8276337: Use override specifier in HeapDumper

[lkorinth]

Use override specifier in HeapDumper. It is safer.

/label add serviceability

---

Progress

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Issue

• JDK-8276337: Use override specifier in HeapDumper

Reviewers

• Thomas Stuefe (@tstuefe - Reviewer)
• David Holmes (@dholmes-ora - Reviewer)

Reviewing

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[bridgekeeper]

👋 Welcome back lkorinth! A progress list of the required criteria for merging this PR into master will be added to the body of your pull request. There are additional pull request commands available for use with this pull request.

[openjdk]

@lkorinth
The serviceability label was successfully added.

[mlbridge]

Webrevs

• 01: Full - Incremental (dacd7355)
• 00: Full (cf6ca4fd)

[dholmes-ora]

In what way is it "safer" ?? What are you trying to guard against?

[lkorinth]

In what way is it "safer" ?? What are you trying to guard against?

If you use override, you can not forget to update a method signature if you change the method signature in the base class. You can also not by mistake change the method signature in this class without realizing you should change the base class. There is no downside of using override that I know of.

[lkorinth]

I have some new code in the pipe, and I want to use override in that code without changing unrelated code in heapDumper.cpp. Thus I first make this change so that my future change can keep the "style" of the file.

[tstuefe]

Hi Leo, seems fine.

..Thomas

[tstuefe]

Unrelated, but could be a const method, no?

[lkorinth]

Not easily I think, if I make the method const, I would have to return a const pointer, and then I need to do const operations on the backend etc.

[openjdk]

@lkorinth 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:

8276337: Use override specifier in HeapDumper

Reviewed-by: stuefe, dholmes

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 11 new commits pushed to the master branch:

• 59c3dcc: 8276746: Add section on reproducible builds in building.md
• 0e0dd33: 8276129: PretouchTask should page-align the chunk size
• a472433: 8276572: Fake libsyslookup.so library causes tooling issues
• b01f107: 8276252: java/nio/channels/Channels/TransferTo.java failed with OOM java heap space error
• 92d2176: 8273967: gtest os.dll_address_to_function_and_library_name_vm fails on macOS12
• a74a839: 8276571: C2: pass compilation options as structure
• c393ee8: 8276632: Use blessed modifier order in security-libs code
• 7023b3f: 8276628: Use blessed modifier order in serviceability code
• b933136: 8276641: Use blessed modifier order in jshell
• 0616d86: 8276635: Use blessed modifier order in compiler code
• ... and 1 more: https://git.openjdk.java.net/jdk/compare/3c0faa73522bd004b66cb9e477f43e15a29842e6...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.

[tstuefe]

In what way is it "safer" ?? What are you trying to guard against?

If you use override, you can not forget to update a method signature if you change the method signature in the base class. You can also not by mistake change the method signature in this class without realizing you should change the base class. There is no downside of using override that I know of.

In addition to that, its a helpful documentation for the code reader.

[dholmes-ora]

The only "downside" to using override is that if you use it on one method then you must use it on all applicable methods in a class, so it can tend to have a viral affect in terms of the scope of changes needed just to add the case(s) you're really interested in.

My experience with override in Java is a negative one as I often fail to add the annotation and then get chastised by the compiler for my oversight. It might be useful when writing larger libraries with class hierarchies but I find it a hinderence when writing simple code like tests.

For C++ I find the placement of override awkward and less visible than virtual.

[lkorinth]

Thanks Thomas and David!
/integrate

[openjdk]

Going to push as commit daf77eb.
Since your change was applied there have been 46 commits pushed to the master branch:

• 93692ea: 8274395: Use enhanced-for instead of plain 'for' in jdk.internal.jvmstat
• e35abe3: 8256208: Javadoc's generated overview does not show classes of unnamed package
• f65db88: 8276841: Add support for Visual Studio 2022
• c27afb3: 8276863: Remove test/jdk/sun/security/ec/ECDSAJavaVerify.java
• e198594: 8250678: ModuleDescriptor.Version parsing treats empty segments inconsistently
• 4bd5bfd: 8276731: Metaspace chunks are uncommitted twice
• 5c7f77c: 8276850: Remove outdated comment in HeapRegionManager::par_iterate
• 945f408: 8276098: Do precise BOT updates in G1 evacuation phase
• 8747882: 8276790: Rename GenericCDSFileMapHeader::_base_archive_path_offset
• 38e6d5d: 8276677: Malformed Javadoc inline tags in JDK source in javax/net/ssl
• ... and 36 more: https://git.openjdk.java.net/jdk/compare/3c0faa73522bd004b66cb9e477f43e15a29842e6...master

Your commit was automatically rebased without conflicts.

[openjdk]

@lkorinth Pushed as commit daf77eb.

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