+ this_mod = mi_module mod_iface
+ fixity_env = mi_fixities mod_iface
+
+ get_fixity :: Name -> Maybe Fixity
+ get_fixity nm = lookupNameEnv fixity_env nm
+
+ tcIfaceImports pcs hst get_fixity this_mod decls
+ = fixTc (\ ~(unf_env, _, _, _, _) ->
+ tcImports unf_env pcs hst get_fixity this_mod decls
+ ) `thenTc` \ (env, new_pcs, local_inst_info,
+ deriv_binds, local_rules) ->
+ ASSERT(nullBinds deriv_binds)
+ let
+ local_things = filter (isLocalThing this_mod) (nameEnvElts (getTcGEnv env))
+
+ mod_details = ModDetails { md_types = mkTypeEnv local_things,
+ md_insts = map iDFunId local_inst_info,
+ md_rules = [(id,rule) | IfaceRuleOut id rule <- local_rules],
+ md_binds = [] }
+ -- All the rules from an interface are of the IfaceRuleOut form
+ in
+ returnTc (new_pcs, mod_details)
+
+tcImports :: RecTcEnv
+ -> PersistentCompilerState
+ -> HomeSymbolTable
+ -> (Name -> Maybe Fixity)
+ -> Module
+ -> [RenamedHsDecl]
+ -> TcM (TcEnv, PersistentCompilerState, [InstInfo],
+ RenamedHsBinds, [TypecheckedRuleDecl])
+
+-- tcImports is a slight mis-nomer.
+-- It deals with everything that could be an import:
+-- type and class decls
+-- interface signatures (checked lazily)
+-- instance decls
+-- rule decls
+-- These can occur in source code too, of course
+
+tcImports unf_env pcs hst get_fixity this_mod decls
+ -- (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
+
+ = checkNoErrsTc $
+ -- tcImports recovers internally, but if anything gave rise to
+ -- an error we'd better stop now, to avoid a cascade
+
+ 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_insts, deriv_binds) ->
+ tcSetInstEnv inst_env $
+
+ -- Interface type signatures
+ -- We tie a knot so that the Ids read out of interfaces are in scope
+ -- when we read their pragmas.
+ -- What we rely on is that pragmas are typechecked lazily; if
+ -- any type errors are found (ie there's an inconsistency)
+ -- we silently discard the pragma
+ traceTc (text "Tc3") `thenNF_Tc_`
+ tcInterfaceSigs unf_env this_mod tycl_decls `thenTc` \ sig_ids ->
+ tcExtendGlobalValEnv sig_ids $
+
+
+ tcIfaceRules (pcs_rules pcs) this_mod iface_rules `thenNF_Tc` \ (new_pcs_rules, local_rules) ->
+ -- When relinking this module from its interface-file decls
+ -- we'll have IfaceRules that are in fact local to this module
+ -- That's the reason we we get any local_rules out here
+
+ tcGetEnv `thenTc` \ unf_env ->
+ let
+ all_things = nameEnvElts (getTcGEnv unf_env)
+
+ -- sometimes we're compiling in the context of a package module
+ -- (on the GHCi command line, for example). In this case, we
+ -- want to treat everything we pulled in as an imported thing.
+ imported_things
+ = filter (not . isLocalThing this_mod) all_things
+
+ new_pte :: PackageTypeEnv
+ new_pte = extendTypeEnvList (pcs_PTE pcs) imported_things
+
+ new_pcs :: PersistentCompilerState
+ new_pcs = pcs { pcs_PTE = new_pte,
+ pcs_insts = new_pcs_insts,
+ pcs_rules = new_pcs_rules
+ }
+ in
+ returnTc (unf_env, new_pcs, local_insts, deriv_binds, local_rules)
+ where
+ tycl_decls = [d | TyClD d <- decls]
+ iface_rules = [d | RuleD d <- decls, isIfaceRuleDecl d]
+\end{code}