1 files changed, 50 insertions, 0 deletions
diff --git a/js/src/frontend/ParseNodeVerify.cpp b/js/src/frontend/ParseNodeVerify.cpp
new file mode 100644
index 0000000000..b23a60649e
--- /dev/null
+++ b/js/src/frontend/ParseNodeVerify.cpp
@@ -0,0 +1,50 @@
+/* -*- 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/ParseNodeVerify.h"
+
+#include "frontend/ParseNodeVisitor.h"
+
+using namespace js;
+
+#ifdef DEBUG
+
+namespace js {
+namespace frontend {
+
+class ParseNodeVerifier : public ParseNodeVisitor<ParseNodeVerifier> {
+  using Base = ParseNodeVisitor<ParseNodeVerifier>;
+
+  const LifoAlloc& alloc_;
+
+ public:
+  ParseNodeVerifier(FrontendContext* fc, const LifoAlloc& alloc)
+      : Base(fc), alloc_(alloc) {}
+
+  [[nodiscard]] bool visit(ParseNode* pn) {
+    // pn->size() asserts that pn->pn_kind is valid, so we don't redundantly
+    // assert that here.
+    JS_PARSE_NODE_ASSERT(alloc_.contains(pn),
+                         "start of parse node is in alloc");
+    JS_PARSE_NODE_ASSERT(alloc_.contains((unsigned char*)pn + pn->size()),
+                         "end of parse node is in alloc");
+    if (pn->is<ListNode>()) {
+      pn->as<ListNode>().checkConsistency();
+    }
+    return Base::visit(pn);
+  }
+};
+
+}  // namespace frontend
+}  // namespace js
+
+bool frontend::CheckParseTree(FrontendContext* fc, const LifoAlloc& alloc,
+                              ParseNode* pn) {
+  ParseNodeVerifier verifier(fc, alloc);
+  return verifier.visit(pn);
+}
+
+#endif  // DEBUG