Python 3.5 compatibility for clang-format.py

[jacquelinekay]

Summary

Some platforms (e.g. Ubuntu 16.04) ship a version of vim which supports Python 3 but not Python 2.7 (the output of vim --version contains -python and +python3 under the list of supported features). This patch updates clang-format.py to be Python 3.5 compatible. vim integration should still work with Python 2.7.

In Python 3, universal_newlines=True is needed for subprocess.communicate to accept a string. Without it, the script errors during runtime with: "TypeError: memoryview: a bytes-like object is required, not 'str'"

[SylvainCorlay]

Turns out that there are also Python 3 issues in

• clang-format-diff.py (legacy-python style print statements)
• ScanView.py (legacy-python style print statements and old style except statements).

[djasper]

Looks good.

[v.g.vassilev]

The print related changes were added in in r280240 (https://reviews.llvm.org/D23319). Could you rebase the patch?

[jacquelinekay]

I tested clang-format in vim with the recent state of trunk and it seems to work without my patch. The bug I ran into initially was fixed in D23319 with added encoding. So I think this can be closed without merging.

[v.g.vassilev]

Thanks I am closing it!

tools/clang-format/clang-format.py

 # 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

   # 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.

     command.extend(['-assume-filename', vim.current.buffer.name])
   p = subprocess.Popen(command,
                        stdout=subprocess.PIPE, stderr=subprocess.PIPE,
-                       stdin=subprocess.PIPE, startupinfo=startupinfo)
+                       stdin=subprocess.PIPE, startupinfo=startupinfo, universal_newlines=True)
   stdout, stderr = p.communicate(input=text)
 
   # If successful, replace buffer contents.
   if stderr:
-    print stderr
+    print(stderr)
 
   if not stdout:
-    print ('No output from clang-format (crashed?).\n' +
+    print('No output from clang-format (crashed?).\n' +
         'Please report to bugs.llvm.org.')
   else:
     lines = stdout.split('\n')

       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()