defaultArg

This internal meta annotation is used by the compiler to support default annotation arguments.

For an annotation definition class ann(x: Int = defaultExpr) extends Annotation, the compiler adds @defaultArg(defaultExpr) to the parameter x. This causes the syntax tree of defaultExpr to be stored in the classfile.

When using a default annotation argument, the compiler can recover the syntax tree and insert it in the AnnotationInfo.

For details, see scala.reflect.internal.AnnotationInfos.AnnotationInfo.