8310133: Effectivelly final condition not enforced in guards for binding variables from the same case

[lahodaj]

Consider code containing snippet like:

...
case String s when s.isEmpty() -> {
s = null;
}
...

The s binding variable is obviously not effectively final, but the specification currently requires variables used inside the guard to be effectively final or final.

The cause here is in a position check - for error reporting we need to sent a shared variable currentTree to the case, but the effectively final check will only check variables declared before the start of currentTree (to avoid reporting issues for variables inside a lambda, for example). The proposed fix is to keep the case inside currentTree, but ensure the guard's starting position is used, to allow a proper effectively final check.

---

Progress

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Issue

• JDK-8310133: Effectivelly final condition not enforced in guards for binding variables from the same case (Bug - P3)

Reviewers

• Vicente Romero (@vicente-romero-oracle - Reviewer)

Reviewing

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Checkout this PR locally:
$ git fetch https://git.openjdk.org/jdk.git pull/14498/head:pull/14498
$ git checkout pull/14498

Update a local copy of the PR:
$ git checkout pull/14498
$ git pull https://git.openjdk.org/jdk.git pull/14498/head

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Checkout this PR locally:
$ git pr checkout 14498

View PR using the GUI difftool:
$ git pr show -t 14498

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https://git.openjdk.org/jdk/pull/14498.diff

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[bridgekeeper]

👋 Welcome back jlahoda! 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]

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[mlbridge]

Webrevs

• 00: Full (07305360)

[lahodaj]

/backport jdk21

[openjdk]

@lahodaj Backport for repo openjdk/jdk21 on branch master was successfully enabled and will be performed once this pull request has been integrated. Further instructions will be provided at that time.

[vicente-romero-oracle]

looks sensible

[openjdk]

@lahodaj 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:

8310133: Effectivelly final condition not enforced in guards for binding variables from the same case

Reviewed-by: vromero

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 117 new commits pushed to the master branch:

• 09174e0: 8310049: Refactor Charset tests to use JUnit
• 99d2a9a: 8310330: HttpClient: debugging interestOps/readyOps could cause exceptions and smaller cleanup
• 31b6fd7: 8309258: RISC-V: Add riscv_hwprobe syscall
• 4a9cc8a: 8309266: C2: assert(final_con == (jlong)final_int) failed: final value should be integer
• 4e4e586: 8310194: Generational ZGC: Lock-order asserts in JVMTI IterateThroughHeap
• e1906e7: 8310027: Fix -Wconversion warnings in nmethod and compiledMethod related code
• 4ca548f: 8310326: Incorrect position of the synthetic unnamed class
• a059576: 8310187: Improve Generational ZGC jtreg testing
• 9a68ec8: 8219357: G1: G1GCPhaseTimes::debug_phase uses unnecessary ResourceMark
• 0878872: 8310020: MacroAssembler::call_VM(_leaf) doesn't consistently check for conflict with C calling convention.
• ... and 107 more: https://git.openjdk.org/jdk/compare/cf9e6353cc6fe9e57a7a9883813d09892e7e7621...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.

[lahodaj]

/integrate

[openjdk]

Going to push as commit 01623f6.
Since your change was applied there have been 128 commits pushed to the master branch:

• a15db1a: 8302865: Illegal bytecode for break from if with instanceof pattern matching condition
• 67fbd87: 8310143: RandomCommandsTest fails due to unexpected VM exit code after JDK-8282797
• 9eed049: 8310321: make JDKOPT_CHECK_CODESIGN_PARAMS more verbose
• 3faba07: 8307145: windowsaccessbridge.dll erroneously includes private methods in its C API
• 886ac1c: 8308606: C2 SuperWord: remove alignment checks when not required
• 47d00a4: 8310265: (process) jspawnhelper should not use argv[0]
• e022e87: 8310053: VarHandle and slice handle derived from layout are lacking alignment check
• 45eaf5e: 8298443: Remove expired flags in JDK 22
• 28415ad: 8310225: Reduce inclusion of oopMapCache.hpp and generateOopMap.hpp
• 4c3efb3: 8309034: NoClassDefFoundError when initializing Long$LongCache
• ... and 118 more: https://git.openjdk.org/jdk/compare/cf9e6353cc6fe9e57a7a9883813d09892e7e7621...master

Your commit was automatically rebased without conflicts.

[openjdk]

Creating backport for repo openjdk/jdk21 on branch master

/backport openjdk/jdk21 master

[openjdk]

@lahodaj Pushed as commit 01623f6.

💡 You may see a message that your pull request was closed with unmerged commits. This can be safely ignored.

[openjdk]

@openjdk[bot] @lahodaj the backport was successfully created on the branch lahodaj-backport-01623f6a in my personal fork of openjdk/jdk21. To create a pull request with this backport targeting openjdk/jdk21:master, just click the following link:

➡️ Create pull request

The title of the pull request is automatically filled in correctly and below you find a suggestion for the pull request body:

Hi all,

This pull request contains a backport of commit 01623f6a from the openjdk/jdk repository.

The commit being backported was authored by Jan Lahoda on 21 Jun 2023 and was reviewed by Vicente Romero.

Thanks!

If you need to update the source branch of the pull then run the following commands in a local clone of your personal fork of openjdk/jdk21:

$ git fetch https://github.com/openjdk-bots/jdk21.git lahodaj-backport-01623f6a:lahodaj-backport-01623f6a
$ git checkout lahodaj-backport-01623f6a
# make changes
$ git add paths/to/changed/files
$ git commit --message 'Describe additional changes made'
$ git push https://github.com/openjdk-bots/jdk21.git lahodaj-backport-01623f6a