Use powershell only if it will work

Reworked the script so that it detects the version of powershell and knows if it can use it as a true fallback of curl and 7zip for download and extract.
Truth is: Windows 8/powershell 3 is required for download fallback and windows 10/powershell 5 is required for unzip fallback.
So, in the end, plain Windows 7 still requires manual download and unzip.

1 files changed, 65 insertions, 37 deletions

diff --git a/build/windows/install_buildenv.bat b/build/windows/install_buildenv.bat
index 8ceefc64b5..a797e88c82 100644
--- a/build/windows/install_buildenv.bat
+++ b/build/windows/install_buildenv.bat
@@ -10,55 +10,83 @@ SET WINLIB_NAME=%2
 REM The local directory to cache build environments in.
 SET WINLIBS_PATH=%3
 
-IF NOT EXIST "%WINLIBS_PATH%\%WINLIB_NAME%" (
+IF EXIST "%WINLIBS_PATH%\%WINLIB_NAME%" (
+  echo %WINLIB_NAME% already exists at %WINLIBS_PATH%
+  REM TODO(XXX) check fingerprint on build environment?
+  ENDLOCAL && EXIT /B 0
+)
+
 
-  REM Install build env base dir
-  IF NOT EXIST "%WINLIBS_PATH%" MKDIR "%WINLIBS_PATH%"
+REM Install build env base dir
+IF NOT EXIST "%WINLIBS_PATH%" MKDIR "%WINLIBS_PATH%"
 
-  where /q 7za
+where /q 7za
+IF ERRORLEVEL 1 (
+  where /q 7z
   IF ERRORLEVEL 1 (
-    where /q 7z
-    if ERRORLEVEL 1 (
-      where /q powershell
-      if ERRORLEVEL 1 (
-         echo Could not find 7z or 7za on the path, and powershell is not available. 
-         echo Either install http://7-zip.org and retry
-         echo or download %BASEURL%/%WINLIB_NAME%.zip
-         echo yourself and unzip it at %WINLIBS_PATH%
-         ENDLOCAL && EXIT /b 1
-      ) else (
-        set POWERSHELL=powershell
-      )
+    REM In case it is not present in PATH
+    IF EXIST "%PROGRAMFILES%\7-zip\7z.exe" (
+      set "ZIP=%PROGRAMFILES%\7-zip\7z.exe"
     ) else (
-      set ZIP=7z
+      call :get_powershell_version
+      IF !POWERSHELL! LSS 5 (
+        echo Could not find 7z or 7za on the path, and cannot use powershell ^(version !POWERSHELL!^)
+        echo Either install http://7-zip.org ^(and add it to the PATH^) and retry
+        echo or download %BASEURL%/%WINLIB_NAME%.zip
+        echo yourself and unzip it at %WINLIBS_PATH%
+        ENDLOCAL && EXIT /b 1
+      )
     )
   ) else (
-    set ZIP=7za
+    set ZIP=7z
   )
+) else (
+  set ZIP=7za
+)
 
-  echo Installing winlib %WINLIB_NAME%.
-  CD "%WINLIBS_PATH%"
-  echo ..Downloading %WINLIB_NAME%.zip
-  where /q curl
-  IF ERRORLEVEL 1 (
-    echo curl not found. Please download %WINLIB_NAME%.zip from %BASEURL%/ and unzip it yourself at %WINLIBS_PATH%
+echo Installing winlib %WINLIB_NAME%.
+CD "%WINLIBS_PATH%"
+echo ..Downloading %WINLIB_NAME%.zip
+where /q curl
+IF ERRORLEVEL 1 (
+  call :get_powershell_version
+  IF !POWERSHELL! LSS 3 (
+    echo curl not found and cannot use powershell ^(version !POWERSHELL!^)
+    echo Please download %WINLIB_NAME%.zip 
+    echo from %BASEURL%/ 
+    echo and unzip it yourself at %WINLIBS_PATH%
     ENDLOCAL && EXIT /b 1
-  )
-  curl -fsS -L -o %WINLIB_NAME%.zip %BASEURL%/%WINLIB_NAME%.zip
-  IF ERRORLEVEL 1 ENDLOCAL && EXIT /b 1
-  REM TODO(XXX) check fingerprint on zip file.
-  echo ..unzipping %WINLIB_NAME%.zip
-  IF "!POWERSHELL!" == "powershell" (
-    powershell -Command "& {Expand-Archive \"%WINLIBS_PATH%/%WINLIB_NAME%.zip\" \"%WINLIBS_PATH%\\\"}"
-    IF ERRORLEVEL 1 ENDLOCAL && EXIT /b 1
-  ) ELSE (
-    !ZIP! x %WINLIB_NAME%.zip
+  ) else (
+    powershell -Command "& {Invoke-WebRequest -Uri %BASEURL%/%WINLIB_NAME%.zip -OutFile \"%WINLIBS_PATH%/%WINLIB_NAME%.zip\"}"
     IF ERRORLEVEL 1 ENDLOCAL && EXIT /b 1
   )
-  DEL %WINLIB_NAME%.zip
 ) else (
-  echo %WINLIB_NAME% already exists at %WINLIBS_PATH%
-  REM TODO(XXX) check fingerprint on build environment?
+  curl -fsS -L -o %WINLIB_NAME%.zip %BASEURL%/%WINLIB_NAME%.zip
+  IF ERRORLEVEL 1 ENDLOCAL && EXIT /b 1
 )
+REM TODO(XXX) check fingerprint on zip file.
+
+
+echo ..unzipping %WINLIB_NAME%.zip
+IF "!ZIP!" NEQ "" (
+  "!ZIP!" x %WINLIB_NAME%.zip
+  IF ERRORLEVEL 1 ENDLOCAL && EXIT /b 1
+) ELSE (
+  powershell -Command "& {Expand-Archive \"%WINLIBS_PATH%/%WINLIB_NAME%.zip\" \"%WINLIBS_PATH%\\\"}"
+  IF ERRORLEVEL 1 ENDLOCAL && EXIT /b 1
+)
+DEL %WINLIB_NAME%.zip
 
 ENDLOCAL
+EXIT /B 0
+
+
+:get_powershell_version
+  where /q powershell
+  if ERRORLEVEL 1 (
+    set POWERSHELL=0
+  ) else (
+    REM DETECT powershell major version
+    FOR /F "tokens=* USEBACKQ" %%F IN (`powershell -Command "& {$PSVersionTable.PSVersion.Major}"`) DO ( set POWERSHELL=%%F )
+  )
+EXIT /B 1