[clang-format-vim] Support vim linked against py3

clang-format.py previously only worked in vim compiled against python2.

This patch adds the necessary syntax changes to make this work with vim
linked against python3, which is now shipped by default for at least Ubuntu16 and Arch.

Differential Revision: https://reviews.llvm.org/D23319

Subscribers: cfe-commits
llvm-svn: 280240

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

@@ -25,6 +25,7 @@
 #
 # 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
@@ -49,6 +50,7 @@
 
 def main():
   # Get the current text.
+  encoding = vim.eval("&encoding")
   buf = vim.current.buffer
   text = '\n'.join(buf)
 
@@ -61,7 +63,7 @@ def main():
   # 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.
@@ -82,25 +84,27 @@ def main():
   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()