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..84b40f4f24ecfae6bf57aeb2dd06f101c736bf28
--- /dev/null
+++ b/runtime/vm/tags.cc
@@ -0,0 +1,44 @@
+// 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(uword id) {
+  ASSERT(id != kInvalidTagId);
+  ASSERT(id < kNumVMTags);
+  const TagEntry& entry = entries_[id];
+  ASSERT(entry.id == id);
+  return entry.name;
+}
+
+
+VMTag::TagEntry VMTag::entries_[] = {
+  { "InvalidTag", kInvalidTagId, },
+#define DEFINE_VM_TAG_ENTRY(tag)                                               \
+  { ""#tag, k##tag##TagId },
+  VM_TAG_LIST(DEFINE_VM_TAG_ENTRY)
+#undef DEFINE_VM_TAG_ENTRY
+  { "kNumVMTags", kNumVMTags },
+};
+
+
+VMTagScope::VMTagScope(Isolate* base_isolate, uword tag)
+    : StackResource(base_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