kapt: Support Kotlin code generation

libraries/tools/kotlin-gradle-plugin/src/main/kotlin/org/jetbrains/kotlin/gradle/internal/AnnotationProcessingManager.kt

@@ -54,6 +54,12 @@ public class AnnotationProcessingManager(
         return File(aptWorkingDir, "$WRAPPERS_DIRECTORY/annotations.$taskQualifier.txt")
     }
 
+    fun getGeneratedKotlinSourceDir(): File {
+        val kotlinGeneratedDir = File(aptWorkingDir, "kotlinGenerated")
+        if (!kotlinGeneratedDir.exists()) kotlinGeneratedDir.mkdirs()
+        return kotlinGeneratedDir
+    }
+
     fun setupKapt() {
         if (aptFiles.isEmpty()) return
 
@@ -72,7 +78,8 @@ public class AnnotationProcessingManager(
 
         addGeneratedSourcesOutputToCompilerArgs(javaTask, aptOutputDir)
 
-        appendAnnotationsFileLocationArgument()
+
+        appendAnnotationsArguments()
         appendAdditionalComplerArgs()
     }
 
@@ -102,9 +109,10 @@ public class AnnotationProcessingManager(
         }
     }
 
-    private fun appendAnnotationsFileLocationArgument() {
+    private fun appendAnnotationsArguments() {
         javaTask.modifyCompilerArguments { list ->
             list.add("-Akapt.annotations=" + getAnnotationFile())
+            list.add("-Akapt.kotlin.generated=" + getGeneratedKotlinSourceDir())
         }
     }
 

libraries/tools/kotlin-gradle-plugin/src/main/kotlin/org/jetbrains/kotlin/gradle/plugin/KotlinPlugin.kt

@@ -609,11 +609,13 @@ private fun Project.initKapt(
 
     kotlinTask.doFirst {
         kaptManager.generateJavaHackFile()
+        kotlinAfterJavaTask?.source(kaptManager.getGeneratedKotlinSourceDir())
     }
 
     javaTask.doFirst {
         kaptManager.setupKapt()
         kaptManager.generateJavaHackFile()
+        kotlinAfterJavaTask?.source(kaptManager.getGeneratedKotlinSourceDir())
     }
 
     javaTask.doLast {

libraries/tools/kotlin-gradle-plugin/src/test/kotlin/org/jetbrains/kotlin/gradle/KotlinGradlePluginIT.kt

@@ -158,4 +158,19 @@ class KotlinGradleIT: BaseGradleIT() {
             assertFileExists("build/classes/main/example/AncestorClassGenerated.class")
         }
     }
+
+    Test fun testKaptOutputKotlinCode() {
+        Project("kaptOutputKotlinCode", "1.12").build("build") {
+            assertSuccessful()
+            assertContains("kapt: Using class file stubs")
+            assertContains(":compileKotlin")
+            assertContains(":compileJava")
+            assertFileExists("build/tmp/kapt/main/wrappers/annotations.main.txt")
+            assertFileExists("build/generated/source/kapt/main/TestClassCustomized.java")
+            assertFileExists("build/tmp/kapt/main/kotlinGenerated/TestClass.kt")
+            assertFileExists("build/classes/main/example/TestClass.class")
+            assertFileExists("build/classes/main/example/TestClassCustomized.class")
+        }
+    }
+
 }

libraries/tools/kotlin-gradle-plugin/src/test/resources/testProject/kaptOutputKotlinCode/build.gradle

@@ -0,0 +1,43 @@
+buildscript {
+    repositories {
+        mavenCentral()
+        maven {
+            url 'file://' + pathToKotlinPlugin
+        }
+    }
+    dependencies {
+        classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:0.1-SNAPSHOT"
+    }
+}
+
+apply plugin: "java"
+apply plugin: "kotlin"
+
+repositories {
+    maven {
+        url 'file://' + pathToKotlinPlugin
+    }
+    mavenCentral()
+}
+
+dependencies {
+    compile "org.jetbrains.kotlin:kotlin-stdlib:0.1-SNAPSHOT"
+    compile "org.jetbrains.kotlin:annotation-processor-example:0.1-SNAPSHOT"
+    kapt "org.jetbrains.kotlin:annotation-processor-example:0.1-SNAPSHOT"
+}
+
+task show << {
+    buildscript.configurations.classpath.each { println it }
+}
+
+task wrapper(type: Wrapper) {
+    gradleVersion="1.12"
+}
+
+kapt {
+    generateStubs = true
+    arguments {
+        arg("suffix", "Customized")
+        arg("generate.kotlin.code", "true")
+    }
+}

libraries/tools/kotlin-gradle-plugin/src/test/resources/testProject/kaptOutputKotlinCode/src/main/java/test.kt

@@ -0,0 +1,10 @@
+package example
+
+@example.ExampleAnnotation
+public class TestClass {
+
+    fun test() {
+        println(this.customToString())
+    }
+
+}