tools/licenses.py - chromium/src - Git at Google

 #!/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.

 """Utility for checking and processing licensing information in third_party
 directories.

 Usage: licenses.py <command>

 Commands:
   scan     scan third_party directories, verifying that we have licensing info
   credits  generate about:credits on stdout

 (You can also import this as a module.)
 """

 import cgi
 import os
 import sys

 # Paths from the root of the tree to directories to skip.
 PRUNE_PATHS = set([
     # Same module occurs in crypto/third_party/nss and net/third_party/nss, so
     # skip this one.
     os.path.join('third_party','nss'),

     # Placeholder directory only, not third-party code.
     os.path.join('third_party','adobe'),

     # Build files only, not third-party code.
     os.path.join('third_party','widevine'),

     # Only binaries, used during development.
     os.path.join('third_party','valgrind'),

     # Used for development and test, not in the shipping product.
     os.path.join('build','secondary'),
     os.path.join('third_party','bison'),
     os.path.join('third_party','blanketjs'),
     os.path.join('third_party','cygwin'),
     os.path.join('third_party','gnu_binutils'),
     os.path.join('third_party','gold'),
     os.path.join('third_party','gperf'),
     os.path.join('third_party','lighttpd'),
     os.path.join('third_party','llvm'),
     os.path.join('third_party','llvm-build'),
     os.path.join('third_party','mingw-w64'),
     os.path.join('third_party','nacl_sdk_binaries'),
     os.path.join('third_party','pefile'),
     os.path.join('third_party','perl'),
     os.path.join('third_party','psyco_win32'),
     os.path.join('third_party','pylib'),
     os.path.join('third_party','pywebsocket'),
     os.path.join('third_party','qunit'),
     os.path.join('third_party','sinonjs'),
     os.path.join('third_party','syzygy'),
     os.path.join('tools', 'profile_chrome', 'third_party'),

     # Chromium code in third_party.
     os.path.join('third_party','fuzzymatch'),
     os.path.join('tools', 'swarming_client'),

     # Stuff pulled in from chrome-internal for official builds/tools.
     os.path.join('third_party', 'clear_cache'),
     os.path.join('third_party', 'gnu'),
     os.path.join('third_party', 'googlemac'),
     os.path.join('third_party', 'pcre'),
     os.path.join('third_party', 'psutils'),
     os.path.join('third_party', 'sawbuck'),

     # Redistribution does not require attribution in documentation.
     os.path.join('third_party','directxsdk'),
     os.path.join('third_party','platformsdk_win2008_6_1'),
     os.path.join('third_party','platformsdk_win7'),
 ])

 # Directories we don't scan through.
 VCS_METADATA_DIRS = ('.svn', '.git')
 PRUNE_DIRS = (VCS_METADATA_DIRS +
               ('out', 'Debug', 'Release',  # build files
                'layout_tests'))            # lots of subdirs

 ADDITIONAL_PATHS = (
     os.path.join('breakpad'),
     os.path.join('chrome', 'common', 'extensions', 'docs', 'examples'),
     os.path.join('chrome', 'test', 'chromeos', 'autotest'),
     os.path.join('chrome', 'test', 'data'),
     os.path.join('native_client'),
     os.path.join('net', 'tools', 'spdyshark'),
     os.path.join('sdch', 'open-vcdiff'),
     os.path.join('testing', 'gmock'),
     os.path.join('testing', 'gtest'),
     os.path.join('tools', 'grit'),
     os.path.join('tools', 'gyp'),
     os.path.join('tools', 'page_cycler', 'acid3'),
     os.path.join('url', 'third_party', 'mozilla'),
     os.path.join('v8'),
     # Fake directory so we can include the strongtalk license.
     os.path.join('v8', 'strongtalk'),
     os.path.join('v8', 'third_party', 'fdlibm'),
 )


 # Directories where we check out directly from upstream, and therefore
 # can't provide a README.chromium.  Please prefer a README.chromium
 # wherever possible.
 SPECIAL_CASES = {
     os.path.join('native_client'): {
         "Name": "native client",
         "URL": "http://code.google.com/p/nativeclient",
         "License": "BSD",
     },
     os.path.join('sdch', 'open-vcdiff'): {
         "Name": "open-vcdiff",
         "URL": "http://code.google.com/p/open-vcdiff",
         "License": "Apache 2.0, MIT, GPL v2 and custom licenses",
         "License Android Compatible": "yes",
     },
     os.path.join('testing', 'gmock'): {
         "Name": "gmock",
         "URL": "http://code.google.com/p/googlemock",
         "License": "BSD",
         "License File": "NOT_SHIPPED",
     },
     os.path.join('testing', 'gtest'): {
         "Name": "gtest",
         "URL": "http://code.google.com/p/googletest",
         "License": "BSD",
         "License File": "NOT_SHIPPED",
     },
     os.path.join('third_party', 'angle'): {
         "Name": "Almost Native Graphics Layer Engine",
         "URL": "http://code.google.com/p/angleproject/",
         "License": "BSD",
     },
     os.path.join('third_party', 'cros_system_api'): {
         "Name": "Chromium OS system API",
         "URL": "http://www.chromium.org/chromium-os",
         "License": "BSD",
         # Absolute path here is resolved as relative to the source root.
         "License File": "/LICENSE.chromium_os",
     },
     os.path.join('third_party', 'lss'): {
         "Name": "linux-syscall-support",
         "URL": "http://code.google.com/p/linux-syscall-support/",
         "License": "BSD",
         "License File": "/LICENSE",
     },
     os.path.join('third_party', 'ots'): {
         "Name": "OTS (OpenType Sanitizer)",
         "URL": "http://code.google.com/p/ots/",
         "License": "BSD",
     },
     os.path.join('third_party', 'pdfium'): {
         "Name": "PDFium",
         "URL": "http://code.google.com/p/pdfium/",
         "License": "BSD",
     },
     os.path.join('third_party', 'pdfsqueeze'): {
         "Name": "pdfsqueeze",
         "URL": "http://code.google.com/p/pdfsqueeze/",
         "License": "Apache 2.0",
         "License File": "COPYING",
     },
     os.path.join('third_party', 'ppapi'): {
         "Name": "ppapi",
         "URL": "http://code.google.com/p/ppapi/",
     },
     os.path.join('third_party', 'scons-2.0.1'): {
         "Name": "scons-2.0.1",
         "URL": "http://www.scons.org",
         "License": "MIT",
         "License File": "NOT_SHIPPED",
     },
     os.path.join('third_party', 'trace-viewer'): {
         "Name": "trace-viewer",
         "URL": "http://code.google.com/p/trace-viewer",
         "License": "BSD",
         "License File": "NOT_SHIPPED",
     },
     os.path.join('third_party', 'v8-i18n'): {
         "Name": "Internationalization Library for v8",
         "URL": "http://code.google.com/p/v8-i18n/",
         "License": "Apache 2.0",
     },
     os.path.join('third_party', 'WebKit'): {
         "Name": "WebKit",
         "URL": "http://webkit.org/",
         "License": "BSD and GPL v2",
         # Absolute path here is resolved as relative to the source root.
         "License File": "/webkit/LICENSE",
     },
     os.path.join('third_party', 'webpagereplay'): {
         "Name": "webpagereplay",
         "URL": "http://code.google.com/p/web-page-replay",
         "License": "Apache 2.0",
         "License File": "NOT_SHIPPED",
     },
     os.path.join('tools', 'grit'): {
         "Name": "grit",
         "URL": "http://code.google.com/p/grit-i18n",
         "License": "BSD",
         "License File": "NOT_SHIPPED",
     },
     os.path.join('tools', 'gyp'): {
         "Name": "gyp",
         "URL": "http://code.google.com/p/gyp",
         "License": "BSD",
         "License File": "NOT_SHIPPED",
     },
     os.path.join('v8'): {
         "Name": "V8 JavaScript Engine",
         "URL": "http://code.google.com/p/v8",
         "License": "BSD",
     },
     os.path.join('v8', 'strongtalk'): {
         "Name": "Strongtalk",
         "URL": "http://www.strongtalk.org/",
         "License": "BSD",
         # Absolute path here is resolved as relative to the source root.
         "License File": "/v8/LICENSE.strongtalk",
     },
     os.path.join('v8', 'third_party', 'fdlibm'): {
         "Name": "fdlibm",
         "URL": "http://www.netlib.org/fdlibm/",
         "License": "Freely Distributable",
         # Absolute path here is resolved as relative to the source root.
         "License File" : "/v8/third_party/fdlibm/LICENSE",
         "License Android Compatible" : "yes",
     },
     os.path.join('third_party', 'khronos_glcts'): {
         # These sources are not shipped, are not public, and it isn't
         # clear why they're tripping the license check.
         "Name": "khronos_glcts",
         "URL": "http://no-public-url",
         "License": "Khronos",
         "License File": "NOT_SHIPPED",
     },
 }

 # Special value for 'License File' field used to indicate that the license file
 # should not be used in about:credits.
 NOT_SHIPPED = "NOT_SHIPPED"


 class LicenseError(Exception):
     """We raise this exception when a directory's licensing info isn't
     fully filled out."""
     pass

 def AbsolutePath(path, filename, root):
     """Convert a path in README.chromium to be absolute based on the source
     root."""
     if filename.startswith('/'):
         # Absolute-looking paths are relative to the source root
         # (which is the directory we're run from).
         absolute_path = os.path.join(root, filename[1:])
     else:
         absolute_path = os.path.join(root, path, filename)
     if os.path.exists(absolute_path):
         return absolute_path
     return None

 def ParseDir(path, root, require_license_file=True, optional_keys=None):
     """Examine a third_party/foo component and extract its metadata."""

     # Parse metadata fields out of README.chromium.
     # We examine "LICENSE" for the license file by default.
     metadata = {
         "License File": "LICENSE",  # Relative path to license text.
         "Name": None,               # Short name (for header on about:credits).
         "URL": None,                # Project home page.
         "License": None,            # Software license.
         }

     if optional_keys is None:
         optional_keys = []

     if path in SPECIAL_CASES:
         metadata.update(SPECIAL_CASES[path])
     else:
         # Try to find README.chromium.
         readme_path = os.path.join(root, path, 'README.chromium')
         if not os.path.exists(readme_path):
             raise LicenseError("missing README.chromium or licenses.py "
                                "SPECIAL_CASES entry")

         for line in open(readme_path):
             line = line.strip()
             if not line:
                 break
             for key in metadata.keys() + optional_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 or licences.py "
                                "SPECIAL_CASES")

     # Special-case modules that aren't in the shipping product, so don't need
     # their license in about:credits.
     if metadata["License File"] != NOT_SHIPPED:
         # Check that the license file exists.
         for filename in (metadata["License File"], "COPYING"):
             license_path = AbsolutePath(path, filename, root)
             if license_path is not None:
                 break

         if require_license_file and not license_path:
             raise LicenseError("License file not found. "
                                "Either add a file named LICENSE, "
                                "import upstream's COPYING if available, "
                                "or add a 'License File:' line to "
                                "README.chromium with the appropriate path.")
         metadata["License File"] = license_path

     return metadata


 def ContainsFiles(path, root):
     """Determines whether any files exist in a directory or in any of its
     subdirectories."""
     for _, dirs, files in os.walk(os.path.join(root, path)):
         if files:
             return True
         for vcs_metadata in VCS_METADATA_DIRS:
             if vcs_metadata in dirs:
                 dirs.remove(vcs_metadata)
     return False


 def FilterDirsWithFiles(dirs_list, root):
     # If a directory contains no files, assume it's a DEPS directory for a
     # project not used by our current configuration and skip it.
     return [x for x in dirs_list if ContainsFiles(x, root)]


 def FindThirdPartyDirs(prune_paths, root):
     """Find all third_party directories underneath the source root."""
     third_party_dirs = set()
     for path, dirs, files in os.walk(root):
         path = path[len(root)+1:]  # Pretty up the path.

         if path in prune_paths:
             dirs[:] = []
             continue

         # Prune out directories we want to skip.
         # (Note that we loop over PRUNE_DIRS so we're not iterating over a
         # list that we're simultaneously mutating.)
         for skip in PRUNE_DIRS:
             if skip in dirs:
                 dirs.remove(skip)

         if os.path.basename(path) == 'third_party':
             # Add all subdirectories that are not marked for skipping.
             for dir in dirs:
                 dirpath = os.path.join(path, dir)
                 if dirpath not in prune_paths:
                     third_party_dirs.add(dirpath)

             # Don't recurse into any subdirs from here.
             dirs[:] = []
             continue

         # Don't recurse into paths in ADDITIONAL_PATHS, like we do with regular
         # third_party/foo paths.
         if path in ADDITIONAL_PATHS:
             dirs[:] = []

     for dir in ADDITIONAL_PATHS:
         if dir not in prune_paths:
             third_party_dirs.add(dir)

     return third_party_dirs


 def ScanThirdPartyDirs(root=None):
     """Scan a list of directories and report on any problems we find."""
     if root is None:
       root = os.getcwd()
     third_party_dirs = FindThirdPartyDirs(PRUNE_PATHS, root)
     third_party_dirs = FilterDirsWithFiles(third_party_dirs, root)

     errors = []
     for path in sorted(third_party_dirs):
         try:
             metadata = ParseDir(path, root)
         except LicenseError, e:
             errors.append((path, e.args[0]))
             continue

     for path, error in sorted(errors):
         print path + ": " + error

     return len(errors) == 0


 def GenerateCredits():
     """Generate about:credits."""

     if len(sys.argv) not in (2, 3):
       print 'usage: licenses.py credits [output_file]'
       return False

     def EvaluateTemplate(template, env, escape=True):
         """Expand a template with variables like {{foo}} using a
         dictionary of expansions."""
         for key, val in env.items():
             if escape:
                 val = cgi.escape(val)
             template = template.replace('{{%s}}' % key, val)
         return template

     root = os.path.join(os.path.dirname(__file__), '..')
     third_party_dirs = FindThirdPartyDirs(PRUNE_PATHS, root)

     entry_template = open(os.path.join(root, 'chrome', 'browser', 'resources',
                                        'about_credits_entry.tmpl'), 'rb').read()
     entries = []
     for path in sorted(third_party_dirs):
         try:
             metadata = ParseDir(path, root)
         except LicenseError:
             # TODO(phajdan.jr): Convert to fatal error (http://crbug.com/39240).
             continue
         if metadata['License File'] == NOT_SHIPPED:
             continue
         env = {
             'name': metadata['Name'],
             'url': metadata['URL'],
             'license': open(metadata['License File'], 'rb').read(),
         }
         entries.append(EvaluateTemplate(entry_template, env))

     file_template = open(os.path.join(root, 'chrome', 'browser', 'resources',
                                       'about_credits.tmpl'), 'rb').read()
     template_contents = "<!-- Generated by licenses.py; do not edit. -->"
     template_contents += EvaluateTemplate(file_template,
                                           {'entries': '\n'.join(entries)},
                                           escape=False)

     if len(sys.argv) == 3:
       with open(sys.argv[2], 'w') as output_file:
         output_file.write(template_contents)
     elif len(sys.argv) == 2:
       print template_contents

     return True


 def main():
     command = 'help'
     if len(sys.argv) > 1:
         command = sys.argv[1]

     if command == 'scan':
         if not ScanThirdPartyDirs():
             return 1
     elif command == 'credits':
         if not GenerateCredits():
             return 1
     else:
         print __doc__
         return 1


 if __name__ == '__main__':
   sys.exit(main())
	#!/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.

	"""Utility for checking and processing licensing information in third_party
	directories.

	Usage: licenses.py <command>

	Commands:
	scan scan third_party directories, verifying that we have licensing info
	credits generate about:credits on stdout

	(You can also import this as a module.)
	"""

	import cgi
	import os
	import sys

	# Paths from the root of the tree to directories to skip.
	PRUNE_PATHS = set([
	# Same module occurs in crypto/third_party/nss and net/third_party/nss, so
	# skip this one.
	os.path.join('third_party','nss'),

	# Placeholder directory only, not third-party code.
	os.path.join('third_party','adobe'),

	# Build files only, not third-party code.
	os.path.join('third_party','widevine'),

	# Only binaries, used during development.
	os.path.join('third_party','valgrind'),

	# Used for development and test, not in the shipping product.
	os.path.join('build','secondary'),
	os.path.join('third_party','bison'),
	os.path.join('third_party','blanketjs'),
	os.path.join('third_party','cygwin'),
	os.path.join('third_party','gnu_binutils'),
	os.path.join('third_party','gold'),
	os.path.join('third_party','gperf'),
	os.path.join('third_party','lighttpd'),
	os.path.join('third_party','llvm'),
	os.path.join('third_party','llvm-build'),
	os.path.join('third_party','mingw-w64'),
	os.path.join('third_party','nacl_sdk_binaries'),
	os.path.join('third_party','pefile'),
	os.path.join('third_party','perl'),
	os.path.join('third_party','psyco_win32'),
	os.path.join('third_party','pylib'),
	os.path.join('third_party','pywebsocket'),
	os.path.join('third_party','qunit'),
	os.path.join('third_party','sinonjs'),
	os.path.join('third_party','syzygy'),
	os.path.join('tools', 'profile_chrome', 'third_party'),

	# Chromium code in third_party.
	os.path.join('third_party','fuzzymatch'),
	os.path.join('tools', 'swarming_client'),

	# Stuff pulled in from chrome-internal for official builds/tools.
	os.path.join('third_party', 'clear_cache'),
	os.path.join('third_party', 'gnu'),
	os.path.join('third_party', 'googlemac'),
	os.path.join('third_party', 'pcre'),
	os.path.join('third_party', 'psutils'),
	os.path.join('third_party', 'sawbuck'),

	# Redistribution does not require attribution in documentation.
	os.path.join('third_party','directxsdk'),
	os.path.join('third_party','platformsdk_win2008_6_1'),
	os.path.join('third_party','platformsdk_win7'),
	])

	# Directories we don't scan through.
	VCS_METADATA_DIRS = ('.svn', '.git')
	PRUNE_DIRS = (VCS_METADATA_DIRS +
	('out', 'Debug', 'Release', # build files
	'layout_tests')) # lots of subdirs

	ADDITIONAL_PATHS = (
	os.path.join('breakpad'),
	os.path.join('chrome', 'common', 'extensions', 'docs', 'examples'),
	os.path.join('chrome', 'test', 'chromeos', 'autotest'),
	os.path.join('chrome', 'test', 'data'),
	os.path.join('native_client'),
	os.path.join('net', 'tools', 'spdyshark'),
	os.path.join('sdch', 'open-vcdiff'),
	os.path.join('testing', 'gmock'),
	os.path.join('testing', 'gtest'),
	os.path.join('tools', 'grit'),
	os.path.join('tools', 'gyp'),
	os.path.join('tools', 'page_cycler', 'acid3'),
	os.path.join('url', 'third_party', 'mozilla'),
	os.path.join('v8'),
	# Fake directory so we can include the strongtalk license.
	os.path.join('v8', 'strongtalk'),
	os.path.join('v8', 'third_party', 'fdlibm'),
	)


	# Directories where we check out directly from upstream, and therefore
	# can't provide a README.chromium. Please prefer a README.chromium
	# wherever possible.
	SPECIAL_CASES = {
	os.path.join('native_client'): {
	"Name": "native client",
	"URL": "http://code.google.com/p/nativeclient",
	"License": "BSD",
	},
	os.path.join('sdch', 'open-vcdiff'): {
	"Name": "open-vcdiff",
	"URL": "http://code.google.com/p/open-vcdiff",
	"License": "Apache 2.0, MIT, GPL v2 and custom licenses",
	"License Android Compatible": "yes",
	},
	os.path.join('testing', 'gmock'): {
	"Name": "gmock",
	"URL": "http://code.google.com/p/googlemock",
	"License": "BSD",
	"License File": "NOT_SHIPPED",
	},
	os.path.join('testing', 'gtest'): {
	"Name": "gtest",
	"URL": "http://code.google.com/p/googletest",
	"License": "BSD",
	"License File": "NOT_SHIPPED",
	},
	os.path.join('third_party', 'angle'): {
	"Name": "Almost Native Graphics Layer Engine",
	"URL": "http://code.google.com/p/angleproject/",
	"License": "BSD",
	},
	os.path.join('third_party', 'cros_system_api'): {
	"Name": "Chromium OS system API",
	"URL": "http://www.chromium.org/chromium-os",
	"License": "BSD",
	# Absolute path here is resolved as relative to the source root.
	"License File": "/LICENSE.chromium_os",
	},
	os.path.join('third_party', 'lss'): {
	"Name": "linux-syscall-support",
	"URL": "http://code.google.com/p/linux-syscall-support/",
	"License": "BSD",
	"License File": "/LICENSE",
	},
	os.path.join('third_party', 'ots'): {
	"Name": "OTS (OpenType Sanitizer)",
	"URL": "http://code.google.com/p/ots/",
	"License": "BSD",
	},
	os.path.join('third_party', 'pdfium'): {
	"Name": "PDFium",
	"URL": "http://code.google.com/p/pdfium/",
	"License": "BSD",
	},
	os.path.join('third_party', 'pdfsqueeze'): {
	"Name": "pdfsqueeze",
	"URL": "http://code.google.com/p/pdfsqueeze/",
	"License": "Apache 2.0",
	"License File": "COPYING",
	},
	os.path.join('third_party', 'ppapi'): {
	"Name": "ppapi",
	"URL": "http://code.google.com/p/ppapi/",
	},
	os.path.join('third_party', 'scons-2.0.1'): {
	"Name": "scons-2.0.1",
	"URL": "http://www.scons.org",
	"License": "MIT",
	"License File": "NOT_SHIPPED",
	},
	os.path.join('third_party', 'trace-viewer'): {
	"Name": "trace-viewer",
	"URL": "http://code.google.com/p/trace-viewer",
	"License": "BSD",
	"License File": "NOT_SHIPPED",
	},
	os.path.join('third_party', 'v8-i18n'): {
	"Name": "Internationalization Library for v8",
	"URL": "http://code.google.com/p/v8-i18n/",
	"License": "Apache 2.0",
	},
	os.path.join('third_party', 'WebKit'): {
	"Name": "WebKit",
	"URL": "http://webkit.org/",
	"License": "BSD and GPL v2",
	# Absolute path here is resolved as relative to the source root.
	"License File": "/webkit/LICENSE",
	},
	os.path.join('third_party', 'webpagereplay'): {
	"Name": "webpagereplay",
	"URL": "http://code.google.com/p/web-page-replay",
	"License": "Apache 2.0",
	"License File": "NOT_SHIPPED",
	},
	os.path.join('tools', 'grit'): {
	"Name": "grit",
	"URL": "http://code.google.com/p/grit-i18n",
	"License": "BSD",
	"License File": "NOT_SHIPPED",
	},
	os.path.join('tools', 'gyp'): {
	"Name": "gyp",
	"URL": "http://code.google.com/p/gyp",
	"License": "BSD",
	"License File": "NOT_SHIPPED",
	},
	os.path.join('v8'): {
	"Name": "V8 JavaScript Engine",
	"URL": "http://code.google.com/p/v8",
	"License": "BSD",
	},
	os.path.join('v8', 'strongtalk'): {
	"Name": "Strongtalk",
	"URL": "http://www.strongtalk.org/",
	"License": "BSD",
	# Absolute path here is resolved as relative to the source root.
	"License File": "/v8/LICENSE.strongtalk",
	},
	os.path.join('v8', 'third_party', 'fdlibm'): {
	"Name": "fdlibm",
	"URL": "http://www.netlib.org/fdlibm/",
	"License": "Freely Distributable",
	# Absolute path here is resolved as relative to the source root.
	"License File" : "/v8/third_party/fdlibm/LICENSE",
	"License Android Compatible" : "yes",
	},
	os.path.join('third_party', 'khronos_glcts'): {
	# These sources are not shipped, are not public, and it isn't
	# clear why they're tripping the license check.
	"Name": "khronos_glcts",
	"URL": "http://no-public-url",
	"License": "Khronos",
	"License File": "NOT_SHIPPED",
	},
	}

	# Special value for 'License File' field used to indicate that the license file
	# should not be used in about:credits.
	NOT_SHIPPED = "NOT_SHIPPED"


	class LicenseError(Exception):
	"""We raise this exception when a directory's licensing info isn't
	fully filled out."""
	pass

	def AbsolutePath(path, filename, root):
	"""Convert a path in README.chromium to be absolute based on the source
	root."""
	if filename.startswith('/'):
	# Absolute-looking paths are relative to the source root
	# (which is the directory we're run from).
	absolute_path = os.path.join(root, filename[1:])
	else:
	absolute_path = os.path.join(root, path, filename)
	if os.path.exists(absolute_path):
	return absolute_path
	return None

	def ParseDir(path, root, require_license_file=True, optional_keys=None):
	"""Examine a third_party/foo component and extract its metadata."""

	# Parse metadata fields out of README.chromium.
	# We examine "LICENSE" for the license file by default.
	metadata = {
	"License File": "LICENSE", # Relative path to license text.
	"Name": None, # Short name (for header on about:credits).
	"URL": None, # Project home page.
	"License": None, # Software license.
	}

	if optional_keys is None:
	optional_keys = []

	if path in SPECIAL_CASES:
	metadata.update(SPECIAL_CASES[path])
	else:
	# Try to find README.chromium.
	readme_path = os.path.join(root, path, 'README.chromium')
	if not os.path.exists(readme_path):
	raise LicenseError("missing README.chromium or licenses.py "
	"SPECIAL_CASES entry")

	for line in open(readme_path):
	line = line.strip()
	if not line:
	break
	for key in metadata.keys() + optional_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 or licences.py "
	"SPECIAL_CASES")

	# Special-case modules that aren't in the shipping product, so don't need
	# their license in about:credits.
	if metadata["License File"] != NOT_SHIPPED:
	# Check that the license file exists.
	for filename in (metadata["License File"], "COPYING"):
	license_path = AbsolutePath(path, filename, root)
	if license_path is not None:
	break

	if require_license_file and not license_path:
	raise LicenseError("License file not found. "
	"Either add a file named LICENSE, "
	"import upstream's COPYING if available, "
	"or add a 'License File:' line to "
	"README.chromium with the appropriate path.")
	metadata["License File"] = license_path

	return metadata


	def ContainsFiles(path, root):
	"""Determines whether any files exist in a directory or in any of its
	subdirectories."""
	for _, dirs, files in os.walk(os.path.join(root, path)):
	if files:
	return True
	for vcs_metadata in VCS_METADATA_DIRS:
	if vcs_metadata in dirs:
	dirs.remove(vcs_metadata)
	return False


	def FilterDirsWithFiles(dirs_list, root):
	# If a directory contains no files, assume it's a DEPS directory for a
	# project not used by our current configuration and skip it.
	return [x for x in dirs_list if ContainsFiles(x, root)]


	def FindThirdPartyDirs(prune_paths, root):
	"""Find all third_party directories underneath the source root."""
	third_party_dirs = set()
	for path, dirs, files in os.walk(root):
	path = path[len(root)+1:] # Pretty up the path.

	if path in prune_paths:
	dirs[:] = []
	continue

	# Prune out directories we want to skip.
	# (Note that we loop over PRUNE_DIRS so we're not iterating over a
	# list that we're simultaneously mutating.)
	for skip in PRUNE_DIRS:
	if skip in dirs:
	dirs.remove(skip)

	if os.path.basename(path) == 'third_party':
	# Add all subdirectories that are not marked for skipping.
	for dir in dirs:
	dirpath = os.path.join(path, dir)
	if dirpath not in prune_paths:
	third_party_dirs.add(dirpath)

	# Don't recurse into any subdirs from here.
	dirs[:] = []
	continue

	# Don't recurse into paths in ADDITIONAL_PATHS, like we do with regular
	# third_party/foo paths.
	if path in ADDITIONAL_PATHS:
	dirs[:] = []

	for dir in ADDITIONAL_PATHS:
	if dir not in prune_paths:
	third_party_dirs.add(dir)

	return third_party_dirs


	def ScanThirdPartyDirs(root=None):
	"""Scan a list of directories and report on any problems we find."""
	if root is None:
	root = os.getcwd()
	third_party_dirs = FindThirdPartyDirs(PRUNE_PATHS, root)
	third_party_dirs = FilterDirsWithFiles(third_party_dirs, root)

	errors = []
	for path in sorted(third_party_dirs):
	try:
	metadata = ParseDir(path, root)
	except LicenseError, e:
	errors.append((path, e.args[0]))
	continue

	for path, error in sorted(errors):
	print path + ": " + error

	return len(errors) == 0


	def GenerateCredits():
	"""Generate about:credits."""

	if len(sys.argv) not in (2, 3):
	print 'usage: licenses.py credits [output_file]'
	return False

	def EvaluateTemplate(template, env, escape=True):
	"""Expand a template with variables like {{foo}} using a
	dictionary of expansions."""
	for key, val in env.items():
	if escape:
	val = cgi.escape(val)
	template = template.replace('{{%s}}' % key, val)
	return template

	root = os.path.join(os.path.dirname(__file__), '..')
	third_party_dirs = FindThirdPartyDirs(PRUNE_PATHS, root)

	entry_template = open(os.path.join(root, 'chrome', 'browser', 'resources',
	'about_credits_entry.tmpl'), 'rb').read()
	entries = []
	for path in sorted(third_party_dirs):
	try:
	metadata = ParseDir(path, root)
	except LicenseError:
	# TODO(phajdan.jr): Convert to fatal error (http://crbug.com/39240).
	continue
	if metadata['License File'] == NOT_SHIPPED:
	continue
	env = {
	'name': metadata['Name'],
	'url': metadata['URL'],
	'license': open(metadata['License File'], 'rb').read(),
	}
	entries.append(EvaluateTemplate(entry_template, env))

	file_template = open(os.path.join(root, 'chrome', 'browser', 'resources',
	'about_credits.tmpl'), 'rb').read()
	template_contents = "<!-- Generated by licenses.py; do not edit. -->"
	template_contents += EvaluateTemplate(file_template,
	{'entries': '\n'.join(entries)},
	escape=False)

	if len(sys.argv) == 3:
	with open(sys.argv[2], 'w') as output_file:
	output_file.write(template_contents)
	elif len(sys.argv) == 2:
	print template_contents

	return True


	def main():
	command = 'help'
	if len(sys.argv) > 1:
	command = sys.argv[1]

	if command == 'scan':
	if not ScanThirdPartyDirs():
	return 1
	elif command == 'credits':
	if not GenerateCredits():
	return 1
	else:
	print __doc__
	return 1


	if __name__ == '__main__':
	sys.exit(main())