view contrib/fuzz/README.rst @ 47072:4c041c71ec01

revlog: introduce an explicit tracking of what the revlog is about

Since the dawn of time, people have been forced to rely to lossy introspection
of the index filename to determine what the purpose and role of the revlog they
encounter is. This is hacky, error prone, inflexible, abstraction-leaky,
<insert-your-own-complaints-here>.

In f63299ee7e4d Raphaël introduced a new attribute to track this information:
`revlog_kind`. However it is initialized in an odd place and various instances
end up not having it set. In addition is only tracking some of the information
we end up having to introspect in various pieces of code.

So we add a new attribute that holds more data and is more strictly enforced.
This work is done in collaboration with Raphaël.

The `revlog_kind` one will be removed/adapted in the next changeset. We expect
to be able to clean up various existing piece of code and to simplify coming
work around the newer revlog format.

Differential Revision: https://phab.mercurial-scm.org/D10352

How to add fuzzers (partially cribbed from oss-fuzz[0]):

  1) git clone https://github.com/google/oss-fuzz
  2) cd oss-fuzz
  3) python infra/helper.py build_image mercurial
  4) docker run --cap-add=SYS_PTRACE -it -v $HG_REPO_PATH:/hg-new \
         gcr.io/oss-fuzz/mercurial bash
  5) cd /src
  6) rm -r mercurial
  7) ln -s /hg-new mercurial
  8) cd mercurial
  9) compile
  10) ls $OUT

Step 9 is literally running the command "compile", which is part of
the docker container. Once you have that working, you can build the
fuzzers like this (in the oss-fuzz repo):

python infra/helper.py build_fuzzers --sanitizer address mercurial $HG_REPO_PATH

(you can also say "memory", "undefined" or "coverage" for
sanitizer). Then run the built fuzzers like this:

python infra/helper.py run_fuzzer mercurial -- $FUZZER

0: https://github.com/google/oss-fuzz/blob/master/docs/new_project_guide.md