1 files changed, 38 insertions, 0 deletions
diff --git a/build/clang-plugin/ParamTraitsEnumChecker.cpp b/build/clang-plugin/ParamTraitsEnumChecker.cpp
new file mode 100644
index 0000000000..7214e9fe5b
--- /dev/null
+++ b/build/clang-plugin/ParamTraitsEnumChecker.cpp
@@ -0,0 +1,38 @@
+/* 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 "ParamTraitsEnumChecker.h"
+#include "CustomMatchers.h"
+
+void ParamTraitsEnumChecker::registerMatchers(MatchFinder *AstMatcher) {
+  AstMatcher->addMatcher(
+      classTemplateSpecializationDecl(hasName("ParamTraits")).bind("decl"),
+      this);
+}
+
+void ParamTraitsEnumChecker::check(const MatchFinder::MatchResult &Result) {
+  const ClassTemplateSpecializationDecl *Decl =
+      Result.Nodes.getNodeAs<ClassTemplateSpecializationDecl>("decl");
+
+  for (auto &Inner : Decl->decls()) {
+    if (auto *Def = dyn_cast<TypedefDecl>(Inner)) {
+      QualType UnderlyingType = Def->getUnderlyingType();
+      QualType CanonicalType = UnderlyingType.getCanonicalType();
+
+      const clang::Type *TypePtr = CanonicalType.getTypePtrOrNull();
+      if (!TypePtr) {
+        return;
+      }
+
+      if (TypePtr->isEnumeralType()) {
+        diag(Decl->getBeginLoc(),
+             "Custom ParamTraits implementation for an enum type",
+             DiagnosticIDs::Error);
+        diag(Decl->getBeginLoc(),
+             "Please use a helper class for example ContiguousEnumSerializer",
+             DiagnosticIDs::Note);
+      }
+    }
+  }
+}