Index: include/llvm/Support/DynamicLibrary.h
===================================================================
--- include/llvm/Support/DynamicLibrary.h
+++ include/llvm/Support/DynamicLibrary.h
@@ -65,8 +65,19 @@
     ///
     /// It is safe to call this function multiple times for the same library.
     /// @brief Open a dynamic library permanently.
-    static DynamicLibrary getPermanentLibrary(const char *filename,
-                                              std::string *errMsg = nullptr);
+    /// @param Filename The path to the library.
+    /// @param ErrMsg Any error encountered will be stored here.
+    /// @param RTLocal Open with RTLD_LOCAL flag on platforms supporting dlopen,
+    /// otherwise ignored.
+    static DynamicLibrary getPermanentLibrary(const char *Filename,
+                                              std::string *ErrMsg = nullptr,
+                                              bool RTLocal = false);
+
+    /// @brief Convenience function for using RTLocal without error reporting.
+    static DynamicLibrary getPermanentLibrary(const char *Filename,
+                                              bool RTLocal) {
+      return getPermanentLibrary(Filename, nullptr, RTLocal);
+    }
 
     /// Registers an externally loaded library. The library will be unloaded
     /// when the program terminates.
Index: lib/Support/DynamicLibrary.cpp
===================================================================
--- lib/Support/DynamicLibrary.cpp
+++ lib/Support/DynamicLibrary.cpp
@@ -33,7 +33,7 @@
   void *Process;
 
 public:
-  static void *DLOpen(const char *Filename, std::string *Err);
+  static void *DLOpen(const char *Filename, std::string *Err, bool Local);
   static void DLClose(void *Handle);
   static void *DLSym(void *Handle, const char *Symbol);
 
@@ -141,12 +141,12 @@
 }
 
 DynamicLibrary DynamicLibrary::getPermanentLibrary(const char *FileName,
-                                                   std::string *Err) {
+                                                   std::string *Err, bool Lcl) {
   // Force OpenedHandles to be added into the ManagedStatic list before any
   // ManagedStatic can be added from static constructors in HandleSet::DLOpen.
   HandleSet& HS = *OpenedHandles;
 
-  void *Handle = HandleSet::DLOpen(FileName, Err);
+  void *Handle = HandleSet::DLOpen(FileName, Err, Lcl);
   if (Handle != &Invalid) {
     SmartScopedLock<true> Lock(*SymbolsMutex);
     HS.AddLibrary(Handle, /*IsProcess*/ FileName == nullptr);
Index: lib/Support/Unix/DynamicLibrary.inc
===================================================================
--- lib/Support/Unix/DynamicLibrary.inc
+++ lib/Support/Unix/DynamicLibrary.inc
@@ -25,10 +25,12 @@
   DynamicLibrary::SearchOrder = DynamicLibrary::SO_Linker;
 }
 
-void *DynamicLibrary::HandleSet::DLOpen(const char *File, std::string *Err) {
-  void *Handle = ::dlopen(File, RTLD_LAZY|RTLD_GLOBAL);
+void *DynamicLibrary::HandleSet::DLOpen(const char *File, std::string *Err,
+                                        bool Local) {
+  void *Handle = ::dlopen(File, RTLD_LAZY | (Local ? RTLD_LOCAL : RTLD_GLOBAL));
   if (!Handle) {
-    if (Err) *Err = ::dlerror();
+    if (Err)
+      *Err = ::dlerror();
     return &DynamicLibrary::Invalid;
   }
 
Index: lib/Support/Windows/DynamicLibrary.inc
===================================================================
--- lib/Support/Windows/DynamicLibrary.inc
+++ lib/Support/Windows/DynamicLibrary.inc
@@ -32,7 +32,8 @@
   DynamicLibrary::SearchOrder = DynamicLibrary::SO_Linker;
 }
 
-void *DynamicLibrary::HandleSet::DLOpen(const char *File, std::string *Err) {
+void *DynamicLibrary::HandleSet::DLOpen(const char *File, std::string *Err,
+                                        bool /*Local*/) {
   // Create the instance and return it to be the *Process* handle
   // simillar to dlopen(NULL, RTLD_LAZY|RTLD_GLOBAL)
   if (!File)
Index: unittests/Support/DynamicLibrary/DynamicLibraryTest.cpp
===================================================================
--- unittests/Support/DynamicLibrary/DynamicLibraryTest.cpp
+++ unittests/Support/DynamicLibrary/DynamicLibraryTest.cpp
@@ -58,12 +58,12 @@
 
 std::string StdString(const char *Ptr) { return Ptr ? Ptr : ""; }
 
-TEST(DynamicLibrary, Overload) {
+static void TestOverload(bool RTLocal = false) {
   {
     std::string Err;
     llvm_shutdown_obj Shutdown;
     DynamicLibrary DL =
-        DynamicLibrary::getPermanentLibrary(LibPath().c_str(), &Err);
+        DynamicLibrary::getPermanentLibrary(LibPath().c_str(), &Err, RTLocal);
     EXPECT_TRUE(DL.isValid());
     EXPECT_TRUE(Err.empty());
 
@@ -88,11 +88,37 @@
     EXPECT_TRUE(GS != nullptr && GS == &TestA);
     EXPECT_EQ(StdString(GS()), "ProcessCall");
 
-    // Test overloading by forcing library priority when searching for a symbol
-    DynamicLibrary::SearchOrder = DynamicLibrary::SO_LoadedFirst;
-    GS = FuncPtr<GetString>(DynamicLibrary::SearchForAddressOfSymbol("TestA"));
-    EXPECT_TRUE(GS != nullptr && GS != &TestA);
-    EXPECT_EQ(StdString(GS()), "LibCall");
+    // Test overloading by forcing a priority when searching for a symbol
+    if (RTLocal) {
+      // SetStrings un-resolved because RTLocal
+      SetStrings SS = FuncPtr<SetStrings>(
+          DynamicLibrary::SearchForAddressOfSymbol("SetStrings"));
+      EXPECT_TRUE(SS == nullptr);
+
+      DynamicLibrary::SearchOrder = DynamicLibrary::SO_LoadedLast;
+
+      // SetStrings now resolved because SO_LoadedLast
+      SS = FuncPtr<SetStrings>(
+          DynamicLibrary::SearchForAddressOfSymbol("SetStrings"));
+      EXPECT_TRUE(SS != nullptr);
+
+      // TestA resolved from Process first
+      GS = FuncPtr<GetString>(DynamicLibrary::SearchForAddressOfSymbol("TestA"));
+      EXPECT_TRUE(GS != nullptr && GS == &TestA);
+      EXPECT_EQ(StdString(GS()), "ProcessCall");
+    } else {
+      // SetStrings resolved because DynamicLibrary::getPermanentLibrary(nullptr)
+      SetStrings SS = FuncPtr<SetStrings>(
+          DynamicLibrary::SearchForAddressOfSymbol("SetStrings"));
+      EXPECT_TRUE(SS != nullptr);
+
+      DynamicLibrary::SearchOrder = DynamicLibrary::SO_LoadedFirst;
+
+      // TestA resolved from Library first
+      GS = FuncPtr<GetString>(DynamicLibrary::SearchForAddressOfSymbol("TestA"));
+      EXPECT_TRUE(GS != nullptr && GS != &TestA);
+      EXPECT_EQ(StdString(GS()), "LibCall");
+    }
 
     DynamicLibrary::AddSymbol("TestA", PtrFunc(&OverloadTestA));
     GS = FuncPtr<GetString>(DL.getAddressOfSymbol("TestA"));
@@ -109,6 +135,16 @@
   EXPECT_TRUE(DynamicLibrary::SearchOrder == DynamicLibrary::SO_Linker);
 }
 
+TEST(DynamicLibrary, Overload) {
+  TestOverload();
+}
+
+#if defined(HAVE_DLFCN_H) && defined(HAVE_DLOPEN)
+TEST(DynamicLibrary, RTLocal) {
+  TestOverload(true);
+}
+#endif
+
 TEST(DynamicLibrary, Shutdown) {
   std::string A, B;
   {