- -- 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_`
- 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 ifwe don't slurp any new
- -- decls we can get some apparently-new gates from wired-in names
-
- go_inner decls fvs gates []
- = returnRn (decls, fvs, gates)
-
- go_inner decls fvs gates (wanted_name:refs)
- | isWiredInName wanted_name
- = load_home wanted_name `thenRn_`
- go_inner decls fvs (gates `plusFV` getWiredInGates wanted_name) refs
-
- | otherwise
- = importDecl wanted_name `thenRn` \ maybe_decl ->
- case maybe_decl of
- Nothing -> go_inner decls fvs gates refs -- No declaration... (already slurped, or local)
- Just decl -> rnIfaceDecl decl `thenRn` \ (new_decl, fvs1) ->
- go_inner (new_decl : decls)
- (fvs1 `plusFV` fvs)
- (gates `plusFV` getGates source_fvs new_decl)
- refs
-
- -- When we find a wired-in name we must load its
- -- home module so that we find any instance decls therein
- load_home name
- | name `elemNameSet` source_binders = returnRn ()
- -- When compiling the prelude, a wired-in thing may
- -- be defined in this module, in which case we don't
- -- want to load its home module!
- -- Using 'isLocallyDefined' doesn't work because some of
- -- the free variables returned are simply 'listTyCon_Name',
- -- with a system provenance. We could look them up every time
- -- but that seems a waste.
- | otherwise = loadHomeInterface doc name `thenRn_`
- returnRn ()
- where
- doc = ptext SLIT("need home module for wired in thing") <+> ppr name
-
-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
-
-
--------------------------------------------------------
-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)
-
-
--------------------------------------------------------
--- 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` \ maybe_decl ->
- case maybe_decl of
- -- No declaration... (wired in thing)
- Nothing -> returnRn (decls, fvs)
-
- -- Found a declaration... rename it
- Just decl -> rnIfaceDecl decl `thenRn` \ (new_decl, fvs1) ->
- returnRn (new_decl:decls, fvs1 `plusFV` fvs)