Initial UserTag and dart:profiler library

runtime/lib/profiler.cc

+// Copyright (c) 2014, the Dart project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+#include "vm/bootstrap_natives.h"
+
+#include "include/dart_api.h"
+
+#include "vm/bigint_operations.h"
+#include "vm/exceptions.h"
+#include "vm/native_entry.h"
+#include "vm/object.h"
+#include "vm/object_store.h"
+
+namespace dart {
+
+// dart:profiler.
+
+DEFINE_NATIVE_ENTRY(UserTag_new, 2) {
+  ASSERT(TypeArguments::CheckedHandle(arguments->NativeArgAt(0)).IsNull());
+  GET_NON_NULL_NATIVE_ARGUMENT(String, tag_label, arguments->NativeArgAt(1));
+  return UserTag::New(tag_label);
+}
+
+
+DEFINE_NATIVE_ENTRY(UserTag_label, 1) {
+  const UserTag& self = UserTag::CheckedHandle(arguments->NativeArgAt(0));
+  return self.label();
+}
+
+
+DEFINE_NATIVE_ENTRY(UserTag_makeCurrent, 1) {
+  const UserTag& self = UserTag::CheckedHandle(arguments->NativeArgAt(0));
+  self.MakeActive();
+  return Object::null();
+}
+
+
+DEFINE_NATIVE_ENTRY(Profiler_getCurrentTag, 0) {
+  return isolate->current_tag();
+}
+
+
+DEFINE_NATIVE_ENTRY(Profiler_clearCurrentTag, 0) {
+  // Use a NoGCScope to avoid creating a handle for the old current.
+  NoGCScope no_gc;
+  RawUserTag* old_current = isolate->current_tag();
+  UserTag::ClearActive();
+  return old_current;
+}
+
+}  // namespace dart