Make javac and jar a single build action

build/android/gyp/jar.py

 #!/usr/bin/env python
 #
 # Copyright 2013 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.
 
 import fnmatch
 import optparse
 import os
 import sys
 
 from util import build_utils
 from util import md5_check
 
-
-def DoJar(options):
-  class_files = build_utils.FindInDirectory(options.classes_dir, '*.class')
-  for exclude in build_utils.ParseGypList(options.excluded_classes):
-    class_files = filter(
-        lambda f: not fnmatch.fnmatch(f, exclude), class_files)
-
-  jar_path = os.path.abspath(options.jar_path)
+def Jar(class_files, classes_dir, jar_path):
+  jar_path = os.path.abspath(jar_path)
 
   # The paths of the files in the jar will be the same as they are passed in to
   # the command. Because of this, the command should be run in
   # options.classes_dir so the .class file paths in the jar are correct.
-  jar_cwd = options.classes_dir
+  jar_cwd = classes_dir
   class_files_rel = [os.path.relpath(f, jar_cwd) for f in class_files]
   jar_cmd = ['jar', 'cf0', jar_path] + class_files_rel
 
-  record_path = '%s.md5.stamp' % options.jar_path
+  record_path = '%s.md5.stamp' % jar_path
   md5_check.CallAndRecordIfStale(
       lambda: build_utils.CheckOutput(jar_cmd, cwd=jar_cwd),
       record_path=record_path,
       input_paths=class_files,
-      input_strings=jar_cmd)
+      input_strings=jar_cmd,
+      force=not os.path.exists(jar_path),
+      )
 
-  build_utils.Touch(options.jar_path)
+  build_utils.Touch(jar_path, fail_if_missing=True)
 
 
+def JarDirectory(classes_dir, excluded_classes, jar_path):
+  class_files = build_utils.FindInDirectory(classes_dir, '*.class')
+  for exclude in excluded_classes:
+    class_files = filter(
+        lambda f: not fnmatch.fnmatch(f, exclude), class_files)
+
+  Jar(class_files, classes_dir, jar_path)
+
 def main():
   parser = optparse.OptionParser()
   parser.add_option('--classes-dir', help='Directory containing .class files.')
   parser.add_option('--jar-path', help='Jar output path.')
   parser.add_option('--excluded-classes',
       help='List of .class file patterns to exclude from the jar.')
   parser.add_option('--stamp', help='Path to touch on success.')
 
   options, _ = parser.parse_args()
 
-  DoJar(options)
+  JarDirectory(options.classes_dir,
+               build_utils.ParseGypList(options.excluded_classes),
+               options.jar_path)
 
   if options.stamp:
     build_utils.Touch(options.stamp)
 
 
 if __name__ == '__main__':
   sys.exit(main())