Index: clang-tidy/google/UsingNamespaceDirectiveCheck.h =================================================================== --- clang-tidy/google/UsingNamespaceDirectiveCheck.h +++ clang-tidy/google/UsingNamespaceDirectiveCheck.h @@ -38,6 +38,9 @@ : ClangTidyCheck(Name, Context) {} void registerMatchers(ast_matchers::MatchFinder *Finder) override; void check(const ast_matchers::MatchFinder::MatchResult &Result) override; + +private: + static bool isStdLiteralsNamespace(const NamespaceDecl *NS); }; } // namespace build Index: clang-tidy/google/UsingNamespaceDirectiveCheck.cpp =================================================================== --- clang-tidy/google/UsingNamespaceDirectiveCheck.cpp +++ clang-tidy/google/UsingNamespaceDirectiveCheck.cpp @@ -34,12 +34,32 @@ if (U->isImplicit() || !Loc.isValid()) return; + // Do not warn if namespace is a std namespace with user-defined literals. The + // user-defined literals can only be used with a using directive. + if (isStdLiteralsNamespace(U->getNominatedNamespace())) + return; + diag(Loc, "do not use namespace using-directives; " "use using-declarations instead"); // TODO: We could suggest a list of using directives replacing the using // namespace directive. } +bool UsingNamespaceDirectiveCheck::isStdLiteralsNamespace( + const NamespaceDecl *NS) { + if (!NS->getName().endswith("literals")) + return false; + + const auto *Parent = dyn_cast_or_null(NS->getParent()); + if (!Parent) + return false; + + if (Parent->isStdNamespace()) + return true; + + return Parent->getName() == "literals" && Parent->getParent() && + Parent->getParent()->isStdNamespace(); +} } // namespace build } // namespace google } // namespace tidy Index: test/clang-tidy/google-namespaces.cpp =================================================================== --- test/clang-tidy/google-namespaces.cpp +++ test/clang-tidy/google-namespaces.cpp @@ -6,3 +6,47 @@ // CHECK: :[[@LINE-1]]:1: warning: do not use namespace using-directives; use using-declarations instead [google-build-using-namespace] using spaaaace::core; // no-warning + +namespace std { +inline namespace literals { +inline namespace chrono_literals { +} +inline namespace complex_literals { +} +inline namespace string_literals { +} +} +} + +using namespace std::chrono_literals; // no-warning +using namespace std::complex_literals; // no-warning +using namespace std::literals; // no-warning +using namespace std::literals::chrono_literals; // no-warning +using namespace std::literals::complex_literals; // no-warning +using namespace std::literals::string_literals; // no-warning +using namespace std::string_literals; // no-warning + +namespace literals {} + +using namespace literals; +// CHECK: :[[@LINE-1]]:1: warning: do not use namespace using-directives; use using-declarations instead [google-build-using-namespace] + +namespace foo { +inline namespace literals { +inline namespace bar_literals {} +} +} + +using namespace foo::literals; +// CHECK: :[[@LINE-1]]:1: warning: do not use namespace using-directives; use using-declarations instead [google-build-using-namespace] + +using namespace foo::bar_literals; +// CHECK: :[[@LINE-1]]:1: warning: do not use namespace using-directives; use using-declarations instead [google-build-using-namespace] + +using namespace foo::literals::bar_literals; +// CHECK: :[[@LINE-1]]:1: warning: do not use namespace using-directives; use using-declarations instead [google-build-using-namespace] + +namespace foo_literals {} + +using namespace foo_literals; +// CHECK: :[[@LINE-1]]:1: warning: do not use namespace using-directives; use using-declarations instead [google-build-using-namespace]