%
-% (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, opt_IgnoreIfacePragmas )
+import CmdLineOpts ( opt_WarnNameShadowing, opt_WarnUnusedMatches,
+ opt_WarnUnusedBinds, opt_WarnUnusedImports )
import HsSyn
-import RdrHsSyn ( RdrName(..), SYN_IE(RdrNameIE),
- rdrNameOcc, isQual, qual
+import RdrHsSyn ( RdrNameIE )
+import RnHsSyn ( RenamedHsType )
+import RdrName ( RdrName, rdrNameModule, rdrNameOcc, isQual, isUnqual,
+ mkRdrUnqual, qualifyRdrName
)
import HsTypes ( getTyVarName, replaceTyVarName )
+
import RnMonad
-import Name ( Name, OccName(..), Provenance(..), DefnInfo(..), ExportFlag(..),
- occNameString, occNameFlavour,
- SYN_IE(NameSet), emptyNameSet, addListToNameSet,
- mkLocalName, mkGlobalName, modAndOcc,
- isLocalName, isWiredInName, nameOccName, setNameProvenance,
- pprProvenance, pprOccName, pprModule, pprNonSymOcc, pprNameProvenance
+import Name ( Name, Provenance(..), ExportFlag(..), NamedThing(..),
+ ImportReason(..), getSrcLoc,
+ mkLocalName, mkImportedLocalName, mkGlobalName, isSystemName,
+ nameOccName, setNameModule, nameModule,
+ pprOccName, isLocallyDefined, nameUnique, nameOccName,
+ occNameUserString,
+ setNameProvenance, getNameProvenance, pprNameProvenance
)
+import NameSet
+import OccName ( OccName,
+ mkDFunOcc, occNameUserString, occNameString,
+ occNameFlavour
+ )
+import TysWiredIn ( tupleTyCon, unboxedTupleTyCon, listTyCon )
+import Type ( funTyCon )
+import Module ( ModuleName, mkThisModule, mkVanillaModule, moduleName )
import TyCon ( TyCon )
-import TysWiredIn ( tupleTyCon, listTyCon, charTyCon, intTyCon )
import FiniteMap
-import Unique ( Unique, unboundKey )
-import Maybes ( maybeToBool )
+import Unique ( Unique, Uniquable(..) )
+import UniqFM ( emptyUFM, listToUFM, plusUFM_C )
import UniqSupply
import SrcLoc ( SrcLoc, noSrcLoc )
-import Pretty
-import PprStyle ( PprStyle(..) )
-import Util ( panic, removeDups, pprTrace, assertPanic )
+import Outputable
+import Util ( removeDups, equivClasses, thenCmp )
+import List ( nub )
+import Maybes ( mapMaybe )
\end{code}
%*********************************************************
\begin{code}
-newGlobalName :: Module -> OccName -> RnM s d Name
-newGlobalName mod occ
- = -- First check the cache
- getNameSupplyRn `thenRn` \ (us, inst_ns, cache) ->
- case lookupFM cache (mod,occ) 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 (mod,occ) 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
+newImportedGlobalName mod_name occ mod
+ = getNameSupplyRn `thenRn` \ (us, inst_ns, cache) ->
+ let
+ key = (mod_name, occ)
+ in
+ case lookupFM cache key of
+ Just name -> returnRn name
+ Nothing -> setNameSupplyRn (us', inst_ns, new_cache) `thenRn_`
+ returnRn name
+ where
+ (us', us1) = splitUniqSupply us
+ uniq = uniqFromSupply us1
+ name = mkGlobalName uniq mod occ (NonLocalDef ImplicitImport False)
+ new_cache = addToFM cache key name
+
+updateProvenances :: [Name] -> RnM d ()
+updateProvenances names
+ = getNameSupplyRn `thenRn` \ (us, inst_ns, cache) ->
+ setNameSupplyRn (us, inst_ns, update cache names)
+ 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)
+
+newImportedBinder :: Module -> RdrName -> RnM d Name
+newImportedBinder mod rdr_name
+ = ASSERT2( isUnqual rdr_name, ppr rdr_name )
+ newImportedGlobalName (moduleName mod) (rdrNameOcc rdr_name) mod
+
+-- Make an imported global name, checking first to see if it's in the cache
+mkImportedGlobalName :: ModuleName -> OccName -> RnM d Name
+mkImportedGlobalName mod_name occ
+ = lookupModuleRn mod_name `thenRn` \ mod ->
+ newImportedGlobalName mod_name occ mod --(mkVanillaModule mod_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)
+
+
+newLocalTopBinder :: Module -> OccName
+ -> (Name -> ExportFlag) -> SrcLoc
+ -> RnM d Name
+newLocalTopBinder 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)
- let
- provenance = LocalDef (rec_exp_fn new_name) loc
- (us', us1) = splitUniqSupply us
- uniq = getUnique us1
- new_name = case lookupFM cache (mod,occ) of
- Just name -> setNameProvenance name provenance
- Nothing -> mkGlobalName uniq mod occ VanillaDefn provenance
- cache' = addToFM cache (mod,occ) new_name
+ let
+ key = (moduleName mod,occ)
+ mk_prov 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 newLocallyDefinedGlobalName is used only
+ -- at binding occurrences, we may as well get the provenance
+ -- dead right first time; hence the rec_exp_fn passed in
in
- setNameSupplyRn (us', inst_ns, cache') `thenRn_`
- returnRn new_name
+ 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.
+ --
+ -- It also means that if there are two defns for the same thing
+ -- in a module, then each gets a separate SrcLoc
+ Just name -> let
+ new_name = setNameProvenance name (mk_prov new_name)
+ new_cache = addToFM cache key new_name
+ in
+ setNameSupplyRn (us, inst_ns, new_cache) `thenRn_`
+ returnRn new_name
+
+ -- Miss in the cache!
+ -- Build a new original name, and put it in the cache
+ Nothing -> let
+ (us', us1) = splitUniqSupply us
+ uniq = uniqFromSupply us1
+ new_name = mkGlobalName uniq mod occ (mk_prov new_name)
+ new_cache = addToFM cache key new_name
+ in
+ setNameSupplyRn (us', inst_ns, new_cache) `thenRn_`
+ returnRn new_name
+\end{code}
--- newDfunName is used to allocate a name for the dictionary function for
--- a local instance declaration. No need to put it in the cache (I think!).
-newDfunName :: SrcLoc -> RnMS s Name
-newDfunName src_loc
- = getNameSupplyRn `thenRn` \ (us, inst_ns, cache) ->
- getModuleRn `thenRn` \ mod_name ->
- let
- (us', us1) = splitUniqSupply us
- uniq = getUnique us1
- dfun_name = mkGlobalName uniq mod_name (VarOcc (_PK_ ("df" ++ show inst_ns)))
- VanillaDefn (LocalDef Exported src_loc)
- in
- setNameSupplyRn (us', inst_ns+1, cache) `thenRn_`
- returnRn dfun_name
+%*********************************************************
+%* *
+\subsection{Dfuns and default methods}
+%* *
+%*********************************************************
+@newImplicitBinder@ is used for (a) dfuns
+(b) default methods, defined in this module.
-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
+\begin{code}
+newImplicitBinder occ src_loc
+ = getModuleRn `thenRn` \ mod_name ->
+ newLocalTopBinder (mkThisModule mod_name) occ (\_ -> Exported) src_loc
+\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
+Make a name for the dict fun for an instance decl
-isUnboundName :: Name -> Bool
-isUnboundName name = uniqueOf name == unboundKey
+\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
\end{code}
\begin{code}
-bindLocatedLocalsRn :: String -- Documentation string for error message
+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
+\end{code}
+
+
+%*********************************************************
+%* *
+\subsection{Binding}
+%* *
+%*********************************************************
+
+\begin{code}
+-------------------------------------
+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
- = -- Check for use of qualified names
- mapRn (qualNameErr doc_str) quals `thenRn_`
- -- Check for dupicated names in a binding group
- mapRn (dupNamesErr doc_str) dups `thenRn_`
+ = checkDupOrQualNames doc_str rdr_names_w_loc `thenRn_`
- getNameEnv `thenRn` \ name_env ->
+ getLocalNameEnv `thenRn` \ name_env ->
(if opt_WarnNameShadowing
then
- mapRn (check_shadow name_env) rdr_names_w_loc
+ mapRn_ (check_shadow name_env) rdr_names_w_loc
else
- returnRn []
+ returnRn ()
) `thenRn_`
- newLocalNames rdr_names_w_loc `thenRn` \ names ->
+ getNameSupplyRn `thenRn` \ (us, inst_ns, cache) ->
+ getModeRn `thenRn` \ mode ->
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
- setNameEnv new_name_env (enclosed_scope names)
+ setNameSupplyRn (us', inst_ns, cache) `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
- quals = filter (isQual.fst) rdr_names_w_loc
- (these, dups) = removeDups (\(n1,l1) (n2,l2) -> n1 `cmp` n2) rdr_names_w_loc
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, inst_ns, cache) ->
+ let
+ (us', us1) = splitUniqSupply us
+ uniq = uniqFromSupply us1
+ name = mkImportedLocalName uniq (rdrNameOcc rdr_name) loc
+ in
+ setNameSupplyRn (us', inst_ns, cache) `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')
+
+-------------------------------------
+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 doc_str (rdr_names `zip` repeat loc) enclosed_scope
+ 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 :: [HsTyVar 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) ->
+ returnRn (thing, delListFromNameSet fvs tyvar_names)
+bindTyVarsRn :: SDoc -> [HsTyVar RdrName]
+ -> ([HsTyVar 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)
+ -> RnMS a
+bindTyVars2Rn doc_str tyvar_names enclosed_scope
= getSrcLocRn `thenRn` \ loc ->
let
located_tyvars = [(getTyVarName tv, loc) | tv <- tyvar_names]
in
bindLocatedLocalsRn doc_str located_tyvars $ \ names ->
- enclosed_scope (zipWith replaceTyVarName tyvar_names names)
+ enclosed_scope names (zipWith replaceTyVarName tyvar_names names)
+
+bindTyVarsFVRn :: SDoc -> [HsTyVar RdrName]
+ -> ([HsTyVar 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))
+ -> 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 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_`
+ 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 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
\end{code}
Looking up a name in the RnEnv.
\begin{code}
-lookupRn :: RdrName -> RnMS s Name
-lookupRn rdr_name
- = getNameEnv `thenRn` \ name_env ->
- case lookupFM name_env rdr_name of
+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)
+ }
- -- Found it!
- Just name -> returnRn name
-
- -- Not found
+-- 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)
+ (unknownNameErr rdr_name)
-- Not found when processing an imported declaration,
-- so we create a new name for the purpose
- InterfaceMode ->
- case rdr_name of
+ 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.
- Qual mod_name occ -> newGlobalName mod_name occ
+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).
- -- 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
+ \fbox{{\em Jan 98: this comment is wrong: @rnHsType@ uses it quite a bit.}}
-
--- 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
- = lookupRn rdr_name `thenRn` \ name ->
- if isLocalName name then
- returnRn name
- else
- addOccurrenceName Compulsory name `thenRn_`
- returnRn 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
- = lookupRn rdr_name `thenRn` \ name ->
- if opt_IgnoreIfacePragmas || isLocalName name then
- -- Never look for optional things if we're
- -- ignoring optional input interface information
- returnRn name
- else
- addOccurrenceName Optional name `thenRn_`
- returnRn 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 `thenRn_`
- returnRn name
-
-addImplicitOccRn :: Name -> RnM s d ()
-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}
+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}
-lookupFixity :: RdrName -> RnMS s Fixity
-lookupFixity rdr_name
- = getFixityEnv `thenRn` \ fixity_env ->
- returnRn (lookupFixityEnv fixity_env rdr_name)
+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}
%************************************************************************
%* *
%* *
%************************************************************************
-=============== 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)
-
-addOneToNameEnvRn :: NameEnv -> RdrName -> Name -> RnM s d NameEnv
-addOneToNameEnvRn env rdr_name name
- = mapRn (addErrRn.nameClashErr) (conflictFM (/=) env rdr_name name) `thenRn_`
- returnRn (addToFM env rdr_name name)
-
-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]
+
+delOneFromGlobalRdrEnv :: GlobalRdrEnv -> RdrName -> GlobalRdrEnv
+delOneFromGlobalRdrEnv env rdr_name = delFromFM env rdr_name
-addOneToFixityEnvRn env rdr_name fixity
- = mapRn (addErrRn.fixityClashErr) (conflictFM bad_fix env rdr_name fixity) `thenRn_`
- returnRn (addToFM env rdr_name fixity)
+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 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
+
+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.
-lookupFixityEnv env rdr_name
- = case lookupFM env rdr_name of
- Just (fixity,_) -> fixity
- Nothing -> Fixity 9 InfixL -- Default case
+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.
-bad_fix :: (Fixity, Provenance) -> (Fixity, Provenance) -> Bool
-bad_fix (f1,_) (f2,_) = f1 /= f2
+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.
-pprFixityProvenance :: PprStyle -> (Fixity,Provenance) -> Pretty
-pprFixityProvenance sty (fixity, prov) = pprProvenance sty prov
-\end{code}
+\subsubsection{ExportAvails}% ================
-=============== Avails ================
\begin{code}
-emptyModuleAvails :: ModuleAvails
-plusModuleAvails :: ModuleAvails -> ModuleAvails -> ModuleAvails
-lookupModuleAvails :: ModuleAvails -> Module -> Maybe [AvailInfo]
+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
-emptyModuleAvails = emptyFM
-plusModuleAvails = plusFM_C (++)
-lookupModuleAvails = lookupFM
+ entity_avail_env = listToUFM [ (name,avail) | avail <- avails,
+ name <- availNames avail]
+
+plusExportAvails :: ExportAvails -> ExportAvails -> ExportAvails
+plusExportAvails (m1, e1) (m2, e2)
+ = (plusFM_C (++) m1 m2, plusUFM_C plusAvail e1 e2)
+ -- ToDo: wasteful: we do this once for each constructor!
\end{code}
-=============== AvailInfo ================
+\subsubsection{AvailInfo}% ================
+
\begin{code}
-plusAvail (Avail n1 ns1) (Avail n2 ns2) = Avail n1 (nub (ns1 ++ ns2))
-plusAvail a NotAvailable = a
-plusAvail NotAvailable a = a
+plusAvail (Avail n1) (Avail n2) = Avail n1
+plusAvail (AvailTC n1 ns1) (AvailTC n2 ns2) = AvailTC n1 (nub (ns1 ++ ns2))
+-- Added SOF 4/97
+#ifdef DEBUG
+plusAvail a1 a2 = pprPanic "RnEnv.plusAvail" (hsep [pprAvail a1,pprAvail a2])
+#endif
addAvailToNameSet :: NameSet -> AvailInfo -> NameSet
-addAvailToNameSet names NotAvailable = names
-addAvailToNameSet names (Avail n ns) = addListToNameSet names (n:ns)
+addAvailToNameSet names avail = addListToNameSet names (availNames avail)
availsToNameSet :: [AvailInfo] -> NameSet
availsToNameSet avails = foldl addAvailToNameSet emptyNameSet avails
+availName :: AvailInfo -> Name
+availName (Avail n) = n
+availName (AvailTC n _) = n
+
availNames :: AvailInfo -> [Name]
-availNames NotAvailable = []
-availNames (Avail n ns) = n:ns
-
-filterAvail :: RdrNameIE -> AvailInfo -> AvailInfo
-filterAvail (IEThingWith _ wanted) NotAvailable = NotAvailable
-filterAvail (IEThingWith _ wanted) (Avail n ns)
- | sub_names_ok = Avail n (filter is_wanted ns)
- | otherwise = NotAvailable
+availNames (Avail n) = [n]
+availNames (AvailTC n ns) = ns
+
+filterAvail :: RdrNameIE -- Wanted
+ -> AvailInfo -- Available
+ -> Maybe AvailInfo -- Resulting available;
+ -- Nothing if (any of the) wanted stuff isn't there
+
+filterAvail ie@(IEThingWith want wants) avail@(AvailTC n ns)
+ | sub_names_ok = Just (AvailTC n (filter is_wanted ns))
+ | otherwise = Nothing
where
is_wanted name = nameOccName name `elem` wanted_occs
sub_names_ok = all (`elem` avail_occs) wanted_occs
- wanted_occs = map rdrNameOcc wanted
avail_occs = map nameOccName ns
+ wanted_occs = map rdrNameOcc (want:wants)
+
+filterAvail (IEThingAbs _) (AvailTC n ns) = ASSERT( n `elem` ns )
+ Just (AvailTC n [n])
+
+filterAvail (IEThingAbs _) avail@(Avail n) = Just avail -- Type synonyms
+filterAvail (IEVar _) avail@(Avail n) = Just avail
+filterAvail (IEVar v) avail@(AvailTC n ns) = Just (AvailTC n (filter wanted ns))
+ where
+ wanted n = nameOccName n == occ
+ occ = rdrNameOcc v
+ -- The second equation happens if we import a class op, thus
+ -- import A( op )
+ -- where op is a class operation
-filterAvail (IEThingAll _) avail = avail
-filterAvail ie (Avail n ns) = Avail n [] -- IEThingAbs and IEVar
+filterAvail (IEThingAll _) avail@(AvailTC _ _) = Just avail
--- pprAvail gets given the OccName of the "host" thing
-pprAvail sty NotAvailable = ppStr "NotAvailable"
-pprAvail sty (Avail n ns) = ppCat [pprOccName sty (nameOccName n),
- ppStr "(",
- ppInterleave ppComma (map (pprOccName sty.nameOccName) ns),
- ppStr ")"]
+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
+
+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
\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
- = ppHang (ppCat [ppStr "Conflicting definitions for: ", ppr sty rdr_name])
- 4 (ppAboves [pprNameProvenance sty name1,
- pprNameProvenance sty name2])
+warnUnusedLocalBinds, warnUnusedTopNames, warnUnusedMatches :: [Name] -> RnM d ()
+
+warnUnusedTopNames names
+ | not opt_WarnUnusedBinds && not opt_WarnUnusedImports
+ = returnRn () -- Don't force ns unless necessary
+ | otherwise
+ = warnUnusedBinds (\ is_local -> not is_local) names
+
+warnUnusedLocalBinds ns
+ | not opt_WarnUnusedBinds = returnRn ()
+ | otherwise = warnUnusedBinds (\ is_local -> is_local) ns
-fixityClashErr (rdr_name, (fp1,fp2)) sty
- = ppHang (ppCat [ppStr "Conflicting fixities for: ", ppr sty rdr_name])
- 4 (ppAboves [pprFixityProvenance sty fp1,
- pprFixityProvenance sty fp2])
+warnUnusedMatches names
+ | opt_WarnUnusedMatches = warnUnusedGroup (const True) names
+ | otherwise = returnRn ()
-shadowedNameWarn shadow sty
- = ppBesides [ppStr "More than one value with the same name (shadowing): ", ppr sty shadow]
+-------------------------
-unknownNameErr name sty
- = ppSep [ppStr flavour, ppStr "not in scope:", ppr sty name]
+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
+
+-------------------------
+
+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
+ = sep [text flavour, ptext SLIT("not in scope:"), quotes (ppr name)]
where
flavour = occNameFlavour (rdrNameOcc name)
qualNameErr descriptor (name,loc)
= pushSrcLocRn loc $
- addErrRn (\sty -> ppBesides [ppStr "invalid use of qualified ",
- ppStr descriptor, ppStr ": ",
- pprNonSymOcc sty (rdrNameOcc name) ])
+ 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 -> ppBesides [ppStr "duplicate bindings of `",
- ppr sty name, ppStr "' in ",
- ppStr descriptor])
+ addErrRn ((ptext SLIT("Conflicting definitions for") <+> quotes (ppr name))
+ $$
+ (ptext SLIT("in") <+> descriptor))
\end{code}
-