Package/Install the Windows 10 Universal C Runtime for VS 2015

win_toolchain/get_toolchain_if_necessary.py

Index: win_toolchain/get_toolchain_if_necessary.py
diff --git a/win_toolchain/get_toolchain_if_necessary.py b/win_toolchain/get_toolchain_if_necessary.py
index 27fa18120dd11acf5903470bf8ef46758c0f279e..e86c81f624393d9f4ec93c96fa2f7227cac6ee36 100755
--- a/win_toolchain/get_toolchain_if_necessary.py
+++ b/win_toolchain/get_toolchain_if_necessary.py
@@ -30,6 +30,8 @@ import hashlib
 import json
 import optparse
 import os
+import platform
+import re
 import shutil
 import subprocess
 import sys
@@ -217,6 +219,71 @@ def DoTreeMirror(target_dir, tree_sha1):
     RmDir(temp_dir)
 
 
+def GetInstallerName():
+  """Return the name of the Windows 10 Universal C Runtime installer for the
+  current platform, or None if installer is not needed or not applicable.
+  The registry has to be used instead of sys.getwindowsversion() because
+  Python 2.7 is only manifested as being compatible up to Windows 8, so the
+  version APIs helpfully return a maximum of 6.2 (Windows 8).
+  """
+  ver_re = re.compile('.*REG_SZ * (\d+)\.(\d+)')
+  key_name = '"HKLM\Software\Microsoft\Windows NT\CurrentVersion"'
+  output = subprocess.check_output('reg query %s /v CurrentVersion' % key_name)
+  match = ver_re.match(output.replace('\n', ' '))
+  if match.groups() == ('6', '1'):
+    # Windows 7 and Windows Server 2008 R2
+    return 'Windows6.1-KB2999226-x64.msu'
+  elif match.groups() == ('6', '2'):
+    # Windows 8 and Windows Server 2012
+    return 'Windows8-RT-KB2999226-x64.msu'
+  elif match.groups() == ('6', '3'):
+    # Windows 8.1 and Windows Server 2012 R2
+    return 'Windows8.1-KB2999226-x64.msu'
+  else:
+    # Windows 10 or higher assumed
+    return None
+
+
+def InstallUniversalCRTIfNeeded(abs_target_dir):
+  installer_name = GetInstallerName()
+  if not installer_name:
+    # Assumed to be Windows 10+ so nothing to do
+    return
+
+  bitness = platform.architecture()[0]
+  # When running 64-bit python the x64 DLLs will be in System32
+  x64_path = 'System32' if bitness == '64bit' else 'Sysnative'
+  x64_path = os.path.join(r'C:\Windows', x64_path)
+  sample_crt_file = os.path.join(x64_path, 'api-ms-win-crt-math-l1-1-0.dll')
+
+  if os.path.exists(sample_crt_file):
+    # Nothing to do.
+    return
+
+  print ('%s does not exist - installing Windows 10 Universal C Runtime' %
+        sample_crt_file)
+
+  installer = os.path.join(abs_target_dir, "installers", installer_name)
+  command = r'wusa.exe /quiet "%s"' % installer
+  print 'Running %s' % command
+
+  try:
+    subprocess.check_call(command)
+  except WindowsError as e:
+    if e.winerror == 740: # The requested operation requires elevation
+      print
+      print '-'*80
+      print
+      print 'Elevation required. You must manually install this update:'
+      print '  %s' % installer
+      print
+      print '-'*80
+      print
+      raise Exception('Elevation required. You must manually install %s' %
+                      installer)
+    raise e
+
+
 def main():
   parser = optparse.OptionParser(description=sys.modules[__name__].__doc__)
   parser.add_option('--output-json', metavar='FILE',
@@ -331,6 +398,8 @@ def main():
     shutil.copyfile(os.path.join(target_dir, '..', 'data.json'),
                     options.output_json)
 
+  InstallUniversalCRTIfNeeded(abs_target_dir)
+
   return 0