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HI,<br>
<br>
One way to detect getting out of sync, is to structure the test
cases for the native verifier such that they can be run by the
classfile verifier. Especially use for for test cases developed for
the latest spec changes.<br>
<br>
$.02, Roger<br>
<br>
<div class="moz-cite-prefix">On 6/6/25 9:31 PM, Chen Liang wrote:<br>
</div>
<blockquote type="cite" cite="mid:CABe8uE1vnCEP3jOxYKqCCQjaNyKs0gOnkONjTgFHvxZrN=1ObA@mail.gmail.com">
<div dir="ltr">Thanks for the clarification. I totally agree with
this decision of staying on track of Option 2, as verification
in the ClassFile API is mostly a debug tool instead of a
performance sensitive component.
<div><br>
</div>
<div>That said, I noted we are a bit out of sync - for example,
JDK-8350029 is applied to runtime recently and it is clearly
not in the ClassFile API. On the mainline, lack of
synchronization is not that big a deal as we have only minor
updates; however, project valhalla introduces strict fields,
which makes this synchronization more necessary, especially
that otherwise strict fields and early_larval_frame will be
regarded as verification errors.</div>
<div><br>
</div>
<div>We can probably start our updating on mainline so we can
help valhalla. We currently can claim the CF verifier lacks
any patch after the initial 6/10/2022 publication in
jdk-sandbox, but it is still helpful to know which commit or
which JDK release of verifier.cpp was the copy based off - we
can probably drop this "up-to-date-to-tag/commit" info in our
shadow so we can sync more easily.</div>
<div><br>
</div>
<div>Adam, do you know about the exact fork version of the
verifier code? Once we have a point in history, it's quite
easy to check the hotspot commits and see if we need to update
our copy accordingly.</div>
<div><br>
</div>
<div>Regards, Chen</div>
</div>
<br>
<div class="gmail_quote gmail_quote_container">
<div dir="ltr" class="gmail_attr">On Fri, Jun 6, 2025 at
11:46 PM Brian Goetz <<a href="mailto:brian.goetz@oracle.com" moz-do-not-send="true" class="moz-txt-link-freetext">brian.goetz@oracle.com</a>>
wrote:<br>
</div>
<blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">
<div> <font size="4" face="monospace">We had some discussions
about this when the verifier was hand-translated from the
C++ code. At the time, some care was taken to ensure that
we _not_ refactor-as-we-go, to preserve some structural
similarity with the C++ code, so that deltas in the C++
code could be forward-ported. <br>
<br>
We were initially skeptical that duplicating this code
would work, but it turned out to be quite effective. Of
course, long-term maintenance has to be part of the story.<br>
<br>
Going forward, I think we are still in the phase where the
"keep it synchronized" strategy (Adam's #2) can work. We
have to be diligent to not make stylistic changes as we
go, and keep up with changes in the runtime. <br>
<br>
Long term, I think there may be something we can do with
#1, now that Panama is finalized, but that is not enough.
While calling into the C++ code is now more practical, but
that's not enough; the runtime code is designed solely to
support on-the-fly analysis during class loading. Some
refactoring of the C++ API, undertaken by the runtime
team, would be needed to allow it to serve multiple
masters. <br>
</font><br>
<div>On 6/5/2025 10:01 PM, Chen Liang wrote:<br>
</div>
<blockquote type="cite">
<div dir="ltr">Hello,
<div>I have noted that the classfile API's copy of
migrated verifier seems to naturally diverge from the
c++ code: for example, JDK-8350029 that restricts
invokespecial to not allow invoking arbitrary
interface methods is not shadowed to the classfile
verifier. This problem will only get more serious once
strict fields are added. Meanwhile, people expect
ClassFile.verify to be up-to-date with the runtime
verifier.</div>
<div><br>
</div>
<div>What should we do to resolve this discrepancy?
Should we have a separately maintained Java-based
verifier implementing JVMS 4.10, or should we just
increase our frequency of synchronizing with runtime?</div>
<div><br>
</div>
<div>Regards,</div>
<div>Chen Liang</div>
</div>
</blockquote>
<br>
</div>
</blockquote>
</div>
</blockquote>
<br>
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