text: #!/usr/bin/env python
  # Copyright 2017 The Chromium Authors. All rights reserved.
  # Use of this source code is governed by a BSD-style license that can be
  # found in the LICENSE file.
  
  """usage: rc.py [options] input.res
  A resource compiler for .rc files.
  
  options:
  -h, --help     Print this message.
  -I<dir>        Add include path.
  -D<sym>        Define a macro for the preprocessor.
  /fo<out>       Set path of output .res file.
  /nologo        Ignored (rc.py doesn't print a logo by default).
  /showIncludes  Print referenced header and resource files."""
  
  from __future__ import print_function
  from collections import namedtuple
  import codecs
  import os
  import re
  import subprocess
  import sys
  import tempfile
  
  
  THIS_DIR = os.path.abspath(os.path.dirname(__file__))
  SRC_DIR = \
      os.path.dirname(os.path.dirname(os.path.dirname(os.path.dirname(THIS_DIR))))
  
  
  def ParseFlags():
    """Parses flags off sys.argv and returns the parsed flags."""
    # Can't use optparse / argparse because of /fo flag :-/
    includes = []
    defines = []
    output = None
    input = None
    show_includes = False
    # Parse.
    for flag in sys.argv[1:]:
      if flag == '-h' or flag == '--help':
        print(__doc__)
        sys.exit(0)
      if flag.startswith('-I'):
        includes.append(flag)
      elif flag.startswith('-D'):
        defines.append(flag)
      elif flag.startswith('/fo'):
        if output:
          print('rc.py: error: multiple /fo flags', '/fo' + output, flag,
                file=sys.stderr)
          sys.exit(1)
        output = flag[3:]
      elif flag == '/nologo':
        pass
      elif flag == '/showIncludes':
        show_includes = True
      elif (flag.startswith('-') or
            (flag.startswith('/') and not os.path.exists(flag))):
        print('rc.py: error: unknown flag', flag, file=sys.stderr)
        print(__doc__, file=sys.stderr)
        sys.exit(1)
      else:
        if input:
          print('rc.py: error: multiple inputs:', input, flag, file=sys.stderr)
          sys.exit(1)
        input = flag
    # Validate and set default values.
    if not input:
      print('rc.py: error: no input file', file=sys.stderr)
      sys.exit(1)
    if not output:
      output = os.path.splitext(input)[0] + '.res'
    Flags = namedtuple('Flags', ['includes', 'defines', 'output', 'input',
                                 'show_includes'])
    return Flags(includes=includes, defines=defines, output=output, input=input,
                 show_includes=show_includes)
  
  
  def ReadInput(input):
    """"Reads input and returns it. For UTF-16LEBOM input, converts to UTF-8."""
    # Microsoft's rc.exe only supports unicode in the form of UTF-16LE with a BOM.
    # Our rc binary sniffs for UTF-16LE.  If that's not found, if /utf-8 is
    # passed, the input is treated as UTF-8.  If /utf-8 is not passed and the
    # input is not UTF-16LE, then our rc errors out on characters outside of
    # 7-bit ASCII.  Since the driver always converts UTF-16LE to UTF-8 here (for
    # the preprocessor, which doesn't support UTF-16LE), our rc will either see
    # UTF-8 with the /utf-8 flag (for UTF-16LE input), or ASCII input.
    # This is compatible with Microsoft rc.exe.  If we wanted, we could expose
    # a /utf-8 flag for the driver for UTF-8 .rc inputs too.
    # TODO(thakis): Microsoft's rc.exe supports BOM-less UTF-16LE. We currently
    # don't, but for chrome it currently doesn't matter.
    is_utf8 = False
    try:
      with open(input, 'rb') as rc_file:
        rc_file_data = rc_file.read()
        if rc_file_data.startswith(codecs.BOM_UTF16_LE):
          rc_file_data = rc_file_data[2:].decode('utf-16le').encode('utf-8')
          is_utf8 = True
    except IOError:
      print('rc.py: failed to open', input, file=sys.stderr)
      sys.exit(1)
    except UnicodeDecodeError:
      print('rc.py: failed to decode UTF-16 despite BOM', input, file=sys.stderr)
      sys.exit(1)
    return rc_file_data, is_utf8
  
  
  def Preprocess(rc_file_data, flags):
    """Runs the input file through the preprocessor."""
    clang = os.path.join(SRC_DIR, 'third_party', 'llvm-build',
                         'Release+Asserts', 'bin', 'clang-cl')
    # Let preprocessor write to a temp file so that it doesn't interfere
    # with /showIncludes output on stdout.
    if sys.platform == 'win32':
      clang += '.exe'
    temp_handle, temp_file = tempfile.mkstemp(suffix='.i')
    # Closing temp_handle immediately defeats the purpose of mkstemp(), but I
    # can't figure out how to let write to the temp file on Windows otherwise.
    os.close(temp_handle)
    clang_cmd = [clang, '/P', '/DRC_INVOKED', '/TC', '-', '/Fi' + temp_file]
    if os.path.dirname(flags.input):
      # This must precede flags.includes.
      clang_cmd.append('-I' + os.path.dirname(flags.input))
    if flags.show_includes:
      clang_cmd.append('/showIncludes')
    clang_cmd += flags.includes + flags.defines
    p = subprocess.Popen(clang_cmd, stdin=subprocess.PIPE)
    p.communicate(input=rc_file_data)
    if p.returncode != 0:
      sys.exit(p.returncode)
    preprocessed_output = open(temp_file, 'rb').read()
    os.remove(temp_file)
  
    # rc.exe has a wacko preprocessor:
    # https://msdn.microsoft.com/en-us/library/windows/desktop/aa381033(v=vs.85).aspx
    # """RC treats files with the .c and .h extensions in a special manner. It
    # assumes that a file with one of these extensions does not contain
    # resources. If a file has the .c or .h file name extension, RC ignores all
    # lines in the file except the preprocessor directives."""
    # Thankfully, the Microsoft headers are mostly good about putting everything
    # in the system headers behind `if !defined(RC_INVOKED)`, so regular
    # preprocessing with RC_INVOKED defined works.
    return preprocessed_output
  
  
  def RunRc(preprocessed_output, is_utf8, flags):
    if sys.platform.startswith('linux'):
      rc = os.path.join(THIS_DIR, 'linux64', 'rc')
    elif sys.platform == 'darwin':
      rc = os.path.join(THIS_DIR, 'mac', 'rc')
    elif sys.platform == 'win32':
      rc = os.path.join(THIS_DIR, 'win', 'rc.exe')
    else:
      print('rc.py: error: unsupported platform', sys.platform, file=sys.stderr)
      sys.exit(1)
    rc_cmd = [rc]
    # Make sure rc-relative resources can be found:
    if os.path.dirname(flags.input):
      rc_cmd.append('/cd' + os.path.dirname(flags.input))
    rc_cmd.append('/fo' + flags.output)
    if is_utf8:
      rc_cmd.append('/utf-8')
    # TODO(thakis): rc currently always prints full paths for /showIncludes,
    # but clang-cl /P doesn't.  Which one is right?
    if flags.show_includes:
      rc_cmd.append('/showIncludes')
    # Microsoft rc.exe searches for referenced files relative to -I flags in
    # addition to the pwd, so -I flags need to be passed both to both
    # the preprocessor and rc.
    rc_cmd += flags.includes
    p = subprocess.Popen(rc_cmd, stdin=subprocess.PIPE)
    p.communicate(input=preprocessed_output)
    return p.returncode
  
  
  def main():
    # This driver has to do these things:
    # 1. Parse flags.
    # 2. Convert the input from UTF-16LE to UTF-8 if needed.
    # 3. Pass the input through a preprocessor (and clean up the preprocessor's
    #    output in minor ways).
    # 4. Call rc for the heavy lifting.
    flags = ParseFlags()
    rc_file_data, is_utf8 = ReadInput(flags.input)
    preprocessed_output = Preprocess(rc_file_data, flags)
    return RunRc(preprocessed_output, is_utf8, flags)
  
  
  if __name__ == '__main__':
    sys.exit(main())
  