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

[Tobias Hartmann]

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