Added orphaned compiled Python file checks.

presubmit_support.py

 #!/usr/bin/env python
 # Copyright (c) 2012 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 """Enables directory-specific presubmit checks to run at upload and/or commit.
 """
 
 __version__ = '1.8.0'
 
@@ skipping 1268 matching lines @@
     """Executes a single presubmit script.
 
     Args:
       script_text: The text of the presubmit script.
       presubmit_path: The path to the presubmit file (this will be reported via
         input_api.PresubmitLocalPath()).
 
     Return:
       A list of result objects, empty if no problems.
     """
-
     # Change to the presubmit file's directory to support local imports.
     main_path = os.getcwd()
     os.chdir(os.path.dirname(presubmit_path))
 
     # Load the presubmit script into context.
     input_api = InputApi(self.change, presubmit_path, self.committing,
                          self.rietveld, self.verbose)
     context = {}
     try:
       exec script_text in context
@@ skipping 28 matching lines @@
     return result
 
 
 def DoPresubmitChecks(change,
                       committing,
                       verbose,
                       output_stream,
                       input_stream,
                       default_presubmit,
                       may_prompt,
-                      rietveld_obj):
+                      rietveld_obj,
+                      cleanup=False):
   """Runs all presubmit checks that apply to the files in the change.
 
   This finds all PRESUBMIT.py files in directories enclosing the files in the
   change (up to the repository root) and calls the relevant entrypoint function
   depending on whether the change is being committed or uploaded.
 
   Prints errors, warnings and notifications.  Prompts the user for warnings
   when needed.
 
   Args:
     change: The Change object.
     committing: True if 'gcl commit' is running, False if 'gcl upload' is.
     verbose: Prints debug info.
     output_stream: A stream to write output from presubmit tests to.
     input_stream: A stream to read input from the user.
     default_presubmit: A default presubmit script to execute in any case.
     may_prompt: Enable (y/n) questions on warning or error.
     rietveld_obj: rietveld.Rietveld object.
+    cleanup: If True, filesystem modifications may be made as necessary to
+             clean up repository state to ensure reliable checks.
 
   Warning:
     If may_prompt is true, output_stream SHOULD be sys.stdout and input_stream
     SHOULD be sys.stdin.
 
   Return:
     A PresubmitOutput object. Use output.should_continue() to figure out
     if there were errors or warnings and the caller should abort.
   """
   old_environ = os.environ
   try:
+    # Clear all orphaned compiled Python files.
+    CleanOrphanedCompiledPython(output_stream, change.RepositoryRoot(),
+                                remove=cleanup)
+
     # Make sure python subprocesses won't generate .pyc files.
     os.environ = os.environ.copy()
     os.environ['PYTHONDONTWRITEBYTECODE'] = '1'
 
     output = PresubmitOutput(input_stream, output_stream)
     if committing:
       output.write("Running presubmit commit checks ...\n")
     else:
       output.write("Running presubmit upload checks ...\n")
     start_time = time.time()
@@ skipping 56 matching lines @@
       output.write(
           'Was the presubmit check useful? If not, run "git cl presubmit -v"\n'
           'to figure out which PRESUBMIT.py was run, then run git blame\n'
           'on the file to figure out who to ask for help.\n')
       _ASKED_FOR_FEEDBACK = True
     return output
   finally:
     os.environ = old_environ
 
 
+def IsCompiledPython(path):
+  """Tests whether a given path looks like a compiled Python file."""
+  # Validate the magic number.
+  with open(path, 'rb') as fd:
+    magic = fd.read(8)
+  return len(magic) == 8 and magic[2:4] == '\x0d\x0a'
+
+
+def CleanOrphanedCompiledPython(output, path, remove):
+  """Clears all compiled Python files in a directory recursively."""
+  pyc_files = []
+  for dirpath, _, filenames in os.walk(path):
+    for filename in filenames:
+      name, ext = os.path.splitext(filename)
+      if ext != '.pyc':
+        continue
+
+      # Is there an accompanying Python script? If so, leave the compiled file.
+      py_path = os.path.join(dirpath, '%s.py' % (name,))
+      if os.path.isfile(py_path):
+        continue
+
+      # Make sure this is compiled Python before we delete it.
+      path = os.path.join(dirpath, filename)
+      if not IsCompiledPython(path):
+        continue
+      pyc_files.append(path)
+  if pyc_files and not remove:
+    output.write(
+        'Warning: Found orphaned compiled Python files. These should be\n'
+        'removed before running PRESUBMIT, as they can have unexpected impact\n'
+        'on checks and tests:\n')
+    for pyc_file in pyc_files:
+      output.write('  %s\n' % (pyc_file,))
+  else:
+    for pyc_file in pyc_files:
+      output.write('Removing orphaned compiled Python file: %s\n' % (pyc_file,))
+      os.remove(pyc_file)
+
+
 def ScanSubDirs(mask, recursive):
   if not recursive:
     return [x for x in glob.glob(mask) if x not in ('.svn', '.git')]
   else:
     results = []
     for root, dirs, files in os.walk('.'):
       if '.svn' in dirs:
         dirs.remove('.svn')
       if '.git' in dirs:
         dirs.remove('.git')
@@ skipping 214 matching lines @@
   except PresubmitFailure, e:
     print >> sys.stderr, e
     print >> sys.stderr, 'Maybe your depot_tools is out of date?'
     print >> sys.stderr, 'If all fails, contact maruel@'
     return 2
 
 
 if __name__ == '__main__':
   fix_encoding.fix_encoding()
   sys.exit(Main(None))