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1#!/bin/bash -eu
2# Copyright 2016 Google Inc.
3#
4# Licensed under the Apache License, Version 2.0 (the "License");
5# you may not use this file except in compliance with the License.
6# You may obtain a copy of the License at
7#
8#      http://www.apache.org/licenses/LICENSE-2.0
9#
10# Unless required by applicable law or agreed to in writing, software
11# distributed under the License is distributed on an "AS IS" BASIS,
12# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13# See the License for the specific language governing permissions and
14# limitations under the License.
15#
16################################################################################
17
18# afl++ configuration options.
19# The 'env|grep' setup ensures we do not trigger the linter.
20# The variables need to be set to "1" here - or before running this script.
21
22# AFL++ settings.
23export AFL_LLVM_MODE_WORKAROUND=0
24export AFL_ENABLE_DICTIONARY=0
25export AFL_ENABLE_CMPLOG=1
26export AFL_LAF_CHANCE=3
27
28# Start compiling afl++.
29echo "Copying precompiled afl++"
30
31# Copy afl++ tools necessary for fuzzing.
32pushd $SRC/aflplusplus > /dev/null
33
34cp -f libAFLDriver.a $LIB_FUZZING_ENGINE
35
36# Some important projects include libraries, copy those even when they don't
37# start with "afl-". Use "sort -u" to avoid a warning about duplicates.
38ls afl-* *.txt *.a *.o *.so | sort -u | xargs cp -t $OUT
39export CC="$SRC/aflplusplus/afl-clang-fast"
40export CXX="$SRC/aflplusplus/afl-clang-fast++"
41
42# Set sane afl++ environment defaults:
43# Be quiet, otherwise this can break some builds.
44export AFL_QUIET=1
45# No leak errors during builds.
46export ASAN_OPTIONS="detect_leaks=0:symbolize=0:detect_odr_violation=0:abort_on_error=1"
47
48# AFL compile option roulette. It is OK if they all happen together.
49
50# 20% chance for CTX-2 coverage instrumentation (Caller conTeXt sensitive
51# edge coverage).
52test $(($RANDOM % 100)) -lt 20 && {
53  export AFL_LLVM_INSTRUMENT=CLASSIC,CTX-2
54  export AFL_ENABLE_CMPLOG=0
55  export AFL_LAF_CHANCE=30
56}
57
58# 40% chance to create a dictionary.
59test $(($RANDOM % 100)) -lt 40 && {
60  export AFL_ENABLE_DICTIONARY=1
61}
62
63# 60% chance to perform CMPLOG/REDQUEEN.
64rm -f "$OUT/afl_cmplog.txt"
65test "$AFL_ENABLE_CMPLOG" = "1" -a $(($RANDOM % 100)) -lt 60 && {
66  export AFL_LLVM_CMPLOG=1
67  touch "$OUT/afl_cmplog.txt"
68}
69
70# 3% chance to perform COMPCOV/LAF_INTEL.
71test $(($RANDOM % 100)) -lt $AFL_LAF_CHANCE && {
72  export AFL_LLVM_LAF_ALL=1
73}
74
75# Create a dictionary if one is wanted.
76test "$AFL_ENABLE_DICTIONARY" = "1" && {
77  export AFL_LLVM_DICT2FILE="$OUT/afl++.dict"
78}
79
80# In case afl-clang-fast ever breaks, this is a workaround:
81test "$AFL_LLVM_MODE_WORKAROUND" = "1" && {
82  export CC=clang
83  export CXX=clang++
84  WORKAROUND_FLAGS=-fsanitize-coverage=trace-pc-guard
85  # We can still do CMPLOG light:
86  test -e "$OUT/afl_cmplog.txt" && {
87    WORKAROUND_FLAGS="$WORKAROUND_FLAGS",trace-cmp
88  }
89  export CFLAGS="$CFLAGS $WORKAROUND_FLAGS"
90  export CXXFLAGS="$CXXFLAGS $WORKAROUND_FLAGS"
91  unset AFL_LLVM_LAF_ALL
92  unset AFL_LLVM_DICT2FILE
93  unset AFL_ENABLE_DICTIONARY
94  # We need to create a new fuzzer lib however.
95  ar ru libAFLDrivernew.a afl-compiler-rt.o utils/aflpp_driver/aflpp_driver.o
96  cp -f libAFLDrivernew.a $LIB_FUZZING_ENGINE
97}
98
99# Provide a way to document the afl++ options used in this build:
100echo
101echo afl++ target compilation setup:
102env | grep AFL_ | tee "$OUT/afl_options.txt"
103echo
104
105popd > /dev/null
106
107echo " done."
108