android: Remove cygprofile/reorder_native_library.py.

LLD optimized the layout of ordered sections, making this reordering
step unnecessary. See attached bug.

Bug: 801601
Change-Id: I349d370fc847fe9be3482c764030d5b149c62c32
Reviewed-on: https://chromium-review.googlesource.com/992333
Commit-Queue: Benoit L <lizeb@chromium.org>
Reviewed-by: Egor Pasko <pasko@chromium.org>
Cr-Commit-Position: refs/heads/master@{#547684}

tools/cygprofile/reorder_native_library.py

-#!/usr/bin/env vpython
-# Copyright 2018 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.
-
-"""From an ordered native library, puts ordered code in the middle of the code
-segment.
-
-Putting ordered code (a superset of frequently called code) in the
-middle of the binary reduces the number of relative jumps with an offset >16MB,
-which requires a thunk with the THUMB-2 instruction set.
-
-This is done the following way:
-- Look for the current ordering in an ordered libchrome.
-- Crate a complete orderfile (with all the symbols), with the ordered
-  symbols in the middle.
-
-The middle is computed by counting symbols, irrespective of their sizes. Local
-testing shows that this is sufficient.
-
-Note: only works with LLD, as the output orderfile is tailored to it.
-"""
-
-import argparse
-import logging
-import operator
-
-import symbol_extractor
-
-
-def _ExtractAndProcessSymbols(native_library_filename):
-  """Extracts, sorts and filters symbols.
-
-  Args:
-    native_library_filename: (str) Path to the native library
-
-  Returns:
-   [symbol_extractor.SymbolInfo], sorted by offset, without thunks.
-  """
-  logging.info('Extracting symbols')
-  symbol_infos = symbol_extractor.SymbolInfosFromBinary(native_library_filename)
-  logging.info('%d symbols' % len(symbol_infos))
-  symbol_infos.sort(key=operator.attrgetter('offset'))
-  real_symbols = [s for s in symbol_infos
-                  if not s.name.startswith('__ThumbV7PILongThunk_')]
-  logging.info('%d long jumps Thunks' % (len(symbol_infos) - len(real_symbols)))
-  return real_symbols
-
-
-def _ReorderSymbols(symbol_infos):
-  """Puts ordered symbols in the middle.
-
-  Args:
-    symbols_infos: ([symbol_extractor.SymbolInfo]) as returned by
-                   |_ExtractAndProcessSymbols()|.
-
-  Returns:
-    [str] Reordered list of symbols.
-  """
-  symbols = [s.name for s in symbol_infos]
-  assert symbols[0] == 'dummy_function_to_anchor_text'
-  start_of_ordered_index = symbols.index('dummy_function_start_of_ordered_text')
-  end_of_ordered_index = symbols.index('dummy_function_end_of_ordered_text')
-  assert end_of_ordered_index > start_of_ordered_index
-  logging.info('%d ordered symbols' % (
-      end_of_ordered_index - start_of_ordered_index))
-  ordered = symbols[start_of_ordered_index:end_of_ordered_index + 1]
-  others = symbols[:start_of_ordered_index] + symbols[end_of_ordered_index + 1:]
-  middle = len(others) / 2
-  reordered = others[:middle] + ordered + others[middle:]
-  return reordered
-
-
-def _CreateNewOrderfile(native_library_filename, output_orderfile, arch):
-  """Creates a new reordered orderfile.
-
-  Args:
-    native_library_filename: (str) Native library filename.
-    output_orderfile: (str) Path to the output orderfile.
-    arch: (str) Architecture
-  """
-  symbol_extractor.SetArchitecture(arch)
-  symbol_infos = _ExtractAndProcessSymbols(native_library_filename)
-  reordered = _ReorderSymbols(symbol_infos)
-  with open(output_orderfile, 'w') as f:
-    for s in reordered:
-      f.write('%s\n' % s)
-
-
-def _CreateArgumentParser():
-  parser = argparse.ArgumentParser()
-  parser.add_argument('--native-library', help='Path to the native library',
-                      required=True)
-  parser.add_argument('--output-orderfile', help='Path to the output orderfile',
-                      required=True)
-  parser.add_argument('--arch', help='Architecture', default='arm')
-  return parser
-
-
-def main():
-  logging.basicConfig(level=logging.INFO)
-  parser = _CreateArgumentParser()
-  args = parser.parse_args()
-  _CreateNewOrderfile(args.native_library, args.output_orderfile, args.arch)
-
-
-if __name__ == '__main__':
-  main()