Package com.android.tools.r8.keepanno.annotations

Annotation Type UsesReflection

  • @Target({TYPE,FIELD,METHOD,CONSTRUCTOR})
@Retention(CLASS)
public @interface UsesReflection
    Annotation to declare the reflective usages made by a class, method or field.

    The annotation's 'value' is a list of targets to be kept if the annotated item is used. The annotated item is a precondition for keeping any of the specified targets. Thus, if an annotated method is determined to be unused by the program, the annotation itself will not be in effect and the targets will not be kept (assuming nothing else is otherwise keeping them).

    The annotation's 'additionalPreconditions' is optional and can specify additional conditions that should be satisfied for the annotation to be in effect.

    The translation of the UsesReflection annotation into a KeepEdge is as follows:

    Assume the item of the annotation is denoted by 'CTX' and referred to as its context. 

     @UsesReflection(value = targets, [additionalPreconditions = preconditions])
 ==>
 @KeepEdge(
   consequences = targets,
   preconditions = {createConditionFromContext(CTX)} + preconditions
 )

 where
   KeepCondition createConditionFromContext(ctx) {
     if (ctx.isClass()) {
       return new KeepCondition(classTypeName = ctx.getClassTypeName());
     }
     if (ctx.isMethod()) {
       return new KeepCondition(
         classTypeName = ctx.getClassTypeName(),
         methodName = ctx.getMethodName(),
         methodReturnType = ctx.getMethodReturnType(),
         methodParameterTypes = ctx.getMethodParameterTypes());
     }
     if (ctx.isField()) {
       return new KeepCondition(
         classTypeName = ctx.getClassTypeName(),
         fieldName = ctx.getFieldName()
         fieldType = ctx.getFieldType());
     }
     // unreachable
   }

    • Required Element Summary

      Required Elements 
      Modifier and Type Required Element Description
      KeepTarget[] value
      Consequences that must be kept if the annotation is in effect.

    • Optional Element Summary

      Optional Elements 
      Modifier and Type Optional Element Description
      KeepCondition[] additionalPreconditions
      Additional preconditions for the annotation to be in effect.
      java.lang.String description
      Optional description to document the reason for this annotation.

    • Element Detail

      • value

        KeepTarget[] value
        Consequences that must be kept if the annotation is in effect.
        Returns:
        The list of target consequences.

      • description

        java.lang.String description
        Optional description to document the reason for this annotation.
        Returns:
        The descriptive message. Defaults to no description.
        Default:
        ""

      • additionalPreconditions

        KeepCondition[] additionalPreconditions
        Additional preconditions for the annotation to be in effect.
        Returns:
        The list of additional preconditions. Defaults to no additional preconditions.
        Default:
        {}