final Object backedObject = loadTool("org.antlr.v4.Tool", toArray(arguments));
            if (inputDirectory != null) {
                setField(backedObject, "inputDirectory", inputDirectory);
            }
            JavaMethod.of(backedObject, Void.class, "processGrammarsOnCommandLine").invoke(backedObject);

                File inputOne
                File inputTwo

                @Incremental
                @InputDirectory
                File getInputOne() {
                    inputOne
                }

                @Incremental
                @InputDirectory
                File getInputTwo() {
                    inputTwo
                }

                @OutputDirectory

For the input of our task, we use a `DirectoryProperty` from Gradle.
We annotate it with `@InputDirectory` to indicate that it is an input to the task:

====
[.multi-language-sample]
=====
.buildSrc/src/main/kotlin/GenerateReportTask.kt
[source,kotlin]
----
import org.gradle.api.DefaultTask
import org.gradle.api.tasks.InputDirectory

public abstract class GenerateReportTask : DefaultTask() {

    @get:InputDirectory

 * limitations under the License.
 */
package org.gradle.api.file

import org.gradle.api.tasks.Classpath
import org.gradle.api.tasks.CompileClasspath
import org.gradle.api.tasks.InputDirectory
import org.gradle.api.tasks.InputFile
import org.gradle.integtests.fixtures.AbstractIntegrationSpec
import org.gradle.internal.reflect.validation.ValidationMessageChecker
import org.gradle.test.precondition.Requires

        def inputDirectory = inputFilesDir.createDir('dir1')
        writeClass(inputDirectory, "org/gradle/MyFirstClass")
        writeClass(inputDirectory, "org/gradle/MyAClass")
        writeClass(inputDirectory, "org/gradle/MyBClass")

        when:
        relocatedJarCreator.create(outputJar, [jarFile1, jarFile2, jarFile3, jarFile4, jarFile5, jarFile6, inputDirectory])

        then:

            class MyTask extends DefaultTask {
                @Input String inputString
                @Nested MyConfig nested = new MyConfig()
                @InputFile File inputFile
                @InputDirectory File inputDirectory
                @InputFiles FileCollection inputFiles

                @OutputFile File outputFile
                @OutputFiles FileCollection outputFiles

    @SuppressWarnings("GrDeprecatedAPIUsage")
    static class SimpleTask extends DefaultTask {
        @Input
        String inputString
        @InputFile
        File inputFile
        @InputDirectory
        File inputDirectory
        @InputFiles
        File inputFiles
        @OutputFile
        File outputFile
        @OutputFiles
        Set<File> outputFiles
        @OutputDirectory

import org.gradle.api.tasks.Console;
import org.gradle.api.tasks.Destroys;
import org.gradle.api.tasks.IgnoreEmptyDirectories;
import org.gradle.api.tasks.Input;
import org.gradle.api.tasks.InputDirectory;
import org.gradle.api.tasks.InputFile;
import org.gradle.api.tasks.InputFiles;
import org.gradle.api.tasks.Internal;
import org.gradle.api.tasks.LocalState;
import org.gradle.api.tasks.Nested;

            task customTask(type: CustomTask) {
                input = null
            }
        """

        expect:
        succeeds "customTask"

        where:
        annotation << [InputFile, InputDirectory, InputFiles]
    }

    def "TaskInputs.#method shows error message when used with complex input"() {
        buildFile << """
            task dependencyTask {
            }

            task test {

                    outputDir.file("tracked.txt").get().asFile.text = "tracked"
                }
            }

            abstract class Consumer extends DefaultTask {
                @InputDirectory
                abstract DirectoryProperty getInputDir()

                @OutputFile
                abstract RegularFileProperty getOutputFile()

                @TaskAction