llvm-project/clang-tools-extra/clang-tidy/google/OverloadedUnaryAndCheck.cpp

//===--- OverloadedUnaryAndCheck.cpp - clang-tidy ---------------*- C++ -*-===//
//
//                     The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//

#include "OverloadedUnaryAndCheck.h"
#include "clang/AST/ASTContext.h"
#include "clang/ASTMatchers/ASTMatchFinder.h"
#include "clang/ASTMatchers/ASTMatchers.h"

using namespace clang::ast_matchers;

namespace clang {
namespace tidy {
namespace google {
namespace runtime {

void OverloadedUnaryAndCheck::registerMatchers(
    ast_matchers::MatchFinder *Finder) {
  // Only register the matchers for C++; the functionality currently does not
  // provide any benefit to other languages, despite being benign.
  if (!getLangOpts().CPlusPlus)
    return;

  // Match unary methods that overload operator&.
  Finder->addMatcher(
      cxxMethodDecl(parameterCountIs(0), hasOverloadedOperatorName("&"))
          .bind("overload"),
      this);
  // Also match freestanding unary operator& overloads. Be careful not to match
  // binary methods.
  Finder->addMatcher(
      functionDecl(allOf(
          unless(cxxMethodDecl()),
          functionDecl(parameterCountIs(1), hasOverloadedOperatorName("&"))
              .bind("overload"))),
      this);
}

void OverloadedUnaryAndCheck::check(const MatchFinder::MatchResult &Result) {
  const auto *Decl = Result.Nodes.getNodeAs<FunctionDecl>("overload");
  diag(Decl->getLocStart(),
       "do not overload unary operator&, it is dangerous.");
}

} // namespace runtime
} // namespace google
} // namespace tidy
} // namespace clang