vs_toolchain.py 文件源码

def _CopyRuntimeImpl(target, source, verbose=True):
  """Copy |source| to |target| if it doesn't already exist or if it needs to be
  updated (comparing last modified time as an approximate float match as for
  some reason the values tend to differ by ~1e-07 despite being copies of the
  same file... https://crbug.com/603603).
  """
  if (os.path.isdir(os.path.dirname(target)) and
      (not os.path.isfile(target) or
       abs(os.stat(target).st_mtime - os.stat(source).st_mtime) >= 0.01)):
    if verbose:
      print 'Copying %s to %s...' % (source, target)
    if os.path.exists(target):
      # Make the file writable so that we can delete it now, and keep it
      # readable.
      os.chmod(target, stat.S_IWRITE | stat.S_IREAD)
      os.unlink(target)
    shutil.copy2(source, target)
    # Make the file writable so that we can overwrite or delete it later,
    # keep it readable.
    os.chmod(target, stat.S_IWRITE | stat.S_IREAD)