8314621: ClassNotFoundException due to lambda reference to elided anonymous inner class

[vicente-romero-oracle]

If code like the one below is executed:

class ClassNotFoundExceptionDueToPrunedCodeTest {
    public static void main(String... args) {
        var o = false ? new Object() {} : null;
        Runnable r = () -> {
            System.out.println(o == o);
        };
        r.run();
    }
}

the runtime throws ClassNotFoundException. What is happening here is that the compiler is doing some "optimizations" basically in this case not generating code for the "true part" of the conditional as it will never be executed. The issue here is that the type of o will be the type of the anonymous class pruned by this optimization. Later on o is captured by the lambda and thus the exception. The proposed solution here is not to prune dead code if it is defining an anonymous class to avoid similar situations.
TIA

---

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Issue

• JDK-8314621: ClassNotFoundException due to lambda reference to elided anonymous inner class (Bug - P4)

Reviewers

• Jan Lahoda (@lahodaj - Reviewer)

Reviewing

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[lahodaj]

Looks OK to me.

[openjdk]

@vicente-romero-oracle This change now passes all automated pre-integration checks.

ℹ️ This project also has non-automated pre-integration requirements. Please see the file CONTRIBUTING.md for details.

After integration, the commit message for the final commit will be:

8314621: ClassNotFoundException due to lambda reference to elided anonymous inner class

Reviewed-by: jlahoda

You can use pull request commands such as /summary, /contributor and /issue to adjust it as needed.

At the time when this comment was updated there had been 56 new commits pushed to the master branch:

• 9faead1: 8319927: Log that IEEE rounding mode was corrupted by loading a library
• f33c874: 8319764: C2 compilation asserts during incremental inlining because Phi input is out of bounds
• 6868b37: 8318826: C2: "Bad graph detected in build_loop_late" with incremental inlining
• 1d96886: 8319531: FileServerHandler::discardRequestBody could be improved
• 73e19f6: 8319825: jdk.net/jdk.net.ExtendedSocketOptions::IP_DONTFRAGMENT is missing @SInCE 19
• faeea07: 8319747: galoisCounterMode_AESCrypt stack walking broken
• b4c2d1c: 8319542: Fix boundaries of region to be tested with os::is_readable_range
• c36ec2c: 8316653: Large NMethodSizeLimit triggers assert during C1 code buffer allocation
• 2db9ea9: 8317723: C2: CountedLoopEndNodes and Zero Trip Guards are wrongly treated as Runtime Predicate
• eaa4417: 8319301: Static analysis warnings after JDK-8318016
• ... and 46 more: https://git.openjdk.org/jdk/compare/3684b4b5f24b413408b1b6d206917931b855844e...master

As there are no conflicts, your changes will automatically be rebased on top of these commits when integrating. If you prefer to avoid this automatic rebasing, please check the documentation for the /integrate command for further details.

➡️ To integrate this PR with the above commit message to the master branch, type /integrate in a new comment.

[vicente-romero-oracle]

Looks OK to me.

@lahodaj thanks for the reviews

[vicente-romero-oracle]

/integrate

[openjdk]

Going to push as commit d6aa7c8.
Since your change was applied there have been 61 commits pushed to the master branch:

• 52e2878: 8319987: compilation of sealed classes leads to infinite recursion
• b05e69f: 8320209: VectorMaskGen clobbers rflags on x86_64
• f3ed275: 8319103: Popups that request focus are not shown on Linux with Wayland
• 9e7a3ae: 8319630: Monitor final audit log lacks separator
• 87be6b6: 8318757: VM_ThreadDump asserts in interleaved ObjectMonitor::deflate_monitor calls
• 9faead1: 8319927: Log that IEEE rounding mode was corrupted by loading a library
• f33c874: 8319764: C2 compilation asserts during incremental inlining because Phi input is out of bounds
• 6868b37: 8318826: C2: "Bad graph detected in build_loop_late" with incremental inlining
• 1d96886: 8319531: FileServerHandler::discardRequestBody could be improved
• 73e19f6: 8319825: jdk.net/jdk.net.ExtendedSocketOptions::IP_DONTFRAGMENT is missing @SInCE 19
• ... and 51 more: https://git.openjdk.org/jdk/compare/3684b4b5f24b413408b1b6d206917931b855844e...master

Your commit was automatically rebased without conflicts.

[openjdk]

@vicente-romero-oracle Pushed as commit d6aa7c8.

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