[vim clang-format.py] python3 support

[ldrumm]

Summary

clang-format.py currently only works in vim compiled against python2. This patch adds the necessary syntax changes to make this work with python3. Ubuntu16 and Arch (at least) ship vim compiled against python3 by default, so this affected me during my recent upgrade.

I've tested this with python3 on ASCII scripts, but have not taken the time to verify this with non-ascii characters in the source. Following the advice here the text piped to clang-format is encoded in the same encoding vim is using. If someone more familiar with clang-format proper is able to comment on the correctness of this behaviour, I'd appreciate it.

[ldrumm]

Make print output the same 2-3

[djasper]

Looks good.

[ldrumm]

@djasper, I don't seem to have commit access to cfe so awould you be willing to commit this on my behalf?

Many thanks

Luke

[scottmg]

cfe/trunk/tools/clang-format/clang-format.py

87

Hi, I'm using py2 and I get the problem I described here https://bugs.chromium.org/p/chromium/issues/detail?id=651204 with this change.

Wouldn't we want to be first decode()ing from Vim's buffer format in the specified encoding to get to a Python string, and then encode()ing to whatever format we want to interact with clang-format in?

[pseyfert]

cfe/trunk/tools/clang-format/clang-format.py

6

For python3 usage, should these lines updated to :py3f instead of :pyf?

[pseyfert]

cfe/trunk/tools/clang-format/clang-format.py

6

searching around, maybe even better to put it in if statements:

(following https://vi.stackexchange.com/a/10915)

if has('python')
  map <C-K> :pyf <path-to-this-file>/clang-format.py<cr>
elseif has('python3')
  map <C-K> :py3f <path-to-this-file>/clang-format.py<cr>
endif

created D38446

cfe/trunk/tools/clang-format/clang-format.py

 # This file is a minimal clang-format vim-integration. To install:
 # - Change 'binary' if clang-format is not on the path (see below).
 # - Add to your .vimrc:
 #
 #   map <C-I> :pyf <path-to-this-file>/clang-format.py<cr>
 #   imap <C-I> <c-o>:pyf <path-to-this-file>/clang-format.py<cr>
 #
 # The first line enables clang-format for NORMAL and VISUAL mode, the second
 # line adds support for INSERT mode. Change "C-I" to another binding if you
 # need clang-format on a different key (C-I stands for Ctrl+i).
 #
 # With this integration you can press the bound key and clang-format will
 # format the current line in NORMAL and INSERT mode or the selected region in
 # VISUAL mode. The line or region is extended to the next bigger syntactic
 # entity.
 #
 # You can also pass in the variable "l:lines" to choose the range for
 # formatting. This variable can either contain "<start line>:<end line>" or
 # "all" to format the full file. So, to format the full file, write a function
 # like:
 # :function FormatFile()
 # :  let l:lines="all"
 # :  pyf <path-to-this-file>/clang-format.py
 # :endfunction
 #
 # It operates on the current, potentially unsaved buffer and does not create
 # or save any files. To revert a formatting, just undo.
+from __future__ import print_function
 
 import difflib
 import json
 import subprocess
 import sys
 import vim
 
 # set g:clang_format_path to the path to clang-format if it is not on the path
 # Change this to the full path if clang-format is not on the path.
 binary = 'clang-format'
 if vim.eval('exists("g:clang_format_path")') == "1":
   binary = vim.eval('g:clang_format_path')
 
 # Change this to format according to other formatting styles. See the output of
 # 'clang-format --help' for a list of supported styles. The default looks for
 # a '.clang-format' or '_clang-format' file to indicate the style that should be
 # used.
 style = 'file'
 fallback_style = None
 if vim.eval('exists("g:clang_format_fallback_style")') == "1":
   fallback_style = vim.eval('g:clang_format_fallback_style')
 
 def main():
   # Get the current text.
+  encoding = vim.eval("&encoding")
   buf = vim.current.buffer
   text = '\n'.join(buf)
 
   # Determine range to format.
   if vim.eval('exists("l:lines")') == '1':
     lines = vim.eval('l:lines')
   else:
     lines = '%s:%s' % (vim.current.range.start + 1, vim.current.range.end + 1)
 
   # Determine the cursor position.
   cursor = int(vim.eval('line2byte(line("."))+col(".")')) - 2
   if cursor < 0:
-    print 'Couldn\'t determine cursor position. Is your file empty?'
+    print('Couldn\'t determine cursor position. Is your file empty?')
     return
 
   # Avoid flashing an ugly, ugly cmd prompt on Windows when invoking clang-format.
   startupinfo = None
   if sys.platform.startswith('win32'):
     startupinfo = subprocess.STARTUPINFO()
     startupinfo.dwFlags |= subprocess.STARTF_USESHOWWINDOW
     startupinfo.wShowWindow = subprocess.SW_HIDE
 
   # Call formatter.
   command = [binary, '-style', style, '-cursor', str(cursor)]
   if lines != 'all':
     command.extend(['-lines', lines])
   if fallback_style:
     command.extend(['-fallback-style', fallback_style])
   if vim.current.buffer.name:
     command.extend(['-assume-filename', vim.current.buffer.name])
   p = subprocess.Popen(command,
                        stdout=subprocess.PIPE, stderr=subprocess.PIPE,
                        stdin=subprocess.PIPE, startupinfo=startupinfo)
-  stdout, stderr = p.communicate(input=text)
+  stdout, stderr = p.communicate(input=text.encode(encoding))
 
   # If successful, replace buffer contents.
   if stderr:
-    print stderr
+    print(stderr)
 
   if not stdout:
-    print ('No output from clang-format (crashed?).\n' +
-        'Please report to bugs.llvm.org.')
+    print(
+        'No output from clang-format (crashed?).\n'
+        'Please report to bugs.llvm.org.'
+    )
   else:
-    lines = stdout.split('\n')
+    lines = stdout.decode(encoding).split('\n')
     output = json.loads(lines[0])
     lines = lines[1:]
     sequence = difflib.SequenceMatcher(None, vim.current.buffer, lines)
     for op in reversed(sequence.get_opcodes()):
       if op[0] is not 'equal':
         vim.current.buffer[op[1]:op[2]] = lines[op[3]:op[4]]
     if output.get('IncompleteFormat'):
-      print 'clang-format: incomplete (syntax errors)'
+      print('clang-format: incomplete (syntax errors)')
     vim.command('goto %d' % (output['Cursor'] + 1))
 
 main()