[llvm-dev] -sanitizer-coverage-prune-blocks=true and LibFuzzer

[Jonas Wagner via llvm-dev]

Hello,

Is this reproducible?
> Fuzzing is a probabilistic business and one or even two runs don't prove
> much.
>

I've reproduced the behavior on two different machines. Attached is a
script to do so. To use the script,

- create an empty folder and copy both prune-blocks.sh and
ff-http-parser.sh in there
- ensure clang and clang++ are in your $PATH
- cd /path/to/prune-blocks.sh
- ./prune-blocks.sh

Let me know how it goes.



> Note that I am going to change all of these coverage options soon.
> The new thing will be
> http://clang.llvm.org/docs/SanitizerCoverage.html#tracing-pcs-with-guards
> It will replace regular (boolean) and 8-bit-counters coverage.
>

Yay, sounds exciting! I've done a couple experiments to measure the
performance and effect of the different coverage options in the recent
past. If you're interested, I'd be happy to discuss off-list; simply send
me an email.

Best,
Jonas
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