Bump language version for Gradle plugins' dependencies to 1.5

#KT-58569 Fixed

buildSrc/src/main/kotlin/GradleCommon.kt

@@ -29,6 +29,7 @@ import org.jetbrains.dokka.DokkaVersion
 import org.jetbrains.dokka.gradle.DokkaTask
 import org.jetbrains.dokka.gradle.GradleExternalDocumentationLinkBuilder
 import org.jetbrains.kotlin.gradle.dsl.KotlinSingleJavaTargetExtension
+import org.jetbrains.kotlin.gradle.dsl.KotlinVersion
 import org.jetbrains.kotlin.gradle.plugin.KotlinPlatformType
 import org.jetbrains.kotlin.gradle.tasks.KotlinCompile
 import plugins.configureDefaultPublishing
@@ -504,15 +505,25 @@ private fun Project.commonVariantAttributes(): Action<Configuration> = Action<Co
 }
 
 fun Project.configureKotlinCompileTasksGradleCompatibility() {
-    @Suppress("DEPRECATION")
     tasks.withType<KotlinCompile>().configureEach {
-        kotlinOptions.languageVersion = "1.4"
-        kotlinOptions.apiVersion = "1.4"
-        kotlinOptions.freeCompilerArgs += listOf(
-            "-Xskip-prerelease-check",
-            "-Xsuppress-version-warnings",
-            "-Xuse-ir" // Needed as long as languageVersion is less than 1.5.
-        )
+        compilerOptions {
+            // check https://docs.gradle.org/current/userguide/compatibility.html#kotlin for Kotlin-Gradle versions matrix
+            @Suppress("DEPRECATION") // we can't use language version greater than 1.5 as minimal supported Gradle embeds Kotlin 1.4
+            languageVersion.set(KotlinVersion.KOTLIN_1_5)
+            @Suppress("DEPRECATION") // we can't use api version greater than 1.4 as minimal supported Gradle version uses kotlin-stdlib 1.4
+            apiVersion.set(KotlinVersion.KOTLIN_1_4)
+            freeCompilerArgs.addAll(
+                listOf(
+                    "-Xskip-prerelease-check",
+                    "-Xsuppress-version-warnings",
+                    // We have to override the default value for `-Xsam-conversions` to `class`
+                    // otherwise the compiler would compile lambdas using invokedynamic,
+                    // such lambdas are not serializable so are not compatible with Gradle configuration cache.
+                    // It doesn't lead to a significant difference in binaries sizes, and previously (before LV 1.5) the `class` value was set by default.
+                    "-Xsam-conversions=class",
+                )
+            )
+        }
     }
 }
 

compiler/util-io/build.gradle.kts

@@ -14,15 +14,7 @@ sourceSets {
     "test" { projectDefault() }
 }
 
-tasks {
-    withType<org.jetbrains.kotlin.gradle.tasks.KotlinCompile> {
-        kotlinOptions {
-            languageVersion = "1.4"
-            apiVersion = "1.4"
-            freeCompilerArgs += listOf("-Xsuppress-version-warnings", "-Xinline-classes")
-        }
-    }
-}
+configureKotlinCompileTasksGradleCompatibility()
 
 publish()
 

compiler/util-klib/build.gradle.kts

@@ -18,13 +18,7 @@ sourceSets {
     "test" { projectDefault() }
 }
 
-tasks.withType<KotlinCompile>().configureEach {
-    kotlinOptions {
-        languageVersion = "1.4"
-        apiVersion = "1.4"
-        freeCompilerArgs += listOf("-Xsuppress-version-warnings")
-    }
-}
+configureKotlinCompileTasksGradleCompatibility()
 
 publish()
 

libraries/tools/kotlin-project-model/build.gradle.kts

@@ -24,13 +24,7 @@ projectTest(jUnitMode = JUnitMode.JUnit5) {
     useJUnitPlatform()
 }
 
-tasks.withType<KotlinJvmCompile>().configureEach {
-    kotlinOptions {
-        languageVersion = "1.4"
-        apiVersion = "1.4"
-        freeCompilerArgs += listOf("-Xskip-prerelease-check", "-Xsuppress-version-warnings")
-    }
-}
+configureKotlinCompileTasksGradleCompatibility()
 
 tasks.named<KotlinJvmCompile>("compileTestFixturesKotlin") {
     kotlinOptions {

libraries/tools/kotlin-tooling-core/build.gradle.kts

@@ -9,11 +9,6 @@ sourcesJar()
 javadocJar()
 configureKotlinCompileTasksGradleCompatibility()
 
-kotlin.sourceSets.configureEach {
-    languageSettings.apiVersion = "1.4"
-    languageSettings.languageVersion = "1.4"
-}
-
 dependencies {
     api(platform(project(":kotlin-gradle-plugins-bom")))
     compileOnly(kotlinStdlib())

native/utils/build.gradle.kts

@@ -22,15 +22,9 @@ sourceSets {
     "test" { projectDefault() }
 }
 
-tasks {
-    withType<org.jetbrains.kotlin.gradle.tasks.KotlinCompile> {
-        kotlinOptions {
-            languageVersion = "1.4"
-            apiVersion = "1.4"
-            freeCompilerArgs += "-Xsuppress-version-warnings"
-        }
-    }
+configureKotlinCompileTasksGradleCompatibility()
 
+tasks {
     withType<Test>().configureEach {
         useJUnitPlatform()
     }