2 files changed, 104 insertions, 2 deletions

diff --git a/lib/compiler/test/map_SUITE.erl b/lib/compiler/test/map_SUITE.erl
index c004dca834..3e0ab78390 100644
--- a/lib/compiler/test/map_SUITE.erl
+++ b/lib/compiler/test/map_SUITE.erl
@@ -1258,6 +1258,38 @@ t_guard_bifs(Config) when is_list(Config) ->
     {'EXIT',{{badkey,k},_}} = (catch erl_699(#{})),
     {'EXIT',{{badmap,not_a_map},_}} = (catch erl_699(not_a_map)),
 
+    %% Cover optimizations in beam_dead.
+
+    ok = beam_dead_1(#{a=>any,k=>true}),
+    error = beam_dead_1(#{a=>any,k=>false}),
+    error = beam_dead_1(#{a=>any}),
+    error = beam_dead_1(#{}),
+
+    ok = beam_dead_2(#{a=>any,k=>true}),
+    error = beam_dead_2(#{a=>any,k=>false}),
+    error = beam_dead_2(#{a=>any}),
+    error = beam_dead_2(#{}),
+
+    ok = beam_dead_3(#{k=>true}),
+    error = beam_dead_3(#{k=>false}),
+    error = beam_dead_3(#{}),
+
+    ok = beam_dead_4(#{k=>true}),
+    error = beam_dead_4(#{k=>false}),
+    error = beam_dead_4(#{}),
+    error = beam_dead_4(not_a_map),
+
+    ok = beam_dead_5(#{k=>true}),
+    error = beam_dead_5(#{k=>false}),
+    error = beam_dead_3(#{}),
+
+    %% Test is_map_key/2 followed by map update.
+
+    Used0 = map_usage(var, #{other=>value}),
+    Used0 = #{other=>value,var=>dead},
+    Used1 = map_usage(var, #{var=>live}),
+    Used1 = #{var=>live},
+
     ok.
 
 map_guard_empty() when is_map(#{}); false -> true.
@@ -1298,6 +1330,48 @@ erl_699(M) ->
     %% Used to cause an internal consistency failure.
     {is_map_key(k, M),maps:get(k, M)}.
 
+beam_dead_1(#{a:=_,k:=_}=M) when map_get(k, M) ->
+    ok;
+beam_dead_1(#{}) ->
+    error.
+
+beam_dead_2(M) ->
+    case M of
+        #{a:=_,k:=_} when map_get(k, M) ->
+            ok;
+        #{} ->
+            error
+    end.
+
+beam_dead_3(M) ->
+    case M of
+        #{k:=_} when map_get(k, M) ->
+            ok;
+        #{} ->
+            error
+    end.
+
+beam_dead_4(M) ->
+    case M of
+        #{} when map_get(k, M) ->
+            ok;
+        _ ->
+            error
+    end.
+
+beam_dead_5(#{}=M) when map_get(k, M) ->
+    ok;
+beam_dead_5(#{}) ->
+    error.
+
+%% Test is_map_key/2, followed by an update of the map.
+map_usage(Def, Used) ->
+    case is_map_key(Def, Used) of
+        true -> Used;
+        false -> Used#{Def=>dead}
+    end.
+
+
 t_guard_sequence(Config) when is_list(Config) ->
 	{1, "a"} = map_guard_sequence_1(#{seq=>1,val=>id("a")}),
 	{2, "b"} = map_guard_sequence_1(#{seq=>2,val=>id("b")}),
diff --git a/lib/compiler/test/receive_SUITE.erl b/lib/compiler/test/receive_SUITE.erl
index 37e737084a..4219768d6f 100644
--- a/lib/compiler/test/receive_SUITE.erl
+++ b/lib/compiler/test/receive_SUITE.erl
@@ -25,7 +25,7 @@
 	 init_per_group/2,end_per_group/2,
 	 init_per_testcase/2,end_per_testcase/2,
 	 export/1,recv/1,coverage/1,otp_7980/1,ref_opt/1,
-	 wait/1,recv_in_try/1]).
+	 wait/1,recv_in_try/1,double_recv/1]).
 
 -include_lib("common_test/include/ct.hrl").
 
@@ -45,7 +45,7 @@ all() ->
 groups() -> 
     [{p,test_lib:parallel(),
       [recv,coverage,otp_7980,ref_opt,export,wait,
-       recv_in_try]}].
+       recv_in_try,double_recv]}].
 
 
 init_per_suite(Config) ->
@@ -349,5 +349,33 @@ recv_in_try(Timeout, Format) ->
 	    {nok,Reason}
     end.
 
+%% ERL-703. The compiler would crash because beam_utils:anno_defs/1
+%% failed to take into account that code after loop_rec_end is
+%% unreachable.
+
+double_recv(_Config) ->
+    self() ! {more,{a,term}},
+    ok = do_double_recv({more,{a,term}}, any),
+    self() ! message,
+    ok = do_double_recv(whatever, message),
+
+    error = do_double_recv({more,42}, whatever),
+    error = do_double_recv(whatever, whatever),
+    ok.
+
+do_double_recv({more, Rest}, _Msg) ->
+    receive
+        {more, Rest} ->
+            ok
+    after 0 ->
+            error
+    end;
+do_double_recv(_, Msg) ->
+    receive
+        Msg ->
+            ok
+    after 0 ->
+            error
+    end.
 
 id(I) -> I.