+ -- Second pass over class and instance declarations,
+ -- to compile the bindings themselves.
+ tcInstDecls2 local_inst_info `thenNF_Tc` \ (lie_instdecls, inst_binds) ->
+ tcClassDecls2 this_mod tycl_decls `thenNF_Tc` \ (lie_clasdecls, cls_dm_binds) ->
+ tcSourceRules source_rules `thenNF_Tc` \ (lie_rules, more_local_rules) ->
+
+ -- Deal with constant or ambiguous InstIds. How could
+ -- there be ambiguous ones? They can only arise if a
+ -- top-level decl falls under the monomorphism
+ -- restriction, and no subsequent decl instantiates its
+ -- type. (Usually, ambiguous type variables are resolved
+ -- during the generalisation step.)
+ let
+ lie_alldecls = lie_valdecls `plusLIE`
+ lie_instdecls `plusLIE`
+ lie_clasdecls `plusLIE`
+ lie_fodecls `plusLIE`
+ lie_rules
+ in
+ tcSimplifyTop lie_alldecls `thenTc` \ const_inst_binds ->
+
+ -- Backsubstitution. This must be done last.
+ -- Even tcSimplifyTop may do some unification.
+ let
+ all_binds = val_binds `AndMonoBinds`
+ inst_binds `AndMonoBinds`
+ cls_dm_binds `AndMonoBinds`
+ const_inst_binds `AndMonoBinds`
+ foe_binds
+ in
+-- traceTc (text "Tc9") `thenNF_Tc_`
+ zonkTopBinds all_binds `thenNF_Tc` \ (all_binds', final_env) ->
+ tcSetEnv final_env $
+ -- zonkTopBinds puts all the top-level Ids into the tcGEnv
+ zonkForeignExports foe_decls `thenNF_Tc` \ foe_decls' ->
+ zonkRules more_local_rules `thenNF_Tc` \ more_local_rules' ->
+
+
+ let local_things = filter (isLocalThing this_mod) (nameEnvElts (getTcGEnv final_env))
+
+ -- Create any necessary "implicit" bindings (data constructors etc)
+ -- Should we create bindings for dictionary constructors?
+ -- They are always fully applied, and the bindings are just there
+ -- to support partial applications. But it's easier to let them through.
+ implicit_binds = andMonoBindList [ CoreMonoBind id (unfoldingTemplate unf)
+ | id <- implicitTyThingIds local_things
+ , let unf = idUnfolding id
+ , hasUnfolding unf
+ ]
+
+ local_type_env :: TypeEnv
+ local_type_env = mkTypeEnv local_things
+
+ all_local_rules = local_rules ++ more_local_rules'
+ in
+-- traceTc (text "Tc10") `thenNF_Tc_`
+ returnTc (new_pcs,
+ TcResults { tc_env = local_type_env,
+ tc_binds = implicit_binds `AndMonoBinds` all_binds',
+ tc_insts = map iDFunId local_inst_info,
+ tc_fords = foi_decls ++ foe_decls',
+ tc_rules = all_local_rules
+ }
+ )
+ where
+ tycl_decls = [d | TyClD d <- decls]
+ val_binds = foldr ThenBinds EmptyBinds [binds | ValD binds <- decls]
+ source_rules = [d | RuleD d <- decls, not (isIfaceRuleDecl d)]
+\end{code}
+
+
+\begin{code}
+tcImports :: PersistentCompilerState
+ -> HomeSymbolTable
+ -> (Name -> Maybe Fixity)
+ -> Module
+ -> [RenamedHsDecl]
+ -> TcM (TcEnv, PersistentCompilerState,
+ [InstInfo], RenamedHsBinds, [TypecheckedRuleDecl])
+
+-- tcImports is a slight mis-nomer.
+-- It deals with everythign that could be an import:
+-- type and class decls
+-- interface signatures
+-- instance decls
+-- rule decls
+-- These can occur in source code too, of course
+
+tcImports pcs hst get_fixity this_mod decls
+ = fixTc (\ ~(unf_env, _, _, _, _) ->
+ -- (unf_env :: RecTcEnv) is used for type-checking interface pragmas
+ -- which is done lazily [ie failure just drops the pragma
+ -- without having any global-failure effect].
+ --
+ -- unf_env is also used to get the pragama info
+ -- for imported dfuns and default methods
+
+-- traceTc (text "Tc1") `thenNF_Tc_`
+ tcTyAndClassDecls unf_env tycl_decls `thenTc` \ env ->
+ tcSetEnv env $
+
+ -- Typecheck the instance decls, includes deriving
+-- traceTc (text "Tc2") `thenNF_Tc_`
+ tcInstDecls1 (pcs_insts pcs) (pcs_PRS pcs)
+ hst unf_env get_fixity this_mod
+ decls `thenTc` \ (new_pcs_insts, inst_env, local_inst_info, deriv_binds) ->
+ tcSetInstEnv inst_env $
+