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      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> <c-o>:pyf <path-to-this-file>/clang-format.py<cr>
      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 # You can also pass in the variable "l:lines" to choose the range for
     18 # formatting. This variable can either contain "<start line>:<end line>" or
     19 # "all" to format the full file. So, to format the full file, write a function
     20 # like:
     21 # :function FormatFile()
     22 # :  let l:lines="all"
     23 # :  pyf <path-to-this-file>/clang-format.py
     24 # :endfunction
     25 #
     26 # It operates on the current, potentially unsaved buffer and does not create
     27 # or save any files. To revert a formatting, just undo.
     28 from __future__ import print_function
     29 
     30 import difflib
     31 import json
     32 import platform
     33 import subprocess
     34 import sys
     35 import vim
     36 
     37 # set g:clang_format_path to the path to clang-format if it is not on the path
     38 # Change this to the full path if clang-format is not on the path.
     39 binary = 'clang-format'
     40 if vim.eval('exists("g:clang_format_path")') == "1":
     41   binary = vim.eval('g:clang_format_path')
     42 
     43 # Change this to format according to other formatting styles. See the output of
     44 # 'clang-format --help' for a list of supported styles. The default looks for
     45 # a '.clang-format' or '_clang-format' file to indicate the style that should be
     46 # used.
     47 style = 'file'
     48 fallback_style = None
     49 if vim.eval('exists("g:clang_format_fallback_style")') == "1":
     50   fallback_style = vim.eval('g:clang_format_fallback_style')
     51 
     52 def get_buffer(encoding):
     53   if platform.python_version_tuple()[0] == '3':
     54     return vim.current.buffer
     55   return [ line.decode(encoding) for line in vim.current.buffer ]
     56 
     57 def main():
     58   # Get the current text.
     59   encoding = vim.eval("&encoding")
     60   buf = get_buffer(encoding)
     61   text = '\n'.join(buf)
     62 
     63   # Determine range to format.
     64   if vim.eval('exists("l:lines")') == '1':
     65     lines = vim.eval('l:lines')
     66   else:
     67     lines = '%s:%s' % (vim.current.range.start + 1, vim.current.range.end + 1)
     68 
     69   # Determine the cursor position.
     70   cursor = int(vim.eval('line2byte(line("."))+col(".")')) - 2
     71   if cursor < 0:
     72     print('Couldn\'t determine cursor position. Is your file empty?')
     73     return
     74 
     75   # Avoid flashing an ugly, ugly cmd prompt on Windows when invoking clang-format.
     76   startupinfo = None
     77   if sys.platform.startswith('win32'):
     78     startupinfo = subprocess.STARTUPINFO()
     79     startupinfo.dwFlags |= subprocess.STARTF_USESHOWWINDOW
     80     startupinfo.wShowWindow = subprocess.SW_HIDE
     81 
     82   # Call formatter.
     83   command = [binary, '-style', style, '-cursor', str(cursor)]
     84   if lines != 'all':
     85     command.extend(['-lines', lines])
     86   if fallback_style:
     87     command.extend(['-fallback-style', fallback_style])
     88   if vim.current.buffer.name:
     89     command.extend(['-assume-filename', vim.current.buffer.name])
     90   p = subprocess.Popen(command,
     91                        stdout=subprocess.PIPE, stderr=subprocess.PIPE,
     92                        stdin=subprocess.PIPE, startupinfo=startupinfo)
     93   stdout, stderr = p.communicate(input=text.encode(encoding))
     94 
     95   # If successful, replace buffer contents.
     96   if stderr:
     97     print(stderr)
     98 
     99   if not stdout:
    100     print(
    101         'No output from clang-format (crashed?).\n'
    102         'Please report to bugs.llvm.org.'
    103     )
    104   else:
    105     lines = stdout.decode(encoding).split('\n')
    106     output = json.loads(lines[0])
    107     lines = lines[1:]
    108     sequence = difflib.SequenceMatcher(None, buf, lines)
    109     for op in reversed(sequence.get_opcodes()):
    110       if op[0] is not 'equal':
    111         vim.current.buffer[op[1]:op[2]] = lines[op[3]:op[4]]
    112     if output.get('IncompleteFormat'):
    113       print('clang-format: incomplete (syntax errors)')
    114     vim.command('goto %d' % (output['Cursor'] + 1))
    115 
    116 main()
    117