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 os.path
  45 import platform
  46 import subprocess
  47 import sys
  48 import 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.
  52 binary = "clang-format"
  53 if 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.
  60 style = None
  61 fallback_style = None
  62 if vim.eval('exists("g:clang_format_fallback_style")') == "1":
  63     fallback_style = vim.eval("g:clang_format_fallback_style")
  64
  65
  66 def get_buffer(encoding):
  67     if platform.python_version_tuple()[0] == "3":
  68         return vim.current.buffer
  69     return [line.decode(encoding) for line in vim.current.buffer]
  70
  71
  72 def main():
  73     # Get the current text.
  74     encoding = vim.eval("&encoding")
  75     buf = get_buffer(encoding)
  76     # Join the buffer into a single string with a terminating newline
  77     text = ("\n".join(buf) + "\n").encode(encoding)
  78
  79     # Determine range to format.
  80     if vim.eval('exists("l:lines")') == "1":
  81         lines = ["--lines", vim.eval("l:lines")]
  82     elif vim.eval('exists("l:formatdiff")') == "1" and os.path.exists(
  83         vim.current.buffer.name
  84     ):
  85         with open(vim.current.buffer.name, "r") as f:
  86             ondisk = f.read().splitlines()
  87         sequence = difflib.SequenceMatcher(None, ondisk, vim.current.buffer)
  88         lines = []
  89         for op in reversed(sequence.get_opcodes()):
  90             if op[0] not in ["equal", "delete"]:
  91                 lines += ["--lines", "%s:%s" % (op[3] + 1, op[4])]
  92         if lines == []:
  93             return
  94     else:
  95         lines = [
  96             "--lines",
  97             "%s:%s" % (vim.current.range.start + 1, vim.current.range.end + 1),
  98         ]
  99
 100     # Convert cursor (line, col) to bytes.
 101     # Don't use line2byte: https://github.com/vim/vim/issues/5930
 102     _, cursor_line, cursor_col, _ = vim.eval('getpos(".")')  # 1-based
 103     cursor_byte = 0
 104     for line in text.split(b"\n")[: int(cursor_line) - 1]:
 105         cursor_byte += len(line) + 1
 106     cursor_byte += int(cursor_col) - 1
 107     if cursor_byte < 0:
 108         print("Couldn't determine cursor position. Is your file empty?")
 109         return
 110
 111     # Avoid flashing an ugly, ugly cmd prompt on Windows when invoking clang-format.
 112     startupinfo = None
 113     if sys.platform.startswith("win32"):
 114         startupinfo = subprocess.STARTUPINFO()
 115         startupinfo.dwFlags |= subprocess.STARTF_USESHOWWINDOW
 116         startupinfo.wShowWindow = subprocess.SW_HIDE
 117
 118     # Call formatter.
 119     command = [binary, "--cursor", str(cursor_byte)]
 120     if lines != ["--lines", "all"]:
 121         command += lines
 122     if style:
 123         command.extend(["--style", style])
 124     if fallback_style:
 125         command.extend(["--fallback-style", fallback_style])
 126     if vim.current.buffer.name:
 127         command.extend(["--assume-filename", vim.current.buffer.name])
 128     p = subprocess.Popen(
 129         command,
 130         stdout=subprocess.PIPE,
 131         stderr=subprocess.PIPE,
 132         stdin=subprocess.PIPE,
 133         startupinfo=startupinfo,
 134     )
 135     stdout, stderr = p.communicate(input=text)
 136
 137     # If successful, replace buffer contents.
 138     if stderr:
 139         print(stderr)
 140
 141     if not stdout:
 142         print(
 143             "No output from clang-format (crashed?).\n"
 144             "Please report to bugs.llvm.org."
 145         )
 146     else:
 147         header, content = stdout.split(b"\n", 1)
 148         header = json.loads(header.decode("utf-8"))
 149         # Strip off the trailing newline (added above).
 150         # This maintains trailing empty lines present in the buffer if
 151         # the -lines specification requests them to remain unchanged.
 152         lines = content.decode(encoding).split("\n")[:-1]
 153         sequence = difflib.SequenceMatcher(None, buf, lines)
 154         for op in reversed(sequence.get_opcodes()):
 155             if op[0] != "equal":
 156                 vim.current.buffer[op[1] : op[2]] = lines[op[3] : op[4]]
 157         if header.get("IncompleteFormat"):
 158             print("clang-format: incomplete (syntax errors)")
 159         # Convert cursor bytes to (line, col)
 160         # Don't use goto: https://github.com/vim/vim/issues/5930
 161         cursor_byte = int(header["Cursor"])
 162         prefix = content[0:cursor_byte]
 163         cursor_line = 1 + prefix.count(b"\n")
 164         cursor_column = 1 + len(prefix.rsplit(b"\n", 1)[-1])
 165         vim.command("call cursor(%d, %d)" % (cursor_line, cursor_column))
 166
 167
 168 main()