[Android] Create and use .TOC files for jars

build/android/gyp/jar_toc.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.
+
+"""Creates a TOC file from a Java jar.
+
+The TOC file contains the non-package API of the jar. This includes all
+public/protected classes/functions/members and the values of static final
+variables. Some other information (major/minor javac version) is also included.
+
+This TOC file then can be used to determine if a dependent library should be
+rebuilt when this jar changes. I.e. any change to the jar that would require a
+rebuild, will have a corresponding change in the TOC file.
+"""
+
+import optparse
+import os
+import re
+import sys
+import zipfile
+
+from util import build_utils
+from util import md5_check
+
+
+def GetClassesInZipFile(zip_file):
+  classes = []
+  files = zip_file.namelist()
+  for f in files:
+    if f.endswith('.class'):
+      # f is of the form org/chromium/base/Class$Inner.class
+      classes.append(f.replace('/', '.')[:-6])
+  return classes
+
+
+def CallJavap(classpath, classes):
+  javap_cmd = [
+      'javap',
+      '-public',
+      '-protected',
+      # -verbose is required to get constant values (which can be inlined in
+      # dependents).
+      '-verbose',
+      '-classpath', classpath
+      ] + classes
+  return build_utils.CheckCallDie(javap_cmd, suppress_output=True)
+
+
+def ExtractToc(disassembled_classes):
+  # javap output is structured by indent (2-space) levels.
+  good_patterns = [
+      '^[^ ]', # This includes all class/function/member signatures.
+      '^  SourceFile:',
+      '^  minor version:',
+      '^  major version:',
+      '^  Constant value:',
+      ]
+  bad_patterns = [
+      '^const #', # Matches the constant pool (i.e. literals used in the class).
+    ]
+
+  def JavapFilter(line):
+    return (re.match('|'.join(good_patterns), line) and
+        not re.match('|'.join(bad_patterns), line))
+  toc = filter(JavapFilter, disassembled_classes.split('\n'))
+
+  return '\n'.join(toc)
+
+
+def UpdateToc(jar_path, toc_path):
+  classes = GetClassesInZipFile(zipfile.ZipFile(jar_path))
+  javap_output = CallJavap(classpath=jar_path, classes=classes)
+  toc = ExtractToc(javap_output)
+
+  with open(toc_path, 'w') as tocfile:
+    tocfile.write(toc)
+
+
+def DoJarToc(options):
+  jar_path = options.jar_path
+  toc_path = options.toc_path
+  md5_stamp_path = '%s.md5' % toc_path
+  md5_checker = md5_check.Md5Checker(stamp=md5_stamp_path, inputs=[jar_path])
+  if md5_checker.IsStale():
+    UpdateToc(jar_path, toc_path)
+    md5_checker.Write()
+  else:
+    build_utils.Touch(toc_path)
+
+
+def main(argv):
+  parser = optparse.OptionParser()
+  parser.add_option('--jar-path', help='Input .jar path.')
+  parser.add_option('--toc-path', help='Output .jar.TOC path.')
+  parser.add_option('--stamp', help='Path to touch on success.')
+
+  # TODO(newt): remove this once http://crbug.com/177552 is fixed in ninja.
+  parser.add_option('--ignore', help='Ignored.')
+
+  options, _ = parser.parse_args()
+
+  DoJarToc(options)
+
+  if options.stamp:
+    build_utils.Touch(options.stamp)
+
+
+if __name__ == '__main__':
+  sys.exit(main(sys.argv))
+