Hi Alex,
On Sunday, 2020-09-20 at 22:25:01 -04, Alexander Bulekov wrote:
> This parses a yaml file containing general-fuzzer configs and builds a
> separate oss-fuzz wrapper binary for each one, changing some
> preprocessor macros for each configuration. To avoid dealing with
> escaping and stringifying, convert each string into a byte-array
> representation
>
> Signed-off-by: Alexander Bulekov <alx...@bu.edu>
> ---
> scripts/oss-fuzz/build_general_fuzzers.py | 69 +++++++++++++++++++++++
> 1 file changed, 69 insertions(+)
> create mode 100755 scripts/oss-fuzz/build_general_fuzzers.py
>
> diff --git a/scripts/oss-fuzz/build_general_fuzzers.py
> b/scripts/oss-fuzz/build_general_fuzzers.py
> new file mode 100755
> index 0000000000..918f1143a5
> --- /dev/null
> +++ b/scripts/oss-fuzz/build_general_fuzzers.py
> @@ -0,0 +1,69 @@
> +#!/usr/bin/env python3
> +# -*- coding: utf-8 -*-
> +
> +"""
> +This script creates wrapper binaries that invoke the general-device-fuzzer
> with
> +configurations specified in a yaml config file.
> +"""
> +import sys
> +import os
> +import yaml
> +import tempfile
> +
> +CC = ""
> +TEMPLATE_FILENAME = "target_template.c"
> +TEMPLATE_PATH = ""
> +
> +
> +def usage():
> + print("Usage: CC=COMPILER {} CONFIG_PATH \
> +OUTPUT_PATH_PREFIX".format(sys.argv[0]))
The indentation of this seems off.
Python will concatenate 2 or more strings that appear one after the
other, so it might be cleaner to write them like:
print("Usage: CC=COMPILER {} CONFIG_PATH "
"OUTPUT_PATH_PREFIX".format(sys.argv[0]))
There is no need for the backslash at the end due to the use of the
braces '()' here.
> + sys.exit(0)
> +
> +
> +def str_to_c_byte_array(s):
> + """
> + Convert strings to byte-arrays so we don't worry about formatting
> + strings to play nicely with cc -DQEMU_FUZZARGS etc
> + """
> + return ','.join('0x{:02x}'.format(ord(x)) for x in s)
> +
> +
> +def compile_wrapper(cfg, path):
> + os.system('$CC -DQEMU_FUZZ_ARGS="{fuzz_args}" \
> + -DQEMU_FUZZ_OBJECTS="{fuzz_objs}" \
> + {wrapper_template} -o {output_bin}'.format(
> + fuzz_args=str_to_c_byte_array(cfg["args"].replace("\n", "
> ")),
> +
> fuzz_objs=str_to_c_byte_array(cfg["objects"].replace("\n", " ")),
> + wrapper_template=TEMPLATE_PATH,
> + output_bin=path))
> +
Similarly here, it might look better as:
os.system('$CC -DQEMU_FUZZ_ARGS="{fuzz_args}" '
'-DQEMU_FUZZ_OBJECTS="{fuzz_objs}" '
'{wrapper_template} -o {output_bin}'.format(
fuzz_args=str_to_c_byte_array(cfg["args"].replace("\n", "
")),
fuzz_objs=str_to_c_byte_array(cfg["objects"].replace("\n", "
")),
wrapper_template=TEMPLATE_PATH,
output_bin=path))
> +
> +
> +def main():
> + global CC
> + global TEMPLATE_PATH
> + global OUTPUT_BIN_NAME
> +
> + if len(sys.argv) != 3:
> + usage()
> +
> + cfg_path = sys.argv[1]
> + out_path = sys.argv[2]
> +
> + CC = os.getenv("CC", default="cc")
> + TEMPLATE_PATH = os.path.join(os.path.dirname(__file__),
> TEMPLATE_FILENAME)
> + if not os.path.exists(TEMPLATE_PATH):
> + print("Error {} doesn't exist".format(TEMPLATE_PATH))
> + sys.exit(1)
> +
> + with open(cfg_path, "r") as f:
> + configs = yaml.load(f)["configs"]
Just in case, the use of .get("config". []) might work better here.
But also check if yaml.load() could possibly throw an exception if the
file, despite existing isn't able to be parsed.
Thanks,
Darren.
