fuzzcheck-view is a tool to visualise the code coverage of inputs generated by fuzzcheck. It is currently very basic and does not handle errors well, but it seems to work.
Please note that it is currently published under the Anti-Capitalist Software
License. This means that you are free to use, copy, modify, and distribute or
sell copies of it if you are an individual, a non-profit organisation, an
educational institution, or an organisation that seeks shared profit for all
of its members, and allows non-members to set the cost of their labor. If you
do not meet any of these requirements but would still like to use
fuzzcheck-view, please contact me at [email protected] . I am also
automatically granting the permission to use, copy, and modify the tool to all
of my sponsors.
To install it, run:
cargo +nightly install --git https://github.com/loiclec/fuzzcheck-view
After running the fuzz test tests::fuzz on the crate my_crate with
fuzzcheck, you can launch fuzzcheck-view as follows:
fuzzcheck-view -d "my_crate" -t "tests::fuzz"where the argument to -d (directory) is a path to the top folder of a Rust
crate (containing a Cargo.toml). The argument to -t is the exact path to
the test function run by fuzzcheck. Additionally, if you are using cargo
workspace, you need to give the path to the top folder of the workspace with
-w. For example, if you have a workspace called compiler that contains a
crate called parser. Then, assuming the current directory is the top-level
folder of the workspace, you should use something like:
fuzzcheck-view -w "." -d "my_crate" -t "parse_ident::tests::fuzz1"fuzzcheck-view expects the following folder structure:
- my_crate # (path given to -d )
- fuzz
- tests::fuzz
- stats
- <timestamp>
- ...
- <timestamp>
- simples_cov,json
- coverage_sensor.json
- world.json
- ...
- tests::fuzz2
- ...This folder structure is generated by fuzzcheck when fuzzing a function using
the default options.
If it launches properly, it serves a webpage on localhost:8000 looking like
this:
On the top left is a list of options about what code coverage to visualise. You can choose to visualise the coverage of all test cases combined, or of a particular one. You can also choose to filter the list of functions shown to make it easier to navigate.
On the top right is the list of inputs saved by fuzzcheck’s simplest_cov pool.
They are sorted by their “interestingness” score. You can hover the mouse over
an input to see a preview of it underneath, or select one to view its
associated code coverage (if you have selected that option in the top left
panel).
On the second row is a list of files and functions. Only the code coverage of
the selected function will be shown. You can quickly switch between files
using the a and s keys and switch between functions using the k and l
keys.
Finally, on the bottom left, we have the code coverage. The parts highlighted in green were reached by the fuzzer/input. The parts highlighted in red were not. The parts that are not highlighted were not instrumented.
If you hover over a region of green highlighted code, the smallest input that reaches this region of code is shown on the right.