1# This file is a minimal clang-format vim-integration. To install:
2# - Change 'binary' if clang-format is not on the path (see below).
3# - Add to your .vimrc:
4#
5#   map <C-I> :pyf <path-to-this-file>/clang-format.py<CR>
6#   imap <C-I> <ESC>:pyf <path-to-this-file>/clang-format.py<CR>i
7#
8# The first line enables clang-format for NORMAL and VISUAL mode, the second
9# line adds support for INSERT mode. Change "C-I" to another binding if you
10# need clang-format on a different key (C-I stands for Ctrl+i).
11#
12# With this integration you can press the bound key and clang-format will
13# format the current line in NORMAL and INSERT mode or the selected region in
14# VISUAL mode. The line or region is extended to the next bigger syntactic
15# entity.
16#
17# It operates on the current, potentially unsaved buffer and does not create
18# or save any files. To revert a formatting, just undo.
19
20import difflib
21import json
22import subprocess
23import sys
24import vim
25
26# Change this to the full path if clang-format is not on the path.
27binary = 'clang-format'
28
29# Change this to format according to other formatting styles. See the output of
30# 'clang-format --help' for a list of supported styles. The default looks for
31# a '.clang-format' or '_clang-format' file to indicate the style that should be
32# used.
33style = 'file'
34
35# Get the current text.
36buf = vim.current.buffer
37text = '\n'.join(buf)
38
39# Determine range to format.
40cursor = int(vim.eval('line2byte(line("."))+col(".")')) - 2
41lines = '%s:%s' % (vim.current.range.start + 1, vim.current.range.end + 1)
42
43# Avoid flashing an ugly, ugly cmd prompt on Windows when invoking clang-format.
44startupinfo = None
45if sys.platform.startswith('win32'):
46  startupinfo = subprocess.STARTUPINFO()
47  startupinfo.dwFlags |= subprocess.STARTF_USESHOWWINDOW
48  startupinfo.wShowWindow = subprocess.SW_HIDE
49
50# Call formatter.
51command = [binary, '-lines', lines, '-style', style, '-cursor', str(cursor)]
52if vim.current.buffer.name:
53  command.extend(['-assume-filename', vim.current.buffer.name])
54p = subprocess.Popen(command,
55                     stdout=subprocess.PIPE, stderr=subprocess.PIPE,
56                     stdin=subprocess.PIPE, startupinfo=startupinfo)
57stdout, stderr = p.communicate(input=text)
58
59# If successful, replace buffer contents.
60if stderr:
61  message = stderr.splitlines()[0]
62  parts = message.split(' ', 2)
63  if len(parts) > 2:
64    message = parts[2]
65  print 'Formatting failed: %s (total %d warnings, %d errors)' % (
66      message, stderr.count('warning:'), stderr.count('error:'))
67
68if not stdout:
69  print ('No output from clang-format (crashed?).\n' +
70      'Please report to bugs.llvm.org.')
71else:
72  lines = stdout.split('\n')
73  output = json.loads(lines[0])
74  lines = lines[1:]
75  sequence = difflib.SequenceMatcher(None, vim.current.buffer, lines)
76  for op in reversed(sequence.get_opcodes()):
77    if op[0] is not 'equal':
78      vim.current.buffer[op[1]:op[2]] = lines[op[3]:op[4]]
79  vim.command('goto %d' % (output['Cursor'] + 1))
80