Index: clang-tidy/readability/CMakeLists.txt
===================================================================
--- clang-tidy/readability/CMakeLists.txt
+++ clang-tidy/readability/CMakeLists.txt
@@ -3,6 +3,7 @@
 add_clang_library(clangTidyReadabilityModule
   AvoidConstParamsInDecls.cpp
   BracesAroundStatementsCheck.cpp
+  ConstValueReturnCheck.cpp
   ContainerSizeEmptyCheck.cpp
   DeleteNullPointerCheck.cpp
   DeletedDefaultCheck.cpp
Index: clang-tidy/readability/ConstValueReturnCheck.h
===================================================================
--- clang-tidy/readability/ConstValueReturnCheck.h
+++ clang-tidy/readability/ConstValueReturnCheck.h
@@ -0,0 +1,35 @@
+//===--- ConstValueReturnCheck.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_READABILITY_CONST_VALUE_RETURN_H
+#define LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_READABILITY_CONST_VALUE_RETURN_H
+
+#include "../ClangTidy.h"
+
+namespace clang {
+namespace tidy {
+namespace readability {
+
+/// Checks for functions that return a const-qualified value type.
+///
+/// For the user-facing documentation see:
+/// http://clang.llvm.org/extra/clang-tidy/checks/readability-const-value-return.html
+class ConstValueReturnCheck : public ClangTidyCheck {
+public:
+  ConstValueReturnCheck(StringRef Name, ClangTidyContext *Context)
+      : ClangTidyCheck(Name, Context) {}
+  void registerMatchers(ast_matchers::MatchFinder *Finder) override;
+  void check(const ast_matchers::MatchFinder::MatchResult &Result) override;
+};
+
+} // namespace readability
+} // namespace tidy
+} // namespace clang
+
+#endif // LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_READABILITY_CONST_VALUE_RETURN_H
Index: clang-tidy/readability/ConstValueReturnCheck.cpp
===================================================================
--- clang-tidy/readability/ConstValueReturnCheck.cpp
+++ clang-tidy/readability/ConstValueReturnCheck.cpp
@@ -0,0 +1,47 @@
+//===--- ConstValueReturnCheck.cpp - clang-tidy----------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include "ConstValueReturnCheck.h"
+#include "clang/AST/ASTContext.h"
+#include "clang/ASTMatchers/ASTMatchFinder.h"
+
+using namespace clang::ast_matchers;
+
+namespace clang {
+namespace tidy {
+namespace readability {
+
+void ConstValueReturnCheck::registerMatchers(MatchFinder *Finder) {
+  // Returning const pointers (not pointers to const) does not make much sense,
+  // returning const references even less so, but it is harmless and we don't
+  // bother checking it.
+  // Template parameter types may end up being pointers or references, so we
+  // skip those too.
+  Finder->addMatcher(functionDecl(returns(qualType(
+        isConstQualified(),
+        unless(anyOf(
+          isAnyPointer(),
+          references(type()),
+          templateTypeParmType(),
+          hasCanonicalType(templateTypeParmType())
+      ))))).bind("func"), this);
+}
+
+void ConstValueReturnCheck::check(const MatchFinder::MatchResult &Result) {
+  const auto *Func = Result.Nodes.getNodeAs<FunctionDecl>("func");
+  diag(Func->getLocation(), "function %0 has a const value return type; this "
+                            "can cause unnecessary copies")
+      << Func;
+  // We do not have a FixItHint, because we cannot get the source range for the
+  // return type (getReturnTypeSourceRange excludes the const qualifier).
+}
+
+} // namespace readability
+} // namespace tidy
+} // namespace clang
Index: clang-tidy/readability/ReadabilityTidyModule.cpp
===================================================================
--- clang-tidy/readability/ReadabilityTidyModule.cpp
+++ clang-tidy/readability/ReadabilityTidyModule.cpp
@@ -12,6 +12,7 @@
 #include "../ClangTidyModuleRegistry.h"
 #include "AvoidConstParamsInDecls.h"
 #include "BracesAroundStatementsCheck.h"
+#include "ConstValueReturnCheck.h"
 #include "ContainerSizeEmptyCheck.h"
 #include "DeleteNullPointerCheck.h"
 #include "DeletedDefaultCheck.h"
@@ -46,6 +47,8 @@
         "readability-avoid-const-params-in-decls");
     CheckFactories.registerCheck<BracesAroundStatementsCheck>(
         "readability-braces-around-statements");
+    CheckFactories.registerCheck<ConstValueReturnCheck>(
+        "readability-const-value-return");
     CheckFactories.registerCheck<ContainerSizeEmptyCheck>(
         "readability-container-size-empty");
     CheckFactories.registerCheck<DeleteNullPointerCheck>(
Index: docs/clang-tidy/checks/list.rst
===================================================================
--- docs/clang-tidy/checks/list.rst
+++ docs/clang-tidy/checks/list.rst
@@ -150,6 +150,7 @@
    performance-unnecessary-value-param
    readability-avoid-const-params-in-decls
    readability-braces-around-statements
+   readability-const-value-return
    readability-container-size-empty
    readability-delete-null-pointer
    readability-deleted-default
Index: docs/clang-tidy/checks/readability-const-value-return.rst
===================================================================
--- docs/clang-tidy/checks/readability-const-value-return.rst
+++ docs/clang-tidy/checks/readability-const-value-return.rst
@@ -0,0 +1,28 @@
+.. title:: clang-tidy - readability-const-value-return
+
+readability-const-value-return
+==============================
+
+Checks for functions that return a ``const``-qualified value type. That use of
+``const`` is superfluous, and prevents moving the object. Therefore, it should
+be avoided.
+
+Examples:
+
+.. code-block:: c++
+
+  const Foo f_bad();
+  Foo f_good();
+
+  Foo foo;
+  foo = f_bad();   // This requires a copy.
+  foo = f_good();  // This can use a move.
+
+
+Note that this does not apply to returning pointers or references to const
+objects:
+
+.. code-block:: c++
+
+  const Foo* f_ptr();  // No issue.
+  const Foo& f_ref();  // No issue.
Index: test/clang-tidy/readability-const-value-return.cpp
===================================================================
--- test/clang-tidy/readability-const-value-return.cpp
+++ test/clang-tidy/readability-const-value-return.cpp
@@ -0,0 +1,33 @@
+// RUN: %check_clang_tidy %s readability-const-value-return %t
+
+struct X {
+  int a;
+};
+
+// This should trigger the check.
+const X f_returns_const_value();
+// CHECK-MESSAGES: :[[@LINE-1]]:9: warning: function 'f_returns_const_value' has a const value return type; this can cause unnecessary copies [readability-const-value-return]
+
+// These should not trigger the check.
+X f_returns_nonconst_value();
+const X* f_returns_pointer_to_const();
+X* const f_returns_const_pointer();
+const X& f_returns_reference_to_const();
+
+typedef X* Xptr;
+typedef X& Xref;
+const Xptr f_returns_typedef_pointer();
+const Xref f_returns_typedef_reference();
+
+// A template parameter type may end up being a pointer or a reference, so we skip it too.
+template <typename T>
+const T f_returns_template_param();
+
+template <typename T>
+struct S {
+  using Q = T;
+  const Q f_returns_template_param_alias();
+};
+
+using R = X&;
+const R f_returns_reference_alias();