Index: cfe/trunk/lib/Driver/MinGWToolChain.cpp
===================================================================
--- cfe/trunk/lib/Driver/MinGWToolChain.cpp
+++ cfe/trunk/lib/Driver/MinGWToolChain.cpp
@@ -192,16 +192,18 @@
   if (DriverArgs.hasArg(options::OPT_nostdlibinc))
     return;
 
-  llvm::SmallString<1024> IncludeDir(GccLibDir);
-  llvm::sys::path::append(IncludeDir, "include");
-  addSystemInclude(DriverArgs, CC1Args, IncludeDir.c_str());
-  IncludeDir += "-fixed";
+  if (GetRuntimeLibType(DriverArgs) == ToolChain::RLT_Libgcc) {
+    llvm::SmallString<1024> IncludeDir(GccLibDir);
+    llvm::sys::path::append(IncludeDir, "include");
+    addSystemInclude(DriverArgs, CC1Args, IncludeDir.c_str());
+    IncludeDir += "-fixed";
 #ifdef LLVM_ON_UNIX
-  // openSUSE
-  addSystemInclude(DriverArgs, CC1Args,
-                   "/usr/x86_64-w64-mingw32/sys-root/mingw/include");
+    // openSUSE
+    addSystemInclude(DriverArgs, CC1Args,
+                     "/usr/x86_64-w64-mingw32/sys-root/mingw/include");
 #endif
-  addSystemInclude(DriverArgs, CC1Args, IncludeDir.c_str());
+    addSystemInclude(DriverArgs, CC1Args, IncludeDir.c_str());
+  }
   addSystemInclude(DriverArgs, CC1Args, Base + Arch + "include");
   addSystemInclude(DriverArgs, CC1Args, Base + "include");
 }
@@ -212,19 +214,29 @@
       DriverArgs.hasArg(options::OPT_nostdincxx))
     return;
 
-  llvm::SmallVector<llvm::SmallString<1024>, 4> CppIncludeBases;
-  CppIncludeBases.emplace_back(Base);
-  llvm::sys::path::append(CppIncludeBases[0], Arch, "include", "c++");
-  CppIncludeBases.emplace_back(Base);
-  llvm::sys::path::append(CppIncludeBases[1], Arch, "include", "c++", Ver);
-  CppIncludeBases.emplace_back(Base);
-  llvm::sys::path::append(CppIncludeBases[2], "include", "c++", Ver);
-  CppIncludeBases.emplace_back(GccLibDir);
-  llvm::sys::path::append(CppIncludeBases[3], "include", "c++");
-  for (auto &CppIncludeBase : CppIncludeBases) {
-    CppIncludeBase += llvm::sys::path::get_separator();
-    addSystemInclude(DriverArgs, CC1Args, CppIncludeBase);
-    addSystemInclude(DriverArgs, CC1Args, CppIncludeBase + Arch);
-    addSystemInclude(DriverArgs, CC1Args, CppIncludeBase + "backward");
+  switch (GetCXXStdlibType(DriverArgs)) {
+  case ToolChain::CST_Libcxx:
+    addSystemInclude(DriverArgs, CC1Args, Base        + "include" +
+                     llvm::sys::path::get_separator() + "c++"     +
+                     llvm::sys::path::get_separator() + "v1");
+    break;
+
+  case ToolChain::CST_Libstdcxx:
+    llvm::SmallVector<llvm::SmallString<1024>, 4> CppIncludeBases;
+    CppIncludeBases.emplace_back(Base);
+    llvm::sys::path::append(CppIncludeBases[0], Arch, "include", "c++");
+    CppIncludeBases.emplace_back(Base);
+    llvm::sys::path::append(CppIncludeBases[1], Arch, "include", "c++", Ver);
+    CppIncludeBases.emplace_back(Base);
+    llvm::sys::path::append(CppIncludeBases[2], "include", "c++", Ver);
+    CppIncludeBases.emplace_back(GccLibDir);
+    llvm::sys::path::append(CppIncludeBases[3], "include", "c++");
+    for (auto &CppIncludeBase : CppIncludeBases) {
+      CppIncludeBase += llvm::sys::path::get_separator();
+      addSystemInclude(DriverArgs, CC1Args, CppIncludeBase);
+      addSystemInclude(DriverArgs, CC1Args, CppIncludeBase + Arch);
+      addSystemInclude(DriverArgs, CC1Args, CppIncludeBase + "backward");
+    }
+    break;
   }
 }
Index: cfe/trunk/lib/Driver/Tools.cpp
===================================================================
--- cfe/trunk/lib/Driver/Tools.cpp
+++ cfe/trunk/lib/Driver/Tools.cpp
@@ -2247,8 +2247,7 @@
 
 // Until ARM libraries are build separately, we have them all in one library
 static StringRef getArchNameForCompilerRTLib(const ToolChain &TC) {
-  if (TC.getTriple().isOSWindows() &&
-      !TC.getTriple().isWindowsItaniumEnvironment() &&
+  if (TC.getTriple().isWindowsMSVCEnvironment() &&
       TC.getArch() == llvm::Triple::x86)
     return "i386";
   if (TC.getArch() == llvm::Triple::arm || TC.getArch() == llvm::Triple::armeb)
@@ -2274,10 +2273,12 @@
                         : "";
 
   bool IsOSWindows = TC.getTriple().isOSWindows();
+  bool IsITANMSVCWindows = TC.getTriple().isWindowsMSVCEnvironment() ||
+                           TC.getTriple().isWindowsItaniumEnvironment();
   StringRef Arch = getArchNameForCompilerRTLib(TC);
-  const char *Prefix = IsOSWindows ? "" : "lib";
+  const char *Prefix = IsITANMSVCWindows ? "" : "lib";
   const char *Suffix =
-      Shared ? (IsOSWindows ? ".dll" : ".so") : (IsOSWindows ? ".lib" : ".a");
+      Shared ? (IsOSWindows ? ".dll" : ".so") : (IsITANMSVCWindows ? ".lib" : ".a");
 
   SmallString<128> Path = getCompilerRTLibDir(TC);
   llvm::sys::path::append(Path, Prefix + Twine("clang_rt.") + Component + "-" +
@@ -7840,6 +7841,7 @@
 static void AddLibgcc(const llvm::Triple &Triple, const Driver &D,
                       ArgStringList &CmdArgs, const ArgList &Args) {
   bool isAndroid = Triple.getEnvironment() == llvm::Triple::Android;
+  bool isCygMing = Triple.isOSCygMing();
   bool StaticLibgcc = Args.hasArg(options::OPT_static_libgcc) ||
                       Args.hasArg(options::OPT_static);
   if (!D.CCCIsCXX())
@@ -7849,10 +7851,10 @@
     if (D.CCCIsCXX())
       CmdArgs.push_back("-lgcc");
   } else {
-    if (!D.CCCIsCXX())
+    if (!D.CCCIsCXX() && !isCygMing)
       CmdArgs.push_back("--as-needed");
     CmdArgs.push_back("-lgcc_s");
-    if (!D.CCCIsCXX())
+    if (!D.CCCIsCXX() && !isCygMing)
       CmdArgs.push_back("--no-as-needed");
   }
 
@@ -8934,15 +8936,10 @@
   if (Args.hasArg(options::OPT_mthreads))
     CmdArgs.push_back("-lmingwthrd");
   CmdArgs.push_back("-lmingw32");
-  if (Args.hasArg(options::OPT_shared) ||
-      Args.hasArg(options::OPT_shared_libgcc) ||
-      !Args.hasArg(options::OPT_static_libgcc)) {
-    CmdArgs.push_back("-lgcc_s");
-    CmdArgs.push_back("-lgcc");
-  } else {
-    CmdArgs.push_back("-lgcc");
-    CmdArgs.push_back("-lgcc_eh");
-  }
+
+  // Add libgcc or compiler-rt.
+  AddRunTimeLibs(getToolChain(), getToolChain().getDriver(), CmdArgs, Args);
+
   CmdArgs.push_back("-lmoldname");
   CmdArgs.push_back("-lmingwex");
   CmdArgs.push_back("-lmsvcrt");