tools/gn/bin/gn-format.py

   1 # Copyright 2014 The Chromium Authors. All rights reserved.
   2 # Use of this source code is governed by a BSD-style license that can be
   3 # found in the LICENSE file.
   4 #
   5 # Based on clang-format.py.
   6 #
   7 # This file is a minimal gn format vim-integration. To install:
   8 # - Change 'binary' if gn is not on the path (see below).
   9 # - Add to your .vimrc:
  10 #
  11 #   map <F1> :pyf <path-to-this-file>/gn-format.py<CR>
  12 #
  13 # gn format currently formats only a complete file so visual ranges, etc. won't
  14 # be used. It operates on the current, potentially unsaved buffer and does not
  15 # create or save any files. To revert a formatting, just undo.
  16
  17 import difflib
  18 import subprocess
  19 import sys
  20 import vim
  21
  22 # Change this to the full path if gn is not on the path.
  23 binary = 'gn'
  24
  25 def main():
  26   # Get the current text.
  27   buf = vim.current.buffer
  28   text = '\n'.join(buf)
  29
  30   # Avoid flashing an ugly cmd prompt on Windows when invoking gn.
  31   startupinfo = None
  32   if sys.platform.startswith('win32'):
  33     startupinfo = subprocess.STARTUPINFO()
  34     startupinfo.dwFlags |= subprocess.STARTF_USESHOWWINDOW
  35     startupinfo.wShowWindow = subprocess.SW_HIDE
  36
  37   # Call formatter.
  38   p = subprocess.Popen([binary, 'format', '--stdin'],
  39                        stdout=subprocess.PIPE, stderr=subprocess.PIPE,
  40                        stdin=subprocess.PIPE, startupinfo=startupinfo,
  41                        universal_newlines=True)
  42   stdout, stderr = p.communicate(input=text)
  43   if p.returncode != 0:
  44     print 'Formatting failed, please report to gn-dev@chromium.org.'
  45     print stdout, stderr
  46   else:
  47     # Otherwise, replace current buffer.
  48     lines = stdout.split('\n')
  49     # Last line should have trailing \n, but we don't want to insert a blank
  50     # line at the end of the buffer, so remove that.
  51     if lines[-1] == '':
  52       lines = lines[:-1]
  53     sequence = difflib.SequenceMatcher(None, vim.current.buffer, lines)
  54     for op in reversed(sequence.get_opcodes()):
  55       if op[0] is not 'equal':
  56         vim.current.buffer[op[1]:op[2]] = lines[op[3]:op[4]]
  57
  58 main()