Index: clang-tidy/google/CMakeLists.txt
===================================================================
--- clang-tidy/google/CMakeLists.txt
+++ clang-tidy/google/CMakeLists.txt
@@ -6,6 +6,7 @@
   ExplicitMakePairCheck.cpp
   GoogleTidyModule.cpp
   NamedParameterCheck.cpp
+  NamespacesCheck.cpp
   OverloadedUnaryAndCheck.cpp
 
   LINK_LIBS
Index: clang-tidy/google/GoogleTidyModule.cpp
===================================================================
--- clang-tidy/google/GoogleTidyModule.cpp
+++ clang-tidy/google/GoogleTidyModule.cpp
@@ -14,6 +14,7 @@
 #include "ExplicitConstructorCheck.h"
 #include "ExplicitMakePairCheck.h"
 #include "NamedParameterCheck.h"
+#include "NamespacesCheck.h"
 #include "OverloadedUnaryAndCheck.h"
 
 using namespace clang::ast_matchers;
@@ -28,6 +29,9 @@
         "google-build-explicit-make-pair",
         new ClangTidyCheckFactory<build::ExplicitMakePairCheck>());
     CheckFactories.addCheckFactory(
+        "google-build-namespaces",
+        new ClangTidyCheckFactory<build::NamespacesCheck>());
+    CheckFactories.addCheckFactory(
         "google-explicit-constructor",
         new ClangTidyCheckFactory<ExplicitConstructorCheck>());
     CheckFactories.addCheckFactory(
Index: clang-tidy/google/NamespacesCheck.h
===================================================================
--- /dev/null
+++ clang-tidy/google/NamespacesCheck.h
@@ -0,0 +1,31 @@
+//===--- NamespacesCheck.h - clang-tidy -------------------------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_GOOGLE_NAMESPACES_CHECK_H
+#define LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_GOOGLE_NAMESPACES_CHECK_H
+
+#include "../ClangTidy.h"
+
+namespace clang {
+namespace tidy {
+namespace build {
+
+/// \brief Finds anonymous namespaces in headers and using namespace directives.
+/// Corresponding cpplint.py check name: 'build/namespaces'.
+class NamespacesCheck : public ClangTidyCheck {
+public:
+  void registerMatchers(ast_matchers::MatchFinder *Finder) override;
+  void check(const ast_matchers::MatchFinder::MatchResult &Result) override;
+};
+
+} // namespace build
+} // namespace tidy
+} // namespace clang
+
+#endif // LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_GOOGLE_NAMESPACES_CHECK_H
Index: clang-tidy/google/NamespacesCheck.cpp
===================================================================
--- /dev/null
+++ clang-tidy/google/NamespacesCheck.cpp
@@ -0,0 +1,60 @@
+//===--- NamespacesCheck.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 "NamespacesCheck.h"
+#include "clang/ASTMatchers/ASTMatchFinder.h"
+#include "clang/ASTMatchers/ASTMatchers.h"
+#include "clang/AST/ASTContext.h"
+
+using namespace clang::ast_matchers;
+
+namespace clang {
+namespace ast_matchers {
+
+AST_MATCHER(NamespaceDecl, isAnonymousNamespace) {
+  return Node.isAnonymousNamespace();
+}
+
+const internal::VariadicDynCastAllOfMatcher<Decl, UsingDirectiveDecl>
+    usingDirectiveDecl;
+
+} // namespace ast_matchers
+namespace tidy {
+namespace build {
+
+void NamespacesCheck::registerMatchers(ast_matchers::MatchFinder *Finder) {
+  Finder->addMatcher(
+      namespaceDecl(isAnonymousNamespace()).bind("anonymousNamespace"), this);
+  Finder->addMatcher(usingDirectiveDecl().bind("usingNamespace"), this);
+}
+
+void NamespacesCheck::check(const MatchFinder::MatchResult &Result) {
+  SourceManager *SM = Result.SourceManager;
+  if (const auto *N =
+          Result.Nodes.getNodeAs<NamespaceDecl>("anonymousNamespace")) {
+    SourceLocation Loc = N->getLocStart();
+    if (Loc.isValid()) {
+      // Check for common suffixes only
+      StringRef FileName = SM->getPresumedLoc(Loc).getFilename();
+      if (FileName.endswith(".h") || FileName.endswith(".hh") ||
+          FileName.endswith(".hpp") || FileName.endswith(".hxx"))
+        diag(Loc, "do not use unnamed namespaces in header files.");
+    }
+  } else if (const auto *U =
+                 Result.Nodes.getNodeAs<UsingDirectiveDecl>("usingNamespace")) {
+    SourceLocation Loc = U->getLocStart();
+    if (!U->isImplicit() && Loc.isValid())
+      diag(Loc, "do not use namespace using-directives. Use using-declarations "
+                "instead.");
+  }
+}
+
+} // namespace build
+} // namespace tidy
+} // namespace clang
Index: test/clang-tidy/Inputs/google-namespaces.h
===================================================================
--- /dev/null
+++ test/clang-tidy/Inputs/google-namespaces.h
@@ -0,0 +1,7 @@
+namespace {
+int x;
+}
+
+namespace spaaaace {
+class core;
+}
Index: test/clang-tidy/google-namespaces.cpp
===================================================================
--- /dev/null
+++ test/clang-tidy/google-namespaces.cpp
@@ -0,0 +1,8 @@
+// RUN: clang-tidy %s -checks='-*,google-build-namespaces' -header-filter='.*' -- | FileCheck %s -implicit-check-not="{{warning|error}}:"
+#include "Inputs/google-namespaces.h"
+// CHECK: warning: do not use unnamed namespaces in header files.
+
+using namespace spaaaace;
+// CHECK: :[[@LINE-1]]:1: warning: do not use namespace using-directives. Use using-declarations instead.
+
+using spaaaace::core; // no-warning