8308642: Unhelpful pattern switch error: illegal fall-through to a pattern

[biboudis]

Improves two error messages regarding fall-through. Two examples source files after this patch is applied:

> javac jdk/test/langtools/tools/javac/diags/examples/FlowsThroughFromPattern.java                                                                                                       1m 35s
jdk/test/langtools/tools/javac/diags/examples/FlowsThroughFromPattern.java:29: error: illegal fall-through from a pattern
            case String str:
                 ^
  the current case label is missing a break
1 error

> javac jdk/test/langtools/tools/javac/diags/examples/FlowsThroughToPattern.java  
jdk/test/langtools/tools/javac/diags/examples/FlowsThroughToPattern.java:30: error: illegal fall-through to a pattern
            case Object obj: break;
                 ^
  the previous case label is missing a break
1 error

---

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Issue

• JDK-8308642: Unhelpful pattern switch error: illegal fall-through to a pattern (Enhancement - P4)

Reviewers

• Maurizio Cimadamore (@mcimadamore - Reviewer)

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[openjdk]

@biboudis This change now passes all automated pre-integration checks.

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After integration, the commit message for the final commit will be:

8308642: Unhelpful pattern switch error: illegal fall-through to a pattern

Reviewed-by: mcimadamore

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At the time when this comment was updated there had been 220 new commits pushed to the master branch:

• bb4aed9: 8332961: Parallel: Limit PSParallelCompact::verify_complete range
• 95c8a69: 8332032: C2: Remove ExpandSubTypeCheckAtParseTime flag
• ba323b5: 8333047: Remove arena-size-workaround in jvmtiUtils.cpp
• 22ef827: 8320396: Class-File API ClassModel::verify should include checks from hotspot/share/classfile/classFileParser.cpp
• 2ab8ab5: 8332858: References with escapes have broken positions after they are transformed
• 1b7d59f: 8333303: Issues with DottedVersion class
• e304a8a: 8333307: Don't suppress jpackage logging in tests when it is detecting packaging tools in the system
• 3634a91: 8332751: Broken link in VirtualMachine.html
• ffb0867: 8331485: Odd Results when Parsing Scientific Notation with Large Exponent
• 79f4998: 8321314: Reinstate disabling the compiler's default active annotation processing
• ... and 210 more: https://git.openjdk.org/jdk/compare/2f10a316ff0c5a4c124b94f6fabb38fb119d2c82...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.

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[mlbridge]

Webrevs

• 01: Full - Incremental (39eb5359)
• 00: Full (c3143be1)

[mcimadamore]

Nitpick: we do have some other error messages where the second line provides more details. If you search in compiler.properties you will find that, often, that second line is wrapped in parenthesis. I suggest the same should be done here.

[biboudis]

@mcimadamore updated!

[biboudis]

/integrate

[openjdk]

Going to push as commit 778ad00.
Since your change was applied there have been 220 commits pushed to the master branch:

• bb4aed9: 8332961: Parallel: Limit PSParallelCompact::verify_complete range
• 95c8a69: 8332032: C2: Remove ExpandSubTypeCheckAtParseTime flag
• ba323b5: 8333047: Remove arena-size-workaround in jvmtiUtils.cpp
• 22ef827: 8320396: Class-File API ClassModel::verify should include checks from hotspot/share/classfile/classFileParser.cpp
• 2ab8ab5: 8332858: References with escapes have broken positions after they are transformed
• 1b7d59f: 8333303: Issues with DottedVersion class
• e304a8a: 8333307: Don't suppress jpackage logging in tests when it is detecting packaging tools in the system
• 3634a91: 8332751: Broken link in VirtualMachine.html
• ffb0867: 8331485: Odd Results when Parsing Scientific Notation with Large Exponent
• 79f4998: 8321314: Reinstate disabling the compiler's default active annotation processing
• ... and 210 more: https://git.openjdk.org/jdk/compare/2f10a316ff0c5a4c124b94f6fabb38fb119d2c82...master

Your commit was automatically rebased without conflicts.

[openjdk]

@biboudis Pushed as commit 778ad00.

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