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#!/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.
import glob
import optparse
import os
import shutil
import subprocess
import sys
sys.path.insert(
0,
os.path.join(os.path.dirname(__file__), '..', '..', 'third_party',
'pefile_py3'))
import pefile
def reorder_imports(input_dir, output_dir, architecture):
"""Swap chrome_elf.dll to be the first import of chrome.exe.
Also copy over any related files that might be needed
(pdbs, manifests etc.).
"""
# TODO(thakis): See if there is a reliable way to write the
# correct executable in the first place, so that this script
# only needs to verify that and not write a whole new exe.
input_image = os.path.join(input_dir, 'chrome.exe')
output_image = os.path.join(output_dir, 'chrome.exe')
# pefile mmap()s the whole executable, and then parses parts of
# it into python data structures for ease of processing.
# To write the file again, only the mmap'd data is written back,
# so modifying the parsed python objects generally has no effect.
# However, parsed raw data ends up in pe.Structure instances,
# and these all get serialized back when the file gets written.
# So things that are in a Structure must have their data set
# through the Structure, while other data must bet set through
# the set_bytes_*() methods.
pe = pefile.PE(input_image, fast_load=True)
if architecture == 'x64' or architecture == 'arm64':
assert pe.PE_TYPE == pefile.OPTIONAL_HEADER_MAGIC_PE_PLUS
else:
assert pe.PE_TYPE == pefile.OPTIONAL_HEADER_MAGIC_PE
pe.parse_data_directories(directories=[
pefile.DIRECTORY_ENTRY['IMAGE_DIRECTORY_ENTRY_IMPORT']])
found_elf = False
for i, peimport in enumerate(pe.DIRECTORY_ENTRY_IMPORT):
if peimport.dll.lower() == b'chrome_elf.dll':
assert not found_elf, 'only one chrome_elf.dll import expected'
found_elf = True
if i > 0:
swap = pe.DIRECTORY_ENTRY_IMPORT[0]
# Morally we want to swap peimport.struct and swap.struct here,
# but the pe module doesn't expose a public method on Structure
# to get all data of a Structure without explicitly listing all
# field names.
# NB: OriginalFirstThunk and Characteristics are an union both at
# offset 0, handling just one of them is enough.
peimport.struct.OriginalFirstThunk, swap.struct.OriginalFirstThunk = \
swap.struct.OriginalFirstThunk, peimport.struct.OriginalFirstThunk
peimport.struct.TimeDateStamp, swap.struct.TimeDateStamp = \
swap.struct.TimeDateStamp, peimport.struct.TimeDateStamp
peimport.struct.ForwarderChain, swap.struct.ForwarderChain = \
swap.struct.ForwarderChain, peimport.struct.ForwarderChain
peimport.struct.Name, swap.struct.Name = \
swap.struct.Name, peimport.struct.Name
peimport.struct.FirstThunk, swap.struct.FirstThunk = \
swap.struct.FirstThunk, peimport.struct.FirstThunk
assert found_elf, 'chrome_elf.dll import not found'
pe.write(filename=output_image)
for fname in glob.iglob(os.path.join(input_dir, 'chrome.exe.*')):
shutil.copy(fname, os.path.join(output_dir, os.path.basename(fname)))
return 0
def main(argv):
usage = 'reorder_imports.py -i <input_dir> -o <output_dir> -a <target_arch>'
parser = optparse.OptionParser(usage=usage)
parser.add_option('-i', '--input', help='reorder chrome.exe in DIR',
metavar='DIR')
parser.add_option('-o', '--output', help='write new chrome.exe to DIR',
metavar='DIR')
parser.add_option('-a', '--arch', help='architecture of build (optional)',
default='ia32')
opts, args = parser.parse_args()
if not opts.input or not opts.output:
parser.error('Please provide and input and output directory')
return reorder_imports(opts.input, opts.output, opts.arch)
if __name__ == "__main__":
sys.exit(main(sys.argv[1:]))
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