Add JS DCE gradle plugin

build-common/src/org/jetbrains/kotlin/compilerRunner/ArgumentUtils.java

@@ -18,7 +18,7 @@ package org.jetbrains.kotlin.compilerRunner;
 
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.kotlin.cli.common.arguments.Argument;
-import org.jetbrains.kotlin.cli.common.arguments.CommonCompilerArguments;
+import org.jetbrains.kotlin.cli.common.arguments.CommonToolArguments;
 import org.jetbrains.kotlin.cli.common.arguments.ParseCommandLineArgumentsKt;
 import org.jetbrains.kotlin.utils.StringsKt;
 
@@ -32,7 +32,7 @@ public class ArgumentUtils {
     private ArgumentUtils() {}
 
     @NotNull
-    public static List<String> convertArgumentsToStringList(@NotNull CommonCompilerArguments arguments)
+    public static List<String> convertArgumentsToStringList(@NotNull CommonToolArguments arguments)
             throws InstantiationException, IllegalAccessException {
         List<String> result = new ArrayList<>();
         convertArgumentsToStringList(arguments, arguments.getClass().newInstance(), arguments.getClass(), result);
@@ -41,8 +41,8 @@ public class ArgumentUtils {
     }
 
     private static void convertArgumentsToStringList(
-            @NotNull CommonCompilerArguments arguments,
-            @NotNull CommonCompilerArguments defaultArguments,
+            @NotNull CommonToolArguments arguments,
+            @NotNull CommonToolArguments defaultArguments,
             @NotNull Class<?> clazz,
             @NotNull List<String> result
     ) throws IllegalAccessException, InstantiationException {

compiler/cli/cli-common/src/org/jetbrains/kotlin/cli/common/arguments/DefaultValues.kt

@@ -28,6 +28,8 @@ open class DefaultValues(val defaultValue: String, val possibleValues: List<Stri
 
     object StringNullDefault : DefaultValues("null")
 
+    object ListEmptyDefault : DefaultValues("<empty list>")
+
     object LanguageVersions : DefaultValues(
             "null",
             LanguageVersion.values().map { "\"${it.description}\"" }

compiler/cli/cli-common/src/org/jetbrains/kotlin/cli/common/arguments/K2JSDceArguments.java

@@ -14,27 +14,28 @@
  * limitations under the License.
  */
 
-package org.jetbrains.kotlin.cli.common.arguments
+package org.jetbrains.kotlin.cli.common.arguments;
 
-class K2JSDceArguments : CommonToolArguments() {
-    companion object {
-        const val serialVersionUID = 0L
-    }
+public class K2JSDceArguments extends CommonToolArguments {
+    private static final long serialVersionUID = 0;
 
-    @field:GradleOption(DefaultValues.StringNullDefault::class)
-    @field:Argument(value = "-output-dir", valueDescription = "<path>", description = "Output directory")
-    @JvmField
-    var outputDirectory: String? = null
+    @Argument(
+            value = "-output-dir",
+            valueDescription = "<path>",
+            description = "Output directory"
+    )
+    public String outputDirectory;
 
-    @field:Argument(
+    @Argument(
             value = "-keep",
             valueDescription = "<fully.qualified.name[,]>",
-            description = "List of fully-qualified names of declarations that shouldn't be eliminated")
-    @JvmField
-    var declarationsToKeep: Array<String>? = null
+            description = "List of fully-qualified names of declarations that shouldn't be eliminated"
+    )
+    public String[] declarationsToKeep;
 
-    @field:GradleOption(DefaultValues.BooleanFalseDefault::class)
-    @field:Argument(value = "-Xprint-reachability-info", description = "Print declarations marked as reachable")
-    @JvmField
-    var printReachabilityInfo: Boolean = false
+    @Argument(
+            value = "-Xprint-reachability-info",
+            description = "Print declarations marked as reachable"
+    )
+    public boolean printReachabilityInfo;
 }

generators/src/org/jetbrains/kotlin/generators/arguments/GenerateGradleOptions.kt

@@ -39,24 +39,35 @@ fun generateKotlinGradleOptions(withPrinterToFile: (targetFile: File, Printer.()
     val srcDir = File("libraries/tools/kotlin-gradle-plugin/src/main/kotlin")
 
     // common interface
-    val commonInterfaceFqName = FqName("org.jetbrains.kotlin.gradle.dsl.KotlinCommonOptions")
-    val commonOptions = gradleOptions<CommonCompilerArguments>() + gradleOptions<CommonToolArguments>()
+    val commonInterfaceFqName = FqName("org.jetbrains.kotlin.gradle.dsl.KotlinCommonToolOptions")
+    val commonOptions =  gradleOptions<CommonToolArguments>()
     val additionalOptions = gradleOptions<AdditionalGradleProperties>()
     withPrinterToFile(File(srcDir, commonInterfaceFqName)) {
         generateInterface(commonInterfaceFqName,
                           commonOptions + additionalOptions)
     }
 
-    println("### Attributes common for 'kotlin' and 'kotlin2js'\n")
+    println("### Attributes common for 'kotlin', 'kotlin2js' and 'kotlin2jsDce\n")
     generateMarkdown(commonOptions + additionalOptions)
 
+    val commonCompilerInterfaceFqName = FqName("org.jetbrains.kotlin.gradle.dsl.KotlinCommonOptions")
+    val commonCompilerOptions = gradleOptions<CommonCompilerArguments>()
+    withPrinterToFile(File(srcDir, commonCompilerInterfaceFqName)) {
+        generateInterface(commonCompilerInterfaceFqName,
+                          commonCompilerOptions,
+                          parentType = commonInterfaceFqName)
+    }
+
+    println("\n### Attributes common for 'kotlin' and 'kotlin2js'\n")
+    generateMarkdown(commonCompilerOptions)
+
     // generate jvm interface
     val jvmInterfaceFqName = FqName("org.jetbrains.kotlin.gradle.dsl.KotlinJvmOptions")
     val jvmOptions = gradleOptions<K2JVMCompilerArguments>()
     withPrinterToFile(File(srcDir, jvmInterfaceFqName)) {
         generateInterface(jvmInterfaceFqName,
                           jvmOptions,
-                          parentType = commonInterfaceFqName)
+                          parentType = commonCompilerInterfaceFqName)
     }
 
     // generate jvm impl
@@ -66,7 +77,7 @@ fun generateKotlinGradleOptions(withPrinterToFile: (targetFile: File, Printer.()
         generateImpl(jvmImplFqName,
                      jvmInterfaceFqName,
                      k2JvmCompilerArgumentsFqName,
-                     commonOptions + jvmOptions)
+                     commonOptions + commonCompilerOptions + jvmOptions)
     }
 
     println("\n### Attributes specific for 'kotlin'\n")
@@ -78,7 +89,7 @@ fun generateKotlinGradleOptions(withPrinterToFile: (targetFile: File, Printer.()
     withPrinterToFile(File(srcDir, jsInterfaceFqName)) {
         generateInterface(jsInterfaceFqName,
                           jsOptions,
-                          parentType = commonInterfaceFqName)
+                          parentType = commonCompilerInterfaceFqName)
     }
 
     val k2JsCompilerArgumentsFqName = FqName(K2JSCompilerArguments::class.qualifiedName!!)
@@ -87,11 +98,29 @@ fun generateKotlinGradleOptions(withPrinterToFile: (targetFile: File, Printer.()
         generateImpl(jsImplFqName,
                      jsInterfaceFqName,
                      k2JsCompilerArgumentsFqName,
-                     commonOptions + jsOptions)
+                     commonOptions + commonCompilerOptions + jsOptions)
     }
 
     println("\n### Attributes specific for 'kotlin2js'\n")
     generateMarkdown(jsOptions)
+
+    // generate JS DCE interface and implementation
+    val jsDceInterfaceFqName = FqName("org.jetbrains.kotlin.gradle.dsl.KotlinJsDceOptions")
+    val jsDceOptions = gradleOptions<K2JSDceArguments>()
+    withPrinterToFile(File(srcDir, jsDceInterfaceFqName)) {
+        generateInterface(jsDceInterfaceFqName,
+                          jsDceOptions,
+                          parentType = commonInterfaceFqName)
+    }
+
+    val k2JsDceArgumentsFqName = FqName(K2JSDceArguments::class.qualifiedName!!)
+    val jsDceImplFqName = FqName("org.jetbrains.kotlin.gradle.dsl.KotlinJsDceOptionsBase")
+    withPrinterToFile(File(srcDir, jsDceImplFqName)) {
+        generateImpl(jsDceImplFqName,
+                     jsDceInterfaceFqName,
+                     k2JsDceArgumentsFqName,
+                     commonOptions + jsDceOptions)
+    }
 }
 
 fun main(args: Array<String>) {

libraries/tools/kotlin-gradle-plugin-integration-tests/src/test/kotlin/org/jetbrains/kotlin/gradle/Kotlin2JsGradlePluginIT.kt

@@ -1,5 +1,6 @@
 package org.jetbrains.kotlin.gradle
 
+import org.gradle.api.logging.LogLevel
 import org.jetbrains.kotlin.gradle.util.getFileByName
 import org.jetbrains.kotlin.gradle.util.modify
 import org.junit.Test
@@ -214,4 +215,14 @@ class Kotlin2JsGradlePluginIT : BaseGradleIT() {
             assertTrue("Source map should contain source of foo.kt") { map.contains("\"inline fun foo(): String {\\n") }
         }
     }
+
+    @Test
+    fun testDce() {
+        val project = Project("kotlin2JsDceProject", "2.10", minLogLevel = LogLevel.INFO)
+
+        project.build("runRhino") {
+            println(output)
+            assertSuccessful()
+        }
+    }
 }

libraries/tools/kotlin-gradle-plugin-integration-tests/src/test/resources/testProject/kotlin2JsDceProject/libraryProject/build.gradle

@@ -0,0 +1,27 @@
+buildscript {
+    repositories {
+        mavenLocal()
+    }
+    dependencies {
+        classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:$kotlin_version"
+    }
+}
+
+apply plugin: 'kotlin2js'
+
+repositories {
+    mavenLocal()
+}
+
+dependencies {
+    compile "org.jetbrains.kotlin:kotlin-stdlib-js:$kotlin_version"
+}
+
+compileKotlin2Js.kotlinOptions.outputFile = "${buildDir}/examplelib.js"
+
+jar {
+    from buildDir
+    include "**/*.js"
+}
+
+jar.dependsOn(compileKotlin2Js)

libraries/tools/kotlin-gradle-plugin-integration-tests/src/test/resources/testProject/kotlin2JsDceProject/libraryProject/src/main/kotlin/examplelib/lib.kt

@@ -0,0 +1,6 @@
+package examplelib
+
+fun foo() = "foo"
+
+fun bar() = "bar"
+

libraries/tools/kotlin-gradle-plugin-integration-tests/src/test/resources/testProject/kotlin2JsDceProject/mainProject/build.gradle

@@ -0,0 +1,36 @@
+buildscript {
+    repositories {
+        mavenLocal()
+    }
+    dependencies {
+        classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:$kotlin_version"
+    }
+}
+
+apply plugin: "kotlin2js"
+apply plugin: "kotlin-dce-js"
+
+repositories {
+    mavenLocal()
+}
+
+dependencies {
+    compile project(":libraryProject")
+    compile "org.jetbrains.kotlin:kotlin-stdlib-js:$kotlin_version"
+    compile "org.mozilla:rhino:1.7.7.1"
+}
+
+compileKotlin2Js.kotlinOptions.sourceMap = true
+compileKotlin2Js.kotlinOptions.outputFile = "${buildDir}/exampleapp.js"
+compileKotlin2Js.kotlinOptions.suppressWarnings = true
+compileKotlin2Js.kotlinOptions.verbose = true
+runDceKotlinJs.keep("exampleapp.exampleapp.status")
+
+task runRhino(type: JavaExec) {
+    classpath = sourceSets.main.runtimeClasspath
+    workingDir = "${buildDir}"
+    main = 'org.mozilla.javascript.tools.shell.Main'
+    args = ["-opt", "-1", "-f", "min/kotlin.js", "-f", "min/examplelib.js", "-f", "min/exampleapp.js", "-f", "../check.js"]
+}
+
+runRhino.dependsOn(runDceKotlinJs)

libraries/tools/kotlin-gradle-plugin-integration-tests/src/test/resources/testProject/kotlin2JsDceProject/mainProject/check.js

@@ -0,0 +1,6 @@
+(function() {
+    var status = exampleapp.exampleapp.status;
+    if (status !== "foo") {
+        throw new Error("Unexpected status: " + status);
+    }
+})();

libraries/tools/kotlin-gradle-plugin-integration-tests/src/test/resources/testProject/kotlin2JsDceProject/mainProject/src/main/kotlin/exampleapp/main.kt

@@ -0,0 +1,9 @@
+package exampleapp
+
+import examplelib.*
+
+var status = "failure"
+
+fun main(args: Array<String>) {
+    status = foo()
+}

libraries/tools/kotlin-gradle-plugin-integration-tests/src/test/resources/testProject/kotlin2JsDceProject/settings.gradle

@@ -0,0 +1 @@
+include 'mainProject', 'libraryProject'

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

@@ -2,7 +2,7 @@
 // Generated by org/jetbrains/kotlin/generators/arguments/GenerateGradleOptions.kt
 package org.jetbrains.kotlin.gradle.dsl
 
-interface KotlinCommonOptions {
+interface KotlinCommonOptions  : org.jetbrains.kotlin.gradle.dsl.KotlinCommonToolOptions {
 
     /**
      * Allow to use declarations only from the specified version of bundled libraries
@@ -17,22 +17,4 @@ interface KotlinCommonOptions {
      * Default value: null
      */
      var languageVersion: kotlin.String?
-
-    /**
-     * Generate no warnings
-     * Default value: false
-     */
-     var suppressWarnings: kotlin.Boolean
-
-    /**
-     * Enable verbose logging output
-     * Default value: false
-     */
-     var verbose: kotlin.Boolean
-
-    /**
-     * A list of additional compiler arguments
-     * Default value: emptyList()
-     */
-     var freeCompilerArgs: kotlin.collections.List<kotlin.String>
 }

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

@@ -0,0 +1,24 @@
+// DO NOT EDIT MANUALLY!
+// Generated by org/jetbrains/kotlin/generators/arguments/GenerateGradleOptions.kt
+package org.jetbrains.kotlin.gradle.dsl
+
+interface KotlinCommonToolOptions {
+
+    /**
+     * Generate no warnings
+     * Default value: false
+     */
+     var suppressWarnings: kotlin.Boolean
+
+    /**
+     * Enable verbose logging output
+     * Default value: false
+     */
+     var verbose: kotlin.Boolean
+
+    /**
+     * A list of additional compiler arguments
+     * Default value: emptyList()
+     */
+     var freeCompilerArgs: kotlin.collections.List<kotlin.String>
+}

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

@@ -39,4 +39,21 @@ interface KotlinCompile<T : KotlinCommonOptions> : Task, CompilerArgumentAware {
 
 interface KotlinJsCompile : KotlinCompile<KotlinJsOptions>
 
-interface KotlinJvmCompile : KotlinCompile<KotlinJvmOptions>
+interface KotlinJvmCompile : KotlinCompile<KotlinJvmOptions>
+
+interface KotlinJsDce : Task {
+    val dceOptions: KotlinJsDceOptions
+
+    val keep: MutableList<String>
+
+    fun dceOptions(fn: KotlinJsDceOptions.() -> Unit) {
+        dceOptions.fn()
+    }
+
+    fun dceOptions(fn: Closure<*>) {
+        fn.delegate = dceOptions
+        fn.call()
+    }
+
+    fun keep(vararg fqn: String)
+}

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

@@ -0,0 +1,6 @@
+// DO NOT EDIT MANUALLY!
+// Generated by org/jetbrains/kotlin/generators/arguments/GenerateGradleOptions.kt
+package org.jetbrains.kotlin.gradle.dsl
+
+interface KotlinJsDceOptions  : org.jetbrains.kotlin.gradle.dsl.KotlinCommonToolOptions {
+}

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

@@ -0,0 +1,26 @@
+// DO NOT EDIT MANUALLY!
+// Generated by org/jetbrains/kotlin/generators/arguments/GenerateGradleOptions.kt
+package org.jetbrains.kotlin.gradle.dsl
+
+internal abstract class KotlinJsDceOptionsBase : org.jetbrains.kotlin.gradle.dsl.KotlinJsDceOptions {
+
+    private var suppressWarningsField: kotlin.Boolean? = null
+    override var suppressWarnings: kotlin.Boolean
+        get() = suppressWarningsField ?: false
+        set(value) { suppressWarningsField = value }
+
+    private var verboseField: kotlin.Boolean? = null
+    override var verbose: kotlin.Boolean
+        get() = verboseField ?: false
+        set(value) { verboseField = value }
+
+    internal open fun updateArguments(args: org.jetbrains.kotlin.cli.common.arguments.K2JSDceArguments) {
+        suppressWarningsField?.let { args.suppressWarnings = it }
+        verboseField?.let { args.verbose = it }
+    }
+}
+
+internal fun org.jetbrains.kotlin.cli.common.arguments.K2JSDceArguments.fillDefaultValues() {
+    suppressWarnings = false
+    verbose = false
+}

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

@@ -0,0 +1,30 @@
+/*
+ * Copyright 2010-2017 JetBrains s.r.o.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.jetbrains.kotlin.gradle.dsl
+
+import org.jetbrains.kotlin.cli.common.arguments.K2JSDceArguments
+import org.jetbrains.kotlin.cli.js.dce.K2JSDce
+
+internal class KotlinJsDceOptionsImpl : KotlinJsDceOptionsBase() {
+    override var freeCompilerArgs: List<String> = listOf()
+
+    override fun updateArguments(args: K2JSDceArguments) {
+        super.updateArguments(args)
+        val freeArgsArray = (freeCompilerArgs as List<Any>).map(Any::toString).toTypedArray()
+        K2JSDce().parseArguments(freeArgsArray, args)
+    }
+}

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

@@ -4,16 +4,6 @@ package org.jetbrains.kotlin.gradle.dsl
 
 internal abstract class KotlinJsOptionsBase : org.jetbrains.kotlin.gradle.dsl.KotlinJsOptions {
 
-    private var apiVersionField: kotlin.String?? = null
-    override var apiVersion: kotlin.String?
-        get() = apiVersionField ?: null
-        set(value) { apiVersionField = value }
-
-    private var languageVersionField: kotlin.String?? = null
-    override var languageVersion: kotlin.String?
-        get() = languageVersionField ?: null
-        set(value) { languageVersionField = value }
-
     private var suppressWarningsField: kotlin.Boolean? = null
     override var suppressWarnings: kotlin.Boolean
         get() = suppressWarningsField ?: false
@@ -24,6 +14,16 @@ internal abstract class KotlinJsOptionsBase : org.jetbrains.kotlin.gradle.dsl.Ko
         get() = verboseField ?: false
         set(value) { verboseField = value }
 
+    private var apiVersionField: kotlin.String?? = null
+    override var apiVersion: kotlin.String?
+        get() = apiVersionField ?: null
+        set(value) { apiVersionField = value }
+
+    private var languageVersionField: kotlin.String?? = null
+    override var languageVersion: kotlin.String?
+        get() = languageVersionField ?: null
+        set(value) { languageVersionField = value }
+
     private var friendModulesDisabledField: kotlin.Boolean? = null
     override var friendModulesDisabled: kotlin.Boolean
         get() = friendModulesDisabledField ?: false
@@ -80,10 +80,10 @@ internal abstract class KotlinJsOptionsBase : org.jetbrains.kotlin.gradle.dsl.Ko
         set(value) { typedArraysField = value }
 
     internal open fun updateArguments(args: org.jetbrains.kotlin.cli.common.arguments.K2JSCompilerArguments) {
-        apiVersionField?.let { args.apiVersion = it }
-        languageVersionField?.let { args.languageVersion = it }
         suppressWarningsField?.let { args.suppressWarnings = it }
         verboseField?.let { args.verbose = it }
+        apiVersionField?.let { args.apiVersion = it }
+        languageVersionField?.let { args.languageVersion = it }
         friendModulesDisabledField?.let { args.friendModulesDisabled = it }
         mainField?.let { args.main = it }
         metaInfoField?.let { args.metaInfo = it }
@@ -99,10 +99,10 @@ internal abstract class KotlinJsOptionsBase : org.jetbrains.kotlin.gradle.dsl.Ko
 }
 
 internal fun org.jetbrains.kotlin.cli.common.arguments.K2JSCompilerArguments.fillDefaultValues() {
-    apiVersion = null
-    languageVersion = null
     suppressWarnings = false
     verbose = false
+    apiVersion = null
+    languageVersion = null
     friendModulesDisabled = false
     main = "call"
     metaInfo = true

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

@@ -4,16 +4,6 @@ package org.jetbrains.kotlin.gradle.dsl
 
 internal abstract class KotlinJvmOptionsBase : org.jetbrains.kotlin.gradle.dsl.KotlinJvmOptions {
 
-    private var apiVersionField: kotlin.String?? = null
-    override var apiVersion: kotlin.String?
-        get() = apiVersionField ?: null
-        set(value) { apiVersionField = value }
-
-    private var languageVersionField: kotlin.String?? = null
-    override var languageVersion: kotlin.String?
-        get() = languageVersionField ?: null
-        set(value) { languageVersionField = value }
-
     private var suppressWarningsField: kotlin.Boolean? = null
     override var suppressWarnings: kotlin.Boolean
         get() = suppressWarningsField ?: false
@@ -24,6 +14,16 @@ internal abstract class KotlinJvmOptionsBase : org.jetbrains.kotlin.gradle.dsl.K
         get() = verboseField ?: false
         set(value) { verboseField = value }
 
+    private var apiVersionField: kotlin.String?? = null
+    override var apiVersion: kotlin.String?
+        get() = apiVersionField ?: null
+        set(value) { apiVersionField = value }
+
+    private var languageVersionField: kotlin.String?? = null
+    override var languageVersion: kotlin.String?
+        get() = languageVersionField ?: null
+        set(value) { languageVersionField = value }
+
     private var includeRuntimeField: kotlin.Boolean? = null
     override var includeRuntime: kotlin.Boolean
         get() = includeRuntimeField ?: false
@@ -60,10 +60,10 @@ internal abstract class KotlinJvmOptionsBase : org.jetbrains.kotlin.gradle.dsl.K
         set(value) { noStdlibField = value }
 
     internal open fun updateArguments(args: org.jetbrains.kotlin.cli.common.arguments.K2JVMCompilerArguments) {
-        apiVersionField?.let { args.apiVersion = it }
-        languageVersionField?.let { args.languageVersion = it }
         suppressWarningsField?.let { args.suppressWarnings = it }
         verboseField?.let { args.verbose = it }
+        apiVersionField?.let { args.apiVersion = it }
+        languageVersionField?.let { args.languageVersion = it }
         includeRuntimeField?.let { args.includeRuntime = it }
         javaParametersField?.let { args.javaParameters = it }
         jdkHomeField?.let { args.jdkHome = it }
@@ -75,10 +75,10 @@ internal abstract class KotlinJvmOptionsBase : org.jetbrains.kotlin.gradle.dsl.K
 }
 
 internal fun org.jetbrains.kotlin.cli.common.arguments.K2JVMCompilerArguments.fillDefaultValues() {
-    apiVersion = null
-    languageVersion = null
     suppressWarnings = false
     verbose = false
+    apiVersion = null
+    languageVersion = null
     includeRuntime = false
     javaParameters = false
     jdkHome = null

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

@@ -0,0 +1,90 @@
+/*
+ * Copyright 2010-2017 JetBrains s.r.o.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.jetbrains.kotlin.gradle.plugin
+
+import org.gradle.api.Plugin
+import org.gradle.api.Project
+import org.gradle.api.Task
+import org.gradle.api.internal.file.UnionFileCollection
+import org.gradle.api.internal.file.UnionFileTree
+import org.gradle.api.plugins.JavaPluginConvention
+import org.gradle.api.tasks.Copy
+import org.gradle.api.tasks.SourceSet
+import org.jetbrains.kotlin.gradle.tasks.Kotlin2JsCompile
+import org.jetbrains.kotlin.gradle.tasks.KotlinJsDce
+import java.io.File
+
+class KotlinJsDcePlugin : Plugin<Project> {
+    override fun apply(project: Project) {
+        project.pluginManager.apply(Kotlin2JsPluginWrapper::class.java)
+
+        val javaPluginConvention = project.convention.getPlugin(JavaPluginConvention::class.java)
+        javaPluginConvention.sourceSets?.forEach { processSourceSet(project, it) }
+    }
+
+    private fun processSourceSet(project: Project, sourceSet: SourceSet) {
+        val kotlinTaskName = sourceSet.getCompileTaskName("kotlin2Js")
+        val kotlinTask = project.tasks.findByName(kotlinTaskName) as? Kotlin2JsCompile ?: return
+        val dceTaskName = sourceSet.getTaskName(DCE_TASK_PREFIX, TASK_SUFFIX)
+        val dceTask = project.tasks.create(dceTaskName, KotlinJsDce::class.java).also {
+            it.dependsOn(kotlinTask)
+            project.tasks.findByName("build")?.dependsOn(it)
+        }
+
+        project.afterEvaluate {
+            val outputDir = File(kotlinTask.outputFile).parentFile
+
+            val dependenciesDir = File(outputDir, "dependencies")
+            copyDependencies(project, sourceSet, dependenciesDir, dceTask)
+
+            val dceInputTrees = listOf(project.fileTree(kotlinTask.outputFile), project.fileTree(dependenciesDir))
+            val dceInputFiles = UnionFileTree("dce-input", dceInputTrees)
+
+            with (dceTask) {
+                classpath = sourceSet.compileClasspath
+                destinationDir = File(outputDir, "min")
+                source(dceInputFiles.filter { it.path.endsWith(".js") })
+            }
+        }
+    }
+
+    private fun copyDependencies(project: Project, sourceSet: SourceSet, outputDir: File, dceTask: Task) {
+        val configuration = project.configurations.findByName(sourceSet.compileConfigurationName) ?: return
+
+        val files = UnionFileCollection(configuration.map { project.zipTree(it) })
+                .filter { it.path.endsWith(".js") }
+                .filter { File(it.path.removeSuffix(".js") + ".meta.js").exists() }
+
+        val name = sourceSet.getTaskName(DEPENDENCIES_TASK_PREFIX, TASK_SUFFIX)
+        with(project.tasks.create(name, Copy::class.java)) {
+            from(files)
+            into(outputDir)
+            includeEmptyDirs = true
+            include {
+                it.path.let { it.endsWith(".js") && !it.endsWith(".meta.js") }
+            }
+
+            dceTask.dependsOn(this)
+        }
+    }
+
+    companion object {
+        private const val TASK_SUFFIX = "kotlinJs"
+        private const val DEPENDENCIES_TASK_PREFIX = "copyDependencies"
+        private const val DCE_TASK_PREFIX = "runDce"
+    }
+}

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

@@ -0,0 +1,59 @@
+/*
+ * Copyright 2010-2017 JetBrains s.r.o.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.jetbrains.kotlin.gradle.tasks
+
+import org.gradle.api.Project
+import org.gradle.api.tasks.TaskAction
+import org.jetbrains.kotlin.cli.common.CLITool
+import org.jetbrains.kotlin.cli.common.arguments.K2JSDceArguments
+import org.jetbrains.kotlin.cli.js.dce.K2JSDce
+import org.jetbrains.kotlin.compilerRunner.ArgumentUtils
+import org.jetbrains.kotlin.gradle.dsl.KotlinJsDce
+import org.jetbrains.kotlin.gradle.dsl.KotlinJsDceOptions
+import org.jetbrains.kotlin.gradle.dsl.KotlinJsDceOptionsImpl
+import java.io.File
+
+open class KotlinJsDce : AbstractKotlinCompileTool<K2JSDceArguments>(), KotlinJsDce {
+    private val dceOptionsImpl = KotlinJsDceOptionsImpl()
+
+    override val dceOptions: KotlinJsDceOptions
+        get() = dceOptionsImpl
+
+    override val keep: MutableList<String> = mutableListOf()
+
+    override fun findKotlinCompilerJar(project: Project): File? = findKotlinJsDceJar(project)
+
+    override fun compile() {}
+
+    override fun keep(vararg fqn: String) {
+        keep += fqn
+    }
+
+    @TaskAction
+    fun performDce() {
+        val inputFiles = getSource().files.map { it.path }
+
+        val outputDirArgs = arrayOf("-output-dir", destinationDir.path)
+
+        val args = K2JSDceArguments()
+        dceOptionsImpl.updateArguments(args)
+        args.declarationsToKeep = keep.toTypedArray()
+        val argsArray = ArgumentUtils.convertArgumentsToStringList(args).toTypedArray()
+        val exitCode = CLITool.doMainNoExit(K2JSDce(), argsArray + outputDirArgs + inputFiles)
+        throwGradleExceptionIfError(exitCode)
+    }
+}

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

@@ -29,6 +29,7 @@ import org.jetbrains.kotlin.annotation.AnnotationFileUpdater
 import org.jetbrains.kotlin.annotation.AnnotationFileUpdaterImpl
 import org.jetbrains.kotlin.cli.common.ExitCode
 import org.jetbrains.kotlin.cli.common.arguments.CommonCompilerArguments
+import org.jetbrains.kotlin.cli.common.arguments.CommonToolArguments
 import org.jetbrains.kotlin.cli.common.arguments.K2JSCompilerArguments
 import org.jetbrains.kotlin.cli.common.arguments.K2JVMCompilerArguments
 import org.jetbrains.kotlin.cli.common.messages.CompilerMessageLocation
@@ -51,7 +52,16 @@ const val ANNOTATIONS_PLUGIN_NAME = "org.jetbrains.kotlin.kapt"
 const val KOTLIN_BUILD_DIR_NAME = "kotlin"
 const val USING_INCREMENTAL_COMPILATION_MESSAGE = "Using kotlin incremental compilation"
 
-abstract class AbstractKotlinCompile<T : CommonCompilerArguments>() : AbstractCompile(), CompilerArgumentAware {
+abstract class AbstractKotlinCompileTool<T : CommonToolArguments>() : AbstractCompile() {
+    var compilerJarFile: File? = null
+    internal val compilerJar: File
+        get() = compilerJarFile
+                ?: findKotlinCompilerJar(project)
+                ?: throw IllegalStateException("Could not find Kotlin Compiler jar. Please specify $name.compilerJarFile")
+    protected abstract fun findKotlinCompilerJar(project: Project): File?
+}
+
+abstract class AbstractKotlinCompile<T : CommonCompilerArguments>() : AbstractKotlinCompileTool<T>(), CompilerArgumentAware {
     abstract protected fun createCompilerArgs(): T
 
     protected val additionalClasspath = arrayListOf<File>()
@@ -102,13 +112,6 @@ abstract class AbstractKotlinCompile<T : CommonCompilerArguments>() : AbstractCo
                 ?: coroutinesFromGradleProperties
                 ?: Coroutines.DEFAULT
 
-    var compilerJarFile: File? = null
-    internal val compilerJar: File
-            get() = compilerJarFile
-                    ?: findKotlinCompilerJar(project)
-                    ?: throw IllegalStateException("Could not find Kotlin Compiler jar. Please specify $name.compilerJarFile")
-    protected abstract fun findKotlinCompilerJar(project: Project): File?
-
     internal var compilerCalled: Boolean = false
     // TODO: consider more reliable approach (see usage)
     internal var anyClassesCompiled: Boolean = false

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

@@ -30,6 +30,7 @@ import java.util.zip.ZipFile
 
 private val K2JVM_COMPILER_CLASS = "org.jetbrains.kotlin.cli.jvm.K2JVMCompiler"
 private val K2JS_COMPILER_CLASS = "org.jetbrains.kotlin.cli.js.K2JSCompiler"
+private val K2JS_DCE_CLASS = "org.jetbrains.kotlin.cli.js.dce.K2JSDce"
 private val K2METADATA_COMPILER_CLASS = "org.jetbrains.kotlin.cli.metadata.K2MetadataCompiler"
 private val KOTLIN_MODULE_GROUP = "org.jetbrains.kotlin"
 private val KOTLIN_GRADLE_PLUGIN = "kotlin-gradle-plugin"
@@ -44,6 +45,9 @@ internal fun findKotlinJsCompilerJar(project: Project): File? =
 internal fun findKotlinMetadataCompilerJar(project: Project): File? =
         findKotlinCompilerJar(project, K2METADATA_COMPILER_CLASS)
 
+internal fun findKotlinJsDceJar(project: Project): File? =
+        findKotlinCompilerJar(project, K2JS_DCE_CLASS)
+
 internal fun findToolsJar(): File? =
         Class.forName("com.sun.tools.javac.util.Context")?.let(::findJarByClass)
 

libraries/tools/kotlin-gradle-plugin/src/main/resources/META-INF/gradle-plugins/kotlin-dce-js.properties

@@ -0,0 +1 @@
+implementation-class=org.jetbrains.kotlin.gradle.plugin.KotlinJsDcePlugin