Explicitly enable Dokka javadocs generation

Actually we don't need javadoc generation for our internal stuff like
':kotlin-gradle-plugin'. But ':kotlin-gradle-plugin-api' is a public api
 and should have properly generated javadocs.

^KT-55520 In Progress

buildSrc/src/main/kotlin/GradleCommon.kt

@@ -54,6 +54,8 @@ enum class GradlePluginVariant(
     GRADLE_76("gradle76", "7.6", "7.6"),
 }
 
+val commonSourceSetName = "common"
+
 /**
  * Configures common pom configuration parameters
  */
@@ -103,7 +105,7 @@ fun Project.excludeGradleCommonDependencies(sourceSet: SourceSet) {
  * Should contain classes that are independent of Gradle API version or using minimal supported Gradle api.
  */
 fun Project.createGradleCommonSourceSet(): SourceSet {
-    val commonSourceSet = sourceSets.create("common") {
+    val commonSourceSet = sourceSets.create(commonSourceSetName) {
         excludeGradleCommonDependencies(this)
 
         // Adding Gradle API to separate configuration, so version will not leak into variants
@@ -299,28 +301,6 @@ fun Project.reconfigureMainSourcesSetForGradlePlugin(
                 }
         }
 
-        if (kotlinBuildProperties.publishGradlePluginsJavadoc) {
-            plugins.withId("org.jetbrains.dokka") {
-                val dokkaTask = tasks.named<DokkaTask>("dokkaJavadoc") {
-                    dokkaSourceSets {
-                        named(commonSourceSet.name) {
-                            suppress.set(false)
-                        }
-
-                        named("main") {
-                            dependsOn(commonSourceSet)
-                        }
-                    }
-                }
-
-                tasks.withType<Jar>().configureEach {
-                    if (name == javadocJarTaskName) {
-                        from(dokkaTask.flatMap { it.outputDirectory })
-                    }
-                }
-            }
-        }
-
         // Workaround for https://youtrack.jetbrains.com/issue/KT-52987
         val javaComponent = project.components["java"] as AdhocComponentWithVariants
         listOf(
@@ -446,36 +426,6 @@ fun Project.createGradlePluginVariant(
         }
     }
 
-    if (kotlinBuildProperties.publishGradlePluginsJavadoc) {
-        plugins.withId("org.jetbrains.dokka") {
-            val dokkaTask = tasks.register<DokkaTask>(
-                "dokka${
-                    variantSourceSet.javadocTaskName.replaceFirstChar { it.uppercase() }
-                }") {
-                description = "Generates documentation in 'javadoc' format for '${variantSourceSet.javadocTaskName}' variant"
-
-                plugins.dependencies.add(
-                    project.dependencies.create("org.jetbrains.dokka:javadoc-plugin:${DokkaVersion.version}")
-                )
-
-                dokkaSourceSets {
-                    named(commonSourceSet.name) {
-                        suppress.set(false)
-                    }
-
-                    named(variantSourceSet.name) {
-                        dependsOn(commonSourceSet)
-                        suppress.set(false)
-                    }
-                }
-            }
-
-            tasks.named<Jar>(variantSourceSet.javadocJarTaskName) {
-                from(dokkaTask.flatMap { it.outputDirectory })
-            }
-        }
-    }
-
     plugins.withId("java-gradle-plugin") {
         tasks.named<Copy>(variantSourceSet.processResourcesTaskName) {
             val copyPluginDescriptors = rootSpec.addChild()
@@ -632,4 +582,46 @@ fun Project.addBomCheckTask() {
     tasks.named("check") {
         dependsOn(checkBomTask)
     }
+}
+
+fun Project.configureDokkaPublication() {
+    if (!kotlinBuildProperties.publishGradlePluginsJavadoc) return
+
+    plugins.apply("org.jetbrains.dokka")
+    plugins.withId("org.jetbrains.dokka") {
+        val commonSourceSet = sourceSets.getByName(commonSourceSetName)
+
+        GradlePluginVariant.values().forEach { pluginVariant ->
+            val variantSourceSet = sourceSets.getByName(pluginVariant.sourceSetName)
+            val dokkaTaskName = "dokka${variantSourceSet.javadocTaskName.replaceFirstChar { it.uppercase() }}"
+
+            val dokkaTask = if (tasks.names.contains(dokkaTaskName)) {
+                tasks.named<DokkaTask>(dokkaTaskName)
+            } else {
+                tasks.register<DokkaTask>(dokkaTaskName)
+            }
+            dokkaTask.configure {
+                description = "Generates documentation in 'javadoc' format for '${variantSourceSet.javadocTaskName}' variant"
+
+                plugins.dependencies.add(
+                    project.dependencies.create("org.jetbrains.dokka:javadoc-plugin:${DokkaVersion.version}")
+                )
+
+                dokkaSourceSets {
+                    named(commonSourceSet.name) {
+                        suppress.set(false)
+                    }
+
+                    named(variantSourceSet.name) {
+                        dependsOn(commonSourceSet)
+                        suppress.set(false)
+                    }
+                }
+            }
+
+            tasks.named<Jar>(variantSourceSet.javadocJarTaskName) {
+                from(dokkaTask.flatMap { it.outputDirectory })
+            }
+        }
+    }
 }

buildSrc/src/main/kotlin/gradle-plugin-common-configuration.gradle.kts

@@ -8,7 +8,6 @@ import plugins.signLibraryPublication
 plugins {
     kotlin("jvm")
     `java-gradle-plugin`
-    id("org.jetbrains.dokka")
     `maven-publish`
     id("com.gradle.plugin-publish")
 }

buildSrc/src/main/kotlin/gradle-plugin-dependency-configuration.gradle.kts

@@ -9,7 +9,6 @@ import plugins.signLibraryPublication
 plugins {
     `java-library`
     kotlin("jvm")
-    id("org.jetbrains.dokka")
     `maven-publish`
 }
 

libraries/tools/kotlin-gradle-plugin-api/build.gradle.kts

@@ -4,6 +4,8 @@ plugins {
     id("org.jetbrains.kotlinx.binary-compatibility-validator")
 }
 
+configureDokkaPublication()
+
 dependencies {
     commonApi(platform(project(":kotlin-gradle-plugins-bom")))
     commonApi(project(":kotlin-gradle-plugin-annotations"))

libraries/tools/kotlin-gradle-plugin/Module.md

@@ -1,117 +0,0 @@
-# Module kotlin-gradle-plugin
-
-`kotlin-gradle-plugin` artifact provides multiple plugins.
-
-### kotlin
-
-How to apply:
-
-```
-apply plugin: 'kotlin'
-```
-
-Tasks:
-
-| Name | Type | Description
-|------------------------------|--------------------|---------------|
-| compileKotlin                | [KotlinJvmCompile] | A task is created for `main` source set |
-| compileTestKotlin            | [KotlinJvmCompile] | A task is created for `test` source set |
-| compile*SourceSetName*Kotlin | [KotlinJvmCompile] | A task is created for each additional source set |
-
-Each [KotlinJvmCompile] task provides `kotlinOptions` ([KotlinJvmOptions]) extension:
-
-```
-compileKotlin {
-    kotlinOptions {
-        noStdlib = true
-    }
-    // kotlinOptions.noStdlib = true
-}
-```
-
-### kotlin-android
-
-A plugin that should be used for Android development.
-
-How to apply:
-
-```
-apply plugin: 'kotlin-android'
-```
-
-Tasks:
-
-| Name | Type | Description
-|------------------------------|--------------------|---------------|
-| compile*VariantName*Kotlin | [KotlinJvmCompile] | A task is created for each variant |
-
-Note that tasks are created after evaluation, so all references to tasks should be done in `afterEvaluate` section:
-
-```
-afterEvaluate {
-    compileDebugKotlin {
-        kotlinOptions {
-            noStdlib = true
-        }
-    }
-}
-```
-
-Android plugin also adds `kotlinOptions` extension to `android` section to set options for all kotlin tasks:
-
-```
-android {
-    kotlinOptions {
-        noStdlib = true
-    }
-}
-```
-
-Task's `kotlinOptions` "override" ones in `android` section:
-
-```
-android {
-    kotlinOptions {
-        noStdlib = true
-    }
-}
-
-afterEvaluate {
-    compileDebugKotlin {
-        kotlinOptions {
-            noStdlib = false
-        }
-    }
-}
-// compileProductionKotlin.noStdlib == true
-// compileDebugKotlin.noStdlib == false
-```
-
-### Kotlin/JS
-
-How to apply:
-
-```
-plugins {
-    id 'org.jetbrains.kotlin.js'
-}
-```
-
-Tasks:
-
-| Name | Type | Description
-|--------------------------------|--------------------|---------------|
-| compileKotlin2Js               | [KotlinJsCompile] | A task is created for `main` source set |
-| compileTestKotlin2Js           | [KotlinJsCompile] | A task is created for `test` source set |
-| compile*SourceSetName*Kotlin2Js| [KotlinJsCompile] | A task is created for each additional source set |
-
-Each [KotlinJsCompile] task provides `kotlinOptions` ([KotlinJsOptions]) extension:
-
-```
-compileKotlinJs {
-    kotlinOptions {
-        noStdlib = true
-    }
-    // kotlinOptions.noStdlib = true
-}
-```

libraries/tools/kotlin-gradle-plugin/build.gradle.kts

@@ -125,15 +125,6 @@ tasks {
         enableStricterValidation.set(true)
     }
 
-    withType<DokkaTask>().configureEach {
-        dokkaSourceSets.configureEach {
-            includes.from("Module.md")
-        }
-    }
-    register("dokka") {
-        dependsOn(named("dokkaJavadoc"))
-    }
-
     withType<ShadowJar>().configureEach {
         relocate("com.github.gundy", "$kotlinEmbeddableRootPackage.com.github.gundy")
         relocate("de.undercouch.gradle.tasks.download", "$kotlinEmbeddableRootPackage.de.undercouch.gradle.tasks.download")