8294020: improve errors for record declarations

[vicente-romero-oracle]

Although the reporter originally referred to the error message for records with no header, I think the issue is deeper. We intentionally didn't follow the same path for parsing record declarations as we do for, for example, classes. This is mainly because class is a keyword but record is a contextual keyword. So when we find record we are not sure if it is an identifier or a record declaration. Although I think that given a context where the compiler expects a type declaration, we can be more aggressive than before and if we find record + identifier consider it a record declaration. The current implementation of JavacParser::isRecordStart is trying to be too clever but it is actually leaving several cases uncovered. So the proposed simpler version should be more stable and make record related errors more similar to those for other class declarations. Test RecordDeclarationSyntaxTest.java has been added just to have a golden file that stores the error position.

TIA

---

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Issue

• JDK-8294020: improve errors for record declarations

Reviewers

• Jan Lahoda (@lahodaj - Reviewer)

Reviewing

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[openjdk]

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[mlbridge]

Webrevs

• 00: Full (0be97b73)

[jaikiran]

Hello Vicente, I built this PR locally and compiled the same previous code that was reporting that odd error message:

public record Record {

}

With the change in this PR, the error message is much more understandable:

javac /tmp/Record.java 
/tmp/Record.java:1: error: '(' expected
public record Record {
                    ^
/tmp/Record.java:1: error: illegal start of type
public record Record {
                     ^
2 errors

Thank you.

[forax]

There is also the dual problem, students are writing classes with parenthesis after the name and the error message is not obvious too

FooNotARecord.java:1: error: '{' expected
public class FooNotARecord(String s) {
                          ^
1 error

[forax]

I believe in both cases, the error message should mention that a record requires parenthesis (the word record should be in the error message).

By example here is the error message reported by IntelliJ when a class is declared with parenthesis
"record header declared for non record".

[vicente-romero-oracle]

Hello Vicente, I built this PR locally and compiled the same previous code that was reporting that odd error message:

public record Record {

}

With the change in this PR, the error message is much more understandable:

javac /tmp/Record.java 
/tmp/Record.java:1: error: '(' expected
public record Record {
                    ^
/tmp/Record.java:1: error: illegal start of type
public record Record {
                     ^
2 errors

Thank you.

nice, thanks for your feedback

[jaikiran]

I wasn't complaining :) I am just happily stating that your change in this PR makes the error message more understandable than what was before.

[vicente-romero-oracle]

I wasn't complaining :) I am just happily stating that your change in this PR makes the error message more understandable than what was before.

hehe, right I think I was pre-coffee sorry, thanks for your feedback

[lahodaj]

Looks OK.

[openjdk]

@vicente-romero-oracle 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:

8294020: improve errors for record declarations

Reviewed-by: jlahoda

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 66 new commits pushed to the master branch:

• 00d22f6: 8279164: Disable TLS_ECDH_* cipher suites
• d634dde: 8295354: Remove G1 incremental non-copy time calculation
• 8836b92: 8296226: Add constructors (String,Throwable) and (Throwable) to InvalidParameterException
• 51f8e9b: 8296443: NMT: Remove cmdline_tracking_level handling code
• 087cedc: 8295261: RISC-V: Support ReductionV instructions for Vector API
• 556377a: 8296270: Memory leak in ClassLoader::setup_bootstrap_search_path_impl
• c2f7638: 8296335: Fix accessibility manual test instruction
• 91292d5: 8286301: Port JEP 425 to RISC-V
• 581133a: 8294696: BufferedInputStream.transferTo should drain buffer when mark set
• d8573b2: 8294488: Delete KCMS transforms wrappers
• ... and 56 more: https://git.openjdk.org/jdk/compare/50d91a31d495adf8e189d0188918f4ff22f93876...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.

[vicente-romero-oracle]

@lahodaj thanks for the review

[vicente-romero-oracle]

/integrate

[openjdk]

Going to push as commit 60db5f2.
Since your change was applied there have been 72 commits pushed to the master branch:

• 520db1e: 8296485: BuildEEBasicConstraints.java test fails with SunCertPathBuilderException
• b29817a: 8296479: Remove stray comment about POST_STRIP_CMD
• b6ea69c: 8296480: java/security/cert/pkix/policyChanges/TestPolicy.java is failing
• 3baad06: 8295953: Use enhanced-for cycle instead of Enumeration in sun.security
• ba303c0: 8295893: Improve printing of Constant Pool Cache Entries
• f8b2574: 8296137: diags-examples.xml is broken
• 00d22f6: 8279164: Disable TLS_ECDH_* cipher suites
• d634dde: 8295354: Remove G1 incremental non-copy time calculation
• 8836b92: 8296226: Add constructors (String,Throwable) and (Throwable) to InvalidParameterException
• 51f8e9b: 8296443: NMT: Remove cmdline_tracking_level handling code
• ... and 62 more: https://git.openjdk.org/jdk/compare/50d91a31d495adf8e189d0188918f4ff22f93876...master

Your commit was automatically rebased without conflicts.

[openjdk]

@vicente-romero-oracle Pushed as commit 60db5f2.

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