Replace -Xuse-experimental with -Xopt-in in codebase

compiler/frontend/src/org/jetbrains/kotlin/resolve/checkers/ExperimentalUsageChecker.kt

@@ -314,8 +314,8 @@ class ExperimentalUsageChecker(project: Project) : CallChecker {
             reportError: (String) -> Unit,
             reportWarning: (String) -> Unit
         ) {
-            // Ideally, we should run full resolution (with all classifier usage checkers) on classifiers used in "-Xexperimental" and
-            // "-Xuse-experimental" arguments. However, it's not easy to do this. This should be solved in the future with the support of
+            // Ideally, we should run full resolution (with all classifier usage checkers) on classifiers used in
+            // "-Xopt-in" arguments. However, it's not easy to do this. This should be solved in the future with the support of
             // module annotations. For now, we only check deprecations because this is needed to correctly retire unneeded compiler arguments.
             val deprecationResolver = DeprecationResolver(
                 LockBasedStorageManager("ExperimentalUsageChecker"),

kotlin-native/Interop/Runtime/build.gradle.kts

@@ -72,8 +72,7 @@ sourceSets.main.get().java.srcDir("src/jvm/kotlin")
 
 tasks.withType<org.jetbrains.kotlin.gradle.tasks.KotlinCompile>().configureEach {
     kotlinOptions {
-        freeCompilerArgs = listOf("-Xuse-experimental=kotlin.ExperimentalUnsignedTypes",
-                                  "-Xuse-experimental=kotlin.Experimental",
+        freeCompilerArgs = listOf("-Xopt-in=kotlin.ExperimentalUnsignedTypes",
                                   "-Xopt-in=kotlin.RequiresOptIn",
                                   "-Xinline-classes",
                                   "-Xskip-prerelease-check")

kotlin-native/endorsedLibraries/kotlinx.cli/src/main/kotlin/kotlinx/cli/ExperimentalCli.kt

@@ -15,7 +15,7 @@ import kotlin.annotation.AnnotationTarget.*
  *
  * Any usage of a declaration annotated with `@ExperimentalCli` must be accepted either by
  * annotating that usage with the [UseExperimental] annotation, e.g. `@UseExperimental(ExperimentalCli::class)`,
- * or by using the compiler argument `-Xuse-experimental=kotlinx.cli.ExperimentalCli`.
+ * or by using the compiler argument `-Xopt-in=kotlinx.cli.ExperimentalCli`.
  */
 @RequiresOptIn("This API is experimental. It may be changed in the future without notice.", RequiresOptIn.Level.WARNING)
 @Retention(AnnotationRetention.BINARY)

libraries/kotlin.test/js-ir/build.gradle.kts

@@ -50,9 +50,8 @@ tasks.withType<KotlinCompile<*>>().configureEach {
     kotlinOptions.freeCompilerArgs += listOf(
         "-Xallow-kotlin-package",
         "-Xallow-result-return-type",
-        "-Xuse-experimental=kotlin.Experimental",
-        "-Xuse-experimental=kotlin.ExperimentalMultiplatform",
-        "-Xuse-experimental=kotlin.contracts.ExperimentalContracts",
+        "-Xopt-in=kotlin.ExperimentalMultiplatform",
+        "-Xopt-in=kotlin.contracts.ExperimentalContracts",
         "-Xinline-classes"
     )
 }

libraries/stdlib/js-ir-minimal-for-test/build.gradle.kts

@@ -122,9 +122,8 @@ tasks.withType<KotlinCompile<*>> {
     kotlinOptions.freeCompilerArgs += listOf(
         "-Xallow-kotlin-package",
         "-Xallow-result-return-type",
-        "-Xuse-experimental=kotlin.Experimental",
-        "-Xuse-experimental=kotlin.ExperimentalMultiplatform",
-        "-Xuse-experimental=kotlin.contracts.ExperimentalContracts",
+        "-Xopt-in=kotlin.ExperimentalMultiplatform",
+        "-Xopt-in=kotlin.contracts.ExperimentalContracts",
         "-Xinline-classes",
         "-Xopt-in=kotlin.RequiresOptIn",
         "-Xopt-in=kotlin.ExperimentalUnsignedTypes",

libraries/stdlib/js-ir/build.gradle.kts

@@ -138,9 +138,8 @@ tasks.withType<KotlinCompile<*>>().configureEach {
     kotlinOptions.freeCompilerArgs += listOf(
         "-Xallow-kotlin-package",
         "-Xallow-result-return-type",
-        "-Xuse-experimental=kotlin.Experimental",
-        "-Xuse-experimental=kotlin.ExperimentalMultiplatform",
-        "-Xuse-experimental=kotlin.contracts.ExperimentalContracts",
+        "-Xopt-in=kotlin.ExperimentalMultiplatform",
+        "-Xopt-in=kotlin.contracts.ExperimentalContracts",
         "-Xinline-classes",
         "-Xopt-in=kotlin.RequiresOptIn",
         "-Xopt-in=kotlin.ExperimentalUnsignedTypes",

libraries/stdlib/wasm/build.gradle.kts

@@ -74,9 +74,8 @@ tasks.withType<KotlinCompile<*>>().configureEach {
     kotlinOptions.freeCompilerArgs += listOf(
         "-Xallow-kotlin-package",
         "-Xallow-result-return-type",
-        "-Xuse-experimental=kotlin.Experimental",
-        "-Xuse-experimental=kotlin.ExperimentalMultiplatform",
-        "-Xuse-experimental=kotlin.contracts.ExperimentalContracts",
+        "-Xopt-in=kotlin.ExperimentalMultiplatform",
+        "-Xopt-in=kotlin.contracts.ExperimentalContracts",
         "-Xinline-classes",
         "-Xopt-in=kotlin.RequiresOptIn",
         "-Xopt-in=kotlin.ExperimentalUnsignedTypes",