Make script portable across Python versions

Support both Python 2 and 3.

clint.py

@@ -1,4 +1,4 @@
-#!/usr/bin/python
+#!/usr/bin/env python
 #
 # Copyright (c) 2009 Google Inc. All rights reserved.
 #
@@ -41,6 +41,11 @@ We do a small hack, which is to ignore //'s with "'s after them on the
 same line, but it is far from perfect (in either direction).
 """
 
+from __future__ import absolute_import
+from __future__ import division
+from __future__ import print_function
+from __future__ import unicode_literals
+
 import codecs
 import copy
 import getopt
@@ -763,7 +768,7 @@ class _CppLintState(object):
 
   def PrintErrorCounts(self):
     """Print a summary of errors by category, and the total."""
-    for category, count in self.errors_by_category.iteritems():
+    for category, count in self.errors_by_category.items():
       sys.stderr.write('Category \'%s\' errors found: %d\n' %
                        (category, count))
     sys.stderr.write('Total errors found: %d\n' % self.error_count)
@@ -1248,7 +1253,7 @@ def FindEndOfExpressionInLine(line, startpos, depth, startchar, endchar):
     On finding matching endchar: (index just after matching endchar, 0)
     Otherwise: (-1, new depth at end of this line)
   """
-  for i in xrange(startpos, len(line)):
+  for i in range(startpos, len(line)):
     if line[i] == startchar:
       depth += 1
     elif line[i] == endchar:
@@ -1321,7 +1326,7 @@ def FindStartOfExpressionInLine(line, endpos, depth, startchar, endchar):
     On finding matching startchar: (index at matching startchar, 0)
     Otherwise: (-1, new depth at beginning of this line)
   """
-  for i in xrange(endpos, -1, -1):
+  for i in range(endpos, -1, -1):
     if line[i] == endchar:
       depth += 1
     elif line[i] == startchar:
@@ -1381,7 +1386,7 @@ def CheckForCopyright(filename, lines, error):
 
   # We'll say it should occur by line 10. Don't forget there's a
   # dummy line at the front.
-  for line in xrange(1, min(len(lines), 11)):
+  for line in range(1, min(len(lines), 11)):
     if re.search(r'Copyright', lines[line], re.I): break
   else:                       # means no copyright line was found
     error(filename, 0, 'legal/copyright', 5,
@@ -2313,8 +2318,6 @@ def CheckForFunctionLengths(filename, clean_lines, linenum,
   """
   lines = clean_lines.lines
   line = lines[linenum]
-  raw = clean_lines.raw_lines
-  raw_line = raw[linenum]
   joined_line = ''
 
   starting_func = False
@@ -2330,7 +2333,7 @@ def CheckForFunctionLengths(filename, clean_lines, linenum,
 
   if starting_func:
     body_found = False
-    for start_linenum in xrange(linenum, clean_lines.NumLines()):
+    for start_linenum in range(linenum, clean_lines.NumLines()):
       start_line = lines[start_linenum]
       joined_line += ' ' + start_line.lstrip()
       if Search(r'(;|})', start_line):  # Declarations and trivial functions
@@ -2853,7 +2856,7 @@ def CheckSpacing(filename, clean_lines, linenum, nesting_state, error):
     trailing_text = ''
     if endpos > -1:
       trailing_text = endline[endpos:]
-    for offset in xrange(endlinenum + 1,
+    for offset in range(endlinenum + 1,
                          min(endlinenum + 3, clean_lines.NumLines() - 1)):
       trailing_text += clean_lines.elided[offset]
     if not Match(r'^[\s}]*[{.;,)<\]]', trailing_text):
@@ -3224,7 +3227,7 @@ def CheckCheck(filename, clean_lines, linenum, error):
     expression = lines[linenum][start_pos + 1:end_pos - 1]
   else:
     expression = lines[linenum][start_pos + 1:]
-    for i in xrange(linenum + 1, end_line):
+    for i in range(linenum + 1, end_line):
       expression += lines[i]
     expression += last_line[0:end_pos - 1]
 
@@ -3352,7 +3355,7 @@ def GetLineWidth(line):
     The width of the line in column positions, accounting for Unicode
     combining characters and wide characters.
   """
-  if isinstance(line, unicode):
+  if isinstance(line, str):
     width = 0
     for uc in unicodedata.normalize('NFC', line):
       if unicodedata.east_asian_width(uc) in ('W', 'F'):
@@ -3683,7 +3686,7 @@ def _GetTextInside(text, start_pattern):
 
   # Give opening punctuations to get the matching close-punctuations.
   matching_punctuation = {'(': ')', '{': '}', '[': ']'}
-  closing_punctuation = set(matching_punctuation.itervalues())
+  closing_punctuation = set(matching_punctuation.values())
 
   # Find the position to start extracting text.
   match = re.search(start_pattern, text, re.M)
@@ -3773,9 +3776,6 @@ def CheckLanguage(filename, clean_lines, linenum, file_extension,
   if Match(r'^\s*#\s*(?:ifdef|elif|else|endif)\b', line):
     include_state.ResetSection()
 
-  # Make Windows paths like Unix.
-  fullname = os.path.abspath(filename).replace('\\', '/')
-
   # TODO(unknown): figure out if they're using default arguments in fn proto.
 
   # Check to see if they're using an conversion function cast.
@@ -3856,14 +3856,6 @@ def CheckLanguage(filename, clean_lines, linenum, file_extension,
            'This is dangerous: could be a temp var.  '
            'Take the address before doing the cast, rather than after'))
 
-  # Create an extended_line, which is the concatenation of the current and
-  # next lines, for more effective checking of code that may span more than one
-  # line.
-  if linenum + 1 < clean_lines.NumLines():
-    extended_line = line + clean_lines.elided[linenum + 1]
-  else:
-    extended_line = line
-
   # Check for people declaring static/global STL strings at the top level.
   # This is dangerous because the C++ language does not guarantee that
   # globals with constructors are initialized before the first access.
@@ -4100,7 +4092,7 @@ def CheckForNonConstReference(filename, clean_lines, linenum,
           # Found the matching < on an earlier line, collect all
           # pieces up to current line.
           line = ''
-          for i in xrange(startline, linenum + 1):
+          for i in range(startline, linenum + 1):
             line += clean_lines.elided[i].strip()
 
   # Check for non-const references in function parameters.  A single '&' may
@@ -4139,7 +4131,7 @@ def CheckForNonConstReference(filename, clean_lines, linenum,
     # Don't see a whitelisted function on this line.  Actually we
     # didn't see any function name on this line, so this is likely a
     # multi-line parameter list.  Try a bit harder to catch this case.
-    for i in xrange(2):
+    for i in range(2):
       if (linenum > i and
           Search(whitelisted_functions, clean_lines.elided[linenum - i - 1])):
         check_params = False
@@ -4412,7 +4404,7 @@ def CheckForIncludeWhatYouUse(filename, clean_lines, include_state, error,
   required = {}  # A map of header name to linenumber and the template entity.
                  # Example of required: { '<functional>': (1219, 'less<>') }
 
-  for linenum in xrange(clean_lines.NumLines()):
+  for linenum in range(clean_lines.NumLines()):
     line = clean_lines.elided[linenum]
     if not line or line[0] == '#':
       continue
@@ -4460,7 +4452,7 @@ def CheckForIncludeWhatYouUse(filename, clean_lines, include_state, error,
 
   # include_state is modified during iteration, so we iterate over a copy of
   # the keys.
-  header_keys = include_state.keys()
+  header_keys = list(include_state.keys())
   for header in header_keys:
     (same_module, common_path) = FilesBelongToSameModule(abs_filename, header)
     fullpath = common_path + header
@@ -4580,7 +4572,7 @@ def ProcessFileData(filename, file_extension, lines, error,
 
   RemoveMultiLineComments(filename, lines, error)
   clean_lines = CleansedLines(lines)
-  for line in xrange(clean_lines.NumLines()):
+  for line in range(clean_lines.NumLines()):
     ProcessLine(filename, file_extension, clean_lines, line,
                 include_state, function_state, nesting_state, error,
                 extra_check_functions)
@@ -4757,13 +4749,6 @@ def ParseArguments(args):
 def main():
   filenames = ParseArguments(sys.argv[1:])
 
-  # Change stderr to write with replacement characters so we don't die
-  # if we try to print something containing non-ASCII characters.
-  sys.stderr = codecs.StreamReaderWriter(sys.stderr,
-                                         codecs.getreader('utf8'),
-                                         codecs.getwriter('utf8'),
-                                         'replace')
-
   _cpplint_state.ResetErrorCounts()
   for filename in filenames:
     ProcessFile(filename, _cpplint_state.verbose_level)