Make EXPERIMENTAL_ANNOTATION_ON_OVERRIDE warning till 1.6

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

@@ -34867,6 +34867,12 @@ public class FirOldFrontendDiagnosticsTestGenerated extends AbstractFirDiagnosti
                 runTest("compiler/testData/diagnostics/testsWithStdLib/experimental/experimentalIsNotEnabled.kt");
             }
 
+            @Test
+            @TestMetadata("experimentalOnOverrideWarning.kt")
+            public void testExperimentalOnOverrideWarning() throws Exception {
+                runTest("compiler/testData/diagnostics/testsWithStdLib/experimental/experimentalOnOverrideWarning.kt");
+            }
+
             @Test
             @TestMetadata("experimentalSetter.kt")
             public void testExperimentalSetter() throws Exception {

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

@@ -34867,6 +34867,12 @@ public class FirOldFrontendDiagnosticsWithLightTreeTestGenerated extends Abstrac
                 runTest("compiler/testData/diagnostics/testsWithStdLib/experimental/experimentalIsNotEnabled.kt");
             }
 
+            @Test
+            @TestMetadata("experimentalOnOverrideWarning.kt")
+            public void testExperimentalOnOverrideWarning() throws Exception {
+                runTest("compiler/testData/diagnostics/testsWithStdLib/experimental/experimentalOnOverrideWarning.kt");
+            }
+
             @Test
             @TestMetadata("experimentalSetter.kt")
             public void testExperimentalSetter() throws Exception {

compiler/frontend.java/src/org/jetbrains/kotlin/resolve/jvm/checkers/ExplicitMetadataChecker.kt

@@ -5,6 +5,7 @@
 
 package org.jetbrains.kotlin.resolve.jvm.checkers
 
+import org.jetbrains.kotlin.config.LanguageVersionSettings
 import org.jetbrains.kotlin.descriptors.annotations.KotlinTarget
 import org.jetbrains.kotlin.name.FqName
 import org.jetbrains.kotlin.psi.KtAnnotationEntry
@@ -16,7 +17,12 @@ import org.jetbrains.kotlin.resolve.jvm.diagnostics.ErrorsJvm
 object ExplicitMetadataChecker : AdditionalAnnotationChecker {
     private val METADATA_FQ_NAME = FqName("kotlin.Metadata")
 
-    override fun checkEntries(entries: List<KtAnnotationEntry>, actualTargets: List<KotlinTarget>, trace: BindingTrace) {
+    override fun checkEntries(
+        entries: List<KtAnnotationEntry>,
+        actualTargets: List<KotlinTarget>,
+        trace: BindingTrace,
+        languageVersionSettings: LanguageVersionSettings
+    ) {
         for (entry in entries) {
             val descriptor = trace.get(BindingContext.ANNOTATION, entry) ?: continue
             if (descriptor.fqName == METADATA_FQ_NAME) {

compiler/frontend.java/src/org/jetbrains/kotlin/resolve/jvm/checkers/FileClassAnnotationsChecker.kt

@@ -16,6 +16,7 @@
 
 package org.jetbrains.kotlin.resolve.jvm.checkers
 
+import org.jetbrains.kotlin.config.LanguageVersionSettings
 import org.jetbrains.kotlin.descriptors.ClassDescriptor
 import org.jetbrains.kotlin.descriptors.annotations.AnnotationUseSiteTarget
 import org.jetbrains.kotlin.descriptors.annotations.KotlinRetention
@@ -36,7 +37,12 @@ object FileClassAnnotationsChecker : AdditionalAnnotationChecker {
     // JvmName & JvmMultifileClass annotations are applicable to multi-file class parts regardless of their retention.
     private val alwaysApplicable = hashSetOf(JvmFileClassUtil.JVM_NAME, JvmFileClassUtil.JVM_MULTIFILE_CLASS)
 
-    override fun checkEntries(entries: List<KtAnnotationEntry>, actualTargets: List<KotlinTarget>, trace: BindingTrace) {
+    override fun checkEntries(
+        entries: List<KtAnnotationEntry>,
+        actualTargets: List<KotlinTarget>,
+        trace: BindingTrace,
+        languageVersionSettings: LanguageVersionSettings
+    ) {
         val fileAnnotationsToCheck = arrayListOf<Pair<KtAnnotationEntry, ClassDescriptor>>()
         for (entry in entries) {
             if (entry.useSiteTarget?.getAnnotationUseSiteTarget() != AnnotationUseSiteTarget.FILE) continue

compiler/frontend.java/src/org/jetbrains/kotlin/resolve/jvm/checkers/RepeatableAnnotationChecker.kt

@@ -5,6 +5,7 @@
 
 package org.jetbrains.kotlin.resolve.jvm.checkers
 
+import org.jetbrains.kotlin.config.LanguageVersionSettings
 import org.jetbrains.kotlin.descriptors.annotations.AnnotationUseSiteTarget
 import org.jetbrains.kotlin.descriptors.annotations.KotlinRetention
 import org.jetbrains.kotlin.descriptors.annotations.KotlinTarget
@@ -19,7 +20,12 @@ import org.jetbrains.kotlin.resolve.descriptorUtil.isRepeatableAnnotation
 import org.jetbrains.kotlin.resolve.jvm.diagnostics.ErrorsJvm
 
 object RepeatableAnnotationChecker : AdditionalAnnotationChecker {
-    override fun checkEntries(entries: List<KtAnnotationEntry>, actualTargets: List<KotlinTarget>, trace: BindingTrace) {
+    override fun checkEntries(
+        entries: List<KtAnnotationEntry>,
+        actualTargets: List<KotlinTarget>,
+        trace: BindingTrace,
+        languageVersionSettings: LanguageVersionSettings
+    ) {
         val entryTypesWithAnnotations = hashMapOf<FqName, MutableList<AnnotationUseSiteTarget?>>()
 
         for (entry in entries) {

compiler/frontend/src/org/jetbrains/kotlin/diagnostics/Errors.java

@@ -292,6 +292,7 @@ public interface Errors {
 
     DiagnosticFactory1<KtAnnotationEntry, String> EXPERIMENTAL_ANNOTATION_ON_WRONG_TARGET = DiagnosticFactory1.create(ERROR);
     DiagnosticFactory0<KtAnnotationEntry> EXPERIMENTAL_ANNOTATION_ON_OVERRIDE = DiagnosticFactory0.create(ERROR);
+    DiagnosticFactory0<KtAnnotationEntry> EXPERIMENTAL_ANNOTATION_ON_OVERRIDE_WARNING = DiagnosticFactory0.create(WARNING);
 
     DiagnosticFactory1<PsiElement, String> EXPERIMENTAL_UNSIGNED_LITERALS = DiagnosticFactory1.create(WARNING);
     DiagnosticFactory1<PsiElement, String> EXPERIMENTAL_UNSIGNED_LITERALS_ERROR = DiagnosticFactory1.create(ERROR);

compiler/frontend/src/org/jetbrains/kotlin/diagnostics/rendering/DefaultErrorMessages.java

@@ -174,6 +174,7 @@ public class DefaultErrorMessages {
 
         MAP.put(EXPERIMENTAL_ANNOTATION_ON_WRONG_TARGET, "Opt-in requirement marker annotation cannot be used on {0}", STRING);
         MAP.put(EXPERIMENTAL_ANNOTATION_ON_OVERRIDE, "Opt-in requirement marker annotation on override requires the same marker on base declaration");
+        MAP.put(EXPERIMENTAL_ANNOTATION_ON_OVERRIDE_WARNING, "Opt-in requirement marker annotation on override requires the same marker on base declaration (will be an error in 1.6)");
 
         MAP.put(EXPERIMENTAL_UNSIGNED_LITERALS, "{0}", STRING);
         MAP.put(EXPERIMENTAL_UNSIGNED_LITERALS_ERROR, "{0}", STRING);

compiler/frontend/src/org/jetbrains/kotlin/resolve/AnnotationChecker.kt

@@ -230,7 +230,7 @@ class AnnotationChecker(
         }
 
         for (checker in additionalCheckers) {
-            checker.checkEntries(entries, actualTargets.defaultTargets, trace)
+            checker.checkEntries(entries, actualTargets.defaultTargets, trace, languageVersionSettings)
         }
     }
 
@@ -381,5 +381,10 @@ private typealias TargetLists = AnnotationTargetLists
 private typealias TargetList = AnnotationTargetList
 
 interface AdditionalAnnotationChecker {
-    fun checkEntries(entries: List<KtAnnotationEntry>, actualTargets: List<KotlinTarget>, trace: BindingTrace)
+    fun checkEntries(
+        entries: List<KtAnnotationEntry>,
+        actualTargets: List<KotlinTarget>,
+        trace: BindingTrace,
+        languageVersionSettings: LanguageVersionSettings
+    )
 }

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

@@ -6,6 +6,8 @@
 package org.jetbrains.kotlin.resolve.checkers
 
 import org.jetbrains.kotlin.builtins.StandardNames
+import org.jetbrains.kotlin.config.LanguageFeature
+import org.jetbrains.kotlin.config.LanguageVersionSettings
 import org.jetbrains.kotlin.descriptors.CallableMemberDescriptor
 import org.jetbrains.kotlin.descriptors.ClassDescriptor
 import org.jetbrains.kotlin.descriptors.ModuleDescriptor
@@ -37,7 +39,8 @@ class ExperimentalMarkerDeclarationAnnotationChecker(private val module: ModuleD
     override fun checkEntries(
         entries: List<KtAnnotationEntry>,
         actualTargets: List<KotlinTarget>,
-        trace: BindingTrace
+        trace: BindingTrace,
+        languageVersionSettings: LanguageVersionSettings
     ) {
         var isAnnotatedWithExperimental = false
 
@@ -88,7 +91,11 @@ class ExperimentalMarkerDeclarationAnnotationChecker(private val module: ModuleD
                     if (descriptor is CallableMemberDescriptor &&
                         !descriptor.hasExperimentalOverriddenDescriptors(annotationClass.fqNameSafe)
                     ) {
-                        trace.report(Errors.EXPERIMENTAL_ANNOTATION_ON_OVERRIDE.on(entry))
+                        if (languageVersionSettings.supportsFeature(LanguageFeature.OptInOnOverrideForbidden)) {
+                            trace.report(Errors.EXPERIMENTAL_ANNOTATION_ON_OVERRIDE.on(entry))
+                        } else {
+                            trace.report(Errors.EXPERIMENTAL_ANNOTATION_ON_OVERRIDE_WARNING.on(entry))
+                        }
                     }
                 }
             }

compiler/testData/diagnostics/testsWithStdLib/experimental/experimentalOnOverrideWarning.fir.kt

@@ -0,0 +1,12 @@
+// !USE_EXPERIMENTAL: kotlin.RequiresOptIn
+// !LANGUAGE: -OptInOnOverrideForbidden
+
+@RequiresOptIn(level = RequiresOptIn.Level.WARNING)
+@Retention(AnnotationRetention.BINARY)
+annotation class E
+
+class My {
+    @E
+    override fun hashCode() = 0
+}
+

compiler/testData/diagnostics/testsWithStdLib/experimental/experimentalOnOverrideWarning.kt

@@ -0,0 +1,12 @@
+// !USE_EXPERIMENTAL: kotlin.RequiresOptIn
+// !LANGUAGE: -OptInOnOverrideForbidden
+
+@RequiresOptIn(level = RequiresOptIn.Level.WARNING)
+@Retention(AnnotationRetention.BINARY)
+annotation class E
+
+class My {
+    <!EXPERIMENTAL_ANNOTATION_ON_OVERRIDE_WARNING!>@E<!>
+    override fun hashCode() = 0
+}
+

compiler/testData/diagnostics/testsWithStdLib/experimental/experimentalOnOverrideWarning.txt

@@ -0,0 +1,15 @@
+package
+
+@kotlin.RequiresOptIn(level = Level.WARNING) @kotlin.annotation.Retention(value = AnnotationRetention.BINARY) public final annotation class E : kotlin.Annotation {
+    public constructor E()
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}
+
+public final class My {
+    public constructor My()
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    @E public open override /*1*/ fun hashCode(): kotlin.Int
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}

compiler/testData/diagnostics/testsWithStdLib/experimental/incorrectTargetsForExperimentalAnnotation.fir.kt

@@ -1,4 +1,5 @@
 // !USE_EXPERIMENTAL: kotlin.RequiresOptIn
+// !LANGUAGE: +OptInOnOverrideForbidden
 // FILE: api.kt
 
 package api

compiler/testData/diagnostics/testsWithStdLib/experimental/incorrectTargetsForExperimentalAnnotation.kt

@@ -1,4 +1,5 @@
 // !USE_EXPERIMENTAL: kotlin.RequiresOptIn
+// !LANGUAGE: +OptInOnOverrideForbidden
 // FILE: api.kt
 
 package api

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

@@ -34963,6 +34963,12 @@ public class DiagnosticTestGenerated extends AbstractDiagnosticTest {
                 runTest("compiler/testData/diagnostics/testsWithStdLib/experimental/experimentalIsNotEnabled.kt");
             }
 
+            @Test
+            @TestMetadata("experimentalOnOverrideWarning.kt")
+            public void testExperimentalOnOverrideWarning() throws Exception {
+                runTest("compiler/testData/diagnostics/testsWithStdLib/experimental/experimentalOnOverrideWarning.kt");
+            }
+
             @Test
             @TestMetadata("experimentalSetter.kt")
             public void testExperimentalSetter() throws Exception {

compiler/util/src/org/jetbrains/kotlin/config/LanguageVersionSettings.kt

@@ -216,6 +216,7 @@ enum class LanguageFeature(
     TypeInferenceOnCallsWithSelfTypes(KOTLIN_1_6),
     WarnAboutNonExhaustiveWhenOnAlgebraicTypes(KOTLIN_1_6, kind = BUG_FIX),
     InstantiationOfAnnotationClasses(KOTLIN_1_6),
+    OptInOnOverrideForbidden(KOTLIN_1_6, kind = BUG_FIX),
 
     // 1.7
 

idea/idea-frontend-fir/idea-fir-low-level-api/tests/org/jetbrains/kotlin/idea/fir/low/level/api/diagnostic/compiler/based/DiagnosisCompilerTestFE10TestdataTestGenerated.java

@@ -34867,6 +34867,12 @@ public class DiagnosisCompilerTestFE10TestdataTestGenerated extends AbstractDiag
                 runTest("compiler/testData/diagnostics/testsWithStdLib/experimental/experimentalIsNotEnabled.kt");
             }
 
+            @Test
+            @TestMetadata("experimentalOnOverrideWarning.kt")
+            public void testExperimentalOnOverrideWarning() throws Exception {
+                runTest("compiler/testData/diagnostics/testsWithStdLib/experimental/experimentalOnOverrideWarning.kt");
+            }
+
             @Test
             @TestMetadata("experimentalSetter.kt")
             public void testExperimentalSetter() throws Exception {

js/js.frontend/src/org/jetbrains/kotlin/js/resolve/diagnostics/JsQualifierChecker.kt

@@ -16,6 +16,7 @@
 
 package org.jetbrains.kotlin.js.resolve.diagnostics
 
+import org.jetbrains.kotlin.config.LanguageVersionSettings
 import org.jetbrains.kotlin.descriptors.annotations.KotlinTarget
 import org.jetbrains.kotlin.js.translate.utils.AnnotationsUtils
 import org.jetbrains.kotlin.psi.KtAnnotationEntry
@@ -24,7 +25,12 @@ import org.jetbrains.kotlin.resolve.BindingContext
 import org.jetbrains.kotlin.resolve.BindingTrace
 
 object JsQualifierChecker : AdditionalAnnotationChecker {
-    override fun checkEntries(entries: List<KtAnnotationEntry>, actualTargets: List<KotlinTarget>, trace: BindingTrace) {
+    override fun checkEntries(
+        entries: List<KtAnnotationEntry>,
+        actualTargets: List<KotlinTarget>,
+        trace: BindingTrace,
+        languageVersionSettings: LanguageVersionSettings
+    ) {
         val bindingContext = trace.bindingContext
         for (entry in entries) {
             val annotation = bindingContext[BindingContext.ANNOTATION, entry] ?: continue