[clang-tidy] Add namespaces checkers.

This change contains of two checkers that warn about
1. anonymous namespaces in header files.
2. 'using namespace' directives everywhere.

Differential Revision: http://reviews.llvm.org/D4523

llvm-svn: 213153

1 files changed, 41 insertions, 0 deletions

diff --git a/clang-tools-extra/clang-tidy/google/UsingNamespaceDirectiveCheck.cpp b/clang-tools-extra/clang-tidy/google/UsingNamespaceDirectiveCheck.cpp
new file mode 100644
index 00000000000..d8f38cbef1f
--- /dev/null
+++ b/clang-tools-extra/clang-tidy/google/UsingNamespaceDirectiveCheck.cpp
@@ -0,0 +1,41 @@
+//===--- UsingNamespaceDirectiveCheck.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 "UsingNamespaceDirectiveCheck.h"
+#include "clang/ASTMatchers/ASTMatchFinder.h"
+#include "clang/ASTMatchers/ASTMatchers.h"
+#include "clang/AST/ASTContext.h"
+
+using namespace clang::ast_matchers;
+
+namespace clang {
+namespace tidy {
+namespace build {
+
+void UsingNamespaceDirectiveCheck::registerMatchers(
+    ast_matchers::MatchFinder *Finder) {
+  Finder->addMatcher(usingDirectiveDecl().bind("usingNamespace"), this);
+}
+
+void
+UsingNamespaceDirectiveCheck::check(const MatchFinder::MatchResult &Result) {
+  const auto *U = Result.Nodes.getNodeAs<UsingDirectiveDecl>("usingNamespace");
+  SourceLocation Loc = U->getLocStart();
+  if (U->isImplicit() || !Loc.isValid())
+    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.
+}
+
+} // namespace build
+} // namespace tidy
+} // namespace clang