Class KotlinDefaultArgumentsFilter

  • All Implemented Interfaces:
    IFilter

    public final class KotlinDefaultArgumentsFilter
    extends java.lang.Object
    implements IFilter
    Filters branches that Kotlin compiler generates for default arguments. For methods and constructors with default arguments Kotlin compiler generates synthetic method with suffix "$default" or a synthetic constructor with last argument "kotlin.jvm.internal.DefaultConstructorMarker" respectively. And in this synthetic method for each default argument Kotlin compiler generates following bytecode to determine if it should be used or not:
     ILOAD maskVar
     ICONST_x, BIPUSH, SIPUSH, LDC or LDC_W
     IAND
     IFEQ label
     default argument
     label:
     
    If original method has X arguments, then in synthetic method maskVar is one of arguments from X+1 to X+1+(X/32). At least one of such arguments is not zero - invocation without default arguments uses original non synthetic method. This filter marks IFEQ instructions as ignored.
    • Constructor Detail

      • KotlinDefaultArgumentsFilter

        public KotlinDefaultArgumentsFilter()
    • Method Detail

      • isDefaultArgumentsMethod

        static boolean isDefaultArgumentsMethod​(org.objectweb.asm.tree.MethodNode methodNode)
      • isDefaultArgumentsConstructor

        static boolean isDefaultArgumentsConstructor​(org.objectweb.asm.tree.MethodNode methodNode)
      • filter

        public void filter​(org.objectweb.asm.tree.MethodNode methodNode,
                           IFilterContext context,
                           IFilterOutput output)
        Description copied from interface: IFilter
        This method is called for every method. The filter implementation is expected to inspect the provided method and report its result to the given IFilterOutput instance.
        Specified by:
        filter in interface IFilter
        Parameters:
        methodNode - method to inspect
        context - context information for the method
        output - callback to report filtering results to
      • computeNumberOfMaskArguments

        static int computeNumberOfMaskArguments​(int arguments)
        Parameters:
        arguments - number of arguments of synthetic method
        Returns:
        number of arguments holding mask