Merge pull request #747 from Kriskras99/master

clang-format update and addition

6 files changed, 606 insertions, 100 deletions

diff --git a/third_party/clang-format/LICENSE.TXT b/third_party/clang-format/LICENSE.TXT
new file mode 100644
index 000000000..b452ca2ef
--- /dev/null
+++ b/third_party/clang-format/LICENSE.TXT
@@ -0,0 +1,63 @@
+==============================================================================
+LLVM Release License
+==============================================================================
+University of Illinois/NCSA
+Open Source License
+
+Copyright (c) 2007-2016 University of Illinois at Urbana-Champaign.
+All rights reserved.
+
+Developed by:
+
+    LLVM Team
+
+    University of Illinois at Urbana-Champaign
+
+    http://llvm.org
+
+Permission is hereby granted, free of charge, to any person obtaining a copy of
+this software and associated documentation files (the "Software"), to deal with
+the Software without restriction, including without limitation the rights to
+use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies
+of the Software, and to permit persons to whom the Software is furnished to do
+so, subject to the following conditions:
+
+    * Redistributions of source code must retain the above copyright notice,
+      this list of conditions and the following disclaimers.
+
+    * Redistributions in binary form must reproduce the above copyright notice,
+      this list of conditions and the following disclaimers in the
+      documentation and/or other materials provided with the distribution.
+
+    * Neither the names of the LLVM Team, University of Illinois at
+      Urbana-Champaign, nor the names of its contributors may be used to
+      endorse or promote products derived from this Software without specific
+      prior written permission.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
+FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL THE
+CONTRIBUTORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS WITH THE
+SOFTWARE.
+
+==============================================================================
+The LLVM software contains code written by third parties.  Such software will
+have its own individual LICENSE.TXT file in the directory in which it appears.
+This file will describe the copyrights, license, and restrictions which apply
+to that code.
+
+The disclaimer of warranty in the University of Illinois Open Source License
+applies to all code in the LLVM Distribution, and nothing in any of the
+other licenses gives permission to use the names of the LLVM Team or the
+University of Illinois to endorse or promote products derived from this
+Software.
+
+The following pieces of software have additional or alternate copyrights,
+licenses, and/or restrictions:
+
+Program             Directory
+-------             ---------
+<none yet>
+
diff --git a/third_party/clang-format/clang-format-bbedit.applescript b/third_party/clang-format/clang-format-bbedit.applescript
new file mode 100644
index 000000000..fa88fe900
--- /dev/null
+++ b/third_party/clang-format/clang-format-bbedit.applescript
@@ -0,0 +1,27 @@
+-- In this file, change "/path/to/" to the path where you installed clang-format
+-- and save it to ~/Library/Application Support/BBEdit/Scripts. You can then
+-- select the script from the Script menu and clang-format will format the
+-- selection. Note that you can rename the menu item by renaming the script, and
+-- can assign the menu item a keyboard shortcut in the BBEdit preferences, under
+-- Menus & Shortcuts.
+on urlToPOSIXPath(theURL)
+	return do shell script "python -c \"import urllib, urlparse, sys; print urllib.unquote(urlparse.urlparse(sys.argv[1])[2])\" " & quoted form of theURL
+end urlToPOSIXPath
+
+tell application "BBEdit"
+	set selectionOffset to characterOffset of selection
+	set selectionLength to length of selection
+	set fileURL to URL of text document 1
+end tell
+
+set filePath to urlToPOSIXPath(fileURL)
+set newContents to do shell script "/path/to/clang-format -offset=" & selectionOffset & " -length=" & selectionLength & " " & quoted form of filePath
+
+tell application "BBEdit"
+	-- "set contents of text document 1 to newContents" scrolls to the bottom while
+	-- replacing a selection flashes a bit but doesn't affect the scroll position.
+	set currentLength to length of contents of text document 1
+	select characters 1 thru currentLength of text document 1
+	set text of selection to newContents
+	select characters selectionOffset thru (selectionOffset + selectionLength - 1) of text document 1
+end tell
diff --git a/third_party/clang-format/clang-format-diff.py b/third_party/clang-format/clang-format-diff.py
index 23adb077c..ffa30e70d 100644
--- a/third_party/clang-format/clang-format-diff.py
+++ b/third_party/clang-format/clang-format-diff.py
@@ -17,7 +17,7 @@ This script reads input from a unified diff and reformats all the changed
 lines. This is useful to reformat all the lines touched by a specific patch.
 Example usage for git/svn users:
 
-  git diff -U0 HEAD^ | clang-format-diff.py -p1 -i
+  git diff -U0 --no-color HEAD^ | clang-format-diff.py -p1 -i
   svn diff --diff-cmd=diff -x-U0 | clang-format-diff.py -i
 
 """
@@ -31,10 +31,6 @@ import StringIO
 import sys
 
 
-# Change this to the full path if clang-format is not on the path.
-binary = 'clang-format'
-
-
 def main():
   parser = argparse.ArgumentParser(description=
                                    'Reformat changed lines in diff. Without -i '
@@ -48,16 +44,19 @@ def main():
                       help='custom pattern selecting file paths to reformat '
                       '(case sensitive, overrides -iregex)')
   parser.add_argument('-iregex', metavar='PATTERN', default=
-                      r'.*\.(cpp|cc|c\+\+|cxx|c|cl|h|hpp|m|mm|inc|js|proto'
+                      r'.*\.(cpp|cc|c\+\+|cxx|c|cl|h|hpp|m|mm|inc|js|ts|proto'
                       r'|protodevel|java)',
                       help='custom pattern selecting file paths to reformat '
                       '(case insensitive, overridden by -regex)')
+  parser.add_argument('-sort-includes', action='store_true', default=False,
+                      help='let clang-format sort include blocks')
   parser.add_argument('-v', '--verbose', action='store_true',
                       help='be more verbose, ineffective without -i')
-  parser.add_argument(
-      '-style',
-      help=
-      'formatting style to apply (LLVM, Google, Chromium, Mozilla, WebKit)')
+  parser.add_argument('-style',
+                      help='formatting style to apply (LLVM, Google, Chromium, '
+                      'Mozilla, WebKit)')
+  parser.add_argument('-binary', default='clang-format',
+                      help='location of binary to use for clang-format')
   args = parser.parse_args()
 
   # Extract changed lines for each file.
@@ -93,9 +92,11 @@ def main():
   for filename, lines in lines_by_file.iteritems():
     if args.i and args.verbose:
       print 'Formatting', filename
-    command = [binary, filename]
+    command = [args.binary, filename]
     if args.i:
       command.append('-i')
+    if args.sort_includes:
+      command.append('-sort-includes')
     command.extend(lines)
     if args.style:
       command.extend(['-style', args.style])
diff --git a/third_party/clang-format/clang-format.el b/third_party/clang-format/clang-format.el
new file mode 100644
index 000000000..aa9c3ff4c
--- /dev/null
+++ b/third_party/clang-format/clang-format.el
@@ -0,0 +1,193 @@
+;;; clang-format.el --- Format code using clang-format  -*- lexical-binding: t; -*-
+
+;; Keywords: tools, c
+;; Package-Requires: ((cl-lib "0.3"))
+
+;;; Commentary:
+
+;; This package allows to filter code through clang-format to fix its formatting.
+;; clang-format is a tool that formats C/C++/Obj-C code according to a set of
+;; style options, see <http://clang.llvm.org/docs/ClangFormatStyleOptions.html>.
+;; Note that clang-format 3.4 or newer is required.
+
+;; clang-format.el is available via MELPA and can be installed via
+;;
+;;   M-x package-install clang-format
+;;
+;; when ("melpa" . "http://melpa.org/packages/") is included in
+;; `package-archives'.  Alternatively, ensure the directory of this
+;; file is in your `load-path' and add
+;;
+;;   (require 'clang-format)
+;;
+;; to your .emacs configuration.
+
+;; You may also want to bind `clang-format-region' to a key:
+;;
+;;   (global-set-key [C-M-tab] 'clang-format-region)
+
+;;; Code:
+
+(require 'cl-lib)
+(require 'xml)
+
+(defgroup clang-format nil
+  "Format code using clang-format."
+  :group 'tools)
+
+(defcustom clang-format-executable
+  (or (executable-find "clang-format")
+      "clang-format")
+  "Location of the clang-format executable.
+
+A string containing the name or the full path of the executable."
+  :group 'clang-format
+  :type '(file :must-match t)
+  :risky t)
+
+(defcustom clang-format-style "file"
+  "Style argument to pass to clang-format.
+
+By default clang-format will load the style configuration from
+a file named .clang-format located in one of the parent directories
+of the buffer."
+  :group 'clang-format
+  :type 'string
+  :safe #'stringp)
+(make-variable-buffer-local 'clang-format-style)
+
+(defun clang-format--extract (xml-node)
+  "Extract replacements and cursor information from XML-NODE."
+  (unless (and (listp xml-node) (eq (xml-node-name xml-node) 'replacements))
+    (error "Expected <replacements> node"))
+  (let ((nodes (xml-node-children xml-node))
+        (incomplete-format (xml-get-attribute xml-node 'incomplete_format))
+        replacements
+        cursor)
+    (dolist (node nodes)
+      (when (listp node)
+        (let* ((children (xml-node-children node))
+               (text (car children)))
+          (cl-case (xml-node-name node)
+            ('replacement
+             (let* ((offset (xml-get-attribute-or-nil node 'offset))
+                    (length (xml-get-attribute-or-nil node 'length)))
+               (when (or (null offset) (null length))
+                 (error "<replacement> node does not have offset and length attributes"))
+               (when (cdr children)
+                 (error "More than one child node in <replacement> node"))
+
+               (setq offset (string-to-number offset))
+               (setq length (string-to-number length))
+               (push (list offset length text) replacements)))
+            ('cursor
+             (setq cursor (string-to-number text)))))))
+
+    ;; Sort by decreasing offset, length.
+    (setq replacements (sort (delq nil replacements)
+                             (lambda (a b)
+                               (or (> (car a) (car b))
+                                   (and (= (car a) (car b))
+                                        (> (cadr a) (cadr b)))))))
+
+    (list replacements cursor (string= incomplete-format "true"))))
+
+(defun clang-format--replace (offset length &optional text)
+  "Replace the region defined by OFFSET and LENGTH with TEXT.
+OFFSET and LENGTH are measured in bytes, not characters.  OFFSET
+is a zero-based file offset, assuming ‘utf-8-unix’ coding."
+  (let ((start (clang-format--filepos-to-bufferpos offset 'exact 'utf-8-unix))
+        (end (clang-format--filepos-to-bufferpos (+ offset length) 'exact
+                                                 'utf-8-unix)))
+    (goto-char start)
+    (delete-region start end)
+    (when text
+      (insert text))))
+
+;; ‘bufferpos-to-filepos’ and ‘filepos-to-bufferpos’ are new in Emacs 25.1.
+;; Provide fallbacks for older versions.
+(defalias 'clang-format--bufferpos-to-filepos
+  (if (fboundp 'bufferpos-to-filepos)
+      'bufferpos-to-filepos
+    (lambda (position &optional _quality _coding-system)
+      (1- (position-bytes position)))))
+
+(defalias 'clang-format--filepos-to-bufferpos
+  (if (fboundp 'filepos-to-bufferpos)
+      'filepos-to-bufferpos
+    (lambda (byte &optional _quality _coding-system)
+      (byte-to-position (1+ byte)))))
+
+;;;###autoload
+(defun clang-format-region (start end &optional style)
+  "Use clang-format to format the code between START and END according to STYLE.
+If called interactively uses the region or the current statement if there
+is no active region.  If no style is given uses `clang-format-style'."
+  (interactive
+   (if (use-region-p)
+       (list (region-beginning) (region-end))
+     (list (point) (point))))
+
+  (unless style
+    (setq style clang-format-style))
+
+  (let ((file-start (clang-format--bufferpos-to-filepos start 'approximate
+                                                        'utf-8-unix))
+        (file-end (clang-format--bufferpos-to-filepos end 'approximate
+                                                      'utf-8-unix))
+        (cursor (clang-format--bufferpos-to-filepos (point) 'exact 'utf-8-unix))
+        (temp-buffer (generate-new-buffer " *clang-format-temp*"))
+        (temp-file (make-temp-file "clang-format"))
+        ;; Output is XML, which is always UTF-8.  Input encoding should match
+        ;; the encoding used to convert between buffer and file positions,
+        ;; otherwise the offsets calculated above are off.  For simplicity, we
+        ;; always use ‘utf-8-unix’ and ignore the buffer coding system.
+        (default-process-coding-system '(utf-8-unix . utf-8-unix)))
+    (unwind-protect
+        (let ((status (call-process-region
+                       nil nil clang-format-executable
+                       nil `(,temp-buffer ,temp-file) nil
+
+                       "-output-replacements-xml"
+                       "-assume-filename" (or (buffer-file-name) "")
+                       "-style" style
+                       "-offset" (number-to-string file-start)
+                       "-length" (number-to-string (- file-end file-start))
+                       "-cursor" (number-to-string cursor)))
+              (stderr (with-temp-buffer
+                        (unless (zerop (cadr (insert-file-contents temp-file)))
+                          (insert ": "))
+                        (buffer-substring-no-properties
+                         (point-min) (line-end-position)))))
+          (cond
+           ((stringp status)
+            (error "(clang-format killed by signal %s%s)" status stderr))
+           ((not (zerop status))
+            (error "(clang-format failed with code %d%s)" status stderr)))
+
+          (cl-destructuring-bind (replacements cursor incomplete-format)
+              (with-current-buffer temp-buffer
+                (clang-format--extract (car (xml-parse-region))))
+            (save-excursion
+              (dolist (rpl replacements)
+                (apply #'clang-format--replace rpl)))
+            (when cursor
+              (goto-char (clang-format--filepos-to-bufferpos cursor 'exact
+                                                             'utf-8-unix)))
+            (if incomplete-format
+                (message "(clang-format: incomplete (syntax errors)%s)" stderr)
+              (message "(clang-format: success%s)" stderr))))
+      (delete-file temp-file)
+      (when (buffer-name temp-buffer) (kill-buffer temp-buffer)))))
+
+;;;###autoload
+(defun clang-format-buffer (&optional style)
+  "Use clang-format to format the current buffer according to STYLE."
+  (interactive)
+  (clang-format-region (point-min) (point-max) style))
+
+;;;###autoload
+(defalias 'clang-format 'clang-format-region)
+
+(provide 'clang-format)
+;;; clang-format.el ends here
diff --git a/third_party/clang-format/clang-format.py b/third_party/clang-format/clang-format.py
new file mode 100644
index 000000000..241256634
--- /dev/null
+++ b/third_party/clang-format/clang-format.py
@@ -0,0 +1,127 @@
+# 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 platform
+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 get_buffer(encoding):
+  if platform.python_version_tuple()[0] == '3':
+    return vim.current.buffer
+  return [ line.decode(encoding) for line in vim.current.buffer ]
+
+def main():
+  # Get the current text.
+  encoding = vim.eval("&encoding")
+  buf = get_buffer(encoding)
+  text = '\n'.join(buf)
+
+  # Determine range to format.
+  if vim.eval('exists("l:lines")') == '1':
+    lines = vim.eval('l:lines')
+  elif vim.eval('exists("l:formatdiff")') == '1':
+    with open(vim.current.buffer.name, 'r') as f:
+      ondisk = f.read().splitlines();
+    sequence = difflib.SequenceMatcher(None, ondisk, vim.current.buffer)
+    lines = []
+    for op in reversed(sequence.get_opcodes()):
+      if op[0] not in ['equal', 'delete']:
+        lines += ['-lines', '%s:%s' % (op[3] + 1, op[4])]
+    if lines == []:
+      return
+  else:
+    lines = ['-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?')
+    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 += 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.encode(encoding))
+
+  # If successful, replace buffer contents.
+  if stderr:
+    print(stderr)
+
+  if not stdout:
+    print(
+        'No output from clang-format (crashed?).\n'
+        'Please report to bugs.llvm.org.'
+    )
+  else:
+    lines = stdout.decode(encoding).split('\n')
+    output = json.loads(lines[0])
+    lines = lines[1:]
+    sequence = difflib.SequenceMatcher(None, buf, 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)')
+    vim.command('goto %d' % (output['Cursor'] + 1))
+
+main()
diff --git a/third_party/clang-format/git-clang-format b/third_party/clang-format/git-clang-format
index 78cf7307c..60cd4fb25 100644
--- a/third_party/clang-format/git-clang-format
+++ b/third_party/clang-format/git-clang-format
@@ -9,20 +9,21 @@
 #
 #===------------------------------------------------------------------------===#
 
-r"""
-clang-format git integration
-============================
-
-This file provides a clang-format integration for git. Put it somewhere in your
-path and ensure that it is executable. Then, "git clang-format" will invoke
-clang-format on the changes in current files or a specific commit.
-
-For further details, run:
-git clang-format -h
-
-Requires Python 2.7
-"""
-
+r"""                                                                             
+clang-format git integration                                                     
+============================                                                     
+                                                                                 
+This file provides a clang-format integration for git. Put it somewhere in your  
+path and ensure that it is executable. Then, "git clang-format" will invoke      
+clang-format on the changes in current files or a specific commit.               
+                                                                                 
+For further details, run:                                                        
+git clang-format -h                                                              
+                                                                                 
+Requires Python 2.7 or Python 3                                                  
+"""               
+
+from __future__ import print_function
 import argparse
 import collections
 import contextlib
@@ -32,12 +33,15 @@ import re
 import subprocess
 import sys
 
-usage = 'git clang-format [OPTIONS] [<commit>] [--] [<file>...]'
+usage = 'git clang-format [OPTIONS] [<commit>] [<commit>] [--] [<file>...]'
 
 desc = '''
-Run clang-format on all lines that differ between the working directory
-and <commit>, which defaults to HEAD.  Changes are only applied to the working
-directory.
+If zero or one commits are given, run clang-format on all lines that differ
+between the working directory and <commit>, which defaults to HEAD.  Changes are
+only applied to the working directory.
+
+If two commits are given (requires --diff), run clang-format on all lines in the
+second <commit> that differ from the first <commit>.
 
 The following git-config settings set the default of the corresponding option:
   clangFormat.binary
@@ -77,7 +81,9 @@ def main():
       'cc', 'cp', 'cpp', 'c++', 'cxx', 'hpp',  # C++
       # Other languages that clang-format supports
       'proto', 'protodevel',  # Protocol Buffers
+      'java',  # Java
       'js',  # JavaScript
+      'ts',  # TypeScript
       ])
 
   p = argparse.ArgumentParser(
@@ -119,46 +125,59 @@ def main():
   opts.verbose -= opts.quiet
   del opts.quiet
 
-  commit, files = interpret_args(opts.args, dash_dash, opts.commit)
-  changed_lines = compute_diff_and_extract_lines(commit, files)
+  commits, files = interpret_args(opts.args, dash_dash, opts.commit)
+  if len(commits) > 1:
+    if not opts.diff:
+      die('--diff is required when two commits are given')
+  else:
+    if len(commits) > 2:
+      die('at most two commits allowed; %d given' % len(commits))
+  changed_lines = compute_diff_and_extract_lines(commits, files)
   if opts.verbose >= 1:
     ignored_files = set(changed_lines)
   filter_by_extension(changed_lines, opts.extensions.lower().split(','))
   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.
   cd_to_toplevel()
-  old_tree = create_tree_from_workdir(changed_lines)
-  new_tree = run_clang_format_and_save_to_tree(changed_lines,
-                                               binary=opts.binary,
-                                               style=opts.style)
+  if len(commits) > 1:
+    old_tree = commits[1]
+    new_tree = run_clang_format_and_save_to_tree(changed_lines,
+                                                 revision=commits[1],
+                                                 binary=opts.binary,
+                                                 style=opts.style)
+  else:
+    old_tree = create_tree_from_workdir(changed_lines)
+    new_tree = run_clang_format_and_save_to_tree(changed_lines,
+                                                 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):
@@ -180,40 +199,41 @@ def load_git_config(non_string_options=None):
 
 
 def interpret_args(args, dash_dash, default_commit):
-  """Interpret `args` as "[commit] [--] [files...]" and return (commit, files).
+  """Interpret `args` as "[commits] [--] [files]" and return (commits, files).
 
   It is assumed that "--" and everything that follows has been removed from
   args and placed in `dash_dash`.
 
-  If "--" is present (i.e., `dash_dash` is non-empty), the argument to its
-  left (if present) is taken as commit.  Otherwise, the first argument is
-  checked if it is a commit or a file.  If commit is not given,
-  `default_commit` is used."""
+  If "--" is present (i.e., `dash_dash` is non-empty), the arguments to its
+  left (if present) are taken as commits.  Otherwise, the arguments are checked
+  from left to right if they are commits or files.  If commits are not given,
+  a list with `default_commit` is used."""
   if dash_dash:
     if len(args) == 0:
-      commit = default_commit
-    elif len(args) > 1:
-      die('at most one commit allowed; %d given' % len(args))
+      commits = [default_commit]
     else:
-      commit = args[0]
-    object_type = get_object_type(commit)
-    if object_type not in ('commit', 'tag'):
-      if object_type is None:
-        die("'%s' is not a commit" % commit)
-      else:
-        die("'%s' is a %s, but a commit was expected" % (commit, object_type))
+      commits = args
+    for commit in commits:
+      object_type = get_object_type(commit)
+      if object_type not in ('commit', 'tag'):
+        if object_type is None:
+          die("'%s' is not a commit" % commit)
+        else:
+          die("'%s' is a %s, but a commit was expected" % (commit, object_type))
     files = dash_dash[1:]
   elif args:
-    if disambiguate_revision(args[0]):
-      commit = args[0]
-      files = args[1:]
-    else:
-      commit = default_commit
-      files = args
+    commits = []
+    while args:
+      if not disambiguate_revision(args[0]):
+        break
+      commits.append(args.pop(0))
+    if not commits:
+      commits = [default_commit]
+    files = args
   else:
-    commit = default_commit
+    commits = [default_commit]
     files = []
-  return commit, files
+  return commits, files
 
 
 def disambiguate_revision(value):
@@ -238,12 +258,12 @@ def get_object_type(value):
   stdout, stderr = p.communicate()
   if p.returncode != 0:
     return None
-  return stdout.strip()
+  return convert_string(stdout.strip())
 
 
-def compute_diff_and_extract_lines(commit, files):
+def compute_diff_and_extract_lines(commits, files):
   """Calls compute_diff() followed by extract_lines()."""
-  diff_process = compute_diff(commit, files)
+  diff_process = compute_diff(commits, files)
   changed_lines = extract_lines(diff_process.stdout)
   diff_process.stdout.close()
   diff_process.wait()
@@ -253,13 +273,17 @@ def compute_diff_and_extract_lines(commit, files):
   return changed_lines
 
 
-def compute_diff(commit, files):
-  """Return a subprocess object producing the diff from `commit`.
+def compute_diff(commits, files):
+  """Return a subprocess object producing the diff from `commits`.
 
   The return value's `stdin` file object will produce a patch with the
-  differences between the working directory and `commit`, filtered on `files`
-  (if non-empty).  Zero context lines are used in the patch."""
-  cmd = ['git', 'diff-index', '-p', '-U0', commit, '--']
+  differences between the working directory and the first commit if a single
+  one was specified, or the difference between both specified commits, filtered
+  on `files` (if non-empty).  Zero context lines are used in the patch."""
+  git_tool = 'diff-index'
+  if len(commits) > 1:
+    git_tool = 'diff-tree'
+  cmd = ['git', git_tool, '-p', '-U0'] + commits + ['--']
   cmd.extend(files)
   p = subprocess.Popen(cmd, stdin=subprocess.PIPE, stdout=subprocess.PIPE)
   p.stdin.close()
@@ -277,6 +301,7 @@ def extract_lines(patch_file):
   list of line `Range`s."""
   matches = {}
   for line in patch_file:
+    line = convert_string(line)
     match = re.search(r'^\+\+\+\ [^/]+/(.*)', line)
     if match:
       filename = match.group(1).rstrip('\r\n')
@@ -297,8 +322,10 @@ 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 and '' in allowed_extensions:
+        continue
     if len(base_ext) == 1 or base_ext[1].lower() not in allowed_extensions:
       del dictionary[filename]
 
@@ -316,15 +343,34 @@ def create_tree_from_workdir(filenames):
   return create_tree(filenames, '--stdin')
 
 
-def run_clang_format_and_save_to_tree(changed_lines, binary='clang-format',
-                                      style=None):
+def run_clang_format_and_save_to_tree(changed_lines, revision=None,
+                                      binary='clang-format', style=None):
   """Run clang-format on each file and save the result to a git tree.
 
   Returns the object ID (SHA-1) of the created tree."""
+  def iteritems(container):
+      try:
+          return container.iteritems() # Python 2
+      except AttributeError:
+          return container.items() # Python 3
   def index_info_generator():
-    for filename, line_ranges in changed_lines.iteritems():
-      mode = oct(os.stat(filename).st_mode)
-      blob_id = clang_format_to_blob(filename, line_ranges, binary=binary,
+    for filename, line_ranges in iteritems(changed_lines):
+      if revision:
+        git_metadata_cmd = ['git', 'ls-tree',
+                            '%s:%s' % (revision, os.path.dirname(filename)),
+                            os.path.basename(filename)]
+        git_metadata = subprocess.Popen(git_metadata_cmd, stdin=subprocess.PIPE,
+                                        stdout=subprocess.PIPE)
+        stdout = git_metadata.communicate()[0]
+        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,
                                      style=style)
       yield '%s %s\t%s' % (mode, blob_id, filename)
   return create_tree(index_info_generator(), '--index-info')
@@ -342,7 +388,7 @@ def create_tree(input_lines, mode):
   with temporary_index_file():
     p = subprocess.Popen(cmd, stdin=subprocess.PIPE)
     for line in input_lines:
-      p.stdin.write('%s\0' % line)
+      p.stdin.write(to_bytes('%s\0' % line))
     p.stdin.close()
     if p.wait() != 0:
       die('`%s` failed' % ' '.join(cmd))
@@ -350,26 +396,42 @@ def create_tree(input_lines, mode):
     return tree_id
 
 
-def clang_format_to_blob(filename, line_ranges, binary='clang-format',
-                         style=None):
+def clang_format_to_blob(filename, line_ranges, revision=None,
+                         binary='clang-format', style=None):
   """Run clang-format on the given file and save the result to a git blob.
 
+  Runs on the file in `revision` if not None, or on the file in the working
+  directory if `revision` is None.
+
   Returns the object ID (SHA-1) of the created blob."""
-  clang_format_cmd = [binary, filename]
+  clang_format_cmd = [binary]
   if style:
     clang_format_cmd.extend(['-style='+style])
   clang_format_cmd.extend([
       '-lines=%s:%s' % (start_line, start_line+line_count-1)
       for start_line, line_count in line_ranges])
+  if revision:
+    clang_format_cmd.extend(['-assume-filename='+filename])
+    git_show_cmd = ['git', 'cat-file', 'blob', '%s:%s' % (revision, filename)]
+    git_show = subprocess.Popen(git_show_cmd, stdin=subprocess.PIPE,
+                                stdout=subprocess.PIPE)
+    git_show.stdin.close()
+    clang_format_stdin = git_show.stdout
+  else:
+    clang_format_cmd.extend([filename])
+    git_show = None
+    clang_format_stdin = subprocess.PIPE
   try:
-    clang_format = subprocess.Popen(clang_format_cmd, stdin=subprocess.PIPE,
+    clang_format = subprocess.Popen(clang_format_cmd, stdin=clang_format_stdin,
                                     stdout=subprocess.PIPE)
+    if clang_format_stdin == subprocess.PIPE:
+      clang_format_stdin = clang_format.stdin
   except OSError as e:
     if e.errno == errno.ENOENT:
       die('cannot find executable "%s"' % binary)
     else:
       raise
-  clang_format.stdin.close()
+  clang_format_stdin.close()
   hash_object_cmd = ['git', 'hash-object', '-w', '--path='+filename, '--stdin']
   hash_object = subprocess.Popen(hash_object_cmd, stdin=clang_format.stdout,
                                  stdout=subprocess.PIPE)
@@ -379,7 +441,9 @@ def clang_format_to_blob(filename, line_ranges, binary='clang-format',
     die('`%s` failed' % ' '.join(hash_object_cmd))
   if clang_format.wait() != 0:
     die('`%s` failed' % ' '.join(clang_format_cmd))
-  return stdout.rstrip('\r\n')
+  if git_show and git_show.wait() != 0:
+    die('`%s` failed' % ' '.join(git_show_cmd))
+  return convert_string(stdout).rstrip('\r\n')
 
 
 @contextlib.contextmanager
@@ -417,7 +481,12 @@ def print_diff(old_tree, new_tree):
   # We use the porcelain 'diff' and not plumbing 'diff-tree' because the output
   # is expected to be viewed by the user, and only the former does nice things
   # like color and pagination.
-  subprocess.check_call(['git', 'diff', old_tree, new_tree, '--'])
+  #
+  # We also only print modified files since `new_tree` only contains the files
+  # that were modified, so unmodified files would show as deleted without the
+  # filter.
+  subprocess.check_call(['git', 'diff', '--diff-filter=M', old_tree, new_tree,
+                         '--'])
 
 
 def apply_changes(old_tree, new_tree, force=False, patch_mode=False):
@@ -425,15 +494,16 @@ def apply_changes(old_tree, new_tree, force=False, patch_mode=False):
 
   Bails if there are local changes in those files and not `force`.  If
   `patch_mode`, runs `git checkout --patch` to select hunks interactively."""
-  changed_files = run('git', 'diff-tree', '-r', '-z', '--name-only', old_tree,
+  changed_files = run('git', 'diff-tree', '--diff-filter=M', '-r', '-z',
+                      '--name-only', old_tree,
                       new_tree).rstrip('\0').split('\0')
   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
@@ -460,25 +530,50 @@ def run(*args, **kwargs):
   p = subprocess.Popen(args, stdout=subprocess.PIPE, stderr=subprocess.PIPE,
                        stdin=subprocess.PIPE)
   stdout, stderr = p.communicate(input=stdin)
+
+  stdout = convert_string(stdout)
+  stderr = convert_string(stderr)
+
   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)
 
 
+def to_bytes(str_input):
+    # Encode to UTF-8 to get binary data.
+    if isinstance(str_input, bytes):
+        return str_input
+    return str_input.encode('utf-8')
+
+
+def to_string(bytes_input):
+    if isinstance(bytes_input, str):
+        return bytes_input
+    return bytes_input.encode('utf-8')
+
+
+def convert_string(bytes_input):
+    try:
+        return to_string(bytes_input.decode('utf-8'))
+    except AttributeError: # 'str' object has no attribute 'decode'.
+        return str(bytes_input)
+    except UnicodeError:
+        return str(bytes_input)
+
 if __name__ == '__main__':
   main()