Begin making git-clang-format python3 compatible.

This patch fixes most of the python3 incompatabilities
within git-clang-format while keeping the script python2 compatible.
There is still one remaining incompatability that prevents using Python3
which is the `str` vs `byte` type change. I plan to put those fixes
up for review separately.

This patch contains fixes for the following incompatabilities:

1) Use the new style Python3 `print` function. This requires importing
   __future__.print_function.

2) Fix incompatability between the Python3 octal prefix and the
   octal prefix Git uses.

3) Replace use of dict.iteritems() with dict.viewitems() because iteritems()
   has been removed in Python3. viewitems() reviews python 2.7 but that is
   also what the script is documented as requiring.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@300891 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 25 insertions, 21 deletions

diff --git a/tools/clang-format/git-clang-format b/tools/clang-format/git-clang-format
index 74fd451a84..12146bf77c 100755
--- a/tools/clang-format/git-clang-format
+++ b/tools/clang-format/git-clang-format
@@ -23,6 +23,7 @@ git clang-format -h
 Requires Python 2.7                                                              
 """               
 
+from __future__ import print_function
 import argparse
 import collections
 import contextlib
@@ -138,15 +139,15 @@ def main():
   if opts.verbose >= 1:
     ignored_files.difference_update(changed_lines)
     if ignored_files:
-      print 'Ignoring changes in the following files (wrong extension):'
+      print('Ignoring changes in the following files (wrong extension):')
       for filename in ignored_files:
-        print '   ', filename
+        print('    %s' % filename)
     if changed_lines:
-      print 'Running clang-format on the following files:'
+      print('Running clang-format on the following files:')
       for filename in changed_lines:
-        print '   ', filename
+        print('    %s' % filename)
   if not changed_lines:
-    print 'no modified files to format'
+    print('no modified files to format')
     return
   # The computed diff outputs absolute paths, so we must cd before accessing
   # those files.
@@ -163,20 +164,20 @@ def main():
                                                  binary=opts.binary,
                                                  style=opts.style)
   if opts.verbose >= 1:
-    print 'old tree:', old_tree
-    print 'new tree:', new_tree
+    print('old tree: %s' % old_tree)
+    print('new tree: %s' % new_tree)
   if old_tree == new_tree:
     if opts.verbose >= 0:
-      print 'clang-format did not modify any files'
+      print('clang-format did not modify any files')
   elif opts.diff:
     print_diff(old_tree, new_tree)
   else:
     changed_files = apply_changes(old_tree, new_tree, force=opts.force,
                                   patch_mode=opts.patch)
     if (opts.verbose >= 0 and not opts.patch) or opts.verbose >= 1:
-      print 'changed files:'
+      print('changed files:')
       for filename in changed_files:
-        print '   ', filename
+        print('    %s' % filename)
 
 
 def load_git_config(non_string_options=None):
@@ -320,7 +321,7 @@ def filter_by_extension(dictionary, allowed_extensions):
   `allowed_extensions` must be a collection of lowercase file extensions,
   excluding the period."""
   allowed_extensions = frozenset(allowed_extensions)
-  for filename in dictionary.keys():
+  for filename in list(dictionary.keys()):
     base_ext = filename.rsplit('.', 1)
     if len(base_ext) == 1 or base_ext[1].lower() not in allowed_extensions:
       del dictionary[filename]
@@ -345,7 +346,7 @@ def run_clang_format_and_save_to_tree(changed_lines, revision=None,
 
   Returns the object ID (SHA-1) of the created tree."""
   def index_info_generator():
-    for filename, line_ranges in changed_lines.iteritems():
+    for filename, line_ranges in changed_lines.viewitems():
       if revision:
         git_metadata_cmd = ['git', 'ls-tree',
                             '%s:%s' % (revision, os.path.dirname(filename)),
@@ -356,6 +357,9 @@ def run_clang_format_and_save_to_tree(changed_lines, revision=None,
         mode = oct(int(stdout.split()[0], 8))
       else:
         mode = oct(os.stat(filename).st_mode)
+      # Adjust python3 octal format so that it matches what git expects
+      if mode.startswith('0o'):
+          mode = '0' + mode[2:]
       blob_id = clang_format_to_blob(filename, line_ranges,
                                      revision=revision,
                                      binary=binary,
@@ -488,10 +492,10 @@ def apply_changes(old_tree, new_tree, force=False, patch_mode=False):
   if not force:
     unstaged_files = run('git', 'diff-files', '--name-status', *changed_files)
     if unstaged_files:
-      print >>sys.stderr, ('The following files would be modified but '
-                           'have unstaged changes:')
-      print >>sys.stderr, unstaged_files
-      print >>sys.stderr, 'Please commit, stage, or stash them first.'
+      print('The following files would be modified but '
+                'have unstaged changes:', file=sys.stderr)
+      print(unstaged_files, file=sys.stderr)
+      print('Please commit, stage, or stash them first.', file=sys.stderr)
       sys.exit(2)
   if patch_mode:
     # In patch mode, we could just as well create an index from the new tree
@@ -521,20 +525,20 @@ def run(*args, **kwargs):
   if p.returncode == 0:
     if stderr:
       if verbose:
-        print >>sys.stderr, '`%s` printed to stderr:' % ' '.join(args)
-      print >>sys.stderr, stderr.rstrip()
+        print('`%s` printed to stderr:' % ' '.join(args), file=sys.stderr)
+      print(stderr.rstrip(), file=sys.stderr)
     if strip:
       stdout = stdout.rstrip('\r\n')
     return stdout
   if verbose:
-    print >>sys.stderr, '`%s` returned %s' % (' '.join(args), p.returncode)
+    print('`%s` returned %s' % (' '.join(args), p.returncode), file=sys.stderr)
   if stderr:
-    print >>sys.stderr, stderr.rstrip()
+    print(stderr.rstrip(), file=sys.stderr)
   sys.exit(2)
 
 
 def die(message):
-  print >>sys.stderr, 'error:', message
+  print('error:', message, file=sys.stderr)
   sys.exit(2)