8336081: Fix -Wzero-as-null-pointer-constant warnings in JVMTypedFlagLimit ctors

[kimbarrett]

Please review this change to member initializers in the JVMTypedFlagLimit
class template. It has two members of type T, which were being initialized
with a literal value of 0, triggering -Wzero-as-null-pointer-constant when T
is a pointer type and that warning is enabled.

We instead value initialize these members. For scalar types this performs
zero-initialization, without triggering -Wzero-as-null-pointer-constant if
it's a pointer type.

Testing: mach5 tier1

---

Progress

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• Commit message must refer to an issue

Issue

• JDK-8336081: Fix -Wzero-as-null-pointer-constant warnings in JVMTypedFlagLimit ctors (Enhancement - P4)

Reviewers

• David Holmes (@dholmes-ora - Reviewer)
• Julian Waters (@TheShermanTanker - Committer)

Reviewing

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Update a local copy of the PR:
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$ git pull https://git.openjdk.org/jdk.git pull/20112/head

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$ git pr checkout 20112

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https://git.openjdk.org/jdk/pull/20112.diff

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[openjdk]

@kimbarrett This change now passes all automated pre-integration checks.

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

8336081: Fix -Wzero-as-null-pointer-constant warnings in JVMTypedFlagLimit ctors

Reviewed-by: dholmes, jwaters

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:

• b363de8: 8335946: DTrace code snippets should be generated when DTrace flags are enabled
• d6c6847: 8335743: jhsdb jstack cannot print some information on the waiting thread
• cad68e0: 8335935: Chained builders not sending transformed models to next transforms
• 242f113: 8334481: [JVMCI] add LINK_TO_NATIVE to MethodHandleAccessProvider.IntrinsicMethod
• 66db715: 8335637: Add explicit non-null return value expectations to Object.toString()
• 7ab96c7: 8335409: Can't allocate and retain memory from resource area in frame::oops_interpreted_do oop closure after 8329665
• fb66716: 8331725: ubsan: pc may not always be the entry point for a VtableStub
• fb9a227: 8313909: [JVMCI] assert(cp->tag_at(index).is_unresolved_klass()) in lookupKlassInPool
• e6c5aa7: 8336012: Fix usages of jtreg-reserved properties
• e0fb949: 8335779: JFR: Hide sleep events
• ... and 1 more: https://git.openjdk.org/jdk/compare/a44b60c8c14ad998e51239f48e64779304aaac50...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.

[openjdk]

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[mlbridge]

Webrevs

• 00: Full (03fa720d)

[dholmes-ora]

Okay.

[kimbarrett]

Thanks for reviews @dholmes-ora and @TheShermanTanker

[kimbarrett]

/integrate

[openjdk]

Going to push as commit 7a62032.
Since your change was applied there have been 32 commits pushed to the master branch:

• f677b90: 8267887: RMIConnector_NPETest.java fails after removal of RMI Activation (JDK-8267123)
• 1fe3ada: 8336284: Test TestClhsdbJstackLock.java/TestJhsdbJstackLock.java fails with -Xcomp after JDK-8335743
• c703d29: 8335710: serviceability/dcmd/vm/SystemDumpMapTest.java and SystemMapTest.java fail on Linux Alpine after 8322475
• 81a0d1b: 8325525: Create jtreg test case for JDK-8325203
• b3ef2a6: 8336036: Synthetic documentation for a record's equals is incorrect for floating-point types
• 687601e: 8336257: Additional tests in jmxremote/startstop to match on PID not app name
• 8890557: 8335623: Clean up HtmlTag.HtmlTag and make the ARIA role attribute global
• 73e3e0e: 8321509: False positive in get_trampoline fast path causes crash
• 9eb611e: 8334055: Unhelpful 'required: reference' diagnostics after JDK-8043226
• 5100303: 8335668: NumberFormat integer only parsing should throw exception for edge case
• ... and 22 more: https://git.openjdk.org/jdk/compare/a44b60c8c14ad998e51239f48e64779304aaac50...master

Your commit was automatically rebased without conflicts.

[openjdk]

@kimbarrett Pushed as commit 7a62032.

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