util: Add config option checker.

There are several cases in the EC code base where a CONFIG_* option is
used somewhere, but not defined within the include/config.h file.  This
script aims to fix that.  Eventually, it will become a presubmit hook to
actively prevent future offenses.

BUG=chrome-os-partner:26304
BRANCH=none
TEST=cros lint --debug util/config_option_check.py
TEST=Ran script and found offending config options.
TEST=make -j buildall tests

Change-Id: I999d32ebacc636b3fff9e857f3cc46feee475e80
Signed-off-by: Aseda Aboagye <aaboagye@google.com>
Reviewed-on: https://chromium-review.googlesource.com/281626
Tested-by: Aseda Aboagye <aaboagye@chromium.org>
Reviewed-by: Randall Spangler <rspangler@chromium.org>
Commit-Queue: Aseda Aboagye <aaboagye@chromium.org>
Trybot-Ready: Aseda Aboagye <aaboagye@chromium.org>

util/config_option_check.py

@@ -0,0 +1,103 @@
+#!/usr/bin/python2
+# Copyright 2015 The Chromium OS Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+"""Configuration Option Checker.
+
+Script to ensure that all configuration options for the Chrome EC are defined
+in config.h.
+"""
+from __future__ import print_function
+import re
+import os
+import argparse
+
+def find_files_to_check(args):
+  """Returns a list of files to check."""
+  file_list = []
+  if args.all_files:
+    cwd = os.getcwd()
+    for (dirpath, dirnames, filenames) in os.walk(cwd, topdown=True):
+      # Ignore the build and private directories (taken from .gitignore)
+      if 'build' in dirnames:
+        dirnames.remove('build')
+      if 'private' in dirnames:
+        dirnames.remove('private')
+      for f in filenames:
+        # Only consider C source and assembler files.
+        if f.endswith(('.c', '.h', '.inc', '.S')):
+          file_list.append(os.path.join(dirpath, f))
+  else:
+    # Form list from presubmit environment variable.
+    file_list = os.environ['PRESUBMIT_FILES'].split()
+  return file_list
+
+def obtain_current_config_options():
+  """Obtains current config options from include/config.h"""
+  config_options = []
+  config_option_re = re.compile(r'\s+(CONFIG_[a-zA-Z0-9_]*)\s*')
+  with open('include/config.h', 'r') as config_file:
+    for line in config_file:
+      match = re.search(config_option_re, line)
+      if match:
+        if match.group(1) not in config_options:
+          config_options.append(match.group(1))
+  return config_options
+
+def print_missing_config_options(file_list, config_options):
+  """Searches through all files in file_list for missing config options."""
+  missing_config_option = False
+  print_banner = True
+  # Determine longest CONFIG_* length to be used for formatting.
+  max_option_length = max(len(option) for option in config_options)
+  config_option_re = re.compile(r'\s+(CONFIG_[a-zA-Z0-9_]*)\s*')
+  for f in file_list:
+    with open(f, 'r') as cur_file:
+      line_num = 0
+      for line in cur_file:
+        line_num += 1
+        match = re.search(config_option_re, line)
+        if match:
+          if match.group(1) not in config_options:
+            missing_config_option = True
+            # Print the banner once.
+            if print_banner:
+              print('Please add all new config options to include/config.h' \
+                    ' along with a description of the option.\n\n' \
+                    'The following config options were found to be missing ' \
+                    'from include/config.h.\n')
+              print_banner = False
+            # Print the misssing config option.
+            print('> %-*s %s:%s' % (max_option_length, match.group(1), f,
+                                    line_num))
+  return missing_config_option
+
+def main():
+  """Searches through specified source files for missing config options.
+
+  Checks through specified C source and assembler file (not in the build/ and
+  private/ directories) for CONFIG_* options.  Then checks to make sure that
+  all CONFIG_* options are defined in include/config.h.  Finally, reports any
+  missing config options.  By default, it will check just the files in the CL.
+  To check all files in EC code base, run with the flag --all_files.
+  """
+  # Create argument options to specify checking either all the files in the EC
+  # code base or just the files in the CL.
+  parser = argparse.ArgumentParser(description='configuration option checker.')
+  parser.add_argument('--all_files', help='check all files in EC code base',
+                      action='store_true')
+  args = parser.parse_args()
+
+  # Create list of files to search.
+  file_list = find_files_to_check(args)
+  # Obtain config options from include/config.h.
+  config_options = obtain_current_config_options()
+  # Find any missing config options from file list and print them.
+  missing_opts = print_missing_config_options(file_list, config_options)
+
+  if missing_opts:
+    print('\nIt may also be possible that you have a typo.')
+    os.sys.exit(1)
+
+if __name__ == '__main__':
+  main()