Introduce -opt-in stable compiler option instead of -Xopt-in

#KT-47099 Fixed

compiler/cli/cli-common/src/org/jetbrains/kotlin/cli/common/arguments/CommonCompilerArguments.kt

@@ -83,6 +83,15 @@ abstract class CommonCompilerArguments : CommonToolArguments() {
     @Argument(value = "-P", valueDescription = PLUGIN_OPTION_FORMAT, description = "Pass an option to a plugin")
     var pluginOptions: Array<String>? by FreezableVar(null)
 
+    @Argument(
+        value = "-opt-in",
+        // Uncomment after deletion of optInDeprecated
+        // deprecatedName = "-Xopt-in",
+        valueDescription = "<fq.name>",
+        description = "Enable usages of API that requires opt-in with an opt-in requirement marker with the given fully qualified name"
+    )
+    var optIn: Array<String>? by FreezableVar(null)
+
     // Advanced options
 
     @Argument(value = "-Xno-inline", description = "Disable method inlining")
@@ -172,12 +181,13 @@ abstract class CommonCompilerArguments : CommonToolArguments() {
     )
     var useExperimental: Array<String>? by FreezableVar(null)
 
+    // NB: we have to keep this flag for some time due to bootstrapping problems
     @Argument(
         value = "-Xopt-in",
         valueDescription = "<fq.name>",
         description = "Enable usages of API that requires opt-in with an opt-in requirement marker with the given fully qualified name"
     )
-    var optIn: Array<String>? by FreezableVar(null)
+    var optInDeprecated: Array<String>? by FreezableVar(null)
 
     @Argument(
         value = "-Xproper-ieee754-comparisons",
@@ -384,9 +394,17 @@ abstract class CommonCompilerArguments : CommonToolArguments() {
             }
             val useExperimentalFqNames = useExperimental?.toList().orEmpty()
             if (useExperimentalFqNames.isNotEmpty()) {
-                collector.report(WARNING, "'-Xuse-experimental' is deprecated and will be removed in a future release")
+                collector.report(
+                    WARNING, "'-Xuse-experimental' is deprecated and will be removed in a future release, please use -opt-in instead"
+                )
             }
-            put(AnalysisFlags.useExperimental, useExperimentalFqNames + optIn?.toList().orEmpty())
+            val optInDeprecatedFqNames = optInDeprecated?.toList().orEmpty()
+            if (optInDeprecatedFqNames.isNotEmpty()) {
+                collector.report(
+                    WARNING, "'-Xopt-in' is deprecated and will be removed in a future release, please use -opt-in instead"
+                )
+            }
+            put(AnalysisFlags.useExperimental, useExperimentalFqNames + optInDeprecatedFqNames + optIn?.toList().orEmpty())
             put(AnalysisFlags.expectActualLinker, expectActualLinker)
             put(AnalysisFlags.explicitApiVersion, apiVersion != null)
             put(AnalysisFlags.allowResultReturnType, allowResultReturnType)

compiler/fir/checkers/src/org/jetbrains/kotlin/fir/analysis/diagnostics/FirDefaultErrorMessages.kt

@@ -596,7 +596,7 @@ class FirDefaultErrorMessages {
             map.put(EXPERIMENTAL_OVERRIDE, "{1}", TO_STRING, STRING)
             map.put(EXPERIMENTAL_OVERRIDE_ERROR, "{1}", TO_STRING, STRING)
 
-            map.put(EXPERIMENTAL_IS_NOT_ENABLED, "This class can only be used with the compiler argument '-Xopt-in=kotlin.RequiresOptIn'")
+            map.put(EXPERIMENTAL_IS_NOT_ENABLED, "This class can only be used with the compiler argument '-opt-in=kotlin.RequiresOptIn'")
             map.put(EXPERIMENTAL_CAN_ONLY_BE_USED_AS_ANNOTATION, "This class can only be used as an annotation")
             map.put(
                 EXPERIMENTAL_MARKER_CAN_ONLY_BE_USED_AS_ANNOTATION_OR_ARGUMENT_IN_USE_EXPERIMENTAL,

compiler/testData/cli/js/jsHelp.out

@@ -21,6 +21,7 @@ where possible options include:
   -help (-h)                 Print a synopsis of standard options
   -kotlin-home <path>        Path to the home directory of Kotlin compiler used for discovery of runtime libraries
   -language-version <version> Provide source compatibility with the specified version of Kotlin
+  -opt-in <fq.name>          Enable usages of API that requires opt-in with an opt-in requirement marker with the given fully qualified name
   -P plugin:<pluginId>:<optionName>=<value>
                              Pass an option to a plugin
   -progressive               Enable progressive compiler mode.

compiler/testData/cli/jvm/experimentalAndUseExperimentalWithSameAnnotation.args

@@ -1,6 +1,8 @@
 $TESTDATA_DIR$/experimentalAndUseExperimentalWithSameAnnotation.kt
 -d
 $TEMP_DIR$
--Xopt-in=kotlin.RequiresOptIn
+-opt-in
+kotlin.RequiresOptIn
+-opt-in
+org.test.ExperimentalAPI
 -Xexperimental=org.test.ExperimentalAPI
--Xopt-in=org.test.ExperimentalAPI

compiler/testData/cli/jvm/experimentalDeprecated.args

@@ -1,8 +1,11 @@
 $TESTDATA_DIR$/experimentalDeprecated.kt
 -d
 $TEMP_DIR$
--Xopt-in=kotlin.RequiresOptIn
+-opt-in
+kotlin.RequiresOptIn
 -Xexperimental=org.test.Error1
 -Xexperimental=org.test.Hidden1
--Xopt-in=org.test.Error2
+-opt-in
--Xopt-in=org.test.Hidden2
+org.test.Error2
+-opt-in
+org.test.Hidden2

compiler/testData/cli/jvm/experimentalDeprecatedWarning.args

@@ -2,6 +2,9 @@ $TESTDATA_DIR$/experimentalDeprecatedWarning.kt
 -d
 $TEMP_DIR$
 -Xopt-in=kotlin.RequiresOptIn
--Xopt-in=org.test.Warning1
+-opt-in
+kotlin.RequiresOptIn
+-opt-in
+org.test.Warning1
 -Xexperimental=org.test.Warning2
 -Xuse-experimental=org.test.OneMore

compiler/testData/cli/jvm/experimentalDeprecatedWarning.out

@@ -1,5 +1,6 @@
 warning: '-Xexperimental' is deprecated and will be removed in a future release
-warning: '-Xuse-experimental' is deprecated and will be removed in a future release
+warning: '-Xuse-experimental' is deprecated and will be removed in a future release, please use -opt-in instead
+warning: '-Xopt-in' is deprecated and will be removed in a future release, please use -opt-in instead
 warning: opt-in requirement marker org.test.Warning2 is deprecated. Warning2
 warning: opt-in requirement marker org.test.Warning1 is deprecated. Warning1
 OK

compiler/testData/cli/jvm/experimentalIsNotAnnotation.args

@@ -2,4 +2,5 @@ $TESTDATA_DIR$/experimentalIsNotAnnotation.kt
 -d
 $TEMP_DIR$
 -Xexperimental=org.test.NotAnAnnotation1
--Xopt-in=org.test.NotAnAnnotation2
+-opt-in
+org.test.NotAnAnnotation2

compiler/testData/cli/jvm/experimentalIsNotMarker.args

@@ -2,4 +2,5 @@ $TESTDATA_DIR$/experimentalIsNotMarker.kt
 -d
 $TEMP_DIR$
 -Xexperimental=org.test.NotAMarker1
--Xopt-in=org.test.NotAMarker2
+-opt-in
+org.test.NotAMarker2

compiler/testData/cli/jvm/experimentalNested.args

@@ -1,5 +1,6 @@
 $TESTDATA_DIR$/experimentalNested.kt
 -d
 $TEMP_DIR$
--Xopt-in=kotlin.RequiresOptIn
+-opt-in
+kotlin.RequiresOptIn
 -Xexperimental=org.test.Outer.Nested

compiler/testData/cli/jvm/experimentalUnresolved.args

@@ -1,6 +1,9 @@
 $TESTDATA_DIR$/experimentalUnresolved.kt
 -d
 $TEMP_DIR$
--Xopt-in=org.test.Unresolved1
+-opt-in
+org.test.Unresolved1
+-opt-in
+org.test.Unresolved3
 -Xexperimental=org.test.Unresolved2
--Xopt-in=org.test.Unresolved3
+

compiler/testData/cli/jvm/help.out

@@ -19,6 +19,7 @@ where possible options include:
   -help (-h)                 Print a synopsis of standard options
   -kotlin-home <path>        Path to the home directory of Kotlin compiler used for discovery of runtime libraries
   -language-version <version> Provide source compatibility with the specified version of Kotlin
+  -opt-in <fq.name>          Enable usages of API that requires opt-in with an opt-in requirement marker with the given fully qualified name
   -P plugin:<pluginId>:<optionName>=<value>
                              Pass an option to a plugin
   -progressive               Enable progressive compiler mode.

compiler/testData/cli/jvm/useDeclarationThatWasExperimentalWithoutExplicitImportCommandLine.args

@@ -3,4 +3,5 @@ $TESTDATA_DIR$/useDeclarationThatWasExperimentalWithoutMarker.kt
 $TEMP_DIR$
 -language-version
 1.3
--Xopt-in=kotlin.ExperimentalStdlibApi
+-opt-in
+kotlin.ExperimentalStdlibApi

compiler/testData/multiplatform/optionalExpectation/common.kt

@@ -1,5 +1,5 @@
 // WITH_RUNTIME
-// ADDITIONAL_COMPILER_ARGUMENTS: -Xopt-in=kotlin.ExperimentalMultiplatform
+// ADDITIONAL_COMPILER_ARGUMENTS: -opt-in=kotlin.ExperimentalMultiplatform
 
 @OptionalExpectation
 expect annotation class A()

compiler/testData/multiplatform/optionalExpectationIncorrectUse/common.kt

@@ -1,5 +1,5 @@
 // WITH_RUNTIME
-// ADDITIONAL_COMPILER_ARGUMENTS: -Xopt-in=kotlin.ExperimentalMultiplatform
+// ADDITIONAL_COMPILER_ARGUMENTS: -opt-in=kotlin.ExperimentalMultiplatform
 
 @OptionalExpectation
 expect annotation class A()

idea/testData/quickfix/experimental/experimentalUnused.kt

@@ -1,5 +1,5 @@
 // "Safe delete 'Marker'" "false"
-// COMPILER_ARGUMENTS: -Xopt-in=kotlin.RequiresOptIn -Xopt-in=test.Marker
+// COMPILER_ARGUMENTS: -opt-in=kotlin.RequiresOptIn -opt-in=test.Marker
 // WITH_RUNTIME
 // ACTION: Rename file to Marker.kt
 // TOOL: org.jetbrains.kotlin.idea.inspections.UnusedSymbolInspection