I want to create a custom compilation. How do I setup srcDir of this compilation that accepts a Task...

# gradle

[hfhbd]

I want to create a custom compilation. How do I setup srcDir of this compilation that accepts a Task which produces a folder?

[hfhbd]

val s = tasks.named("myCustomTask")

kotlin.target.compilations.register("foo") {
    kotlinSourceSets.forAll { 
        it.kotlin.srcDir(s)
    }
}

If I run: compileFooKotlin, the task myCustomTask won't be executed.

[Javier]

https://kotlinlang.org/docs/multiplatform-configure-compilations.html#create-a-custom-compilation

[hfhbd]

Yeah, I read the docs but even using this code:

kotlin.target.compilations.register("foo") {
    defaultSourceSet {
        kotlin.srcDir(s)
    }
}

Does not execute the task, but creating a Java feature does (compileBarKotlin):

val bar by sourceSets.registering {
    kotlin.srcDir(s)
}

java.registerFeature("bar") {
    usingSourceSet(bar.get())
}

[Albert Chang]

Shouldn't you add the output dir of the task instead of the task itself to srcDir?
I used this code to add generated source to commonMain, and it worked.

val kotlinSourceDir = project.files(task.map { it.generatedSrcMainDirectory }).builtBy(task)
extensions.getByType(KotlinMultiplatformExtension::class).sourceSets["commonMain"].kotlin.srcDir(kotlinSourceDir)

(task.generatedSrcMainDirectory is an @Output of task.)

[Javier]

Adding the directory instead of the task will not help Gradle to determine the correct tasks execution order

[Albert Chang]

It does.

[hfhbd]

Yeah, I will try the project.files workaround, always forget it.
It adds the task dependency using builtBy

[mbonnin]

Feels super weird that passing the task provider does not carry the task dependency. But that wouldn't be the first inconsistency....

[hfhbd]

Well it also does not work: https://youtrack.jetbrains.com/issue/KT-74264/KGP-Adding-srcDir-to-compilation-does-not-execute-task-dependencies

[mbonnin]

This reminds me of a issue I had with AGP where the task dependency was also lost (although compiling worked fine): https://issuetracker.google.com/u/1/issues/376709932

[mbonnin]

But I think it's a different code path: AGP variants vs Kotlin compilations (but same symptom)

[Javier]

Calling

./gradlew jvmFooClasses --dry-run

Shows

:kotlin-stdlib:checkKotlinGradlePluginConfigurationErrors SKIPPED
:kotlin-stdlib:compileKotlinJvm SKIPPED
:kotlin-stdlib:jvmProcessResources SKIPPED
:kotlin-stdlib:jvmMainClasses SKIPPED
:kotlin-stdlib:random SKIPPED
:kotlin-stdlib:compileFooKotlinJvm SKIPPED
:kotlin-stdlib:jvmFooProcessResources SKIPPED
:kotlin-stdlib:jvmFooClasses SKIPPED

random is executed, so using implementation + getting the output files from the task does the trick.

[Javier]

implementation + adding directly the task does not work (you need to call map and get the files manually). IMO, it should be possible, so probably it could be a feature request for Gradle.

[mbonnin]

getting the output files from the task does the trick

I'm guessing the output files are source files, not class files?

[Javier]

Technically I am getting the random task output files, so it could be whatever thing, no?

[mbonnin]

Yea but implementation is adding files to the compile classpath of the compiler, not to the source files

[mbonnin]

If you put *.kt in implementation , not sure if the Kotlin compiler is going to like it

[Javier]

haven't tried tbh, if @hfhbd has time and tries this, share the output as I am interested too 🙂

[hfhbd]

Well, I tested this code and it doesn’t work, the task is not executed and even if so, I don’t think implementation will support source files.
Anyway, the sourceSet workaround does work, so I won’t try it further.

val outputFolder = layout.buildDirectory.dir("a")

val t = tasks.register("a") {
    outputs.dir(outputFolder)
    doLast { 
        outputFolder.get().file("foo.kt").asFile.writeText(
            "invalid code to fail compilation"
        )
    }
}

kotlin.target.compilations.register("foo") {
    defaultSourceSet {
        dependencies {
            implementation(t.map { it.outputs.files })
        }
    }
}

[Javier]

That is weird as it is shown in the list. If you use dry run it is appearing?

[hfhbd]

I used --info

[hfhbd]

And it didn’t show up in the list