8322532: JShell : Unnamed variable issue

[lahodaj]

The parser that estimates the type and completeness of snippets categorizes tokens to several categories. Underscore is currently not considered to be a token that may appear in an expression, and hence:

Func f = _ -> 0;

is not recognized as a full valid variable declaration snippet, leading to further problems with splitting input into snippets, like:

jshell> interface Func { public void t(int i); }
   ...> Func f = _ -> {};
   ...> System.err.println("This should be printed, but is not!");
   ...> 
|  created interface Func
f ==> $Lambda/0x00000000b3099000@2833cc44

jshell> 

Note the output This should be printed, but is not! is missing.

The proposed change here is to mark underscore as an expression token, which then allows JShell to split the snippets correctly:

jshell> interface Func { public void t(int i); }
   ...> Func f = _ -> {};
   ...> System.err.println("This should be printed, but is not!");
|  created interface Func
f ==> $Lambda/0x0000000084099000@2833cc44
This should be printed, but is not!

---

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

Issue

• JDK-8322532: JShell : Unnamed variable issue (Bug - P4)

Reviewers

• Adam Sotona (@asotona - Reviewer)

Reviewing

Using git

Checkout this PR locally:
$ git fetch https://git.openjdk.org/jdk.git pull/17225/head:pull/17225
$ git checkout pull/17225

Update a local copy of the PR:
$ git checkout pull/17225
$ git pull https://git.openjdk.org/jdk.git pull/17225/head

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Checkout this PR locally:
$ git pr checkout 17225

View PR using the GUI difftool:
$ git pr show -t 17225

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Download this PR as a diff file:
https://git.openjdk.org/jdk/pull/17225.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]

@lahodaj The following label will be automatically applied to this pull request:

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[mlbridge]

Webrevs

• 00: Full (5c2eef8b)

[asotona]

It looks good.

[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:

8322532: JShell : Unnamed variable issue

Reviewed-by: asotona

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 130 new commits pushed to the master branch:

• 3fbccb0: 8322978: Remove debug agent debugMonitorTimedWait() function. It is no longer used.
• ad31ec5: 8322647: Short name for the Europe/Lisbon time zone is incorrect
• 15cf8f8: 8319626: Override toString() for ZipFile
• ade4074: 8322976: Remove reference to transform_no_reclaim
• ea19e9c: 8323011: ProblemList serviceability/HeapDump/FullGCHeapDumpLimitTest.java
• d33dfe5: 8323002: test/jdk/java/lang/Thread/virtual/stress/GetStackTraceALotWhenPinned.java times out on macosx-x64
• 27d5f5c: 8322781: C1: Debug build crash in GraphBuilder::vmap() when print stats
• df22fb3: 8322512: StringBuffer.repeat does not work correctly after toString() was called
• c3cd1f1: 8323000: Parallel: Remove unused class declarations in psScavenge
• dd517c6: 8237842: Separate definitions for default cache line and padding sizes
• ... and 120 more: https://git.openjdk.org/jdk/compare/62b7c5eaed1e6ffd6f2c8371eb4cf01dd9d53a06...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

[lahodaj]

/backport jdk22

[openjdk]

Going to push as commit f0cfd36.
Since your change was applied there have been 138 commits pushed to the master branch:

• 78623c9: 8323012: C2 fails with fatal error: no reachable node should have no use
• f0e2e43: 8323021: Shenandoah: Encountered reference count always attributed to first worker thread
• 3dc4bd8: 8322989: New test serviceability/HeapDump/FullGCHeapDumpLimitTest.java fails
• 1d1cd32: 8321812: Update GC tests to use execute[Limited]TestJava
• 868f874: 8322920: Some ProcessTools.execute* functions are declared to throw Throwable
• 2a9c358: 8322725: (tz) Update Timezone Data to 2023d
• 5235cc9: 8322583: RISC-V: Enable fast class initialization checks
• 3b1e56a: 8322322: Support archived full module graph when -Xbootclasspath/a is used
• 3fbccb0: 8322978: Remove debug agent debugMonitorTimedWait() function. It is no longer used.
• ad31ec5: 8322647: Short name for the Europe/Lisbon time zone is incorrect
• ... and 128 more: https://git.openjdk.org/jdk/compare/62b7c5eaed1e6ffd6f2c8371eb4cf01dd9d53a06...master

Your commit was automatically rebased without conflicts.

[openjdk]

@lahodaj Pushed as commit f0cfd36.

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

[openjdk]

@lahodaj the backport was successfully created on the branch backport-lahodaj-f0cfd361 in my personal fork of openjdk/jdk22. To create a pull request with this backport targeting openjdk/jdk22: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 f0cfd361 from the openjdk/jdk repository.

The commit being backported was authored by Jan Lahoda on 5 Jan 2024 and was reviewed by Adam Sotona.

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/jdk22:

$ git fetch https://github.com/openjdk-bots/jdk22.git backport-lahodaj-f0cfd361:backport-lahodaj-f0cfd361
$ git checkout backport-lahodaj-f0cfd361
# make changes
$ git add paths/to/changed/files
$ git commit --message 'Describe additional changes made'
$ git push https://github.com/openjdk-bots/jdk22.git backport-lahodaj-f0cfd361