Basic tag infrastructure

runtime/vm/tags.cc

Index: runtime/vm/tags.cc
diff --git a/runtime/vm/tags.cc b/runtime/vm/tags.cc
new file mode 100644
index 0000000000000000000000000000000000000000..c2bab467a6fc947801bd60a91bcb583f0251fb63
--- /dev/null
+++ b/runtime/vm/tags.cc
@@ -0,0 +1,43 @@
+// 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/tags.h"
+
+#include "vm/isolate.h"
+
+namespace dart {
+
+const char* VMTag::TagName(intptr_t id) {
+  ASSERT(id >= 0);
+  ASSERT(id < kNumVMTags);
+  const TagEntry& entry = entries_[id];
+  ASSERT(entry.id == id);
+  return entry.name;
+}
+
+
+VMTag::TagEntry VMTag::entries_[] = {
+#define DEFINE_VM_TAG_ENTRY(tag)                                               \
+  { ""#tag, k##tag##TagId },
+  VM_TAG_LIST(DEFINE_VM_TAG_ENTRY)
+#undef DEFINE_VM_TAG_ENTRY
+};
+
+
+VMTagScope::VMTagScope(intptr_t tag, Isolate* isolate)
+    : StackResource(isolate),
+      isolate_(isolate) {
+  ASSERT(isolate_ != NULL);
+  previous_tag_ = isolate_->vm_tag();
+  isolate_->set_vm_tag(tag);
+}
+
+
+VMTagScope::~VMTagScope() {
+  ASSERT(isolate_ != NULL);
+  isolate_->set_vm_tag(previous_tag_);
+}
+
+
+}  // namespace dart