Index: lib/Driver/MSVCToolChain.cpp
===================================================================
--- lib/Driver/MSVCToolChain.cpp
+++ lib/Driver/MSVCToolChain.cpp
@@ -37,6 +37,8 @@
     #define NOMINMAX
   #endif
   #include <windows.h>
+
+  #pragma comment(lib, "version.lib")
 #endif
 
 using namespace clang::driver;
@@ -457,6 +459,42 @@
   return true;
 }
 
+VersionTuple MSVCToolChain::getMSVCVersionFromExe() const {
+  VersionTuple Version;
+#ifdef USE_WIN32
+  std::string BinPath;
+  if (!getVisualStudioBinariesFolder("", BinPath)) {
+    return Version;
+  }
+  SmallString<128> ClExe = BinPath;
+  llvm::sys::path::append(ClExe, "cl.exe");
+
+  const DWORD VersionSize = ::GetFileVersionInfoSizeA(ClExe.c_str(), nullptr);
+  if (VersionSize == 0) {
+    return Version;
+  }
+  std::vector<char> VersionBlock(VersionSize);
+  if (!::GetFileVersionInfoA(ClExe.c_str(), 0, VersionSize,
+                             VersionBlock.data())) {
+    return Version;
+  }
+  VS_FIXEDFILEINFO *FileInfo = nullptr;
+  UINT FileInfoSize = 0;
+  if (!::VerQueryValueA(VersionBlock.data(), "\\",
+                        reinterpret_cast<LPVOID *>(&FileInfo), &FileInfoSize) ||
+      FileInfoSize < sizeof(*FileInfo)) {
+    return Version;
+  }
+
+  const unsigned Major = (FileInfo->dwFileVersionMS >> 16) & 0xFFFF;
+  const unsigned Minor = (FileInfo->dwFileVersionMS      ) & 0xFFFF;
+  const unsigned Micro = (FileInfo->dwFileVersionLS >> 16) & 0xFFFF;
+
+  Version = VersionTuple(Major, Minor, Micro);
+#endif
+  return Version;
+}
+
 // Get Visual Studio installation directory.
 bool MSVCToolChain::getVisualStudioInstallDir(std::string &path) const {
   // First check the environment variables that vsvars32.bat sets.
@@ -618,7 +656,7 @@
       ToolChain::ComputeEffectiveClangTriple(Args, InputType);
   llvm::Triple Triple(TripleStr);
   VersionTuple MSVT =
-      tools::visualstudio::getMSVCVersion(/*D=*/nullptr, Triple, Args,
+      tools::visualstudio::getMSVCVersion(/*D=*/nullptr, *this, Triple, Args,
                                           /*IsWindowsMSVC=*/true);
   if (MSVT.empty())
     return TripleStr;
Index: lib/Driver/ToolChains.h
===================================================================
--- lib/Driver/ToolChains.h
+++ lib/Driver/ToolChains.h
@@ -1016,6 +1016,7 @@
   bool getVisualStudioInstallDir(std::string &path) const;
   bool getVisualStudioBinariesFolder(const char *clangProgramPath,
                                      std::string &path) const;
+  VersionTuple getMSVCVersionFromExe() const;
 
   std::string ComputeEffectiveClangTriple(const llvm::opt::ArgList &Args,
                                           types::ID InputType) const override;
Index: lib/Driver/Tools.h
===================================================================
--- lib/Driver/Tools.h
+++ lib/Driver/Tools.h
@@ -682,7 +682,8 @@
 
 /// Visual studio tools.
 namespace visualstudio {
-VersionTuple getMSVCVersion(const Driver *D, const llvm::Triple &Triple,
+VersionTuple getMSVCVersion(const Driver *D, const ToolChain &TC,
+                            const llvm::Triple &Triple,
                             const llvm::opt::ArgList &Args, bool IsWindowsMSVC);
 
 class LLVM_LIBRARY_VISIBILITY Linker : public Tool {
Index: lib/Driver/Tools.cpp
===================================================================
--- lib/Driver/Tools.cpp
+++ lib/Driver/Tools.cpp
@@ -3291,7 +3291,7 @@
   Result.append(UID.begin(), UID.end());
 }
 
-VersionTuple visualstudio::getMSVCVersion(const Driver *D,
+VersionTuple visualstudio::getMSVCVersion(const Driver *D, const ToolChain &TC,
                                           const llvm::Triple &Triple,
                                           const llvm::opt::ArgList &Args,
                                           bool IsWindowsMSVC) {
@@ -3333,8 +3333,15 @@
     if (Major || Minor || Micro)
       return VersionTuple(Major, Minor, Micro);
 
-    // FIXME: Consider bumping this to 19 (MSVC2015) soon.
-    return VersionTuple(18);
+    if (IsWindowsMSVC) {
+      const auto &MSVC = static_cast<const toolchains::MSVCToolChain &>(TC);
+      VersionTuple MSVT = MSVC.getMSVCVersionFromExe();
+      if (!MSVT.empty())
+        return MSVT;
+
+      // FIXME: Consider bumping this to 19 (MSVC2015) soon.
+      return VersionTuple(18);
+    }
   }
   return VersionTuple();
 }
@@ -5224,7 +5231,7 @@
 
   // -fms-compatibility-version=18.00 is default.
   VersionTuple MSVT = visualstudio::getMSVCVersion(
-      &D, getToolChain().getTriple(), Args, IsWindowsMSVC);
+      &D, getToolChain(), getToolChain().getTriple(), Args, IsWindowsMSVC);
   if (!MSVT.empty())
     CmdArgs.push_back(
         Args.MakeArgString("-fms-compatibility-version=" + MSVT.getAsString()));
Index: test/Driver/cl-options.c
===================================================================
--- test/Driver/cl-options.c
+++ test/Driver/cl-options.c
@@ -387,7 +387,7 @@
 // RTTI-NOT: "-fno-rtti"
 
 // thread safe statics are off for versions < 19.
-// RUN: %clang_cl /c -### -- %s 2>&1 | FileCheck -check-prefix=NoThreadSafeStatics %s
+// RUN: %clang_cl /c -### -fms-compatibility-version=18 -- %s 2>&1 | FileCheck -check-prefix=NoThreadSafeStatics %s
 // RUN: %clang_cl /Zc:threadSafeInit /Zc:threadSafeInit- /c -### -- %s 2>&1 | FileCheck -check-prefix=NoThreadSafeStatics %s
 // NoThreadSafeStatics: "-fno-threadsafe-statics"
 
Index: test/Driver/msc-version.c
===================================================================
--- test/Driver/msc-version.c
+++ test/Driver/msc-version.c
@@ -1,15 +1,4 @@
 //
-// Verify defaults
-//
-
-// RUN: %clang -target i686-windows -fms-compatibility -dM -E - </dev/null -o - | FileCheck %s -check-prefix CHECK-NO-MSC-VERSION
-
-// CHECK-NO-MSC-VERSION: _MSC_BUILD 1
-// CHECK-NO-MSC-VERSION: _MSC_FULL_VER 180000000
-// CHECK-NO-MSC-VERSION: _MSC_VER 1800
-
-
-//
 // Verify -fms-compatibility-version parsing
 //
 
Index: test/Driver/msvc-triple.c
===================================================================
--- test/Driver/msvc-triple.c
+++ test/Driver/msvc-triple.c
@@ -1,9 +1,7 @@
-// RUN: %clang -target i686-pc-windows-msvc   -S -emit-llvm %s -o - | FileCheck %s --check-prefix=DEFAULT
 // RUN: %clang -target i686-pc-windows-msvc19 -S -emit-llvm %s -o - | FileCheck %s --check-prefix=TARGET-19
 // RUN: %clang -target i686-pc-windows-msvc   -S -emit-llvm %s -o - -fms-compatibility-version=19 | FileCheck %s --check-prefix=OVERRIDE-19
 // RUN: %clang -target i686-pc-windows-msvc-elf -S -emit-llvm %s -o - | FileCheck %s --check-prefix=ELF-DEFAULT
 
-// DEFAULT:     target triple = "i686-pc-windows-msvc18.0.0"
 // TARGET-19:   target triple = "i686-pc-windows-msvc19.0.0"
 // OVERRIDE-19: target triple = "i686-pc-windows-msvc19.0.0"
-// ELF-DEFAULT: target triple = "i686-pc-windows-msvc18.0.0-elf"
+// ELF-DEFAULT: target triple = "i686-pc-windows-msvc{{.*}}-elf"
Index: test/Misc/diag-format.c
===================================================================
--- test/Misc/diag-format.c
+++ test/Misc/diag-format.c
@@ -37,7 +37,7 @@
 // DEFAULT: {{.*}}:36:8: warning: extra tokens at end of #endif directive [-Wextra-tokens]
 // MSVC2010: {{.*}}(36,7) : warning: extra tokens at end of #endif directive [-Wextra-tokens]
 // MSVC2013: {{.*}}(36,8) : warning: extra tokens at end of #endif directive [-Wextra-tokens]
-// MSVC: {{.*}}(36,8) : warning: extra tokens at end of #endif directive [-Wextra-tokens]
+// MSVC: {{.*}}(36,8){{ ?}}: warning: extra tokens at end of #endif directive [-Wextra-tokens]
 // MSVC2015: {{.*}}(36,8): warning: extra tokens at end of #endif directive [-Wextra-tokens]
 // VI: {{.*}} +36:8: warning: extra tokens at end of #endif directive [-Wextra-tokens]
 // MSVC2015_ORIG: {{.*}}(36): warning: extra tokens at end of #endif directive [-Wextra-tokens]
Index: tools/driver/driver.cpp
===================================================================
--- tools/driver/driver.cpp
+++ tools/driver/driver.cpp
@@ -501,7 +501,7 @@
 
 #ifdef LLVM_ON_WIN32
   // Exit status should not be negative on Win32, unless abnormal termination.
-  // Once abnormal termiation was caught, negative status should not be
+  // Once abnormal termination was caught, negative status should not be
   // propagated.
   if (Res < 0)
     Res = 1;