1#!/bin/bash 2# 3# Copyright 2016 Google Inc. All Rights Reserved. 4# 5# This is an example script to show users the steps for bisecting an NDK 6# application for Android. Our example is the Teapot app that comes bundled with 7# the NDK as a sample app. 8# 9# Our Teapot app only has 12 or so object files generated per build. Bisection 10# for just 12 object files is overkill, but this bisection process easily scales 11# to thousands of object files (as seen with the Android source). 12# 13# Setup: 14# 1. Install NDK (make sure it is in your PATH) 15# 2. Install compiler_wrapper.py 16# 3. Connect an arm7 device (tested with Nexus 5X) 17# a. See README for supporting other device archs 18# 19# Tested in bash on Linux. 20 21# Set CWD to where this script lives 22pushd "$(dirname "$0")" 23 24# If Teapot dir already exists remove it. 25if [[ -d Teapot ]]; then 26 rm -rf Teapot 27fi 28 29# Unzip our repository we'll be testing with. 30tar -xzf Teapot.tar.gz 31 32# Apply small setup patch. This patch makes a small change to the build system 33# to make this bisecting example a little easier. It inserts the option to only 34# build for an arm7. See the patch file for details. 35# (This patch file was generated with git, -p1 will remove the a/ and b/) 36patch -p1 -i PATCH1 37 38# We want all of our cached files to be stored in ~/NDK_EXAMPLE_BISECT 39# Remove directory if already exists 40export BISECT_DIR=~/NDK_EXAMPLE_BISECT 41if [[ -d ${BISECT_DIR} ]]; then 42 rm -rf ${BISECT_DIR} 43fi 44 45# We will now take our normal "good compiler" and do a full build of the app. We 46# need to clean before building. This ensures that all objects are generated and 47# can be cached. 48pushd Teapot 49export BISECT_STAGE=POPULATE_GOOD 50./gradlew clean 51./gradlew installArm7Debug 52popd 53 54# Inserting "compiler error". Really this is just a patch that inserts a simple 55# error in the code, but this is used to simulate our compiler error. This patch 56# will simply cause the app to crash as soon as it starts. See the patch file 57# for details. 58# (This patch file was generated with git, -p1 will remove the a/ and b/) 59patch -p1 -i PATCH2 60 61# Now that we have installed our bad compiler (i.e. applied the above patch that 62# acts like a compiler error), we want to enumerate and cache all objects 63# generated by this "bad compiler". So again, we clean the build tree so that 64# all objects are regenerated and can be cached. 65pushd Teapot 66export BISECT_STAGE=POPULATE_BAD 67./gradlew clean 68./gradlew installArm7Debug 69popd 70 71# Now ~/NDK_EXAMPLE_BISECT holds the caches for both good and bad compiler 72# outputs. We will now use these to bisect our problem. We should find that 73# TeapotRenderer.o is the bad file (because this is where PATCH2 inserted the 74# "compiler error"). 75 76# Tell the compiler wrapper to not cache outputs, and instead begin bisecting. 77export BISECT_STAGE=TRIAGE 78 79# Run the actual bisection tool. This will automatically narrow down which 80# object file has the error. The test_setup.sh script will rebuild our app 81# with gradle, and boot_test.sh will ping the device to see if the app crashed 82# or not. 83cd .. 84./binary_search_state.py \ 85 --get_initial_items=ndk/get_initial_items.sh \ 86 --switch_to_good=ndk/switch_to_good.sh \ 87 --switch_to_bad=ndk/switch_to_bad.sh \ 88 --test_setup_script=ndk/test_setup.sh \ 89 --test_script=ndk/boot_test.sh \ 90 --file_args 91 92popd 93