xref: /openbmc/qemu/scripts/oss-fuzz/build.sh (revision eabfeb0c) 
1#!/bin/sh -e
2#
3# OSS-Fuzz build script. See:
4# https://google.github.io/oss-fuzz/getting-started/new-project-guide/#buildsh
5#
6# The file is consumed by:
7# https://github.com/google/oss-fuzz/blob/master/projects/qemu/Dockerfiles
8#
9# This code is licensed under the GPL version 2 or later.  See
10# the COPYING file in the top-level directory.
11#
12
13# build project
14# e.g.
15# ./autogen.sh
16# ./configure
17# make -j$(nproc) all
18
19# build fuzzers
20# e.g.
21# $CXX $CXXFLAGS -std=c++11 -Iinclude \
22#     /path/to/name_of_fuzzer.cc -o $OUT/name_of_fuzzer \
23#     $LIB_FUZZING_ENGINE /path/to/library.a
24
25fatal () {
26    echo "Error : ${*}, exiting."
27    exit 1
28}
29
30OSS_FUZZ_BUILD_DIR="./build-oss-fuzz/"
31
32# There seems to be a bug in clang-11 (used for builds on oss-fuzz) :
33#   accel/tcg/cputlb.o: In function `load_memop':
34#   accel/tcg/cputlb.c:1505: undefined reference to `qemu_build_not_reached'
35#
36# When building with optimization, the compiler is expected to prove that the
37# statement cannot be reached, and remove it. For some reason clang-11 doesn't
38# remove it, resulting in an unresolved reference to qemu_build_not_reached
39# Undefine the __OPTIMIZE__ macro which compiler.h relies on to choose whether
40# to " #define qemu_build_not_reached()  g_assert_not_reached() "
41EXTRA_CFLAGS="$CFLAGS -U __OPTIMIZE__"
42
43if ! { [ -e "./COPYING" ] &&
44   [ -e "./MAINTAINERS" ] &&
45   [ -e "./Makefile" ] &&
46   [ -e "./docs" ] &&
47   [ -e "./VERSION" ] &&
48   [ -e "./linux-user" ] &&
49   [ -e "./softmmu" ];} ; then
50    fatal "Please run the script from the top of the QEMU tree"
51fi
52
53mkdir -p $OSS_FUZZ_BUILD_DIR || fatal "mkdir $OSS_FUZZ_BUILD_DIR failed"
54cd $OSS_FUZZ_BUILD_DIR || fatal "cd $OSS_FUZZ_BUILD_DIR failed"
55
56
57if [ -z ${LIB_FUZZING_ENGINE+x} ]; then
58    LIB_FUZZING_ENGINE="-fsanitize=fuzzer"
59fi
60
61if [ -z ${OUT+x} ]; then
62    DEST_DIR=$(realpath "./DEST_DIR")
63else
64    DEST_DIR=$OUT
65fi
66
67mkdir -p "$DEST_DIR/lib/"  # Copy the shared libraries here
68
69# Build once to get the list of dynamic lib paths, and copy them over
70../configure --disable-werror --cc="$CC" --cxx="$CXX" \
71    --extra-cflags="$EXTRA_CFLAGS" --target-list="i386-softmmu"
72
73if ! make CONFIG_FUZZ=y CFLAGS="$LIB_FUZZING_ENGINE" "-j$(nproc)" \
74    i386-softmmu/fuzz; then
75    fatal "Build failed. Please specify a compiler with fuzzing support"\
76          "using the \$CC and \$CXX environemnt variables, or specify a"\
77          "\$LIB_FUZZING_ENGINE compatible with your compiler"\
78          "\nFor example: CC=clang CXX=clang++ $0"
79fi
80
81for i in $(ldd ./i386-softmmu/qemu-fuzz-i386 | cut -f3 -d' '); do
82    cp "$i" "$DEST_DIR/lib/"
83done
84rm ./i386-softmmu/qemu-fuzz-i386
85
86# Build a second time to build the final binary with correct rpath
87../configure --bindir="$DEST_DIR" --datadir="$DEST_DIR/data/" --disable-werror \
88    --cc="$CC" --cxx="$CXX" --extra-cflags="$EXTRA_CFLAGS" \
89    --extra-ldflags="-Wl,-rpath,'\$\$ORIGIN/lib'"
90make CONFIG_FUZZ=y CFLAGS="$LIB_FUZZING_ENGINE" "-j$(nproc)" i386-softmmu/fuzz
91
92# Copy over the datadir
93cp  -r ../pc-bios/ "$DEST_DIR/pc-bios"
94
95# Run the fuzzer with no arguments, to print the help-string and get the list
96# of available fuzz-targets. Copy over the qemu-fuzz-i386, naming it according
97# to each available fuzz target (See 05509c8e6d fuzz: select fuzz target using
98# executable name)
99for target in $(./i386-softmmu/qemu-fuzz-i386 | awk '$1 ~ /\*/  {print $2}');
100do
101    cp ./i386-softmmu/qemu-fuzz-i386 "$DEST_DIR/qemu-fuzz-i386-target-$target"
102done
103
104echo "Done. The fuzzers are located in $DEST_DIR"
105exit 0
106