1 //===--- UsingNamespaceDirectiveCheck.cpp - clang-tidy ----------*- C++ -*-===// 2 // 3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4 // See https://llvm.org/LICENSE.txt for license information. 5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6 // 7 //===----------------------------------------------------------------------===// 8 9 #include "UsingNamespaceDirectiveCheck.h" 10 #include "clang/AST/ASTContext.h" 11 #include "clang/ASTMatchers/ASTMatchFinder.h" 12 #include "clang/ASTMatchers/ASTMatchers.h" 13 14 using namespace clang::ast_matchers; 15 16 namespace clang { 17 namespace tidy { 18 namespace google { 19 namespace build { 20 registerMatchers(ast_matchers::MatchFinder * Finder)21void UsingNamespaceDirectiveCheck::registerMatchers( 22 ast_matchers::MatchFinder *Finder) { 23 Finder->addMatcher(usingDirectiveDecl().bind("usingNamespace"), this); 24 } 25 check(const MatchFinder::MatchResult & Result)26void UsingNamespaceDirectiveCheck::check( 27 const MatchFinder::MatchResult &Result) { 28 const auto *U = Result.Nodes.getNodeAs<UsingDirectiveDecl>("usingNamespace"); 29 SourceLocation Loc = U->getBeginLoc(); 30 if (U->isImplicit() || !Loc.isValid()) 31 return; 32 33 // Do not warn if namespace is a std namespace with user-defined literals. The 34 // user-defined literals can only be used with a using directive. 35 if (isStdLiteralsNamespace(U->getNominatedNamespace())) 36 return; 37 38 diag(Loc, "do not use namespace using-directives; " 39 "use using-declarations instead"); 40 // TODO: We could suggest a list of using directives replacing the using 41 // namespace directive. 42 } 43 isStdLiteralsNamespace(const NamespaceDecl * NS)44bool UsingNamespaceDirectiveCheck::isStdLiteralsNamespace( 45 const NamespaceDecl *NS) { 46 if (!NS->getName().endswith("literals")) 47 return false; 48 49 const auto *Parent = dyn_cast_or_null<NamespaceDecl>(NS->getParent()); 50 if (!Parent) 51 return false; 52 53 if (Parent->isStdNamespace()) 54 return true; 55 56 return Parent->getName() == "literals" && Parent->getParent() && 57 Parent->getParent()->isStdNamespace(); 58 } 59 } // namespace build 60 } // namespace google 61 } // namespace tidy 62 } // namespace clang 63