8266496: WBIsKlassAliveClosure.do_klass() fails for hidden classes

[hseigel]

Please review this small fix for JDK-8266496. The fix changes WBIsKlassAliveClosure.do_klass() so that when it compares the specified name with the name of a hidden class, it truncates the hidden class's name at the first '+' character before doing the comparison. This should work except in the rare case when the pre-mangled hidden class name contains a '+' character.

The fix was tested with Mach5 tiers 1 and 2 on Linux, Mac OS, and Windows, and tiers 3-5 on Linux x64.

Thanks, Harold

---

Progress

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Issue

• JDK-8266496: WBIsKlassAliveClosure.do_klass() fails for hidden classes

Reviewers

• David Holmes (@dholmes-ora - Reviewer) ⚠️ Review applies to c5e9692
• Coleen Phillimore (@coleenp - Reviewer)
• Mikhailo Seledtsov (@mseledts - Committer)
• Lois Foltan (@lfoltan - Reviewer)

Reviewing

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Webrevs

• 01: Full - Incremental (36739c57)
• 00: Full (c5e96925)

[dholmes-ora]

Hi Harold,

Fix seems fine - certainly good enough for whitebox purposes.

Does the test need to generate the classfile? can't you just define a class in the same source file and then read the class file from disk? Whenever I see asm being used I wonder what it is about the class that prevented it being written in Java.

Thanks,
David

[openjdk]

@hseigel 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:

8266496: WBIsKlassAliveClosure.do_klass() fails for hidden classes

Reviewed-by: dholmes, coleenp, mseledtsov, lfoltan

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 8 new commits pushed to the master branch:

• 138d573: 8262392: Update Mesa 3-D Headers to version 21.0.3
• 9de62a4: 8266505: Cleanup LibraryCallKit::make_unsafe_address()
• 1885c83: 8266504: Remove leftovers from BarrierSetAssemblerC1
• 6018336: 8259316: [REDO] C1/C2 compiler support for blackholes
• f07bb2f: 8250766: javadoc adds redundant spaces when @see program element is wrapped
• 61bb6ec: 8266453: Shenandoah: Disable write protections before patching nmethod in nmethod_barrier on MacOSX/AArch64
• a05e8e2: 8266497: Remove unnecessary EMCP liveness indication
• 6ba911d: 8266498: Make debug ps() call print_stack

Please see this link for an up-to-date comparison between the source branch of this pull request and the master branch.
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.

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[hseigel]

Hi David,
Thanks for reviewing this. The test doesn't need to use asm. It could load the class from disk as you suggested, or even use InMemoryJavaCompiler. Please let me know if I should change the test.

Thanks, Harold

[coleenp]

LGTM!

[mseledts]

Change looks good to me.

[lfoltan]

Looks good.
Lois

[dholmes-ora]

No need to change test.

Thanks,
David

[hseigel]

Thanks David, Coleen, Misha and Lois for the reviews.

/integrate

[openjdk]

@hseigel Since your change was applied there have been 16 commits pushed to the master branch:

• 51f5adf: 8265047: Inconsistent warning message in jcmd VM.log
• ea30bd6: 8263362: Avoid division by 0 in java/awt/font/TextJustifier.java justify
• 0f9852c: 8266168: -Wmaybe-uninitialized happens in check_code.c
• a86ee9b: 8266545: 8261169 broke Harfbuzz build with gcc 7 and 8
• 2dd5667: 8266018: Shenandoah: fix an incorrect assert
• 22ca62c: 8266542: Remove broken -XX:-UseLoopSafepoints flag
• 7835cdb: 8265915: adjust state_unloading_cycle compuation order in nmethod::is_unloading
• 20ad428: 8180568: Refactor javax/crypto shell tests to plain java tests
• 138d573: 8262392: Update Mesa 3-D Headers to version 21.0.3
• 9de62a4: 8266505: Cleanup LibraryCallKit::make_unsafe_address()
• ... and 6 more: https://git.openjdk.java.net/jdk/compare/ef0f693065eddd5c86b9e0fc52d57eafb0b1dc50...master

Your commit was automatically rebased without conflicts.

Pushed as commit eb3b96d.

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