[9] RFR(S): 8142500: missing null checks in IfNode::has_only_uncommon_traps

[Rickard Bäckman]

Looks good.

/R

On 11/13, Tobias Hartmann wrote:
> Hi,
> 
> please review the following patch:
> 
> https://bugs.openjdk.java.net/browse/JDK-8142500
> http://cr.openjdk.java.net/~thartmann/8142500/webrev.00/
> 
> C2 crashes in 'IfNode::has_only_uncommon_traps()' after calling 'dom_caller->same_calls_as(caller)' because 'dom_caller' or 'caller' is NULL. This may happen if the method containing the corresponding uncommon trap is not inlined and therefore has no caller in its JVMState. We should bail out if either 'dom_caller' or 'caller' is NULL (it's fine if both are NULL).
> 
> Since we check that the uncommon traps belong to the same method, this can only happen if the method is recursively inlined.
> 
> Tom Rodriguez verified that this solves the problem.
> 
> Thanks,
> Tobias