Has --dump-debug-dir behaviour changed in JDK9?

[Chris Newland]

Thank you Sundar, that explains it perfectly.

JITWatch visualises JavaScript/bytecode/asm correctly with -ot=false on
JDK9. I'll now try and make it work with optimistic typing enabled.

Cheers,

Chris
@chriswhocodes

On Wed, June 10, 2015 05:22, A. Sundararajan wrote:
> Hi,
>
>
> Filed a bug to track for future reference:
> https://bugs.openjdk.java.net/browse/JDK-8087102
>
>
> Actually, this is not a bug. Two things:
>
>
> 1) --compile-only / -co option is no longer mandatory to use
> --debug-dump-dir option/
> 2) optimistic types is off by default in jdk8u and it is on by default
> with jdk9.
>
> With optimistic types, code generation is lazier & optimistic -- code is
> generated/re-generated as you run the code. With jdk9, you can either
>
> 1) Turn off optimistic types with jdk9 (using -ot=false option) and dump
> similar code as in jdk8u 2) or run the code (i.e., remove -co /
> --compile-only option) and get
> all generated (and regenerated) code dumped.
>
> PS. I've resolved the bug as "not an issue".
>
>
> Hope this explains,
> -Sundar
>
>
> On Wednesday 10 June 2015 02:55 AM, Chris Newland wrote:
>
>> Hi,
>>
>>
>> Has Nashorn's behaviour for dumping bytecode changed in JDK9?
>>
>>
>> Given this JavaScript:
>> https://gist.github.com/chriswhocodes/bfe139592adb846967d8
>>
>>
>> Executed using
>> $JAVA_HOME/bin/jjs -co --dump-debug-dir=. run.js
>>
>>
>> Under 8u60b18 the bytecode is produced as expected:
>>
>>
>> https://gist.github.com/chriswhocodes/e3a85c3613b084e45356
>>
>>
>> This visualises correctly in JITWatch[1] and the bytecode maps back to
>> the source as expected.
>>
>> But under 9b67 only a small amount of bytecode is output that doesn't
>> represent the source program:
>>
>> https://gist.github.com/chriswhocodes/c6c6e33e7994c98d4975
>>
>>
>> The correct program output is produced under both executions so I don't
>>  think the difference is down to dead code elimination.
>>
>> Possible regression?
>>
>>
>> Thanks,
>>
>>
>> Chris
>> @chriswhocodes
>>
>>
>> [1] https://github.com/AdoptOpenJDK/jitwatch
>>
>>
>>
>
>