RFR: 8339488: Extended NPE message doesn't handle CONSTANT_Dynamic [v2]

[Leonid Mesnik]

On Fri, 6 Sep 2024 15:02:25 GMT, Oli Gillespie <ogillespie at openjdk.org> wrote:

>> Extended NPE messages require walking the bytecode in the method where it was created, and simulating the effect on the stack. `ldc` for dynamic constants is not handled, which can lead to assertion failures in debug builds, or incorrect NPE messages in release builds (possibly worse with the right conditions?).
>> 
>> Simply handle dynamic constants by figuring out their return type so we know how they will affect the stack.
>> 
>> The new test fails without the fix in both release and debug builds. In release, it fails because the NPE message is wrong: `Exception in thread "main" java.lang.NullPointerException: Cannot invoke "Object.notify()" because "`, and in debug builds it hits this assert:
>> 
>> 
>> #
>> # A fatal error has been detected by the Java Runtime Environment:
>> #
>> # Internal Error (<redacted>/src/hotspot/share/interpreter/bytecodeUtils.cpp:660), pid=12677, tid=12678
>> # assert(false) failed: Unexpected tag
>
> Oli Gillespie has updated the pull request incrementally with one additional commit since the last revision:
> 
>   Remove unused import

Marked as reviewed by lmesnik (Reviewer).

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PR Review: https://git.openjdk.org/jdk/pull/20889#pullrequestreview-2286986787