Add explicit module-info's for JPMS compatability

buildSrc/build.gradle.kts

@@ -9,6 +9,10 @@ repositories {
     mavenCentral()
 }
 
+dependencies {
+    implementation("org.jetbrains.kotlin:kotlin-gradle-plugin:1.5.30-RC")
+}
+
 kotlinDslPluginOptions {
     experimentalWarning.set(false)
 }

buildSrc/src/main/kotlin/Java9Modularity.kt

@@ -0,0 +1,108 @@
+import org.gradle.api.*
+import org.gradle.api.file.*
+import org.gradle.api.tasks.bundling.*
+import org.gradle.api.tasks.compile.*
+import org.gradle.kotlin.dsl.*
+import org.gradle.util.GUtil.*
+import org.jetbrains.kotlin.gradle.dsl.*
+import org.jetbrains.kotlin.gradle.plugin.*
+import org.jetbrains.kotlin.gradle.plugin.mpp.*
+import org.jetbrains.kotlin.gradle.plugin.mpp.pm20.*
+import org.jetbrains.kotlin.gradle.targets.jvm.*
+import java.io.*
+import java.lang.module.*
+import java.util.spi.*
+
+object Java9Modularity {
+
+    @JvmStatic
+    @JvmOverloads
+    fun Project.configureJava9ModuleInfo(multiRelease: Boolean = true) {
+        val kotlin = extensions.findByType<KotlinProjectExtension>() ?: return
+        val jvmTargets = kotlin.targets.filter { it is KotlinJvmTarget || it is KotlinWithJavaTarget<*> }
+        if (jvmTargets.isEmpty()) {
+            logger.warn("No Kotlin JVM targets found, can't configure compilation of module-info!")
+        }
+        jvmTargets.forEach { target ->
+            target.compilations.forEach { compilation ->
+                val defaultSourceSet = compilation.defaultSourceSet.kotlin
+                val moduleInfoSourceFile = defaultSourceSet.find { it.name == "module-info.java" }
+
+                if (moduleInfoSourceFile == null) {
+                    logger.info("No module-info.java file found in ${defaultSourceSet.srcDirs}, can't configure compilation of module-info!")
+                } else {
+                    val targetName = toCamelCase(target.targetName)
+                    val compilationName = if (compilation.name != KotlinCompilation.MAIN_COMPILATION_NAME) toCamelCase(compilation.name) else ""
+                    val compileModuleInfoTaskName = "compile${compilationName}ModuleInfo$targetName"
+                    val checkModuleInfoTaskName = "check${compilationName}ModuleInfo$targetName"
+
+                    val compileKotlinTask = compilation.compileKotlinTask as AbstractCompile
+                    val modulePath = compileKotlinTask.classpath
+                    val moduleInfoClassFile = compileKotlinTask.destinationDirectory.file("module-info.class").get().asFile
+
+                    val compileModuleInfoTask = registerCompileModuleInfoTask(compileModuleInfoTaskName, modulePath, compileKotlinTask.destinationDirectory, moduleInfoSourceFile)
+                    tasks.getByName(compilation.compileAllTaskName).dependsOn(compileModuleInfoTask)
+
+                    val checkModuleInfoTask = registerCheckModuleInfoTask(checkModuleInfoTaskName, modulePath, moduleInfoClassFile)
+                    checkModuleInfoTask.configure { dependsOn(compilation.compileAllTaskName) }
+                    tasks.getByName("check").dependsOn(checkModuleInfoTask)
+                }
+            }
+
+            if (multiRelease) {
+                tasks.getByName<Jar>(target.artifactsTaskName) {
+                    rename("module-info.class", "META-INF/versions/9/module-info.class")
+                    manifest {
+                        attributes("Multi-Release" to true)
+                    }
+                }
+            }
+        }
+    }
+
+    private fun Project.registerCompileModuleInfoTask(taskName: String, modulePath: FileCollection, destinationDir: DirectoryProperty, moduleInfoSourceFile: File) =
+        tasks.register(taskName, JavaCompile::class) {
+            dependsOn(modulePath)
+            source(moduleInfoSourceFile)
+            classpath = files()
+            destinationDirectory.set(destinationDir)
+            sourceCompatibility = JavaVersion.VERSION_1_9.toString()
+            targetCompatibility = JavaVersion.VERSION_1_9.toString()
+            doFirst {
+                options.compilerArgs = listOf(
+                    "--release", "9",
+                    "--module-path", modulePath.asPath,
+                    "-Xlint:-requires-transitive-automatic"
+                )
+            }
+        }
+
+    private fun Project.registerCheckModuleInfoTask(taskName: String, modulePath: FileCollection, moduleInfoClassFile: File) =
+        tasks.register(taskName) {
+            dependsOn(modulePath)
+            doLast {
+                val jdeps = ToolProvider.findFirst("jdeps").orElseThrow { IllegalStateException("Tool 'jdeps' is not available") }
+                val moduleDescriptor = moduleInfoClassFile.inputStream().use { ModuleDescriptor.read(it) }
+                val moduleName = moduleDescriptor.name()
+                val expectedOutput = moduleDescriptor.toJdepsOutput(moduleInfoClassFile)
+
+                val outputCaptureStream = ByteArrayOutputStream()
+                val printStream = PrintStream(outputCaptureStream, true, Charsets.UTF_8)
+                jdeps.run(
+                    printStream, printStream,
+                    "--multi-release", "9",
+                    "--module-path", (modulePath + files(moduleInfoClassFile.parentFile)).asPath,
+                    "--check", moduleName
+                )
+                val actualOutput = outputCaptureStream.toString(Charsets.UTF_8).trim()
+
+                if (actualOutput != expectedOutput) {
+                    throw IllegalStateException("Module-info does not match!\n$actualOutput")
+                }
+            }
+        }
+
+    private fun ModuleDescriptor.toJdepsOutput(file: File, separator: String = System.lineSeparator()) =
+        "${name()} (${file.parentFile.toURI().toString().replace("file:", "file://")})$separator  [Module descriptor]$separator" +
+                requires().sortedBy { it.name() }.joinToString(separator) { requirement -> "    requires $requirement;" }
+}

core/build.gradle

@@ -42,3 +42,5 @@ tasks.withType(Jar).named(kotlin.jvm().artifactsTaskName) {
         )
     }
 }
+
+Java9Modularity.configureJava9ModuleInfo(project)

core/jvmMain/src/module-info.java

@@ -0,0 +1,10 @@
+module kotlinx.serialization.core {
+    requires transitive kotlin.stdlib;
+
+    exports kotlinx.serialization;
+    exports kotlinx.serialization.builtins;
+    exports kotlinx.serialization.descriptors;
+    exports kotlinx.serialization.encoding;
+    exports kotlinx.serialization.internal;
+    exports kotlinx.serialization.modules;
+}

docs/building.md

@@ -1,5 +1,10 @@
 # Building Kotlin Serialization from the source
 
+## JDK version
+
+To build Kotlin Serialization JDK version 9 or higher is required.
+This is needed to compile the `module-info` file included for JPMS support.
+
 ## Runtime library
 
 Kotlin Serialization runtime library itself is a [multiplatform](http://kotlinlang.org/docs/reference/multiplatform.html) project.

formats/cbor/build.gradle

@@ -29,3 +29,5 @@ kotlin {
         }
     }
 }
+
+Java9Modularity.configureJava9ModuleInfo(project)

formats/cbor/jvmMain/src/module-info.java

@@ -0,0 +1,6 @@
+module kotlinx.serialization.cbor {
+    requires transitive kotlin.stdlib;
+    requires transitive kotlinx.serialization.core;
+
+    exports kotlinx.serialization.cbor;
+}

formats/hocon/build.gradle

@@ -13,8 +13,10 @@ dependencies {
     compile project(':kotlinx-serialization-core')
     api 'org.jetbrains.kotlin:kotlin-stdlib'
 
-    api 'com.typesafe:config:1.3.2'
+    api 'com.typesafe:config:1.4.1'
 
     testCompile "org.jetbrains.kotlin:kotlin-test"
     testCompile group: 'junit', name: 'junit', version: '4.12'
 }
+
+Java9Modularity.configureJava9ModuleInfo(project)

formats/hocon/src/main/kotlin/module-info.java

@@ -0,0 +1,7 @@
+module kotlinx.serialization.hocon {
+    requires transitive kotlin.stdlib;
+    requires transitive kotlinx.serialization.core;
+    requires transitive typesafe.config;
+
+    exports kotlinx.serialization.hocon;
+}

formats/json/build.gradle

@@ -28,3 +28,5 @@ kotlin {
 compileTestKotlinJsLegacy {
     exclude '**/PropertyInitializerTest.kt'
 }
+
+Java9Modularity.configureJava9ModuleInfo(project)

formats/json/jvmMain/src/module-info.java

@@ -0,0 +1,6 @@
+module kotlinx.serialization.json {
+    requires transitive kotlin.stdlib;
+    requires transitive kotlinx.serialization.core;
+
+    exports kotlinx.serialization.json;
+}

formats/properties/build.gradle

@@ -29,3 +29,5 @@ kotlin {
         }
     }
 }
+
+Java9Modularity.configureJava9ModuleInfo(project)

formats/properties/jvmMain/src/module-info.java

@@ -0,0 +1,6 @@
+module kotlinx.serialization.properties {
+    requires transitive kotlin.stdlib;
+    requires transitive kotlinx.serialization.core;
+
+    exports kotlinx.serialization.properties;
+}

formats/protobuf/build.gradle

@@ -46,3 +46,5 @@ sourceSets.test.proto {
 compileTestKotlinJvm {
     dependsOn 'generateTestProto'
 }
+
+Java9Modularity.configureJava9ModuleInfo(project)

formats/protobuf/jvmMain/src/module-info.java

@@ -0,0 +1,7 @@
+module kotlinx.serialization.protobuf {
+    requires transitive kotlin.stdlib;
+    requires transitive kotlinx.serialization.core;
+
+    exports kotlinx.serialization.protobuf;
+    exports kotlinx.serialization.protobuf.schema;
+}