oss-fuzz/projects/elfutils/build.sh

#!/bin/bash -eu
# Copyright 2021 Google LLC
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#      http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
#
################################################################################

# This script is supposed to be compatible with OSS-Fuzz, i.e. it has to use
# environment variables like $CC, $CFLAGS, $OUT, link the fuzz targets with CXX
# (even though the project is written in C) and so on:
# https://google.github.io/oss-fuzz/getting-started/new-project-guide/#buildsh

# It can be used to build and run the fuzz targets using Docker and the images
# provided by the OSS-Fuzz project: https://google.github.io/oss-fuzz/advanced-topics/reproducing/#building-using-docker

# It can also be used to build and run the fuzz target locally without Docker.
# After installing clang and the build dependencies of libelf by running something
# like `dnf build-dep elfutils-devel` on Fedora or `apt-get build-dep libelf-dev`
# on Debian/Ubuntu, the following commands should be run:
#
#  $ git clone https://github.com/google/oss-fuzz
#  $ cd oss-fuzz/projects/elfutils
#  $ git clone git://sourceware.org/git/elfutils.git
#  $ ./build.sh
#  $ unzip -d CORPUS fuzz-dwfl-core_seed_corpus.zip
#  $ ./out/fuzz-dwfl-core CORPUS/

set -eux

SANITIZER=${SANITIZER:-address}
flags="-O1 -fno-omit-frame-pointer -gline-tables-only -DFUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION -fsanitize=$SANITIZER -fsanitize=fuzzer-no-link"

export CC=${CC:-clang}
export CFLAGS=${CFLAGS:-$flags}

export CXX=${CXX:-clang++}
export CXXFLAGS=${CXXFLAGS:-$flags}

export SRC=${SRC:-$(realpath -- $(dirname -- "$0"))}
export OUT=${OUT:-"$SRC/out"}
mkdir -p "$OUT"

export LIB_FUZZING_ENGINE=${LIB_FUZZING_ENGINE:--fsanitize=fuzzer}

cd "$SRC/elfutils"

# ASan isn't compatible with -Wl,--no-undefined: https://github.com/google/sanitizers/issues/380
find -name Makefile.am | xargs sed -i 's/,--no-undefined//' &&

# ASan isn't compatible with -Wl,-z,defs either:
# https://clang.llvm.org/docs/AddressSanitizer.html#usage
sed -i 's/^\(ZDEFS_LDFLAGS=\).*/\1/' configure.ac &&

autoreconf -i -f &&
./configure --enable-maintainer-mode --disable-debuginfod --disable-libdebuginfod \
            --without-bzlib --without-lzma --without-zstd \
	    CC="$CC" CFLAGS="-Wno-error $CFLAGS" CXX="-Wno-error $CXX" CXXFLAGS="$CXXFLAGS" LDFLAGS="$CFLAGS" &&
ASAN_OPTIONS=detect_leaks=0 make -j$(nproc) V=1


ZLIB_DIR=$(pkg-config --variable=libdir zlib)
$CC $CFLAGS \
	-D_GNU_SOURCE -DHAVE_CONFIG_H \
	-I. -I./lib -I./libelf -I./libebl -I./libdw -I./libdwelf -I./libdwfl -I./libasm \
	-c "$SRC/fuzz-dwfl-core.c" -o fuzz-dwfl-core.o
$CXX $CXXFLAGS $LIB_FUZZING_ENGINE fuzz-dwfl-core.o \
	./libdw/libdw.a ./libelf/libelf.a "$ZLIB_DIR/libz.a" \
	-o "$OUT/fuzz-dwfl-core"
cp "$SRC/fuzz-dwfl-core_seed_corpus.zip" "$OUT"