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 os.path
45import platform
46import subprocess
47import sys
48import vim
49
50# set g:clang_format_path to the path to clang-format if it is not on the path
51# Change this to the full path if clang-format is not on the path.
52binary = 'clang-format'
53if vim.eval('exists("g:clang_format_path")') == "1":
54  binary = vim.eval('g:clang_format_path')
55
56# Change this to format according to other formatting styles. See the output of
57# 'clang-format --help' for a list of supported styles. The default looks for
58# a '.clang-format' or '_clang-format' file to indicate the style that should be
59# used.
60style = None
61fallback_style = None
62if vim.eval('exists("g:clang_format_fallback_style")') == "1":
63  fallback_style = vim.eval('g:clang_format_fallback_style')
64
65def get_buffer(encoding):
66  if platform.python_version_tuple()[0] == '3':
67    return vim.current.buffer
68  return [ line.decode(encoding) for line in vim.current.buffer ]
69
70def main():
71  # Get the current text.
72  encoding = vim.eval("&encoding")
73  buf = get_buffer(encoding)
74  # Join the buffer into a single string with a terminating newline
75  text = ('\n'.join(buf) + '\n').encode(encoding)
76
77  # Determine range to format.
78  if vim.eval('exists("l:lines")') == '1':
79    lines = ['-lines', vim.eval('l:lines')]
80  elif vim.eval('exists("l:formatdiff")') == '1' and \
81       os.path.exists(vim.current.buffer.name):
82    with open(vim.current.buffer.name, 'r') as f:
83      ondisk = f.read().splitlines();
84    sequence = difflib.SequenceMatcher(None, ondisk, vim.current.buffer)
85    lines = []
86    for op in reversed(sequence.get_opcodes()):
87      if op[0] not in ['equal', 'delete']:
88        lines += ['-lines', '%s:%s' % (op[3] + 1, op[4])]
89    if lines == []:
90      return
91  else:
92    lines = ['-lines', '%s:%s' % (vim.current.range.start + 1,
93                                  vim.current.range.end + 1)]
94
95  # Convert cursor (line, col) to bytes.
96  # Don't use line2byte: https://github.com/vim/vim/issues/5930
97  _, cursor_line, cursor_col, _ = vim.eval('getpos(".")') # 1-based
98  cursor_byte = 0
99  for line in text.split(b'\n')[:int(cursor_line) - 1]:
100    cursor_byte += len(line) + 1
101  cursor_byte += int(cursor_col) - 1
102  if cursor_byte < 0:
103    print('Couldn\'t determine cursor position. Is your file empty?')
104    return
105
106  # Avoid flashing an ugly, ugly cmd prompt on Windows when invoking clang-format.
107  startupinfo = None
108  if sys.platform.startswith('win32'):
109    startupinfo = subprocess.STARTUPINFO()
110    startupinfo.dwFlags |= subprocess.STARTF_USESHOWWINDOW
111    startupinfo.wShowWindow = subprocess.SW_HIDE
112
113  # Call formatter.
114  command = [binary, '-cursor', str(cursor_byte)]
115  if lines != ['-lines', 'all']:
116    command += lines
117  if style:
118    command.extend(['-style', style])
119  if fallback_style:
120    command.extend(['-fallback-style', fallback_style])
121  if vim.current.buffer.name:
122    command.extend(['-assume-filename', vim.current.buffer.name])
123  p = subprocess.Popen(command,
124                       stdout=subprocess.PIPE, stderr=subprocess.PIPE,
125                       stdin=subprocess.PIPE, startupinfo=startupinfo)
126  stdout, stderr = p.communicate(input=text)
127
128  # If successful, replace buffer contents.
129  if stderr:
130    print(stderr)
131
132  if not stdout:
133    print(
134        'No output from clang-format (crashed?).\n'
135        'Please report to bugs.llvm.org.'
136    )
137  else:
138    header, content = stdout.split(b'\n', 1)
139    header = json.loads(header.decode('utf-8'))
140    # Strip off the trailing newline (added above).
141    # This maintains trailing empty lines present in the buffer if
142    # the -lines specification requests them to remain unchanged.
143    lines = content.decode(encoding).split('\n')[:-1]
144    sequence = difflib.SequenceMatcher(None, buf, lines)
145    for op in reversed(sequence.get_opcodes()):
146      if op[0] != 'equal':
147        vim.current.buffer[op[1]:op[2]] = lines[op[3]:op[4]]
148    if header.get('IncompleteFormat'):
149      print('clang-format: incomplete (syntax errors)')
150    # Convert cursor bytes to (line, col)
151    # Don't use goto: https://github.com/vim/vim/issues/5930
152    cursor_byte = int(header['Cursor'])
153    prefix = content[0:cursor_byte]
154    cursor_line = 1 + prefix.count(b'\n')
155    cursor_column = 1 + len(prefix.rsplit(b'\n', 1)[-1])
156    vim.command('call cursor(%d, %d)' % (cursor_line, cursor_column))
157
158main()
159