Kotlin Support for Java 9 Module System?

10

I currently use the following gradle code in my root build.gradle, where I can place the module-info.java under src/module

if (JavaVersion.current() >= JavaVersion.VERSION_1_9) {
    subprojects {
        def moduleInfo = file("${project.projectDir}/src/module/module-info.java")
        if (moduleInfo.exists()) {

            sourceSets {
                module {
                    java {
                        srcDirs = ['src/module']
                        compileClasspath = main.compileClasspath
                        sourceCompatibility = '9'
                        targetCompatibility = '9'
                    }
                }
                main {
                    kotlin { srcDirs += ['src/module'] }
                }
            }

            compileModuleJava.configure {
                dependsOn compileKotlin
                destinationDir = compileKotlin.destinationDir
                doFirst {
                    options.compilerArgs = ['--module-path', classpath.asPath,]
                    classpath = files()
                }
            }
            jar.dependsOn compileModuleJava
        }
    }
}

Edit: I added src/module to the source of main.kotlin in order that the kotlin compiler analyses the module-info.java and complains if necessary.

@ilya.gorbunov when is kotlin turning its jars into modules? I currently get the following warning because I do not want to specify kotlin.stlib for every module:

warning: requires transitive directive for an automatic module
    requires transitive kotlin.stdlib;