JDK-8324530: Build error with gcc 10

[tstuefe]

This is a trivial fix to a build error (and the underlying off-by-one error, which is only theoretical) gcc 10 warns about.

Note that this issue has been fixed in JDK 11 and later as part of 8140594: "Various minor code improvements (compiler)", but that patch is much larger and would need more intense review. Here, I'd like to just fix this one problem that breaks the build with gcc 10.

---

Progress

• Change must be properly reviewed (1 review required, with at least 1 Reviewer)
• Change must not contain extraneous whitespace
• Commit message must refer to an issue
• JDK-8324530 needs maintainer approval

Issue

• JDK-8324530: Build error with gcc 10 (Bug - P4 - Approved)

Reviewers

• Andrew John Hughes (@gnu-andrew - Reviewer)

Reviewing

Using git

Checkout this PR locally:
$ git fetch https://git.openjdk.org/jdk8u-dev.git pull/424/head:pull/424
$ git checkout pull/424

Update a local copy of the PR:
$ git checkout pull/424
$ git pull https://git.openjdk.org/jdk8u-dev.git pull/424/head

Using Skara CLI tools

Checkout this PR locally:
$ git pr checkout 424

View PR using the GUI difftool:
$ git pr show -t 424

Using diff file

Download this PR as a diff file:
https://git.openjdk.org/jdk8u-dev/pull/424.diff

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[bridgekeeper]

👋 Welcome back stuefe! 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.

[mlbridge]

Webrevs

• 00: Full (2c6da4bd)

[tstuefe]

Build errors unrelated but annoying.

[tstuefe]

@gnu-andrew ?

[gnu-andrew]

Sorry, Thomas, I only just saw this.

I seem to remember looking at JDK-8140594 myself a while back and it does have a lot of unrelated changes, some of which potentially change behaviour. I agree cherry-picking the fix we actually need here is the better approach.

I have built 8u myself on GCC 13 (with the help of #357) but I guess that was a product build and this code is inside #ifndef PRODUCT.

[openjdk]

⚠️ @tstuefe This change is now ready for you to apply for maintainer approval. This can be done directly in each associated issue or by using the /approval command.

[gnu-andrew]

Windows x86 issue was a result of the January 2024 security changes and should now have been resolved by JDK-8324184

[tstuefe]

/approval this is a small fix for a compile problem and a (non-critical) off-by-one when building with GCC 10

[openjdk]

@tstuefe usage: /approval [<id>] (request|cancel) [<text>]

[tstuefe]

/approval JDK-8324530 request this is a small fix for a compile problem and a (non-critical) off-by-one when building with GCC 10

[openjdk]

@tstuefe
JDK-8324530: The approval request has been created successfully.

[gnu-andrew]

/approve yes

[openjdk]

@gnu-andrew
8324530: The approval request has been approved.

[openjdk]

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

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

8324530: Build error with gcc 10

Reviewed-by: andrew

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 14 new commits pushed to the master branch:

• b7bda28: 8325150: (tz) Update Timezone Data to 2024a
• ae516a3: 8074860: Structured Exception Catcher missing around CreateJavaVM on Windows
• 9bd600c: 8079441: Intermittent failures on Windows with "Unexpected exit from test [exit code: 1080890248]" (0x406d1388)
• e926edc: 8276139: TestJpsHostName.java not reliable, better to expand HostIdentifierCreate.java test
• 9aabf22: 8270517: Add Zero support for LoongArch
• dce5300: 8168518: rcache interop with krb5-1.15
• 3dc011b: 8323202: [8u] Remove get_source.sh and hgforest.sh
• abb4975: 8011180: Delete obsolete scripts
• cfed45d: 8155590: Dubious collection management in sun.net.www.http.KeepAliveCache
• 818c53e: 8315042: NPE in PKCS7.parseOldSignedData
• ... and 4 more: https://git.openjdk.org/jdk8u-dev/compare/552c6866d8ad71ef247b5303f78fa7a65506aea9...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]

Thanks @gnu-andrew .

/integrate

[openjdk]

Going to push as commit 5e70a86.
Since your change was applied there have been 16 commits pushed to the master branch:

• 53e0826: 8323640: [TESTBUG]testMemoryFailCount in jdk/internal/platform/docker/TestDockerMemoryMetrics.java always fail because OOM killed
• a37b856: 8016451: Scary messages emitted by build.tools.generatenimbus.PainterGenerator during build
• b7bda28: 8325150: (tz) Update Timezone Data to 2024a
• ae516a3: 8074860: Structured Exception Catcher missing around CreateJavaVM on Windows
• 9bd600c: 8079441: Intermittent failures on Windows with "Unexpected exit from test [exit code: 1080890248]" (0x406d1388)
• e926edc: 8276139: TestJpsHostName.java not reliable, better to expand HostIdentifierCreate.java test
• 9aabf22: 8270517: Add Zero support for LoongArch
• dce5300: 8168518: rcache interop with krb5-1.15
• 3dc011b: 8323202: [8u] Remove get_source.sh and hgforest.sh
• abb4975: 8011180: Delete obsolete scripts
• ... and 6 more: https://git.openjdk.org/jdk8u-dev/compare/552c6866d8ad71ef247b5303f78fa7a65506aea9...master

Your commit was automatically rebased without conflicts.

[openjdk]

@tstuefe Pushed as commit 5e70a86.

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