Pass license-checker script for base/third_party/*.

tools/licenses.py

 #!/usr/bin/python
 # Copyright (c) 2010 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.
 
 """
 Utilities for checking and processing licensing information in third_party
 directories.
 """
 
 import os
 
 
 class LicenseError(Exception):
     """We raise this exception when a directory's licensing info isn't
     fully filled out."""
     pass
 
 
 def ParseDir(path):
     """Examine a third_party/foo component and extract its metadata."""
 
     # Try to find README.chromium.
     readme_path = os.path.join(path, 'README.chromium')
     if not os.path.exists(readme_path):
         raise LicenseError("missing README.chromium")
 
     # Parse metadata fields out of README.chromium.
+    # We provide a default value of "LICENSE" for the license file.
     metadata = {
-        "License File": None,  # Relative path to license text.
-        "Name": None,          # Short name (for header on about:credits).
-        "URL": None,           # Project home page.
+        "License File": "LICENSE",  # Relative path to license text.
+        "Name": None,               # Short name (for header on about:credits).
+        "URL": None,                # Project home page.
         }
     for line in open(readme_path):
         line = line.strip()
         for key in metadata.keys():
             field = key + ": "
             if line.startswith(field):
                 metadata[key] = line[len(field):]
 
     # Check that all expected metadata is present.
     for key, value in metadata.iteritems():
         if not value:
             raise LicenseError("couldn't find '" + key + "' line "
                                "in README.chromium")
 
     # Check that the license file exists.
     license_file = metadata["License File"]
     license_path = os.path.join(path, license_file)
     if not os.path.exists(license_path):
-        raise LicenseError("README.chromium mentions license file '" +
-                           license_file + "' that doesn't exist")
+        raise LicenseError("License file '" + license_file + "' doesn't exist. "
+                           "Either add a 'License File:' section to "
+                           "README.chromium or add the missing file.")
 
     return metadata
 
 
 def ScanThirdPartyDirs(third_party_dirs):
     """Scan a list of directories and report on any problems we find."""
     errors = []
     for path in sorted(third_party_dirs):
         try:
             metadata = ParseDir(path)
@@ skipping 26 matching lines @@
             # Don't recurse into any subdirs from here.
             dirs[:] = []
             continue
 
     return third_party_dirs
 
 
 if __name__ == '__main__':
     third_party_dirs = FindThirdPartyDirs()
     ScanThirdPartyDirs(third_party_dirs)