+%
+% (c) The GRASP/AQUA Project, Glasgow University, 1992-1996
+%
+\section[RnEnv]{Environment manipulation for the renamer monad}
+
+\begin{code}
+#include "HsVersions.h"
+
+module RnEnv where -- Export everything
+
+IMP_Ubiq()
+
+import CmdLineOpts ( opt_WarnNameShadowing, opt_IgnoreIfacePragmas )
+import HsSyn
+import RdrHsSyn ( RdrName(..), SYN_IE(RdrNameIE),
+ rdrNameOcc, isQual, qual
+ )
+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 TyCon ( TyCon )
+import TysWiredIn ( tupleTyCon, listTyCon, charTyCon, intTyCon )
+import FiniteMap
+import Unique ( Unique, unboundKey )
+import Maybes ( maybeToBool )
+import UniqSupply
+import SrcLoc ( SrcLoc, noSrcLoc )
+import Pretty
+import PprStyle ( PprStyle(..) )
+import Util ( panic, removeDups, pprTrace, assertPanic )
+\end{code}
+
+
+
+%*********************************************************
+%* *
+\subsection{Making new names}
+%* *
+%*********************************************************
+
+\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
+ = -- 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
+ in
+ setNameSupplyRn (us', inst_ns, cache') `thenRn_`
+ returnRn new_name
+
+-- 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
+
+
+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
+
+-- 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
+
+isUnboundName :: Name -> Bool
+isUnboundName name = uniqueOf name == unboundKey
+\end{code}
+
+\begin{code}
+bindLocatedLocalsRn :: String -- Documentation string for error message
+ -> [(RdrName,SrcLoc)]
+ -> ([Name] -> RnMS s a)
+ -> RnMS s 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_`
+
+ getNameEnv `thenRn` \ name_env ->
+ (if opt_WarnNameShadowing
+ then
+ mapRn (check_shadow name_env) rdr_names_w_loc
+ else
+ returnRn []
+ ) `thenRn_`
+
+ newLocalNames rdr_names_w_loc `thenRn` \ names ->
+ let
+ new_name_env = addListToFM name_env (map fst rdr_names_w_loc `zip` names)
+ in
+ setNameEnv 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
+ Nothing -> returnRn ()
+ Just name -> pushSrcLocRn loc $
+ addWarnRn (shadowedNameWarn rdr_name)
+
+bindLocalsRn doc_str rdr_names enclosed_scope
+ = getSrcLocRn `thenRn` \ loc ->
+ bindLocatedLocalsRn doc_str (rdr_names `zip` repeat loc) enclosed_scope
+
+bindTyVarsRn 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)
+\end{code}
+
+
+%*********************************************************
+%* *
+\subsection{Looking up names}
+%* *
+%*********************************************************
+
+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
+
+ -- 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
+
+
+-- 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
+
+intType_RDR = qual (modAndOcc (getName intTyCon))
+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}
+
+=============== 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}
+
+=============== FixityEnv ================
+\begin{code}
+plusFixityEnvRn f1 f2
+ = mapRn (addErrRn.fixityClashErr) (conflictsFM bad_fix f1 f2) `thenRn_`
+ returnRn (f1 `plusFM` f2)
+
+addOneToFixityEnvRn env rdr_name fixity
+ = mapRn (addErrRn.fixityClashErr) (conflictFM bad_fix env rdr_name fixity) `thenRn_`
+ returnRn (addToFM env rdr_name fixity)
+
+lookupFixityEnv env rdr_name
+ = case lookupFM env rdr_name of
+ Just (fixity,_) -> fixity
+ Nothing -> Fixity 9 InfixL -- Default case
+
+bad_fix :: (Fixity, Provenance) -> (Fixity, Provenance) -> Bool
+bad_fix (f1,_) (f2,_) = f1 /= f2
+
+pprFixityProvenance :: PprStyle -> (Fixity,Provenance) -> Pretty
+pprFixityProvenance sty (fixity, prov) = pprProvenance sty prov
+\end{code}
+
+
+
+=============== Avails ================
+\begin{code}
+emptyModuleAvails :: ModuleAvails
+plusModuleAvails :: ModuleAvails -> ModuleAvails -> ModuleAvails
+lookupModuleAvails :: ModuleAvails -> Module -> Maybe [AvailInfo]
+
+emptyModuleAvails = emptyFM
+plusModuleAvails = plusFM_C (++)
+lookupModuleAvails = lookupFM
+\end{code}
+
+
+=============== AvailInfo ================
+\begin{code}
+plusAvail (Avail n1 ns1) (Avail n2 ns2) = Avail n1 (nub (ns1 ++ ns2))
+plusAvail a NotAvailable = a
+plusAvail NotAvailable a = a
+
+addAvailToNameSet :: NameSet -> AvailInfo -> NameSet
+addAvailToNameSet names NotAvailable = names
+addAvailToNameSet names (Avail n ns) = addListToNameSet names (n:ns)
+
+availsToNameSet :: [AvailInfo] -> NameSet
+availsToNameSet avails = foldl addAvailToNameSet emptyNameSet avails
+
+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
+ 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
+
+
+filterAvail (IEThingAll _) avail = avail
+filterAvail ie (Avail n ns) = Avail n [] -- IEThingAbs and IEVar
+
+-- 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 ")"]
+\end{code}
+
+
+
+
+%************************************************************************
+%* *
+\subsection{Finite map utilities}
+%* *
+%************************************************************************
+
+
+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 -> []
+\end{code}
+
+
+%************************************************************************
+%* *
+\subsection{Envt utility functions}
+%* *
+%************************************************************************
+
+
+\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])
+
+fixityClashErr (rdr_name, (fp1,fp2)) sty
+ = ppHang (ppCat [ppStr "Conflicting fixities for: ", ppr sty rdr_name])
+ 4 (ppAboves [pprFixityProvenance sty fp1,
+ pprFixityProvenance sty fp2])
+
+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]
+ 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) ])
+
+dupNamesErr descriptor ((name,loc) : dup_things)
+ = pushSrcLocRn loc $
+ addErrRn (\sty -> ppBesides [ppStr "duplicate bindings of `",
+ ppr sty name, ppStr "' in ",
+ ppStr descriptor])
+\end{code}
+
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