Avoid assertion in bridges-generation for light classes

^KT-11656

compiler/backend-common/src/org/jetbrains/kotlin/backend/common/bridges/bridges.kt

@@ -56,7 +56,7 @@ fun <Function : FunctionHandle, Signature> generateBridges(
     // into some of the super-classes and will be inherited in this class
     if (fake && function.getOverridden().none { it.isAbstract }) return setOf()
 
-    val implementation = findConcreteSuperDeclaration(function)
+    val implementation = findConcreteSuperDeclaration(function) ?: return setOf()
 
     val bridgesToGenerate = findAllReachableDeclarations(function).mapTo(LinkedHashSet<Signature>(), signature)
 
@@ -94,7 +94,7 @@ fun <Function : FunctionHandle> findAllReachableDeclarations(function: Function)
  * Given a concrete function, finds an implementation (a concrete declaration) of this function in the supertypes.
  * The implementation is guaranteed to exist because if it wouldn't, the given function would've been abstract
  */
-fun <Function : FunctionHandle> findConcreteSuperDeclaration(function: Function): Function {
+fun <Function : FunctionHandle> findConcreteSuperDeclaration(function: Function): Function? {
     require(!function.isAbstract, { "Only concrete functions have implementations: $function" })
 
     if (function.isDeclaration) return function
@@ -118,7 +118,11 @@ fun <Function : FunctionHandle> findConcreteSuperDeclaration(function: Function)
 
     val concreteRelevantDeclarations = result.filter { !it.isAbstract && it.mayBeUsedAsSuperImplementation }
     if (concreteRelevantDeclarations.size != 1) {
-        error("Concrete fake override $function should have exactly one concrete super-declaration: $concreteRelevantDeclarations")
+        if (!function.mightBeIncorrectCode) {
+            error("Concrete fake override $function should have exactly one concrete super-declaration: $concreteRelevantDeclarations")
+        } else {
+            return null
+        }
     }
 
     return concreteRelevantDeclarations[0]

compiler/backend/src/org/jetbrains/kotlin/codegen/builtinSpecialBridges.kt

@@ -153,7 +153,7 @@ private fun <Signature> findSuperImplementationForStubDelegation(
     state: GenerationState,
     signatureByDescriptor: (FunctionDescriptor) -> Signature
 ): FunctionDescriptor? {
-    val implementation = findConcreteSuperDeclaration(DescriptorBasedFunctionHandleForJvm(function, state))
+    val implementation = findConcreteSuperDeclaration(DescriptorBasedFunctionHandleForJvm(function, state)) ?: return null
 
     // Implementation from interface will be generated by common mechanism
     if (!implementation.mayBeUsedAsSuperImplementation) return null

compiler/testData/asJava/lightClasses/compilationErrors/EnumNameOverride.java

@@ -0,0 +1,5 @@
+public enum EnumNameOverride implements Bar {
+    ;
+
+    private EnumNameOverride() { /* compiled code */ }
+}

compiler/testData/asJava/lightClasses/compilationErrors/EnumNameOverride.kt

@@ -0,0 +1,11 @@
+// EnumNameOverride
+interface Foo {
+    fun name(): String
+}
+
+interface Bar : Foo {
+    override fun name() = name
+    var name: String
+}
+
+enum class EnumNameOverride : Bar

compiler/testData/asJava/lightClasses/compilationErrors/TwoOverrides.java

@@ -0,0 +1,9 @@
+public final class TwoOverrides implements java.lang.Iterable<java.lang.String>, kotlin.collections.Iterable<java.lang.String>, kotlin.jvm.internal.markers.KMappedMarker {
+    @org.jetbrains.annotations.Nullable
+    public java.lang.Void iterator() { /* compiled code */ }
+
+    @org.jetbrains.annotations.Nullable
+    public java.lang.Void iterator() { /* compiled code */ }
+
+    public TwoOverrides() { /* compiled code */ }
+}

compiler/testData/asJava/lightClasses/compilationErrors/TwoOverrides.kt

@@ -0,0 +1,6 @@
+// TwoOverrides
+class TwoOverrides : Iterable<String> {
+    override fun iterator() = null
+
+    override fun iterator() = null
+}

compiler/tests/org/jetbrains/kotlin/asJava/CompilerLightClassTestGenerated.java

@@ -181,6 +181,11 @@ public class CompilerLightClassTestGenerated extends AbstractCompilerLightClassT
             runTest("compiler/testData/asJava/lightClasses/compilationErrors/AnnotationModifiers.kt");
         }
 
+        @TestMetadata("EnumNameOverride.kt")
+        public void testEnumNameOverride() throws Exception {
+            runTest("compiler/testData/asJava/lightClasses/compilationErrors/EnumNameOverride.kt");
+        }
+
         @TestMetadata("ExpectClass.kt")
         public void testExpectClass() throws Exception {
             runTest("compiler/testData/asJava/lightClasses/compilationErrors/ExpectClass.kt");
@@ -236,6 +241,11 @@ public class CompilerLightClassTestGenerated extends AbstractCompilerLightClassT
             runTest("compiler/testData/asJava/lightClasses/compilationErrors/TraitClassObjectField.kt");
         }
 
+        @TestMetadata("TwoOverrides.kt")
+        public void testTwoOverrides() throws Exception {
+            runTest("compiler/testData/asJava/lightClasses/compilationErrors/TwoOverrides.kt");
+        }
+
         @TestMetadata("WrongAnnotations.kt")
         public void testWrongAnnotations() throws Exception {
             runTest("compiler/testData/asJava/lightClasses/compilationErrors/WrongAnnotations.kt");

idea/tests/org/jetbrains/kotlin/asJava/classes/UltraLightClassSanityTestGenerated.java

@@ -181,6 +181,11 @@ public class UltraLightClassSanityTestGenerated extends AbstractUltraLightClassS
             runTest("compiler/testData/asJava/lightClasses/compilationErrors/AnnotationModifiers.kt");
         }
 
+        @TestMetadata("EnumNameOverride.kt")
+        public void testEnumNameOverride() throws Exception {
+            runTest("compiler/testData/asJava/lightClasses/compilationErrors/EnumNameOverride.kt");
+        }
+
         @TestMetadata("ExpectClass.kt")
         public void testExpectClass() throws Exception {
             runTest("compiler/testData/asJava/lightClasses/compilationErrors/ExpectClass.kt");
@@ -236,6 +241,11 @@ public class UltraLightClassSanityTestGenerated extends AbstractUltraLightClassS
             runTest("compiler/testData/asJava/lightClasses/compilationErrors/TraitClassObjectField.kt");
         }
 
+        @TestMetadata("TwoOverrides.kt")
+        public void testTwoOverrides() throws Exception {
+            runTest("compiler/testData/asJava/lightClasses/compilationErrors/TwoOverrides.kt");
+        }
+
         @TestMetadata("WrongAnnotations.kt")
         public void testWrongAnnotations() throws Exception {
             runTest("compiler/testData/asJava/lightClasses/compilationErrors/WrongAnnotations.kt");

idea/tests/org/jetbrains/kotlin/idea/caches/resolve/IdeLightClassTestGenerated.java

@@ -181,6 +181,11 @@ public class IdeLightClassTestGenerated extends AbstractIdeLightClassTest {
             runTest("compiler/testData/asJava/lightClasses/compilationErrors/AnnotationModifiers.kt");
         }
 
+        @TestMetadata("EnumNameOverride.kt")
+        public void testEnumNameOverride() throws Exception {
+            runTest("compiler/testData/asJava/lightClasses/compilationErrors/EnumNameOverride.kt");
+        }
+
         @TestMetadata("ExpectClass.kt")
         public void testExpectClass() throws Exception {
             runTest("compiler/testData/asJava/lightClasses/compilationErrors/ExpectClass.kt");
@@ -236,6 +241,11 @@ public class IdeLightClassTestGenerated extends AbstractIdeLightClassTest {
             runTest("compiler/testData/asJava/lightClasses/compilationErrors/TraitClassObjectField.kt");
         }
 
+        @TestMetadata("TwoOverrides.kt")
+        public void testTwoOverrides() throws Exception {
+            runTest("compiler/testData/asJava/lightClasses/compilationErrors/TwoOverrides.kt");
+        }
+
         @TestMetadata("WrongAnnotations.kt")
         public void testWrongAnnotations() throws Exception {
             runTest("compiler/testData/asJava/lightClasses/compilationErrors/WrongAnnotations.kt");