diff options
5 files changed, 82 insertions, 11 deletions
diff --git a/lib/dialyzer/src/dialyzer_dataflow.erl b/lib/dialyzer/src/dialyzer_dataflow.erl index 5ab0c39c04..3349b12932 100644 --- a/lib/dialyzer/src/dialyzer_dataflow.erl +++ b/lib/dialyzer/src/dialyzer_dataflow.erl @@ -430,17 +430,35 @@ handle_apply(Tree, Map, State) -> handle_apply_or_call(FunInfoList, Args, ArgTypes, Map, Tree, State) -> None = t_none(), + %% Call-site analysis may be inaccurate and consider more funs than those that + %% are actually possible. If all of them are incorrect, then warnings can be + %% emitted. If at least one fun is ok, however, then no warning is emitted, + %% just in case the bad ones are not really possible. The last argument is + %% used for this, with the following encoding: + %% Initial value: {none, []} + %% First fun checked: {one, <List of warns>} + %% More funs checked: {many, <List of warns>} + %% A '{one, []}' can only become '{many, []}'. + %% If at any point an fun does not add warnings, then the list is also + %% replaced with an empty list. handle_apply_or_call(FunInfoList, Args, ArgTypes, Map, Tree, State, - [None || _ <- ArgTypes], None, false). + [None || _ <- ArgTypes], None, false, {none, []}). handle_apply_or_call([{local, external}|Left], Args, ArgTypes, Map, Tree, State, - _AccArgTypes, _AccRet, _HadExternal) -> + _AccArgTypes, _AccRet, _HadExternal, Warns) -> + {HowMany, _} = Warns, + NewHowMany = + case HowMany of + none -> one; + _ -> many + end, + NewWarns = {NewHowMany, []}, handle_apply_or_call(Left, Args, ArgTypes, Map, Tree, State, - ArgTypes, t_any(), true); + ArgTypes, t_any(), true, NewWarns); handle_apply_or_call([{TypeOfApply, {Fun, Sig, Contr, LocalRet}}|Left], Args, ArgTypes, Map, Tree, #state{opaques = Opaques} = State, - AccArgTypes, AccRet, HadExternal) -> + AccArgTypes, AccRet, HadExternal, Warns) -> Any = t_any(), AnyArgs = [Any || _ <- Args], GenSig = {AnyArgs, fun(_) -> t_any() end}, @@ -586,16 +604,32 @@ handle_apply_or_call([{TypeOfApply, {Fun, Sig, Contr, LocalRet}}|Left], end, NewAccRet = t_sup(AccRet, TotalRet), ?debug("NewAccRet: ~s\n", [t_to_string(NewAccRet)]), + {NewWarnings, State4} = state__remove_added_warnings(State, State3), + {HowMany, OldWarnings} = Warns, + NewWarns = + case HowMany of + none -> {one, NewWarnings}; + _ -> + case OldWarnings =:= [] of + true -> {many, []}; + false -> + case NewWarnings =:= [] of + true -> {many, []}; + false -> {many, NewWarnings ++ OldWarnings} + end + end + end, handle_apply_or_call(Left, Args, ArgTypes, Map, Tree, - State3, NewAccArgTypes, NewAccRet, HadExternal); + State4, NewAccArgTypes, NewAccRet, HadExternal, NewWarns); handle_apply_or_call([], Args, _ArgTypes, Map, _Tree, State, - AccArgTypes, AccRet, HadExternal) -> + AccArgTypes, AccRet, HadExternal, {_, Warnings}) -> + State1 = state__add_warnings(Warnings, State), case HadExternal of false -> NewMap = enter_type_lists(Args, AccArgTypes, Map), - {State, NewMap, AccRet}; + {State1, NewMap, AccRet}; true -> - {had_external, State} + {had_external, State1} end. apply_fail_reason(FailedSig, FailedBif, FailedContract) -> @@ -3038,6 +3072,14 @@ state__add_warning(#state{warnings = Warnings, warning_mode = true} = State, end end. +state__remove_added_warnings(OldState, NewState) -> + #state{warnings = OldWarnings} = OldState, + #state{warnings = NewWarnings} = NewState, + {NewWarnings -- OldWarnings, NewState#state{warnings = OldWarnings}}. + +state__add_warnings(Warns, #state{warnings = Warnings} = State) -> + State#state{warnings = Warns ++ Warnings}. + -spec state__set_curr_fun(curr_fun(), state()) -> state(). state__set_curr_fun(undefined, State) -> diff --git a/lib/dialyzer/test/small_SUITE_data/results/higher_order_discrepancy b/lib/dialyzer/test/small_SUITE_data/results/higher_order_discrepancy index 7ce440a60d..11b9ecade6 100644 --- a/lib/dialyzer/test/small_SUITE_data/results/higher_order_discrepancy +++ b/lib/dialyzer/test/small_SUITE_data/results/higher_order_discrepancy @@ -1,4 +1,3 @@ -higher_order_discrepancy.erl:11: The call higher_order_discrepancy:g('foo') will never return since it differs in the 1st argument from the success typing arguments: ('bar') -higher_order_discrepancy.erl:14: Function g/1 has no local return -higher_order_discrepancy.erl:14: The pattern 'bar' can never match the type 'foo' +higher_order_discrepancy.erl:19: Function g/1 has no local return +higher_order_discrepancy.erl:19: The pattern 'bar' can never match the type 'foo' diff --git a/lib/dialyzer/test/small_SUITE_data/src/higher_order_discrepancy.erl b/lib/dialyzer/test/small_SUITE_data/src/higher_order_discrepancy.erl index ff5ee6bac4..f9547d4929 100644 --- a/lib/dialyzer/test/small_SUITE_data/src/higher_order_discrepancy.erl +++ b/lib/dialyzer/test/small_SUITE_data/src/higher_order_discrepancy.erl @@ -1,3 +1,8 @@ +%% With the patch introduced to avoid false warnings in +%% user_SUITE_data/src/wpc_hlines.erl we can unfortunately no longer precisely +%% catch problems like this one... The refinement procedure is still enough to +%% keep some of the details, nevertheless. + -module(higher_order_discrepancy). -export([test/1]). diff --git a/lib/dialyzer/test/user_SUITE_data/results/wpc_hlines b/lib/dialyzer/test/user_SUITE_data/results/wpc_hlines new file mode 100644 index 0000000000..d6e3f29ab9 --- /dev/null +++ b/lib/dialyzer/test/user_SUITE_data/results/wpc_hlines @@ -0,0 +1,3 @@ + +wpc_hlines.erl:22: Function bad/1 has no local return +wpc_hlines.erl:22: The pattern 'false' can never match the type 'true' diff --git a/lib/dialyzer/test/user_SUITE_data/src/wpc_hlines.erl b/lib/dialyzer/test/user_SUITE_data/src/wpc_hlines.erl new file mode 100644 index 0000000000..8c205a8247 --- /dev/null +++ b/lib/dialyzer/test/user_SUITE_data/src/wpc_hlines.erl @@ -0,0 +1,22 @@ +%% Bug reported by Dan Gudmundsson, test shrunk down by Magnus Lång. + +%% The problem is that dialyzer_dep generates edges from the fun +%% application to both of the functions, and then during the warning pass +%% dialyzer_dataflow:handle_apply_or_call generates warnings for any such +%% edge that won't return. + +%% Since dialyzer_dep is currently supposed to overapproximate rather than +%% underapproximate, the fix was to modify handle_apply_or_call to not generate +%% warnings if some of the possible funs can succeed. + +-module(wpc_hlines). + +-export([do_export/0]). + +do_export() -> + {Proj, _} = % The culprit seems to be putting the funs in a tuple + {fun good/1, fun bad/1}, + Proj(true). + +good(_) -> ok. +bad(false) -> ok. |