1 files changed, 34 insertions, 0 deletions
diff --git a/build/clang-plugin/RefCountedCopyConstructorChecker.cpp b/build/clang-plugin/RefCountedCopyConstructorChecker.cpp
new file mode 100644
index 0000000000..569d4eecec
--- /dev/null
+++ b/build/clang-plugin/RefCountedCopyConstructorChecker.cpp
@@ -0,0 +1,34 @@
+/* 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 "RefCountedCopyConstructorChecker.h"
+#include "CustomMatchers.h"
+
+void RefCountedCopyConstructorChecker::registerMatchers(
+    MatchFinder *AstMatcher) {
+  AstMatcher->addMatcher(
+      cxxConstructExpr(
+          hasDeclaration(cxxConstructorDecl(isCompilerProvidedCopyConstructor(),
+                                            ofClass(hasRefCntMember()))))
+          .bind("node"),
+      this);
+}
+
+void RefCountedCopyConstructorChecker::check(
+    const MatchFinder::MatchResult &Result) {
+  const char *Error =
+      "Invalid use of compiler-provided copy constructor on refcounted type";
+  const char *Note = "The default copy constructor also copies the "
+                     "default mRefCnt property, leading to reference "
+                     "count imbalance issues. Please provide your own "
+                     "copy constructor which only copies the fields which "
+                     "need to be copied";
+
+  // Everything we needed to know was checked in the matcher - we just report
+  // the error here
+  const CXXConstructExpr *E = Result.Nodes.getNodeAs<CXXConstructExpr>("node");
+
+  diag(E->getLocation(), Error, DiagnosticIDs::Error);
+  diag(E->getLocation(), Note, DiagnosticIDs::Note);
+}