Fix infinite loop in dataflow

2 files changed, 123 insertions, 0 deletions

diff --git a/lib/dialyzer/test/small_SUITE_data/results/common_eunit b/lib/dialyzer/test/small_SUITE_data/results/common_eunit
new file mode 100644
index 0000000000..bb5fd1c9ac
--- /dev/null
+++ b/lib/dialyzer/test/small_SUITE_data/results/common_eunit
@@ -0,0 +1,2 @@
+
+common_eunit.erl:57: The created fun has no local return
diff --git a/lib/dialyzer/test/small_SUITE_data/src/common_eunit.erl b/lib/dialyzer/test/small_SUITE_data/src/common_eunit.erl
new file mode 100644
index 0000000000..bca390068e
--- /dev/null
+++ b/lib/dialyzer/test/small_SUITE_data/src/common_eunit.erl
@@ -0,0 +1,121 @@
+%%=====================================================================
+%% Program with an erroneous type declaration that caused dialyzer to
+%% go into an infinite loop. There are some comments that explain the
+%% symptoms and the culprit: the return of test_fun() is erroneous and
+%% its type should read
+%%	fun((config()) -> test_rep() | [test_rep()])
+%% instead. But this should not throw dialyzer into an infinite loop.
+%% This concerned dialyzer in R14B02 (and probably prior).
+%%=====================================================================
+-module(common_eunit).
+
+-export([expand_cases/2]).
+
+-type test_name() :: atom() | {'group', atom()}.
+
+-type test_rep()  :: {{atom(), atom(), arity()}, fun()}
+                   | {'setup', fun(), fun()}
+                   | {'setup', fun(), fun(), fun()}
+                   | {atom(), test_rep()}
+                   | {atom(), term(), test_rep()}.
+
+-type config()    :: [proplists:property()].
+
+-type control()   :: tuple() | atom().
+
+%% The combination of the following type and the (erroneous) spec for
+%% expand_cases/2 is the reason for the infinite loop in dialyzer.
+-type test_fun()  :: fun((config()) -> test_rep()).
+
+%% If one comments out this spec the infinite loop disappears.
+-spec expand_cases(atom(), test_name() | [test_name()]) -> test_fun().
+expand_cases(Module, Cases) ->
+    if is_list(Cases) ->
+            TestFuns = [expand_case(Module, Case) || Case <- Cases],
+            fun(Config) -> [F(Config) || F <- TestFuns] end;
+       is_atom(Cases); is_tuple(Cases) ->
+           expand_cases(Module, [Cases])
+    end.
+
+-spec expand_case(atom(), test_name()) -> test_fun().
+expand_case(Module, CaseName) when is_atom(CaseName) ->
+    TestFun = fun(Config) ->
+		      {{Module, CaseName, 1},
+		       fun() -> apply(Module, CaseName, [Config]) end}
+	      end,
+    setup_wrapper(Module, TestFun, {init_per_testcase, [CaseName]},
+		  {end_per_testcase, [CaseName]});
+expand_case(Module, {group, GroupName}) ->
+    {Control, Cases} = group_specification(Module, GroupName),
+    TestFun = control_wrapper(Control, expand_cases(Module, Cases)),
+    setup_wrapper(Module, TestFun, {init_per_group, [GroupName]},
+		  {end_per_group, [GroupName]}).
+
+-spec control_wrapper([control()], test_fun()) -> test_fun().
+control_wrapper([Control|T], TestFun0) ->
+    TestFun1 = control_wrapper(T, TestFun0),
+    fun(Config) ->
+	    case Control of
+		parallel ->
+		    {inparallel, TestFun1(Config)};
+		sequence ->
+		    {inorder, TestFun1(Config)};
+		{timetrap, Time} ->
+		    Seconds = case Time of
+				  {hours, Hs}   -> Hs * 60 * 60;
+				  {minutes, Ms} -> Ms * 60;
+				  {seconds, Ss} -> Ss;
+				  MSs           -> MSs / 1000
+			      end,
+		    {timeout, Seconds, TestFun1(Config)};
+		C when is_atom(C) ->
+		    {C, TestFun1(Config)};
+		{C, Arg} ->
+		    {C, Arg, TestFun1(Config)}
+	    end
+    end;
+control_wrapper([], TestFun) ->
+    TestFun.
+
+-spec setup_wrapper(atom(), test_fun(), Callback, Callback) -> test_fun()
+        when Callback :: {atom(), list()}.
+setup_wrapper(Module, TestFun, {Setup, SA}, {Cleanup, CA}) ->
+    case erlang:function_exported(Module, Setup, length(SA) + 1) of
+        true ->
+            case erlang:function_exported(Module, Cleanup, length(CA) + 1) of
+                true ->
+                    fun(Config0) ->
+			    {setup,
+			     fun() ->
+				     apply(Module, Setup, SA ++ [Config0])
+			     end,
+			     fun(Config1) ->
+				     apply(Module, Cleanup, CA ++ [Config1])
+			     end,
+			     TestFun}
+                    end;
+                false ->
+                    fun(Config) ->
+			    {setup,
+			     fun() ->
+				     apply(Module, Setup, SA ++ [Config])
+			     end,
+			     TestFun}
+                    end
+            end;
+        false ->
+            TestFun
+    end.
+
+-spec group_specification(atom(), atom()) -> {[control()], [test_name()]}.
+group_specification(Module, GroupName) ->
+    case lists:keyfind(GroupName, 1, Module:groups()) of
+        {_, Control, Cases} when is_list(Control), is_list(Cases) ->
+            {Control, Cases};
+        {_, Cases} when is_list(Cases) ->
+            {[], Cases};
+        false ->
+            exit({missing_group, GroupName});
+        _ ->
+            exit({bad_group_spec, GroupName})
+    end.