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  1. JDK
  2. JDK-8247352

improve error messages for sealed classes and records

    Details

    • Type: Bug
    • Status: In Progress
    • Priority: P3
    • Resolution: Unresolved
    • Affects Version/s: None
    • Fix Version/s: 16
    • Component/s: tools
    • Labels:

      Description

      1) public record Foo(int bar) {
              public Foo() {
                  super();
                  this.bar = 0;
              }
          }

      Fails to compile with "constructor is not canonical, so its first statement must invoke another constructor".

      change to: "constructor is not canonical, so its first statement must invoke another constructor of class $$$"

      2) rather than:

        class is not allowed to extend sealed class: {0}

      consider:

        class {0} in unnamed module cannot extend a sealed class in a different package

        class {0} in module {1} cannot extend a sealed class in a different module

      reported in amber-dev: https://mail.openjdk.java.net/pipermail/amber-dev/2020-June/006185.html

      3) also:
      Compiling this program

      public class Main {
          public static void main(String[] args) {
              Shape shape = new Shape() {};
          }
      }

      sealed interface Shape {
      }

      leads to an error:

      error: local classes must not extend sealed classes
              Shape shape = new Shape() {};
                                        ^

      But the class of `shape` is an anonymous class rather than a local class.
      By definition, a local class must have a name (JLS 14.3). I think the error
      message should say " anonymous classes must not extend sealed classes".

      reported at amber-dev: https://mail.openjdk.java.net/pipermail/amber-dev/2020-June/006186.html

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              • Assignee:
                vromero Vicente Arturo Romero Zaldivar
                Reporter:
                vromero Vicente Arturo Romero Zaldivar
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                Dates

                • Created:
                  Updated: