Make VS2017\install.bat works for both Visual Studio 2017 and 2019.

VS2017/install.bat

@@ -2,39 +2,33 @@
 SETLOCAL ENABLEEXTENSIONS
 
 SET "EXIT_ON_ERROR=%~1"
+SET SUCCESS=0
 
-FOR /f "delims=" %%A IN (
-'"%ProgramFiles(x86)%\Microsoft Visual Studio\Installer\vswhere.exe" -property installationPath'
-) DO SET "VS_PATH=%%A"
+PUSHD %~dp0
 
-@rem VSINSTALLDIR is set by vsdevcmd_start.bat
-IF "%VS_PATH%" == ""  (
-	IF EXIST "%VSINSTALLDIR%" SET "VS_PATH=%VSINSTALLDIR%"
-)
-IF NOT EXIST "%VS_PATH%" (
-	IF EXIST "%EXIT_ON_ERROR%" SET "VS_PATH=%EXIT_ON_ERROR%" & SET "EXIT_ON_ERROR=%~2"
+SET VSWHERE=%ProgramFiles(x86)%\Microsoft Visual Studio\Installer\vswhere.exe
+@rem Visual Studio 2017 and 2019
+FOR /f "delims=" %%A IN ('"%VSWHERE%" -property installationPath -prerelease -version ^[15.0^,17.0^)') DO (
+	IF EXIST "%%A\Common7\IDE\VC\VCTargets\Platforms" CALL :SUB_VS2017 "%%A\Common7\IDE\VC\VCTargets\Platforms"
 )
 
-SET VCT_PATH=%VS_PATH%\Common7\IDE\VC\VCTargets\Platforms
-IF NOT EXIST "%VCT_PATH%" (
+IF %SUCCESS% == 0 (
 	ECHO Visual C++ 2017 or 2019 NOT Installed.
 	IF "%EXIT_ON_ERROR%" == "" PAUSE
-	ENDLOCAL
-	EXIT /B
 )
 
-ECHO VCTargetsPath: %VCT_PATH%
-
-PUSHD %~dp0
-
-XCOPY /Q /Y "LLVM" "%VCT_PATH%\..\LLVM\"
-XCOPY /Q /Y "LLVM_v141" "%VCT_PATH%\x64\PlatformToolsets\LLVM_v141\"
-XCOPY /Q /Y "LLVM_v141_xp" "%VCT_PATH%\x64\PlatformToolsets\LLVM_v141_xp\"
-XCOPY /Q /Y "LLVM_v141" "%VCT_PATH%\Win32\PlatformToolsets\LLVM_v141\"
-XCOPY /Q /Y "LLVM_v141_xp" "%VCT_PATH%\Win32\PlatformToolsets\LLVM_v141_xp\"
-XCOPY /Q /Y "LLVM_v141" "%VCT_PATH%\ARM64\PlatformToolsets\LLVM_v141\"
-
-IF "%EXIT_ON_ERROR%" == "" PAUSE
 POPD
 ENDLOCAL
 EXIT /B
+
+
+:SUB_VS2017
+ECHO VCTargetsPath: %~1
+XCOPY /Q /Y "LLVM" "%~1\..\LLVM\"
+XCOPY /Q /Y "LLVM_v141" "%~1\x64\PlatformToolsets\LLVM_v141\"
+XCOPY /Q /Y "LLVM_v141_xp" "%~1\x64\PlatformToolsets\LLVM_v141_xp\"
+XCOPY /Q /Y "LLVM_v141" "%~1\Win32\PlatformToolsets\LLVM_v141\"
+XCOPY /Q /Y "LLVM_v141_xp" "%~1\Win32\PlatformToolsets\LLVM_v141_xp\"
+XCOPY /Q /Y "LLVM_v141" "%~1\ARM64\PlatformToolsets\LLVM_v141\"
+SET SUCCESS=1
+EXIT /B

readme.md

@@ -24,8 +24,6 @@ please manually copy folder `LLVM_v141` and `LLVM_v141_xp` under `VS2017` to fol
 
 or run `VS2017\install.bat` directly (may require Administrator privilege. In Windows 8 or later, you can quickly open an elevated PowerShell prompt by File -> Open Windows PowerShell -> Open PowerShell as Administrator).
 
-Because `vswhere` doesn't print the installation path for Visual Studio 2019 Preview, please call the script with installation path, e.g: `CALL VS2017\install.bat "C:\Program Files (x86)\Microsoft Visual Studio\2019\Preview"` or call vsdevcmd.bat (or vcvarsall.bat, etc.) before this script.
-
 ## LLVM for Visual Studio 2010, 2012, 2013 and 2015
 Assume `MB_PATH` is the MSBuild path for Visual C++ (e.g.: `C:\Program Files (x86)\MSBuild\Microsoft.Cpp\v4.0` or `C:\Program Files\MSBuild\Microsoft.Cpp\v4.0`), please manually copy `VS2017\LLVM` and related folders under `VS2015` to following target paths.