8216995: Clean up JFR command line processing

Reviewed-by: gziemski, mgronlun

src/share/vm/jfr/recorder/jfrRecorder.cpp

 /*
- * Copyright (c) 2012, 2018, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2012, 2019, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -42,32 +42,24 @@
 #include "jfr/writers/jfrJavaEventWriter.hpp"
 #include "memory/resourceArea.hpp"
 #include "runtime/handles.inline.hpp"
-#include "runtime/globals.hpp"
+#include "runtime/globals_extension.hpp"
 #include "utilities/growableArray.hpp"
 
 bool JfrRecorder::_shutting_down = false;
 
-static bool is_disabled_on_command_line() {
-  static const size_t length = strlen("FlightRecorder");
-  static Flag* const flight_recorder_flag = Flag::find_flag("FlightRecorder", length);
-  assert(flight_recorder_flag != NULL, "invariant");
-  return flight_recorder_flag->is_command_line() ? !FlightRecorder : false;
-}
-
 bool JfrRecorder::is_disabled() {
-  return is_disabled_on_command_line();
-}
-
-static bool set_flight_recorder_flag(bool flag_value) {
-  CommandLineFlags::boolAtPut((char*)"FlightRecorder", &flag_value, Flag::MANAGEMENT);
-  return FlightRecorder;
+  // True if -XX:-FlightRecorder has been explicitly set on the
+  // command line
+  return FLAG_IS_CMDLINE(FlightRecorder) ? !FlightRecorder : false;
 }
 
 static bool _enabled = false;
 
 static bool enable() {
   assert(!_enabled, "invariant");
-  _enabled = set_flight_recorder_flag(true);
+  FLAG_SET_MGMT(bool, FlightRecorder, true);
+  _enabled = FlightRecorder;
+  assert(_enabled, "invariant");
   return _enabled;
 }
 

src/share/vm/runtime/globals_extension.hpp

@@ -191,6 +191,7 @@ typedef enum {
 
 #define FLAG_SET_CMDLINE(type, name, value) (CommandLineFlagsEx::type##AtPut(FLAG_MEMBER_WITH_TYPE(name,type), (type)(value), Flag::COMMAND_LINE))
 #define FLAG_SET_ERGO(type, name, value)    (CommandLineFlagsEx::type##AtPut(FLAG_MEMBER_WITH_TYPE(name,type), (type)(value), Flag::ERGONOMIC))
+#define FLAG_SET_MGMT(type, name, value)    (CommandLineFlagsEx::type##AtPut(FLAG_MEMBER_WITH_TYPE(name, type), (type)(value), Flag::MANAGEMENT))
 
 // Can't put the following in CommandLineFlags because
 // of a circular dependency on the enum definition.