KMP: Put "prohibit expect actual OptIn annotations" under the flag

^KT-61668 Fixed

Review: https://jetbrains.team/p/kt/reviews/12062/timeline

compiler/fir/analysis-tests/tests-gen/org/jetbrains/kotlin/test/runners/FirOldFrontendMPPDiagnosticsWithLightTreeTestGenerated.java

@@ -163,6 +163,12 @@ public class FirOldFrontendMPPDiagnosticsWithLightTreeTestGenerated extends Abst
         runTest("compiler/testData/diagnostics/tests/multiplatform/expectOptInAnnotation.kt");
     }
 
+    @Test
+    @TestMetadata("expectOptInAnnotation_oldLanguageVersion.kt")
+    public void testExpectOptInAnnotation_oldLanguageVersion() throws Exception {
+        runTest("compiler/testData/diagnostics/tests/multiplatform/expectOptInAnnotation_oldLanguageVersion.kt");
+    }
+
     @Test
     @TestMetadata("expectTailrec.kt")
     public void testExpectTailrec() throws Exception {

compiler/fir/analysis-tests/tests-gen/org/jetbrains/kotlin/test/runners/FirOldFrontendMPPDiagnosticsWithPsiTestGenerated.java

@@ -163,6 +163,12 @@ public class FirOldFrontendMPPDiagnosticsWithPsiTestGenerated extends AbstractFi
         runTest("compiler/testData/diagnostics/tests/multiplatform/expectOptInAnnotation.kt");
     }
 
+    @Test
+    @TestMetadata("expectOptInAnnotation_oldLanguageVersion.kt")
+    public void testExpectOptInAnnotation_oldLanguageVersion() throws Exception {
+        runTest("compiler/testData/diagnostics/tests/multiplatform/expectOptInAnnotation_oldLanguageVersion.kt");
+    }
+
     @Test
     @TestMetadata("expectTailrec.kt")
     public void testExpectTailrec() throws Exception {

compiler/fir/checkers/src/org/jetbrains/kotlin/fir/analysis/checkers/declaration/FirExpectActualDeclarationChecker.kt

@@ -291,7 +291,8 @@ object FirExpectActualDeclarationChecker : FirBasicDeclarationChecker() {
         context: CheckerContext,
         reporter: DiagnosticReporter,
     ) {
-        if (declaration is FirClass &&
+        if (context.languageVersionSettings.supportsFeature(LanguageFeature.MultiplatformRestrictions) &&
+            declaration is FirClass &&
             declaration.classKind == ClassKind.ANNOTATION_CLASS &&
             !expectDeclarationSymbol.hasAnnotation(StandardClassIds.Annotations.OptionalExpectation, context.session) &&
             declaration.hasAnnotation(OptInNames.REQUIRES_OPT_IN_CLASS_ID, context.session)

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

@@ -70,7 +70,7 @@ class ExpectedActualDeclarationChecker(
                 declaration, descriptor, context.trace,
                 checkActualModifier, context
             )
-            checkOptInAnnotation(declaration, descriptor, descriptor, context.trace)
+            checkOptInAnnotation(declaration, descriptor, descriptor, context)
         }
         if (descriptor.isActualOrSomeContainerIsActual()) {
             val allDependsOnModules = moduleStructureOracle.findAllDependsOnPaths(descriptor.module).flatMap { it.nodes }.toHashSet()
@@ -376,7 +376,7 @@ class ExpectedActualDeclarationChecker(
                 if (expectedConstructor != null && actualConstructor != null) {
                     checkAnnotationConstructors(expectedConstructor, actualConstructor, trace, reportOn)
                 }
-                checkOptInAnnotation(reportOn, descriptor, expected, trace)
+                checkOptInAnnotation(reportOn, descriptor, expected, context)
             }
         }
         // We want to report errors even if a candidate is incompatible, but it's single
@@ -475,14 +475,15 @@ class ExpectedActualDeclarationChecker(
         reportOn: KtNamedDeclaration,
         descriptor: MemberDescriptor,
         expectDescriptor: MemberDescriptor,
-        trace: BindingTrace,
+        context: DeclarationCheckerContext,
     ) {
-        if (descriptor is ClassDescriptor &&
+        if (context.languageVersionSettings.supportsFeature(LanguageFeature.MultiplatformRestrictions) &&
+            descriptor is ClassDescriptor &&
             descriptor.kind == ClassKind.ANNOTATION_CLASS &&
             descriptor.annotations.hasAnnotation(OptInNames.REQUIRES_OPT_IN_FQ_NAME) &&
             !expectDescriptor.annotations.hasAnnotation(OptionalAnnotationUtil.OPTIONAL_EXPECTATION_FQ_NAME)
         ) {
-            trace.report(Errors.EXPECT_ACTUAL_OPT_IN_ANNOTATION.on(reportOn))
+            context.trace.report(Errors.EXPECT_ACTUAL_OPT_IN_ANNOTATION.on(reportOn))
         }
     }
 

compiler/testData/diagnostics/tests/multiplatform/expectOptInAnnotation_oldLanguageVersion.kt

@@ -0,0 +1,19 @@
+// FIR_IDENTICAL
+// LANGUAGE: -MultiplatformRestrictions
+// WITH_STDLIB
+// MODULE: m1-common
+// FILE: common.kt
+@file:OptIn(ExperimentalMultiplatform::class)
+
+expect annotation class ActualOnly
+
+@RequiresOptIn
+expect annotation class Both
+
+// MODULE: m1-jvm()()(m1-common)
+// FILE: jvm.kt
+@RequiresOptIn
+actual annotation class ActualOnly
+
+@RequiresOptIn
+actual annotation class Both

compiler/tests-common-new/tests-gen/org/jetbrains/kotlin/test/runners/DiagnosticTestGenerated.java

@@ -23158,6 +23158,12 @@ public class DiagnosticTestGenerated extends AbstractDiagnosticTest {
                 runTest("compiler/testData/diagnostics/tests/multiplatform/expectOptInAnnotation.kt");
             }
 
+            @Test
+            @TestMetadata("expectOptInAnnotation_oldLanguageVersion.kt")
+            public void testExpectOptInAnnotation_oldLanguageVersion() throws Exception {
+                runTest("compiler/testData/diagnostics/tests/multiplatform/expectOptInAnnotation_oldLanguageVersion.kt");
+            }
+
             @Test
             @TestMetadata("expectTailrec.kt")
             public void testExpectTailrec() throws Exception {