incorrect warning about unused import for import used in permits clause

[softwareCobbler]

Incorrect warning about unused import when that import

• references a nested class in the same file
• is used only in a permits clause on the file's top-level class

Environment

• Operating System: Win10
• JDK version: 21
• Visual Studio Code version: 1.85
• Java extension version: v1.26.2023122208

Steps To Reproduce

The following code issues a warning in the IDE about unused imports:

package foo.x;

// these imports are warned against as unused,
// but the permits clause doesn't compile without them
import foo.x.A.B;
import foo.x.A.C;

public sealed interface A permits B, C {
    record B(int data) implements A {}
    record C(String data) implements A {}
}

Current Result

warning on the import of foo.x.A.B and foo.x.A.C

Expected Result

no warnings

Additional Informations

[snjeza]

This is an upstream JDT issue - https://github.com/eclipse-jdt/eclipse.jdt.core/issues/1808