Re: [PATCH v2] fuzz: add oss-fuzz build.sh script

[Darren Kenny <darren.kenny@oracle.com>]

Hi Alex,

From looking at another OSS Fuzz project recently (a coincidence) I
wonder if we could make this script work so that it can be run outside
of the OSS-Fuzz environment?

Specifically, for example, if $OUT is not set, then creating a subdir in
the build directory, and setting it to be that.

Similarly for some other things like $LIB_FUZZING_ENGINE?

I'm just thinking that it might help someone that is not familiar with
OSS-Fuzz to validate that the script still works without having to go
through setting up the containers, etc that would be required to
validate it.

Also, I would definitely recommend running ShellCheck against any script
to ensure that you're catching any mistakes that can so easily be put in
to shell scripts - speaking from experience here ;)

Thanks,

Darren.


On Friday, 2020-06-05 at 13:50:28 -04, Alexander Bulekov wrote:
> It is neater to keep this in the QEMU repo, since any change that
> requires an update to the oss-fuzz build configuration, can make the
> necessary changes in the same series.
>
> Suggested-by: Philippe Mathieu-Daude <f4bug@amsat.org>
> Signed-off-by: Alexander Bulekov <alxndr@bu.edu>
> ---
>
> v2 updates the script header comment.
>
>  scripts/oss-fuzz/build.sh | 50 +++++++++++++++++++++++++++++++++++++++
>  1 file changed, 50 insertions(+)
>  create mode 100755 scripts/oss-fuzz/build.sh
>
> diff --git a/scripts/oss-fuzz/build.sh b/scripts/oss-fuzz/build.sh
> new file mode 100755
> index 0000000000..e93d6f2e03
> --- /dev/null
> +++ b/scripts/oss-fuzz/build.sh
> @@ -0,0 +1,50 @@
> +#!/bin/sh
> +#
> +# OSS-Fuzz build script. See:
> +# https://google.github.io/oss-fuzz/getting-started/new-project-guide/#buildsh
> +#
> +# This code is licensed under the GPL version 2 or later.  See
> +# the COPYING file in the top-level directory.
> +#
> +
> +# build project
> +# e.g.
> +# ./autogen.sh
> +# ./configure
> +# make -j$(nproc) all
> +
> +# build fuzzers
> +# e.g.
> +# $CXX $CXXFLAGS -std=c++11 -Iinclude \
> +#     /path/to/name_of_fuzzer.cc -o $OUT/name_of_fuzzer \
> +#     $LIB_FUZZING_ENGINE /path/to/library.a
> +
> +mkdir -p $OUT/lib/              # Shared libraries
> +
> +# Build once to get the list of dynamic lib paths, and copy them over
> +./configure --datadir="./data/" --disable-werror --cc="$CC" --cxx="$CXX" \
> +    --extra-cflags="$CFLAGS -U __OPTIMIZE__ "
> +make CONFIG_FUZZ=y CFLAGS="$LIB_FUZZING_ENGINE" -j$(nproc) i386-softmmu/fuzz
> +
> +for i in $(ldd ./i386-softmmu/qemu-fuzz-i386  | cut -f3 -d' '); do 
> +    cp $i $OUT/lib/
> +done
> +rm ./i386-softmmu/qemu-fuzz-i386
> +
> +# Build a second time to build the final binary with correct rpath
> +./configure --datadir="./data/" --disable-werror --cc="$CC" --cxx="$CXX" \
> +    --extra-cflags="$CFLAGS -U __OPTIMIZE__" \
> +    --extra-ldflags="-Wl,-rpath,'\$\$ORIGIN/lib'"
> +make CONFIG_FUZZ=y CFLAGS="$LIB_FUZZING_ENGINE" -j$(nproc) i386-softmmu/fuzz
> +
> +# Copy over the datadir
> +cp  -r ./pc-bios/ $OUT/pc-bios
> +
> +# Run the fuzzer with no arguments, to print the help-string and get the list
> +# of available fuzz-targets. Copy over the qemu-fuzz-i386, naming it according
> +# to each available fuzz target (See 05509c8e6d fuzz: select fuzz target using
> +# executable name)
> +for target in $(./i386-softmmu/qemu-fuzz-i386 | awk '$1 ~ /\*/  {print $2}');
> +do
> +    cp ./i386-softmmu/qemu-fuzz-i386 $OUT/qemu-fuzz-i386-target-$target
> +done
> -- 
> 2.26.2