Remove unused/unusable relocation packer files.
Removes:
- src/run_length_encoder.h
artifact of the original packing tool, not used here
- test_data/generate_elf_file_unittest_relocs.sh
- test_data/generate_elf_file_unittest_relocs.py
test data generation for chromium/gyp, not usable here
- README.TXT
because it is now almost entirely outdated
Change-Id: Ic4cd372647d9a365dc52833a6cc1cf66f0c95ec9
diff --git a/tools/relocation_packer/README.TXT b/tools/relocation_packer/README.TXT
deleted file mode 100644
index 071ab5d..0000000
--- a/tools/relocation_packer/README.TXT
+++ /dev/null
@@ -1,135 +0,0 @@
-Introduction:
--------------
-
-Relative relocations are the bulk of dynamic relocations (the .rel.dyn
-or .rela.dyn sections) in libchrome.<version>.so. The ELF standard
-representation of them is wasteful.
-
-Packing uses a combination of run length encoding, delta encoding, and LEB128
-encoding to store them more efficiently. Packed relocations are placed in
-a new .android.rel.dyn or .android.rela.dyn section. Packing reduces
-the footprint of libchrome.<version>.so in the filesystem, in APK downloads,
-and in memory when loaded on the device.
-
-A packed libchrome.<version>.so is designed so that it can be loaded directly
-on Android, but requires the explicit support of a crazy linker that has been
-extended to understand packed relocations. Packed relocations are currently
-only supported on ARM.
-
-A packed libchrome.<version>.so cannot currently be used with the standard
-Android runtime linker.
-
-See src/*.h for design and implementation notes.
-
-
-Notes:
-------
-
-Packing does not adjust debug data. An unstripped libchrome.<version>.so
-can be packed and will run, but may no longer be useful for debugging.
-
-Unpacking on the device requires the explicit support of an extended crazy
-linker. Adds the following new .dynamic tags, used by the crazy linker to
-find the packed .android.rel.dyn or .android.rela.dyn section data:
-
- DT_ANDROID_REL_OFFSET = DT_LOOS (Operating System specific: 0x6000000d)
- - The offset of packed relocation data in libchrome.<version>.so
- DT_ANDROID_REL_SIZE = DT_LOOS + 1 (Operating System Specific: 0x6000000e)
- - The size of packed relocation data in bytes
-
-32 bit ARM libraries use relocations without addends. 64 bit ARM libraries
-use relocations with addends. The packing strategy necessarily differs for
-the two relocation types.
-
-Where libchrome.<version>.so contains relocations without addends, the format
-of .android.rel.dyn data is:
-
- "APR1" identifier
- N: the number of count-delta pairs in the encoding
- A: the initial offset
- N * C,D: N count-delta pairs
-
-Where libchrome.<version>.so contains relocations with addends, the format
-of .android.rela.dyn data is:
-
- "APA1" identifier
- N: the number of addr-addend delta pairs in the encoding
- N * A,V: N addr-addend delta pairs
-
-All numbers in the encoding stream are stored as LEB128 values. For details
-see http://en.wikipedia.org/wiki/LEB128.
-
-The streaming unpacking algorithm for 32 bit ARM is:
-
- skip over "APR1"
- pairs, addr = next leb128 value, next leb128 value
- emit R_ARM_RELATIVE relocation with r_offset = addr
- while pairs:
- count, delta = next leb128 value, next leb128 value
- while count:
- addr += delta
- emit R_ARM_RELATIVE relocation with r_offset = addr
- count--
- pairs--
-
-The streaming unpacking algorithm for 64 bit ARM is:
-
- skip over "APA1"
- pairs = next signed leb128 value
- addr, addend = 0, 0
- while pairs:
- addr += next signed leb128 value
- addend += next signed leb128 value
- emit R_AARCH64_RELATIVE relocation with r_offset = addr, r_addend = addend
- pairs--
-
-
-Usage instructions:
--------------------
-
-To pack relocations, add an empty .android.rel.dyn or .android.rela.dyn and
-then run the tool:
-
- echo -n 'NULL' >/tmp/small
- if file libchrome.<version>.so | grep -q 'ELF 32'; then
- arm-linux-androideabi-objcopy
- --add-section .android.rel.dyn=/tmp/small
- libchrome.<version>.so libchrome.<version>.so.packed
- else
- aarch64-linux-android-objcopy
- --add-section .android.rela.dyn=/tmp/small
- libchrome.<version>.so libchrome.<version>.so.packed
- fi
- rm /tmp/small
- relocation_packer libchrome.<version>.so.packed
-
-To unpack and restore the shared library to its original state:
-
- cp libchrome.<version>.so.packed unpackable
- relocation_packer -u unpackable
- if file libchrome.<version>.so | grep -q 'ELF 32'; then
- arm-linux-androideabi-objcopy \
- --remove-section=.android.rel.dyn unpackable libchrome.<version>.so
- else
- aarch64-linux-android-objcopy \
- --remove-section=.android.rela.dyn unpackable libchrome.<version>.so
- endif
- rm unpackable
-
-
-Bugs & TODOs:
--------------
-
-Requires two free slots in the .dynamic section. Uses these to add data that
-tells the crazy linker where to find the packed relocation data. Fails
-if insufficient free slots exist (use gold --spare-dynamic-slots to increase
-the allocation).
-
-Requires libelf 0.158 or later. Earlier libelf releases may be buggy in
-ways that prevent the packer from working correctly.
-
-
-Testing:
---------
-
-Unittests run under gtest, on the host system.
diff --git a/tools/relocation_packer/src/run_length_encoder.h b/tools/relocation_packer/src/run_length_encoder.h
deleted file mode 100644
index f3a80e6..0000000
--- a/tools/relocation_packer/src/run_length_encoder.h
+++ /dev/null
@@ -1,81 +0,0 @@
-// 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.
-
-// Run-length encode and decode relative relocations.
-//
-// Relative relocations are the bulk of dynamic relocations (the
-// .rel.dyn or .rela.dyn sections) in libchrome.<version>.so, and the ELF
-// standard representation of them is wasteful. .rel.dyn contains
-// relocations without addends, .rela.dyn relocations with addends.
-//
-// A relocation with no addend is 8 bytes on 32 bit platforms and 16 bytes
-// on 64 bit plaforms, split into offset and info fields. Offsets strictly
-// increase, and each is commonly a few bytes different from its predecessor.
-// There are long runs where the difference does not change. The info field
-// is constant. Example, from 'readelf -x4 libchrome.<version>.so' 32 bit:
-//
-// offset info offset info
-// 808fef01 17000000 848fef01 17000000 ................
-// 888fef01 17000000 8c8fef01 17000000 ................
-// 908fef01 17000000 948fef01 17000000 ................
-//
-// Run length encoding packs this data more efficiently, by representing it
-// as a delta and a count of entries each differing from its predecessor
-// by this delta. The above can be represented as a start address followed
-// by an encoded count of 6 and offset difference of 4:
-//
-// start count diff
-// 01ef8f80 00000006 00000004
-//
-// Because relative relocation offsets strictly increase, the complete
-// set of relative relocations in libchrome.<version>.so can be
-// represented by a single start address followed by one or more difference
-// and count encoded word pairs:
-//
-// start run1 count run1 diff run2 count run2 diff
-// 01ef8f80 00000006 00000004 00000010 00000008 ...
-//
-// Decoding regenerates relative relocations beginning at address
-// 'start' and for each encoded run, incrementing the address by 'difference'
-// for 'count' iterations and emitting a new relative relocation.
-//
-// Once encoded, data is prefixed by a single word count of packed delta and
-// count pairs. A final run-length encoded relative relocations vector
-// might therefore look something like:
-//
-// pairs start run 1 run 2 ... run 15
-// 0000000f 01ef8f80 00000006 00000004 00000010 00000008 ...
-// Interpreted as:
-// pairs=15 start=.. count=6,delta=4 count=16,delta=8
-
-#ifndef TOOLS_RELOCATION_PACKER_SRC_RUN_LENGTH_ENCODER_H_
-#define TOOLS_RELOCATION_PACKER_SRC_RUN_LENGTH_ENCODER_H_
-
-#include <vector>
-
-#include "elf.h"
-#include "elf_traits.h"
-
-namespace relocation_packer {
-
-// A RelocationRunLengthCodec packs vectors of relative relocations
-// into more compact forms, and unpacks them to reproduce the pre-packed data.
-class RelocationRunLengthCodec {
- public:
- // Encode relative relocations into a more compact form.
- // |relocations| is a vector of relative relocation structs.
- // |packed| is the vector of packed words into which relocations are packed.
- static void Encode(const std::vector<ELF::Rel>& relocations,
- std::vector<ELF::Xword>* packed);
-
- // Decode relative relocations from their more compact form.
- // |packed| is the vector of packed relocations.
- // |relocations| is a vector of unpacked relative relocation structs.
- static void Decode(const std::vector<ELF::Xword>& packed,
- std::vector<ELF::Rel>* relocations);
-};
-
-} // namespace relocation_packer
-
-#endif // TOOLS_RELOCATION_PACKER_SRC_RUN_LENGTH_ENCODER_H_
diff --git a/tools/relocation_packer/test_data/generate_elf_file_unittest_relocs.py b/tools/relocation_packer/test_data/generate_elf_file_unittest_relocs.py
deleted file mode 100755
index e71b5cb..0000000
--- a/tools/relocation_packer/test_data/generate_elf_file_unittest_relocs.py
+++ /dev/null
@@ -1,88 +0,0 @@
-#!/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.
-
-"""Build relocation packer unit test data.
-
-Uses a built relocation packer to generate 'golden' reference test data
-files for elf_file_unittests.cc.
-"""
-
-import optparse
-import os
-import shutil
-import subprocess
-import sys
-import tempfile
-
-def PackArmLibraryRelocations(android_pack_relocations,
- android_objcopy,
- added_section,
- input_path,
- output_path):
- # Copy and add a 'NULL' .android.rel.dyn section for the packing tool.
- with tempfile.NamedTemporaryFile() as stream:
- stream.write('NULL')
- stream.flush()
- objcopy_command = [android_objcopy,
- '--add-section', '%s=%s' % (added_section, stream.name),
- input_path, output_path]
- subprocess.check_call(objcopy_command)
-
- # Pack relocations.
- pack_command = [android_pack_relocations, output_path]
- subprocess.check_call(pack_command)
-
-
-def UnpackArmLibraryRelocations(android_pack_relocations,
- input_path,
- output_path):
- shutil.copy(input_path, output_path)
-
- # Unpack relocations. We leave the .android.rel.dyn or .android.rela.dyn
- # in place.
- unpack_command = [android_pack_relocations, '-u', output_path]
- subprocess.check_call(unpack_command)
-
-
-def main():
- parser = optparse.OptionParser()
-
- 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')
- parser.add_option('--added-section',
- choices=['.android.rel.dyn', '.android.rela.dyn'],
- help='Section to add, one of ".android.rel.dyn" or ".android.rela.dyn"')
- parser.add_option('--test-file',
- help='Path to the input test file, an unpacked ARM .so')
- parser.add_option('--unpacked-output',
- help='Path to the output file for reference unpacked data')
- parser.add_option('--packed-output',
- help='Path to the output file for reference packed data')
-
- options, _ = parser.parse_args()
-
- for output in [options.unpacked_output, options.packed_output]:
- directory = os.path.dirname(output)
- if not os.path.exists(directory):
- os.makedirs(directory)
-
- PackArmLibraryRelocations(options.android_pack_relocations,
- options.android_objcopy,
- options.added_section,
- options.test_file,
- options.packed_output)
-
- UnpackArmLibraryRelocations(options.android_pack_relocations,
- options.packed_output,
- options.unpacked_output)
-
- return 0
-
-
-if __name__ == '__main__':
- sys.exit(main())
diff --git a/tools/relocation_packer/test_data/generate_elf_file_unittest_relocs.sh b/tools/relocation_packer/test_data/generate_elf_file_unittest_relocs.sh
deleted file mode 100755
index f90a2f6..0000000
--- a/tools/relocation_packer/test_data/generate_elf_file_unittest_relocs.sh
+++ /dev/null
@@ -1,35 +0,0 @@
-#!/bin/bash
-#
-# 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.
-
-# Generates elf_file_unittest_relocs_arm{32,64}{,_packed}.so test data files
-# from elf_file_unittest_relocs.cc. Run once to create these test data
-# files; the files are checked into the source tree.
-#
-# To use:
-# ./generate_elf_file_unittest_relocs.sh
-# git add elf_file_unittest_relocs_arm{32,64}{,_packed}.so
-
-function main() {
- local '-r' test_data_directory="$(pwd)"
- cd '../../..'
-
- source tools/cr/cr-bash-helpers.sh
- local arch
- for arch in 'arm32' 'arm64'; do
- cr 'init' '--platform=android' '--type=Debug' '--architecture='"${arch}"
- cr 'build' 'relocation_packer_unittests_test_data'
- done
-
- local '-r' packer='out_android/Debug/obj/tools/relocation_packer'
- local '-r' gen="${packer}/relocation_packer_unittests_test_data.gen"
-
- cp "${gen}/elf_file_unittest_relocs_arm"{32,64}{,_packed}'.so' \
- "${test_data_directory}"
-
- return 0
-}
-
-main
