8312984: javac may crash on a record pattern with too few components

[lahodaj]

Processing code like:

public class Err {
    record R(String x) {}

    public void(Object obj) {
        switch(obj) {
            case R(var v, ) -> 1; //note the missing component/nested pattern
        }
    }
} 

may crash with an ArrayIndexOutOfBoundsException, because requesting component type for a non-existing component, while evaluating exhaustivity.

The proposal is to simply use errType for this case, to prevent the crash.

---

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-8312984: javac may crash on a record pattern with too few components (Bug - P4)

Reviewers

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

Reviewing

Using git

Checkout this PR locally:
$ git fetch https://git.openjdk.org/jdk.git pull/15024/head:pull/15024
$ git checkout pull/15024

Update a local copy of the PR:
$ git checkout pull/15024
$ git pull https://git.openjdk.org/jdk.git pull/15024/head

Using Skara CLI tools

Checkout this PR locally:
$ git pr checkout 15024

View PR using the GUI difftool:
$ git pr show -t 15024

Using diff file

Download this PR as a diff file:
https://git.openjdk.org/jdk/pull/15024.diff

Webrev

Link to Webrev Comment

[lahodaj]

/backport jdk21u

[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 Backport for repo openjdk/jdk21u 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.

[openjdk]

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

• compiler

When this pull request is ready to be reviewed, an "RFR" email will be sent to the corresponding mailing list. If you would like to change these labels, use the /label pull request command.

[mlbridge]

Webrevs

• 00: Full (ce85e7c6)

[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:

8312984: javac may crash on a record pattern with too few components

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 86 new commits pushed to the master branch:

• cff25dd: 8306582: Remove MetaspaceShared::exit_after_static_dump()
• 4ba81f6: 8313368: (fc) FileChannel.size returns 0 on block special files
• c1a3f14: 8312078: [PPC] JcmdScale.java Failing on AIX
• 6446792: 8312617: SIGSEGV in ConnectionGraph::verify_ram_nodes
• b093880: 8313322: RISC-V: implement MD5 intrinsic
• 19e2c8c: 8313593: Generational ZGC: NMT assert when the heap fails to expand
• 46fbedb: 8313402: C1: Incorrect LoadIndexed value numbering
• 6faf05c: 8311989: Test java/lang/Thread/virtual/Reflection.java timed out
• 5d1b911: 8310311: Serial: move Generation::contribute_scratch to DefNewGeneration
• 9454b2b: 8312591: GCC 6 build failure after JDK-8280982
• ... and 76 more: https://git.openjdk.org/jdk/compare/9606cbcd2314506d0054ecba1804e5e0c2670cd6...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 c386091.
Since your change was applied there have been 95 commits pushed to the master branch:

• 3212b64: 8313582: Problemlist failing test on linux x86
• bdac348: 8313602: increase timeout for jdk/classfile/CorpusTest.java
• 58906bf: 4893524: Swing drop targets should call close() on transferred readers and streams
• 3c920f9: 8313274: [BACKOUT] Relax prerequisites for java.base-jmod target
• 53ca75b: 8313312: Add missing classpath exception copyright header
• 87d7e97: 8311031: JTable header border vertical lines are not aligned with data grid lines
• 8248e35: 8313576: GCC 7 reports compiler warning in bundled freetype 2.13.0
• 6d180d5: 8313349: Introduce abstract void HtmlDocletWriter.buildPage()
• bc1d2ea: 8312821: Javac accepts char literal as template
• cff25dd: 8306582: Remove MetaspaceShared::exit_after_static_dump()
• ... and 85 more: https://git.openjdk.org/jdk/compare/9606cbcd2314506d0054ecba1804e5e0c2670cd6...master

Your commit was automatically rebased without conflicts.

[openjdk]

Creating backport for repo openjdk/jdk21u on branch master

/backport openjdk/jdk21u master

[openjdk]

@lahodaj Pushed as commit c386091.

💡 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-c3860917 in my personal fork of openjdk/jdk21u. To create a pull request with this backport targeting openjdk/jdk21u: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 c3860917 from the openjdk/jdk repository.

The commit being backported was authored by Jan Lahoda on 3 Aug 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/jdk21u:

$ git fetch https://github.com/openjdk-bots/jdk21u.git lahodaj-backport-c3860917:lahodaj-backport-c3860917
$ git checkout lahodaj-backport-c3860917
# make changes
$ git add paths/to/changed/files
$ git commit --message 'Describe additional changes made'
$ git push https://github.com/openjdk-bots/jdk21u.git lahodaj-backport-c3860917