Incomplete "fake exception" stacktraces

[Chris Plummer]

Hi David,

The "fake exception" was never meant to give you a stack trace, but only 
indicate which line the failure happened at. Unfortunately you are hitting:

void exitOnError(jvmtiError error) {
     if (!NSK_JVMTI_VERIFY(error)) {
         exit(error);
     }
}

So this isn't really the point of failure, just a detection of it after, 
and buried in a C call. An example of the "fake exception" doing better 
would be https://bugs.openjdk.java.net/browse/JDK-8224555:

# ERROR: tc02t001.cpp, 126: line == lines[enterEventsCount] || line == 
(lines[enterEventsCount] + 1)
# verified assertion is FALSE

         if (!NSK_VERIFY(line == lines[enterEventsCount] ||
                 line == (lines[enterEventsCount] + 1))) {

I haven't looked at NSK_JVMTI_VERIFY yet, but possibly it could do 
better, and maybe exitOnError would play a role in that (would need to 
be macroized) so we know who is calling exitOnError().

Chris

On 11/4/19 3:10 PM, David Holmes wrote:
> I'm investigating some JVM TI scenario test failures following a 
> change I made in hotspot. The log shows:
>
> The following fake exception stacktrace is for failure analysis.
> nsk.share.Fake_Exception_for_RULE_Creation: (jvmti_tools.cpp:683) error
>     at nsk_lvcomplain(nsk_tools.cpp:172)
> # ERROR: jvmti_tools.cpp, 683: error
> #   jvmti error: code=52, name=JVMTI_ERROR_INTERRUPT
>
> and that is it. This stacktrace is completely useless as it doesn't 
> show from where nsk_lvcomplain is called!
>
> Does anyone know how this is supposed to work and whether there is 
> some way for me to get a real stacktrace?
>
> Thanks,
> David