Make run-clang-tidy compatible with Python 3.x

[alexfh]

Please don't forget go add cfe-commits to subscribers when you create a differential revision.

LG with one comment.

clang-tidy/tool/run-clang-tidy.py

242

let's give it a more meaningful name, e.g. file_queue or task_queue.

clang-tidy/tool/run-clang-tidy.py

for clang-tidy headers.
     run-clang-tidy.py -fix -checks=-*,llvm-header-guard extra/clang-tidy \
                       -header-filter=extra/clang-tidy
 
 Compilation database setup:
 http://clang.llvm.org/docs/HowToSetupToolingForLLVM.html
 """
 
 from __future__ import print_function
+
 import argparse
 import glob
 import json
 import multiprocessing
 import os
-import Queue
 import re
 import shutil
 import subprocess
 import sys
 import tempfile
 import threading
 import traceback
 import yaml
 
+is_py2 = sys.version[0] == '2'
+
+if is_py2:
+    import Queue as queue
+else:
+    import queue as queue
 
 def find_compilation_database(path):
   """Adjusts the directory until a compilation database is found."""
   result = './'
   while not os.path.isfile(os.path.join(result, path)):
     if os.path.realpath(result) == '/':
       print('Error: could not find compilation database.')
       sys.exit(1)
if args.fix or args.export_fixes:
     check_clang_apply_replacements_binary(args)
     tmpdir = tempfile.mkdtemp()
 
   # Build up a big regexy filter from all command line arguments.
   file_name_re = re.compile('|'.join(args.files))
 
   try:
     # Spin up a bunch of tidy-launching threads.
-    queue = Queue.Queue(max_task)
+    q = queue.Queue(max_task)
     for _ in range(max_task):
       t = threading.Thread(target=run_tidy,
-                           args=(args, tmpdir, build_path, queue))
+                           args=(args, tmpdir, build_path, q))
       t.daemon = True
       t.start()
 
     # Fill the queue with files.
     for name in files:
       if file_name_re.search(name):
-        queue.put(name)
+        q.put(name)
 
     # Wait for all threads to be done.
-    queue.join()
+    q.join()
 
   except KeyboardInterrupt:
     # This is a sad hack. Unfortunately subprocess goes
     # bonkers with ctrl-c and we start forking merrily.
     print('\nCtrl-C detected, goodbye.')
     if tmpdir:
       shutil.rmtree(tmpdir)
     os.kill(0, 9)