\begin{code}
module RnIfaces
- (
+ (
getInterfaceExports,
- getImportedInstDecls, getImportedRules,
- lookupFixityRn,
- importDecl, ImportDeclResult(..), recordLocalSlurps,
- mkImportInfo, getSlurped,
+ recordLocalSlurps,
+ mkImportInfo,
+
+ slurpImpDecls, closeDecls,
RecompileRequired, outOfDate, upToDate, recompileRequired
)
import CmdLineOpts ( DynFlags, opt_NoPruneDecls, opt_NoPruneTyDecls, opt_IgnoreIfacePragmas )
import HscTypes
-import HsSyn ( HsDecl(..), InstDecl(..), HsType(..) )
+import HsSyn ( HsDecl(..), Sig(..), TyClDecl(..), ConDecl(..), ConDetails(..),
+ InstDecl(..), HsType(..), hsTyVarNames, getBangType
+ )
import HsImpExp ( ImportDecl(..) )
-import BasicTypes ( Version, defaultFixity )
import RdrHsSyn ( RdrNameHsDecl, RdrNameTyClDecl, RdrNameInstDecl )
+import RnHsSyn ( RenamedHsDecl, extractHsTyNames, extractHsCtxtTyNames, tyClDeclFVs )
import RnHiFiles ( tryLoadInterface, loadHomeInterface, loadInterface,
loadOrphanModules
)
+import RnSource ( rnTyClDecl, rnDecl )
import RnEnv
import RnMonad
+import Id ( idType )
+import Type ( namesOfType )
+import TyCon ( isSynTyCon, getSynTyConDefn )
import Name ( Name {-instance NamedThing-}, nameOccName,
- nameModule, isLocallyDefined,
+ nameModule, isLocallyDefined, nameUnique,
NamedThing(..),
elemNameEnv
)
extendModuleEnv_C, lookupWithDefaultModuleEnv
)
import NameSet
-import PrelInfo ( wiredInThingEnv )
+import PrelInfo ( wiredInThingEnv, fractionalClassKeys )
+import TysWiredIn ( doubleTyCon )
import Maybes ( orElse )
import FiniteMap
import Outputable
@getInterfaceExports@ is called only for directly-imported modules.
\begin{code}
-getInterfaceExports :: ModuleName -> WhereFrom -> RnMG (Module, Avails)
+getInterfaceExports :: ModuleName -> WhereFrom -> RnMG (Module, [(ModuleName,Avails)])
getInterfaceExports mod_name from
= getHomeIfaceTableRn `thenRn` \ hit ->
case lookupModuleEnvByName hit mod_name of {
%* *
%*********************************************************
-This has to be in RnIfaces (or RnHiFiles) because it calls loadHomeInterface
-
-\begin{code}
-lookupFixityRn :: Name -> RnMS Fixity
-lookupFixityRn name
- | isLocallyDefined name
- = getFixityEnv `thenRn` \ local_fix_env ->
- returnRn (lookupLocalFixity local_fix_env name)
-
- | otherwise -- Imported
- -- For imported names, we have to get their fixities by doing a loadHomeInterface,
- -- and consulting the Ifaces that comes back from that, because the interface
- -- file for the Name might not have been loaded yet. Why not? Suppose you import module A,
- -- which exports a function 'f', which is defined in module B. Then B isn't loaded
- -- right away (after all, it's possible that nothing from B will be used).
- -- When we come across a use of 'f', we need to know its fixity, and it's then,
- -- and only then, that we load B.hi. That is what's happening here.
- = getHomeIfaceTableRn `thenRn` \ hit ->
- loadHomeInterface doc name `thenRn` \ ifaces ->
- case lookupTable hit (iPIT ifaces) name of
- Just iface -> returnRn (lookupNameEnv (mi_fixities iface) name `orElse` defaultFixity)
- Nothing -> returnRn defaultFixity
- where
- doc = ptext SLIT("Checking fixity for") <+> ppr name
-\end{code}
-
-
-%*********************************************************
-%* *
-\subsection{Instance declarations are handled specially}
-%* *
-%*********************************************************
-
\begin{code}
getImportedInstDecls :: NameSet -> RnMG [(Module,RdrNameHsDecl)]
getImportedInstDecls gates
add_item xs _ = x:xs
\end{code}
+%*********************************************************
+%* *
+\subsection{Slurping declarations}
+%* *
+%*********************************************************
+
+\begin{code}
+-------------------------------------------------------
+slurpImpDecls source_fvs
+ = traceRn (text "slurpImp" <+> fsep (map ppr (nameSetToList source_fvs))) `thenRn_`
+
+ -- The current slurped-set records all local things
+ getSlurped `thenRn` \ source_binders ->
+ slurpSourceRefs source_binders source_fvs `thenRn` \ (decls, needed) ->
+
+ -- Then get everything else
+ closeDecls decls needed `thenRn` \ decls1 ->
+
+ -- Finally, get any deferred data type decls
+ slurpDeferredDecls decls1 `thenRn` \ final_decls ->
+
+ returnRn final_decls
+
+
+-------------------------------------------------------
+slurpSourceRefs :: NameSet -- Variables defined in source
+ -> FreeVars -- Variables referenced in source
+ -> RnMG ([RenamedHsDecl],
+ FreeVars) -- Un-satisfied needs
+-- The declaration (and hence home module) of each gate has
+-- already been loaded
+
+slurpSourceRefs source_binders source_fvs
+ = go_outer [] -- Accumulating decls
+ emptyFVs -- Unsatisfied needs
+ emptyFVs -- Accumulating gates
+ (nameSetToList source_fvs) -- Things whose defn hasn't been loaded yet
+ where
+ -- The outer loop repeatedly slurps the decls for the current gates
+ -- and the instance decls
+
+ -- The outer loop is needed because consider
+ -- instance Foo a => Baz (Maybe a) where ...
+ -- It may be that @Baz@ and @Maybe@ are used in the source module,
+ -- but not @Foo@; so we need to chase @Foo@ too.
+ --
+ -- We also need to follow superclass refs. In particular, 'chasing @Foo@' must
+ -- include actually getting in Foo's class decl
+ -- class Wib a => Foo a where ..
+ -- so that its superclasses are discovered. The point is that Wib is a gate too.
+ -- We do this for tycons too, so that we look through type synonyms.
+
+ go_outer decls fvs all_gates []
+ = returnRn (decls, fvs)
+
+ go_outer decls fvs all_gates refs -- refs are not necessarily slurped yet
+ = traceRn (text "go_outer" <+> ppr refs) `thenRn_`
+ foldlRn go_inner (decls, fvs, emptyFVs) refs `thenRn` \ (decls1, fvs1, gates1) ->
+ getImportedInstDecls (all_gates `plusFV` gates1) `thenRn` \ inst_decls ->
+ rnInstDecls decls1 fvs1 gates1 inst_decls `thenRn` \ (decls2, fvs2, gates2) ->
+ go_outer decls2 fvs2 (all_gates `plusFV` gates2)
+ (nameSetToList (gates2 `minusNameSet` all_gates))
+ -- Knock out the all_gates because even if we don't slurp any new
+ -- decls we can get some apparently-new gates from wired-in names
+
+ go_inner (decls, fvs, gates) wanted_name
+ = importDecl wanted_name `thenRn` \ import_result ->
+ case import_result of
+ AlreadySlurped -> returnRn (decls, fvs, gates)
+ WiredIn -> returnRn (decls, fvs, gates `plusFV` getWiredInGates wanted_name)
+ Deferred -> returnRn (decls, fvs, gates `addOneFV` wanted_name) -- It's a type constructor
+
+ HereItIs decl -> rnIfaceTyClDecl decl `thenRn` \ (new_decl, fvs1) ->
+ returnRn (TyClD new_decl : decls,
+ fvs1 `plusFV` fvs,
+ gates `plusFV` getGates source_fvs new_decl)
+
+rnInstDecls decls fvs gates []
+ = returnRn (decls, fvs, gates)
+rnInstDecls decls fvs gates (d:ds)
+ = rnIfaceDecl d `thenRn` \ (new_decl, fvs1) ->
+ rnInstDecls (new_decl:decls)
+ (fvs1 `plusFV` fvs)
+ (gates `plusFV` getInstDeclGates new_decl)
+ ds
+\end{code}
+
+
+\begin{code}
+-------------------------------------------------------
+-- closeDecls keeps going until the free-var set is empty
+closeDecls decls needed
+ | not (isEmptyFVs needed)
+ = slurpDecls decls needed `thenRn` \ (decls1, needed1) ->
+ closeDecls decls1 needed1
+
+ | otherwise
+ = getImportedRules `thenRn` \ rule_decls ->
+ case rule_decls of
+ [] -> returnRn decls -- No new rules, so we are done
+ other -> rnIfaceDecls decls emptyFVs rule_decls `thenRn` \ (decls1, needed1) ->
+ closeDecls decls1 needed1
+
+
+-------------------------------------------------------
+-- Augment decls with any decls needed by needed.
+-- Return also free vars of the new decls (only)
+slurpDecls decls needed
+ = go decls emptyFVs (nameSetToList needed)
+ where
+ go decls fvs [] = returnRn (decls, fvs)
+ go decls fvs (ref:refs) = slurpDecl decls fvs ref `thenRn` \ (decls1, fvs1) ->
+ go decls1 fvs1 refs
+
+-------------------------------------------------------
+slurpDecl decls fvs wanted_name
+ = importDecl wanted_name `thenRn` \ import_result ->
+ case import_result of
+ -- Found a declaration... rename it
+ HereItIs decl -> rnIfaceTyClDecl decl `thenRn` \ (new_decl, fvs1) ->
+ returnRn (TyClD new_decl:decls, fvs1 `plusFV` fvs)
+
+ -- No declaration... (wired in thing, or deferred, or already slurped)
+ other -> returnRn (decls, fvs)
+
+
+-------------------------------------------------------
+rnIfaceDecls :: [RenamedHsDecl] -> FreeVars
+ -> [(Module, RdrNameHsDecl)]
+ -> RnM d ([RenamedHsDecl], FreeVars)
+rnIfaceDecls decls fvs [] = returnRn (decls, fvs)
+rnIfaceDecls decls fvs (d:ds) = rnIfaceDecl d `thenRn` \ (new_decl, fvs1) ->
+ rnIfaceDecls (new_decl:decls) (fvs1 `plusFV` fvs) ds
+
+rnIfaceDecl (mod, decl) = initIfaceRnMS mod (rnDecl decl)
+rnIfaceTyClDecl (mod, decl) = initIfaceRnMS mod (rnTyClDecl decl) `thenRn` \ decl' ->
+ returnRn (decl', tyClDeclFVs decl')
+\end{code}
+
+
\begin{code}
getSlurped
= getIfacesRn `thenRn` \ ifaces ->
\end{code}
+
+%*********************************************************
+%* *
+\subsection{Deferred declarations}
+%* *
+%*********************************************************
+
+The idea of deferred declarations is this. Suppose we have a function
+ f :: T -> Int
+ data T = T1 A | T2 B
+ data A = A1 X | A2 Y
+ data B = B1 P | B2 Q
+Then we don't want to load T and all its constructors, and all
+the types those constructors refer to, and all the types *those*
+constructors refer to, and so on. That might mean loading many more
+interface files than is really necessary. So we 'defer' loading T.
+
+But f might be strict, and the calling convention for evaluating
+values of type T depends on how many constructors T has, so
+we do need to load T, but not the full details of the type T.
+So we load the full decl for T, but only skeleton decls for A and B:
+ f :: T -> Int
+ data T = {- 2 constructors -}
+
+Whether all this is worth it is moot.
+
+\begin{code}
+slurpDeferredDecls :: [RenamedHsDecl] -> RnMG [RenamedHsDecl]
+slurpDeferredDecls decls = returnRn decls
+
+{- OMIT FOR NOW
+slurpDeferredDecls :: [RenamedHsDecl] -> RnMG [RenamedHsDecl]
+slurpDeferredDecls decls
+ = getDeferredDecls `thenRn` \ def_decls ->
+ rnIfaceDecls decls emptyFVs (map stripDecl def_decls) `thenRn` \ (decls1, fvs) ->
+ ASSERT( isEmptyFVs fvs )
+ returnRn decls1
+
+stripDecl (mod, TyClD (TyData dt _ tc tvs _ nconstrs _ loc name1 name2))
+ = (mod, TyClD (TyData dt [] tc tvs [] nconstrs Nothing loc
+ name1 name2))
+ -- Nuke the context and constructors
+ -- But retain the *number* of constructors!
+ -- Also the tvs will have kinds on them.
+-}
+\end{code}
+
+
+%*********************************************************
+%* *
+\subsection{Extracting the `gates'}
+%* *
+%*********************************************************
+
+When we import a declaration like
+\begin{verbatim}
+ data T = T1 Wibble | T2 Wobble
+\end{verbatim}
+we don't want to treat @Wibble@ and @Wobble@ as gates
+{\em unless} @T1@, @T2@ respectively are mentioned by the user program.
+If only @T@ is mentioned
+we want only @T@ to be a gate;
+that way we don't suck in useless instance
+decls for (say) @Eq Wibble@, when they can't possibly be useful.
+
+@getGates@ takes a newly imported (and renamed) decl, and the free
+vars of the source program, and extracts from the decl the gate names.
+
+\begin{code}
+getGates source_fvs (IfaceSig _ ty _ _)
+ = extractHsTyNames ty
+
+getGates source_fvs (ClassDecl ctxt cls tvs _ sigs _ _ _ )
+ = (delListFromNameSet (foldr (plusFV . get) (extractHsCtxtTyNames ctxt) sigs)
+ (hsTyVarNames tvs)
+ `addOneToNameSet` cls)
+ `plusFV` maybe_double
+ where
+ get (ClassOpSig n _ ty _)
+ | n `elemNameSet` source_fvs = extractHsTyNames ty
+ | otherwise = emptyFVs
+
+ -- If we load any numeric class that doesn't have
+ -- Int as an instance, add Double to the gates.
+ -- This takes account of the fact that Double might be needed for
+ -- defaulting, but we don't want to load Double (and all its baggage)
+ -- if the more exotic classes aren't used at all.
+ maybe_double | nameUnique cls `elem` fractionalClassKeys
+ = unitFV (getName doubleTyCon)
+ | otherwise
+ = emptyFVs
+
+getGates source_fvs (TySynonym tycon tvs ty _)
+ = delListFromNameSet (extractHsTyNames ty)
+ (hsTyVarNames tvs)
+ -- A type synonym type constructor isn't a "gate" for instance decls
+
+getGates source_fvs (TyData _ ctxt tycon tvs cons _ _ _ _ _)
+ = delListFromNameSet (foldr (plusFV . get) (extractHsCtxtTyNames ctxt) cons)
+ (hsTyVarNames tvs)
+ `addOneToNameSet` tycon
+ where
+ get (ConDecl n _ tvs ctxt details _)
+ | n `elemNameSet` source_fvs
+ -- If the constructor is method, get fvs from all its fields
+ = delListFromNameSet (get_details details `plusFV`
+ extractHsCtxtTyNames ctxt)
+ (hsTyVarNames tvs)
+ get (ConDecl n _ tvs ctxt (RecCon fields) _)
+ -- Even if the constructor isn't mentioned, the fields
+ -- might be, as selectors. They can't mention existentially
+ -- bound tyvars (typechecker checks for that) so no need for
+ -- the deleteListFromNameSet part
+ = foldr (plusFV . get_field) emptyFVs fields
+
+ get other_con = emptyFVs
+
+ get_details (VanillaCon tys) = plusFVs (map get_bang tys)
+ get_details (InfixCon t1 t2) = get_bang t1 `plusFV` get_bang t2
+ get_details (RecCon fields) = plusFVs [get_bang t | (_, t) <- fields]
+
+ get_field (fs,t) | any (`elemNameSet` source_fvs) fs = get_bang t
+ | otherwise = emptyFVs
+
+ get_bang bty = extractHsTyNames (getBangType bty)
+\end{code}
+
+@getWiredInGates@ is just like @getGates@, but it sees a wired-in @Name@
+rather than a declaration.
+
+\begin{code}
+getWiredInGates :: Name -> FreeVars
+getWiredInGates name -- No classes are wired in
+ = case lookupNameEnv wiredInThingEnv name of
+ Just (AnId the_id) -> getWiredInGates_s (namesOfType (idType the_id))
+
+ Just (ATyCon tc)
+ | isSynTyCon tc
+ -> getWiredInGates_s (delListFromNameSet (namesOfType ty) (map getName tyvars))
+ where
+ (tyvars,ty) = getSynTyConDefn tc
+
+ other -> unitFV name
+
+getWiredInGates_s names = foldr (plusFV . getWiredInGates) emptyFVs (nameSetToList names)
+\end{code}
+
+\begin{code}
+getInstDeclGates (InstD (InstDecl inst_ty _ _ _ _)) = extractHsTyNames inst_ty
+getInstDeclGates other = emptyFVs
+\end{code}
+
+
%*********************************************************
%* *
\subsection{Getting in a declaration}
projects / ghc-hetmet.git / blobdiff