1 files changed, 34 insertions, 0 deletions
diff --git a/build/clang-plugin/ExplicitOperatorBoolChecker.cpp b/build/clang-plugin/ExplicitOperatorBoolChecker.cpp
new file mode 100644
index 0000000000..db2c19e517
--- /dev/null
+++ b/build/clang-plugin/ExplicitOperatorBoolChecker.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 "ExplicitOperatorBoolChecker.h"
+#include "CustomMatchers.h"
+
+void ExplicitOperatorBoolChecker::registerMatchers(MatchFinder *AstMatcher) {
+  // Older clang versions such as the ones used on the infra recognize these
+  // conversions as 'operator _Bool', but newer clang versions recognize these
+  // as 'operator bool'.
+  AstMatcher->addMatcher(
+      cxxMethodDecl(anyOf(hasName("operator bool"), hasName("operator _Bool")))
+          .bind("node"),
+      this);
+}
+
+void ExplicitOperatorBoolChecker::check(
+    const MatchFinder::MatchResult &Result) {
+  const CXXConversionDecl *Method =
+      Result.Nodes.getNodeAs<CXXConversionDecl>("node");
+  const CXXRecordDecl *Clazz = Method->getParent();
+
+  if (!Method->isExplicit() && !hasCustomAttribute<moz_implicit>(Method) &&
+      !ASTIsInSystemHeader(Method->getASTContext(), *Method) &&
+      isInterestingDeclForImplicitConversion(Method)) {
+    diag(Method->getBeginLoc(), "bad implicit conversion operator for %0",
+         DiagnosticIDs::Error)
+        << Clazz;
+    diag(Method->getBeginLoc(), "consider adding the explicit keyword to %0",
+         DiagnosticIDs::Note)
+        << "'operator bool'";
+  }
+}