8262889: Compiler implementation for Record Patterns

[lahodaj]

8262889: Compiler implementation for Record Patterns

A first version of a patch that introduces record patterns into javac as a preview feature. For the specification, please see:
http://cr.openjdk.java.net/~gbierman/jep427+405/jep427+405-20220426/specs/patterns-switch-record-patterns-jls.html

There are two notable tricky parts:
-in the parser, it was necessary to improve the analyzePattern method to handle nested/record patterns, while still keeping error recovery reasonable
-in the TransPatterns, the desugaring of the record patterns is very straightforward - effectivelly the record patterns are desugared into guards/conditions. This will likely be improved in some future version/preview

MatchException has been extended to cover additional cases related to record patterns.

---

Progress

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• Commit message must refer to an issue
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• Change must be properly reviewed (1 review required, with at least 1 reviewer)

Issues

• JDK-8262889: Compiler implementation for Record Patterns
• JDK-8284529: Compiler implementation for Record Patterns (CSR)

Reviewers

• Maurizio Cimadamore (@mcimadamore - Reviewer) ⚠️ Review applies to 90b37c3a
• Vicente Romero (@vicente-romero-oracle - Reviewer) ⚠️ Review applies to a0d0c78b

Contributors

• Brian Goetz <briangoetz@openjdk.org>
• Jan Lahoda <jlahoda@openjdk.org>
• Aggelos Biboudis <abimpoudis@openjdk.org>

Reviewing

Using git

Checkout this PR locally:
$ git fetch https://git.openjdk.java.net/jdk pull/8516/head:pull/8516
$ git checkout pull/8516

Update a local copy of the PR:
$ git checkout pull/8516
$ git pull https://git.openjdk.java.net/jdk pull/8516/head

Using Skara CLI tools

Checkout this PR locally:
$ git pr checkout 8516

View PR using the GUI difftool:
$ git pr show -t 8516

Using diff file

Download this PR as a diff file:
https://git.openjdk.java.net/jdk/pull/8516.diff

[bridgekeeper]

👋 Welcome back jlahoda! A progress list of the required criteria for merging this PR into pr/8182 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 labels will be automatically applied to this pull request:

• compiler
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[mlbridge]

Webrevs

• 06: Full (f49d3f0a)
• 05: Full (924daa0c)
• 04: Full - Incremental (a0d0c78b)
• 03: Full (10cd9d0c)
• 02: Full - Incremental (0e384fb3)
• 01: Full - Incremental (90b37c3a)
• 00: Full (56020b0b)

[lahodaj]

/contributor briangoetz

[vicente-romero-oracle]

I've noticed that this code:

class Test {
    String e(E e) {
        return switch (e) {
            case A -> "42";
        };
    }

    enum E {
        A, B;
    }
}

fails with:

Test.java:3: error: the switch expression does not cover all possible input values
        return switch (e) {
               ^
1 error

before this change but gets accepted with no errors after the change in this PR

[lahodaj]

I've noticed that this code:

class Test {
    String e(E e) {
        return switch (e) {
            case A -> "42";
        };
    }

    enum E {
        A, B;
    }
}

fails with:

Test.java:3: error: the switch expression does not cover all possible input values
        return switch (e) {
               ^
1 error

before this change but gets accepted with no errors after the change in this PR

Oops, sorry, should be fixed now (a0d0c78).

[vicente-romero-oracle]

looks good to me, great job!

[openjdk-notifier]

The dependent pull request has now been integrated, and the target branch of this pull request has been updated. This means that changes from the dependent pull request can start to show up as belonging to this pull request, which may be confusing for reviewers. To remedy this situation, simply merge the latest changes from the new target branch into this pull request by running commands similar to these in the local repository for your personal fork:

git checkout patterns-record-deconstruction3
git fetch https://git.openjdk.java.net/jdk master
git merge FETCH_HEAD
# if there are conflicts, follow the instructions given by git merge
git commit -m "Merge master"
git push

[openjdk]

@lahodaj this pull request can not be integrated into master due to one or more merge conflicts. To resolve these merge conflicts and update this pull request you can run the following commands in the local repository for your personal fork:

git checkout patterns-record-deconstruction3
git fetch https://git.openjdk.java.net/jdk master
git merge FETCH_HEAD
# resolve conflicts and follow the instructions given by git merge
git commit -m "Merge master"
git push

[openjdk]

⚠️ @lahodaj This pull request contains merges that bring in commits not present in the target repository. Since this is not a "merge style" pull request, these changes will be squashed when this pull request in integrated. If this is your intention, then please ignore this message. If you want to preserve the commit structure, you must change the title of this pull request to Merge <project>:<branch> where <project> is the name of another project in the OpenJDK organization (for example Merge jdk:master).

[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:

8262889: Compiler implementation for Record Patterns

Co-authored-by: Brian Goetz <briangoetz@openjdk.org>
Co-authored-by: Jan Lahoda <jlahoda@openjdk.org>
Co-authored-by: Aggelos Biboudis <abimpoudis@openjdk.org>
Reviewed-by: mcimadamore, 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 no new commits pushed to the master branch. If another commit should be pushed before you perform the /integrate command, your PR will be automatically rebased. If you prefer to avoid any potential 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]

/contributor abimpoudis

[openjdk]

@lahodaj Syntax: /contributor (add|remove) [@user | openjdk-user | Full Name <email@address>]. For example:

• /contributor add @openjdk-bot
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[lahodaj]

/contributor add @lahodaj

[openjdk]

@lahodaj
Contributor Jan Lahoda <jlahoda@openjdk.org> successfully added.

[lahodaj]

/contributor add abimpoudis

[openjdk]

@lahodaj
Contributor Aggelos Biboudis <abimpoudis@openjdk.org> successfully added.

[lahodaj]

/integrate

[openjdk]

Going to push as commit e9bddc1.
Since your change was applied there have been 9 commits pushed to the master branch:

• ebfa27b: 8284690: [macos] VoiceOver : Getting java.lang.IllegalArgumentException: Invalid location on Editable JComboBox
• e32377e: 8286304: Removal of diagnostic flag GCParallelVerificationEnabled
• e1f140d: 8287206: Use WrongThreadException for confinement errors
• e17118a: 8272791: java -XX:BlockZeroingLowLimit=1 crashes after 8270947
• f7a37f5: 8287202: GHA: Add macOS aarch64 to the list of default platforms for workflow_dispatch event
• d889319: 8287254: Clean up Xcode sysroot logic
• 593d2b7: 8287091: aarch64 : guarantee(val < (1ULL << nbits)) failed: Field too big for insn
• 6585043: 8287181: Avoid redundant HashMap.containsKey calls in InternalLocaleBuilder.setExtension
• a0cccb5: 8286490: JvmtiEventControllerPrivate::set_event_callbacks CLEARING_MASK computation is incorrect

Your commit was automatically rebased without conflicts.

[openjdk]

@lahodaj Pushed as commit e9bddc1.

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

[forax]

Yai ! champagne (at least virtual).