[clang-tidy] Adding Fuchsia checker for overloaded operators

Adds a check to the Fuchsia module to warn if an operator is overloaded,
except move and copy operators.

See https://fuchsia.googlesource.com/zircon/+/master/docs/cxx.md for
reference.

Differential Revision: https://reviews.llvm.org/D41363

llvm-svn: 321363

1 files changed, 39 insertions, 0 deletions

diff --git a/clang-tools-extra/clang-tidy/fuchsia/OverloadedOperatorCheck.cpp b/clang-tools-extra/clang-tidy/fuchsia/OverloadedOperatorCheck.cpp
new file mode 100644
index 0000000..57b4628
--- /dev/null
+++ b/clang-tools-extra/clang-tidy/fuchsia/OverloadedOperatorCheck.cpp
@@ -0,0 +1,39 @@
+//===--- OverloadedOperatorCheck.cpp - clang-tidy--------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include "OverloadedOperatorCheck.h"
+
+using namespace clang::ast_matchers;
+
+namespace clang {
+namespace tidy {
+namespace fuchsia {
+
+AST_MATCHER(FunctionDecl, isFuchsiaOverloadedOperator) {
+  if (const auto *CXXMethodNode = dyn_cast<CXXMethodDecl>(&Node)) {
+    if (CXXMethodNode->isCopyAssignmentOperator() ||
+        CXXMethodNode->isMoveAssignmentOperator())
+      return false;
+  }
+  return Node.isOverloadedOperator();
+}
+
+void OverloadedOperatorCheck::registerMatchers(MatchFinder *Finder) {
+  Finder->addMatcher(functionDecl(isFuchsiaOverloadedOperator()).bind("decl"),
+                     this);
+}
+
+void OverloadedOperatorCheck::check(const MatchFinder::MatchResult &Result) {
+  if (const auto *D = Result.Nodes.getNodeAs<FunctionDecl>("decl"))
+    diag(D->getLocStart(), "cannot overload %0") << D;
+}
+
+} // namespace fuchsia
+} // namespace tidy
+} // namespace clang