[Android WebView] Make 3rd party licenses checker to turn bot red

android_webview/tools/webview_licenses.py

Index: android_webview/tools/webview_licenses.py
diff --git a/android_webview/tools/webview_licenses.py b/android_webview/tools/webview_licenses.py
index 3e9aef6a6cdf030c1f8275bffc7509435b6da01e..86bff383fc564c148516178f79baa12617d79749 100755
--- a/android_webview/tools/webview_licenses.py
+++ b/android_webview/tools/webview_licenses.py
@@ -74,6 +74,8 @@ def GetIncompatibleDirectories():
         break
   return result
 
+class ScanResult(object):
+  Ok, Warnings, Errors = range(3)
 
 def _CheckLicenseHeaders(excluded_dirs_list, whitelisted_files):
   """Checks that all files which are not in a listed third-party directory,
@@ -82,8 +84,10 @@ def _CheckLicenseHeaders(excluded_dirs_list, whitelisted_files):
     excluded_dirs_list: The list of directories to exclude from scanning.
     whitelisted_files: The whitelist of files.
   Returns:
-    True if all files with non-standard license headers are whitelisted and the
-    whitelist contains no stale entries, otherwise false.
+    ScanResult.Ok if all files with non-standard license headers are whitelisted
+    and the whitelist contains no stale entries;
+    ScanResult.Warnings if there are stale entries;
+    ScanResult.Errors if new non-whitelisted entries found.
   """
 
   excluded_dirs_list = [d for d in excluded_dirs_list if not 'third_party' in d]
@@ -129,23 +133,25 @@ def _CheckLicenseHeaders(excluded_dirs_list, whitelisted_files):
         offending_files.append(os.path.normpath(entries[0]))
         break
 
-  all_files_valid = True
   unknown = set(offending_files) - set(whitelisted_files)
   if unknown:
     print 'The following files contain a third-party license but are not in ' \
           'a listed third-party directory and are not whitelisted. You must ' \
           'add the following files to the whitelist.\n%s' % \
           '\n'.join(sorted(unknown))
-    all_files_valid = False
 
   stale = set(whitelisted_files) - set(offending_files)
   if stale:
     print 'The following files are whitelisted unnecessarily. You must ' \
           ' remove the following files from the whitelist.\n%s' % \
           '\n'.join(sorted(stale))
-    all_files_valid = False
 
-  return all_files_valid
+  if unknown:
+    return ScanResult.Errors
+  elif stale:
+    return ScanResult.Warnings
+  else:
+    return ScanResult.Ok
 
 
 def _ReadFile(path):
@@ -186,9 +192,13 @@ def _FindThirdPartyDirs():
 
 
 def _Scan():
-  """Checks that license meta-data is present for all third-party code.
+  """Checks that license meta-data is present for all third-party code and
+     that all non third-party code doesn't contain external copyrighted code.
   Returns:
-    Whether the check succeeded.
+    ScanResult.Ok if everything is in order;
+    ScanResult.Warnings if there are non-fatal problems (e.g. stale whitelist
+      entries)
+    ScanResult.Errors otherwise.
   """
 
   third_party_dirs = _FindThirdPartyDirs()
@@ -211,8 +221,9 @@ def _Scan():
     match = re.match(r'([^#\s]+)', line)
     if match:
       whitelisted_files.append(match.group(1))
-  return _CheckLicenseHeaders(third_party_dirs, whitelisted_files) \
-      and all_licenses_valid
+  licenses_check = _CheckLicenseHeaders(third_party_dirs, whitelisted_files)
+
+  return licenses_check if all_licenses_valid else ScanResult.Errors
 
 
 def GenerateNoticeFile():
@@ -255,20 +266,19 @@ def main():
   (options, args) = parser.parse_args()
   if len(args) != 1:
     parser.print_help()
-    return 1
+    return ScanResult.Errors
 
   if args[0] == 'scan':
-    if _Scan():
+    scan_result = _Scan()
+    if scan_result == ScanResult.Ok:
       print 'OK!'
-      return 0
-    else:
-      return 1
+    return scan_result
   elif args[0] == 'notice':
     print GenerateNoticeFile()
-    return 0
+    return ScanResult.Ok
 
   parser.print_help()
-  return 1
+  return ScanResult.Errors
 
 if __name__ == '__main__':
   sys.exit(main())