[Cronet] Use gn desc to find third party licenses on Android.

components/cronet/tools/cronet_licenses.py

 #!/usr/bin/python
 # Copyright 2014 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.
 
 """Generates the contents of an Cronet LICENSE file for the third-party code.
 
 It makes use of src/tools/licenses.py and the README.chromium files on which
 it depends. Based on android_webview/tools/webview_licenses.py.
 """
@@ skipping 33 matching lines @@
 
 def GenerateLicense():
   """Generates the contents of an Cronet LICENSE file for the third-party code.
   Returns:
     The contents of the LICENSE file.
   """
   # Start with Chromium's LICENSE file
   content = [_ReadFile('LICENSE')]
 
   # Add necessary third_party.
-  for directory in sorted(third_party_dirs):
+  for directory in sorted(third_party_dirs, key=os.path.basename):
     metadata = licenses.ParseDir(directory, REPOSITORY_ROOT,
                                  require_license_file=True)
     content.append('-' * 20)
     content.append(directory.split("/")[-1])
     content.append('-' * 20)
     license_file = metadata['License File']
     if license_file and license_file != licenses.NOT_SHIPPED:
       content.append(_ReadFile(license_file))
 
   return '\n'.join(content)
 
 
 def FindThirdPartyDeps(gn_out_dir):
   # Generate gn project in temp directory and use it to find dependencies.
   # Current gn directory cannot ba used because gn doesn't allow recursive
   # invocations due to potential side effects.
   try:
-    tmp_dir = tempfile.mkdtemp(dir = gn_out_dir)
-    shutil.copy(gn_out_dir + "/args.gn", tmp_dir)
+    tmp_dir = tempfile.mkdtemp(dir = os.path.join(gn_out_dir, ".."))
+    shutil.copy(os.path.join(gn_out_dir, "args.gn"), tmp_dir)
     subprocess.check_output(["gn", "gen", tmp_dir])
     gn_deps = subprocess.check_output(["gn", "desc", tmp_dir, \
                                     "//net", "deps", "--as=buildfile", "--all"])
   finally:
     if os.path.exists(tmp_dir):
       shutil.rmtree(tmp_dir)
 
   third_party_deps = []
   for build_dep in gn_deps.split():
-    if ("third_party" in build_dep and build_dep.endswith("/BUILD.gn")):
-      third_party_deps.append(build_dep.replace("/BUILD.gn", ""))
-  third_party_deps.sort()
+    if ("third_party" in build_dep and not "android_tools" in build_dep and

[xunjieli, 2016/07/18 14:54:50]

Could you add a brief comment here on why we are excluding "android_tools" ?

[mef, 2016/07/18 15:45:20]

Done. There is no license in build/secondary/third_party/android_tools.

+        os.path.basename(build_dep) == "BUILD.gn"):
+      third_party_deps.append(os.path.dirname(build_dep))
   return third_party_deps
 
 
 def main():
   class FormatterWithNewLines(optparse.IndentedHelpFormatter):
     def format_description(self, description):
       paras = description.split('\n')
       formatted_paras = [textwrap.fill(para, self.width) for para in paras]
       return '\n'.join(formatted_paras) + '\n'
 
   parser = optparse.OptionParser(formatter=FormatterWithNewLines(),
                                  usage='%prog command [options]')
   parser.add_option('--gn', help='Use gn deps to find third party dependencies',

[xunjieli, 2016/07/18 14:54:50]

The "--gn" option is added here, why do we need it in
components/cronet/android/BUILD.gn line 820 too?

[mef, 2016/07/18 15:45:20]

It is added here to option parser, so it is recognized.
We need it in components/cronet/android/BUILD.gn line 820 to pass it to the
script (otherwise it will use hard-coded list defined at line 26).

[xunjieli, 2016/07/18 21:33:12]

You are right! I missed that part of the code. Thanks for explaining.

                     action='store_true')
   parser.description = (__doc__ +
                        '\nCommands:\n' \
                        '  license [filename]\n' \
                        '    Generate Cronet LICENSE to filename or stdout.\n')
   (_, args) = parser.parse_args()
 
   if _.gn:
     global third_party_dirs
     third_party_dirs = FindThirdPartyDeps(os.getcwd())
@@ skipping 13 matching lines @@
     else:
       print GenerateLicense()
     return 0
 
   parser.print_help()
   return 1
 
 
 if __name__ == '__main__':
   sys.exit(main())