Index: tools/msbuild/CMakeLists.txt
===================================================================
--- tools/msbuild/CMakeLists.txt
+++ tools/msbuild/CMakeLists.txt
@@ -12,6 +12,8 @@
     set(prop_file_v120_xp "toolset-vs2013_xp.props")
     set(prop_file_v140 "toolset-vs2014.props")
     set(prop_file_v140_xp "toolset-vs2014_xp.props")
+    set(prop_file_v141 "toolset-vs2017.props")
+    set(prop_file_v141_xp "toolset-vs2017_xp.props")
 
     if (platform STREQUAL "Win32")
       set(mflag "m32")
@@ -36,6 +38,11 @@
     configure_file(${prop_file_in} ${platform}/${prop_file_v140})
     set(VS_VERSION "v140_xp")
     configure_file(${prop_file_in} ${platform}/${prop_file_v140_xp})
+    set(VS_VERSION "v141")
+    set(MSC_VERSION "1911")
+    configure_file(${prop_file_in} ${platform}/${prop_file_v141})
+    set(VS_VERSION "v141_xp")
+    configure_file(${prop_file_in} ${platform}/${prop_file_v141_xp})
     set(VS_VERSION)
     set(MSC_VERSION)
     set(mflag)
@@ -47,6 +54,8 @@
     install(FILES "${CMAKE_CURRENT_BINARY_DIR}/${platform}/${prop_file_v120_xp}" DESTINATION tools/msbuild/${platform})
     install(FILES "${CMAKE_CURRENT_BINARY_DIR}/${platform}/${prop_file_v140}" DESTINATION tools/msbuild/${platform})
     install(FILES "${CMAKE_CURRENT_BINARY_DIR}/${platform}/${prop_file_v140_xp}" DESTINATION tools/msbuild/${platform})
+    install(FILES "${CMAKE_CURRENT_BINARY_DIR}/${platform}/${prop_file_v141}" DESTINATION tools/msbuild/${platform})
+    install(FILES "${CMAKE_CURRENT_BINARY_DIR}/${platform}/${prop_file_v141_xp}" DESTINATION tools/msbuild/${platform})
 
     install(FILES "Microsoft.Cpp.Win32.LLVM-vs2010.targets" DESTINATION "tools/msbuild/${platform}" RENAME "Microsoft.Cpp.${platform}.LLVM-vs2010.targets")
     install(FILES "Microsoft.Cpp.Win32.LLVM-vs2012.targets" DESTINATION "tools/msbuild/${platform}" RENAME "Microsoft.Cpp.${platform}.LLVM-vs2012.targets")
@@ -55,6 +64,8 @@
     install(FILES "toolset-vs2013_xp.targets" DESTINATION "tools/msbuild/${platform}")
     install(FILES "toolset-vs2014.targets" DESTINATION "tools/msbuild/${platform}")
     install(FILES "toolset-vs2014_xp.targets" DESTINATION "tools/msbuild/${platform}")
+    install(FILES "toolset-vs2017.targets" DESTINATION "tools/msbuild/${platform}")
+    install(FILES "toolset-vs2017_xp.targets" DESTINATION "tools/msbuild/${platform}")
   endforeach()
 
   set(LIB_PATH_VERSION)
Index: tools/msbuild/install.bat
===================================================================
--- tools/msbuild/install.bat
+++ tools/msbuild/install.bat
@@ -40,6 +40,21 @@
 
 :TRY_V150
 
+REM MSBuild is now under the Visual Studio installation.  VSWhere is a new executable placed in a known
+REM location that can be used to find the VS installation, starting with VS 2017 SP1
+IF EXIST "%ProgramFiles(x86)%\Microsoft Visual Studio\Installer\vswhere.exe" (
+  FOR /f "usebackq delims=" %%i IN (`"%ProgramFiles(x86)%\Microsoft Visual Studio\Installer\vswhere.exe" -prerelease -latest -version 15 -property installationPath`) DO (
+    SET D="%%i\Common7\IDE\VC\VCTargets\Platforms\%PLATFORM%\PlatformToolsets"
+  )
+)
+REM On 32-bit Windows OSes before Windows 10, vswhere will be installed under %ProgramFiles%
+IF EXIST "%ProgramFiles%\Microsoft Visual Studio\Installer\vswhere.exe" (
+  FOR /f "usebackq delims=" %%i IN (`"%ProgramFiles%\Microsoft Visual Studio\Installer\vswhere.exe" -prerelease -latest -version 15 -property installationPath`) DO (
+    SET D="%%i\Common7\IDE\VC\VCTargets\Platforms\%PLATFORM%\PlatformToolsets"
+  )
+)
+if EXIST %D% GOTO FOUND_V150
+
 GOTO PLATFORMLOOPHEAD
 
 :PLATFORMLOOPEND
@@ -110,6 +125,21 @@
 set SUCCESS=1
 GOTO TRY_V150
 
+:FOUND_V150
+REM Routine for installing v150 toolchain.
+IF NOT EXIST %D%\LLVM-vs2017 mkdir %D%\LLVM-vs2017
+IF NOT %ERRORLEVEL% == 0 GOTO FAILED
+copy %PLATFORM%\toolset-vs2017.props %D%\LLVM-vs2017\toolset.props
+IF NOT %ERRORLEVEL% == 0 GOTO FAILED
+copy %PLATFORM%\toolset-vs2017.targets %D%\LLVM-vs2017\toolset.targets
+IF NOT %ERRORLEVEL% == 0 GOTO FAILED
+IF NOT EXIST %D%\LLVM-vs2017_xp mkdir %D%\LLVM-vs2017_xp
+IF NOT %ERRORLEVEL% == 0 GOTO FAILED
+copy %PLATFORM%\toolset-vs2017_xp.props %D%\LLVM-vs2017_xp\toolset.props
+IF NOT %ERRORLEVEL% == 0 GOTO FAILED
+copy %PLATFORM%\toolset-vs2017_xp.targets %D%\LLVM-vs2017_xp\toolset.targets
+IF NOT %ERRORLEVEL% == 0 GOTO FAILED
+set SUCCESS=1
 
 :DONE
 echo Done!
Index: tools/msbuild/toolset-vs2017.targets
===================================================================
--- tools/msbuild/toolset-vs2017.targets
+++ tools/msbuild/toolset-vs2017.targets
@@ -0,0 +1,3 @@
+<Project ToolsVersion="15.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <Import Project="$(VCTargetsPath)\Microsoft.CppCommon.targets" />
+</Project>
Index: tools/msbuild/toolset-vs2017_xp.targets
===================================================================
--- tools/msbuild/toolset-vs2017_xp.targets
+++ tools/msbuild/toolset-vs2017_xp.targets
@@ -0,0 +1,21 @@
+<Project ToolsVersion="15.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <!-- Force TargetFrameworkVersion to v4.0 to support XP-->
+  <PropertyGroup>
+    <TargetFrameworkVersion>v4.0</TargetFrameworkVersion>
+    <BeforeClCompileTargets>NoSupportCodeAnalysisXP;$(BeforeClCompileTargets)</BeforeClCompileTargets>
+  </PropertyGroup>
+
+  <Import Project="$(VCTargetsPath)\Microsoft.CppCommon.targets" />
+
+  <Target Name="NoSupportCodeAnalysisXP" Condition="'$(ErrorNoSupportCodeAnalysisXP)' != 'false'">
+    <VCMessage Condition="'$(DesignTimeBuild)' != 'true' and '@(ClCompile->AnyHaveMetadataValue('EnablePREfast', 'true'))'=='true'" Code="MSB8026" Type="Error"/>
+  </Target>
+
+  <PropertyGroup>
+    <PrepareForBuildDependsOn>CheckWindowsSDK71A;$(PrepareForBuildDependsOn)</PrepareForBuildDependsOn>
+  </PropertyGroup>
+
+  <Target Name="CheckWindowsSDK71A">
+    <VCMessage Code="MSB8003" Type="Warning" Arguments="WindowsSdkDir_71A" Condition="'$(WindowsSdkDir_71A)'=='' and '$(UseEnv)' != 'true'" />
+  </Target>
+</Project>
Index: tools/msbuild/uninstall.bat
===================================================================
--- tools/msbuild/uninstall.bat
+++ tools/msbuild/uninstall.bat
@@ -66,6 +66,26 @@
 IF EXIST %D%\LLVM-vs2014_xp del %D%\LLVM-vs2014_xp\toolset.targets
 IF EXIST %D%\LLVM-vs2014_xp rmdir %D%\LLVM-vs2014_xp
 
+REM MSBuild is now under the Visual Studio installation.  VSWhere is a new executable placed in a known
+REM location that can be used to find the VS installation, starting with VS 2017 SP1
+IF EXIST "%ProgramFiles(x86)%\Microsoft Visual Studio\Installer\vswhere.exe" (
+  FOR /f "usebackq delims=" %%i IN (`"%ProgramFiles(x86)%\Microsoft Visual Studio\Installer\vswhere.exe" -latest -prerelease -version 15 -property installationPath`) DO (
+    SET D="%%i\Common7\IDE\VC\VCTargets\Platforms\%PLATFORM%\PlatformToolsets"
+  )
+)
+
+REM On 32-bit Windows OSes before Windows 10, vswhere will be installed under %ProgramFiles%
+IF EXIST "%ProgramFiles%\Microsoft Visual Studio\Installer\vswhere.exe" (
+  FOR /f "usebackq delims=" %%i IN (`"%ProgramFiles%\Microsoft Visual Studio\Installer\vswhere.exe" -latest -prerelease -version 15 -property installationPath`) DO (
+    SET D="%%i\Common7\IDE\VC\VCTargets\Platforms\%PLATFORM%\PlatformToolsets"
+  )
+)
+IF EXIST %D%\LLVM-vs2017 del %D%\LLVM-vs2017\toolset.props
+IF EXIST %D%\LLVM-vs2017 del %D%\LLVM-vs2017\toolset.targets
+IF EXIST %D%\LLVM-vs2017 rmdir %D%\LLVM-vs2017
+IF EXIST %D%\LLVM-vs2017_xp del %D%\LLVM-vs2017_xp\toolset.props
+IF EXIST %D%\LLVM-vs2017_xp del %D%\LLVM-vs2017_xp\toolset.targets
+IF EXIST %D%\LLVM-vs2017_xp rmdir %D%\LLVM-vs2017_xp
 
 GOTO LOOPHEAD
 
Index: utils/lit/lit/TestingConfig.py
===================================================================
--- utils/lit/lit/TestingConfig.py
+++ utils/lit/lit/TestingConfig.py
@@ -37,6 +37,7 @@
             environment.update({
                     'INCLUDE' : os.environ.get('INCLUDE',''),
                     'PATHEXT' : os.environ.get('PATHEXT',''),
+                    'PROGRAMDATA' : os.environ.get('PROGRAMDATA',''),
                     'PYTHONUNBUFFERED' : '1',
                     'TEMP' : os.environ.get('TEMP',''),
                     'TMP' : os.environ.get('TMP',''),