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
30# clang-format -help)
31style = 'LLVM'
32
33# Get the current text.
34buf = vim.current.buffer
35text = '\n'.join(buf)
36
37# Determine range to format.
38cursor = int(vim.eval('line2byte(line("."))+col(".")')) - 2
39lines = '%s:%s' % (vim.current.range.start + 1, vim.current.range.end + 1)
40
41# Avoid flashing an ugly, ugly cmd prompt on Windows when invoking clang-format.
42startupinfo = None
43if sys.platform.startswith('win32'):
44  startupinfo = subprocess.STARTUPINFO()
45  startupinfo.dwFlags |= subprocess.STARTF_USESHOWWINDOW
46  startupinfo.wShowWindow = subprocess.SW_HIDE
47
48# Call formatter.
49p = subprocess.Popen([binary, '-lines', lines, '-style', style,
50                      '-cursor', str(cursor)],
51                     stdout=subprocess.PIPE, stderr=subprocess.PIPE,
52                     stdin=subprocess.PIPE, startupinfo=startupinfo)
53stdout, stderr = p.communicate(input=text)
54
55# If successful, replace buffer contents.
56if stderr:
57  message = stderr.splitlines()[0]
58  parts = message.split(' ', 2)
59  if len(parts) > 2:
60    message = parts[2]
61  print 'Formatting failed: %s (total %d warnings, %d errors)' % (
62      message, stderr.count('warning:'), stderr.count('error:'))
63
64if not stdout:
65  print ('No output from clang-format (crashed?).\n' +
66      'Please report to bugs.llvm.org.')
67else:
68  lines = stdout.split('\n')
69  output = json.loads(lines[0])
70  lines = lines[1:]
71  sequence = difflib.SequenceMatcher(None, vim.current.buffer, lines)
72  for op in reversed(sequence.get_opcodes()):
73    if op[0] is not 'equal':
74      vim.current.buffer[op[1]:op[2]] = lines[op[3]:op[4]]
75  vim.command('goto %d' % (output['Cursor'] + 1))
76