Assuming this is what Gerd is indeed looking for, I can confirm that Bisect_ppx
still supports it. See

https://github.com/rleonid/bisect_ppx/blob/master/doc/advanced.md#unreachable-code <https://github.com/rleonid/bisect_ppx/blob/master/doc/advanced.md#unreachable-code>

We preferred to document only BISECT_VISIT (which does the same thing), in order
to have only option. But both Bisect_ppx and Bisect support BISECT_MARK and
BISECT_VISIT.

> On Feb 10, 2016, at 13:23, Gabriel Scherer <gabriel.scherer@gmail.com> wrote:
> 
> 
> 
> On Wed, Feb 10, 2016 at 2:00 PM, Gerd Stolpmann <info@gerd-stolpmann.de <mailto:info@gerd-stolpmann.de>> wrote:
> That's interesting news. In my last job I used (the old) bisect
> frequently.
> 
> What I really would love to see is negative coverage: Mark code sections
> where you expect that they are never executed. That could be a simple
> "assert false" but also more extensive error handling. Ideally, the tool
> would automatically recognize certain patterns.
> 
> The old bisect supports special (*BISECT-MARK*) comment to mark dead code for this reason. Do you have something else in mind?
>  
> That's especially useful when you have a management that is after high
> coverage numbers...
> 
> Gerd
> 
> 
> Am Mittwoch, den 10.02.2016, 09:33 -0600 schrieb Anton Bachin:
> > Hello,
> >
> > We would like to announce the release of Bisect_ppx 1.0.0, a code coverage tool
> > for OCaml with appealing reports:
> >
> >   https://github.com/rleonid/bisect_ppx <https://github.com/rleonid/bisect_ppx>
> >
> >
> > You can see a live coverage report here:
> >
> >   http://rleonid.github.io/bisect_ppx/coverage/ <http://rleonid.github.io/bisect_ppx/coverage/>
> >
> > Reports can also be submitted to Coveralls.io using ocveralls [1]. See an
> > example here [2].
> >
> >
> > Bisect_ppx is a fork of the original Bisect by Xavier Clerc, with extensive
> > further development. Differences from Bisect, and from earlier versions of
> > Bisect_ppx, include:
> >
> > - the nicer and more legible HTML reports,
> > - more thorough instrumentation, now including nested functions and or-patterns,
> > - improved compatibility with other PPX rewriters,
> > - an Ocamlbuild plugin,
> > - many bugfixes, and
> > - usage, performance, and documentation improvements.
> >
> >
> > Bisect_ppx was originally forked to update and maintain Bisect's PPX mode, with
> > the OCaml community moving to PPX. Bisect_ppx does not have Bisect's Camlp4
> > dependency. We do not believe that the original Bisect is being actively
> > maintained.
> >
> >
> > Regards,
> > Anton & Leonid
> >
> >
> > P.S. If you are working on a project that uses Bisect_ppx, please let us know!
> >
> >
> > [1]: https://github.com/sagotch/ocveralls <https://github.com/sagotch/ocveralls>
> > [2]: https://coveralls.io/builds/4913198/source?filename=src%2Fsyntax%2FinstrumentPpx.ml <https://coveralls.io/builds/4913198/source?filename=src%2Fsyntax%2FinstrumentPpx.ml>
> >
> >
> 
> --
> ------------------------------------------------------------
> Gerd Stolpmann, Darmstadt, Germany    gerd@gerd-stolpmann.de <mailto:gerd@gerd-stolpmann.de>
> My OCaml site:          http://www.camlcity.org <http://www.camlcity.org/>
> Contact details:        http://www.camlcity.org/contact.html <http://www.camlcity.org/contact.html>
> Company homepage:       http://www.gerd-stolpmann.de <http://www.gerd-stolpmann.de/>
> ------------------------------------------------------------
> 
>