1 files changed, 40 insertions, 0 deletions
diff --git a/js/src/frontend/LabelEmitter.cpp b/js/src/frontend/LabelEmitter.cpp
new file mode 100644
index 0000000000..8b9b6233e6
--- /dev/null
+++ b/js/src/frontend/LabelEmitter.cpp
@@ -0,0 +1,40 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*-
+ * vim: set ts=8 sts=2 et sw=2 tw=80:
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "frontend/LabelEmitter.h"
+
+#include "mozilla/Assertions.h"  // MOZ_ASSERT
+
+#include "frontend/BytecodeEmitter.h"  // BytecodeEmitter
+
+using namespace js;
+using namespace js::frontend;
+
+void LabelEmitter::emitLabel(TaggedParserAtomIndex name) {
+  MOZ_ASSERT(state_ == State::Start);
+
+  controlInfo_.emplace(bce_, name, bce_->bytecodeSection().offset());
+
+#ifdef DEBUG
+  state_ = State::Label;
+#endif
+}
+
+bool LabelEmitter::emitEnd() {
+  MOZ_ASSERT(state_ == State::Label);
+
+  // Patch the break/continue to this label.
+  if (!controlInfo_->patchBreaks(bce_)) {
+    return false;
+  }
+
+  controlInfo_.reset();
+
+#ifdef DEBUG
+  state_ = State::End;
+#endif
+  return true;
+}