RFR: Report oops and fwdptrs verification failures fully

[Roman Kennke]

Am 06.07.2017 um 15:19 schrieb Aleksey Shipilev:
> In our current Verifier, we have to check obj and fwdptr before starting deeper
> verification. The downside for that is, if obj or fwdptr are broken, we would
> never get a full verification report, but rather failure on guarantee(...)-s.
> Which is inconvenient, because it would not mention the phase where it failed,
> the location the object was referenced from, etc.
>
> The better way to handle this would be carefully verify in steps, then knowing
> during the failure print what we can deem safe, and what we cannot:
>   http://cr.openjdk.java.net/~shade/shenandoah/verifier-safelevels/webrev.01/
>
> For example, new hs_err for a code root pointing to a dead region would look
> like this:
>
> http://cr.openjdk.java.net/~shade/shenandoah/verifier-safelevels/hs_err_pid24663.log
>
> Testing: hotspot_gc_shenandoah, failing testcases
>
> Thanks,
> -Aleksey
>
>
This is a great idea! How many times have I needed info further down the
road...


Roman