'Enum.getDeclaringClass' is among "hidden" Java functions which aren't normally visible by resolve. However, it's visible via synthetic property that is a front-end bug.

More details: KT-49653 Deprecate and remove Enum.declaringClass synthetic property

The quick-fix replaces a call with 'declaringJavaClass'.

Example:

  fun <E: Enum<E>> foo(values: Array<E>) {
    EnumSet.noneOf(values.first().declaringClass)
  }

After the quick-fix is applied:

  fun <E: Enum<E>> foo(values: Array<E>) {
    EnumSet.noneOf(values.first().declaringJavaClass)
  }

This inspection only reports if the Kotlin language level of the project or module is 1.7 or higher.