diff options
| -rw-r--r-- | lib/dialyzer/src/dialyzer_dataflow.erl | 44 | ||||
| -rw-r--r-- | lib/dialyzer/test/small_SUITE_data/results/unused_funs | 5 | ||||
| -rw-r--r-- | lib/dialyzer/test/small_SUITE_data/src/unused_funs.erl | 21 |
3 files changed, 60 insertions, 10 deletions
diff --git a/lib/dialyzer/src/dialyzer_dataflow.erl b/lib/dialyzer/src/dialyzer_dataflow.erl index c5f93a3392..45b4abb253 100644 --- a/lib/dialyzer/src/dialyzer_dataflow.erl +++ b/lib/dialyzer/src/dialyzer_dataflow.erl @@ -102,6 +102,8 @@ | 'undefined', % race fun_homes :: dict:dict(label(), mfa()) | 'undefined', % race + reachable_funs :: sets:set(label()) + | 'undefined', % race plt :: dialyzer_plt:plt() | 'undefined', % race opaques :: [type()] @@ -269,9 +271,11 @@ traverse(Tree, Map, State) -> case state__warning_mode(State) of true -> {State, Map, Type}; false -> - State2 = state__add_work(get_label(Tree), State), + FunLbl = get_label(Tree), + State2 = state__add_work(FunLbl, State), State3 = state__update_fun_env(Tree, Map, State2), - {State3, Map, Type} + State4 = state__add_reachable(FunLbl, State3), + {State4, Map, Type} end; 'let' -> handle_let(Tree, Map, State); @@ -3039,25 +3043,35 @@ state__new(Callgraph, Codeserver, Tree, Plt, Module, Records) -> {TreeMap, FunHomes} = build_tree_map(Tree, Callgraph), Funs = dict:fetch_keys(TreeMap), FunTab = init_fun_tab(Funs, dict:new(), TreeMap, Callgraph, Plt), - ExportedFuns = - [Fun || Fun <- Funs--[top], dialyzer_callgraph:is_escaping(Fun, Callgraph)], - Work = init_work(ExportedFuns), + ExportedFunctions = + [Fun || + Fun <- Funs--[top], + dialyzer_callgraph:is_escaping(Fun, Callgraph), + dialyzer_callgraph:lookup_name(Fun, Callgraph) =/= error + ], + Work = init_work(ExportedFunctions), Env = lists:foldl(fun(Fun, Env) -> dict:store(Fun, map__new(), Env) end, dict:new(), Funs), #state{callgraph = Callgraph, codeserver = Codeserver, envs = Env, fun_tab = FunTab, fun_homes = FunHomes, opaques = Opaques, plt = Plt, races = dialyzer_races:new(), records = Records, warning_mode = false, warnings = [], work = Work, tree_map = TreeMap, - module = Module}. + module = Module, reachable_funs = sets:new()}. state__warning_mode(#state{warning_mode = WM}) -> WM. state__set_warning_mode(#state{tree_map = TreeMap, fun_tab = FunTab, - races = Races} = State) -> + races = Races, callgraph = Callgraph, + reachable_funs = ReachableFuns} = State) -> ?debug("==========\nStarting warning pass\n==========\n", []), Funs = dict:fetch_keys(TreeMap), - State#state{work = init_work([top|Funs--[top]]), + Work = + [Fun || + Fun <- Funs--[top], + dialyzer_callgraph:lookup_name(Fun, Callgraph) =/= error orelse + sets:is_element(Fun, ReachableFuns)], + State#state{work = init_work(Work), fun_tab = FunTab, warning_mode = true, races = dialyzer_races:put_race_analysis(true, Races)}. @@ -3149,7 +3163,8 @@ state__get_race_warnings(#state{races = Races} = State) -> State1#state{races = Races1}. state__get_warnings(#state{tree_map = TreeMap, fun_tab = FunTab, - callgraph = Callgraph, plt = Plt} = State) -> + callgraph = Callgraph, plt = Plt, + reachable_funs = ReachableFuns} = State) -> FoldFun = fun({top, _}, AccState) -> AccState; ({FunLbl, Fun}, AccState) -> @@ -3184,7 +3199,12 @@ state__get_warnings(#state{tree_map = TreeMap, fun_tab = FunTab, GenRet = dialyzer_contracts:get_contract_return(C), not t_is_unit(GenRet) end, - case Warn of + %% Do not output warnings for unreachable funs. + case + Warn andalso + (dialyzer_callgraph:lookup_name(FunLbl, Callgraph) =/= error + orelse sets:is_element(FunLbl, ReachableFuns)) + of true -> case classify_returns(Fun) of no_match -> @@ -3255,6 +3275,10 @@ state__get_args_and_status(Tree, #state{fun_tab = FunTab}) -> {ok, {ArgTypes, _}} -> {ArgTypes, true} end. +state__add_reachable(FunLbl, #state{reachable_funs = ReachableFuns}=State) -> + NewReachableFuns = sets:add_element(FunLbl, ReachableFuns), + State#state{reachable_funs = NewReachableFuns}. + build_tree_map(Tree, Callgraph) -> Fun = fun(T, {Dict, Homes, FunLbls} = Acc) -> diff --git a/lib/dialyzer/test/small_SUITE_data/results/unused_funs b/lib/dialyzer/test/small_SUITE_data/results/unused_funs new file mode 100644 index 0000000000..c468457ead --- /dev/null +++ b/lib/dialyzer/test/small_SUITE_data/results/unused_funs @@ -0,0 +1,5 @@ + +unused_funs.erl:10: The pattern 'error' can never match the type 'other_error' +unused_funs.erl:15: Function not_used/0 will never be called +unused_funs.erl:19: Function foo/1 will never be called +unused_funs.erl:7: Function test/0 has no local return diff --git a/lib/dialyzer/test/small_SUITE_data/src/unused_funs.erl b/lib/dialyzer/test/small_SUITE_data/src/unused_funs.erl new file mode 100644 index 0000000000..c24cf3ea81 --- /dev/null +++ b/lib/dialyzer/test/small_SUITE_data/src/unused_funs.erl @@ -0,0 +1,21 @@ +%% See also ERL-593. + +-module(unused_funs). + +-export([test/0]). + +test() -> % "has no local return" + Var = outer_scope, + case other_error of + error -> % "can never match" + %% No warnings "no local return" and "_ = 1 can never match 0" (!) + foo(fun() -> {Var, 1 = 0} end) + end. + +not_used() -> % "will never be called" + %% No warnings "no local return" and "1 can never match 0". + foo(fun() -> 1 = 0 end). + +foo(Fun) -> % "will never be called" + 1 = 0, % No pattern match warning (foo/1 is not traversed at all). + Fun(). |