compiler: Eliminate EXIT messages from the temporary compiler process

If a process trap exits, calling the compiler would leave an EXIT
message in the message queue of the calling process because the
compiler spawns a temporary work process. Eliminate the EXIT process
by monitoring the temporary process instead of linking to it.

Reported-by: Jeremy Heater

2 files changed, 22 insertions, 8 deletions

diff --git a/lib/compiler/src/compile.erl b/lib/compiler/src/compile.erl
index 7911f51a73..7365706b94 100644
--- a/lib/compiler/src/compile.erl
+++ b/lib/compiler/src/compile.erl
@@ -146,10 +146,17 @@ env_default_opts() ->
 
 do_compile(Input, Opts0) ->
     Opts = expand_opts(Opts0),
-    Self = self(),
-    Serv = spawn_link(fun() -> internal(Self, Input, Opts) end),
+    {Pid,Ref} =
+	spawn_monitor(fun() ->
+			      exit(try
+				       internal(Input, Opts)
+				   catch
+				       error:Reason ->
+					   {error,Reason}
+				   end)
+		      end),
     receive
-	{Serv,Rep} -> Rep
+	{'DOWN',Ref,process,Pid,Rep} -> Rep
     end.
 
 expand_opts(Opts0) ->
@@ -242,11 +249,6 @@ format_error({module_name,Mod,Filename}) ->
 		  errors=[],
 		  warnings=[]}).
 
-internal(Master, Input, Opts) ->
-    Master ! {self(), try internal(Input, Opts)
-		      catch error:Reason -> {error, Reason}
-		      end}.
-
 internal({forms,Forms}, Opts0) ->
     {_,Ps} = passes(forms, Opts0),
     Source = proplists:get_value(source, Opts0, ""),
diff --git a/lib/compiler/test/compile_SUITE.erl b/lib/compiler/test/compile_SUITE.erl
index 9dbfb5883b..da53a6ba9c 100644
--- a/lib/compiler/test/compile_SUITE.erl
+++ b/lib/compiler/test/compile_SUITE.erl
@@ -76,6 +76,9 @@ app_test(Config) when is_list(Config) ->
 
 file_1(Config) when is_list(Config) ->
     ?line Dog = test_server:timetrap(test_server:minutes(5)),
+
+    process_flag(trap_exit, true),
+
     ?line {Simple, Target} = files(Config, "file_1"),
     ?line {ok, Cwd} = file:get_cwd(),
     ?line ok = file:set_cwd(filename:dirname(Target)),
@@ -102,6 +105,15 @@ file_1(Config) when is_list(Config) ->
     %% Cleanup.
     ?line ok = file:delete(Target),
     ?line ok = file:del_dir(filename:dirname(Target)),
+
+    %% There should not be any messages in the messages.
+    receive
+	Any ->
+	    ?t:fail({unexpected,Any})
+    after 10 ->
+	    ok
+    end,
+
     ?line test_server:timetrap_cancel(Dog),
     ok.