1 //===--- UsingNamespaceDirectiveCheck.cpp - clang-tidy ----------*- C++ -*-===//
2 //
3 //                     The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 
10 #include "UsingNamespaceDirectiveCheck.h"
11 #include "clang/AST/ASTContext.h"
12 #include "clang/ASTMatchers/ASTMatchFinder.h"
13 #include "clang/ASTMatchers/ASTMatchers.h"
14 
15 using namespace clang::ast_matchers;
16 
17 namespace clang {
18 namespace tidy {
19 namespace google {
20 namespace build {
21 
22 void UsingNamespaceDirectiveCheck::registerMatchers(
23     ast_matchers::MatchFinder *Finder) {
24   // Only register the matchers for C++; the functionality currently does not
25   // provide any benefit to other languages, despite being benign.
26   if (getLangOpts().CPlusPlus)
27     Finder->addMatcher(usingDirectiveDecl().bind("usingNamespace"), this);
28 }
29 
30 void
31 UsingNamespaceDirectiveCheck::check(const MatchFinder::MatchResult &Result) {
32   const auto *U = Result.Nodes.getNodeAs<UsingDirectiveDecl>("usingNamespace");
33   SourceLocation Loc = U->getLocStart();
34   if (U->isImplicit() || !Loc.isValid())
35     return;
36 
37   diag(Loc, "do not use namespace using-directives; "
38             "use using-declarations instead");
39   // TODO: We could suggest a list of using directives replacing the using
40   //       namespace directive.
41 }
42 
43 } // namespace build
44 } // namespace google
45 } // namespace tidy
46 } // namespace clang
47