[dom binding] JEP 409 - sealed modifiers and permitted types not accessible through ITypeBinding

[subyssurendran666]

code trying to access the sealed modifiers through ITypeBinding interface

The 'sealed' and 'non-sealed' modifiers are visible and accessible through the AST, but not when trying to get the same information with the associated type binding.

Also, permitted types are not available from ITypeBinding (while they are part of 'org.eclipse.jdt.internal.compiler.lookup.SourceTypeBinding').

Reproducer

ASTParser astParser = ASTParser.newParser(AST.JLS17);
    Map<String, String> options = new HashMap<>();
    options.put(JavaCore.COMPILER_COMPLIANCE, "17");
    options.put(JavaCore.COMPILER_SOURCE, "17");

    options.put(JavaCore.COMPILER_PB_ENABLE_PREVIEW_FEATURES, "enabled");

    astParser.setCompilerOptions(options);
    astParser.setEnvironment(new String[] {}, new String[] {}, new String[] {}, true);
    astParser.setUnitName("Example.java");
    astParser.setResolveBindings(true);
    astParser.setBindingsRecovery(true);

    String source =
      "sealed class A permits B, C {}\n"
      + "final class B extends A {}\n"
      + "non-sealed class C extends A {}";
    astParser.setSource(source.toCharArray());

    CompilationUnit compilationUnit = (CompilationUnit) astParser.createAST(null);
    TypeDeclaration a = (TypeDeclaration) compilationUnit.types().get(0);

    if (!Modifier.isSealed(a.getModifiers())) {
      throw new AssertionError("Modifier is not present in AST");
    }

    if (a.permittedTypes().size() != 2) {
      throw new AssertionError("permitted types are not present in AST");
    }

    ITypeBinding aBinding = a.resolveBinding();
    if (!Modifier.isSealed(aBinding.getModifiers())) {
      // permitted types not even available through the ITypeBinding interface
      throw new AssertionError("'sealed' modifier is not set in binding");
    }

Ref: https://bugs.eclipse.org/bugs/show_bug.cgi?id=578061

[jarthana]

@subyssurendran666 please take this forward.