Migrate from ASM to Class-File API

build.gradle.kts

@@ -7,6 +7,7 @@ import org.gradle.api.plugins.JavaPlugin.SOURCES_ELEMENTS_CONFIGURATION_NAME
 import org.gradle.plugin.compatibility.compatibility
 import org.jetbrains.kotlin.gradle.dsl.JvmDefaultMode
 import org.jetbrains.kotlin.gradle.dsl.JvmTarget
+import org.jetbrains.kotlin.gradle.dsl.KotlinJvmCompilerOptions
 import org.jetbrains.kotlin.gradle.dsl.KotlinVersion
 import org.jetbrains.kotlin.gradle.dsl.abi.ExperimentalAbiValidation
 
@@ -45,6 +46,8 @@ kotlin {
   }
 }
 
+addMultiReleaseSourceSet(24)
+
 lint {
   baseline = file("gradle/lint-baseline.xml")
   ignoreTestFixturesSources = true
@@ -222,6 +225,8 @@ kotlin.target.compilations {
   }
 }
 
+tasks.jar { manifest.attributes("Multi-Release" to true) }
+
 tasks.pluginUnderTestMetadata { pluginClasspath.from(testPluginClasspath) }
 
 tasks.check { dependsOn(tasks.withType<Test>()) }
@@ -236,3 +241,21 @@ tasks.clean {
       rootDir.resolve("site"),
     )
 }
+
+fun addMultiReleaseSourceSet(version: Int) {
+  kotlin.target.compilations.create("java${version}") {
+    associateWith(kotlin.target.compilations.getByName("main"))
+    compileTaskProvider {
+      compilerOptions {
+        this@compilerOptions as KotlinJvmCompilerOptions
+        jvmTarget = JvmTarget.fromTarget(version.toString())
+        freeCompilerArgs.add("-Xjdk-release=$version")
+      }
+    }
+    compileJavaTaskProvider { options.release = version }
+
+    tasks.jar { from(output.allOutputs) { into("META-INF/versions/$version") } }
+
+    tasks.withType<Test>().configureEach { inputs.files(output.allOutputs) }
+  }
+}

gradle.properties

@@ -2,6 +2,11 @@
 # https://kotlinlang.org/docs/gradle-configure-project.html#dependency-on-the-standard-library
 kotlin.stdlib.default.dependency=false
 
+# Keep associated Kotlin compilations from depending on archive tasks (e.g., jar), which can create circular task graphs in multi-release setups.
+# https://kotlinlang.org/docs/gradle-configure-project.html#disable-use-of-artifact-in-compilation-task
+# https://kotlinlang.org/docs/whatsnew2020.html#added-task-dependency-for-rare-cases-when-the-compile-task-lacks-one-on-an-artifact
+kotlin.build.archivesTaskOutputAsFriendModule=false
+
 org.gradle.caching=true
 org.gradle.configuration-cache=true
 org.gradle.configuration-cache.parallel=true

src/functionalTest/kotlin/com/github/jengelman/gradle/plugins/shadow/RelocationTest.kt

@@ -533,6 +533,45 @@ class RelocationTest : BasePluginTest() {
     }
   }
 
+  @Test
+  fun relocateAnnotationStringConstants() {
+    writeClass {
+      """
+      package my;
+      import java.lang.annotation.Retention;
+      import java.lang.annotation.RetentionPolicy;
+      @Retention(RetentionPolicy.RUNTIME)
+      @interface MyAnnotation {
+        String value();
+      }
+      @MyAnnotation("foo.Bar")
+      public class Main {
+        public static void main(String[] args) {
+          MyAnnotation ann = Main.class.getAnnotation(MyAnnotation.class);
+          System.out.println(ann.value());
+        }
+      }
+      """
+        .trimIndent()
+    }
+    projectScript.appendText(
+      """
+        $shadowJarTask {
+          manifest {
+            attributes '$mainClassAttributeKey': 'my.Main'
+          }
+          relocate('foo', 'shadow.foo')
+        }
+      """
+        .trimIndent()
+    )
+
+    runWithSuccess(shadowJarPath)
+    val result = runProcess("java", "-jar", outputShadowedJar.use { it.toString() })
+
+    assertThat(result).contains("shadow.foo.Bar")
+  }
+
   @Issue("https://github.com/GradleUp/shadow/issues/1403")
   @Test
   fun relocateMultiClassSignatureStringConstants() {