+tcInstDecls1 -- Deal with source-code instance decls
+ :: PersistentCompilerState
+ -> HomeSymbolTable -- Contains instances
+ -> TcEnv -- Contains IdInfo for dfun ids
+ -> (Name -> Maybe Fixity) -- for deriving Show and Read
+ -> Module -- Module for deriving
+ -> [RenamedTyClDecl] -- For deriving stuff
+ -> [RenamedInstDecl] -- Source code instance decls
+ -> TcM (InstEnv, -- the full inst env
+ [InstInfo], -- instance decls to process; contains all dfuns
+ -- for this module
+ RenamedHsBinds) -- derived instances
+
+tcInstDecls1 pcs hst unf_env get_fixity
+ this_mod tycl_decls inst_decls
+ = let
+ pkg_inst_env = pcs_insts pcs
+ prs = pcs_PRS pcs
+ clas_decls = filter isClassDecl tycl_decls
+ in
+ -- (1) Do the ordinary instance declarations
+ mapNF_Tc tcLocalInstDecl1 inst_decls `thenNF_Tc` \ local_inst_infos ->
+
+ -- (2) Instances from generic class declarations
+ getGenericInstances clas_decls `thenTc` \ generic_inst_info ->
+
+ -- Next, construct the instance environment so far, consisting of
+ -- a) cached non-home-package InstEnv (gotten from pcs) inst_env0
+ -- b) imported instance decls (not in the home package) inst_env1
+ -- c) other modules in this package (gotten from hst) inst_env2
+ -- d) imported instance decls (from this module) inst_env3
+ -- e) local instance decls inst_env4
+ -- f) generic instances inst_env5
+ -- The result of (b) replaces the cached InstEnv in the PCS
+ --
+ -- Note that iface_dfuns may contain not only insts that we
+ -- demand-loaded from interface files, but also instances from
+ -- the current module in the case where we are loading this
+ -- module's interface file in GHCi, so we partition the
+ -- iface_dfuns into non-local and local instances so that we
+ -- don't end up with home package instances in the PCS.
+ --
+ -- There can't be any instance declarations from the home
+ -- package other than from the current module (with the
+ -- compilation manager) because they are loaded explicitly by
+ -- the compilation manager.
+ let
+ local_inst_info = catMaybes local_inst_infos
+ hst_dfuns = foldModuleEnv ((++) . md_insts) [] hst
+ in
+
+-- pprTrace "tcInstDecls" (vcat [ppr imported_dfuns, ppr hst_dfuns]) $
+
+ addInstDFuns pkg_inst_env hst_dfuns `thenNF_Tc` \ inst_env2 ->
+ addInstInfos inst_env2 local_inst_info `thenNF_Tc` \ inst_env3 ->
+ addInstInfos inst_env3 generic_inst_info `thenNF_Tc` \ inst_env4 ->
+
+ -- (3) Compute instances from "deriving" clauses;
+ -- note that we only do derivings for things in this module;
+ -- we ignore deriving decls from interfaces!
+ -- This stuff computes a context for the derived instance decl, so it
+ -- needs to know about all the instances possible; hence inst_env4
+ tcDeriving prs this_mod inst_env4
+ get_fixity tycl_decls `thenTc` \ (deriv_inst_info, deriv_binds) ->
+ addInstInfos inst_env4 deriv_inst_info `thenNF_Tc` \ final_inst_env ->
+
+ returnTc (final_inst_env,
+ generic_inst_info ++ deriv_inst_info ++ local_inst_info,
+ deriv_binds)
+
+addInstInfos :: InstEnv -> [InstInfo] -> NF_TcM InstEnv
+addInstInfos inst_env infos = addInstDFuns inst_env (map iDFunId infos)
+
+addInstDFuns :: InstEnv -> [DFunId] -> NF_TcM InstEnv
+addInstDFuns inst_env dfuns
+ = getDOptsTc `thenNF_Tc` \ dflags ->