clang/tools/clang-format/clang-format.py

   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.
  40 from __future__ import absolute_import, division, print_function
  41
  42 import difflib
  43 import json
  44 import platform
  45 import subprocess
  46 import sys
  47 import 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.
  51 binary = 'clang-format'
  52 if 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.
  59 style = None
  60 fallback_style = None
  61 if vim.eval('exists("g:clang_format_fallback_style")') == "1":
  62   fallback_style = vim.eval('g:clang_format_fallback_style')
  63
  64 def 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
  69 def 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').encode(encoding)
  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   # Convert cursor (line, col) to bytes.
  94   # Don't use line2byte: https://github.com/vim/vim/issues/5930
  95   _, cursor_line, cursor_col, _ = vim.eval('getpos(".")') # 1-based
  96   cursor_byte = 0
  97   for line in text.split(b'\n')[:int(cursor_line) - 1]:
  98     cursor_byte += len(line) + 1
  99   cursor_byte += int(cursor_col) - 1
 100   if cursor_byte < 0:
 101     print('Couldn\'t determine cursor position. Is your file empty?')
 102     return
 103
 104   # Avoid flashing an ugly, ugly cmd prompt on Windows when invoking clang-format.
 105   startupinfo = None
 106   if sys.platform.startswith('win32'):
 107     startupinfo = subprocess.STARTUPINFO()
 108     startupinfo.dwFlags |= subprocess.STARTF_USESHOWWINDOW
 109     startupinfo.wShowWindow = subprocess.SW_HIDE
 110
 111   # Call formatter.
 112   command = [binary, '-cursor', str(cursor_byte)]
 113   if lines != ['-lines', 'all']:
 114     command += lines
 115   if style:
 116     command.extend(['-style', style])
 117   if fallback_style:
 118     command.extend(['-fallback-style', fallback_style])
 119   if vim.current.buffer.name:
 120     command.extend(['-assume-filename', vim.current.buffer.name])
 121   p = subprocess.Popen(command,
 122                        stdout=subprocess.PIPE, stderr=subprocess.PIPE,
 123                        stdin=subprocess.PIPE, startupinfo=startupinfo)
 124   stdout, stderr = p.communicate(input=text)
 125
 126   # If successful, replace buffer contents.
 127   if stderr:
 128     print(stderr)
 129
 130   if not stdout:
 131     print(
 132         'No output from clang-format (crashed?).\n'
 133         'Please report to bugs.llvm.org.'
 134     )
 135   else:
 136     header, content = stdout.split(b'\n', 1)
 137     header = json.loads(header)
 138     # Strip off the trailing newline (added above).
 139     # This maintains trailing empty lines present in the buffer if
 140     # the -lines specification requests them to remain unchanged.
 141     lines = content.decode(encoding).split('\n')[:-1]
 142     sequence = difflib.SequenceMatcher(None, buf, lines)
 143     for op in reversed(sequence.get_opcodes()):
 144       if op[0] != 'equal':
 145         vim.current.buffer[op[1]:op[2]] = lines[op[3]:op[4]]
 146     if header.get('IncompleteFormat'):
 147       print('clang-format: incomplete (syntax errors)')
 148     # Convert cursor bytes to (line, col)
 149     # Don't use goto: https://github.com/vim/vim/issues/5930
 150     cursor_byte = int(header['Cursor'])
 151     prefix = content[0:cursor_byte]
 152     cursor_line = 1 + prefix.count(b'\n')
 153     cursor_column = 1 + len(prefix.rsplit(b'\n', 1)[-1])
 154     vim.command('call cursor(%d, %d)' % (cursor_line, cursor_column))
 155
 156 main()