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#   if has('python')
6#     map <C-I> :pyf <path-to-this-file>/clang-format.py<cr>
7#     imap <C-I> <c-o>:pyf <path-to-this-file>/clang-format.py<cr>
8#   elseif has('python3')
9#     map <C-I> :py3f <path-to-this-file>/clang-format.py<cr>
10#     imap <C-I> <c-o>:py3f <path-to-this-file>/clang-format.py<cr>
11#   endif
12#
13# The if-elseif-endif conditional should pick either the python3 or python2
14# integration depending on your vim setup.
15#
16# The first mapping enables clang-format for NORMAL and VISUAL mode, the second
17# mapping adds support for INSERT mode. Change "C-I" to another binding if you
18# need clang-format on a different key (C-I stands for Ctrl+i).
19#
20# With this integration you can press the bound key and clang-format will
21# format the current line in NORMAL and INSERT mode or the selected region in
22# VISUAL mode. The line or region is extended to the next bigger syntactic
23# entity.
24#
25# You can also pass in the variable "l:lines" to choose the range for
26# formatting. This variable can either contain "<start line>:<end line>" or
27# "all" to format the full file. So, to format the full file, write a function
28# like:
29# :function FormatFile()
30# :  let l:lines="all"
31# :  if has('python')
32# :    pyf <path-to-this-file>/clang-format.py
33# :  elseif has('python3')
34# :    py3f <path-to-this-file>/clang-format.py
35# :  endif
36# :endfunction
37#
38# It operates on the current, potentially unsaved buffer and does not create
39# or save any files. To revert a formatting, just undo.
40from __future__ import absolute_import, division, print_function
41
42import difflib
43import json
44import platform
45import subprocess
46import sys
47import vim
48
49# set g:clang_format_path to the path to clang-format if it is not on the path
50# Change this to the full path if clang-format is not on the path.
51binary = 'clang-format'
52if vim.eval('exists("g:clang_format_path")') == "1":
53  binary = vim.eval('g:clang_format_path')
54
55# Change this to format according to other formatting styles. See the output of
56# 'clang-format --help' for a list of supported styles. The default looks for
57# a '.clang-format' or '_clang-format' file to indicate the style that should be
58# used.
59style = None
60fallback_style = None
61if vim.eval('exists("g:clang_format_fallback_style")') == "1":
62  fallback_style = vim.eval('g:clang_format_fallback_style')
63
64def get_buffer(encoding):
65  if platform.python_version_tuple()[0] == '3':
66    return vim.current.buffer
67  return [ line.decode(encoding) for line in vim.current.buffer ]
68
69def main():
70  # Get the current text.
71  encoding = vim.eval("&encoding")
72  buf = get_buffer(encoding)
73  # Join the buffer into a single string with a terminating newline
74  text = '\n'.join(buf) + '\n'
75
76  # Determine range to format.
77  if vim.eval('exists("l:lines")') == '1':
78    lines = ['-lines', vim.eval('l:lines')]
79  elif vim.eval('exists("l:formatdiff")') == '1':
80    with open(vim.current.buffer.name, 'r') as f:
81      ondisk = f.read().splitlines();
82    sequence = difflib.SequenceMatcher(None, ondisk, vim.current.buffer)
83    lines = []
84    for op in reversed(sequence.get_opcodes()):
85      if op[0] not in ['equal', 'delete']:
86        lines += ['-lines', '%s:%s' % (op[3] + 1, op[4])]
87    if lines == []:
88      return
89  else:
90    lines = ['-lines', '%s:%s' % (vim.current.range.start + 1,
91                                  vim.current.range.end + 1)]
92
93  # Determine the cursor position.
94  cursor = int(vim.eval('line2byte(line("."))+col(".")')) - 2
95  if cursor < 0:
96    print('Couldn\'t determine cursor position. Is your file empty?')
97    return
98
99  # Avoid flashing an ugly, ugly cmd prompt on Windows when invoking clang-format.
100  startupinfo = None
101  if sys.platform.startswith('win32'):
102    startupinfo = subprocess.STARTUPINFO()
103    startupinfo.dwFlags |= subprocess.STARTF_USESHOWWINDOW
104    startupinfo.wShowWindow = subprocess.SW_HIDE
105
106  # Call formatter.
107  command = [binary, '-cursor', str(cursor)]
108  if lines != ['-lines', 'all']:
109    command += lines
110  if style:
111    command.extend(['-style', style])
112  if fallback_style:
113    command.extend(['-fallback-style', fallback_style])
114  if vim.current.buffer.name:
115    command.extend(['-assume-filename', vim.current.buffer.name])
116  p = subprocess.Popen(command,
117                       stdout=subprocess.PIPE, stderr=subprocess.PIPE,
118                       stdin=subprocess.PIPE, startupinfo=startupinfo)
119  stdout, stderr = p.communicate(input=text.encode(encoding))
120
121  # If successful, replace buffer contents.
122  if stderr:
123    print(stderr)
124
125  if not stdout:
126    print(
127        'No output from clang-format (crashed?).\n'
128        'Please report to bugs.llvm.org.'
129    )
130  else:
131    lines = stdout.decode(encoding).split('\n')
132    output = json.loads(lines[0])
133    # Strip off the trailing newline (added above).
134    # This maintains trailing empty lines present in the buffer if
135    # the -lines specification requests them to remain unchanged.
136    lines = lines[1:-1]
137    sequence = difflib.SequenceMatcher(None, buf, lines)
138    for op in reversed(sequence.get_opcodes()):
139      if op[0] != 'equal':
140        vim.current.buffer[op[1]:op[2]] = lines[op[3]:op[4]]
141    if output.get('IncompleteFormat'):
142      print('clang-format: incomplete (syntax errors)')
143    vim.command('goto %d' % (output['Cursor'] + 1))
144
145main()
146