RFR: 8271055: Crash during deoptimization with "assert(bb->is_reachable()) failed: getting result from unreachable basicblock" with -XX:+VerifyStack [v3]

[Yi Yang]

On Tue, 10 Aug 2021 08:14:27 GMT, Tobias Hartmann <thartmann at openjdk.org> wrote:

> Okay but then the fix is incomplete because the VM also needs to handle bytecode not generated by javac. Other compilers or hand written bytecode might still miss these traps.Of course, if the bytecode violates the Spec, the verifier should catch this but otherwise the VM should not crash or assert.
> 
> > Maybe I should file a new issue for that and fix it?
> 
> I think it's just a different failure mode and should be fixed with this bug.
> 
> > Later when javac bug is solved, this bug can also be set to resolve.
> 
> No, as explained above, other compilers could still generate this bytecode shape. We need to handle it properly in the VM.

Make sense! I will prepare a more proper fix to solve this even without javac change. (But it may take a while since I'm busy on other stuffs now...)

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PR: https://git.openjdk.java.net/jdk/pull/4902