crazy linker: convert relocation unpacking to Android style.

build/android/gyp/pack_arm_relocations.py

 #!/usr/bin/env 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.
 
-"""Pack ARM relative relocations in a library (or copy unchanged).
+"""Pack relocations in a library (or copy unchanged).
 
 If --enable-packing and --configuration-name=='Release', invoke the
 relocation_packer tool to pack the .rel.dyn or .rela.dyn section in the given
 library files.  This step is inserted after the libraries are stripped.
-Packing adds a new .android.rel.dyn or .android.rela.dyn section to the file
-and reduces the size of .rel.dyn or .rela.dyn accordingly.
 
-Currently packing only understands ARM32 shared libraries.  For all other
-architectures --enable-packing should be set to zero.  In this case the
-script copies files verbatim, with no attempt to pack relative relocations.
+If --enable-packing is zero, the script copies files verbatim, with no
+attempt to pack relocations.
 
 Any library listed in --exclude-packing-list is also copied verbatim,
 irrespective of any --enable-packing setting.  Typically this would be
 'libchromium_android_linker.so'.
 """
 
 import optparse
 import os
 import shlex
 import shutil
 import sys
 import tempfile
 
 from util import build_utils
 
-def PackArmLibraryRelocations(android_pack_relocations,
-                              android_objcopy,
-                              has_relocations_with_addends,
-                              library_path,
-                              output_path):
-  # Select an appropriate name for the section we add.
-  if has_relocations_with_addends:
-    new_section = '.android.rela.dyn'
-  else:
-    new_section = '.android.rel.dyn'
-
-  # Copy and add a 'NULL' packed relocations section for the packing tool.
-  with tempfile.NamedTemporaryFile() as stream:
-    stream.write('NULL')
-    stream.flush()
-    objcopy_command = [android_objcopy,
-                       '--add-section', '%s=%s' % (new_section, stream.name),
-                       library_path, output_path]
-    build_utils.CheckOutput(objcopy_command)
-
-  # Pack R_ARM_RELATIVE relocations.
+def PackLibraryRelocations(android_pack_relocations, library_path, output_path):
+  shutil.copy(library_path, output_path)
   pack_command = [android_pack_relocations, output_path]
   build_utils.CheckOutput(pack_command)
 
 
-def CopyArmLibraryUnchanged(library_path, output_path):
+def CopyLibraryUnchanged(library_path, output_path):
   shutil.copy(library_path, output_path)
 
 
 def main(args):
   args = build_utils.ExpandFileArgs(args)
   parser = optparse.OptionParser()
   build_utils.AddDepfileOption(parser)
   parser.add_option('--clear-dir', action='store_true',
                     help='If set, the destination directory will be deleted '
                     'before copying files to it. This is highly recommended to '
                     'ensure that no stale files are left in the directory.')
 
   parser.add_option('--configuration-name',
       default='Release',
       help='Gyp configuration name (i.e. Debug, Release)')
   parser.add_option('--enable-packing',
       choices=['0', '1'],
       help=('Pack relocations if 1 and configuration name is \'Release\','
             ' otherwise plain file copy'))
-  parser.add_option('--has-relocations-with-addends',
-      choices=['0', '1'],
-      help=('Pack into \'.android.rela.dyn\' if 1, else \'.android.rel.dyn\''))
   parser.add_option('--exclude-packing-list',
       default='',
       help='Names of any libraries explicitly not packed')
   parser.add_option('--android-pack-relocations',
-      help='Path to the ARM relocations packer binary')
-  parser.add_option('--android-objcopy',
-      help='Path to the toolchain\'s objcopy binary')
+      help='Path to the relocations packer binary')
   parser.add_option('--stripped-libraries-dir',
       help='Directory for stripped libraries')
   parser.add_option('--packed-libraries-dir',
       help='Directory for packed libraries')
   parser.add_option('--libraries', action='append',
       help='List of libraries')
   parser.add_option('--stamp', help='Path to touch on success')
 
   options, _ = parser.parse_args(args)
   enable_packing = (options.enable_packing == '1' and
                     options.configuration_name == 'Release')
-  has_relocations_with_addends = (options.has_relocations_with_addends == '1')
   exclude_packing_set = set(shlex.split(options.exclude_packing_list))
 
   libraries = []
   for libs_arg in options.libraries:
     libraries += build_utils.ParseGypList(libs_arg)
 
   if options.clear_dir:
     build_utils.DeleteDirectory(options.packed_libraries_dir)
 
   build_utils.MakeDirectory(options.packed_libraries_dir)
 
   for library in libraries:
     library_path = os.path.join(options.stripped_libraries_dir, library)
     output_path = os.path.join(
         options.packed_libraries_dir, os.path.basename(library))
 
     if enable_packing and library not in exclude_packing_set:
-      PackArmLibraryRelocations(options.android_pack_relocations,
-                                options.android_objcopy,
-                                has_relocations_with_addends,
-                                library_path,
-                                output_path)
+      PackLibraryRelocations(options.android_pack_relocations,
+                             library_path,
+                             output_path)
     else:
-      CopyArmLibraryUnchanged(library_path, output_path)
+      CopyLibraryUnchanged(library_path, output_path)
 
   if options.depfile:
     build_utils.WriteDepfile(
         options.depfile,
         libraries + build_utils.GetPythonDependencies())
 
   if options.stamp:
     build_utils.Touch(options.stamp)
 
   return 0
 
 
 if __name__ == '__main__':
   sys.exit(main(sys.argv[1:]))