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"
+
+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));
+  if (UserTag::TagTableFull(isolate)) {
+    const String& error = String::Handle(
+        String::NewFormatted("UserTag instance limit (%" Pd ") reached.",
+                             UserTagHelper::kMaxUserTags));
+    const Array& args = Array::Handle(Array::New(1));
+    args.SetAt(0, error);
+    Exceptions::ThrowByType(Exceptions::kUnsupported, args);
+  }
+  return UserTag::New(tag_label);
+}
+
+
+DEFINE_NATIVE_ENTRY(UserTag_label, 1) {
+  GET_NON_NULL_NATIVE_ARGUMENT(UserTag, self, arguments->NativeArgAt(0));

[srdjan, 2014/04/09 17:08:18]

Use UserTag::CheckedHandle where type is known (e.g., it is the receiver)

[Cutch, 2014/04/09 20:28:54]

Done.

+  return self.label();
+}
+
+
+DEFINE_NATIVE_ENTRY(UserTag_makeCurrent, 1) {
+  GET_NON_NULL_NATIVE_ARGUMENT(UserTag, self, arguments->NativeArgAt(0));

[srdjan, 2014/04/09 17:08:18]

ditto

[Cutch, 2014/04/09 20:28:54]

Done.

+  isolate->set_user_tag(static_cast<uword>(self.tag()));
+  return Object::null();
+}
+
+}  // namespace dart