet), emptyNameSet, addListToNameSet,
- mkLocalName, mkGlobalName, modAndOcc, isLocallyDefinedName,
- nameOccName, setNameProvenance, isVarOcc, getNameProvenance,
- pprProvenance, pprOccName, pprModule, pprNameProvenance,
- NamedThing(..)
+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, intTyCon )
+import TysWiredIn ( listTyCon )
+import Type ( funTyCon )
+import Module ( ModuleName, mkThisModule, moduleName, mkVanillaModule, pprModuleName )
import FiniteMap
-import Outputable
-import Unique ( Unique, unboundKey )
-import UniqFM ( Uniquable(..) )
-import Maybes ( maybeToBool )
import UniqSupply
import SrcLoc ( SrcLoc, noSrcLoc )
-import Pretty
-import PprStyle ( PprStyle(..) )
-import Util --( panic, removeDups, pprTrace, assertPanic )
-#if __GLASGOW_HASKELL__ >= 202
-import List (nub)
-#endif
+import Outputable
+import Util ( removeDups, equivClasses, thenCmp, sortLt )
+import List ( nub )
\end{code}
%*********************************************************
\begin{code}
-newGlobalName :: Module -> OccName -> RnM s d Name
-newGlobalName mod occ
+implicitImportProvenance = NonLocalDef ImplicitImport False
+
+newTopBinder :: Module -> OccName -> RnM d Name
+newTopBinder mod occ
= -- First check the cache
- getNameSupplyRn `thenRn` \ (us, inst_ns, cache) ->
- let key = (mod,occ) in
+ traceRn (text "newTopBinder" <+> ppr mod <+> ppr occ) `thenRn_`
+
+ getNameSupplyRn `thenRn` \ (us, cache, ipcache) ->
+ let
+ key = (moduleName mod, occ)
+ in
case lookupFM cache key of
- -- A hit in the cache! Return it, but change the src loc
- -- of the thing we've found if this is a second definition site
- -- (that is, if loc /= NoSrcLoc)
- Just name -> returnRn name
-
- -- Miss in the cache, so build a new original name,
- -- and put it in the cache
- Nothing ->
- let
- (us', us1) = splitUniqSupply us
- uniq = getUnique us1
- name = mkGlobalName uniq mod occ VanillaDefn Implicit
- cache' = addToFM cache key name
- in
- setNameSupplyRn (us', inst_ns, cache') `thenRn_`
- returnRn name
-
-newLocallyDefinedGlobalName :: Module -> OccName
- -> (Name -> ExportFlag) -> SrcLoc
- -> RnM s d Name
-newLocallyDefinedGlobalName mod occ rec_exp_fn loc
- = -- First check the cache
- getNameSupplyRn `thenRn` \ (us, inst_ns, cache) ->
-
- -- We are at the binding site for a locally-defined thing, so
- -- you might think it can't be in the cache, but it can if it's a
- -- wired in thing. In that case we need to use the correct unique etc...
- -- so all we do is replace its provenance.
- -- If it's not in the cache we put it there with the correct provenance.
- -- The idea is that, after all this, the cache
- -- will contain a Name with the correct Provenance (i.e. Local)
+ -- 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.
--
- -- Actually, there's a catch. If this is the *second* binding for something
- -- we want to allocate a *fresh* unique, rather than using the same Name as before.
- -- Otherwise we don't detect conflicting definitions of the same top-level name!
- -- So the only time we re-use a Name already in the cache is when it's one of
- -- the Implicit magic-unique ones mentioned in the previous para
+ -- 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 = setNameModule name mod
+ new_cache = addToFM cache key new_name
+ in
+ 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 implicitImportProvenance
+ new_cache = addToFM cache key new_name
+ in
+ setNameSupplyRn (us', new_cache, ipcache) `thenRn_`
+ traceRn (text "newTopBinder: new" <+> ppr new_name) `thenRn_`
+ returnRn new_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.
+ --
+ -- (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
- provenance = LocalDef (rec_exp_fn new_name) loc
- (us', us1) = splitUniqSupply us
- uniq = getUnique us1
- key = (mod,occ)
- new_name = case lookupFM cache key of
- Just name | is_implicit_prov
- -> setNameProvenance name provenance
- where
- is_implicit_prov = case getNameProvenance name of
- Implicit -> True
- other -> False
- other -> mkGlobalName uniq mod occ VanillaDefn provenance
-
- new_cache = addToFM cache key new_name
+ key = (mod_name, occ)
in
- setNameSupplyRn (us', inst_ns, new_cache) `thenRn_`
- returnRn new_name
-
--- newSysName is used to create the names for
--- a) default methods
--- These are never mentioned explicitly in source code (hence no point in looking
--- them up in the NameEnv), but when reading an interface file
--- we may want to slurp in their pragma info. In the source file itself we
--- need to create these names too so that we export them into the inferface file for this module.
-
-newSysName :: OccName -> ExportFlag -> SrcLoc -> RnMS s Name
-newSysName occ export_flag loc
+ 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)
+
+ update_prov name_in_cache name_with_prov
+ = setNameProvenance name_in_cache (getNameProvenance name_with_prov)
+\end{code}
+
+%*********************************************************
+%* *
+\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 ->
- getModuleRn `thenRn` \ mod_name ->
case mode of
- SourceMode -> newLocallyDefinedGlobalName
- mod_name occ
- (\_ -> export_flag)
- loc
- InterfaceMode -> newGlobalName mod_name occ
-
--- 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 :: Maybe RdrName -> SrcLoc -> RnMS s Name
-newDfunName Nothing src_loc -- Local instance decls have a "Nothing"
- = getModuleRn `thenRn` \ mod_name ->
- newInstUniq `thenRn` \ inst_uniq ->
- let
- dfun_occ = VarOcc (_PK_ ("$d" ++ show inst_uniq))
- in
- newLocallyDefinedGlobalName mod_name dfun_occ
- (\_ -> Exported) src_loc
+ 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
-newDfunName (Just n) src_loc -- Imported ones have "Just n"
- = getModuleRn `thenRn` \ mod_name ->
- newGlobalName mod_name (rdrNameOcc n)
+-- 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.
-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
+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.
+
+\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}
--- 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
+@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 :: (PprStyle -> Doc) -- 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_`
- getNameEnv `thenRn` \ name_env ->
- (if opt_WarnNameShadowing
- then
- mapRn (check_shadow name_env) rdr_names_w_loc
- else
- returnRn []
+ getModeRn `thenRn` \ mode ->
+ getLocalNameEnv `thenRn` \ name_env ->
+
+ -- 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
+ 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 = addListToFM name_env (map fst rdr_names_w_loc `zip` names)
+ new_name_env = addListToRdrEnv name_env (map fst rdr_names_w_loc `zip` names)
in
- setNameEnv new_name_env (enclosed_scope names)
+ 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
-checkDupOrQualNames, checkDupNames :: (PprStyle -> Doc)
+ 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 `cmp` n2) rdr_names_w_loc
+ (_, dups) = removeDups (\(n1,l1) (n2,l2) -> n1 `compare` n2) rdr_names_w_loc
\end{code}
-%*********************************************************
-%* *
-\subsection{Looking up names}
-%* *
-%*********************************************************
-
-Looking up a name in the RnEnv.
-
-\begin{code}
-lookupRn :: NameEnv -> RdrName -> RnMS s Name
-lookupRn name_env rdr_name
- = case lookupFM name_env rdr_name of
-
- -- Found it!
- Just name -> returnRn name
-
- -- Not found
- 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 ->
- case rdr_name of
-
- Qual mod_name occ -> newGlobalName mod_name occ
-
- -- 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 ->
- newGlobalName mod_name occ
-
-
-lookupBndrRn rdr_name
- = getNameEnv `thenRn` \ name_env ->
- lookupRn name_env 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 s Name
-lookupOccRn rdr_name
- = getNameEnv `thenRn` \ name_env ->
- lookupRn name_env rdr_name `thenRn` \ name ->
- addOccurrenceName Compulsory name
-
--- lookupGlobalOccRn is like lookupOccRn, except that it looks in the global
--- environment. It's used for record field names only.
-lookupGlobalOccRn :: RdrName -> RnMS s Name
-lookupGlobalOccRn rdr_name
- = getGlobalNameEnv `thenRn` \ name_env ->
- lookupRn name_env rdr_name `thenRn` \ name ->
- addOccurrenceName Compulsory name
-
--- lookupOptionalOccRn is similar, but it's used in places where
--- we don't *have* to find a definition for the thing.
-lookupOptionalOccRn :: RdrName -> RnMS s Name
-lookupOptionalOccRn rdr_name
- = getNameEnv `thenRn` \ name_env ->
- lookupRn name_env rdr_name `thenRn` \ name ->
- addOccurrenceName Optional name
-
-
-
--- 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).
---
--- 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)
- = newGlobalName mod occ `thenRn` \ name ->
- addOccurrenceName Compulsory name
-
-addImplicitOccRn :: Name -> RnM s d Name
-addImplicitOccRn name = addOccurrenceName Compulsory name
-
-addImplicitOccsRn :: [Name] -> RnM s d ()
-addImplicitOccsRn names = addOccurrenceNames Compulsory 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}
-
-
-
%************************************************************************
%* *
\subsection{Envt utility functions}
%* *
%************************************************************************
-=============== RnEnv ================
-\begin{code}
-plusRnEnv (RnEnv n1 f1) (RnEnv n2 f2)
- = plusNameEnvRn n1 n2 `thenRn` \ n ->
- plusFixityEnvRn f1 f2 `thenRn` \ f ->
- returnRn (RnEnv n f)
-\end{code}
+\subsubsection{NameEnv}% ================
-=============== NameEnv ================
\begin{code}
-plusNameEnvRn :: NameEnv -> NameEnv -> RnM s d NameEnv
-plusNameEnvRn n1 n2
- = mapRn (addErrRn.nameClashErr) (conflictsFM (/=) n1 n2) `thenRn_`
- returnRn (n1 `plusFM` n2)
+plusGlobalRdrEnv :: GlobalRdrEnv -> GlobalRdrEnv -> GlobalRdrEnv
+plusGlobalRdrEnv env1 env2 = plusFM_C combine_globals env1 env2
-addOneToNameEnv :: NameEnv -> RdrName -> Name -> NameEnv
-addOneToNameEnv env rdr_name name = addToFM env rdr_name name
+addOneToGlobalRdrEnv :: GlobalRdrEnv -> RdrName -> Name -> GlobalRdrEnv
+addOneToGlobalRdrEnv env rdr_name name = addToFM_C combine_globals env rdr_name [name]
-lookupNameEnv :: NameEnv -> RdrName -> Maybe Name
-lookupNameEnv = lookupFM
-
-delOneFromNameEnv :: NameEnv -> RdrName -> NameEnv
-delOneFromNameEnv env rdr_name = delFromFM env rdr_name
-\end{code}
+delOneFromGlobalRdrEnv :: GlobalRdrEnv -> RdrName -> GlobalRdrEnv
+delOneFromGlobalRdrEnv env rdr_name = delFromFM env rdr_name
-=============== FixityEnv ================
-\begin{code}
-plusFixityEnvRn f1 f2
- = mapRn (addErrRn.fixityClashErr) (conflictsFM bad_fix f1 f2) `thenRn_`
- returnRn (f1 `plusFM` f2)
-
-addOneToFixityEnv env rdr_name fixity = addToFM env rdr_name fixity
-
-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, Provenance) -> (Fixity, Provenance) -> Bool
-bad_fix (f1,_) (f2,_) = f1 /= f2
-pprFixityProvenance :: PprStyle -> (Fixity,Provenance) -> Doc
-pprFixityProvenance sty (fixity, prov) = pprProvenance sty prov
+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.
-=============== Avails ================
-\begin{code}
-emptyModuleAvails :: ModuleAvails
-plusModuleAvails :: ModuleAvails -> ModuleAvails -> ModuleAvails
-lookupModuleAvails :: ModuleAvails -> Module -> Maybe [AvailInfo]
+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.
-emptyModuleAvails = emptyFM
-plusModuleAvails = plusFM_C (++)
-lookupModuleAvails = lookupFM
-\end{code}
-=============== AvailInfo ================
+\subsubsection{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 = panic ("RnEnv.plusAvail " ++ (show (hsep [pprAvail PprDebug a1,pprAvail PprDebug a2])))
+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 = pprTrace "filterAvail" (hsep [ppr PprDebug ie, pprAvail PprDebug avail]) $
- 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
avail_occs = map nameOccName ns
wanted_occs = map rdrNameOcc (want:wants)
-filterAvail (IEThingAbs _) (AvailTC n ns)
- | n `elem` ns = AvailTC n [n]
+filterAvail (IEThingAbs _) (AvailTC n ns) = ASSERT( n `elem` ns )
+ 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
-
-{- OLD to be deleted
-hideAvail :: RdrNameIE -- Hide this
- -> AvailInfo -- Available
- -> AvailInfo -- Resulting available;
--- Don't complain about hiding non-existent things; that's done elsewhere
-
-hideAvail ie NotAvailable
- = NotAvailable
-
-hideAvail ie (Avail n)
- | not (ieOcc ie == nameOccName n) = Avail n -- No match
- | otherwise = NotAvailable -- Names match
-
-hideAvail ie (AvailTC n ns)
- | not (ieOcc ie == nameOccName n) -- No match
- = case ie of -- But in case we are faced with ...hiding( (+) )
- -- we filter the "ns" anyhow
- IEVar op -> AvailTC n (filter keep ns)
- where
- op_occ = rdrNameOcc op
- keep n = nameOccName n /= op_occ
-
- other -> AvailTC n ns
-
- | otherwise -- Names match
- = case ie of
- IEThingAbs _ -> AvailTC n (filter (/= n) ns)
- IEThingAll _ -> NotAvailable
- IEThingWith hide hides -> AvailTC n (filter keep ns)
- where
- keep n = nameOccName n `notElem` hide_occs
- hide_occs = map rdrNameOcc (hide : hides)
--}
-
--- In interfaces, pprAvail gets given the OccName of the "host" thing
-pprAvail PprInterface avail = ppr_avail (pprOccName PprInterface . nameOccName) avail
-pprAvail sty avail = ppr_avail (ppr sty) avail
-
-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
+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
+
+pprAvail :: AvailInfo -> SDoc
+pprAvail (AvailTC n ns) = ppr n <> case filter (/= n) ns of
+ [] -> empty
+ ns' -> parens (hsep (punctuate comma (map ppr ns')))
+
+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
- -> [(a,(b,b))]
-conflictFM bad fm key elt
- = case lookupFM fm key of
- Just elt' | bad elt elt' -> [(key,(elt,elt'))]
- other -> []
+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}
-nameClashErr (rdr_name, (name1,name2)) sty
- = hang (hsep [ptext SLIT("Conflicting definitions for: "), ppr sty rdr_name])
- 4 (vcat [pprNameProvenance sty name1,
- pprNameProvenance sty name2])
-
-fixityClashErr (rdr_name, (fp1,fp2)) sty
- = hang (hsep [ptext SLIT("Conflicting fixities for: "), ppr sty rdr_name])
- 4 (vcat [pprFixityProvenance sty fp1,
- pprFixityProvenance sty fp2])
-
-shadowedNameWarn shadow sty
- = hcat [ptext SLIT("This binding for"),
- ppr sty shadow,
+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
+ | otherwise
+ = warnUnusedBinds (const True) names
+
+warnUnusedLocalBinds ns
+ | not opt_WarnUnusedBinds = returnRn ()
+ | otherwise = warnUnusedBinds (const True) ns
+
+warnUnusedMatches names
+ | opt_WarnUnusedMatches = warnUnusedGroup (const True) names
+ | otherwise = 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
+ = 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)])
+ 4 (vcat [ppr how_in_scope1,
+ ppr how_in_scope2])
+
+shadowedNameWarn shadow
+ = hsep [ptext SLIT("This binding for"),
+ quotes (ppr shadow),
ptext SLIT("shadows an existing binding")]
-unknownNameErr name sty
- = sep [text flavour, ptext SLIT("not in scope:"), ppr sty name]
+unknownNameErr name
+ = sep [text flavour, ptext SLIT("not in scope:"), quotes (ppr name)]
where
flavour = occNameFlavour (rdrNameOcc name)
qualNameErr descriptor (name,loc)
= pushSrcLocRn loc $
- addErrRn (\sty -> hsep [ ptext SLIT("invalid use of qualified name"),
- ppr sty name,
- ptext SLIT("in"),
- descriptor sty])
+ addErrRn (hsep [ ptext SLIT("Invalid use of qualified name"),
+ quotes (ppr name),
+ ptext SLIT("in"),
+ descriptor])
dupNamesErr descriptor ((name,loc) : dup_things)
= pushSrcLocRn loc $
- addErrRn (\sty -> hsep [ptext SLIT("duplicate bindings of"),
- ppr sty name,
- ptext SLIT("in"), descriptor sty])
+ addErrRn ((ptext SLIT("Conflicting definitions for") <+> quotes (ppr name))
+ $$
+ (ptext SLIT("in") <+> descriptor))
\end{code}
-
projects / ghc-hetmet.git / blobdiff