Fix warnings after making getKotlinPluginVersion non-null

See 4cb6303fa8.

libraries/tools/kotlin-gradle-plugin/src/functionalTest/kotlin/org/jetbrains/kotlin/gradle/BuildKotlinToolingMetadataTest.kt

@@ -54,7 +54,7 @@ class BuildKotlinToolingMetadataTest {
         assertEquals("Gradle", metadata.buildSystem)
         assertEquals(project.gradle.gradleVersion, metadata.buildSystemVersion)
         assertEquals(KotlinMultiplatformPluginWrapper::class.java.canonicalName, metadata.buildPlugin)
-        assertEquals(project.getKotlinPluginVersion().toString(), metadata.buildPluginVersion)
+        assertEquals(project.getKotlinPluginVersion(), metadata.buildPluginVersion)
         assertEquals(1, metadata.projectTargets.size, "Expected one target (metadata)")
         assertTrue(
             KotlinMetadataTarget::class.java.isAssignableFrom(Class.forName(metadata.projectTargets.single().target)),

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

@@ -27,7 +27,7 @@ internal class KotlinNativeCommonizerToolRunner(project: Project) : KotlinToolRu
         }
     }
 
-    override val isolatedClassLoaderCacheKey get() = project.getKotlinPluginVersion()!!
+    override val isolatedClassLoaderCacheKey get() = project.getKotlinPluginVersion()
 
     override val defaultMaxHeapSize: String get() = "4G"
 

libraries/tools/kotlin-gradle-plugin/src/main/kotlin/org/jetbrains/kotlin/gradle/internal/kapt/Kapt3KotlinGradleSubplugin.kt

@@ -11,7 +11,6 @@ import com.android.build.gradle.api.BaseVariant
 import com.android.build.gradle.api.SourceKind
 import com.intellij.openapi.util.SystemInfo
 import com.intellij.util.lang.JavaVersion
-import org.gradle.api.GradleException
 import org.gradle.api.Project
 import org.gradle.api.artifacts.Configuration
 import org.gradle.api.artifacts.Dependency
@@ -54,10 +53,8 @@ class Kapt3GradleSubplugin @Inject internal constructor(private val registry: To
         target.extensions.create("kapt", KaptExtension::class.java)
 
         target.configurations.create(KAPT_WORKER_DEPENDENCIES_CONFIGURATION_NAME).apply {
-            target.getKotlinPluginVersion()?.let { kotlinPluginVersion ->
-                val kaptDependency = getPluginArtifact().run { "$groupId:$artifactId:$kotlinPluginVersion" }
-                dependencies.add(target.dependencies.create(kaptDependency))
-            } ?: throw GradleException("Kotlin plugin should be enabled before 'kotlin-kapt'")
+            val kaptDependency = getPluginArtifact().run { "$groupId:$artifactId:${target.getKotlinPluginVersion()}" }
+            dependencies.add(target.dependencies.create(kaptDependency))
         }
 
         registry.register(KaptModelBuilder())

libraries/tools/kotlin-gradle-plugin/src/main/kotlin/org/jetbrains/kotlin/gradle/targets/android/internal/AndroidSubplugin.kt

@@ -48,10 +48,7 @@ class AndroidExtensionsSubpluginIndicator @Inject internal constructor(private v
     }
 
     private fun addAndroidExtensionsRuntime(project: Project) {
-        val kotlinPluginVersion = project.getKotlinPluginVersion() ?: run {
-            project.logger.error("Kotlin plugin should be enabled before 'kotlin-android-extensions'")
-            return
-        }
+        val kotlinPluginVersion = project.getKotlinPluginVersion()
 
         project.configurations.all { configuration ->
             val name = configuration.name

libraries/tools/kotlin-gradle-plugin/src/main/kotlin/org/jetbrains/kotlin/gradle/targets/android/internal/ParcelizeSubplugin.kt

@@ -46,10 +46,7 @@ class ParcelizeSubplugin : KotlinCompilerPluginSupportPlugin {
     override fun getPluginArtifact(): SubpluginArtifact = JetBrainsSubpluginArtifact(artifactId = "kotlin-parcelize-compiler")
 
     private fun addParcelizeRuntime(project: Project) {
-        val kotlinPluginVersion = project.getKotlinPluginVersion() ?: run {
-            project.logger.error("Kotlin plugin should be enabled before 'kotlin-parcelize'")
-            return
-        }
+        val kotlinPluginVersion = project.getKotlinPluginVersion()
 
         project.configurations.all { configuration ->
             val name = configuration.name

libraries/tools/kotlin-gradle-plugin/src/main/kotlin/org/jetbrains/kotlin/gradle/targets/native/internal/HierarchicalNativeDistributionCommonizerTask.kt

@@ -75,7 +75,7 @@ internal open class HierarchicalNativeDistributionCommonizerTask : DefaultTask()
         get() = commonizerRunner.getCustomJvmArgs()
 
     internal fun getRootOutputDirectory(target: SharedCommonizerTarget): File {
-        val kotlinVersion = checkNotNull(project.getKotlinPluginVersion()) { "Missing Kotlin Plugin version" }
+        val kotlinVersion = project.getKotlinPluginVersion()
 
         val discriminator = buildString {
             append(target.identityString)

libraries/tools/kotlin-gradle-plugin/src/main/kotlin/org/jetbrains/kotlin/gradle/targets/native/internal/KotlinNativePlatformDependencies.kt

@@ -31,7 +31,7 @@ private val Project.isNativeDependencyPropagationEnabled: Boolean
 @JvmOverloads
 @JvmName("isAllowCommonizer")
 internal fun Project.isAllowCommonizer(
-    kotlinVersion: String = getKotlinPluginVersion()!!
+    kotlinVersion: String = getKotlinPluginVersion()
 ): Boolean {
     multiplatformExtensionOrNull ?: return false
 
@@ -47,7 +47,7 @@ internal fun Project.setUpKotlinNativePlatformDependencies() {
         // not a multiplatform project, nothing to set up
         return
     }
-    val kotlinVersion = getKotlinPluginVersion()!!
+    val kotlinVersion = getKotlinPluginVersion()
     val allowCommonizer = isAllowCommonizer(kotlinVersion)
     if (allowCommonizer && isHierarchicalCommonizationEnabled) {
         return setUpHierarchicalKotlinNativePlatformDependencies()

libraries/tools/kotlin-gradle-plugin/src/main/kotlin/org/jetbrains/kotlin/gradle/targets/native/internal/NativeDistributionCommonizerTask.kt

@@ -166,7 +166,7 @@ private class TemporaryStagedDirectory(val temporaryDirectoryFile: File, private
 }
 
 internal fun Project.nativeDistributionCommonizerOutputDirectory(targets: KonanTargetGroup): File {
-    val kotlinVersion = checkNotNull(project.getKotlinPluginVersion()) { "Failed infering Kotlin Plugin version" }
+    val kotlinVersion = project.getKotlinPluginVersion()
     val orderedTargetNames = targets.map { it.name }.sorted()
     val discriminator = buildString {
         orderedTargetNames.joinTo(this, separator = "-")

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

@@ -21,7 +21,6 @@ import org.gradle.api.Project
 import org.gradle.api.artifacts.Configuration
 import org.gradle.api.artifacts.ResolvedDependency
 import org.gradle.api.initialization.dsl.ScriptHandler
-import org.jetbrains.kotlin.gradle.plugin.KotlinBasePluginWrapper
 import org.jetbrains.kotlin.gradle.plugin.KotlinPlugin
 import org.jetbrains.kotlin.gradle.plugin.getKotlinPluginVersion
 import java.io.File
@@ -133,10 +132,10 @@ internal fun findJarByClass(klass: Class<*>): File? {
 private fun findKotlinModuleJar(project: Project, expectedClassName: String, moduleId: String): List<File> {
     val pluginVersion = project.getKotlinPluginVersion()
 
-    val filesToCheck = sequenceOf(pluginVersion?.let { version -> getModuleFromClassLoader(moduleId, version) }) +
+    val filesToCheck = sequenceOf(getModuleFromClassLoader(moduleId, pluginVersion)) +
             Sequence { findPotentialModuleJars(project, moduleId).iterator() } //call the body only when queried
     val entryToFind = expectedClassName.replace(".", "/") + ".class"
-    return filesToCheck.filterNotNull().firstOrNull { it.hasEntry(entryToFind) }?.let { listOf(it) } ?: emptyList()
+    return filesToCheck.filterNotNull().firstOrNull { it.hasEntry(entryToFind) }?.let { listOf(it) }.orEmpty()
 }
 
 private fun getModuleFromClassLoader(moduleId: String, moduleVersion: String): File? {

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

@@ -81,9 +81,7 @@ private fun KotlinProjectExtension.getKotlinToolingMetadata(): KotlinToolingMeta
         buildSystem = "Gradle",
         buildSystemVersion = project.gradle.gradleVersion,
         buildPlugin = project.plugins.withType(KotlinBasePluginWrapper::class.java).joinToString(";") { it.javaClass.canonicalName },
-        buildPluginVersion = project.getKotlinPluginVersion() ?: throw IllegalStateException(
-            "Failed to infer Kotlin Plugin version"
-        ),
+        buildPluginVersion = project.getKotlinPluginVersion(),
         projectSettings = buildProjectSettings(),
         projectTargets = buildProjectTargets()
     )