def _varsall_bat_path()

in python/treelite/contrib/msvc.py [0:0]

• 49 lines of code
• 20 McCabe index (conditional complexity)

def _varsall_bat_path():
  # if a custom location is given, try that first
  if 'TREELITE_VCVARSALL' in os.environ:
    candidate = os.environ['TREELITE_VCVARSALL']
    if os.path.basename(candidate).lower() != 'vcvarsall.bat':
      raise OSError('Environment variable TREELITE_VCVARSALL must point to '+\
                    'file vcvarsall.bat')
    if os.path.isfile(candidate):
      return candidate
    raise OSError('Environment variable TREELITE_VCVARSALL does not refer '+\
                  'to existing vcvarsall.bat')

  ## Bunch of heuristics to locate vcvarsall.bat
  candidate_paths = []     # List of possible paths to vcvarsall.bat
  try:
    import winreg                 # pylint: disable=E0401
    if _is_64bit_windows():
      key_name = 'SOFTWARE\\Wow6432Node\\Microsoft\\VisualStudio\\SxS\\VS7'
    else:
      key_name = 'SOFTWARE\\Microsoft\\VisualStudio\\SxS\\VC7'
    key = winreg.OpenKey(winreg.HKEY_LOCAL_MACHINE, key_name)
    i = 0
    while True:
      try:
        version, vcroot, _ = winreg.EnumValue(key, i)
        if StrictVersion(version) >= StrictVersion('15.0'):
          # Visual Studio 2017 revamped directory structure
          candidate_paths.append(os.path.join(vcroot, 'VC\\Auxiliary\\Build\\vcvarsall.bat'))
        else:
          candidate_paths.append(os.path.join(vcroot, 'VC\\vcvarsall.bat'))
      except WindowsError:   # pylint: disable=E0602
        break
      i += 1
  except FileNotFoundError:
    pass   # No registry key found
  except ImportError:
    pass   # No winreg module

  for candidate in candidate_paths:
    if os.path.isfile(candidate):
      return candidate

  # If registry method fails, try a bunch of pre-defined paths

  # Visual Studio 2017 and higher
  for vcroot in glob.glob('C:\\Program Files (x86)\\Microsoft Visual Studio\\*') + \
                glob.glob('C:\\Program Files\\Microsoft Visual Studio\\*'):
    if re.fullmatch(r'[0-9]+', os.path.basename(vcroot)):
      for candidate in glob.glob(vcroot + '\\*\\VC\\Auxiliary\\Build\\vcvarsall.bat'):
        if os.path.isfile(candidate):
          return candidate
  # Previous versions of Visual Studio
  pattern = '\\Microsoft Visual Studio*\\VC\\vcvarsall.bat'
  for candidate in glob.glob('C:\\Program Files (x86)' + pattern) + \
                   glob.glob('C:\\Program Files' + pattern):
    if os.path.isfile(candidate):
      return candidate

  raise OSError('vcvarsall.bat not found; please specify its full path in '+\
                'the environment variable TREELITE_VCVARSALL')